JPH0255403B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to a heating transpiration insecticidal method, more specifically, a part of a liquid-absorbing wick is immersed in an insecticidal liquid to cause the wick to absorb the insecticidal liquid, and the upper part of the wick is indirectly heated to absorb the insecticidal liquid. The present invention relates to a heating transpiration insecticidal method that evaporates a liquid insecticidal liquid. Conventional technology and its problems Traditionally, the method of heating and evaporating chemicals for the purpose of killing insects, etc. is to adsorb them onto a porous substrate (solid pine) such as fiberboard using a device such as an electric mosquito repellent. A commonly used method is to evaporate the insecticide by heating it. However, in this method, the amount of insecticide that can be impregnated into one solid pine is naturally limited, and it is necessary to replace the pine and dispose of the used pine. Moreover, the volatilization rate of insecticides adsorbed to pine trees decreases over time, which is a serious drawback, and the effective volatilization rate of insecticides adsorbed to pine trees is only about 50% at most. The insecticide residual rate is as high as about 10%, making it impossible to maintain a stable insecticidal effect over a long period of time, and resulting in considerable economic disadvantages. As a heating transpiration method that can maintain the insecticidal effect over a long period of time, it solves the problem of replacing the pine and the disadvantage that the insecticidal effect disappears within a short period of time when using solid pine. A method of heating and evaporating the insecticide while sucking it up with a liquid-absorbing wick has been considered, and in fact, various insecticide evaporation devices using such a liquid-absorbing wick have been proposed. In these devices, a solvent solution of an insecticide is placed in a suitable container, which is sucked up using a liquid-absorbing wick made of felt, etc., and then heated and evaporated from the upper part of the liquid-absorbing wick. However, such a suction type heating evaporation type device,
When this is actually used, the solvent that makes up the insecticide liquid quickly evaporates due to the heating of the liquid-absorbing core, and the insecticide liquid gradually becomes concentrated inside the core, turning into a resin or causing the core material to evaporate. Smoking or burning causes clogging, making it impossible to subsequently suck up and evaporate the insecticidal liquid, making it impossible to achieve a long-term sustained effect, and furthermore, the insecticidal effect inevitably decreases over time, and the effective volatilization rate was low and the survival rate was high. There are many possible causes of the various adverse effects seen in such heating transpiration methods using wicks, including the type of wick and the type of solvent, as well as the type of insecticide, concentration, heating conditions, etc. It was thought that it would be difficult to eliminate the above-mentioned disadvantages. An object of the present invention is to provide a heat transpiration insecticidal method that eliminates the drawbacks of the conventional heat transpiration insecticide methods. In particular, it is an object of the present invention to provide an improved method as described above, which can avoid clogging of the liquid absorbent wick, achieve a long-lasting effect, and improve the total amount of insecticide volatilization and effective volatilization rate. With the goal. Means for Solving the Problems The present invention involves immersing a part of a liquid-absorbing wick in an insecticidal liquid to make the wick absorb the insecticidal liquid, and indirectly heating the upper part of the wick to kill insects. In the heating transpiration insecticidal method of evaporating a liquid, a pyrethroid compound with a carbon number of 10 is used as the insecticidal liquid as an active ingredient of the insecticide.
A solution dissolved in ~18 aliphatic hydrocarbon solvents is used, and a liquid absorbent core made of inorganic powder caked with a glue is used as the liquid absorbent core, and the surface temperature is 70 to 150℃.
The surface temperature of the upper part of the above wick is approximately 60℃~ with the heating element.
The present invention relates to a heat transpiration insecticidal method characterized by indirect heating to a temperature of less than 130°C. According to the method of the present invention, it is possible to extend the life of the liquid absorbent wick without causing clogging, and based on this, it is possible to significantly improve the transpiration performance (volatilization amount and effective volatilization rate) of the insecticide. Excellent insecticidal effect can be maintained for a long period of about 200 hours. The above-mentioned effects achieved by the method of the present invention are particularly achieved by using a specific insecticidal liquid, using a wick having the above-mentioned specific composition, and controlling the surface temperature of the heating element that heats the wick and the heating temperature of the upper part of the wick within the above-mentioned specific range. It is recognized if In the present invention, the insecticide includes various pyrethroid insecticides conventionally used for pest control. Specific examples thereof include the following. 〇 3-allyl-2-methylcyclopent-2-
En-4-one-1-yl dl-cis/trans-chrysanthemate (generic name: allethrin; trade name: pinamine; manufactured by Sumitomo Chemical Co., Ltd.; hereinafter referred to as
AA) 〇 3-allyl-2-methylcyclopent-2-
En-4-one-1-yl d-cis/trans-chrysanthemate (trade name: Pinamine Forte: manufactured by Sumitomo Chemical Co., Ltd., hereinafter referred to as AB) 〇 d-3-allyl-2-methylcyclopenta-
2-en-4-one-1-yl d-trans-chrysanthemate (trade name Exrin: manufactured by Sumitomo Chemical Co., Ltd., hereinafter referred to as AC) 〇 3-allyl-2-methylcyclopenta-2-
En-4-one-1-yl d-trans-chrysanthemate (generic name bioallethrin, hereinafter referred to as AD) 〇 N-(3,4,5,6-tetrahydrophthalimido)-methyl dl-cis/trans- Chrysantemate (generic name: phthalthrin; trade name: neopinamine; manufactured by Sumitomo Chemical Co., Ltd., hereinafter AE)
〇 2-Methyl-4-oxo-3-(2-propynyl)cyclopent-2-enyl-chrysanthemate 〇 (S)-2-methyl-oxo-3-(2-propynyl)cyclopent-2-enyl (1R)-cis/trans-chrysanthemate (generic name prarethrin: Japanese Patent Publication No. 52-45768 〇 [(pentafluorophenyl)-methyl]-
1R,3R-3-(2,2-dichloroethynyl)-
2,2-dimethyl-cyclopropanecarboxylate (common name: fenfluthrin: JP-A-1986-
133302) 〇 5-benzyl-3-furylmethyl d-cis/trans-chrysanthemate (generic name: Resmethrin; trade name: Chryslonfuorte; manufactured by Sumitomo Chemical Co., Ltd., hereinafter referred to as AF) 〇 5-(2 -propargyl) 6-furylmethyl chrysanmate (generic name: flamethrin, hereafter
〇 3-Phenoxybenzyl 2,2-dimethyl-3-(2',2'-dichloro)vinylcyclopropane carboxylate (generic name: permethrin; trade name: Exmin: manufactured by Sumitomo Chemical Co., Ltd., hereinafter AH) 3-Phenoxybenzyl d-cis/trans-chrysanthemate (common name: phenothrin:
Product name Sumitrin: Manufactured by Sumitomo Chemical Co., Ltd.
(hereinafter referred to as AI) 〇 α-cyanophenoxybenzyl isopropyl-4-chlorophenyl acetate (generic name: Fuenvalerate; trade name: Sumicidine: manufactured by Sumitomo Chemical Co., Ltd., hereinafter referred to as AJ) 〇 (S)-α-cyano- 3-Phenoxybenzyl (1R, cis)-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate (hereinafter referred to as AL) 〇 (R,S)-α-cyano-3- Phenoxybenzyl (1R, 1S)-cis/trans-3-(2,
2-dichlorovinyl) 2,2-dimethylchloropropanecarboxylate (hereinafter referred to as AM) 〇 α-Cyano-3-phenoxybenzyl d-
cis/trans-chrysanthemate (hereinafter referred to as AN)
〇 1-ethynyl-2-methyl-2-pentenyl cis/trans-chrysanthemate (hereinafter referred to as
AO) 〇 1-ethynyl-2-methyl-2-pentenyl 2,2-dimethyl-3-(2-methyl-1-
propenyl) cyclopropane-1-carboxylate (hereinafter referred to as AP) 〇 1-ethynyl-2-methyl-2-pentenyl 2,2,3,3-tetramethylcyclopropanecarboxylate (hereinafter referred to as AQ) 〇 1-ethynyl- 2-Methyl-2-pentenyl 2,2-dimethyl-3-(2,2-dichlorovinyl)cyclopropyne-2-carboxylate (hereinafter referred to as AR) 〇 3-allyl-2-methylcyclopenta-2-
En-4-one-1-yl 2,2,3,3-
Tetramethyl cyclopropane carboxylate (common name: telarethrin) Various commonly used additives such as efficacy enhancers, volatilization rate improvers, deodorants, fragrances, etc. can be optionally added to the above insecticide. Efficacy enhancers include piperonyl butoxide, N-propylisome, MGK-264, cinepirin 222, cinepirin 500, Riesen 384, IBTA, S-421, etc.
As a volatilization rate improver, use phenethyl isothiocyanate, dimethyl himixate, etc., as a deodorizer, use lauric acid methacrylate (LMA), etc.
Examples of fragrances include citral and citronellal. The above insecticides are prepared in solution form. As a solvent for preparing the insecticide solution, various organic solvents, typically hydrocarbon solvents, can be used, but aliphatic hydrocarbons (paraffinic hydrocarbons) with a boiling point range of 150 to 350°C can be used. Hydrogen and unsaturated aliphatic hydrocarbons) are preferred, and the n-paraffins having the boiling point range above include those having 10 to 18 carbon atoms [Dictionary of Organic Compounds, 5th
ed.1982]. Among these, n-paraffin, isoparaffin, etc. are particularly preferred because they are practically non-toxic, odorless, and pose a very low risk of fire. The solvent solution of the above insecticide is appropriately determined depending on the type of pyrethroid insecticide to be used and is not particularly limited, but the insecticide concentration is usually about 1.
The content is preferably adjusted to 10% by weight, preferably 3 to 8% by weight. In the present invention, an inorganic molded core made by caking inorganic powder with a sizing agent is used as the liquid-absorbing core. Specific examples include porous porcelain, glass fiber, inorganic fibers such as asbestos hardened with binders such as gypsum and bentonite, kaolin, activated clay, talc, etc.
Mineral powders such as diatomaceous earth, clay, perlite, gypsum, bentonite, alumina, silica, alumina-silica, titanium, glassy volcanic rock fired powder, glassy volcanic ash fired powder, etc. alone or wood powder,
Examples include those hardened with charcoal powder, activated carbon, etc., as well as adhesives such as dextrin, starch, gum arabic, synthetic glue CMC, etc. A particularly preferred liquid-absorbing wick includes the above-mentioned mineral powder alone or 100 parts by weight of the mineral powder and 10 to 300 parts by weight of wood flour or a mixture of the wood flour and charcoal powder and/or activated carbon up to an equal weight.
It is manufactured by blending a sizing agent to 5 to 25% by weight of the total weight of the absorbent core, adding water to the mixture, kneading, extrusion molding, and drying. It is desirable that the liquid absorption core has a liquid absorption rate of 1 to 40 hours, preferably 8 to 21 hours. This liquid absorption rate is determined by immersing a liquid absorbent core with a diameter of 7 mm x length of 70 mm in an n-paraffin liquid at a temperature of 25°C to a depth of 15 mm from the bottom, and measuring the time it takes for the n-paraffin to reach the top of the core. means the value determined by Furthermore, in addition to the mineral powder, wood flour, and sizing agent mentioned above, pigments such as macarite green, sorbic acid and its salts, and mold inhibitors such as dehydroacetic acid may be added to the liquid-absorbing core as necessary. You can also do it. As an apparatus suitable for carrying out the method of the present invention, any of various conventionally known suction type heating evaporation apparatuses can be used. As an example, for example,
Examples include those described in Japanese Utility Model Publication No. 12106, Japanese Utility Model Application Publication No. 58-45670, etc., and one specific example thereof is shown in the attached drawing. FIG. 1 is a schematic diagram of a suction type heating evaporation type device suitable for carrying out the method of the present invention, and the device includes an insecticide liquid storage container 3 having a wick support 2 for supporting a liquid absorption wick 1; , a liquid-absorbing wick 1 inserted into the container with its upper part protruding, a hollow disk-shaped heating element 4 for indirectly heating the upper side surface thereof, and a support part for supporting the heating element 4. 5 and a heating element support stand 7 having support legs 6, the heating element 4 has:
It has a cord (not shown) for energizing it to generate heat. In addition, as the heating element used in the above-mentioned device, a heating element that generates heat when energized is commonly used, but it is not limited to this, and examples include heating elements using air oxidation heating materials, platinum catalysts, etc. Any known heating element may be used. According to the method of the present invention, the desired insecticidal effect is achieved by heating the liquid absorbent core to an appropriate temperature at which the insecticidal liquid composition can evaporate from the liquid absorbent core. The above-mentioned heating temperature is appropriately determined depending on the type of insecticide, etc., and is not particularly limited, but it is usually a heating element surface temperature in the range of about 70 to 150 degrees Celsius, preferably 135 to 145 degrees Celsius, and this It needs to be selected so as to satisfy the condition that the core surface temperature is less than 130°C, preferably about 60°C or more and less than 130°C. If this condition is not met, even if the above-mentioned insecticidal liquid and liquid-absorbing core are combined, it will be difficult to achieve the desired effect of the present invention. Thus, according to the present invention, it is possible to reliably avoid clogging of the liquid-absorbing wick and volatilize the insecticide for a long period of time at an insecticide concentration that provides a sufficient insecticidal effect. Examples Examples will be given below to explain the present invention in more detail. Example 1 60 parts by weight of perlite, 20 parts by weight of wood flour and 20 parts by weight of starch
After adding part by weight and water and kneading, extrusion molding and drying,
Porous liquid absorbent core (diameter 7mm x length 70mm, oil absorption rate approx.
14 hours) was prepared. In addition, insecticidal liquid compositions (No. 1 to
13).

[Table] The symbols in the solvent section of Table 1 indicate the following. BB...Aliphatic hydrocarbon with a boiling point of 180-210℃/760mmHg BC...Aliphatic hydrocarbon with a boiling point of 210-240℃/760mmHg BD...Aliphatic hydrocarbon with a boiling point of 240-270℃/760mmHg BE...Boiling point 270-300℃/ Aliphatic hydrocarbon at 760 mmHg 50 ml of each of the insecticidal liquid compositions prepared above were placed in the container 3 shown in Fig. 1, and the heating element 4 was energized to heat the upper side of the liquid absorbent wick 1 to a temperature of 135°C. Then, a transpiration test of the insecticide in the composition sample by heating was conducted. As the heating element 4, a hollow disc-shaped heating element with an inner diameter of 10 mm and a thickness of 10 mm was used. In addition, the volatilized vapor of the insecticide was collected by suction into a silica gel column every hour, and the silica gel was extracted with chloroform, concentrated, and quantitatively analyzed using a gas chromatograph. 10 hours after the start of heating the insecticidal liquid composition sample,
The results of calculating the amount of insecticide volatilization mg/hr per hour after 100 hours, 200 hours, and 300 hours are shown in the second section below.
Shown in the table.

[Table] From Table 2 above, it is clear that according to the present invention, the improved amount of pesticide volatilization can be sustained over a long period of time. Comparative Example 1 A composition prepared by dissolving 2.1 Wt% of insecticide AG in solvent BC was used as the insecticidal liquid composition, and a porous liquid absorbent core [perlite] prepared in the same manner as in Example 1 was used as the liquid absorbent core. 80 parts by weight of starch, 20 parts by weight of starch, and water were added, kneaded, extruded and dried, diameter 7 mm x length 70 mm, oil absorption rate of about 14 hours], and in the same manner as in Example 1. 50 ml of the above composition was placed in a container 3 of a device similar to the device shown in Fig. 1, and the heating element 4 was energized to variously change the surface temperature of the heating element and the surface temperature of the liquid absorbent wick. was heated, and a transpiration test of the insecticide in the composition due to the heating was conducted to determine the amount of insecticide volatilized per hour (mg/hr) 10, 100, and 200 hours after the start of heating. The obtained results are shown in Table 3 below, along with the surface temperature (°C) of the heating element and the surface temperature (°C) of the liquid absorbent core used in the above test.

[Table] As shown in Comparisons 1 to 6 above, when the liquid absorption core temperature is satisfied but the heating element temperature is out of range, the amount of pesticide volatilization is not only extremely low, but also the amount of pesticide volatilization may vary. I understand. In addition, if the heating element temperature is satisfied but the liquid absorption core temperature is out of range, as shown in Comparisons 7 to 9, the amount of volatilization up to 10 hours is too large, and
On the other hand, up to 100 hours, the amount of volatilization suddenly becomes low,
It can be seen that almost no volatilization occurs up to 200 hours. In contrast, it is clear that excellent effects can be obtained in the case of the present invention, which satisfies both the temperature of the heating element and the temperature of the liquid absorbing core.

[Brief explanation of drawings]

FIG. 1 is a schematic view of an example of an apparatus suitable for carrying out the method of the present invention, in which 1 indicates a liquid absorbent wick, 3 indicates an insecticidal composition container, and 4 indicates a heating element.

Claims (1)

[Claims] 1. A heating transpiration insecticidal method in which a part of a liquid-absorbing wick is immersed in an insecticidal liquid to cause the wick to absorb the insecticidal liquid, and the upper part of the wick is indirectly heated to evaporate the sucked insecticidal liquid, As the insecticidal liquid, a solution in which a pyrethroid compound as an active ingredient of the insecticide is dissolved in an aliphatic hydrocarbon solvent having 10 to 18 carbon atoms is used. Using a liquid core, heat the upper part of the wick with a heating element whose surface temperature is approximately 60 to 130 degrees Celsius.
A heating transpiration insecticidal method characterized by indirect heating to a temperature below.