JPS61204108A - Stable injurious insect exterminating composition - Google Patents

Abstract

PURPOSE:The titled composition, containing a specific compound as an active constitutent and further a specific phosphite based compound as a stabilizer, and capable of enhancing the stability of high insecticidal and acaricidal efficacy of the active constituent and putting the composition into practical use as a heating fumigant. CONSTITUTION:A stable injurious insect exterminating composition containing 3-(2-methoxyphenyl)-5-methoxy-1,3,4- oxadiazol-2(3H)-one known to have a high injurious insect exterminating activity as an active constituent and a phosphite based compound expressed by formula I [n is 1 or 2; R1-R3 are alkyl or (alkyl- substituted) phenyl when n is 1, and when n is 2, R1 is same as R1 when n is 1; R2 and R3 together form a gorup expressed by formula II], e.g. a compound expressed by formula III, IV or V, as a stabilizer. The above-mentioned composition is capable of sufficiently exterminating various injurious insects, e.g. houseflies, mosquitoes, cockroaches, aphids, leaf-hoppers, mites, etc., without deteriorating the efficacy even in preservation for a long period and heating fumigation.

Description

Detailed Description of the Invention The present invention uses 3-(2-methoxyphenyl)-5-methoxy-1,8,4-oxadiazole-2 as an active ingredient.
The present invention relates to pest control compositions containing (3111[)-one.

8-(2-methoxyphenyl)-5-methoxy-1,8
, 4-oxadiazole-2 (3H non-one (hereinafter referred to as compound) is known to have high pest control activity [D, Ambrosiat al (1979
) :Proc, Br1t, Prot, 0onf, Pe
5ts 5nd Diseases, page 53g] The compound has poor stability, especially thermal stability, and there are various restrictions when putting it to practical use as a pest control agent.

For example, when chemical compounds are stored at 40°C to 60°C, they decompose significantly and cannot maintain their purity over a long period of time. This leads to problems, making it virtually impossible to put it into practical use. In particular, when the compound is used in the form of a heating fumigant at a heating temperature of 150° C. to 850° C., its decomposition is significant, making its use practically impossible.

As a result of various studies in order to improve the stability of Compound A and to enable the use of Compound A as a heat fumigant, the present inventors discovered that Compound A has a phosphite compound represented by the following general formula. The present invention was completed based on the discovery that the stability of the compound was significantly increased by adding it as a stabilizer, and that it could be put to practical use as a heat fumigation agent.

(In the formula, n represents 1 or 2. When n represents 1, R1, R2 and R3 are the same or different and represent an alkyl group or a phenyl group which may be substituted with an alkyl group.

When n represents 2, R1 represents an alkyl group or a phenyl group which may be substituted with an alkyl group, and R2 and R3 are collectively a group. The present invention provides a stable pest control composition containing a phosphite compound represented by the above general formula [I] as a stabilizer.

The composition of the present invention can sufficiently kill various pests such as houseflies, mosquitoes, cockroaches, aphids, planthoppers, and mites without losing the high insecticidal and acaricidal efficacy of the compound during long-term storage or heat fumigation. can be exterminated.

The composition of the present invention will be explained in detail below.

Examples of the phosphite compound represented by the general formula CI) used as a stabilizer in the composition of the present invention include the following.

Compound Number Structure Formula Furthermore, the composition of the present invention has the following general formula (It) (wherein, R
1 and R2 are the same or different and represent a hydroxyl group or a -00-C-CH=CH2 group; R3 and R4 are the same or different and represent a methyl group or an ethyl group.

However, either one of R1 and R2 is a hydroxyl group. ) It is also possible to improve the stability of the composition of the present invention by adding a phenolic antioxidant shown in the following.

Specific examples of phenolic antioxidants include the following.

In the case of stabilizing Compound A, the content of the phosphite-based compound used as a stabilizing substance in the present invention is from 1/1000 to 175, preferably from 1750 to 1/1000 of the weight of Compound A. In the case of stabilizing a heat fumigant, it is twice the amount from 1/20 amount, preferably from 1/10 amount to the same amount.

The content ratio of the phosphite compound and the phenolic antioxidant is 10:1 to 1:1, preferably 8:1 to 1:1, by weight.

Furthermore, the composition of the present invention may contain pyrethroid compounds such as permethrin, cypermethrin, cyphenothrin, phenothrin, and tetramethrin in addition to compounds as active ingredients.

As a preparation for heat fumigation containing the composition of the present invention, for example, the composition of the present invention may be kneaded into a mosquito coil base material and punched out in the shape of an incense coil to make a mosquito coil, or the composition of the present invention may be prepared by applying the composition to an organic solvent. The composition of the present invention can be kneaded with an inorganic carrier such as talc or clay and made into granules, which can then be used. For example, the composition of the present invention may be placed in a container to be heated as a fumigating agent, or a small block of asbestos, ceramic, alumina, etc. may be impregnated with the composition of the present invention, and the composition may be fumigated by electric heating during use.

Next, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples.

Example 1 Various phosphate compounds were added to a compound at a weight ratio of 2% to the compound, dissolved in acetone, mixed thoroughly in liquid form, and the acetone was distilled off to remove the remaining compound. The mixture (solid) with the stabilizer was ground to obtain the present composition. Put these in a glass bottle, seal it tightly and keep it at 50°C.
After storage for 8 months at 60°C and 1 month at 60°C, it was taken out and analyzed for purity.

The purity after 8 months at 50°C and the purity after 1 month at 60°C were multiplied by the purity at the start of each test, and multiplied by 100 to determine the respective survival rates.

Example 2 Compound subjects were given 2% by weight of the compound (1
) was added, kept warm at 90°C for 80 minutes, melted and cooled, and then ground to separate compound m and compound (
The present composition consisting of 1) was obtained. 60℃1 of this composition
The survival rate after 2 months was 98.8%.

Example 8 A compound (2%) was added to Compound M in an amount ratio of M to Compound M.
) was added thereto, and the mixture was vigorously mixed with a mixer to obtain the present composition consisting of Compound A and Compound (2). The survival rate of this composition after one month at 60°C was 97.9%.

Example 4 Compound 500 mj' and compound (1) 250 mt
Dissolve this in 2m of acetone, and make a 4cm+square, 1cm thick
．． A preparation for electric heating fumigation is obtained by impregnating a porous ceramic block of two countries.

Example 5 100 mF of compound (2), 50 mt of compound (2), and a small amount of fragrance are dissolved in hexane tsg, and a normal valve mat for electric mats is impregnated with this to obtain an electric mat preparation.

Example 6, Compound A 100 mt and Compound (3) 50 mt
A mosquito coil preparation is obtained by kneading the mixture with a mosquito coil base material and blowing it out in the shape of an incense stick.

Example 7 Compound 500 nat and compound (1) 250 mt were dissolved in 2-acetone, and this was dissolved in 4ts square, 125 mt.
mj' and 125 mP of the compound (Crow) were dissolved in 2-acetone and impregnated into a ceramic porous plate of 41 sides and 1.2 aI in thickness.

On the other hand, dissolve 500 m9 of compound A alone in 2 d of acetone, and impregnate a porous ceramic plate of the same shape with this. Each of these was placed in an electric heater and heated at 300°C. Place a bell-shaped funnel on top of the heater, and from now on
01 length Liebig cooler and further 55F-
A device was constructed so as to lead to a glass tube filled with silica gel (60-80 mesh) and plugged with cotton at both ends, and air was sucked through these devices at a rate of 20/min.
Collect fumigated compounds. The collected compounds were extracted with acetone and analyzed to measure the volatilization rate. The volatilization rate was calculated using the following formula.

The volatilization rate under each condition is shown in the table below.

Example 8 Compound A500mj', Hermesrin 5ooWf and Compound (3) 250 m? was dissolved in 2-m2 acetone and impregnated into a ceramic porous plate of 4a square and 1.21mm thick. These were heated in the same manner as in Example 7,
When the volatilization rate at that time was determined, the volatilization rate of compound A was 92.9%, and the volatilization rate of permethrin was 98.8%, both of which showed high volatilization rates.

Claims (1)

[Scope of Claims] 3-(2-methoxyphenyl)-5-methoxy-1,3,4-oxadiazol-2(3H)-one as an active ingredient and the general formula ▲mathematical formula as a stabilizer, There are chemical formulas, tables, etc. Represents a group. When n represents 2, R_1 represents an alkyl group or a phenyl group which may be substituted with an alkyl group, and R_2 and R_3 together represent a group ▲There are mathematical formulas, chemical formulas, tables, etc.▼ A stable pest control composition characterized by containing a phosphite-based compound represented by: