JPS64364B2 - - Google Patents

Description

[Detailed description of the invention]

(a) Field of industrial application of the invention The present invention relates to a novel invention that can be used in agriculture, particularly in the field of manufacturing agricultural chemical granules. More specifically, the present invention relates to an improved technique for stabilizing the active ingredient over time and reducing transdermal toxicity to mammals in a granular agricultural chemical composition containing esoprophos shown below as an active ingredient. It is something. Esoprophos O-ethyl S,S-dipropyl phosphorodithioate Conventional technology A method of adding alkylene or polyalkylene glycol as a substance to suppress changes over time in granules of esoprophos is known (US Pat. No. 2,970,080). Specification). In addition, boiled linseed oil or linseed oil, which is a vegetable oil, is added to esoprofos,
It is disclosed that by adding propylene glycol at the same time, deodorization and stabilization can be achieved and toxicity to the skin of humans and animals can be reduced (Japanese Patent Publication No. 57-5201). On the other hand, abietic acid can be used as paints such as lacquer and varnish, growth promoters such as lactic acid, butyric acid, and yeast, and antibacterial agents, and as a solvent for rubber, varnish, and synthetic resins, such as methyl ester, and as a metal salt for paper size. It is used for various purposes. Problems to be Solved by the Invention Esoprophos is a soil insecticide and nematocide that is already known to be effective against various nematodes, including Gypsum nematode and Sweet potato nematode, as well as scarab beetles, scarab beetles, scale insects, etc. It is. However, when esoprofos is made into granules, the active ingredient changes significantly over time. Therefore, in order to guarantee the amount of active ingredients for two years, which is usually the case with agricultural chemicals, it is necessary to significantly increase the amount of esoprophos used when manufacturing granules. However, because of this, esoprofos has high dermal toxicity to humans and livestock, so it becomes even more dangerous when it is formulated into granules or dispersed, and on the other hand, it causes chemical damage to crops. In addition, increasing the amount of preparation increases the cost, which is economically disadvantageous. There is also concern that large amounts of decomposed products produced over time may cause harmful effects to crops, such as phytotoxicity. Furthermore, esoprofos has very strong dermal toxicity to mammals, and strict care is required when handling this preparation. In response to the current situation, none of the conventional techniques is satisfactory in stabilizing esoprofos in granules and reducing transdermal toxicity. In view of these circumstances, the present invention provides a new type of esoprofos granules that are stable over a long period of time (at least 2 years) without changing over time, and are non-dermal toxic, in place of the conventional technology. It is about providing. (b) Means for solving the structural problems of the invention The present inventors have conducted extensive research on stabilizing esoprofos when made into granules and on techniques for reducing the transdermal toxicity of esoprophos granules to mammals. . As a result, it was discovered that by adding abietic acid (also called cylvic acid), the temporal change of esoprofos can be significantly suppressed, and at the same time, the transdermal toxicity can be significantly reduced. I've reached it. As the abietic acid of the present invention, not only high-purity products but also rosin or tall oil containing abietic acid can be used. The amount of abietic acid used in the present invention is effective if it is 0.1% (weight%) or more in the granules, but from the viewpoint of both effectiveness and economy, it is 0.1 to 5%.
% is desirable. Effect When the abietic acid of the present invention is added to esoprofos granules, it becomes possible to reduce the decomposition rate of esoprofos to 1% or less even when stored at room temperature for 2 years.
Further, transdermal toxicity can be significantly reduced. Furthermore, even if abietic acid is added, the above-mentioned inherent biological effects of esoprofos will not be impaired. The preparation method of the present invention is not particularly limited,
A conventional method for preparing pesticide granules may be used. for example,
It can be prepared by the following method. Preparation method 1 Abietic acid of the present invention dissolved in an organic solvent (for example, methanol, etc.) is sprayed and adsorbed onto a granular mineral carrier impregnated with esoprophos in advance,
Dry to obtain granules. Preparation method 2 Organic solvent (e.g. methanol, etc.)
A solution in which esoprophos and the abietic acid of the present invention are simultaneously dissolved is sprayed and adsorbed onto a granular mineral carrier and dried to obtain granules. Preparation Method 3 After adding and mixing the abietic acid of the present invention to esoprofos, a mineral carrier, a binder, etc., water is added and kneaded, followed by granulation using an extrusion granulator or a rolling granulator. Dry and sieve to obtain granules. As the mineral carrier used in the present invention, any carrier used in agricultural chemical formulations can be used. Examples include clay, diatomaceous earth, talc, bentonite, attapulgite, vermiculite, zeolite, pumice, cellulose powder, white carbon, etc. When using a granular mineral carrier, these minerals should be adjusted to an appropriate particle size. They may be prepared in the same way, or they may be empty granules containing no active ingredient prepared by a normal granulation method. Examples are given below to specifically explain the present invention, but the present invention is not limited to these examples. In addition, all parts in the examples are parts by weight. Example 1 (Preparation method 1) 5 parts of esoprophos is sprayed and adsorbed onto 94 parts of granular attapulgite (14 to 48 mesh). Next, 20 parts of a 5% abietic acid methanol solution is adsorbed by spraying, and after drying, granules containing 5% esoprophos are obtained. Example 2 (Preparation method 2) 94 parts of granular zeolite (14 to 48 mesh) was sprayed and adsorbed with 40 parts of a methanol solution containing 12.5% esoprophos and 2.5% abietic acid at the same time, and after drying, granules containing 5% esoprophos were obtained. get the agent. Example 3 (Preparation method 3) 1 part of abietic acid was added to 5 parts of esoprophos, 3 parts of white carbon, and 91 parts of clay, mixed, and mixed with water.
After adding 15 parts and kneading, the mixture is granulated using an extrusion granulator. Next, drying and grading (14 to 48 mesh)
Granules containing 5% esoprofos are obtained. (c) Effect of the invention Test examples will be given to prove the usefulness of the present invention. In addition, the samples prepared by removing the abietic acid of the present invention from Examples 1 to 3 were designated as Control Examples 1 to 3, and the samples prepared by the following method were designated as Control Example 4. [Preparation method of Comparative Example 4] Esoprophos granules described in Japanese Patent Publication No. 57-5201 A mixture of 5 parts of esoprophos, 1 part of linseed oil, and 2.5 parts of propylene glycol was mixed with granular attapulgite (14 to 48 mesh).
Spray adsorb to 91.5 parts, 5% as esoprophos
Obtain granules containing: Test Example 1 Changes in active ingredients over time due to abuse 50 g of a sample prepared according to the example was placed in a 140 ml mayonnaise bottle, the bottle was capped, and the bottle was left in a thermostat at 45°C. After 30 days (equivalent to storage at room temperature for 1 year) and 60 days (equivalent to 2 years), the sample was taken out and the esoprophos content in the sample was analyzed using GC (gas chromatography) to determine the content before abuse. The decomposition rate (%) relative to the amount was calculated. Results first
Shown in the table.

[Table] Test Example 2 Dermal toxicity test using mice Gauze part of patch test bandage (diameter 1.5cm)
moisten with distilled water, and apply a sample prepared according to the example (50 mg of esoprophos per 1 kg of mouse). This was then applied to the depilated skin of mice, and the number of deaths was observed over time. Five mice were used for each sample in this test. The results are shown in Table 2.

[Table] Test Example 3 Control effect of tomato on sweet potato nematode
It was applied to soil contaminated with sweet potato knotweed in a 00R pot and mixed uniformly. After mixing, five tomato seeds were sown, watered, and left in a greenhouse. 20 days after sowing, the tomato seedlings that had germinated and grown were pulled out and the degree of Nekobu expression in the roots was examined.
The control value (%) was determined. In addition, the evaluation of the level of Nekobu expression and the control value were determined by the following method. Degree of occurrence of Nekobub 0: None 1: Slight 2: Slight 3: Medium 4: High 5: Extremely Control value (%) = (1 - Average degree of Nekobuki in the treated area/Average degree of Nekob in the non-treated area) x 100 trees The test was conducted with 1 pot per section and 5 repetitions. The results are shown in Table 3.

[Table] Note 2) The amount of rosin and tall oil added is the amount added as rosin or tall oil.

Claims (1)

[Claims] 1. A granular agricultural chemical composition comprising O-ethyl S,S-dipropyl phosphorodithioate as an active ingredient and abietic acid added thereto.