JPS605561B2 - Manufacturing method of granular pesticide - Google Patents

Description

[Detailed description of the invention] The present invention relates to an improvement in a method for producing granular agricultural chemicals.

Currently, pesticides are used in several formulations, but among them, granular formulations are easy to apply, and unlike powder or liquid spraying, there is no scattering and drifting of the formulation, which is a major feature of the granular formulation, and it can be used in large quantities. used in

Incidentally, methods for producing granules in this field can be broadly divided into three types.

'1} Kneading method: The active ingredient, carrier, and optionally additives are kneaded with water, molded by extrusion, etc., and dried.

{2' Impregnation method: A liquid active ingredient is impregnated into a particle base having a predetermined particle size.

[3' Coating Method 3] An active ingredient is added to a grain base of a predetermined particle size and the surface of the grain base is coated.

Among the above methods, the m-kneading method has the disadvantage that the active ingredient is hydrated and enters the drying process, so it decomposes and releases a large amount of exhaust gas containing bad odors and harmful components. "
Compared to other methods, this method has the disadvantage that the amount of active ingredient retained in the grain base cannot be increased much.

In this respect, {21] The impregnation method can be used to transfer the active ingredient to the granular base without decomposing the active ingredient or emitting a large amount of bad odor or harmful gas, provided that a granular base with a predetermined particle size and oil absorption capacity can be obtained. It can be manufactured by a simple process of just adding and mixing, and can be said to be the most preferable manufacturing method. The granular base, which is the premise of this method, can be obtained naturally, but by processing only the carrier using the Kawakneading method, it is possible to create particles with arbitrary particle size and oil absorption ability. Recently, it has become possible to manufacture many granules by the impregnation method. However, a major drawback of the impregnation method is that the active ingredient must be liquid at least during impregnation. Therefore, when trying to impregnate an active ingredient that is solid at room temperature, it must be heated above its melting point to melt it. Alternatively, it is necessary to liquefy it using a solvent.

In the method of adding a heated and molten active ingredient to a granular base, when the molten active ingredient is added to a granular base, it is immediately cooled and solidified, so it is almost impossible to impregnate it.

In order to avoid this, it is possible to heat the granular base material to the melting point of the active ingredient, but this would be almost impossible in practice and would be uneconomical. On the other hand, in the method of adding a solvent,
Many solvents are emissive, which changes the quality of the product;
In order to prevent changes in quality, it becomes necessary to use special packaging materials.

Furthermore, if the solvent is to be removed during the manufacturing process, additional capital investment will be required. Furthermore, considering the flammability and inhalation toxicity of solvents, it is not desirable to use them in the granule manufacturing process. The reality is that granule manufacturing is not carried out, but solutions to the above-mentioned problems are strongly required from the viewpoints of simplifying equipment and preventing the emission of harmful exhaust gases.

The inventors of the present invention stated, ``Because of this current situation,'' as a result of various studies on methods of impregnating solid active ingredients, we found that ``lower alkylene glycols or their ethers, and lower dialkylene glycols or their ethers'' were selected as impregnation methods. By adding one or more of the selected compounds (hereinafter referred to as glycols) to the pesticide active ingredient, which is solid at room temperature, and heating and melting the mixture, to a granular carrier, the above-mentioned disadvantages can be removed, and granular pesticides can be produced. We have discovered that it is possible to produce

Examples of glycols that can be used in the present invention include the following.

'1} Ethylene glycol (2) Ethylene glycol monomethyl ether '3} Ethylene glycol monoethyl ether {4} Ethylene glycol monopropyl ether '5) Ethylene glycol monobutyl ether (61 Ethylene glycol monophenyl ether '7) Diethylene glycol monomethyl ether {8)
Diethylene glycol monoethyl ether side Diethylene glycol monobutyl ether side Propylene glycol monomethyl ether QU Dipropylene glycol monomethyl ether 021.4-Butanediol monomethyl ether 03 Hexylene glycol (2-methylbentane-2,4-diol) The above glycols,
When added to a pesticide active ingredient that is solid at room temperature, the pesticide active ingredient melts at a temperature lower than its own melting point,
Moreover, when it is cooled, it does not solidify easily and remains in a liquid state for a long time.

Therefore, compared to humidifying and melting the active ingredient as it is, the heating temperature is lower and it does not solidify immediately even when it comes into contact with the granular carrier whose temperature is lower than that of the melt, so the active ingredient completely soaks into the carrier and mixes. can be evenly dispersed. Glycols are generally known as solvents, but the issue is not whether they have the ability to dissolve solid agricultural chemicals; in other words, they are added for the purpose of prolonging the coagulation time and lowering the coagulation point. The purpose can be fully achieved with an addition amount of 10 to 100% (by weight) of the amount of the active ingredient. Since all glycols have high boiling points and low vapor pressures, they are maintained stably without disappearing from the granules. Therefore, compared to the method of dissolving the active ingredient in a large amount of an aromatic solvent and impregnating it, the present invention does not require the trouble of recovering the solvent and can provide granules of stable quality. When producing granular pesticides according to the present invention, glycols are added to the pesticide active ingredients, heated and melted, and then the process can be carried out using the same equipment as the commonly used impregnation method for producing granules.

That is, the granular carrier may be added to a Nauta mixer, a concrete mixer type mixer, a V type mixer, etc., and the active ingredient melt may be added thereto by spraying, dropping, or pouring.
Any agricultural chemical active ingredient can be used in the present invention as long as it is solid at room temperature.

Pesticides here refer to not only those defined in the Agricultural Chemicals Control Law, but also those used for epidemic prevention, which are not conventionally called agricultural chemicals, and are used in a wide range of non-medical fields to kill harmful organisms. decrease,
Including those used for pest control. Some examples of agricultural chemical active ingredients used in the present invention are as follows, but are not limited to these.M old CP
,DEP,NAC,MTMC,Niji PC,PHC,M
CPCA, MCC, CAT, NIP, CNP, dimethoate, methomyl, cymetrine, promethrin, chromethoxynil (2,4-dichlorophenyl-3'-methoxy-4'-nitrophenyl ether), isoprothiolane (diipropyl-1,3-dithiolane-2) -ylidene malonate) (However, those listed only by the common name are based on the nomenclature in "Pesticide Handbook - 1974-" published by the Japan Plant Protection Association, September 30, 1974).

) Granular carriers used in the present invention include pentonite, acid clay, zeolite, clay, pumice, siliceous earth, crushed clay mineral particles obtained by firing these, or extrusion granulation method of clay mineral powder, dry compression method, etc. Examples include grains of plant materials such as granulated grains, corn cobs, and walnut kernels.

The size of the granular carrier can be selected from the range of 40 to 2,000 mm, and depending on the product to be obtained, for example, in the case of granules, particles with a particle size distribution of 95% or more in the range of 500 to 1,000 mm; In the case of fine grain agent F, 9 to 62 to 210r
The particle carrier size may be selected such that it has a particle size distribution of 0% or more, and the size of the particle carrier does not essentially affect the implementation of the present invention. Next, some test examples will be given to prove the usefulness of the present invention.

Test Example 1 10 parts of the solid agricultural chemical raw material and 1 to 10 parts of the additives were heated and melted in a 50' beaker, and 10 to 10 parts of the solid agricultural chemical raw material were heated and melted in a 10 parts constant temperature water bath.
The temperature at which crystals precipitate and the time until crystal precipitation were measured by lighting the lamp while blowing cold air at a temperature of 1 or 0.

The results are shown in Table 1. Table 1 From Table 1, it was found that solid pesticide active ingredients "remain in a liquid state for a sufficient period of time to be impregnated into a granular carrier because the melting point is significantly lowered by the addition of glycols.

Test example 2 {1) Sample preparation ■ Pumice granules (10 to 48 mesh) 25k9 were placed in a Nauta mixer (NX-S type manufactured by Hosokawa Seisakusho), and a heated and melted isoprothiolane source 3.5k9 was poured into it. and mixed for 30 minutes.

■ Granular carrier in Nauta mixer (same as above) 23.
Add 5kg of isoprothiolane raw material 3.5k9
and ethylene glycol phenyl ether) 1.5k9 were heated, strained and melted, and mixed for 3 minutes.

{2} Test method ■ Investigation of mixing variations After completion of mixing, randomly select 10 locations in the mixer, take one sample from each location, and check the content.

Lothiolane was analyzed. ■ Measurement of the amount eluted in water The above sample ■, both of which have an inprothiolane content of 12%,
Select ■ and put 100's each into 800 screams of water,
The concentration of isoprothiolane in water was measured over time.

(Water temperature i8oo) ■ Investigation of rice blast control effect (pot test) Four-leaf stage rice (variety: Tangin) was transplanted into a 4-inch diameter pot, and a sample (same as the one used to measure the amount of rice blast in water) was transplanted into a pot with a diameter of 4 inches. Sample) was treated at a rate of 3kg/ship after 3L7 and 12 days.
The rice blast fungus was inoculated, and four days after each inoculation, the disease state was investigated using the following calculation method.

Control value (%) = Muyama treatment area - number of lesions per leaf Treatment area - number of lesions per hollyhocks x.

〇Number of lesions per plan in untreated area {3} Test results ■ Mixing variation Table 2 ■ Amount eluted into water (concentration in water pph) Table 3 ■ Urushi effect by Imochi-do sub-type (control value) Table 4 {3'1 According to the results of ■, “Adjustment method not based on the present invention ■
In the case of , the molten active ingredient crystallizes during mixing, making it impossible to mix uniformly, whereas in the case of adjustment method This shows that uniform mixing is possible.

According to the results of {3}-■, even if the granules contain the same amount of active ingredients, those prepared by the preparation method (■) of the present invention show that the ingredients dissolve better into water.

This is because in the case of the preparation method (3) which is not based on the present invention, the active ingredient condenses on the surface of the grains, reducing the surface area, whereas in the case of the present invention, the active ingredients completely penetrate into the pores of the grains. We believe that this is because the surface area is expanded. (According to the results of 3--■, it is shown that the preparation method (■) according to the present invention is more effective than the preparation method (■) not according to the present invention. But this is '3}
From the results of -■, this naturally occurs and shows the usefulness of the present invention.

Next, some embodiments of the present invention will be shown, but the present invention is not limited to these.

Example 1 12 parts of isoprothiolane raw material and 6 parts of ethylene glycol phenyl ether were heated and mixed, and this was mixed with 8 parts of granular pumice of 10 to 48 mesh.
Add 2 parts and mix for 30 minutes in a Nauta mixer to obtain isoprothiolane 12% granules.

Example 2 12 isoprothiolane raw materials and 4 parts of ethylene glycol ethyl ether (HOC 3 days 40C 2 days 5) were heated and melted, and this was added to 84 parts of calcined montmorillonite grains of 65 to 250 mesh, and mixed in a concrete mixer. Mix for 2 minutes using a mold mixer to obtain 12% isoprothiolane granules.

Example 3 7 parts of isoprothiolane drug substance and diethylene glycol ethyl ether (HOC2HOC2 ratio ○C2 days 3
) 3 parts are heated and melted, and this is poured into 9 pieces of calcined montmorillonite grains of 65 to 250 mesh, and the two powders are mixed in a Nauta mixer to obtain Isopthiolane 7% fine granules F.

Example 4 5 parts of dimethoate base material and ethylene glycol phenyl ether part are heated and melted.

On the other hand, 87 parts of clay and 4 parts of IJ guninsulfonate calcium were mixed with 14 parts of water, extruded into granules with a diameter of 1 rib, dried, and divided into 14 to 32 mesh pieces, prepared using a drum mixer. Put it in.

The above melt is added and mixed to obtain 5% dimethoate granules. Example 5 2 parts of diethylene glycol-n-butyl ether (HOC 2 days 40C 3 days 40C 4 days 91N) was added to 4 parts of the DEP raw material, heated and melted, and this was added to 94 parts of pumice grains of 65 to 250 mesh, Mix with a Nauta mixer to obtain Dibuterex 4% fine granules F.

Claims (1)

[Claims] 1 Agrochemical active ingredients that are solid at room temperature include 1 selected from the group consisting of lower alkylene glycols or their ethers and lower dialkylene glycols or their ethers.
A method for producing a granular agricultural chemical, which comprises adding two or more of them and melting them under heating, and mixing the mixture with a granular carrier.