JPS58213702A - Preparation of stable emulsion agricultural chemical - Google Patents

Abstract

PURPOSE:In preparing an emulsion agricultural chemical containing an organophosphorus-based insecticidal component as an active ingredient, to improve the storage stability of the emulsion by adding a specific amount of a specified alcohol to it. CONSTITUTION:An emulsion of agricultural chemical such as malathion, etc. containing an organophosphorus-based insecticidal component as an active ingredient is blended with 0.3-5wt%, preferably 1-2wt% based on the emulsion of alcohol such as methyl alcohol, ethyl alcohol, ethylene glycol isopropyl alcohol, etc. having >=20wt% solubility in water at 20 deg.C, to give a stable emulsion of agricultural chemical. Since the alcohol not only has a preventing action on the precipitate in the emulsion, but also can provide a stable effect on the long-term storage of the emulsion and a uniform emulsion when the emulsion is diluted with water, stable controlling effects can be expected without causing unevenness of application and phytotoxicity.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing an agrochemical emulsion that provides stable properties. Specifically, in the production of a pesticide emulsion containing an organic phosphorus insecticidal component as an active ingredient, one type of alcohol having a solubility in water at 20°C of 20% or more is added to the emulsion Venus at a concentration of 0.0%. The present invention relates to a method for producing an agrochemical emulsion with improved stability during storage, characterized in that 3 to 5% is added.

Conventionally, 0.0-dimethyl 0-4-nitro-m-tolylphosphorothioate (MEP), 0.0-diethyl 0-2-isopropyl-4-methyl-6-pyrimidinyl phosphorothioate (Diazinon), 0. 0-dimethyl 0-2,2-dichlorovinyl phosphate (DDVP
I), O,O-dimethyl S-(1,2-bis(ethoxycarbonyl)ethyl)phosphorothiolothionate (Marathon), methanarsine bislaurylsulfite (MA
Insecticidal emulsions, bactericidal emulsions, and herbicidal emulsions containing various organic synthetic compounds as active ingredients, such as LS), 3, 4-', and chloroprobionanili F (DCPA), have been used. These emulsions are made by adding an organic solvent and an emulsifier to an active ingredient, mixing and dissolving them to form an emulsion, and before use, the emulsion is diluted with water to form an emulsion, which is then sprayed onto an object.

However, conventional emulsions containing MEP, diazinon, DDVP, Marathon, MALS, DCPA, etc. as active ingredients have been found to cause precipitation in the emulsion due to fluctuations in the quality of raw materials for the active ingredients that can be used up or when the emulsion itself is stored for a long period of time. There was a drawback that this occurred. When such an emulsion is diluted with water to form an emulsion, the precipitates are difficult to form into an emulsion and cause clogging of spray nozzles.

Furthermore, even if the nozzle is clogged, it is difficult to form a uniform emulsion, resulting in uneven spraying, which can cause phytotoxicity to useful plants and reduce efficacy. In addition, the formation of precipitates in the emulsion itself causes poor quality, and the appearance is also unfavorable.

Conventionally, as a method for improving the emulsion stability of emulsions containing organic phosphors such as DDVP and Marathon, the solubility at 20°C is 0.2 per 100 g of water. A method has been proposed in which 0.5 to 4% of aliphatic alcohol (such as isomyl alcohol) or aromatic alcohol (such as benzyl alcohol) is added in an amount of 15 g (Japanese Patent Publication No. 46-6438). However, this method has excellent emulsion stability when the emulsion is diluted with water, but when the emulsion itself is stored for a long period of time, the active ingredient precipitates in the emulsion, resulting in poor stability. I couldn't do it.

The present inventors conducted various tests on the production of agrochemical emulsions free of such defects. As a result, in pesticide emulsions containing organic phosphorus synthetic compounds as active ingredients, one type of alcohol, such as methyl alcohol or ethyl alcohol, whose solubility in water at 20°C is 20% or more, is added to conventional emulsions. It has been found that by this method, precipitation in the emulsion can be prevented and an agrochemical emulsion that is stable over a long period of time can be obtained.

In the present invention, the alcohol used as an emulsion stabilizer not only has the effect of preventing precipitation in the emulsion, but also stabilizes the emulsion itself during long-term storage. Even when the emulsion is diluted with water and actually sprayed, it can be made into a uniform emulsion, so it can be expected to have a stable pest control effect without uneven spraying or chemical damage.

Examples of alcohols added to stabilize the agricultural chemical emulsion in the present invention include methyl alcohol, ethyl alcohol, ethylene glycol, and isopropyl alcohol. In addition, these additives are effective at 0.3 to 5% of the total emulsion, and optimally 1 to 2%.
It is preferable to add a heavy weight percent. The emulsifier used in the production of the stable agrochemical emulsion of the present invention is an anionic surfactant or a nonionic surfactant that is normally used in the production of emulsions.

Next, the stability of the agrochemical emulsion produced by the method of the present invention will be specifically explained using test examples.

Test Example 100 mJ1 of the emulsion produced under the specified test conditions was placed in a brown narrow 11 bottle, tightly capped and left at room temperature for one year.
The amount of precipitation in the emulsion was measured, and the effect was expressed using the following index. The results are shown in Table 1 below.

Indicator of effectiveness■: A large amount of sediment is observed (spreading is impossible):
Quite a lot of sediment is observed (spreading is not possible)+:
Slightly observed precipitation: Almost no precipitation observed Table 1 (Emulsion Composition and Stability Efficacy Notes) 1. Tsurupol indicates an emulsifier manufactured by Toho Kaji Kogyo Co., Ltd.

2. All numbers in the table indicate weight %.

As is clear from the test example described in -I-, the emulsion produced by the method of the present invention is far more stable than the emulsion produced when methyl alcohol, ethyl alcohol, etc. are not added.

Patent applicant: Hokuko Chemical Industry Co., Ltd.

Claims (1)

[Claims] In the production of agrochemical emulsions containing organophosphorus insecticidal components as active ingredients, alcohols having a solubility in water at 20°C of 20% or more are mixed with 0.3 to 5% of the emulsion metal lid. Method for producing stable agrochemical emulsion characterized by heavy stitching