JPH0482121B2 - - Google Patents

Description

[Detailed description of the invention]

Industrial applications N,N-bis(2,4-
xylyliminomethyl)methylamine [hereinafter simply referred to as amitraz (common name). ] is provided as an emulsified oily liquid (usually called an emulsion), which is one of the forms of agrochemical preparations, but amitraz is often used in combination with trace amounts of water and emulsifiers (surfactants) in the emulsion. It may decompose, producing turbidity or precipitate, or in extreme cases, the entire product may turn into a gel. The object of the present invention is to prevent decomposition caused by trace amounts of moisture and to provide a stable amitraz emulsion. Conventional technology When producing amitraz emulsion, a solvent and an emulsifier with low water content are selected, but during production during periods of high humidity, or when using the emulsion, there may be cases where the bottle is left uncovered with residual liquid. As a way to prevent decomposition caused by moisture absorption when left for a long time,
It has been proposed to add compounds containing epoxy groups such as epichlorohydrin, glycidyl esters containing epoxy groups, and ethers containing epoxy groups. Problems to be Solved by the Invention Many of the compounds containing epoxy groups have low vapor pressure or are highly reactive, which are undesirable in terms of safety. Epoxy compounds derived from linseed oil, rapeseed oil, soybean oil, etc. have also been proposed to improve these drawbacks. These epoxy compounds contain trace amounts of moisture in aromatic hydrocarbon solvents such as xylene and hygroscopic emulsifiers, and in order to prevent the decomposition of amitraz due to moisture, compounds containing epoxy groups must be used. Ideally, it would react with water before acting on amitraz and decomposing it. However, from this point of view, none of the epoxy compounds hitherto proposed are necessarily satisfactory. Furthermore, epoxidized soybean oils are undesirable because they react with water in the emulsion and then change in quality, causing turbidity. Therefore, there is a need to establish a method for stabilizing amitraz emulsions that is an alternative to the method using epoxy compounds. Means for Solving the Problem The present inventor has conducted various studies on stabilizers to replace epoxy compounds, and found that alkaline earth metal oxides are extremely safe and effective in stabilizing amitraz emulsion. The present invention was completed based on the discovery that it has a much superior stabilizing effect when compared to the conventional method. Alkaline earth metal oxides are often used as dry-keeping agents for foods, and a method of stabilizing agricultural chemical formulations has been proposed in which they are coexisted in a solid formulation in a separate package and stored in a hermetically sealed state. However, the use of alkaline earth metal oxides to stabilize active ingredients in formulations using non-aqueous organic solvents, generally called emulsions, has not been known at all, and it is difficult to predict based on conventional technology. The alkaline earth metal oxides herein refer to calcium oxide, magnesium oxide, and barium oxide. The alkaline earth metal oxide can be applied to the amitraz emulsion by suspending the alkaline earth metal oxide powder as it is in the amitraz emulsion, or by crushing and adding a ribbon-like powder to the amitraz emulsion. Good too. Alternatively, a pellet or film obtained by melt-mixing an alkaline earth metal oxide powder with a resin such as low-density polyethylene may be used. It works by adding alkaline earth metal oxides or pellets, films, etc. containing them directly to the amitraz emulsion, or by coating the inside of pesticide bottles with them. In addition, alkaline earth metal oxides or pellets, films, etc. containing them can be stabilized by allowing them to coexist inside the pesticide bottle without coming into direct contact with the amitraz emulsion, or by using them, for example, on the inner lid of the bottle. can be measured. The effects of the present invention will be explained below using specific examples, but the present invention is not limited to these examples. In addition, in the following description, parts indicate parts by weight. Formulation example A Stabilizer-free group A-1 Amitraz bulk substance......20 parts Solpol 2680 ^*1 ...8 parts Xylol...72 parts A-2 Amitraz bulk substance...20 parts Solpol 2680 ^*1 ...8 parts Cielzol A ^*2 ...72 parts A-3 Amitraz technical substance ...20 parts Solpol 2680 ^*1 ...8 parts Cielzol AB ^*3 ...72 parts A-4 Amitraz technical substance ...20 parts Solpol 2680 ^*1 ...5 Part xylol...65 parts Methylnaphthalene...10 parts A-5 Amitraz drug substance...20 parts Solpol 2680 ^*1 ...10 parts Solpol 3008K ^*4 ...2 parts Xylene...60 parts Machine oil...3 parts White Kerosene...5 parts B Epoxy compound addition group B-1 Amitraz drug substance...20 parts Solpol 2680 ^*1 ...8 parts Xylol...69 parts epichlorohydrin 3 parts B-2 Amitraz drug substance...20 parts Solpol 2680 ^*1 ...8 parts xylol ...69 parts glycidyl methyl ether ...3 parts B-3 Amitraz drug substance ...20 parts Solpol 2680 ^*1 ...8 parts xylol ...68 parts glycidyl propyl ether ...4 parts B-4 Amitraz Drug substance...20 parts Solpol 2680 ^*1 ...8 parts xylol...67 parts glycidyl butyl ether...5 parts B-5 Amitraz drug substance...20 parts Solpol 2680 ^*1 ...8 parts xylol...68 parts glycidyl allyl Ether...4 parts B-6 Amitraz technical substance...20 parts Solpol 2680 ^*1 ...8 parts Xylol...68 parts styrene oxide...4 parts B-7 Amitraz technical substance...20 parts Solpol 2680 ^*1 ... 8 parts xylol ... 68 parts glycidyl caprate ester ... 4 parts B-8 Amitraz drug substance ... 20 parts Solpol 2680 ^*1 ... 8 parts xylol ... 67 parts glycidyl methacrylate ester ... 5 parts B-9 Amitraz Technical substance ...20 parts Solpol 2680 ^*1 ...5 parts Xylol ...70 parts Neuser 510R ^*5 ...5 parts B-10 Amitraz drug substance ...20 parts Solpol 2680 ^*1 ...5 parts Xylene ...70 Part New Calgen K800 ^*6 ... Part 5 ^*1 Toho Chemical product name ^*2 Ciel Chemical product name ^*3 Ciel Chemical product name * ⁴ Toho Chemical product name ^*5 Nippon Yusashi epoxidized soybean oil product name ^*6 Takemoto Yushi Epoxy Compounded soybean oil product name reference example Prepare 100g of the emulsion of the formulation described in the formulation example,
Amitraz content was determined. This was divided into two 100 c.c. pesticide bottles. One was left as is, and 0.25 g of water was added to the other, both of which were sealed tightly and stored in a constant temperature room at 45°C. After 15 days, the amitraz content was measured by gas chromatography. The decomposition rate was determined according to the following formula. The results of each formulation example along with the control example stored in a constant temperature room at 45℃ are shown in Table 1, with the result of adding water as decomposition rate A, and the result of the control without adding water as decomposition rate B. show. Degradation rate = Analysis value immediately after formulation - Analysis value after 15 days / Analysis value immediately after formulation x 100

【table】

[Table] Addition of water leads to decomposition of amitraz. Example 1 50g of Formulation Examples A-1 to A-5 was prepared, and the amitraz content was determined. Pour this into a 100 c.c. No. 1 pesticide bottle, add 0.25 g of water, and then powder quicklime.
After adding 0.85 g, the mixture was sealed tightly and stored in a constant temperature room at 45°C.
After 15 days, the amitraz content was measured by gas chromatography. The decomposition rate was determined in the same manner as in the reference example. The results are shown in Table 2.

[Table] Addition of quicklime powder significantly suppressed the decomposition of amitraz. Example 2 50g of Formulation Examples A-1 to A-5 was prepared, and the amitraz content was determined. Pour this into a 100 c.c. No. 1 pesticide bottle, add 0.25 g of water, and then add pellets with a particle size of about 3 mm obtained by melting and mixing equal amounts of quicklime powder and low-density polyethylene. 1.7 g of the crushed material was added to approximately 1 mm, and the mixture was sealed and stored in a constant temperature room at 45°C. After 15 and 25 days, the amitraz content was measured by gas chromatography. The decomposition rate was determined in the same manner as in the reference example. The results are shown in Table 3.

[Table] Addition of pellets obtained by melt-mixing equal amounts of quicklime powder and low density polyethylene significantly suppressed the decomposition of amitraz. Example 3 50g of Formulation Examples A-1 to A-5 was prepared, and the amitraz content was determined. Put this in a 100 c.c. No. 1 pesticide bottle, add 0.25 g of water, and then add 50% quicklime.
3.2g of a 100μ film of low density polyethylene coated on both sides with 40μ of low density polyethylene, cut into approximately 3 mm squares, was added, sealed tightly and stored in a constant temperature room at 45°C. After 15 days, the amitraz content was measured by gas chromatography. The decomposition rate was determined in the same manner as in the reference example. The results are shown in Table 4.

[Table] Addition of sandwich film, which is a low-density polyethylene film containing quicklime coated on both sides with low-density polyethylene, significantly suppressed the decomposition of amitraz. Example 4 1.2 formulations of Formulation Examples A-1 to A-5 were prepared, and the amitraz content was determined. Divide this into 4 parts and put each in an oxadiazone emulsion (herbicide) container (500c.c.)
Place the inside of a plastic bottle distributed as a plastic bottle into a container coated with polybutylene phthalate. Add 1 g of the quicklime-containing film strips used in Example 3 to one container, seal the container, and mix (a)
And so. In one case, 1 g of the film containing quicklime used in Example 3 was suspended from the inner lid using a 0.15 mm stainless steel wire so as not to touch the emulsion contained therein, and this was used as (b). In addition, a piece of ribbon of magnesium oxide was added to one of the containers, and the container was sealed tightly, which was designated as (c). As a control, a sealed bottle without adding anything was prepared. Each was stored in a constant temperature room at 40°C. After 30 days, the amitraz content was measured by gas chromatography. The decomposition rate was determined in the same manner as in the reference example. The results are shown in Table 5.

[Table] Example 5 50g of Formulation Examples A-1 to A-5 was prepared, and the amitraz content was determined. This was put into a 100 c.c. No. 1 pesticide bottle, and 0.25 g of water was added thereto. 3.0g of barium oxide powder was added to this, the mixture was sealed tightly and stored in a constant temperature room at 45°C. After 15 days, the amitraz content was measured by gas chromatography.
The decomposition rate was determined in the same manner as in the reference example. The results are shown in Table 6.

[Table] Addition of barium oxide powder significantly suppressed the decomposition of amitraz. Example 6 Four formulations of Formulation Example A-3 were prepared. Take 500 c.c. of this and put each into a plastic bottle that is distributed as an oxadiazone emulsion (herbicide) container (500 c.c.) and whose inside is coated with polybutylene phthalate. In one container, put 32 g of the film strips containing quicklime used in Example 3 (width approx.
cm, 30 strips with a length of 22 cm) were added and this was designated as (a). To one was added 15 g of epichlorohydrin, which was designated as (b). In addition, two strips of quicklime-containing low-density polyethylene film approximately 2 cm wide and 15 cm long were added to one, and this was designated as (c). As a control, a sealed bottle without adding anything was prepared. The amitraz content of each bottle of emulsion was determined by gas chromatography. Next, add water to (a) and (b) respectively.
2.5 g was added, all bottles were tightly capped, and each was left in a warehouse with a slate roof for one year. One year later, the amitraz content in each sample was measured using gas chromatography. The decomposition rate was determined in the same manner as in the reference example. The results are shown in Table 7.

[Table] Low-density polyethylene film containing quicklime exhibited a much more significant decomposition inhibiting effect than the addition of epichlorohydrin. In addition, the emulsion (c) is a one-year-old product that was diluted 100 times and 1000 times with well water and left at room temperature for 24 hours, and the emulsification state was extremely good, with an oil layer on the top layer, a cream layer on the bottom layer, and amitra in the entire layer. No phenomena such as precipitation of crystals that would be a hindrance during actual dispersion were observed.

Claims (1)

[Claims] 1. A method for stabilizing an acaricidal emulsion containing N,N-bis(2,4-xylyliminomethyl)methylamine, which comprises acting with an alkaline earth metal oxide.