JPH04117312A - Suspended agricultural chemical composition - Google Patents

Abstract

PURPOSE:To obtain a suspended agricultural chemical composition having low density, ready handleability and excellent suspension stability during storage by blending tralomethrin of agricultural chemical active ingredient with sodium montmorillonite and a specific solvent. CONSTITUTION:0.1-10wt.% tralomethrin of slightly water-soluble agricultural chemical active ingredient, 0.01-2wt.% sodium montmorillonite and 3-30wt.% solvent are properly blended with antifreezing agent, a surfactant, a pH adjuster, a thickening agent, a stabilizer, an anti-foaming agent and adjusted to <=200cPs, preferably 20cPs viscosity to give the objective substance. The substance neither causes separation and settling even by log-term preservation nor forms a hard caking layer. The substance has low viscosity, is readily weighed, easily prepares a spraying solution and can eliminate an ignition point. The substance will not cause decomposition because no organic polymer-based thickening agent is used.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a suspended agricultural chemical composition that contains tralomethrin, which is a poorly water-soluble agricultural chemical active ingredient, as an active ingredient and that has a low viscosity and maintains stable properties over a long period of time. It is about things.

[Conventional technology]

Conventionally, agrochemical active ingredients have been used in the form of formulations such as powders, wettable powders, liquids, or emulsions. Among these, powders have advantages in that they are easy to formulate and can be sprayed as they are, but they also have disadvantages such as a large amount of scattering to the surroundings when sprayed. In addition, since hydrating powders are diluted in water and sprayed, they have the advantage of using water as a medium to ensure that the pesticide active ingredients adhere to crops uniformly and efficiently. It is unfavorable in terms of safety and health for people.

In addition, because emulsions are liquids, they do not form powder and can be easily diluted with water, allowing them to adhere to crops more effectively. and have toxicity issues.

In recent years, suspended agricultural chemical compositions in which micronized agricultural chemical active ingredients are dispersed and suspended in water, that is, formulations called sols or flowable agents (hereinafter referred to as flowable agents), have come into widespread use. Flowable agents, like wettable powders, are diluted with water and sprayed. Since this flowable agent is in liquid form, it does not form powder when diluted with water, is easier to measure than wettable powders, and has excellent properties such as being non-flammable.

As a flowable agent, a formulation prepared by adding water, a solvent, an anionic and nonionic surfactant, and a water-soluble polymer such as carboxymethyl cellulose to a poorly water-soluble agricultural chemical active ingredient and suspending the mixture in water (Japanese Patent Publication No. 58 -24401),
A preparation prepared by adding a nonionic surfactant and a heteropolysaccharide gum and suspending it in water (Japanese Patent Publication No. 53-46880) A preparation prepared by adding a nonionic surfactant and a heteropolysaccharide gum and suspending it in water. Cloudy preparation (Special Publication No. 52-1282
No. 26), a preparation in which a surfactant and colloidal hydrated aluminum silicate are added and suspended (Japanese Patent Publication No. 11368/1983) are known.

With the flowable preparations according to the prior art, a preparation with satisfactory suspension stability during storage cannot be obtained, and furthermore, the resulting sedimentation product may form a hard caking layer that cannot be reseparated. In order to prevent this separation and achieve a sufficiently satisfactory dispersion stability during storage, it is common practice to increase the amount of thickener and set the viscosity of the flowable to be high.

However, although setting a high viscosity prevents the formation of a heart-caking layer that cannot be redispersed, many problems have occurred due to the high formulation viscosity. For example, in the case of the currently commercially available scout flowable agent containing tralomethrin as an active ingredient, when using it, it is difficult to remove it from the container, and a lot of it adheres to the measuring container during measurement, resulting in inaccurate measurements. Problems arise such as clogging and hindering spraying. Furthermore, problems during production include slow filling speed into containers, lowering work efficiency, and failure to mix the active ingredients uniformly even when stirred and mixed.

[Means to solve the problem]

The present inventors have worked on developing a flowable agent that has two excellent properties that are contradictory to those of conventional technology: low viscosity, easy handling, and excellent suspension stability during storage, and conducted tests on a large number of additives and their combinations. As a result of repeated
By blending an agricultural chemical active ingredient (tralomethrin), sodium montmorillonite, and a specific solvent, it has a low viscosity that was unimaginable using conventional technology, but also has excellent storage and suspension stability. The present invention was completed by discovering that it is possible to obtain a suspended agricultural chemical composition that simultaneously satisfies the contradictory and excellent physical properties and is resistant to spoilage.

That is, the present invention contains (a) a poorly water-soluble agrochemical active ingredient tralomethrin, (bll rhidium morillonite), and (c) a solvent mainly composed of trimethylbenzene, and has a viscosity of 200 cps or less. A suspension agricultural chemical composition characterized by Additives such as thickeners, stabilizers, antifoaming agents, etc. are suspended in an aqueous component, in which case (b)
The content of sodium montmorillonite or other components is adjusted so that the viscosity is 200 cps, preferably 20 cps or less. The viscosity here is measured using a B-type viscometer (DVL-B manufactured by Tokyo Keiki Co., Ltd.), and the measurement conditions are: rotor size 2, rotation speed 30 rpm, and measurement temperature 20°C. be.

The aqueous component is water or water plus an antifreeze agent.

Water is usually added in an amount of 60 to 90% by weight based on the agricultural chemical composition.

Examples of antifreeze agents include propylene glycol, ethylene glycol, glycerin, ammonium sulfate, ammonium chloride, urea, etc.
5% by weight can be added.

(a) Tralomethrin, which is an agrochemical active ingredient, is blended in an amount of 0.1 to 10% by weight based on the agrochemical composition.

The (bll rhidium morrillonite used in the present invention) is a product of bentonite, which is an ultrafine particle thin film-like clay mineral composed of silica, alumina, and magnesia.
The exchangeable cations between the crystal layers are mainly Na cations. Sodium-montmorillonite is manufactured by dispersing bentonite in sufficient water and allowing it to stand for a long time to form a colloidal sol of pure sodium-montmorillonite in the upper layer, and then collecting only this upper layer and concentrating and drying it.

The amount of sodium montmorillonite used is 0.01 to 2% by weight based on the agricultural chemical composition.

The solvent (c) containing trimethylbenzene as the main component used in the present invention is an aromatic solvent with a xylene content of 4% by weight or less, and a 95% distillate of 170°C or less. Examples include Tsurupetz-100 (manufactured by Exxon Chemical Co., Ltd.). The amount of this solvent used is 5 to 30% by weight, preferably 10 to 20% by weight, based on the agricultural chemical composition.

As a surfactant, anionic surfactants such as lignin sulfonate, alkylbenzene sulfonate, polyoxyethylene styrylphenyl ether sulfate, styrene maleate polymer, polyoxyethylene/polyoxypropylene block copolymer, polyoxyethylene Examples include nonionic surfactants such as fatty acid ester, polyoxyethylene nonylphenyl ester, and sorbitan oleate; one or more of these surfactants may be added in an amount of 1 to 10% by weight to the agricultural chemical composition. It's coming.

To produce the agrochemical composition of the present invention, first, a predetermined amount of sodium montmorillonite, an antifreeze agent, a pH adjuster, and other ingredients as necessary are added to a predetermined amount of water, and dispersed with a stirrer. This is called the aqueous phase. Next, a surfactant and tralomethrin, which is an active ingredient for agricultural chemicals, are dissolved in a solvent to form an oil phase. Both are mixed and made homogeneous using a stirrer to obtain the desired suspended agricultural chemical composition.

〔Example〕

EXAMPLES Next, the present invention will be specifically explained with reference to Examples, but the present invention is not limited thereto. In addition, all parts and percentages in each example indicate parts by weight and percentages by weight.

Example 1 10 parts of urea and 1 part of radium-montmorillonite were added to 72 parts of water.
This mixture is mixed and dispersed into aqueous phase. 1.4 parts of tralomethrin drug substance, 1 part of polyoxene ethylene/polyoxypropylene block copolymer, and 1 part of alkylbenzenesulfonic acid Ca salt were mixed with 1.4 parts of the solvent trimethylbenzene.
Dissolve in 6 parts and use this as the oil phase. The aqueous phase and oil phase were mixed for 1 hour using a high-speed stirrer to obtain a homogeneous flowable agent.

The viscosity of this flowable agent was measured by the test shown below and was 8.8 cps.

Example 2 71 parts of water from Example 1 and 14.6 parts of trimethylbenzene
A homogeneous flowable agent with a viscosity of 11.7 cps was obtained.

Example 3 70 parts of water from Example 1 and 15.6 parts of trimethylbenzene
A homogeneous flowable agent with a viscosity of 11.9 cps was obtained.

Example 4 69 parts of water from Example 1 and 16.6 parts of trimethylbenzene
A homogeneous flowable agent with a viscosity of 10.7 cps was obtained.

Comparative Example 1 13.6 parts of trimethylbenzene in Example 1 was replaced with 13.6 parts of a paraffinic solvent (trade name: MLDW 5W60LP; manufactured by Esso Oil Co., Ltd.) to obtain a homogeneous flowable agent. When the viscosity was measured, it was 246 CpS.

Comparative Example 2 1 part of sodium montmorillonite of Example 1 and 72 parts of water
0.2 parts of xanthan gum and 72.8 parts of water to obtain a homogeneous flowable agent with a viscosity of 528 cps.

Comparative Example 3 1 part of sodium montmorillonite of Example 1 and 72 parts of water
0.05 parts of xanthan gum and 72.95 parts of water to obtain a homogeneous flowable agent with a viscosity of 15.6 cps.

Comparative Example 4 1.52 parts of tralomethrin drug substance, 15.5 parts of 1.2-propanediol, 2 parts of anionic surfactant carrier mixture, 3 parts of silicon dioxide, 0.37 parts of heteropolysaccharide, 1 part of dimethylpolysiloxane derivative , 0.09 part of 4-hydroxybenzenic acid propyl ether, 0.09 part of citric acid.
0.06 parts of propyl gallate, 0.01 part of 2-hydroxy-4-n-octylbenzophenone, 4.3 parts of trimethylbenzene, and 71.95 parts of water were stirred with a high-speed stirring device to form a homogeneous product with a viscosity of 788 cps. We obtained a flowable agent.

Viscosity test Put 100 g of flowable formulation into a 120-capacity glass bottle 2
The viscosity was measured after inverting once every second for 1 minute. Measurement was carried out using a B-type viscometer (DVL-B type manufactured by Tokyo Keiki Co., Ltd.)
was used, and the measurement conditions were rotor N (L 2, rotation speed 30
rpm and set temperature are 20°C. In addition, 15 cps
When measuring samples with the following viscosities, the Nα20-ter was replaced with an L adapter.

〔Effect of the invention〕

The suspension agricultural chemical composition according to the present invention has excellent storage stability and can be stored for a long period of time, as is clear from the test examples below, by incorporating sodium montmorillonite, which is an ultrafine particle thin film clay mineral, and trimethylbenzene. Separation and sedimentation do not occur, nor does a hard caking layer that cannot be redispersed form.

Furthermore, the viscosity is low, making it easy to remove from the packaging container and making it easy to accurately measure when used.
It has good dispersibility in water, makes it easy to prepare a spray liquid, and virtually eliminates the flash point. Also, since no organic polymer thickener is used, there is no risk of spoilage.

Test Example 1 Storage Stability Test Flowable formulation long was placed in a 120-I glass bottle and stored for one month in a constant temperature bath where the set temperature was changed alternately between 50°C and -10'C every 72 hours. The test measured the degree of separation and sedimentation of the flowable formulation taken out after one month. The investigation was calculated based on the ratio (%) of the height of the supernatant liquid to the height of the entire liquid.

The storage stability is better as the proportion (%) of the supernatant liquid is smaller.

The results are shown in Table 1.

Test Example 2 Dispersibility test in water Put 100ml of 3 degree hard water into a 100mt Spitz tube, drop the flowable formulation with a micro dispenser, observe the dispersion state, and then invert once every 2 seconds for 20 seconds. The dispersion state was observed and evaluated on the following four levels.

8. The state of dispersion is very good. The drug is not inverted (but is dispersed evenly).It is the best formulation for a flowable drug.

B: Good dispersion state. The drug will partially diffuse into the water and fall in the form of droplets, or it will be evenly dispersed if the drug is inverted.

It is a good formulation as a flowable agent.

C The dispersion state is somewhat poor. Most of the medicine falls in the form of droplets, but if you hold it upside down, it will be dispersed evenly. It may not be suitable for practical use as a flowable agent.

D: Poor dispersion. The drug falls in the form of droplets and is not easily dispersed even if the drug is repeatedly inverted. Not suitable as a flowable agent.

The results are shown in Table 1.

Test Example 3 Adhesion Test to Container Approximately 80% of the capacity of a flowable agent is placed in a 500-meter graduated cylinder with a stopcock, and after the cylinder is left to stand for 24 hours, the graduated cylinder is tilted at 45' for 60 seconds to release the flowable agent inside. The adhesion rate is the ratio (%) obtained by dividing the weight of the flowable agent remaining in the measuring cylinder by the weight of the flowable agent initially added. This test method is based on the CIPAC method MT-14.
This was done based on 8.

The results are shown in Table 1.

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Claims (1)

[Claims] (1) It is characterized by containing a solvent whose main components are (a) tralomethrin, a poorly water-soluble agrochemical active ingredient, (b) sodium montmorillonite, and (c) trimethylbenzene, and having a viscosity of 200 cps or less. Suspended pesticide composition.