JP2949811B2 - Suspended pesticide composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention comprises a pesticidal active ingredient, which is a poorly water-soluble pesticidal active ingredient, having a low viscosity and maintaining stable properties for a long period of time. It is about things.

[Conventional technology]

Conventionally, pesticidal active ingredients have been used in the form of powders, wettable powders, liquid formulations or emulsions. Among them, powders have advantages such as being easy to formulate and being able to be sprayed as they are, but have disadvantages such as scattered to surroundings when spraying. In addition, the wettable powder is diluted with water and sprayed, so it has the advantage that the pesticidal active ingredient adheres to the crops uniformly and efficiently using water as a medium. Is unfavorable in terms of health and safety of the elderly. Emulsions have the advantage that they are liquid and do not powder, can be easily diluted in water, and adhere more effectively to crops.However, since most of the emulsions are composed of organic solvents, they are flammable and Has toxicity problems.

2. Description of the Related Art In recent years, a suspension-type agricultural chemical composition in which a finely divided agricultural chemical active ingredient is dispersed and suspended in water, that is, a formulation called a sol or a flowable agent (hereinafter, referred to as a flowable agent) has been widely used. The flowable is diluted with water and sprayed, like the wettable powder. Since the flowable agent is liquid, it has excellent properties such as no powdering at the time of dilution with water, easy measurement as compared with a wettable powder, and no flammability.

So far, as a flowable agent, a formulation in which water, a solvent, an anionic or nonionic surfactant, and a water-soluble polymer such as carboxymethylcellulose are added to a poorly water-soluble agricultural chemical active ingredient and suspended in water (Japanese Patent Publication No. No. 24401), a non-ionic surfactant and a heteropolysaccharide gum, and a suspension prepared in water (JP-B No. 53-46880). A non-ionic surfactant and a heteropolysaccharide gum are added, wet-ground, and ground in water. Suspended preparations (JP-B-52-128226) and preparations in which a surfactant and colloidal hydrous aluminum silicate are added and suspended (JP-B-54-11368) are known.

The flowables according to the prior art do not give a formulation which is satisfactory in suspension stability during storage, and furthermore the sedimented sediment may form a hard-caking layer which cannot be separated again. In order to prevent this separation and sufficiently satisfy the dispersion stability during storage, it is common practice to increase the viscosity of the thickener and increase the viscosity of the flowable.

However, by setting the viscosity to be high, it is possible to prevent the formation of a hard-caking layer that cannot be redispersed. However, since the viscosity of the preparation is high, many problems have occurred. For example, in the case of a currently available scout flowable agent containing tralomethrin as an active ingredient, it is difficult to take it out of the container when using it, so that it adheres to the measuring container at the time of weighing and the measurement becomes inaccurate, the dilution dispersibility is poor, and the nozzle dispersibility is poor. This causes problems such as clogging and hindering spraying. Further problems at the time of production include that the filling speed into the container is slowed down, the working efficiency is reduced, and the active ingredients are not evenly mixed even with stirring and mixing.

[Means for solving the problem]

The present inventors have worked on a flowable agent having low viscosity, easy handling, and excellent suspension stability during storage, which has two excellent properties that are inconsistent with the prior art, and conducted tests on a large number of additives and combinations thereof. As a result of the repetition, the combination of pesticidal active ingredient (tralomethrin), sodium montmorillonite, and a specific solvent also contributes to storage suspension stability despite low viscosity that could not be considered by the prior art. It has been found that a suspension-type pesticide composition that simultaneously satisfies the superior and contradictory superior physical properties and is less likely to rot is obtained, and completed the present invention.

That is, the present invention provides (a) tralomethrin, which is a poorly water-soluble agrochemical active ingredient, (b) sodium montmorillonite,
And (c) a suspended pesticidal composition comprising a solvent containing trimethylbenzene as a main component and having a viscosity of 200 cps or less. The suspended pesticidal composition of the present invention,
(A), (b), (c) components and, if necessary, other additives such as a surfactant, a pH adjuster, a thickener, a stabilizer, and an antifoaming agent are suspended in an aqueous component; At this time, (b) the content of sodium montmorillonite or other components is adjusted so that the viscosity becomes 200 cps, preferably 20 cps or less. The viscosity referred to here is a B-type viscometer (DVL-
(Type B manufactured by Tokyo Keiki Co., Ltd.).
rpm, measurement temperature is 20 ° C. The aqueous component is water or water obtained by adding an antifreezing agent to water.

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

Examples of the antifreeze include propylene glycol, ethylene glycol, glycerin, ammonium sulfate, ammonium chloride, urea, and the like.
15% 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.

(B) Sodium montmorillonite used in the present invention is a main component of bentonite which is a viscous mineral in the form of an ultrafine particle thin film composed of silica, alumina and magnesia, and the exchangeable cation between the crystal layers is mainly Na cation. It is of an ion. Sodium montmorillonite disperses bentonite in sufficient water for a long time and forms a colloid sol of pure sodium montmorillonite in the upper layer when left standing.
The upper layer alone is collected, concentrated and dried to produce the product.

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

The solvent (c) containing trimethylbenzene as a main component used in the present invention is an aromatic solvent having a xylene content of 4% by weight or less and a 95% distillate of 170 ° C. or less. Solvesso 100 (Exxon Chemical Co., Ltd.)
Etc. The amount of the solvent used is 5 to 5 per pesticide composition.
It is 30% by weight, preferably 10 to 20% by weight.

As surfactants, anionic surfactants such as lignin sulfonate, alkylbenzene sulfonate, polyoxyethylene styryl phenyl ether sulfate, styrene maleate polymer, and polyoxyethylene / polyoxypropylene block copolymer, polyoxyethylene Nonionic surfactants such as fatty acid esters, polyoxyethylene nonylphenyl esters, and sorbitan oleic acid esters are included. One or more of these surfactants are added in an amount of 1 to 10% by weight based on the pesticide composition. Can be.

To produce the pesticidal composition of the present invention, first add a predetermined amount of sodium montmorillonite and, if necessary, a deicing agent, a pH adjuster, and if necessary, other components to a predetermined amount of water, disperse with a stirrer, This is the aqueous phase. Next, the surfactant and the pesticidal active ingredient tralomethrin are dissolved in a solvent, and this is used as an oil phase. Both are mixed and made uniform with a stirrer to obtain a target suspended pesticide composition.

〔Example〕

Next, the present invention will be described in detail with reference to examples, but the present invention is not limited thereto. still,
All parts and percentages in the examples are parts by weight and percentage by weight.

Example 1 10 parts of urea and 1 part of sodium montmorillonite were mixed and dispersed in 72 parts of water to obtain an aqueous phase. Tralomethrin drug substance
1.4 parts, 1 part of a polyoxyethylene / polyoxypropylene block copolymer, and 1 part of a calcium salt of alkylbenzenesulfonic acid are dissolved in 13.6 parts of a solvent, trimethylbenzene, and this is used as an oil phase. The aqueous phase and the oil phase were mixed for 1 hour with a high-speed stirrer to obtain a homogeneous flowable agent. When the viscosity of this flowable agent was measured by the test shown below, 8.
8 cps.

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

Example 3 The same flowable agent having a viscosity of 11.9 cps was obtained by replacing 70 parts of water and 15.6 parts of trimethylbenzene of Example 1.

Example 4 The same flowable agent having a viscosity of 10.7 cps was obtained by replacing water of Example 1 with 69 parts and trimethylbenzene with 16.6 parts.

Comparative Example 1 13.6 parts of trimethylbenzene of Example 1 was replaced with a paraffinic solvent (trade name: MLDW SW60LP; manufactured by Esso Oil Co., Ltd.)
Replaced with 13.6 parts to obtain a homogeneous flowable. The measured viscosity was 246 cps.

Comparative Example 2 1 part of sodium montmorillonite of Example 1 and water 72
Was replaced with 0.2 part of xanthan gum and 72.8 parts of water.
A homogeneous flowable of 28 cps was obtained.

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

Comparative Example 4 1.52 parts of tralomethrin drug substance, 1,2-propanediol 1
5.5 parts, anionic surfactant carrier mixed 2 parts, silicon dioxide 3 parts, heteropolysaccharide 0.37 part, dimethylpolysiloxane derivative 1 part, 4-hydroxybenzene propyl ether 0.09 part, citric acid 0.06 part, propyl gallate 0.01 Part, 2-hydroxy-4-n-octylbenzophenone, 0.2 part, trimethylbenzene 4.3 parts, and water 71.95 parts were stirred with a high-speed stirrer to obtain a homogeneous flowable agent having a viscosity of 788 cps.

Viscosity test: 100 g of the flowable preparation was placed in a 120-ml glass bottle, inverted once every 2 seconds for 1 minute, and the viscosity was measured. The measurement was performed using a B-type viscometer (DVL-B type, manufactured by Tokyo Keiki Co., Ltd.), the measurement conditions were rotor No. 2, the rotation speed was 30 rpm, and the set temperature was 20 ° C. When measuring a sample having a viscosity of 15 cps or less, the measurement was performed by replacing the No. 2 rotor with an L adapter.

〔The invention's effect〕

The suspension-type pesticide composition according to the present invention has excellent storage stability as evident from the following test examples by blending sodium-montmorillonite and trimethylbenzene, which are ultrafine particle-like clay minerals, and is stored for a long time. No sedimentation and sedimentation occur, and no hard-caking layer that cannot be redispersed is formed. In addition, since the viscosity is low, it is easy to take out from the packaging container, accurate weighing is easy in the use scene, the dispersibility in water is good, the preparation of the spray liquid is easy, and the flash point is virtually eliminated. Becomes possible. In addition, since no organic polymer thickener is used, there is no decay.

Test Example 1 Storage stability test 100 g of a flowable preparation was placed in a 120 ml glass bottle, and 72
It was stored for one month in a constant temperature bath where the set temperature alternated between 50 ° C and -10 ° C every hour. In the test, the degree of separation and sedimentation of the flowable preparation taken out one month later was measured. The survey is
The ratio was calculated as a ratio (%) of the height of the supernatant portion to the height of the whole liquid. The lower the proportion (%) of the supernatant liquid, the better the storage stability.

 The results are shown in Table 1.

Test Example 2 Dispersibility test in water 100 ml of hard water 3 times was put into a 100 ml Spitz tube, the flowable preparation was dropped with a microdispenser, and the dispersion state was observed. Then, the suspension was inverted once every 2 seconds for 20 seconds. Was observed, and the following four grades were evaluated.

A: The dispersion state is extremely good. The drug is uniformly dispersed without inverting. It is the most suitable formulation as a flowable.

B: Good dispersion state. The drug partially diffuses in water and drops in the form of a part of droplets, but is uniformly dispersed when inverted. It is a good formulation as a flowable.

C: The dispersion state is somewhat poor. Most of the drug falls in the form of droplets, but when it is inverted, it is uniformly dispersed. It may not be suitable for practical use as a flowable agent.

D: Dispersion state is poor. The drug falls in a liquid state, and does not easily disperse even if it is repeatedly inverted. Unsuitable as a flowable.

 The results are shown in Table 1.

Test Example 3 Adhesion Test to Container A 500 ml measuring cylinder with a stopcock was filled with about 80% volume of a flowable agent, allowed to stand for 24 hours, and then the measuring cylinder was replaced with 45 ml.
Tilt to フ ロ ア for 60 seconds to take out the inside flowable. 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 initially added flowable agent.
In addition, this test method was performed based on MT-148 of CIPAC method.

 The results are shown in Table 1.

Claims (1)

(57) [Claims] 1. It contains (a) a poorly water-soluble pesticidal active ingredient, tralomethrin, (b) sodium montmorillonite, and (c) a solvent mainly composed of trimethylbenzene, and has a viscosity of 200 cps or less. A pesticidal suspension composition.