JPH01203302A - Agricultural chemical composition - Google Patents

Abstract

PURPOSE:To obtain a composition having the upper part comprising W/O type emulsion phase or oil phase containing a main agent of agricultural chemical during standing, readily becoming a suspension by light shaking, consisting of a water-insoluble organic solvent, surfactant, fine powdery or liquid main agent of agricultural chemical and water. CONSTITUTION:An agricultural chemical composition consisting of (A) 0.5-10wt.% (preferably 1-3wt.%) water-insoluble organic solvent (e.g., toluene or hexane) having <=1 specific gravity, (B) 0.1-1wt.% (preferably 0.1-0.5wt.%) surfactant of a nonionic surfactant having <=10 HLB or of a mixture of the nonionic surfactant and <=30wt.% based on sum of the surfactant of an oily anionic surfactant, (C) 0.01-1wt.% (preferably 0.1-0.5wt.%) fine powdery of liquid main agent of agricultural chemical (e.g., germicide, herbicide or insecticide) and (D) >=90wt.% (preferably 95-99wt.%) water. The composition is used without dilution and has excellent dispersibility and stability with time of the active ingredient.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an agrochemical composition that can be used by simply shaking lightly without diluting with water etc. when applied to plants, and which protects plants from harmful pests and diseases. The present invention relates to agrochemical compositions that can be used in a wide range of agricultural and horticultural applications, including various protective agents, herbicides, and growth regulators.

[Conventional technology]

Conventionally, emulsions and wettable powders have been generally used as agrochemical formulations for liquid spraying. Emulsions generally consist of a main pesticide, a surfactant, and a large amount of organic solvent, but the organic solvents that make up most of the formulation have drawbacks such as flammability, bad odor, and phytotoxicity to plants. On the other hand, wettable powders are made by mixing powdered pesticide main ingredients with a hydrophilic clay mineral carrier, making them homogeneous, using a surfactant together to make a formulation, and suspending it in water before use. It is inconvenient to handle because the powder scatters or does not disperse quickly and uniformly when suspended in water, and it also has disadvantages such as insufficient stability over time and concerns about solidification. There were many things.

For this reason, the pesticide main ingredient is dispersed using a surfactant in water or an aqueous medium so that no dust is generated when preparing the spray solution and it can be handled quantitatively like a conventional emulsion. Water-suspended agricultural chemical compositions prepared by wet-pulverizing a main agricultural chemical agent in water or an aqueous medium, and water-solubilized agricultural chemical compositions made by
Aqueous emulsion compositions consisting of a surfactant-pesticide main ingredient have been studied and developed. In addition, these formulations generally have the disadvantage that the dispersed particles tend to settle or the oil component tends to separate, making redispersion difficult. Various proposals have been made to overcome these disadvantages (Japanese Patent Application Laid-Open No. 148825/1983). , JP-A-53-20411, JP-A-55-17301).

[Problem to be solved by the invention]

The above-mentioned conventional emulsions and wettable powders are highly concentrated emulsions or aqueous solutions that are diluted with water and then sprayed to exterminate or cure target pests or plant diseases. In addition, water-suspended agricultural chemical compositions and aqueous emulsion compositions are basically compositions that are intended to be used after being diluted with water, like other emulsions. When using such agrochemical compositions to exterminate plant pests or weeds, there is the need to dilute highly concentrated chemicals to the working concentration, and the discomfort caused to workers during the work, such as bad odors and dirty hands. , there are drawbacks. In addition, unlike other emulsions, aqueous emulsion compositions do not have much lubricating properties, so unlike other emulsions, they are sometimes used as a concentrated micro-spraying solution, but this spraying method (ULV method) requires a special spraying machine. Therefore, in a narrow sense, this method can be said to be a technology in a different field from the diluted spray method.

In addition, conventionally commercially available emulsions, hydrating powders, etc. do not cause much of a problem if they are diluted with water and then sprayed immediately, but they do not take into account the stability of the main agricultural chemical ingredient in the diluted solution over time, so it may take some time. If stored while standing still, the powder will settle and the oil will aggregate and float, making it easy for the drug to decompose, so there is a problem that it cannot be stored for a long time.

Therefore, it is not possible to dilute it to the working concentration in advance. The same applies to water-suspended agricultural chemical compositions and aqueous emulsion compositions, and various studies and proposals have been made regarding the suspension and dispersibility of the agricultural chemical base in the agricultural chemical composition before dilution. There has been almost no study on suspension and dispersibility over time. This is thought to be because conventional agrochemical compositions are premised on being diluted with water and then sprayed.

Therefore, an object of the present invention is to provide a so-called undiluted agrochemical composition, which is diluted in advance with water to a working concentration and can be used as it is, unlike such conventional methods. .

Another object of the present invention, in relation to the above object, is to provide an undiluted agricultural chemical composition which has excellent dispersibility and stability over time of active ingredients, and which also has good redispersibility and dispersion stability after shaking. There is a particular thing.

[Means and effects for solving the problem] According to the present invention, in order to achieve the above object, (A) a water-insoluble organic solvent having a specific gravity of 1 or less and having a weight of 0.15 to 10%; CB) a water-insoluble organic solvent of 0.1 to 10% 1% by weight of HLBl 0 or less nonionic surfactant or 30% by weight of the total amount of surfactants
A surfactant consisting of a combination of the following oil-soluble anionic surfactants (C) 0.01 to 1% by weight of a finely powdered or liquid pesticide main ingredient, and (D) at least 90% by weight of water, A water-in-oil emulsion phase or an oil phase containing a finely powdered or liquid pesticide main ingredient exists above the aqueous phase when left to stand still, and a pesticide composition that easily becomes a suspension by light shaking is provided. .

That is, the agrochemical composition of the present invention has problems with conventional diluted solutions such as emulsions, that is, when stored for a while, if the agrochemical main ingredient is a powder, it will precipitate and have poor redispersibility. By using the above-mentioned specific organic solvent and surfactant, we can solve the problem of agglomeration and floating of the chemical, which results in oxidative decomposition and crystallization. This problem was solved by having the water-in-oil emulsion phase or the oil phase. Furthermore, by using a large amount of water, the composition is already within the dilution range, and the main pesticide can be redispersed by shaking lightly, making it a composition that can be applied as is. It constitutes a diluted pesticide composition. Such a low-concentration, undiluted agricultural chemical composition that can be applied as is without dilution is a completely new agricultural chemical composition that has not existed in the past.

As a result of intensive research by the present inventors, by using a specific organic solvent and surfactant, and by blending these with water and the main pesticide ingredient in a specific quantitative ratio, a small amount of There is a water-in-oil emulsion phase or an oil phase that disperses and contains a powdered or liquid (oil) pesticide main ingredient, and when used, it can be easily turned into a homogeneous suspension by shaking lightly during use, and can be used for a relatively long time ( It has been found that an agrochemical composition with excellent redispersibility and resuspension properties that can be stably maintained in its original state (on the order of several minutes to several tens of minutes) can be obtained. Furthermore, the active ingredient is stably dispersed in the water-in-oil emulsion phase or the oil phase, and therefore the active ingredient hardly decomposes and is extremely stable over time.

[Aspects of the invention]

Hereinafter, each component will be explained. First, as the organic solvent used in the present invention, a solvent insoluble in water and having a specific gravity of 1 or less is used. Examples include aromatic hydrocarbons such as toluene and xylene, and non-aromatic hydrocarbons having 6 or more carbon atoms such as hexane, n-paraffin and kerosene. In addition, any other material can be used depending on the purpose of the product. The amount of this organic solvent is
In terms of suspension stability, redispersibility, and resuspension, it should be 0.5 to 10% by weight of the total composition, preferably 1 to 3% by weight.
Weight%.

As the surfactant, a nonionic surfactant with an HLB of 10 or less, preferably 4 to 10, which can produce a water-in-oil emulsion, or 30% by weight of the total amount of surfactants.
A surfactant containing the following oil-soluble anionic surfactant is used.

Nonionic surfactants with HLB of 10 or less that can produce a water-in-oil emulsion include sorbitan monooleate, sorbitan monolaurate, and polyethylene glycol fatty acids with an HLB of less than 8, which can produce a water-in-oil emulsion by themselves. Ester etc. singly or as a mixture, or in addition to these surfactants, polyoxyethylene alkyl allyl ether or polyoxyethylene sorbitan with an HLB of 8 or higher which does not produce a water-in-oil emulsion but adjusts the properties of the water-in-oil emulsion. A mixed surfactant containing a nonionic surfactant such as a fatty acid ester or a polyethylene glycol fatty acid ester, which has an HLB value of 10 or less, can be used.

Oil-soluble anionic surfactants are added to improve the dispersibility of agricultural chemicals, and include alkaline earth metal salts of alkylbenzenesulfonic acids such as calcium dodecylbenzenesulfonate, alkaline earth metal salts of higher fatty acids, etc. Available.

The amount of surfactant used in the present invention is 1% by weight or less, preferably 0.1 to 0.5% by weight of the total composition, from the viewpoint of suspension stability or redispersion/suspendability. .

The main pesticide used in the present invention can be in either fine powder or liquid (oil) form, and examples of powdered ingredients include NAC, TPN, and MBc.

Examples include fungicides such as sulfur, zineb, thiophanate methyl, and benomyl, and herbicides such as glyphosate and bialaphos, and the particle size thereof is usually 100 μm or less, preferably 30 μm or less.
It is desirable that the thickness be less than μm. MEP is a liquid pesticide main ingredient.

Examples include organophosphorus insecticides such as malathion, and pyrethroid insecticides such as allethrin and permethrin.

The amount of the above pesticide main ingredient used is 0.01 to 1% by weight of the total composition.
, preferably 0.1 to 0.5% by weight.

Further, in the present invention, the water used as a diluting medium or a suspending medium for the emulsion phase or oil phase is preferably ion-exchanged water, and the amount used is 90% by weight or more, preferably 95 to 99% by weight of the total composition. .

To give an example of the method for producing the undiluted agricultural chemical composition according to the present invention, first, a predetermined amount of a powdered agricultural chemical base and/or a liquid agricultural chemical base, an organic solvent, and a surfactant are mixed, and the mixture is heated for a certain period of time, e.g. After stirring for about 1 minute to dissolve the liquid agricultural chemical base and thoroughly blend the powdered agricultural chemical base with the organic solvent and surfactant, a predetermined amount of water is added and stirred again. A homogeneous suspension is obtained by this, but if this is left for a long time, a water-in-oil emulsion phase containing the pesticide main ingredient may exist above the aqueous phase depending on the balance of the emulsification state. mosquito,
Alternatively, an oil phase separates further above. In terms of suspension stability after shaking, the former suspension state is relatively better than the latter, but in either state, a homogeneous suspension can be obtained by gently shaking several times, and this state can be maintained for a relatively long period of time. (Several minutes to several tens of minutes), so there is plenty of time for spraying.

〔Example〕

Hereinafter, the present invention will be specifically explained by showing Examples and Comparative Examples.

Examples 1 to 11 and Comparative Examples 1 to 3 Agrochemical compositions using various surfactants were prepared according to the following compositions.

Powdered main agent T P N 0.30% by weight Liquid main agent Permethrin 0.18% by weight Organic solvent n-Pa5fin 1.0
0% by weight (C12-C16) Surfactant Listed in Table-1 and Table-2 0.
30% by weight water Ion exchange water 98.22% by weight total 100.00% by weight The manufacturing method is to mix predetermined amounts of powdered and liquid main ingredients, organic solvent, and surfactant and stir for 10 to 30 minutes to form a liquid. The target base agent was dissolved, and the powdered target base agent was thoroughly blended with the organic solvent and surfactant, and then a predetermined amount of water was added and stirred to prepare an agricultural chemical composition.

Each composition was evaluated for dispersibility, redispersibility, dispersion stability, and precipitation of fine powder upon standing.

The results are shown in Table-1 and Table-2.

In addition, the meaning of the code of each evaluation item in each table below is as follows.

a) Dispersion state A of the agricultural chemical base agent when left still The agricultural chemical base agent exists in the upper part of the aqueous phase as a water-in-oil emulsion.

B: A pesticide main agent is present between the water-in-oil emulsion phase of A above and the upper part of the aqueous phase.

C A state in which the main pesticide agent is aggregated and dispersed and is not dispersed in a state that can be used as a pesticide.

b) Redispersibility (situation when lightly shaken several times after standing still) ◎ Distributes evenly.

O is dispersed almost uniformly, but there are some aggregates. be.

× Cannot be used as a pesticide due to large aggregates.

C) Dispersion stability When it is redispersed and becomes an emulsion I checked the space.

◎ More than 30 minutes 03-30 minutes X 0-3 minutes d) Precipitation of fine powder and precipitation of aggregates (situation when standing still) ◎ There is no or only a slight amount of precipitate.

0 There is a small amount of precipitate.

X There is a large amount of precipitate.

As is clear from the results shown in Tables 1 and 2 above,
In each example, a preferable agrochemical composition was obtained which had excellent dispersion state when left still, excellent redispersibility and dispersion stability when lightly shaken several times after being left still, and did not have fine powder precipitation. In Nos. 1 to 3, since the compositions used a surfactant with an HLB of 10 or more, the agricultural chemical main ingredient was dispersed as small aggregates, and a homogeneous dispersion state could not be obtained.

Examples 12-26 Various agrochemical compositions were prepared using the various agrochemical main ingredients shown in Table 3 and the same surfactant as used in Example 3, according to the same manufacturing method as in Examples 1-11. Table 3 also shows the evaluation results of the dispersion state of each composition.

As shown in Table 3, preferred agricultural chemical compositions were obtained in each Example.

Example 27 A pesticide composition having the following composition was prepared in the same manner as Examples 1-11.

Powder base material T P N O, 30 times high temperature Liquid base material Bervarin 0.18 times high temperature organic solvent D-Paraffin 1.00 times high temperature (012-C16) Surfactant Sorbitan monooleate polyoxyethylene (20 times high temperature) ) Solvita 7 triolate dodecylbenzene sulfate calcium 0.30% by weight Water Ion exchange water 98.22% by weight Total
Table 4 shows the results of testing the stability over time of the agrochemical composition obtained over 100.00 times. In addition, for comparison, the test results of the stability over time of a diluted solution (300 times solution) obtained by diluting a commercially available emulsion (5%) in which permethrin is dissolved in the solvent kerosene to a concentration similar to that of Example 27 are shown in Table-- 5.

According to the practical manual for applying for agricultural chemical registration (Pesticide Industry Association), 4
One month of storage at 0°C is considered one year of storage at room temperature.

Table 4 Time-course analysis values of each agricultural chemical base in Example 27 Table 5 Results of active ingredient stability test over time of diluted permethrin emulsion 300-fold dilution of commercially available permethrin emulsion 5% As is clear from the above results, the conventional In the case of a diluted emulsion, significant decomposition of the active ingredient is observed during storage, but in the case of the agrochemical composition of the present invention, such a phenomenon is hardly observed, indicating that it has excellent stability over time.

Examples 28-34 Agrochemical compositions were prepared in the same manner as Examples 1-11 using the compositions shown in Table-6.

Each of the obtained agrochemical compositions was subjected to an efficacy test against plant pests and a phytotoxicity test. The results are also shown in Table-6.

In the test, roses (Sonia, 70 cm, 5 years old, planted in an alley) were used to target aphids.

As is clear from the test results shown in Table 6, if the amount of the pesticide main ingredient is too small, sufficient insecticidal efficacy will not be obtained, and if it is too large, chemical damage will occur. Although it depends on the type of agricultural chemical base used, it is generally 0.01 to 1% by weight, preferably 0.1 to 1% by weight.
A concentration within the range of 0.5% by weight is desirable.

[Effects of the Invention] 1. As described above, the agricultural chemical composition of the present invention uses a water-insoluble organic solvent with a specific gravity of 0.01 or less and a specific surfactant with an HLB of 10 or less; By blending these in a specific quantitative ratio, a water-in-oil emulsion phase or an oil phase containing a finely powdered or liquid agricultural chemical base is present on top of the aqueous phase when left to stand. By shaking lightly, a homogeneous suspension is easily formed, and this state is maintained for a relatively long period of time.

Therefore, the agrochemical composition of the present invention has excellent redispersibility and dispersion stability after shaking, and since the agrochemical main ingredient is already set at the concentration used, there is no need to further dilute it with water.
It can be applied to plants as is as a so-called undiluted agricultural chemical composition by simply shaking it lightly, and there is also sufficient room for spraying.

In addition, during standing and storage, the pesticide main ingredient is stable in the water-in-water emulsion phase or oil phase; since it is dispersed, there is no precipitation or agglomerate precipitation of the pesticide main ingredient (fine powder of the pesticide main ingredient), and the active ingredient ) There is almost no decomposition, and it is extremely stable over time.

Claims (1)

Scope of Claims: (A) 0.5 to 10% by weight of a water-insoluble organic solvent with a specific gravity of 1 or less; (B) 0.1 to 1% by weight of a nonionic surfactant with an HLB of 10 or less, or a surfactant thereof A surfactant formed by combining an oil-soluble anionic surfactant in an amount of 30% by weight or less based on the total amount of the agent (C) 0.01 to 1% by weight of a fine powder or liquid pesticide main ingredient, and (D) at least 90% by weight % of water, and when left standing, there is a water-in-oil emulsion phase or oil phase containing a fine powder or liquid pesticide main ingredient above the water phase, and the pesticide easily becomes a suspension with light shaking. Composition.