JP2022088222A - Herbicide composition - Google Patents

Abstract

To provide a herbicide that has excellent stability with the lapse of day and high fast-acting property.SOLUTION: Provided is a herbicide composition that contains pelargonic acid and any one or more cationic surfactant selected from monoalkyl-type cationic surfactant and dialkyl-type cationic surfactant, and in which the pelargonic acid forms a mixed vesicle and exists in water.SELECTED DRAWING: None

Description

The present invention relates to a herbicide composition and belongs to a technical field particularly containing pelargonic acid. More specifically, the present invention relates to a herbicide composition having excellent circadian stability and quick-acting effect by forming a mixed vesicle of pelargonic acid, which is a herbicidal active ingredient, and one or more kinds of cationic surfactants. It is a thing.

Pelargonic acid (generic name Pelargonic acid, IUPAC name Nonanoic acid) with 6 to 12 carbon atoms, especially pelargonic acid with 9 carbon atoms, is a compound with safe and fast-acting herbicidal activity and is widely used all over the world. (See, for example, Patent Document 1).

In addition, since pelargonic acid is also used as a food additive, it is attracting attention as a herbicide active ingredient with a safe image, and the need for herbicides using pelargonic acid is increasing.

Pelargonic acid is a hydrophobic substance with a solubility in water of 32 ppm (30 ° C.), and a technique for solubilizing or emulsifying pelargonic acid is required in the development of a herbicide using pelargonic acid.

For example, Patent Document 1 discloses a formulation technique in which water is used as a main solvent and verargonic acid is stably present in water as an acid by using an anionic surfactant and a nonionic surfactant in combination.

Further, Patent Document 2 discloses a technique for emulsifying pelargonic acid using a quaternary ammonium salt as a surfactant.

On the other hand, Patent Documents 3 and 4 disclose a preparation having improved water solubility by neutralizing pelargonic acid with an organic base.

Japanese Unexamined Patent Publication No. 2016-190832 Special Table No. 5-502216 Gazette Japanese Unexamined Patent Publication No. 2013-216643 Japanese Unexamined Patent Publication No. 2014-91739

As described above, conventional techniques include preparations (Patent Documents 1 and 2) in which pelargonic acid exists in water and is emulsified or solubilized with a surfactant, and pelargonic acid is neutralized with a basic substance. As a result, it is known that the pharmaceutical product has improved water solubility (Patent Documents 3 and 4). The former, in which pelargonic acid is present as an acid, is known to exhibit a faster herbicidal effect on the latter, and is more desirable from the viewpoint that consumers can easily feel the herbicidal effect.

By the way, commercially available general-purpose herbicides are often sold in a spray container. In ordinary households, such herbicides are often left outdoors or in warehouses while still in containers, and are likely to be exposed to low and high temperature conditions. In such a harsh storage environment, conventional pelargonic acid herbicides emulsified and solubilized with a surfactant may separate pelargonic acid.

Therefore, there is a demand for a pelargonic acid herbicide composition that can stably maintain a uniform dissolution / dispersion state even in such a harsh storage environment. It is conceivable to increase the amount of surfactant in order to improve the stability of storage, but at the same time as the price increases due to the increase in surfactant, the product viscosity increases, resulting in a decrease in spraying efficiency and uneven spraying. It is not realistic because problems such as occurrence occur. As described above, the conventional pelargonic acid herbicide produced by the conventional emulsification / solubilization method is still insufficient in stability and has room for improvement.

The present invention has been made in view of these respects, and an object of the present invention is to provide a herbicide composition having excellent circadian stability and high fast-acting effect.

In order to achieve the above object, the inventor of the present application interacts with pelargonic acid having a carbonyl group and a cationic surfactant having a specific quaternary amine group in water to form a self-assembled mixed vesicle. We have found a possible concentration range. The present invention was completed by finding that pelargonic acid can be uniformly dissolved and dispersed in water and stabilized for a long period of time by forming the mixed vesicles in this way.

That is, a mixed vesicle is a self-aggregate in which amphipathic molecules having both hydrophobicity and hydrophilicity are arranged without gaps so as to form a spherical shape, a rod shape, a layer shape, etc. Therefore, since pelargonic acid is uniformly contained, high-concentration pelargonic acid can be stabilized in water for a long period of time.

The herbicide composition according to the present disclosure includes pelargonic acid, which is a herbicidal active ingredient, and any one or more cations selected from monoalkyl-type cationic surfactants and dialkyl-type cationic surfactants. It contains a sex surfactant and water. The pelargonic acid is uniformly dissolved and dispersed in water by the interaction between the pelargonic acid and the cationic surfactant to form a mixed vesicle.

By the way, in a herbicide containing pelargonic acid as a herbicidal active ingredient, it is considered that a sufficient herbicidal effect cannot be obtained unless pelargonic acid adheres to the weed surface when the herbicide is sprayed. On the other hand, the mixed vesicled pelargonic acid according to the present invention is contained in the self-association body by interacting with the cationic surfactant, and when this is sprayed on weeds, the pelargonic acid is contained in the weeds. It has never been investigated whether or not it can adhere to the surface. According to the studies by the inventors of the present application, a high herbicidal effect was confirmed for the first time by the mixed vesicled pelargonic acid herbicide composition.

That is, any one or any two from the group composed of a plurality of surfactants which are monoalkyl-type cationic surfactants and a plurality of surfactants which are dialkyl-type cationic surfactants. By containing more than a species of cationic surfactant, pelargonic acid is uniformly dispersed and dissolved as a self-aggregate of mixed vesicles in water, and pelargonic acid that constituted the mixed vesicles at the time of spraying is a weed. Adheres to the surface. As a result, even if it is left under low temperature or high temperature conditions, it has excellent circadian stability and a high herbicidal effect can be obtained.

The concentration range of the pelargonic acid can be 1.5% by mass or more and 7.0% by mass or less. Further, the concentration range of the pelargonic acid may be 2.0% by mass or more and 6.0% by mass or less.

The concentration range of the cationic surfactant can be 1.8% by mass or more and 18.0% by mass or less. Further, the concentration range of the cationic surfactant may be 2.5% by mass or more and 16.0% by mass or less.

The concentration ratio of the cationic surfactant to the pelargonic acid can be 0.83 or more and 6.00 or less. Further, the concentration ratio of the cationic surfactant to the pelargonic acid can be 1.00 or more.

The herbicide composition may contain a monohydric or polyhydric alcohol. This configuration facilitates the formation of mixed vesicles. The alcohol may have 2 or more and 6 or less carbon atoms and 1 or more and 6 or less hydroxy groups. The concentration range of the alcohol can be 2.0% by mass or more and 6.0% by mass or less. Further, the concentration range of the alcohol may be 2.5% by mass or more and 5.0% by mass or less.

The pH of the herbicide composition can be 2.5 or more and 5.0 or less. In addition, the herbicide composition can be a translucent liquid having a mixed vesicle.

According to the present invention, a specific cationic surfactant and pelargonic acid form a mixed vesicle in water, and high-concentration pelargonic acid is uniformly dispersed and dissolved in water, resulting in excellent circadian stability and high rapid effect. You can get a herbicide with.

Hereinafter, embodiments of the present invention will be described in detail. It should be noted that the following description of the preferred embodiment is essentially merely an example and is not intended to limit the present invention, its application or its use.

The herbicide composition according to the embodiment of the present invention is a liquid herbicide containing pelargonic acid, which is a herbicidal active ingredient, a specific cationic surfactant, water, and a specific alcohol. The herbicide can be stored, for example, in various containers. By containing the herbicide in a container, the product used for weeding is constructed. The herbicide can be used directly from the container stored at the time of storage to the weeds, or can be transferred to a container different from the container stored at the time of storage and applied to the weeds. The container containing the herbicide may be provided with a shower nozzle with a large number of openings. Further, the container containing the herbicide may be provided with a sprayer provided with a pump mechanism. Further, the container for accommodating the herbicide may be an aerosol container provided with a valve and a nozzle, in which case the herbicide composition according to the present invention is filled in the aerosol container together with the propellant.

(Pelargonic acid, an active herbicidal ingredient)
The herbicidal active ingredient pelargonic acid of the present invention can be used alone or as a major ingredient (eg, 90% or more) of a mixture containing other fatty acids. When other fatty acids are included, the herbicidal active ingredient can be one or a mixture of carboquil fatty acids having a hydrocarbon chain having 8 to 12 carbon atoms including pelargonic acid.

Pelargonic acid exists in water to form a mixed vesicle by interacting with a cationic surfactant. That is, a mixed vesicle is a self-assembly in which amphipathic molecules having both hydrophobicity and hydrophilicity are arranged in a spherical shell shape or a bag shape without gaps in water, and multiple layers of self-assembly are arranged. Therefore, the uniform content of pelargonic acid makes it possible to stabilize pelargonic acid in water for a long period of time.

The lower limit of the concentration range of pelargonic acid in the herbicide composition is 1.5% by mass or more, more preferably 2.0% by mass or more. The upper limit of the concentration range of pelargonic acid is 7.0% by mass or less, more preferably 6.0% by mass or less. When the concentration range of pelargonic acid exceeds the above upper limit, it becomes difficult to form a mixed vesicle, and the formed mixed vesicle becomes fragile. Further, when the concentration range of pelargonic acid is lower than the above lower limit, the herbicidal effect becomes insufficient.

(Cationic surfactant)
In order to form the mixed vesicles in water, the specific cationic surfactant is required. A specific cationic surfactant is an interface composed of a plurality of surfactants classified as monoalkyl-type cationic surfactants and a plurality of surfactants classified as dialkyl-type cationic surfactants. Any one or any two or more cationic surfactants selected from the group of activators. As the specific cationic surfactant, only the monoalkyl-type cationic surfactant may be used, or only the dialkyl-type cationic surfactant may be used. Further, as the specific cationic surfactant, a monoalkyl-type cationic surfactant and a dialkyl-type cationic surfactant may be contained, and in this case, the monoalkyl-type cationic surfactant may be contained. One type may contain two or more types of dialkyl-type cationic surfactant, or two or more types of monoalkyl-type cationic surfactant and one type of dialkyl-type cationic surfactant may be contained. good.

Examples of the monoalkyl type cationic surfactant include lauryltrimethylammonium chloride, myristyltrimethylammonium chloride, cetyltrimethylammonium chloride, stearyltrimethylammonium chloride, behenyltrimethylammonium chloride, alkyl (C12-C16) trimethylammonium, and alkyl chloride (C16). -C18) trimethylammonium, etc. can be mentioned.

Dialkyl-type cationic surfactants include dioctyldimethylammonium chloride, didecyldimethylammonium chloride, dilauryldimethylammonium chloride, dialkyl (C12-C18) dimethylammonium, didecyldimethylammonium chloride, dialkyldimethylammonium chloride, and dialkyl chloride. (C16-18) Dimethylammonium, etc. can be mentioned.

The lower limit of the concentration range of the specific cationic surfactant is 1.8% by mass or more, more preferably 2.5% by mass or more. The upper limit of the concentration range of the cationic surfactant is 18.0% by mass or less, more preferably 16.0% by mass or less. When the concentration range of a specific cationic surfactant is out of the above range, it becomes difficult to form a mixed vesicle.

(Monohydric or multivalent alcohol)
In order to ensure the formation of the mixed vesicles, it is preferable that the herbicide composition contains a specific alcohol. The specific alcohol is a monohydric or polyhydric alcohol, and an alcohol having 2 or more and 6 or less carbon atoms and 1 or more and 6 or less hydroxy groups is preferable. Examples of such alcohols include ethyl alcohol, propyl alcohol, isopropyl alcohol, 1,3 butylene glycol, propylene glycol, dipropylene glycol, glycerin, sorbitol and the like.

By using the above alcohol, the formation of mixed vesicles becomes more reliable. The lower limit of the alcohol concentration range is 0.01% by mass or more, preferably 2.0% by mass or more, and more preferably 2.5% by mass or more. The upper limit of the alcohol concentration range is 6.0% by mass or less, more preferably 5.0% by mass or less. If the alcohol concentration range is out of the above range, it becomes difficult for the mixed vesicles to be formed, or the formed mixed vesicles are easily broken.

(Concentration ratio of pelargonic acid and cationic surfactant R = b / a)
Further, the concentration ratio R of the specific cationic surfactant to the pelargonic acid when the concentration of the pelargonic acid is a and the concentration of the specific cationic surfactant is b can be expressed by the following formula 1.

R = b / a equation 1

The lower limit of R is 0.83 or more, more preferably 1.00 or more. The upper limit of R is 6.00 or less, more preferably 5.00 or less. If the value of R is out of the above range, it becomes difficult to form a mixed vesicle.

(Other ingredients)
Purified water or ion-exchanged water can be used as the water. In addition, the herbicide may contain a preservative. Examples of the preservative include, but are not limited to, isothiazolinone derivatives.

In addition, the herbicide may contain a pest control component. Examples of the pest control component include, but are not limited to, pyrethroid insecticides, neonicotinoid insecticides, and diamide insecticides. Pyrethroid insecticides include transfluthrin, pyrethrin, allethrin, phthalthrin, tetramethrin, prarethrin, phenothrin, tralomethrin, cifluthrin, resmethrin, permethrin, empentrin, ciphenotrin, imiprothrin, fenpropathrin, fenvalerate, etofenprox, etc. Can be mentioned. Examples of neonicotinoid insecticides include imidacloprid, nitenpyram, acetamiprid, thiamethoxam, clothianidin, and dinotefuran. Examples of the diamide insecticide include flubendiamide, chlorantraniliprole, cyantraniliprole and the like. Of these, one type or a mixture of two or more types can be used.

(Manufacturing method of herbicide composition)
An example of a method for producing a herbicide composition will be described. First, purified water heated to 70 ° C. is prepared. The above-mentioned specific cationic surfactant, pelargonic acid, and alcohol are dissolved in this purified water. If the pest control component is contained, the pest control component is also dissolved. Then, after cooling to room temperature, a preservative is added.

Hereinafter, examples of the present invention will be described, but the present invention is not limited to the examples.

Table 1 shows the composition of the herbicide according to Examples 1 to 16 of the present invention. The concentration of pelargonic acid in Examples 1 to 16 is 1.50% by mass or more and 7.00% by mass or less. The concentration of the monoalkyl-type cationic surfactant is 0.90% by mass or more and 9.00% by mass or less. The concentration of the dialkyl-type cationic surfactant is 0.90% by mass or more and 15.00% by mass or less. The concentration of alcohol is 3.00% by mass. The concentration of preservative is 0.02% by mass. The residue (balance) is purified water.

The range of the concentration ratio R of the concentration b of the cationic surfactant to the concentration a of the herbicide active ingredient is set to 0.83 or more and 6.00 or less.

(Evaluation of appearance)
After preparing the herbicide composition sample of the example, it was placed in a 100 ml glass bottle, and the appearance was visually evaluated at room temperature (RT). The comparative examples described later were also evaluated in the same manner.

Clear gel: Clear liquid or gel Translucent: Translucent liquid White turbidity: White turbid liquid

(Confirmation and evaluation of mixed vesicles)
After preparing the herbicide composition sample of the example, it is placed in a 100 ml glass bottle and placed in a box having an orthogonal polarizing plate (Cross Nicol) at room temperature (RT). The presence or absence of mixed vesicle formation was evaluated by shining light on the sample bottle from the outside of the polarizing plate box and visually observing the state of the light passing through the sample bottle through the polarizing plate. The comparative examples described later were also evaluated in the same manner.

○: With mixed vesicles ×: Without mixed vesicles

As shown in Table 1, mixed vesicles were formed in all of Examples 1 to 16.

(Stability evaluation)
Next, the results of the stability test will be described. In the stability test, the herbicide composition sample of the example was placed in a 100 ml glass bottle and stored at room temperature (RT) at 5 ° C. and 50 ° C. for 1 month, respectively. The state (appearance) of the herbicide composition after storage for 1 month was visually evaluated, and the stability was evaluated according to the following criteria. The comparative examples described later were also evaluated in the same manner.

〇: No separation (uniform 1 phase).
Δ: The upper layer and the lower layer are partially separated.
X: Completely separated into two phases.

As shown in Table 1, Examples 1 to 16 were "◯" in all of "RT", "5 ° C" and "50 ° C". That is, since the mixed vesicles continued to exist with almost no breakage, separation and changes in properties are unlikely to occur even when stored in an extremely wide temperature range of 5 ° C to 50 ° C and for an extremely long period of one month. I understand. The same result can be obtained even if the preservative is not contained.

Next, Comparative Examples 1 to 5 will be described.

Comparative Example 1 is an example in which alcohol is not contained. In Comparative Example 1, the “appearance (immediately after production)” was cloudy, and the mixed vesicle was not formed immediately after production. That is, the mixed vesicles were not formed immediately after production, and the composition was "x" at all of "RT", "5 ° C" and "50 ° C", that is, an unstable composition.

Comparative Example 2 is an example in which the concentration ratio R of the concentration b of the cationic surfactant to the concentration a of the herbicide active ingredient is 0.33. In Comparative Example 2, the item "appearance (immediately after production)" was cloudy, and the mixed vesicle was not formed immediately after production. Further, it was stable at "RT" and "5 ° C.", but separation occurred at "50 ° C.". That is, it was stable in a relatively low temperature environment, but unstable in a high temperature environment.

In Comparative Example 3, a transparent gel was formed in the item of "appearance (immediately after production)", and a mixed vesicle was not formed immediately after production. Further, it was stable at "RT" and "5 ° C.", but separation occurred at "50 ° C.". That is, it was stable in a relatively low temperature environment, but unstable in a high temperature environment.

In Comparative Example 4, the item "appearance (immediately after production)" was cloudy, and the mixed vesicle was not formed immediately after production. It was stable at "5 ° C" but unstable at "RT" and "50 ° C".

In Comparative Example 5, a transparent gel was formed in the item of "appearance (immediately after production)", and a mixed vesicle was not formed immediately after production. Moreover, it was stable at "RT" and "5 ° C", but unstable at "50 ° C".

Next, Examples 17 to 25 will be described.

The concentration of pelargonic acid in Examples 17 to 25 is 3.00% by mass or more and 6.00% by mass or less. The concentration of the monoalkyl-type cationic surfactant is 1.50% by mass or more and 3.00% by mass or less. The concentration of the dialkyl-type cationic surfactant is 1.50% by mass or more and 3.00% by mass or less. The concentration of alcohol is 3.00% by mass or more and 5.00% by mass or less. The concentration of preservative is 0.02% by mass. The range of the concentration ratio R of the concentration b of the cationic surfactant to the concentration a of the herbicide active ingredient is set to 1.00.

Further, in Examples 17 to 25, a pest control component (insecticide component) is contained. The concentration of transfluthrin or tralomethrin is 0.01% by mass or more and 0.10% by mass or less.

As described in the column of "Appearance (immediately after production)" in Table 3, mixed vesicles were formed in all of Examples 17 to 25.

Next, Comparative Examples 6 to 11 will be described.

In Comparative Examples 6 to 8, the concentration of the cationic surfactant is 1.00% by mass. In Comparative Examples 6 to 8, the item "appearance (immediately after production)" was cloudy, and the mixed vesicle was not formed immediately after production. In addition, separation occurred at all of "RT", "5 ° C" and "50 ° C".

In Comparative Examples 9 to 11, the concentration of the cationic surfactant is 15.00% by mass. In Comparative Example 9, the item "appearance (immediately after production)" was cloudy, and the mixed vesicle was not formed immediately after production. In addition, separation occurred at all of "RT", "5 ° C" and "50 ° C". Further, in the cases of Comparative Examples 10 and 11, although it was stable at "5 ° C", separation occurred at "RT" and "50 ° C".

From the above results, it can be seen that the composition in which the mixed vesicles are formed is stable from low temperature to high temperature, while the composition in which the mixed vesicles are not formed is unstable in any temperature range.

(Herbicide test)
Next, the herbicide test will be described. Table 5 shows the prescription of Comparative Example 12.

Comparative Example 12 is an example containing pelargonic acid and triethanolamine.

The herbicide test method is as follows. First, weeds for testing were oxalis, crabgrass, and green foxtail. Each weed was transplanted into a pot, and the herbicides of Examples and Comparative Examples were evenly sprayed on each weed using a hand spray having a discharge rate of 1 ml. After that, the pot was housed in an artificial meteorological device (temperature 25 ° C., humidity 60%), and the state of weeds was recorded using the interval shooting function of the camera. The results are shown in Table 6. The examples in Table 6 were the prescriptions of Example 18.

In Example 18, compared to Comparative Example 12, the time until the oxalis, crabgrass, and green foxtail all start to die is significantly shorter. In addition, the time until withering is also significantly shorter in Example 18. In particular, in Comparative Example 12, the crabgrass could not be completely withered, but in Example 18, the crabgrass could be completely withered. It should be noted that the same herbicidal effect can be obtained with the prescriptions of Examples other than Example 18, although there are some advantages and disadvantages.

(Effect of embodiment)
As described above, the herbicide according to the present embodiment is any one or more selected from pelargonic acid, monoalkyl-type cationic surfactant and dialkyl-type cationic surfactant. Since it contains a cationic surfactant and pelargonic acid forms a mixed vesicle and exists in water, it can be a herbicide having excellent circadian stability and high fast-acting effect.

The above embodiments are merely exemplary in all respects and should not be construed in a limited way. Further, all modifications and modifications belonging to the equivalent scope of the claims are within the scope of the present invention.

As described above, the herbicide according to the present invention can be used for various weeds.

Claims (13)

Pelargonic acid, an active herbicidal ingredient, and
Any one or more cationic surfactants selected from monoalkyl-type cationic surfactants and dialkyl-type cationic surfactants, and
Contains water,
A herbicide composition characterized in that a mixed vesicle of the pelargonic acid and the cationic surfactant is formed in the water. In the herbicide composition according to claim 1,
The herbicide composition, wherein the concentration range of pelargonic acid is 1.5% by mass or more and 7.0% by mass or less. In the herbicide composition according to claim 2,
A herbicide composition having a concentration range of pelargonic acid of 2.0% by mass or more and 6.0% by mass or less. In the herbicide composition according to any one of claims 1 to 3.
A herbicide composition characterized in that the concentration range of the cationic surfactant is 1.8% by mass or more and 18.0% by mass or less. In the herbicide composition according to claim 4,
A herbicide composition characterized in that the concentration range of the cationic surfactant is 2.5% by mass or more and 16.0% by mass or less. In the herbicide composition according to any one of claims 1 or 5.
A herbicide composition having a concentration ratio R = b / a of 0.83 or more and 6.00 or less when the concentration of the pelargonic acid is a and the concentration of the cationic surfactant is b. In the herbicide composition according to claim 6,
A herbicide composition having a concentration ratio R = b / a of 1.00 or more. In the herbicide composition according to any one of claims 1 to 5.
A herbicide composition characterized by containing a monohydric or polyhydric alcohol. In the herbicide composition according to claim 8,
The alcohol is a herbicide composition having 2 or more and 6 or less carbon atoms and 1 or more and 6 or less hydroxy groups. In the herbicide composition according to claim 9,
The herbicide composition, wherein the concentration range of the alcohol is 2.0% by mass or more and 6.0% by mass or less. In the herbicide composition according to claim 10,
The herbicide composition, wherein the concentration range of the alcohol is 2.5% by mass or more and 5.0% by mass or less. In the herbicide composition according to any one of claims 1 to 11.
A herbicide composition having a pH of 2.5 or more and 5.0 or less. In the herbicide composition according to any one of claims 1 to 12.
A herbicide composition characterized by being a translucent liquid.