JPH1087414A - Stabilization of flowable formulation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for stabilizing a flowable preparation, make it possible to prevent the increase in particle diameter of dymron on its storage without deteriorating its original excellent characteristics by dispersing and make coexist a specific compound in the flowable preparation containing the dymron. SOLUTION: This method for stabilizing a flowable formulation containing (α,α-dimethylbenzyl)-N'-p-tolylurea (dymron) comprises adding a lignin sulfonic acid salt to the formulation. The lignin sulfonic acid salt is added in an amount of 0.01-2wt.% per wt.% of the dymron. The lignin sulfonic acid salt is a water- soluble polymer sulfonic acid salt produced by sulfonating lignin, the main component of wood, and subsequently neutralizing the sulfonation product with an alkali such as NaOH. The content of the dymron is approximately 0.5-60wt.%. The flowable formulation obtained by the method can maintain the particles of the active ingredient in a stable suspension state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to N- (α, α-dimethylbenzyl) -N′-p useful as a paddy field herbicide.
The present invention relates to a method for stabilizing a flowable preparation containing tolyl urea (generic name: Daimron), and more specifically to a method for stabilizing a flowable preparation by preventing an increase in the particle size of Daimron in the flowable preparation.

[0002]

BACKGROUND OF THE INVENTION Daimlon is a non-hormonal herbicide with absorption and transferability, is highly safe against rice, and is specifically used for weeds of the family Cyperaceae, such as pine byes, fireflies, sedges, and kuroguwai in paddy fields. Works. On the other hand, the effect is not always sufficient for grasses and broadleaf weeds,
Practically, it is generally used as a mixture with other active ingredients that are effective against them, especially for sulfonylurea herbicides that are effective in controlling broadleaf weeds in recent years. Since its admission, it has been increasingly used as a mixture with these.

[0003] Initially, there were many types of preparations in the form of granules, but recently, they can be uniformly dispersed with good diffusibility into paddy fields. In many cases, it is used as a flowable formulation because of its ease of use. Flowable preparations crush water-insoluble solid active ingredients into fine particles,
This is a preparation obtained by dispersing this in water using a dispersant, and is also referred to as a suspension preparation or sol. The appearance is cloudy and opaque, and the preparation is usually stabilized by adding a protective colloid agent, a thickener and the like.

In the case of Daimlon and a flowable preparation containing the same and other active ingredients, usually, Daimlon and other active ingredients to be used in combination, if necessary, are pulverized into fine particles of about 0.5 to 5 μm (μm), and this is pulverized. It contains a dispersing agent selected from anionic surfactants or nonionic surfactants, a protective colloid agent (thickener), etc., and is dispersed in water. It is relatively stable under normal conditions, but sometimes it is relatively stable. Suspension stability under storage conditions may be lost.

As for the cause, the solubility of Daimlon in water at room temperature is about 1.7 ppm, which can be said to be almost insoluble in water.
It is conceivable that the solubility changes due to the influence of other compounding components and a small amount dissolves during storage, which breaks out and agglomerates, or grows around the fine particles and causes an increase in particles,
The details are not always clear, and the fact is that they are struggling with preventive measures.

[0006]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a flowable preparation containing Daimlon as at least one of the active ingredients, which is essentially excellent in the herbicidal action of the active ingredient and the properties of the preparation itself. An object of the present invention is to provide a method for preventing an increase in the particle size of Daimlon during storage without impairment.

[0007]

Means for Solving the Problems As a result of various studies to solve the above problems, the present inventor has found that the dispersion of lignin sulfonate can prevent the increase in the particle size of Daimlon, and Find that they can achieve their purpose,
The present invention has been completed.

Incidentally, there is the following prior art related to the present invention. A long-term stable aqueous suspension pesticide formulation which is solid and hardly water-soluble or insoluble at room temperature and which contains a lignin sulfonate as a dispersant and a wetting surfactant in a specific active ingredient has been disclosed. JP-A-5-43401). However, the active ingredient described therein is a compound having a completely different structure from that of Daimlon, and contains a wettable surfactant as an essential component. It is difficult to easily guide the method of the present invention which can prevent the increase in the particle size of Daimlon and stabilize the flowable formulation without requiring a surfactant.

[0009] In addition, as a preparation containing a lignin sulfonate, a flowable preparation of a specific quinoline carboxylic acid derivative (Japanese Patent Application Laid-Open No. 2-129106), a paddy field adjusted to have a specific surface tension, and especially a paddy field under drought Herbicide composition (Japanese Patent Application Laid-Open No. 62-289502), in which water is used as a dispersion medium, and a herbicidal active ingredient and a surfactant are mixed so that the active ingredient is uniformly spread and dispersed in water and on the water surface. In addition, those in which the initial spreading speed is adjusted (Japanese Patent Application Laid-Open No. Hei 5-94804) and those in which the pH is adjusted in order to ensure the storage stability of the aqueous suspension containing the sulfonylurea compound (Japanese Patent Application Laid-Open No.
All of them have different objects or configurations from those of the present invention which aims at stabilization by preventing an increase in the particle size of Daimlon.

[0010]

The present invention provides: 1) N- (α, α-dimethylbenzyl) as an active ingredient
N- (α, α-dimethylbenzyl) -N′-p in a flowable preparation containing -N'-p-tolylurea, wherein a small amount of ligninsulfonate coexists.
A method for preventing an increase in the particle size of tolyl urea, and 2) the amount of the lignin sulfonate is determined by the amount of the active ingredient N- (α,
(α-dimethylbenzyl) -N′-p-tolyl urea The present invention provides the method according to the above 1, wherein the amount is 0.01 to 2 parts by weight based on 1 part by weight.

Hereinafter, the method of the present invention will be described in more detail. The method of the present invention is characterized in that lignin sulfonate having a function of preventing an increase in the particle size of Daimlon in a flowable preparation is dispersed and coexisted. The lignin sulfonate used in the present invention is a water-soluble polymer sulfonate obtained by sulfonating lignin, which is a main component of wood, and neutralizing it with an alkali such as sodium hydroxide.

In the present invention, the method itself for preparing a flowable formulation containing Daimlon is not particularly limited, and a method known as a general method for preparing an agricultural chemical flowable formulation is applied. That is, Daimlon and other active ingredients are pulverized together with a dispersing agent, a protective colloid agent or a thickening agent, an antifreezing agent, an antifoaming agent, a wetting agent and the like by a wet method or a dry method to prepare a mixture.

[0013] Other active ingredients used together with Daimulon include, for example, imazosulfuron (generic name of agricultural chemical; the same applies hereinafter), pyrazosulfuron, bensulfuron-methyl,
Ethoxysulfuron, cyclosulfamuron, pentoxazone, dimethamethrin, naproanilide, benzofenap, pletilachlor, tenylchlor, mefenacet, cafenstrole, esprocarb, amylophos, cyhalofopbutyl, pyriminobac-methyl, etc.
MK243 (test name, same hereafter), MY100, NBA
061 or a mixture of two or more thereof.

The content of Daimlon is not particularly limited, but is about 0.5 to 60% by weight, usually 5 to 40% by weight.
When mixed with other active ingredients, the mixing ratio of the other active ingredients is about 0.01 to 2 times the amount of Daimlon. The amount of the lignin sulfonate as a dispersant used in the present invention is based on 1 part by weight of the active ingredient Daimulon.
0.01 to 2 parts by weight, and the amount in the flowable preparation is 1
-10% by weight. If the amount is too small, it is difficult to expect a sufficient effect. On the other hand, if the amount is used in an excessively large amount, the suppression effect can be obtained as it is, but there is a possibility that a problem may occur in the original characteristics of the agricultural chemical formulation. Usually, the amount 2 in the flowable preparation
A practically sufficient effect can be obtained in the range of about 5% by weight.

In the present invention, if a lignin sulfonate coexists, it is not necessary to use another dispersant. However, in some cases, for example, an alkyl benzene sulfonate, an alkyl naphthalene sulfonate, an alkyl aryl sulfonate is used. Salt, alkyl naphthalene sulfonate formalin condensate, lignin sulfonate,
Anionic surfactants such as dialkyl sulfosuccinates, alkyl sulfates, polyoxyalkylene alkyl aryl ether sulfates, polyoxyalkylene alkyl aryl phosphates, polycarboxylates, or, for example, polyoxyalkylene alkyl ethers, polyoxyalkylenes Nonionic surfactants such as alkyl phenyl ether, polyoxyalkylene aryl ether, polyoxyalkylene alkyl aryl ether, polyoxyalkylene alkyl ester, sorbitan alkyl ester, and polyoxyalkylene sorbitan alkyl ester may be used in combination. When other dispersants are added, the amount is about 0.5 to 50% by weight in the flowable preparation.

As other compounding components, for example, antifreezing agents, wetting agents, thickeners, fungicides, defoamers, pH control agents and the like are used. Specific examples of the antifreezing agent include, for example, ethylene glycol, propylene glycol, and glycerin. The wetting agent is not particularly limited as long as it is a surfactant having a surface tension lowering ability.

Specific examples of the thickener (anti-settling agent) include xanthan gum, colloidal hydrous aluminum magnesium silicate, carboxymethyl cellulose,
Bentonite and the like can be mentioned. As the antifungal agent (preservative), specifically, for example, sodium benzoate, 1,2,
And benzisothiazolin-3-one (BIT). Specific examples of the antifoaming agent include, for example, silicone compounds. Phosphoric acid, sulfuric acid, and sulfonate are examples of the pH control agent. And various inorganic acids and organic acids such as carboxylic acid, and salts and esters thereof. Specifically, acidic phosphate, citric acid, maleic acid,
Sorbic acid, lactic acid, tartaric acid and the like are exemplified. In addition, citric acid-disodium hydrogen phosphate, potassium dihydrogen phosphate-disodium hydrogen phosphate and the like can be mentioned.

[0018]

[Manufacturing method] In the case of the wet method generally employed, the pesticide activator (Dimron) of the above-mentioned components, lignin sulfonate of a dispersant, an antifreezing agent, a wetting agent, a defoaming agent, a pH control agent, After mixing and dispersing water as a dispersion medium using a polytron homogenizer or the like of a mixer, a pulverizer, preferably, using a dyno mill or the like of a wet pulverizer, the pulverized particle size is 0.5 to 5 μm, preferably 1.5 to 5 μm. Grind to about μm. The wet pulverizer is not limited to the above-mentioned dyno mill, but may be a wet pulverizer such as an attritor, a sand grinder, a pearl mill, an apex mill, a biscomil, and an ultraviscomill. Next, a thickener and an antifungal agent (preservative) are added to the obtained pulverized liquid, followed by stirring and mixing to obtain a flowable preparation.

The aqueous suspension according to the present invention can also be obtained by the following dry pulverization method. That is, Daimron or the like is pulverized into a fine powder having the above particle size by a dry pulverizer such as a jet mill, a hammer mill, and a pin mill, and the obtained pulverized product is lignin sulfonate, a deicing agent, a wetting agent, and a defoaming agent. Agents, pH control agents, thickeners, fungicides (preservatives) and the like may be added to the dispersed liquid. Examples of formulations of stabilized Daimlon flowables according to the present invention are shown in Table 1 below.

Table 1 Ingredient Combination amount Daimlon 300-500 g / l Lignin sulfonate soda 30-60 g / l Antifreeze agent 10-80 g / l Defoamer 1-4 g / l Thickener 1-30 g / l Water

[0021]

EXAMPLES The method of the present invention will be described in more detail with reference to representative examples. However, these are merely examples for explanation, and therefore, the present invention is not limited only to these examples. In the following examples, "parts" means "parts by weight" unless otherwise specified.

Example 1 Daimlon (30 parts), lignin sulfonate (3 parts)
Parts), propylene glycol (4.5 parts) and silicone-based emulsion (0.3 parts), ion-exchanged water was added to make a total amount of 93 parts, mixed and dispersed with a polytron homogenizer, and then pulverized with a wet pulverizer Dynomill. On the other hand, xanthan gum (2 parts) and a fungicide (2 parts) were added to ion-exchanged water (96 parts) and dispersed to prepare a thickener liquid. 7 parts of the prepared thickener liquid was added to 93 parts of the pulverized liquid of Daimlon to make the total amount 100 parts, and a 30% flowable preparation of Daimron was obtained.

COMPARATIVE EXAMPLE 1 A polyoxyethylene / polyoxypropylene block polymer was added in place of the ligninsulfonate of Example 1, and the same operation as in Example 1 was carried out, except that Daimlon 3
A 0% flowable formulation was obtained.

Comparative Example 2 Daimlon (30 parts), polyoxyethylene / polyoxypropylene block polymer (3 parts), propylene glycol (4.5 parts), silicone emulsion (0.3 part)
Parts), 5% bentonite aqueous solution (20 parts), and dialkyl sulfosuccinate (2 parts), ion-exchanged water was added to make a total amount of 95 parts, mixed and dispersed with a polytron homogenizer, and then pulverized with a wet pulverizer Dynomill. . 5 parts of a 2% carboxymethylcellulose aqueous solution was added to 95 parts of the pulverized liquid to make the total amount 100 parts, and 30% of Daimlon was added.
A flowable formulation was obtained.

Test Example 1 30% of Daimlon obtained in Example 1, Comparative Examples 1 and 2
The flowable was allowed to stand in a constant temperature room at 25 ° C., and the average particle size in each flowable after 24 hours was determined at the time of production and in Production 2.
Measured after 4 hours. The particle size was measured using a laser diffraction particle size distribution analyzer. Table 2 shows the results.

Table 2: Results of particle size measurement during production and after 24 hours at 25 ° C. At manufacture 25 hours after 25 ° C. Example 1 1.4 μm 1.4 μm Comparative Example 1 1.5 μm 2.0 μm Comparative Example 2 1.7 μm 2.2 μm

From Table 2, it can be seen that the average particle size of the robles using the lignin sulfonate of Example 1 as a dispersant did not change after 24 hours, but the average particle size of the flowables of Comparative Examples 1 and 2 increased. You can see that it is doing.

Test Example 2 A 30% flowable of Daimlon obtained in Example 1 and Comparative Example 1 was left in a recycle room at −5 ° C. and 50 ° C. every 24 hours, and one week later, average particles in each flowable were measured. The diameter was measured. The particle size was measured using a laser diffraction particle size distribution analyzer. In addition, the ratio of the supernatant liquid caused by the sedimentation of the particles (the ratio of the supernatant liquid amount to the total amount) was also measured. Table 3 shows the results.

Table 3: Measurement results of particle size and ratio of supernatant Average particle size (μm) 1 week after production 1 week after supernatant ratio Example 1 1.4 μm 1.4 μm None Comparative example 1 1.5 μm 3.5 μm 8%

From Table 3, no increase in the particle size of Daimlon in the flowable containing the ligninsulfonate of Example 1 was observed, but an increase in the particle size was confirmed in Comparative Example 1, indicating that the particles were stable. It can be seen that the suspension is impaired.

[0031]

According to the present invention, by dispersing and coexisting lignin sulfonate, excellent properties inherent in a flowable preparation containing Daimlon as at least one of the active ingredients, that is, as a herbicide for paddy fields, The herbicidal action and the properties of the flowable formulation itself are not impaired at all, and depending on the conditions during storage, it is possible to prevent the increase in the particle size of Daimron as a cause of sometimes impairing a stable suspension state. The finely divided active ingredient, which is a characteristic, can be maintained in a stable suspension state.

Claims (2)

[Claims] 1. A flowable preparation containing N- (α, α-dimethylbenzyl) -N′-p-tolylurea as an active ingredient, characterized in that ligninsulfonate coexists with N- (α, α). -Dimethylbenzyl) -N'-
A method for preventing an increase in the particle size of p-tolyl urea. 2. The method according to claim 1, wherein the amount of the lignin sulfonate is 0.01 to 2 parts by weight based on 1 part by weight of the active ingredient N- (α, α-dimethylbenzyl) -N′-p-tolylurea. The described method.