JP2001122710A - Stabilized aqueous suspension herbicidal formulation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new aqueous suspension herbicidal formulation. SOLUTION: This aqueous suspension formulation having a pH value of <=6 and containing imazosulfuron.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION The present invention relates to a stabilized aqueous suspension herbicidal preparation.

[0002]

2. Description of the Related Art Sulfonylurea herbicidal active compounds include:
It is known that it has an extremely high activity as an active ingredient of a herbicide. The active ingredient itself is hardly decomposed under ordinary storage conditions and is chemically stable, but is known to have relatively high hydrolyzability. During the decomposition of the active ingredient is promoted. Therefore, there is a demand for a technique for suppressing and stabilizing the aqueous suspension formulation.

[0003] On the other hand, in order to reduce the labor for spraying, a paddy field impregnated with an aqueous suspension herbicidal formulation has a water content of 500 per 10 al.
In recent years, a method of directly dropping and spraying so as to be about 1000 ml has been actively researched and developed. When an aqueous suspension formulation of a sulfonylurea herbicidal active compound is directly dropped and sprayed on a paddy field, it is necessary to set the active ingredient concentration in the formulation to be extremely low because the compound is a highly active compound. It was a big problem.

[0004]

An object of the present invention is to provide an aqueous suspension preparation which suppresses the promotion of decomposition of a sulfonylurea herbicidal active ingredient having a relatively high hydrolyzability.

[0005]

The present invention will be described in detail below. The present invention relates to an aqueous suspension preparation containing a sulfonylurea herbicidally active compound, wherein the pH of the aqueous suspension preparation is 6 or less. The sulfonylurea-based herbicidally active compound that can be used in the present invention is not particularly limited, but for example, the following formula: Q-SO ₂ NHCONH-R (wherein Q may be substituted with various substituents) A good phenyl, benzyl, or heterocyclic group;
Represents a pyrimidyl group or a triazyl group which may be substituted with various substituents. For example, ethyl 5- (4,6-dimethoxypyrimidin-2-ylcarbamoylsulfamoyl) -1-
Methylpyrazole-4-carboxylate (generic name: pyrazosulfuronethyl), methyl α- (4,6-dimethoxypyrimidin-2-ylcarbamoylsulfamoyl) -Ο-toluate (generic name: Bens) Ruflonmethyl), 1- (4,6-dimethoxy-1,3,5-triazin-2-yl) -3- [2- (2-methoxyethoxy) phenylsulfonyl] urea (generic name: sinosulfuron), N- (2-chloroimidazo [1,2-a] pyridin-3-ylsulfonyl) -N- (4,6-dimethoxy-2-pyrimidinyl) urea (generic name: imazosulfuron).

[0006] The content of the sulfonylurea herbicidal active compound is not particularly limited, but is preferably 0.1 to 50% by weight based on the aqueous suspension pesticide preparation of the present invention. The method for producing a powder containing a sulfonylurea-based herbicidally active compound, a mineral substance fine powder and a paraffin wax solid at ordinary temperature is as follows. A paraffin wax that is solid at room temperature is heated and melted to a temperature equal to or higher than its melting point, and a sulfonylurea-based herbicidal active compound and a clay mineral are uniformly mixed, granulated, pulverized, and sieved to obtain a powder. The mineral fine powder is not particularly limited, and examples thereof include clay, talc, bentonite, diatomaceous earth, calcium carbonate, white carbon, and the like. The paraffin wax solid at room temperature is not particularly limited, but includes, for example, ordinary petroleum-based solid paraffin wax, wood wax, beeswax, carnauba wax, etc., and is preferably a petroleum-based solid paraffin wax, and isoparaffin, Normal paraffin or a mixture thereof with a melting point range of 5
Those having a temperature of 0 to 95 ° C are suitable.

[0007] The particle size of the powder is not particularly limited, but is suitably in the range of 10 to 200 microns. Since the sulfonylurea herbicidal active compound has a very high herbicidal activity and a low content in an aqueous suspension preparation, the active compound is rapidly dissolved in paddy water when applied by a usual method, so that the rice plant The active compound is washed away from the paddy field due to phytotoxicity or water leakage, resulting in no sustained efficacy.

[0008] Therefore, it is important to gradually elute into paddy water as little as possible. For this purpose, a powder comprising a sulfonylurea-based herbicidally active compound, a mineral substance fine powder and a paraffin wax which is solid at ordinary temperature is required. Is preferred. Depending on the type of weeds to be herbicidally, one or two of the following herbicidal active ingredients are used.
More than one kind may be mixed.

An example will be described below. (1) 4- (2,4-dichlorobenzoyl) -1,3-dimethyl-5-pyrazolyl-p-toluenesulfonate (general name: pyrazolate), (2) 2- [4- (2 , 4-
Dichlorobenzoyl) -1,3-dimethylpyrazol-
5-yloxy] acetophenone (generic name: pyrazoxyfen), (3) 2- [4- (2,4-dichloro-m-toluoyl) -1,3-dimethylpyrazol-5-yloxy] -4-methylacetophenone ( Generic name: benzofenap), (4) 1- (α, α-dimethylbenzyl)-
3- (paratolyl) urea (generic name: Daimron), (5)
(RS) -2-bromo-N- (α, α-dimethylbenzyl) -3,3-dimethylbutyramide (generic name: bromobutide), (6) α- (2-naphthoxy) propionanilide (generic name: naproanilide) ), (7) (RS) -2-
(2,4-dichloro-m-tolyloxy) propionanilide (generic name: clomeprop), (8) 2,4,6-
Trichlorophenyl-4'-nitrophenyl ether (general name: CNP), (9) 2,4-dichlorophenyl-
3'-methoxy-4'-nitrophenyl ether (generic name: chloromethoxynil), (10) methyl 5- (2,4-dichlorophenoxy) -2-nitrobenzoate (general name:
Bifenox), (11) 5-tert-butyl-3
-(2,4-dichloro-5-isopropoxyphenyl)
-1,3,4-oxadiazolin-2-one (generic name:
Oxadiazone), (12) 2-benzothiazole-2-
Iloxy-N-methylacetanilide (generic name: mefenacet), (13) 2-Chloro-2'-6'-diethyl-N- (butoxymethyl) acetanilide (generic name:
Butachlor), (14) S, S'-dimethyl 2-difluoromethyl-4-isobutyl-6-trifluoromethylpyridine-3,5-dicarbothioate (generic name: dithiopyr), (15) (Z ) -N-but-2-enyloxymethyl-2-chloro-2 ', 6'-diethylacetanilide (generic name: butenachlor), (16) 2-chloro-2', 6'-diethyl-N- (2-propoxyethyl) acetanilide (generic name: pretilachlor), (1
7) 2-3-Dihydro-3,3-dimethylbenzofuran-5-ylethanesulfonate (generic name: benfreside), (18) O-3-tert-butylphenyl 6
-Methoxy-2-pyridyl (methyl) thiocarbamate (generic name: pyributicarb), (19) S- (4-chlorobenzyl) -N, N-diethylthiocarbamate (generic name: benthiocarb), ( 20) S-1-methyl-1-phenylethylpiperidine-1-carbothiate (generic name: dimepiperate), (21) S-benzyl 1,2-
Dimethylpropyl (ethyl) thiocarbamate (generic name: esprocarb), (22) S-ethylhexahydro-1H-azepine-1-carbothioate (generic name: molinate), (23) O-ethyl -O- (3-methyl-6
-Nitrophenyl) secondary-butyl phosphoramidothioate (generic name: butamiphos), (24) 3,7-dichloroquinoline-8-carboxylic acid (generic name: quinclorac), (25) (1RS, 2SR , 4SR) -1, 4-
Epoxy-p-mens-2-yl 2-methylbenzyl ether (generic name: symmetrine), (26) 2-methylthio-4,6-bis (ethylamino) -s-triazine (generic name: simethrin), (27) O, O-diisopropyl-2- (benzenesulfonamido) ethyldithiophosphate (general name: SAP), (28) 2-methylthio-
4-ethylamino-6- (1,2-dimethylpropylamino) -S-triazine (generic name: dimethamethrin),
(29) 2-methylthio-4,6-bis (isopropylamino) -s-triazine (generic name: promethrin), (3
0) 2-amino-3-chloro-1,4-naphthoquinone (general name: ACN), (31) 2-methyl-4-chlorophenoxybutyric acid (generic name: MCBP), (32) 2-methyl-4- Chlorphenoxyacetic acid (generic name: MCP), (3
3) 2 ', 3'-dichloro-4-ethoxymethoxybenzanilide, (34) 1- (2-chlorobenzyl) -3-
(Α, α-dimethylbenzyl) urea, (35) N- [2 ′
-(3'-methoxy) -thienylmethyl] -N-chloroaceto-2,6-dimethylanilide.

The method of controlling the hydrogen ion concentration of the aqueous suspension preparation is not particularly limited, but the compound to be controlled may be various compounds such as hydrochloric acid, sulfuric acid, phosphoric acid, sulfonic acid and carboxylic acid. Inorganic acids and organic acids, and salts and esters thereof. Specific examples include acidic phosphate, citric acid, maleic acid, sorbic acid, lactic acid, tartaric acid, and the like. Also, disodium hydrogen phosphate-citric acid, sodium acetate-hydrochloric acid, formic acid-sodium formate,
Various buffers such as lactic acid-sodium lactate, tartaric acid-sodium tartrate, sodium citrate-hydrochloric acid and the like can be added in a predetermined amount.

When the pH of the aqueous suspension preparation is adjusted to 6 or less, the hydrolyzability of the sulfonylurea-based herbicidally active compound is considered to be reduced due to a decrease in water solubility.
The surfactant may be one generally used as a wetting agent or dispersant in an agricultural chemical formulation, and is not particularly limited, but an anionic or nonionic surfactant is mainly used. The specific list is as follows.

Various polycarboxylates, alkyl naphthalene sulfonates, alkyl naphthalene sulfonates, formalin condensates, lignin sulfonates, alkyl benzene sulfonates, dialkyl sulfosuccinates, lauryl sulfates, polyoxyethylene alkyl esters −
Tersulphate salts, polyoxyethylene alkyl aryl ether sulphate salts and the like can be mentioned, and examples of such salts include alkali metal salts, ammonium salts and amine salts.

The nonionic surfactants include polyoxyethylene alkyl ether, polyoxyethylene alkyl aryl ether, polyoxyethylene alkyl aryl phenyl ether, polyoxyethylene sorbitan fatty acid ester, and polyoxyethylene. And polyoxypropylene glycol. These surfactants may be used alone or in combination of two or more.

If necessary, a freezing point depressant, an antisettling agent, an antifoaming agent, a preservative and the like can be used. Examples of freezing point depressants include ethylene glycol, propylene glycol, and glycerin.
Examples include xanthan gum, lanthanum, colloidal hydrous aluminum magnesium silicate, and the like. Examples of the antifoaming agent include silicone-based compounds.
Sodium benzoate, 1,2-benzisothiazoline-
3-one and the like are exemplified.

The method for producing the aqueous suspension preparation of the present invention is not particularly limited.
It is obtained by mixing with a stirrer. If necessary, other herbicidal active ingredients other than the sulfonylurea type may be finely pulverized by a wet pulverizer. Fine pulverization by wet pulverization can be carried out by a wet pulverizer such as an attritor, a sand grinder, a dyno mill, a par mill, an apex mill, a biscomil, an ultrabiscomil.

[0016]

EXAMPLES Next, the present invention will be described specifically with reference to Examples, but the present invention is not limited to these Examples.
All parts are by weight.

Example 1 13.0 parts of 0.2M disodium hydrogen phosphate and 0.1M
1.0 part of pyrazosulfuron-ethyl (generic name) obtained by dissolving 3.0 parts of polyoxyethylene styryl phenyl ether in 50.0 parts of citric acid and finely pulverizing with a jet-omizer (manufactured by Seishin Enterprise) in advance. Was added and mixed by stirring, and 25.0 parts of a 1% xanthan gum aqueous solution and 8.0 parts of propylene glycol were further added and mixed by stirring to obtain an aqueous suspension formulation of the present invention. PH of this aqueous suspension formulation
Was 3.1.

Example 2 Pyrazosulfuron-ethyl (generic name) finely pulverized in advance with a jet-omizer (manufactured by Seishin Enterprise Co., Ltd.)
3.5 parts was added little by little to 44.9 parts of petroleum paraffin wax (melting point: 69-72 ° C.) melted at about 80 ° C., and mixed with a homomixer (manufactured by Tokushu Kika Co., Ltd.). The mixture was stirred to uniformly disperse the pyrazosulfuron-ethyl. Then, 51.6 parts of a fine powder of Cray were added little by little, and the mixture was stirred and dispersed. The mixture was cooled to 60 ° C., granulated by an extrusion granulator having a screen of 0.5 mm in diameter, pulverized by Coroplex (manufactured by Makino Sangyo Co., Ltd.), and passed through a 106-micron sieve. This was used as a powder (powder A).

A powder A was prepared by dissolving 3.0 parts of polyoxyethylene styryl phenyl ether in 35.4 parts of distilled water.
28.6 parts were added and mixed with stirring, and 25.0 parts of a 1% xanthan gum aqueous solution and 8.0 parts of propylene glycol were further added and mixed with stirring to obtain an aqueous suspension preparation of the present invention. The pH of this aqueous suspension preparation was 6.3.

EXAMPLE 3 3.0 parts of polyoxyethylene styryl phenyl ether was dissolved in 7.3 parts of 0.2 M disodium hydrogen phosphate and 28.1 parts of 0.1 M citric acid to obtain the compound of Example 2. 28.6 parts of powder A were added, mixed with stirring, and further 25.0 parts of a 1% xanthan gum aqueous solution and propylene glycol 8.
0 parts were added and mixed by stirring to obtain an aqueous suspension preparation of the present invention. The pH of this aqueous suspension preparation was 3.4.

Example 4 40.0 parts of oxadiazone (general name), 3.0 parts of polyoxyethylene styryl phenyl ether and 57.0 parts of water were mixed, and 100 g of the mixture was mixed with a sand grinder (trade name).
(Made by IMEX) and placed in a 1-liter container.
100 milliliters of 2 mm glass beads were added and crushed at a peripheral speed of 10 m / sec for 90 minutes. The pulverized slurry obtained by the above method-30.0 parts, distilled water 10.775
Parts, 28.6 parts of the powdery substance A obtained in Example 2, 20.0 parts of a 1% xanthan gum aqueous solution, and propylene glycol 8.
0 parts, 2.5 parts of polyoxyethylene styryl phenyl ether and 0.125 parts of propyl phosphoric acid were stirred and mixed to obtain an aqueous suspension preparation of the present invention. The pH of this aqueous suspension preparation was 3.6.

Comparative Example 1 Pyrazosulfuron-ethyl (generic name) finely pulverized with a jet-omizer (manufactured by Seisin Corporation) in advance
1.0 part, 3.0 parts of polyoxyethylene styryl phenyl ether, 25.0 parts of a 1% aqueous solution of xanthan gum, 8.0 parts of propylene glycol, and 63.0 parts of distilled water are stirred and mixed to obtain an aqueous suspension preparation. Was. PH of this aqueous suspension formulation
Was 6.3.

Test Example 1 Abuse Test The aqueous suspension preparations obtained in Examples and Comparative Examples were
An abuse test was conducted at 40 ° C. for one month to determine the residual ratio of the active ingredient, pyrazosulfuron-ethyl (generic name). The residual ratio was determined by the following equation. The results are shown in Table 1.

[0024]

## EQU1 ## Residual rate (%) = [(amount of active ingredient after test) /
(Amount of active ingredient before test)] × 100

[0025]

[Table 1] Table 1 Residual rate of pyrazosulfuron-ethyl after abuse test ――――――――――――――――――― Residual rate% ―――――――――― ――――――――― Example 1 85% ――――――――――――――――――― Example 2 80% ―――――――――――― ――――――― Example 3 95% ――――――――――――――――――― Example 4 96% ―――――――――――――― ――――― Comparative Example 1 58% ―――――――――――――――――――――

Test Example 2 Herbicidal effect test and phytotoxicity test Paddy soil was packed in a plastic container of 40 cm (length) × 47 cm (width) × 23 cm (height).
Konagi and Kikasigusa were sown, and the tubers of Urikawa and Spodoptera cricket were placed. Eight rice seedlings were planted per pot at a depth of 2 cm and grown in a greenhouse. Five days after planting, the aqueous suspension preparation of Example 4 was applied to the surface of the water using a microsyringe so as to be 25 ml per are. Twenty-five days after the treatment, the effects on each weed and paddy rice were evaluated according to the following criteria.

Criteria 5: Complete withering or suppression of 90% or more 4: Suppression of 70 to 90% 3: Suppression of 40 to 70% 2: Suppression of 20 to 40% 1: Suppression of 5 to 20% 0: 5 Suppression of% or less The degree of suppression was determined by visual observation.

The results are shown in Table 2.

[0029]

[Table 2] Table 2 Herbicidal effect and effect on rice paddy ――――――――――――――――――――――――――― Application rate A B C D E FG (ml / al) ――――――――――――――――――――――――――――― Example 3 25 0 4 4 4 4 4 4 Example 4 25 0 5 5 5 5 5 5 ―――――――――――――――――――――――――――――

The symbols in Table 2 have the following meanings. A: Paddy rice, B: Nobie, C: Firefly, D: Konagi,
E: Kikasigusa, F: Urikawa, G: Mizugayatsuri

[0031]

Industrial Applicability The present invention contributes to stabilization of an active ingredient during storage of an aqueous suspension containing a sulfonylurea herbicidal active compound.

 ──────────────────────────────────────────────────続 き Continued on front page (72) Inventor Yutaka Kasai 722 Tsuboi-cho, Funabashi-shi, Chiba Pref. Nissan Chemical Industry Co., Ltd.

Claims (1)

[Claims] 1. An aqueous suspension formulation containing imazosulfuron, wherein the pH of the aqueous suspension formulation is 6 or less.