JPH04290802A - Aqueous suspended herbicide composition - Google Patents

Abstract

PURPOSE:To provide a spreadable aqueous suspended herbicide composition rapidly spreading on a paddy field without locally stagnating, exhibiting an uniform herbicidal activity, capable of avoiding chemical damages to paddy rice and reducing the labor for spraying the herbicide composition. CONSTITUTION:An aqueous suspended herbicide composition comprises (A) a water-slightly soluble herbicidal ingredient, preferably the fine particles thereof having a water solubility (25 deg.C) of <=100ppm and an average particle diameter of 0.5-10mum, preferably 0.5-5mum, (B) a surfactant, (C) a paraffinic hydrocarbon, preferably a liquid 6-20C paraffinic hydrocarbon having especially a specific gravity of <=1 (at 25 deg.C) and a boiling point of 50-350 deg.C, and (D) water as essential components. The composition is dropped on a watered paddy field in a rate of 1-500g/10 ares to spread the composition on the paddy field for the removal of weeds. Even when locally dropped, the composition does not precipitate or stagnate at the dropping positions, does not adhere to obstructions and can rapidly diffuse in the paddy field, because the specific gravity (25 deg.C) of the composition is below 1 and because the surface tension of the composition is low.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spreadable aqueous herbicidal suspension composition, particularly to an aqueous suspension herbicidal composition suitable for application to flooded paddy fields.

0002

[Prior Art] Currently, the most commonly used method is to apply an aqueous suspension herbicidal composition in which fine particles of a herbicidal component that is sparingly soluble in water are dispersed and suspended in water together with a surfactant, to flooded paddy fields. Compared to the currently practiced method of dispersing wettable powders and granules,
Since it does not require much dilution water or solid carrier, it is advantageous in terms of drug transportation and storage. In addition, with this method, the chemical can be applied locally rather than all over the rice field, so there is no need to walk around the rice field much, which prevents damage to rice growth and reduces the labor required for spraying the chemical. Research and development is actively underway. Specifically, for example, JP-A No. 62-84003, No. 62-87501, No. 63-
Examples include those described in each No. 107901 publication. However, there is still no aqueous suspension herbicidal composition that satisfies all aspects such as formulation stability, herbicidal effect, phytotoxicity to paddy rice, and labor saving in spraying work, and there is a desire for a suitable one.

0003

DISCLOSURE OF THE INVENTION The present inventors have discovered that when a paraffinic hydrocarbon is added to an aqueous herbicidal suspension composition consisting of a poorly water-soluble herbicidal component, a surfactant, and water, the herbicidal Since the composition does not remain localized and quickly spreads through rice fields, it provides an even weeding effect and avoids chemical damage to paddy rice.The spraying labor can be further reduced, and the formulation can be stored for a long time. It was found that the formulation had a sufficiently tolerable stability.

That is, the present invention is an aqueous herbicidal suspension composition characterized by containing a herbicidal component that is poorly soluble in water, a surfactant, a paraffinic hydrocarbon, and water. This is a weeding method for paddy fields, which is characterized in that the herbicidal component is dropped into a flooded paddy field at a rate of 1 to 500 g per 10 ares to spread the herbicidal composition into the paddy water.

Examples of the slightly water-soluble herbicidal component used in the present invention include 4-(2,4-dichlorobenzoyl)-1,3-dimethyl-5-phenacyloxypyrazole (common name: pyrazoxyfen). ), 4-(2,4-
dichlorobenzoyl)-1,3-dimethyl-5-pyrazolyl p-toluenesulfonate (common name: pyrazolate), 4-(2,4-dichloro-3-methylbenzoyl)-1,3-dimethyl-5-(4- Methylphenacyloxy)pyrazole (generic name: benzofenap), 5
-benzyloxy-4-(2,4-dichlorobenzoyl)-1-methylpyrazole (Code No.; NC-31
Pyrazole compounds such as 0); 2,4-dichlorophenyl 3-methoxy-4-nitrophenyl ether (common name: chlormethoxynil), 2,4,6-trichlorophenyl 4-nitrophenyl ether (common name: chlornitrophen), 2 , 4-dichlorophenyl 3-methoxycarbonyl-4-nitrophenyl ether (common name: bifenox), 2,4-dichlorophenyl 4-nitrophenyl ether (common name: nitrophen), 2-chloro-4-trifluoromethylphenyl 4- Nitro-3-(tetrahydrofuran-3-yloxy)phenyl ether (Code No.
．． ; MT-124); S-(4-chlorobenzyl)-N,N-diethylthiocarbamate (common name: bentiocarb), S-benzyl-N-(1,2-dimethylpropyl)-N -Ethylthiocarbamate (generic name: Esprocarp), S-(α
, α-dimethylbenzyl)-N,N-pentamethylene thiocarbamate (common name: dimepiperate), S-ethyl-N,N-hexamethylene thiocarbamate (common name: molinate), O-(3-tert-butylphenyl) )-N-(6-methoxypyridin-2-yl)-N-methylthiocarbamate (common name: pyributicarb) and other thiocarbamate compounds; 2-chloro, 2', 6'
-diethyl-N-(2-propoxyethyl)acetanilide (common name; pretilachlor), N-butoxymethyl-2-chloro-2',6'-diethylacetanilide (common name; butachlor), 2-(2-naphthyloxy) ) Propionanilide (generic name: nabroanilide), 2
-(2,4-dichloro-3-methylphenoxy)propionanilide (common name: clomeprop), 2',3'
-dichloro-4-ethoxymethoxybenzanilide (Code No.: HW-52), cis-N-[(2-butenooxy)methyl]-2-chloro-2',6'-diethylacetanilide (common name: butenachlor) , 2-chloro-2',6'-diethyl-N-[(3-methoxythienyl)methyl]acetanilide (Code No.; NSK
2-bromo-N-(α,α-dimethylbenzyl)-3,3 -Amide compounds such as dimethylbutyramide (common name: bromobutide), N-[(
4,6-dimethoxypyrimidin-2-yl)aminocarbonyl]-5-(2-chloro-2,2-difluoroethoxy)-3-methyl-4-isothiazolesulfonamide, 5-[(4,6-dimethoxy pyrimidin-2-yl) aminocarbonylaminosulfonyl]-1-methylpyrazole-4-carboxylic acid ethyl ester (common name: pyrazosulfuronethyl), 2-[(4,6-dimethoxypyrimidin-2-yl)aminocarbonyl Aminosulfonylmethyl] benzoic acid methyl ester (common name: bensulfuron methyl), N-(2-chloroimidazo[1,2
-a]pyridin-3-ylsulfonyl)-N'-(4,
6-dimethoxy-2-pyrimidinyl)urea (code N
o. ;TH-913), 3-(4,6-dimethoxy-1
,3,5-triazin-2-yl)-1-[2-(2-
Sulfonamide compounds such as methoxyethoxy)phenylsulfonyl]urea (common name: sinosulfuron);
5-tert-butyl-3-(2,4-dichloro-5-
Oxadiazone compounds such as (isopropoxyphenyl) 1,3,4-oxadiazol-2(3H)-one (common name: oxadiazone); 4,6-bis(ethylamino)-2-methylthio-s-triazine (generic name: cymetrine), 2-(1,2-dimethylpropylamino)
-Triazine compounds such as -4-ethylamino-6-methylthio-s-triazine (common name: dimethamethrine); 2-amino-3-chloro-1,4-naphthoquinone (
Generic name: Naphthoquinone compounds such as ACN); 1-(α,α-dimethylbenzyl)-3-(4
-methylphenyl)urea (generic name: Daimeron), 3
, 7-dichloro-8-quinolinecarboxylic acid (common name: quinclorac), 3-chloro-2-[4-chloro-2-
Fluoro-5-(2-propynyloxy)phenyl]-
4,5,6,7-tetrahydro-2H-indazole (Code No.; S-275), 2,3-dihydro-3
, 3-dimethyl-5-benzofuranylethanesulfonate (common name: benfresate), S,S-dimethyl 2-
(difluoromethyl)-4-(2-methylpropyl)-
6-(trifluoromethyl)-3,5-pyridine dicarbothioate (common name: dithiopyl), 1-(2-chlorobenzyl)-3-(α,α-dimethylbenzyl)urea (code No.: JC -940), exo-1-methyl-2-(2-methylbenzyloxy)-4-isopropyl-7-okiribicyclo[2.2.1]heptane (common name: synmethrin), etc., and in the present invention, At least one type selected from this group is used.

Among them, pyrazole compounds, thiocarbamate compounds, anilide compounds, amide compounds,
Solubility of naphthoquinone compounds in water (25℃
) is preferably 100 ppm or less, but even if it is higher, it can be used as long as it shows the desired effect. The herbicidal component usually has a specific gravity of 1 or more, and can be used in either solid or liquid form at room temperature. When the herbicidal component is solid, the average particle size of the herbicidal component is generally 0.5 to 10 μm, preferably 0.5 μm, in order to uniformly disperse and suspend the formulation in water and to spread it rapidly in field water. ~
It is used as fine particles of 5 μm.

The paraffinic hydrocarbons used in the present invention include saturated aliphatic hydrocarbons having 6 to 20 carbon atoms, especially those with a specific gravity of 1 or less (25°C) and a boiling point of 5.
Preferably, it is liquid at room temperature of 0 to 350°C. Specific examples include hexane, heptane, octane, decane, undecane, tetradecane, hexadecane, icosane, etc., and these also include structural isomers of linear or aliphatic chains.

[0008] The surfactant used in the present invention is one that imparts hydrophilicity to the herbicidal component, and includes, for example, polyoxyethylene alkyl ether, polyoxyethylene phenyl alkylaryl ether, polyoxyethylene alkylaryl ether, polyoxyethylene styrylphenyl. ether, polyoxyethylene sorbitan alkylate,
Nonionic surfactants such as polyoxyalkylene glycol, sorbitan alkylate, oxyethylene/oxypropylene block polymer, acetylene glycol; alkyl sulfate, polyoxyethylene alkyl ether phosphate, polyoxyethylene phenyl alkylaryl ether sulfate, polyoxy Ethylene phenyl alkylaryl ether phosphate, polyoxyethylene alkylaryl ether sulfate, alkylaryl sulfate, alkylaryl phosphate, alkylaryl sulfonate, polystyrene sulfonate, lignin sulfonate, naphthalene sulfonate, oxyethylated polyarylphenol phosphate triethanolamine salt, β-naphthalenesulfonic acid sodium salt formalin condensate, and anionic surfactants such as polycarboxylic acid-based special polymer surfactants. and use one or more of them.

The aqueous herbicidal suspension composition of the present invention can be easily produced by adding a paraffinic hydrocarbon to a composition such as a conventional aqueous suspension herbicidal composition; It can also be easily produced directly by a conventional method. For example, it can be produced by simultaneously mixing a herbicidal component, a surfactant, a paraffinic hydrocarbon, and water and wet-pulverizing the mixture if necessary, or by pre-pulverizing the herbicidal component into a fine powder, and then combining the herbicidal component with the surfactant and paraffinic hydrocarbon. It can be produced by uniformly mixing and water, and wet-pulverizing if necessary, but in industrial implementation, it is generally simple and advantageous to mix the four components at the same time and wet-pulverize. This wet pulverization is usually carried out using rigid media having a particle size of 0.1 to 5 mm and a pulverizer such as a sand mill or a sand grinder. When producing the herbicidal composition, the type of surfactant and paraffin hydrocarbon differs depending on the type of herbicidal component, the proportion of each component in the entire formulation, etc., so in practice, suitable ones are selected through trial and error experiments. All you have to do is select.

[0010] The blending ratio (weight) of the herbicidal composition varies depending on the purpose of use, the scene of use, the type of each component, etc., and cannot be unconditionally defined, but usually the herbicidal components are in the range of 2 to 40%.
preferably 2 to 35 parts, surfactant 1 to 10 parts, preferably 2 to 8 parts, paraffin hydrocarbon 10 to 40 parts, preferably 15 to 40 parts, water 20 to 85 parts, preferably 25 to 70 parts. Department. On the other hand, the herbicidal composition of the present invention contains water-soluble polymer compounds such as gum arabic, xanthan gum, and carboxymethylcellulose; bentonite, white carbon, and calcium carbonate to further stabilize the dispersion and suspension of the herbicidal component in the formulation. solid carriers such as , magnesium aluminum silicate; and ethylene glycol, to prevent the formulation from freezing at low temperatures.
Antifreeze agents such as propylene glycol, glycerin, and urea may be included as appropriate. The herbicidal composition can maintain a state in which the herbicidal component is well dispersed and suspended in the formulation water for a long period of time. Even if it separates into an oil layer, an aqueous layer, and a solid layer during storage, it will not pose any problem in the application of the drug because it can be re-obtained into a uniformly dispersed/suspended state by applying slight vibrations.

Even when the herbicidal composition of the present invention is dropped locally in a flooded paddy field, its specific gravity (at 25°C) is usually 1 or less, preferably 1 to 0.94, and the surface tension is low, for example, 20 to 0.94. 60dyne/cm, preferably 20-35dy
ne/cm (25°C), this product does not precipitate or stagnate at the point where the drug is dropped, nor does it adhere to obstacles such as rice seedlings or weed fragments, and does not deposit on the water surface or It can be quickly expanded into rice fields. The herbicidal component dissolves uniformly in the field water or settles on the soil surface and is uniformly dispersed. In the present invention, when the herbicidal composition is dropped into a flooded paddy field in an amount of 1 to 500 g, preferably 3 to 400 g per 10 ares, an excellent and uniform herbicidal effect can be obtained without causing chemical damage to paddy rice. It will be done. When dropping the drug, use a container that dispenses a certain amount, and drop the drug along the ridge or in a container with an area of 10 to 100 m2.
For example, 0 per 10 ares by dropping each drop.
．． 3 to 2 liters, preferably 0.5 to 1.5 liters is applied. Therefore, in the present invention, the leaf age of weeds is generally 3 to 3 years before germination.
The most favorable effect is obtained when applied during the leaf stage, but it may be applied at other times and situations unless there is a particular problem in terms of formulation, medicinal efficacy, phytotoxicity, spraying work, etc. You can also do it.

0012

[Example] (Formulation Examples) The components used in each formulation example and their abbreviations are shown below. The amount of each component used is expressed on a weight basis.

Herbicidal ingredient (A) A-1: 4-(2,4-dichlorobenzoyl)-1,3
-Dimethyl-5-phenacyloxypyrazole A-2:
2-Chloro-2',6'-diethyl-N-(2-propoxyethyl)acetanilide A-3: 2-chloro-2',6'-diethyl-N-[(
3-Methoxythienyl)methyl]acetanilide A-4
:2,3-dihydro-3,3-dimethyl-5-benzofuranylethanesulfonate A-5:2-amino-3-chloro-1,4-naphthoquinone A-6:2-promo-N-(α, α-dimethylbenzyl)-3,3-dimethyl-butyramide A-7: S,S-
Dimethyl 2-(difluoromethyl)-4-(2-methylpropyl)-6-(trifluoromethyl)-3,5
-Pyridine carbothioate A-8: O-(3-tert-butylphenyl)-N-(6-methoxypyridin-2-yl)-N-methyl thiocarbamate

Surfactant (B) B-1: Polyoxyethylene styrylphenyl ether and alkylaryl sulfonate (trade name, Sorp
ol-355: Toho Chemical Industry Co., Ltd.) B-2: Oxyethylated polyarylphenol phosphate salt with triethanolamine (trade name,
Soprophor-FL: Made by Rhone Poulenc) B
-3: Acetylene glycol (trade name, Surfino
l 104: Nissin Chemical Co., Ltd.) B-4: Mixture of alkylaryl sulfonate, polyoxyethylene alkylaryl ether sulfate, phosphate, inorganic carbonate and white carbon (trade name, Sorpol-5146: Toho Chemical Co., Ltd.) B
-5: Calcium ligninsulfonate

Paraffinic hydrocarbon (C) C-1: Isoparaffinic hydrocarbon (trade name, IP Solvent 1620: Idemitsu Petrochemical Manufacturing - specific gravity 0.762, flash point 52°C) C-2: n-hexane C -3: Isoparaffinic hydrocarbon (trade name, IP Solvent 2028: Idemitsu Petrochemical Manufacturing - specific gravity 0.790,
Flash point: 90°C) C-4: Isoparaffinic hydrocarbon (trade name, IP Solvent 2835: Idemitsu Petrochemical Manufacturing - specific gravity 0.820,
Flash point 140°C) C-5: n-paraffin hydrocarbon (trade name, normal paraffin N-14: manufactured by Nippon Mining Co., Ltd. - specific gravity 0.7
67, flash point 30℃)

Others (D) D-1: Ethylene glycol D-2: Water D-3: Bentonite D-4: Calcium carbonate D-5: Propylene glycol D-6: Magnesium aluminum silicate (trade name, Veegum: Vanderbilt) manufactured by)

[0017]
Formulation Example 1 Herbicidal ingredients A-1 19.1 parts and A-2 4.8 parts, surfactant B-1 3.0 parts and B-3 1.0
25.0 parts of paraffinic hydrocarbon C-1, 4.0 parts of other components D-1, and 43.1 parts of D-2.
The mixture consisting of
%, peripheral speed: 15 m/sec) for 15 minutes to obtain an aqueous suspension. The specific gravity of this material is 0.
988, and surface tension (Kyowa CBVP surface tension meter:
(manufactured by Kyowa Kagaku Co., Ltd.) was 28.6 dyne/cm, and the average particle size of the herbicidal component was 1 to 3 μm. This product had good storage stability and maintained a uniform dispersion state.

Formulation Examples 2 to 17 The aqueous suspensions prepared according to Formulation Example 1 are shown in Table 1, and the specific gravity and surface tension of each are shown in Table 2. All of the preparations had good storage stability. Maintained uniform dispersion. In addition,
The average particle size of the herbicidal components was 1 to 3 μm.

[0019]

[Table 1]

[0020]

[Table 2]

[0021]

[Table 3]

[0022]

[Table 4]

Comparative formulation example Herbicidal ingredient A-1 10.1 parts, other ingredients D-3
25.0 parts of D-4 and 1.5 parts of powdered surfactant B-4 were ground and mixed;
Add kneading water containing 51.5 parts and knead and mix. The kneaded material is extruded and granulated through a 0.8 mm screen, dried, and then sized to obtain granules.

(Test Example) Test Example 1 A paddy field was plowed with a tractor, and granular chemical fertilizer (N-P2O5-K2O:14-10-13) was applied as a base fertilizer for 10 minutes.
20 kg was applied per a. After that, the area was flooded, and the rice seedlings (variety: Nihonbare) at the two-leaf stage, grown in boxes, were transplanted mechanically. Then, two test areas of 3.5 m x 2 m were set up using plastic sheets. At the edges of the test plots, three tubers of Spermia japonica that had germinated were planted per plot. Other weeds were allowed to grow naturally, but they all grew in large numbers.

[0025] The flooding depth was adjusted to 5 to 7 cm, and the aqueous suspension prepared in the above formulation example was placed in the center of the test plot at a rate of 1 per 10 a.
Dropped per liter. The comparison area corresponds to the above suspending agent,
Granules prepared by a conventional formulation method (similar to the comparative formulation example) were uniformly spread to 3 kg per 10a. The leaf age of each weed at the time of chemical treatment was 1 to 1.2 leaf stage for Novie, 1 to 1.5 leaf stage for Firefly and Japanese cypress, and 1 leaf stage for Azena and Cyperus. On the 21st, 35th, and 45th days after chemical treatment, the growth status of paddy rice and weeds was observed with the naked eye, and the results shown in Table 3 were obtained by expressing the degree of weed growth inhibition and the degree of chemical damage using the following criteria.

Evaluation criteria: Degree of growth inhibition

[0027] Degree of chemical damage Paddy rice growth rate (ratio to untreated plot)

[0028]

[Table 5]

[0029] As can be seen from the results of this test, the aqueous suspension of the present invention exhibited a high herbicidal effect on the entire area by central treatment (local treatment), similar to that of the uniform granule treatment in the comparison group, and caused no chemical damage to paddy rice. I didn't even recognize it.

Test Example 2 A paddy field was prepared in the same manner as in Test Example 1, and paddy rice seedlings were mechanically transplanted, and 5×6 paddy seedlings were transplanted using plastic sheets.
A test plot of m was established, and the germinated tubers of Cyperus japonica were planted, and other weeds were allowed to grow naturally. Water depth 5-7cm
It was adjusted and treated with chemicals. In the test plots of the present invention, the aqueous suspensions prepared in Formulation Examples 1 and 4 were dropped at 1 liter per 10 a along a 5m-long sheet in the center or on one side of each test plot. 3 kg/10a of granules prepared by conventional formulation methods corresponding to suspensions
It was evenly distributed to each address. The leaf age of each weed at the time of chemical treatment was 1.3 to 1.5 leaf stage for Japanese barnyard grass, 1 leaf stage for Japanese oak, and 1.5 leaf stage for Japanese cypress. On the 30th day after the chemical treatment, the growth status of the paddy rice and weeds was observed with the naked eye, and the degree of weed growth inhibition and the degree of chemical damage were expressed using the same criteria as in Test Example 1, and the results shown in Table 4 were obtained.

[0031]

[Table 6]

[0032] As can be seen from the results of this test, the aqueous suspension of the present invention exhibited high herbicidal effects in both the central treatment and one-sided treatment (local treatment), similar to the uniform granule treatment in the comparison group, and caused no chemical damage to paddy rice. was also not recognized.

Test Example 3 A paddy field was prepared in the same manner as in Test Example 1, and paddy rice seedlings were mechanically transplanted, and 3×17 paddy seedlings were transplanted using plastic sheets.
A test plot of m (Figure 1 below) was established, and each weed was allowed to grow naturally. The water depth was adjusted to 5 to 7 cm, and the aqueous suspension prepared in the above formulation example was applied once along the sheet 3 m on one side of the test area.
Dropwise treatment was carried out at 1 liter per 0a. At the time of chemical treatment, the leaf age of each weed was 1.2 leaf stage for firefly, the early emergence stage for azalea and Japanese chinensis, and the ungerminated state for black croaker. On the 41st day after chemical treatment, the growth status of paddy rice and weeds at three points X, Y, and Z in Figure 1 was observed with the naked eye, and the degree of weed growth suppression and the degree of chemical damage were determined using the same standards as in Test Example 1. The results shown in Table 5 were obtained.

[0034]

[Table 7]

[0035] As can be seen from the results of this test, the aqueous suspension of the present invention exhibited high herbicidal effects on the entire test plot by treating only one side (local treatment) of the test plot, and no phytotoxicity to paddy rice was observed.

Test Example 4 A wooden frame test plot measuring 6.25 m long, 0.75 m wide, and 20 cm high was set up in a greenhouse (see Figure 2 below), and paddy soil was evenly spread on the bottom of the test plot. Two days later, two-leaf stage rice seedlings (variety: Nihonbare) were transplanted in two rows with a spacing of 30 cm. After that, the water depth was 2 to 3 cm.
managed at the 1.5-leaf stage for Japanese millet and 1.5-leaf stage for firefly.
When the two-leaf stage has been reached, the aqueous suspension prepared in the above formulation example is dropped at a rate of 1 liter per 10 a along the 0.75 m side of the test plot at a distance of 0.25 m from one side (0.75 m side). did. On the 21st day after the chemical treatment, the growth status of paddy rice and weeds was observed with the naked eye at regular intervals from the chemical treatment point, and the degree of weed growth suppression and the degree of chemical damage were expressed using the same criteria as in Test Example 1, and the results are shown in Table 6. Got the results.

[0037]

[Table 8]

As can be seen from the results of the tree test, the aqueous suspension of the present invention showed a high herbicidal effect on the whole test plot by treating only one side of the test plot (local treatment), and no phytotoxicity to paddy rice was observed.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a 3×17 m paddy field test plot, where the wavy lines indicate the points treated with chemicals, and X, Y, and Z indicate the points where weed growth was observed with the naked eye.

FIG. 2 shows a wooden frame test area with a length of 6.25 m, a width of 0.75 m, and a height of 20 cm, and the wavy lines indicate the points where the chemical was applied.

Claims (2)

[Claims] 1. An aqueous herbicidal suspension composition comprising a herbicidal component that is poorly soluble in water, a surfactant, a paraffinic hydrocarbon, and water. 2. An aqueous suspension herbicidal composition containing a herbicidal component that is poorly soluble in water, a surfactant, a paraffinic hydrocarbon, and water is applied to a flooded paddy field at a rate of 1 to 10 mA per 10 ares of the herbicidal component. A method for weeding rice fields, which comprises spreading the herbicidal composition into rice fields by dropping the composition in an amount of 500 g.