JPH04297403A - Herbicidal tablet or capsule for paddy field - Google Patents

Abstract

PURPOSE:To provide a tablet or capsule containing a sulfonylurea herbicidal component completely soluble in paddy water and a liquid herbicidal component impregnated in an oil-absorbing substrate and enabling uniform application of the herbicidal components by throwing into a paddy field. CONSTITUTION:The objective tablet or capsule for the control of weeds of paddy field contains (A) a sulfonylurea herbicidal component essentially completely soluble in paddy water, e.g. 2-[[(4,6-dimethoxypyrimidin-2-yl) aminocarbonyl]aminosulfonylmethyl]benzoic acid methyl ester, (B) other liquid herbicidal component such as S-benzyl-N-(1,2-dimethylpropyl)-N- ethylthiocarbamate, (C) a surfactant (e.g. fatty acid salt and alkylsulfuric acid salt), a foaming agent consisting of an acidic substance (e.g. organic acid) and an alkaline substance (e.g. carbonate) and a binder and (D) an oil-absorbing substrate having an oil absorption of >=50wt.% (e.g. fine powder of amorphous silicon dioxide and hydrolyzed starch).

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION The object of the present invention is to provide tablets or capsules for easy application of chemicals in paddy field weeding, and thereby to provide a simple method of chemical treatment.

0002

[Conventional techniques] Conventional methods for weeding rice fields, especially during the early to mid-stage of rice cultivation, include methods of spraying fine granules prepared with herbicidal ingredients together with a finely powdered solid carrier and other adjuvants, methods of spraying granules as they are, and methods of spraying granules as they are. One method is to dilute the herbicidal agent with a large amount of water and then spray it, but other methods that do not use a finely powdered solid carrier include spraying an emulsion of the herbicidal component dissolved in an organic solvent as it is, and a method in which the herbicidal component is sprayed as is by dissolving the herbicidal component in an organic solvent. An example of this method is to directly spray a flowable agent that has been dispersed or suspended in water.

0003

[Problems to be Solved by the Invention] However, when applying fine granules, granules, and wettable powders, it is necessary to use a heavy sprayer or granulator containing the drug, for example, The chemical must be uniformly distributed by walking around the rice fields or by using a large Niagara hose from the ridges to spread 3-4 kg of granules per rice field. Therefore, transportation and spraying of chemicals not only requires severe labor, but also often damages rice seedlings, which is undesirable for their growth. When applying emulsions and flowables, although the weight of the drug can be reduced to some extent and a large sprayer is not required, it is still necessary to use a container that dispenses a fixed amount of the drug, and it is still difficult to distribute the drug uniformly. It is necessary to walk around the rice fields.

[0004] The present applicant has solved the above-mentioned drawbacks of the conventional methods, and has developed a tablet or capsule that can weed rice fields in a simple manner without using a special chemical sprayer, that is, a medicine applied to rice fields. An application has already been filed for a tablet or capsule for weeding rice fields that contains a sulfonylurea herbicidal ingredient, a surfactant, a foaming agent, and a binder, the entire amount of which is substantially soluble in rice water, and may also contain other herbicidal ingredients if necessary. did.

However, when other herbicidal ingredients in the tablets or capsules are liquid at room temperature, the tablets or capsules may not have sufficient hardness, or the liquid substances may ooze out from the tablets or capsules. It has been found that it is often not possible to obtain fully satisfactory tablets or capsules.

[0006]

[Means for solving the problem] The present inventors have tried impregnating a solid carrier with other liquid herbicidal ingredients, and have found that the above problem can be solved by using a specific oil-absorbing base material. The present invention was completed.

[0007]

DISCLOSURE OF THE INVENTION That is, the present invention provides a sulfonylurea herbicidal component and other liquid herbicidal components, surfactants, blowing agents,
The present invention relates to tablets or capsules for weeding rice fields containing a binder and an oil-absorbing base material. In addition, the present invention applies the tablets or capsules to a flooded paddy field at a rate of 10 to 200 tablets or capsules per 10 ares and a total weight of 200 to 1,500 g, thereby eliminating substantially the entire amount of the herbicidal component. This invention relates to a method for weeding rice fields by dissolving and dispersing them in rice water.

[0008] In the present invention, the sulfonylurea herbicidal ingredients and other liquid herbicidal ingredients defined as “the entire amount applied to rice fields is substantially dissolved in rice water” are those that do not substantially cause phytotoxicity to rice seedlings. When a herbicidal ingredient is applied to a paddy field in a sufficient amount to have a herbicidal effect, that is, a practical amount, and assuming that the entire amount is dissolved in the rice field water, the concentration of the herbicidal ingredient in the rice field water is determined by the solubility of the herbicidal ingredient in water ( 25°C) or below.

For example, 2-[[(4,6-dimethoxypyrimidin-2-yl)aminocarbonyl]aminosulfonylmethyl]benzoic acid methyl ester (hereinafter abbreviated as A-2) is a practical herbicide in the early to mid-stage of rice cultivation. Normal dosage 1
It is applied at 5 to 7.5 g per 0 are, and the concentration in field water is 0.1 to 0.15 assuming a flooded depth of 5 cm.
ppm (practical dosage), and solubility in water (25℃
) is 8 ppm, so it corresponds to the herbicidal component defined in the present invention.

On the other hand, the herbicidal ingredient 4-(2,4-dichlorobenzoyl)-1, which has recently been put into practical use as a herbicide for paddy fields,
, 3-dimethyl-5-phenacyloxypyrazole (hereinafter abbreviated as pyrazoxifene) is usually used as a practical dosage for herbicides in the early to middle stages of rice cultivation, usually 180 to 300 g per 10 ares.
The concentration in field water at a depth of 5 cm was 3.6.
~6 ppm (practical drug amount), and the solubility in water (2
5° C.) is 0.9 ppm, so it does not fall under the herbicidal component defined in the present invention. This means that the herbicidal component A-2
Since the content of A-2 is lower than that of pyrazoxifene, it is not only easy to formulate into the tablets or capsules of the present invention, but also when the formulation is applied to paddy fields, A-2 has high solubility and dissolves quickly in the paddy water. In contrast, pyrazoxifene does not dissolve very well and is difficult to disperse, so it settles to the bottom of the water in a solid state.

Specific examples of the sulfonylurea herbicidal ingredients include N-[(4,6-dimethoxypyrimidin-2-yl)aminocarbonyl]-3-methyl-5-
(2-chloro-2,2-difluoroethoxy-4-isothiazolesulfonamide (hereinafter abbreviated as A-1), 2-
[[(4,6-dimethoxypyrimidin-2-yl)aminocarbonyl]aminosulfonylmethyl]benzoic acid methyl ester (A-2), N-[(4,6-dimethoxypyrimidin-2-yl)]aminocarbonyl] -4-Ethoxycarbonyl-1-methyl-5-pyrazolesulfonamide (hereinafter abbreviated as A-3), N-(2-chloroimidazo[1,2-a]pyridin-3-ylsulfonyl)-N
'-(4,6-dimethoxy-2-pyrimidinyl)urea (hereinafter abbreviated as A-4) and 3-(4,6-dimethoxy-2-pyrimidinyl)
1,3,5-triazin-2-yl)-1-[2-(2
-methoxyethoxy)-phenylsulfonyl]urea (
(hereinafter abbreviated as A-5).

Other liquid herbicidal ingredients include S-benzyl-N-(1,2-dimethylpropyl)-N-ethylthiocarbamate (hereinafter abbreviated as B-1), S-1-methyl-1-phenylethyl- Piperidine-1-carbothioate (hereinafter referred to as B-2), S-(4-chlorobenzyl) N,N-diethylthiol carbamate (hereinafter referred to as B-3),
thiocarbamates such as 2, chloro-2'
, 6'-diethyl-N-(2-propoxyethyl)acetanilide (hereinafter abbreviated as B-4).

[0013] The surfactant in the present invention includes a herbicidal component,
It imparts hydrophilicity to binders, oil-absorbing base materials, etc.
For example, fatty acid salts such as mixed fatty acid soda soap and castor oil potassium soap; alkyl sulfate ester salts such as sodium lauryl sulfate, sodium higher alcohol sulfate, triethanolamine lauryl sulfate, and ammonium lauryl sulfate; such as sodium dodecylbenzenesulfonate. alkylbenzene sulfonates such as sodium alkylnaphthalene sulfonates; alkyl sulfosuccinates such as sodium dioctyl sulfosuccinate; alkyl diphenyl ether disulfonates such as sodium alkyl diphenyl ether disulfonates; potassium alkyl phosphates. Alkyl phosphate ester salts such as; polyoxyethylene alkyl ether sulfate salts such as sodium polyoxyethylene lauryl ether sulfate, sodium polyoxyethylene alkyl ether sulfate, triethanolamine polyoxyethylene alkyl ether sulfate;
Polyoxyethylene alkylaryl ether sulfate ester salts such as polyoxyethylene alkylphenyl ether sodium sulfate; naphthalene sulfonic acid formalin condensation such as β-naphthalene sulfonic acid sodium salt formalin condensate, special aromatic sulfonic acid sodium salt formalin condensate salts of compounds; polycarboxylic acid salts such as sodium polycarboxylate; polystyrene sulfonates;
Polyoxyethylene alkyl ether phosphate; anionic surfactant such as lignin sulfonate: polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether,
Polyoxyethylene alkyl ether such as polyoxyethylene higher alcohol ether; polyoxyethylene alkylaryl ether such as polyoxyethylene octylphenyl ether, polyoxyethylene nonylphenyl ether; polyoxyethylene such as polyoxyethylene styryl phenyl ether Styryl aryl ether; oxyethylene/oxypropylene block polymers such as polyoxyethylene/polyoxypropylene block polymers; sorbitan monolaurate, sorbitan monopalmylate, sorbitan monostearate, sorbitan tristearate, sorbitan monooleate, sorbitan Sorbitan fatty acid esters such as trioleate, sorbitan sesquioleate, sorbitan distearate; polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan tristearate, polyoxyethylene sorbitan monooleate Polyoxyethylene sorbitan fatty acid esters such as; glycerol fatty acid esters such as glycerol monostearate, glycerol monooleate; polyoxyethylene hydrogenated castor oil; polyoxyethylene glycerol stearate, polyoxyethylene glycerol oleate, etc. polyoxyethylene glycerin fatty acid ester; acetylene glycol such as 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,6-dimethyl-4-octyne-3,6-diol; Examples include nonionic surfactants such as alcohol. One or two of these surfactants are used.
It may be used as a mixture of more than one species, or as a mixture of anionic and nonionic species.

The blowing agent in the present invention is a combination of acidic and alkaline substances that react in the presence of water to generate gas. Acidic substances include those that themselves are acidic or those that dissolve in water and exhibit acidity, such as citric acid, tartaric acid, oxalic acid, succinic acid, maleic acid, phthalic acid, malic acid, and adipic acid. organic acids; hydrogen salts such as sodium dihydrogen phosphate, potassium dihydrogen phosphate, ammonium dihydrogen phosphate, potassium hydrogen sulfate; alums such as potassium alum and ammonium alum; examples of alkaline substances include: Examples include carbonates such as sodium carbonate, potassium carbonate, calcium carbonate, magnesium carbonate, and ammonium carbonate; bicarbonates such as sodium bicarbonate and potassium bicarbonate; and percarbonates such as sodium percarbonate.

[0015] The binder used in the present invention binds the constituent particles, and may preferably be any water-soluble binder, such as carboxymethyl cellulose, its salts, dextrin, polyethylene glycol, etc. , polyvinyl alcohol, polyalkylene glycol, polyvinyl pyrrolidone, lignin sulfonate, gum arabic, starch paste, other starches, and sucrose. Moreover, as a binder in the present invention,
Even if the binder itself is not a common binder, any binder that serves to bind the constituent particles can be used as appropriate. Examples of substances that can be used in this manner include acidic substances such as stearic acid, succinic acid, adipic acid, phosphoric acid and their salts; alkaline substances such as sodium carbonate and sodium bicarbonate.

The oil-absorbing base material used in the present invention can be impregnated with other liquid herbicidal ingredients, and has an oil absorption of 50 wt%.
Any of the above substances may be used as long as it does not adversely affect the resulting tablets or capsules, such as fine granular amorphous silicon dioxide (trade names: Carplex, Thyroid, Nipsil, Toxil, Aerosil, etc.). ), starch hydrolyzate (product name: Pine Flow, Pine Index, etc.), kaolin (product name: Satenton No. 5)
etc.), clay (product name: NN kaolin clay, etc.), talc (product name: LM-P, LM-R, High Filler, etc.),
Diatomaceous earth (product name: Radiolite F, Radiolite SPF
, CELITE SSC, CELITE FIOSS, CERATOM MW
-23, Ceratom MW-25), artificial composites of diatomaceous earth and lime (product name: Microcell, etc.), asbestos (product name: 7TS)
-3, 7TF-88, 7W, etc.), World Cerabone, mixtures of kaolinite and sericite (product name: Sieglite MC, etc.), calcium silicate (product name: Trohero, etc.), light calcium carbonate (product name: :Toyostar TF
– Anhydrous aluminum oxide (product name:
aluminum oxide C, etc.), ultrafine titanium oxide (product name: titanium dioxide P25, etc.), basic magnesium carbonate, magnesium aluminate silicate (product name: Neusilin, etc.), silica/alumina synthetic filler (product name: Zeofir) etc.), hydrated magnesium silicate (trade name: Miraclay, etc.), and the like. In addition,
The oil absorption amount referred to here is measured using jISK5101.

In addition, in the tablet or capsule formulation of the present invention, if there is a possibility that the sulfonylurea compound, which is one of the herbicidal ingredients, may decompose, conventional methods of inhibiting decomposition, such as petroleum-based paraffin wax,
Method using wax such as wood wax, beeswax, carnauba wax;
Methods using vegetable oils such as olive oil, linseed oil, cottonseed oil, soybean oil, corn oil, or high boiling point solvents; Methods using specific surfactants; Methods using cyclodextrin; Gelatin, gum arabic, pullulan, hydroxypropylcellulose, hydroxyl Propyl methyl cellulose, polyvinyl acetal diethylamino acetate, aminoalkyl methacrylate copolymer, cellulose acetate phthalate, methacrylic acid copolymer, hydroxypropyl methyl cellulose phthalate, hydroxypropyl methyl cellulose acetate succinate, carboxymethyl ethyl cellulose, ethyl cellulose, ethyl acrylate/methyl methacrylate・This can be dealt with by methods such as protection using copolymers, etc.

[0018] The selection of surfactants, foaming agents, binders and oil-absorbing base materials differs depending on the type of herbicidal ingredient and the proportion of the entire formulation, so in practice, suitable ones are selected through trial and error experiments. Must be selected.

The tablet or capsule for weeding rice fields of the present invention is
It consists of the above-mentioned sulfonylurea herbicidal ingredients, other liquid herbicidal ingredients, surfactants, foaming agents, binders, and oil-absorbing base materials, and although their blending ratio cannot be unconditionally specified, it is common to use all herbicidal ingredients (sulfonylurea and other liquid herbicidal ingredients). Other liquid herbicidal ingredients) 0.01 part by weight of the above surfactant
~100 parts by weight, preferably 0.05 to 20 parts by weight, more preferably 0.1 to 1 part by weight, and 0.15 to 100 parts by weight of a blowing agent.
180 parts by weight, preferably 0.5 to 100 parts by weight, more preferably 1 to 30 parts by weight, and 0.01 to 18 parts by weight of the binder.
0 parts by weight, preferably 0.05 to 20 parts by weight, more preferably 0.1 to 10 parts by weight, and 0.0 parts by weight of the oil-absorbing base material.
15 to 200 parts by weight, preferably 0.5 to 10 parts by weight,
More preferably, it is contained in a proportion of 0.8 to 5 parts by weight, and it goes without saying that substances outside these ranges are also included in the present invention as long as they exhibit the desired effect.

[0020] The oil-absorbing base material has a content of 0.00 parts by weight based on 1 part by weight of the total liquid components contained in the tablets or capsules of the present invention.
It can also be contained in a ratio of 15 to 2 parts by weight.

[0021] When impregnating the oil-absorbing base material with other liquid herbicidal ingredients, if necessary, the liquid herbicidal ingredient may be mixed with a surfactant in order to emulsify and disperse the liquid herbicidal ingredient and impart hydrophilicity to the oil-absorbing base material. The ratio is 0.01 to 1 part by weight per 1 part by weight of the liquid herbicidal component,
The amount is preferably 0.05 to 0.5 parts by weight, more preferably 0.05 to 0.3 parts by weight. The surfactant used here emulsifies and disperses the liquid herbicidal component and imparts hydrophilicity to the oil-absorbing base material, and specifically includes polyoxyethylene styryl phenyl ether and polyoxyethylene alkylaryl ether. , polyoxyethylene alkyl ether, polyoxyethylene hydrogenated castor oil, polyoxyethylene/polyoxypropylene block polymer, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, and other nonionic surfactants; alkylbenzene sulfonate, alkyl sulfosuccinate Examples include anionic surfactants such as acid salts and alkyl phosphate ester salts. These surfactants may be used alone or as a mixture of two or more thereof, or may be used as a mixture of nonionic and anionic surfactants.

The tablets or capsules of the present invention may contain solid carriers and other agrochemical auxiliaries in addition to the above-mentioned ingredients. In addition, herbicidal ingredients, fungicidal ingredients, insecticidal ingredients other than the above-mentioned sulfonylurea herbicidal ingredients and other liquid herbicidal ingredients of the present invention, as long as the water solubility and dispersibility of the herbicidal ingredients defined in the present invention are not significantly impaired, growth regulating ingredients,
Fertilizer components and the like can also be included as appropriate. Examples of solid carriers include fine mineral powders such as kaolin, talc, clay, and bentonite; inorganic salts such as anhydrous sodium sulfate; and organic substances such as urea; other agricultural aids include commonly used solvents. , decomposition inhibitors, phytotoxicity reducers, dispersion stabilizers, disintegrants, desiccants, and the like. The amount of solid carrier to be used cannot be categorically defined, but in general, the proportion of the solid carrier in the entire tablet or capsule is 0.1 to 5.
0 parts by weight as well as 0.1 to 20 parts by weight of other agrochemical auxiliaries.

[0023] In addition, the herbicidal ingredients other than the above-mentioned herbicidal ingredients specified in the present invention, which may be contained as appropriate, include S
,S-dimethyl-2-difluoromethyl-4-(2-methylpropyl)-6-(trifluoromethyl)-3.5
- Pyridines such as pyridine carbothioate (hereinafter abbreviated as C-1); 2-methylthio-4,6-bis(ethylamino)-S-triazine (hereinafter abbreviated as C-2), 2-
Triazines such as methylthio-4-ethylamino-6-(1,2-dimethylpropylamino) and -s-triazine (hereinafter abbreviated as C-3); 2-benzothiazole-2
-yloxy-N-methylacetanilide (hereinafter C-4
Among them, those that are solid at room temperature are desirable. Similarly, the blending ratio cannot be defined unconditionally, but 0.
The amount is 0.01 to 5 parts by weight, preferably 0.01 to 3 parts by weight, and more preferably 0.02 to 2 parts by weight. In this case, except for special cases such as using a large amount of the above-mentioned herbicidal ingredients, in the tablets or capsules of the present invention, the above-mentioned surfactant, foaming agent, binder, and oil-absorbing base should be added to all the herbicidal ingredients. The blending ratio may be within the same range as mentioned above, and of course, even those outside the above range are included in the present invention as long as they exhibit the desired effect.

[0024] The tablets or capsules of the present invention are usually easily manufactured by the following method or a method analogous thereto. In general, the sulfonylurea herbicidal component is used as fine particles with a particle size of 1 to 200 μm, preferably 1 to 100 μm, by crushing in advance to improve solubility and dispersibility in water, and the other liquid herbicidal components are is used by impregnating the oil-absorbing base material together with a surfactant, if necessary. The tablets can be manufactured by, for example, simultaneously mixing the herbicidal component, surfactant, foaming agent, and binder that have been treated as described above, or by mixing the remaining components with any pre-mixed component. A method of uniformly mixing the mixture, pulverizing it to a particle size of 1 to 200μ, and compressing it using a tablet machine in a conventional manner to form a tablet. Examples include a method of crushing or crushing and mixing to form tablets.

[0025] The tableting pressure of the tableting machine varies depending on the ingredients in the formulation, the blending ratio, and the type and performance of the tableting machine, so in reality, the appropriate pressure must be selected through trial and error experiments. I have to do it. When using a solid carrier and/or other agrochemical auxiliary, it is mixed uniformly with the herbicidal component and surfactant treated in advance as described above and ground to form a wettable powder, and then a foaming agent is added. and a method of mixing with a binder,
Examples include a method in which the herbicidal component, surfactant, foaming agent, and binder treated as described above are mixed at the same time, or in advance mixed with an arbitrary component and further mixed with the remaining components. Of course, the above-mentioned method for manufacturing tablets may be modified as appropriate in consideration of medicinal efficacy, formulation properties, etc., and an appropriate method may be implemented. Tablets are manufactured in various shapes and sizes, such as circular plates, oval plates, square plates, and rods, depending on the manufacturing method, tablet press, etc. Since the shape of the tablet does not greatly affect its medicinal efficacy, it may be of any shape, size, and weight, but tablets with a circular plate shape, a diameter of 1 to 5 cm, and a thickness of 0.5 cm are acceptable. 2-3cm, weight 1
~150g is preferable from the viewpoint of formulation and drug application.

The method for manufacturing the capsules of the present invention includes, for example, uniformly mixing the herbicidal component, surfactant, blowing agent, and binder treated as described above, and adding a solid carrier and/or other agrochemical additives if necessary. The pulverized product is granulated to a particle size of 0.25 to 1.5 mm, and the granules are filled into capsules made of water-soluble cellulose, water-soluble starch, gelatin, etc. Alternatively, the pulverized product and the wettable powder are directly filled into capsules without granulation, and furthermore, the method for producing the tablets by granulating one herbicidal ingredient as described above and the other herbicidal ingredient. An example of this method is to form tablets according to the method described above, then crush the tablets and fill them into capsules in the same manner. These capsules may have the same shape as tablets, and may also be spherical, ellipsoidal, or have any size and weight;
It is preferable to have a length of 1 to 10 cm and a weight of 1 to 150 g. In addition to the capsules prepared as described above, the capsules of the present invention may be prepared by using a water-soluble film containing water-soluble cellulose, water-soluble starch, polyvinyl alcohol, gelatin, etc., without filling the pulverized product or hydrating agent into a capsule container. Including those wrapped in

When the tablets or capsules of the present invention are applied to flooded rice fields, they generate gas upon contact with water, and the herbicidal ingredients are rapidly eluted into the rice fields, and the surfactant also acts to kill weeds. The ingredients diffuse into the water and are evenly distributed. Thus, when the tablets or capsules of the present invention are administered to paddy fields, substantially the entire amount of the herbicidal component can be dissolved and dispersed in the paddy water, and for example, after several hours to 20-odd hours, the herbicidal component can be uniformly distributed in the paddy water. As a result, weeds can be uniformly controlled without applying chemicals to paddy rice.

[0028] When weeding rice fields using the tablets or capsules of the present invention, they are applied in an amount of 10 to 200 weeds per 10 ares and the total weight of the tablets or capsules is 200 to 1500 g. Then, the medicinal effect,
It is undesirable due to chemical damage or requires a lot of effort to spray. The preferred method of application cannot be determined unconditionally due to differences in the manufacturing method of tablets or capsules, size, herbicidal ingredients, surfactants, blowing agents, binders, oil-absorbing base materials, and other additive types and blending ratios. However, 5 to 350 g of herbicidal ingredients per 10 ares is 0.0 g per tablet or capsule.
Divide into 5-35g portions and apply 10-100 pieces. In this way, tablets or capsules only need to be applied once per 10 to 100 m2, and can be thrown into the paddy field from the ridge without entering the paddy field, making the dispersion work simple and effective compared to conventional chemical application methods. It is advantageous to do so.

When weeding rice fields using the tablets or capsules of the present invention, in general, in the case of transplanted paddy rice, young seedlings are transplanted.
The most favorable effect can be obtained when applied in the early to mid-stage of rice cultivation, 10 to 20 days after sowing in the case of directly sown paddy rice, but even if the tablets or capsules are applied, there is no particular problem in terms of medicinal efficacy or drug damage. It can also be applied at other times unless otherwise specified. Further, even if the tablets or capsules of the present invention are once dissolved or dispersed in an appropriate amount of water and applied locally to paddy fields, desirable effects in terms of medicinal efficacy and phytotoxicity can be obtained.

[0030]

EXAMPLES Examples relating to the present invention will be described, but the present invention is not limited by these descriptions. In the following examples, "parts" are expressed on a weight basis.

(Preparation of foamable formulation) Preparation example: 42.4 parts of succinic acid, 5.2 parts of sodium carboxymethylcellulose (trade name: Celogen PR, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), 31.4 parts of sodium bicarbonate. 1 part and 21.0 parts of sodium carbonate were uniformly mixed and pulverized using a microsample mill (AP-S type, manufactured by Hosokawa Kogyo Co., Ltd.) to obtain a foamable compound.

(Preparation of Tablets or Capsules) Formulation Example 1 21.2 parts of herbicidal ingredient B-1 and a mixture of polyoxyethylene alkylphenyl ether and alkylbenzene sulfonic acid calcium salt (trade name: Agrisol P-
350, manufactured by Kao Corporation), and 5.4 parts of starch hydrolyzate (
It was impregnated with a mixture of 20.0 parts (trade name: Pine Flow, manufactured by Matsutani Chemical Co., Ltd.) and 13.3 parts of fine granular amorphous silicon dioxide (trade name: Carplex #80, manufactured by Shionogi & Co., Ltd.). and the foamable mixture 40.1
A mixture (a) was obtained. Herbicidal ingredient A-3
10 parts of sorbitan monostearate (trade name: Sorgen 50, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) and 80 parts of the above foaming compound were mixed, and 1 g of the obtained compound was ground in a mortar. Compression molded using a tablet machine (pressure: 4t),
Tablets with a diameter of 2 cm and a thickness of 0.2 cm were obtained. Thereafter, this tablet was crushed and sized to obtain a formulation (a) having a particle size of 297 to 3360 μm. 4.6 g of the above formulation (a) and 0.1 g of formulation (a) were mixed and compression molded using a tablet machine (pressure: 4 t) to obtain a tablet A with a diameter of 2 cm and a thickness of 0.8 cm. Ta.

Formulation Example 2 24.8 parts of herbicidal component B-1 and a mixture of polyoxyethylene alkyl ether, polyoxyethylene/polyoxypropylene block polymer and alkylaryl sulfonate (trade name: Solpol 7660, manufactured by Toho Chemical Co., Ltd.) ) 6.2 parts to Pine Flow (same as above) 31.
The solid material obtained by impregnating 3 parts and the foamable formulation 3
7.5 parts were mixed to obtain a blend (b). Herbicidal ingredient A
-3 5 parts, Sorgen 50 (same as above) 5 parts, and 90 parts of the above foamable formulation were mixed to obtain a formulation (b). Capsules B were obtained by wrapping 4.6 g of the blend (b) and 0.2 g of the blend (b) in a water-soluble film (trade name: Hi-Selon C-200, manufactured by Nihon Gosei Film Co., Ltd.).

Formulation Example 3 21.2 parts of herbicidal ingredient B-1 and Agrisol P-3
50 (same as before) 5.4 parts to Pine Flow (same as before) 20.0
13.3 parts of bentonite (trade name: Hodaka-in, manufactured by Hojun Kogyo) and 40.1 parts of the above foamable compound were mixed to obtain a compound. An appropriate amount of methanol was added to this mixture, and the mixture was thoroughly kneaded, extruded through a screen having a diameter of 0.6 mm, granulated, dried, and sized to obtain granules (c). 4.6 g of the granules (c) and 0.1 g of the formulation (a) obtained in Formulation Example 1 were added to HiSelon C-200.
(same as above) to obtain capsules C.

Formulation Example 4 21.5 parts of herbicidal ingredient B-1 and Agrisol P-3
50 (same as before) 5.4 parts to Pine Flow (same as before) 26.9
The solid material obtained by impregnating the part and the foamable compound 46
．． 2 parts were mixed to obtain a blend (d). Herbicidal ingredient A-
3, 10 parts of Sorgen 50 (same as above), and 80 parts of the above foamable formulation were mixed to obtain a formulation (C). Tablets D are obtained using the formulation (d) and formulation (C) in the same manner as in Formulation Example 1.

Formulation Example 5 In Formulation Example 4, Agrisol P-350 (same as above) was replaced with a mixture of polyoxyethylene styrylphenyl ether and alkylaryl sulfonate (trade name: Solpol 355, manufactured by Toho Chemical Co., Ltd.). A mixture (E) is obtained by using the same procedure as above, and a tablet E is obtained in the same manner as above.

Formulation Example 6 In Formulation Example 4, Agrisol P-350 (same as above) was mixed with a mixture of polyoxyethylene styrylphenyl ether and a special anion (trade name Solpol 3548,
Tablets F were obtained in the same manner except that Blend (f) was used instead of (manufactured by Toho Chemical Co., Ltd.).

Formulation Example 7 4.7 parts of herbicidal ingredient B-4 and Agrisol P-35
A solid product obtained by impregnating 1.2 parts of 0 (same as before) with 11.8 parts of Pineflow (same as before) and the foamable compound 82.
3 parts to obtain a blend (g). 3.9 g of the above formulation (g) and 0 of the formulation (a) obtained in Formulation Example 1
．． 1 g are mixed and compression molded using a tablet press (pressure: 4 t) to obtain tablets G with a diameter of 2 cm and a thickness of 0.8 cm.

Formulation Example 8 22.8 parts of herbicidal ingredient B-3 and Agrisol P-3
50 (same as before) 5.7 parts to Pine Flow (same as before) 28.5
A solid obtained by impregnating a mixture of 5.0 parts of Carplex #80 (same as above) with 38.0 parts of the above foamable formulation.
0 parts to obtain a blend (H). Herbicidal ingredient A-2
1 g of a mixture obtained by grinding 10 parts of Solgene 50 (same as above) and 80 parts of the foamable formulation in a mortar.
Compression molded using a tablet machine (pressure: 4t) to a diameter of 2c.
m, 0.2 cm thick tablets are obtained. Thereafter, this tablet was crushed and sized to form a mixture (d) with a particle size of 297 to 3360μ.
get. 3.8 g of the above formulation (h) and 0 of the formulation (d)
．． 2 g were mixed and compressed using a tablet machine (pressure: 4 t) to obtain tablets H with a diameter of 2 cm and a thickness of 0.8 cm.

Formulation Example 9 21.2 parts of herbicidal ingredient B-1 and Agrisol P-3
50 (same as before) 5.4 parts to Pine Flow (same as before) 26.6
The solid material obtained by impregnating the part and the foamable compound 20
．． 26. Polyethylene glycol (trade name: PEG4000S, manufactured by Sanyo Chemical), which was heated and dissolved after mixing with 2 parts.
6 parts were further mixed and solidified by cooling to obtain a blend (li). 4.6 g of the formulation (li) and 0.1 g of the formulation (a) obtained in Formulation Example 1 were mixed and compression molded to give a diameter of 2 cm.
Tablets I with a thickness of 1.6 cm and a thickness of 1.6 cm were obtained.

Formulation Example 10 22.9 parts of herbicidal component B-1 and Agrisol P-3
50 (same as before) 5.7 copies to Carplex (same as before) 14.
Solid material obtained by impregnating a mixture of 3 parts of Celogen PR (same as above) and 14.3 parts of Pine Flow (same as before), 5.4 parts of Celogen PR (same as before)
1 part and 37.4 parts of the above foamable formulation are mixed to obtain a formulation (nu). Herbicidal ingredient A-3 2.6 parts, C-3
7.4 parts of Solgen 50 (same as above) and 80 parts of the above foamable compound were mixed and ground in a mortar, and 1 g of the obtained compound was compression molded using a tablet machine (pressure: 4 tons). ,
Tablets with a diameter of 2 cm and a thickness of 0.2 cm are obtained. Thereafter, the tablets are crushed and sized to obtain a formulation (e) with a particle size of 297 to 3360μ. Mix 3.67 g of the above blend (nu) and 0.33 g of blend (e) and compression mold using a tablet machine (pressure: 4 t) to obtain tablets J with a diameter of 2 cm and a thickness of 0.8 cm. .

Formulation Example 11 24.4 parts of herbicidal ingredient B-1 and Agrisol P-3
50 (same as before) 6.1 part to Carplex (same as before) 15.
Solid material obtained by impregnating a mixture of 3 parts of Celogen PR (same as above) and 15.4 parts of Pine Flow (same as above), 5.8 parts of Celogen PR (same as above)
and 33.0 parts of the above foamable formulation to obtain a formulation (ru). Herbicidal ingredient A-3 1.5 parts, C-1 8
．． 5 parts of Sorgen 50 (same as above) and 80 parts of the above foamable compound were mixed and ground in a mortar. 1 g of the mixture was compression molded using a tablet machine (pressure: 4 tons), and the diameter A tablet of 2 cm and a thickness of 0.2 cm is obtained. Thereafter, the tablets were crushed and sized to form a compound with a particle size of 297 to 3360μ (
obtain f). 3.44 g of the above formulation (L) and the formulation (
f) 0.56 g were mixed and compressed using a tablet machine (pressure: 4 tons) to obtain tablets K with a diameter of 2 cm and a thickness of 0.8 cm.

Test Example 1 A test plot with a wooden frame (see Figure 1 below) with a length of 6.25 m, a width of 0.75 m, and a height of 20 cm was set up in a greenhouse, and paddy soil was spread uniformly on the bottom of the test plot, and after watering and puddling. Seeds of Japanese millet and firefly were sown at a water depth of 5 cm. Tainubier 1-1
．． When the firefly reached the two-leaf stage and the one-leaf stage, one capsule B prepared in Formulation Example 2 was dropped at point T in FIG. On the other hand, granules corresponding to the capsules were prepared according to a conventional method and uniformly dispersed. The application amount of the chemical is herbicidal ingredient A.
-3 is 0.21 g/a, and B-1 is 21 g/a. On the 17th day after the chemical treatment, the growth status of the weeds was observed with the naked eye, and the degree of growth inhibition was expressed using the following criteria, and the results shown in Table 1 were obtained.

[0044]

[Table 1]

[0045] As can be seen from the results of this test, the herbicidal effect equivalent to that obtained by uniformly dispersing the granules was obtained by mere dropping treatment.

Test Example 2 The same test plot as in Test Example 1 was prepared, paddy soil was evenly spread on the bottom of the plot, and after watering and puddling, seeds of Japanese millet and firefly were sown to a water depth of 4 cm. Tainubier is 1.8
Leaf stage, when the firefly reaches the 1-1.5 leaf stage, T in Figure 1
One tablet prepared in the above formulation example was dropped at the point. The amount of the drug applied was the same as in Test Example 2 above. On the 12th day after the chemical treatment, the degree of growth inhibition was determined in the same manner as in Test Example 1, and the results shown in Table 2 were obtained.

[0047]

[Table 2]

As can be seen from the results of this test, the same excellent herbicidal effect as in Test Example 1 can be obtained by simply dropping the tablets.

Test Example 3 A plastic container measuring 37 cm long, 29 cm wide and 10 cm high was filled with paddy soil to the bottom 4 cm, water was added and mixed, and seeds of Japanese millet and firefly were sown. Approximately 3c
Grow in a greenhouse while maintaining a water-logged condition of 1.5 m.
~1.2 leaf stage, when the firefly reached the 1 leaf stage, the mixture of the formulation prepared in the above formulation example was gently dropped into the center of the plastic container. The application amount of the chemical is herbicidal ingredient A-3.
is 0.21 g/a, and B-1 is 21 g/a. On the 21st and 32nd days after the chemical treatment, the degree of growth inhibition was determined in the same manner as in Test Example 1, and the results shown in Table 3 were obtained.

[0050]

[Table 3]

*Compounds (b), (d), (e) and (f) are 0.1g, and compounds (b) and (c) are 0.00g.
22g each was used. As can be seen from the results of this test,
A high overall effect was obtained with just a simple injection. In addition,
In this test example, each compound was put into water as is, but from the results in Tables 1 to 3 above, it is also possible to formulate each compound into a tablet or capsule and then put it into water. A similar effect can be obtained.

[Brief explanation of the drawing]

FIG. 1 shows a wooden frame with a length of 6.25 m, a width of 0.75 m, and a height of 20 cm, and point T indicates the point at which a capsule is inserted.

Claims (2)

[Claims] Claim 1: The entire amount of the drug applied to the rice fields contains a sulfonylurea herbicidal ingredient that is substantially soluble in the rice water, other liquid herbicidal ingredients, a surfactant, a foaming agent, a binder, and an oil-absorbing base material. A tablet or capsule for weeding rice fields, characterized by: 2. The tablets or capsules for weeding rice fields according to claim 1 are applied to flooded rice fields at a rate of 10 to 200 tablets or capsules per 10 ares, and the total weight of the tablets or capsules is 200 to 1,500 g. , a rice field weeding method characterized by dissolving and dispersing substantially the entire amount of herbicidal ingredients in rice field water.