JPH03223203A - Tablet or capsule for controlling weed in paddy field - Google Patents

Abstract

PURPOSE:To control weeds in a paddy field by preparing a weed-controlling tablet or capsule containing a sulfonylurea herbicidal component, a surfactant, a foaming agent and a binder in amounts to enable the dissolution of whole components in the water of a paddy field and simply throwing the tablet or capsule into a paddy field. CONSTITUTION:The subject substance can be prepared by uniformly mixing 1 pt.wt. of a sulfonylurea herbicidal component, 1-5 pts.wt. of a surfactant (e.g. polyoxyethylene nonylphenyl ether), 5-25 pts.wt. of a foaming agent (e.g. sodium bicarbonate) and 0.4-1.5 pts.wt. of a binder (e.g. carboxymethyl cellulose), crushing the mixture to particle diameter of 1-200mum and tableting the powder or by uniformly mixing and crushing the above components, granulating to particle diameter of 1mum to 1.5mm and filling the granules in a capsule made of gelatin, etc. The herbicide component is selected to get a concentration smaller than the solubility in water (at 25 deg.C) when the whole amount of the practical dose is dissolved in water of the paddy field. It can be applied without using a particular applicator.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" 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 for chemical treatment.

``Prior art'' Conventionally, methods for weeding rice fields, especially during the early to mid-stage of rice cultivation, include methods of spraying fine granules containing herbicidal ingredients in a finely powdered solid carrier and other adjuvants, spraying the granules as they are, and spraying the granules as they are. One method is to dilute the powder in a large amount of water and then spray it, but other methods that do not use a powdered solid carrier include spraying an emulsion of the herbicidal ingredient dissolved in an organic solvent as it is, and finely pulverized weed control. One method is to directly spray a flowable agent in which the ingredients are dispersed/suspended in water.

[Problem to be solved by invention] However, when applying fine particles, granules, and wettable powders,
While carrying a heavy sprayer or granulator containing a chemical,
For example, the usual method is to walk around the rice fields to spray 3 to 4 kg of granules per 100 acres, but it is also necessary to spread the chemicals evenly and evenly by using a large Niagara hose from the ridges. No. Therefore, transporting and spraying the chemicals is extremely labor-intensive and often damages the paddy rice seedlings, which is undesirable for their growth.

Even when applying emulsions and flowables, the weight of the drug is reduced to a certain degree and a large-sized sprayer is not required, but it is necessary to use a container that dispenses a fixed amount of drug, and it is difficult to distribute the drug evenly. I still need to walk around the rice fields.

[Means for Solving the Problems J] The present invention solves the above-mentioned drawbacks of the conventional methods, and makes it possible to weed rice fields by a simple method without using a special chemical sprayer. That is, the present invention relates to a tablet or capsule for weeding rice fields containing a sulfonylurea herbicidal component, a surfactant, a foaming agent, and a binder that dissolve substantially all of the amount of the drug applied to rice fields, and further, The present invention relates to tablets or capsules for weeding rice fields containing the entire amount of the drug applied to rice fields or the addition of other herbicidal ingredients that are substantially soluble in rice water. The present invention also provides the tablet or capsule with 1O
It relates to a method for weeding rice fields, in which the tablets or capsules are applied to flooded rice fields at a rate of 10 to 200 tablets or capsules per are, and the total weight of the tablets or capsules is 200 to 1500 g, and substantially the entire amount of herbicidal ingredients is dissolved and dispersed in the rice water. .

In the present invention, the sulfonylurea herbicidal ingredients or other herbicidal ingredients defined as ``the entire amount applied to paddy fields or substantially dissolved in the rice water'' are defined as sulfonylurea herbicidal ingredients or other herbicidal ingredients that do not substantially cause phytotoxicity to paddy rice seedlings or have a herbicidal effect. If we apply a sufficient amount of herbicidal ingredient, that is, a practical amount, to a rice field, and assume that the entire amount is dissolved in the rice water, the concentration of the herbicidal ingredient in the rice field water or the solubility of the herbicidal ingredient in water (25°C ) means a herbicidal ingredient which is the following, for example methyl-2-(4,6-cymethoxypyrimidin-2-ylcarbamoylsulfamoyl)o-
Toluylate (hereinafter abbreviated as A-2) is used as a practical herbicide in the early to mid-stage of paddy rice cultivation, usually in an amount of 5 to 7.
Assuming that 5g is applied and the water depth is 5cm, the concentration in field water will be O, 1 to 0.15ppm (practical dosage), and the solubility in water (25'C) is 8ppm. This corresponds to the sulfonylurea herbicidal ingredients defined in the 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 biradixifene) is usually used in a practical dose of 180 to 300 g per 10 ares as a herbicide in the early to middle stages of rice cultivation.
The concentration in field water at a depth of 5 cm was 3.6.
~6 ppm (practical dosage), and its solubility in water (
25°C) is 0.9 ppm, so it does not fall under the other herbicidal ingredients defined in the present invention. This means that it is not easy to formulate the herbicidal ingredient A-2 into the tablets or capsules of the present invention because its content is lower than that of biradixifene, and even when the formulation is applied to paddy fields, A-2 is Because of its high solubility, it quickly dissolves in rice water and is dispersed widely and uniformly, whereas biradixifene 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-cymethoxypyrimidin-2-yl)
aminocarbonyl]-3-methyl 5-(2-chloro-2
, 2-difluoroethoxy 4-isothiazolesulfonamide (hereinafter abbreviated as A-1), methyl-α-(4,6-
cymethoxypyrimidin-2-ylcarbamoylsulfamoyl) o-toluylate (A-2), N-((4,
6-Simethoxypyrimidin-2-yl)aminocarbonyl]-4-ethoxycarbonyl-1-methyl-2-pyrazole sulfonamide (hereinafter abbreviated as A-3), N-(2
-chloroimitazo(1,2-a)pyridin-3-ylsulfonyl) -N'-(4,6-simethoxy2-pyrimidinyl)urea (hereinafter abbreviated as A-4) and 3-(4,
6-Simethoxy1.3.5-hRyazin-2-yl)
-1-(2-(2-methoxyethoxy)-phenylsulfonyl)urea (hereinafter abbreviated as A5).

Other herbicidal ingredients include 2-methylthio-4,6-his(ethylamino)-6-1 riazine (hereinafter abbreviated as B-1), 2-methylthio-4-ethylamino-6-(1,2
-dimethylpropylamino) -S trianone (hereinafter B
-2) triazines; 3,7-dichloro-
Quinoline carboxylic acids such as 8-quinoline carboxylic acid (hereinafter abbreviated as B-3), 2-chloro-2', 6'-
Diethyl-N-(2propoxyethyl)acetanilide (hereinafter abbreviated as B4), N-(2°-(3′-methoxy)
-thienylmethyl)-N-chloroaceto-2,6-cystylanilide (hereinafter abbreviated as B-5), 2', 6'-
diethyl-N-((2-cis-butenooxy)methyl)
Anilides such as 2-chloroacetanilide (hereinafter abbreviated as B-6); S,S-dimethyl-2-difluoromethyl-4-(2-methylpropyl)-6(trifluoromethyl)-3,5-pyridine di Power sulfothioate (hereinafter referred to as B-
(abbreviated as 7), solubility in water, paddy rice,
Considering the effects on weeds, triazines and quinolinecarphonic acids are preferable.

The surfactant in the present invention is one that imparts hydrophilicity to herbicidal ingredients, binders, etc., such as sodium dodecylhensensulfonate, dialkyl sulfosuccinate,
Sodium dialkyl sulfosuccinate, sodium lauryl sulfate, sodium higher alcohol sulfate, sodium lignin sulfonate, polyoxyethylene alkylaryl ether sulfate, sodium β-naphthalene sulfate formalin condensate dinaphthalene methanesulfonate, alkylaryl sulfonate, alkylaryl sulfone Anionic surfactants such as sodium acid and sodium alkylnaphthalene sulfonate:
Polyoxyethylene nonylphenyl ether, polyoxyethylene oleyl ether, polyoxyethylene oleate, polyoxyethylene alkylaryl ether, polyoxyethylene alkyl ether, polyoxyethylene solhitane monolaurate, polyoxyethylene fatty acid ester, polyoxy Examples include nonionic surfactants such as ethylene styrylphenyl ether, sorbitan monooleate, sorbitan monolaurate, sorbitan monostearate, sorbitan sesquioleate, sorbitan palmitate, acetylene glycol, and diglycerol phorate monostearate. These surfactants may be used alone or as a mixture of two or more thereof, or may be used as a mixture of anionic and nonionic surfactants.

Furthermore, it has been found that the use of a specific surfactant in the tablet or capsule formulation of the present invention inhibits the decomposition of the sulfonylurea compound, which is the main herbicidal component.

This specific surfactant has one or more than several tens of oxyalkylene groups such as oxyethylene group or oxypropylene group in its structure, such as the aforementioned polyoxyethylene alkylaryl ether sulfate. , other than polyoxyethylene nonylphenylethyl. Furthermore, even if the surfactant has an oxyalkylene group, it may be used in combination with other surfactants within the quantitative range as long as it does not promote the decomposition of the sulfonylurea herbicidal component.

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 are those that show acidity themselves or those that show acidity when dissolved in water,
Organic acids such as citric acid, tartaric acid, oxalic acid, succinic acid, maleic acid, phthalic acid, malic acid, adipic acid; sodium dihydrogen phosphate, potassium dihydrogen phosphate, ammonium dihydrogen phosphate, potassium hydrogen sulfate, etc. hydrogen salts; alums such as potassium alum and ammonium alum; examples of alkaline substances include carbonates such as sodium carbonate, potassium carbonate, calcium carbonate, magnesium carbonate, and ammonium carbonate; Examples include bicarbonates such as potassium carbonate; percarbonates such as sodium percarbonate.

The binder used in the present invention binds each component particle, and any binder may be used as long as it is preferably water-soluble, and examples include carboxymethyl cellulose, its salts, dextrin, polyethylene glycol, and polyvinyl alcohol. , polyalkylene glycol, lignin sulfonate, gum arabic, starch paste, etc.
Examples include starches and sucrose. Further, as the binder in the present invention, it is not necessary to use the binder itself or a general binder, but any suitable binder can be used as long as it fulfills the role of binding the constituent particles. Examples of substances that can be used in this way include stearic acid,
Acidic substances such as succinic acid, adipic acid, and phosphoric acid and their salts; alkaline substances such as sodium carbonate and sodium bicarbonate; and the like.

Also, some binders, such as the surfactants mentioned above, inhibit the decomposition of sulfonylurea herbicidal components. Examples of such compounds include compounds other than compounds containing oxyalkylene groups, such as polyethylene glycol, polyvinyl alcohol, and polyalkylene glycol.

However, even the above-mentioned binders may be used within the quantitative range as long as they do not promote the decomposition of the sulfonylurea herbicidal components.

The selection of surfactants, foaming agents, and binders differs depending on the type of herbicidal component and the proportion of the entire formulation, so in practice, suitable ones must be selected through trial-and-error experiments.

The tablet or capsule for weeding rice fields of the present invention comprises the above-mentioned sulfonylurea herbicidal component, surfactant, foaming agent, and binder, and further contains the above-mentioned other herbicidal component added, For example, for 1 part by weight of the sulfonylurea herbicidal component, 1 to 20 parts by weight of the surfactant, preferably 1 to 10 parts by weight, more preferably 1 to 5 parts by weight, and 1 to 800 parts by weight of the blowing agent. , preferably 5 to 100 parts by weight, more preferably 5 to 100 parts by weight
25 parts by weight, and a binder of O, 1 to 20 parts by weight, preferably 0.2 to 10 parts by weight, more preferably 0.4 to 20 parts by weight.
The content is 1.5 parts by weight. In addition, other herbicidal components may be added in an amount of 0.5 to 100 parts by weight per 1 part by weight of the sulfonylurea herbicidal component, and in this case, the blending ratio of the surfactant, foaming agent, and binder to all the herbicidal components The above mentioned range may be the same, and of course, even those outside the above mentioned range are included in the present invention as long as they show initial effects.

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, weeding ingredients other than the herbicidal ingredients of the present invention, fungicidal ingredients, insecticidal ingredients, plant growth regulating ingredients, and fertilizer ingredients may be used as appropriate, as long as the water solubility and dispersibility of the herbicidal ingredients specified in the present invention are not significantly impaired. It can also contain. Examples of solid carriers include fine mineral powders such as kaolin, talc, clay, bentonite, and finely powdered silica; inorganic salts such as anhydrous sodium sulfate; and organic substances such as urea; commonly used as other pesticide aids. Examples include solvents, decomposition inhibitors, phytotoxicity reducers, dispersion stabilizers, disintegrants, desiccants, etc. Although the amounts used cannot be absolutely regulated, generally the solid carrier is 0.1 to 50 parts by weight and the other agricultural chemical auxiliaries are 0.1 to 20 parts by weight relative to the entire tablet or capsule. .

The tablets or capsules of the present invention are usually easily manufactured by the following method or a method analogous thereto.

Generally, when the herbicidal component is solid, it is possible to reduce the particle size by pulverizing it in advance to increase its solubility and dispersibility in water.
It is used as fine particles of ~200μ, preferably 1~1OOμ. As a method for manufacturing tablets, for example, herbicidal ingredients,
Mix all the ingredients uniformly by mixing the surfactant, foaming agent and binder at the same time, or by mixing the remaining ingredients with any pre-mixed ingredients, grind to a particle size of 1~200μ, and grind this. Tablets are formed by compression molding using a tablet machine in accordance with a conventional method. When using a solid carrier or agrochemical auxiliary agent, a method such as mixing it uniformly with a herbicidal component and a surfactant in advance, pulverizing it to form a wettable powder, and then mixing it with a foaming agent and a binder. can be mentioned. Of course, the above-mentioned method for manufacturing tablets may be modified as appropriate in consideration of medicinal efficacy, formulation properties, etc., and any suitable methods may be implemented. Tablets are manufactured in various shapes and sizes, such as circular plates, elliptical plates, square plates, and rods, depending on the manufacturing method and tablet press. Since the shape of the tablet does not greatly affect its medicinal efficacy, it may be of any shape, size, or weight, but tablets with a circular plate shape and a diameter of I to 5.
Thickness of 0.2 to 3 cm and weight of up to 150 g are preferable from the viewpoint of formulation and drug application.

The method for manufacturing the capsules of the present invention includes, for example, uniformly mixing a herbicidal component, a surfactant, a blowing agent, and a binder, and if necessary, adding a solid carrier or an agrochemical auxiliary agent and mixing them uniformly; The pulverized material has a particle size lμ~1.5n+m
The granules are then filled into capsules made of water-soluble cellulose or ceratin, or the pulverized product or wettable powder is directly filled into capsules without granulation. These capsules may have the same shape as tablets, and may also be spherical, oval, or spherical in size and weight. ~150g is preferred. In addition to those formulated as described above, the capsules of the present invention also include those in which the pulverized product or hydrating agent is not filled into a capsule container, but is wrapped as it is in a water-soluble film of water-soluble cellulose or seratin.

When the tablets or capsules of the present invention are applied to flooded paddy fields, they generate gas upon contact with water, and the herbicidal ingredients are quickly eluted into the rice water, and the surfactant also acts to remove the herbicidal ingredients from the water. to disperse evenly. Thus, when the tablets or capsules of the present invention are administered to rice fields, substantially the entire amount of the herbicidal ingredient can be dissolved and dispersed in the rice field water, and for example, after several hours to 202 hours, the herbicidal ingredient is evenly distributed in the rice field water. This makes it possible to uniformly control weeds without causing chemical damage to paddy rice.

When weeding rice fields using the tablets or capsules of the present invention, the dosage is 10 to 200 per 10 ares and the total weight of the tablets or capsules is 200 to 1,500 g; however, if the tablets or capsules greatly deviate from this range, the medicinal effect may be affected. It is undesirable due to chemical damage or requires a lot of effort to spray. The preferred method of application cannot be unconditionally defined due to differences in the manufacturing method of tablets or capsules, their size, types of herbicidal ingredients, surfactants, blowing agents, binders, and other additives, and their blending ratios, but 10 Divide 5 to 150 g of herbicidal ingredient per area into 0.05 to 15 g of tablets or capsules, and apply 10 to 100 tablets or capsules. In this way, tablets or capsules only need to be applied once every 10 to 100 m, and therefore, they can be thrown into the paddy fields of the relevant area from the ridges into which they enter the paddy fields.
The spraying operation is simple and has advantages over conventional chemical application methods.

When weeding rice fields using the tablets or capsules of the present invention, in general, in the case of transplanted paddy rice, 5 to 15 days after transplanting young seedlings,
In the case of direct-seeded paddy rice, the most favorable effect can be obtained when applied during the early to mid-stage of paddy rice cultivation, 10 to 20 days after sowing. It can also be applied at different times. 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.

Examples related 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.

"Example" (Preparation of foamable formulation) Preparation example 1 42.4 parts of succinic acid, sodium carboxymethyl cellulose (trade name: Celogen PR1 manufactured by Dai-Kogyo Seiyaku Aji) 5
．． 2 parts, 31.4 parts of bicarbonate of soda, and 21 parts of carbonate sorter.
Mix 0 parts uniformly and use a micro sample mill (AP-3
The mixture was pulverized using a mold (manufactured by Saiyo Kogyo ■) to obtain a foamable formulation A.

Preparation Example 2 In Preparation Example 1 above, dyes (trade names: Food Blue No. 1, Brilliant Blue FCF,
(manufactured by Tokyo Kasei) was mixed uniformly, and the above Preparation Example 1 was prepared.
A foamable formulation B was obtained in the same manner as in Example 1.

(Preparation of Tablets A-P and Comparative Tablets (a) to (A)) Formulation Example 1 Herbicidal ingredient A ground in advance in a mortar to a particle size of approximately 5 to 10μ
I 0.46 parts and other herbicidal ingredients B 33.34 parts,
3.8 parts of polyoxyethylene nonylphenyl ether 5096 and a 50% mixture of finely powdered silica (trade name: Deixsol W-92, manufactured by Dai-Kogyo Seiyaku Ami) and 92.4 parts of the foamable compound A were mixed, and It was pulverized using a sample mill (same as above) to obtain a pulverized product. This crushed material 48
．． 2 g using a tablet press at a pressure of 150-160 kg
/cnf and compression molded for 2 minutes to a diameter of 5cm and a thickness of 1.6cm.
cm tablet A (48.0 g) was obtained.

Formulation Example 2 A pigment (Food Blue No. 1,
In the same manner as in Formulation Example 1 above, except that approximately 2% of the total weight of B (38 , 4g) was obtained.

Formulation Example 3 In the same manner as in Formulation Example 1, 10.7 g of the pulverized material was compression-molded using a tablet machine to form tablets C (10.5 g) with a diameter of 2.5 cm and a thickness of 0.8 cm. ) was obtained.

Formulation Example 4 In Formulation Example 1, 11.2 parts of herbicidal component A, 38.8 parts of other herbicidal component B, polyoxyethylene alkylaryl ether sulfate (trade name: Tsurupol 5039, manufactured by Toho Kagaku Kogyo ■)3. 0 parts, sodium naphthalene sulfonate formalin condensate (trade name: Lavelin FAN, manufactured by Daiichi Kogyo Seiyaku ■) 2.0 parts, fine powder silica (trade name: Carplex, manufactured by Shionogi & Co., Ltd.) 6 parts, and kaolinite The above formulation example was prepared using 37.9 parts of a wettable powder consisting of 79.0 parts of a mixed pulverized product of sericite (trade name: Zeekrite, manufactured by Zeeklite) and 62.1 parts of the foamable formulation A. In the same way as in case 1, crush 1
Compression mold 0.7 g using a tablet machine to a diameter of 2.5
Tablets D (10.5 g) with a thickness of 0.8 cm and a thickness of 0.8 cm were obtained.

Formulation Example 5 Pulverized in the same manner as in Formulation Example 4 48,2
Tablet E (48
,0g) was obtained.

Formulation Example 6 In Formulation Example 1, 20.52 parts of herbicidal component A, 33.33 parts of other herbicidal component B, and Deixsol W-92 were added.
(same as above) 3.85 parts and the foamable formulation A 92
．． Using 3 parts, tablets F with a diameter of 5 cm and a thickness of 1°6 cm were prepared from 48.2 g of the crushed product in the same manner as in Formulation Example 1.
(48.0 g) was obtained.

Formulation Example 7 In Formulation Example 1, 21.35 parts of herbicidal component A, 38.65 parts of other herbicidal component B, 3.0 parts of Tsurupol 5039 (same as above), 2.0 parts of Ravelin FAN (same as above), Plex (same as before) 6.0 parts and Sickle (same as before)
Using 38.53 parts of a hydrating powder consisting of 79.0 parts and 61.47 parts of the foamable formulation A, 48.2 g of the ground product was prepared in the same manner as in Formulation Example 1, with a diameter of 5 cm and a thickness of 1. ．．
6 cm tablets G (48.0 g) were obtained.

Formulation Example 8 In Formulation Example 1, 10,455 parts of herbicidal component A, 33,34 parts of other herbicidal component B-1, and other herbicidal component B-1
1,53 copies, Deixsol W-92 (same as above) 5.3
Tablets H (48.0 g) with a diameter of 5 cm and a thickness of 1.6 cm were prepared from 48.2 g of the crushed product in the same manner as in Formulation Example 1 using 3 parts of the effervescent formulation A and 89.36 parts of the effervescent formulation A.
I got it.

Formulation Example 9 In Formulation Example 1, 10.85 parts of herbicidal ingredient A, 36.27 parts of other herbicidal ingredient B-12, and other herbicidal ingredient B-12.
, 87 parts, Tsurupol 5039 (same as before), 3.0 parts, Labelin FAN (same as before) 2.0 parts, Carplex (same as before) 6.0 parts, and Zeekrite (same as before) 79.0 parts. 53.19 parts of a hydrating agent and the foamable formulation A 46.
Tablet 1 (48.0 g) with a diameter of 5 cm and a thickness of 1.6 cm was obtained from 48.2 g of the crushed product in the same manner as in Formulation Example 1 using 81 parts.

Comparative Formulation Example 1 38.08 parts of the effervescent formulation A, 30.96 parts of biradixifene, and 30 parts of Deixsol W-92 (same as above)
, 38.6 g of the pulverized product was compressed and molded using a tablet machine in the same manner as in Formulation Example 2, except that 96 parts of . a)
(38.4 g) was obtained.

Formulation Examples IO to I4 and Comparative Formulation Examples 2 to 4 Herbicidal ingredient A-30, 2 parts previously ground in a mortar, and other herbicidal ingredients B-3
3.3 parts, 3.5 parts of the surfactant shown in Table 1 below, 88.0 parts of the foamable formulation B, and 5 parts of magnesium oxide.
The mixture was mixed and ground again to obtain a pulverized product. Using a tablet press, press 4.05 g of this pulverized material at 150 to 60 liters.
Compression molded for 2 minutes at kg/cnr to a diameter of 2cm and a thickness of 0.
．． Each tablet of 8 cm (4.0 g) was obtained.

Table 1 Formulation Example 15 Herbicidal ingredient A-30.21 parts, other herbicidal ingredients 833.3
2 parts, Tsuruken 90 (same as before) 3.54 parts, magnesium oxide 5.00 parts, pigment (Food Blue No. 1, same as before) 0.44
and 87.49 parts of the foamable blend A were mixed and pulverized using a micro sample mill (same as above) to obtain a pulverized product.

4.05 g of this pulverized material was compressed to 15 g using a tablet press.
C) - Compression molded for 2 minutes at 160kg/cnf to diameter 2
A tablet 0 (4.0 g) with a thickness of 0.8 cm and a thickness of 0.8 cm was obtained.

Formulation Example 16 Tablets P with a diameter of 2 cm and a thickness of 0.8 cm were prepared in the same manner as in Formulation Example 15, except that Tsuruken 90 (same as above) was replaced with Tsuruken 50 (same as above).
(4.0 g) was obtained.

Formulation Example 17 30.22 parts of herbicidal ingredient A previously ground in a mortar, 33.43 parts of other herbicidal ingredients B-7, 1.01 parts of B-7, 4.66 parts of Tsurken 50 (same as above), 5.0 parts of magnesium oxide. 0
0 parts and 885.68 parts of the above foamable blend were mixed and ground again in a mortar to obtain a pulverized product.

4.05 g of this pulverized material was compressed at a pressure of 150~ using a tablet machine.
Compression molded at 160 kg/cw for 2 minutes to a diameter of 2 cm.
, Tablets Q (4.0 g) with a thickness of 0.8 cm were obtained.

Formulation Example 18 In Formulation Example 17, other herbicidal ingredient B-7 was replaced with B-
52.90 copies, 4.66 copies of Tsuruken 50 (same as above) 6
．． 55 parts and 8 parts of the foamable formulation B85, 68 parts.
Tablets R (4,0
g) was obtained.

Formulation Example 19 In Formulation Example 17, other herbicidal ingredient B-7 was replaced with B-
65.21 copies, 4.66 copies of Tsuruken 50 (same as before), 8
．． 86 parts and 7.68 parts of the foamable formulation B85.
Tablets S (4,0
g) was obtained.

Test Example 1 (Dispersibility Test-I) Water was poured at a depth of about 5 cm into a concrete circular pool (Figure ■) with a radius of 3.5 m and a cylinder with a radius of 0.5 m at the center as an obstacle. As shown in Figure 1, the tablet prepared in the above formulation example was applied to point W-1, 0.75 m away from the center of the circle, and 4 hours after application, the tablet was 0.7 m away from the center of the circle.
Water was sampled at each point 5 m, 1.75 m, or 2.75 m apart to investigate the dispersion status of the herbicidal components. The results are shown in Table 2 below.

Table 2 (Note) Four hours after application of the tablets, no tablet precipitates were observed in the invention area in point (2), but a large amount of precipitates were observed on the bottom of the water in the control area.

As can be seen from the above test results, in the control plot it was difficult to uniformly disperse the herbicidal component biradixifen, whereas in the invention plot both the herbicidal components A-1 and B-3 were uniformly dispersed.

Test Example 2 (Dispersibility Test - ■) A test plot was set up in a paddy field with a width of 8 m and a length of 6 m as one section, and water was poured to a depth of 3 to 6 cm. Nine days after the plowing, one tablet prepared in the above formulation example was put into each test plot (point W- in FIG. 2). W after 24 hours
Field water was sampled at each point -1, X, and Y, and the dispersion status of herbicidal components was investigated.

In addition, many obstacles such as straw waste and weeds were observed in the rice fields.

Table 3 (Note) Herbicidal ingredient B-1 was not analyzed in test plots N (15 and 6), and granules A and B corresponded to tablets in test plots Na 1 and 2 and Nα5 and 6, respectively. It is formulated according to the law.

As can be seen from the above test results, the test area Nα of the invention area
The dispersibility of the herbicidal ingredients A-1 and B-3 in 1.2.5 and 6 was not inferior to that of the comparative test plots Nα7 and 8, so it was found that the herbicidal ingredients were not sufficiently contained by simply adding them. A uniform dispersion result can be obtained.

Test Example 3 (Weeding Test-1) After plowing a paddy field with a tractor on June 7th, granular chemical fertilizer (NP2O6K214-10-13) was used as the base fertilizer.
20 kg per 1Oa was applied. Entered the water on June 12th, 2
A few days later, the seedlings were plowed with a tractor, and on June 16, the two-leaf stage seedlings (variety: Nihonbare) grown in boxes were transplanted mechanically.

3.5mX using plastic ridge sheet on June 20th
Two 3m test plots were set up. The next day, three tubers of Cyperus japonica that had germinated were planted at the edges of the test plots. Other weeds were allowed to grow naturally, but they all grew in large numbers.

The flooding depth was adjusted to 5 to 7 cm, and on June 26th, one tablet prepared in the above formulation example was thrown into the center of the test area. In the comparative plot, granules prepared by a conventional formulation method were uniformly dispersed, corresponding to the above-mentioned tablets. The drug is herbicidal ingredient A-1 or 0.45 g/
a, B-3 or 3g/a. At the time of chemical treatment, the leaf age of each weed was 1.5 to 1.8 leaf stage for Japanese field weed, and 1.5 to 2 leaf stage for firefly, Japanese cypress, Japanese azalea, and cypress. On the 45th day after the chemical treatment, the growth status of paddy rice and weeds was observed with the naked eye, and the degree of growth inhibition was expressed using the following criteria to obtain the results shown in Table 4.

Growth suppression degree 5: 10096 t: 96-99% 5-4 ・91-9596 5-4: 85-9096 4-5: 81-84% 4.70-80?6 Table (Note) Is it a weed? It is shown that a small amount re-occurred after being completely removed.

As can be seen from the results of this test, the herbicidal effect equivalent to that of the control plot can be obtained by simply applying the product without causing chemical damage to rice.

Test Example 4 (Weeding Test-■) A paddy field was plowed with a tractor on July 17th and flooded on July 21st. The next day, after raking with a tractor, a test plot measuring 8 m x 6 m was set up using a plastic ridge sheet. 24 tubers of Cyperus japonica that germinated on July 24th per plot Figure 3
It was implanted at the position indicated by the x point. The barnyard grass and the grasshopper were naturally generated. On July 31st, the water depth was adjusted to 3 to 6 cm, and 1 or 2 tablets prepared in the above formulation example were added to each area.
3 was thrown into each position of w-i, W-2, and W-3 in Fig. 3. Weeds at the time of chemical treatment were 1.5 to 2 leaf stage for Japanese barnyard grass and Japanese grasshopper, and 2 leaf stage for Japanese cypress.

On the 30th day after the chemical treatment, the degree of growth inhibition was determined in the same manner as in Test Example 3, and the results shown in Table 5 were obtained.

Table 5 QD application 11A and B 3 surface stabbing ωD +jc6) (paralyzed hairy Konagi and Mizuriki guy January d and ℃ shift 1 (1) 9 female appeasement) shows the degree t Test Example 5 (Digital Product Time Change Test) Tablets J-N prepared by the above formulation method and comparative tablets (b
) to (d), one is used as a standard sample, and the remaining one is sealed in a laminated bag.
It was placed in a thermostatic chamber at 4°C, stored for 7 days, and then subjected to an abuse test.

A portion of the standard sample and the sample after the abuse test were taken, and the content of the active ingredient in the sample was determined by an internal standard method using liquid chromatography, and the rate of change over time (degradation rate) was calculated using the following formula.

R. Content of active ingredient in standard sample S: Content of active ingredient in sample after abuse test These results are shown in Table 6.

As can be seen from the results in Table 1 and above, surfactants that do not contain polyoxyethylene groups can stabilize sulfonylurea herbicidal ingredients compared to surfactants that contain polyoxyethylene groups.

Test Example 6 (Diffusion Test) Each test plot was a wooden frame measuring 1 m in length, 4 m in width, and 20 cm in height. Paddy soil was evenly spread on the bottom of each test plot, and the water depth was 5 cm after watering and puddling. As shown in Figure 4 below, the tablet O or P was placed in each test area at one end of the short side (point W), and the tablet O or P was placed in the center (point X, 2 m from one end of the short side). and the other end of the short side (point X) for a predetermined time (
After 3.5 hours, 1 day, 2 days, 4 days, and 6 days), field water was collected and the dispersion status (concentration: ppm) of the herbicidal components was examined.

The results are shown in Table 7.

Table 7 "Effects of the Invention" The tablets or capsules for weeding rice fields provided by the present invention can evenly kill various weeds by simply throwing them into rice fields without using a special chemical sprayer. It can be prevented.

[Brief explanation of drawings]

Figure 1 shows a circular pool made of concrete that has a cylinder at its center that protrudes above the water surface with a radius of 0.5 m.
1 indicates the tablet insertion point, W-1 to 3, X-1 to 3, Y-1.
-3 and Z-1 to Z-3 are diagrams showing water sampling points, respectively. FIG. 2 shows a rice field, W-1 to W-3 indicate tablet input points, and W-1, X, and Y indicate rice water sampling points. Figure-3 shows a paddy field, w-1,
W2 and W-3 are diagrams showing the tablet insertion points, and the x point is the implantation point of water snails, respectively. Figure 4 is 1m long.
, represents a test area of a wooden frame with a width of 4 m and a height of 20 cm, where W point indicates the tablet input point, and X and Y points indicate the sampling points of rice water.

Claims (1)

[Scope of Claims] 1. For weeding rice fields, characterized in that the entire amount of the drug applied to rice fields contains a sulfonylurea herbicidal component, a surfactant, a foaming agent, and a binder that are substantially soluble in rice water. tablets or capsules. 2. The tablet or capsule for weeding rice fields according to claim 1, wherein the tablet or capsule contains other herbicidal ingredients such that substantially the entire amount of the drug applied to the rice fields dissolves in the rice water. 3. The tablets or capsules for weeding rice fields according to claim 1 or 2 are applied to flooded rice fields at a rate of 10 to 200 tablets 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 the entire amount of herbicidal ingredients in rice field water.