JP2980959B2 - Tablets or capsules for paddy weeding - Google Patents

Description

[Detailed Description of the Invention] [Industrial application field] The present invention is to provide a simple tablet or capsule for application of a medicine in paddy field weeding, and to provide a simple method of treating a medicine thereby.

`` Conventional technology '' Conventionally, as a method of weeding paddy fields, especially in the early to middle stages of paddy rice cultivation, a method of spraying fine granules prepared by combining a herbicidal component with a fine powder solid carrier, other auxiliaries, granules as it is, water A method in which a wetting agent is diluted in a large amount of water and then sprayed is mentioned. Other methods not using a fine powder solid carrier include a method in which an emulsion in which a herbicidal component is dissolved in an organic solvent is sprayed as it is, a finely pulverized herbicide. There is a method in which a Floatable agent in which components are dispersed and suspended in water is sprayed as it is.

"Problems to be Solved by the Invention" However, when applying fine granules, granules and wettable powders, it is necessary to have a heavy sprayer or a granulator containing the medicine, for example, usually 10 ares. The drug must be sprayed evenly, either by walking around the paddy to spray 3-4 kg of granules per day, or by using a large Niagara hose from the levee. Therefore, the transporting and spraying of the chemicals requires not only severe labor, but also the rice seedlings, which are often damaged, which is not desirable in terms of growth.
Even when applying emulsions and Flourables, the weight of the drug is reduced to some extent and a large sprayer is not required, but it is necessary to use a container that discharges a fixed amount of drug, and even more uniform drug spraying is still required. You need to walk around rice fields.

"Means for Solving the Problems" The present invention solves the above-mentioned drawbacks of the conventional method, and enables weeding of paddy fields by a simple method without using a special chemical sprayer. That is, the present invention relates to a paddy field herbicidal tablet or capsule containing a sulfonylurea-based herbicidal component in which the total amount of the drug applied to the paddy field is substantially dissolved in the field water, a surfactant, a foaming agent and a binder, The present invention relates to a paddy field herbicidal tablet or capsule containing a paddy field in which the total amount of the drug applied is substantially soluble in the rice field and to which other herbicidal components are added. The present invention also relates to the tablet or capsule 10
The present invention relates to a paddy field herbicidal method which is applied to a paddy field flooded so that the total weight of the tablets or capsules becomes 200 to 1500 g per are and the herbicidal components are substantially dissolved and dispersed in the field water. .

In the present invention, the term "sulfonylurea-based herbicidal component or other herbicidal component" which defines that "the total amount of the drug applied to the paddy field substantially dissolves in the paddy water" refers to a herbicidal effect which does not substantially harm the rice seedlings. Assuming that a sufficient amount of herbicidal component is applied to the paddy field, that is, the herbicidal component is dissolved in the paddy water, the concentration of the herbicidal component in the paddy water is the solubility of the herbicidal component in water (25 ° C). The following herbicidal components are meant. For example, methyl-2- (4,6-dimethoxypyrimidin-2-ylcarbamoylsulfamoyl) -o-toluylate (hereinafter abbreviated as A-2) is usually 10 areal as a practical dosage of a herbicide at the early to middle stage of rice cultivation. 5 to 7.5 g per application, assuming a flooding depth of 5 cm, the concentration in the field water is 0.1 to 0.15 ppm (practical amount), and the solubility in water (25 ° C) is 8 ppm. It corresponds to the sulfonylurea herbicidal component specified in the invention. On the other hand, the herbicidal component 4- (2,4-dichlorobenzoyl) -1,3-dimethyl-5-phenacyloxypyrazole (hereinafter abbreviated as pyrazoxyfen), which has recently been put to practical use as a paddy herbicide, is used in early to middle rice cultivation. The practical dose of herbicide is usually 18 per 10 ares
It is applied in 0-300g and the concentration in the field water at the depth of 5cm is 3.
6 to 6 ppm (practical dose) and solubility in water (25
° C) is 0.9 ppm and does not fall under the other herbicidal components defined in the present invention. This means that the herbicidal component A-2 has a lower content than pyrazoxifen, so that it can be easily formulated into the tablet or capsule of the present invention. The high solubility indicates that it dissolves quickly in the tap water, diffuses widely, and disperses uniformly, whereas pyrazoxifene hardly dissolves and is difficult to disperse.

Specific examples of the sulfonylurea herbicidal component include:
For example, N-[(4,6-dimethoxypyrimidin-2-yl) aminocarbonyl] -3-methyl-5- (2-chloro-2,2-difluoroethoxy-4-isothiazolesulfonamide (hereinafter A-1) Abbreviated), methyl-α- (4,
6-dimethoxypyrimidin-2-ylcarbamoylsulfamoyl) -o-toluylate (A-2), N-
[(4,6-Dimethoxypyrimidin-2-yl) aminocarbonyl] -4-ethoxycarbonyl-1-methyl-5
-Pyrazole sulfonamide (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-1,3,5-triazin-2-yl) -1-
[2- (2-methoxyethoxy) -phenylsulfonyl] urea (hereinafter abbreviated as A-5) and the like.

Other herbicidal components include 2-methylthio-4,6-bis (ethylamino) -s-triazine (hereinafter abbreviated as B-1) and 2-methylthio-4-ethylamino-6- (1,2
-Dimethylpropylamino) -s-triazine (hereinafter referred to as B
-2); 3,7-dichloro-8-
Quinoline carboxylic acids such as quinoline carboxylic acid (hereinafter abbreviated as B-3); 2-chloro-2 ', 6'-diethyl-N
-(2-propoxyethyl) acetanilide (hereinafter referred to as B-
4), N- [2 '-(3'-methoxy) -thienylmethyl] -N-chloroaceto-2,6-dimethylanilide (hereinafter abbreviated as B-5), 2', 6'-diethyl-N −
Anilides such as [(2-cis-butenooxy) methyl] -2-chloroacetanilide (hereinafter abbreviated as B-6);
S, S-dimethyl-2-difluoromethyl-4- (2-methylpropyl) -6- (trifluoromethyl) -3,5-
Pyridine dicarbothioate (hereinafter abbreviated as B-7) and the like can be mentioned, but triazines and quinoline carboxylic acids are desirable in view of solubility in water, an effect on rice and weeds.

The surfactant in the present invention imparts hydrophilicity to the herbicidal component, the binder and the like, and includes, for example, sodium dodecylbenzenesulfonate, dialkylsulfosuccinate, sodium dialkylsulfosuccinate, sodium lauryl sulfate, sodium higher alcohol sulfate, Anionic surfactants such as sodium lignin sulfonate, polyoxyethylene alkyl aryl ether sulfate, sodium β-naphthalene sulphonate formalin condensate, dinaphthalene methane sulfonate, alkyl aryl sulfonate, sodium alkyl aryl sulfonate, sodium alkyl naphthalene sulfonate Agent: polyoxyethylene nonyl phenyl ether,
Polyoxyethylene oleyl ether, polyoxyethylene oleate, polyoxyethylene alkyl aryl ether, polyoxyethylene alkyl ether, polyoxyethylene sorbitan monolaurate, polyoxyethylene fatty acid ester, polyoxyethylene styryl phenyl ether, sorbitan monooleate ,
Examples include nonionic surfactants such as sorbitan monolaurate, sorbitan monostearate, sorbitan sesquioleate, sorbitan palmitate, acetylene glycol, diglycerin borate 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.

In addition, it has been found that the use of a specific surfactant in the tablet or capsule preparation of the present invention suppresses the decomposition of the sulfonylurea compound, which is the main herbicidal component. Examples of the specific surfactant include those having no oxyalkylene group such as oxyethylene group and oxypropylene group in its structure, such as polyoxyethylene alkyl aryl ether sulfate and polyoxyethylene group. Other than oxyethylene nonylphenyl ether. Furthermore, a surfactant containing an oxyalkylene group may be used in combination with other surfactants within the quantitative range, provided that it does not promote the decomposition of the sulfonylurea-based herbicidal component.

The foaming agent in the present invention is a combination of an acidic substance and an alkaline substance that react in the presence of water to generate gas. As the acidic substance, the substance itself is acidic or dissolved in water and exhibits acidic properties, 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 and potassium hydrogen sulfate; alums such as potassium alum, ammonium alum; and the like; examples of the alkaline substance include sodium carbonate, Carbonates such as potassium carbonate, calcium carbonate, magnesium carbonate and ammonium carbonate; bicarbonates such as sodium bicarbonate and potassium bicarbonate; percarbonates such as sodium percarbonate;

The binder used in the present invention binds each component particle, and may be any one as long as it is preferably water-soluble.For example, carboxymethyl cellulose, a salt thereof, dextrin, polyethylene glycol,
Examples thereof include polyvinyl alcohol, polyalkylene glycol, lignin sulfonate, gum arabic, starch paste, other starches, and sucrose. Further, as the binder in the present invention, even if the binder itself is not a general binder, any binder can be used as long as it plays a role of binding the respective component particles. Among those that can be used in this way are, for example, stearic acid,
Acidic substances such as succinic acid, adipic acid and phosphoric acid and salts thereof; alkaline substances such as sodium carbonate and sodium bicarbonate;

Some binders, such as the above-mentioned surfactants, suppress the decomposition of the sulfonylurea-based herbicidal components. Examples of such a compound include compounds other than compounds having an oxyalkylene group, such as polyethylene glycol, polyvinyl alcohol, and polyalkylene glycol. However, the above-mentioned binder may be used within the quantitative range as long as it does not promote the decomposition of the sulfonylurea-based herbicidal component.

Since the selection of the surfactant, the foaming agent and the binder varies depending on the type of the herbicidal component and the blending ratio of the whole preparation, an appropriate one must be actually selected by trial and error experiments.

Tablets or capsules for paddy field herbicides of the present invention are those comprising the sulfonylurea-based herbicidal component, a surfactant, a foaming agent and a binder, and further, those containing the other herbicidal components added thereto, For example, based on 1 part by weight of the sulfonylurea-based herbicidal component, the surfactant is 0.1 to 20 parts by weight, desirably 1 to 10 parts by weight, more desirably 1 to 5 parts by weight, and the foaming agent is 1 to 800 parts by weight, desirably. Is 5 to 100 parts by weight, more preferably 5 to 25 parts by weight, and 0.1 to 20 parts by weight of the binder, preferably 0.2 to 10 parts by weight.
Parts by weight, more preferably 0.4 to 1.5 parts by weight. Further, 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-based herbicidal component. In this case, the mixing ratio of the surfactant, the foaming agent and the binder to all the herbicidal components is as described above. The range may be the same as that described above, and, of course, a range outside the above range is included in the present invention as long as the initial effect is exhibited.

The tablet or capsule of the present invention can contain a solid carrier and other agricultural chemical auxiliaries in addition to the above-mentioned components. In addition, the solubility of the herbicidal component in water as defined in the present invention, as long as the herbicidal component other than the herbicidal component of the present invention is not significantly impaired, a herbicidal component, a bactericidal component, an insecticidal component, a plant growth regulating component, a fertilizer component, etc. It can also be contained. Examples of the solid carrier include powders having good properties such as kaolin, talc, clay, bentonite, and finely divided silica; inorganic salts such as anhydrous sodium sulfate; and organic substances such as urea. Usually used as other agricultural chemical auxiliaries. Solvents, decomposition inhibitors, safeners, dispersion stabilizers, disintegrants, desiccants and the like.
Their amounts cannot be specified unconditionally, but are generally 0.1 to 50 parts by weight of solid carrier and 0.1 to 20 parts by weight of other pesticidal auxiliaries as a proportion of the whole tablet or capsule.

The tablet or capsule of the present invention is usually easily produced by the following method or a method analogous thereto. In general, when the herbicidal component is a solid, the herbicidal component is used as fine particles having a particle size of 1 to 200 µ, preferably 1 to 100 µ by being pulverized in advance to enhance solubility and dispersibility in water. As a method for producing a tablet, for example, all the components are uniformly mixed by simultaneously mixing a herbicidal component, a surfactant, a foaming agent and a binder, or by mixing the remaining components with any premixed components, The powder is pulverized to a particle size of 1 to 200 μm and compression-molded using a tableting machine according to a usual method to form a tablet. When using a solid carrier or other pesticide auxiliaries here, a method in which this is uniformly mixed with a herbicidal component and a surfactant in advance, crushed to form a wettable powder, and then mixed with a foaming agent and a binder. Is mentioned. The above-mentioned tablet production method is, of course, appropriately changed in consideration of the medicinal properties, formulation properties, and the like, and an appropriate one is implemented. Tablets are manufactured in various shapes and sizes, such as circular plates, oval plates, square plates, and rods, depending on the manufacturing method and tableting machine. Since the drug effect is not greatly affected by the shape of the tablet,
Any shape, size, weight may be used,
The shape is a circular plate, the size is 1-5cm in diameter, 0.2-3cm in thickness,
Those having a weight of 1 to 150 g are preferable for formulation and drug application.

As a method for producing the capsule of the present invention, for example, a herbicidal component, a surfactant, a foaming agent and a binder are uniformly mixed, and if necessary, a solid carrier or other pesticide auxiliaries are added and uniformly mixed, The pulverized material is granulated to a particle size of 1 μm to 1.5 mm, and the granules are filled in capsules made of water-soluble cellulose, gelatin or the like, or the granulated material is not granulated,
The wettable powder is filled in the capsule as it is. This capsule also has the same shape as that of the tablet, and may be any of a spherical shape, an elliptical spherical shape, a size and a weight, but the shape is an elliptical spherical shape and the size is 1 to 5 cm in diameter, 1 to 10 cm in length, and weight. Saga 1-150g
Are preferred. In addition to the capsules prepared as described above, the capsules of the present invention also include those in which the above-mentioned pulverized product or wettable powder is not filled in a capsule container but is wrapped as it is in a water-soluble film such as water-soluble cellulose or gelatin.

When the tablet or capsule of the present invention is applied to a flooded paddy field, gas is generated by contact with water, the herbicidal component is rapidly eluted into the tap water, a surfactant is also acted on, and the herbicidal component is dissolved in the water. And uniformly dispersed. Thus, when the tablet or capsule of the present invention is administered to a paddy field, substantially the entire amount of the herbicidal component can be rapidly dissolved and dispersed in the field water, and for example, the herbicidal component can be uniformly distributed in the field water after several hours to several tens of hours. Therefore, weeds can be uniformly controlled without damaging the rice.

When weeding a paddy field using the tablets or capsules of the present invention, the application is performed so that the total weight of the tablets or capsules is 10 to 200 pieces per 10 ares, and the total weight of the tablets or capsules is 200 to 1500 g. It is not desirable in terms of phytotoxicity, or requires a great deal of labor for spraying. Desirable application methods cannot be specified unconditionally due to differences in tablet or capsule production methods, sizes, herbicidal ingredients, surfactants, foaming agents, types of binders and other additives, and mixing ratios. 5 to 150 g of the herbicidal component is divided into 0.05 to 15 g portions per tablet or capsule, and 10 to 100 portions are applied.
Thus, tablets or capsules need only be applied once per 10 to 100 m ² , so they can be injected into the paddy field of the area from the ridge without entering the paddy field. It is advantageous in comparison.

When performing weeding in a paddy field using the tablet or capsule of the present invention, generally 5 to 15 days after transplantation of seedlings for transplanted rice,
In the case of direct sowing paddy rice, the most favorable effect is obtained when applied in the early to middle stages of paddy rice cultivation 10 to 20 days after sowing, but even if the tablets or capsules are applied, other effects are obtained as long as they do not hinder medicinal effects or phytotoxicity. It can also be applied at the time. Even if the tablet or capsule of the present invention is once dissolved or dispersed in an appropriate amount of water and applied locally to a paddy field, desirable effects in terms of medicinal properties and phytotoxicity can be obtained.

Examples of 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 effervescent compound) Preparation Example 1 42.4 parts of succinic acid, sodium carboxymethylcellulose (trade name; Cellogen PR, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 5.
2 parts, 31.4 parts of sodium bicarbonate and 21.0 parts of sodium carbonate were uniformly mixed and pulverized with a micro sample mill (AP-S type, manufactured by Hosokawa Industry Co., Ltd.) to obtain a foamable compound A.

Preparation Example 2 In the above Preparation Example 1, the mixture before pulverization was further added with a pigment (trade name: Food Blue No. 1, Brilliant Blue FCF,
0.5 part of Tokyo Chemical Industry Co., Ltd.) were uniformly mixed, and a foamable compound B was obtained in the same manner as in Preparation Example 1.

(Preparation of Tablets A to P and Comparative Tablets (a) to (g)) Formulation Example 1 Herbicidal component A previously ground to a particle size of about 5 to 10 μm in a mortar
-1 0.46 part and other herbicidal component B-3 3.34 part, mixture of 50% polyoxyethylene nonylphenyl ether and 50% fine powder silica (trade name: Dixsol W-92, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 3.8 parts And the foamable composition A9
2.4 parts were mixed and pulverized with a micro sample mill (the same as above) to obtain a pulverized product. 48.2 g of this pulverized material was compression-molded at a pressure of 150 to 160 kg / cm ² for 2 minutes using a tableting machine to give a diameter of 5 c.
m, a tablet A (48.0 g) having a thickness of 1.6 cm was obtained.

Formulation Example 2 A pigment (edible blue 1
In the same manner as in Formulation Example 1 except that about 2% of the total weight was added to a tablet B (38.4 g) having a diameter of 5 cm and a thickness of 1.3 cm using a tableting machine. ) Got.

Formulation Example 3 In the same manner as in Formulation Example 1, 10.7 g of the pulverized product was compression-molded using a tableting machine to obtain Tablet C (10.5 g) having a diameter of 2.5 cm and a thickness of 0.8 cm.

Formulation Example 4 In Formulation Example 1, 1.2 parts of herbicidal component A-1, 8.8 parts of other herbicidal component B-3, and 3.0 parts of polyoxyethylene alkyl aryl ether sulfate (trade name: Solpol 5039, manufactured by Toho Chemical Industry Co., Ltd.) 2.0 parts of sodium naphthalenesulfonate formalin condensate (trade name: Labelin FAN, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), 6 parts of fine powdered silica (trade name: Carplex, manufactured by Shionogi & Co., Ltd.) and kaolinite And 39.1 parts of a wettable powder consisting of 79.0 parts of a mixed and crushed product of Sericite (trade name: Sigleite, manufactured by Sigleite Co., Ltd.) and 62.1 parts of the effervescent compound A, and the same as in the case of Formulation Example 1. In the same way, crushed 10.7g
Was compression-molded using a tableting machine to obtain a tablet D (10.5 g) having a diameter of 2.5 cm and a thickness of 0.8 cm.

Formulation Example 5 48.2 g crushed in the same manner as in Formulation Example 4
Gave a tablet E (48.0 g) having a diameter of 5 cm and a thickness of 1.6 cm.

Formulation Example 6 Using the herbicidal component A-2 (0.52 parts), the other herbicidal component B-3 (3.33 parts), Discozol W-92 (same as above) 3.85 parts and the effervescent composition A92.3 parts in the above-mentioned Formulation Example 1, In the same manner as in the case of Formulation Example 1, 48.2 g of the crushed material and a diameter of 5 cm,
A tablet F (48.0 g) having a thickness of 1.6 cm was obtained.

Formulation Example 7 In Formulation Example 1, 1.35 parts of herbicidal component A-2, 8.65 parts of other herbicidal component B-3, and Solpol 5039 (the same as above).
0 parts, 2.0 parts of Labelin FAN (same as above), 38.53 parts of a wettable powder consisting of 6.0 parts of carplex (same as above) and 79.0 parts of ziglite (same as before) and 61.47 parts of the foamable composition A, In the same manner as in Formulation Example 1, 48.2 g of the pulverized material and 5 c in diameter were used.
m, a tablet G (48.0 g) having a thickness of 1.6 cm was obtained.

Formulation Example 8 In Formulation Example 1, 0.455 parts of herbicidal component A-1, 3.34 parts of other herbicidal component B-3, and other herbicidal component B-1 1.
Using 53 parts, 5.33 parts of Disczol W-92 (the same as above), and 89.36 parts of the foaming composition A, in the same manner as in Preparation Example 1, a diameter of 5 cm and a thickness of 1.6 cm were obtained from 48.2 g of the pulverized product. Tablet H
(48.0 g) was obtained.

Formulation Example 9 Herbicidal component A-1 0.85 part, other herbicidal component B-3 6.27 parts, other herbicidal component B-1 2.
53.19 parts of a wettable powder consisting of 87 parts, 3.0 parts of Solpol 5039 (same as above), 2.0 parts of LABELIN FAN (same as above), 6.0 parts of carplex (same as before) and 79.0 parts of ziglite (same as above) and the foaming composition In the same manner as in Formulation Example 1, using 46.81 parts of product A, tablet I (4 cm in diameter and 1.6 cm in thickness) was prepared from 48.2 g of the pulverized product.
8.0 g).

Comparative Formulation Example 1 38.08 parts of the effervescent composition A, pyrazoxifen 30.96
Parts and Dixsol W-92 (same as above) were mixed and crushed, except that 38.6 g of the crushed product was compression-molded using a tableting machine in the same manner as in Preparation Example 2 except that the mixture was crushed. 1.
A 6 cm comparative tablet (a) (38.4 g) was obtained.

Formulation Examples 10 to 14 and Comparative Formulation Examples 2 to 4 0.2 parts of herbicidal component A-3 previously ground in a mortar, 3.3 parts of other herbicidal component B-3, 3.5 parts of surfactant shown in Table 1 below, foaming 88.0 parts of the water-soluble compound B and 5 parts of magnesium oxide were blended and ground again to obtain a ground product. 4.05 g of this pulverized product was compressed using a tableting machine at a pressure of 150 to 160 kg / cm ² .
Each tablet with a diameter of 2 cm and a thickness of 0.8 cm (4.
0g).

Formulation Example 15 herbicidal component A-3 0.21 part, other herbicidal component B-3 3.
32 parts, Sorgen 90 (same as above) 3.54 parts, magnesium oxide 5.
00 parts, 0.44 part of a pigment (edible blue No. 1, same as above) and 87.49 parts of the foamable compound A were mixed and pulverized with a micro sample mill (same as above) to obtain a pulverized product. 4.05 g of this crushed material,
Using a tableting machine, compression molding was performed at a pressure of 150 to 160 kg / cm ² for 2 minutes to obtain tablets O (4.0 g) having a diameter of 2 cm and a thickness of 0.8 cm.

Formulation Example 16 A tablet P (4.0 g) having a diameter of 2 cm and a thickness of 0.8 cm was prepared in the same manner as in Formulation Example 15 except that Sorgen 90 (same as above) was replaced with Sorgen 50 (same as before). ) Got.

Formulation Example 17: 0.22 part of herbicidal component A-3 previously ground in a mortar, 3.43 part of other herbicidal component B-3, 1.01 part of B-7, solgen
4.66 parts (the same as above), 5.00 parts of magnesium oxide and 85.68 parts of the foaming compound B were mixed and ground again with a mortar to obtain a pulverized product.

Using a tableting machine, 4.05 g of this pulverized material was subjected to a pressure of 150 to 160 kg / cm.
Tablets 2cm in diameter and 0.8cm in thickness by compression molding with ² for 2 minutes
(4.0 g).

Formulation Example 18 In the above Formulation Example 17, the other herbicidal component B-7 was replaced with B-
5 In the same manner as in Formulation Example 17, except that 2.90 parts, 4.66 parts of Sorgen 50 (same as above) were replaced by 6.55 parts, and 85.68 parts of the effervescent composition B were replaced by 81.90 parts, the diameter was 2 cm, and the thickness was 2 cm. 0.8
cm tablets R (4.0 g) were obtained.

Formulation Example 19 In the above Formulation Example 17, the other herbicidal component B-7 was replaced with B-
6 In the same manner as in the case of Formulation Example 17, except that 4.66 parts of Sorgen 50 (the same as above) were placed in 8.86 parts, and 85.68 parts of the foamable composition B were replaced with 77.28 parts, the diameter was 2 cm and the thickness was 5.21 parts. 0.8cm
Tablet S (4.0 g) was obtained.

Test Example 1 (Dispersibility test-I) Radius having a 0.5 m radius column at the center of the circle as an obstacle
Approximately 5cm deep in a 3.5m concrete circular pool (Figure 1)
And water. As shown in FIG. 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 the application, 0.75 m, 1.75 m or 2.75 from the center of the center was applied.
Water was collected from each point at a distance of m, and the state of dispersion of the herbicidal components was investigated. The results are shown in Table 2 below.

As can be seen from the above test results, it is difficult to uniformly disperse the herbicidal component pyrazoxifene in the contrast group, whereas in the present invention group, both the herbicidal components A-1 and B-3 are uniformly dispersed.

Test Example 2 (Dispersibility Test-II) A test section was set up in a paddy field that had been scraped for a test, measuring 8 m in width and 6 m in length, and a test section was provided, and water was poured to a depth of 3 to 6 cm. Nine days after scratching, one tablet prepared in the above formulation example was injected per test section (point W-1 in FIG. 2). 24 hours later, W-1, X
At each of the points Y and Y, field water was sampled to examine the state of dispersion of the herbicidal components. Many obstacles such as straw chips and weed fragments were observed in the paddy fields.

As can be seen from the above test results, the test plot N
o. Herbicidal components A-1 and B-3 in 1, 2, 5 and 6
Is not inferior to Test Nos. 7 and 8 in the comparison plots, and a sufficient uniform dispersion of the herbicidal components can be obtained by mere injection.

Test Example 3 (Herbicidal test -I) after plowing water paddy field tractor on June 7, granular compound fertilizer as basal _{(N-P 2 O 5 -K} : 14-10-13) to 10a per 2
0 kg was applied. Water was entered on June 12, and two days later, a tractor was used as a substitute, and a two-leaf seedling (variety: Nipponbare) that had been box-raised on June 16 was mechanically transplanted.

On June 20, a 3.5m x 3m test plot was set up using plastic levee sheets in duplicate. The next day, three shoots of sprout, which were germinated at the end of the test plot, were planted three per plot. Other weeds were spontaneously generated, but all were high.

The immersion depth was adjusted to 5 to 7 cm, and on June 26, one tablet prepared in the above formulation example was thrown into the center of the test plot. In the comparative group, granules according to the conventional formulation method were uniformly applied, corresponding to the tablets. The herbicidal component A-1 was 0.45 g / a and B-3
Is 3 g / a. Leaf age of each weed at the time of chemical treatment is 1.
The fireflies, puppies, azaleas, and shrubs had the 1.5- to 2-leaf stage at the 5- to 1.8-leaf stage. On the 45th day after the chemical treatment, the growth status of paddy rice and weeds was visually observed, and the degree of growth inhibition was represented by the following criteria, and the results in Table 4 were obtained.

Growth inhibition about 5: 100% t: 96~99% 5- 4: 91~95% 5-4: 85~90% 4-5: 81~84% 4: 70~80% As can be seen from the test results, the herbicidal effect equivalent to that of the control group can be obtained without causing phytotoxicity to the paddy rice by merely throwing the rice.

Test Example 4 (Weeding Test-II) A paddy field was plowed with a tractor on July 17 and water was entered on July 21. The next day, a tractor was used to set up an 8m x 6m test plot using a plastic ridge sheet. Tubers of Spodoptera cricket, germinated on July 24, were planted at the position indicated by the crosses in FIG. Millet and pupa were naturally generated. On July 31, the flooding depth was adjusted to 3 to 6 cm.
1 or W-2 and W-3. The weeds at the time of the chemical treatment were in the 1.5 to 2 leaf stage for barnyardgrass and corn, and in the 2 leaf stage for Spodoptera litura. On the 30th day after the chemical treatment, the degree of growth inhibition was determined in the same manner as in Test Example 3 above, and the results shown in Table 5 were obtained.

Test Example 5 (Aging test of drug substance) Using two samples each of tablets J to N and comparative tablets (b) to (d) prepared by the above-mentioned formulation method, one as a standard sample, Each was sealed in a laminate bag, placed in a 54 ° C. thermostat, stored for 7 days, and subjected to an abuse test.

The standard sample and a part of the sample after the abuse test were taken, and the content of the active ingredient in the sample was quantified by an internal standard method using liquid chromatography, and the time-dependent change rate (decomposition rate) was calculated by the following equation.

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 above results, the surfactant containing no polyoxyethylene group can stabilize the sulfonylurea-based herbicidal component as compared to the surfactant containing a polyoxyethylene group.

Test Example 6 (Diffusion test) Each test section with a wooden frame of 1m in length, 4m in width and 20cm in height was set up, and paddy soil was spread evenly on the bottom, and the water depth was 5c after entering and scraping.
m. As shown in FIG. 4 described later, one end (W
The tablet O or P is put into each test section at the point (point), and at a central portion (point X, a position 2 m from one end of the short side) and the other end of the short side (point Y), a predetermined time (point Y) 3.5 hours,
After 1 day, 2 days, 4 days and 6 days), the water was collected and the state of dispersion (concentration: ppm) of the herbicidal components was examined. Table 7 shows the results.

[Effects of the Invention] According to the tablet or capsule for paddy field weeding provided by the present invention, various weeds can be uniformly controlled by a simple method of simply throwing into a paddy field without using a special chemical sprayer. Can be.

[Brief description of the drawings]

FIG. 1 shows a circular pool made of concrete having a column having a radius of 0.5 m at the center of the water and projecting on the surface of the water. , Y-1-3
And Z-1 to 3 are diagrams showing sampling points of water, respectively.
FIG. 2 shows a paddy field, where W-1 to 3 indicate tablet input points, and W-1, X and Y indicate sampling water sampling points. Figure 3 shows paddy fields, W-1, W-
2 and W-3 are the points of input of the tablet, and the point X is the point of implantation of the horned frog. Figure 4 is 1m long,
FIG. 4 shows a test section with a wooden frame of 4 m in width and 20 cm in height, where point W is a tablet input point, and points X and Y are sampling water points.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Mikio Miyaji 2-3-1, Nishi-Shibukawa, Kusatsu-shi, Shiga Prefecture Inside the Central Research Laboratory of Ishihara Sangyo Co., Ltd. (72) Akira Nakagawa 2-3-3 Nishi-Shibukawa, Kusatsu-shi, Shiga Prefecture No. 1 Inside the Central Research Laboratory of Ishihara Sangyo Co., Ltd. (72) Noboru Yoshikawa 2-3-1 Nishi-Shibukawa, Kusatsu-shi, Shiga Prefecture Inside the Central Research Laboratory of Ishihara Sangyo Co., Ltd. (56) References JP-A-63-190887 ( JP, A) JP-A-63-264508 (JP, A) JP-A-3-128301 (JP, A) JP-A-3-193705 (JP, A) JP-A-3-173802 (JP, A) 47-72930 (JP, B1) JP-B-51-46816 (JP, B1) (58) Fields investigated (Int. Cl. ⁶ , DB name) A01N 25/34 A01N 25/26 A01N 25/08 CAPLUS ( STN) REGISTRY (STN) WPI DS (STN)

Claims (4)

(57) [Claims] 1. A sulfonylurea-based herbicidal component wherein the concentration of the herbicidal component in the water is not more than the solubility of the herbicidal component in water (25 ° C.), assuming that the whole amount of the drug is dissolved in the field water at the time of application. A paddy field herbicidal method comprising directly applying a tablet or capsule containing a surfactant containing no oxyalkylene group in its structure, (3) a foaming agent and (4) a binder to a flooded paddy field. 2. A capsule wrapped by a water-soluble film, either (1) a mixed ground product of the herbicidal component, surfactant, foaming agent and binder, or (2) a granulated granulated mixed ground product. The paddy field weeding method according to claim 1, wherein 3. The herbicide according to claim 3, wherein the tablet or capsule has a concentration of the water in the paddy water which is less than the solubility of the herbicidal component in water (25 ° C.), assuming that the whole amount of the tablet or capsule is dissolved in the paddy water at the time of application. The paddy field weeding method according to claim 1, comprising a component. 4. Herbicidal tablets or capsules directly applied to a flooded paddy field are introduced into a paddy field flooded so that 10 to 200 tablets per 10 ares and the total weight of the tablets or capsules is 200 to 1500 g. 2. The method according to claim 1, wherein the application is performed.
4. The paddy field weeding method according to any one of items 1 to 3.