JPH11246317A - Casting herbicidal preparation for paddy field - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject preparation enabling the wide dispersion of an active component into water, having high efficiency, free from chemical injury against paddy rice and having no troubles such as the leakage of the content during transportation by enclosing a specific emulsion in water-soluble containers. SOLUTION: This preparation is obtained by enclosing (A) an emulsion composed of (i) an active component for paddy field, (ii) 20-99 pts.wt. of a solvent (e.g. xylene) and (iii) 0.1-20 pts.wt. of a surfactant (e.g. polyoxyethylene alkyl ether) in (B) water-soluble containers. An example of the component (i) is pentoxazone [3-(4-chloro-5-cyclopentyloxy-2-fluorophenyl)-5-isopropylidene-1,3- oxazolidine-2,4-dione]. Polyvinyl alcohol is preferred as the material of the component B. The thickness of the component B is preferably 0.1-3 mm. It is preferred that the preparation is applied in an amount of 1-100 pieces and the total weight of 100-1000 g per 10 acre.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a herbicidal preparation which can be applied in paddy fields in a labor-saving manner.

[0002]

2. Description of the Related Art In recent years, paddy fields have been rapidly increased in size and mechanized in order to reduce the cost of rice cultivation. In response to this, various labor-saving formulations and spraying machines have been developed for spraying pesticides. As such a labor-saving spray formulation, JP-A-4-334302 discloses a labor-saving herbicide in which an emulsion in which an active ingredient of a herbicide and a surfactant are dissolved or suspended in an organic solvent is sealed in a container of a water-soluble polymer film. An agent formulation is disclosed. However, in this case, since the thickness of the water-soluble polymer film is 20 to 40 μm, there is a concern that the film may be damaged during transportation and the contents may leak out. Dangerous substances such as organic solvents are used in emulsions, so leakage of contents at the distribution stage may cause serious disasters such as fires, and the shape of the bag makes it difficult to throw from the ridge to the paddy field Operability problem, and the practicability is poor.

On the other hand, Japanese Patent Application Laid-Open No. 5-339103 discloses a labor-saving insecticide preparation in which a solution obtained by dissolving an insecticidal active ingredient in a high-boiling solvent such as phthalic acid diester is enclosed in a water-soluble container. However, since the water surface expands without emulsification of the contents, when this is applied to a herbicide, the solvent may cause harm to the rice and the practicality is questioned.

[0004]

DISCLOSURE OF THE INVENTION The present invention diffuses an active ingredient widely into water, has a high effect, does not cause phytotoxicity to paddy rice, and has a danger of leakage of contents during transportation. The goal is to develop a labor-saving throw-in formulation.

[0005]

Means for Solving the Problems The present inventors have conducted intensive studies in order to solve the above-mentioned problems, and as a result, obtained an emulsion obtained by dissolving a paddy field herbicidal active ingredient together with a surfactant in a solvent using a material such as polyvinyl alcohol. By enclosing it in a water-soluble container with a thickness of 0.3 to 3 mm, there is no leakage of contents due to damage during transportation, and when put into a paddy field,
It has been found that the active ingredient is widely diffused in water by dissolving a part of the container and the contents are gradually released and emulsified in the paddy water, whereby the herbicidal activity can be expressed with it, and the present invention has been completed. .

[0006] That is, the present invention is a castable herbicide for paddy fields, characterized in that an emulsion containing at least a herbicidal active ingredient for paddy fields, a solvent and a surfactant is contained in a water-soluble container. Pentoxazone (3- (4-chloro-5-cyclopentyloxy-2-fluorophenyl) -5-isopropylidene-1,3-oxazolidine-2,4-dione) is an active ingredient of the paddy field herbicide of the present invention. Is mentioned. Examples of the solvent that can be used in the present invention include xylene, alkylbenzenes such as Solvesso 150 (manufactured by Exxon Chemical Co., Ltd.), methylnaphthalene, diphenylmethanes, fatty acid esters, phthalic esters, and adipic esters. However, the present invention is not particularly limited to these. These solvents may be used alone or in an arbitrary ratio, and the amount of the solvent is 20 to 99 parts by weight.

The surfactants usable in the present invention include:
Polyoxyethylene alkyl ethers, polyoxyethylene fatty acid esters, nonionic surfactants such as polyoxyethylene fatty acid amide, alkyl naphthalene sulfonate, anionic surfactants such as alkyl benzene sulfonate, and the like, It is not limited to these. The amount of these compounds in the emulsion is 0.1 to 20.
Parts by weight.

[0008] A typical example is polyvinyl alcohol used as a material of a water-soluble container for filling the emulsion for preparing the present invention. The polyvinyl alcohol is not restricted by the degree of polymerization, saponification degree and the like. What is necessary is that the molded container is dropped on the surface of the rice field and dissolves in about several minutes to 24 hours. If the condition is satisfied, a part of the structure of polyvinyl alcohol is modified with carboxylic acid, cyanoethylated PVA treated with acrylonitrile, hydroxyethyl etherified PVA treated with ethylene oxide, or urea. A modified PVA such as urethane-modified PVA or PVA polyalkyleneoxyacrylate that has been reacted may be used as a material for a water-soluble container.

In order to adjust the dissolution time, water-soluble polymers such as polyethylene glycol, carboxymethylcellulose, hydroxymethylcellulose, dextrin, gelatin and pullulan, and one kind of inorganic mineral fine powder such as talc and calcium carbonate as a filler; Two or more types can be blended into the container material. In addition, the shape of the water-soluble container can be used in various shapes, such as a box shape, a column shape, a spherical shape, a bottle shape, an oval spherical shape, a rod shape, and a blow molding method, an injection molding method, a sheet molding method, and the like. Can be molded.

The thickness of the water-soluble container is a major factor that determines the strength of the container and the time required for the contents to flow out of the paddy field, and is preferably about 0.1 to 3 mm. If the thickness is out of this range and the thickness is too thin, the time required for the contents to flow out will be short, but the strength of the container will be weak. If the thickness is too large, the strength of the container increases, but the time required for the contents to flow out is undesirably long. In the above thickness range, at a normal water temperature of paddy water of 10 to 30 ° C., a part of the container is dissolved within 3 hours and the contents flow out. In the present invention, the throw-in herbicide is applied in an amount of 1 to 100 per 10a, and the total weight of the throw-in preparation is 100 to 1,000 g. In addition, the weight of each cast product is 1g
Can be used at ~ 500g, but weighs 10g ~ 200g
Are preferred.

[0011] Since these throw-in herbicidal preparations are contained in a water-soluble container, they can be sprayed without directly touching the pesticide by a spraying worker, and they are easy to throw because they do not deform greatly even if they are grasped. Spraying is completed in a very short time because the player throws the ridge while walking. For example, when 20 pieces are supplied per 10a, the spraying is completed in about 5 minutes.

[0012]

The present invention will be described in more detail with reference to the following examples.

Example 1 As a herbicidal active ingredient, 3 parts by weight of pentoxazone, 87 parts by weight of Solvesso 150 (manufactured by Exxon Chemical Co., Ltd.),
Solpol 3880L (Toho Chemical Co., Ltd., contents P
OE styryl phenyl ether and alkyl allyl sulfonate (10 parts by weight) were mixed to obtain an emulsion. 50 ml of this emulsion was blow-molded using polyvinyl alcohol (manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) to a thickness of 1.5 m.
m container (body: 35 mm in diameter x 85 m in height)
m), and the filling port was closed by heat sealing to obtain a cast-in preparation containing an emulsion containing 3% of pentoxazone as a herbicidal active ingredient.

Example 2 5 parts by weight of pentoxazone as a herbicidal active ingredient, 85 parts by weight of Swazol 1000 (manufactured by Maruzen Petrochemical Co., Ltd.)
An emulsion was obtained by mixing 10 parts by weight of Newcalgen 3000-C (manufactured by Takemoto Yushi Co., Ltd., containing POE allyl phenyl ether and a metal salt of alkylbenzenesulfonic acid). 30 ml of this emulsion was filled into a 0.5 mm-thick rod-shaped container (body: diameter 20 mm × height 120 mm) using polyvinyl alcohol (manufactured by Kuraray Co., Ltd.) by injection molding, and the filling port was closed by heat sealing. A cast-in preparation containing an emulsion containing 5% of pentoxazone as a herbicidal active ingredient was obtained.

Example 3 As a herbicidal active ingredient, 10 parts by weight of pentoxazone, 80 parts by weight of xylene (first grade reagent, manufactured by Junsei Chemical Co., Ltd.), and Solpol 3770L (manufactured by Toho Chemical Co., Ltd., content PO
E styryl phenyl ether and alkyl allyl sulfonate (10 parts by weight) were mixed to obtain an emulsion. 15 ml of this emulsion was filled into a 3 mm-thick cup-shaped container (diameter 20 mm × height 55 mm) obtained by sheet molding using polyvinyl alcohol (manufactured by Shin-Etsu Chemical Co., Ltd.), and the upper portion was prepared by a melting method. It was closed by heat sealing with a PVA film (manufactured by Kuraray Co., Ltd., 200 μm) to obtain a cast-in preparation containing an emulsion containing 10% of pentoxazone as a herbicidal active ingredient.

Comparative Example 1 The emulsion prepared in Example 1 before filling into the water-soluble container was used as it was.

Test Example 1 Test for Herbicidal Effect on Nobies After seedling, seeds of Nobies were sown, and a 10m × 10m test plot was formed in a paddy field in which rice seedlings were transplanted, and the water depth was kept at 5 cm. One of the throw-in preparations of Examples 1 to 3 was thrown into the center of the test plot one day after transplantation. The emulsion of Comparative Example 1 entered the test plot and 50 ml of the whole surface was treated. Twenty days after the treatment, the herbicidal effect on Nobies was investigated. The results are shown in Table 1 (Tables 1 to 3). In the table, the effect was shown by the relative value (%) to the untreated plot at the survey point shown in FIG. 1 (FIG. 1) in the test plot. In addition, rice damage was observed at each survey point, and no
Evaluation was made in eight stages: medium, large, maximum, and withering. The herbicidal activity of the emulsion was maintained even when the emulsion was included in a PVA container, and no phytotoxicity to rice was observed. In addition, the preparations prepared in Examples 1 to 3 do not break the water-soluble container during storage, and are easy to hold because of an appropriate size, shape, and weight when spraying, and easy to throw, so Was easy to operate.

[0018]

[Table 1]

[0019]

[Table 2]

[0020]

[Table 3]

[0021]

According to the present invention, the active ingredient is widely diffused in water, has a high effect, does not cause phytotoxicity to rice, and has no danger of leakage of contents during transportation.
It is possible to provide a labor-saving cast herbicidal preparation that is sprayed efficiently.

[Brief description of the drawings]

FIG. 1 is a sketch of a test plot used in Test Example 1 as viewed from above.

[Explanation of symbols]

 1 to 9: represents a survey point. ×: represents the input point of the cast herbicide.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kazunori Takanaka 1144 Togo, Mogo-shi, Chiba Mitsui Chemicals Co., Ltd. (72) Inventor Yoshishige Nakamura 1144 Togo, Togo, Mobara-shi, Chiba Mitsui Chemicals Co., Ltd. (72) Invention Person Seichi Shimono 1144 Togo, Togo, Mobara-shi, Chiba Prefecture (72) Inventor Sadafumi Eda 1144, Togo, Togo, Mobara-shi, Chiba Mitsui Chemicals, Inc. (72) Inventor Susumu Shingae 301, Gensuke, Fujieda-shi, Shizuoka Address: Kaken Pharmaceutical Co., Ltd. Specialty Drug Laboratory (72) Inventor Hiroshi Ito 2-28-8 Honkomagome, Bunkyo-ku, Tokyo Kaken Pharmaceutical Co., Ltd.

Claims (3)

[Claims] 1. A throw-in herbicidal preparation for paddy fields, wherein an emulsion containing at least an active ingredient for paddy field herbicides, a solvent and a surfactant is contained in a water-soluble container. 2. The throw-in herbicidal preparation for paddy fields according to claim 1, wherein the material of the water-soluble container is polyvinyl alcohol, and the thickness of the container is 0.1 to 3 mm. 3. The throw-in herbicidal preparation for paddy field according to claim 1, wherein the herbicidal active ingredient for paddy field is pentoxazone.