JPH0656604A - Herbicide for paddy field - Google Patents

Abstract

PURPOSE:To obtain a herbicide excellent in disintegration in water and diffusibility and having good long-term storage stability by blending a system consisting of a herbicidal activity ingredient for paddy field and a surfactant with a specific amount of water absorbing resin and a specific amount of carbonic acid salt and a water soluble solid acidic substance. CONSTITUTION:This herbicide for paddy field is obtained by blending a water absorbing resin (e.g. a starch/acrylic acid salt graft polymer) of 2-85wt.%, especially 10-50wt.% based on total weight and a carbonic acid salt (especially preferably selected from a carbonic acid salt, a sesquicarbonic acid salt and a hydrogen carbonic acid salt) and a water soluble solid acidic substance of 1-20wt.%, especially 5-20wt.% based on the total weight. When this herbicide is applied to paddy field filled with water, the water absorbing resin is swollen, and further, the effect is remarkably enhanced by a small amount of a foaming agent and the herbicide is quickly disintegrated and diffused. Thereby, since the herbicidal activity ingredient is quickly diffused in paddy field, sufficient herbicidal effect is exhibited. Further, the herbicide can be prepared as large- sized tablet.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a herbicide for paddy fields, which is excellent in disintegration and diffusion in water.

[0002]

2. Description of the Related Art Conventionally, herbicides for paddy fields have been variously examined for their disintegration and diffusibility in water, and have been improved by surfactants and the like.

However, studies have been made on making a large tablet for the dosage form, and recently there has been a demand for increasing the size of the dosage form in order to save the application labor, and the surfactant alone gives sufficient disintegration and diffusibility in water. I can't.

In order to improve such drawbacks, as a method for improving the disintegration in water and the diffusibility, for example, a method of adding a foaming agent to improve the disintegration in water and the diffusibility (Japanese Patent Publication No. 47-27930). No. 128301, No. 3-264503, No. 3-271201) have been proposed.

[0005]

However, even by the method of blending these foaming agents, the initial disintegrating property at the time of application is not always sufficient, and there is a problem of long-term storage stability. There is.

[0006]

In view of such a situation, the present inventors have found that the herbicide for paddy fields is excellent in water disintegration and diffusibility, has good long-term storage stability, and is compatible with large dosage forms. As a result of repeated intensive studies, the present invention has been completed.

That is, the present invention contains a herbicidal active ingredient for paddy fields, a surfactant, a water absorbent resin, a carbonate and a water-soluble solid acidic substance, and the weight of the water absorbent resin is 2 to 85 with respect to the total weight. %, And the weight of the carbonate and the water-soluble solid acidic substance is 1 to 20% based on the total weight of the paddy field. Further, the carbonate of the present invention,
The present invention relates to a paddy field herbicide which is one kind or a mixture of two or more kinds selected from carbonate, sesquicarbonate and hydrogen carbonate.

The herbicidal active ingredient for paddy field used in the herbicide for paddy field of the present invention is not particularly limited, but examples thereof include the following compounds.

(Compound 1) 2 ', 3'-dichloro-4-ethoxymethoxybenzanilide

(Compound 2) 5-[(4,6-dimethoxypyrimidin-2-yl) aminocarbonylaminosulfonyl] -1-methylpyrazol-4-carboxylic acid ethyl ester

(Compound 3) N- (2-chloroimidazo [1,2-a] pyridin-3-ylsulfonyl) -N'-
(4,6-Dimethoxy-2-pyrimidinyl) urea

(Compound 4) 3 ', 4'-dichloropropionanilide

(Compound 5) 1- (α, α-dimethylbenzyl) -3- (4-methylphenyl) urea

(Compound 6) S- (4-chlorobenzyl)-
N, N-diethyl-thiocarbamate

(Compound 7) 3,5-diethylphenyl-4
-Nitrophenylethyl

The above herbicidal active ingredients for paddy fields may be used alone or in admixture of two or more, if necessary, and when mixed, the compounding ratio can be arbitrarily selected. The amount of these herbicidal active ingredients varies depending on the kind of the active ingredients, but is generally in the range of 0.1 to 60%, preferably 2 to 50% based on the total weight.

Examples of the surfactant used in the paddy field herbicide of the present invention include alkylbenzene sulfonates such as sodium dodecylbenzenesulfonate, alkylnaphthalenesulfonates, formalinic acid condensates of naphthalenesulfonates, and lignin sulfone. Carboxyl salts such as lignin sulfonates such as sodium acid salts, alkyl aryl sulfonates, dialkyl sulfosuccinates, polyoxyethylene alkyl aryl ether sulfates, sodium salts of copolymers of maleic acid and isobutylene Anionic surfactant such as alkali metal salt of group-containing copolymer, polyoxyethylene alkyl ether
Tell, polyoxyethylene alkylphenyl ether,
Examples thereof include nonionic surfactants such as polyoxyethylene styryl phenyl ether, polyoxyethylene alkyl ester, sorbitan alkyl ester, and polyoxyethylene sorbitan alkyl ester.
Moreover, you may use a cationic surfactant, a zwitterionic surfactant, etc. as needed.

These surfactants may be used alone or as a mixture of two or more kinds at an arbitrary ratio. The amount of surfactant is usually 1-40%, preferably 3-20%, based on the total weight.

The weight of the water absorbent resin used in the herbicide of the present invention is preferably 10 to 50% of the total weight. The water-absorbent resin as used herein means a polymeric substance which is hardly soluble or practically insoluble in water, and has a property of absorbing a large amount of water and swelling when contacted with water.

The larger the water absorption capacity of the water absorbent resin is, the better. However, it is usually sufficient if it absorbs 50 times or more, preferably 100 to 2000 times as much water as the weight of the water absorbent resin. Examples of such water absorbent resin include starch / acrylic acid salt graft polymer, carboxymethyl cellulose crosslinked product, vinyl alcohol / acrylic acid salt copolymer, polyacrylonitrile hydrolyzate, crosslinked polyacrylic acid. Examples thereof include salts, modified polyvinyl alcohol, crosslinked polyethylene oxide, vinyl / monomethyl maleate copolymer, isobutylene / maleic anhydride copolymer and the like.

The total weight of the carbonate and the water-soluble solid acidic substance used in the present invention is preferably 5 to 20% of the total weight.

Examples of the carbonate used in the present invention include sodium carbonate, potassium carbonate, lithium carbonate, ammonium carbonate, calcium carbonate and the like. Examples of the sesquicarbonate include sodium sesquicarbonate, potassium sesquicarbonate, ammonium sesquicarbonate and the like. Examples of the hydrogen carbonate include sodium hydrogen carbonate, potassium hydrogen carbonate, ammonium hydrogen carbonate and the like. Of these, sodium hydrogen carbonate and sodium carbonate are particularly preferable. The above-mentioned carbonates and the like are used alone or in combination of two or more kinds in an arbitrary ratio.

Examples of the water-soluble solid acidic substance used in the present invention include citric acid, maleic acid, succinic acid, fumaric acid, tartaric acid, oxalic acid, malonic acid, malic acid, phthalic acid, adipic acid, boric acid and phosphorus. Examples thereof include sodium dihydrogen acid, potassium dihydrogen phosphate, ammonium dihydrogen phosphate, aluminum sulfate, potassium alum, ammonium alum and the like. Of these, citric acid and maleic acid are particularly preferable. These may be used alone or in combination of two or more at an arbitrary ratio. In addition to the combination of the above foaming agents, for example, ammonium nitrate, percarbonate and the like can be used as the foaming agent.

The herbicide of the present invention contains lactose, if necessary,
Powdery water-soluble carrier such as polyethylene glycol powder having an average molecular weight of 6000 to 20000, and gum arabic, tragacanth gum, xanthan gum, methylcellulose
Water-soluble polymers such as sucrose, hydroxypropylcellulose, polyvinylpyrrolidone, polyvinyl alcohol, and soluble starch can also be added. Further, a water-soluble carrier can be added.

When the herbicidal active ingredient for paddy fields is a solid, the herbicidal agent of the present invention is mixed with only the herbicidal active ingredient for paddy fields or a surfactant and / or a water-absorbent resin, and then jet mizer, bottle mill, It can be manufactured by crushing with a dry crusher such as a hammer mill and then mixing the remaining components. When the paddy field herbicidal active ingredient is a liquid or is in a liquid state by adding a solvent, after the paddy field herbicidal active ingredient is absorbed into a powdery oil-absorbing carrier such as hydrous silicic acid, the same as above. It may be manufactured by any method.

The powdery herbicide of the present invention thus obtained may be used as it is, but it may be made into granules or tablets in view of handling, safety and environmental protection. preferable. The granules referred to here are granulated granules of a powdered herbicidal composition, the shape of which varies depending on the granulation method, and various shapes such as cylindrical and spherical shapes to irregular shapes can be used. Is possible. A tablet is produced by compressing the herbicidal composition into a certain shape,
The shape is a disc type with no edges, corners, rounded corners, lens shape with shallow curvature to deep curvature,
Various shapes such as billow-shaped, almond-shaped, finger-shaped, triangular, quadrangular, pentagonal, and capsule-shaped are possible.

The granules are the above-mentioned powdery herbicides of the present invention, using a dry granulator such as a roller compactor or a pre-ketching machine or a slug machine. It can be obtained by crushing or breaking this with a sieving machine or the like. Since this method does not use water, no swelling occurs during the manufacturing process, and therefore significant swelling occurs when the granules are applied to the paddy field, sufficient for subsequent disintegration and diffusion. .

The above granules have a particle size of 100 to 10,000 μm.
m is more preferable, and the range of 250 to 4000 μm is more preferable.

Tablets are obtained by putting a certain weight of the above powder composition into a mortar and tableting it. Industrially, using the above powder or granules, a tabletting machine or a preketting machine, etc. A tablet having a constant weight can be continuously obtained by tableting with.

Although the size of the tablet depends on the application method,
Usually, the diameter is 5 to 60 mm and the thickness is 1 to 40 mm, and the weight per tablet is 0.3 to 100 g, more preferably 1 to 50 g.

The herbicide for paddy field of the present invention is applied to paddy field under flooded water, and its application amount depends on the kind of each active ingredient and is not particularly limited, but usually 5 per 10 aal.
It is applied in the range of 0 to 2000 g, preferably 500 to 1000 g.

The herbicide of the present invention can be easily applied without using any special equipment. For example,
By applying the herbicide of the present invention to the paddy field evenly or at one or more points in the paddy field, by applying the herbicide of the present invention to the side of the ridge or the mouth of the paddy field without entering the paddy field, or by applying from the ridge. , The active ingredient can be spread throughout the paddy field.

When the herbicide for paddy field of the present invention is applied to a flooded paddy field, swollen water-absorbent resin causes rapid disintegration and diffusion, and its effect is remarkably enhanced by a small amount of a foaming agent. The herbicidal active ingredient for paddy fields spreads quickly and uniformly in the paddy field, so it exerts a sufficient herbicidal effect.
In addition, it has excellent performance with little chemical damage to paddy crops. The application rate can be significantly reduced compared to the conventional application rate (for example, in the case of granules, 3000 to 4000 g per 10 al), it is also useful from the viewpoint of labor saving in manufacturing, transportation, storage and application of products. It is expensive.

[0034]

EXAMPLES Next, the present invention will be described in more detail with reference to formulation examples, comparative examples and test examples, but the present invention is not limited to these examples. The parts in the formulation examples and comparative examples represent parts by weight.

First, formulation examples are shown. [Formulation Example 1] 30 parts of (Compound 1), water absorbent resin (Kao P
OIZ-SA20, polyacrylic acid starch system) 45 parts, sodium carbonate 7.5 parts and maleic acid 7.5 parts, SO
10 parts of RPOR5073 (Toho Kagaku Sulfate type / carbonate blended) were mixed well with a juice mixer, and 50 g of this mixture was placed in a tablet molding machine having a diameter of 30 mm and 100 g.
Tablets were obtained by tableting at a pressure of kg / cm2.

[Formulation Example 2] 15 parts of (Compound 1), 30 parts of water absorbent resin (Sanyo Kasei Sunwet 1M-1000, starch starch polyacrylate), 7.5 parts of sodium hydrogen carbonate and 7.5 parts of citric acid. , SORPOR5073 (Toho Chemical Sulfate Type / Carbonate Blend) 10 parts, SORPOR
1070 parts of 8070 (Toho Kagaku Alkylsulfate) and 20 parts of sericite were well mixed with a juice mixer, and 50 g of this mixture was put into a tablet molding machine having a diameter of 30 mmφ.
Tablets were obtained by tableting at a pressure of 00 kg / cm 2.

[Formulation Example 3] 15 parts of (Compound 1), 0.2 part of (Compound 2), water absorbent resin (Sumitomo Seika Aqua-Keep 4
S, polyacrylic acid PVA type) 15 parts, sodium hydrogencarbonate 7.5 parts and fumaric acid 7.5 parts, SORPOR5
073 (Toho Chemical Sulfate type / carbonate combination) 10
Parts, SORPOR8070 (Toho Kagaku Alkylsulfate) 10 parts and sericite 34.8 parts were well mixed with a juice mixer, and 50 g of this mixture was put into a tablet press having a diameter of 30 mm and pressure of 100 kg / cm @ 2. Tablets were obtained by tableting with.

[Formulation Example 4] 30 parts of (Compound 1), 1.8 parts of (Compound 3), water-absorbent resin (Sanyo Kasei Sunwet 1
M-1000MPS, polyacrylic acid starch system) 10 parts,
7.5 parts of sodium hydrogen carbonate and 7.5 parts of succinic acid,
15 parts of SORPOR5073 (Toho Kagaku Sulfate type / carbonate blend) and 28.2 parts of sericite were mixed well with a juice mixer, and 50 g of this mixture was prepared with a diameter of 30 mmφ.
The tablet was put into the tablet molding machine of No. 1 and tableted at a pressure of 100 kg / cm 2 to obtain tablets.

Next, a comparative example will be shown. [Comparative Example 1] 5 parts of (Compound 1), 30 parts of bentonite,
After adding 61 parts of Kaolin clay and 4 parts of Sun Extract C (Sanyo Kokusaku pulp, lignin sulfonic acid type) to the kneader and mixing them well, 17 parts of water was added and mixed well again. Then, after granulating with an extrusion granulator equipped with a 0.7 mmφ screen and sizing, drying at 70 ° C. for 5 hours, 297
Granules of ˜1680 μm were obtained.

[Comparative Example 2] 5 parts of (Compound 1), REAX
85A (Westvaco's sodium lignin sulfonate) 27.5 parts, REAX 88B (Westv
aco, sodium lignin sulfonate) 1.5 parts,
GEROPON SC-211 (Sodium salt of copolymer having carboxyl group manufactured by Rhone-Plain) 6
Parts, 30 parts of sodium carbonate and 30 parts of maleic acid were thoroughly mixed with a juice mixer and then pulverized with a centrifugal pulverizer. Next, this is set to 50 k using a roller compactor.
After forming a sheet-like granulated product at a pressure of g /, it was crushed using a mortar and a pestle and sized to a particle size of 297 to 1000 μm to obtain a granule. Subsequently, 3 g of the obtained granules were put into a tableting molding machine having a diameter of 30 mmφ and tableted under a pressure of 500 kg / to obtain tablets.

Next, a test example will be shown. {Test Example 1} Water was poured to an average water level of 6 cm in a field divided into 5 m and 5 m. Next, the tablets and granules obtained in Formulation Examples 1 and 2 and Comparative Examples 1 and 2 were added so that the amount of the active ingredient was 150 g / 10a, and in Formulation Example 3, the amount of the active ingredient of (Compound 2) was 20 g. The amount of the active ingredient of (Compound 3) is 18 g /
It was charged so as to be 10a, and the moving distance of the sample was visually observed according to the following evaluation criteria. The input position was the center of the plot field. Also, 3 hours after charging, 0 cm, 1 from the charging position
100 ml of the liquid at 00 cm, 200 cm, 300 cm and 0.5 cm from the bottom of the water was placed in a ladle, and then 25 ml was sampled with a hole pipette to evaporate the water, and the amount of active ingredient was determined by gas chromatography. It was quantified. The results are shown in Table 1.

The evaluation criteria for diffusibility in Table 1 are as follows:
It is as follows.

[0043]

[Table 1]

[0044]

EFFECTS OF THE INVENTION Since the present invention is constructed as described above, the herbicide of the present invention can be easily applied without using any special device. For example, the user enters the paddy field and applies the herbicide of the present invention uniformly or at one or more points in the paddy field, or applies to the side of the ridge or the mouth of the paddy field without entering the paddy field, or inputs from the ridge. The active ingredient can be spread throughout the paddy field.

When the herbicide of the present invention is applied to a flooded paddy field, in addition to the water-absorbent resin swelling, its effect is markedly increased by a small amount of a foaming agent, and rapid disintegration and diffusion occur. Since the herbicidal active ingredient for paddy field diffuses rapidly and uniformly in the paddy field, it exerts a sufficient herbicidal effect and exerts an excellent effect that there is little phytotoxicity to crops in the paddy field. Further, since the herbicide of the present invention can significantly reduce the applied amount as compared with the conventional preparations, it is highly useful from the viewpoint of labor saving of production, transportation, storage and spraying of products.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yukihiko Inayoshi 45 Miyukigaoka, Tsukuba, Ibaraki Prefecture Hodogaya Chemical Industry Co., Ltd. Tsukuba Research Laboratory (72) Inventor Tatsuo Ansai 45 Miyukigaoka, Tsukuba, Ibaraki Prefecture Tsuchiya Chemical Industry Co., Ltd. Tsukuba Research Center

Claims (2)

[Claims] 1. A herbicide active ingredient for paddy fields, a surfactant, a water absorbent resin, a carbonate and a water-soluble solid acidic substance are contained, and the weight of the water absorbent resin is 2 to 85% based on the total weight.
A paddy field herbicide in which the total weight of the carbonate and the water-soluble solid acidic substance is 1 to 20% of the total weight. 2. A herbicide for paddy fields, wherein the carbonate according to claim 1 is one kind or a mixture of two or more kinds selected from carbonate, sesquicarbonate and hydrogen carbonate.