JP5336741B2 - Stable suspension formulation with reduced phytotoxicity - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a suspension formulation for a paddy field, having excellent storage stability and giving little chemical injury to a rice body. <P>SOLUTION: The chemical injury-reduced stable suspension formulation comprises (a) 0.1-60 wt.% herbicidal active ingredient having at least 100 ppm water solubility at 20&deg;C, (b) 0.01-1 wt.% surfactant, (c) 0.01-5 wt.% thickener, (d) 5-20 wt.% crystal precipitation inhibitor and (e) 20-90 wt.% water, and has 800-1,400 mPa s viscosity at 20&deg;C when the number of revolution of no. 2 rotor is 12 rpm. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a stable suspension preparation for paddy field with reduced phytotoxicity, comprising a herbicidal active ingredient having a water solubility at 20 ° C. of at least 100 ppm and improved storage stability and contact phytotoxicity to rice plants.

  As an aqueous suspension preparation for direct spraying of paddy fields in which a herbicidal active ingredient is suspended and dispersed in water, for example, a herbicidal active ingredient having a water solubility of 100 ppm (25 ° C.) or less is suspended and dispersed in water with a surfactant. Aqueous suspension formulation (see Patent Documents 1, 2, and 3) Physical properties of a viscosity of 180 to 500 mPa · s (25 ° C.) obtained by suspending a water-insoluble herbicidal active ingredient finely pulverized to 10 μm or less in water An aqueous suspension preparation (see Patent Document 4), a herbicidal active ingredient having an average particle size of 0.5 to 5.0 μm and a water solubility of 100 ppm (25 ° C.) or less is suspended and dispersed in water with a surfactant. Known are aqueous suspension preparations (see Patent Document 5), aqueous suspension preparations obtained by suspending and dispersing an agrochemical active ingredient and crystalline cellulose in water with a surfactant (see Patent Document 6), and the like.

Japanese Examined Patent Publication No. 7-47521 Japanese Patent Laid-Open No. 10-316503 JP 2004-26485 A JP 62-87501 A Japanese Examined Patent Publication No. 7-47522 JP 2006-169167 A

  Aqueous suspension formulation for direct spraying of paddy fields using water as a dispersion medium can be sprayed directly from the container to the paddy fields without diluting with water at the time of spraying, which is excellent in terms of safety, economy and labor saving. It is a dosage form. However, herbicidal active ingredients having a water solubility at 20 ° C. of at least 100 ppm may cause sedimentation of dispersoids and precipitation of crystals during storage when prepared into an aqueous suspension formulation for direct application using conventional techniques as described above. In addition, when sprayed on paddy field, there are drawbacks such as chemical damage due to the fact that the chemical tends to adhere to rice plants.

  It is an object of the present invention to have an excellent formulation stability during storage, have little phytotoxicity to rice plants when used in paddy fields, can exhibit a sufficient herbicidal effect, and has a water solubility at 20 ° C. of at least 100 ppm. An aqueous suspension formulation containing a soluble herbicidal active ingredient is provided.

  As a result of intensive studies to achieve the above object, the present inventors have determined that a herbicidal active ingredient having a water solubility at 20 ° C. of at least 100 ppm, a surfactant, a thickener, and a crystal precipitation inhibitor. And found that a stable aqueous suspension formulation with excellent storage stability and no phytotoxicity to rice plants can be obtained by forming an aqueous suspension formulation with a specific viscosity together with water and water. It came to do.

Thus, the present invention
(A) 0.1 to 60% by weight of a herbicidal active ingredient whose water solubility at 20 ° C. is at least 100 ppm,
(B) Surfactant 0.01-1% by weight,
(C) Thickener 0.01-5% by weight,
(D) Crystal precipitation inhibitor 5-20% by weight, and (e) Water 20-90% by weight.
And a stable suspension preparation with reduced phytotoxicity characterized in that the viscosity at 20 ° C. when the rotational speed of the No. 2 rotor is 12 rpm is in the range of 800 to 1400 mPa · s.

  Hereinafter, the stable suspension preparation with reduced phytotoxicity of the present invention will be described in more detail.

BEST MODE FOR CARRYING OUT THE INVENTION

Herbicidal active ingredient (a) :
The herbicidal active ingredient (a) used in the present invention includes compounds having the ability to kill or suppress generally undesirable plants such as herbicides and plant growth regulators. Of interest are herbicidally active ingredients that are readily soluble in water having a water solubility at 100 ° C. of at least 100 ppm, preferably at least 200 ppm.

  Specific examples of the herbicidal active ingredient (a) include tefryltrione, penoxsulam, cimetrine, bentazone, azimusulfuron, benfreceto, and molinate, with tefryltrione being particularly preferred.

  The herbicidal active ingredient (a) of the present invention is not limited to those described above. For example, “Agricultural Chemicals Handbook 2005 Edition” (issued in October 2005 by the Japan Plant Protection Association), “The Pesticide Manual Fourteenth Edition” Any herbicidal active ingredient having a solubility in water at 20 ° C. of at least 100 ppm described in documents such as (British Crop Protection Council 2006) can be used. These herbicidal active ingredients can be used alone or in combination of two or more.

  The content of the herbicidal active ingredient (a) in the suspension preparation of the present invention is not strictly limited and can be appropriately changed according to the type of herbicidal active ingredient, but the weight of the suspension preparation is not limited. In general, a range of 0.1 to 60% by weight, particularly 0.3 to 40% by weight, more particularly 0.5 to 20% by weight is preferred.

Surfactant (b) :
Examples of the surfactant (b) that can be used in the suspension preparation of the present invention include alkylbenzene sulfonate, alkyl naphthalene sulfonate, naphthalene sulfonate formalin condensate, dialkyl sulfosuccinate, and lignin. Sulfonate, α-olefin sulfonate, alkane sulfonate, polystyrene sulfonate, alkyl ether sulfate salt, polyoxyethylene alkyl ether sulfate salt, polyoxyethylene allyl phenyl ether sulfate amine salt, polyoxyethylene alkylphenyl Ether sulfate salt, polyoxyethylene polystyryl phenyl ether sulfate salt, polyoxyethylene alkyl ether phosphate salt, polyoxyethylene alkyl phenyl ether Anionic surfactants such as phosphate salts, polyoxyethylene polystyryl phenyl ether phosphate salts, fatty acid salts, isobutylene-maleic acid copolymer salts, styrene-maleic acid copolymer salts, polyacrylates; alkylamine salts, Cationic surfactants such as tetraalkylammonium salt, trialkylbenzylammonium salt, dialkylsulfosuccinate; polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene stilphenyl ether, poly Oxyethylene stilphenyl ether polymer, polyoxyethylene sorbitan alkyl ester, polyoxyethylene polyoxypropylene block polymer,
Nonionic surfactants such as polyoxyethylene alkyl esters and polyoxyethylene alkyl amines; silicone surfactants; fluorine surfactants and the like. These surfactants can be used alone or in combination of two or more.

  The content of these surfactants (b) in the suspension preparation of the present invention is not particularly limited, but is usually 0.01 to 1% by weight, particularly 0.05 to 0%, based on the weight of the suspension preparation. It is preferred that the content be within a range of 9.9% by weight, more particularly 0.1 to 0.8% by weight.

Thickener (c) :
As the thickener (c) that can be used in the suspension preparation of the present invention, those commonly used in agricultural chemical preparations such as xanthan gum, tragacanth gum, casein, dextrin, carboxymethyl cellulose, colloidal hydrous silica Examples include magnesium silicate, colloidal hydrous aluminum silicate, colloidal aluminum magnesium silicate, and the like. These thickeners can be used alone or in combination of two or more.

  The content of these thickeners (c) in the suspension preparation of the present invention is not particularly limited, but is usually 0.01 to 5% by weight, particularly 0.05 to 3%, based on the weight of the suspension preparation. It is preferred to be in the range of wt%, more particularly 0.1 to 1 wt%.

Crystalline precipitation inhibitor (d) :
Examples of the crystal precipitation inhibitor (d) that can be used in the suspension preparation of the present invention include polyhydric alcohols such as propylene glycol, ethylene glycol, and glycerin. These crystal precipitation inhibitors can be used alone or in combination of two or more.

  The content of these crystal precipitation preventing agents (d) in the suspension preparation of the present invention is not particularly limited, but is usually 5 to 20% by weight, particularly 6.5 to 18% by weight, based on the weight of the suspension preparation. %, More particularly in the range of 8 to 16% by weight.

Water (e) :
Examples of water (e) that can be used in the suspension preparation of the present invention include drinking water such as tap water and industrial water.

  The content of water (e) in the suspension preparation of the present invention is not particularly limited, but is usually 20 to 90% by weight, particularly 25 to 80% by weight, more particularly 30 to 70%, based on the weight of the suspension preparation. The range of% by weight is preferred.

  In addition to the components described above, the suspension preparation of the present invention includes, as an optional component, for example, for the purpose of improving the herbicidal effect and / or broadening the types of weeds to be weeded. Other herbicidal active ingredients, other additives (for example, for the purpose of improving the formulation properties when formulating a suspension formulation of the above and / or keeping the herbicidal active ingredient stable in the formulation, for example) , Antifoaming agents, preservatives, antioxidants, ultraviolet absorbers, etc.) can be appropriately contained.

As the other herbicidal active ingredient, a herbicidal active ingredient having a water solubility at 20 ° C. of less than 100 ppm, preferably 50 ppm or less can be used. And herbicides such as pretilachlor, butachlor, tenylchlor, benfrate, caffentrol, indanophan, cyhalohopbutyl, pyriminobacmethyl, eprocarb, ettobenzanide, pentoxazone, and pyriftalide.

  Examples of the other additives include antifoaming agents such as silicon-based and fatty acid-based materials; 1,2-benzisothiazolin-3-one, potassium sorbate, p-chloro-metaxylenol, p-oxybenzoic acid Preservatives such as butyl; antioxidants such as triphenyl phosphite, phenyl diisodecyl phosphite, cyclic neopentanetetrayl bis; phenyl salicylate, 2,4-dihydroxybenzophenone, 2- (2′-hydroxy-5′- And ultraviolet absorbers such as methylphenyl) benzotriazole.

  The above optional components can be used alone or in combination of two or more, and their content in the suspension preparation of the present invention is not particularly limited, but in total, based on the weight of the suspension preparation, Usually, it can be in the range of 0.1 to 50% by weight, preferably 0.3 to 40% by weight, more preferably 0.5 to 30% by weight.

  The stable suspension formulation with reduced phytotoxicity of the present invention can be prepared by a suspension formulation method commonly used in the formulation of agricultural chemicals. Specifically, for example, a surfactant is dissolved or dispersed in water, and a herbicidal active ingredient and an antifoaming agent are added thereto. The obtained mixed solution is wet-pulverized with Dynomill (trade name, manufactured by Shinmaru Enterprises Co., Ltd.) using glass beads having a diameter of 1.0 to 1.41 mm as a pulverizing medium. Next, a thickener, a crystal precipitation inhibitor and other auxiliary agents as necessary are added to this mixed solution, and water is added to make 100% by weight. Three-one motor (trade name, manufactured by Shinto Kagaku Co., Ltd.) The suspension preparation of the present invention can be obtained by mixing using

  The stable suspension preparation with reduced phytotoxicity of the present invention obtained by the above-mentioned suspension preparation method has a viscosity at 20 ° C. when the rotation speed of the No. 2 rotor is 12 rpm, usually 800 to 1400 mPa · s, preferably 850 to It exists in the range of 1300 mPa * s, More preferably, 900-1200 mPa * s.

  The stable suspension preparation with reduced phytotoxicity of the present invention thus prepared can be applied to paddy fields in the same manner as suspension preparations of ordinary paddy herbicides. For example, this suspension preparation is put into a 500 mL capacity plastic container with a hole without diluting with water, and it is moved forward in the paddy field by shaking left or right by hand, or 2 to 2 using a stock solution or a small amount of water. It can be applied to paddy fields using a rice transplanter equipped with a machine capable of dropping a high-concentration liquid diluted 10-fold. In addition, it can be sprayed in the air from RC helicopters that are widely used in recent years, and when irrigation water flows in, the inflowing water is dripped at the water intake (pad) of the paddy field and poured into the paddy field together with the inflowing water. You can also.

  The application amount per unit area of the suspension preparation of the present invention is not particularly limited, but it is desirable to spray within a range of usually 50 to 1000 ml, particularly 100 to 500 ml per 10 are.

  When the suspension preparation of the present invention is sprayed onto a paddy field, it hardly adheres to the rice body and immediately falls to the surface of the water, and the active ingredient diffuses quickly in water. Therefore, there is little phytotoxicity to paddy rice and it shows an excellent herbicidal effect. Further, even when the preparation is stored for a long period of time, sedimentation of dispersoids and crystal precipitation of the active ingredient are not observed in the preparation, and the preparation is extremely useful as a preparation having stable quality.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

Example 1
Pyraclonil base 3.75% by weight, tefryltrione base 6.29% by weight, polyoxyethylene allyl phenyl ether sulfate phosphate salt 0.5% by weight, silicone emulsion 0.3% by weight, 1,2-benzoisothiazoline -3-ON 0.2% by weight and water 63.96% by weight were mixed with a three-one motor (trade name, manufactured by Shinto Kagaku Co., Ltd.), and this mixed solution was used as a grinding medium with a diameter of 1.0 to 1.41 mm. The glass beads are wet pulverized with a Dino mill (trade name, manufactured by Shinmaru Enterprises Co., Ltd.). To this pulverized product, 15.0% by weight of a 2% aqueous solution of xantha gum and 10.0% by weight of propylene glycol were added and mixed uniformly with a three-one motor (trade name, manufactured by Shinto Kagaku Co., Ltd.) to stabilize the suspension with reduced chemical damage. A formulation is obtained.

Example 2
18.54% by weight of mefenacet base, 5.71% by weight of tefryltrione base, 0.5% by weight of polyoxyethylene allyl phenyl ether sulfate phosphate salt, 0.3% by weight of silicone emulsion, 1,2-benzoisothiazoline -3-ON 0.2% by weight and water 49.75% by weight were mixed with a three-one motor (trade name, manufactured by Shinto Kagaku Co., Ltd.), and the mixed solution was used as a grinding medium with a diameter of 1.0 to 1.41 mm. The glass beads are wet pulverized with a Dino mill (trade name, manufactured by Shinmaru Enterprises Co., Ltd.). To this pulverized product, 15.0% by weight of xanthamum 2% aqueous solution and 10% by weight of propylene glycol were added and mixed uniformly with a three-one motor (trade name, manufactured by Shinto Kagaku Co., Ltd.). obtain.

Example 3
5.85% by weight of fentrazamide base, 6.02% by weight of tefryltrione base, 0.5% by weight of polyoxyethylene allyl phenyl ether sulfate phosphate salt, 0.3% by weight of silicone emulsion, 1,2-benzoisothiazoline -3-ON 0.2% by weight and 62.13% by weight of water were mixed with a three-one motor (trade name, manufactured by Shinto Kagaku Co., Ltd.), and this mixed solution was used as a grinding medium with a diameter of 1.0 to 1.41 mm. The glass beads are wet pulverized with a Dino mill (trade name, manufactured by Shinmaru Enterprises Co., Ltd.). To this pulverized product, 15.0% by weight of xanthamum 2% aqueous solution and 10% by weight of propylene glycol were added and mixed uniformly with a three-one motor (trade name, manufactured by Shinto Kagaku Co., Ltd.). obtain.

Comparative Example 1
Pyraclonil base 3.75% by weight, tefryltrione base 6.29% by weight, polyoxyethylene allylphenyl ether sulfate phosphate salt 2.0% by weight, silicone emulsion 0.3% by weight, 1,2-benzoisothiazoline -3-ON 0.2% by weight and water 72.46% by weight were mixed with a three-one motor (trade name, manufactured by Shinto Kagaku Co., Ltd.), and this mixed solution was used as a grinding medium with a diameter of 1.0 to 1.41 mm. The glass beads are wet pulverized with a Dino mill (trade name, manufactured by Shinmaru Enterprises Co., Ltd.). To this pulverized product, 10.0% by weight of 2% aqueous solution of xanthamum and 5% by weight of propylene glycol are added and mixed uniformly with a three-one motor (trade name, manufactured by Shinto Kagaku Co., Ltd.) to obtain an aqueous suspension preparation.

Comparative Example 2
Pyraclonil base 3.75% by weight, tefryltrione base 6.29% by weight, polyoxyethylene allylphenyl ether sulfate phosphate salt 5.0% by weight, silicone emulsion 0.3% by weight, 1,2-benzoisothiazoline -3-ON 0.2% by weight and water 69.46% by weight were mixed with a three-one motor (trade name, manufactured by Shinto Kagaku Co., Ltd.), and this mixed solution was used as a grinding medium with a diameter of 1.0 to 1.41 mm. The glass beads are wet pulverized with a Dino mill (trade name, manufactured by Shinmaru Enterprises Co., Ltd.). To this pulverized product, 10.0% by weight of 2% aqueous solution of xanthamum and 5% by weight of propylene glycol are added and mixed uniformly with a three-one motor (trade name, manufactured by Shinto Kagaku Co., Ltd.) to obtain an aqueous suspension preparation.

  Next, the effects of the stable suspension formulations with reduced phytotoxicity obtained in Examples 1 to 3 and the aqueous suspension formulations obtained in Comparative Examples 1 and 2 were evaluated by the following Test Examples 1 and 2.

Test Example 1 (Storage stability test)
50 ml of each of the suspension preparations of Examples 1 to 3 and Comparative Examples 1 and 2 were placed in a 50 ml sample bottle, sealed, and allowed to stand in a temperature-controlled room at 40 ° C. for 3 months. The preparation in the sample bottle is observed in the separated state (the ratio of the suspended layer and the whole layer settled in the lower layer), and the water layer (upper skid layer) formed in the upper layer in the sample bottle and the height of the whole preparation layer ( The height of all layers) was measured, and the suspension stability of the preparation was calculated using the following formula.

Suspension stability (%) = (X−Y / X) × 100
X: Height of all layers (cm)
Y: Upper ski layer (cm)
Moreover, the presence or absence of crystal precipitation was visually observed about the sample bottle which left still in a -15 degreeC thermostat for 3 days, and left still in a 20 degreeC thermostat for 1 day after that. The results are shown in Table 1.

Test example 2 (phytotoxicity test)
Paddy soil was filled in a 1/5000 are Wagner pot, and two 2.5-leaf rice seedlings (Koshihikari) were transplanted per pot. Five days after the transplanting of paddy rice, 50 μl of each suspension preparation similar to Test Example 1 was dropped from the height of 1 cm onto the middle part of the second leaf of the rice with a microsyringe. The degree was investigated. The test was performed in 3 replicates for each treatment. The results are shown in Table 1.

Degree of phytotoxicity 0: No phytotoxicity 1: Marked marks remain on the attached part 2: Less than 1/4 of the attached leaves browned 3: More than 1/4 to less than 1/2 of the attached leaves browned 4: 1/2 of the attached leaves Above-less than 3/4 browned 5: More than 3/4 of the attached leaves browned

  As apparent from Table 1 above, the suspension preparations of Examples 1 to 3 according to the present invention are superior to the suspension preparations of Comparative Examples 1 and 2 in suspension stability and there is no fear of crystal precipitation. Furthermore, no phytotoxicity is observed on rice.

Claims (3)

(A) 0.1 to 60% by weight of a herbicidal active ingredient whose water solubility at 20 ° C. is at least 100 ppm,
(B) Surfactant 0.01-1% by weight,
(C) at least one thickener selected from xanthan gum, colloidal hydrous magnesium silicate, colloidal hydrous aluminum silicate and colloidal hydrous magnesium aluminum silicate 0.01 to 5% by weight,
(D) Crystal precipitation inhibitor 5 to 20% by weight, and (e) Water 20 to 90% by weight.
A stable suspension formulation for direct spraying of paddy fields with reduced phytotoxicity, wherein the viscosity at 20 ° C. when the rotation speed of No. 2 rotor is 12 rpm is in the range of 800 to 1400 mPa · s. Herbicidal active ingredient (a) is tefuryltrione, penoxsulam, simetryn, stable suspension formulation of claim 1 is at least one bentazone, selected from Baie Nfureseto and molinate.   The stable suspension preparation according to claim 1 or 2, wherein the crystal precipitation inhibitor (d) is at least one selected from propylene glycol, ethylene glycol and glycerin.