WO2007031251A2

WO2007031251A2 - Water-suspendable agricultural chemical composition

Info

Publication number: WO2007031251A2
Application number: PCT/EP2006/008825
Authority: WO
Inventors: Atsushi Tomioka; Hiroshi Hasegawa; Yukiko Suda; Morio Yamanaka; Woonsun Jeon
Original assignee: Syngenta Participations Ag
Priority date: 2005-09-12
Filing date: 2006-09-11
Publication date: 2007-03-22
Also published as: KR101339694B1; JP5149185B2; CN101282648A; MY152866A; TW200744446A; CN101282648B; KR20080044871A; JP2010502561A; WO2007031251A3; JP2007077044A; TWI441596B

Abstract

The object of the invention is to provide a water-suspendable agricultural chemical composition comprising a liquid agricultural chemical ingredient and a solid agricultural chemical ingredient that ensures satisfactory dispersion, suspension, emulsification or combinations thereof of the contained ingredients and prevents decomposition of active ingredients while also inhibiting their precipitation and aggregation even when stored for a long period of time. The invention is carried out by preparing a water-suspendable agricultural chemical composition, which comprises at least one liquid agricultural chemical ingredient, at least one solid agricultural chemical ingredient, at least an oil and at least a surfactant.

Description

Water-suspendable agricultural chemical composition

The present invention relates to a stable, water-suspendable agricultural chemical composition comprising at least one liquid agricultural chemical ingredient and at least one solid agricultural chemical ingredient.

Agricultural chemicals are classified on the basis of the drug form of the composition, and in the case of agricultural chemicals used for paddy rice in particular, since the purpose of their application is the eradication of harmful insects and undesired vegetation like, for example, grasses and weeds in rice paddies, solid granules are primarily in consideration for reliably applying the required amount of agricultural chemical while also saving on labor. However, in the case of granular compositions, the problem is that it is difficult to uniformly spray the entire field. In addition, attempts have recently been made to improve work efficiency using technology that increases the size of the granules themselves, that increases the amount of the active ingredient (herbicidal active ingredient), and reduces the sprayed amount.

On the other hand, in addition to solid granules, there are also emulsions used for pre- transplantation treatment and water-suspendable agricultural chemical compositions used for post-transplantation treatment. Liquid agricultural chemical compositions, and particularly water-suspendable agricultural chemical compositions, have attracted attention in recent years for reasons such as their ability to reduce the burden on the environment, their ease of handling, and their ease of uniform spraying, dilution and adjustment of concentration. However, water-suspendable agricultural chemical compositions have problems such as instability of the active ingredient in the presence of moisture, difficulty in homogeneously suspending and dispersing all active ingredients in the case of blending two or more types of active ingredients, and particularly in the case of combining a liquid ingredient with a solid ingredient, and susceptibility of the active ingredients to separation, precipitation or aggregation.

In the case of formulating a liquid composition in which is blended two or more types of active ingredients having different physical properties, it is necessary to design the composition so as to inhibit hydrolysis, precipitation and aggregation of all active ingredients while ensuring adequate dispersion, suspension, emulsification or combinations thereof of the active ingredients. Although auxiliary agents such as emulsifiers, emulsion stabilizers and surfactants are frequently used, there are cases in which hydrolysis and aggregation of the active ingredients are promoted corresponding to the compatibility between the active ingredients and auxiliary agents used. For example, in the case of formulating an aqueous liquid composition comprising pretilachlor, a type of chloroacetoamide-based herbicide that is a liquid at normal temperatures, and bensulfuron-methyl, a type of sulfonylurea-based herbicide that is a solid at normal temperatures, although it is essential to use an auxiliary agent such as an emulsion stabilizer or surfactant in order to suspend and disperse both active ingredients, there are problems such as the occurrence of significant hydrolysis of the bensulfuron-methyl, precipitation and aggregation depending on the type of auxiliary agent used.

For example, Japanese Unexamined Patent Publication No. H 10-287503 describes that an aqueous suspended composition composed of a sulfonylurea-based herbicide as the agricultural chemical active ingredient and/or polyvinyl alcohol having an average degree of polymerization of 2000 or less and a degree of saponification of 69 to 90 mol% as a herbicidal active ingredient having barnyard grass herbicidal activity, and water has satisfactory composition stability, improved diffusivity and is able to prevent chemical damage by preventing adhesion of the chemical to the rice plant bodies. In addition, Japanese Unexamined Patent Publication No. H9-183704 describes that the addition of lignin sulfonate allows the obtaining of an aqueous suspension composition containing a sulfonylurea-based herbicide compound having superior long-term storage stability.

An object of the present invention is to provide a water-suspendable agricultural chemical composition comprising a liquid agricultural chemical ingredient and a solid agricultural chemical ingredient wherein, dispersion, suspension, emulsification or combinations thereof of the contained ingredients are ensured, hydrolysis is inhibited even when stored for a long period of time, and precipitation and aggregation are also inhibited.

As a result of conducting extensive studies that focused on the aforementioned problems, the inventors of the present invention found that the aforementioned problems are solved by blending an oil into a water-suspendable agricultural chemical composition comprising at least a liquid agricultural chemical ingredient and at least a solid agricultural chemical ingredient, thereby leading to completion of the present invention. Thus, the present application includes the following inventions.

In a first aspect, the present invention provides a water-suspendable agricultural chemical composition comprising at least one liquid agricultural chemical ingredient, at least one solid agricultural chemical ingredient, and at least an oil.

In a first embodiment, the present invention provides a water-suspendable agricultural chemical composition wherein the oil is selected from the group consisting of mineral oil, vegetable oil, fatty acid ester, epoxidized vegetable oil and liquid paraffin.

In a second embodiment, the present invention provides a water-suspendable agricultural chemical composition comprising a nonionic surfactant.

In a third embodiment, the present invention provides a water-suspendable agricultural chemical composition wherein the nonionic surfactant is polyoxyethylene- polyoxypropylene block polymer.

In a fourth embodiment, the present invention provides a water-suspendable agricultural chemical composition wherein an agricultural chemical ingredient is at least one herbicide.

In a fifth embodiment, the present invention provides a water-suspendable agricultural chemical composition wherein an agricultural chemical ingredient is at least one insecticide.

In a fourth embodiment, the present invention provides a water-suspendable agricultural chemical composition wherein an agricultural chemical ingredient is at least one bactericide.

In a sixth embodiment, the present invention provides a water-suspendable agricultural chemical composition comprising at least one bactericide and at least one insecticide as agricultural chemical ingredients. - A -

In a seventh embodiment, the present invention provides a water-suspendable agricultural chemical composition wherein at least one of the liquid agricultural chemical ingredients is a chloroacetoamide-based herbicide.

In an eighth embodiment, the present invention provides a water-suspendable agricultural chemical composition wherein the chloroacetoamide- based herbicide is pretilachlor.

In a ninth embodiment, the present invention provides a water-suspendable agricultural chemical composition wherein the chloroacetoamide-based herbicide is metolachlor of

S-metolachlor.

In an eleventh embodiment, the present invention provides a water-suspendable agricultural chemical composition wherein at least one of the solid agricultural chemical ingredients is a sulfonylurea-based herbicide.

In a twelfth embodiment, the present invention provides a water-suspendable agricultural chemical composition wherein the sulfonylurea-based herbicide is bensulfuron-methyl.

In a twelfth embodiment, the present invention provides a water-suspendable agricultural chemical composition that further comprises pyriftalid as a solid agricultural chemical ingredient.

In a second aspect, the present invention provides a method of controlling undesired vegetation in crops of useful plants, especially rice crops, which comprises allowing an effective amount of the water-suspendable agricultural chemical composition to act where control is desired.

In a third aspect, the present invention provides the use of the water-suspendable agricultural chemical composition for controlling grasses and weeds in crops of useful plants, especially in rice crops. In a fourth aspect, the present invention provides a method for the preparation of the the agricultural chemical composition by blending an oil into a water-suspendable agricultural chemical composition comprising at least one liquid agricultural chemical ingredient and at least one solid agricultural chemical ingredient.

According to the present invention, in a water-suspendable agricultural chemical composition comprising a liquid agricultural chemical ingredient and a solid agricultural chemical ingredient, satisfactory dispersion, suspension, emulsification or combinations thereof of the contained ingredients are secured, hydrolysis is inhibited even if stored for a long period of time, and precipitation and aggregation are also inhibited.

The present invention provides a water-suspendable agricultural chemical composition comprising at least one liquid agricultural chemical ingredient, at least one solid agricultural chemical ingredient, and at least an oil.

There are no particular limitations on liquid agricultural chemical ingredients that can be used in the water-suspendable agricultural chemical composition as claimed in the present invention provided they are agricultural chemical ingredients in a vitreous, oily or liquid state at normal temperature and normal pressure such as the temperature during composition production, in a composition or in a sprayed liquid, or depending on the particular case, at a temperature up to about 50⁰C. Typical examples include chloroacetoamide-based compounds such as pretilachlor, carbamate-based compounds and dinitroaniline-based compounds. In addition, ingredients that are in an oily state at the purity at which they are normally used in agricultural chemical compositions are also included in the liquid agricultural chemical ingredients of the present invention even if they are a solid at room temperature when in the pure form. Agricultural chemical ingredients may be, for example, herbicides, bactericides, fungicides, nematocides, parasitocides or other biocides. Liquid agricultural chemical ingredients are preferably herbicides, insecticides, bactericides or insecticide/fungicides, and particularly preferably herbicides.

Examples of liquid herbicides include, but are not limited to, pretilachlor (656), metolachlor (548), prodiamine (661 ), esprocarb (303), prosulfocarb (683), triclopyr (827), fluazifop (681 ), orbencarb (595), molinate (560), dimetinamide (260), pelargonic acid (583), dalapon (214), piperophos (560), butamiphos (102), glyphosate trimesium (419), sethoxydim (726), clethodim (153), S-metolachlor (549) and cinmethylin (153). In the present invention, the chloroacetoamide-based herbicides pretilachlor (656) and metolachlor (548) are preferable, with pretilachlor being particularly preferable. These compounds and agronomically acceptable salts thereof are described, for example, in "The e-Pesticide Manual", version 3.1 , 13th Edition, Ed. CDC Tomlin, British Crop Protection Council, 2004- 2005.

Examples of liquid insecticides include, but are not limited to, cyanophos (184), fenthion (346), fenitrothion (335), dichlofenthion (1051), pirimiphos-methyl (1345), diazinon (227), isoxathion (480), oxydeprofos (1324), marathion, phenthoate (631 ), formothion

(1192), thiometon (801), disulfoton (278), prothiophos (686), sulprofos (1408), propenofos, pyraclofos (689), dichlorvos (236), naled (657), chlorfenvinphos (131 ), propaphos (1356), isofenphos (1236), ethion (309), carbosulfan (119), benfuracarb (60), allethrin (17), permethrin (626), cyhalothrin (196), cyfluthrin (193), fenvalerate (349), flucythrinate (367), fluvalinate (1184), cycloprothrin (188), silafluofen (728), propargite (671), halfenprox (424), ethoprophos (312) and fosthiazate (408). These compounds and agronomically acceptable salts thereof are described, for example, in "The e-Pesticide Manual", version 3.1 , 13th Edition, Ed. CDC Tomlin, British Crop Protection Council, 2004-2005.

Other examples of liquid agricultural chemical ingredients include liquid bactericides , and particularly fungicides such as calcium polysulfide (111), ediphenfos (290), propiconazole (675), pefurazoate (618), pyrifenox (703), tetraconazole (778), echlomezole (321), dinocap (270) and metalaxyl M (516). These compounds and agronomically acceptable salts thereof are described, for example, in "The e-Pesticide Manual", version 3.1 , 13th Edition, Ed. CDC Tomlin, British Crop Protection Council, 2004-2005.

A liquid agricultural chemical ingredient as claimed in the present invention is particularly preferably that which has low water solubility such as water solubility of 1000 mg/l or less at normal temperature and normal pressure, and preferably 500 mg/l or less. Examples of such liquid agricultural chemical ingredients include pretilachlor (water solubility: 50 mg/l), metolachlor (water solubility: 488 mg/l), prodiamine (water solubility: 0.013 mg/l), esprocarb (water solubility: 4.9 mg/l), prosulfocarb (water solubility: 13.2 mg/l) and metalaxyl M (water solubility: 26 mg/l). The aforementioned liquid agricultural chemical ingredients are preferably blended in an amount of 0.1 to 60 parts by weight, and more preferably 5 to 40 parts by weight, based on 100 parts by weight for the total weight of the water-suspendable agricultural chemical composition as claimed in the present invention.

There are no particular limitations on solid agricultural chemical ingredients that can be used in the water-suspendable agricultural chemical composition as claimed in the present invention provided they are agricultural chemical ingredients that are in a solid state at normal temperature and normal pressure such as the temperature during composition production, in a composition or in a sprayed liquid. Typical examples of these ingredients include sulfonylurea-based compounds. The agricultural chemical ingredients may be, for example, herbicides, insecticides, bactericides, fungicides, nematocides, parasitocides and other biocides. Liquid agricultural chemical ingredients are preferably herbicides, insecticides, bactericides or insecticide/bactericides, and particularly preferably herbicides.

Examples of solid herbicides include, but are not limited to, bensulfuron-methyl (64), CNP (974), naproanilide (517), bifenox (75), pyributicarb (698), bromobutide (93), mefenacet (505), daimuron (213), imazosulfuron (456), pyrazosulfuron-ethyl (694), simetryn (732), prometryn (666), dimethametryn (259), chlomethoxynil, oxadiazon (600), pyrazolate (692), pyrazoxyfen (695), clomeprop (160), benzofenap (70), thenylchlor (789), oxaziclomefone (604), pentoxazone (625), cafenstrole (110), azimsulfuron (43), pyriminobac-methyl (707), fentrazamide (348) and bispyribac-sodium salt (82). In the present invention, the sulfonylurea-based herbicide, bensulfuron-methyl (64), is particularly preferable. These compounds and agronomically acceptable salts thereof are described, for example, in "The e-Pesticide Manual", version 3.1 , 13th Edition, Ed. CDC Tomlin, British Crop Protection Council, 2004-2005.

Examples of solid insecticides include, but are not limited to, imidacloprid (458), dinotefuran (271 ), thiamethoxam (792), acetamiprid (4), thiacloprid (791), nitenpyram (579), NAC (115), pyridaphenthion (701 ), chlorpyrifos-methyl (146), dimethoate (262), acephate (2), cartap (123), thiocyclam (798), bensultap (66) and buprofezin (99). These compounds and agronomically acceptable salts thereof are described, for example, in "The e-Pesticide Manual", version 3.1 , 13th Edition, Ed. CDC Tomlin, British Crop Protection Council, 2004- 2005. Examples of solid bactericides , and particularly solid fungicides include, but are not limited to, cyprodinil (208), mepanipyrim (508), pyrimethanil (705), metalaxyl (516), mepronil (510), flutolanil (396), tecloftalam (766), pencycuron (620), diclomezine (239), triflumizole (834), kasugamycin (483), validamycin (846), probenazole (658), isoprothiolane (474), cyproconazole (207), metconazole (525), tricyclazole (828), pyroquilon (710), oxolinic acid (606), ferimzone (351), iprodione (470), triforine (838), picoxystrobin (647), azoxystrobin (47), kresoxim-methyl (485), orysastrobin, pyraclostrobin (690), trifloxystrobin (832) and metominostrobin (551 ). These compounds and agronomically acceptable salts thereof are described, for example, in "The e-Pesticide Manual", version 3.1 , 13th Edition, Ed. CDC Tomlin, British Crop Protection Council, 2004-2005.

The aforementioned solid agricultural chemical ingredients are preferably blended in an amount of 0.1 to 60 parts by weight, and more preferably 0.1 to 40 parts by weight, based on 100 parts by weight for the total weight of the water-suspendable agricultural chemical composition as claimed in the present invention.

A water-suspendable agricultural chemical composition as claimed in the present invention contains at least an oil as an emulsion stabilizer for maintaining dispersivity and suspendability of liquid agricultural chemical ingredients and solid agricultural chemical ingredients, and to inhibit decomposition of solid agricultural chemical ingredients by liquid agricultural chemical ingredients. Examples of this oil include mineral oils such as spindle oil, machine oil and liquid paraffin, aromatic solvents such as Solvesso and Shellsol, vegetable oils such as rapeseed oil, soybean oil, sunflower seed oil, castor oil, pine oil and cottonseed oil, and derivatives of these oils such as methyl esters and other ester derivatives, epoxidized derivatives and fatty acid esters, and these can be used alone or in combination. Particularly preferable oils in the present invention are vegetable oils and liquid paraffin. These oils are preferably blended in an amount of 0.1 to 30 parts by weight, and more preferably 1 to 10 parts by weight, based on 100 parts by weight for the total weight of the water-suspendable agricultural chemical composition as claimed in the present invention.

A surfactant is preferably contained in a water-suspendable agricultural chemical composition as claimed in the present invention. Examples of preferable surfactants include polyoxyethylene-polyoxypropylene block polymer types of surfactants such as polyoxyethylene- polyoxypropylene block polymer and alkyl polyoxyethylene- polyoxypropylene block polymer ether, while polyoxyethylene- polyoxypropylene (POE-POP) block polymers are particularly preferable. The use of the aforementioned surfactants is preferable because it makes it possible to expect satisfactory emulsification of liquid agricultural chemical ingredients and satisfactory dispersion of solid agricultural chemical ingredients, as well as inhibit the decomposition of solid agricultural chemical ingredients by liquid agricultural chemical ingredients. The aforementioned surfactants are preferably blended in an amount of 0.01 to 10 parts by weight, and more preferably 0.1 to 5 parts by weight, based on 100 parts by weight for the total weight of the water-suspendable agricultural chemical composition as claimed in the present invention.

A preferable surfactant is a POE-POP block polymer, and those having an average molecular weight of 10,000 or more and an ethylene oxide weight ratio of 50% or more (such as Epan U-108, Daiichi Kogyo Seiyaku) are particularly preferable since they are able to inhibit the occurrence of aggregation under severe testing conditions. However, even those having an average molecular weight of 10,000 or less or ethylene oxide weight ratio of 50% or less are able to achieve satisfactory emulsification of liquid active ingredients and inhibit decomposition of solid active ingredients. In addition, the combined use of a plurality of POE-POP block polymers having different average molecular weights or different ethylene oxide weight ratios makes it possible to obtain compositions having desired physical properties.

Other surfactants may also be blended into a water-suspendable agricultural chemical composition as claimed in the present invention, examples of which include nonionic surfactants such as polyoxyalkylene tristyryl phenols, polyethylene glycol higher fatty acid esters, polyoxyalkylene alkyl ethers, polyoxyalkylene alkyl aryl ethers, polyoxyalkylene aryl phenyl ethers, sorbitan alkylates, acetylene alcohols, acetylene diols and their alkylene oxide addition products, polyalkylene sorbitan alkylates, polyalkyl glycosides, sucrose fatty acid esters and polyalkylene alkyl amines, anionic surfactants such as alkyl aryl sulfonates, dialkyl sulfonates, lignin sulfonates, alkylated or non-alkylated naphthalene sulfonates and their condensation products, alkyl sulfuric acid esters and ester salts, alkyl phosphoric acid esters and ester salts, alkyl aryl sulfuric acid esters and ester salts, alkyl aryl phosphoric acid esters and ester salts, polyoxyethylene alkyl ether sulfuric acid esters and ester salts, polyoxyethylene alkyl aryl sulfuric acid esters and ester salts, polyoxyethylene aryl phenyl ether sulfuric acid esters and ester salts and polycarboxylic acid polymer activating agents, amphoteric surfactants such as silicone-based surfactants, fluorine-based surfactants and alkyl betaine, and cationic surfactants such as alkyl methyl ammonium salts and polyoxyalkylene alkyl methyl ammonium salts. In a preferable mode, a water-suspendable agricultural chemical composition as claimed in the present invention contains polyoxyethylene tristyryl phenol as another surfactant. This surfactant is preferably blended in an amount of 0.001 to 10 parts by weight, and more preferably 0.01 to 1 part by weight, based on 100 parts by weight for the total weight of the water-suspendable agricultural chemical composition as claimed in the present invention.

In addition to each of the aforementioned ingredients, a water-suspendable agricultural chemical composition as claimed in the present invention can also contain a commonly used vehicle typically used in water-suspendable agricultural chemical compositions, examples of which include antifoaming agents such as silicone, anti-mold agents such as 1 ,3- benzisothiazolin-3-one and other benzisothiazolinone compounds, pH adjusters such as K₂PO₄, antifreeze agents such as propylene glycol, thickeners such as xanthane gum, silica and bentonite, inert carriers such as clay, diatomaceous earth and calcium carbonate, preservatives, bonding agents, fertilizers and other active ingredients.

A water-suspendable agricultural chemical composition as claimed in the present invention may be produced using ordinary methods, such as by mixing the aforementioned active ingredients directly with the aforementioned blending vehicles and liquid or solid carriers, and/or crushing them together.

Preferably, a water-suspendable agricultural chemical composition as claimed in the present invention can be prepared in the manner described below.

(a) Composition of concentrated crushed slurry of solid agricultural chemical ingredient

A portion of various types of surfactants and other assistants are mixed by dissolving or dispersing in water followed by addition of a solid agricultural chemical ingredient. The mixture is then suitably wet crushed with a bead mill such as a batch-type bead mill to prepare a concentrated slurry. (b) Composition of emulsion of liquid agricultural chemical ingredient

Various types of surfactants and other assistants are mixed in water. An oily phase in which an oil has been dissolved is added to the liquid agricultural chemical ingredient while forcibly stirring with a homogenizer and so forth to emulsify the oily phase in the aqueous phase. This mixture is then suitably forcibly emulsified to a desired particle diameter.

(c) Production of the composition

The solid agricultural chemical ingredient slurry is added to the liquid agricultural chemical ingredient emulsion (in the ratio emulsion to slurry of, for example, 9:1 ) followed by suitably mixing with a mixer and so forth to obtain a composition.

An herbicide according to a water-suspendable agricultural chemical composition as claimed in the present invention is preferable for controlling rice paddy weeds when under water. This is preferably carried out by applying the required amount of the water- suspendable agricultural chemical composition as claimed in the present invention directly to the rice paddy either directly or after diluting to a suitable concentration with water, or by adding to water that flows into the rice paddy (so-called spout treatment). Moreover, a composition as claimed in the present invention can also be applied simultaneous to planting by a planting machine.

Although a water-suspendable agricultural chemical composition as claimed in the present invention can be applied in the same manner as ordinary spraying, it can also be diluted in a larger amount of water. A water-suspendable agricultural chemical composition as claimed in the present invention can be preferably used in an applied amount of 100 to 50,000 ml/ha, and more preferably 1 ,000 to 10,000 ml/ha.

The following provides a more detailed explanation of the present invention through its examples. Furthermore, the present invention is not limited by these examples.

Examples: Water-suspendable agricultural chemical compositions are prepared as described below at the blends indicated in Tables 1 and 2. Table 1

ro

Table 2

In the tables, PFT represents pyriftalid, and BSM represents bensulfuron-methyl. Furthermore, NK-PTC is an emulsifier blend manufactured by Coseal that has for its main ingredient POE-POP block polymer.

0.1 parts by weight of Sopropore BSU (surfactant, Rhodia), 2.0 parts by weight of Epan U 108 (surfactant, Daiichi Kogyo Seiyaku) and 0.1 parts by weight of Rhodosil 454 (antifoaming agent, Rhodia, silicone) and 0.1 parts by weight of Rhodopore 23 (thickener, Rhodia, xanthane gum) are mixed by dissolving or dispersing in water followed by addition of solid agricultural chemical ingredient. Either bensulfuron-methyl (common name) alone or a combination of bensulfuron-methyl and pyriftalid (common name) are used for the solid agricultural chemical ingredient. The concentration of each active ingredient in the slurry is adjusted to 15% for bensulfuron-methyl and 30% for pyriftalid. A concentrated slurry is prepared by wet crushing with a batch-type bead mill (Imex, four-barrel sand mill, 1/8 gallon, using 1 mm glass beads) at 1000 rpm/hr (10-fold concentration of composition). (b) Composition of emulsion of liquid agricultural chemical ingredient

An emulsifier (Epan U108, Epan U103, Epan U105 or NK-PTC), propylene glycol (antifreeze, Showa Denko), KH₂PO₄ (pH adjuster, Nippon Kayaku), xanthane gum (thickener, Rhodia) and Proxel GXL (1 ,3-benzisothiazolin-3-one, anti-mold agent, Arch Chemicals) are mixed in water. Refer to Tables 1 and 2 for the amounts of each ingredient added. An oily phase in which oil is dissolved is added to the liquid agricultural chemical ingredient while forcibly stirring with a homogenizer to emulsify the oily phase in the aqueous phase. Pretilachlor (common name), S-metolachlor (common name), esprocarb (common name) or prosulfocarb (common name) is used for the liquid agricultural chemical ingredient. In addition, soybean oil (Honen Corporation) or liquid paraffin (Matsuken, Moresco White P- 70) is used for the oil. Refer to Tables 1 and 2 for the amounts of each ingredient added. The emulsion is forcibly emulsified for about 2 minutes to obtain the desired particle diameter.

(c) Production of water-suspendable agricultural chemical composition

The solid agricultural chemical ingredient slurry is added to the liquid agricultural chemical ingredient emulsion (ratio of emulsion to slurry = 9:1) followed by mixing for 5 minutes with a laboratory mixer having a propeller-type stirring blade attached to the shaft to obtain a composition.

Stability Test

A storage stability test is conducted at 40⁰C on each water-suspendable agricultural chemical composition prepared in the manner described above to follow the decomposition of the agricultural chemical ingredients in the composition, the presence or absence of the formation of an oil fraction or cream fraction in the composition, the presence or absence of the occurrence of aggregation or precipitation, and the presence of absence of the formation of a supernatant over time. Those results are shown in Tables 3 to 6. Table 3

en

Table 4

Table 5

Table 6

00

About 100 ml of the agricultural chemical compositions prepared according to the composition method described above are sealed in glass containers and allowed to stand undisturbed in a constant temperature bath at 40⁰C. The agricultural chemical compositions are removed from the bath after a predetermined time followed by measurement of the content of agricultural chemical ingredients by high-performance liquid chromatography.

About 100 ml of the agricultural chemical compositions prepared according to the composition method described above are sealed in glass containers and allowed to stand undisturbed in a constant temperature bath at 40⁰C. The agricultural chemical compositions are removed from the bath after the a predetermined time followed by visually confirming the presence or absence of the formation of a supernatant, the presence or absence of separation of the oil fraction or cream fraction, and presence or absence of the formation of an aggregate or precipitate, and measurement of the degrees of each.

On the basis of the results shown in the tables, the blending of an oil is determined to inhibit separation of agricultural chemical ingredients in the composition as well as to inhibit separation, aggregation and precipitation of ingredients in the composition.

The water-suspendable agricultural chemical composition according to the present invention, that contains a liquid agricultural chemical ingredient and a solid agricultural chemical ingredient, ensures satisfactory suspension or dispersion of the contained ingredients and prevents their decomposition while also inhibiting their precipitation and aggregation even when stored for a long period of time.

Claims

What is claimed is:

1. A water-suspendable agricultural chemical composition comprising at least one liquid agricultural chemical ingredient, at least one solid agricultural chemical ingredient, and at least an oil.

2. The composition according to claim 1 wherein the oil is selected from the group consisting of mineral oil, vegetable oil, fatty acid ester, epoxidized vegetable oil and liquid paraffin.

3. The composition according to either claims 1 or 2 comprising at least one nonionic surfactant.

4. The composition according to any one of claims 1 to 3 wherein the nonionic surfactant is polyoxyethylene-polyoxypropylene block polymer.

5. The composition according to any one of claims 1 to 4 wherein the agricultural chemical ingredient is at least one herbicide.

6. The composition according to any one of claims 1 to 5 wherein the agricultural chemical ingredient is at least one insecticide.

7. The composition according to any one of claims 1 to 6 wherein the agricultural chemical ingredient is at least one bactericide.

8. The composition according to any one of claims 1 to 4 comprising at least one bactericide and and at least one insecticide as agricultural chemical ingredients.

9. The composition according to any one of claims 1 to 5 wherein at least one of the liquid agricultural chemical ingredients is a chloroacetoamide-based herbicide.

10. The composition according to claim 9 wherein the chloroacetoamide-based herbicide is pretilachlor.

11. The composition according to any one of claims 1 to 5 and 9 wherein the chloroacetoamide-based herbicide is metolachlor or S-metolachlor.

12. The composition according to any one of claims 1 to 5 and 9 to 11 wherein at least one of the solid agricultural chemical ingredients is a sulfonylurea-based herbicide.

13. The composition according to claim 12 wherein the sulfonylurea-based herbicide is bensulfuron-methyl.

14. The composition according to any one of claims 1 to 5 and 9 to 13 that further comprises pyriftalid as a solid agricultural chemical ingredient.

15. A method of controlling undesired vegetation in crops of useful plants, which comprises allowing an effective amount of the composition as defined in any one of claims 1 to 14 to act where control is desired.

16. The method according to claim 15, wherein the crop of useful plants is rice.

17. Use of the composition as defined in any one of claims 1 to 14 for controlling grasses and weeds in crops of useful plants.

18. The use according to claim 11 wherein the crop of useful plants is rice.

19. A method for the preparation of the composition as defined in any one of claims 1 to 14, by blending an oil into a water-suspendable agricultural chemical composition comprising at least one liquid agricultural chemical ingredient and at least one solid agricultural chemical ingredient.