JPH10212205A - Time interval release type coated agrochemical granule - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an agrochemical preparation useful as an agrochemical by coating the surface of the agrochemical granule containing agrochemical active ingredient, with a coating film containing a specific amount of powder. SOLUTION: The objective preparation having a character hard to be influenced from outside temperature, especially, in use of the release controlling term by applying the coating film comprising 50-98wt.% (based on coating material) of powder at least one kind selected from a water insoluble powder and powder (talc, clay, kaolin, etc.) which has poor solubility to water, and a thermoplastic resin (an olefinic resin, for example, a compound resin of <=15wt.% of ethylene-vinylacetate copolymer and other thermoplastic resin) as the active component, on the surface of the agrochemical granule which is obtained by pelletizing at least one kind of agrochemical active component (having insecticidal, bactericidal, weeding, acaricidal, nematocidal action, etc.), if necessary, mixed with at least one kind of water swelling material (e.g. montmorillonite).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a coated pesticide granule having a timed release function. More specifically, at least one
A time-release function in which the surface of pesticide particles containing more than one kind of pesticide active ingredient is coated with a film containing at least one kind of powder selected from water-insoluble powder and poorly water-soluble powder and a thermoplastic resin as an active ingredient. The present invention relates to a coated controlled-release pesticide granule having a content of the powder in a coating film in the range of 5 to 98% by weight.

[0002]

2. Description of the Related Art In recent agricultural environments in which the number of farmers is decreasing and the population is aging, labor saving in crop cultivation management has long been said to be urgent. Control, which is one of the most important tasks in cultivation management, can be broadly divided into those of pests and weeds, and timely spraying and applying pesticides compatible with the target disease and weed throughout the cultivation period It is necessary and a control system is formed by spraying and applying several times. Agricultural chemical spraying requires a lot of labor due to the number of types and the types of chemicals. There are potato diseases, leafhoppers and planthoppers, sheath blight, stink bugs, etc. during the same period. Herbicides such as barley and broadleaf weeds are sprayed and applied to weeds. As described above, the types and the number of times of the control work are extremely large, which is an obstacle to the construction of a labor-saving cultivation system.

[0003] Under such circumstances, the present inventors can only spray and apply various pesticides several times during the cultivation period, only once, at the time of sowing or transplanting of seedlings. The control method was considered to be the ideal labor-saving control method when using chemicals. To achieve this, pesticides of different types are not released until the required time, and the pesticide granules have the function of releasing the pesticide active ingredient only when the appropriate time comes and continuing to release for the required period. Agent is required. In other words, a period during which release is suppressed for a certain period after application (hereinafter referred to as a release suppression period), and a period from the start of the release of the pesticide active ingredient to the end after a certain period (hereinafter, the component release period). (Described), that is, pesticide granules having a so-called timed release function.

Until now, sustained release of pesticides has been carried out by granulating the pesticides into granules. As a method for producing pesticide granules, generally, (1) a pesticide active ingredient, a binder and various auxiliary agents are added to mineral fine powder, kneaded with water, extruded from fine pores, dried, and dried. Extrusion granulation method of granulating, (2) impregnation method of impregnating inactive granules composed of minerals and the like with liquid pesticide active ingredient,
(3) There are known three kinds of production methods of a coating method in which a pesticidal active ingredient is adhered to the surface of an inert particle made of a mineral or the like with a binder, and the above method is appropriately selected depending on the application field. . However, in these pesticide granules, the pesticide active ingredient elutes in a short time. With such a release control function, it is impossible to establish an ideal labor-saving control method as described above due to the occurrence of chemical damage during application.

In recent years, Japanese Patent Application Laid-Open No. 6-9303 discloses a coated pesticide granule coated with a multi-layer coating composed of a highly water-swellable substance layer and an olefin polymer layer.
Japanese Patent Application Laid-Open No. Hei 6-72805 discloses a coated pesticide granule obtained by coating a pesticide granule with a multilayer coating comprising a mixture layer of an alkali substance layer and an olefin resin and an alkali water-soluble polymer. Coated pesticide granules obtained by coating pesticide granules with a multilayer coating comprising a mixture layer of a condensation polymer and an alkali water-soluble polymer. In JP-A-6-80514, a highly water-swellable substance layer and a condensation polymer layer are disclosed. The present invention discloses a coated pesticide granule in which a pesticide granule is coated with a multilayer film comprising: Each of these coated pesticide granules has a timed release control function and is promising as a material for realizing the ideal labor-saving control method described above. Since all of these coated pesticide granules are coated with a thermoplastic resin, their release function, particularly the length of the release suppression period, fluctuates greatly under the influence of the external temperature when the pesticide granules are used. When the temperature of the outside world such as air temperature, ground temperature, or water temperature is high, the emission suppression period tends to be short, and when it is low, it tends to be long. Depending on the type of resin used and the coating composition, the temperature is 10 ° C. Release control period is 1/5 with increase
Some were shorter by now. When such coated pesticide granules are used for labor-saving control methods in which the application and application of various pesticides that were performed during the cultivation period are completed at the time of sowing or transplanting of seedlings, changes in weather and temperature in house cultivation If the temperature in the initial stage of cultivation changes to a high temperature due to negligence or trouble in management, the release of the pesticide active ingredient is started immediately after application because the predetermined release suppression period can not be secured, and even if it has a timed release suppression function In addition, phytotoxicity is caused by excessive pesticides.

[0006] As described above, there is still a risk just by having a time-release function of pesticides, and this is an obstacle to realizing an ideal labor-saving control method. In crop cultivation, it has long been referred to as "seedling", and the quality of growth at the initial stage of cultivation greatly affects cropping. No particular failure is allowed in annual crops such as rice. In order to avoid the risks in the labor-saving control method described above,
It is desirable to use a coated pesticide granule whose release function of the time-release type coated pesticide granule to be used, in particular, its release suppression period is hardly affected by the external temperature when the pesticide granule is used. However, coated pesticide granules having such a timed release function have not been developed so far.

[0007]

DISCLOSURE OF THE INVENTION The present inventors have made intensive studies to develop pesticide granules that enable an ideal labor-saving control method. As a result, the surface of the pesticide particles containing at least one or more pesticidal active ingredients is coated with a coating containing at least one powder selected from water-insoluble powder and poorly water-soluble powder and a thermoplastic resin as an active ingredient. Coated pesticide granules having a timed release function, wherein the content of the powder in the coating is 5%.
It has been found that coated pesticide granules in the range of up to 98% by weight have a release function, in particular, a property that is hardly affected by the temperature of the external environment during use during the release suppression period. completed.

[0008]

The present invention comprises the following (1) to (6). (1) The surface of pesticide particles containing at least one or more pesticidal active ingredients is coated with a coating containing at least one powder selected from a water-insoluble powder and a poorly water-soluble powder and a thermoplastic resin as active ingredients. A coated controlled-release pesticide granule having a coated time-release function, wherein the content of the powder in the coating material is in the range of 5 to 98% by weight. (2) The time-controlled release-type coated pesticide according to the above (1), wherein the content of one or more powders selected from water-insoluble and poorly water-soluble powders is 50 to 95% by weight. . (3) The controlled-release controlled-release pesticide particle according to (1), wherein the content of at least one powder selected from water-insoluble and poorly water-soluble powders is 85 to 95% by weight. Agent. (4) that the pesticide particles used in the coated pesticide granules having a time-release function are pesticide particles obtained by adding at least one or more water-swellable substances to at least one or more pesticidal active ingredients and granulating them. 4. The time-controlled release-type coated pesticide according to any one of the first to third aspects. (5) The timed controlled release coated agricultural chemical granule according to any one of the first to fourth aspects, wherein the thermoplastic resin is an olefin-based resin. (6) The thermoplastic resin in the coating material is a composite resin of an ethylene / vinyl acetate copolymer and another thermoplastic resin, and the content of the ethylene / vinyl acetate copolymer in the coating material is 15% by weight. 6. The timed controlled release coated pesticide granule according to the above item 5, characterized in that:

Hereinafter, the present invention will be described in detail. The term “timed release” as used in the present invention means a component release function in which release is suppressed for a certain period of time after application to a field and is released immediately after a certain period of time. The timed release function includes a period during which release is suppressed for a certain period after application to the field (release suppression period) and a period from the start to the end of release (component release period). The timed release function comprising the release suppression period and the component release period of the present invention specifically refers to the release suppression period from application to a field until the release of 20% by weight of the pesticidal active ingredient in the capsule. And a component release period from 20% by weight to 80% by weight, and the release function can be defined as having a release suppression period / component release period ratio of 0.1 or more.

A pesticide particle (hereinafter referred to as a core material) is coated with at least one powder selected from a water-insoluble powder and a poorly water-soluble powder, and a coating containing a thermoplastic resin as an active ingredient. In a coated pesticide granule that has achieved the timed release function described above, it is essential to form a complete film that has no pinholes or cracks, allows water vapor to pass through, but does not allow water to pass. If the coating has pinholes or cracks, water enters into the coating immediately after application to the field, etc., and the pesticidal active ingredient inside the coating is released quickly, so that the timed release function as specified above is obtained. I can't. During the release suppression period in the timed release function, a certain amount of water vapor enters the coating from outside the coating,
It is considered to be the period before setting. On the other hand, the mechanism for releasing the pesticidal active ingredient is various, and is not particularly limited in the present invention. As a rough release mechanism, a water-soluble substance is blended in the coating film, and is fixed after application to a field or the like. When the water-soluble substance is dissolved, the coating becomes porous at the elapse of the period, and a substance that starts to release the pesticidal active ingredient, or when a water-swellable substance is blended in the coating and a certain period of time has passed after application to the field etc. When the coating disintegrates due to the swelling of the water-swellable substance in the coating and releases the pesticidal active ingredient, or when the water-swellable substance is added to the core material and a certain period of time has passed after application to the field etc. In addition, there can be mentioned those in which the film is disintegrated by the swelling of the water-swellable substance and the release of the pesticidal active ingredient is started.

The specific composition for achieving each of the above pesticide release mechanisms is not particularly limited. For example, the composition of the release mechanism may be a pesticide active ingredient as disclosed in JP-A-6-9304. A first coating layer made of an alkali substance is formed on the surface of the granular carrier containing, and a second coating layer made of a mixture of an olefin polymer and an alkali water-soluble polymer is formed on the surface of the first coating layer. And the composition of the release mechanism is disclosed in
No. 9303, a first coating layer made of a highly water-swellable substance is formed on the surface of a granular carrier containing an agricultural chemical active ingredient, and a first coating layer made of an olefin-based polymer is formed on the surface of the first coating layer. Coated pesticide granules in which two coating layers are formed, and as a composition of the release mechanism, the surface of a core material comprising at least one or more pesticidal active ingredients and at least one or more water-swellable substances, A coated pesticide granule coated with a coating containing a thermoplastic resin as an active ingredient can be mentioned.

[0012] Of these coated pesticide granules having a timed release function, those requiring the formation of a multi-layered film in order to cause the film to become porous or disintegrate require more manufacturing steps than a single-layer film. Need and obviously costly. On the other hand, if the release mechanism breaks the film by swelling of the water-swellable substance in which the core material itself is blended, the time-release function can be achieved even with a single-layer film. Is most preferred.

[0013] Water swelling used for coated pesticide granules in which the surface of a core material comprising at least one or more pesticidal active ingredients and at least one or more water swellable substances is coated with a coating containing a thermoplastic resin as an active ingredient. Any substance that can absorb water and increase its volume can be used, and is not particularly limited.Specifically, clay minerals mainly composed of montmorillonite, starch, water-absorbing polymers, etc. No. The method for adjusting the swelling force of the core material is not particularly limited, but can be adjusted by selecting the type and content of the water-swellable substance used for the core material.

Among the above water-swellable substances, clay minerals mainly composed of montmorillonite are most preferable from the viewpoint of cost and production. Montmorillonite has a sandwich-like three-layer structure (2: 1 type) in which one alumina octahedral sheet is sandwiched between two silicate tetrahedral sheets, and the trivalent aluminum of this octahedral sheet is However, it is composed of a crystal lattice partially substituted with magnesium or iron having a lower valence. A typical example of the smectite clay mainly composed of the clay mineral montmorillonite is bentonite, which is the most preferable substance as a water-swellable substance because it is the finest particle and has the highest activity among various clays. Bentonite is the name of a clay mineral mainly composed of a clay mineral having an expanded crystal lattice and accompanied by quartz, feldspar, cristobalite, fluorite, mica, and earth metal carbonates and sulfates. This is a mineral clay mainly composed of smectite. Bentonite is rich in sodium ions, sodium-based bentonite that absorbs a large amount of water and exhibits high swelling properties, low-swelling calcium-based bentonite rich in calcium ions and magnesium ions, and artificially increases the swelling activity by soda treatment. There are three types of activated bentonite applied. The swelling power of bentonite increases and decreases depending on the montmorillonite content, and the properties and quality vary depending on the place of production and product.Furthermore, the degree of swelling varies depending on the particle size. There is a need.

As the starch, processed starch or starch derivatives such as oxidized starch, pregelatinized starch, inorganic acid or fatty acid ester starch, and alkyl or hydroalkyl ether starch can be used in addition to corn starch and potato starch. Ester-type starches include starch acetate, starch phosphate, starch nitrate,
Succinic starch, xanthate starch and the like can be exemplified.Examples of ether-type starch include carboxymethyl starch, methyl starch, hydroxyalkyl starch, allyl ether starch, and cationic starch.
It is not limited to these.

[0016] The water-absorbing polymer is a substance that expands in volume by absorbing water, and the natural polymer is starch or cellulose.
, Hyaluronic acid, agarose, collagen and other proteins.Examples of synthetic polymers include polyvinyl alcohol-based polymers, acrylic polymers, other maleic anhydride-based polymers, and vinylpyrrolidone-based polymers. , A polyether-based polymer, a condensation-based polymer, and the like, but are not limited thereto.

As the thermoplastic resin used in the present invention, polyethylene, polypropylene, ethylene / propylene copolymer, ethylene / carbon monoxide copolymer, polybutene,
Butene / ethylene copolymer, butene / propylene copolymer, olefin polymer such as polystyrene, ethylene / vinyl acetate copolymer, ethylene / vinyl acetate / carbon monoxide copolymer, ethylene / acrylic acid copolymer, ethylene・
Olefin resins such as methacrylate copolymers, vinylidene chloride resins such as butadiene polymers, isoprene polymers, chloroprene polymers, butadiene / styrene copolymers, EPDM polymers, styrene / isoprene copolymers, etc. Diene resins, beeswax, wood wax, waxes such as paraffin, natural rubber, natural resins such as rosin,
Examples thereof include cured products, fats and oils such as solid fatty acids and metal salts and modified products thereof, polymers of hydroxycarboxylic acids such as polycaprolactone, polylactic acid, and poly-3-hydroxybutyric acid, and aliphatic polyesters. Among these, an olefin polymer having a small moisture permeability is preferable.

As the thermoplastic resin used for the coating material, ethylene-vinyl acetate copolymer, ethylene-vinyl acetate
The use of a composite resin of a rubber-like substance such as a carbon monoxide copolymer and a diene-based polymer and another thermoplastic resin in the coating composition of the above-described release mechanism controls the time until cracks occur in the coating material. It is effective for This is particularly effective when other water-permeable resins such as polyethylene, polypropylene, ethylene / carbon monoxide copolymer, and vinylidene chloride / vinyl chloride copolymer are used. However, when the rubbery polymer is present in a large amount in the coating material,
Since the release control period may be extremely short or cracks may not be generated, the blending amount of these polymers in the coating material is preferably less than 20% by weight, particularly ethylene / vinyl acetate copolymer. In this case, the content is preferably 15% by weight or less.

The coated pesticide granule of the present invention is obtained by coating the surface of a core material with a coating containing at least one powder selected from a water-insoluble powder and a water-insoluble powder in the thermoplastic resin. The release function, particularly the influence of the ambient temperature such as air temperature, ground temperature, and water temperature on the emission suppression period, can be reduced by the inclusion of the powder, and the fluctuation of the emission suppression period can be suppressed. When the coated pesticide granules of the present invention are used in a labor-saving control method in which spraying and application of various pesticides required during the cultivation period are completed at the time of sowing or transplanting of seedlings, the release of the coated pesticide granules is performed. Since the function is not easily affected by the ambient temperature, even if the temperature in the initial stage of cultivation is higher due to changes in weather or negligence or trouble in temperature management in house cultivation, excessive release of pesticide active ingredients during the release suppression period It can be suppressed and cultivation can be performed more safely.

The water-insoluble powder and the poorly water-soluble powder used in the present invention have a solubility in water at 25 ° C. of 0.1 g / 1.
There is no particular limitation as long as it is not more than 00 mL. Examples thereof include talc, clay, kaolin, muscovite, phlogopite, mica-like iron oxide, metal oxides, siliceous substances, carbonates and sulfates of glass and alkaline earth metals. It is preferably a flat fine powder, and talc, muscovite, seriteite and the like are typical examples. These shapes are in the form of flakes. Specifically, the particle size / thickness is 2 or more, and more preferably the particle size / thickness is 10 or more, since the release accuracy tends to be high, and it is more preferable.

The particle size of the powder is not particularly limited as long as it has the above-mentioned shape.
Or less, preferably 20 μm or less. The particle size is not particularly limited as long as it is completely contained in the coating, and is selected in consideration of the thickness of the coating and is uniformly distributed in the coating. Is preferred.

The content of the powder is 5 to 9 in terms of the content in the coating.
It is in the range of 8% by weight. If the content is less than 5% by weight, the effect of the external temperature on the release function is large, and the fluctuation of the release suppression period cannot be suppressed. Also, 98
If the amount is more than the weight percentage, it becomes difficult to form a complete film without pinholes or cracks on the surface of the core material, and the timed release function cannot be obtained. The content of the powder is preferably in the range of 50 to 95% by weight, more preferably 85 to 95% by weight, in order to more reliably suppress the fluctuation of the outflow suppression period and to surely form a complete film. % Range. When the coated pesticide granules of the present invention are used in the above-mentioned ideal method for controlling labor-saving, the higher the content of the powder, the less the fluctuation of the release suppression period due to the change in temperature is preferable. However, as the content of the powder increases, it becomes difficult to obtain a complete coating without pinholes and cracks, and the strength of the coating decreases. Since it is easy to be damaged and the possibility of impairing the timed release function increases, the content of the powder should be selected from the relationship between the allowable range of the elution variation and the coating strength at the time of implementation. It is.

In the present invention, any auxiliary components such as a surfactant and powders other than those described above may be added to the coating in a range not to impair the effects of the present invention. In particular, a surfactant can improve the moisture permeability of the coating material, and is therefore effective as a moisture permeability adjusting agent.

Since the coated pesticide granules of the present invention have a form in which the surface of the core material is coated, the form in which the pesticidal active ingredient is carried is preferably spherical. Particle size is 0.3-10
mm, preferably 0.8 to 5 mm, and may be 10 mm or more. These granulation methods can be performed according to known methods, but the extrusion granulation method is the simplest.

The pesticidal active ingredient used in the present invention is not particularly limited, but mainly has an action of killing insects, killing nematodes, etc. in addition to insecticide, sterilization, weeding and plant growth regulation. Furthermore, these also include repellents and attractants, and any of these can be applied without limitation to their types.
Preferably, the powder is solid at room temperature, but liquid at room temperature is acceptable. Further, the present invention can be applied without any particular limitation on the water solubility of the pesticidal active ingredient. Specific examples of the pesticidal active ingredient that can be used in the present invention are shown below, but these are merely illustrative and not restrictive. For example, 1- (6-chloro-3-
Pyridylmethyl) -N-nitroimidazolidin-2-ylideneamine, O, O-diethyl-S-2- (ethylthio) ethyl phosphorodithioate, 1,3-bis (carbamoylthio) -2- (N, N-dimethylamino ) Propane hydrochloride, 2,3-dihydro-2,2-dimethyl-7
-Benzo [b] furanyl = N-dibutylaminothio-N
-Methylcarbamate, (2-isopropyl-4-methylpyrimidyl-6) -diethylthiophosphate, 5-
Dimethylamino-1,2,3-trithiane oxalate,
O, O-dipropyl-O-4-methylthiophenyl phosphate, ethyl = N- [2,3-dihydro-2,2-
Dimethylbenzofuran-7-yloxycarbonyl (methyl) aminothio] -N-isopropyl-β-alaninate, 1-naphthyl-N-methylcarbamate, 2-isopropoxyphenyl-N-methylcarbamate, diisopropyl-1,3-dithiolane- 2-ylidene-malonate, 5-methyl-1,2,4-triazolo [3,4
-B] benzothiazole, 1,2,5,6-tetrahydropyrrolo [3,2,1-ij] quinolin-4-one, 3
-Allyloxy-1,2-benzisothiazole-1,
1-dioxide, sodium salt or dimethylamine salt of 2,4-dichlorophenoxyacetic acid, ethyl ester.
Sodium salt of 2-methyl-4-chlorophenoxyacetic acid or ethyl, butyl ester. Sodium salt or ethyl ester of 2-methyl-4-chlorophenoxybutyric acid. α- (2-naphthoxy) propionanilide, S-
1-methyl-1-phenylethyl piperidine-1-carbothioate, S- (4-chlorobenzyl) -N, N
-Diethylthiocarbamate, 5-tert-butyl-3- (2,4-dichloro-5-isopropoxyphenyl) -1,3,4-oxadiazolin-2-one, 2-
[4- (2,4-dichlorobenzoyl) -1,3-dimethylpyrazol-5-yloxy] acetophenone,
-(2,4-dichlorobenzoyl) -1,3-dimethyl-5-pyrazolyl-p-toluenesulfonate, 3-isopropyl-2,1,3-benzo-thiadiazinone-
(4) -2,2-dioxide or its sodium salt,
2-chloro-4-ethylamino-6-isopropylamino-s-triazine, 2-methylthio-4-ethylamino-6- (1,2-dimethylpropylamino) -s-triazine, 2-methylthio-4,6 -Bis (ethylamino) -s-triazine, 2-methylthio-4,6-bis (isopropylamino) -s-triazine, 1- (α,
α-dimethylbenzyl) -3- (paratolyl) urea, methyl = α- (4,6-dimethoxypyrimidin-2-ylcarbamoylsulfamoyl) -ο-toluate, 2-
Benzothiazol-2-yloxy-N-methylacetanilide, 1- (2-chloroimidazo [1,2-a] pyridin-3-ylsulfonyl) -3- (4,6-dimethoxypyrimidin-2-ylurea, S -Benzyl = 1,2
-Dimethylpropyl (ethyl) thiocarbamate, 2-
Chloro-N- (3-methoxy-2-thenyl) -2 ', 6
'-Dimethylacetanilide and the like.

Furthermore, the pesticidal active ingredient in the present invention also includes phytoalexin, a low-molecular-weight antibacterial substance that is synthesized by plants and accumulates in plants after the plants come into contact with microorganisms.

Bacteria having an effect of suppressing the propagation of pathogenic bacteria can also be used. Filamentous fungi such as Coniosilium, Sporidesmium, Laetizaria, Agrobacterium (Agrobacterium radiobacter), Bacillus (Bacillus subtilis), Pseudomonas (Pseudomonas cepacia, Pseudomonas gourmet, Pseudomonas gladioli, Pseudomonas floressens) Faciens, Pseudomonas putida, Pseudomonas solanacearum, etc.), Xanthomonas, Erwinia, Arthrobacter, E. coli Bacterium belonging to the genus,
Enterobacter, Azotobacter, Flavobacterium, Streptomyces (Streptomyces achromogenus, Streptomyces phaeoperpurens, Streptomyces hygroscopicus, Streptomyces nitrosporence, Streptomyces barnensis, etc.) , Actinoplanes, Alcaligenes, Amorphosporangium, Cellulomonas, Micromonospora, Pasteuria, Hafnia, Rhizobium, Bradyrhizobium, Serratia, and other bacteria and actinomycetes. it can.
Of these, antibacterial active substance-producing bacteria are preferred. Specifically, it is a Pseudomonas genus bacterium having a high antibacterial substance-producing ability. Pyrrolnitrin, piorteolin (against cotton seedling wilt, cucumber seedling wilt),
Pseudomonas flora essence, which produces oomysin A (for cotton seedling), cyanide (tobacco black root), and diacetylphloroglucinol (for wheat seedling), and iron in soil that are not used as pathogens for plants Fluorescent Pseudomonas spp. (Pseudomonas putida, Pseudomonas flor essence, Fluorescent Pseudomonas, etc.) that produces iron chelate siderophores (pseudobactin, fluorescent siderophore: pioverdin) that can be used only in E. coli. Other growth-promoting rhizosphere bacteria (PGPR) that produce growth-promoting substances such as Agrobacterium radiobacter, which produces the bacteriocin agrosine 84 (antiapical carcinoma), and plant growth hormones, such as fluorescent Pseudomonas, Pseudomonas putida, Pseudomonas florence and Bacillus genus. In particular, CDU-degrading bacteria (Pseudomonas, Arthrobacter, Corynebacterium, Agrobacterium, etc.) and Streptomyces strains (JP-B 5-26462) are soil-borne pathogenic fungi. It is preferably used because it has a significant deterrent.

As the core material used in the present invention, a substance known as a granulation aid can be used in addition to the pesticidal active ingredient. For example, mineral carrier, vegetable carrier, slaked lime, urea,
Ammonium sulfate, salt ammonium, chemical fertilizer, plastic foam and the like can be added to and mixed with the core material. Mineral carriers include clay, kaolin, sericite, talc, acid clay, pumice, silica sand,
Examples are silica stone, calcium carbonate, zeolite, perlite, vermiculite, and the like, and the vegetable carrier is firgrass, sawdust, wood flour, pulp floc, soy flour, corn stalk and the like. Further, as the binder for obtaining the core material used in the present invention, known substances can be used, and gum arabic, carboxymethylcellulose, hydroxyethylcellulose, lignin sulfonates, polyvinyl alcohol, polyethylene glycol, surfactants, Liquid paraffin or the like can be used.

In the method for producing a coated pesticide granule of the present invention, a mixed solution in which a coating material containing a thermoplastic resin as a main component is dissolved by a solvent is sprayed on a core material in a fluid state.
This is a production method in which the solvent on the surface of the core material is removed and dried by a high-speed hot air flow to coat the surface of the core material with a coating. An example of a coating apparatus that can be used in the manufacturing method will be described with reference to the accompanying drawings. The production method of the present invention is most preferably performed using the spouted bed shown in FIG. This spouted bed sprays a mixed solution 12 of a coating material onto a core material 5 in a rolling or flowing state by a spray nozzle 4 with a pump 6 by a spray nozzle 4 and sprays the solution onto the surface of the core material 5 to coat the surface. Then, at the same time, the high-temperature gas heated by the heat exchanger 8 is caused to flow into the jet tower 1 from below by the blower 10, and the high-speed hot air flow causes the solvent in the mixed solution adhering to the core material surface to flow. Is instantaneously evaporated to dryness.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the details will be described with reference to adjustment of a core material, production examples and examples. Note that the present embodiment does not limit the present invention at all. In the following examples, "%" is "% by weight" unless otherwise specified.

"Manufacture of core material" Core material: 5 parts by weight of an agricultural chemical containing 95% of O, S-dimethyl-N-acetylphosphoramidothioate as an active ingredient of an agricultural chemical, 70 parts by weight of calcium carbonate, clay 2
2 parts by weight and 3 parts by weight of polyvinyl alcohol were uniformly mixed with a kneader and kneaded with water. The mixture was extruded and granulated by a screw extrusion granulator (screen diameter: 0.8 mmφ), and then sized by a spherical granulator to obtain a granulated product.
Next, the granulated product was dried at 100 ° C. using a hot air circulating drier and sieved to obtain a core material having a particle size of 0.8 to 1.4 mmφ containing 4.5% of an agricultural chemical active ingredient. . Core material: 3 parts by weight of a pesticide containing 98% of 1,2,5,6-tetrahydropyrrolo [3,2,1-ij] quinolin-4-one as a pesticide active ingredient, bentonite 70 having water swelling property Parts by weight and 27 parts by weight of clay were uniformly mixed with a kneader and kneaded with water. The mixture was extruded and granulated by a screw extrusion granulator (screen diameter: 0.8 mmφ), and then sized by a spherical granulator to obtain a granulated product. Next, the granulated product was dried at 100 ° C. using a circulating hot air dryer and sieved to obtain a core material having a particle diameter of 0.8 to 1.4 mmφ containing 2.8% of an agrochemical active ingredient. .

[Production of Coated Granule] Using the spouted bed coating apparatus shown in FIG. 1, the core material obtained by the above-mentioned “Production of core material” was obtained using the coating material composition shown in Table 1, Coating was carried out until a predetermined coverage was obtained to obtain coated pesticide granules of Examples and Comparative Examples. The production was performed according to the following method. The coverage is the ratio of the weight (b) of the coating to the coated pesticide granules when the sum of the weight (a) of the core material and the weight (b) of the coating is 100% by weight. /
(A + b)]. The production of the coated pesticide granule will be described with reference to the flow sheet of FIG. Tower diameter 250 mm,
High-temperature hot air for jet (nitrogen gas) flows from the lower part to the upper part into the jet tower 1 having a height of 2,000 mm, a nitrogen gas outlet diameter of 50 mm, and a cone angle of 50 degrees. High-temperature hot air is blown from a blower 10 and is supplied to an orifice flow meter 9.
, Is heated to a high temperature by the heat exchanger 8, flows into the jet tower 1, and is discharged from the exhaust gas outlet 3 installed at the upper part of the jet tower 1. The core material 5 obtained as described above is introduced into the inside of the jet tower 1 in which the high-temperature hot air is circulated, by 3 kg from the core material input port 2 installed on the side surface of the jet tower 1.
Then, the core material 5 is caused to flow as shown in FIG. At this time, it is necessary to appropriately adjust the flow rate and the hot air temperature for each sample. The flow rate is adjusted while measuring with an orifice flow meter. The hot air temperature is T1 hot air temperature, T2 core material temperature, and T3 exhaust air. Adjust while measuring the temperature. In each embodiment, the flow rate (orifice flow meter 9) is 4 m ³ / m
in, hot air temperature (hot air temperature T1) 80 ° C. ± 2 ° C. On the other hand, each component of the coating material composition shown in Table 1 and toluene as a solvent are charged into the dissolution tank 11 and mixed and stirred to obtain 2.5 parts by weight of a uniform coating material solution. The dissolving liquid is supplied to a spray nozzle 4 which is a 0.6 mm full cone type one-fluid nozzle installed at the lower part of the jet tower 1 by a pump 6 at a flow rate of 0.2 kg / min.
Is sprayed and sprayed on the flowing core material 5. In the spraying step, the core material temperature T
2 is started when the temperature reaches a predetermined temperature. After spraying for a predetermined time, drying is performed for a predetermined time. When drying is completed, the blower 10 is stopped, and the coated core material 5 is removed from the jet tower 1. Was discharged from the withdrawal port 7 at the bottom of the sample to obtain coated pesticide granules of Examples 1 to 8 and Comparative Examples 1 to 5. In the case where the coating is formed from the first and second coating layers, the coating material solution of the first coating layer is first sprayed and sprayed, and the second coating is sprayed and sprayed as soon as the first coating layer is sprayed and sprayed. The coating material solution of the coating layer was sprayed and sprayed, and drying was performed after the spraying of the second coating layer was completed.

[Release Confirmation Test] Using 0.1 g of each coated pesticide granule obtained in the above-mentioned production example, it was poured into a 250 mL cap-filled plastic bottle containing 200 mL of water, and a part of the solution was periodically sampled. The content of the pesticide active ingredient was analyzed to calculate the ingredient release rate. This analysis was performed until release was complete. The water temperature was set at two levels of 20 ° C. and 30 ° C., and the number of days until the cumulative release rate reached 20% was defined as the release suppression period.

In Comparative Examples 1, 2 and 5, the ratio of the release suppression period at 20 ° C. to the release suppression period at 30 ° C.
(A / B) is large from 3.7 to 4.3, and it can be seen that the fluctuation of the release suppression period due to the temperature change is quite large. Comparative Example 3, which is a coating containing 20% of an ethylene / vinyl acetate copolymer, has an A / B of 2.0, which is as small as that of the Example.
At 20 ° C, the release suppression period is 8 days,
The component release period is 93 days, and this release function cannot be said to be a timed release function in the present invention. By the way,
In Examples and Comparative Examples other than Comparative Example 3, all the release suppression periods / component release periods had a timed release function of 0.2 or more. In Comparative Example 4 in which the content of talc in the coating was 99%, all particles were disintegrated 3 hours after the start of the release confirmation test, probably because the formation of the coating was incomplete, and the internal pesticide active ingredient was not coated. It was confirmed that it was exposed outside. In comparison with these comparative examples, in Examples 1 to 8, which are coated pesticide particles shown in the present invention, A /
B was very small, from 1.5 to 2.8, and it was clarified that the fluctuation of the release suppression period due to the temperature change was considerably suppressed.

[0035]

[Table 1] Ca (OH) ₂ : Calcium hydroxide Reagent PEG: Polyethylene glycol Nippon Oil & Fats Co., Ltd.
ECO: Ethylene / carbon monoxide copolymer MI = 0.75, CO
= 0.95wt% BM: Maleimide-modified isobutylene / maleic anhydride copolymer, manufactured by Kuraray Co., Ltd., trade name:
BM-30 talc: average particle size 5 μm KI: cross-linked isobutylene polymer Kuraray Co., Ltd., trade name: KI gel-201 K-F2 EVA: ethylene / vinyl acetate copolymer MI = 20, vinyl acetate content = 30 wt% SA: surfactant hexaoxyethylene nonylphenyl ether HLB = 13

[0036]

[Table 2]

[0037]

According to the present invention, the coated pesticide granules of the present invention are selected from water-insoluble powders and hardly water-soluble powders in the thermoplastic resin.
The surface of pesticide particles is coated with a film containing more than one kind of powder, and the release function is affected by the inclusion of the powder, especially the influence of the ambient temperature such as air temperature, ground temperature and water temperature during the release control period. Can be reduced, and the fluctuation of the release suppression period can be suppressed. The coated pesticide granules of the present invention,
When the spraying / application of various pesticides required during the cultivation period is used for the labor-saving control method at the time of sowing or transplanting of seedlings, the release function of the coated pesticide granules is hardly affected by the ambient temperature. Therefore, even if the temperature in the initial stage of cultivation is higher due to changes in weather or negligence or trouble in temperature management in house cultivation, it is possible to suppress excessive release of pesticide active ingredients during the release suppression period, and to cultivate more safely It can be performed.

[Brief description of the drawings]

FIG. 1 is a diagram of a flow sheet of a spouted bed.

[Explanation of Codes] Spout tower 2. 2. Core material inlet Exhaust gas outlet 4. Spray nozzle 5. Core material 6. Pump 7. Outlet 8. Heat exchanger 9. Orifice flow meter 10. Blower 11. Dissolution tank 12. Mixed solution of coating material T ₁ . Hot air temperature T ₂ . Core material temperature T ₃ . Exhaust temperature SL. steam

Claims (6)

[Claims] 1. The surface of pesticide particles containing at least one or more pesticidal active ingredients is made of a thermoplastic resin and one or more powders selected from a water-insoluble powder and a poorly water-soluble powder as active ingredients. Coated pesticide granules coated with a coating and having a time-release function, wherein the content of the powder in the coating material is in the range of 5 to 98% by weight. . 2. A powder selected from water-insoluble and hardly water-soluble powders.
2. The time-controlled release-type coated pesticide granule according to claim 1, wherein the content of at least one kind of powder is 50 to 95% by weight. 3. A powder selected from water-insoluble and poorly water-soluble powders.
The time-controlled release-type coated pesticide granule according to claim 1, wherein the content of at least one kind of powder is 85 to 95% by weight. 4. A pesticide particle used in a coated pesticide granule having a time-release function is a pesticide particle obtained by adding at least one or more water-swellable substances to at least one or more pesticidal active ingredients and granulating. The time-controlled release coated pesticide granule according to any one of claims 1 to 3, characterized in that: 5. The time-controlled release coated pesticide granule according to claim 1, wherein the thermoplastic resin is an olefin resin. 6. The thermoplastic resin in the coating material is a composite resin of an ethylene / vinyl acetate copolymer and another thermoplastic resin, and the content of the ethylene / vinyl acetate copolymer in the coating material is 15%. The time-controlled release coated pesticide granule according to claim 5, which is not more than 10% by weight.