JP2003252702A - Improved method for producing agrochemical granule - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing an agrochemical granule with which homogeneous sustained release properties are maintained to afford stable and high productivity in the agrochemical granule composed of an agrochemically active ingredient, one kind of a thermoplastic material and an inorganic diluting carrier. <P>SOLUTION: The method for producing the agrochemical granule composed of the agrochemically active ingredient, one kind of thermoplastic material and an inorganic diluting carrier is carried out as follows. The agrochemical granule is produced through (i) a mixing step, (ii) a kneading step and (iii) an extruding step. In the method, extruding granulation is carried out at a temperature not lower than the freezing point of the thermoplastic material and lower than the melting point thereof. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a sustained-release agricultural chemical granule applied to soil. More specifically, it relates to a production method in which the production efficiency of the agricultural chemical granules is enhanced.

[0002]

2. Description of the Related Art In recent years, in the agricultural field, the cultivation scale and cultivation method have been rapidly changed in order to reduce costs and save labor. Correspondingly, technological innovations related to pesticide application methods have advanced, various labor-saving formulations and application methods have been studied, and pesticide formulations that have been considered impossible until now have been developed. As an example,
The development of sustained-release preparations that sustain the release of pesticide active ingredients from pesticide preparations for a long period of time is mentioned. Due to its sustained release mechanism, this formulation can efficiently absorb into the plant a pesticidal active ingredient that has not been effectively absorbed into the plant until now because it has been washed away into the environment. The concentration in the body can be maintained, and thus pest control can be achieved for a long period of time. Therefore, a sustained-release preparation that maintains the efficacy of pesticide active ingredients for a long period of time is an ideal preparation.

As a method for producing an agrochemical formulation in which the release of such an agrochemical active ingredient is controlled, WO95 / 09532 discloses an agrochemical composition containing an agrochemical active ingredient, a hydrophobic substance having a melting point of 50 ° C. or higher and a substance having an oil absorbing ability. The method of extruding and granulating a product under heating conditions above the melting point of the hydrophobic substance is W
O95 / 28835 uses a multi-screw extruder with a plurality of waxes having different physical properties such as melting points and agrochemical active ingredients as essential components, and among the waxes used, below the melting point of the highest melting wax, the extruder barrel Also disclosed is a method for producing a pesticide-containing wax matrix, in which the temperature of a die is set, and kneading and extrusion granulation are collectively performed. This method also discloses that it is desirable to set the set temperature of the barrel and die of the extruder to a temperature about 5 to 30 ° C. lower than the melting point of the highest melting wax among the waxes used. In JP-A-2000-26206, a pesticide active ingredient, an ester-based hydrophobic substance having a melting point of 60 ° C. or higher and lower than the pesticide active ingredient and an acid value within a certain range, and an inorganic diluent carrier are heated. While mixing, the method of granulating is disclosed.

In the method described in WO95 / 09532,
Since extrusion granulation is performed at a temperature above the melting point of the hydrophobic substance, the surface of the granulated product immediately after extrusion is adhered with the molten hydrophobic substance, and therefore, the granulated product is sticky and has a dango-like granulation. There is a problem in that the production amount is large and the production efficiency is low.

[0005] WO95 / 28835 discloses only the set temperature of the barrel and die of the extruder. Even if the present inventor carries out the present method, there are many nonstandard products containing a large amount of powder, and the production efficiency is high. It was bad.

[0006] Japanese Patent Application Laid-Open No. 2000-26206 also does not disclose a specific temperature condition during granulation.

That is, in a method for producing an agricultural chemical granule comprising an agricultural chemical active ingredient, a thermoplastic material, and an inorganic diluent carrier, high production efficiency can be obtained while maintaining sustained release of the agricultural chemical active ingredient. As a method, suitable temperature conditions for extrusion granulation are not known.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide a pesticide granule comprising a pesticide active ingredient, one kind of thermoplastic material, and an inorganic diluent carrier, while maintaining a uniform sustained release property and stable, and It is to provide a manufacturing method capable of achieving high productivity.

[0009]

Means for Solving the Problems In order to solve these problems, the present inventors have prepared (a) a mixing step, (ii) a kneading step, and (iii) an extrusion step for producing pesticide granules. As a result of diligent study, when extruding and granulating an agrochemical composition comprising an agrochemical active ingredient, one kind of thermoplastic material, and an inorganic diluent carrier, extrusion granulation at a temperature not lower than the freezing point of the thermoplastic material and lower than the melting point. By carrying out the above, it was found that defective products caused by manufacturing can be reduced and high productivity can be secured, and the present invention was completed.

That is, the present invention is as follows. [1] A pesticide granule comprising an agrochemical active ingredient, one kind of thermoplastic material, and an inorganic diluent carrier, (i) mixing step,
A method for producing an agrochemical granule, which comprises performing extrusion granulation at a temperature not lower than the freezing point and lower than the melting point of the thermoplastic material in the method of producing through the (ii) kneading step and (iii) extrusion step. [2] The method for producing a pesticide granule according to [1], wherein the pesticide active ingredient is a substance having a water solubility of 60 ppm or more. [3] Agrochemical active ingredients are nitenpyram, imidacloprid, acetamiprid, 3- (2-chlorothiazol-5-ylmethyl) -5-methyl-1,3,5-oxadiazinane-4-ylidene-N
-(Nitro) amine (generic name thiamethoxam), (E) -1-
(2-chloro-1,3-thiazol-5-ylmethyl) -3-methyl-2-
Nitroguanidine (generic name clothianidin), N- [3- (6-
From (chloropyridin-3-ylmethyl) thiazolidin-2-ylidene] cyanamide (generic name thiacloprid), (RS) -1-methyl-2-nitro-3-[(3-tetrahydrofuryl) methyl] guanidine (generic name dinotefuran) The method for producing an agricultural chemical granule according to [2], which is one or more compounds selected. [4] The method for producing an agricultural chemical granule according to any one of [1] to [3], wherein the thermoplastic material is a hydrophobic substance. [5] The method for producing an agricultural chemical granule according to [4], wherein the hydrophobic substance is montanic acid ester wax. [6] In extrusion granulation of an agricultural chemical composition comprising an agricultural chemical active ingredient, one kind of thermoplastic material, and an inorganic diluent carrier, the extruder used is a screw type extruder [1] ] The manufacturing method of the agricultural chemical granule as described in any one of [5].

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The agrochemical active ingredient used in the present invention is not particularly limited, but it is preferable that the water solubility is 60 ppm or more. This is because when the amount is 60 ppm or less, when applied to the soil, the pesticide active ingredient does not move much in the soil even if the amount of rainfall is large, and it is not necessary to control the release. Examples of the agricultural chemical active ingredient that can be used in the present invention include the following.

Herbicides include molinate, propanil, alachlor, metolachlor, bensulfuron-methyl,
Imazosulfuron, cimetrin, cyanazine, benfresate and the like can be mentioned.

Examples of insecticides include MPP, acephate, bamidothion, DMTP, pyraclofos, dimethylvinphos, CVP, BPMC, ethiophencarb, cycloprotoline, tralomethrin, cartap, thiocyclam, imidacloprid, fosthiazate, acetamiprid, NAC, pymetrozine, nitenpyram3. -(2-chlorothiazol-5-ylmethyl) -5-methyl-1,3,5-oxadiazinane-4-ylidene-N- (nitro) amine (generic name thiamethoxam), (E) -1- (2-chloro -1,3-thiazol-5-ylmethyl) -3-methyl-2-nitroguanidine (generic name clothianidin), and N- [3- (6-chloropyridin-3-ylmethyl) thiazolidine-2-ylidene] cyanamide ( Generic name thiacloprid), or (RS) -1-methyl-2-nitro-3-[(3
-Tetrahydrofuryl) methyl] guanidine (generic name dinotefuran) and the like.

Examples of the fungicides include pyroquilon, blasticidin S, kasugamycin, probenazole, ferrimzone, tricyclazole, metaminostrobin, flametopyr, validamycin and the like.

The pesticidal active ingredient is not usually limited to one type, and the same type or different types among these may be used in combination. In the present invention, the agrochemical active ingredient is 0.01 to 50% by weight, preferably 0.01 to the agrochemical composition.
It is used so as to be about 20% by weight.

The present invention uses one type of thermoplastic material. Thermoplastic materials have a melting point of 50 from the viewpoint of easy handling.
C. to 120.degree. C. is preferable, and melting point is 50.degree. C. to 1
It is more preferably at 00 ° C. The thermoplastic material can be used regardless of whether it is hydrophilic or hydrophobic, but a hydrophobic material is suitable for achieving sustained release of the agricultural chemical active ingredient having a relatively high water solubility. The amount of the thermoplastic material used is usually 5% by weight or more, preferably 10% by weight or more, based on the total weight of the pesticide granules of the present invention, and is determined depending on the amount of the pesticide active ingredient added and the physical properties of the diluent carrier. You can From the economical aspect, the upper limit of the amount of thermoplastic material used is 3
It is 0% by weight.

Illustrative of the thermoplastic material used in the present invention, the hydrophobic thermoplastic material includes plant waxes such as candelilla wax, carnauba wax, sugarken wax, rice wax, montanic acid ester wax, ozokerite and ceresin. Mineral wax such as
Paraffin wax, microcrystalline wax,
Petroleum wax such as petrolatum, synthetic hydrocarbon such as Fischer-Tropsch wax, paraffin wax derivative, modified wax such as microcrystalline wax derivative, fatty acid such as stearic acid and behenic acid, hydrogenated castor oil, hydrogenated wax of hydrogenated castor oil derivative , Higher alcohols such as stearyl alcohol, fatty acid esters of fatty acids and higher alcohols such as stearyl stearate, 12-hydroxystearic acid, stearic acid amide, phthalic anhydride, fatty acids such as chlorinated hydrocarbons, acid amides, esters, Examples include ketones. Examples of hydrophilic thermoplastic materials include polyethylene glycol 20000, polyoxyethylene polyoxypropylene glycol, polyoxyethylene, and the like, and surfactants such as ethylene glycol distearate, sorbitan distearate, and sucrose fatty acid ester. Can also be mentioned. Among these, montanic acid ester wax is suitable for sustained release of the agricultural chemical active ingredient.

The inorganic diluent carrier used in the present invention is not particularly limited, and examples thereof include clay, silica stone, talc, bentonite, calcium carbonate, pumice stone, diatomaceous earth, vermiculite, perlite, attapulgite and amorphous dioxide. Silicon, commonly known as white carbon and the like can be mentioned. Usually, one kind or two or more kinds of so-called bulking agents and carriers, which are generally used for pesticide powders and granules, can be used in combination.

The pesticide granules of the present invention can appropriately contain a surfactant and a water-soluble polymer within a range that does not impair the objects and effects of the present invention. These are for fine-tuning the sustained release rate of the pesticide active ingredient contained in the pesticide granules,
It is used for stabilizing the effect of pesticide active ingredients by the water-stopping effect.

The pesticide granules of the present invention may be made into granules by using various additives such as antioxidants, ultraviolet absorbers, antistatic agents, etc. within the range that does not impair the objects and effects of the present invention. You can also

Next, the method for producing the agricultural chemical granules of the present invention will be described. The pesticide granules of the present invention include (i) a mixing step, (i)
It is manufactured through i) a kneading process and (iii) an extrusion process.

(I) Mixing step: In this step, the agricultural chemical composition ingredients including the agricultural chemical active ingredient, one kind of thermoplastic material, and the inorganic diluent carrier are mixed under heating conditions. In order to easily handle the mixture such as transfer to the next step after mixing, the state after mixing is preferably powdery or granular. Therefore,
The mixing step may be any temperature as long as the state after mixing can maintain a powdery state or a powdery state, and in some cases,
The kneading step of the next step can also be performed in this step. Also,
This mixing step can be performed simultaneously with the kneading in the kneading step of the next step.

(Ii) Kneading step: In the kneading step, the mixture obtained in the mixing step is kneaded under heating conditions to form a matrix of thermoplastic material. In this step, it is essential to melt the thermoplastic material partially or entirely. Therefore, it is necessary to carry out the kneading at a temperature not lower than the melting point of the thermoplastic material. As the kneading device used in this step, a fixed container horizontal single-axis type or a fixed container horizontal multi-axis type in which external forces such as compression, shear, and friction are efficiently applied to the material, specifically, a Banbury mixer, a screw A type extruder or the like is suitable.
Among them, a screw type extruder, particularly a multi-screw type extruder such as a double screw type extruder is suitable. When a screw type extruder is used for the kneading operation, the kneading step and the subsequent extrusion step can be simultaneously performed on the same machine. In this case, the kneaded product is discharged from the discharge port of the extruder, and a pesticide molded product can be obtained by installing and extruding a die having a predetermined hole diameter at the opening of the discharge port.

(Iii) Extrusion step: a step of extruding the pesticide composition obtained in the kneading step with an extruder to obtain a pesticide molding. When a screw type extruder is used, the kneading step of the previous step can be performed at the same time. In the present invention, extrusion granulation is carried out under a temperature condition that is equal to or higher than the freezing point of the thermoplastic material and lower than the melting point. If extruded at a temperature above the melting point of the thermoplastic material, the thermoplastic material in the molded product will show tackiness, causing adhesion and fusion of the molded product, eventually becoming a candy-like or dango-like, pesticide grain. The productivity of the agent is extremely poor. Further, when extruded at a temperature lower than the freezing point of the thermoplastic material, the obtained molded product is not molded into a columnar shape, and there are many nonstandard products with many powdery substances, resulting in extremely poor productivity. Thus, by extruding the agrochemical composition under a temperature condition of not less than the freezing point of the thermoplastic material and less than its melting point, a clean columnar pesticide molded article can be obtained and the productivity is remarkably improved.

The extruded pesticide molding product is subjected to the subsequent cooling step and sizing step to obtain pesticide granules.

The pesticide granules can be obtained with high productivity by the production method of the present invention. Further, the obtained agricultural chemical granules also maintain a uniform sustained release property of the agricultural chemical active ingredient.

[0027]

EXAMPLES The present invention will be described in more detail with reference to examples, but the formulation of the agricultural chemical granules described in the examples is not limited thereto. The mixing ratios shown here are all weight%.

Example 1 2% by weight of dinotefuran as an agrochemical active ingredient and montanic acid ester wax as a thermoplastic material (manufactured by BASF, trade name Luwax-E, melting point; 7
5 to 85 ° C., freezing point: 70 to 75 ° C.) 20% by weight, white carbon 5% by weight as an inorganic diluent carrier, talc 1
0% by weight and 63% by weight of calcium carbonate were put into a Henschel mixer, mixed, and discharged in a powder state at 76 ° C. This powder was introduced into a Fuji Paudal screw-type extrusion granulator (EXR-130) and kneaded at 78 ° C. Extrusion and granulation were carried out at 73 ° C through a die having an opening of 0.8 mm to obtain a pesticide molded article. This was crushed with a crusher to obtain a pesticide granule. (Product yield, 94%)

Example 2 2% by weight of dinotefuran as an agrochemical active ingredient and montanic acid ester wax as a thermoplastic material (manufactured by BASF, trade name Luwax-E, melting point;
75-85 ° C., freezing point; 70-75 ° C.) 20% by weight, 5% by weight of white carbon as an inorganic diluent, 10% by weight of talc, 63% by weight of calcium carbonate are put into a Henschel mixer and mixed at 78 ° C. , Was discharged in the form of powder. This powder was introduced into a Fuji Paudal screw-type extrusion granulator (EXR-130) and kneaded at 78 ° C. Extrusion and granulation were carried out at 73 ° C through a die having an opening of 0.8 mm to obtain a pesticide molded article. This was crushed with a crusher to obtain a pesticide granule. (Product yield, 93%)

Example 3 2% by weight of dinotefuran as an agrochemical active ingredient and carnauba wax as a thermoplastic material (trade name: Refined Granul, manufactured by Toa Kasei Co., Ltd.)
arCarnauba, melting point; 83 ° C., freezing point 73-74
20% by weight, 5% by weight of white carbon as an inorganic diluent, 10% by weight of talc and 63% by weight of calcium carbonate were put into a Henschel mixer and mixed, and discharged at 80 ° C. in the form of powder particles. This powder was charged into a Fuji Paudal screw-type extrusion granulator (EXR-130) and kneaded at 85 ° C. 0.8 mm opening at 78 ° C
The mixture was extruded and granulated through the above die to obtain a pesticide molded product. This was crushed with a crusher to obtain a pesticide granule. (Product yield, 92%)

Comparative Example 1 The temperature during extrusion granulation was 78 ° C.
The same procedure as in Example 1 was carried out except that the above procedure was performed. As a result, a block-shaped pesticide molded product was obtained. This was crushed with a crusher to obtain a pesticide granule. (Product yield, 38%)

Comparative Example 2 The temperature during extrusion granulation was 68 ° C.
The same procedure as in Example 1 was carried out except that the above procedure was performed. As a result, a pesticide molded product containing a large amount of powder was obtained. Crush this with a crusher,
A pesticide granule was obtained. (Product yield, 41%)

Test Example 1 (Dissolution test of pesticide granules) The pesticide granules obtained in Examples 1 to 3 were treated with standard 3 degree hard water of 25 m.
Into a 50 ml sample tube with a sealed stopper containing 1 liter, an amount corresponding to 920 ppm as an agrochemical active ingredient was put and submerged in water, and after standing at 25 ° C. for a predetermined time, the whole amount was filtered off to obtain the amount of the agrochemical active ingredient in the filtrate. Was measured by HPLC. From the measurement, the dissolution rate was calculated based on the following formula. Dissolution rate = (amount of pesticide active ingredient in filtrate / amount of pesticide active ingredient in granule) × 100 The results are shown in Table 1. From this result, a uniform sustained release property was maintained.

[0034]

[Table 1]

[0035]

Industrial Applicability According to the production method of the present invention, the agricultural chemical granules obtained through the manufacturing process can maintain the sustained release of the agricultural chemical active ingredient and can obtain the agricultural chemical granules with a high product yield. Therefore, there is an advantage that the manufacturing cost can be kept low.

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Claims (6)

[Claims] 1. An agrochemical active ingredient, one kind of thermoplastic material,
And a method for producing an agricultural chemical granule comprising an inorganic diluent carrier through (i) a mixing step, (ii) a kneading step, and (iii) an extrusion step, at a temperature not lower than the freezing point and lower than the melting point of the thermoplastic material A method for producing a pesticide granule, which comprises granulating. 2. The method for producing a pesticide granule according to claim 1, wherein the pesticide active ingredient is a substance having a water solubility of 60 ppm or more. 3. The pesticide active ingredient is nitenpyram, imidacloprid, acetamiprid, 3- (2-chlorothiazol-5-ylmethyl) -5-methyl-1,3,5-oxadiazinane-4-ylidene-N- (nitro) amine. (Generic name thiamethoxam), (E)
-1- (2-chloro-1,3-thiazol-5-ylmethyl) -3-methyl
-2-Nitroguanidine (generic name clothianidin), N- [3-
(6-chloropyridin-3-ylmethyl) thiazolidin-2-ylidene] cyanamide (generic name thiacloprid), (RS) -1-
Methyl-2-nitro-3-[(3-tetrahydrofuryl) methyl]
The method for producing a pesticide granule according to claim 2, which is one or more compounds selected from guanidine (generic name dinotefuran). 4. The method for producing an agrochemical granule according to claim 1, wherein the thermoplastic material is a hydrophobic substance. 5. The method for producing an agricultural chemical granule according to claim 4, wherein the hydrophobic substance is montanic acid ester wax. 6. A pesticide active ingredient, one kind of thermoplastic material,
In the case of extruding and granulating an agrochemical composition consisting of an inorganic diluent carrier, the extruder used is a screw type extruder, and the agrochemical granules according to any one of claims 1 to 5. Manufacturing method.