JP2002179505A - Covered type controlled releasing agrochemical granular agent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mixed agrochemical granular agent capable of performing a controlled release of >=2 different kinds of agrochemical active ingredients having especially different solubility in water from each other and suitable for the treating method of seedling box of the rice at an individual eluting rate, and a method for producing the same. SOLUTION: This controlled releasing mixed agrochemical granular agent is obtained by preparing a granulated material consisting of >=1 kind of agrochemical active ingredient having a high water solubility, an inorganic diluting carrier and a first thermoplastic material hardly soluble in water, setting the granulated material as an inner core and covering the surface of the core with a mixture of >=1 kind of agrochemical active ingredient different from the agrochemical active ingredients contained in the inner core and having a low water solubility, an inorganic diluting carrier and a second thermoplastic material hardly soluble in water to make an outer surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a sustained-release pesticide granule containing two or more different kinds of pesticide active ingredients and used for eluting and supplying each pesticide active ingredient to an aqueous medium. And, for the production method, more specifically, for example, when applied to a nursery box used for raising rice seedlings, and then when transplanting rice, after a certain period of time after being transferred to the rice field with the stored seedlings, in such granules The present invention relates to a sustained-release pesticide granule that can be suitably used as a sustained-release pesticide granule for a nursery box in which a plurality of kinds of contained pesticide active ingredients are continuously released at individual dissolution rates, and a method for producing the same.

[0002]

2. Description of the Related Art In recent years, paddy fields have been rapidly scaled up and mechanized to reduce the cost of rice cultivation. In response to this, technological innovation in the method of spraying pesticides has progressed,
Various labor-saving formulations and application methods are being studied. As one example, the development of a nursery box treatment method in which a pesticide composition is applied to a paddy rice nursery box before rice transplanting is being promoted.
The greatest advantage of the nursery box treatment method in paddy rice cultivation is that the seedlings can be treated with pesticides simultaneously with rice planting. In addition, even after the transfer to the rice field together with the seedlings, the controlled release of the pesticidal active ingredient contained in the pesticide formulation used enables the control of pests to be achieved for a long time after rice planting. Due to this advantage, the nursery box treatment method is used for pesticides that need to be sprayed during rice planting.
It is an ideal labor-saving application method.

On the other hand, in recent years, two or more pesticidal active ingredients, for example,
There is a demand for a pesticide formulation that enables simultaneous control in a single treatment by combining an insecticidal active ingredient and a bactericidal active ingredient. In other words, a mixed preparation in which two or more kinds of pesticidal active ingredients showing different actions are sustained-released, specifically, during the cultivation period of paddy rice, 30 to 60 days required for pest control,
In some cases, there is a need for a mixed preparation that continuously releases the pesticidal active ingredient for a longer period of time.

Japanese Patent Application Laid-Open No. 2000-44404 discloses an example of sustained release of two or more kinds of pesticidal active ingredients. After the coated particles are coated with resin,
A mixed preparation having a structure in which an outer layer containing another pesticidal active ingredient is provided outside the coated particles is disclosed. An important feature in the composition of the mixed preparation described herein is that it is essential that the surface of the inner core particle is coated with a resin, and that the outer layer does not necessarily need to be controlled-release, Furthermore, no special consideration is given to the difference in water solubility between the two pesticidal active ingredients mainly contained in the inner core particle and the outer layer portion.

[0005] Referring to JP-A-2000-44404 in more detail, Table 4 showing the results of Test Example 1 (dissolution test) shows the effect of coating inner core particles with a resin.
In the comparison of the results of Examples 2 to 4 and Comparative Examples 2 to 4, the cores of Examples 2 to 4 in which the inner core particles are coated with the resin are higher than those of Comparative Examples 2 to 4 in which the inner core particles are not coated. Since the elution of the compound contained in the grains is suppressed, it is clear that the provision of the resin coating has a significant contribution to the sustained release of the pesticide active ingredient contained in the inner core grains (elution is controlled). It is. In addition, once the inner core particles have been prepared, a step of coating the surface with a resin is further provided, so that the number of granule manufacturing steps naturally increases, and consequently, the operating cost increases. Is what you do.

Regarding the point that the sustained release of the outer layer is not indispensable, Examples 1 to 3 whose dissolution characteristics are verified in Test Example 1 (dissolution test) use There is no controversy since there are cases where molding is carried out using a carrier and, in particular, there is no treatment for sustained release. However, Table 4 shows the result that the pesticidal active ingredient benflacarb contained in the outer layer portion was gradually eluted into water. This gentle elution is because the water solubility of benflacarb at 20 ° C. is 80 ppm, and benflacarb itself is a compound that is relatively hardly soluble in water. It is understood that it reflects that In addition, the test period is a relatively short period of 10 days, and within this period, the collapse of the inorganic solid carrier molded layer constituting the outer layer is slight, and the treatment for sustained release is not necessarily performed. It is also presumed that the contact with the aqueous medium is suppressed even without the application.

[0007] Two types of pesticidal active ingredients contained in the inner core particle and the outer layer portion, respectively, are disclosed in JP-A-2000-444.
In Japanese Patent Publication No. 04, the water solubility of the pesticidal active ingredient used is not particularly taken into consideration, and much less the difference in water solubility between the two is taken into consideration. By the way,
In the mixed preparation shown in the example, the water solubility of benflacarb contained in the outer layer portion was 80 ppm as described above.
And 20 of propenazole contained in the inner core particle.
The water solubility at 150C is 150 ppm, the difference is only 70 ppm, not much different.

As shown in Japanese Patent Application Laid-Open No. 2000-26206, it is already known to use a wax for sustained release of agrochemical active ingredients having high water solubility. However, using the sustained release method using a hydrophobic substance such as wax, the same method is applied to two or more pesticidal active ingredients, particularly, two pesticidal active ingredients having extremely different solubility in water. When trying to achieve sustained release using wax, if a wax is selected that has the optimal release rate of one pesticide active ingredient, the release rate of the other pesticide active ingredient will be extremely fast, or conversely, extremely extreme. Will you be late,
In both cases, it was difficult to achieve an appropriately slow release rate. That is, as far as the present inventors know, two or more pesticidal active ingredients having extremely different water solubilities are contained in one granule, and the two or more pesticidal active ingredients are simultaneously released as a pesticide formulation, No suitable dosage form is known, and there is no report on the use of two or more waxes for sustained release of different pesticidal active ingredients.

[0009]

As described above, as described above,
A pesticide containing two or more pesticidal active ingredients, and with respect to at least one of the pesticidal active ingredients, although a sustained-release pesticide formulation has been proposed, a pesticide containing at least two pesticide active ingredients having extremely different water solubilities. In the formulation, if both of them are capable of simultaneous sustained release so as to be released at individual dissolution rates, for example, it is suitable as a pesticide granule used in a rice seedling box treatment method. ,
There is no proposal of a dosage form that satisfies this demand.

[0010] The present invention solves the above-mentioned problems, and an object of the present invention is to provide two different kinds of pesticide preparations desired for a pesticide granule used in, for example, a method for treating a nursery box for paddy rice. Or more, containing a pesticidal active ingredient whose water solubility is extremely different, and for each pesticidal active ingredient whose water solubility is extremely different, a sustained release is simultaneously performed so as to be released at a desired dissolution rate respectively. It is an object of the present invention to provide a sustained-release pesticide granule of various dosage forms and an efficient production method thereof.

[0011]

Means for Solving the Problems The present inventors have conducted intensive studies and studies to solve the above-mentioned problems. As a result, two or more pesticidal active ingredients having extremely different water solubilities were gradually reduced. Upon release, the pesticidal active ingredient having high water solubility is dispersed in a wax matrix and formed into a granulated product and used as an inner core, while the pesticide active ingredient having low water solubility has a lower melting point than the wax in the inner core. By mixing with another wax and coating the surface of the inner core to form an outer layer portion, a double-structured granule was considered.

The present inventors have found that by adopting such a constitution, both the pesticidal active ingredient having high water solubility in the inner core and the pesticidal active ingredient having low water solubility in the outer layer are gradually released. Was.

The pesticide granule of the present invention is produced more specifically as follows.

First, heating, mixing and granulating at least one or more highly water-soluble agricultural chemical active ingredients, an inorganic diluent carrier and a first thermoplastic material which is hardly soluble in water used as a wax component, An inner core granulated material in which each component is uniformly dispersed is prepared.

Next, at least one or more agrochemical active ingredients having low water solubility, an inorganic diluent carrier and a second thermoplastic material having a lower melting point than the first thermoplastic material and being hardly soluble in water are added to the first thermoplastic material. A mixture in which each component obtained by heating and mixing at a temperature not exceeding the melting point of the thermoplastic material is uniformly dispersed is coated on the surface of the granulated material serving as the inner core and then cooled, and the double structure of the present invention is obtained. Is prepared.

According to the study of the present inventors, by adopting the double structure prepared as described above, the pesticidal active ingredient contained in the inner core of the granule of the present invention has a water solubility. Despite the high pesticide content, a sufficient sustained release is achieved by the action of the first thermoplastic material, and other pesticide active ingredients contained in the outer layer part are not only water-soluble of the pesticide active ingredient itself but also second By the action of the thermoplastic material, sufficient sustained release was achieved, and in the end, it was found that two or more pesticidal active ingredients having different water solubilities in one granule can be appropriately sustained released, respectively. . The present inventors have conducted these studies and
The present invention has been completed based on the knowledge obtained by the study.

That is, the sustained-release pesticide granule of the present invention is a sustained-release pesticide granule used for continuously dissolving and supplying an agricultural chemical active ingredient to an aqueous medium. It has a configuration of a coated granule comprising an inner core and an outer layer covering the surface, wherein the inner core has a water solubility at 20 ° C of 100.
A granulated product comprising at least one kind of agrochemical active ingredient of 0 ppm or more and 10% or less, an inorganic diluent carrier, and a first thermoplastic material which is hardly soluble in water;
Water solubility at 0 ° C. is at least one kind of agrochemical active ingredient of 0.01 to 500 ppm, an inorganic diluent carrier, and a material having a lower melting point and a different melting point than the first thermoplastic material contained in the inner core, A coating layer made of a second thermoplastic material that is hardly soluble in water, and the configuration of the coated granule allows the pesticide active ingredient contained in the inner core and the pesticide active ingredient contained in the outer layer to be gradually released. This is a sustained-release pesticide granule characterized in that its dissolution is controlled.

In the sustained-release pesticide granules of the present invention,
The outer layer may further contain a surfactant.
Further, for example, the first thermoplastic material that is hardly soluble in water contained in the inner core may be a montanic acid wax and / or a montanic acid ester wax. On the other hand, it is preferable that the second thermoplastic material that is hardly soluble in water contained in the outer layer portion is a paraffin wax.

In the sustained-release pesticide granule of the present invention, for example, the pesticidal active ingredient contained in the inner core is (RS) -1-methyl-
2-nitro-3- (tetrahydro-3-furylmethyl)
It is guanidine, the pesticide active ingredient contained in the outer layer part,
A configuration that is probenazole can be selected.

In addition, the method for producing a sustained-release pesticide granule of the present invention is a method for producing a sustained-release pesticide granule having the above-mentioned structure, wherein When forming a coating layer serving as an outer layer portion on the surface, by heating and melting the second thermoplastic material constituting the coating layer, to achieve coating on the surface of the granulated material, the core contained in the inner core A method for producing a granule, comprising heating to a temperature below the melting point of the first thermoplastic material.

In the two-layer structure of the sustained-release pesticide granule of the present invention, the term “inner core” is used to mean a portion that becomes a pesticide core in the central part inside the granule, and the term “outer layer part” is used. It is used to mean the surface of the granule or a portion covering the outer periphery of the inner core.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the sustained-release pesticide granules of the present invention will be described in more detail.

The sustained-release pesticide granule of the present invention comprises, for example, a pesticide active ingredient having at least two kinds of actions in one granule, which is used for a nursery box treatment of paddy rice. It is a dosage form that can be suitably used when preparing a mixed preparation. That is, after spraying as a seedling box granule, different periods of time are gradually eluted, and two or more kinds of pesticide active ingredients that need to maintain a desired concentration are supplied when the action of the pesticide active ingredient is different. By using the sustained-release pesticide granules of the present invention having a two-layer structure, the release of one pesticide active ingredient from the outer layer for a certain period of time, and the other pesticide active ingredient from the inner core for a long time The release can be sustained. Therefore, the dissolution control achieved by the sustained-release pesticide granules of the present invention means that different types of pesticide active ingredients contained in the outer layer and the inner core, respectively, are simultaneously and gradually eluted.

The sustained-release pesticide granule of the present invention has a two-layer structure composed of an inner core and an outer layer, in which two or more pesticidal active ingredients having extremely different water solubilities are contained. Although contained, the inner core contains the pesticide active ingredient with high water solubility, and the outer layer part contains the pesticide active ingredient with low water solubility, and according to the level of water solubility of the pesticide active ingredient, in the whole granule, The location is classified. In particular,
The pesticide active ingredient to be contained in the inner core is selected from those having a water solubility at 20 ° C. of 1,000 ppm or more and 10% or less,
Conversely, the pesticidal active ingredient contained in the outer layer is limited to those having a water solubility at 20 ° C. of 0.01 to 500 ppm, and is a combination having a remarkable difference in water solubility between the two.

At this time, the pesticidal active ingredient, which is contained in the inner core and has extremely high water solubility, is dispersed in a wax matrix in order to control the dissolution and release rate and to provide sufficient sustained release. However, as a wax component for the matrix, a first thermoplastic material that is hardly soluble in water is used. As a result of forming the first thermoplastic material that is hardly soluble in water into a matrix, contact between the aqueous medium and the pesticidal active ingredient is suppressed. In addition, although the outer layer portion is also made of a second thermoplastic material that is hardly soluble in another kind of water, it also functions as a coating layer using a wax as a binder, so that the pesticide active ingredient contained in the inner core is further increased. Has an increased sustained release. On the other hand, the pesticidal active ingredient having low water solubility contained in the outer layer portion is dispersed in the wax matrix using the second thermoplastic material which is hardly soluble in water, and the low water solubility is also combined. Thus, the dissolution release rate is controlled, and a desired sustained release property is imparted.

As described above, the sustained-release pesticide granule of the present invention has a two-layer structure composed of an inner core and an outer layer according to the difference in water solubility of a plurality of kinds of pesticide active ingredients contained therein. Is selected, and in addition to the water solubility, the type of wax to be used is distinguished so that a wax matrix optimal for achieving a desired sustained release can be obtained. At that time, the release rate also depends on the particle size of the granule (the ratio between surface area and volume), so that the desired particle size of the inner core and the total particle size covering the outer layer portion are set to predetermined values. In addition to each pesticidal active ingredient, an inorganic diluent carrier is added, and the pesticidal active ingredient and the inorganic diluent carrier are dispersed uniformly in a wax matrix composed of a thermoplastic material, in a unitary form. The content of the pesticidal active ingredient per volume is adjusted to an appropriate range.

As described above, in the sustained-release pesticide granule of the present invention, the two-layer structure composed of the inner core and the outer layer is made of a wax matrix using different thermoplastic materials. To form a shape clearly defined by the inner core and the outer layer. To make the structure simple,
As the inner core, using the first thermoplastic material, after heating and mixing, to prepare a granulated product molded into a desired particle size, coating the surface with a coating composition to be an outer layer portion, under heating, After the second thermoplastic material is melted and made into a liquid state, the second thermoplastic material is configured to be suitable for the manufacturing method of coating on the granulated material. Specifically, in the step of coating the outer layer portion, in the heating environment, in order to avoid re-melting of the first thermoplastic material that maintains the shape of the inner core granules, it is used in the outer layer portion The melting point of the second thermoplastic material is chosen to be lower than the melting point of the first thermoplastic material. Accordingly, the heating conditions in the step of coating and forming the outer layer portion are not lower than the melting point of the second thermoplastic material, but do not cause melting of the first thermoplastic material, so that the first thermoplastic material is not melted. Choose a temperature that does not exceed the melting point of

As described above, in the sustained-release pesticide granule of the present invention, as a result of performing the sustained-release treatment using different thermoplastic materials on the inner core and the outer layer, for example, different control periods are required. Even when two or more pesticidal active ingredients having a controlling action against pathogens and pests are contained, a sustained release function in which the release of these two or more pesticidal active ingredients individually can be ensured.

Further, the method for producing the sustained-release pesticide granule of the present invention will be described more specifically. First, the pesticidal active ingredient is dissolved at 20 ° C. so that the dissolution of the pesticidal active ingredient having a water solubility of 1000 ppm or more and 10% or less is gradually released.
Inorganic diluent carrier, using a first thermoplastic material that is hardly soluble in water, heated to a temperature equal to or higher than the melting point of the first thermoplastic material, uniformly mixed composition of desired shape, particles It is molded to a diameter and cooled to prepare a granulated product for the inner core. Subsequently, on the surface of the granulated product for an inner core, an agrochemical active ingredient having a water solubility of 0.01 to 500 ppm at 20 ° C. and an inorganic diluent carrier are uniformly mixed with a second thermoplastic material that is hardly soluble in water. By using the composition mixed in, and coating while heating to a temperature equal to or higher than the melting point of the second thermoplastic material, to obtain a granule having a two-layer structure in which an inner layer and an outer layer portion are provided on the surface thereof Can be. At this time, the material is selected so that the melting point of the second thermoplastic material is lower than the melting point of the first thermoplastic material. It is possible to set the temperature not to reach the melting point of the thermoplastic material. The state in which the dissolution of the pesticide active ingredient in the inner core is gradually released means that the first thermoplastic material, which is hardly soluble in water, is heated and melted to form a matrix, thereby releasing the pesticide active ingredient into water. Means that it is a controlled pesticide granule.

That is, the sustained-release pesticide granules of the present invention can be specifically produced by the following steps. Process First, the water solubility at 20 ° C. is 1000 pp
The pesticidal active ingredient having high water solubility in the range of m to 10%, the inorganic diluent carrier, and the first thermoplastic material are heated and mixed by a mixer equipped with a heating device (for example, a floating mixer). At this time, the heating temperature is set to a temperature not lower than the melting temperature of the first thermoplastic material and not reaching the melting point of the pesticidal active ingredient contained therein. Step After heating and mixing, the obtained uniform mixture is granulated by a granulator equipped with a heating device. The type of granulator is
It is appropriately selected in consideration of the shape, particle size, and the like of the target granulated product. Specifically, when obtaining a cylindrical molded product, an extrusion granulator equipped with a screen that matches the target particle size,
When a spherical molded product is obtained, a rolling granulator and the like are exemplified. The granulation temperature is preferably not lower than the temperature at which the first thermoplastic material to be used melts and not reaching the melting point of the contained agricultural chemical active ingredient. Process The obtained granules often adhere to each other, and are crushed, and if necessary, classified with a sieve to obtain a controlled-release granule (inner core) having a desired shape and particle diameter. I do. Step Unlike the pesticidal active ingredient having high water solubility contained in the inner core, the water solubility at 20 ° C. is 0.01 to 500.
An agrochemical active ingredient having a low water solubility in the range of ppm and an inorganic diluent carrier are different from the first thermoplastic material contained in the inner core and have a lower melting point than the first thermoplastic material. The second thermoplastic material, which is hardly soluble in water, and, if necessary, a surfactant and an auxiliary agent are mixed together by a mixer (for example, a floating mixer) to obtain a raw material powder for an outer layer portion. Step The inner core prepared in the step is put into a mixer equipped with a heating device (for example, a floating mixer, a tumbling granulator, a cooler mixer, a drum mixer, a marmalizer, etc.), mixed while heating, and prepared in the step. The raw material powder for the outer layer is quantitatively charged and coated so as to obtain particles having a target particle size distribution. At that time, the outer layer portion to be coated is heated to a temperature at which the melting of the second thermoplastic material containing the second thermoplastic material occurs, so that the molten second thermoplastic material as a binder has a low water-soluble agrochemical active ingredient. And an inorganic diluent carrier are uniformly dispersed to form a coating layer, whereby the coated sustained-release pesticide granule of the present invention is obtained. In addition,
During such a heating / coating step, adhesion / fusion of inner core particles due to softening / melting of the first thermoplastic material in the inner core, and further,
In order to avoid adhesion and compression of the inner core to the inner wall of the mixing tank, the heating temperature must be equal to or higher than the temperature at which the second thermoplastic material used for the outer layer melts and reach the melting point of the first thermoplastic material used for the inner core. It is essential that the temperature not be changed.

In the coated sustained-release pesticide granule of the present invention having the above-mentioned structural characteristics, the composition ratio of the outer layer portion and each composition constituting the inner core is not particularly limited. Included in the inner core, respectively, the dissolution rate of at least one or more pesticide active ingredients, the rate of metabolic decomposition in the plant and the rate of absorption into the plant, and further, in the field where plant seedlings are replanted, each pesticide The concentration may be appropriately determined in consideration of the concentration range in which the active ingredient should be maintained, for example, the concentration at which the controlling effect is exhibited, and the period in which the concentration is to be maintained. At that time, in general, the weight of at least one or more pesticidal active ingredients to be contained in the outer layer portion and the inner core per granule is respectively subtotaled, and the ratio of the subtotal weight is calculated as follows: inner core: outer layer = 1: 1
The range is preferably 5 to 15: 1. In addition, the coated sustained release pesticide granule of the present invention is a solid preparation comprising an outer layer portion and an inner core, and its outer size and dosage form are not limited.
For example, any shape such as a normal granule type, a pill type, a tablet type and the like may be used. In addition, when taking the above-mentioned dosage form, its size can also be appropriately selected according to the use form. For example, the diameter of a columnar or spherical shape is not particularly limited as long as it is in the range of 0.1 to 3 mm. Specifically, in the coated sustained release pesticide granule of the present invention, the particle size is appropriately selected according to the form to be sprayed, and is applied to, for example, a granule for a nursery box for paddy rice. In this case, it is preferable to select the aperture of the screen for adjusting the particle size and the outer shape in the range of 0.3 to 3 mm. In addition, it is preferable that the length of the columnar shape is selected in a range that does not become excessively long according to the diameter. For example, if the diameter of the columnar shape is within the range of 0.1 to 3 mm, the length is preferably selected. Is desirably selected in the range of 0.1 to 10 mm.

In the coated sustained-release pesticide granules of the present invention, for example, in the case of a spherical shape, the diameter ratio of the inner core portion to the outer layer portion is not particularly limited, and generally exceeds 1: 3. You can choose no range. In general, the elution of the contained pesticidal active ingredient is accelerated accordingly as the particle size of the granule decreases and the surface area of the granule per unit content of the pesticide active ingredient increases. In the sustained-release pesticide granules, the inner core and the outer layer are each made of a thermoplastic material that is hardly soluble in different water, and by independently controlling the sustained release, the particle size, and the inner core As long as the diameter ratio of the outer layer portion is within the above range, desired elution characteristics can be achieved.

More specifically, the inner core portion and the outer layer portion each contain an inorganic diluent carrier in addition to the pesticidal active ingredient, so that the amount of the pesticidal active ingredient per unit volume can be widened. Can be adjusted with
It is also possible to adjust the granule surface area per unit content of the pesticidal active ingredient to a certain range. At that time, in each of the inner core part and the outer layer part, in order to uniformly dilute each pesticide active ingredient with the inorganic diluent carrier, a method of mixing each pesticide active ingredient and the inorganic diluent carrier together in powder form together It is more preferable to use

In the coated sustained release pesticide granule of the present invention,
Different types of pesticidal active ingredients to be contained in the inner core and the outer layer, respectively, generally include, among the pesticidal active ingredients available for the target plant, for example, paddy rice, 20%.
At least one or more high-solubility agricultural chemical active ingredients having a water solubility in the range of 1000 ppm or more and 10% or less at 20 ° C;
It is preferable to use a compound which has biocidal activity and is used for agricultural and horticultural use with at least one or more pesticidal active ingredients having low water solubility in the ppm range. For example, preferably, the compound having the biocidal activity is selected from a combination of an insecticide and a fungicide, such as a combination of insecticides having different action mechanisms from each other, or a combination of fungicides. Selection of a drug combination having a difference in the effective control period is not excluded from the preferable combination. Further, the content of these pesticidal active ingredients in the coated sustained release pesticide granule, there is no distinction depending on whether the content site is the inner core or the outer layer portion, in each part, usually 0.01 mass % To 50
It can be selected in a range of 0.5% by mass, preferably in a range of 0.5% by mass to 30% by mass, but is not particularly limited.
That is, the content of each pesticide active ingredient contained per granule is determined by the physical properties of the active ingredient and the application scene, and depending on its spraying form, for example, 10 rounds depending on the form to be sprayed as a seedling box granule. The amount sprayed per
The content may be selected so as to satisfy the required processing amount per 10 ares.

In the coated sustained release pesticide granule of the present invention,
In order to obtain a mixed granule in which two or more kinds of pesticidal active ingredients having significantly different water solubilities are individually sustained-released, the water solubility at 20 ° C. of the pesticide active ingredient contained in the inner core is contained in the outer layer. It is essential that it be significantly higher than the water solubility of the pesticidal active ingredient. That is, the water solubility at 20 ° C. of the pesticidal active ingredient contained in the inner core is at least 100%.
0 ppm or more and 10% or less, preferably 5000 ppm or more and 10% or less, more preferably 10,000 ppm or more and 1% or less.
0% or less, on the other hand, the water solubility at 20 ° C. of the pesticidal active ingredient contained in the outer layer portion is at least:
0.01 to 500 ppm, preferably 0.1 to 300 p
pm, more preferably in the range of 0.5 to 200 ppm, so that there is an order of magnitude difference between the water solubilities of the two.

When the melting point of the pesticidal active ingredient contained in the inner core is equal to or lower than the melting point of the first thermoplastic material used in the inner core, in the step of producing the sustained-release pesticide granules of the present invention, When the first thermoplastic material is heated in order to prepare the granulated product, the pesticidal active ingredient mixed therein is also melted. In this state, there is a possibility that they are not uniformly mixed with each other in a liquid state, and even if they are uniformly mixed, when coagulating thereafter, the pesticidal active ingredient may be localized and may not be uniformly dispersed. In such a case, in the core, together with the added inorganic diluent carrier, the form in which the pesticidal active ingredient is uniformly dispersed in the wax matrix of the first thermoplastic material is not achieved,
There is a major concern that the expected sustained release will not be achieved.
In order to eliminate such a concern, the melting point of the pesticidal active ingredient contained in the inner core is desirably higher than the melting point of the first thermoplastic material used, and preferably, the one having a melting point of 100 ° C. or more is used. With such a selection, the pesticidal active ingredient contained in the inner core does not melt, but the first thermoplastic material is softened and heated to a melting temperature, for example, a powdery pesticide active ingredient and an inorganic diluent carrier. Is preferably mixed and dispersed uniformly in the first thermoplastic material. Similarly, when the melting point of the pesticidal active ingredient contained in the outer layer portion is the same as or lower than the melting point of the second thermoplastic material used in the outer layer portion, in the step of coating the outer layer portion, the second thermoplastic material is melted. Therefore, when heated, the pesticidal active ingredient mixed therein will also melt. At that time, there is a concern that similar problems may occur. In order to avoid it in advance, the melting point of the pesticidal active ingredient contained in the outer layer portion is at least higher than the melting point of the second thermoplastic material used, preferably higher than that of the first thermoplastic material. Desirably, the melting point is higher than the melting point, and preferably, the melting point is 100 ° C. or higher.

As the pesticidal active ingredient satisfying the above conditions,
Specific examples include the following. As the pesticidal active ingredient contained in the inner core, for example, the pesticide has a melting point of 2
Thiocyclam (125-128 ° C., about 8%), acetamiprid (101-103.3 ° C., 4200 pp) having water solubility at 0 ° C. each having the value shown in parentheses.
m), thiamethoxam (139.1 ° C., 4100 pp)
m) or the compound (RS) -1-methyl-2-nitro-3- (tetrahydro-3-furylmethyl) guanidine (about 105) disclosed in JP-A-7-179448.
C., 54000 ppm), and examples of the bactericide include pyrochilone (112 ° C., 4000 ppm), blasticidin S (235 ° C., 3%) and the like.

On the other hand, as an agrochemical active ingredient contained in the outer layer, for example, in the case of an insecticide, NAC (14) having a melting point and a water solubility at 20 ° C. each having the values shown in parentheses.
2 ° C, about 100 ppm), bendiocarb (124.
6-128.7 ° C., 40 ppm), clothianidin (1
76-178 ° C, 270 ppm), pymetrozine (23
4.4 ° C, 270 ppm), fipronil (about 200
1.9 ppm), buprofezin (about 105 ° C,
0.9 ppm), tebufenozide (191 ° C., 0.83
ppm), and bactericides include thiuram (155 ° C., 30 ppm) and iprodione (136 ° C.,
13 ppm), Flutranil (102 ° C., 9.6 pp)
m), thifluzamide (about 178 ° C, 1.59 ppm),
Carpropamide (147-149 ° C, 3.6 ppm),
Azoxystrobin (about 118 ° C., 10 ppm), probenazole (138 ° C., 150 ppm), diclosimet (about 150 ° C., 5 ppm), oxolinic acid (31
0 ° C, 3.2 ppm), teclophthalam (198 ° C, 1
4 ppm), ferimzone (175 ° C., 162 pp)
m), diclomedine (250-253.5 ° C, 0.74
ppm), captan (178 ° C., 3.3 ppm) and the like. Among them, the insecticide (RS) -1-
The combination of methyl-2-nitro-3- (tetrahydro-3-furylmethyl) guanidine and probenazole, a fungicide, in the outer layer is used as the sustained-release pesticide granule of the present invention as a seedling box granule. It is one of the suitable combinations when preparing.

The first thermoplastic material for the inner core used in the sustained-release pesticide granules of the present invention has a water solubility at 20 ° C. of less than 0.5% and is insoluble or hardly soluble in water at ordinary temperature. It is preferable to use a solid organic substance having a melting point in the range of 70 ° C to 110 ° C, preferably 72 ° C to 100 ° C, more preferably 74 ° C to 98 ° C. For example, vegetable waxes such as candelilla wax, sugar wax, and rice wax, mineral waxes such as montanic acid wax, ozokerite, and ceresin, petroleum waxes such as microcrystalline wax and petrolatum, and synthetic hydrocarbons such as Fischer-Tropsch wax , Modified waxes such as montanic acid wax derivatives, paraffin wax derivatives, microcrystalline wax derivatives, hydrogenated castor oil, hydrogenated waxes of hydrogenated castor oil derivatives, 12-hydroxystearic acid, stearamide, phthalic anhydride, and Fatty acids having a chlorinated hydrocarbon group, acid amides, esters, ketones and the like can be mentioned. Among them, those having an acid value of 10 mgKOH / g or more as an acid value determined by titration with an alkali according to the test method specified in ASTM D1386 are preferable. For example, sugarken wax (melting point;
75 ° C., acid value: about 21 mg KOH / g) or montanic acid wax (manufactured by BASF, trade name Luwax S, melting point: 75)
-85 ° C, acid value; 135-160 mgKOH / g), montanic acid ester wax (manufactured by BASF, trade name Luwa)
xE, melting point: 75-85 ° C, acid value: 10-25 mgK
OH / g) is particularly preferable because it can release nearly 100% of the pesticidal active ingredient contained in the inner core while imparting sustained release. In addition, these waxes, thermoplastic materials,
In addition to using only one kind, two or more kinds may be used in combination. The total amount of the first thermoplastic material used is usually selected to be 5% by mass or more, preferably 10% by mass or more, based on the total weight of the inner core composition constituting the sustained-release pesticide granule of the present invention. Can be appropriately determined in consideration of the amount of the added pesticidal active ingredient, the physical properties and the amount of the inorganic diluent carrier. Preferably, from an economical point of view, the upper limit of the amount of the first thermoplastic material to be added is selected to be 20% by mass.

The inorganic diluent carrier for the inner core used in the sustained-release pesticide granules of the present invention is not particularly limited as long as it does not show at least almost water solubility. For example, clay, silica, talc, Bentonite, calcium carbonate,
Examples include pumice, diatomaceous earth, vermiculite, perlite, attapulgite, amorphous hydrated silicic acid, and so-called white carbon. One or more of so-called extenders and carriers usually used for pesticide powders and granules can be used in combination.

Further, in the sustained-release pesticide granule of the present invention,
The inner core, in addition to the inorganic diluent carrier, as long as the object and effects of the present invention are not impaired, an antioxidant or an ultraviolet absorber,
Various additives such as an antistatic agent may also be added to form granules. For example, examples of antioxidants include hindered phenol-based antioxidants, sulfur-based antioxidants, phosphorus-based antioxidants, amine-based antioxidants, lactone-based antioxidants, and vitamin E-based antioxidants. Can be Examples of the ultraviolet absorber include inorganic compound ultraviolet absorbers such as titanium dioxide, and organic compound ultraviolet absorbers such as benzotriazole, benzophenone, triazine, benzoate, and salicylate. that time,
These antioxidants and ultraviolet absorbers may be selected depending on the physicochemical properties of the pesticidal active ingredient contained in the inner core, and may be added in an amount that shows the effect.

Further, examples of the antistatic agent include inorganic compounds such as titanium oxide, zinc oxide and magnesium oxide, and calcium phosphate compounds. Phosphate ester surfactants such as polyoxyethylene alkyl ether phosphates can also be used as antistatic agents. The antistatic agent may be used as needed, and the amount of the antistatic agent may be such that the antistatic effect is recognized as long as the object and effects of the present invention are not impaired.

On the other hand, in the sustained-release pesticide granules of the present invention,
The second thermoplastic material that is hardly soluble in water in the outer layer portion is substantially the same as the thermoplastic material used for the inner core, and may be used in combination of two or more. The melting point of the first thermoplastic material contained in the inner core must be lower than that of the first thermoplastic material.
It is preferable to select a temperature in the range of 0 ° C to 70 ° C, preferably 50 ° C to 69 ° C, more preferably 60 ° C to 68 ° C.
Furthermore, since the second thermoplastic material is heated and melted into a binder in the step of coating, if the melt viscosity is low, adhesion of particles during coating is reduced, which is preferable. Specific examples of those suitable for the second thermoplastic material satisfying the above-mentioned various conditions include candelilla wax, vegetable wax such as wood wax, beeswax, laurin, whale wax, animal wax such as tallow, paraffin wax. And petroleum waxes such as petrolatum, synthetic hydrocarbons such as Fischer-Tropsch wax, and modified waxes such as paraffin wax derivatives. Among these, in particular, paraffin wax (manufactured by Nippon Seiwa Co., Ltd., trade name: paraffin wax 140, melting point: 61 ° C, trade name: SP-0145, melting point: 63 ° C, paraffin wax 1
50, melting point; 66 ° C.). Its usage is
The amount of the pesticidal active ingredient contained in the outer layer portion and the physical properties of the inorganic diluent carrier are determined. In the sustained-release pesticide granule of the present invention, the amount is usually 1% by mass to the total weight of the composition of the outer layer portion. 20% by weight, preferably in the range of 1% to 15% by weight. Incidentally, the content of the second thermoplastic material,
The total oil absorbing capacity of the composition in the outer layer portion is set to be equal to or less than the total oil absorbing capacity.

The inorganic diluent carrier for the outer layer used in the sustained-release pesticide granules of the present invention is not particularly limited as long as it does not exhibit at least almost water solubility. If the material is substantially the same as the inorganic diluent carrier, the object can be sufficiently achieved. Thus, for example, clay, quartzite, talc, bentonite, calcium carbonate,
Examples include pumice, diatomaceous earth, vermiculite, perlite, attapulgite, and amorphous hydrated silicate, commonly known as white carbon. One or more so-called bulking agents and carriers usually used in agricultural chemical powders and granules can be used in combination.

In the sustained-release pesticide granules of the present invention,
The outer layer may contain, in addition to the inorganic diluent carrier, a surfactant and an auxiliary agent as long as the object and effects of the present invention are not impaired.

In the sustained-release pesticide granule of the present invention, the surfactant that can be added to the outer layer portion includes a nonionic surfactant, an anionic surfactant, and the like which are generally used in agricultural chemical formulations.
Cationic and amphoteric surfactants are included. For example, alkyl ether, polyoxyethylene alkylaryl ether, polyoxyethylene styryl phenyl ether, polyoxyethylene alkyl ester, potioxyethylene sorbitan alkylate, polyoxyethylene phenyl ether polymer, polyoxyethylene alkylene aryl phenyl ether, polyoxyethylene Non-ionic surfactants such as alkylene glycol, polyoxyethylene polyoxypropylene block polymer, lignin sulfonate, alkyl aryl sulfonate, dialkyl sulfosuccinate, polyoxyethylene alkyl aryl ether sulfate, alkyl naphthalene sulfonate, Anionic surfactants such as polyoxyethylene styryl phenyl ether sulfate; Amine salts, quaternary ammonium salts, alkyl betaines, cationic surfactants and amphoteric surfactants such as an amine oxide. When adding these surfactants, one type may be used, or the same type or different types may be used in combination.

In addition to the surfactant, examples of the auxiliary agent that can be added to the outer layer include solid organic acids such as aromatic carboxylic acids, polycarboxylic acids, and sugar-derived carboxylic acids, and water-soluble polymers. No. Specifically, examples of the organic acid include dibasic acids such as oxalic acid, malonic acid, succinic acid, maleic acid, and fumaric acid; or hydroxy-substituted dibasic acids such as malic acid and tartaric acid; and sugar-derived acids such as ascorbic acid and citric acid. Type carboxylic acids. Examples of the water-soluble polymer include polyvinyl alcohol, carboxymethylcellulose, dextrin, hydroxyethylcellulose, methylcellulose, alginate, gelatin, pectin, pullulan, polyvinylpyrrolidone, polyacrylate, polyethylene oxide, and the like. The total amount of the surfactant and these auxiliary agents is usually 0.01 to 20% by mass, preferably 0.01 to 10% by mass, based on the total weight of the composition of the outer layer. %.

The sustained-release pesticide granules of the present invention having the above-described structure are controlled so that two or more different pesticide active ingredients having particularly extremely different water solubilities are released at individual dissolution rates. The pesticide granules can be released, and can be particularly preferably used as granules for rice seedling raising boxes. By using the sustained-release pesticide granules of the present invention, 30 to 60 days required for pest control during paddy rice cultivation period from rice planting, which is required for granules for nursery boxes for paddy rice, and in some cases more than that It is possible to release the pesticidal active ingredient continuously and almost completely. In addition, the sustained-release pesticide granule of the present invention can eliminate the drying step required in the method described in Japanese Patent Application Laid-Open No. 2000-44404 during production, and thus has the advantage of keeping production costs low. There is also. The sustained-release pesticide granule of the present invention is applied to, for example, a paddy rice nursery box before rice planting when used as a paddy rice seedling box granule. When the granules are used for a nursery box, the application rate is 10 g to 100 g per paddy rice nursery box (about 30 cm × 60 cm).
g, usually about 50 g, but is not particularly limited, and may be determined according to the content of the pesticidal active ingredient in the preparation, the required period of controlling pests and pests, and the number of nursery boxes used per 10 a.

Further, the pesticide granules of the present invention, for example, when applied to a paddy rice nursery box, spray the granules uniformly over the entire seedling box,
When the seedlings are transplanted in the paddy field, it is preferable that the number of accompanying pesticide granules per seedling does not vary widely. For that purpose, the particle size of the granules, specifically,
It is desirable to avoid making the aperture used for sieving or the like that determines the particle size distribution too large, so that the number of pesticide granules corresponding to a predetermined application rate becomes too small. That is, when used as granules for a nursery box for paddy rice, the number of grains per gram of the pesticide granules is 300 or more, preferably 40 or more.
It is desirable to select the openings so that there are zero or more openings. However, the content of the inorganic diluent carrier contained,
Although it depends on the bulk specific gravity and the like, it is necessary to avoid that the particle size of the granules becomes too small and the granules are suspended in water. In the outer layer portion, it is possible to add a surfactant or the like to increase the affinity of the surface for water and prevent the above-mentioned problems, but the number of particles per gram of the pesticide granule is as follows.
It is desirable to keep the number not exceeding 2,000.

[0050]

Next, the present invention will be described in more detail by way of examples. In particular, the case where the sustained-release pesticide granule of the present invention is used as a granule for a nursery box for paddy rice will be described, but the method for preparing the granule for a nursery box and the resulting formulation are not limited at all. For example, (RS) -1-methyl-2-nitro-3- (tetrahydro-3-furylmethyl) guanidine exemplified as the core pesticide active ingredient, probenazole exemplified as the pesticide active ingredient in the outer layer, and the various pesticides described above. Instead of the active ingredient, or each of the thermoplastic materials used for the inner core and the outer layer exemplified in the examples, such as replacing the inorganic diluent carrier with the others described above, the sustained-release pesticide granules of the present invention , A granule for a nursery box for paddy rice can also be obtained.

The mixing ratios shown in the following specific examples are as follows:
Except where otherwise specified, all are% by mass.

(Reference Examples 1 to 6)
The cores of Reference Examples 1 to 6 were obtained according to the following production method.

As the pesticidal active ingredient contained in the inner core, (RS) -1-methyl-2-nitro-3- (tetrahydro-3-furylmethyl) guanidine (hereinafter referred to as a compound) synthesized according to the method described in JP-A-7-179448. "Compound 1"
), White carbon, talc, calcium carbonate as the inorganic diluent carrier, montanic acid wax (manufactured by BASF, trade name Luwax as the first thermoplastic material)
S, melting point: 75-85 ° C, acid value: 135-160 mg
KOH / g) and / or montanic acid ester wax (manufactured by BASF, trade name Luwax E, melting point: 75-8)
5 ° C., acid value; 10 to 25 mg KOH / g) were put all at once into a floating mixer equipped with a heating device.
The mixture was heated to 3 ° C. or 90 ° C. and mixed. This mixture is
The particles were extruded and granulated using a horizontal extrusion granulator (a screen having an aperture of 0.7 mm or 0.8 mm) maintained at 90 ° C. by a heating device. The charged composition shown in Table 1 respectively,
The granules obtained under the manufacturing conditions were crushed and sieved to obtain granules (inner cores) of Reference Examples 1 to 6.

[0054]

[Table 1]

(Test Example 1): Dissolution Test of Inner Core The dissolution rate of the pesticide active ingredient (compound 1) released from the inner core obtained in Reference Examples 1 to 6 was measured by the following method.

That is, 50 ml containing 25 ml of standard 3 degree hard water was added.
When all the pesticidal active ingredients contained in each of the inner cores obtained in Reference Examples 1 to 6 eluted into a sample tube with a sealed stopper of ml volume, the concentration of the pesticidal active ingredient (Compound 1) was 920 p.
The amount corresponding to the amount of pm was added and submerged in water. In this state, after standing at 25 ° C. for a predetermined time, the whole amount is separated by filtration, and the amount of the pesticide active ingredient (compound 1) dissolved in the filtrate is determined by HP.
It was measured by LC. From the measured values, the dissolution rate was calculated based on the following formula, and the results are summarized in Table 2.

Dissolution rate = (amount of pesticide active ingredient in filtrate / amount of pesticide active ingredient in granule) × 100 As is evident from the results shown in Table 2, the sustained-release pesticide granule of the present invention contains The corresponding granulated products (inner core) of Reference Examples 1 to 6 can release the contained pesticide active ingredient (compound 1) gradually and completely for an arbitrary period in a range of one week to two months. It is possible.

[0058]

[Table 2]

(Examples 1 to 12) The granules of Reference Examples 1 to 6 as the inner core were formed by coating the outer layer portion by the following method at the compounding ratios shown in Table 3. Of a rice seedling raising box was obtained.

First, a raw material powder for the outer layer portion, a probenazole active ingredient of an agrochemical active ingredient to be contained, a clay as an inorganic diluent carrier, and a paraffin wax as a second thermoplastic material (trade name: paraffin manufactured by Nippon Seiro Co., Ltd.) Wax 150, melting point 66 ° C.) and, if necessary, floating dialkyl sulfosuccinate as surfactant (trade name: Sorpol-5050, manufactured by Toho Chemical Industry Co., Ltd.) or citric acid as an auxiliary. Mix in a mixer.

Next, one of the granules (inner core) obtained in Reference Examples 1 to 6 was placed in a floating mixer equipped with a heating device and mixed while heating to 70 ° C. Parts raw material powder was added quantitatively, and coated so as to obtain particles having a target particle size distribution and a particle size corresponding to a mesh opening of 1.0 to 2.0 mm, respectively.
As a result, 12 granules for raising rice seedlings were obtained. Each of the granules obtained here had a particle number of about 400 per gram.
It was a grain.

[0062]

[Table 3]

(Comparative Examples 1 and 2) Two types of pesticidal active ingredients; granules containing both an insecticidal active ingredient (compound 1) and a bactericidal active ingredient (probenazole) in a granulated product and having no coating layer In order to obtain the compound of Example 1, the compounding ratio shown in Table 4 was used.
Granules were prepared by the same granulation method as for the granules (inner core) of Nos. 6 to 6. Granules obtained under the charged composition and production conditions shown in Table 4 were crushed and sieved to obtain granules of Comparative Examples 1 and 2.

[0064]

[Table 4]

(Comparative Examples 3 to 5) As shown in Table 5, two kinds of pesticidal active ingredients; an insecticidal active ingredient (compound 1) and a fungicidal active ingredient (probenazole) were mixed together, and Reference Examples 1 to 6
A granulated product (inner core) was obtained by the same granulation method as in Example 1. Then, the outer layer raw material powder containing no pesticide active ingredient was coated in the same procedure as in Examples 1 to 12, to obtain granules of Comparative Examples 3 to 5.

[0066]

[Table 5]

(Comparative Examples 6 to 8) As shown in Table 6, a fungicidal active ingredient (probenazole) was blended in the inner core, and
A granulated product (inner core) was obtained by the same granulation method as in Examples 6 to 6. Next, the outer layer material powder mixed with the insecticidal active ingredient (compound 1) was coated on the surface of the granulated material (inner core) in the same procedure as in Examples 1 to 12, and the granules of Comparative Examples 6 to 8 were prepared. I got

[0068]

[Table 6]

(Comparative Example 9) A methanol solution in which an insecticidal active ingredient (compound 1) was previously dissolved so as to have the composition shown in Table 7 was added to a spherical solid carrier (trade name: Izu Silica Stone, manufactured by Tokai Kogyo Co., Ltd.) (Particles, particle size: 0.3 to 1 mm) After spraying on the surface, the mixture was allowed to stand in a 50 ° C. drier for 3 hours to remove methanol, thereby obtaining an inner core that had not been sustained-released. Next, the outer core material powder having the composition shown in Table 7 and mixed with a bactericidal active ingredient (probenazole) was coated on the inner core surface in the same manner as in Examples 1 to 12, and the granules of Comparative Example 9 were prepared. I got

[0070]

[Table 7]

(Test Example 2): Dissolution test of granules for nursery box of paddy rice Pesticide active ingredient released from each of granules obtained in Examples 1 to 12 and Comparative Examples 1 to 9 above Was measured.

(1) Elution rate of pesticidal active ingredient (compound 1) Among the two pesticidal active ingredients contained in the granules obtained in Examples 1 to 12 and Comparative Examples 1 to 9 and Comparative Examples, The dissolution rate of the insecticidal active ingredient (compound 1) released from the granules was measured by the following method.

That is, 50 ml of 25 ml of standard 3 degree hard water was added.
When the pesticidally active ingredient (compound 1) containing each of the granules obtained in Examples and Comparative Examples was eluted into a sample tube with a sealed cap having a capacity of ml, the concentration of the insecticidally active ingredient (compound 1) was eluted. Of 920 ppm, and submerged in water. In this state, after standing at 25 ° C. for a predetermined time, the whole amount was separated by filtration, and the amount of the insecticidal active ingredient (compound 1) dissolved in the filtrate was measured by HPLC. From the measured value,
The dissolution rate was calculated based on the following formula, and the results are summarized in Table 8.

Dissolution rate = (pesticidal active ingredient in filtrate / pesticidal active ingredient in granule) × 100

[0075]

[Table 8]

As is clear from the results shown in Table 8, in the granules of the examples, the insecticidal active ingredient contained in the inner core was about 1%.
It was possible to release continuously over a period of one to three months, and almost all of the contained pesticidally active ingredient was released. On the other hand, Comparative Examples 1 and 2 without the coating layer, Comparative Examples 6 to 8 containing the compound 1 in the outer layer instead of the inner core, or the inner core without the sustained release technology Comparative Example 9 in which Compound 1 is contained
Then, none of them were sustained-released, and almost 1 to 3 days
The elution rate approached 00%.

(2) Dissolution rate of bactericidal active ingredient (probenazole) Each of the two pesticide active ingredients contained in the granules obtained in Examples 1 to 12 and Comparative Examples 1 to 9 and Comparative Example The dissolution rate of the bactericidal active ingredient (probenazole) released from the preparation was measured by the following method.

That is, when all the germicidal active ingredients (probenazole) containing the granules obtained in Examples and Comparative Examples were eluted into a 1000 ml conical flask equipped with a stopper and filled with 1000 ml of ion-exchanged water. Was placed in water by adding an amount corresponding to an amount at which the concentration of the bactericidal active ingredient (probenazole) became 30 ppm. In that state,
It was left still at 25 ° C. Next, 1 ml of water was sampled every predetermined time from a depth of 5 cm, and the bactericidal active ingredient concentration in the sampled water was measured by HPLC. The concentration when the total amount of the bactericidal active ingredient in the test granules eluted into 1000 ml of water in the Erlenmeyer flask is a condition that reaches 30 ppm,
The measured value of the concentration of the bactericidal active ingredient was divided by 30 ppm to obtain an elution rate. The results are summarized in Table 9.

[0079]

[Table 9]

As is clear from the results shown in Table 9, each of the granules of the examples is capable of releasing a constant germicidal active ingredient for about three months, and the germicidal active ingredient contained in the outer layer portion. All of the active ingredient had been almost completely released. In contrast, Comparative Example 3 containing a bactericidal active ingredient in the inner core
In the granules No. to No. 8, only a part of the content was eluted even after about two months had elapsed, and therefore, the elution rate was extremely low.

[0081]

The coated sustained-release pesticide granules of the present invention contain two or more pesticidal active ingredients having extremely different water solubilities, especially when one of them has a water solubility of 1,000 ppm or more. The two or more kinds of pesticidal active ingredients can be controlled-release, respectively, and for example, pesticide-mixed granules suitable for granules for raising rice seedling boxes can be obtained. In the coated sustained-release pesticide granule of the present invention, the total amount of the two or more pesticidal active ingredients contained can be almost completely released, so that the pesticide is gradually added to the field during a desired period. There is no danger that the pesticidal active ingredient to be sprayed does not finish dissolving and a part thereof remains in the granules. Furthermore, the coated sustained-release pesticide granule of the present invention does not require an inner core to be a coated particle whose surface is coated with a resin at the time of its production. Therefore, there is also an advantage that the production cost can be kept low while employing a dosage form having a two-layer structure.

[Procedure amendment]

[Submission date] February 8, 2002 (2002.2.8)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0003

[Correction method] Change

[Correction contents]

On the other hand, in recent years, two or more pesticidal active ingredients, for example,
There is a need for an agricultural chemical formulation that enables simultaneous control in a single treatment by combining an insecticide and a fungicide .
In other words, a mixed preparation in which two or more pesticidal active ingredients exhibiting different actions are sustained-released, specifically, during the rice cultivation period,
There is a need for a mixed preparation that continuously releases the pesticidal active ingredient for a period of 30 to 60 days, or even longer, in which pest control is required.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0063

[Correction method] Change

[Correction contents]

[0063] (Comparative Examples 1 and 2) two types of pesticidal active ingredient (of
Compound 1 (insecticide) and probenazole (bactericide)) were both contained in the granulated material, and in order to obtain granules having no coating layer, Reference Examples 1 to 3 were obtained at the compounding ratio shown in Table 4. A granulated product was prepared by the same granulation method as for the granulated product (inner core) of No. 6 . Get
The obtained granules were crushed and then sieved to obtain granules of Comparative Examples 1 and 2.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0065

[Correction method] Change

[Correction contents]

Comparative Examples 3 to 5 As shown in Table 5, two pesticidal active ingredients (compound 1 (pesticide) and probenazole)
(Bactericide)) and a granulated product (inner core) was obtained by the same granulation method as in Reference Examples 1 to 6. Then, Examples 1-1
In the same procedure as in 2, the outer layer raw material powder containing no pesticide active ingredient was coated to obtain granules of Comparative Examples 3 to 5.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0067

[Correction method] Change

[Correction contents]

(Comparative Examples 6 to 8) As shown in Table 6, probenazole (a bactericide) was blended in the inner core.
A granulated product (inner core) was obtained by the same granulation method as in Example 1. Then, of
Compound 1 (pesticide) is mixed with the outer layer raw material powder,
In the same manner as in Examples 1 to 12, the granules (inner core) were coated on the surfaces to obtain granules of Comparative Examples 6 to 8.

[Procedure amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0069

[Correction method] Change

[Correction contents]

(Comparative Example 9) A methanol solution in which Compound 1 (an insecticide) had been dissolved in advance so as to have the composition shown in Table 7 was added to a spherical solid carrier (trade name: Izu silica stone manufactured by Tokai Kogyo Co., Ltd.) , Particle size 0.3-1mm)
Leave in a 50 ° C. oven for 3 hours to remove methanol,
An inner core that was not sustained release was obtained. Next, the outer layer raw material powder having the composition shown in Table 7 and mixed with probenazole (bactericide) was coated on the inner core surface in the same manner as in Examples 1 to 12, and the granules of Comparative Example 9 were coated. Obtained.

[Procedure amendment 6]

[Document name to be amended] Statement

[Correction target item name] 0072

[Correction method] Change

[Correction contents]

(1) Elution rate of compound 1 (pesticide) Among the two kinds of pesticidal active ingredients contained in the granules obtained in Examples 1 to 12 and Comparative Examples 1 to 9, the elution rate was released from each granule. The elution rate of Compound 1 (pesticide) was measured by the method described below.

[Procedure amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0073

[Correction method] Change

[Correction contents]

That is, 50 ml of 25 ml of standard 3 degree hard water was added.
Compound 1 containing each of the granules obtained in Examples and Comparative Examples (insecticidal)
Agent) upon all elution, the concentration of the compound 1 (insecticide) was submerged by introducing an amount corresponding to the amount to be 920 ppm. In this state, after standing at 25 ° C. for a predetermined time, the entire amount was separated by filtration, and the amount of compound 1 (pesticide) dissolved in the filtrate was measured by HPLC. From the measured values, the dissolution rate was calculated based on the following formula, and the results are summarized in Table 8.

[Procedure amendment 8]

[Document name to be amended] Statement

[Correction target item name]

[Correction method] Change

[Correction contents]

Dissolution rate = ( pesticide amount in filtrate / killing amount in granule)
Insect dosage ) x 100

[Procedure amendment 9]

[Document name to be amended] Statement

[Correction target item name] 0075

[Correction method] Change

[Correction contents]

[0075]

[Table 8]

[Procedure amendment 10]

[Document name to be amended] Statement

[Correction target item name] 0077

[Correction method] Change

[Correction contents]

(2) Elution rate of probenazole (bactericide) Among the two pesticidal active ingredients contained in the granules obtained in Examples 1 to 12 and Comparative Examples 1 to 9, released from each granule The dissolution rate of probenazole (bactericide) was measured by the following method.

[Procedure amendment 11]

[Document name to be amended] Statement

[Correction target item name] 0078

[Correction method] Change

[Correction contents]

That is, a probe containing each of the granules obtained in Examples and Comparative Examples was placed in a 1000 ml conical flask equipped with a stopper and filled with 1000 ml of ion-exchanged water.
Nazoru when (fungicide) has all elution Purobenazo
Then , an amount corresponding to an amount at which the concentration of the disinfectant (bactericide) became 30 ppm was added and submerged in water. In that state, it was left still at 25 ° C. Then, every predetermined time, from the depth of 5 cm,
and disinfectant concentration in the sampled sample is determined by HP
It was measured by LC. When the total amount of the bactericide in the test granules eluted in 1000 ml of water in the Erlenmeyer flask, the concentration was 30
ppm, and the measured bactericide concentration is 3
The elution rate was obtained by dividing by 0 ppm. The results are summarized in Table 9.

[Procedure amendment 12]

[Document name to be amended] Statement

[Correction target item name] 0079

[Correction method] Change

[Correction contents]

[0079]

[Table 9]

[Procedure amendment 13]

[Document name to be amended] Statement

[Correction target item name] 0080

[Correction method] Change

[Correction contents]

As is clear from the results shown in Table 9, each of the granules of the examples can release a constant germicide for about three months, and the germicide contained in the outer layer portion Was almost completely released. In contrast, in the granules of Comparative Examples 3 to 8 containing a bactericide in the inner core, even after about 2 months, only a part of the content was eluted,
Therefore, the dissolution rate was extremely low.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) A01N 43/80 103 A01N 43/80 103 47/44 47/44 B01J 2/28 B01J 2/28 (72) Inventor Koichi Nagashima 1144 Togo, Mobara City, Chiba Prefecture Mitsui Chemicals, Inc. (72) Inventor Takashi Watanabe 1144 Togo, Mobara City, Chiba Mitsui Chemicals, Inc. Inside the Pharmaceutical Research Institute, Confectionery Co., Ltd. (72) Inventor Shinji Sakurai 760, Shiokaokacho, Kohoku-ku, Yokohama, Kanagawa Prefecture BC06 BC07 BC18 BC19 BC20 DA02 DC03 DC05 DC06 DC09 DC10 DF02 DH13

Claims (6)

[Claims] 1. A sustained-release pesticide granule used to continuously elute and supply an agricultural chemical active ingredient to an aqueous medium, wherein the granule comprises an inner core and an outer layer covering the surface thereof. Wherein the inner core has a water solubility at 20 ° C. of 1000 ppm.
Not less than 10% and at least one pesticide active ingredient,
A granulated product comprising an inorganic diluent carrier and a first thermoplastic material that is hardly soluble in water, wherein the outer layer portion has a water solubility at 20 ° C. of 0.01 to 5
00 ppm of at least one pesticidal active ingredient, an inorganic diluent carrier, and a second thermoplastic which has a lower melting point and is different from the first thermoplastic material contained in the inner core and which is hardly soluble in water. A coating layer made of a material, wherein the composition of the coating type granule is characterized in that the pesticide active ingredient contained in the inner core and the pesticide active ingredient contained in the outer layer part are each controlled to release slowly. Controlled release pesticide granules. 2. The sustained-release pesticide granule according to claim 1, wherein the outer layer further contains a surfactant. 3. The first thermoplastic material which is hardly soluble in water contained in the inner core is montanic acid wax and / or montanic acid ester wax.
3. The sustained-release pesticide granule according to item 1. 4. The sustained-release pesticide granule according to claim 1, wherein the second thermoplastic material that is hardly soluble in water contained in the outer layer portion is paraffin wax. 5. The pesticidal active ingredient contained in the inner core is (R)
S) -1-Methyl-2-nitro-3- (tetrahydro-
The sustained-release pesticide granule according to any one of claims 1 to 4, which is (3-furylmethyl) guanidine, and the pesticidal active ingredient contained in the outer layer portion is probenazole. 6. The method for producing a sustained-release pesticide granule according to claim 1, wherein, when forming a coating layer serving as an outer layer portion on the surface of the granule serving as an inner core, The second thermoplastic material constituting the coating layer is heated and melted to achieve coating on the surface of the granulated material, and is heated to a temperature not reaching the melting point of the first thermoplastic material contained in the inner core. A method for producing a sustained-release pesticide granule, comprising: