JP4091346B2 - Elution-controlled agrochemical mixed granule - Google Patents

Description

【００５１】
表１に示す結果より明らかなように、本発明の溶出制御された農薬混合粒剤においてその内核に相当する参考例１の造粒物（内核）は、含有する化合物１を約２ヶ月間徐放化するとともに、ほぼ完全に放出させることが可能である。
【００５２】
（実施例１〜４）
表２に示す配合割合で、内核とする参考例１の造粒物に、外層部を以下に示す方法により被覆して、実施例１〜４の粒剤を得た。
まず、外層部に含有させる農薬活性成分として殺菌活性成分ジクロシメット原末８０（ジクロシメット原体８０部と非晶質含水珪酸２０部とを混合し、粉砕して得られたもの）、無機系希釈担体としてクレー、第二の熱可塑性材料としてパラフィンワックス（日本精蝋（株）製、商品名パラフィンワックス１５０、融点６６℃）、および崩壊剤としてベントナイト（クニミネ工業（株）製、商品名クニゲルＶＡ）、キサンタンガム（ユングブンツラウヤー社製、商品名キサンタンガムＦＪ）、またはデンプン・アクリル酸グラフト重合体部分ナトリウムウ塩（三洋化成工業（株）製、サンフレッシュＳＴ−１００ＭＰＳ）を、一括してフローティングミキサーに入れ混合し、外層部原料粉末を得た。
【００５３】
次に、参考例１にて得られた造粒物（内核）を、加熱装置を装着したフローティングミキサーの中に入れ７０℃まで加熱しながら混合し、先の外層部原料粉末を定量的に添加していき、それぞれ目標の粒度分布、目開き１．０〜２．０ｍｍに相当する粒径を持つ粒子となるように被覆して、実施例１〜４の粒剤を得た。なお、ここで得られた粒剤は、いずれも１ｇ当たりの粒子数はおよそ４００粒であった。
【００５４】
【表２】

【００５５】
（比較例１）
２種の農薬活性成分；化合物１とジクロシメットをともに造粒物中に含み、かつ被覆層を設けていない粒剤を得るために、表３に示す配合割合で参考例１と同様の方法で作製して比較例１の粒剤を得た。
【００５６】
（比較例２）
表３に示すように、内核にジクロシメットを配合して参考例１と同様の方法で造粒物（内核）を得、次いで化合物１を入れて混合した外層部原料粉末を実施例１〜４と同様の方法で内核表面に被覆して比較例２の粒剤を得た。
【００５７】
（比較例３）
外層部に崩壊剤を含まない粒剤を得るために、表３に示すように参考例１で得られた造粒物を内核とし、実施例で示した崩壊剤をクレーで置き換えた外層部原料粉末を用いて、実施例と同様の方法で前記内核に被覆して、比較例３の粒剤を得た。
【００５８】
（比較例４）
外層部に水溶性物質を含む場合の効果を検証するため、表３に示すように参考例１で得られた造粒物を内核とし、実施例で示した崩壊剤を含まず、かつクレーを水溶性物質である塩化カリウムに置き換えた外層部原料粉末を用いて、実施例と同様の方法で前記内核に被覆して、比較例４の粒剤を得た。
【００５９】
（比較例５）
外層部に界面活性剤を含む場合の項かを検証するため、表３に示すように参考例１で得られた造粒物を内核とし、実施例で示した崩壊剤を界面活性剤（Ｓｏｒｐｏｌ−５０５０；東邦化学工業（株）製）に置き換えた外層部原料粉末を用いて、実施例と同様の方法で前記内核に被覆して、比較例４の粒剤を得た。
【００６０】
【表３】

【００６１】
（試験例２）：各粒剤からの農薬活性成分の溶出試験
上記の実施例１〜４ならびに比較例１〜５で得られた粒剤について、各粒剤から放出される農薬活性成分の溶出率を測定した。
（１）化合物１の溶出率
実施例１〜４ならびに比較例１〜５で得られた粒剤に含まれる２種の農薬活性成分のうち、各粒剤から放出される化合物１の溶出率を前述の試験例１と同様の方法により測定した。結果を表４にまとめた。
【００６２】
【表４】

【００６３】
表４に示す結果より明らかなように、実施例の粒剤では、内核に含有している殺虫活性成分を約２ヶ月間、持続して放出させることが可能であり、しかも、ほぼ全量が放出された。これに対して、ジクロシメットと共に内核に含有させかつ被覆層を設けていない比較例１、また内核でなく、外層部中に化合物１を含有させた比較例２では、いずれも徐放化されず、ほぼ７〜１４日の間に、１００％近い溶出率に達していた。
【００６４】
（２）ジクロシメットの溶出率
実施例１〜４ならびに比較例１〜５で得られた粒剤に含まれる２種の農薬活性成分のうち、各粒剤から放出されるジクロシメットの溶出率を以下に示す方法で測定した。
即ち、イオン交換水１０００ｍｌを入れた１０００ｍｌ容の密栓付き三角フラスコに、実施例および比較例で得られた各粒剤を、それぞれ含有するジクロシメットが全て溶出した際の濃度が３ｐｐｍになる量に相当する量を投入して水中に沈めた。その状態で、２５℃下静置した。次いで、所定時間毎に水深５ｃｍの深さより、１ｍｌを採水し、その採水サンプル中のジクロシメット成分濃度をＨＰＬＣにて測定した。測定結果より、下記式に基づいて溶出率を計算した。結果を表５にまとめた。
溶出率＝（濾液中のジクロシメットの成分量／粒剤中のジクロシメットの成分量）×１００
【００６５】
【表５】

【００６６】
表５に示す結果より明らかなように、実施例の各粒剤は、粒剤中のジクロシメットの半量を１４日以内に放出させることが可能であり、しかも３０日以内に全量がほぼ完全に放出されていた。これに対して、内核にジクロシメットを含有している比較例１、２においては約２ケ月経過しても、含有量の一部しか溶出しておらず、極端に低い溶出率となっていた。また、ジクロシメットを外層部に含有している場合において、崩壊剤を含まない比較例３あるいは、崩壊剤の代わりに水溶性物質あるいは界面活性剤とした比較例４、５でも、約２ケ月経過しても、含有量の一部しか溶出しておらず、極端に低い溶出率となっており、ジクロシメットの速やかな溶出には崩壊剤が必要であることが明らかである。
【００６７】
【発明の効果】
本発明の溶出制御された農薬混合粒剤においては、水溶解度が極端に異なる２種以上の農薬活性成分、特に一方の水溶解度が１０００ｐｐｍ以上で徐放化を必要とし、他方の水溶解度が１００ｐｐｍ以下で速放化を必要としている場合においても、それら農薬活性成分をそれぞれ所望の溶出速度で放出させることができる。また、本発明の溶出制御された農薬混合粒剤では、含有する農薬活性成分の全量をほぼ完全に放出することができるため、所望の期間中に圃場に放出すべき農薬活性成分が溶出を終えず、その一部が粒剤中に残留する恐れもない。さらには、本発明の溶出制御された農薬混合粒剤は、その製造に際して、内核の表面を樹脂で被覆した被覆粒とする必要がなく、この樹脂被覆後に設ける乾燥工程など、余剰な工程を省くことができるため、二層構造の剤型を採用しつつ、その製造コストを低く抑えることができる利点も有する。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an agrochemical granule that contains two or more different types of pesticidal active ingredients and is used to elute and supply each pesticidal active ingredient to an aqueous medium, and more specifically, a method for producing the same. For example, when it is applied to a seedling box used for raising rice seedlings and then planted in a rice field, it is transferred to a rice field together with stored seedlings, and a plurality of kinds of pesticidal active ingredients contained in such granules are individually stored for a certain period of time. The present invention relates to an agrochemical granule released at an elution rate and a method for producing the same.
[0002]
[Prior 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 related to the spraying method of agricultural chemicals has progressed, and various labor-saving preparations and spraying methods have been studied. As an example, development of a seedling box treatment method in which an agrochemical composition is applied to a paddy rice seedling box before planting rice is being promoted. The greatest advantage of the seedling box treatment method in paddy rice cultivation is that it is possible to treat pesticides simultaneously with rice planting. Moreover, even after being transferred to the rice field together with the seedlings, pest control can be achieved over a long period of time after rice planting by slow release of the pesticidal active ingredient contained in the agricultural chemical preparation to be used. Because of this advantage, the seedling box processing method is an ideal labor-saving application method.
[0003]
On the other hand, in recent years, preparations that enable simultaneous control by a single treatment, for example, by combining an insecticidal active ingredient and a bactericidal active ingredient are preferred over preparations containing only one kind of agrochemical active ingredient. . In other words, there is a need for a mixed preparation that maintains the efficacy of two or more different agrochemical active ingredients for 30 to 60 days, which may require pest control during the rice cultivation period, and in some cases longer.
[0004]
Here, in order to maintain the efficacy of the pesticidal active ingredient over the above-mentioned long period, the pesticidal preparation is taken into consideration of the absorption and transfer rate into the plant body, the metabolic rate, etc. in addition to the physicochemical properties of the pesticidal active ingredient such as water solubility. It is important to control the release rate from the. In other words, the pesticidal active ingredient which has high water solubility and is likely to be washed away in a paddy field environment needs to be subjected to sustained release that suppresses excessive elution from the pesticidal preparation and releases it for a long period of time. On the other hand, pesticide active ingredients with low water solubility and slow absorption and transfer rate into the plant body are not effective since the initial control activity against pests is low unless they are taken into the plant body early. Rapid release is required to release the agricultural chemical active ingredient at an early stage. In other words, for example, a pesticide mixed preparation that controls elution of a pesticide active ingredient having high water solubility and requiring sustained release and a pesticide active ingredient having low water solubility and requiring immediate release at a desired rate is desired. It is rare.
[0005]
As an example of controlling the elution of two or more kinds of pesticidal active ingredients, Japanese Patent Application Laid-Open No. 2000-44404 discloses that inner core particles containing pesticidal active ingredients that require sustained release are coated with a resin on the surface. A mixed preparation having a structure in which an outer layer portion containing another pesticidal active ingredient is further provided outside the coated grain after the coated grain is formed is disclosed. The important features in the composition of the mixed preparation described here are that (1) it is essential to coat the surface of the inner core particles with resin, and (2) the outer layer part is not necessarily subjected to elution control. Further, (3) no particular consideration is given to the difference in water solubility between the two types of pesticidal active ingredients contained in the inner core particle and the outer layer part, respectively.
[0006]
Specifically, when comparing the results of Examples 2 to 4 and Comparative Examples 2 to 4 in Table 4 showing the results of Test Example 1 (dissolution test), Examples 2 to 4 in which the inner core particles were coated with a resin were used. The elution of the compound contained in the inner core particles is suppressed as compared with Comparative Examples 2 to 4 that do not cover the inner core particles. This clearly shows that the provision of the resin coating significantly contributes to the sustained release of the pesticidal active ingredient contained in the inner core particles (the elution is controlled). In addition, once the inner core particles are prepared, a step of coating with resin is further provided. Naturally, the number of steps for producing granules is increased accordingly, and the operation cost is increased accordingly. .
[0007]
Moreover, about the point which the outer layer part does not necessarily give elution control, Examples 1-3 which the elution characteristic is verified in Test Example 1 (elution test) use an inorganic solid support for the outer layer part. There is no room for debate because it shows a case where it is molded, and in particular, the process of elution control is not performed. However, Table 4 shows the results of the benfuracarb, which is an agrochemical active ingredient contained in the outer layer, gradually eluting into water. This gentle elution has a water solubility of 80 ppm at 20 ° C., and Benfuracarb itself is a compound that is relatively difficult to dissolve in water, and as a result, the elution rate in a stationary state also decreases. Is understood to reflect that. In addition, the test period is a relatively short period of 10 days. Within this period, the inorganic solid carrier molding layer constituting the outer layer portion is slightly disintegrated and is not necessarily subjected to elution control processing. Even if not, it is guessed that the contact with an aqueous medium is suppressed.
[0008]
And about two kinds of agrochemical active ingredients contained in an inner core grain and an outer layer part, respectively, those water solubility is not especially taken into consideration, Moreover, consideration is not taken at all about the difference in water solubility of both. Incidentally, in the mixed preparation shown in the examples, the water solubility of benfuracarb contained in the outer layer part is 80 ppm as described above, and the water solubility of probenazole contained in the inner core particle at 20 ° C. is 150 ppm, The difference is only 70 ppm, which is not very different.
[0009]
On the other hand, as disclosed in Japanese Patent Application Laid-Open No. 2000-26206, it is already known to use a wax for sustained release of an agrochemical active ingredient having high water solubility. However, the same method is used for two or more kinds of pesticidal active ingredients, particularly two pesticidal active ingredients whose solubility in water is extremely different by using a sustained release method utilizing a hydrophobic substance such as wax. When trying to release slowly using a wax, if the wax with the optimal release rate of one pesticidal active ingredient is selected, the release rate of the other pesticidal active ingredient is either extremely fast or extremely slow. However, it has been difficult for both to achieve the desired release rate. That is, as far as the present inventors know, it is suitable as an agrochemical formulation containing two or more kinds of pesticidal active ingredients having extremely different water solubility in one granule and controlling the elution of the two or more pesticidal active ingredients at the same time. No one is known, and there is no example of using two or more types of waxes for controlling the elution of different pesticidal active ingredients.
[0010]
As described above, although an agrochemical formulation containing two or more agrochemical active ingredients and sustained release of at least one of the agrochemical active ingredients has been proposed, an agrochemical active ingredient with extremely different water solubility is proposed. In the agrochemical formulation containing two or more kinds, there is no proposal of a dosage form that enables simultaneous elution control so that both are released at a desired elution rate as described above.
[0011]
[Problems to be solved by the invention]
The present invention solves the above problems, and in the agricultural chemical granules used in the seedling box treatment method for paddy rice, two or more different agricultural chemical active ingredients having extremely different water solubility, particularly in one agricultural chemical formulation, It is an object of the present invention to provide an agrochemical mixed granule whose elution is controlled simultaneously so that each is released at a desired elution rate, and a method for producing the same.
[0012]
[Means for Solving the Problems]
In order to solve these problems, the present inventors have intensively studied paying attention to the water solubility of the pesticidal active ingredient, the location in the granules, the type of wax, the melting point, etc. A pesticidal active ingredient that needs to be treated is placed in the inner core to form a sustained release formulation with a wax matrix. On the surface, the agrochemical active ingredient that has low water solubility and requires immediate release is used together with a disintegrant and another wax. It was found that the dissolution rate of two kinds of agricultural chemical active ingredients having extremely different water solubility and different required dissolution rates can be controlled simultaneously. In other words, a granulated product obtained by mixing one kind of agrochemical active ingredient with high water solubility, an inorganic diluent carrier, and a first thermoplastic material that is hardly soluble in water while heating is formed into an inner core (center inside the granule). 1 or more pesticidal active ingredients that are different from the pesticidal active ingredient contained in the inner core and have a lower water solubility, inorganic dilution carrier A disintegrant, and a second thermoplastic material having a lower melting point than the first thermoplastic material contained in the inner core and a different material, which is slightly soluble in water, and is coated as a outer layer with heating. It was found that the release of two or more kinds of pesticidal active ingredients, which require different control periods, can be secured individually by using the agent, and the present invention has been completed.
[0013]
That is, the present invention is as described in the following [1] to [6].
[1] A granulated product comprising at least one agrochemical active ingredient having a water solubility at 20 ° C. of 1000 ppm or more and 10% or less, an inorganic diluent carrier, and a first thermoplastic material hardly soluble in water. The melting point of the surface is at least one pesticidal active ingredient having an aqueous solubility of 0.01 to 100 ppm at 20 ° C., an inorganic diluent, a disintegrant, and the first thermoplastic material contained in the inner core. An agrochemical mixed granule for controlling the elution of an agrochemical active ingredient contained in the inner core and the outer layer, obtained by coating with an outer layer made of a second thermoplastic material that is low and different from water, and is a different material.
[2] Disintegrant is montmorillonite mineral, xanthan gum, guar gum and derivatives thereof, carboxymethylcellulose salt, methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, polyacrylate and derivatives thereof, starch / acrylic acid graft polymer partial sodium salt The agrochemical mixed granule according to [1], which is used in combination of one or more selected from among the above.
[3] The agricultural chemical mixture according to any one of [1] to [2], wherein the first thermoplastic material that is sparingly soluble in water contained in the inner core is a montanic acid wax and / or a montanic acid ester wax. Granules.
[4] The agrochemical mixed granule according to any one of [1] to [3], wherein the second thermoplastic material that is sparingly soluble in water contained in the outer layer portion is paraffin wax.
[5] The pesticidal active ingredient contained in the inner core is (RS) -1-methyl-2-nitro-3- (tetrahydro-3-furylmethyl) guanidine, and the pesticidal active ingredient contained in the outer layer is diclocimet. The agrochemical mixed granule according to any one of [1] to [4], wherein:
[6] The method for producing an agrochemical mixed granule according to [1], wherein when the surface of the inner core is coated with the outer layer portion, heating to a temperature not higher than the melting point of the first thermoplastic material contained in the inner core. The manufacturing method of the agrochemical mixed granule characterized by these.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the dissolution-controlled pesticide mixed granules of the present invention will be described in more detail.
The elution-controlled agrochemical mixed granule of the present invention is, for example, a seedling box granule for use in a seedling box treatment of paddy rice, wherein at least two kinds of pesticide active ingredients having different actions are combined into one. It is a dosage form that can be suitably used when preparing a mixed preparation contained in a granule. That is, supply of two or more pesticide active ingredients with different actions that need to be dissolved at desired rates for different periods of time after spraying as seedling box granules and maintain the desired pest control effect With regard to the present invention, it is possible to quickly release one pesticidal active ingredient from the outer layer portion and to release the other pesticidal active ingredient from the inner core for a long period of time by utilizing the dissolution-controlled pesticide mixed granule of the present invention having a two-layer structure. It is possible to sustain the release over a long period of time. Therefore, the elution control achieved with the elution-controlled pesticide mixed granule of the present invention means that different types of pesticide active ingredients contained in the outer layer part and the inner core, respectively, are eluted simultaneously and at a desired rate. Is.
[0015]
Here, the controlled release and rapid release of the pesticidal active ingredient are the physicochemical properties such as the water solubility of the pesticidal active ingredient, the absorption transfer rate into the plant body, the metabolic rate, and the runoff into the environment (absorbed by the plant body). It should be judged as the performance required for the preparation for the purpose of maximizing and maintaining the effect of the agrochemical active ingredient. In the present invention, for the sake of convenience, the effect as an agrochemical active ingredient is not sustained because the water solubility is high and easily washed away in the environment, and in particular, the agrochemical active ingredient having a water solubility of 1000 ppm to 10% for a long period of 30 days or more, Sustained release from the formulation is called sustained release. On the other hand, the amount of the pesticidal active ingredient having a water solubility of 0.01 to 100 ppm is reduced to 30% from the preparation, because the water solubility is low and the release from the preparation is slow, so that the effect of the pesticidal active ingredient is insufficient. Release within a day, preferably 50% or more within 14 days is referred to as rapid release for convenience.
[0016]
In addition, the leaching-controlled agrochemical mixed granule of the present invention has a two-layer structure composed of an inner core and an outer layer part, and there are two or more water solubility extremely different and required. Pesticide active ingredients with different elution rates are contained, but the inner core contains pesticide active ingredients with high water solubility, and the outer layer contains pesticide active ingredients with low water solubility. , The location in the whole granule is divided.
[0017]
Specifically, the agrochemical active ingredient contained in the inner core is selected so that the water solubility at 20 ° C. is 1000 ppm or more and 10% or less, and conversely, the agrochemical active ingredient contained in the outer layer portion has a water solubility of 0 at 20 ° C. The combination is limited to those of 0.01 to 100 ppm, and has a remarkable difference in water solubility between the two.
[0018]
At that time, the agrochemical active ingredient with extremely high water solubility contained in the inner core is in a dispersed form in a wax matrix in order to control its dissolution rate and give sufficient sustained release properties. A first thermoplastic material that is sparingly soluble in water is used as a component. As a result of forming the first thermoplastic material, which is hardly soluble in water, as a matrix, contact between the aqueous medium and the agrochemical active ingredient is suppressed.
[0019]
On the other hand, the agrochemical active ingredient with low water solubility contained in the outer layer part is coated and molded while heating the inner core using the second thermoplastic material that is hardly soluble in water as a binder. . When this covering molding is performed, the disintegrating agent is simultaneously coated with the agrochemical active ingredient, so that when the dissolution-controlled pesticide mixed granule of the present invention is thrown into the water environment, the outer layer portion is disintegrated and the surface area is increased. As a result, the pesticidal active ingredient having low water solubility is quickly released. Moreover, the elution speed | rate can also be finely prepared by containing surfactant in the outer layer part with the said disintegrating agent.
[0020]
That is, the elution-controlled agrochemical mixed granule of the present invention can be specifically produced by the following steps.
[0021]
Step (1) First, an agrochemical active ingredient with high water solubility (agrochemical active ingredient requiring sustained release) having an aqueous solubility at 20 ° C. in the range of 1000 ppm to 10%, an inorganic diluent carrier, One thermoplastic material is heated and mixed by a mixer equipped with a heating device (for example, a floating mixer) or the like. The heating temperature at this time takes into consideration the time during which the mixture is heated to the melting point or more of the first thermoplastic material in the next heating granulation step, the formability of the matrix due to melting of the thermoplastic material, and the like. You can decide. However, in order to facilitate handling of the mixture, a powdery state is preferable as the state after mixing. Therefore, the upper limit of the heating temperature should be less than the melting point of the first thermoplastic material.
[0022]
Step {circle around (2)} After the heating and mixing, the obtained uniform mixture is heated and granulated by a granulator equipped with a heating device. The type of granulator is appropriately selected in consideration of the shape of the intended granulated product, the particle diameter, and the like. Specifically, when a cylindrical molded product is obtained, an extrusion granulator equipped with a screen suitable for the target particle size is exemplified, and when a spherical molded product is obtained, a rolling granulator is exemplified. . The granulation temperature is preferably set to a temperature not lower than the temperature at which the first thermoplastic material to be used is melted and not reaching the melting point of the agrochemical active ingredient contained therein.
[0023]
Step {circle around (3)} The obtained molded product is allowed to cool or forcibly cool, crushed, and classified as needed at a node to obtain a granulated product having a desired shape and particle size.
[0024]
Process {circle around (4)} Unlike pesticidal active ingredients with high water solubility contained in the inner core, pesticidal active ingredients with low water solubility in the range of 0.01 to 100 ppm in water at 20 ° C. (immediate release is required) Agrochemical active ingredient), inorganic diluent carrier, and disintegrant are different from the first thermoplastic material contained in the inner core and have a melting point lower than that of the first thermoplastic material. The second thermoplastic material and, if necessary, the surfactant and the auxiliary agent are mixed together with a mixer (for example, a floating mixer) to obtain an outer layer raw material powder.
[0025]
Step (5) Put the inner core obtained in step (3) above into a mixer equipped with a heating device (eg floating mixer, rolling granulator, cooler mixer, drum mixer, malmerizer, etc.) and mix while heating. However, the outer layer raw material powder prepared in step (4) is quantitatively charged and coated so as to be 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 second thermoplastic material is dissolved, so that the melted second thermoplastic material serves as a binder, and the agrochemical active ingredient and the inorganic material having low water solubility. The covering layer in which the systemic support carrier and the disintegrant are uniformly dispersed is formed, and the dissolution-controlled pesticide mixed granule of the present invention is obtained. In order to avoid adhesion and fusion of inner core particles due to softening / melting of the first thermoplastic material in the inner core during the heating / coating process, and further to avoid adhesion / crimping of the inner core to the inner wall of the mixing tank, It is essential that the heating temperature is equal to or higher than the temperature at which the second thermoplastic material used for the outer layer is melted and does not reach the melting point of the first thermoplastic material used for the inner core.
[0026]
In the leached controlled agrochemical mixed granule of the present invention having the structural features described above, the composition ratio of each composition constituting the inner core and the outer layer portion is not particularly limited, and each of the inner core and the outer layer portion is respectively limited. The dissolution rate of each at least one pesticidal active ingredient to be contained, the rate of metabolic degradation and absorption into the plant body, and the maintenance of each pesticidal active ingredient in the field where plant seedlings are replanted What is necessary is just to determine suitably considering the density | concentration range which should be considered, for example, the period which should maintain the control effect expression density | concentration, and the density | concentration.
[0027]
On the other hand, also in the outer layer portion, the weight of each at least one pesticidal active ingredient contained in the outer layer portion and the inner core is subtotaled, and the ratio of the subtotaled weight is determined as inner core: outer layer portion = 1: 15 to 15: 1. It is good to be in the range. In addition, the pesticide-mixed granule for which elution is controlled according to the present invention is not limited in its outer size and dosage form as long as it is a solid agent composed of an inner core and an outer layer portion. For example, a normal granule type, a pill Any shape such as a type and a tablet type may be used. Moreover, when taking the said dosage form, the magnitude | size can also be suitably selected according to a usage form, For example, if a cylindrical shape and a spherical diameter are in the range of 0.1-3 mm, it will not specifically limit. Specifically, in the pesticidal mixed granule of the present invention whose elution is controlled, the particle size is appropriately selected according to the form to be sprayed. For example, it is applied to a granule for a seedling box of paddy rice. In this case, it is preferable to select a screen opening for adjusting the particle diameter and the outer shape in the range of 0.1 to 3 mm. The columnar length is preferably selected in a range that does not become excessively long depending on the diameter. For example, if the columnar diameter is in the range of 0.1 to 3 mm, the length is long. Is preferably selected in the range of 0.1 to 10 mm.
[0028]
In addition, in the elution-controlled pesticide mixed granule of the present invention, for example, when taking a spherical shape, the diameter ratio between the inner core and the outer layer is not particularly limited and is generally selected within a range not exceeding 1: 3. can do. In general, the elution of contained pesticidal active ingredient is accelerated as the particle size of the granule is reduced and the granule surface area per unit content of the pesticidal active ingredient is increased. In the mixed pesticide granules, elution control is performed independently for both the inner core and the outer layer, and as long as the particle size and the diameter ratio of the inner core to the outer layer are within the above ranges, the desired elution characteristics Can be achieved.
[0029]
In the pesticidal mixed granule of the present invention whose elution is controlled, different types of pesticidal active ingredients to be contained in the inner core, the surface layer portion, and the outer layer portion each have a water solubility at 20 ° C. in the range of 1000 ppm to 10%. And at least one pesticidal active ingredient having a high water solubility and one or more pesticidal active ingredients having a water solubility at 20 ° C. in the range of 0.01 to 100 ppm, both exhibit biocidal activity. Uses compounds used for agriculture and horticulture. For example, a combination of an insecticidal active ingredient and two kinds of bactericidal active ingredients is preferable, but effective target pests or control such as a combination of insecticidal active ingredients having different mechanisms of action or a combination of bactericidal active ingredients. It does not exclude combinations of drugs that differ in duration. Further, the content of these pesticidal active ingredients in the pesticidal mixed granule whose elution is controlled is preferably in the range of 0.01% by mass to 50% by mass in the inner core when the content site is in the inner core. Can be selected in the range of 0.5 mass% to 30 mass%, but is not particularly limited. Further, even when the containing part is in the outer layer part, it can be selected in the range of usually 0.01% by mass to 50% by mass, preferably 0.5% by mass to 30% by mass in the outer layer part. It is not limited. That is, the content of each pesticidal active ingredient contained per granule is determined by the physical properties of the active ingredient and the application scene, and depending on its application form, for example, the form of application as a seedling box granule, What is necessary is just to select content so that the quantity spread | dispersed per hit may satisfy | fill the required processing amount per 10 are.
[0030]
In order to obtain a mixed granule in which two or more kinds of pesticide active ingredients having significantly different water solubility are individually controlled in the dissolution controlled pesticide mixed granule of the present invention, the pesticide active ingredient contained in the inner core It is essential that the water solubility at 20 ° C. is significantly higher than the water solubility of the agrochemical active ingredient contained in the surface layer portion and the outer layer portion. That is, the water solubility at 20 ° C. of the pesticidal active ingredient contained in the inner core is selected in the range of at least 1000 ppm to 10%, preferably 5000 ppm to 10%, more preferably 10,000 ppm to 10%. On the other hand, the water solubility at 20 ° C. of the pesticidal active ingredient to be contained in the outer layer is at least 0.01-100 ppm, preferably 0.1-50 ppm, more preferably 0.5-30 ppm. It is preferred to select such that there is a difference between the aqueous solubility of the three pesticidal active ingredients.
[0031]
Further, when the melting point of the pesticidal active ingredient to be contained in the inner core is the same as or lower than the melting point of the first thermoplastic material used for the inner core, it becomes the inner core in the process of producing the pesticidal mixed granule of the present invention. When preparing the granulated product, the agrochemical active ingredient is also melted by the heating for melting the first thermoplastic material. 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, there is a possibility that the agrochemical active ingredient is localized and not uniformly dispersed when solidified thereafter. In such a case, in the inner core, the form in which the pesticidal active ingredient is uniformly dispersed in the wax matrix of the first thermoplastic material together with the added inorganic diluent carrier is not achieved, and the expected slowdown is not achieved. There is great concern that liberalization will not be achieved. In order to eliminate the 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, and preferably one having a melting point of 100 ° C. or higher is used.
[0032]
The same can be said for the pesticidal active ingredient to be contained in the outer layer part. Even when the melting point is the same as or lower than the melting point of the second thermoplastic material used in the outer layer part, the thermoplastic material is used in the step of coating the outer layer part. When heated to melt the pesticidal active ingredient mixed with it, it will also melt. In that case, there is a concern that the same problem occurs. In order to avoid this in advance, it is desirable that 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, preferably more than the melting point of the first thermoplastic material, more preferably Is preferably 100 ° C. or higher.
[0033]
Specific examples of the pesticidal active ingredient satisfying the above conditions include the following. As an agrochemical active ingredient to be contained in the inner core, for example, as an insecticidal active ingredient, thiocyclam (125-128 ° C., about 8%), acetamiprid (101-103) having melting point and water solubility at 20 ° C. are shown in parentheses, respectively. 3 ° C., 4200 ppm), thiamethoxam (139.1 ° C., 4100 ppm), or compound (RS) -1-methyl-2-nitro-3- (tetrahydro-3-furylmethyl) guanidine disclosed in JP-A-7-179448 (About 105 ° C., 54000 ppm) can be exemplified, and examples of the bactericidal active ingredient include pyrokilone (112 ° C., 4000 ppm), blasticidin S (235 ° C., 3%) and the like.
On the other hand, as an agrochemical active ingredient to be contained in the outer layer portion, for example, as an insecticidal active ingredient, NAC (142 ° C., about 100 ppm), Bendio Calp (124.6-128.7 ° C., 40 ppm), Fipronil (about 200 ° C., 1 0.9 ppm), buprofezin (about 105 ° C., 0.9 ppm), tebufenozide (191 ° C., 0.83 ppm), and as bactericidal active ingredients, thiuram (155 ° C., 30 ppm), iprodione (136 ° C., 13 ppm) ), Flutolanil (102 ° C., 9.6 ppm), tifluzamide (about 178 ° C., 1.59 ppm), carpropamide (147-149 ° C., 3.6 ppm), azoxystrobin (about 118 ° C., 10 ppm), diclosimet (about 150 ° C., 5 ppm), oxolinic acid (310 ° C., 3.2 ppm), Kurofutaramu (198 ℃, 14ppm), Jikuromejin (250~253.5 ℃, 0.74ppm), captan (178 ℃, 3.3ppm) and the like. Among them, the combination in which the insecticidal active ingredient (RS) -1-methyl-2-nitro-3- (tetrahydro-3-monofurylmethyl) guanidine is arranged in the inner core and the bactericidal active ingredient diclosimet is arranged in the outer layer is the elution control of the present invention. Is one of the preferred combinations in agrochemical mixed granules
[0034]
The first thermoplastic material for the inner core used in the controlled dissolution pesticide granule of the present invention has a water solubility at 20 ° C. of less than 0.5% by mass, at room temperature insoluble or sparingly soluble in water. It is preferable to use a solid organic substance having a melting point of 70 ° C to 110 ° C, preferably 72 ° C to 100 ° C, more preferably 74 ° C to 98 ° C. For example, plant wax such as candelilla wax, sugarken wax, rice wax, carnauba wax, mineral wax such as montanic acid wax, ozokerite, ceresin, petroleum wax such as microcrystalline wax, petrolatum, Fischer-Tropsch wax, etc. Synthetic hydrocarbons, modified waxes such as montanic acid wax derivatives, paraffin wax derivatives, microcrystalline wax derivatives, hydrogenated waxes of hardened castor oil, hardened castor oil derivatives, 12-hydroxystearic acid, stearamide, phthalic anhydride Furthermore, fatty acids having a chlorinated hydrocarbon group, acid amides, esters, ketones and the like can be mentioned. Among them, an acid value of 10 mgKOH / g or more is preferable as an acid value determined by titration with an alkali in accordance with a test method defined in ASTM D1386. For example, sugarken wax (melting point: 75 ° C., acid value: about 21 mg KOH / g) and montanic acid wax (manufactured by BASF, trade name Luwax S, melting point: 75-85 ° C., acid value: 135-160 mg KOH / g), Montanic acid ester wax (manufactured by BASF, trade name Luwax E, melting point: 75 to 85 ° C., acid value: 10 to 25 mg KOH / g) and the like are imparted with sustained release, but are contained in the inner core of an agrochemical active ingredient Can be released almost 100%, which is particularly preferable. These waxes and thermoplastic materials may be used alone or in combination of two or more. The total amount of the first thermoplastic material used is usually 5% by mass or more, preferably 10% by mass or more with respect to the total weight of the composition of the inner core constituting the elution-controlled agrochemical mixed granule of the present invention. Depending on the amount of the pesticidal active ingredient to be added and the physical properties and amount of the inorganic diluent carrier, it can be determined as appropriate. Preferably, from the economical viewpoint, the upper limit of the amount of the first thermoplastic material added is preferably 20% by mass.
[0035]
The inorganic diluent carrier for the inner core used in the controlled-release pesticidal mixed granule of the present invention is not particularly limited as long as it shows at least almost no water solubility. For example, clay, silica stone, talc, Totonite, calcium carbonate, pumice, diatomaceous earth, vermiculite, pearlite, attapulgite and amorphous hydrous silicic acid (commonly known as white carbon). More than that available.
[0036]
In addition, in the elution-controlled agrochemical mixed granule according to the present invention, the inner core includes an antioxidant, an ultraviolet absorber, and an antistatic agent as long as the purpose and effect of the present invention are not impaired in addition to the inorganic diluent carrier. Various additives such as these can also be added to form granules. Examples of antioxidants include hindered phenol antioxidants, sulfur antioxidants, phosphorus antioxidants, amine antioxidants, lactone antioxidants, vitamin E antioxidants, and the like. It is done. Examples of the UV absorber include inorganic compound UV absorbers such as titanium dioxide, and organic compound UV absorbers such as benzotriazole, benzophenone, triazine, benzoate, and salicylate. In that case, 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 blended in an amount in which the effect is recognized.
[0037]
Furthermore, examples of the antistatic agent include inorganic compounds such as titanium oxide, zinc oxide, and magnesium oxide, and calcium phosphate compounds. Further, phosphate ester surfactants such as polyoxyethylene alkyl ether phosphates can also be used as antistatic agents. In addition, what is necessary is just to use an antistatic agent as needed, and should just make it the quantity which the antistatic effect is recognized in the range which does not impair the objective and effect of this invention.
[0038]
On the other hand, in the pesticidal mixed granule whose elution is controlled according to the present invention, the second thermoplastic material that is hardly soluble in water of the outer layer portion is substantially the same material as the thermoplastic material used for the inner core, You may mix and use the above. Its melting point must be lower than that of the first thermoplastic material contained in the inner core. Specifically, the melting point of the second thermoplastic material is 40 ° C. to 70 ° C., preferably 50 ° C. to 69 ° C., More preferably, it is preferable to select in the range of 60 ° C to 68 ° C. Furthermore, since the second thermoplastic material is heated and melted to form a binder in the coating step, if the melt viscosity is low, adhesion of particles at the time of coating is reduced, which is preferable. Specific examples of materials suitable for the second thermoplastic material that satisfy the above-mentioned various conditions include plant waxes such as candelilla wax and wax, animal waxes such as beeswax, lanolin, whale wax, and beef tallow, and paraffin wax. And petroleum-based waxes such as petrolatum, synthetic hydrocarbons such as Fitzia Tropsch wax, and modified waxes such as paraffin wax derivatives. Among these, 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 150, melting point: 66 ° C.) is more preferable. . The amount used depends on the amount of the pesticidal active ingredient contained in the outer layer part and the physical properties of the inorganic diluent carrier, but in the elution-controlled pesticide mixed granule of the present invention, the total amount of the composition in the outer layer part In general, it is selected in the range of 1% by mass to 20% by mass, preferably 1% by mass to 15% by mass. In addition, content of a 2nd thermoplastic material is set to below the total oil absorption capacity of the composition of this outer layer part.
[0039]
The inorganic diluent carrier for the outer layer part used in the controlled-release pesticidal mixed granule of the present invention is not particularly limited as long as it shows at least almost no water solubility. If the material is almost the same as the system dilution carrier, the object can be sufficiently achieved. Therefore, for example, clay, silica, talc, calcium carbonate, pumice, diatomaceous earth, vermiculite, pearlite, attapulgite, and amorphous hydrous silicic acid, commonly known as white carbon, are commonly used for agricultural chemical powders and granules. One or more agents and carriers can be used in combination.
[0040]
The outer layer part can further contain a disintegrant for the purpose of rapid release in which the agrochemical active ingredient contained in the outer layer part is quickly eluted. Here, the collapsed state refers to a state in which a crack has been generated and then subdivided and dropped from the main body. Since the agrochemical active ingredient contained in the outer layer portion has low water solubility, when dispersed in a wax matrix as in the present invention, it tends to be gradually released due to the effect of suppressing wax. However, even for agrochemical active ingredients that have low water solubility and are required to elute quickly, disintegrating and subdividing the wax matrix increases the surface area, that is, increases the contact area with the aqueous medium. The elution of the agrochemical active ingredient can be promoted and completely eluted. Various disintegration mechanisms by the disintegrant can be considered, but any mechanism may be used. For example, a swelling / disintegration type mechanism in which a water-swellable substance is added to absorb water and disintegrate using the swelling pressure, a biodegradable type disintegration mechanism that disintegrates by decomposing microorganisms using a biodegradable resin as a constituent material, Examples include a dissolution type disintegration mechanism that contains a water-soluble substance and that disintegrates by dissolving in water, and a foam type disintegration mechanism that disintegrates by adding sodium bicarbonate and an acidic substance and foaming by reaction with water. Among these, a swelling type disintegration mechanism to which a water-swelling biomaterial is added is preferable because the disintegration rate can be easily controlled, the disintegration rate is appropriate, the production is easy, and the preservability is good.
[0041]
Specifically, the disintegrant contained in the outer layer portion may be either inorganic or organic, and examples of inorganic include montmorillonite minerals, among which Na-type bentonite and Ca-type bentonite. Etc. are preferred. On the other hand, examples of organic systems include water-soluble natural polymers, water-soluble semi-synthetic polymers, water-soluble synthetic polymers, and the like. Water-soluble natural polymers or water-soluble semi-synthetic polymers include alginic acid and its salts, Pectin, gum arabic, tragacanth gum, locust bean gum, agar, pullulan, gelatin, chitosan, starch and derivatives thereof, xanthan gum, guar gum and derivatives thereof, carrageenan, crystalline cellulose, croscarmellose sodium, carboxymethylcellulose salt, methylcellulose, hydroxyethylcellulose, Examples thereof include hydroxypropylcellulose. Synthetic polymers include polyacrylate and its derivatives, polystyrene sulfonate, polyvinyl alcohol, polyvinyl methyl ether, polyvinyl pyrrolidone, polyacrylamide, polyethylene oxide, partially saponified vinyl acetate and vinyl ether copolymer, methacrylic acid, Examples thereof include polymers or copolymers of maleic acid and esters or salts thereof, starch / acrylic acid graft polymer partial sodium salts, and the like. Of these, montmorillonite minerals, xanthan gum, polyacrylic acid derivatives and the like are preferably used. When adding these disintegrants, one type may be used, but the same type or different types may be used in combination. Moreover, depending on the amount of addition, the disintegration rate of the outer layer portion can be changed, and the elution rate of the pesticidal active ingredient in the outer layer portion can be finely adjusted. Therefore, the amount added may be an amount that provides a desired elution rate of the pesticidal active ingredient, but usually 0.1 to 10% by mass as the proportion of the entire pesticidal mixed granule of the present invention is its economy. From the viewpoint of sex.
[0042]
In addition, in the elution-controlled agrochemical mixed granule of the present invention, the outer layer portion can contain a surfactant in addition to the inorganic diluent carrier as long as the object and effect of the present invention are not impaired. Examples of surfactants that can be added include nonionic surfactants, anionic surfactants, cationic surfactants and amphoteric surfactants that are commonly used in agricultural chemical formulations. For example, alkyl ether, polyoxyethylene alkyl aryl ether, polyoxyethylene styryl phenyl ether, polyoxyethylene alkyl ester, polyoxyethylene sorbitan alkylate, polyoxyethylene phenyl ether polymer, polyoxyethylene alkylene aryl phenyl ether, polyoxyethylene Nonionic surfactants such as alkylene glycol, polyoxyethylene polyoxypropylene block polymer, lignin sulfonate, alkylaryl sulfonate, dialkylsulfosuccinate, polyoxyethylene alkylaryl ether sulfate, alkylnaphthalene 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 these surfactants are added, one type may be used, but the same type or different types may be used in combination. Moreover, the addition amount is 0.01 mass%-20 mass% normally with respect to the composition total weight of an outer-layer part, Preferably it is preferable to keep in the range of 0.01 mass%-10 mass%.
[0043]
Moreover, in the elution-controlled agrochemical mixed granule of the present invention, fine mineral powder such as amorphous hydrous silicic acid (commonly known as white carbon) can be adhered to the surface. This adhesion improves the hydrophobicity of the surface of the agrochemical mixed granule, and prevents the granule from floating on the water surface in the paddy environment and from flowing down due to watering after application to the nursery box. As the mineral fine powder that can adhere to the surface, the object can be sufficiently achieved as long as the material is almost the same as the inorganic diluent carrier that can be used in ordinary agricultural chemical formulations. Therefore, for example, clay, silica, talc, bentonite, calcium carbonate, pumice, diatomaceous earth, vermiculite, perlite, attapulgite, and the above-mentioned amorphous hydrous silicic acid, etc. One or more agents and carriers can be used in combination. Moreover, the effect is so high that it is a fine powder, and an amorphous hydrous silicic acid is the most preferable especially.
[0044]
The elution-controlled pesticide mixed granule of the present invention having the structure described above can release two or more different pesticide active ingredients having extremely different water solubility at individual elution rates. The agrochemical granule can be suitably used for a rice seedling box granule. By utilizing the dissolution-controlled pesticide mixed granule of the present invention, it is required for a rice seedling box granule, from 30 days to 60 days, which is necessary for pest control during rice planting to paddy rice cultivation, and sometimes more It is possible to maintain the effect of the pesticidal active ingredient for the period of time. Moreover, since the elution-controlled agrochemical mixed granule of the present invention can omit the drying step required in the method described in JP-A-2000-44404, the production cost can be kept low. There are also benefits.
[0045]
The elution-controlled agrochemical mixed granule of the present invention is applied to a paddy rice seedling box before rice planting, for example, when it is used as a granule for a paddy rice seedling box. Moreover, when it is used as a granule for a seedling box, the application amount is 10 g to 100 g per paddy rice seedling box (about 30 cm × 60 cm), usually about 50 g, but is not particularly limited, and the agrochemical active ingredient in the preparation What is necessary is just to decide by content, the required control period of a pest, and the number of seedling boxes used per 10a.
[0046]
In addition, when the pesticide granule of the present invention is applied to, for example, a paddy rice seedling box, the pesticide granule that is entrained per seedling when the seedling is sprayed uniformly over the entire seedling box and the seedling is transplanted into a paddy field. It is preferable not to cause a large variation in the number of pieces. Therefore, the number of grains per gram of agricultural chemical granules is 300 or more, preferably 400 or more. On the other hand, since it is necessary to avoid that the particle size of the granule becomes too small and reach a state of floating in water, it is desirable to keep the number of particles per 1 g of the agricultural chemical granule not exceeding 2000. .
[0047]
【Example】
Next, the present invention will be described in more detail by way of examples. However, the preparation method and the resulting pharmaceutical formulation are not limited in any way. For example, (RS) -1-methyl-2-nitro-3- (tetrahydro-3-furylmethyl) guanidine exemplified as an agrochemical active ingredient in the inner core, diclosimet exemplified as an agrochemical active ingredient in the outer layer, and various pesticides described above The elution controlled pesticide mixture according to the present invention may be used in place of the active ingredient, or each thermoplastic material and inorganic diluent used in the inner core and the outer layer exemplified in the examples may be replaced with the other ones described above. Granules can also be obtained.
In addition, all the mixture ratios shown here shall be the mass%.
[0048]
(Reference Example 1)
The inner core of Reference Example 1 was obtained according to the following blending ratio and production method.
As an agrochemical active ingredient contained in the inner core, an insecticidal active ingredient (RS) -1-methyl-2-nitro-3- (tetrahydro-3-furylmethyl) guanidine (hereinafter referred to as “pesticide active ingredient”) synthesized according to the method described in JP-A-7-179448 (Abbreviated as "compound 1") 3.0%, white diluent 3.8% as inorganic diluent carrier, talc 10%, calcium carbonate 65.2%, montanic acid ester wax (first thermoplastic material) BASF, trade name Luwax-E, melting point: 75 to 85 ° C., acid value: 10 to 25 mg KOH / g) 18.0% are put in a floating mixer equipped with a heating device in a lump and heated to 83 ° C. Mixed. This mixture was extruded and granulated using a horizontal extrusion granulator (screen having an opening of 0.8 mm) maintained at 90 ° C. by a heating device. The obtained granulated product was crushed and sectioned to obtain a granulated product (inner core) of Reference Example 1.
[0049]
(Test Example 1): Dissolution test from inner core
The elution rate of Compound 1 released from the inner core obtained in Reference Example 1 was measured by the method shown below.
That is, when the compound 1 containing each of the inner cores obtained in Reference Example 1 was eluted into a 50 ml sealed sample tube containing 25 ml of standard 3 degree hard water, the concentration of compound 1 was 920 ppm. An amount corresponding to the amount was added 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 Compound 1 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 1.
Elution rate = (component amount of compound 1 in filtrate / component amount of compound 1 in granule) × 100
[0050]
[Table 1]

[0051]
As is apparent from the results shown in Table 1, the granulated product of Reference Example 1 (inner core) corresponding to the inner core in the controlled-release agricultural chemical mixed granule of the present invention gradually contained Compound 1 contained for about 2 months. It is possible to release almost completely while releasing.
[0052]
(Examples 1-4)
The outer layer part was coat | covered with the method shown below to the granulated material of the reference example 1 made into an inner core by the mixture ratio shown in Table 2, and the granule of Examples 1-4 was obtained.
First, as an agrochemical active ingredient to be contained in the outer layer part, bactericidal active ingredient diclocimet bulk 80 (obtained by mixing and grinding 80 parts of dicrosimet base and 20 parts of amorphous hydrous silicate), inorganic diluted carrier As clay, paraffin wax (manufactured by Nippon Seiwa Co., Ltd., trade name: paraffin wax 150, melting point: 66 ° C.) as a second thermoplastic material, and bentonite (trade name: Kunigel VA, manufactured by Kunimine Industries, Ltd.) , Xanthan gum (manufactured by Jungbunzlauer, trade name xanthan gum FJ), or starch / acrylic acid graft polymer partial sodium salt (manufactured by Sanyo Chemical Industries, Ltd., Sunfresh ST-100MPS) And mixed to obtain an outer layer part raw material powder.
[0053]
Next, the granulated product (inner core) obtained in Reference Example 1 is placed in a floating mixer equipped with a heating device and mixed while heating to 70 ° C., and the previous outer layer raw material powder is quantitatively added. Then, each particle was coated so as to have a particle size corresponding to a target particle size distribution and an opening of 1.0 to 2.0 mm, thereby obtaining granules of Examples 1 to 4. In addition, as for the granule obtained here, the number of particles per 1g was about 400.
[0054]
[Table 2]

[0055]
(Comparative Example 1)
Two kinds of agrochemical active ingredients; prepared in the same manner as in Reference Example 1 at the blending ratio shown in Table 3 in order to obtain a granule containing both Compound 1 and dicrosimet in the granulated product and having no coating layer Thus, a granule of Comparative Example 1 was obtained.
[0056]
(Comparative Example 2)
As shown in Table 3, outer layer raw material powders obtained by blending diclosimet into the inner core and obtaining a granulated product (inner core) in the same manner as in Reference Example 1 and then adding Compound 1 and mixing them with Examples 1-4 The inner core surface was coated in the same manner to obtain a granule of Comparative Example 2.
[0057]
(Comparative Example 3)
In order to obtain a granule containing no disintegrant in the outer layer part, as shown in Table 3, the granulated product obtained in Reference Example 1 was used as the inner core, and the disintegrant shown in the examples was replaced with clay. Using the powder, the inner core was coated in the same manner as in Example to obtain a granule of Comparative Example 3.
[0058]
(Comparative Example 4)
In order to verify the effect when the outer layer contains a water-soluble substance, as shown in Table 3, the granulated product obtained in Reference Example 1 was used as the inner core, the disintegrant shown in the Examples was not included, and clay was used. Using the outer layer raw material powder replaced with potassium chloride, which is a water-soluble substance, the inner core was coated in the same manner as in Example to obtain a granule of Comparative Example 4.
[0059]
(Comparative Example 5)
In order to verify whether the outer layer contains a surfactant, the granulated product obtained in Reference Example 1 was used as the inner core as shown in Table 3, and the disintegrant shown in the examples was used as a surfactant (Sorpol). -5050; manufactured by Toho Chemical Industry Co., Ltd.) Using the outer layer raw material powder, the inner core was coated in the same manner as in Example to obtain a granule of Comparative Example 4.
[0060]
[Table 3]

[0061]
(Test Example 2): Dissolution test of agrochemical active ingredients from each granule
About the granule obtained in said Examples 1-4 and Comparative Examples 1-5, the elution rate of the agrochemical active component discharge | released from each granule was measured.
(1) Elution rate of compound 1
Of the two agrochemical active ingredients contained in the granules obtained in Examples 1 to 4 and Comparative Examples 1 to 5, the elution rate of Compound 1 released from each granule is the same as in Test Example 1 described above. Measured by the method. The results are summarized in Table 4.
[0062]
[Table 4]

[0063]
As is clear from the results shown in Table 4, in the granule of the example, the insecticidal active ingredient contained in the inner core can be continuously released for about 2 months, and almost the whole amount is released. It was done. On the other hand, in Comparative Example 1 containing diclosimet in the inner core and not having a coating layer, and in Comparative Example 2 containing Compound 1 in the outer layer portion instead of the inner core, none was sustained-released, Nearly 100% elution rate was reached in about 7-14 days.
[0064]
(2) Diclocimet dissolution rate
Of the two agrochemical active ingredients contained in the granules obtained in Examples 1 to 4 and Comparative Examples 1 to 5, the elution rate of diclocimet released from each granule was measured by the method shown below.
That is, it corresponds to an amount of 3 ppm when the diclosimet containing each of the granules obtained in the examples and comparative examples is eluted into a 1000 ml sealed Erlenmeyer flask containing 1000 ml of ion-exchanged water. The amount to be submerged was submerged. In that state, it was allowed to stand at 25 ° C. Next, 1 ml of water was sampled from a depth of 5 cm every predetermined time, and the concentration of the diclosimet component in the sample was measured by HPLC. From the measurement results, the dissolution rate was calculated based on the following formula. The results are summarized in Table 5.
Dissolution rate = (diclosimet component amount in filtrate / diclosimet component amount in granules) × 100
[0065]
[Table 5]

[0066]
As is clear from the results shown in Table 5, each granule of the example can release half of the diclosimet in the granule within 14 days, and the entire amount is almost completely released within 30 days. It had been. On the other hand, in Comparative Examples 1 and 2 containing diclosimet in the inner core, only a part of the content was eluted even after about 2 months, and the dissolution rate was extremely low. Further, in the case where diclosimet is contained in the outer layer portion, about 2 months have passed even in Comparative Example 3 which does not contain a disintegrant, or in Comparative Examples 4 and 5 in which a water-soluble substance or a surfactant is used instead of the disintegrant. However, only a part of the content is eluted, the dissolution rate is extremely low, and it is clear that a disintegrant is necessary for the rapid dissolution of diclocimet.
[0067]
【The invention's effect】
In the elution-controlled pesticide mixed granule according to the present invention, two or more kinds of pesticide active ingredients having extremely different water solubility, particularly one of which has a water solubility of 1000 ppm or more and requires sustained release, and the other has a water solubility of 100 ppm. Even in the case where rapid release is required below, these agrochemical active ingredients can be released at a desired elution rate. In addition, since the dissolution-controlled pesticide mixed granule of the present invention can almost completely release the total amount of the pesticidal active ingredient contained therein, the pesticidal active ingredient to be released to the field during the desired period has been completely eluted. In addition, there is no fear that a part thereof remains in the granule. Furthermore, the elution-controlled pesticide mixed granule of the present invention does not need to be coated particles in which the surface of the inner core is coated with a resin in the production thereof, and an extra step such as a drying step provided after the resin coating is omitted. Therefore, there is an advantage that the manufacturing cost can be kept low while adopting the dosage form having a two-layer structure.

Claims (6)

A granulated product comprising at least one pesticidal active ingredient having a water solubility at 20 ° C. of 1000 ppm or more and 10% or less, an inorganic diluent carrier, and a first thermoplastic material hardly soluble in water as an inner core, The surface has a melting point lower than that of the first thermoplastic material contained in the inner core, at least one agrochemical active ingredient having an aqueous solubility at 20 ° C. of 0.01 to 100 ppm, an inorganic diluent carrier, a disintegrant, and A pesticide mixed granule for controlling the elution of a pesticide active ingredient contained in the inner core and the outer layer part, obtained by coating with a different thermoplastic layer which is made of a second thermoplastic material hardly soluble in water. Disintegrating agents include montmorillonite mineral, xanthan gum, guar gum and derivatives thereof, carboxymethylcellulose salt, methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, polyacrylate and derivatives thereof, starch / acrylic acid graft polymer partial sodium salt The agrochemical mixed granule according to claim 1, which is used in combination of one or more selected. The agrochemical mixed granule according to any one of claims 1 to 2, wherein the first thermoplastic material that is sparingly soluble in water contained in the inner core is a montanic acid wax and / or a montanic acid ester wax. The agrochemical mixed granule according to any one of claims 1 to 3, wherein the second thermoplastic material that is sparingly soluble in water contained in the outer layer portion is paraffin wax. The agrochemical active ingredient contained in the inner core is (RS) -1-methyl-2-nitro-3- (tetrahydro-3-furylmethyl) guanidine, and the agrochemical active ingredient contained in the outer layer is diclocimet The agrochemical mixed granule according to any one of claims 1 to 4. It is a manufacturing method of the agrochemical mixed granule of Claim 1, Comprising: When coat | covering the surface of an inner core with an outer layer part, it heats to the temperature below the melting | fusing point of the 1st thermoplastic material contained in an inner core, It is characterized by the above-mentioned. A manufacturing method of mixed agricultural chemicals.