WO1995031900A1

WO1995031900A1 - Pesticide composition, production process, and pesticidal preparation

Info

Publication number: WO1995031900A1
Application number: PCT/JP1995/000987
Authority: WO
Inventors: Kouichi Nakamichi; Shougo Izumi; Hiroyuki Yasuura
Original assignee: Nippon Shinyaku Co., Ltd.
Priority date: 1994-05-24
Filing date: 1995-05-23
Publication date: 1995-11-30

Abstract

A pesticide composition fixable on the surface of the top soil layer of a paddy field, which has a configuration entirely different from that of conventional pesticide compositions for paddy field. It is characterized in that (1) the pesticidally active ingredient thereof is dispersed or dissolved in a macromolecular compound which swells by forming a gel in water and (2) it has an apparent specific gravity of at least 1 at least until it reaches the surface of the top soil layer of a paddy field. The composition expands in water to undergo a volume increase, thus being effectively prevented from being embedded under the surface of the top soil layer.

Description

Specification

Pesticide composition, manufacturing method and formulation

The present invention relates to a pesticide composition. More specifically, the present invention relates to a pesticide composition having a surface fixation on a paddy rice top soil layer.

Background technology

Sedimentation-type pesticide compositions applied to paddy fields tend to be buried in the soil due to the shape, weight, and sieving phenomenon of the product. Once the pesticide composition is buried in the soil, it is adsorbed and decomposed by the soil, making it difficult to diffuse the active pesticide active ingredient. Disappears. In some cases, the buried pesticide composition may affect the roots of transplanted rice and cause chemical damage such as leaf color (Weed Research, 1983).

As a pesticide composition for preventing burial under the surface of paddy rice paddy soil, Japanese Patent Publication No. Hei 6-72802 reports that a large granule is made into a disc, a donut or a flat polygonal column. Such granules are devised in the form of the preparation itself without substantially changing the conventional composition.

On the other hand, the multi-screw extruder is one of the screw-type kneading extruders that have completely different performances and applications from the single-screw extruder.The multi-screw extruder has multiple screws. Because they are entangled and interfere with each other and can generate physically high energy, it is possible to perform processing on the raw material that cannot be obtained with a single-screw extruder. Multi-axle extruders are mainly used in the food and plastic It is widely used in the processing of foods (cereals, proteins, livestock, fish, etc.) and injection molding of plastics, etc. Recently, its use in the pharmaceutical field has also been reported (PCT W092 / 18106, PCT W094 / 08568, PCT W095 / 05809, etc.).

Disclosure of the invention

A main object of the present invention is to provide a paddy rice topsoil layer surface-fixing pesticide composition having a completely different shape from conventional paddy field pesticide compositions.

The present invention is based on (1) that the pesticide is dispersed or dissolved in a polymer compound that swells by forming a gel in water; (2) that the apparent specific gravity is at least greater than 1 until it reaches the surface of the paddy soil layer It is a pesticidal composition having a surface soil layer fixed on a paddy field characterized by the following features:

The pesticide composition according to the present invention (hereinafter referred to as “the present composition”), when put into water, forms a gel and swells to increase its volume. <This increase in volume and the accompanying increase in surface area Thereby, the composition of the present invention is easily susceptible to water resistance, and the burying phenomenon of the composition of the present invention beneath the surface of the paddy field topsoil layer is prevented. In addition, such an increase in volume reduces the apparent specific gravity compared to before the introduction, and plays a role in preventing the burial phenomenon.

The composition of the present invention has an apparent specific gravity greater than 1 at least until it reaches the surface of the paddy rice topsoil layer. Therefore, after being put into a paddy field, the composition of the present invention can reach the surface of the paddy field topsoil layer. Preferably, the apparent specific gravity is in the range of more than 1 and 2 or less. After reaching the surface of the paddy rice topsoil layer, it is more preferable that it approaches 1 without limit.

If it is 1 or less, it does not settle to the paddy rice topsoil surface, which is not preferable. 2 yo Larger particles can be included in the composition of the present invention, but if the apparent specific gravity in water exceeds 2, the sedimentation velocity becomes extremely high at once, which is not preferable. However, even if the apparent specific gravity in water exceeds 2, the sedimentation speed can be slowed by, for example, forming a flat composition.

The composition of the present invention does not need to have an apparent specific gravity larger than 1 semipermanently even after reaching the surface of the paddy rice topsoil layer. If the desired purpose is achieved by reaching the surface of the paddy rice topsoil layer, the apparent specific gravity may be 1 or less. In addition, the apparent specific gravity of the composition of the present invention before being introduced into water is greater than 1, but even if the apparent specific gravity is greater than 1, it does not reach the surface of the paddy rice topsoil layer, for example, it sinks due to the surface tension of water. Those which are not present and those whose apparent specific gravity becomes 1 or less before reaching the surface of the paddy rice topsoil layer are not the compositions of the present invention.

The composition of the present invention can be produced by selecting raw materials and, for example, a production method described later.

Examples of the polymer compound according to the present invention that swells by forming a gel in water (hereinafter referred to as “gel-forming polymer J”) include, for example, glycomannan, pregelatinized starch, gelatin, partially a-starch, and Pyrcellulose, hydroxypropyl pillmethylcellulose, hydroxypyl propylmethylcellulose, hydroxyxyl cellulose, methylcellulose, sodium alginate, sodium polyacrylate, sodium carboxyvinyl polymer, carboxyvinyl polymer Starch, carboxymethyl starch sodium, burlan, Bolibul alcohol, polyvinylpyrrolidone, tragacanth powder, carmellose sodium, casein, gluten, carrageenan, gum arabic powder, Agar powder, xanthan gum and the like can be mentioned. Two or more of these may be contained.

The composition ratio of the gel-forming polymer varies depending on the gel-forming polymer, other components, the intended composition of the present invention, etc., but is suitably 5 to 90% (w / w), and 10 to 85% (w / w). w / w) is preferred, and 20-80% (w / w) is more preferred. A composition having a composition ratio of more than 90% (w / w) can be included in the composition of the present invention, but is not practical. Those having a composition ratio of less than 59 (w / w) may not have starvation of the composition of the present invention. The pesticidal active ingredient according to the present invention is not particularly limited. For example, the following can be mentioned.

1. herbicide

Mefenacet, Oxaziazone, Virazolate, MCP, MC PB, Phunothiol, Esbrocalp, Clomeprop, Nabuguchi anilide, Clomethoxinil, Bifunox, MCC, Bentocarb, Molinate, Zimepirate, DC PA, Bu Evening Chlor, Bretirachlor, Bromotide, Daimlon, Bensulfuron Methyl, Simetrin, Bromethrin, Dimethamethrin, Benzozon, Pyrazoxifen, Benzofu: t-nap, trifluralin, Viverofos, ACN, Glyphosate, Pilipticalp, Sinosulfuron, Dimethametrine Viverofos, DBN, Birazosulfronethyl.

2. Insecticides

Dimethate, Etofenblock, Cyclobrothrin, BPMC, MIPC, Ethylthiomethone, Carbosulfan, MPP, MEP, Pirimiphos-methyl, Diazinon, Isoxathion, Pyri Duff: L-thione, chlorpyrifos-methyl, di-midothione, marathon, ethylthiomethone, monocrotophos, dimethylvinphos, bendiocarp, carbosulfan, benfracarp, thiodicarp, riutap, thiocyclam, bensulbub, buprofezin E PN, B PMC, MPMC, PHC, XMC;

3. Fungicide

Pyroquilon, EDD P, probenazole, fusaride, basic copper sulfate, cupric hydroxide, capitan, TPN, IBP, benomyl, iblogion, mebronil, flutolanil, pencyclon, metalaxyl, triflumibule , Kasugamycin, polyoxin, gludamycin A, oxytetracycline, hydroxyisoxazole, MAF, benciabul, diclomedine, isobrothiolane, pyroquilon, guazatine.

Two or more of these may be contained.

The composition ratio of the pesticide active ingredient varies depending on the pesticide active ingredient and other components, but is preferably 0.001 to 80% (w / w), preferably 0.01 to 60% (w / w), and 0.1 -50% (w / w) is more preferred. If the composition ratio is less than 0.001% (w / w), the effect of the pesticidal active ingredient may not be sufficiently obtained.If the composition ratio is more than 80% (w / w), the composition of the present invention may be used. It may not have the concept of an object.

The composition of the present invention may contain a physiologically inert powder additive or a release controlling adjuvant. Physiologically inert powder additives correspond to so-called common excipients, such as smooth processing in extruder barrels, composition stability, formulation handling, and cost aspects. Include for purpose You can. The release control adjuvant can be basically included to assist the sustained release of the pesticidal active ingredient.

Physiologically inert powder additives include, for example, corn starch, rice starch, wheat starch, rice starch, soy flour, tobacco flour, flour, walnut, wood flour, corn fertilizer, crystalline cellulose , Low-substituted hydroxybile bilcellulose, carmellose, carmellose calcium, croscarmellose sodium, lactose, mannitol, maltose, dextrin, cyclodextrin, calcium hydrogen phosphate, carbonate Sodium hydrogen, sodium carbonate, citric acid, fumaric acid, tartaric acid, kaolin, synthetic aluminum diamate, aluminum hydroxide gel, gay anhydride, hydrous silicon dioxide, synthetic hydrotalcite, Titanium oxide, magnesium metasilicate aluminate, talc, precipitated acid Calcium, Ben Tokyo theft and the like may be 举 gel. Two or more of these may be contained.

The composition ratio of the physiologically inert powder additive varies depending on the physiologically inert powder additive, other components, the intended composition of the present invention, etc., but is 1 to 85% (w / w) is suitable, preferably 5 to 80¾ (w / w), more preferably 8 to 75% (w / w).

As release control adjuvants, carnaupa wax, hydrogenated castor oil, soybean oil, rapeseed oil, paraffin, beeswax, oils and fats such as microcrystalline cellulose, stearinic acid, lauric acid, palmitic acid, quenching oil Triethyl phosphate, triacetin, medium chain fatty acid triglyceride, magnesium stearate, isopropyl myristate, stearyl alcohol, cetanol, propylene glycol, polyethylene glycol Poly (400), Poly (ethylene glycol) 1500, Poly (ethylene glycol) 4000, Poly (ethylene glycol) 6000, etc., high fatty acids or high alcohols, sucrose fatty acid esters, polyoxydiethylene polyoxypropylene propylene glycol, polyoxyethylene Hardened castor oil, surfactants such as boroxyl stearate, polysorbate 60, polysorbate 80, sodium lauryl sulfate and the like can be mentioned. Two or more of these may be contained.

The composition ratio of the above-mentioned release control adjuvant varies depending on the release control adjuvant, other constituent components, the intended composition of the present invention, etc., but is preferably 0.1 to 80% (w / w), and is preferably Is suitably 0.5 to 75% (w / w), more preferably 1 to 70% (w / w).

Preferably, the composition of the present invention is mainly composed of natural products. For example, the composition of the present invention in which a pesticidal active ingredient is blended with a combination of glucomannan, corn starch, lactose, and stearic acid is preferable. By using a composition mainly composed of natural products, environmental safety can be enhanced.

The composition of the present invention comprises a gel-forming polymer and a pesticidally active ingredient, optionally containing a physiologically inactive powder additive and a release control adjuvant, and a solvent as essential raw materials. Including solvent. The same shall apply hereinafter) is referred to as a multiaxial extruder (hereinafter simply referred to as an extruder j).

) Can be manufactured by batch processing.

Here, “batch processing j” means that all the raw materials are subjected to the processing provided by the extruder such as shearing, mixing, kneading, compression, and extrusion at the same time. The main part of the extruder is mainly composed of a barrel called a barrel, a die corresponding to the exit, and a screw mounted with various screw elements. There are usually multiple barrels through which the screw passes. The screen elements include trapezoidal screen elements, trapezoidal cut screen elements, trapezoidal reverse cuts, ball screen elements, and evening paddles (also known as needing discs). The combination can be made arbitrarily. The sample sent into the barrel is moved inside the barrel by a screw, and is subjected to processing such as shearing and mixing by a screw element such as a kneading paddle in the barrel, and is extruded from a hole in the die. It is. Normally, each barrel and die are independently temperature controlled.

In the present invention, basic characteristics such as a function of transporting a high moisture and high oil content raw material, a mixing function, a shearing function, a compressing function, a crushing function and a heating function, which are generally used in the food and plastic fields, etc., are used. If it is equipped with an extruder, it can be used as it is. -

If a biaxial extruder having two screws is used, the composition of the present invention can be sufficiently obtained.

Although it was difficult with conventional technology to mix a gel-forming polymer and a solvent such as water uniformly to obtain a molded product, this is possible by using the above extruder. It became. Therefore, the use of the above extruder is the greatest feature of the present invention.

Batch processing in the extruder applies to all barrels in the extruder. And not necessarily in the die. The composition of the present invention can be obtained by performing batch processing in and after a certain barrel.

As a method of batch-processing all raw materials in the extruder, ① a method of mixing all raw materials in advance and supplying this from the main supply hole of the extruder to collectively process them; ② a method of pre-mixing “some raw materials” This is supplied from the main supply hole of the extruder, and the “remaining raw material” is supplied from the auxiliary supply hole to perform batch processing. ③ “One raw material” is supplied from the main supply hole of the extruder. And a method of supplying the “remaining raw materials” from the auxiliary supply holes and performing batch processing. Among these methods, the above method (2) is preferable.

Here, the main supply hole is the most basic supply hole capable of supplying a raw material into the barrel, and the auxiliary supply hole is a main supply hole capable of additionally supplying a solvent or a raw material into the barrel. Refers to supply holes other than supply holes.

In the above item (2), an arbitrary raw material can be further supplied from the auxiliary supply hole as needed.

In the above ①, for example, the gel-forming polymer, the physiologically inert powder additive, the pesticide active ingredient can be “some raw materials”, and the solvent can be “the remaining raw materials”. Polymers, physiologically inert powder additives can be used as “some raw materials”, and solvents, pesticide active ingredients, and other raw materials can be used as “remaining raw materials”. It is preferably one of several raw materials. “The remaining raw material J can be supplied as a mixture through one auxiliary supply hole, or individual raw materials or a mixture of arbitrary raw materials can be supplied through a plurality of auxiliary supply holes. You can also. In any case, the composition of the present invention can be obtained. A part of "some raw materials" supplied from the main supply hole can be included in "remaining raw materials" and supplied from the auxiliary supply hole.

In (3) above, “one raw material” is optional except for the solvent. It is preferable that the gel-forming polymer be “one raw material”. "The remaining raw material J can be supplied as a mixture from one auxiliary supply hole, or individual raw materials or a mixture of arbitrary raw materials can be supplied from the auxiliary supply hole. The composition of the present invention can be obtained, and a part of “several raw materials” supplied from the main supply hole can be included in the remaining raw material j and supplied from the auxiliary supply hole. .

As the solvent, for example, water (tap water, distilled water, purified water, isotonic water such as physiological saline, neutral or acidic or basic buffer, or ammonia water, etc.), methanol, ethanol, isobrovanol, Examples thereof include alcohols such as ethanol, hydrogen halides such as chloroform, methylene chloride and trichloroethane, hydrocarbons such as hexane, benzene and toluene, and organic solvents such as ethers and ketones. Of these, water is most preferred. In order to consider the effect on the human body, and by using water, the gel-forming polymer is erected by water during the extruder treatment process, thereby greatly increasing the gel strength of the composition. This is because the form of the composition of the present invention in water can be maintained for as long as possible.

Premixing of the raw materials can be performed manually or by a machine such as a kneader mixer, a V-type mixer, a double fiber mixer, a cubic mixer, a ribbon mixer, or the like. The supply of raw materials into the barrel can be performed manually or by a raw material feeder generally provided in the extruder used, but there is no particular limitation as long as a device capable of supplying raw materials at a constant speed is used. It can be carried out. As such an apparatus, for example, a screw feeder, a table feeder, a belt conveyer-type quantitative feeder, an electromagnetic feeder and the like can be mentioned.

The amount of the raw materials charged to the extruder can be appropriately set within the range of the above-mentioned respective composition ratios.

The amount of the solvent used varies depending on the solvent, other raw materials, the type and type of extruder, the processing conditions, the intended composition of the present invention, and the like. w / w). If it is less than l% (w / w), the frictional resistance in the barrel increases, resulting in overloading and the risk of exhausting. If it exceeds 90% (w / w), the resulting product may become softened, which may hinder subsequent operations.

After the extruder treatment, a drying treatment can be carried out. The agricultural chemical composition subjected to the drying treatment is also the composition of the present invention.

Such drying can be performed by a usual method, for example, using a dryer. Specific examples of the dryer include a shelf dryer, a rotary dryer, a fluidized bed dryer, and the like. The drying temperature is not particularly limited unless agrochemical active Ingredient and gel-forming polymer or decomposes, it is appropriate to set 30 to 80 ^e C The example embodiment.

The processing conditions of the extruder will be described.

Extruder barrel and die temperatures depend on raw materials, It can be appropriately set depending on the model and type of the device, the intended composition of the present invention, and the like. Specifically, it can be set to 0 to 150, preferably 30 to 120'C. Even if the temperature is set to a higher value of 150, the present invention composition can be obtained. However, if the temperature is set too high, there is a possibility that the pesticide active ingredient and the like are decomposed. At a temperature lower than O′C, the present invention composition may not be obtained.

The screw rotation speed (processing speed) can be set as appropriate depending on the type and type of extruder, raw materials, screw shape, etc., and can be set within the allowable range of the extruder used. it can. An extruder with a longer barrel length can increase the rotation speed. This is because the longer the barrel length, the higher the processing capacity such as mixing and shearing. Specifically, 50 rpm or more is appropriate, and 50 to 300 rpni is preferable.

Discharge pressure, 10~150kg / cm ^a are suitable, 30~120kg / cm ² is favorable preferable.

The shape and combination of the screw elements that can be used in the present invention can be selected without any particular limitation. However, it is preferable to use at least one pair of a kneading paddle (kneading disc) having strong kneading action and shearing action. The gel-forming polymer can be mixed more evenly by the action of the kneading paddle.

The discharge die can be appropriately changed depending on the intended composition of the present invention. Specific examples include a circular die having various diameters for obtaining a columnar processed product, and a flat die for obtaining a plate-shaped processed product. Hereinafter, the pesticide formulation according to the present invention (hereinafter referred to as “the present formulation”) will be described in detail. The preparation of the present invention can be produced by formulating the composition of the present invention by a conventional method. For example, the following method can be used.

The raw material batch-processed by the extruder is continuously extruded from the pores of the die as the composition of the present invention. This can be cut to a desired length by an appropriate cutting machine, for example, a roller type crusher, a cutter mill, a pin mill, or the like. This cut product can be used as such or dried to obtain the abducted preparation of the present invention. In addition, the composition of the present invention extruded from the pores of the die is subjected to a desired length using, for example, a rotary power cutter (for example, a rotary cutter for KBXN-30, manufactured by Kurimoto Tekkosho Co., Ltd.) equipped at the tip of the die. By cutting into pieces, the preparation of the present invention can be directly or dried without a special sizing operation.

If the granular composition of the present invention is packed in capsules or the like, the capsule preparation of the present invention can be obtained. By compression molding, the tablet preparation of the present invention can be obtained.

The preparation of the present invention can also be prepared by packing a coarse-grained composition of the present invention with a coating treatment or the like, or a granular composition of the present invention or a composition obtained by coating the same with a capsule, and filling the capsule into a capsule. As a result, the strength of the preparation of the present invention can be further improved, and the stability of the pesticidally active ingredient can be increased.

Furthermore, the above-mentioned preparation of the present invention may be encapsulated in a bag made of a water-soluble polymer compound such as polyvinyl alcohol, carboxymethylcellulose, burlan, and gelatin. it can.

The invention's effect

The composition of the present invention (the preparation of the present invention) has a small bulk and is excellent in storage stability without taking up space before being put into water. When the composition of the present invention (the present invention preparation) is put into water, it expands and increases its volume, so that burial under the surface soil layer of a paddy field is effectively prevented. In addition, the swollen composition of the present invention (formulation of the present invention) can keep the swollen state in a prolonged state.

Furthermore, since the composition of the present invention (the preparation of the present invention) can be easily manufactured in a large amount by an extruder and can be produced basically continuously, it is said that it is an agricultural chemical composition excellent in practicality and industrial properties. be able to.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described in more detail with reference to Examples, Comparative Examples, and Test Examples. The following barrel numbers are assigned in ascending order from the barrel on the sample supply side (entrance side).

Example 1

A mixture consisting of 16 g of a mesh sieved through a 100-mesh sieve, 150 g of glucomannan, 134 g of pregelatinized starch, 60 g of olefin, 40 g of powdered stearate, diameter: 32 sleep ø, effective L / D : 20, Screw pattern: 16P, 12P. 9.6P, 30deg. 60deg. 9.6P. 8P screw and a 2-axis type extruder equipped with a 5.0mm 0 x 1 hole die. (KEXN-30 S-20; manufactured by Kurimoto Iron Works, same hereafter) at a speed of 30 g / min from the main supply hole, while an auxiliary provided between barrel 1 (main supply hole barrel) and barrel 2 Purified water was added at a rate of 4 g / min from the feed hole, and at a barrel temperature of 100, Die temperature 100 ^e C, performed under conditions of risk Li Yu speed l OOR pm, drying the extrudates obtained in 50'C to give the composition of the present invention. The leverage composition is sized at 900 rpm using a Fuzamiru (FM-1; manufactured by Hosokawa Miclon Co., Ltd .; same hereafter) equipped with a 10-mesh screen, sieved, and sieved. I got The apparent specific gravity of the composition of the present invention (formulation of the present invention) before being charged in water was 1.39. The composition of the present invention reaches the bottom of the water immediately after being introduced into water and is fixed for at least 4 days.

Example 2

A mixture consisting of 8 g of oxadiazone, 200 g of corn starch, 100 g of modified starch, 60 g of calcium hydrogen phosphate, and 32 g of hydrogenated castor oil, which has been subjected to 100 mesh sieving, has a diameter of 32 ø, an effective L / D of 20, and a screen. One pattern: 16P, 12P, 9.6P, 30deg, 60deg. 9.6P. 8P screw and 2-axis type screw with 5.0mm x 2.0mm x 1 hole plate die Purified water is supplied at a rate of 30 g / min from the main supply hole of the truder, while purified water is added at a rate of 4 g / min from the auxiliary supply hole provided between barrel 1 (main supply hole barrel) and barrel 2. performed barrel temperature 100 ^e C, die temperature 100 'C, the treatment at the disk Li Yu rotational speed l OOrpm, the resulting extrudates were dried at 50'C to give the composition of the present invention. Subsequently, this composition was sized at 900 rpm by a fusar mill equipped with a 10-mesh screen, and sieved to obtain the preparation of the present invention. The apparent specific gravity of the composition of the present invention (formulation of the present invention) before being introduced into water was 1.42. The composition of the present invention reaches the water bottom immediately after being introduced into water, and is fixed for at least 4 days. Example 3

A mixture of 40 g of pyrazolate, 40 g of microcrystalline cellulose, 100 g of cornstarch, 200 g of pregelatinized starch, and 20 g of carnauba wax, which has been sieved through 100 mesh, has a diameter of 32 sleep ø, an effective L / D of 20, and a screen pattern. : 16P, 12P. 9.6P. 30deg. 60deg. 9.6P, 8P screw and bore size 3. Omm ø X 30g from the main feed hole of a 2-axis extruder equipped with a 3-hole die / min at the same time, and purified water is added at a rate of 4 g / min from an auxiliary supply hole provided between barrel 1 (main supply hole barrel) and barrel 2 at a barrel temperature of 1 10 ° C and a die. temperature 1 10 performs processing under conditions of risk Li Yu speed l OOR pm, the extrudates obtained were dried at 50 ^e C to give the composition of the present invention. Subsequently, the composition was abducted at 900 rpm using a fuser mill equipped with a 10-mesh screen and sieved to obtain the present invention preparation. The apparent specific gravity of the composition of the present invention (the present preparation) before being charged in water was 1.34. The composition of the present invention immediately reached the bottom of the water after being charged in water and settled for at least 4 days.

Example 4

A mixture consisting of 8 g of etofen blox, 200 g of powdered gelatin, 60 g of corn starch, 60 g of pregelatinized starch, 40 g of lactose, and 32 g of powdered stearate, which has been subjected to 100 mesh sieving, has a diameter of 32 關 and an effective L / D of 20, Screw pattern: 16P, 12P. 9.6P, 30deg, 60deg. 9.6P. 8P screw and diameter 3.0mmn ø x 1-axis main extruder equipped with a 1-hole die Purified water is supplied from the supply hole at a rate of 30 g / ra in, while purified water is added at a rate of 5 g An in from the auxiliary supply hole provided between barrel 1 (main supply hole barrel) and barrel 2 and the barrel temperature is 90 'C, die temperature 90'C, screw times The treatment was performed under the conditions of a rotation speed of lOOr pm, and the obtained extrudate was dried at 40'C to obtain a composition of the present invention. This composition was abducted at a rotation speed of 900 rpm using a feather mill equipped with a 10-mesh screen, and sieved to obtain the preparation of the present invention. The apparent specific gravity of such a composition of the present invention (formulation of the present invention) before being introduced into water was 1.28. The composition of the present invention immediately reached the bottom of the water after being charged in water and settled for at least 4 days.

Example 5

A mixture consisting of 20 g of dimethate which had been subjected to 100 mesh sieving, 200 g of sucrose fatty acid ester, 200 g of hydroxybile bilcellulose, 40 g of precipitated calcium carbonate, and 60 g of powdered stearate was used. Effective L / D: 20, screw pattern: 16P. 12P, 9.6P, 30deg. 60deg. 9.6P, 8P screw and 10, Omm x 2.0mm x 1 hole plate die Supplied at a speed of 30 g / min from the main supply hole of the attached twin-screw extruder, while 2 g of purified water was supplied from the auxiliary supply hole provided between barrel 1 (main supply hole barrel) and barrel 2. The mixture was added at a speed of / min, processed at a barrel temperature of 80, a die temperature of 70 ° C, and a screw rotation speed of 100 rpm to obtain the present invention composition. Subsequently, the composition was abducted at a rotation speed of 900 rpm by a fuser mill equipped with a 10-mesh screen, and sieved to obtain the preparation of the present invention. The apparent specific gravity of the composition of the present invention (formulation of the present invention) before being introduced into water was 1.36. The composition of the present invention immediately reached the bottom of the water after being charged in water and settled for at least 4 days.

Example 6

The condyla obtained in Example 1 was pulverized with a tabletop pulverizer (manufactured by Konishi Medical Instruments, same hereafter), and this was autographed (AG-5000A; manufactured by Shimadzu Corporation; The same formulation was used to obtain a preparation of the present invention molded to a weight of 300 mg, a diameter of 10 and a thickness of 4.5 mra under the conditions of a pressure of 800 kg and a pressurization rate of l Omm / min. The apparent specific gravity of the preparation of the present invention before introduction in water was 1.42. The formulation of the present invention reached the bottom of the water promptly after being introduced into water and settled for at least 4 days. The obtained preparation was used for an apparent specific gravity test accompanying water absorption.

Example 7

The condyla obtained in Example 4 was disintegrated with a tabletop disintegrator, and was crushed using an autograph under the conditions of a pressure of 800 kg, a pressurizing speed of 10 liters, a weight of 300 mg, a diameter of 10 and a thickness. A preparation of the present invention having a size of 4.5 mm was obtained. The apparent specific gravity of the preparation of the present invention before being introduced into water was 1.35. The formulation of the present invention reached the bottom of the water promptly after being charged in water and settled for at least 4 days. The obtained preparation was used for an apparent specific gravity test accompanying water absorption. Comparative Example 1

100 Mesh sieved 40g Mesh unaset, Lactose 350g, Cornstarch 400ί! A mixture of 210 g of powdered stearate is mixed with a small kneader (KDH-3; manufactured by Fuji Electric Industries, same hereafter), and 100 ml of a 20% aqueous polyvinyl alcohol solution is added thereto, followed by mixing for 10 minutes. Was done. The kneaded material is extruded at a speed of 30 rpm by a single-shaft granule manufacturing machine equipped with a 5.0 mm diameter screen (EK Pelletator BXK-1; manufactured by Fuji Electric Co., Ltd .; same hereafter) and dried at 50 ° C. did. Next, the granules were sieved at 900 rpm using a FUZA MILL equipped with a 10 mesh screen, and sieved. Using a fluid coating machine (STREA-1; manufactured by Perek Co., Ltd.), 300 g of the granules were mixed with 5% ethyl cellulose. The evening solution was sprayed to an amount of 20% based on the charged weight to obtain a controlled-release granule for coating for comparison.

Comparative Example 2

Using a mixture of 8 g of oxadiazone, 92 g of hydrogenated castor oil and 300 g of calcium hydrogen phosphate, which had been sieved through a 100 mesh screen, using an autograph, under the conditions of a pressure of 400 kg and a pressing speed of 10 faces / min, the weight was It was molded to 60 mg, diameter 5.0 mm and thickness 2.0 mm. By leaving the molded product under 85'C for 30 min, the hardened castor oil was melt-crosslinked to obtain a wax matrix for controlled release particles for comparison.

Comparative Example 3

The elementary granules obtained by the uniaxial granule manufacturing machine of Comparative Example 1 were used as granules for a comparative test of strength in water with the preparation of the present invention.

Comparative Example 4

The elementary granules obtained by the single-shaft Laila manufacturing machine of Comparative Example 1 were pulverized by a tabletop pulverizer, and the weight was 300 mg using an autograph under the conditions of a pressure of 800 kg and a pressing speed of 10 mm / min. It was molded to a diameter of 10 mm and a thickness of 4.5 mm. The obtained molded body was used for an apparent specific gravity test accompanying water absorption.

Comparative Example 5

The condyla obtained in Comparative Example 2 was pulverized with a tabletop pulverizer, and was crushed using an autograph under the conditions of a pressure of 800 kg, a pressurizing speed of 10 bands / min, a weight of 300 mg, a diameter of 10 and a thickness. 4. Molded to 5mm. The obtained molded body was used for an apparent specific gravity test accompanying water absorption.

Test Example 1 Burial test

In order to evaluate the burial of particles, a 10 x 10 cm square cell was used as shown in Fig. 1. A prototype of 30-cm-wide, 40-cm-long, 30-cm-depth Acrylic tester with twelve holes was fabricated. Paddy soil that had been harbored in advance and that had been padded was poured up to 20 cm from the bottom, and water was injected to a height of 5 cm from the surface. Each granule (2 granules) obtained in Examples 1 and 2 and Comparative Examples 1 and 2 was charged into each cell, and the granules were attached to a penetrator (SA-31; manufactured by Yamato), and then stood for 30 st. It was dissipated at the speed of roke / min. Thereafter, the position of the abductant at a predetermined time was observed and determined as the burial distance from the surface.

As a result, as shown in Fig. 2, the conventional coating Eve and PEXMATRIX type preparations buried 7 to 13 cm below the topsoil layer, whereas the preparation of the present invention showed slight burial, It formed a gel and remained near the topsoil layer for a long time in a swollen state.

Test example 2 Strength test

The granules obtained in Examples 1 and 2 and Comparative Examples 2 and 3 were tested according to the tablet disintegration test method in the Japanese Pharmacopoeia, and the strength of the preparation during gel formation was evaluated. The results are shown in Table 1.

Table 1 Strength of formulation in water

As shown in Table 1, the preparations of the present invention (Examples 1 and 2) swelled extremely in water, compared to the conventional granules containing no gel-forming polymer (Comparative Examples 2 and 3). It is clear that the shape is maintained for a long time.

Test Example 3 Volume change of drug product in water The granules obtained in Examples 1 and 2 and Comparative Examples 1 and 2 were placed in a square plastic container (inner dimensions 3 × 3 × 3 cm), and water was gently poured from the upper portion and immersed. This was left under 40 ^e C, every predetermined number of days, to measure the diameter and length using Roh Gisu than the outer container. In the evaluation of the results, since it was judged that the sample could be regarded as having a columnar shape (Example 2 was regarded as a rectangular parallelepiped), the volume was obtained by a usual method and compared with that before the test.

As a result, as shown in FIG. 3, it is apparent that the preparation of the present invention shows an extremely large increase in volume, as compared to the conventional coating type and the preparation of PEXMATRIX Eeve which hardly change in water. .

Test Example 4 Change in apparent specific gravity of drug product due to absorption of water

Example 6, 7 and Comparative Example 4, the 5 obtained molded body was left in 1 under 00¾ RH 40 ^e C, was measured over time by weight, diameter, thickness, apparent density (weight that put upon moisture absorption Divided by the whole body).

As a result, as shown in Fig. 4, the conventional formulation increased in apparent specific gravity with the absorption of water, whereas the formulation of the present invention formed a gel and swelled, resulting in an extreme increase in volume. However, it was confirmed that the apparent specific gravity tends to decrease.

Test Example 5 Release control test

As a test example regarding the release control of the preparation of the present invention, a dissolution test of granules was conducted by the Japanese Pharmacopoeia Dissolution Test Method 2 (paddle method) under the conditions of 900 ml of water and a rotation speed of 50 rpm. The sample used in the test was a 3.0 mm ø columnar drug consisting of mef; nasset as an active ingredient and glucomannan as a gel-forming polymer in Table 2. Table 2 Formulation of granules used in the release control test

Unit: ¾ (w / w)

As a result, as shown in FIG. 5, the preparation of the present invention can control release over a long period of time by combining a swellable polymer, a physiologically inert powder additive, and a release control auxiliary. It is clear that is possible.

BRIEF DESCRIPTION OF THE FIGURES

Figure 1 shows the schematic top and side views of the burial tester. An abductant was injected into each cell, and the burial distance was measured thereafter according to the sampling time.

Figure 2 shows the burial of granules in paddy soil.

The vertical axis shows the burial distance (cm), and the horizontal axis shows the elapsed time (hours).一 and 一 show the results of the granules obtained in Examples 1 and 2, and 〇 and □ show the results of Comparative Examples 1 and 2, respectively.

FIG. 3 shows the increase rate of the granular body contact in water.

The vertical axis shows the increase ratio to the volume before the test, and the horizontal axis shows the elapsed time (time

) Are shown. Okina and I used the results of the granules obtained in Examples 1 and 2,

〇 and □ show the results of Comparative Examples 1 and 2, respectively.

Figure 4 shows the change in the apparent specific gravity of the abduct with the absorption of water.

The vertical axis shows the apparent specific gravity, and the horizontal axis shows the elapsed days (days).鲁, one shows the results of the granules obtained in Examples 6 and 7, and 〇 and □ show the results of Comparative Examples 4 and 5. Are shown.

FIG. 5 shows a release control test of the preparation of the present invention in which mefnaset was prepared as an agrochemical active ingredient.

The vertical axis shows the dissolution rate (%), and the horizontal axis shows the elapsed days (days). Hata shows the results for abductory A, one for granules B, and * for granules C.

Claims

The scope of the claims

1. ① Agrochemical active ingredients are dispersed or dissolved in a polymer compound which swells by forming a gel in water. ② At least the apparent specific gravity is greater than 1 until it reaches the surface of paddy rice topsoil layer. No

② Paddy rice topsoil characterized by ② Surface-fixing pesticide composition.

2. ① Agrochemical active ingredients are dispersed or dissolved in a polymer compound which swells by forming a gel in water. ② Apparent specific gravity is larger than 1 at least until it reaches the surface of paddy rice topsoil layer. A pesticidal composition having a surface soil layer on a paddy field, wherein the pesticide composition is characterized by the following.

3. The polymer compound that swells by forming a gel in water is glucomannan, pregelatinized starch, gelatin, partially modified starch, hydroxybile bilcellulose, hydroxybyl virmethylcellulose, and hydroxypropyl pilethyl. Cellulose, hydroxyshethyl cellulose, methylcellulose, sodium alginate, sodium poly (sodium acrylate), carboxyvinyl polymer, hydroxybromostarch, sodium carboxymethylstarch, burlan, bolivine At least one selected from the group consisting of nyl alcohol, bolivibulpyrrolidone, tragacanth powder, carmellose sodium, casein, gluten, carrageenan powder, arabic powder powder, agar powder powder, and xanthan gum Item 1 or 2 Pesticidal compositions of the mounting.

4. The pesticidal composition according to any one of claims 1 to 3, further comprising a physiologically inert powder additive and / or a release control adjuvant.

5. The constituent components according to claims 1 to 4 and a solvent are used as essential raw materials, and all raw materials are collectively processed by a multiaxial extruder. A method for producing the agricultural chemical composition according to any one of claims 1 to 4.

6. The pesticide according to any one of claims 1 to 4, wherein the constituent components and the solvent according to claims 1 to 4 are used as essential raw materials, and all the raw materials are collectively processed by a multiaxial extruder and then dried. Preparation of the composition.

7. The constituent components and the solvent as defined in claims 1 to 4 are used as essential raw materials, and all raw materials are subjected to collective treatment by a twin-screw extruder or dried after the collective treatment. 5. The method for producing the pharmaceutical composition according to any one of 1 to 4 above.

8. The components described in claims 1 to 4 and water are used as essential raw materials, and all the raw materials are batch-processed by a twin-screw extruder set at a barrel temperature of 0 to 15 O'C with a kneading paddle. The method for producing an agricultural chemical composition according to any one of claims 1 to 4, wherein drying is performed after the batch processing.

9. A pesticide preparation having a surface-fixed surface layer in a paddy field derived from the pesticide composition according to any one of claims 1 to 4.