JPH02108604A - Water-soluble agricultural chemical granule composition - Google Patents

Abstract

PURPOSE:To obtain the title composition having excellent storage stability useful wholly similarly to emulsion, comprising a water-insoluble agricultural chemical, nonvolatile polyaromatic ring solvent, emulsifying agent consisting of nonionic and anionic surfactants and water-soluble excipient. CONSTITUTION:The title composition comprising 1-25wt.% water-insoluble agricultural chemical having <=50 deg.C melting point, 0-25wt.% nonvolatile polyaromatic ring solvent (e.g. methylnaphthalene), 0.5-25wt.% emulsifying agent consisting of nonionic and anionic surfactants (e.g. sorbitan alkylate) and the rest of a water-soluble excipient consisting one or more of urea, thiourea, water- soluble polymer substance (e.g. PVA or gum arabic), saccharide (e.g. glucose) and water-insoluble inorganic salt. The composition is granules as formulation, the water-insoluble agricultural chemical is readily dissolved in water, stably emulsified or solubilized and has no adhesion to containers, no malodor and no flammability.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to the creation of a new water-soluble agricultural chemical granular composition, and more specifically, to the creation of a new water-soluble agricultural chemical granular composition. In addition, it relates to formulation techniques that can be used as granules.

That is, although the present invention is a granule as a preparation, water-insoluble pesticides easily dissolve in water and are stably emulsified or solubilized, so they can be used in exactly the same way as emulsions and can be used for a long period of time. It has good storage stability, does not stick to containers or remains, and has no odor, flammability, or risk of adhesion to the human body, and can be prepared into an aqueous spray solution or applied directly. The present invention relates to a technology that can make water-insoluble agricultural chemicals into water-soluble granules.

[Prior Art and Problems] In general, agricultural chemical ingredients are generally used in the form of formulations, but in recent years, from the viewpoints of reducing toxicity, preventing drifting and scattering, preventing flammability and bad odors, and saving resources, The usefulness of granular dosage forms has been recognized.

Granular agents are more susceptible to drifting, scattering, and
Not only is there an extremely low risk of leaks, ignition, and bad odors, but
There is no adhesion or residue to storage containers, and no scattering or residue on the human body or clothing.
It has characteristics such as non-stickiness, easy metering, and the ability to be applied directly as well as being prepared as a spray liquid.

Generally, when the agricultural chemical is solid, granules are made into fine particles by dry or wet grinding in advance, and then kneaded granules, impregnated adsorbent granules, 1 surface coated granules, or kneaded crushed granules are prepared using a solid carrier and a binder. It is formulated into granules, etc., and is applied directly as is without diluting with water. This technology can also be applied to pesticides that are liquid or have a low melting point. In recent years, 111 granular wettable powders have been released, but since these are granular wettable powders, they need to quickly disintegrate and disperse in water when preparing the spray solution, so they are not suitable for solid pesticides with a high melting point. Even if it is possible to do so, it has the disadvantage that it cannot be applied to agricultural chemicals that are liquid or have a melting point of approximately 60 to 70°C or lower. A water-solvent is a water-soluble solid pesticide mixed with a water-soluble carrier or formed into a tablet or the like.

On the other hand, emulsions are liquid formulations in which solid or liquid pesticides are dissolved in an organic solvent and an emulsifier is added to this, so there is a risk of ignition and bad odors, and they may stick or remain in containers or stick to the human body or clothing.
Although there is a risk of accidental ingestion, it has the characteristics of high biological effects and fast-acting after application.

Thus, it has long been desired to complete a formulation technology that takes advantage of the characteristics of emulsions by turning water-insoluble agricultural chemicals that are liquid or have a melting point of about 50 to 60°C or less into granules.

There have been several attempts in the past. In other words, the special public
-2049 and JP-A-47-16645 disclose a technique for solidifying a mixture or emulsion of a liquid agricultural chemical and an emulsifier using urea. It has the disadvantage that it cannot be made into powder, making it impractical. Also, JP-A-48-19737, JP-A-47-16645, JP-A-49-6
135 and Japanese Patent Publication No. 52-48182, a large amount of PPG-PEG derivatives or polyoxyethylene nonionic surfactants are mixed with liquid agricultural chemicals as a solidifying agent,
Furthermore, a granulation technology using an inorganic carrier and a water-soluble polymer as a binder has been disclosed, but since a large amount of PPG-PEG derivatives or polyoxyethylene nonionic surfactants are used, disintegration in water is difficult. In addition, the emulsifying power is insufficient and not stable, and it has not been put into practical use.In addition, the adsorption of emulsions to cork powder (Japanese Patent Application Laid-open No. 18902/1983)
, solidification with nitrocellulose (JP-A-55-379)
62), adsorption to anhydrite powder and granulation (Japanese Unexamined Patent Publication No. 56-83403), etc., but there are studies on the adsorption and granulation of agrochemicals on anhydrite powder (Japanese Patent Laid-Open No. 56-83403). At present, a practical formulation that has both the functions of an emulsion and a granule has not yet been completed.

[Problems to be Solved by the Invention] The present invention attempts to complete a technology for formulating water-insoluble agricultural chemicals as water-soluble granules that can be emulsified or solubilized in water without using a large amount of solvent. be. Therefore, a technology for solidifying a liquid mixture of a water-insoluble agricultural chemical and an emulsifier, and a technology for quickly disintegrating in water and emulsifying or solubilizing the agricultural chemical in water were combined into a granule formulation, and the conventional technology The objective is to develop granules that are easily soluble in water, which is impossible with other methods.

[Means for Solving the Problems] The present invention consists of a technique for liquefying a water-insoluble agricultural chemical and an emulsifier by mixing it, and for making it into water-soluble granules.

in general! ! Since the pharmaceutical agent is stored at a temperature of about 40 to -5°C, agricultural chemicals that are liquid at this temperature can be directly mixed with an emulsifier. In addition, solid pesticides with a melting point of about 50°C or lower are dissolved in a polyaromatic solvent with a high boiling point, nonvolatile, insoluble in water, and highly soluble in pesticides, and then an emulsifier is added. By adding, an emulsifiable liquid mixture can be obtained. Such nonvolatile polyaromatic ring solvents include methylnaphthalene, phenylxylylethane, diphenylethane, alkyldiphenyl, bis(
Examples thereof include α-methylbenzyl)xylene and reactants of high-boiling fractions produced as by-products from catalytic reforming or thermal decomposition of petroleum. These non-volatile polyaromatic ring solvents are
2-38094, JP 5B-19841, JP 58-14402, JP 62-286
902, JP-A No. 62-29501, JP-A No. 62-29502, etc. disclose techniques for use as a solvent for agricultural chemical emulsions or as a quality deterioration preventive agent for agricultural chemical solid agents. These non-volatile polyaromatic ring solvents used in the present invention are used for the purpose of maintaining a liquid compatible mixture of a water-insoluble pesticide and an emulsifier with a melting point of about 50°C or less, and are also used as described below. It is solidified and granulated with organic and inorganic excipients. Therefore, as the non-volatile polyaromatic ring solvent used in the present invention, water-insoluble high boiling point compounds and solvents comprising polyaromatic rings similar to the above examples may be used as well. Usually, it is often sufficient to mix 30 to 100% (by weight) of these polyaromatic ring compounds and solvents to the pesticide.

Emulsifiers are generally selected and blended with one or more of nonionic surfactants and anionic surfactants, but when preparing emulsifiers, emulsifiers have excellent emulsification properties, self-emulsifying properties,
It is important that the emulsion stability is good, the emulsion particles are made as fine as possible, and that the emulsifying power, self-emulsifying property, and emulsion stability are not impaired during the solidification and granulation process. Surfactants used for this purpose include, but are not limited to, nonionic surfactants such as sorbitan alkylate and fatty acid tauride.

The emulsifier is generally about 20 to 100% (the same applies below 2 by weight), preferably 40 to 60% of the mixture of liquid J:4'a or a solid agricultural chemical having a melting point of about 50°C or less and a nonvolatile polyaromatic solvent. It is often %.

Next, the above pesticide + emulsifier + (non-volatile polyaromatic solvent, etc.)
As a carrier for solidifying and granulating a liquid mixture.

Water-soluble organic and inorganic excipients may be mentioned, including water-soluble polymeric compounds, water-soluble inorganic salts, sugars, and urea/thiourea. Examples of water-soluble polymer substances include synthetic polymers such as PVA, CMC, MC, HEC, PEG, polystyrene sulfonate, polyacrylate, and polyvinyl sulfonate, and natural polymers such as gum arabic, xanthan gum, guar gum, locust gum, carrageenan, and starch. Molecules and sugars include glucose,
Examples of water-soluble inorganic salts such as dextrin, sorbitol, and sucrose include ammonium sulfate, mirabilite, sodium phosphate, ammonium phosphate, sodium tripolyphosphate, sodium hexametaphosphate, common salt,
Potassium chloride, ammonium chloride, sodium bicarbonate, etc. can be mentioned, but should not be limited to these compounds.

These excipients should be appropriately selected and blended in consideration of the solidification state with the pesticide, moisture absorption, difficulty of granulation, particle strength, disintegration/solubility in water, emulsification/solubilization state of the pesticide, etc. It is. In particular, the properties of excipients often cause disintegration and solubility of particles in water and deterioration of the emulsified state of pesticides, so care must be taken in their selection and formulation.

Agricultural chemicals to which the present invention is applicable include fungicides, insecticides, herbicides,
It is not limited to plant preparations, etc., but is a pesticide that has a melting point of approximately 50°C or less and is insoluble or poorly soluble in water, and is particularly preferably applied to organophosphorus, synthetic pyrethroid, carbamate, thiocarbamate, etc. There are many cases where

The water-soluble a-drug granules having the above composition can generally be expressed as follows.

(1) Water-insoluble solid agricultural chemicals with a melting point of approximately 50°C or less 1-25% 0-25 0.5-25 Remaining total 100 In actual granulation, first the agricultural chemicals, non-volatile polyaromatic ring solvent and the emulsifier are heated or mixed without heating to form a uniform liquid mixture, and the remaining components and water are added in an amount of 5 to 10% (by weight) based on the other compositions and mixed well,
Enter the granulation process. For granulation, various conventional granulators such as an extrusion granulator (beretter type or basket type), a mixing granulator, a transfer granulator, a fluidized bed granulator, etc. can be used. After drying in a fluidized bed at about 50 to 60°C, the granules are sized or cut and sieved to obtain granules of generally about 0.2 to 3 mm. This granulation process does not require any special method, and conventional granulation machines and methods for agricultural chemical granules may be used.

The granules obtained in this way can be stored for a long period of time at -5°C to 40°C in the same packaging form as general pesticide granules. (2) Non-volatile polyaromatic solvent, etc. (3) Emulsifier (4) It does not deform or break in the presence of a water-soluble excipient, and does not exhibit particularly significant hygroscopicity. In use, the apparent volume can be measured using a cylinder or the like to prepare an aqueous solution for spraying, or it can be applied directly to the field using a granulator or by hand. In water, the granules disintegrate within about 1 to 2 minutes and dissolve to form a slightly cloudy emulsion or an almost transparent solubilized state, emulsifying and dissolving water-insoluble pesticides as fine particles in water. Can be dissolved.

Even in soils with low moisture content, such as upland fields, if particles are directly sprinkled on the topsoil and then plowed or mixed into the soil, they will disintegrate on contact with rainwater, dew, and soil water, and the JI drug will be emulsified or disintegrated in water. It is released in a solubilized state.

In this way, the water-soluble agricultural chemical granules according to the present invention can dissolve water-insoluble agricultural chemicals in water and exert the biological effects of the agricultural chemicals, similar to emulsions.

C Effect] The water-soluble granular composition of a water-insoluble agricultural chemical according to the present invention is prepared by mixing the water-insoluble agricultural chemical with an emulsifier in advance, and then solidifying and granulating this with a water-soluble excipient.

Emulsifiers emulsify or solubilize pesticides in water as the granules disintegrate with water, while organic and inorganic excipients
It solidifies a liquid mixture of agrochemical emulsifiers in the form of a solid solution.

In particular, urea or thiourea has a strong effect of forming inclusion bodies, promoting solidification by water-soluble polymeric substances, and facilitating granulation. Water-soluble excipients such as inorganic salts, sugars, and other paper molecules have the purpose of facilitating the disintegration of the granules in water and promoting the dissolution of agricultural chemicals by the emulsifier. Therefore, it is necessary to select and combine these excipients appropriately from the viewpoint of solidification growth, granulation properties, disintegration/dissolution properties in water, prevention of moisture absorption, particle hardness, etc. In addition, it is usually assumed that the preparation will be stored for a long period of time at a temperature between -5°C to -10°C to 40°C, and even in this case, adhesion between particles and crystallization of excipients and pesticides may occur. Care must also be taken to ensure that the physical properties of the granules do not deteriorate significantly due to deterioration in disintegration and dissolution properties due to granules, caking or insolubilization of granules due to moisture absorption, etc.

The water-soluble granules according to the present invention, like emulsions, can be diluted with water to form a spray solution, or, like granules, can be applied directly. Compared to general granules, which are made by kneading or adsorbing/coating a water-insoluble agricultural chemical with a water-insoluble inorganic mineral carrier, they disintegrate quickly in water and all the granules dissolve. In addition, because pesticides are emulsified or solubilized by emulsifiers and quickly eluted into water, they have a high biological effect in the field, are fast-acting, and can be used in rice fields, fields, non-agricultural lands, etc. It has the following advantages.

Of course, the technology related to the present invention can be similarly applied to water-soluble liquid or solid agricultural chemicals, and the surfactants contained can be anionic and nonionic as well as cationic. The technical contents of the present invention will be explained below by giving Examples and Comparative Examples. [Example] (Example-1) 0.0-dimethyl-〇-4-nitro m-Tolylphosfluoroate (common name: fenitrothion).

After adding and mixing 5 g of emulsifier Tsurupol 355 (registered trademark of Toho Chemical, nonionic surfactant/anionic surfactant combination product) to 1 g (room temperature liquid), add 25 g of powdered urea and 56.6 g of ammonium sulfate. The mixture was added and mixed until it was sufficiently homogeneous. After adding 6 g of 40% aqueous gum arabic solution and mixing again, a basket type extrusion granulator (RG-5M model manufactured by Kikusui Seisakusho, screen pore size 0, 6 m) was added.
), dried in a fluidized bed at 50-55°C for about 2 hours, sized to a length of 1-2M, and fenitrothion 1
92 g of water-soluble granules containing 0% were obtained.

(Example-2) Add 10 g of emulsifier Tsurpol 3080 to 21 g of 0, O-dimethyl-〇-4-methylthio m-tolylphosfluorothioate (generic name: fenthion, liquid at room temperature), mix, and then add 35 g of powdered thiourea and Glauber's salt. 24g and polystyrene sulfone sodium salt (molecular weight 3000) 50
% aqueous solution was added thereto, mixed uniformly, and granulated according to Example 1 to obtain 95 g of water-soluble granules containing 20% of fenthion.

(Example-3) 8 g of phenylxylylethane and 2680.10 g of Trupol were added to 1 g of 0-sec-butylphenylmethyl carbamate (common name BPMC1, melting point 31-32° C.) and mixed by heating to about 50° C.

Add powdered urea at 30℃ and 30g of sodium hexametaphosphate.
, 1 g of dextrin and 7 g of water were added and mixed until homogeneous, and then granulated in the same manner as in Example 1.
95 g of water-soluble granules containing 0% were obtained.

(Example-4) 2-chloro-2',6'-diethyl-N-methoxymethylacetanilide (generic name alachlor, melting point 40~
41°C), 10g of bis(α-methylbenzyl)xylene, and 2,680.8g of Trupol were added, and the mixture was humidified to about 60°C to dissolve and mix.

To this, 30 g of powdered urea, 36 g of CMC and 7 g of water were added and mixed until uniform, and then granulated in the same manner as in Example 1.
92 g of water-soluble granules containing 15% alachlor were obtained.

(Example-5) α-cyano-3-(IR5) cis, trans-3=(2
, 2-dichlorovinyl)-2,2-dimethyl-cyclopropanecarboxylate (generic name Cybermethrin, normal temperature liquid) and 6035 g of Tulpol were mixed, followed by 88.4 g of dextrose, 1 g of gum arabic, and 6 g of water. The mixture was added and mixed until uniform. The mixture was granulated using Example 1 to obtain 95 g of water-soluble granules containing 5% Cypermethrin.

(Comparative Example-1) 355.8 g of Tsurpol was added to 21 g of 0,O-dimethyl-0,4-nitro-m-tolylphosfluorothioate (common name: fenitrothion, liquid at room temperature), mixed well, and then stirred vigorously. 71 g of powdered urea was gradually added and mixed to obtain a homogeneous slurry. After leaving it at room temperature and starting to solidify,
When the condition was suitable for granulation (about 2 hours later), granulation was carried out as in Example 1, and solidification was completed by standing at room temperature for 24 hours. Thereafter, the particles were sized to obtain 98 g of granules containing 20% fenitrothion.

(Comparative Example-2) 0, O-dimethyl 0.4-methylthio-m-tolylphosfluorothioate (generic name: fenthion, liquid at room temperature)
After heating and mixing 79 g of polyoxyethylene-polyoxybrobylene block polymer (containing 70% polyethylene oxide, molecular weight 11,000) to 21 g at about 50°C, the mixture was granulated and solidified according to Comparative Example 1. Ta. Granules containing 20 g of fenthion 98. I got g.

(Comparative Example-3) S-1,2-bis(ethoxycarbonyl)ethyl-〇,
To 11 g of 0-dimethylphospho-dithioate (general name Marathon, liquid at room temperature), 60 g of polyethylene glycol (molecular weight 11,000), polyoxyethylene-polyoxypropylene block polymer (polyethylene oxide 8 g)
0% content, molecular 18000) was added, heated to about 70'C and mixed, and then granulated and solidified in accordance with Comparative Example 1 to obtain 97g of granules containing 10% Marathon.

(Comparative Example-4) 11 g of 0-see-butylphenylmethyl carbamate (common name BPMC, melting point 31-32°C), 5 g of polyoxyethylene (10 mol) dilaurate, and Trupol 5M
-1oss, 5g and 79g of powdered urea were heated to 80°C and mixed, granulated and solidified according to Comparative Example 1, and BPM
98 g of granules containing 10% C were obtained.6 [Efficacy test method table (1) Measurement of disintegration/dissolution time Petri dish (diameter 9 an, depth 2 an) filled with test water of 3 degree hard water (25°C) Five sample water-soluble granules were placed on a plate, and the time required for each granule to almost completely disintegrate and dissolve was visually measured, and the average disintegration/dissolution time (seconds) was calculated.

(2) Measurement of emulsification state and average particles 10g of water-soluble granules was placed in a 500mQ stoppered cylinder filled with 3 degree hard water (25℃). After each granule disintegrated and dissolved, the cylinder was inverted 10 times to ensure uniform distribution. Make a solution. The dissolution state was visually observed.
omQ was diluted in physiological saline (0° 90% W/V NacQ solution), and the particle size distribution was measured using a Coulter Counter (manufactured by Nikkaki, Model ZB), and the average particle size was calculated.

(3) Emulsion Stability Test The 500 mQ cylinder from (2) above was left at 25° C. for 24 hours, and separation and sedimentation of emulsified particles and separation of an oil layer were visually observed.

(4) Granule aging test 30g of each sample of water-soluble granules were placed in a 100ml (1 narrow polyethylene bottle, tightly stoppered, stored at -5℃ and 40℃ for 60 days, left at room temperature for 1 day, Tests (1) to (3) above were conducted.

The results are summarized in a table and show that each example had good particle properties, disintegration/dissolution properties, and emulsion stability, and was sufficiently usable.

Claims (1)

[Claims] 1 to 25% (by weight,
(same below), 0-25% non-volatile polyaromatic solvent, 0.5-25% emulsifier consisting of a nonionic surfactant and anionic surfactant, the balance being urea, thiourea, water-soluble polymeric substance, A water-soluble agricultural chemical granule composition comprising a water-soluble excipient that is one or a mixture of two or more of sugars and water-soluble inorganic salts.