JPH0262801A - Suspension-like agricultural chemical formulation - Google Patents

Abstract

PURPOSE:To provide a suspension-like agricultural chemical formulation inhibiting the separative precipitation of the suspension solution and the enlarging growth of the dispersed particles and having excellent storage stability for a long period even under high temperature by adding an extremely small amount of rhamsan gum to a suspension formulation simultaneously using a surfactant having a dispersing effect. CONSTITUTION:An extremely small amount, preferably 0.02-0.1%, of rhamsan gum (namely, a natural gum which is fermented polysaccharide) is added (whereby the formulation exhibits a remarkable thixotropic property and a dispersion effect to effect the suspensory stability of the formulation) to a water- insoluble or-slightly soluble agricultural chemical technical product simultaneously using water as a dispersing medium and a surfactant (e.g., one or more of lignin sulfonate salts, polyoxyethylenealkyl allyl ether, etc.), as a suspension stabilizer to provided a suspension-like agricultural chemical formulation having excellent suspensory stability and flowability.

Description

[Detailed description of the invention] [Industrial use ￥f]

The present invention relates to a suspended agricultural chemical formulation with excellent suspension stability and fluidity.

[Conventional technology]

Conventionally, agricultural chemicals have been formulated and used in the form of powders, emulsions, wettable powders, and the like. However, it also has many drawbacks.6 For example, when powder is sprayed, the powder scatters, creating a public and nuisance problem. Emulsions use large amounts of organic solvents, which goes against resource conservation. In addition, with regard to hydrating powders, the powder scatters when diluted with water, which poses a problem in terms of worker safety. Therefore, suspension preparations (flowable preparations) have been developed as a dosage form to improve these drawbacks. Suspension preparations are generally stabilized preparations for emergency use by blending finely ground agricultural chemical ingredients with surfactants, water-soluble polymers, and the like. When used, it is easily dispersed in water like an emulsion, making it easy to prepare a spray solution, making it suitable for aerial spraying, and expected to have the same medicinal efficacy as an emulsion. In addition, since it contains almost no organic solvent, it is a dosage form that has the advantage of not having the problem of drug damage caused by solvents compared to emulsions, and is also safe in terms of manufacturing, storage, and transportation. However, on the other hand, when stored for a long time, separation and sedimentation occur.
The settled particles become a hard sedimentary layer at the bottom of the container, forming a so-called hard caking layer, which lacks redispersion and fluidity.
This is the biggest problem in commercialization, and there is currently only one suspension preparation that has good storage stability. Various methods have been attempted to stabilize the active substance in suspension, one of which is to use a combination of a surfactant with a dispersing effect and a water-soluble polymer compound as a protective colloid to stabilize the system. It is well known that there is a method of appropriately increasing the viscosity to prevent separation and sedimentation of dispersed particles, and this method is widely used in practice. Conventionally commonly used water-soluble polymer compounds include xanthan gum, gum arabic, sodium alginate,
Examples include tragacanth, dextrin, gelatin, casein, glue, carboxymethylcellulose, polyvinyl alcohol, polyvinylpyrrolidone, soluble starch, sodium polyacrylate, maleic anhydride-styrene copolymer, maleic anhydride-isobutylene copolymer, and the like.

[Problem to be solved by the invention]

However, when these are used in agrochemical suspension formulations, although they have some effect on the stability of the suspension, they also have problems with long-term storage stability and separation when stored under high temperature (40°C) conditions. The results were not completely satisfactory, as no effect was observed in suppressing sedimentation, and the enlarged dispersed particles settled and formed a hard caking layer that was difficult to redisperse, making them unusable.

[Means to solve the problem]

As a result of intensive research to solve the above-mentioned problems, the present inventors have found that by adding a minimal amount of Ramsan gum in combination with a surfactant that has a dispersing effect to a suspension preparation, the suspension can be separated and sedimented. , suppressing the hypertrophic growth of dispersed particles, and high temperature (40℃)
It has been found that a pesticide suspension formulation with excellent long-term storage stability can be obtained even under various conditions. In the present invention, the ramsan gum used is a fermented polysaccharide, and is produced by microorganisms Alcaligeness species,
ATCC 31961 (American
Type Culture C. 11ecLion (registered at 11ecLion) is a natural gum substance made by fermenting glucose and accumulating the polysaccharide outside the bacterial cells, which is purified and powdered. Its chemical structure is as shown below, the main chain is composed of two glucoses, one each of glucuronic acid and 11-nose, and the side chain is composed of two glucoses. Ramzan gum exhibits remarkable chicken tropism and is effective in stabilizing the suspension when added in a very small amount to pesticide suspension preparations, and the amount added is between 0.02 and 0.5.
Z is preferably added from 0.02 to 0, 1z is effective, but if it is less than 0.02 t, sufficient effect cannot be obtained.
If it exceeds 0.5z, the viscosity of the preparation increases rapidly, making it difficult to handle and thus uneconomical. In carrying out the present invention, there is no problem in using other thickeners such as water-soluble polymers. Next, the surfactants used in the present invention include lignin sulfonate, alkylaryl sulfonate, dialkyl sulfosuccinate, polyoxyethylene alkyl allyl phosphate, polyoxyethylene alkyl allyl ether sulfate, alkylnaphthalene sulfone salt resistant, Anionic surfactants such as polyoxyethylene styrylphenyl ether sulfevi, polyoxyethylene alkyl allyl ether, polyoxyethylene styrylphenyl ether, polyoxyethylene alkyl ether, polyoxyethylene alkyl ester, polyoxyethylene sorbitan alkyl ether Nonionic surfactants include, but are not limited to, polyoxyalkylene glycol, polyoxyethylene styrylphenyl ether polymer, and the like. These may be used alone or in combination of two or more.

[Effect]

Ramsan gum, which is a substance constituting the agrochemical formulation of the present invention, has chicken-tropic properties and dispersion effects, and is thought to exhibit excellent FJTI4 stabilization and fluidity due to this.

【Example】

The present invention will be specifically explained with reference to Examples.
The invention is not limited to these examples. All parts and percentages herein are by weight. The suspension pesticide formulation can be obtained using the following formulation and manufacturing method. Mixing recipe Sulfur 50% Ethylene glycol 8% Surfactant 3% 100% 100 parts of the above mixture in a 5001 beaker, 0.8 m
Add 200 parts of Otori Glass Peas and stir and mix at 2000 rps for 1 hour using Homo Disper (manufactured by Nippon Tokushu Kika Co., Ltd.). Then add a predetermined amount of water-soluble polymer to 200
0rpo+X Stir and mix for 1 minute. Thereafter, the glass peas are removed by filtration to obtain a suspended agricultural chemical formulation. Next, examples will be described in which the surfactant and water-soluble polymer in the above formulation are variously changed. Table 1 shows the suspension stability of agrochemical formulations when polyoxyethylene distyrenated phenol ether is used as a surfactant. The stability of the formulation was evaluated by the following method. 20 ml of the suspended single-drug preparation was added to a stoppered test tube of No. 251 and left as it was, and the stability over time at 10°C x 1 month and 40°C x 1 month was calculated and quantified using the following formula. The larger the number, the worse the stability. Table 2 shows the suspension stability of agricultural chemical formulations using polyoxyethylene distyrenated phenol ether sulfate ammonium salt as a surfactant. -゛3 and 7-9 Table 3 shows the suspension stability of agricultural chemical formulations when polyoxyethylene distyrenated phenol ether phosphate was used as a surfactant. (Left below) From the results shown in Table 1 and Table 3, it is clear that when Ramsan gum is used as a water-soluble polymer, it has good fluidity due to its low viscosity, and also has good suspension stability. be.

【Effect of the invention】

Suspension II with excellent suspension stability and fluidity according to the present invention
1 drug is obtained. Patent Applicant: Table 2 - Kogyo Seiyaku Co., Ltd.

Claims (1)

[Claims] 1. A suspended agricultural chemical formulation comprising a surfactant and rhamsan gum for stabilizing the suspension of agricultural chemical ingredients that are insoluble or poorly soluble in water using water as a dispersion medium.