JPH0714841B2 - Dispersant composition for pesticide wettable powder - Google Patents

Description

Detailed Description of the Invention [Industrial applications]

TECHNICAL FIELD The present invention relates to a dispersant composition for granular wettable powders of agricultural chemicals which is easily soluble in water.

[Prior art and its problems]

(Prior Art) Pesticide wettable powders are mainly composed of pesticide active ingredients, clay mineral substances such as montmorillonite, and surfactants. They are easy to handle and cannot be emulsified because there is no suitable solvent. It is widely used today because it has the advantage that it can be used as a pesticide raw material that cannot be fluidized due to body or crystal precipitation over time. In the above, when an anionic surfactant such as a formalin condensate of naphthalenesulfonic acid sodium salt, an alkylbenzenesulfonic acid sodium salt, or a higher alcohol sulfate sodium salt is used as the dispersant, the melting point of the surfactant is high. Therefore, it can be easily pulverized by adding a water-soluble inorganic salt such as Glauber's salt and ammonium sulfate. However, nonionic surfactants (eg, polyoxyethylene alkylaryl ethers, polyoxyethylene / polyoxypropylene block polymers, etc.) and anionic surfactants (eg, polyoxyethylene alkylaryl ethers) commonly used as dispersants for wettable powders are used. In order to powder sulfuric acid ammonium salt of oxyethylene alkyl aryl ether, phosphoric acid ester of polyoxyethylene alkyl ether, etc.), hydrated silicic acid (Si
O ₂ · nH ₂ O; usually called <white carbon> or <silica>) is used. (Problems with conventional technology) By the way, hydrous silicate has an excellent oil absorption capacity, but it does not dissolve in water itself, so when a powdered product with a surfactant adsorbed to it is put into water, Eluted surfactant stays at 30-60% at best. Therefore, when using a nonionic surfactant or anionic surfactant as a dispersant for wettable powders, in order to expect sufficient dispersibility, the adsorbed amount should be taken into consideration when adding more than the required amount of active agent. This caused a rise in prices.

[Object of the Invention]

The present invention, by selecting a starch hydrolyzate that has never been used as a carrier for agricultural chemical wettable powders,
It is an object of the present invention to provide a novel dispersant composition for wettable pesticides that eliminates the drawbacks of conventional hydrous silicates.

[Means for achieving the purpose]

(Summary) In order to achieve the above object, the dispersant composition for agricultural chemical wettable powders according to the present invention has a surfactant, which is spray-dried or drum-dried.
It is characterized in that it is adsorbed to a drier-dried granular starch hydrolyzate and a starch hydrolyzate having a dextrose equivalent (DE) of 30 or less. Hereinafter, various elements constituting the invention will be described. (Starch hydrolyzate) The starch hydrolyzate used in the present invention is potato,
It can be obtained by subjecting starch obtained from sweet corn, wheat or the like to a low molecular weight by a usual method, for example, enzymatic decomposition or acid decomposition, and then drying it with a spray dryer or a drum dryer. To describe a specific method, for example, 100 parts of water and 30 parts of starch are added to a reaction kettle, powdered α-amylase is added thereto, and the temperature is maintained at 50 ° C. with stirring,
When the desired hydrolyzate of DE is obtained, caustic soda is added to inactivate α-amylase, and the mixture is neutralized with an acid to obtain a slurry hydrolyzed starch solution. For the purpose of the invention, the dextrose equivalent (DE) of the starch hydrolyzate is 30 or less. Then, the slurry of the above hydrolyzate is sprayed or drum-dried at an ambient temperature of approximately 80 ° C to 15 ° C.
By drying at 0 ° C., a granular starch hydrolyzate having a content of 30% or more through an 80-mesh screen suitable for carrying out the present invention is obtained. (Surfactant) Examples of the surfactant used in the present invention include nonionic interfaces such as polyoxyethylene alkyl ether, polyoxyalkyl aryl ether, polyoxyethylene / polyoxypropylene block polymer, and polyoxyalkylene fatty acid ester. Activator, polyoxyalkyl ether sulfate, polyoxyalkylaryl ether sulfate, alkyl sulfate, polyoxyalkyl ether phosphate, polyoxyalkylaryl ether phosphate, dialkylsulfosuccinate, etc. Examples thereof include anionic surfactants, but of course, the examples are not limited to the examples. In addition, these surfactants can be used individually or in mixture of 2 or more types. (Method for preparing dispersant for agricultural chemical wettable powder) To prepare the dispersant for agricultural chemical wettable powder of the present invention, for example,
The granular starch hydrolyzate is placed in a ribbon mixer or a Nauta mixer, and the surfactant is injected while stirring to mix uniformly. At this time, you may heat at 50-80 degreeC as needed. (Other Additives) In the present invention, if necessary, Glauber's salt, ammonium sulfate, ammonium chloride, glucose, urea or the like can be added as a fluidity improver.

[Action]

The coarse-grained starch hydrolyzate used in the present invention has a large specific surface area and does not inhibit the fluidity of the composition (agrochemical wettable powder) by adsorbing a large amount of a surfactant. When the pesticide wettable powder containing the composition of the present invention is added to water, the starch hydrolyzate itself is dissolved in water, so the surfactant adsorbed to the hydrolyzate is completely dissolved in water, Fully effective. In addition, since the lysate has an appropriate viscosity derived from the starch hydrolyzate and has the effect of adhering to the target plant, the effect of the pesticide can be maximized.

【Example】

Hereinafter, the embodiments and effects of the present invention will be described in detail with reference to Experimental Examples and Comparative Examples, but the idea of the present invention is not limited by these exemplifications. Experimental Example-1 Various DEs were prepared by using Hitenol NF-13 (trade name of sulfuric acid ester ammonium salt of polyoxyethylene alkylaryl ether manufactured by the applicant company) which is a dispersant for wettable powders.
The adsorptive ability of the starch hydrolyzate having γ was measured. The term "adsorption capacity" as used herein means the amount of Hitenol NF-13 adsorbed until the fluidity of the starch hydrolyzate disappears. Experimental Example-2 Carplex ^# 80 (trade name of hydrous silicic acid manufactured by Shionogi Pharmaceutical Co., Ltd.) was adsorbed to 100 parts of Hitenol NF-13, and the solubility of Hitenol NF-13 in water was dissolved. Was compared with Sample No. 7 in Table-1. The results are shown in Table 2 below. <Measurement method> Weigh 5 g of the above sample into a 100 ml beaker, add 95 g of water, and stir with a stirrer. Use a glass filter (3G-4) every measurement time,
The supernatant is suction filtered. Glass filter at 105 ℃
After drying for 1 hour, the water-insoluble matter is obtained. Examples and Comparative Examples NAC (1-naphthyl-N-methylcarbamate) wettable powders shown below were prepared, and Sample No. 7 and Carplex ^# 80 in Table 1 were added to 100 parts of Hitenol NF-13 100 parts. A comparative test of the dispersant adsorbed with was conducted. The results are shown in Table 3 below. 1) Compounding formulation NAC drug substance 50 Dikelite C 35 Radiolite 200 15-x Dispersant x 100 2) Sample preparation method Mixing for 2 hours with a ball mill, 80 mesh all through. 3) Test method (1) Hydration property According to the official test method for agricultural chemicals (5 ° hard water is used). (2) Suspension rate Take 0.5g sample into a beaker, disperse well with a small amount of water, transfer to a 250ml graduated cylinder (inner diameter 3.8cmφ), make 250ml with 5 ° hard water (water temperature 20 ° C), and invert up and down 30 times. To do. 3
After standing for 0 minutes, the top 225 ml is extracted, the remaining 25 ml is filtered with a glass filter (3G-4), dried, and the suspension rate is calculated by the following formula. In view of the suspension ratio in Table 3 above, it is clear that the conventional dispersant must be added at 5%, but the addition of 1 to 2% is sufficient for the product of the present invention.

【The invention's effect】

As described above, according to the present invention, by selecting a starch hydrolyzate that has never been used as a carrier for pesticide wettable powder, a new economical solution that overcomes the drawbacks of conventional hydrous silicates. By providing the dispersant composition for agricultural chemical wettable powder, it can contribute to agriculture and horticulture and related industries.

Claims (5)

[Claims] 1. A dispersant composition for agricultural chemical wettable powders, characterized in that a surfactant is adsorbed to a starch hydrolyzate having a granular dextrose equivalent (DE) of 30 or less. 2. The dispersant composition for agricultural chemical wettable powders according to claim 1, wherein the granular starch hydrolyzate contains 30% or more of granules of 80 mesh or more. 3. A dispersant composition for agricultural chemical wettable powders according to claim 1 or 2, which contains 50 to 120 parts by weight of a surfactant based on 100 parts by weight of a granular starch hydrolyzate. object. 4. The dispersant composition for agricultural chemical wettable powder according to any one of claims 1 to 3, wherein the granular starch hydrolyzate is obtained by spray-drying a starch hydrolyzate. . 5. The dispersant for agricultural chemical wettable powders according to any one of claims 1 to 3, wherein the granular starch hydrolyzate is a starch hydrolyzate dried by a drum dryer. Composition.