JPS644484B2 - - Google Patents

Description

[Detailed description of the invention]

[Object of the Invention] The present invention relates to a method for producing coated agricultural and horticultural granules. [Prior Art] In recent years, the use of granular formulations has rapidly increased as a method of spraying agricultural chemicals from the viewpoints of preventing environmental pollution due to drift, applying the entire amount to the desired field, saving labor in spraying, and preventing harm to the sprayer. ing. The manufacturing methods for agricultural and horticultural granules currently in use can be roughly divided into three types: kneading method, adsorption method, and coating method.
However, each method also has drawbacks. First, regarding the "kneading method": This method is the mainstream method for producing granules, but it requires a drying step after granulation, and is not suitable for active ingredients that are unstable to heat or active ingredients that are highly toxic and easily volatilized. do not have. Regarding the "adsorption method": The suitability of this method depends on the physical properties of the active ingredient. For example, in the case of a solid active ingredient, it must be dissolved in a high-boiling point solvent or dissolved in a low-boiling point solvent and adsorbed, and then the solvent must be recovered, which increases the cost. Not suitable for active ingredients. Compared to these methods, the "coating method" involves adhering and coating the active ingredient onto a granular carrier using a binder or the like, and is relatively inexpensive in terms of cost. However, conventional coating methods use polyethylene glycol,
Polypropylene glycol (Special Publication No. 40-8920),
The active ingredient is simply attached to the granular carrier due to the viscosity of the binder such as polybutene (Japanese Patent Publication No. 47-1240), and the active ingredient is more easily peeled off from the granular carrier during storage, transportation, and spraying. It loses its original characteristics and lacks safety. To avoid this peeling, polyvinyl alcohol
24660), gum arabic (Special Publication No. 28699, Showa 42)
However, in these cases, since they are used as an aqueous solution or dissolved in an organic solvent, a drying step or a solvent recovery step is required, and they are subject to the same restrictions as the kneading method. In order to solve these problems, methods using various resins have been studied, but a method for producing coated granules that is practically satisfactory has not yet been completed. When a resin is used, workability during production is poor and it is difficult to obtain coated granules with uniformity. Furthermore, prevention of peeling of the active ingredient and prevention of solidification (agglomeration) during storage are contradictory, and it has not been possible to obtain a formulation that satisfies both. The present invention was completed as a result of intensive research aimed at solving various problems of conventional methods for coating granular carriers with agricultural chemical active ingredients. [Configuration of the Invention] The present invention provides a method for coating a particulate carrier with an agrochemical active ingredient using an organic isocyanate and the general formula: RO(CH ₂ CH ₂ O) _o CONHX [wherein R is an alkyl group having 1 to 4 carbon atoms]. , n is an integer from 1 to 120, and X is a di- or poly-containing group containing at least one free isocyanato group.
Shows isocyanate residues. ] A water-emulsifiable isocyanate compound containing a nonionic surfactant represented by the above and water or a low-viscosity hydroxyl group-containing liquid compound are used, and if necessary, a physical property improver,
This is achieved by adding auxiliary agents such as stabilizers, colorants, or surfactants. The following method can be adopted as the manufacturing method of the present invention. (1) Put the granular carrier into a mixer, add a small amount of water and/or a low viscosity hydroxyl group-containing liquid compound, such as methanol, ethanol, polyethylene glycol or polypropylene glycol, etc. while mixing and homogenize it, and then Add a fixed amount of water-emulsified isocyanate compound and mix thoroughly until uniform. Further, agrochemical active ingredients and, if necessary, auxiliary agents are added and mixed. (2) A water emulsified isocyanate compound and water or a hydroxyl group-containing liquid compound are placed in a small container, mixed in advance, and added to the granular carrier in a mixer while being mixed. After thoroughly mixing until homogeneous, agrochemically active ingredients and, if necessary, auxiliary agents are added and further mixed. Conventional equipment, mixing methods, etc. can be used in this method. Next, the water-emulsifiable isocyanate compound, granular carrier, and agrochemical active ingredient used in the present invention will be explained. (1) Water emulsion type isocyanate compound Consists of organic isocyanate and nonionic surfactant. (a) Organic isocyanate: Any organic isocyanate can be used in the present invention, but organic isocyanates having a large number of isocyanate groups are particularly valuable. As illustrated below, they may be used alone or in a mixture of two or more. Aliphatic isocyanates such as hexamethylene diisocyanate; m-phenylene diisocyanate, p-phenylene diisocyanate, tolylene-2,4-diisocyanate,
Tolylene-2,6-diisocyanate, diphenylmethane-4,4'-diisocyanate,
Chlorphenylene-2,4-diisocyanate, naphthalene-1,5-diisocyanate, diphenyl-4,4'-diisocyanate, 4,4'-diisocyanato-3,3'-dimethyldiphenyl, 3-methyl-diphenylmethane-4,4 Aromatic isocyanates such as '-diisocyanate and diphenyl ether diisocyanate; cyclohexane-2,4-
Diisocyanate, cyclohexane-2,3
-Diisocyanate, 1-methylcyclohexyl-2,4-diisocyanate, 1-methylcyclohexyl-2,6-diisocyanate, bis(isocyanatocyclohexyl)-
Cycloaliphatic diisocyanates such as methane; 2,
4,6-triisocyanatotoluene, 2,
Triisocyanates such as 4,4'-triisocyanat diphenyl ether; general formula A methylene-crosslinked polyphenylene polyisocyanate produced by phosgenating a corresponding mixture of polyamines represented by the formula (wherein n represents an integer of 1 or more) obtained by condensation of aniline and formaldehyde. Included, but preferably,
aromatic diisocyanates or highly functional polyisocyanates, especially diisocyanates,
A crude mixture of methylene crosslinked polyphenylene polyisocyanates containing triisocyanates and highly functional polyisocyanates. (b) Nonionic surfactant General formula: RO(CH ₂ CH ₂ O) _o CONHX (wherein, R represents an alkyl group having 1 to 4 carbon atoms, and is particularly preferably a methyl group. n is It represents an integer of 1 to 120, preferably in the range of 5 to 25.
represents a polyisocyanate residue having isocyanate groups, and the organic isocyanate described above,
For example, it may be a residue of diisocyanate, triisocyanate, or polyisocyanate. In the case of tolylene diisocyanate, X is

〔Effect of the invention〕

According to the present invention, since heating is not required in the manufacturing process, it can be applied to active ingredients that are unstable to heat and volatile active ingredients that are weak in toxicity, and of course, there is no need for heat treatment equipment, which is advantageous in terms of cost. It is. By reacting a water-emulsifiable isocyanate compound with water or a low-viscosity hydroxyl group-containing liquid compound to form polyurethane and firmly adhering the agricultural chemical active ingredient to the granular carrier, the active ingredient can be peeled off from the granular carrier during storage, transportation, and spraying. There is no scattering, which prevents harm to workers and environmental pollution. Furthermore, because the coating is uniform, there is no solidification (agglomeration) during storage, and the granules have physical properties suitable for agricultural and horticultural granules. Further, according to the present invention, it has the advantage that it becomes a long-lasting granule with controlled elution of the active ingredient, and that it is less likely to adhere to plants, thereby reducing contact damage. Next, the effects of the present invention will be explained with reference to test examples.
The following drugs were manufactured and used in the test for comparison. Reference example 1 Silica sand (particle size 16-42 mesh) (93 parts) was put into a mixer, and while mixing, polybutene (average molecular weight
310) (2 parts). After thorough mixing, bendiocarb (5 parts) is added and mixed to obtain coated granules. Reference example 2 Silica sand (particle size 16-42 mesh) (90 parts) was put into a mixer, and while mixing, polybutene (average molecular weight
310) (2 parts). After mixing thoroughly, add white carbon (3 parts) and bendiocarb (5 parts).
part) is added and mixed to obtain coated granules. Reference Example 3 Silica sand (particle size 16-42 mesh) (93 parts) is placed in a mixer, and while mixing, polyethylene glycol (average molecular weight 200) (2 parts) is added. After thorough mixing, bendiocarb (5 parts) is added and mixed to obtain coated granules. Reference Example 4 Silica sand (particle size 16-42 mesh) (95.7 parts) is put into a mixer, and while mixing, acrylic polyol (described later) (1.2 parts) is added. After thorough mixing, diphenylmethane-4,4'-diisocyanate (0.1 part) is added. After thorough mixing, carbosulfan (3 parts) is added and mixed to obtain coated granules. The acrylic polyol used in this example has the formula It is a polymer of acrylic ester shown by (polymerization degree is 4 to 20, molecular weight is 500 to 2,400, and hydroxyl value is 24). Reference example 5 Calcium carbonate (particle size 65-250 mesh) (97.5
part) into a mixer, and while mixing, add polypropylene glycol (average molecular weight 1000) (0.5 part). After thorough mixing, add diphenyl ether diisocyanate (0.5 part). After thorough mixing, methomyl (1.5 parts) is added and mixed to obtain coated granules. Reference Example 6 Silica sand (particle size 16-42 mesh) (91.55 parts) is placed in a mixer, and water (1.0 part) is added while mixing. After thorough mixing, a crude mixture of methylene-crosslinked polyphenylene polyisocyanate (containing 30% isocyanate groups) (1.2 parts) is added. After thorough mixing, a premixed mixture of CVMP (80 parts) and clay (20 parts) (6.25 parts) is added and mixed to obtain coated granules. Reference Example 7 Clay (93 parts), bendiocarb (5 parts), and sodium lignosulfonate (2 parts) are mixed, water is added, and the mixture is granulated using a granulator to obtain granules. Test Example 1 (Peeling Test of Pesticide Active Ingredients) The measuring device shown in Figure 1 was used. Weigh 10 g of the sample and transfer it into a glass filter (11-G-2). After averaging the sample, open the valve and increase the air flow to 30
Aerate for exactly 2 minutes at a rate of /min. The sample remaining in the glass filter is collected and the active ingredient content (%) is measured, which is defined as the active ingredient content (%) after peeling. The peeling rate (%) was determined by comparison with the active ingredient content (%) before peeling. Results first
Shown in the table. Peeling rate = Active ingredient content before peeling - Active ingredient content after peeling / Active ingredient content before peeling x 100

【table】

【table】

[Table] Test example 2 (Pressure storage test = solidification test) Approximately 100 g of sample was placed on a glass plate with a diameter of 5 cm.
Place it in a cylindrical iron container (bottomless) and pressurize it with iron weights to make it 25g/cm ² . After storing this in a constant temperature bath at 50℃ for 2 days, it was left at room temperature for 1 day.
Remove the cylindrical container and observe the solidification state. Table 2 shows the results based on the following criteria. Judgment criteria -: Good fluidity without solidification. +: Agglomeration is observed in some parts. : Agglomeration is observed throughout and fluidity is lost.

【table】

【table】

[Table] Test Example 3 (Residual efficacy test using rice weevil larvae) Using a Wagner pot of 1/5000 are,
On a given day, 5 rice plants at the 2.5 leaf stage were each treated with a given amount of granules at the base of each plant and transplanted. After transplanting, the pots were stored in a covered field with a water depth of 3 cm.
For inoculation of larvae, adult larvae were spawned in advance in a container in a greenhouse and reared while supplemented with rice. Ten animals of each type were released per pot. In the investigation, one week after inoculating the larvae, the roots of the rice plants were washed with water and the number of larvae was determined. The results are shown in Table 3.

[Table] For example, the data on the 21st day in the table indicates that larvae were inoculated on the 21st day after the drug treatment, and the number of larvae was examined one week later. From the above results, it can be seen that the granules of the present invention are superior in residual effect compared to the reference examples. Test example 4 (Pyrotoxicity test on rice) 20× filled with Pearl Mats No. 1 as the soil
A 3000-fold diluted solution of Kumiten (spreading agent manufactured by Kumiai Chemical Industry Co., Ltd.) was sufficiently sprayed on the leaf surfaces of rice plants (variety: Haremoe) at the 2.5 leaf stage in a 28.5 x 3 cm plastic seedling box. Then process the granules 100 and 15
After a few minutes, the granules were shaken off and 200 ml of water was sprinkled from the top. After 2 to 3 hours, cut the rice seedlings in the nursery box using a rice transplanter, and divide 5 rice plants into 10×
Transplanted into a 10cm square plastic pot. The test was conducted in a greenhouse, and chemical damage and plant height were investigated on a designated day after transplantation. The results are shown in Table 4. Chemical damage determination criteria -: Harmless: Moderate damage +: Slight damage: Severe damage: Light damage 〓〓: Withering

〔Example〕

The present invention will be explained in more detail by showing examples below. In addition, all parts or % in the examples indicate parts by weight or % by weight. Example 1 Silica sand (particle size 16-42 mesh) (93.4 parts) is placed in a mixer, and water (0.7 parts) is added while mixing. After thorough mixing, water emulsion type isocyanate compound A (0.9 parts) described later is added. After thorough mixing, bendiocarb (5 parts) is added and mixed to obtain coated granules. Example 2 Calcium carbonate (particle size 65-250 mesh)
(97.6 parts) into a mixer, and while mixing, polyethylene glycol (average molecular weight 200) (0.4 parts)
Add. After thorough mixing, water emulsion type isocyanate compound B (0.5 part), which will be described later, is added. After thorough mixing, methomyl (1.5 parts) is added and mixed to obtain coated granules. Example 3 Silica sand (particle size 16 to 32 mesh) (94.4 parts) was put into a mixer, and while mixing, water (0.7 parts) previously mixed in a small container and water emulsified isocyanate compound C (0.9 parts) described below were added. Added. After thorough mixing, diazinon (3 parts) and methomyl (1 part) are added and mixed to obtain coated granules. Example 4 Urea (particle size 65-250 mesh) (95.7 parts) is placed in a mixer, and while mixing, polyethylene glycol (average molecular weight 200) (0.6 parts) is added. After thorough mixing, water emulsion type isocyanate compound C (0.7 parts) described later is added. After thorough mixing, carbosulfan (3 parts) is added and mixed to obtain coated granules. Example 5 Put silica sand (particle size 16-42 mesh (91.55 parts) into a mixer, and add water (1.0 parts) while mixing. After thorough mixing, add water emulsion type isocyanate compound D (1.2 parts) described below. After mixing thoroughly, a premixed mixture of CVMP (80 parts) and clay (20 parts) (6.25 parts) is added and mixed to obtain coated granules. Example 6 Silica sand (particle size 65~ 250 mesh) (90.3 parts) into a mixer, and while mixing, add water (1.3 parts) previously mixed in a small container and water emulsion type isocyanate compound B (1.4 parts) described below.After mixing thoroughly, put into a bender. Iocarb (5 parts) and tricyclazole (2 parts)
part) is added and mixed to form coated granules. Example 7 Calcium carbonate (particle size 16-32 mesh)
(93.4 parts) into a mixer, and while mixing, add water (0.3 parts) and polypropylene glycol (average molecular weight 1000) (0.4 parts). After thoroughly mixing, add water emulsion type isocyanate compound E (0.9
part). After further mixing thoroughly, naproanilide (2 parts), CNP (1 part), sodium ligninsulfonate (1 part) and colorant (1 part) were added.
Mix to obtain coated granules. Example 8 Silica sand (particle size 65-250 mesh) (97 parts) is placed in a mixer, and while mixing, water (0.4 parts) is added. After thorough mixing, water emulsion type isocyanate compound F (0.6 part), which will be described later, is added. Furthermore, after thorough mixing, MPMC (2 parts) is added and mixed to obtain coated granules. Example 9 Granulation base (particle size 16-32 mesh) (92.3 parts) was put into a mixer, and while mixing, water (1.3 parts) previously mixed in a small container was added to water emulsion type isocyanate compound G (1.4 parts) described below. part). After thorough mixing, MIPC (5 parts) is added and mixed to obtain coated granules. Example 10 Silica sand (particle size 65 to 250 mesh) (94.6 parts) was put into a mixer, and while mixing, water (0.5 parts), which had been mixed in advance in a small container, and water emulsion type isocyanate compound H (0.7 parts) described below were added. Added. After thorough mixing, 4 parts of MAF (10 parts) and clay (90 parts) were added and mixed, and after further mixing, polypropylene glycol (average molecular weight
1000) (0.2 parts) to obtain coated granules. Next, Table 5 shows the water emulsion type isocyanate compounds used in the above examples. The nonionic surfactant is represented by the above-mentioned general formula.

【table】 [Brief explanation of the drawing]

FIG. 1 shows the measuring device used in Test Example 1. In the figure, 1 is a sample, 2 is a glass filter, 3 is a flow meter, 4 is a valve, and 5 is a compressor.

Claims (1)

[Scope of Claims] 1. Organic isocyanate and general formula: RO(CH ₂ CH ₂ O) _o CONHX [wherein R is an alkyl group having 1 to 4 carbon atoms] , n is an integer from 1 to 120, and X is a di- or poly-containing group containing at least one free isocyanato group.
Shows isocyanate residues. A method for producing coated agricultural and horticultural granules, which comprises using a water-emulsifiable isocyanate compound containing a nonionic surfactant represented by the following.