JPS6261901A - Coated agricultural chemical - Google Patents

Abstract

PURPOSE:To provide a coated agricultural chemical composed of a core material containing agricultural chemical and a plurality of specific coating layers cover ing said core material, effective to inhibit the dissipation of the agricultural chemical for certain period after application under a condition contacting with water and dissipating the agricultural chemical at a prescribed rate after the lapse of a certain period. CONSTITUTION:A core material consisting of an agricultural chemical such bas insecticide, pheromone, miticide, fungicide, herbicide, plant-growth promoter, etc., or a mixture of the agricultural chemical and proper polymer, inorganic particle, etc., is coated with a polyvinyl alochol layer compounded with an acid or alkali and the layer is further coated with a polyester layer containing sulfonic acid base. The order of the coating layers may be reversed. The application of the layers to the core material is carried out usually by dissolving or dispersing the layer-forming material in a proper medium and applying the solution or dispersion to the core, however, it may be performed by forming the layer-forming material in the form of film or sheet and integrating the film, etc., to the core material.

Description

Detailed description of the invention: Industrial application field The invention is based on the following: Under conditions of contact with water, the release of pesticides is inhibited at the beginning of application, and after a certain period of time, the release of pesticides is reduced at a set rate. This relates to the progress of coated pesticides.

Competing with conventional technology, pesticides that are stable and have a long lifespan are more effective, but such pesticides are difficult to decompose and may remain for a long time and be incorporated into the food chain. From a safety point of view, IA 4, which has a lifespan of 10 mm, is preferable. However, these short-lived pesticides have low residual efficacy.
In order to maintain the effect for a certain period of time, it is necessary to
It is necessary to apply several times as much pesticide as u td, or to increase the number of applications. However, in the case of poisonous pesticides, it is uneconomical because the pesticides are consumed excessively, and there is a risk of chemical damage due to the pesticides being washed away by mountains and rivers. On the other hand, in the case of the latter, it is necessary to apply it frequently and it is not very troublesome.

Therefore, various attempts have been made to control the dispersion of pesticides, which themselves have a short lifespan.For example, there are methods of blending pesticides into polymers, methods of encapsulating pesticides with polymers, coating them, and laminating them. D, has been researched and some have been put into practical use.

It is used for controlling 1) 11 in such a release 11. As the 56 molecules, microcapsule type materials such as polyamide, polyurea, polyethylene wax, and geladine-gum arabic are known, and laminate type materials such as polyvinyl chloride, acrylic polymer, and polyester are known.

Problems to be Solved by the Invention However, there are no methods for blending pesticides into polymers, encapsulation, coating, and lamination of pesticides in polymers''9.
Depending on the method of application, the release of pesticides begins immediately or shortly after application, so it is first sprayed together with other fast-acting pesticides, and the effects are not achieved until animals and plants have grown to a certain extent. I can't make it work. Therefore, for example, after a certain period of time has elapsed since the planting of paddy rice, and when plants and animals have grown to a certain extent, pesticides must be applied again, making it impossible to reduce the labor force.

, 4: In view of these circumstances, the present invention provides a coated pesticide which exhibits the property that the group 11 interactions of the pesticide are blocked at the beginning of application, and that the release progresses at a desired rate only after a certain period of time has elapsed. The purpose is to provide the following.

Means for Solving the Problems The coated agricultural chemical of the present invention is an agricultural chemical formulation in which a plurality of coating layers are formed on a core material (1) containing an agricultural chemical, and the coating layer is
Sulfonic acid group-containing polyester layer (2) and polyvinyl alcohol layer containing acid or alkali (3)
), and by finding a coated agricultural chemical with such a specific structure, the above problems have been solved.

The present invention will be explained in detail below.

In the present invention, a core material (1) containing an agricultural chemical is used.

Pesticides include fungicides, pheromones, konyu hormones, acaricides, acaricides, slugicides, fungicides, and more! Examples include good luck agents, plant growth promoters, rodenticides, and hormones. These agricultural chemicals are used as the core material (1) as they are or in the form of blending them with suitable polymers, inorganic particles, etc.

A plurality of coating layers are formed on the core material (1), but in the uninvention, the coating layer includes a sulfonic acid group-containing polyester layer (2), and.

Polyvinylalnyl layer containing alcohol or alkali (
3) Use.

Layer (:2) The polyester containing one sulfonic acid group constituting layer (2) refers to a polyester in which a sulfonic acid J (A group) is introduced, and the method of introduction is as follows: (a) acid component Sulfonic acids such as 5-sl·lium sulfoiphthalate, 5-potassium sulfoisophthalic acid, 2-sodium sulfoterephthalic acid, 2-potassium sulfoterephthalic acid or esters thereof!!), ': Containing polyvalent Methods using carboxylic acids (2) Adding acidic ε-acid Jl to polybasic acids having unsaturated bonds
(3) A method of reacting a sulfonate-containing polybasic acid with a polybasic acid and using this as an acid component.
A method in which a sulfate is reacted to form a sulfonate-containing polyhydric alcohol and this is used as a glycol component; (ii) an unsaturated carboxylic acid is used as part of the acid component to produce a polyester having a saturated bond; A method of adding an acidic sulfite to this unsaturated bond, (v) reacting a compound having an epoxy group with an acidic sulfite to form a polyfunctional monomer containing a sulfonic acid group, which is then reacted with an acid component or a polyhydric alcohol. Methods such as

The amount of sulfonate () to be introduced is from 0.001 to the total amount of the acid component and glycol component constituting the polyester.
It is desirable to set it to 10 mol%. 111, or if it is too low, the amount of pesticides in the core material (1) is h! ! Late surface speed,
- If the force 1d is too large, the solubility of the polyester in a solvent will decrease, making it difficult to carry out the coating operation.

Here, the acid components include terephthalic acid, inphthalic acid,
Various saturated carboxylic acids are used, including phthalic acid, adipic acid, sebacic acid, and in some cases maleic acid,
Small amounts of unsaturated carboxylic acids such as maleic anhydride, fumaric acid, and itaconic acid may also be used together.

In addition, as glycol components, ethylene glycol, fluoropylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, l, 3-1
Various glycols are used including 1,4- or 2,3-butanediol, 1,6-hexanediol, and neopentyl glycol, and in some cases, trivalent or higher glycols such as trimethylolethane, trimethylolpropane, glycerin, and pentaerythritol are used. A small amount of alcohol may also be used.

In addition to the above-mentioned components, a small amount of nitrogen-containing compounds such as amines and lactams can also be condensed. It is also possible to use a polyester obtained by condensing the components listed in 1.L and extending the chain length with a diisocyanate compound.

The second Q-layer (3) is composed of polyvinyl alcohol mixed with acid or alkali.

Examples of acids include hydrochloric acid, sulfuric acid, phosphoric acid, pyrophosphoric acid, sulfamic acid, formic acid, acetic acid, propionic acid, oxalic acid, citric acid, tartaric acid, and malic acid. Examples of alkalis include sodium hydroxide and potassium hydroxide. , calcium hydroxide, sodium carbonate, sodium hydrogen carbonate, ammonia, phosphoric acid, birophosphate, etc.

The addition of acid suppresses the hydrolysis of the sulfonic acid group-containing polyester layer (2), and the addition of alkali suppresses the hydrolysis of this layer (2).
Shows the effect of promoting the hydrolysis of

As described in Part 1 of "Reki J Shitomo", the coated agricultural chemical of the present invention comprises a core material (1), a sulfonic acid group-containing polyester layer (2), and a polyvinyl alcohol layer (3) containing an acid or alkali. ), but it is desirable that the arrangement of each layer be as follows.

B. Forming a layer (3) on the core material (1), and further forming the layer (3) on the core material (1)
A structure in which a layer (2) is formed from -.

A structure in which a layer (2) is formed on a core material (1), a layer (3) is formed from the core material (1), and a layer (2) is further formed on top of the layer (3).

It is also possible to combine layer 1 (2) and layer (3) into multiple layers, and if necessary, a water-soluble or oil-soluble coating layer may be added between the core material (1) and the layer above it. It is also possible to provide

The thickness of each layer is appropriately set in consideration of the expected diffusion prevention period and diffusion rate.

FIG. 1 is a partially cutaway front view showing an example of the coated agricultural chemical of the present invention, with the core material (1) as the core, the layer (3)' and the layer (2).
) are arranged in a concentric solid manner, and the whole is spherical.

Figure 2 is a cutaway front view showing another example of an uninvented coated agricultural chemical, in which layers (2), (3), and (2) are arranged around the core (1) as the central axis. It is surrounded by a cylindrical shape, and the whole body is rod-shaped.

FIG. 3 is a perspective view showing another example of the coated agricultural chemical of the present invention, in which layer (3) and layer (2) are arranged on both sides of a core material (1), and the whole structure is It is in the form of sheets or pieces.

Formation of layer (2) and layer (3) on core material (1)
), layer (3) is usually formed by dissolving or dispersing the material forming the layer in an appropriate medium and coating it. Alternatively, they may be formed into a core material (1) and integrated with the core material (1).

Diffusion Behavior The coated agricultural chemical of the present invention having the above configuration has the following properties: under conditions of contact with water, the dispersion of the agricultural chemical is inhibited at the beginning of application;
After a certain period of ItJI has elapsed, the pesticide dispersion proceeds at the set rate.

FIG. 4 is a graph schematically showing the dispersion behavior of the coated agricultural chemical of the present invention in comparison with the dispersion behavior of a conventional pesticide formulation subjected to dispersion control.

The dotted line represents the dispersion behavior of pesticide formulations subjected to conventional dispersion control. Dispersion begins at a certain rate immediately after application, and the rate of release can be adjusted;
Bl't l) - It is difficult to establish a period.

On the other hand, the solid polygonal line represents the dispersion behavior of the coated drug of the present invention, in which no dispersion occurs for a certain period at the beginning of application, and dispersion only begins after the period of -.quantification has elapsed.

Function: In the coated pesticide of the present invention, the sulfonic acid JL group-containing polyester layer (2) plays the role of a barrier layer that prevents the penetration of water from the outside for a certain period of time, thereby preventing the pesticide from dispersing. is inhibited for a certain period of time.

Polyvinyl alcohol layer containing acid or alkali (
3) dissolves in the water that has entered through the sulfonic acid group-containing polyester layer (2), makes the wood that has penetrated acidic or alkaline, and dissolves the layer (2) adjacent to this layer (3). and plays a role in regulating its hydrolysis rate.

That is, when an acid is added to the layer (3), the hydrolysis of the layer (2) is suppressed, and when an alkali is added to the layer (3), the hydrolysis of the layer (2) is promoted.

Example Next, the invention will be further explained with reference to Examples.

Unless otherwise specified, terms such as "part" and "%" are expressed in units of 41" M.

Example 1 Terephthalic acid 0.5 mol/Isophthalic acid 0.35 mol/Adipic acid 0.15 mol/Ethylene glycol 0.6
mol/0.7 mol of neopentyl glycol/0.2 mol of diethylene glycol/0.005 mol of 2-radiosulfo-1,4-butanediol, hydroxyl value 6 KOHmg/g, acid value 0. 8 KOHmg/
g of sulfonic acid (12), a polyester containing semi-Ui
: did.

Also, 0.3% sodium carbonate and 5% polyvinyl)I
An aqueous solution containing y flucol (ffi degree 500, saponification degree 88 mol%) was prepared.

Urine 7, resin, paddy rice pesticide herbicide (4J of ethyl-4-chloro-trioxybutyrate, bentonite, and talc)
The granular /3 drug (1) containing Compound a) was first poured into a 7% ethyl acetate solution of the sulfonic acid group-containing polyester, and then pulled and dried to a thickness of about 10 mm.
μ), ′/X (2) is formed, and then this is poured into the polyvinyl alcohol aqueous solution and pulled out to form a layer (3) with a thickness of about 25 mm. The above sulfone M11. A layer (2) having a thickness of about 10 mm was formed by pouring the polyester into a 7% ethyl acetate solution, pulling it up and drying it.

The coated agricultural chemical thus obtained was immersed in water, and the concentration of the eluted insecticide was determined over time.

The hairstyle is shown in Table 1. The bombardment concentration of the violet remover under this condition was 5 ppm.

Table 1 also shows that in the coated agricultural chemical of Example 1, the core material (
1) Agent XX does not elute at all in water at about 15 [J], but after 18, it begins to elute rapidly, and
It can be seen that after 0F1 elapses, almost the saturated C degree is reached.

Example 2 As layer (3) forming material, an aqueous solution containing 1.5% acetic acid and 5% polyvinyl alcohol (degree of polymerization 500, degree of saponification 88 mol%) was used to form a layer with a thickness of approximately 20μ when dried. A coated pesticide was obtained in the same manner as in Example 1, except that the concentrations of the eluted male and y agents were measured in the same manner as in Example 1.

The nodules are shown in Table 2.

The upper table of Table 2 also shows that in the coated agricultural chemical of Example 2, the core material (1
) The herbicide in the water does not dissolve at all for about 35 days, but
After 35 days, elution begins gradually, and even after 90 days, it only reaches about 7/10 of the saturation concentration.
It can be seen that it has a slow effect.

Example 3 An experiment was conducted in the same manner as in Example 1 except that the inner layer (2) was omitted. The results are shown in Table 3.

(Margin below): 53 Table Example 4 Terephthalic acid 0.48 mol/Isophthalic acid 0.35 mol/Adipic acid 0.15 mol/Ethylene glycol 0.
The composition is 6 mol/neopentyl glycol 0.7 mol/diethylene glycol 0.2 mol 15-sodium dimethyl sulfoisophthalate 0.02 mol, hydroxyl value 10 KOHmg/g, acid value 1.2 KO)Img
/g of sulfonic acid group-containing polyester was prepared.

In addition, an aqueous solution of polyvinyl alcohol (degree of polymerization: 8.00, degree of saponification: 88 mol %) containing 1% of calcium hydroxide and having a resin content of 8% was prepared.

From L of the core material layer (1) consisting of the same herbicide as in Example 1: -,1: 10 of the sulfonic acid group-containing polyester
A 15 μm thick layer (3) of the calcium hydroxide-containing polyvinyl alcohol, and a 4-pot thick layer (2) of the sulfonic acid group-containing polyester were coated.

This product showed the same elution behavior as Example 1.

Example 5 Hormone 61! An experiment was carried out in the same manner as in Example 1, except that (5'-(+-lifluoromethanesulfonamide)-aceto-2',4'-xylide) was used as the core material.

This product showed almost the same elution behavior as Example 1.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway front view showing an example of the coating/triple drug of the present invention, FIG. 2 is a partially cutaway front view showing another example,
FIG. 3 is a perspective view showing another example. FIG. 4 is a graph schematically showing the dispersion behavior of the coated drug of the present invention in comparison with the dispersion behavior of a pesticide formulation subjected to conventional dispersion control. (1) Core material, (2) Sulfonic acid group-containing polyester layer, (3) Polyvinyl alcohol layer containing acid or alkali Patent application: Koshiki Gosei Kagaku Kogyo Co., Ltd. 41FAM application Person: Cubic Engineering Co., Ltd. [Representative: Patent Attorney Masaru Oishi Department I1: J・I, ・

Claims (1)

[Scope of Claims] 1. A pesticide formulation comprising a core material (1) containing an agricultural chemical and a plurality of coating layers formed thereon, the coating layer comprising a sulfonic acid group-containing polyester layer (2) and an acid or A coated agricultural chemical characterized by comprising a polyvinyl alcohol layer (3) containing an alkali. 2. The coated agricultural chemical according to claim 1, wherein a layer (3) is formed on the core material (1), and a layer (2) is further formed on top of the layer (3). 3. Form a layer (2) on the core material (1), and then apply a layer (
3), and a layer (2) is further formed thereon.