JPH07258001A - Sustained release granular pesticide composition - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a controlled-release granular pesticide composition that is excellent in controllability of pesticide component release, workability in use, does not adversely affect workers and the environment, and is inexpensive. . [Structure] A sustained release granular pesticide composition comprising a granule or a fine granule containing a liquid or fine powdery solid pesticide component coated with a polymer, wherein the polymer is a specific ethylene-based monomer (a). 80 to 99.9% by weight, 0.1 to 20% by weight of an ethylene-based monomer having a carboxyl group in the molecule (b), and the monomer (a) and (b) are copolymerizable with the monomer Comonomers other than the bodies (a) and (b) (c) a copolymer having 0 to 30% by weight of repeating constitutional units, and / or a polyvalent metal salt of the copolymer, A sustained release granular pesticide composition.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a controlled release granular pesticide composition which is excellent in controllability of release of pesticide components, workability in use, has no adverse effect on workers and the environment, and is inexpensive. Regarding

[0002]

2. Description of the Related Art Conventionally, many attempts have been made to make pesticide components sustained-released. Sustained release means a property such that the release rate of the active ingredient is suppressed and the active ingredient is released over a longer period of time when compared with other preparations under the same conditions. All of the conventional attempts are aimed at sustaining the medicinal effect, stabilizing the active ingredient, reducing phytotoxicity to crops, reducing fish toxicity, and solving various other problems.

The conventional sustained-release pesticide compositions are roughly classified as follows.
(1) A mixture of a pesticide and a natural or synthetic resin for sustained release (see JP-A-47-20347), (2)
Microcapsules of pesticides (JP-A-48-4643)
(See JP-A-55-104201, JP-A-55-104201)
-126402), etc.

However, all of these sustained-release pesticide compositions have drawbacks. For example, since the composition (1) is a mixture of a pesticide and a synthetic resin, it has a drawback that the amount of resin used increases. Above (2)
The composition requires a high production cost, requires the use of water because it needs to be in a dispersed state during spraying, and when it is in a dispersed state, the microencapsulated pesticide is separated and settled. It has drawbacks such as being easy and poor in stability. The composition of the above (3) does not have the drawbacks of the compositions of the above (1) and (2), and is the most common one, but the conventionally used polymer is a thermoplastic resin, Since an organic solvent is required when coating pesticides, there are many problems such as work hazards, effects on the human body, and effects on the environment. Moreover, since the polymer is coated by spraying, the pesticide composition It has disadvantages such as poor fluidity and stickiness of the agrochemical composition due to the tackiness of the polymer.

Further, a liquid or water-dispersible solid pesticide active ingredient is prepared by polymerizing a monomer selected from acrylic acid, methacrylic acid, maleic acid and its esters or salts. A surface-coated granular pesticide characterized by being coated with a product is disclosed in JP-A-58-13504, but the invention described in the publication is a solid pesticide component coated. It is intended to provide an agrochemical composition having excellent leaching property by utilizing the fact that the polymer and the like are water-soluble, and there is no description of sustained release property in the publication.

Further, JP-A-61-282301 discloses that water containing a repeating structural unit of a monomer selected from acrylic acid, methacrylic acid, maleic acid, itaconic acid, fumaric acid and polyvalent metal salts thereof. Disclosed is a granular sustained-release pesticide composition coated with an insoluble oligomer or polymer.
The oligomer or polymer specifically disclosed in the examples of the proposal is a copolymer of a very large amount of a carboxyl group-containing monomer, for example, 70 mol% or more, but is used for insolubilizing the oligomer or polymer. Therefore, a large amount of polyvalent metal salt is required, and the metal crosslink density of the polymer must be very high, and the coating film formed tends to be brittle, and the resulting pesticide composition is impacted. When applied or soaked in water, stress relaxation becomes insufficient, and as a result, the sustained release effect of pesticide is not always sufficient.

[0007]

DISCLOSURE OF THE INVENTION The present inventor has conducted various studies to develop an inexpensive granular sustained-release pesticide composition which is free from work hazards, effects on the human body and the environment. However, a granular or fine granule containing a liquid or finely divided solid agricultural chemical component is coated with a water-soluble polymer having a specific composition and then made water-insoluble to give a desired sustained-release granular agricultural chemical composition. The inventors have found that the following can be obtained and completed the present invention.

[0008]

The present invention provides a sustained-release granular pesticide composition comprising a granule or a fine granule containing a liquid or fine powdery solid pesticide component coated with a polymer, wherein the polymer is The following (a) ~ (c),

(A) 80 to 99.9% by weight of an ethylene-based monomer represented by the following general formula (1),

[0010]

[Chemical 2]

(Wherein R ¹ represents hydrogen or a methyl group, Y represents hydrogen, an alkyl group having 1 to 8 carbon atoms, or --COOR
² , -OCOR ³ , an aryl group or CN, R ²
Represents an alkyl group having 1 to 12 carbon atoms, and R ³ represents hydrogen or an alkyl group having 1 to 12 carbon atoms)

(B) 0.1 to 20% by weight of an ethylenic monomer having a carboxyl group in the molecule, and

(C) Copolymerizable with (a) and (b),
Provided is a sustained-release granular pesticide composition characterized in that it is a polyvalent metal salt of a copolymer having 0 to 30% by weight of a comonomer other than (a) and (b) as a repeating constitutional unit. It is intended.

The present invention will be described in detail below.

The sustained-release granular pesticide composition of the present invention contains a liquid or fine powder solid pesticide component by using a water-soluble polymer obtained by neutralizing a carboxyl group contained in the polymer with an alkali. And water-insolubilizing the water-soluble polymer by heat treatment, or water-insolubilizing the water-soluble polymer by treating with a polyvalent metal salt solution.

The object to be treated in the present invention is a granule or a fine granule containing a liquid or fine powdery solid agricultural chemical ingredient.

The above-mentioned pesticide component may be any of conventionally known insecticides, herbicides and fungicides, for example, O, S-
Dimethyl-N-acetylphosphoramide thioate, O, O-
Dimethyl-S-phthalylimidomethyldithiophosphate, O, O-diethyl-S-2- (ethylthio) ethyl phosphorodithioate, 2-chloro-1- (2,4,5-trichlorophenyl)
Organophosphorus insecticides such as vinyl dimethyl phosphate and (2-isopropyl-4-methylpyrimidyl-6) -diethylthiophosphate;

For example, 2,3-dihydro-2,2-dimethyl-7-benzofuranyl-N- [N- (2-ethoxycarbonylethyl) -Ni
-Propylaminosulfenyl] -N-methylcarbamate, 2,3-dihydro-2,2-dimethyl-7-benzofuranyl-N-
(N, N-dibutylaminosulphenyl) -N-methylcarbamate, [(2,3-dihydro-2,2-dimethylbenzofuranyl-7-
(Oxy)-(N-methylamino) carbonyl]-[n-butoxy-
(N'-methylamino) carbonyl] sulfide, 2-isopropoxyphenyl-N-methylcarbamate, dimethyl (3-
Carbamate insecticides such as methyl-4-nitrophenyl) thiophosphate and 1-naphthyl-N-methylcarbamate;

For example, diisopropyl-1,3-dithiolane-
2-Ylidene-malonate, O, O-diisopropyl-S-benzylthiophosphate and other fungicides; for example, 2,4-dichlorophenyl-3-methoxy-4'-nitrophenyl ether, 5-
Ethylhexahydro-1H-azepine-1-carbothioate,
2-methylthio-4,6-bis-ethylamino-s-triazine,
2,6-dichlorobenzonitrile, S- (4-chlorobenzyl)-
N, N-diethylthiocarbamate, 2-chloro-4,6-bis (ethylamino) -s-triazine, 2,4-dichlorophenyl-4'-
Nitrophenyl ether, 2,4,6-trichlorophenyl-
Herbicides such as 4'-nitrophenyl ether and 3-isopropyl-2,1,3-benzo-thiadiadinone- (4) -2,2-dioxide;
And so on.

The monomer (a), which is a repeating constitutional unit of the polymer used in the present invention, is an ethylene-based monomer represented by the following general formula (1).

[0021]

[Chemical 3]

(Wherein R ¹ represents hydrogen or a methyl group, Y represents hydrogen, an alkyl group having 1 to 8 carbon atoms, or --COOR
² , -OCOR ³ , an aryl group or CN, R ²
Represents an alkyl group having 1 to 12 carbon atoms, and R ³ represents hydrogen or an alkyl group having 1 to 12 carbon atoms)

As such a monomer (a), a monomer in which Y is hydrogen or an alkyl group having 1 to 8 carbon atoms, for example, ethylene, n-propylene, i-propylene, n-butylene, i -Olefin-based monomer such as butylene; Y is -COO
In R ^2, the monomer wherein R ² is an alkyl group having 1 to 12 carbon atoms,
For example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, i-propyl
(Meth) acrylate, n-butyl (meth) acrylate, i-
Butyl (meth) acrylate, t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl
(Meth) acrylate, i-octyl (meth) acrylate,
(meth) acrylic acid ester-based monomers such as n-nonyl (meth) acrylate, i-nonyl (meth) acrylate, and lauryl (meth) acrylate;

Monomers in which Y is --OCOR ³ and R ³ is hydrogen or an alkyl group having 1 to 12 carbon atoms, such as vinyl formate, vinyl acetate, vinyl propionate, "vinyl versatate" (trade name, (Shell), etc., saturated fatty acid vinyl monomers; monomers in which Y is an aryl group, for example, aromatic vinyl monomers such as styrene, α-methylstyrene, vinyltoluene; Body, for example, (meta)
Vinyl cyanide monomers such as acrylonitrile; and the like,

From the viewpoint of the sustained release effect of the obtained agricultural chemical composition, etc., a (meth) acrylic acid ester-based monomer such as methyl acrylate, ethyl acrylate, and methyl methacrylate, and saturated vinyl acetate, “versa vinylate”, etc. Use of a fatty acid vinyl monomer is preferable, and vinyl acetate is particularly preferable from the viewpoint of safety and economy.

The copolymerization ratio of these monomers (a) is 80 to 99.9% by weight, preferably 85 to 99.5% by weight, based on the total 100% by weight of the monomers (a) to (c). Particularly preferably 90 to 99
It is in the range of% by weight. If the copolymerization ratio of the monomer (a) is too much over the upper limit, it is not preferable because it becomes difficult to be water-soluble when the resulting copolymer is neutralized with an alkali,
On the other hand, if the amount is less than the lower limit, the water resistance of the obtained pesticide composition coating film tends to be insufficient, and a sufficient sustained-release effect is difficult to obtain, which is not preferable.

The monomer (b) is an ethylene monomer having a carboxyl group in the molecule and / or a polyvalent metal salt thereof. Specific examples of such a monomer (b) include:
For example, α, β-unsaturated mono- or di-carboxylic acid having 3 to 5 carbon atoms such as acrylic acid, methacrylic acid, crotonic acid, citraconic acid, itaconic acid, maleic acid, fumaric acid (hereinafter referred to as ethylene-based carboxylic acid May be abbreviated); for example, α having 4 to 5 carbon atoms such as maleic anhydride,
β-unsaturated dicarboxylic acid anhydrides; for example, mono-n-butylmalate, mono-n-butyl fumarate, monoethyl itaconate and other α, β-unsaturated dicarboxylic acids having 1 to 12 carbon atoms Monoalkyl ester monomers of, for example, ethylene carboxylic acids such as sodium acrylate and ammonium methacrylate, or α, β- with 4 to 5 carbon atoms
Examples thereof include ammonium salts or alkali metal salts of unsaturated dicarboxylic acid monoalkyl ester monomers.

Among these monomers (b), when a (meth) acrylic acid ester-based monomer is used as the main component as the monomer (a) from the viewpoint of ease of polymerization reaction, etc. , Methacrylic acid, itaconic acid (particularly acrylic acid, methacrylic acid) is preferably used, and when a saturated fatty acid vinyl monomer is used as the main component as the monomer (a),
Preference is given to using crotonic acid, monomethylmalate, monoethylmalate, monobutylmalate (in particular crotonic acid).

The copolymerization ratio of the monomer (b) is from the monomers (a) to
It is in the range of 0.1 to 20% by weight, preferably 0.5 to 15% by weight, particularly preferably 1 to 10% by weight, based on 100% by weight of the total of (c). If the copolymerization ratio of the monomer (b) is too much over the upper limit, the water resistance of the coating film of the resulting agrochemical composition tends to be insufficient, and a sufficient sustained release effect of the agrochemical component is obtained. Since it is difficult to obtain, it is not preferable. On the other hand, if it is less than the lower limit, too small, it is not preferable because the copolymer obtained is hardly water-soluble when neutralized with alkali.

The monomer (c) is the monomer (a) and (b)
Is a comonomer other than the monomers (a) and (b). Specific examples of such a monomer (c) include:
For example, acrylamide, methacrylamide, diacetone acrylamide, N-methylol acrylamide, N-
Amides of ethylene-based carboxylic acids such as methylolmethacrylamide and derivatives thereof; for example, esters of ethylene-based carboxylic acids such as glycidyl acrylate and glycidyl methacrylate with saturated alcohols having an epoxy group; for example, 2-hydroxyethyl acrylate, 2 -
Examples thereof include esters of ethylene-based carboxylic acids such as hydroxypropyl acrylate, 2-hydroxyethyl methacrylate, and 2-hydroxypropyl methacrylate with polyvalent saturated alcohols.

The copolymerization ratio of the comonomer (c) is from the monomers (a) to
The total amount of (c) is 0 to 30% by weight, preferably 0 to 25% by weight, and particularly preferably 0 to 20% by weight. If the copolymerization ratio of the monomer (c) is not more than the lower limit value, the reactivity and stability during copolymerization will be excellent, and the water resistance of the coating film of the resulting agrochemical composition and the sustained release of agrochemical components will be obtained. It is preferable because it does not impair the effects of the present invention such as effects, and by using the comonomer (c), the polymer obtained, appropriate hydrophilicity, if necessary,
Alternatively, it is preferable to use the comonomer (c) in the range of the copolymerization ratio because it is possible to impart more excellent sustained release controllability by introducing a crosslinked structure.

In the present invention, the water-soluble polymer used for coating the granules or fine granules containing the agrochemical component is obtained by polymerizing the above-mentioned monomers (a) to (c), for example, solution polymerization, emulsion polymerization, It can be prepared by copolymerizing by a known method such as suspension polymerization, and then neutralizing with an alkali such as aqueous ammonia.

The molecular weight of the polymer used in the present invention is
The weight average molecular weight measured by gel permeation chromatography (GPC) is preferably about 3,000 to 100,000, and the viscosity of an aqueous solution having a solid content of about 25% by weight is about 50 to 2000 cps (B-type rotational viscometer, 25 ° C, 20 rpm, below. The same) is preferred.

In the sustained-release granular pesticide composition of the present invention, first, the granules or fine granules containing a liquid or fine powdery solid pesticide component are coated with the above water-soluble polymer and then made water-insoluble. Manufactured by.

In coating the granules or fine granules containing the above-mentioned pesticide components with a water-soluble polymer, conventionally known techniques can be widely applied. For example, an aqueous solution of the polymer (usually 10 to 30% by weight aqueous solution) It may be sprayed or the granules or granules to be coated are immersed in an aqueous solution of the polymer. The coating amount of the water-soluble polymer is not particularly limited, but it is a granule or a fine granule containing the solid agricultural chemical ingredient.
An amount of 0.5 to 20% by weight, preferably 1 to 10% by weight, is applied to 100 parts by weight.

Next, as a method for making water insoluble,
The granules or fine granules coated with the water-soluble polymer may be heat-treated to remove water and simultaneously desorb alkali. The heating temperature varies depending on the type of agrochemical components to be treated and cannot be generally stated, but is generally about 50 to 150 ° C., and the heating time is usually about 3 to 180 minutes.

As a further alternative, a granule or fine granule containing an agrochemical component may be coated with a polymer solution obtained by adding a polyvalent metal salt to the above water-soluble polymer. Examples of the polyvalent metal salt that can be used include calcium chloride, magnesium chloride, zinc chloride, copper chloride, aluminum chloride, calcium sulfate, magnesium sulfate, zinc sulfate, copper sulfate, aluminum sulfate, calcium nitrate, magnesium nitrate, zinc nitrate, nitric acid. Copper, a calcium ammine complex, a zinc ammine complex, etc. can be mentioned. As the amount of the polyvalent metal salt, it is preferable to use an amount that is not less than the gel point.

These methods are all simple methods, and the degree of insolubilization can be adjusted by appropriately selecting the amount of the water-soluble polymer and the heating method and the amount of the polyvalent metal salt used. The release rate of pesticide components can be freely controlled.

[0039]

EXAMPLES The present invention will be described in more detail with reference to Examples, Comparative Examples and Reference Examples. The preparation of test samples and the test methods used in the examples and comparative examples are as follows.

(1) Water resistance test A polymer aqueous solution was applied onto a clean glass plate using a doctor blade so that the film thickness when dried was 30 μm, dried at room temperature for 3 hours, and then heat treated at 120 ° C. for 20 minutes. Then, leave it at room temperature for 16 hours or more to prepare a test plate. This test plate is 20 ℃
After being immersed in the water for 30 minutes, it is taken out, and whitening and cracks of the film are evaluated according to the following criteria.

<Whitening> ○ --- No whitening △-・ Slight whitening ×-・ Large whitening

<Cracks> ○ ・ ・ ・ ・ ・ ・ No cracks △ ・ ・ ・ ・ Slight cracks are generated × ・ ・ ・ ・ ・ ・ Cracks are often generated

(2) Pesticide elution rate test 200 ml of deionized water was put in a 500 cc glass beaker, and 100 mg of the granular pesticide composition as a sample was put in this, and 2
The pesticide active ingredient concentration in water after 1 day, 3 days and 7 days is measured by gas chromatography after standing in a room at 0 ° C., and the dissolution rate of the pesticide is calculated according to the following formula.

[0044]

[Equation 1]

Reference Example 1 In a reaction vessel equipped with a stirrer, a reflux condenser and a thermometer,
Charge 730 parts by weight of deionized water and apply nitrogen while flowing 80
The temperature was raised to ° C. Also, put vinyl acetate (VAc) 285 in a separate container.
Parts by weight and 15 parts by weight of crotonic acid (CA) were added, mixed and uniformly dissolved to obtain a monomer mixture. The total amount of this monomer mixture and 60 parts by weight of a 10% by weight aqueous solution of t-butyl hydroperoxide as an aqueous solution of the polymerization initiator were placed in a reaction vessel.
Continuously added over a period of time, then kept at the same temperature for 1 hour, cooled, and added with a 25 wt% ammonia aqueous solution and a 25 wt% zinc acetate (ZnAc) aqueous solution to adjust the pH to 8.5 to 9.5. An aqueous polymer solution was obtained. Table 1 shows the copolymerization composition and molecular weight of the obtained polymer, the compounding amount of zinc acetate, the properties of the aqueous polymer solution, and the results of the water resistance test.

Reference Example 2 Instead of using 285 parts by weight of VAc in Reference Example 1, VAc
195 parts by weight and "versa vinyl acetate" (trade name) (V
V) An aqueous polymer solution was obtained in the same manner as in Example 1 except that 90 parts by weight was used. Table 1 shows the copolymerization composition and molecular weight of the obtained polymer, the compounding amount of zinc acetate, the properties of the aqueous polymer solution, and the results of the water resistance test.

Reference Examples 3 to 4 Instead of using 285 parts by weight of VAc and 15 parts by weight of CA in Reference Example 1, 150 parts by weight of methyl methacrylate (MMA),
126 parts by weight of ethyl acrylate (EA) and acrylic acid (A
A) An aqueous polymer solution was obtained in the same manner as in Example 1 except that 24 parts by weight, 210 parts by weight of MMA and 90 parts by weight of AA were used. Table 1 shows the copolymerization composition and molecular weight of the obtained polymer, the compounding amount of zinc acetate, the properties of the aqueous polymer solution, and the results of the water resistance test.

[0048]

[Table 1]

Example 1 Carbamate insecticide [2,3-dihydro-2,2-dimethyl-7-
Benzofuranyl-N- [N- (2-ethoxycarbonylethyl) -N
5 parts by weight of -i-propylaminosulphenyl] -N-methylcarbamate] and 95 parts by weight of 48-75 mesh clay,
Mix with a Nauta mixer for 10 minutes. Then, the polymer aqueous solution of Reference Example 1 was sprayed so that the solid content would be 5 parts by weight with respect to 100 parts by weight of the total amount of the insecticide and clay, and further 10
After mixing for 1 minute, heat it in a hot air circulation dryer at 110 ° C for 1
After drying for 5 minutes, the intended sustained-release granular pesticide composition was obtained. Table 2 shows the amounts of the polymers used and the results of the elution rate test of the obtained agrochemical compositions.

Example 2 A sustained-release granular pesticide composition was obtained in the same manner as in Example 1 except that the amount of the aqueous polymer solution used in Reference Example 1 was changed. Table 2 shows the amounts of the polymers used and the results of the elution rate test of the obtained agrochemical compositions.

Examples 3 to 4 and Comparative Example 1 The procedure of Example 1 was repeated except that the polymer aqueous solution of Reference Example 1 was used instead of the polymer aqueous solution of Reference Example 1. A loose granular pesticide composition was obtained. Table 2 shows the amounts of the polymers used and the results of the elution rate test of the obtained agrochemical compositions.

Comparative Example 2 A sustained-release granular pesticide composition was obtained in the same manner as in Example 1 except that the aqueous polymer solution was not sprayed.
Table 2 shows the amounts of the polymers used and the results of the elution rate test of the obtained agrochemical compositions.

[0053]

[Table 2]

[0054]

INDUSTRIAL APPLICABILITY The granular sustained-release pesticide composition of the present invention is capable of sustaining an excellent drug effect for a longer period of time than conventional ones. Further, when using the granular sustained-release pesticide composition of the present invention, there is no danger of work, no effect on human body, no effect on environment. Furthermore, as described above, by appropriately selecting the conditions for producing the composition of the present invention, there is an advantage that the release rate of the agrochemical component can be freely controlled. In addition, the composition of the present invention is easy to produce and economically suitable.

Claims (2)

[Claims] 1. A sustained-release granular pesticide composition obtained by coating a granule or a fine granule containing a liquid or fine powdery solid pesticide component with a polymer, wherein the polymer comprises the following (a) to (a):
(c), (a) an ethylene-based monomer represented by the following general formula (1)
80-99.9% by weight, [Chemical formula 1] (In the formula, R ¹ represents hydrogen or a methyl group, Y is hydrogen, an alkyl group having 1 to 8 carbon atoms, —COOR ² , —OC.
Represents OR ³ , an aryl group or CN, and R ² has 1 carbon atom
~ 12 alkyl groups, R ³ is hydrogen or 1 carbon atom
~ 12 represents an alkyl group) (b) 0.1 to 20% by weight of an ethylene monomer having a carboxyl group in the molecule, and
(c) a copolymer that is copolymerizable with (a) and (b) and has 0 to 30% by weight of a comonomer other than (a) and (b) as a repeating constitutional unit, and / Alternatively, a sustained-release granular pesticide composition, which is a polyvalent metal salt of the copolymer. 2. The composition according to claim 1, wherein the polyvalent metal salt is a calcium salt, a magnesium salt, a zinc salt, a copper salt or an aluminum salt.