JPH0780721B2 - Sustained release pesticide composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an agricultural chemical preparation having excellent sustained release.

(Prior Art) In recent years, environmental pollution by pesticides, safety, and the like have become major problems. In relation to these problems, techniques for more effectively utilizing pesticides are being actively developed. One of them is the technology for controlling the elution of active ingredients during the production of agricultural chemicals, that is, the technology for sustained-release preparations. By the technology of this sustained-release preparation, the elution of the active ingredient can be controlled, the active ingredient used for waste can be reduced, and the efficacy can be maintained for a longer period of time. As a result, the number and amount of pesticides used can be reduced, which leads to labor saving of pesticides. Also, it can be applied to drugs with low residual effect,
The sustained release technology has a great significance in terms of pesticides, such as reduction of phytotoxicity to crops.

Many studies have been conducted on sustained-release pesticides. For example, a method of adjusting adsorption to activated carbon by blending vegetable oil (Japanese Patent Laid-Open Publication No. 56-1696).
01), a method of incorporating a pesticide component into a resin or wax-like substance (Japanese Patent Laid-Open Publication Nos. 56-26811 and 52-28942,
48-5940, 55-124701, Japanese Patent Publication 55-10
561), a method of coating a resin or a wax-like substance on the surface of a granular composition (JP-A-57-126402, JP-A-56-89, JP-A-48-2775, 52-21059), Various methods such as a method of microencapsulation (Japanese Patent Publication Sho 55-38325) have been proposed.

(Problems to be solved by the invention) Regarding the technology of sustained-release pesticides, methods such as those described in the section of the prior art are known, but in any method, dissolution control is difficult, manufacturing methods are difficult, There is a problem that it is not practical in terms of industry and economy such as high manufacturing cost.

The present inventors have conducted extensive studies to establish a technology for dissolution control that is industrially and economically practical, and as a result, by mixing rubber and wax with an agrochemical active ingredient, they have excellent sustained release properties. Found to produce pesticide formulations,
The present invention was completed by further study.

(Means for Solving Problems) The present invention relates to a sustained-release granular substance containing a rubber, a wax and an agrochemical active ingredient. According to the study of the present inventors, when the synthetic resin is coated with a granular pesticide or embedded, the particles cannot be blocked during granulation operation to produce the intended sustained release granule, or , Causes blocking during storage. In addition, when a wax-like substance is coated or mixed, it is difficult to control the elution of the active ingredient, and there are difficult problems such as the sustained-release property that elutes faster than the expected elution rate, or no elution at all. However, it has been found that the above-mentioned various problems can be solved by applying the method of the present invention.

In the present invention, rubber and wax are used as substances for coating or compounding the granular pesticide. The rubber may be natural rubber or synthetic rubber, and synthetic rubber is more preferable. Further, a synthetic rubber latex is even more preferable, and a synthetic rubber latex mainly containing butadiene as described below is most preferable. The wax is more preferably a wax emulsion. When the synthetic rubber latex and the wax emulsion are used, it is preferable to use the synthetic rubber latex and the wax emulsion in a solid component weight ratio of the synthetic rubber latex 8 to at least one wax emulsion.

As the synthetic rubber latex used in the present invention, any synthetic rubber latex can be used. Representative examples include styrene-butadiene rubber latex, methylmethacrylate-styrene-butadiene rubber latex, ethylene-propylene rubber latex, butadiene rubber latex, isoprene rubber latex, and silicone rubber latex, which may be used alone or
It may be a mixture of two or more species.

As described above, in the present invention, synthetic rubber latex,
It is most preferable to use a synthetic rubber latex mainly containing butadiene. The butadiene-based synthetic rubber latex is a homopolymer of butadiene or a copolymer containing 35 mol% or more of butadiene. Examples of the other monomer used in the copolymer include styrene, vinyl chloride, vinyl acetate, vinyl alcohol, acrylic acid ester, and methacrylic acid ester. Accordingly, examples of the synthetic rubber latex containing butadiene as a main component include butadiene rubber latex, styrene-butadiene rubber latex (35 mol% or more of butadiene), and methyl methacrylate-styrene-butadiene rubber latex (35 mol% or more of butadiene).

Examples of the wax emulsion in the present invention include wax emulsions obtained from animals and plants or petroleum resin, such as paraffin wax emulsion, microcrystalline wax emulsion, and polyolefin wax emulsion.

The pesticidal active ingredient to which the present invention can be applied is not particularly limited. For example, cartap [1,3-bis (carbamoylthio) -2- (N, N-dimethylamino) propane hydrochloride], tricyclazole [5-methyl- 1,2,4-Triazolo (3,4-b) -benzothiazole], validamycin, BPMC [o-sec-butylphenyl methylcarbamate], probenazole [3-allyloxy-1,2-benzisothiazole-1,1 -Dioxide], isoprothiolane [diisopropyl-1,3-dithiolane-2-ylidenemalonate], carbofuran [2,3-dihydro-2,2-
Dimethylbenzofuran-7-yl N-methylcarbamate], pretilachlor [2,4-diethyl-N- (propoxyethyl) chloroacetanilide], bethiocarb [S-4-chlorobenzyl diethylthiocarbamate], dimethrin [2,4-bis] (Ethylamino) -6-
Methylthio-1,3,5-triazine], MTMC [m-tolyl
Methyl carbamate], bentazone [3-isopropyl-1H-2,1,3-benzothiadiazin-4 (3H) -one-
2,2-dioxide], butachlor [N-butoxymethyl-2-chloro-2 ', 6'-diethylacetanilide]
And so on. Further, the above pesticidal active ingredients may be used alone or in combination of two or more.

In producing the sustained-release granular material of the present invention, various carriers can be added in addition to rubber, wax and agrochemical active ingredients. Examples of such carriers include vegetable powder (eg, soybean powder, tobacco powder, wheat flour, wood powder, starch, etc.), mineral powder (eg, kaolin, bentonite, clay such as acid clay, talc powder, talc powder, etc.). , Silica such as diatomaceous earth and mica powder), calcium carbonate, sulfur powder, activated carbon and the like. The above-mentioned carrier is not limited to only one type, and two or more types may be used in some cases. Of course, in addition to the carriers mentioned above, antioxidants (eg dibutylhydroxytoluene, 4,4'-thiobis-6-tert.
-Butyl-3-methylphenol, etc., dispersant (eg, ethylene glycol, glycerin, etc.), surfactant (eg, lignin sulfonate, alkylbenzene sulfonate, polyoxyethylene alkylaryl ether, alkylnaphthalene sulfonate) Examples of these salts include inorganic salts such as sodium salts and potassium salts), binders (eg, polyvinyl alcohol, carboxymethyl cellulose, etc.),
Flow aids (for example, white carbon), synergists and the like can be used as appropriate.

The sustained-release granular material of the present invention is produced by compounding the pesticide active ingredient with rubber and wax by a usual method.
The form in which the agrochemical active ingredient is coated with rubber and wax may be used. In the present invention, a method in which a core granular composition is prepared in advance and the core granule is coated or embedded with a mixture of rubber and wax is more suitable.

Such a core particle composition can be prepared by a known method. For example, the above-mentioned plant powder and / or mineral powder may be combined with the pesticidal active ingredient in a total amount of 3 to 30.
A method of adding water in an amount of about 1 part by weight, mixing and kneading, and then extruding through a screen (extrusion granulation method), an oil-absorbing carrier such as porous silica sand, for example, 10 to 40
Examples include a method in which the pesticide active ingredient is impregnated after sizing to a mesh size, or a method in which a non-oil absorbing granular carrier such as silica stone is coated with the pesticide active ingredient.

In addition, the mixture of rubber and wax that coats such a core particle composition may be compounded with the same or different pesticidal active ingredient as the pesticide active ingredient compounded in the core particle composition. In this case, a method for producing granules, in which a pesticidal active ingredient is added to a mixture of rubber and wax and made into a uniform suspension, which is coated on the above-mentioned core granular composition, dried and sized, is convenient. Is.

Further, a method in which a mixture of rubber and wax and an agricultural chemical active ingredient is coated with the above-mentioned various carriers as cores is also used. In this case as well, a method in which the pesticidal active ingredient is added to the rubber and the wax to form a uniform suspension on the core carrier is suitable.

The ratio of each component in the sustained-release pesticide formulation of the present invention is 10 for all formulations.
The pesticide active ingredient is 1 to 50 parts by weight, preferably 1 to 20 parts by weight as 0 parts by weight, and the synthetic rubber latex and the wax emulsion are 5 to 50 parts by weight, preferably 5 to 30 parts by weight, as a mixture (solid weight). 0 to 94 parts by weight of carrier, preferably
50 to 94 parts by weight.

(Operation and effect) By using the sustained-release granular pesticide formulation of the present invention, economic efficiency of pesticide is realized, and its effect is very large.

(Examples and Test Examples) Next, the present invention will be described in more detail with reference to Examples, Reference Examples, and Test Examples, but the present invention should not be limited to these Examples.

Example 1 5.5 parts of Cartap, 4.5 parts of alpha starch (Amicol C, Nippon Starch Chemical Co., Ltd.) and 90 parts of clay were added and mixed, then 15 parts of water was added and kneaded, and a screen having a hole diameter of 1 mm was used for production. Grain. The granulated product is dried and sized to obtain Padan kernel granules.
Take 80 parts of this padan core granule, and add styrene-butadiene rubber latex (Crosslen SK72, Takeda Chemicals), paraffin wax emulsion (Cerosol # 428, Chukyo Yushi).
20 parts of a solid mixture of 4: 1 in a solid fraction were coated and dried,
The particles are sized to obtain a sustained-release padan granule.

Example 2 5 parts tricyclazole, alpha starch (Amicol C)
After adding 5 parts and 90 parts of clay and mixing, a beam nucleus granule is obtained in the same manner as in Example 1. Next, this beam nucleus granule
A mixture of 84 parts of styrene-butadiene latex (Crosslen SK72) and paraffin wax emulsion (Cerosol # 428) mixed in a solid fraction of 4: 1 was coated with 16 parts, dried, sized and controlled release beam particles. Get the agent.

Example 3 5 parts tricyclazole, alpha starch (Amicol C)
After adding 5 parts and 90 parts of clay and mixing, a beam nucleus granule is obtained in the same manner as in Example 1. Next, this beam nucleus granule
Take 86 parts and mix 14 parts of styrene-butadiene rubber latex (Crosslen SK72) and paraffin wax emulsion (Cerosol # 428) at a solid fraction of 5: 1. Get granules.

Example 4 84 parts of the padane core granules obtained in Example 1 were taken, and methyl methacrylate-styrene butadiene rubber latex (Crosslane 2M45, Takeda Pharmaceutical Co., Ltd.) and paraffin wax emulsion (Cerosol # 428) were mixed at a solid fraction of 4: 1. The mixture is mixed with 16 parts, dried and sized to obtain a sustained release padang granule.

Example 5 After adding 5.5 parts of tricyclazole, 5 parts of alpha starch (Amicol C) and 89.5 parts of clay and mixing, a beam nucleus granule is obtained in the same manner as in Example 1. This beam kernel granule
80 parts of methyl methacrylate-styrene-butadiene rubber latex (Crosslane 2M45) and wax emulsion (Cerosol # 428) were mixed at a solid ratio of 4: 1. 20 parts were coated, dried, sized, and slowly released. Obtain sex beam granules.

Example 6 Styrene-butadiene latex (Crosslane SK-7
2), 8 parts of tricyclazole are added to 92 parts of a mixture of paraffin wax (Cerosol # 428) in a solid fraction of 3: 1 to obtain a uniform suspension. Silica stone (silica sand No. 4, 10
(48 mesh) (70 parts) is coated with 30 parts of this suspension, dried and sized to obtain a sustained release beam granule.

Example 7 76 parts of the padane core granules obtained in Example 1 was taken, and styrene-butadiene latex (Crosslen SK-72) and paraffin wax (Cerosol # 428) were mixed in a solid fraction of 7: 1. To 84 parts of the mixture, 16 parts of tricyclazole are added to form a uniform suspension, which is then coated with 24 parts to obtain a sustained-release padan beam granule by drying and sizing.

Reference Example 1 Cartap 4 parts, alpha starch (Amicol C) 4.5
Parts and 91.5 parts of clay are added and mixed, then 15 parts of water is added and kneaded, and granulated using a screen having a hole diameter of 1 mm.
The granulated product is dried and sized to obtain Padan granules.

Reference Example 2 4 parts tricyclazole, alpha starch (Amicol C)
After adding 5 parts and 91 parts of clay and mixing, a beam granule is obtained in the same manner as in Reference Example 1.

Dissolution test in water Test method 1 (Beam granules) Beam granules weighed so that the active ingredient was 100 ppm were put in a 500 ml Erlenmeyer flask with stopper and filled with 500 ml of distilled water.
Let stand at ℃. Over time (1 day, 6 days, 10 days, 30 days, 6
On day 0), 10 ml of water was sampled and analyzed by high performance liquid chromatography, and then the elution rate was calculated. After collecting water, supplement 10 ml of distilled water. The dissolution rate was calculated by the following formula.

The results are shown in Table 1.

Test method 2 (Padan granules) Padan granules weighed so that the active ingredient is 20 ppm are put in a 500 ml Erlenmeyer flask with stopper and filled with 500 ml of distilled water.
Let stand at ℃. Over time (2 minutes, 10 minutes, 20 minutes, 1 day, 3
(2, 6 days, 10 days, 30 days, 60 days), 2 ml each was sampled and analyzed by a colorimetric method, and then the dissolution rate was calculated. 2m after collecting water
Top up with l of distilled water. The dissolution rate was calculated by the method described in Test Method 1. The results are shown in Table 1.

Test Example 1 1. Test method 1) Raising seedlings: Raising seedlings in a seedling raising box (30 cm x 60 cm, depth 3 cm)
The rice of 2.5 leaf stage (Nihonbare) was tested.

2) Leaf treatment: The granules produced in the above Examples and Reference Examples were tested, and on the day of transplantation, 100 g per seedling raising box was dispersed on the soil surface of the seedling raising box.

3) Rice cultivation: On the day of chemical treatment, the rice is cut with a rice transplanter.
It was transplanted to 1 / 10000a Wagner pot.

4) Blast control effect test: The pot was transferred to a greenhouse bed where blast disease is rapidly occurring, and naturally infected to test the control effect, and at the same time, the degree of phytotoxicity was investigated. The control value and phytotoxicity (yellowed leaf area) were calculated by the following formulas.

2. Test Results As is clear from the results shown in Table 2, the pesticide formulation according to the present invention is applied to the nursery box once compared to the normal granules shown as reference examples, and thus 62 days or more after transplantation. , The blast control effect was sustained, and the phytotoxicity at the early stage of transplantation was significantly reduced.

Test Example 2 1. Test Method As in Test Example 1, after transplanting to a potted rice plant treated with a chemical and transplanted (use of soil for chemical damage test, 1 treatment was 5 pots) 2
On the 10th, 10th, 21st, 30th, and 45th, a transparent vinyl chloride cylinder (diameter 11 cm) was set up, and a total of 50 adult green leafhoppers (Nephottix cincticeps UHLER) were bred indoors. Then, the rate of death and poisoning fallen insects after 48 hours was examined. The degree of drug damage was also investigated.

2. Test Results As is clear from the results shown in Table 3, the pesticide formulation according to the present invention has a higher effect of reducing the initial phytotoxicity after transplantation than the ordinary granules shown as Reference Examples.

Claims (1)

[Claims] 1. A sustained-release granular material containing a rubber, a wax and an agrochemical active ingredient.