JP2003183104A - Coated biologically active substance - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a coated biologically active substance whose elution speed and/or pattern is easily controlled, and whose elution is effectively suppressed during initial elution period in the elution pattern of a time-limited elution type. <P>SOLUTION: The surface of the biologically active substance is coated with a polyurethane obtained by reacting a mixture of a polyol having a function that protracts elution period of the coated biologically active substance and a polyol having a function that increases water retention capacity of the coated biologically active substance with an isocyanate. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a coated bioactive substance, a bioactive substance composition, and a method for cultivating a crop.

[0002]

2. Description of the Related Art U.S. Pat. No. 3,264,089,
JP-B-54-39298, JP-A-9-20835
No. 5, JP-A-10-324587 and the like disclose coated fertilizers having a polyurethane film.

[0003]

However, it has been difficult to control the elution rate and elution pattern of coated fertilizers having a polyurethane film. Among them, in the timed dissolution type elution pattern that has a period in which the fertilizer components are not eluted for a certain period after application (the initial dissolution suppression period) and a period in which the fertilizer components are eluted after the elapse of a certain period (the dissolution period), the dissolution during the initial dissolution period It was especially difficult to suppress.

[0004]

DISCLOSURE OF THE INVENTION The inventors of the present invention have made extensive studies in view of the above-mentioned problems of the prior art. As a result, in the coated bioactive substance in which the surface of the bioactive substance is coated with polyurethane, the polyurethane has a function of prolonging the elution period of the coated bioactive substance and the water retention ability of the coated bioactive substance. A polyurethane obtained by reacting a mixture with a polyol having an increasing function and an isocyanate makes it easy to control the elution rate and elution pattern, and even in the timed elution pattern, elution during the initial elution period It was found that an effectively suppressed coated bioactive substance can be obtained,
The present invention has been completed based on this finding.

The present invention has the following configurations (1) to (7). (1) A coated bioactive substance in which the surface of bioactive substance particles is coated with polyurethane obtained by reacting a mixture of a polyol having a hydroxyl equivalent of 120 or less and a polyol having a hydroxyl equivalent of 150 or more with isocyanate.

(2) The hydroxyl group equivalent of the mixture is 120 to 2
The coated bioactive substance according to claim 1, which is in the range of 00.

(3) The coated bioactive substance according to the above item 1, wherein the content ratio of the polyol having a hydroxyl equivalent of 120 or less is in the range of 5 to 90% by weight based on the mixture.

(4) The first, wherein the bioactive substance is a pesticide.
The coated bioactive substance according to the item.

(5) The first, wherein the bioactive substance is a fertilizer.
The coated bioactive substance according to the item.

(6) A bioactive substance composition containing the coated bioactive substance according to any one of the above items 1 to 5 and an uncoated bioactive substance.

(7) A method for cultivating a crop, which comprises using the coated bioactive substance according to any one of the above items 1 to 5 or the bioactive substance composition according to the sixth item.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The bioactive substance used in the present invention means a substance having activity against organisms related to agriculture, forestry, horticulture, etc. Specifically, it is specifically an agricultural crop or a useful plant. It is used for the purpose of raising and protecting plants such as, and increasing the yield, improving the quality of crops, controlling disease, controlling pests, controlling harmful animals, controlling weeds, and further promoting the growth of crops, suppressing growth, dwarfing. It brings about effects such as chemical conversion, and specific examples thereof include pesticides, fertilizers and microorganisms.

Examples of pesticides include disease control agents, pest control agents, pest control agents, weed control agents, plant growth regulators, etc., and any of these can be used without limitation. The disease control agent is an agent used to protect agricultural products and the like from the harmful effects of pathogenic microorganisms, and mainly includes bactericides. The pest control agent is a chemical agent for controlling pests that harm agricultural crops and the like, and mainly includes insecticides.

The pest control agent is a chemical agent used for controlling plant parasitic mites, plant parasitic nematodes, rodents, birds and other harmful animals that harm agricultural crops and the like. The weed control agent is a chemical agent used for controlling plants and plants that are harmful to agricultural crops and trees, and is also called a herbicide. The plant growth regulator is a drug used for the purpose of enhancing or suppressing physiological functions of plants. Among them, pesticides having both an insecticidal action and a bactericidal action or one action are preferable for the present invention, and the types thereof can be used without limitation.

The pesticide used in the present invention is preferably a solid powder at room temperature, but may be a liquid at room temperature. In the present invention, the pesticide may be water-soluble, sparingly water-soluble, or water-insoluble, and is not particularly limited. Among them, in the present invention, a permeation-transferable agricultural chemical that transfers to the plant to be protected by contact or the like and exhibits a medicinal effect is preferable. Specific examples of pesticides that can be used in the present invention are shown below, but the present invention is not limited thereto. Further, the pesticide may be one kind or may be composed of two or more kinds of composite components.

Specifically, (E) -N ¹ -[(6-chloro-3-pyridyl) methyl] -N ² -cyano-N ¹ -methylacetamidine (generic name: acetamiprid), 1-
(6-chloro-3-pyridylmethyl) -N-nitroimidazolidine-2-ylideneamine (generic name: imidacloprid), o, o-diethyl-S-2- (ethylthio) ethylphosphorodithioate (generic name: ethylthiomethone), 2,3-Dihydro-2,2-dimethyl-7-benzo [b] furanyl = N-dibutylaminothio-N-methylcarbamate (generic name: carbosulfan), (E)
-N- (6-chloro-3-pyridylmethyl) -N-ethyl-N'-methyl-2-nitrovinylidene diamine (generic name: nitenpyram), (±) -5-amino- (2,6
-Dichloro-α, α, α-trifluoro-p-toluyl) -4-trifluoromethylsulfinylpyrazole-3-carbonitrile (generic name: fipronil), butyl = 2,3-dihydro-2,2-dimethylbenzofuran -7-yl = N, N'-dimethyl-N, N'-thiodicarbamate (generic name: flatiocarb), ethyl = N
-[2,3-Dihydro-2,2-dimethylbenzofuran-7-yloxycarbonyl (methyl) aminothio]-
N-isopropyl-β-alaninate (generic name: benflacarb),

1-naphthyl-N-methylcarbamate (generic name: NAC), (1RS, 3SR) -2,2-dichloro-N- [1- (4-chlorophenyl) ethyl]-
1-Ethyl-3-methylcyclopropanecarboxamide (generic name: carpropamide), (RS) -2-cyano-N-
[(R) -1- (2,4-dichlorophenyl) ethyl]-
3,3-Dimethylbutyramide (generic name: diclocymet), 5-methyl-1,2,4-triazolo [3,4-
b] benzothiazole (generic name: tricyclazole),
1,2,5,6-tetrahydropyrrolo [3,2,1-i
j] quinolin-4-one (generic name: pyroquilon), (R
S) -5-chloro-N- (1,3-dihydro-1,1,
3-trimethylisobenzofuran-4-yl) -1,3
-Dimethylpyrazole-4-carboxamide (generic name:
Flametopyr), 3-allyloxy-1,2-benzisothiazole-1,1-dioxide (generic name: probenazole),

2-chloro-4-ethylamino-6-isopropylamino-s-triazine (generic name: atrazine), 1- (2-chloroimidazo [1,2-a] pyridin-3-ylsulfonyl) -3 -(4,6-Dimethoxypyrimidin-2-ylurea (generic name: imazosulfuron), S-benzyl = 1,2-dimethylpropyl (ethyl) thiocarbamate (generic name: esprocarb), ethyl = (RS) -2 -[4- (6-chloroquinoxalin-2-yloxy) phenoxy] propionate (generic name: quizalofop-butyl), butyl = (R) -2- [4
-(4-cyano-2-fluoronophenoxy) phenoxy] propionate (generic name: cyhalofop-butyl),
2-Methylthio-4-ethylamino-6- (1,2-dimethylpropylamino) -s-triazine (generic name: dimetamethrin), 2-methylthio-4,6-bis (ethylamino) -s-triazine (general) Name: simethrin),

1- (α, α-dimethylbenzyl) -3-
(Paratolyl) urea (generic name: Daimlon), 2-chloro-N- (3-methoxy-2-thenyl) -2 ', 6'-
Dimethylacetanilide (generic name: tenilchlor),
α- (2-naphthoxy) propionanilide (generic name:
Naproanilide), methyl 3-chloro-5- (4,6
-Dimethoxypyrimidin-2-ylcarbamoylsulfamoyl) -1-methylpyrazole-4-carboxylate (generic name: halosulfuronmethyl), ethyl = 5-
(4,6-dimethoxypyrimidin-2-ylcarbamoylsulfamoyl) -1-methylpyrazole-4-carboxylate (generic name: pyrazosulfuronethyl), S
-(4-Chlorobenzyl) -N, N-diethylthiocarbamate (generic name: ventiocarb), methyl = α-
(4,6-dimethoxypyrimidin-2-ylcarbamoylsulfamoyl) -o-toluate (generic name: bensulfuron-methyl), 2-benzothiazol-2-yloxy-N-methylacetanilide (generic name: mefenacet), etc. Can be mentioned.

Further, examples of the pesticides in the present invention include substances that induce phytoalexin, which is a low-molecular weight antibacterial substance that is synthesized by plants after contact with them and accumulates in the plants.

As the fertilizer, nitrogenous fertilizer, phosphate fertilizer,
In addition to potassium fertilizers, fertilizers containing essential plant elements such as calcium, magnesium, sulfur, iron, trace elements and silicon can be cited. Specific examples of nitrogenous fertilizers include ammonium sulfate, urea, and ammonium nitrate, as well as isobutyraldehyde condensed urea, acetaldehyde condensed urea, and the like. Phosphoric fertilizers include superphosphate lime, fused phosphorus fertilizer, and calcined phosphorus fertilizer. Examples of the potassium fertilizer include potassium sulfate, chloride chloride, and silica silicate fertilizer, and the form thereof is not particularly limited. Advanced chemical fertilizers, compound fertilizers, organic fertilizers with a total content of the three elements of fertilizer of 30% or more,
Further, a fertilizer containing a nitrification inhibitor or a pesticide can also be used in the present invention. Among them, when the bioactive substance particles are urea, a relatively high effect is obtained for the purpose of use.

The shape of the bioactive substance particles used in the present invention is not particularly limited, but it is preferably spherical in the present invention. In particular, the bioactive substance particles used in the present invention are a scale for knowing the circularity of the particles, and the circularity coefficient determined by the following formula is preferably 0.85 or more, more preferably 0. 9
The above is preferable, and 0.93 or more is more preferable. The maximum value of the circularity coefficient is 1, and as the value approaches 1, the particle approaches a perfect circle, and the circularity coefficient decreases as the shape of the particle collapses from the perfect circle. Formula: (4π × projected area of particles) / (contour length of projected particle) ²

The particle size of the bioactive substance particles is not particularly limited, but in the case of fertilizer, for example, 1.
0 to 10.0 mm, 0.3 in the case of pesticides
It is preferably about 3.0 mm. By using a sieve, an arbitrary particle size can be selected within the above range.

The composition of the particles of the bioactive substance used in the present invention is not particularly limited as long as it contains one or more kinds of bioactive substances, and the granules are prepared by granulating the bioactive substance alone. May be, clay, kaolin, talc, bentonite, carrier such as calcium carbonate, polyvinyl alcohol, sodium carboxymethyl cellulose,
It may be granulated using a binder such as starch. Also, if necessary, for example, a surfactant containing polyoxyethylene nonylphenyl ether, molasses, animal oil, vegetable oil, hydrogenated oil, fatty acid, fatty acid metal salt, paraffin, wax, glycerin, etc. may be contained. I do not care.

The method for producing the bioactive substance particles is not particularly limited, but includes extrusion granulation method, fluidized bed granulation method,
Rolling granulation method, compression granulation method, coating granulation method, adsorption granulation method and the like can be used. In the present invention, any of these granulation methods may be used, but the extrusion granulation method is the simplest.

The polyol having the function of prolonging the elution period of the coated bioactive substance used in the present invention is a polyol having a hydroxyl group equivalent of 120 or less, and has the function of increasing the water retention capacity of the coated bioactive substance. Is a polyol having a hydroxyl equivalent of 150 or more.

As the polyol used in the present invention, any polyol can be used as long as it has the above hydroxyl group equivalent. Specifically, ethylene glycol, propylene glycol, butanediol,
Low molecular weight diols such as pentanediol and hexanediol, low molecular weight polyhydric alcohols such as glycerin, trimethylolpropane and pentaerythritol, polyhydric alcohols, amino alcohols, and amines are used as initiators for ethylene oxide and Polyether polyol obtained by polyaddition of propylene oxide,

Polyether type polyol such as polytetramethylene ether glycol obtained by polymerizing tetrahydrofuran, or a method of reacting polyvalent alcohol, polyether polyol and carboxylic acid compound, etc. The polyester type polyol etc. which can be obtained can be mentioned. Also, in consideration of biodegradability, natural products containing OH groups,
Alternatively, a modified product thereof or the like can be used in the present invention.

Further, the polyol used in the present invention is not particularly limited, but it is preferable that they are compatible with each other when mixed.

The hydroxyl equivalent of a mixture of a polyol having a hydroxyl equivalent of 120 or less and a polyol having a hydroxyl equivalent of 150 or more is not particularly limited, but is preferably in the range of 120 to 200 in the present invention. . Within this range, since the polyols having the respective functions are dispersed and present in the coating film, and the respective functions are exhibited at the respective positions, the coated bioactive substance having a time-eluting type elution pattern. Can be easily obtained.

The mixture is a mixture of at least one polyol having a hydroxyl equivalent of 120 or less and at least one polyol having a hydroxyl equivalent of 150 or more as long as the effect of the present invention is not impaired. For example, the hydroxyl equivalent is 12
Polyols higher than 0 and lower than 150 can be used in combination.

Further, the mixture used in the present invention is
1 of a polyol having a hydroxyl equivalent of 30 to 120
A mixture of one or more kinds and one or more kinds of polyols having a hydroxyl equivalent of 150 to 300 is particularly preferable. With this polyol mixture, the moisture permeation rate and elongation of the film can be easily controlled, and the elution suppression period and the elution period can be easily controlled.

As described above, the elution pattern of the timed elution type is a period in which the biologically active substance is not eluted for a certain period after application (initial elution suppression period), and a period for elution after the elapse of a certain period (elution period). And more specifically, the period from the application to the elution of 10% by weight of the bioactive substance (D1), and thereafter the bioactive substance is 8%.
0% by weight until elution (D2), and
The elution pattern has a ratio of 1 / D2 of 0.2 or more. With the coated bioactive substance of the present invention, D1 / D2
Even if the elution pattern has a ratio of 2 or more, it can be easily achieved.

Further, in the present invention, the content ratio of the polyol having a hydroxyl group equivalent of 120 or less in the polyol mixture is preferably in the range of 2 to 95% by weight, more preferably 5 to 5% by weight based on the polyol mixture.
It is in the range of 80% by weight. The content of the polyol having a hydroxyl equivalent of 150 or more in the polyol mixture is preferably 5 to 95% by weight, more preferably 10 to 90% by weight, based on the polyol mixture. Within this range, the effect of suppressing elution particularly at D1 becomes high.

The isocyanate used in the present invention is not particularly limited, but specifically, toluene diisocyanate (sometimes called TDI) and diphenylmethane diisocyanate (MDI are called. , Naphthalene diisocyanate, tolidine isocyanate,
Hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate and the like can be exemplified, and a mixture of these can be used if necessary. Among them, MDI, TDI, and oligomers derived from these are preferably used in the present invention.

Further, in the present invention, a catalyst can be formulated in addition to the above resin component. As the catalyst,
Known and conventional ones can be used, and specifically, triethylamine, triethanolamine, triethylenediamine, N-methylmorpholine, N, N-dimethylmorpholine, diazabicycloundecene, 2, 4, 6,
Examples thereof include amine catalysts such as tris (dimethylaminomethyl) phenol and metal salt catalysts such as tetrabutyltin, dibutyltin dilaurate, tin octylate and lead octylate.

Further, if necessary, a pigment or dye for coloring, or an inorganic / organic powder such as talc, mica, silica, carbon black or resin powder as a filler is added to the polyurethane coating. May be. Further, a surfactant can be added if necessary.

As a method for coating the surface of the bioactive substance with the polyurethane, a known and conventional method can be used. For example, a fluidizer or a jet fluidizer is used to bring the bioactive substance into a fluid state, or the bioactive substance is brought into a rolling state by a rotating pan, a rotary drum, etc., and the polyurethane material is dropped or sprayed to form the organism. The coated bioactive substance can be prepared by adding to the active substance, coating the surface of the bioactive substance, and forming a polyurethane.

The coverage of the polyurethane is preferably 1 to 20% by weight, more preferably 2 to 15% by weight, based on the coated bioactive substance.

The bioactive substance composition of the present invention contains the coated bioactive substance of the present invention and the uncoated bioactive substance. As the uncoated bioactive substance, the bioactive substance used for the coated bioactive substance of the present invention can be used. The shape thereof may be any of powder, granules and granules, but in the present invention, it is preferably granules, and particularly the average particle diameter A1 of the bioactive substance and the average particle of the coated bioactive substance. Ratio A with diameter A2
1 / A2 is preferably in the range of 0.67 to 1.5. The shape is particulate, and A1 / A2 is 0.
When it is in the range of 8 to 1.25, it is preferable because the composition of the bioactive substance is difficult to classify.

The composition of the bioactive substance composition is not particularly limited, but if it is excessively biased, the effect of the application of a small amount may be compromised. The mixing ratio of the granules is preferably 50 times or less by weight, preferably 2 times.
It is preferably 0 times or less, more preferably 15 times or less.

The method for cultivating the crop of the present invention is not particularly limited as long as it uses the coated bioactive substance of the present invention or the bioactive substance composition of the present invention. As a specific example of the cultivation method, a method of applying all or most of the biologically active substance to be sprayed / applied during the cultivation period, at the start of seedling raising, at the time of sowing to the main field, or at the time of transplanting the seedling to the main field. Is mentioned. The coated bioactive substance of the present invention to be used may be one type, or may be a mixture of two or more types of coated bioactive substances having different release functions (release pattern and length of release suppression period) and types. The application time is also not limited, and may be applied to a seedling raising container such as a seedling raising box or seedling raising pot at the start of seedling raising, or may be applied at the same time as sowing or transplanting to the main field.

In the cultivation method, although the target crop is not limited, it can be used for field crops such as food crops, feed crops and industrial crops, and horticultural crops such as fruit trees, vegetables and flowers. Food crops can include rice, wheat, corn, potatoes, and legumes, feed crops can include grasses, legumes, and root crops for feed, and industrial crops can be taste crops (tea Etc.), spice crops (pepper, etc.), oil crops (sesame, etc.), sugar crops (beet, etc.), fiber crops (cotton, etc.), and fruit trees include pome fruits (apples, etc.) and drupes. (Peach, etc.), citrus fruits, tropical fruit trees (pineapple, etc.),
Examples of the vegetables include leaf vegetables, root vegetables, and fruit vegetables, and examples of the flowers include annual grasses, annual grasses, root-root grasses, flowering trees, and the like.

[0044]

The present invention will be described in more detail with reference to experimental examples, but the present invention is not limited to these. (Production of particles A) 90 parts by weight of potassium sulfate (manufactured by Wako Pure Chemical Industries, Ltd .: special grade) crushed to a particle size of 500 μm or less and magnesium sulfate heptahydrate (produced by Wako Pure Chemical Industries, Ltd .: special grade) Using 10 parts by weight as a raw material, a 2-fold diluted liquid of molasses was diluted (water dilution), and the raw material was supplied little by little to a disc rotary granulator for granulation. The obtained particles are a large blast constant temperature dryer (Advantech Toyo Co., Ltd .: FV
-1500) and then removed and sieved to 2.0-4.
Particles of 0 mm were sieved to produce particles A. Disc rotary granulator: dish diameter 400 mm; rotation speed 15 rpm, drying temperature 105 ° C, 12 hours

(Production of particles B) 1- (6-chloro-3-pyridylmethyl) -N as an agricultural chemical ingredient having an insecticidal action
-Nitroimidazolidin-2-ylideneamine (hereinafter,
Abbreviated as CPNIA. ) (Purity of 70 parts by weight) 3 parts by weight,
Bentonite (65 parts by weight), clay (31 parts by weight), and sodium ligninsulfonate (1 part by weight) were uniformly mixed, and water was kneaded in a kneader and kneaded. This mixture was extruded and granulated by a screw extrusion granulator (hole diameter of die: 0.8 mm), and then the granulated material was subjected to a rotary disk granulator (Fuji Paudal, Marumerizer QJ400). Granules were obtained by sizing under the following operating conditions. Next, the granulated product is dried at 100 ° C. using a hot air circulation dryer and then screened to 1.0.
Particles B having a size of ˜1.4 mm (sieve opening) were obtained. Operating condition of granulator: Operation method: Batch operation time: 1 mi
n-th plate pitch: 1 mm rotation speed: 788 r / min Charge amount: 1.5 kg (per time)

Experimental Example 1 920 g of granular urea (average particle size 3.4 mm) was charged into a temperature-controllable inclined pan type rolling granulator (pan diameter 450 mm) equipped with a hot air generator and rotated at 20 to 45 RPM. Then, the granular urea was brought into a rolling state. The apparatus was heated to maintain the temperature of the granular urea at 65 to 75 ° C. to maintain the rolling state. Propylene glycol (molecular weight: 76, hydroxyl equivalent: 38) 6.8 g, polypropylene glycol (molecular weight: 700, hydroxyl equivalent: 350) 35.3
g, and 0.8 g of dimethylethanolamine as an amine catalyst, and Polymeric MDI (viscosity:
38 g of 120 mPa · s / 25 ° C.) was added to each of the granular urea that had been heated and tumbled using a liquid feed pump in 40 minutes. After that, 65-75 ° C for 10 minutes
The coated bioactive substance was obtained by maintaining the range of.

Experimental Examples 2 to 9 Coated bioactive granules were produced according to Experimental Example 1 except that the materials shown in Table 1 were used as the coating material. The coating composition is shown in Table 1.

[0048]

[Table 1] PG: Propylene glycol (hydroxyl equivalent: 38) GC: Glycerin (hydroxyl equivalent: 31) TPG: Tripropylene glycol (hydroxyl equivalent:
96) PPG-1: polypropylene glycol diol (molecular weight: 400, hydroxyl equivalent: 200) PPG-2: polypropylene glycol diol (molecular weight: 700, hydroxyl equivalent: 350) PPG-3: polypropylene glycol triol (molecular weight: 300, hydroxyl equivalent) : 100) PPG-4: Polypropylene glycol triol (molecular weight: 308, hydroxyl equivalent: 103) PPG-5: Polypropylene glycol triol (molecular weight: 700, hydroxyl equivalent: 233) PPG-6: Polypropylene glycol triol (molecular weight: 444, hydroxyl group) Equivalent weight: 148) pMDI: Polymeric MDI (viscosity: 130 mPas)
/ 25 ° C)

Experimental Example 10 A coated bioactive granular material was produced in the same manner as in Experimental Example 1 except that the granular urea was changed to the particle A. The coating composition is shown in Table 1.

Experimental Example 11 A coated bioactive granular material was produced in the same manner as in Experimental Example 4 except that the granular urea was changed to the particle B and the coating rate was changed to 12%. The coating composition is shown in Table 1.

[Evaluation 1] 10 g of each coated bioactive substance was immersed in 200 ml of water in which the temperature for measuring the elution days of urea was kept at 25 ° C. and allowed to stand. After a predetermined period, the coated bioactive substance was separated into water and urea eluted in water was determined by quantitative analysis. The coated bioactive substance was again immersed in 200 ml of water kept at 25 ° C. and allowed to stand still, and after a predetermined period of time, the same analysis was performed. By repeating such operations, the relationship between the total elution of urea dissolved in water and the number of days was graphed to prepare an elution rate curve, and the number of days until the 80% elution rate was obtained. The results are shown in Table 2.

[Evaluation 2] 10 g of each coated bioactive substance was immersed in 200 ml of water whose temperature for measuring the number of days to elute potassium was kept at 25 ° C., and allowed to stand. After a predetermined period, the coated bioactive substance was separated into water, and potassium eluted in water was determined by flame photometry. The coated bioactive substance was again immersed in 200 ml of water kept at 25 ° C. and allowed to stand still, and after a predetermined period of time, the same analysis was performed. By repeating such operations, the relationship between the total elution of urea dissolved in water and the number of days was graphed to prepare an elution rate curve, and the number of days until the 80% elution rate was obtained. The results are shown in Table 2.

[Evaluation 3] Measurement of days of release of pesticides A coated test tube (12 mm x 72
(1.5 mm) of water was added to each of the test tubes, and 1 capsule was added to each test tube, and then the cap was capped. 100 tubes (grains) each for water temperature 2
It was left still at each temperature of 5 ° C. Observation was carried out every day from the start of the test, and the number of film disintegrations of the coated bioactive substance was counted, and the cumulative disintegration number was taken as the cumulative release rate. The results are shown in Table 2.
Shown in.

[0054]

[Table 2]

In Experimental Examples 1 to 6, 10 and 11, D
1 / DT was 0.4 or more, showing a good time-eluting type elution pattern. However, in Experimental Example 7 using the single polyol, D1 was short and the time-eluting type was not obtained. Furthermore, as in Experimental Examples 8 and 9, even when the blended polyol had a large or small hydroxyl group equivalent, the dissolution pattern of the timed dissolution type was not obtained.

A cultivation test was conducted using the coated bioactive substance of the present invention. Experimental Example 12 As a bed soil for raising seedlings, 3000 g of kumiai black grain cultivated soil (manufactured by Kumiai Kyoyusha Co., Ltd.) having internal dimensions of 58 cm in length and 28 c in width
m, 3 cm deep in a rice seedling raising box, the surface thereof was flattened, and 150 g of germinated seeds (variety: Morinokumasan) were sown in a uniform and layered manner, and then the coated bioactive substance of Experimental Example 1 was used as a fertilizer. Applied 500 g. On this, 1000 g of the same soil as the bed soil was used to cover the soil, and the soil was sufficiently watered. The seedling raising box was raised at a temperature of 18 to 28 ° C for 20 days. The seedlings were managed according to the conventional method except that water was appropriately applied to prevent the surface layer from drying.

Experimental Example 13 A cultivation test was carried out according to Experimental Example 12 except that the coated bioactive substance was changed to that of Experimental Example 7.

Experimental Example 14 A cultivation test was conducted according to Experimental Example 12 except that the coated bioactive substance was not added.

As a result of observing the state of raising seedlings in Experimental Examples 12 and 13, it was possible to grow seedlings that were prepared in Experimental Example 12 as in Experimental Example 14, whereas seedlings were not prepared in Experimental Example 13. In addition, there were some signs of fertilization. After the seedlings were raised, they were cultivated in a miniature paddy field in Minamata City, Kumamoto Prefecture, and it was confirmed that the seedlings of Experimental Example 12 grew in the same manner as conventional cultivation.

[0060]

INDUSTRIAL APPLICABILITY The coated bioactive substance of the present invention can easily control the elution rate and the elution pattern, and can effectively suppress the elution during the initial elution period even in the timed elution pattern. . INDUSTRIAL APPLICABILITY The cultivation method of the present invention can remarkably reduce the work of applying the bioactive substance-containing granular material without causing a growth failure in the early stage of cultivation.

Claims (7)

[Claims] 1. A coated bioactive material in which the surface of bioactive substance particles is coated with polyurethane obtained by reacting a mixture of a polyol having a hydroxyl equivalent of 120 or less and a polyol having a hydroxyl equivalent of 150 or more with an isocyanate. material. 2. The hydroxyl equivalent of the mixture is 120 to 200.
The coated bioactive substance according to claim 1, wherein 3. The coated bioactive substance according to claim 1, wherein the content of the polyol having a hydroxyl equivalent of 120 or less is in the range of 5 to 90% by weight based on the mixture. 4. The coated bioactive substance according to claim 1, wherein the bioactive substance is a pesticide. 5. The coated bioactive substance according to claim 1, wherein the bioactive substance is a fertilizer. 6. A bioactive substance composition containing the coated bioactive substance according to claim 1 and an uncoated bioactive substance. 7. A method for cultivating a crop, which comprises using the coated bioactive substance according to any one of claims 1 to 5 or the bioactive substance composition according to claim 6.