JP6891058B2 - Agricultural chemical binder, agricultural chemical granular composition and its manufacturing method - Google Patents

Description

The present invention is a binder for pesticides having excellent water resistance and viscosity stability when made into an aqueous solution, and a pesticide granular composition in which granulated pesticides do not easily disintegrate and the pesticide active ingredient can be slowly released over a long period of time. Regarding the method.

Conventionally, for the purpose of being easy to use and exerting a sufficient control effect, a granular pesticide granular composition in which a mixture in which a binder is added to a pesticide active ingredient is granulated by a granulator is known. In the pesticide granular composition, phytotoxicity to agricultural products due to elution of the pesticide active ingredient in a short time has become a problem, and the sustainability of the effect of the pesticide active ingredient is also an issue from the viewpoint of labor saving in agricultural work. In order to solve these points, various studies have been conducted on pesticide granular compositions capable of controlling the elution amount of pesticide active ingredients.

For example, Patent Document 1 proposes a slow-release granular fertilizer that is surface-coated with a water-insoluble water-soluble polymer or contains a water-insoluble polymer. Patent Document 2 proposes a sustained release pesticide granule in which a pesticide active ingredient, a thermoplastic resin, polyvinyl alcohol, and iron powder or copper powder are uniformly mixed. Patent Document 3 proposes a crosslinked product of a polyvinyl alcohol-based resin and a sustained release pesticide composition containing a pesticide active ingredient.

However, although the pesticide granular compositions described in Patent Documents 1 to 3 are excellent in sustained release of pesticide active ingredients, the pesticide granular composition itself does not have sufficient granular strength and is impacted during transportation or spraying. There was a drawback that it was easily disintegrated when it was received or stored for a long period of time. Against this background, there is a demand for an agricultural binder that does not easily disintegrate the granulated pesticide granular composition and can slowly release the pesticide active ingredient for a long period of time.

Japanese Unexamined Patent Publication No. 8-277191 JP-A-2002-363003 Japanese Unexamined Patent Publication No. 2012-006881

The present invention has been made to solve the above problems, and the binder for pesticides having excellent water resistance and viscosity stability when made into an aqueous solution, and the granulated pesticide granular composition do not easily disintegrate for a long period of time. It is an object of the present invention to provide a pesticide granular composition capable of slowly releasing a pesticide active ingredient and a method for producing the same.

As a result of diligent studies by the present inventors, it has been found that the above-mentioned problems can be solved by a binder for agricultural chemicals containing a specific ethylene-modified vinyl alcohol-based polymer, and the present invention has been completed.

That is, the present invention relates to the following invention.
[1] The content of ethylene units is 1.0 mol% or more and 19 mol% or less, the content of 1,2-glycol bond units is 1.2 mol% or more and 2.0 mol% or less, and the viscosity average. A pesticide binder containing an ethylene-modified vinyl alcohol-based polymer having a degree of polymerization of 200 or more and 5000 or less and a degree of saponification of 80 mol% or more and 99.9 mol% or less.
[2] Agricultural chemical granules containing the agricultural chemical binder and the agricultural chemical active ingredient of the above [1], and the content of the agricultural chemical binder is 0.5 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the agricultural chemical active ingredient. Composition.
[3] The pesticide granular composition according to the above [2], wherein the pesticide active ingredient is a fertilizer.
[4] The pesticide granular composition according to the above [2] or [3], which is granulated by adding a pesticide binder containing the ethylene-modified vinyl alcohol-based polymer to the pesticide active ingredient as an aqueous solution or together with water. Production method.

The pesticide binder of the present invention is excellent in water resistance and viscosity stability when made into an aqueous solution. In addition, the pesticide granular composition obtained by using the pesticide binder is not easily disintegrated, and the pesticide active ingredient can be slowly released over a long period of time. Furthermore, according to the method for producing a pesticide granular composition of the present invention, a pesticide granular composition having excellent performance as described above can be easily produced.

Hereinafter, the present invention will be described in detail. The present invention is not limited to the embodiments described below. Further, in the present specification, the upper limit value and the lower limit value of the numerical range (content of each component, value calculated from each component, each physical property, etc.) can be appropriately combined.

[Agricultural binder]
The agricultural chemical binder of the present invention has an ethylene unit content of 1.0 mol% or more and 19 mol% or less, and a 1,2-glycol bond unit content of 1.2 mol% or more and 2.0 mol% or less. An ethylene-modified vinyl alcohol-based polymer having a viscosity average degree of polymerization of 200 or more and 5000 or less and a saponification degree of 80 mol% or more and 99.9 mol% or less (hereinafter, vinyl alcohol-based polymer is referred to as "PVA". May be abbreviated as). The pesticide binder containing such a specific ethylene-modified PVA is excellent in water resistance and viscosity stability when made into an aqueous solution, and the pesticide granular composition obtained by using the pesticide binder is hard to disintegrate and is long-term. The pesticide active ingredient can be released slowly.

In the above ethylene-modified PVA, the content of ethylene units is 1.0 mol% or more and 19 mol% or less, preferably 1.5 mol% or more and 15 mol% or less, and more preferably 2.0 mol% or more and 12 mol% or less. preferable. When the content of ethylene units is less than 1.0 mol%, the water resistance of the obtained pesticide binder becomes insufficient, and the resulting pesticide granular composition is liable to disintegrate, resulting in a pesticide active ingredient for a long period of time. The effect of sustained release is weakened. On the other hand, when the content of ethylene units exceeds 19 mol%, it becomes difficult to dissolve ethylene-modified PVA in water.

^{In the above ethylene-modified PVA, the content of ethylene units is determined from, for example, 1} H-NMR of a vinyl ester-based copolymer containing ethylene units which is a precursor or revinegared product of the ethylene-modified PVA. That is, the obtained vinyl ester-based copolymer was sufficiently reprecipitated with n-hexane / acetone three times or more, and then dried under reduced pressure at 80 ° C. for 3 days to obtain a vinyl ester-based copolymer for analysis. To make. The polymer is dissolved in _{DMSO-d 6} ^{and measured at 80 ° C. using 1} H-NMR (eg 500 MHz). Ethylene unit using a peak derived from the main chain methylene of vinyl ester (4.7 to 5.2 ppm) and a peak derived from ethylene, vinyl ester and the main chain methylene of the third component (0.8 to 1.6 ppm). The content of can be calculated.

The viscosity average degree of polymerization of the ethylene-modified PVA is 200 or more and 5000 or less, preferably 300 or more and 4000 or less, more preferably 350 or more and 3000 or less, and further preferably 500 or more and 2500 or less. When the viscosity average degree of polymerization is less than 200, the water resistance of the obtained pesticide binder becomes insufficient, the resulting pesticide granular composition tends to disintegrate, and the effect of slowly releasing the pesticide active ingredient over a long period of time. Or the grain strength of the pesticide granular composition becomes insufficient. On the other hand, it is difficult to produce ethylene-modified PVA having a viscosity average degree of polymerization of more than 5000. The viscosity average degree of polymerization (P) of ethylene-modified PVA is measured according to JIS-K6726 (1994). That is, it can be obtained by the following formula from the ultimate viscosity [η] (dl / g) measured in water at 30 ° C. after remineralizing and purifying ethylene-modified PVA.
P = ([η] × 10 ³ / 8.29) ^{(1 / 0.62)}

The saponification degree of the ethylene-modified PVA is 80 mol% or more and 99.9 mol% or less, preferably 85 mol% or more and 99.5 mol% or less, more preferably 90 mol% or more and 99.3 mol% or less, and 95 mol. % To 99 mol% is particularly preferable. When the saponification degree is less than 80 mol%, the solubility in water is lowered, which makes it difficult to prepare an aqueous solution, or the water resistance of the obtained pesticide binder becomes insufficient. On the other hand, when the saponification degree exceeds 99.9 mol%, when the obtained aqueous solution of the pesticide binder is prepared, the viscosity sharply increases during storage of the aqueous solution or the viscosity stability becomes insufficient.

The content of the 1,2-glycol bond unit of the ethylene-modified PVA is 1.2 mol% or more and 2.0 mol% or less, preferably 1.3 mol% or more and 1.9 mol% or less, and 1.4 mol. % Or more and 1.8 mol% or less are more preferable. When the content of the 1,2-glycol bond unit is less than 1.2 mol%, the viscosity stability of the ethylene-modified PVA aqueous solution is lowered. On the other hand, it is difficult to produce ethylene-modified PVA in which the content of 1,2-glycol binding unit exceeds 2.0 mol%. The content of the 1,2-glycol bond unit can be controlled by various methods such as the type of vinyl ester, solvent, polymerization temperature, and copolymerization of vinylene carbonate. As an industrial control method, control by the polymerization temperature is preferable in the present invention.

The content of 1,2-glycol binding unit is determined by dissolving the obtained ethylene-modified PVA in water in an open container for about 2 hours, then pouring the solution onto a polyethylene terephthalate substrate and drying it to cast a film. Was produced. The obtained film was dissolved in _{DMSO-d 6} and measured and calculated at 80 ° C. using ^{1 H-NMR (500 MHz).}

In the ethylene-modified PVA, for example, ethylene and a vinyl ester-based monomer are copolymerized to obtain a vinyl ester-based copolymer having an ethylene unit, and then the vinyl ester-based copolymer is saponified with sodium hydroxide or the like. It is obtained by saponification using a catalyst and crushing and drying as necessary.

Examples of the method for copolymerizing ethylene with a vinyl ester-based monomer include known methods such as a massive polymerization method, a solution polymerization method, a suspension polymerization method, and an emulsion polymerization method. Above all, a massive polymerization method or a solution polymerization method in which polymerization is carried out without a solvent or in a solvent such as alcohol can be usually adopted. Examples of the alcohol include lower alcohols such as methanol, ethanol and propanol. The initiators used in the copolymerization include 2,2'-azobis (isobutyronitrile), 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile), and 2,2'-azobis. Examples thereof include azo-based initiators such as (2,4-dimethyl-valeronitrile), benzoyl peroxide, n-propylperoxydicarbonate, and known initiators such as peroxide-based initiators.

The polymerization temperature is not particularly limited, and is preferably 0 ° C. to 150 ° C., more preferably room temperature or higher and 150 ° C. or lower, further preferably room temperature or higher and lower than the boiling point of the solvent used, and particularly preferably 30 to 60 ° C.

Examples of the vinyl ester-based monomer include vinyl formate, vinyl acetate, vinyl propionate, vinyl valerate, vinyl caprate, vinyl laurate, vinyl stearate, vinyl benzoate, vinyl pivalate, vinyl versatic acid and the like. Among them, vinyl acetate is preferable.

The ethylene-modified PVA may contain monomer units other than vinyl alcohol units, ethylene units and vinyl ester units as long as the effects of the present invention are not impaired. Such units include α-olefins such as propylene, 1-butene, isobutene and 1-hexene; vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, i-propyl vinyl ether and n-butyl vinyl ether; Hydroxy group-containing vinyl ethers such as ethylene glycol vinyl ether, 1,3-propanediol vinyl ether, and 1,4-butanediol vinyl ether; allyl ethers such as allyl acetate, propyl allyl ether, butyl allyl ether, and hexyl allyl ether; oxyalkylene Monomers having a group; Vinyl silanes such as vinyl trimethoxysilane; Isopropenyl acetate, 3-butene-1-ol, 4-pentene-1-ol, 5-hexene-1-ol, 7-octene-1-ol Hydroxy group-containing α-olefins such as oar, 9-decene-1-ol, 3-methyl-3-butene-1-ol; ethylene sulfonic acid, allyl sulfonic acid, methallyl sulfonic acid, 2-acrylamide-2 -A monomer having a sulfonic acid group derived from methylpropanesulfonic acid or the like; vinyloxyethyltrimethylammonium chloride, vinyloxybutyltrimethylammonium chloride, vinyloxyethyldimethylamine, vinyloxymethyldiethylamine, N-acrylamidemethyltrimethylammonium chloride , 3- (N-methacrylamide) propyltrimethylammonium chloride, N-acrylamide ethyltrimethylammonium chloride, N-acrylamide dimethylamine, allyltrimethylammonium chloride, methallyltrimethylammonium chloride, dimethylallylamine, cation group derived from allylethylamine, etc. Examples thereof include monomers having. The content of these monomers varies depending on the purpose and use of use, but is preferably 10 mol% or less, more preferably less than 5.0 mol%, and further preferably 1.0 mol%. It is less than 0.5 mol% and may be less than 0.5 mol%.

The binder for pesticides of the present invention may be substantially composed of only the above ethylene-modified PVA. The fact that it is substantially composed of the ethylene-modified PVA alone means that the components other than the ethylene-modified PVA may be less than 5.0% by mass, less than 1.0% by mass, or 0.5% by mass. It means that it may be less than 0.1% by mass and may be less than 0.1% by mass. Further, the binder for pesticides may contain other components (inorganic substances or organic substances) in addition to ethylene-modified PVA. Examples of the inorganic substance include talc, calcium carbonate, clay, diatomaceous earth, silica, metal oxide, sulfur and the like for the purpose of adjusting or increasing the amount of elution. Examples of organic substances include organic substances such as resin compounds, surfactants, waxes, and organic pigments. These other components may be used alone or in combination of two or more. Examples of the resin compound include thermosetting resins and thermoplastic resins. Examples of the thermosetting resin include polyurethane, epoxy resin, alkyd resin, unsaturated polyester, phenol resin, urea / melamine resin, urea resin, silicon resin and the like. Examples of the thermoplastic resin include polyolefins such as polyethylene, polypropylene, polybutene, and polystyrene; and polymers such as vinyl acetate, polyvinyl chloride, vinylidene chloride, polyacrylic acid, polymethacrylic acid, polyacrylic acid ester, and polymethacrylic acid ester. Vinyl polymerized resin; diene polymers such as polybutadiene, polyisoprene, polychloroprene, butadiene-styrene copolymer, ethylene-propylene-diene copolymer, styrene-isoprene copolymer; ethylene-propylene copolymer, butene-propylene Copolymer, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene-methacrylic acid ester copolymer, ethylene-carbon monoxide copolymer, ethylene-acetic acid Polyolefin copolymers such as vinyl-carbon monoxide copolymers; vinyl chloride copolymers such as vinyl chloride-vinyl acetate copolymers and vinylidene chloride-vinyl chloride copolymers can be mentioned. The content of these other components is not particularly limited, but is usually preferably 10 parts by mass or less, more preferably 5 parts by mass or less, still more preferably 3 parts by mass or less, based on 100 parts by mass of ethylene-modified PVA.

[Agricultural chemical granular composition]
The pesticide granular composition of the present invention contains the pesticide binder and the pesticide active ingredient, and the content of the pesticide binder with respect to 100 parts by mass of the pesticide active ingredient is preferably 0.5 parts by mass or more and 20 parts by mass or less. The pesticide granular composition of the present invention is obtained by granulating a pesticide active ingredient using the pesticide binder containing the above ethylene-modified PVA. Examples of pesticide active ingredients include fertilizers, herbicides, insecticides, fungicides, plant growth regulators and the like. As the pesticide active ingredient, one kind may be used alone, or two or more kinds may be used in combination.

Examples of fertilizers include oxamide, crotonidene diurea (CDU), isobutylidene diurea (IB), ureaform, molten phosphorus fertilizer, mixed phosphoric acid fertilizer, by-acid lime fertilizer, calcium carbonate fertilizer, mixed lime fertilizer, and mineral acidity. Examples include fertilizers, other siliceous fertilizers, hydroxylated fertilizers, by-acid fertilizers, processed fertilizers, mineral manganese fertilizers, and molten trace element fertilizers. In addition, it can be applied to processed ore slag phosphate fertilizer for the purpose of supplying silicic acid and correcting pH by alkali content as well as ore slag acid fertilizer. Of these, oxamide, crotonidene diurea (CDU), isobutylidene diurea (IB), ureaform, processed ore slag phosphate fertilizer, ore slag acid fertilizer, and mixed phosphate fertilizer are preferable.

Herbicides include, for example, 2,4-PA, MCP, MCPB, MCPA thioethyl (phenothiol), clomeprop, naproanilide, CNP, chlomethoxyfen, bifenox, MCC, benthiocarb, esprocarb, molinate, dimepiperate, DCPA, butachlor, pretilachlor, bromobutide. , Mephenacet, dimulon, simethrin, promethrin, dimetamethrin, bendazone, oxadiazone, pyrazolate, pyrazoxifene, benzophenap, trifluralin, piperophos, ACN, benzulfron methyl and the like.

Insecticides include, for example, MPP, MEP, ECP, pyrimiphosmethyl, diazinon, isoxathione, pyridafenthion, fluoropyrifosmethyl, chlorpyrifos, ESP, bamidione, profenophos, marathon, PAP, dimethote, formotione, thiomethon, ethylthiomethrin, hosalon, PMP, DMTP. , Prothiophos, Sulfrophos, Pyraclophos, DDVP, Monochrometophos, BRP, CVMP, Dimethylbinphos, CVP, Propaphos, Acephate, Isophenphos, Salithion, DEP, EPN, Ethion, NAC, MTMC, MIPC, BPMC, PHC, MPMC, XMC, Ethiofencarb, Bendiocarb, Pyrimicurve, Carbosulfane, Benfracarb, Mesomil, Thiodicalve, Alanicalve, Allethrin, Resmethrin, Permethrin, Cypermethrin, Cihalothrin, Cypermethrin, Fenvpropatrin, Tralomethrin, Cycloprothrin, Fenvalerate, Flucitrinate Fluvalinate, Etofenprox, Cartap, Thiocyclum, Bensultap, Diazinon, Teflubenzron, Chlorpyrifosulone, Buflofedin, Phenoxycarb, Insecticide chrysanthemum, Delice, Nicotin sulfate, Machine oil, Rapeseed oil, CPCBS, Kelsen, Chlorpyrifos, Phenisobromo Rate, tetradiphon, BPPS, quinoxalin, amitraz, benzomate, phenothiocarb, hexithiazox, fenvaltic oxide, dienochlor, fenveloximate, fluazinum, pyridaben, chlorpyrifostin, DPC, polynaphthin complex, milbemectin, DCIP, dasomet, benzoepine, metaaldehyde BT, fentrothione and the like can be mentioned.

Examples of the fungicide include kasgamicin, benomil, thiabendazole, thiophanate methyl, thiuram, prochloraz, trifumisol, ipconazole, basic copper chloride, basic copper sulfate, cupric hydroxide, copper nonylphenol sulfonate, DBEDC, copper terephthalate, and inorganic. Sulfur, geneb, manneb, manzeb, ambam, polycarbamate, organic nickel, propineb, dilam, thiadiadin, captan, sulfonic acid, TPN, fusalide, IBP, EDDP, turquophosmethyl, pyrazophos, Josetil, carbendazole, dietofencarb, iprodion, Binclozoline, procimidone, fluorimide, oxycarboxyne, mepronyl, flutranyl, tecrophthalam, tricramide, pencyclon, metalaxyl, oxadixyl, triazimefone, bitertanol, microbutanyl, hexaconazole, propiconazole, phenalimol, pyriphenox, triphorin, blastsaidin S , Polyoxin, Varidamycin, Streptomycin, Oxytetracycline, Mildiomycin, PCNB, Hydroxyisoxazole, Echromezol, Chloroneb, Metasulfocarb, Methylisothiocyanate, Organic arsenic, Zinc sulfate, Dithianone, Benzothiazole, Kinoxaline, CNA, Dimethilimol , Dichromedin, Triazine, Felimzone, Fluazinum, Provenazole, Isoprothiolane, Tricyclazole, Pyroquilone, Oxolinic acid, Iminoctadine acetate, Arginic acid, Antibacterial, Shiitake mycelium extract, Koji fungus product, Agrobacterium radiobacter, Imibenconazole, etc. Can be mentioned.

Examples of the plant growth regulator include inabenfide, oxyethylene docosanol, nicotinamide, benzylaminopurine and the like.

In the pesticide granular composition of the present invention, the content of the pesticide binder with respect to 100 parts by mass of the pesticide active ingredient is preferably 0.5 parts by mass or more and 20 parts by mass or less, and more preferably 0.7 parts by mass or more and 15 parts by mass or less. , 0.8 parts by mass or more and 10 parts by mass or less is more preferable, and 1.0 parts by mass or more and 5 parts by mass or less is particularly preferable. Further, in the pesticide granular composition of the present invention, the content of ethylene-modified PVA in the pesticide binder with respect to 100 parts by mass of the pesticide active ingredient is preferably 0.5 parts by mass or more and 20 parts by mass or less, preferably 0.7% by mass. More than 15 parts by mass, more preferably 0.8 parts by mass or more and 10 parts by mass or less. When the content of the pesticide binder or ethylene-modified PVA with respect to the pesticide active ingredient is within the above range, a pesticide granular composition having excellent grain strength and sustained release property can be easily produced.

[Manufacturing method of pesticide granular composition]
Examples of the method for producing the pesticide granular composition of the present invention include a method of granulating the pesticide active ingredient by adding a pesticide binder containing the ethylene-modified PVA as an aqueous solution or together with water. The pesticide active ingredient is preferably in the form of powder, and is preferably pulverized to an average particle size of 0.1 mm or less. When the pesticide binder is added as an aqueous solution to the powder composed of the pesticide active ingredient, a method of spraying the powder composed of the pesticide active ingredient while stirring the aqueous solution of the pesticide binder to granulate is preferable. On the other hand, when the above pesticide binder is added to the powder composed of the pesticide active ingredient together with water for granulation, a required amount of water is added in advance to the powder composed of the raw material pesticide active ingredient to make it moist or crushed. Examples thereof include a method of adding water to granulate after adding and mixing a powdery pesticide binder to the powder composed of the pesticide active ingredient, or while mixing. Above all, from the viewpoint that the pesticide binder can be more uniformly dispersed in the obtained pesticide granular composition and the binder performance can be further exhibited, the pesticide binder containing the ethylene-modified PVA with respect to the powder composed of the pesticide active ingredient. Is preferable as an aqueous solution for granulation. Here, the average particle size is the average size of the powder consisting of 100 pesticide active ingredients in the field of view when observing an arbitrary cut surface of the powder composed of the pesticide active ingredient of the present invention with an electron microscope. Refers to the calculated value. When the powder composed of the pesticide active ingredient has a shape other than a circle such as an ellipse, the value of the major axis is used for calculation.

The powder composed of the pesticide active ingredient of the raw material is subjected to the granulation step with or after adding the above-mentioned pesticide binder. This granulation step is generally carried out using a dish-type granulator while spraying an aqueous solution or water of the agrochemical binder. As a result, the powder composed of the pesticide active ingredient charged into the granulator associates with the sprayed liquid to form a loose agglomerate, which is tightened by the rolling motion of the granulator to reduce the voids between the particles. It becomes a granular material. The amount of water sprayed during this granulation can be determined by the degree of wetness of the grain surface. When a relatively large amount of water is added, the particle size of the pesticide granular composition obtained becomes large, and when the amount of water is small, the particle size of the pesticide granular composition obtained becomes small and the proportion of powder increases. The amount can be adjusted.

The granulated pesticide granular composition is dried by a shelf-type dryer, a fluidized dryer, a rotary kiln, or the like. For example, when using a shelf-type dryer, it is preferable to spread it thinly and evenly on a drying shelf and dry it at 100 ° C. for about 30 minutes.

The particle size of the pesticide granular composition of the present invention is not particularly limited, and is preferably 0.01 μm or more and 10 mm or less, more preferably 0.1 μm or more and 8 mm or less, and further preferably 1 μm or more and 5 mm or less. Here, the particle size refers to a value calculated by averaging the sizes of 100 pesticide granular compositions in the field of view when observing an arbitrary cut surface of the pesticide granular composition of the present invention with an electron microscope. .. When the pesticide granular composition has a shape other than a circle such as an ellipse, the value of the major axis is used for calculation.

The present invention includes various combinations of the above configurations within the technical scope of the present invention as long as the effects of the present invention are exhibited.

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples, and many modifications are made in the art within the technical idea of the present invention. It is possible by a person with ordinary knowledge. In the following Examples and Comparative Examples, “parts” and “%” indicate “parts by mass” and “% by mass”, respectively, unless otherwise specified.

In the following Examples and Comparative Examples, the viscosity average degree of polymerization of ethylene-modified PVA, the degree of saponification, the content of 1,2-glycol bond units, the water resistance of the pesticide binder, the viscosity stability of the pesticide binder aqueous solution, and the like. The grain strength and sustained release property of the pesticide granular composition were measured or evaluated by the following methods.

[Viscosity average degree of polymerization of ethylene-modified PVA]
The viscosity average degree of polymerization of each ethylene-modified PVA was determined by the method described in JIS K 6726 (1994).

[Saponification degree of ethylene-modified PVA]
The saponification degree of each ethylene-modified PVA was determined by the method described in JIS K 6726 (1994).

[Content of 1,2-glycol bond unit of ethylene-modified PVA]
The ethylene-modified PVA obtained in the following examples was dissolved in water in an open container for about 2 hours, and then the solution was spilled on a polyethylene terephthalate substrate and dried to prepare a cast film.

The film obtained by the above method _{is dissolved in DMSO-d 6} to make a 0.1% by mass solution, and a few drops (about 0.1 ml) of trifluoroacetic acid are added to the solution to make ¹ H-NMR (500 MHz). Was measured at 80 ° C. The content of the 1,2-glycol bond unit (monomer unit bonded by 1,2-glycol bond) is a peak (integrated value α) of 3.2 to 4.0 ppm derived from the methine proton of the vinyl alcohol unit. And a peak of 3.25 ppm (integrated value β) derived from one methine proton of the 1,2-glycol binding unit, which is calculated according to the following formula (I).
Content of 1,2-glycol binding unit of ethylene-modified PVA (mol%)
= 100 × β / α (I)

[Water resistance of pesticide binder]
A 10% by mass (solid content of ethylene-modified PVA) aqueous solution of the agrochemical binder obtained in Examples and Comparative Examples described later was cast to form a film at 50 ° C. to prepare a 50 μm test piece film. A part of the obtained test body membrane was heat-treated at 120 ° C. for 10 minutes. The test body membrane was immersed in water at 20 ° C. for 24 hours and then taken out, and the feel of rubbing the membrane by hand was evaluated on a 5-point scale.
A: The film feels the same as when it is dry and is firm.
B: The film is relatively firm, but it has a slightly slimy feel.
C: The film remains, but it feels slimy.
D: A part of the film remains, but it cannot be taken out.
E: The membrane is completely dissolved.

[Viscosity stability of aqueous binder solution for pesticides]
The agrochemical binders obtained in Examples and Comparative Examples described later were prepared in an amount of 10% by mass (solid content of ethylene-modified PVA) to obtain an aqueous solution. Then, the aqueous solution was placed in a 300 ml glass beaker and left at 5 ° C for 1 day, and after leaving at 5 ° C _{, the ratio of the viscosity (η 1 day} ) to the initial viscosity at 5 ° C (η _initial ) (thickness thickening ratio = η). _{1 day} / _initial stage of η) was calculated and evaluated according to the following criteria. The measurement was carried out at 20 ° C. using a B-type viscometer (rotation speed 12 rpm) according to the rotational viscometer method of JIS K 6726 (1994).
A: η _{1 day} / η _initial was 1 or more and less than 5.
B: η _{1 day} / η _{initial time} was 5 or more.

[Grain strength of pesticide granular composition]
The pesticide granular composition obtained in Examples and Comparative Examples described later is sieved over a standard sieve of 3.55 to 4.0 mm, and the grains remaining on the 3.35 mm sieve are used as a test sample. Place one test sample on a spring-loaded table with a maximum weighing of 70 N, press it with a hard round bar with a cut end of about 10 mm in diameter and a flat end face, and read the indicated value N when the grain breaks. , The average value of the 10 pieces is taken as the grain strength (N / grain) of the product.

[Sustained release (non-collapse) of pesticide granular composition]
The pesticide granular composition granulated in Examples and Comparative Examples described later is sieved by stacking 2 mm and 4 mm standard sieves, and the 2 mm sieve is used as a test sample. Place the test sample on a 2 mm wire mesh and place it in a vat, and gently pour water at 10 ° C. so that the sample is fully immersed in water. After allowing this to stand in a room at 10 ° C. for 5 hours, the proportion (mass) of the pesticide granular composition retained on the sieve was measured and used as an index of sustained release.

[Example 1]
(PVA-1: Production of ethylene-modified PVA)
106.1 kg of vinyl acetate and 43.9 kg of methanol were charged into a 250 L pressure reaction vessel equipped with a stirrer, a nitrogen inlet, an ethylene inlet, an initiator addition port and a delay solution addition port, and the temperature was raised to 60 ° C. and then 30. The system was nitrogen-substituted by nitrogen bubbling for minutes. Next, ethylene was introduced so that the reaction vessel pressure was 1.4 kg / cm ^2. Prepare a 2.8 g / L solution in which 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile) (AMV) was dissolved in methanol as an initiator, and bubbling with nitrogen gas to replace nitrogen. did. After adjusting the temperature inside the polymerization tank to 60 ° C., 53 ml of the above-mentioned initiator solution was injected to initiate polymerization. During the polymerization, ethylene was introduced to maintain the reaction vessel pressure at 1.4 kg / cm ² and the polymerization temperature at 60 ° C., and AMV was continuously added at 168 ml / hr using the above-mentioned initiator solution for polymerization. After 4 hours, when the polymerization rate reached 20%, the mixture was cooled to stop the polymerization. After opening the reaction vessel to remove ethylene, nitrogen gas was further bubbled. Then, the unreacted vinyl acetate monomer was removed under reduced pressure to prepare a methanol solution of ethylene-modified polyvinyl acetate (ethylene-modified PVAc). 46.5 g (acetic acid in ethylene-modified PVAc) was added to 400 g (100 g of ethylene-modified PVAc in the solution) of ethylene-modified PVAc adjusted to have a concentration of 25% by adding methanol to the obtained ethylene-modified PVAc solution. An alkaline solution (10% methanol solution of NaOH) having a molar ratio of [MR] 0.10) was added to the vinyl unit, and saponification was carried out at 40 ° C. After the addition of alkali, the gelled product was pulverized with a pulverizer, and a saponification reaction was carried out for a total of 1 hour, and then 1000 g of methyl acetate was added to neutralize the remaining alkali. After confirming the completion of neutralization using a phenolphthalein indicator, 1000 g of methanol was added to the white solid PVA obtained by filtration, and the mixture was washed at room temperature for 3 hours. After repeating the above washing operation three times, the PVA obtained by centrifugal deflation was left in a dryer at 70 ° C. for 2 days to obtain ethylene-modified PVA (PVA-1). Table 2 shows the results of evaluating the physical characteristics of PVA-1 and the water resistance and viscosity stability of PVA-1 as a binder for agricultural chemicals according to the above method.

(Preparation of pesticide granular composition)
A mini dish-type granulator with a diameter of 240 mm (manufactured by AS ONE Co., Ltd.) while spraying a 10% by mass aqueous solution of PVA-1 as an aqueous solution of a pesticide binder on processed ore diaphosphate fertilizer powder crushed to a particle size suitable for granulation. ) To obtain a pesticide granular composition. In the obtained pesticide granular composition, the solid content of PVA-1 was 3 parts by mass with respect to 100 parts by mass of the processed ore diphosphate fertilizer powder as a raw material. The obtained pesticide granular composition was dried in a shelf-type dryer kept at 100 ° C., and then the grain strength and sustained release were evaluated according to the above method. The results are shown in Table 2.

[Examples 2 to 4]
(Manufacturing of PVA-2 to PVA-4)
Except that the polymerization conditions such as ethylene, vinyl acetate and methanol, the amount of the initiator, the polymerization rate, the amount of the ethylene-modified PVAc solution and the saponification catalyst solution at the time of saponification, the concentration and the saponification temperature were changed as shown in Table 1. Various PVAs (PVA-2 to PVA-4) were produced by the same method as in Example 1. Table 2 shows the results of evaluating the physical characteristics of PVA-2 to PVA-4 and the water resistance and viscosity stability of PVA-2 to PVA-4 as a binder for agricultural chemicals according to the above method.

[Comparative Example 1]
(Manufacturing of PVA-5)
2.4 kg of vinyl acetate and 1.0 kg of methanol were charged into a reaction vessel equipped with a stirrer, a nitrogen inlet, and an initiator addition port, and the temperature was raised to 60 ° C., and then nitrogen was replaced in the system by nitrogen bubbling for 30 minutes. Then, a solution prepared by dissolving 2,2'-azobis (isobutyronitrile) (AIBN) in methanol as an initiator was prepared, and bubbling with nitrogen gas was performed to replace the nitrogen. After adjusting the temperature inside the polymerization tank to 60 ° C., 10 ml of the above-mentioned initiator solution was injected to initiate polymerization. After 1.4 hours, when the polymerization rate reached 30%, the mixture was cooled to stop the polymerization. The unreacted vinyl acetate monomer was removed to prepare a methanol solution of polyvinyl acetate (PVAc). 32.6 g (molar ratio [MR] to vinyl acetate unit in PVAc] to 400 g (100 g of PVAc in the solution) of PVAC adjusted to a concentration of 25% by adding methanol to the obtained PVAc solution. An alkaline solution of 0.07) (10% methanol solution of NaOH) was added, and saponification was carried out at 40 ° C. After the addition of alkali, the gelled product was pulverized with a pulverizer, and a saponification reaction was carried out for a total of 1 hour, and then 1000 g of methyl acetate was added to neutralize the remaining alkali. After confirming the completion of neutralization using a phenolphthalein indicator, 1000 g of methanol was added to the white solid PVA obtained by filtration, and the mixture was washed at room temperature for 3 hours. After repeating the above washing operation three times, PVA obtained by centrifugal deflation was left in a dryer at 70 ° C. for 2 days to dry to obtain PVA (PVA-5). Table 2 shows the results of evaluating the physical characteristics of PVA-5 and the water resistance and viscosity stability of PVA-5 as a binder for agricultural chemicals according to the above method.

[Comparative Example 2]
(Manufacturing of PVA-6)
Comparative Example 1 and Comparative Example 1 except that the polymerization conditions such as vinyl acetate and methanol, the amount of the initiator, the polymerization rate, the amount of the PVAc solution and the saponification catalyst solution at the time of saponification, the concentration and the saponification temperature were changed as shown in Table 1. PVA-6 was produced by the same method. Table 2 shows the results of evaluating the physical characteristics of PVA-6 and the water resistance and viscosity stability of PVA-6 as a binder for agricultural chemicals according to the above method.

[Comparative Example 3]
(Manufacturing of PVA-7)
1.36 kg of vinyl acetate and 2.04 kg of methanol were charged into a 5 L pressurized reaction vessel equipped with a stirrer, nitrogen inlet, ethylene inlet, initiator addition port and delay solution addition port, and nitrogen bubbling was performed at 0 ° C. for 30 minutes. The system was replaced with nitrogen. Next, ethylene was introduced and charged so that the reaction vessel pressure was 0.2 kg / cm ^2. 81.6 g of 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile) (AMV) was added as an initiator to initiate polymerization. During the polymerization, ethylene was introduced to maintain the reaction vessel pressure at 0.2 kg / cm ² and the polymerization temperature at 0 ° C., and the polymerization was carried out. After 35 hours, the polymerization was stopped when the polymerization rate reached 60%. After the reaction vessel was opened to deethylene, nitrogen gas was bubbled to completely deethylene. Then, the unreacted vinyl acetate monomer was removed under reduced pressure to prepare a methanol solution of ethylene-modified polyvinyl acetate (ethylene-modified PVAc). 46.5 g (acetic acid in ethylene-modified PVAc) was added to 400 g (100 g of ethylene-modified PVAc in the solution) of ethylene-modified PVAc adjusted to have a concentration of 25% by adding methanol to the obtained ethylene-modified PVAc solution. An alkaline solution (10% methanol solution of NaOH) having a molar ratio of [MR] 0.10) to the vinyl unit was added, and saponification was carried out at 60 ° C. After the addition of alkali, the gelled product was pulverized with a pulverizer, and a saponification reaction was carried out for a total of 1 hour, and then 1000 g of methyl acetate was added to neutralize the remaining alkali. After confirming the completion of neutralization using a phenolphthalein indicator, 1000 g of methanol was added to the white solid PVA obtained by filtration, and the mixture was washed at room temperature for 3 hours. After repeating the above washing operation three times, PVA obtained by centrifugal deflation was left in a dryer at 70 ° C. for 2 days to dry to obtain PVA (PVA-7). Table 2 shows the results of evaluating the physical characteristics of PVA-7 and the water resistance and viscosity stability of PVA-7 as a binder for agricultural chemicals according to the above method.

[Examples 2 to 4, Comparative Examples 1 to 3]
(Preparation of pesticide granular composition)
A pesticide granular composition was prepared in the same manner as in Example 1 except that various PVAs (PVA-2 to PVA-7) shown in Table 2 were used instead of PVA-1 in Example 1. Table 2 shows the results of evaluating the grain strength and sustained release property of the pesticide granular composition according to the above method.

As is clear from each of the above examples, the pesticide binder containing a specific ethylene-modified PVA as in the present invention has excellent water resistance and viscosity stability when made into an aqueous solution, and the pesticide obtained by using the pesticide binder. It can be seen that the granular composition has a high grain strength, a high residual ratio on the net at 10 ° C., and excellent sustained release over a long period of time. On the other hand, in Comparative Examples 1 and 2 in which the PVA used does not have an ethylene unit, it can be seen that the water resistance of the pesticide binder and the sustained release property of the obtained pesticide active ingredient are particularly lowered. It can be seen that the PVA of Comparative Example 3 having a low content of 1,2-glycol binding unit has poor viscosity stability and poor handleability when used as an aqueous solution as a binder for agricultural chemicals.

The present invention is useful for reducing the amount of pesticides used, improving yield and quality, and protecting the environment. Further, the pesticide granular composition of the present invention maintains the growing environment of crops in a preferable insect repellent state and nutrient state. It is possible to improve the yield and quality.

Claims (4)

The content of ethylene units is 1.0 mol% or more and 19 mol% or less, the content of 1,2-glycol bond units is 1.2 mol% or more and 2.0 mol% or less, and the viscosity average degree of polymerization is A pesticide binder containing an ethylene-modified vinyl alcohol-based polymer having a saponification degree of 80 mol% or more and 99.9 mol% or less, which is 200 or more and 5000 or less. A pesticide granular composition containing the pesticide binder and the pesticide active ingredient according to claim 1, wherein the content of the pesticide binder is 0.5 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the pesticide active ingredient. .. The pesticide granular composition according to claim 2, wherein the pesticide active ingredient is a fertilizer. The method for producing a pesticide granular composition according to claim 2 or 3, wherein a pesticide binder containing the ethylene-modified vinyl alcohol-based polymer is added as an aqueous solution or together with water to granulate the pesticide active ingredient.