JP2019011282A - Agricultural chemical binder, agricultural chemical granular composition, and manufacturing method therefor - Google Patents

Abstract

To provide an agricultural chemical binder excellent in water resistance and viscosity stability when made as a solution, an agricultural chemical composition in which granulated agricultural chemical composition is hardly broken and an agricultural chemical active component can be gradually released over a long time, and a manufacturing method therefor.SOLUTION: There is provided an agricultural chemical binder containing an ethylene modified vinyl alcoholic polymer having a content of an ethylene unit of 1.0 mol% or more and 19 mol% or less, a content of a 1,2-glycol binding unit of 1.2 mol% or more and 2.0 mol% or less, a viscosity average polymerization degree of 200 or more and 5000 or less, and a saponification degree of 80 mol% or more and 99.9 mol% or less.SELECTED DRAWING: None

Description

  INDUSTRIAL APPLICABILITY The present invention relates to a pesticide binder excellent in water resistance and viscosity stability when made into an aqueous solution, and a granulated pesticide granular composition that is less likely to disintegrate and that can slowly release a pesticide active ingredient over a long period of time. Regarding the method.

  2. Description of the Related Art Conventionally, granular pesticidal granular compositions obtained by granulating a mixture obtained by adding a binder to an pesticidal active ingredient with a granulator for the purpose of sufficiently exhibiting the control effect are known. In the pesticide granular composition, phytotoxicity to agricultural crops due to elution of the pesticide active ingredient in a short time is a problem, and the sustainability of the effect of the pesticide active ingredient is also a problem from the viewpoint of labor saving in farm work. In order to solve these points, various researches have been conducted on granular agricultural chemical compositions capable of controlling the elution amount of the agricultural chemical active ingredient.

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

  However, although the pesticidal granular compositions described in Patent Documents 1 to 3 are excellent in sustained release of pesticidal active ingredients, the pesticidal granular composition itself does not have sufficient granule strength, and impact during transportation or spraying There is a drawback that it is easily disintegrated when it is subjected to a long-term storage. From such a background, there is a demand for an agricultural binder that is resistant to disintegration of the granulated agrochemical granular composition and that can release the agrochemical active ingredient over a long period of time.

JP-A-8-277191 JP 2002-363003 A JP 2012-006881 A

  The present invention has been made in order to solve the above problems, and the binder for agricultural chemicals that is excellent in water resistance and viscosity stability when made into an aqueous solution, and the granulated agricultural chemical granular composition are not easily disintegrated, and for a long time. An object of the present invention is to provide an agrochemical granular composition capable of gradually releasing an agrochemical active ingredient and a method for producing the same.

  As a result of extensive 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 polymer, and the present invention has been completed.

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

  The binder for agricultural chemicals of the present invention is excellent in water resistance and viscosity stability when made into an aqueous solution. Moreover, the agrochemical granular composition obtained using the said agrochemical binder is hard to disintegrate, and the agrochemical active ingredient can be gradually released over a long period of time. Furthermore, according to the manufacturing method of the agrochemical granular composition of this invention, the agrochemical granular composition which has the above outstanding performances can be manufactured simply.

  Hereinafter, the present invention will be described in detail. Note that the present invention is not limited to the embodiments described below. In the present specification, the upper limit value and the lower limit value of the numerical ranges (content of each component, values calculated from each component, physical properties, etc.) can be appropriately combined.

[Binder for agricultural chemicals]
The binder for agricultural chemicals of the present invention has an ethylene unit content of 1.0 mol% to 19 mol%, and a 1,2-glycol bond unit content of 1.2 mol% to 2.0 mol%. An ethylene-modified vinyl alcohol polymer having a viscosity average polymerization degree of 200 or more and 5000 or less and a caking degree of 80 mol% or more and 99.9 mol% or less (hereinafter, the vinyl alcohol polymer is referred to as “PVA”). In some cases). The binder for agricultural chemicals containing such specific ethylene-modified PVA is excellent in water resistance and viscosity stability when made into an aqueous solution, and further, the agricultural chemical granular composition obtained using the agricultural chemical binder is not easily disintegrated, The pesticidal active ingredient can be gradually released over the period.

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

In the ethylene-modified PVA, the content of ethylene units is determined, for example, from ¹ H-NMR of a vinyl ester copolymer containing an ethylene unit that is a precursor or re-acetylated product of the ethylene-modified PVA. That is, the obtained vinyl ester copolymer was sufficiently purified by reprecipitation 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 copolymer for analysis. Make it. The polymer is dissolved in DMSO-d ₆ and measured at 80 ° C. using ¹ H-NMR (eg, 500 MHz). Ethylene units using a peak derived from the main chain methylene of the vinyl ester (4.7 to 5.2 ppm) and a peak derived from the main chain methylene of the ethylene, vinyl ester and the third component (0.8 to 1.6 ppm) The content of can be calculated.

The ethylene-modified PVA has a viscosity average polymerization degree of 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 polymerization degree is less than 200, the water resistance of the resulting pesticide binder becomes insufficient, and the resulting pesticide granular composition tends to collapse, and the effect of gradually releasing the pesticide active ingredient over a long period of time Becomes weak or the grain strength of the agrochemical granular composition becomes insufficient. On the other hand, ethylene-modified PVA having a viscosity average polymerization degree exceeding 5000 is difficult to produce. The viscosity average degree of polymerization (P) of ethylene-modified PVA is measured according to JIS-K6726 (1994). That is, after re-saponifying and purifying ethylene-modified PVA, the intrinsic viscosity is calculated from the intrinsic viscosity [η] (dl / g) measured in water at 30 ° C. by the following equation.
P = ([η] × 10 ³ /8.29) ^{(1 / 0.62)}

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

  The ethylene-modified PVA has a 1,2-glycol bond unit content of 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 less. % To 1.8 mol% is more preferable. When the content of 1,2-glycol bond units 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 bond units exceeds 2.0 mol%. The content of 1,2-glycol bonding units 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 polymerization temperature is preferred in the present invention.

The content of 1,2-glycol bonding units was determined by dissolving the obtained ethylene-modified PVA in water in an open container over about 2 hours, and then pouring the solution on a polyethylene terephthalate substrate and drying it to cast film Was made. The obtained film was dissolved in DMSO-d ₆ , measured using ¹ H-NMR (500 MHz) at 80 ° C., and calculated.

  The ethylene-modified PVA is, for example, obtained by copolymerizing ethylene and a vinyl ester monomer to obtain a vinyl ester copolymer having an ethylene unit, and then converting the vinyl ester copolymer to saponification such as sodium hydroxide. It can be obtained by saponification using a catalyst and, if necessary, grinding and drying.

  Examples of the copolymerization method of ethylene and a vinyl ester monomer include known methods such as a bulk polymerization method, a solution polymerization method, a suspension polymerization method, and an emulsion polymerization method. Among them, a bulk polymerization method or a solution polymerization method in which polymerization is performed without solvent or in a solvent such as alcohol can be usually employed. Examples of the alcohol include lower alcohols such as methanol, ethanol, and propanol. As initiators used for copolymerization, 2,2′-azobis (isobutyronitrile), 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2′-azobis Known initiators such as azo initiators or peroxide initiators such as (2,4-dimethyl-valeronitrile), benzoyl peroxide, and n-propyl peroxydicarbonate are included.

  There is no restriction | limiting in particular in superposition | polymerization temperature, 0 to 150 degreeC is preferable, Room temperature or more and 150 degrees C or less are more preferable, Room temperature or more and the boiling point or less of the solvent to be used are more preferable, 30 to 60 degreeC is especially preferable.

  Examples of the vinyl ester monomers include vinyl formate, vinyl acetate, vinyl propionate, vinyl valelate, vinyl caprate, vinyl laurate, vinyl stearate, vinyl benzoate, vinyl pivalate and vinyl versatate. 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. Examples of 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, 1,4-butanediol vinyl ether; allyl ethers such as allyl acetate, propyl allyl ether, butyl allyl ether, hexyl allyl ether; oxyalkylene Monomers having a group; vinylsilanes such as vinyltrimethoxysilane; isopropenyl acetate, 3-buten-1-ol, 4-penten-1-ol, 5-hexen-1-ol , 7-octen-1-ol, 9-decen-1-ol, hydroxy group-containing α-olefins such as 3-methyl-3-buten-1-ol; ethylene sulfonic acid, allyl sulfonic acid, methallyl sulfone Monomers having a sulfonic acid group derived from acid, 2-acrylamido-2-methylpropanesulfonic acid, etc .; vinyloxyethyltrimethylammonium chloride, vinyloxybutyltrimethylammonium chloride, vinyloxyethyldimethylamine, vinyloxymethyldiethylamine, N-acrylamidomethyltrimethylammonium chloride, 3- (N-methacrylamide) propyltrimethylammonium chloride, N-acrylamidoethyltrimethylammonium chloride, N-acrylamidodimethylamine, allylto Methyl ammonium chloride, methallyl trimethylammonium chloride, dimethyl allyl amine include monomers having a cationic group derived from the allyl ethyl amine. The content of these monomers varies depending on the purpose and application used, but is preferably 10 mol% or less, more preferably less than 5.0 mol%, and even more preferably 1.0 mol%. It may be less than 0.5 mol%.

  The binder for agricultural chemicals of the present invention may consist essentially of the ethylene-modified PVA. The term “consisting essentially of the ethylene-modified PVA” means that components other than the ethylene-modified PVA may be less than 5.0% by mass, less than 1.0% by mass, and 0.5% by mass. It means that it may be less than 0.1% by mass. Moreover, the agrochemical binder may contain other components (inorganic or organic) in addition to ethylene-modified PVA. Examples of the inorganic substance include talc, calcium carbonate, clay, diatomaceous earth, silica, metal oxide, and sulfur for the purpose of adjusting elution and increasing the amount. Examples of organic substances include organic substances such as resin compounds, surfactants, waxes, and organic pigments. These other components may be used individually by 1 type, and may use 2 or more types together. Examples of the resin compound include a thermosetting resin and a thermoplastic resin. Examples of the thermosetting resin include polyurethane, epoxy resin, alkyd resin, unsaturated polyester, phenol resin, urea / melamine resin, urea resin, and silicone resin. Examples of the thermoplastic resin include polyolefins such as polyethylene, polypropylene, polybutene and polystyrene; polyvinyl acetate, polyvinyl chloride, polyvinylidene chloride, polyacrylic acid, polymethacrylic acid, polyacrylic acid ester, polymethacrylic acid ester and the like. Vinyl polymer resins; polybutadiene, polyisoprene, polychloroprene, butadiene-styrene copolymers, ethylene-propylene-diene copolymers, diene polymers such as styrene-isoprene copolymers; ethylene-propylene copolymers, 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 Bini - polyolefin copolymer, such as carbon monoxide copolymer; vinyl chloride - vinyl acetate copolymer, vinylidene chloride - vinyl chloride copolymer of a vinyl chloride copolymer, and the like. Although there is no restriction | limiting in particular in content of these other components, Usually, 10 mass parts or less are preferable with respect to 100 mass parts of ethylene modified PVA, 5 mass parts or less are more preferable, and 3 mass parts or less are more preferable.

[Pesticide granular composition]
The agrochemical granular composition of the present invention contains the agrochemical binder and the agrochemical active ingredient, and the content of the agrochemical binder with respect to 100 mass parts of the agrochemical active ingredient is preferably 0.5 parts by mass or more and 20 parts by mass or less. The agrochemical granular composition of the present invention is obtained by granulating an agrochemical active ingredient using the agrochemical binder containing the ethylene-modified PVA. Agrochemical active ingredients include fertilizers, herbicides, insecticides, fungicides, plant regulators and the like. The agrochemical active ingredient may be used alone or in combination of two or more.

  As fertilizers, for example, oxamide, crotonylidene diurea (CDU), isobutylidene diurea (IB), ureaform, molten phosphate fertilizer, mixed phosphate fertilizer, by-acid lime fertilizer, calcium carbonate fertilizer, mixed lime fertilizer, mineral silicic acid Examples include fertilizers, other siliceous fertilizers, hydroxylated bitter fertilizers, by-acid bitter fertilizers, processed bitter fertilizers, mineral manganese fertilizers, and soluble trace element fertilizers. In addition, the present invention can be applied to processed mineral silicic acid fertilizer and the like for the purpose of silicic acid supply and pH correction by alkali as well as mineral silicic acid fertilizer. Among them, oxamide, crotonylidene diurea (CDU), isobutylidene diurea (IB), ureaform, processed mineral phosphophosphate fertilizer, mineral silicate acid fertilizer, and mixed phosphate fertilizer are preferable.

  As herbicides, for example, 2,4-PA, MCP, MCPB, MCPA thioethyl (phenothiol), chromeprop, naproanilide, CNP, clomethoxynil, biphenox, MCC, beniocarb, eprocarb, molinate, dimethylpiperate, DCPA, butachlor, pretilachlor, bromobutide , Mefenacet, diemron, cimethrin, promethrin, dimetamethrin, bedazone, oxadiazone, pyrazolate, pyrazoxifene, benzophenap, trifluralin, piperophos, ACN, bensulfuron methyl and the like.

  Insecticides include, for example, MPP, MEP, ECP, pyrimifosmethyl, diazinon, isoxathion, pyridafenthione, fluropyrifosmethyl, chlorpyrifos, ESP, bamidthione, profenofos, marathon, PAP, dimethoate, formotethione, thiomethone, ethylthiomethone, hosalon, PMP, DMTP , Prothiophos, sulprophos, pyracrofos, DDVP, monocrotophos, BRP, CVMP, dimethylvinphos, CVP, propaphos, acephate, isofenphos, salicione, DEP, EPN, ethion, NAC, MTMC, MIPC, BPMC, PHC, MPMC, XMC, Etiophencarb, bendiocarb, pyrimicarb, carbosulfan, benfracarb, mesomil, thiodicarb, alani Lub, Areslin, Resmethrin, Permethrin, Cypermethrin, Cyhalothrin, Cyfluthrin, Fenpropatoline, Tralomethrin, Cycloproton, Fenvalerate, Flucitratenate, Fulvalinate, Etofenprox, Cartap, Thiocyclam, Bensultap, Diflubenzuron, Chlorbenzuron, Chlor Fluazuron, bufurofezin, phenoxycarb, insecticidal chrysanthemum, delis, nicotine sulfate, machine oil, rapeseed oil, CPCBS, kelsen, chlorbenzilate, phenisobromolate, tetradiphone, BPPS, quinoxaline, amitraz, benzomate, phenothiocarb, hexithiazox, fenbutazin oxide , Dienochlor, fenpyroximate, fluazinam, pyridaben, clofentezine, PC, Porinafuchin complex, milbemectin, DCIP, dazomet, Benzoepin, metaldehyde, DCV, BT, Fentorochion and the like.

  Examples of fungicides include kasugamycin, benomyl, thiabendazole, thiophanate methyl, thiuram, prochloraz, trifumizole, ipconazole, basic copper chloride, basic copper sulfate, cupric hydroxide, copper nonylphenol sulfonate, DBEDC, copper terephthalate, inorganic Sulfur, Dinebu, Mannebu, Manzeb, Amberm, Polycarbamate, Organic nickel, Propineb, Diram, Thiadiazine, Captan, Sulfenic acid, TPN, Fusalide, IBP, EDDP, Torcrofosmethyl, Pyrazophos, Fosetyl, Carbendazole, Dietofencarb, Iprodione, Vinclozoline, Procymidone, Fluorimide, Oxycarboxin, Mepronil, Flutolanil, Tecofhalam, Triclamide, Pencyclone, Metalaxyl Oxadixyl, triadimephone, vitertanol, microbutanyl, hexaconazole, propiconazole, phenarimol, pyrifenox, triphorin, blasticidin S, polyoxin, validamycin, streptomycin, oxytetracycline, mildiomycin, PCNB, hydroxyisoxazole, echromomezol , Chloronebu, metasulfocarb, methyl isothiocyanate, organic arsenic, zinc sulfate, dithianone, benzothiazole, quinoxaline, CNA, dimethymol, dichromedin, triazine, ferimzone, fluazinam, probenazole, isoprothiolane, tricyclazole, pyroxylone, oxolinic acid, iminocudazine acetic acid Salt, alginic acid, antibacterial, shiitake mycelium extract, koji fungus Organism, Agrobacterium radiobacter, imibenconazole, and the like.

  Examples of plant regulators include inabenfide, oxyethylene docosanol, nicotinamide, and benzylaminopurine.

  In the granular agricultural composition of the present invention, the content of the binder for agricultural chemicals is preferably 0.5 parts by mass or more and 20 parts by mass or less, more preferably 0.7 parts by mass or more and 15 parts by mass or less with respect to 100 parts by mass of the agricultural chemical active ingredient. 0.8 parts by mass or more and 10 parts by mass or less are more preferable, and 1.0 part by mass or more and 5 parts by mass or less are particularly preferable. Moreover, in the agrochemical granular composition of the present invention, the content of the ethylene-modified PVA in the agrochemical binder with respect to 100 parts by mass of the agrochemical active ingredient is preferably 0.5 parts by mass or more and 20 parts by mass or less, and 0.7 masses. Part to 15 parts by mass, more preferably 0.8 part to 10 parts by mass. When the content of the pesticide binder or the ethylene-modified PVA with respect to the pesticide active ingredient is within the above range, a pesticide granular composition excellent in grain strength and sustained release can be easily produced.

[Production method of agrochemical granular composition]
As a manufacturing method of the agrochemical granular composition of this invention, the method of granulating by adding the binder for agricultural chemicals containing the said ethylene modified PVA as an aqueous solution or with water with respect to the said agrochemical active ingredient, for example is mentioned. The agrochemical active ingredient is preferably in the form of a powder, and is preferably pulverized to an average particle size of 0.1 mm or less. When the agrochemical binder is added as an aqueous solution to the powder comprising the agrochemical active ingredient, a method of spraying and granulating the agrochemical active ingredient powder while stirring the agrochemical binder aqueous solution is preferable. On the other hand, when adding the agrochemical binder to the powder composed of the agrochemical active ingredient together with water and granulating, the powder composed of the agrochemical active ingredient as a raw material is preliminarily wetted or pulverized. An example is a method of adding and mixing a powdery pesticide binder to a powder composed of the pesticidal active ingredient and granulating it by adding water while mixing. Among them, from the viewpoint of being able to disperse the pesticide binder more uniformly in the resulting pesticide granular composition and further exhibiting the binder performance, the pesticide binder containing the ethylene-modified PVA with respect to the powder comprising the pesticide active ingredient. The method of adding and granulating as an aqueous solution is preferable. Here, the average particle size is obtained by averaging the sizes of 100 powders composed of 100 pesticidal active ingredients that are in the visual field when an arbitrary cut surface of the powder composed of the pesticidal active ingredients of the present invention is observed with an electron microscope. Indicates the calculated value. When the powder composed of the pesticidal active ingredient has a shape other than a circle such as an ellipse, it is calculated using the value of the major axis.

  The powder composed of the raw material agricultural chemical active ingredient is subjected to a granulation step while adding or after adding the above agricultural chemical binder. This granulation step is generally performed using a dish type granulator while spraying the aqueous solution or water of the agrochemical binder. As a result, the powder composed of the pesticidal active ingredient charged into the granulator is associated with the sprayed liquid to form loose agglomerates, which are tightened by the rolling operation of the granulator, and there are few voids between the particles. It becomes a granular material. The amount of water sprayed during this granulation can be determined by the wetness of the grain surface. When a relatively large amount of water is added, the particle size of the resulting pesticidal granular composition is large, and when the amount of water is small, the particle size of the pesticidal granular composition is small and the proportion of the powder is large. The amount can be adjusted.

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

  There is no restriction | limiting in particular in the particle diameter of the agrochemical granular composition of this invention, 0.01 micrometer or more and 10 mm or less are preferable, 0.1 micrometer or more and 8 mm or less are more preferable, and 1 micrometer or more and 5 mm or less are more preferable. Here, the particle diameter refers to a value calculated by averaging the sizes of 100 pesticidal granular compositions that fall within the field of view when an arbitrary cut surface of the pesticidal granular composition of the present invention is observed with an electron microscope. . When the pesticide granular composition has a shape other than a circle such as an ellipse, it is calculated using the value of the major axis.

  The present invention includes embodiments in which the above-described configurations are variously combined within the technical scope of the present invention as long as the effects of the present invention are exhibited.

  EXAMPLES Next, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples at all, and many variations are within the technical idea of the present invention. This is possible by those with ordinary knowledge. In the following Examples and Comparative Examples, “part” and “%” represent “part by mass” and “% by mass”, respectively, unless otherwise specified.

  In the following examples and comparative examples, the viscosity average polymerization degree of ethylene-modified PVA, the degree of saponification, and the content of 1,2-glycol bonding units, the water resistance of agricultural chemical binders, the viscosity stability of agricultural chemical binder aqueous solutions, The grain strength and sustained release properties of the agricultural chemical granular composition were measured or evaluated by the following methods.

[Viscosity average polymerization degree 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 degree of saponification 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 over about 2 hours, and then the solution was poured onto 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, a few drops (about 0.1 ml) of trifluoroacetic acid is added to the solution, and ¹ H-NMR (500 MHz) is added. And measured at 80 ° C. The content of 1,2-glycol bond unit (monomer unit bonded by 1,2-glycol bond) is 3.2 to 4.0 ppm peak (integral value α) derived from methine proton of vinyl alcohol unit. And a peak at 3.25 ppm (integrated value β) derived from one methine proton of a 1,2-glycol bond unit, is calculated according to the following formula (I).
Content of 1,2-glycol bond unit of ethylene-modified PVA (mol%)
= 100 × β / α (I)

[Water resistance of agrochemical binders]
An aqueous 10% by weight (solid content of ethylene-modified PVA) aqueous solution of the binder for agricultural chemicals obtained in Examples and Comparative Examples described later was cast at 50 ° C. to prepare a 50 μm specimen film. A part of the obtained specimen film was heat-treated at 120 ° C. for 10 minutes. The test specimen membrane was taken out after being immersed in water at 20 ° C. for 24 hours, and the feeling of rubbing the membrane by hand was evaluated in five stages.
A: The film is firm and feels the same as when dry.
B: The film is relatively firm, but has a slightly slimy feeling.
C: Although the film remains, there is a slimy feel.
D: Part of the film remains, but cannot be removed.
E: The membrane is completely dissolved.

[Viscosity stability of aqueous binder solution for agricultural chemicals]
The binder for agricultural chemicals obtained in Examples and Comparative Examples described later was prepared to 10% by mass (solid content of ethylene-modified PVA) to obtain an aqueous solution. The aqueous solution was then placed in a 300 ml glass beaker and allowed to stand at 5 ° C. for 1 day. After standing at 5 ° C., the ratio of viscosity (η _{1 day} ) to 5 ° C. initial viscosity (η _initial ) (thickening ratio = η _{1 day} / η _initial ) was determined and evaluated according to the following criteria. The measurement was performed 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 was 5 or more.

[Grain strength of agrochemical granular composition]
The agricultural chemical granular compositions obtained in the examples and comparative examples described later are passed through a sieve in which a 3.35 to 4.0 mm standard sieve is overlapped, and the particles remaining on the 3.35 mm sieve are used as test samples. Place one test sample on a plate of a spring-type table with a maximum weight of 70 N, press the cut end with a hard round bar with a flat end face with a diameter of about 10 mm, 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-disintegrating) of agricultural chemical granular composition]
The agricultural chemical granular compositions granulated in Examples and Comparative Examples described later are sieved with 2 mm and 4 mm standard sieves, and the 2 mm sieve is used as a test sample. The test sample is placed on a 2 mm mesh and placed in a vat, and 10 ° C. water is poured gently so that the sample is sufficiently immersed in water. This was allowed to stand in a room at 10 ° C. for 5 hours, and then the proportion (mass) of the agricultural chemical granular composition kept on the sieve was measured and used as an indicator of sustained release.

[Example 1]
(PVA-1: Production of ethylene-modified PVA)
A 250 L pressure reactor equipped with a stirrer, nitrogen inlet, ethylene inlet, initiator addition port and delay solution addition port was charged with 106.1 kg of vinyl acetate and 43.9 kg of methanol, heated to 60 ° C. and then heated to 30 ° C. The system was purged with nitrogen by nitrogen bubbling for 1 minute. Next, ethylene was introduced so that the reactor pressure was 1.4 kg / cm ² . Prepare a 2.8 g / L solution of 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile) (AMV) dissolved in methanol as an initiator, and perform nitrogen substitution by bubbling with nitrogen gas. did. After adjusting the polymerization tank internal temperature to 60 ° C., 53 ml of the 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 polymerization was carried out by continuously adding AMV at 168 ml / hr using the above initiator solution. After 4 hours, the polymerization rate was stopped when the polymerization rate reached 20%. After opening the reaction vessel and removing ethylene, nitrogen gas was further bubbled. Next, unreacted vinyl acetate monomer was removed under reduced pressure to obtain 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 of ethylene-modified PVAc methanol solution (100 g of ethylene-modified PVAc in the solution) prepared by adding methanol to the obtained ethylene-modified PVAc solution to a concentration of 25%. Saponification was performed at 40 ° C. by adding an alkaline solution (NaOH in 10% methanol) with a molar ratio [MR] of 0.10 to the vinyl unit. After adding the alkali, the gelated product was pulverized with a pulverizer and subjected to a saponification reaction for a total of 1 hour, and then 1000 g of methyl acetate was added to neutralize the remaining alkali. After confirming the end of neutralization using a phenolphthalein indicator, 1000 g of methanol was added to the white solid PVA obtained by filtration, and the mixture was left to wash at room temperature for 3 hours. After the above washing operation was repeated three times, the PVA obtained by centrifugal drainage 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 properties of PVA-1 and the water resistance and viscosity stability of PVA-1 as an agrochemical binder according to the methods described above.

(Preparation of agricultural chemical granular composition)
A mini-plate granulator with a diameter of 240 mm (manufactured by ASONE CORPORATION) while spraying a 10% by mass aqueous solution of PVA-1 as an aqueous solution of a pesticide binder on a processed mineral phosphophosphate fertilizer powder ground to a particle size suitable for granulation ) To obtain an agrochemical granular composition. In the obtained agrochemical granular composition, the solid content of PVA-1 was 3 parts by mass with respect to 100 parts by mass of the processed mineral phosphophosphate fertilizer powder as a raw material. After drying the obtained agrochemical granular composition with a shelf-type dryer maintained at 100 ° C., the grain strength and sustained release were evaluated according to the methods described above. The results are shown in Table 2.

[Examples 2 to 4]
(Production of PVA-2 to PVA-4)
Except for changing the polymerization conditions such as ethylene, vinyl acetate and methanol, the amount of initiator, the polymerization rate, the amount of ethylene-modified PVAc solution and saponification catalyst solution, the concentration and saponification temperature during saponification as shown in Table 1, Various PVA (PVA-2 to PVA-4) were produced in the same manner as in Example 1. Table 2 shows the results of evaluating the physical properties of PVA-2 to PVA-4 and the water resistance and viscosity stability of PVA-2 to PVA-4 as agricultural chemical binders according to the methods described above.

[Comparative Example 1]
(Production of PVA-5)
A reaction tank equipped with a stirrer, a nitrogen inlet, and an initiator addition port was charged with 2.4 kg of vinyl acetate and 1.0 kg of methanol. After the temperature was raised to 60 ° C., the system was purged with nitrogen by nitrogen bubbling for 30 minutes. Next, a 10% concentration solution of 2,2′-azobis (isobutyronitrile) (AIBN) dissolved in methanol as an initiator was prepared, and nitrogen replacement was performed by bubbling with nitrogen gas. After adjusting the temperature in the polymerization tank to 60 ° C., 10 ml of the initiator solution was injected to start polymerization. After 1.4 hours, the polymerization was stopped when the polymerization rate reached 30%. Unreacted vinyl acetate monomer was removed to obtain a methanol solution of polyvinyl acetate (PVAc). To the obtained PVAc solution, methanol was added to 400 g of PVAc methanol solution adjusted to a concentration of 25% (100 g of PVAc in the solution), and 32.6 g (molar ratio to vinyl acetate unit in PVAc [MR]). 0.07) alkaline solution (NaOH in 10% methanol) was added and saponification was carried out at 40 ° C. After adding the alkali, the gelated product was pulverized with a pulverizer and subjected to a saponification reaction for a total of 1 hour, and then 1000 g of methyl acetate was added to neutralize the remaining alkali. After confirming the end of neutralization using a phenolphthalein indicator, 1000 g of methanol was added to the white solid PVA obtained by filtration, and the mixture was left to wash at room temperature for 3 hours. PVA (PVA-5) was obtained by repeating the said washing | cleaning operation 3 times, and leaving PVA obtained by carrying out centrifugal liquid removal at 70 degreeC in a dryer for 2 days, and drying. Table 2 shows the results of evaluating the physical properties of PVA-5 and the water resistance and viscosity stability of PVA-5 as an agrochemical binder according to the methods described above.

[Comparative Example 2]
(Production of PVA-6)
Comparative Example 1 except that the vinyl acetate and methanol, the amount of initiator, the polymerization conditions such as the polymerization rate, the amount of PVAc solution and saponification catalyst solution, the concentration and the saponification temperature during saponification were changed as shown in Table 1. PVA-6 was produced by the same method. Table 2 shows the results of evaluating the physical properties of PVA-6 and the water resistance and viscosity stability of PVA-6 as an agrochemical binder according to the methods described above.

[Comparative Example 3]
(Production of PVA-7)
A 5 L pressure reactor equipped with a stirrer, nitrogen inlet, ethylene inlet, initiator addition port and delay solution addition port was charged with 1.36 kg of vinyl acetate and 2.04 kg of methanol, and bubbled with nitrogen at 0 ° C. for 30 minutes. The system was replaced with nitrogen. Next, ethylene was introduced and charged so that the reactor pressure was 0.2 kg / cm ² . As an initiator, 81.6 g of 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile) (AMV) was added to initiate polymerization. During the polymerization, ethylene was introduced to maintain the reactor pressure at 0.2 kg / cm ² and the polymerization temperature at 0 ° C. to carry out the polymerization. The polymerization was stopped when the polymerization rate reached 60% after 35 hours. After the reaction vessel was opened to remove ethylene, nitrogen gas was bubbled to completely remove ethylene. Next, unreacted vinyl acetate monomer was removed under reduced pressure to obtain 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 of ethylene-modified PVAc methanol solution (100 g of ethylene-modified PVAc in the solution) prepared by adding methanol to the obtained ethylene-modified PVAc solution to a concentration of 25%. Saponification was performed at 60 ° C. by adding an alkaline solution (NaOH in 10% methanol) having a molar ratio [MR] of 0.10 to the vinyl unit. After adding the alkali, the gelated product was pulverized with a pulverizer and subjected to a saponification reaction for a total of 1 hour, and then 1000 g of methyl acetate was added to neutralize the remaining alkali. After confirming the end of neutralization using a phenolphthalein indicator, 1000 g of methanol was added to the white solid PVA obtained by filtration, and the mixture was left to wash at room temperature for 3 hours. PVA (PVA-7) was obtained by repeating the above washing operation three times, and then allowing the PVA obtained by centrifugal dehydration to stand in a dryer at 70 ° C. for 2 days to dry. Table 2 shows the results of evaluating the physical properties of PVA-7 and the water resistance and viscosity stability of PVA-7 as an agrochemical binder according to the methods described above.

[Examples 2 to 4, Comparative Examples 1 to 3]
(Preparation of agricultural chemical granular composition)
Instead of PVA-1 of Example 1, 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. Table 2 shows the results of the evaluation of the grain strength and sustained release properties of the agrochemical granular composition according to the method described above.

  As is clear from the above examples, the agricultural chemical binder containing a specific ethylene-modified PVA as in the present invention is excellent in water resistance and viscosity stability when used as an aqueous solution, and is obtained by using the agricultural chemical binder. It can be seen that the granular composition has a high particle strength, a high net residual ratio at 10 ° C., and excellent long-term sustained release. On the other hand, it can be seen that Comparative Examples 1 and 2 in which the PVA used does not have an ethylene unit deteriorate the water resistance of the binder for agricultural chemicals and the sustained release properties of the resulting agricultural chemical active ingredients. It can be seen that the PVA of Comparative Example 3 having a low 1,2-glycol bond unit content has poor viscosity stability and poor handleability when used as an aqueous solution as a pesticide binder.

  The present invention is useful in reducing the amount of agricultural chemicals used, improving yield and quality, and in terms of environmental conservation, and further, the agricultural chemical granular composition of the present invention maintains the growing environment of crops in favorable insecticidal and nutrient conditions. It is possible to increase the yield and quality.

Claims (4)

  The ethylene unit content is 1.0 mol% or more and 19 mol% or less, the 1,2-glycol bond unit content is 1.2 mol% or more and 2.0 mol% or less, and the viscosity average polymerization degree is A binder for agricultural chemicals comprising an ethylene-modified vinyl alcohol polymer having a saponification degree of not less than 200 and not more than 5000 and a saponification degree of not less than 80 mol% and not more than 99.9 mol%.   The agrochemical granular composition containing the agrochemical binder according to claim 1 and the agrochemical active ingredient, wherein the content of the agrochemical binder with respect to 100 parts by mass of the agrochemical active ingredient is 0.5 parts by mass or more and 20 parts by mass or less. .   The agrochemical granular composition according to claim 2, wherein the agrochemical active ingredient is a fertilizer.   The manufacturing method of the agrochemical granular composition of Claim 2 or 3 which adds the agrochemical binder containing the said ethylene modified vinyl alcohol polymer to the said agrochemical active ingredient as an aqueous solution or with water, and granulates.