JP5161515B2 - Water-soluble film for pesticide packaging - Google Patents

Description

  The present invention relates to a water-soluble film for agricultural chemical packaging in which an agrochemical such as a herbicide is encapsulated and the film dissolves quickly and spreads the encapsulated agricultural chemical when sprayed on the surface of a paddy field or the like.

  Conventionally, chemicals having various shapes and states such as granular, powdery, and liquid have been used for agricultural chemicals used in paddy fields and the like. Among these, agrochemicals having a granular shape are frequently used because they have excellent safety for the pesticide sprayer and the surrounding environment and can be uniformly sprayed in the paddy field.

As a use mode of the above-mentioned granular pesticide, for example, in addition to a method of spraying it on a paddy field as it is, in recent years, it is easy to transport a pesticide and spray it onto a paddy field. A method is used in which a granular pesticide is encapsulated in a product and sprayed onto a paddy field, and the encapsulated pesticide is diffused in the paddy field by dissolving the bag-like material on the surface of the water (for example, see Patent Document 1).
JP-A-4-226901

  However, conventionally, since the water-soluble form of the bag-shaped material enclosing the granular pesticide is insufficient, for example, only the lower surface of the bag-shaped material in contact with the water surface is dissolved, and the upper surface contains air. A raised part is formed to form a dome shape. As a result, this part is not completely dissolved, and there is a problem that the agricultural chemical remaining in the dome part is difficult to diffuse as a lump.

  This invention is made | formed in view of such a situation, and it aims at provision of the water-soluble film for agricultural chemical packaging excellent in water solubility.

  However, in order to further improve the water solubility compared to the prior art, the present inventors have repeated a series of studies with the aim of improving the water-soluble film as a material for forming bags for encapsulating agricultural chemicals, As a result of studying various compounds, focusing on the improvement of water solubility by adding additives, not the polyvinyl alcohol resin itself, which is the main raw material for adhesive films, water-soluble by adding acetylene glycol surfactants The water dissolution time is shorter than before, and when it is used to form a bag, the dome-shaped part that contains air on the water surface dissolves quickly and the dome-shaped part disappears. And reached the present invention.

  That is, the gist of the present invention relates to a water-soluble film for agricultural chemical packaging comprising a resin composition containing polyvinyl alcohol resin (A) and acetylene glycol surfactant (B) as essential components.

  Thus, the water-soluble film for agricultural chemical packaging of the present invention is formed by using a resin composition containing the polyvinyl alcohol resin (A) and the acetylene glycol surfactant (B) as essential components. For this reason, the water-soluble film is excellent in water-solubility while maintaining the shape-retaining property as a film. When sprayed on the surface, the bag breaking property is improved and the dome portion formed on the water surface is also quickly dissolved. Therefore, the encapsulated pesticide does not form a lump, but diffuses into the paddy field, thereby improving the spraying effect of the pesticide.

  And the said acetylene glycol type surfactant (B) is a ratio of 0.1-10 weight part with respect to 100 weight part of polyvinyl alcohol-type resin (A), and the acetylene glycol type surfactant in the film surface The bleed-out phenomenon is suppressed, and the disappearance effect of the swelled portion (air dome shape) containing air on the surface of the water when used as a packaging bag is further improved.

  The polyvinyl alcohol resin (A) has a 4% by weight aqueous solution viscosity of 10 to 70 mPa · s at 20 ° C., and the polyvinyl alcohol resin (A) has an average saponification degree of 70 to 98 mol%. As a result, good strength and film-forming property as an agrochemical packaging bag can be obtained, and the water-soluble film itself has better water solubility.

  Furthermore, when the thickness of the water-soluble film for agricultural chemical packaging is 10 to 100 μm, the film has excellent mechanical strength, improves the solubility in cold water, and obtains good film forming efficiency.

  Thus, the water-soluble film formed using the resin composition containing the polyvinyl alcohol resin (A) and the acetylene glycol surfactant (B) as essential components maintains the shape retention as a film. It is very excellent in solubility in water.

  The water-soluble film for agricultural chemical packaging of the present invention is a water-soluble film for forming a bag-like material for enclosing and packaging various agricultural chemical formulations.

  The various agrochemical preparations to be encapsulated and packaged are not particularly limited. For example, herbicides, fungicides, insecticides, plant growths that can be diffused into water by being put into paddy fields or the like and disintegrating themselves. Examples include preparations containing agrochemical active ingredients such as regulators.

  Examples of the herbicide include 2,4,6-trichlorophenyl-4′-nitrophenyl ether (CNP), 2-methyl-4-chlorophenoxythioacetic acid-S-ethyl (phenothiol), α- ( 2-naphthoxy) propionanilide (naproanilide), methyl 5- (2,4-dichlorophenoxy) -2-nitrobenzoate (biphenox), S- (4-chlorobenzyl) N, N-diethylthiocarbamate (bench curve) S-benzyl = 1,2-dimethylpropyl (ethyl) thiocarbamate (Esprocarb), S-ethylhexahydro-1H-azepine-1-carbothioate (molinate), S-1-methyl-1-phenylethyl = Piperidine-1-carbothioate (dimethylpiperate), o-3-tert-butylphenyl = 6-methyl Xyl-2-pyridyl (methyl) thiocarbamate (pyributycarb), 2-chloro-2 ', 6'-diethyl-N- (butoxymethyl) acetanilide (butachlor), 2-chloro-2', 6'-diethyl- N- (2-propoxyethyl) acetanilide (pretilachlor), (RS) -2-bromo-N- (α, α-dimethylbenzyl) -3,3-dimethylbutyramide (bromobutide), 2-benzothiazol-2 -Yloxy-N-methylacetanilide (mefenacet), 1- (α, α-dimethylbenzyl) -3- (paratolyl) urea (Dimron), methyl = α- (4,6-dimethoxypyrimidin-2-ylcarbamoylsulfa Moyl) -o-toluate (bensulfuron methyl), 1- (2-chloroimidazo [1,2-a] pyridine-3 Ylsulfonyl) -3- (4,6-dimethoxypyrimidin-2-yl) urea (imazosulfuron), ethyl = 5- (4,6-dimethoxypyrimidin-2-ylcarbamoylsulfamoyl) -1-methylpyrazol- 4-carboxylate (pyrazolsulfuronethyl), 2-methylthio-4,6-bis (ethylamino) -s-triazine (cymetrine), 2-methylthio-4,6-bis (isopropylamino) -s- Triazine (promethrin), 2-methylthio-4-ethylamino-6- (1,2-dimethylpropylamino) -s-triazine (dimetamethrin), 2,4-dichlorophenyl-3′-methoxy-4′-nitrophenyl ether (Clomethoxynyl), 5-tert-butyl-3- (2,4-dichloro-5-isopropoxyphe Nyl) -1,3,4-oxadiazolin-2-one (oxadiazone), 4- (2,4-dichlorobenzoyl) -1,3-dimethyl-5-pyrazolyl = p-toluenesulfonate (pyrazolate) ), 2- [4- (2,4-dichlorobenzoyl) -1,3-dimethylpyrazol-5-yloxy] acetophenone (pyrazoxyphene), (RS) -2- (2,4-dichloro-m-tolyloxy) Propionanilide (Chromprop), 2- [4- [2,4-Dichloro-m-toluoyl] -1,3-dimethylpyrazol-5-yloxy] -4'-methylacetophenone (benzophenap), S, S '-Dimethyl = 2-difluoromethyl-4-isobutyl-6-trifluoromethylpyridine-3,5-dicarbothioate (dithiopyr), 2-chloro N- (3-methoxy-2-thenyl) -2 ′, 6′-dimethylacetanilide (tenyl chlor), n-butyl- (R) -2- [4- (2-fluoro-4-cyanophenoxy) phenoxy] propione -To (cyhalohop butyl), 3- [1- (3,5-dichlorophenyl) -1-methylethyl] -2,3-dihydro-6-methyl-5-phenyl-4H-1,3- Oxazin-4-one (oxadichromemephone), 3- (4-chloro-5-cyclopentyloxy-2-fluorophenyl) -5-isopropylidene-1,3-oxazolidine-2,4-dione (pentoxazone), 1- ( Diethylcarbamoyl) -3- (2,4,6-trimethylphenylsulfonyl) -1,2,4-triazol (cafentrol), N-{[(4,6-dimethoxypi Limidin-2-yl) aminocarbonyl]}-1-methyl-4- (2-methyl-2H-tetrazol-5-yl) -1H-pyrazole-5-sulfonamide (azimylsulfuron), methyl = 2 [(4,6-dimethoxypyrimidin-2-yl) oxy] -6-[(E) -1- (methoxyimino) ethyl] benzoate (pyriminobacmethyl), 2,3-dihydro-3,3-dimethyl Benzofuran-5-yl ethanesulfonate (benfresate), (RS) -2 ′-[(4,6-dimethoxypyrimidin-2-yl) (hydroxy) methyl] -1,1-difluoro-6 ′-(methoxymethyl) ) Methanesulfonanilide (pyrimisulphan), 3- (2-chloro-4-mesylbenzoyl) -2-phenylthiobicyclo [3.2.1] oct- - en-4-one (benzobicyclon), and the like. These may be used alone or in combination of two or more.

  Examples of the bactericides include O, O-diisopropyl-S-benzylthiophosphate (IBP), O-ethyl-S, S′-diphenyldithiophosphate (EDDP), and 3′-isopropoxy-2. -Methylbenzanilide (mepronil), α, α, α-trifluoro-3'-isopropoxy-o-toluanilide (flutranyl), 3, 4, 5, 6-tetrachloro-N- (2,3-dichlorophenyl) Phthalamic acid (teclophthalam), 1- (4-chlorobenzyl) -1-cyclopentyl-3-phenylurea (pencyclone), 6- (3,5-dichloro-4-methylphenyl) -3 (2H) -pyridazinone (dicromedin) ), Methyl = N- (2-methoxyacetyl) -N- (2,6-xylyl) -DL-alaninate (metalaxyl), (E) -4- B-α, α, α-trifluoro-N- (1-imidazol-1-yl-2-propoxyethylidene) -o-toluidine (triflumizole), kasugamycin, validamycin, 3-allyloxy-1, 2 -Benzoisothiazol-1,1-dioxide (probenazole), diisopropyl-1,3-dithiolane-2-ylidene-malonate (isoprothiolane), 5-methyl-1,2,4-triazolo [3,4-b Benzothiazol (tricyclazole), 1,2,5,6-tetrahydro-4H-pyrrolo [3,2,1-ij] quinolin-4-one (pyrrololone), 5-ethyl-5,8-dihydro-8 -Oxo [1,3] dioxolo [4,5-g] quinoline-7-carboxylic acid (oxolinic acid), (Z) -2'-methylacetophenone = 4,6-dimethyl Rupyrimidin-2-ylhydrazone (ferimzone), 3- (3,5-dichlorophenyl) -N-isopropyl-2,4-dioxoimidazolidine-1-carboxamide (iprodione), (E) -2-methoxyimino- And N-methyl-2- (2-phenoxyphenyl) acetamide (methinostrobin). These may be used alone or in combination of two or more.

  Examples of the insecticide include O, O-dimethyl-O- (3-methyl-4-nitrophenyl) thiophosphate (MEP), O, O-dimethyl-O- [3-methyl-4- (methylthio) phenyl ] Thiophosphate (MPP), ethyl dimethyldithiophosphorylphenylacetate (PAP), (2-isopropyl-4-methylpyrimidyl-6-yl) -diethylthiophosphate (diazinone), 1-naphthyl-N-methylcarbamate (NAC), O, O-diethyl-O- (3-oxo-2-phenyl-2H-pyridazin-6-yl) phosphorothioate (pyridaphenthion), O, O-dimethyl-O-3,5,6- Trichloro-2-pyridyl phosphorothioate (chlorpyrifosmethyl), O, O-dimethyl-S-dicarbethoxyethyldithiophosphine -To (marathon), O, O-dimethyl-S- (N-methylcarbamoylmethyl) dithiophosphate (dimethoate), O, O-dipropyl-O-4-methylthiophenyl phosphate (propaphos), O, S-dimethyl-N-acetylphosphoramidothioate (acephate), O-ethyl-O- (4-nitrophenyl) thionobenzenephosphonate (EPN), 2-secondary-butylphenyl-N- Methyl carbamate (BPMC), 2,3-dihydro-2,2-dimethyl-7-benzo [b] furanyl = N-dibutylaminothio-N-methylcarbamate (carbosulfan), ethyl = N- [2,3-dihydro-2,2-dimethylbenzofuran-7-yloxycarbonyl (methyl) aminothio] -N-isopropyl-β-alanina (Benfuracarb), (RS) -α-cyano-3-phenoxybenzyl = (RS) -2,2-dichloro-1- (4-ethoxyphenyl) cyclopropanecarboxylate (cycloprotorin), 2- ( 4-Ethoxyphenyl) -2-methylpropyl = 3-phenoxybenzyl = ether (ethofenprox), 1,3-bis (carbamoylthio) -2- (N, N-dimethylamino) propane hydrochloride (Cultap) ), 5-dimethylamino-1,2,3-trithian oxalate (thiocyclam), S, S′-2-dimethylaminotrimethylene di (benzenethiosulfonate) (bensultap), 2-ta -Shari-Butylimino-3-isopropyl-5-phenyl-1,3,5,6-tetrahydro-2H-1,3,5-thiadiazin-4-one Rofejin), a mixture of spinosyn A and spinosyn B (spinosad) and the like. These may be used alone or in combination of two or more.

  Examples of the plant growth regulator include 4′-chloro-2 ′-(α-hydroxybenzyl) isonicotinanilide (inavenfide), (2RS, 3RS) -1- (4-chlorophenyl) -4, 4-dimethyl-2. -(1H-1,2,4-triazol-1-yl) pentan-3-ol (paclobutrazol), (E)-(S) -1- (4-chlorophenyl) -4, 4-dimethyl-2- (1H-1,2,4-triazol-1-yl) pent-1-en-3-ol (uniconazole P) and the like. These may be used alone or in combination of two or more.

  And as said agrochemical formulation, by containing surfactant with the said agrochemical active component, it becomes possible to disintegrate agrochemical formulation on the surface of the water, and to make it spread | diffuse in water.

  As the surfactant, those generally used in agricultural chemical formulations are used, and specifically, polyethylene glycol higher fatty acid ester, polyoxyethylene alkyl ether, polyoxyethylene alkyl aryl ether, polyoxyethylene aryl phenyl ether. , Nonionic surfactants such as sorbitan monoalkylate, acetylene alcohol and acetylenic diol and their alkylene oxide adducts, alkylaryl sulfonates, dialkyl sulfonates, lignin sulfonates, naphthalene sulfonates and condensates thereof Alkyl sulfate ester salt, alkyl phosphate ester salt, alkyl aryl sulfate ester salt, alkyl aryl phosphate ester salt, polyoxyethylene alkyl ether sulfate salt, Anionic surfactants such as ciethylene alkyl aryl ether sulfates, polyoxyethylene aryl phenyl ether sulfates, polycarboxylic acid type polymer surfactants, silicone surfactants, fluorine surfactants I can give you. These may be used alone or in combination of two or more. Note that the liquid surfactant may be used by adsorbing to a solid simple substance such as white carbon, diatomaceous earth, or urea.

  Furthermore, since the agrochemical formulation floats on the water surface and then disintegrates and diffuses, various methods for imparting buoyancy are employed to float the agrochemical formulation on the water surface.

Examples of the method for imparting water surface floatability include pearlite and obsidian pearlite, shirasu foam shirasu, phyllite baked aluminosilicate system, sodium silicate or borax microballoon, pumice, Granular diatomaceous earth, granular activated carbon, wood powder, cork powder, kenaf pieces, phenol microballoon made of phenol resin, ecosphere made of epoxy resin, polyurethane foam made of polyurethane, microsphere made of polyacrylonitrile, ash during coal-fired power generation Examples include a method of incorporating a substance having independent or plural air chambers such as fly ash and fly ash balloon produced in the above into an agricultural chemical preparation.
Other methods include a method of containing a water-repellent substance such as stearic acid and salts thereof and hydrophobic white carbon. Among these, the method of containing the substance having the independent or plural air chambers is more preferable.

  The shape / state of the agrochemical preparation is not particularly limited as long as it can be enclosed in a bag-like product, but a granular product is particularly preferable. Examples of the shape of the granular pesticide preparation include a spherical shape and a cylindrical shape. Specifically, the average particle size is preferably 0.8 mm or more, more preferably 1.2 to 10 mm, and particularly preferably. Is 3-8 mm. The average particle diameter is, for example, the average value of the short diameter, and for the measurement, an arbitrary quantity is extracted from the population, and the short diameter of the granular material is measured and calculated using a caliper. is there.

Next, the water-soluble film is formed from a polyvinyl alcohol (PVOH) resin (A) as a main raw material, and a resin composition containing the acetylene glycol surfactant (B) is formed into a film. Is obtained.
In addition, PVOH type | system | group means PVOH itself or what was modified | denatured by various modified | denatured species, for example. The main raw material is a material (resin composition) for forming a water-soluble film, which characterizes the physical properties of the water-soluble film, and specifically, 60% by weight of the entire water-soluble film-forming material. The thing which occupies the above.

  The PVOH resin (A) is not particularly limited and can be produced by a known method. That is, it can be produced by saponifying a vinyl ester polymer obtained by polymerizing a vinyl ester compound.

  Examples of the vinyl ester compounds include vinyl formate, vinyl acetate, vinyl trifluoroacetate, vinyl propionate, vinyl butyrate, vinyl caprate, vinyl laurate, vinyl versatate, vinyl palmitate, vinyl stearate, etc. Alternatively, two or more types are used in combination, but vinyl acetate is suitable for practical use.

  Further, the PVOH-based resin (A) may be one obtained by copolymerizing a monomer copolymerizable with the vinyl ester-based compound, and is within a range not inhibiting the effect of the present invention, for example, preferably 10 Other monomers can be copolymerized in the range of mol% or less, more preferably 7 mol% or less.

Examples of other monomers to be copolymerized include olefins such as ethylene, propylene, isobutylene, α-octene, α-dodecene, α-octadecene, acrylic acid, methacrylic acid, crotonic acid, maleic acid, maleic anhydride, and the like. Acids, unsaturated acids such as itaconic acid or salts thereof, mono- or dialkyl esters, nitriles such as acrylonitrile and methacrylonitrile, amides such as acrylamide and methacrylamide, ethylene sulfonic acid, allyl sulfonic acid, methallyl sulfonic acid, etc. Olefin sulfonic acids or salts thereof, alkyl vinyl ethers, polyoxyethylene (meth) allyl ether, polyoxyalkylene (meth) allyl ether such as polyoxypropylene (meth) allyl ether, polyoxyethylene (meth) Polyoxyalkylene (meth) acrylates such as acrylate, polyoxypropylene (meth) acrylate, polyoxyalkylene (meth) acrylamides such as polyoxyethylene (meth) acrylamide, polyoxypropylene (meth) acrylamide, polyoxyethylene [1- (Meth) acrylamide-1,1-dimethylpropyl] ester, polyoxyethylene vinyl ether, polyoxypropylene vinyl ether, polyoxyethylene allylamine, polyoxypropylene allylamine, polyoxyethylene vinylamine, polyoxypropylene vinylamine, diacrylacetone amide N-acrylamidomethyltrimethylammonium chloride, allyltrimethylammonium chloride, dimethyldiallyl ammonium Mukurorido, dimethylallyl vinyl ketone, N- vinylpyrrolidone, vinyl chloride, vinylidene chloride and the like. These other monomers may be used alone or in combination of two or more.
In the present invention, (meth) allyl means allyl or methallyl, (meth) acrylate means acrylate or methacrylate, and (meth) acryl means acryl or methacryl.

  In carrying out the polymerization (or copolymerization), there is no particular limitation and a known polymerization method is arbitrarily used. Usually, a solution polymerization method using an alcohol such as methanol, ethanol, isopropyl alcohol or the like as a solvent is carried out. In addition to the above solution polymerization method, emulsion polymerization and suspension polymerization are also possible.

  The polymerization reaction is performed using a known radical polymerization catalyst such as azobisisobutyronitrile, acetyl peroxide, benzoyl peroxide, or lauroyl peroxide. The polymerization reaction temperature is preferably selected from the range of 35 ° C to 100 ° C, more preferably 40 to 80 ° C, and particularly preferably 50 to 80 ° C.

  Next, saponification of the obtained vinyl ester polymer is carried out in the presence of an alkali catalyst by dissolving the vinyl ester polymer in alcohol. Examples of the alcohol include methanol, ethanol, butanol and the like. The concentration of the vinyl ester copolymer in the alcohol is preferably in the range of 20 to 50% by weight.

  As the alkali catalyst in the saponification, alkali catalysts such as hydroxides and alcoholates of alkali metals such as sodium hydroxide, potassium hydroxide, sodium methylate, sodium ethylate and potassium methylate can be used. It is preferable to set the usage-amount of the said alkali catalyst to 1-100 millimol equivalent with respect to a vinyl ester polymer. In some cases, saponification using an acid catalyst is also possible.

  As the PVOH-based resin (A) thus obtained, two or more PVOH-based resins having different saponification degrees may be mixed and used as necessary.

And in this invention, it is preferable that the average saponification degree of PVOH-type resin (A) is 70-98 mol%, More preferably, it is 75-96 mol%. That is, when the average saponification degree of the PVOH-based resin (A) is out of the above range, the solubility of the water-soluble film in water is delayed, the diffusion of the encapsulated agricultural chemicals is hindered, and as a result, it tends to cause chemical damage and the like. This is because of
The average degree of saponification is measured according to JIS K 6726.

Moreover, the average viscosity at 20 ° C. of a 4 wt% aqueous solution of the PVOH-based resin (A) is preferably 10 to 70 mPa · s, and more preferably 15 to 60 mPa · s. That is, when the average viscosity of the 4% by weight aqueous solution is too low, the strength of the pesticide packaging bag tends to be insufficient, which tends to cause bag breakage, and the film tends to be broken and difficult to form. Because it is seen. If the average viscosity is too high, the solubility of the film is delayed, which prevents diffusion of the encapsulated agricultural chemicals and causes phytotoxicity, etc. In addition to the high viscosity, it tends to be difficult to form a film.
The average viscosity is measured according to JIS K 6726.

  Examples of the acetylene glycol surfactant (B) include acetylene glycol compounds represented by the following general formula (1), that is, at least one of acetylene glycol and acetylene glycol derivatives.

In the general formula (1), as described above, R ² and R ³ are each an alkyl group having 1 to 3 carbon atoms, and R ¹ and R ⁴ are each an alkyl group or an allyl group having 1 to 20 carbon atoms. It is. R ² and R ³ , and R ¹ and R ⁴ may be the same as or different from each other.

  And it is preferable that the addition mole number of the ethylene oxide unit (repeating unit m + n) in the acetylene glycol type compound represented by the said General formula (1) is 0 <= m + n <= 30 (mol). That is, if the total number of moles of ethylene oxide units added is too large, the solubility of the acetylene glycol compound itself in water tends to improve, and the solubility of the film tends to decrease.

  In the acetylene glycol compound represented by the general formula (1), as the acetylene glycol in which the number of added moles of ethylene oxide units is 0, specifically, 2,5,8,11-tetramethyl-6- Dodecine-5,8-diol, 5,8-dimethyl-6-dodecine-5,8-diol, 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 4,7-dimethyl -5-decyne-4,7-diol, 2,3,6,7-tetramethyl-4-octyne-3,6-diol, 3,6-dimethyl-4-octyne-3,6-diol, 2, 5-dimethyl-3-hexyne-2,5-diol and the like.

Further, in the acetylene glycol compound represented by the general formula (1), as the acetylene glycol derivative, that is, the ethoxylated compound of the acetylene glycol compound, for example, 2,5,8,11-tetramethyl-6-dodecin- Ethoxylated form of 5,8-diol (total number of moles of ethylene oxide added: 6), ethoxylated form of 2,4,7,9-tetramethyl-5-decyne-4,7-diol (total number of moles of ethylene oxide added: 10), an ethoxylated product of 2,4,7,9-tetramethyl-5-decyne-4,7-diol (total number of added moles of etherene oxide: 4), 3,6-dimethyl-4-octyl-3, Ethylene oxide derivatives of acetylene glycol such as ethoxylated 6-diol (total number of moles of ethylene oxide added: 4) It can be mentioned. Particularly preferably, 2,4,7,9-tetramethyl-5-decyne-4,7-diol ethoxylate (total number of moles of ethylene oxide added: 1.3, R ¹ and R in the above general formula (1)) ⁴ is an iso-butyl group, R ² and R ³ are methyl groups, m + n = 1.3), 2,4,7,9-tetramethyl-5-decyne-4,7-diol ethoxylate (ethylene oxide) Total number of added moles: 3.5, R ¹ and R ⁴ in the general formula (1) are iso-butyl groups, R ² and R ³ are methyl groups, and m + n = 3.5. These acetylene glycol compounds can be used alone or in combination of two or more.

  The content of the acetylene glycol surfactant (B) is preferably 0.1 to 10 parts by weight, more preferably 0.5 to 8 parts by weight with respect to 100 parts by weight of the PVOH resin (A). Particularly preferred is 1 to 6 parts by weight. That is, if the content of the acetylene glycol surfactant (B) is too small, the effect of improving water solubility due to disappearance of the air dome tends to be difficult to obtain. Moreover, when there is too much content of an acetylene glycol compound, it is because the dispersibility of this acetylene glycol type-surfactant (B) will worsen, and it tends to bleed out on the film surface and to produce blocking.

  Furthermore, the resin composition comprising the PVOH resin (A), which is a material for forming the water-soluble film for agricultural chemical packaging of the present invention, as a main raw material and containing the acetylene glycol surfactant (B) in the above, In addition to the blending components, a plasticizer is blended as necessary.

  Examples of the plasticizer include glycerins such as glycerin, diglycerin, and triglycerin, alkylene glycols such as triethylene glycol, polyethylene glycol, polypropylene glycol, and dipropylin glycol, and trimethylolpropane. These may be used alone or in combination of two or more.

  And although it does not specifically limit about content of the said plasticizer, It is preferable that it is 3-45 weight part with respect to 100 weight part of PVOH-type resin (A), Furthermore, 5-40 weight part, Especially 7 is preferable. It is preferable that it is -38 weight part. That is, if the content of the plasticizer is too small, the plastic effect is low, and a tendency to cause film breakage is observed. This is because production tends to be difficult.

  Furthermore, in the material for forming a water-soluble film for agricultural chemical packaging of the present invention, a surfactant (for the purpose of improving the peelability between the metal surface such as a drum or belt of a film-forming apparatus for a water-soluble film and the formed film) The acetylene glycol surfactant (B) is excluded.). The surfactant is not particularly limited, and examples thereof include polyoxyethylene nonyl phenyl ether, polyoxyethylene octyl nonyl ether, polyoxyethylene dodecyl phenyl ether, polyoxyethylene alkyl allyl ether, polyoxyethylene sorbitan monolaur. Rate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monooleate, polyoxyalkylene alkyl ether phosphate monoethanolamine salt, polyoxyethylene laurylamine, polyoxyethylene stearylamine And polyoxyethylene alkylamine. These may be used alone or in combination of two or more. Of these, polyoxyalkylene alkyl ether phosphate monoethanolamine salt, polyoxyethylene alkylamine, and polyoxyethylene sorbitan monolaurate are preferably used in terms of peelability.

  Although it does not specifically limit about content of the said surfactant, It is preferable that it is 0.01-5 weight part with respect to 100 weight part of PVOH-type resin, Furthermore, 0.03-4.5 weight part, especially Is preferably 0.05 to 4 parts by weight. That is, if the content of the surfactant is too small, the peelability between the metal surface such as a drum or belt of the film forming apparatus and the film formed tends to be difficult to manufacture, and if too much, This is because the film tends to block when bleed on the film surface to form a roll.

  Moreover, in the formation material of the water-soluble film for agricultural chemical packaging of this invention, within the range which does not prevent the effect | action and effect of this water-soluble film, antioxidant (phenol type, amine type etc.), stabilizer (phosphate ester) Etc.), coloring agents, fragrances, extenders, anti-packaging agents, rust preventives, UV absorbers, powders (inorganic or organic), and other water-soluble polymers (sodium polyacrylate, polyethylene oxide, polyvinylpyrrolidone) , Dextrin, chitosan, chitin, methylcellulose, hydroxyethylcellulose) and the like may be added.

  The water-soluble film for agricultural chemical packaging according to the present invention is obtained by forming (forming a film) a resin composition comprising the PVOH resin (A) as a main raw material and containing the acetylene glycol surfactant (B). Is obtained. In the film formation, a known method such as a casting method can be adopted without any particular limitation.

The casting method will be specifically described.
That is, the resin composition, preferably a resin composition containing a plasticizer and a surfactant, is dispersed in water, and the solid content concentration is usually 10 to 50% by weight (more preferably 15 to 35% by weight). After preparing an aqueous dispersion of the resin composition and casting it on a metal belt, it is usually dried with hot air of about 80 to 140 ° C. or is usually cast and dried on the surface of a metal drum of about 50 to 100 ° C. Thus, the PVOH-based film of the present invention can be obtained. Specifically, it is preferable to pass an embossing roll having a surface temperature of 50 to 140 ° C. before the film is peeled off after being peeled from the film forming belt or the film forming first drum. In preparing an aqueous dispersion of the resin composition, components such as a PVOH resin (A), an acetylene glycol surfactant (B), a plasticizer, and a surfactant may be mixed together. These may be mixed in any order, and any component may be selected as appropriate, for example, an arbitrary component is previously mixed with water and the remaining components are mixed.

Here, the film-forming belt has an endless belt that runs across a pair of rolls, and the stock solution (resin composition aqueous solution) that flows out from the T-die or the like is cast onto the belt. It is to be dried together. The endless belt is preferably made of, for example, stainless steel, and its outer peripheral surface is mirror-finished.
The film-forming first drum is the uppermost stream side in a film-forming machine that casts a stock solution (resin composition aqueous solution) flowing out from a T-die or the like onto one or more rotating drum-type rolls and dries it. It is a drum-type roll located.
Also, until the film is peeled off from the film-forming belt or film-forming first drum and then wound up, the stock solution (resin composition aqueous solution) discharged from the T-die or the like is on the film-forming belt or the film-forming first drum. The film is dried to form a film, peeled off from the film forming belt or the first film forming drum, passed through a heat treatment machine, subjected to a humidity control treatment as necessary, and the film formed is wound up by a winder. Until.

  The heat treatment conditions by the heat treatment machine are preferably 50 to 140 ° C, more preferably 60 to 130 ° C. That is, if the temperature of the heat treatment is too low, the curling of the surface in contact with the film forming belt or the film forming first drum is strong, and there is a tendency to cause defects in bag making suitability, and if the temperature of the heat treatment is too high, This is because the crystallinity tends to increase so that the water solubility during actual use tends to decrease. The heat treatment is usually carried out by a separate embossing roll following the drying roll treatment for drying the film.

  The production of the water-soluble film for agricultural chemical packaging of the present invention has been described based on the casting method as described above, but the water-soluble film for agricultural chemical packaging of the present invention is not limited to this production method. For example, the water-soluble film for agricultural chemical packaging of the present invention is obtained by casting an aqueous dispersion of a resin composition onto a plastic substrate or a metal substrate such as a polyethylene terephthalate film or a polyethylene film using an applicator, in addition to the above-described production method. The water-soluble film which is a PVOH-type film can also be obtained by making it dry.

  The thickness of the water-soluble film of the present invention thus obtained is appropriately set depending on the type, characteristics, purpose, etc. of the agricultural chemicals to be packaged, but is preferably set to 10 to 100 μm, particularly preferably 15 to 90 μm. That is, if the thickness of the water-soluble film is too thin, the mechanical strength of the water-soluble film tends to decrease, and conversely if it is too thick, the dissolution rate in cold water tends to be significantly slowed, and the efficiency at the time of film formation This is because there is a tendency to decrease.

  Further, the surface of the water-soluble film obtained may be smooth, but various uneven patterns such as an embossed pattern and a satin pattern may be provided on one side or both sides of the film as necessary.

  Further, the water-soluble film of the present invention includes other water-soluble polymers (polyacrylic acid soda, polyethylene oxide, polyvinyl pyrrolidone, dextrin, chitosan, chitin, methylcellulose, hydroxyethylcellulose, etc. as long as the object of the present invention is not impaired. ), A rust inhibitor, a colorant, and the like may be included.

  The water-soluble film obtained as described above is preferably stored in a suspended atmosphere under a temperature condition of 10 to 25 ° C., for example, by applying moisture-proof packaging so that the moisture content does not greatly change. .

  The water-soluble film of the present invention is obtained by forming a resin composition comprising the PVOH-based resin (A) as a main material and an acetylene glycol-based surfactant (B) therein as a film material (film). The acetylene glycol surfactant (B) contained in the water-soluble film can be confirmed by the following method. For example, it can be confirmed by performing a component analysis of the film using a liquid chromatograph (LC), a gas chromatograph (GC) or the like. As analysis conditions at this time, for example, a liquid obtained by extracting the water-soluble film for agricultural chemical packaging of the present invention with a 70% aqueous methanol solution is a gas chromatograph 5890A with FID detector (manufactured by Hewlett Packard), an inner diameter of 0.53 mm and a length of 15 m. By using a Megabore DB-1 column (manufactured by Hewlett-Packard) and performing temperature rise analysis from a column temperature of 100 ° C. to 280 ° C. at a rate of temperature rise of 3 ° C./min, acetylene glycol contained in the water-soluble film for agricultural chemical packaging of the present invention The system surfactant (B) can be measured.

  The water-soluble film thus obtained is a film excellent in water-solubility, and its solubility is dissolved or dispersed in water of 50 ° C. or lower, preferably 30 ° C. or lower, more preferably 25 ° C. or lower. It is.

  In addition to being useful as a water-soluble film for agrochemical drug packaging (unit packaging) as described above, for example, (hydraulic pressure) transfer film, sanitary products such as napkins and paper diapers, ostomy bags, etc. It can also be used as a water-soluble film for various uses such as filth-treating articles such as blood-absorbing sheets, medical articles such as blood-absorbing sheets, and temporary substrates such as nursery sheets and embroidery base fabrics. Especially, it is very useful for the pharmaceutical packaging use of the above-mentioned agricultural chemicals.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples unless it exceeds the gist. In the following description, “%” and “part” are based on weight unless otherwise specified.

[Example 1]
100 parts unmodified PVOH resin (A) having a 4% aqueous solution viscosity of 15 mPa · s (20 ° C.) and an average saponification degree of 88.0 mol%, 15 parts of glycerin, and polyoxyalkylene alkyl ether phosphate ester as a surfactant 2 parts of monoethanolamine salt, water, and Surfynol 440 (ethoxylated product of 2,4,7,9-tetramethyl-5-decyne-4,7-diol) (air products) as acetylene glycol compound (B) 4 parts of Japan Co., Ltd.) was added to obtain an aqueous dispersion of a resin composition having a solid content concentration of 35%.

  After adjusting the surface of SUS placed on the hot plate to 90 ° C., the aqueous dispersion of the above resin composition is cast on a heated SUS plate, and then dried at 80 to 90 ° C. for 2 minutes. The film was peeled from the SUS substrate to obtain a PVOH film having a thickness of 40 μm.

[Example 2]
The amount of Surfynol 440 (produced by Air Products Japan Co., Ltd.), which is an acetylene glycol compound, was changed to 0.5 part. Other than that was carried out similarly to Example 1, and obtained the 40-micrometer-thick PVOH-type film.

Example 3
The amount of Surfynol 440 (produced by Air Products Japan Co., Ltd.), which is an acetylene glycol compound, was changed to 10 parts. Other than that was carried out similarly to Example 1, and obtained the 40-micrometer-thick PVOH-type film.

Example 4
A maleic acid-modified PVOH resin having a 4% aqueous solution viscosity of 28 mPa · s (20 ° C.), an average saponification degree of 96 mol% and a modification amount of 2 mol% was used. Other than that was carried out similarly to Example 1, and obtained the 40-micrometer-thick PVOH-type film.

Example 5
As an acetylene glycol compound, Surfynol 420 (Ethoxylated form of 2,4,7,9-tetramethyl-5-decyne-4,7-diol) instead of Surfynol 440 (produced by Air Products Japan) (Air 5 parts of Products Japan Co., Ltd. were used. Other than that was carried out similarly to Example 1, and obtained the 40-micrometer-thick PVOH-type film.

Example 6
Surfinol 420 (Air Products Japan Co., Ltd.) is used as a acetylene glycol compound, using a maleic acid-modified PVOH resin having a 4% aqueous solution viscosity of 28 mPa · s (20 ° C.), an average saponification degree of 96 mol% and a modification amount of 2 mol%. 5 parts) were used. Other than that was carried out similarly to Example 1, and obtained the 40-micrometer-thick PVOH-type film.

[Comparative Example]
4% aqueous solution viscosity 15 mPa · s (20 ° C.), unmodified PVOH resin having an average saponification degree of 88.0 mol%, 15 parts of glycerin, polyoxyalkylene alkyl ether phosphate monoethanolamine salt 2 as a surfactant And water were added to obtain an aqueous dispersion of a resin composition having a solid content of 35%.

  After adjusting the surface of SUS placed on the hot plate to 90 ° C., the aqueous dispersion of the above resin composition is cast on a heated SUS plate, and then dried at 80 to 90 ° C. for 2 minutes. The film was peeled from the SUS substrate to obtain a PVOH film having a thickness of 40 μm.

  The following evaluation was performed about each PVOH-type film of the Example goods and comparative example goods which were obtained in this way. The results are shown in Table 1 below.

[Air dome disappearance time]
Using a PVOH-based film conditioned for one week under an atmosphere of 23 ° C. and 50% RH, 25 g of a cylindrical herbicide (average particle size 5 mm, Patful Ace L jumbo manufactured by Kumiai Chemical Industry Co., Ltd.) A three-side sealed packaging bag having a size of 80 × 90 mm was produced.

Water was poured into a container having a length of 70 cm, a width of 50 cm, and a height of 10 cm to a height of 5 cm, and the above-described packaging bag in which the herbicide was packaged was naturally dropped from a height of 70 cm on a water surface adjusted to 25 ° C. When the film of the packaging bag dropped on the surface of the water absorbs water and swells and starts to dissolve, the encapsulated drug (herbicide) diffuses on the surface of the water, but at the same time the side not in contact with the surface of the water (upper) The film swells in a dome-like state containing air. The time until the swelling and dissolution progressed and the air dome portion was crushed was measured. And the performance of each film was evaluated according to the following criteria.
○: Air dome disappearance time is less than 400 seconds ×: Air dome disappearance time is 400 seconds or more

  From the above results, it can be seen that the example products have excellent water solubility since the air dome defoaming time is short. Therefore, the packaged herbicide does not stay solid, and when used in, for example, a paddy field, the herbicide is well diffused.

  On the other hand, the comparative example product is inferior in water solubility since the air dome defoaming time is long. Therefore, the herbicide solidifies in the dome-shaped part of the air dome.For example, when used in paddy fields, the herbicide stays without diffusing, and the concentration of the herbicide increases only in this area, which adversely affects rice. Will give.

Claims (5)

  A water-soluble film for pesticide packaging, comprising a resin composition containing polyvinyl alcohol resin (A) and acetylene glycol surfactant (B) as essential components.   The water-soluble film for agricultural chemical packaging according to claim 1, wherein the acetylene glycol surfactant (B) is in a proportion of 0.1 to 10 parts by weight with respect to 100 parts by weight of the polyvinyl alcohol resin (A).   The viscosity of a 4% by weight aqueous solution of the polyvinyl alcohol resin (A) is 10 to 70 mPa · s at 20 ° C, and the average saponification degree of the polyvinyl alcohol resin (A) is 70 to 98 mol%. Or the water-soluble film for agricultural chemical packaging of 2.   The water-soluble film for agricultural chemical packaging according to any one of claims 1 to 3, wherein the water-soluble film for agricultural chemical packaging has a thickness of 10 to 100 µm.   A water-soluble film comprising a resin composition containing a polyvinyl alcohol resin (A) and an acetylene glycol surfactant (B) as essential components.