JP2018164435A - Agricultural film, and agricultural greenhouse, agricultural curtain, or agricultural tunnel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an agricultural film in which light transmission quantity is suppressed in the dry summer season and leaf scorch of cultivated products can be suppressed, and light transmission quantity is large in the winter condensation season and sunlight sufficiently transmits even in the winter season of weak sunlight.SOLUTION: There is provided an agricultural film 1 having at least an A layer 3 and a droplet-flowing layer 2, in which (1) the surface of the agricultural film 1 on the droplet-flowing layer 2 has 0.1 to 3.0 μm of arithmetic average roughness Ra measured in accordance with JISB0601:2013, and (2) the droplet-flowing layer 2 contains hydrophilic inorganic filler.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an agricultural film and an agricultural house, an agricultural curtain, or an agricultural tunnel.

  Conventionally, in the agricultural field, when cultivating agricultural crops, in order to improve marketability and productivity, vinyl chloride film, special films mainly composed of polyethylene, ethylene-vinyl acetate copolymer and polyolefin resin, etc. House cultivation and tunnel cultivation, in which useful crops are cultivated by coating with agricultural films, are being actively performed.

  In the above-mentioned house cultivation and the like, the leaf burning phenomenon is known as a high temperature obstacle especially in summer. The leaf burning phenomenon means that a lot of direct light enters the house and strong light hits the leaves of the cultivation to burn the leaves. As a countermeasure for preventing the burning of leaves, there is a method of reducing the amount of direct light by coloring the house with titanium oxide or the like, but in that case, the total light transmittance is also lowered. When the total light transmittance is reduced, there is a problem that the transmission of sunlight into the house is reduced, which adversely affects the cultivation of the crop itself.

  Moreover, since sunlight becomes weak in winter, it is necessary to transmit sunlight into the house. If the amount of sunlight transmitted through the house is small in winter, the temperature inside the house decreases, which adversely affects crop cultivation.

  As an agricultural film for solving such problems, a mixture in which at least one of the outermost layer and the innermost layer is composed of a mixture of a specific ethylene / vinyl acetate copolymer (A) and a specific low density polyethylene (B). An agricultural film having a multilayer structure composed of a layer and another olefinic resin has been proposed (see Patent Document 1).

Japanese Patent No. 3219319

  However, the above-described agricultural film has not been sufficiently studied to solve the above problems in summer and winter at the same time. In the above-mentioned agricultural film, when the inside of the house is kept warm in winter, there is a problem that condensation occurs due to moisture in the air in the house, and sunlight is diffusely reflected so that it is difficult for the sunlight to pass through the house.

  In addition, the surface shape for reducing direct light rays has not been sufficiently studied even in summer, and the above-described agricultural film has a problem that leaf burn occurs due to direct sunlight in summer.

  Accordingly, there is a demand for the development of an agricultural film that suppresses the amount of light transmission when drying in the summer and has a large amount of light transmission when the condensation occurs in the winter.

  The present invention has been made in view of the above problems, the amount of light transmission is suppressed during drying in the summer, the leaf burn of the cultivation can be suppressed, and the amount of light transmission during condensation in the winter Therefore, an object of the present invention is to provide an agricultural film that can sufficiently transmit sunlight even in winter when sunlight is weak.

  As a result of intensive studies to achieve the above object, the present inventors have found that the agricultural film having at least the A layer and the droplet layer is JIS B0601: 2013 on the surface of the agricultural film on the droplet layer side. According to the agricultural film in which the arithmetic average roughness Ra measured in accordance with the above is 0.1 to 3.0 μm and the droplet layer contains a hydrophilic inorganic filler, the above object can be achieved. The invention has been completed.

That is, the present invention relates to the following agricultural films.
1. An agricultural film having at least an A layer and a droplet layer,
(1) The surface on the droplet layer side of the agricultural film has an arithmetic average roughness Ra of 0.1 to 3.0 μm measured according to JIS B0601: 2013,
(2) The droplet layer contains a hydrophilic inorganic filler.
Agricultural film characterized by that.
2. Item 2. The agricultural film according to Item 1, wherein the layer A contains two or more polyolefin resins having different melt flow rates.
3. Item 3. The agricultural film according to Item 2, wherein the polyolefin-based resin is at least one selected from the group consisting of ethylene-vinyl acetate copolymer, low-density polyethylene, and linear low-density polyethylene.
4). Item 4. The agricultural film according to any one of Items 1 to 3, wherein the droplet layer includes the hydrophilic inorganic filler and a binder resin.
5. Item 5. The agricultural film according to any one of Items 1 to 4, wherein a difference (Hzd−Hzw) between a haze value (Hzd) during drying and a haze value (Hzw) during condensation is 10% or more.
6). The agricultural film of claim | item 5 whose haze value (Hzd) at the time of the said drying is 10 to 50%.
7). Item 7. The agricultural film according to Item 5 or 6, wherein the haze value (Hzw) at the time of condensation is less than 20%.
8). The said A layer is an agricultural film in any one of claim | item 1 -7 which does not contain an inorganic particle.
9. Having at least the droplet layer, the A layer, the B layer, and the C layer in this order,
The B layer is composed of a single layer or a plurality of layers containing a polyolefin resin, and contains an inorganic heat insulating agent in at least one layer,
The C layer includes a polyolefin resin,
The agricultural film in any one of claim | item 1 -8.
10. Item 10. An agricultural house, an agricultural curtain, or an agricultural tunnel having the agricultural film according to any one of Items 1 to 9.

  The agricultural film of the present invention has a light transmission amount that is suppressed when drying in the summer, can suppress leaf burning of the cultivation, and has a large amount of light transmission when condensation occurs in the winter, where the sunlight is weak. Even so, since the sunlight rays are sufficiently transmitted, it can be suitably used for cultivation of agricultural crops.

It is sectional drawing which shows an example of the laminated constitution of the agricultural film of this invention. It is sectional drawing which shows an example of the laminated constitution of the agricultural film of this invention.

  The agricultural film of the present invention is an agricultural film having at least an A layer and a droplet layer. (1) The surface of the agricultural film on the droplet layer side was measured according to JIS B0601: 2013. Arithmetic average roughness Ra is 0.1-3.0 micrometers, (2) The said droplet layer contains a hydrophilic inorganic filler, It is characterized by the above-mentioned.

  The agricultural film has a high haze value because the surface on the droplet layer side has an arithmetic average roughness Ra of 0.1 to 3.0 μm measured according to JIS B0601: 2013. Since the permeation to the inside of the house or the like is suppressed, leaf scorch is suppressed. Further, the agricultural film has an arithmetic average roughness Ra in combination with the arithmetic average roughness Ra of the surface on the droplet layer side being in the above-mentioned range and the droplet layer containing a hydrophilic inorganic filler. By spreading so that the surface showing Ra is inside the house or the like, water is filled into the irregularities on the surface of the agricultural film during dew condensation in winter, and the haze value is lowered. For this reason, the above-mentioned agricultural film has a large amount of light transmission during the dew condensation in the winter, and the sunlight is sufficiently transmitted even in the winter when the sunlight is weak. As described above, the agricultural film of the present invention has a light transmission amount suppressed when it is dried in summer, and a light transmission amount increases when it is condensed in winter.

  Hereinafter, the agricultural film of the present invention will be described in detail.

  The layer structure of the agricultural film of the present invention is not particularly limited as long as it has at least the A layer and the droplet layer. 1 and 2 show the layer structure of the agricultural film of the present invention. 1 and 2 are cross-sectional views showing an example of the layer structure of the agricultural film of the present invention. 1 and 2, the agricultural film 1 of the present invention has a droplet layer 2 formed on one side of the A layer 3, and the droplet layer 2 is formed on the surface of the agricultural film 1.

  The agricultural film of the present invention may have a layer configuration having only an A layer and a droplet layer as shown in FIG. Moreover, as a suitable layer structure, as shown in FIG. 2, a layer structure having at least a droplet layer, an A layer, a B layer, and a C layer in this order can be mentioned. Hereinafter, each layer will be described by taking this preferable layer configuration as an example. In addition, in the agricultural film of this invention, the surface by the side of a droplet layer should just show the said arithmetic mean roughness Ra, and the surface which shows the said arithmetic mean roughness Ra is the inner surface of a house etc. at the time of extension to a house etc. It is a surface.

  The agricultural film of the present invention has an arithmetic average roughness Ra of 0.1 to 3.0 μm measured on the surface of the droplet layer side according to JIS B0601: 2013. If Ra is less than 0.1 μm, direct light rays in summer cannot be reduced, and if it exceeds 3.0 μm, the haze value is not sufficiently lowered during dew condensation in winter and the amount of transmitted light is reduced. It is not possible to transmit sunlight enough in the winter when it is weak. The Ra is preferably 0.3 to 2.0 μm, and more preferably 0.5 to 1.0 μm.

(Drip layer)
The droplet layer is a layer that is formed on the A layer (the side opposite to the side on which the B layer is formed) and is positioned inside the house when the agricultural film of the present invention is spread on the house. is there.

  The droplet layer contains a hydrophilic inorganic filler. The hydrophilic inorganic filler is not particularly limited as long as it can be smoothened by filling the unevenness of the surface of the agricultural film with water at the time of dew condensation in winter, and can reduce the haze value. Silica, titanium oxide, titanium dioxide, talc, etc. Is mentioned. Among these, silica is preferable in that the haze value can be further reduced due to the condensation in winter.

  Examples of the silica include colloidal silica and powdered silica. Among these, colloidal silica is preferable in that the haze value can be further reduced due to dew condensation in winter.

  Colloidal silica is in a state where silica particles are dispersed in a liquid to form a colloid. The average primary particle diameter of the silica particles contained in the colloidal silica is not particularly limited, is preferably 1 to 100 nm, more preferably 4 to 100 nm, still more preferably 20 to 80 nm, and particularly preferably 40 to 60 nm.

  Colloidal silica used in the droplet layer includes colloidal silica in which primary particles of spherical silica particles are dispersed in a liquid to form a colloid, and a necklace containing secondary particles in which the primary particles of silica particles are bonded in a ring shape. Colloidal silica, colloidal silica in any form such as linear colloidal silica containing secondary particles in which the primary particles of silica particles are linked in the form of several to dozens of chains and secondary particles having no cyclic structure are used. May be. Among these, colloidal silica in which primary particles of spherical silica particles are dispersed in a liquid to form a colloid can be used more suitably.

  As a commercial product of colloidal silica in which the primary particles of the above silica particles are dispersed in a liquid to form a colloid, colloidal silica manufactured by Nissan Chemical Industries, Ltd. Product name: “ST-XS” (average particle size 4 to 6 nm) , "ST-S" (average particle size 8-11 nm), "ST-30" (average particle size 10-15 nm), "ST-50" (average particle size 20-25 nm), "ST-20L" (average Particle diameter 40-50 nm), "ST-XL" (average particle diameter 40-60 nm), etc. are mentioned. Moreover, as a commercial item of the said necklace-shaped colloidal silica, Nissan Chemical Industries Ltd. necklace-shaped colloidal silica Brand name: "ST-PS-S", "ST-PS-M", "ST-PS-SO", “ST-PS-MO”, “ST-PS-S-AK” may be mentioned.

  The content of the hydrophilic inorganic filler in the droplet layer is preferably 100 to 300 parts by mass, and more preferably 150 to 250 parts by mass with 100 parts by mass of the binder resin described later. By setting the content of the hydrophilic inorganic filler in the above range, the haze value can be further reduced during dew condensation in winter.

  The content of the hydrophilic inorganic filler in the droplet layer is preferably 2.0 to 12.0% by mass based on 100% by mass of the antifogging composition for forming the droplet layer described later, and 3.0%. -8.0 mass% is more preferable. By setting the content of the hydrophilic inorganic filler in the above range, the haze value can be further reduced during dew condensation in winter.

  The droplet layer preferably contains a binder resin. The binder resin may be either a hydrophilic binder resin or a hydrophobic binder resin.

  Examples of the hydrophilic binder resin include polyvinyl alcohol, ethylene-vinyl alcohol copolymer, vinyl acetate water-soluble resin, polyethylene oxide, cellulose acylate, polyethylene glycol, polyvinyl pyrrolidone, polyacrylamide, polyvinyl butyral, polyether ester amide, Modified cellulose such as poly (N-methylolacrylamide), hydroxyethylcellulose, methylcellulose, hydroxypropylcellulose, carboxymethylcellulose, water-soluble polyester resin, water-soluble polyvinyl acetal, poly-N-vinylacetamide, polyacrylamide, polyacryloylmorpholine, polyhydroxy Examples include acrylic acrylate, polyacrylic acid, and polyether-based materials.

  Examples of the hydrophobic binder resin include acrylic resins, urethane resins, epoxy resins, and polyester resins, and acrylic resins are particularly preferably used.

  Examples of the acrylic resin include a homopolymer or a copolymer of a (meth) acrylic monomer, and a copolymer of a (meth) acrylic monomer and another copolymerizable monomer. . In the present specification, “(meth) acrylic monomer” means an acrylic monomer or a methacrylic monomer, and the same applies to other portions described as (meth). .

  Specific examples of the (meth) acrylic monomer include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, i-propyl (meth) acrylate, and n-butyl (meth) ) Acrylate, t-butyl (meth) acrylate, i-butyl (meth) acrylate, n-hexyl (meth) acrylate, n-octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl Alkyl (meth) acrylates such as (meth) acrylate, phenyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate; 2-hydroxyethyl (meth) acrylate , - hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, glycerol mono (meth) acrylate, containing functional groups such as glycidyl (meth) acrylate (meth) acrylate; (meth) acrylamide. These monomers can be used alone or in combination of two or more.

  Specific examples of other monomers copolymerizable with the (meth) acrylic monomer include aromatic vinyl monomers such as styrene and α-methylstyrene; vinyl pyridine, vinyl alcohol, and vinyl imidazole. Vinyl monomers such as vinyl pyrrolidone, vinyl acetate and 1-vinyl imidazole; itaconic acid esters such as monomethyl itaconate and monoethyl itaconate; monomethyl fumarate, monoethyl fumarate, monopropyl fumarate, monobutyl fumarate And maleic acid esters such as monomethylmalate, monoethylmalate, monopropylmalate, monobutylmalate, and the like. These monomers can be used alone or in combination of two or more.

  As the urethane resin, for example, polyether, polyester, and polycarbonate anionic polyurethane resins can be used. These urethane resins may be used in the form of an aqueous composition or an emulsion.

  The urethane-based resin is preferably a polycarbonate-based anionic polyurethane resin emulsion in terms of excellent adhesion to the A layer, water resistance and surface strength (scratch resistance), and a polycarbonate-based anionic polyurethane resin having a silanol group. The emulsion is more preferred. These urethane resins may be used alone or in combination of two or more.

  The content of the binder resin in the droplet layer is preferably 0.5 to 5% by mass, more preferably 1 to 3% by mass based on 100% by mass of the antifogging composition for forming the droplet layer described later. preferable. By setting the content of the binder resin in the above range, it is possible to further reduce the haze value at the time of dew condensation in winter, and to impart more excellent scratch resistance to the surface of the agricultural film of the present invention. it can.

  In the above-mentioned droplet layer, the mass ratio (Mf / Mb) between the mass (Mf) of the hydrophilic inorganic filler and the mass (Mb) of the binder resin is preferably 1.50 to 3.50, and 1.50 to 3 0.00 is more preferable, and 1.60 to 2.50 is even more preferable. By setting Mf / Mb in the above range, the fluidized droplet layer can exhibit much more excellent transparency and water resistance.

  The thickness of the droplet layer is preferably from 0.1 to 2.0 μm, more preferably from 0.3 to 1.5 μm, still more preferably from 0.5 to 1.0 μm. When the thickness of the droplet layer is within the above range, even more excellent droplet property can be exhibited.

  The droplet layer is formed by applying an antifogging composition for forming the droplet layer onto the surface on which the droplet layer is formed and drying the composition. The antifogging composition is not particularly limited as long as it contains the hydrophilic inorganic filler. For example, the antifogging composition contains the hydrophilic inorganic filler, the binder resin, a surfactant and a dispersion medium. Is mentioned. Hereinafter, among the components of the antifogging composition, components other than the hydrophilic inorganic filler and the binder resin will be described.

  The antifogging composition may contain a surfactant. Examples of the surfactant include polyhydric alcohol partial esters composed of polyhydric alcohols and higher fatty acids, including various known nonionic surfactants, anionic surfactants, and cationic surfactants. Type, silicone surfactants, and fluorine surfactants. Among these, a non-ionic surfactant or a silicone-based interface can be imparted to the antifogging composition because it can impart high leveling properties, and can impart high fluidity to the droplet layer formed using the antifogging composition. Activators are preferred, and silicone surfactants are more preferred. These may be used singly or in combination of two or more, but when used in combination, it is preferable to include at least a nonionic surfactant or a silicone-based surfactant. .

  Specific examples of the silicone surfactant include, for example, dimethyl silicone oil, methyl hydrogen silicone oil, methyl phenyl silicone oil, amino modified silicone oil, alkyl modified silicone oil, phenyl modified silicone oil, carboxyl modified silicone oil, high grade Fatty acid-modified silicone oil, epoxy-modified silicone oil, vinyl group-containing silicone oil, alcohol-modified silicone oil, polyether-modified silicone oil, alkyl / polyether-modified silicone oil, fluorine-modified silicone oil, alkoxysilane, reactive siloxane oligomer, and these Examples include silicone elastomers having the following structure. These may be used alone or in combination of two or more. Among these, polyether-modified silicone oil is preferable in that high leveling property can be imparted to the antifogging composition and high antifogging property can be imparted to the droplet layer formed using the antifogging composition.

  Specific examples of the nonionic surfactant include, for example, sorbitan such as sorbitan monostearate, sorbitan monomyristate, sorbitan monopalmitate, sorbitan monobehenate, sorbitan / alkylene glycol condensate and fatty acid ester. Surfactants: glycerol monopalmitate, glycerol monostearate, glycerol monolaurate, diglycerol monopalmitate, glycerol dipalmitate, glycerol distearate, diglycerol monopalmitate monostearate, triglycerol monostearate Glycerin-based surfactants such as rate, triglycerin distearate or their alkylene oxide adducts; polyethylene glycol monostearate, polyethylene glycol monopalmitate Polyethylene glycol surfactants such as polyethylene glycol alkyl phenyl ether; trimethylolpropane surfactants such as trimethylolpropane monostearate; pentaerythritol surfactants such as pentaerythritol monopalmitate and pentaerythritol monostearate; Alkylene oxide alkylene oxide adduct; sorbitan / glycerin condensate and fatty acid ester; sorbitan / alkylene glycol condensate and fatty acid ester; diglycerin dioleate sodium lauryl sulfate; dodecylbenzenesulfonic acid sodium salt; cetyltrimethylammonium chloride Dodecylamine hydrochloride; lauric acid laurylamide ethyl phosphate; triethylcetylammonium ion Id; oleyl amino diethylamine hydrochloride; dodecyl pyridinium salts and isomers thereof; those containing acetylenic dialcohols and alkylene oxide adducts thereof and the like. Among these, acetylene dialcohol and its alkylene oxide adduct are preferable in that the surface tension can be particularly reduced.

  In the antifogging composition, the content of the surfactant (the total amount when two or more types are used in combination) is: 1. 100 parts by mass in total of the hydrophilic inorganic filler and the binder resin. 0-15.0 mass parts is preferable, 1.2-5.0 mass parts is more preferable, and 1.5-3.5 mass parts is still more preferable. By setting the content of the surfactant in the above range, the droplet layer formed from the antifogging composition can exhibit excellent leveling properties.

  The hydrophilic inorganic filler, binder resin, and surfactant are dispersed in a dispersion medium such as water or a product that is usually marketed, or a product dispersed in a dispersion medium such as water, or a powder that is usually marketed. Any of these may be used.

  The antifogging composition may contain a dispersion medium. That is, the antifogging composition is an antifogging composition in which the colloidal silica and, if necessary, the binder resin, the surfactant, and other components described later are dispersed in a dispersion medium. May be. Examples of the dispersion medium include water, water-miscible solvents containing water, and the like. Specifically, water such as tap water, deionized water, and pure water; monohydric alcohol such as methyl alcohol, ethyl alcohol, and isopropyl alcohol. Polyhydric alcohols such as ethylene glycol, diethylene glycol and glycerine; cyclic alcohols such as benzyl alcohol; cellosolve acetates; ketones and the like. These dispersion media are preferably used alone or in combination with water and other solvents.

  If the anti-fogging composition of the present invention contains the colloidal silica and the binder resin, an ultraviolet absorber, a light stabilizer, an antioxidant, a lubricant, a heat stabilizer, and an antistatic agent are added as necessary. Such other components can be blended in the usual amounts.

  Examples of the UV absorber include UV absorbers such as benzotriazole, benzoate, benzophenone, cyanoacrylate, and phenyl salicylate. Among these, benzophenone ultraviolet absorbers and / or benzotriazole ultraviolet absorbers are preferably used.

  As the light stabilizer, various compounds usually blended in the antifogging composition can be used. Specifically, for example, 4-acetoxy-2,2,6,6-tetramethylpiperidine, bis (2,2,6,6-tetramethyl-4-piperidine) adipate, tris (2,2,6, Examples include hindered amine compounds such as 6-tetramethyl-4-piperidyl) benzene-1,3,5-tricarboxylate.

  Examples of the antioxidant include 2,6-di-tert-butyl-4-methylphenol, 2,2′-methylenebis (6-tert-butyl-4-ethylphenol), dilauryl thiodipropionate, and the like. .

  Examples of lubricants or heat stabilizers include polyethylene wax, liquid paraffin, bisamide, stearic acid, zinc stearate, aliphatic alcohol, calcium stearate, barium stearate, barium ricinoleate, dibutyltin dilaurate, dibutyltin dimaleate, and organic phosphoric acid. Examples thereof include metal salts, organic phosphite compounds, phenols, β-diketone compounds and the like.

  Each of the other components can be used alone or in combination of two or more. The blending amount of each of the other components is preferably in a range that does not deteriorate the performance of the droplet layer. Usually, the solid content of the hydrophilic inorganic filler, the solid content of the binder resin, the surfactant, and the dispersion medium The total of 100 parts by mass can be selected within a total range of 10 parts by mass or less.

(A layer)
The A layer is a layer in which the droplet layer is formed on the upper side (the side opposite to the side on which the B layer is formed).

  The layer A preferably has a surface arithmetic average roughness Ra of 0.1 to 3.0 μm measured according to JIS B0601: 2013. If Ra of the A layer is in the above range, if the droplet layer is formed so as to follow the surface shape of the A layer, Ra of the surface of the droplet layer is in the above range, and the agricultural film of the present invention The Ra on the surface of the droplet layer side can be easily adjusted to 0.1 to 3.0 μm. Ra of the A layer is preferably 0.3 to 2.0 μm, and more preferably 0.5 to 1.0 μm.

  The A layer may contain a polyolefin resin. The polyolefin resin is not particularly limited, and is a homopolymer of ethylene or α-olefin, a copolymer of ethylene and α-olefin, or a copolymer of different monomers mainly composed of ethylene or α-olefin. , Copolymers of ethylene or α-olefin and polyunsaturated compounds such as conjugated or non-conjugated dienes, acrylic acid, methacrylic acid, vinyl acetate, etc. can be used, for example, high density, low density or direct Chain low density polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-butene copolymer, ethylene-4-methyl-1-pentene copolymer, ethylene-vinyl acetate copolymer (EVA), ethylene-acrylic acid A copolymer etc. are mentioned. Of these, low-density polyethylene, linear low-density polyethylene, and ethylene-vinyl acetate copolymer are preferable, and linear low-density polyethylene and ethylene-vinyl acetate copolymer are more preferable. By using the above resin as the polyolefin-based resin, the agricultural film can exhibit more excellent transparency and weather resistance, and the agricultural film can be made inexpensive.

  In the present invention, an ethylene-α-olefin copolymer resin obtained by copolymerization with a metallocene catalyst can be used as at least one component of the polyolefin resin. This is usually referred to as metallocene polyethylene, and is a copolymer of ethylene and an α-olefin such as butene-1, hexene-1, 4-methylpentene-1, octene.

  When an ethylene-α-olefin copolymer is used as the polyolefin resin, the melt flow rate (MFR) measured by JIS-K7210 of the ethylene-α-olefin copolymer is 0.01 to 50 g / 10 min. Preferably, 0.1 to 40 g / 10 min is more preferable, 0.2 to 30 g / 10 min is further preferable, and 0.3 to 20 g / 10 min is particularly preferable. By setting the MFR within the above-mentioned range, it becomes easy to adjust the arithmetic average roughness Ra of the surface of the A layer, and the Ra on the surface of the agricultural film of the present invention on the droplet layer side is 0.1 to 3. It can be easily adjusted to 0 μm. Further, by setting the MFR within the above range, it is possible to reduce the meandering of the film during molding (during film formation) and the load on the molding machine, thereby improving the moldability.

Density measured by JIS K7112 of the ethylene -α- olefin copolymer is preferably 0.880 to 0.930 g / cm ^3, more preferably 0.890~0.920g / cm ^3. By setting the density in a preferable range, it becomes easy to ensure the transparency of the agricultural film, and it is easy to suppress blocking by reducing the surface stickiness.

  The molecular weight distribution (weight average molecular weight / number average molecular weight) determined by gel permeation chromatography (GPC) of the ethylene-α-olefin copolymer is preferably 0.5 to 3.5, and preferably 1.0 to 3. 0 is more preferable. By setting the molecular weight distribution in a preferable range, it is possible to reduce the meandering of the film during molding (during film formation) to improve the moldability, and to easily secure the mechanical strength of the agricultural film.

  When linear low density polyethylene is used as the polyolefin-based resin, the melt flow rate (MFR) measured by JIS-K7210 of the linear low density polyethylene is preferably 0.01 to 50 g / 10 min. 1-40 g / 10 minutes are more preferable, 0.2-30 g / 10 minutes are still more preferable, 0.3-20 g / 10 minutes are especially preferable, and 1.0-2.5 g / 10 minutes are the most preferable. By setting the MFR within the above-mentioned range, it becomes easy to adjust the arithmetic average roughness Ra of the surface of the A layer, and the Ra on the surface of the agricultural film of the present invention on the droplet layer side is 0.1 to 3. It can be easily adjusted to 0 μm. Further, by setting the MFR within the above range, it is possible to reduce the meandering of the film during molding (during film formation) and the load on the molding machine, thereby improving the moldability.

Density measured by JIS K7112 of the linear low-density polyethylene is preferably from 0.880 to 0.930 g / cm ^3, more preferably 0.890~0.925g / cm ^3. By setting the density in a preferable range, it is easy to ensure the transparency of the agricultural film, and it is easy to suppress blocking by reducing surface stickiness.

  When an ethylene-vinyl acetate copolymer is used as the polyolefin-based resin, the melt flow rate (MFR) measured by JIS-K7210 of the vinyl acetate copolymer is preferably 0.01 to 50 g / 10 min. 1-40 g / 10 minutes are more preferable, 0.2-30 g / 10 minutes are still more preferable, 0.3-20 g / 10 minutes are especially preferable, and 0.5-15 g / 10 minutes are the most preferable. By setting the MFR within the above-mentioned range, it becomes easy to adjust the arithmetic average roughness Ra of the surface of the A layer, and the Ra on the surface of the agricultural film of the present invention on the droplet layer side is 0.1 to 3. It can be easily adjusted to 0 μm. Further, by setting the MFR within the above range, it is possible to reduce the meandering of the film during molding (during film formation) and the load on the molding machine, thereby improving the moldability.

The ethylene - density measured by JIS K7112 vinyl acetate copolymer is preferably 0.910~0.940g / cm ^3, more preferably 0.920~0.935g / cm ^3. By setting the density in a preferable range, it is easy to ensure the transparency of the agricultural film, and it is easy to suppress blocking by reducing surface stickiness.

  The ethylene-vinyl acetate copolymer preferably has a vinyl acetate content in the range of 1 to 50 mass%, more preferably in the range of 1 to 30 mass%, still more preferably in the range of 2 to 20 mass%, and 3 to 15 A mass% range is particularly preferred. By setting the vinyl acetate content in a preferable range, the hardness of the agricultural film can be optimized, so that the generation of wrinkles and slack can be effectively suppressed during expansion to a house. In addition, since the slackness of the agricultural film can be suppressed even at high temperatures in summer, it is easy to suppress the breakage due to fluttering due to the slack, rubbing with the house structure, and the like.

  The said polyolefin resin may be used individually by 1 type, and 2 or more types may be mixed and used for it.

  The A layer preferably contains two or more types of polyolefin resins having different melt flow rates as measured according to JIS-K7210. By adopting such a configuration, it becomes easy to adjust the arithmetic average roughness Ra of the surface of the layer A. If the droplet layer is formed so as to follow the surface shape of the layer A, the surface Ra of the droplet layer is It becomes the said range, and Ra of the surface at the side of a droplet layer of the agricultural film of this invention can be easily adjusted to 0.1-3.0 micrometers.

  When the A layer contains two or more polyolefin resins having different melt flow rates measured according to JIS-K7210, the polyolefin resin contains an ethylene-vinyl acetate copolymer, a low density polyethylene, and a linear low resin. It is preferably at least one selected from the group consisting of high density polyethylene, and more preferably at least one selected from ethylene-vinyl acetate copolymer and linear low density polyethylene. By adopting such a configuration, it becomes easy to adjust the arithmetic average roughness Ra of the surface of the layer A. If the droplet layer is formed so as to follow the surface shape of the layer A, the surface Ra of the droplet layer is It becomes the said range, and Ra of the surface at the side of a droplet layer of the agricultural film of this invention can be easily adjusted to 0.1-3.0 micrometers.

  When the polyolefin resin is a linear low density polyethylene, the linear low density polyethylene is a linear low density polyethylene having a melt flow rate measured by JIS-K7210 of 1.7 g / 10 min or more ( It is preferable to include i) and linear low density polyethylene (ii) having a melt flow rate of less than 1.7 g / 10 minutes. By adopting such a configuration, it becomes easy to adjust the arithmetic average roughness Ra of the surface of the layer A. If the droplet layer is formed so as to follow the surface shape of the layer A, the surface Ra of the droplet layer is It becomes the said range, and Ra of the surface at the side of a droplet layer of the agricultural film of this invention can be easily adjusted to 0.1-3.0 micrometers.

  The upper limit of the melt flow rate of the linear low density polyethylene (i) is not particularly limited, and is preferably 50 g / 10 minutes, more preferably 40 g / 10 minutes, still more preferably 30 g / 10 minutes, and 20 g / 10 minutes. Particularly preferred. Moreover, the minimum of the melt flow rate of the said linear low density polyethylene (ii) is not specifically limited, 0.01 g / 10min is preferable, 0.5 g / 10min is more preferable, 1.0 g / 10min is Further preferred.

  When the polyolefin-based resin is an ethylene-vinyl acetate copolymer, the ethylene-vinyl acetate copolymer is an ethylene-vinyl acetate copolymer having a melt flow rate measured by JIS-K7210 of 5.0 g / 10 min or more. It is preferable that the polymer (i) and an ethylene-vinyl acetate copolymer (ii) having a melt flow rate of less than 5.0 g / 10 minutes are included. By adopting such a configuration, it becomes easy to adjust the arithmetic average roughness Ra of the surface of the layer A. If the droplet layer is formed so as to follow the surface shape of the layer A, the surface Ra of the droplet layer is It becomes the said range, and Ra of the surface at the side of a droplet layer of the agricultural film of this invention can be easily adjusted to 0.1-3.0 micrometers.

  The upper limit of the melt flow rate of the ethylene-vinyl acetate copolymer (i) is not particularly limited, is preferably 50 g / 10 minutes, more preferably 40 g / 10 minutes, still more preferably 30 g / 10 minutes, and 20 g / 10 minutes. Is particularly preferred. Moreover, the minimum of the melt flow rate of the said ethylene-vinyl acetate copolymer (ii) is not specifically limited, 0.01 g / 10min is preferable, 0.5 g / 10min is more preferable, 1.0 g / 10min Is more preferable.

  90-100 mass% is preferable and, as for content of the polyolefin-type resin in A layer, 95-99 mass% is more preferable. By setting the content of the polyolefin resin in the layer A within the above range, the amount of light transmitted during condensation in the wintertime of the agricultural film of the present invention is further increased, and even in the wintertime when sunlight is weak Is more transparent.

  The A layer may contain an ultraviolet absorber. It does not specifically limit as a ultraviolet absorber, A conventionally well-known thing can be used, For example, a triazine type ultraviolet absorber, a benzotriazole type ultraviolet absorber, and a benzophenol type ultraviolet absorber are mentioned.

  The said ultraviolet absorber may be used individually by 1 type, and may mix and use 2 or more types.

  0.1-10 mass parts is preferable with respect to 100 mass parts of polyolefin resin contained in A layer, and, as for content of a ultraviolet absorber, 0.1-1 mass part is more preferable. By setting the content in a preferable range, the agricultural film can further exhibit the ultraviolet ray suppressing effect and can suppress the bleed-out of the ultraviolet absorber.

  The A layer may contain a hindered amine light stabilizer in which an organic group or an organic functional group is bonded to the nitrogen atom of the piperidine ring directly or via an oxygen atom (note that the hindered amine light stabilizer is the A layer). In addition, it can be included in at least one of the A layer, the B layer, and the C layer, and is particularly preferable to be included in all of the A layer, the B layer, and the C layer. In addition, the said organic group means a reactive group with little reactivity, for example, a methyl group etc., The said organic functional group means the functional group which has reactivity in itself.

  Examples of such hindered amine light stabilizers include so-called NR type hindered amine light stabilizers and NOR type hindered amine light stabilizers. The NR type hindered amine light stabilizer means a hindered amine type light stabilizer in which a carbon atom is directly bonded to the nitrogen atom of the piperidine ring, and the NOR type hindered amine type light stabilizer is a hindered amine type light stabilizer. Among light stabilizers, those having a carbon atom bonded to the nitrogen atom of the piperidine ring via an oxygen atom.

  The NR hindered amine light stabilizer is not particularly limited, and a conventionally known one can be used. For example, NR type hindered amines having 1 or 2 or more piperidine ring structures represented by the following formula (1) in the molecule may be mentioned.

Here, in Formula (1), R ₁ is an organic group in which a carbon atom is directly bonded to a piperidine ring nitrogen atom, or an organic functional group.

  Examples of the organic group or organic functional group in which a carbon atom is directly bonded to the piperidine ring nitrogen atom include, for example, a carbon atom directly bonded to the piperidine ring nitrogen atom, having 1 or more carbon atoms and at least one or more carbon atoms. And a functional group or compound containing a methyl group or a methylene group. Examples of the compound having 1 or more carbon atoms and containing at least one methyl group or methylene group include alkyl groups, and also include oligomers and polymers.

  Specific examples of the NR-type hindered amine light stabilizer include those represented by the following formulas (2) to (10).

  Here, in Formula (10), n is a natural number indicating the degree of polymerization (the number of repeating units).

  As the NR type hindered amine light stabilizer, it is preferable to use one represented by the above formula (10).

  As a commercial item of the NR type hindered amine light stabilizer represented by the above formula (10), for example, trade name “TINUVIN 622” manufactured by BASF may be mentioned.

  The molecular weight of the NR type hindered amine light stabilizer is preferably 1000 or more, and more preferably 2000 or more. By setting the molecular weight within a preferable range, it becomes easy to suppress bleed out of the NR type hindered amine light stabilizer. The upper limit of the molecular weight is not particularly limited, but is about 5000.

  The NOR type hindered amine light stabilizer is not particularly limited, and conventionally known ones can be used. For example, a NOR-type hindered amine having one or more piperidine ring structures represented by the following formula (11) in the molecule can be mentioned.

Here, in Formula (11), R ₂ is an organic group or an organic functional group.

The organic group or the organic functional group represents, for example, a functional group or compound having 1 or more carbon atoms and containing at least one methyl group or methylene group. The compound having 1 or more carbon atoms and containing at least one methyl group or methylene group includes oligomers and polymers. Specifically, examples of R ₂ include an alkyl group such as a propyl group.

  Specific examples of the NOR-type hindered amine light stabilizer include those represented by the following formula (12).

  As a commercial item of the NOR type hindered amine light stabilizer represented by the above formula (12), for example, trade name “TINUVIN 123” manufactured by BASF Corporation may be mentioned. Moreover, as a commercial item of other NOR type hindered amine light stabilizers, for example, BASF Corporation trade name “TINUVIN NOR 371”, ADEKA Corporation trade name “LA-81”, Clariant Japan Co., Ltd. trade name “Hostavin” NOW ”.

  The molecular weight of the NOR-type hindered amine light stabilizer is preferably 1000 or more, and more preferably 2000 or more. By setting the molecular weight within a preferable range, it becomes easy to suppress bleeding out of the NOR-type hindered amine light stabilizer. The upper limit of the molecular weight is not particularly limited, but is about 5000.

  The A layer may further contain a hindered amine light stabilizer in which a hydrogen atom is bonded directly to a nitrogen atom of the piperidine ring (so-called NH type hindered amine light stabilizer) (note that the hindered amine light stabilizer is A). In addition to the layer, it can be included in at least one of the A layer, the B layer, and the C layer, and particularly preferably included in all the layers of the A layer, the B layer, and the C layer. By including the hindered amine light stabilizer, the agricultural film of the present invention is more excellent in weather resistance.

  It does not specifically limit as NH type hindered amine light stabilizer, A conventionally well-known thing can be used. For example, NH type hindered amine which has 1 or 2 or more piperidine ring structure represented by following formula (13) in a molecule | numerator is mentioned.

  Specific examples of the NH-type hindered amine light stabilizer include those represented by the following formulas (14) to (17).

In Formula (14), R ₃ is a tert-octyl group, and n is a natural number indicating the degree of polymerization.

  As the NH-type hindered amine light stabilizer, one represented by the above formula (14) is preferably used.

  As a commercial item of NH type hindered amine light stabilizer represented by the said Formula (14), BASF Corporation brand name "CHIMASSORB 944" etc. are mentioned, for example.

  1000 or more are preferable and, as for the molecular weight of the said NH type hindered amine light stabilizer, 2000 or more are more preferable. By setting the molecular weight within a preferable range, bleeding out of the NH-type hindered amine light stabilizer can be easily suppressed. The upper limit of the molecular weight is not particularly limited, but is about 5000.

  The hindered amine light stabilizer preferably contains an NR type hindered amine light stabilizer and an NH type hindered amine light stabilizer. By using such a hindered amine light stabilizer, the agricultural film of the present invention is excellent in the initial ultraviolet deterioration suppressing effect and excellent in the long-term sustainability of the ultraviolet deterioration suppressing effect. As a hindered amine light stabilizer (NR-NH mixed type hindered amine light stabilizer) including an NR type hindered amine light stabilizer and an NH type hindered amine light stabilizer, for example, trade names “TINUVIN 622” and BASF manufactured by BASF The product name “TINUVIN 783” manufactured by BASF, which is a mixture with the product name “CHIMASSORB 944” manufactured by the company.

  When the A layer contains the hindered amine light stabilizer, the content is preferably 0.1 to 3 parts by mass, and 0.2 to 2 parts by mass with respect to 100 parts by mass of the polyolefin resin contained in the A layer. More preferably, 0.3-1 mass part is still more preferable. By setting the content in a preferable range, the agricultural film can exhibit much better weather resistance.

  The layer A contains other additives such as an antioxidant, a heat stabilizer, a lubricant, an antistatic agent, a colorant, an antiblocking agent, and an antifoggant as long as the effects of the present invention are not impaired. May be.

  The layer A may contain inorganic particles such as an inorganic heat retaining agent, but preferably does not contain inorganic particles. When the A layer does not contain inorganic particles, the agricultural film of the present invention further increases the amount of light transmitted during condensation in the winter, and further transmits sunlight even in the winter when the sunlight is weak.

  5-50 micrometers is preferable, as for the thickness of A layer, 10-40 micrometers is more preferable, and 15-30 micrometers is still more preferable. When the thickness of the A layer is in the above range, the meandering of the film at the time of molding (film formation) can be further suppressed, and the moldability can be further improved.

(B layer)
The agricultural film of the present invention may have a B layer on the side opposite to the side on which the A droplet layer is formed. The B layer is composed of a single layer or a plurality of layers containing a polyolefin-based resin, and preferably contains an inorganic heat insulating agent in at least one layer.

  It does not specifically limit as polyolefin resin contained in B layer, The same thing as the polyolefin resin which can be used for the said A layer can be used. The polyolefin-based resin contained in the B layer is preferably an ethylene-vinyl acetate copolymer in that the agricultural film becomes more flexible and the stretching work becomes easier.

  The B layer is composed of a single layer or a plurality of layers containing the polyolefin resin. Although the number of layers of B layer is not specifically limited, It is preferable that it is 1-3 layers, and it is more preferable that it is 1 layer.

  At least one layer constituting the B layer of the agricultural film of the present invention may contain an inorganic heat insulating agent.

  The inorganic heat insulating agent is not particularly limited. For example, talc, hydrotalcite, magnesium aluminum composite hydroxide, lithium aluminum composite hydroxide, other composite hydroxides (alkali metal, alkaline earth metal) , Transition metals, 2B group elements, and hydroxides having at least two elements selected from 4B group elements of silicon or more). These may be used alone or in combination of two or more. Among these, it is preferable to use a magnesium aluminum composite hydroxide. By containing the said inorganic heat retention agent, the heat retention of the film for agriculture obtained can improve, and the extrusion fluctuation | variation at the time of film shaping | molding can be improved. Here, the variation in extrusion means, for example, that when a film in which an antifogging agent (for example, higher fatty acid ester) is kneaded is extruded and a lot of a low melting point antifogging agent is kneaded in the extruder, It refers to a phenomenon in which the resin composition slips and is difficult to extrude.

  The content of the inorganic heat insulating agent in the B layer is preferably 1 to 20 parts by mass and more preferably 5 to 15 parts by mass with respect to 100 parts by mass of the polyolefin resin contained in the B layer. By setting the content in a preferable range, in addition to easily imparting good heat retention to the agricultural film, an effect of improving extrusion fluctuation at the time of film formation by extrusion molding can be sufficiently obtained.

  The B layer may contain a hindered amine light stabilizer in which an organic group or an organic functional group is bonded to the nitrogen atom of the piperidine ring directly or via an oxygen atom. By including the hindered amine light stabilizer, the agricultural film of the present invention is further excellent in weather resistance.

  The hindered amine light stabilizer in which an organic group or an organic functional group is bonded to the nitrogen atom of the piperidine ring contained in the B layer directly or through an oxygen atom is not particularly limited, and is the same as that which can be used for the A layer. Things can be used.

  The B layer may further contain a hindered amine light stabilizer in which a hydrogen atom is directly bonded to a nitrogen atom of the piperidine ring. By including the hindered amine light stabilizer, the agricultural film of the present invention is further excellent in weather resistance.

  The hindered amine light stabilizer in which a hydrogen atom is directly bonded to the nitrogen atom of the piperidine ring contained in the B layer is not particularly limited, and the same ones that can be used for the A layer can be used.

  When the layer B is composed of a plurality of layers, the hindered amine light stabilizer in which a hydrogen atom is bonded to the nitrogen atom of the piperidine ring has an organic group or an organic functional group directly or via an oxygen atom to the nitrogen atom of the piperidine ring. It may be contained in the same layer as the bound hindered amine light stabilizer, or may be contained in a different layer. Since the bleeding out of the hindered amine light stabilizer caused by the extrusion effect due to the increase in the concentration of the hindered amine light stabilizer in the same layer can be suppressed, a hydrogen atom is present in the nitrogen atom of the piperidine ring. The bonded hindered amine light stabilizer is preferably contained in a different layer from the hindered amine light stabilizer in which an organic group or an organic functional group is bonded to the nitrogen atom of the piperidine ring directly or through an oxygen atom.

  As described above, the B layer is a hindered amine light stabilizer in which an organic group or an organic functional group is bonded to a nitrogen atom of a piperidine ring directly or via an oxygen atom, as long as the effect of the present invention is not impaired. Alternatively, a hindered amine light stabilizer in which a hydrogen atom is directly bonded to a nitrogen atom of the piperidine ring may be contained. About the kind and content, it is the same as the description in A layer. About content of the hindered amine light stabilizer contained in B layer, even if B layer consists of a several layer, the mass part with respect to 100 mass parts of polyolefin resin contained in the said B layer (B layer whole) is meant. To do.

  Other additions such as antioxidant, heat stabilizer, lubricant, antistatic agent, colorant, antiblocking agent, antifogging agent, antifogging agent, etc., as long as the B layer is within the range not impairing the effects of the present invention An agent may be included.

  40-120 micrometers is preferable, as for the thickness of B layer, 50-110 micrometers is more preferable, and 60-100 micrometers is still more preferable. When the thickness of the B layer is in the above range, an appropriate stiffness can be imparted to the agricultural film of the present invention, and it becomes easier to obtain better handling properties and workability.

(C layer)
The agricultural film of this invention may have C layer in the surface on the opposite side to the surface where the A layer is laminated | stacked among the surfaces of B layer. The C layer preferably contains a polyolefin resin.

  It does not specifically limit as polyolefin resin contained in C layer, The same thing as the polyolefin resin which can be used for the said A layer can be used.

  The C layer may contain a hindered amine light stabilizer in which an organic group or an organic functional group is bonded to the nitrogen atom of the piperidine ring directly or through an oxygen atom. By including the hindered amine light stabilizer, the agricultural film of the present invention is more excellent in weather resistance.

  The hindered amine light stabilizer in which an organic group or an organic functional group is bonded to the nitrogen atom of the piperidine ring contained in the C layer directly or through an oxygen atom is not particularly limited, and is the same as that which can be used for the A layer. Things can be used.

  The C layer may further contain a hindered amine light stabilizer in which a hydrogen atom is directly bonded to a nitrogen atom of the piperidine ring. By including the hindered amine light stabilizer, the agricultural film of the present invention is more excellent in weather resistance. The hindered amine light stabilizer in which a hydrogen atom is directly bonded to the nitrogen atom of the piperidine ring contained in the C layer is not particularly limited, and the same one that can be used for the A layer can be used.

  As described above, the C layer is a hindered amine light stabilizer in which an organic group or an organic functional group is bonded to a nitrogen atom of a piperidine ring directly or via an oxygen atom, as long as the effect of the present invention is not impaired. Alternatively, a hindered amine light stabilizer in which a hydrogen atom is directly bonded to a nitrogen atom of the piperidine ring may be contained. About those kind and content, it is the same as the description in A layer.

  If the C layer is within the range not impairing the effects of the present invention, an inorganic heat retention agent, an antioxidant, a heat stabilizer, a lubricant, an antistatic agent, a colorant, an antiblocking agent, an antifogging agent, an antifogging agent, etc. Other additives may be included.

  The inorganic heat insulating agent is not particularly limited. For example, talc, hydrotalcite, magnesium aluminum composite hydroxide, lithium aluminum composite hydroxide, other composite hydroxides (alkali metal, alkaline earth metal) , Transition metals, 2B group elements, and hydroxides having at least two elements selected from 4B group elements of silicon or more). These may be used alone or in combination of two or more. Among these, it is preferable to use a magnesium aluminum composite hydroxide. By containing an inorganic heat retention agent, the heat retention of the obtained agricultural film can be improved, and extrusion fluctuation during film formation can be improved. When the inorganic heat insulating agent is contained in the resin composition, an effect of suppressing extrusion fluctuation can be obtained.

  5-50 micrometers is preferable, as for the thickness of C layer, 10-40 micrometers is more preferable, and 15-30 micrometers is still more preferable. When the thickness of C layer is the said range, the intensity | strength of the agricultural film of this invention can be improved further.

  When the agricultural film of this invention contains an inorganic heat insulating agent, it is preferable that content of the said inorganic heat insulating agent is 1-10 mass parts with respect to 100 mass parts of polyolefin resin, and is 3-8 mass parts. More preferably. By setting the content in a preferable range, in addition to easily imparting good heat retention to the agricultural film, an effect of improving extrusion fluctuation at the time of film formation by extrusion molding can be sufficiently obtained.

  When the agricultural film of the present invention contains the hindered amine light stabilizer, the content of the hindered amine light stabilizer is preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the polyolefin resin. 0.2-5 mass parts is more preferable, and 0.3-3 mass parts is still more preferable. In addition to ensuring good weather resistance of agricultural films by setting the content in a preferred range, the ultraviolet absorber contained in agricultural films by the content of the light stabilizer being in an appropriate range Bleed-out can be suppressed.

  The agricultural film of the present invention has a dry haze value (Hzd) of preferably 10 to 50%, more preferably 20 to 45%, and even more preferably 25 to 40%. When the haze value at the time of drying is in the above range, the amount of light transmission can be further suppressed during drying in the summer, and leaf burn-up of the cultivation can be further suppressed.

  In the present specification, the haze value at the time of drying is determined according to [How to determine haze of plastic-transparent material] in accordance with JIS K7136 from the surface on the droplet layer side of the agricultural film of the present invention. It is a value measured using a meter.

  The agricultural film of the present invention preferably has a haze value (Hzw) at the time of condensation of less than 20%, more preferably 15% or less. When the haze value at the time of drying is within the above range, the amount of transmitted light is further increased during dew condensation in winter, and sunlight is further transmitted even in winter when sunlight is weak. Moreover, the minimum of the haze value at the time of the said condensation is not specifically limited, 1% is preferable, 5% is more preferable, and 10% is still more preferable.

  In addition, in this specification, the measuring method of the haze value at the time of the said dew condensation is as follows. That is, assuming dew condensation, liquid paraffin is dropped from the surface of the agricultural film of the present invention on the side of the droplet layer, and a sample for measuring the haze value at the time of dew condensation is prepared by covering the glass plate. From the direction of the glass plate of the measurement sample, the haze value of the measurement sample is measured using a haze meter according to [How to determine haze of plastic-transparent material] according to JIS K7136.

  In the agricultural film of the present invention, the difference (Hzd−Hzw) between the haze value at the time of drying (Hzd) and the haze value at the time of condensation (Hzw) is preferably 10% or more, and more preferably 15% or more. More preferably, it is more preferably 20% or more. The difference between the haze value at the time of drying and the haze value at the time of dew condensation is in the above range, so that the amount of light transmission is suppressed at the time of drying in the summer, and it is possible to suppress leaf burning of the cultivation, and in the winter season. Since the amount of light transmitted during condensation is large and the sunlight is sufficiently transmitted even in the winter when the sunlight is weak, the effect of the present invention that can be suitably used for cultivation of agricultural crops is more efficiently exhibited. can do. Further, if the difference between the haze value at the time of drying and the haze value at the time of dew condensation is 10% or more, the direct light rate at the time of dew condensation can be more sufficiently secured, and the outside of the agricultural tunnel and the agricultural house It is possible to further suppress the scattering of light to the water, and to further improve the heat insulation inside the agricultural tunnel and the agricultural house. The upper limit of the difference between the haze value at the time of drying and the haze value at the time of condensation is not particularly limited, is preferably 50%, more preferably 45%, still more preferably 40%, and particularly preferably 30%.

  Although the thickness of the agricultural film of this invention is not specifically limited, 30-300 micrometers is preferable, 40-200 micrometers is more preferable, 50-150 micrometers is still more preferable. By setting the thickness within a preferable range, the agricultural film has an appropriate stiffness, and good handleability and workability are easily obtained.

  The thickness ratio of the A layer, the B layer, and the C layer is preferably A layer: B layer: C layer = 1: 1: 1 to 1: 6: 1, and 1: 2: 1 to 1: 4. : 1 is more preferable.

  The agricultural film of the present invention may have other layers such as an adhesive layer between the respective layers, but has other layers in terms of ensuring the amount of light transmission during condensation in winter. It is preferable that the layer structure does not. Further, the agricultural film of the present invention may have another layer such as a surface protective layer on the surface of the droplet layer opposite to the surface on which the A layer is laminated. A layer structure having a droplet layer on the outermost surface is preferable in that it can easily exhibit the effect that the amount of light transmission is large and sunlight is sufficiently transmitted even in winter when sunlight is weak.

  The present invention is also an agricultural house, an agricultural curtain or an agricultural tunnel having the agricultural film. By spreading the above agricultural film on an agricultural house, agricultural curtain, or agricultural tunnel with the surface on the drip layer side inside, the amount of transmitted light is suppressed when drying in the summer, and leaf burning of the cultivation is prevented. Since it can be suppressed and has a large amount of light transmission at the time of dew condensation in winter and sunlight is sufficiently transmitted even in the winter when the sunlight is weak, the agricultural house, agricultural curtain or agricultural tunnel of the present invention Is suitable for cultivation of agricultural crops.

  Examples of the present invention will be described below. The present invention is not limited to the following examples.

Examples and Comparative Examples In each extruder of the three-layer extruder, the light-stabilization is performed with respect to 100 parts by mass of the polyolefin-based resin so that the layers A, B, and C are blended as shown in Table 1. An agent and a magnesium aluminum composite hydroxide were added and melt-kneaded.

  The materials shown in Table 2 were used as the raw materials used in Table 1.

  Three layers are coextruded by the inflation method so that the thickness of each of the A layer, the B layer, and the C layer is A layer: B layer: C layer = 1: 3: 1 (thickness ratio 20:60:20). A laminate having a thickness of 150 μm was obtained.

  An antifogging composition was prepared by adding a binder resin and a hydrophilic inorganic filler to water, which is a solvent, so that the flowing layer has the composition shown in Table 1. The composition of the antifogging composition was 4% by mass of the hydrophilic inorganic filler, 2% by mass of the binder resin, and 94% by mass of the solvent. On the layer A of the laminate prepared as described above, the antifogging composition was applied and dried at 70 ° C. for 1 minute to form a 1.0 μm-thick droplet layer, Manufactured.

  The following evaluation was performed about the agricultural film of the obtained Example and comparative example.

<Arithmetic average roughness Ra of the surface of an agricultural film>
The arithmetic average roughness Ra of the surface of the agricultural film on the droplet layer side was measured by a measuring method based on JIS B0601: 2013.

<Haze value during drying (Hzd)>
Based on JIS K7136, the haze value of the agricultural film at the time of drying was measured using a haze meter from the surface of the agricultural film on the liquid droplet layer side in accordance with JIS K7136.

<Haze value during condensation (Hzw)>
Assuming the time of dew condensation, liquid paraffin was dropped from the surface of the agricultural film on the droplet layer side, and a sample for measuring the haze value at the time of dew condensation was prepared by covering with a glass plate. From the direction of the glass plate of the measurement sample, the haze value of the measurement sample was measured using a haze meter according to [How to determine haze of plastic-transparent material] in accordance with JIS K7136.

<Difference between haze value during drying and haze value during condensation (Hzd-Hzw)>
The difference between the haze value at the time of drying and the haze value at the time of dew condensation measured by the above method was calculated based on the following formula.
(Hzd−Hzw) (%) = [Haze value during drying (Hzd) (%) − Haze value during condensation (Hzw) (%)]

<Leafburn prevention>
An incandescent lamp irradiation lamp was used for the rice leaf, and the incandescent lamp was irradiated at 120 W for 12 hours under the condition of a distance of 50 cm between the rice and the incandescent lamp. The state of leaves after irradiation with an incandescent lamp was visually observed and evaluated according to the following evaluation criteria. In addition, if it is more than △ evaluation, it is evaluated that there is no problem in actual use.
○: No or little leaf burn is observed.
(Triangle | delta): Although leaf scorch is seen a little, it is a grade without a problem.
X: Leaf burn is strongly generated.

<Visibility inside tunnel, curtain, or house>
The visibility was evaluated assuming the visibility inside the tunnel, the curtain, or the house during condensation. Specifically, the visibility of the agricultural film during condensation was visually observed and evaluated according to the following evaluation criteria. In addition, if it is more than △ evaluation, it is evaluated that there is no problem in actual use.
○: Internally cultivated crops are clearly visible.
Δ: The outline of the cultivated crop inside is slightly blurred but visible.
X: The cultivated crop inside is blurred and cannot be visually recognized.

<Insulation inside tunnel, curtain, or house>
A 120 W incandescent lamp was installed at a position 50 cm away from the spectroradiometer (manufactured by Eiko Seiki Co., Ltd .: model number MS-720). An agricultural film was installed at a position 20 cm from the spectroradiometer between the spectroradiometer and the incandescent lamp, and the amount of radiation (intensity) A1 at a wavelength of 1050 nm was measured. Moreover, the radiation amount (intensity) A0 of light at a wavelength of 1050 nm when no film was installed was measured. The radiation dose ratio was calculated according to the following formula and evaluated according to the following evaluation criteria.
(Radiation dose ratio) (%) = [A1 / A0] × 100
In addition, if it is more than △ evaluation, it is evaluated that there is no problem in actual use.
○: The radiation amount ratio is 95% or more.
Δ: Radiation ratio is 90% or more and less than 95%.
X: The radiation amount ratio is less than 90%.

  The results are shown in Table 1.

  In Table 2, MFR is a value measured under conditions of a temperature of 190 ° C. and a load of 21.18 N in accordance with JIS K-7210.

DESCRIPTION OF SYMBOLS 1 ... Agricultural film 2 ... Drip layer 3 ... A layer 4 ... B layer 5 ... C layer

Claims (10)

An agricultural film having at least an A layer and a droplet layer,
(1) The surface on the droplet layer side of the agricultural film has an arithmetic average roughness Ra of 0.1 to 3.0 μm measured according to JIS B0601: 2013,
(2) The droplet layer contains a hydrophilic inorganic filler.
Agricultural film characterized by that.   The agricultural film according to claim 1, wherein the layer A contains two or more polyolefin resins having different melt flow rates.   The agricultural film according to claim 2, wherein the polyolefin resin is at least one selected from the group consisting of an ethylene-vinyl acetate copolymer, a low density polyethylene, and a linear low density polyethylene.   The agricultural film according to claim 1, wherein the droplet layer includes the hydrophilic inorganic filler and a binder resin.   The agricultural film in any one of Claims 1-4 whose difference (Hzd-Hzw) of the haze value (Hzd) at the time of drying and the haze value (Hzw) at the time of dew condensation is 10% or more.   The agricultural film of Claim 5 whose haze value (Hzd) at the time of the said drying is 10 to 50%.   The agricultural film of Claim 5 or 6 whose haze value (Hzw) at the time of the said condensation is less than 20%.   The agricultural film according to claim 1, wherein the A layer does not contain inorganic particles. Having at least the droplet layer, the A layer, the B layer, and the C layer in this order,
The B layer is composed of a single layer or a plurality of layers containing a polyolefin resin, and contains an inorganic heat insulating agent in at least one layer,
The C layer includes a polyolefin resin,
The agricultural film in any one of Claims 1-8.   An agricultural house, an agricultural curtain, or an agricultural tunnel having the agricultural film according to claim 1.