JP2003094578A - Agricultural film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an agricultural film which develops good weatherability over a long period since its deterioration by ultraviolet rays is reduced, and it is resistant to agricultural chemicals (acid resistant properties) and keeps good anti-clouding properties, transparency, and mechanical properties over a long period. SOLUTION: The agricultural film is a laminated film in which the outermost layer (layer A) and an inner layer (layer b) are laminated when used in an agricultural house. The layer A is made of a polyolefin resin composition containing 100 pts.wt. of a polyolefin resin and 0.1-20 pts.wt. of a laminar silicate, and the layer b is made of a polyolefin resin composition substantially free from the laminar silicate. Alternatively, the layer A is made of a polyolefin resin composition containing 100 pts.wt. of the polyolefin resin and 0.1-20 pts.wt. of the laminar silicate, and the layer b is made of a polyolefin resin composition containing 100 pts.wt. of the polyolefin resin and 0.02-3 pts.wt. of a nonionic surfactant.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an agricultural film.

[0002]

2. Description of the Related Art Greenhouse cultivation is a cultivation method for supplying various crops such as vegetables, fruits, and flowers throughout the year.
Widely used. As an agricultural film used for agricultural greenhouses, tunnels, curtains, etc., a film made of a thermoplastic resin such as polyvinyl chloride resin or polyolefin resin has been widely used. Among them, polyolefin resin is excellent in transparency and mechanical properties, lightweight, and does not generate toxic gas even when incinerated,
It has been especially noticed.

However, since these resins are deteriorated by ultraviolet rays, there is a problem that they are difficult to use for a long period of time due to deterioration of transparency and damage due to deterioration of mechanical properties such as strength and elongation. .

In order to prevent such deterioration due to ultraviolet rays, a method of suppressing deterioration due to ultraviolet rays by adding a UV absorber, a hindered amine light stabilizer and, if necessary, a heat stabilizer to the resin, in other words, weather resistance A method of improving the property is generally adopted, and for example, JP-A-59-86.
Japanese Patent Laid-Open No. 645 and Japanese Patent Laid-Open No. 2-167350 disclose a polyolefin resin composition containing a hindered amine light stabilizer.

On the other hand, various pesticides are used in a closed agricultural house (greenhouse) in order to prevent diseases of crops and improve yield. Such pesticides are mainly composed of an acidic substance such as sulfur, phosphoric acid, and halogen, and decompose the hindered amine light stabilizer, which causes deterioration in weather resistance. Also, similarly, the hindered amine light stabilizer is decomposed by the influence of acid rain, which causes deterioration of weather resistance.

In order to prevent the weather resistance from being deteriorated by such an acidic substance, for example, Japanese Patent Application Laid-Open No. 63-175072 discloses an agricultural resin comprising a thermoplastic resin containing a hindered amine compound and a hydrotalcite compound. A film is disclosed, and JP-A-8-48822 discloses an agricultural film comprising a polyolefin resin composition to which a sterically hindered amine and a metal oxide or hydroxide are added, Also, JP-A-8-2240
Japanese Patent Publication No. 49 discloses an agricultural film made of a polyolefin resin composition containing a hindered amine compound, a hydrotalcite compound and an ultraviolet absorber. An agricultural film comprising a thermoplastic resin composition containing a lithium-magnesium-aluminum complex salt compound and a specific hindered amine compound is disclosed.

However, the polyolefin resin compositions and agricultural films disclosed in these publications do not yet have sufficient weather resistance and pesticide resistance (acid resistance), and the above-mentioned problems are not sufficiently solved. It does not solve the problem.

Further, as an important performance required for an agricultural film, it is excellent in anti-fogging property and anti-fog property. The anti-fogging property is the ability to cause water that has condensed on the film surface to flow out along the film surface without dropping onto agricultural products.

As the antifogging agent for imparting the antifogging property to the agricultural film, for example, a nonionic surfactant such as a fatty acid ester of polyhydric alcohol is generally mentioned, and the above antifogging agent is used as a resin. Use by kneading.

Various attempts have been made to maintain the antifogging property (antifogging effect) of agricultural films for a long period of time, but generally, the amount of the antifogging agent added to the resin is increased to A method of improving the durability of the antifogging property by bleeding out substantially more antifogging agent to the film surface on the inner surface side of the agricultural house is adopted.

For example, in JP-A-9-52332, an outer layer made of an ethylene-α-olefin copolymer having a specific density and an ethylene-α-having a specific density are disclosed.
Ethylene used as an inner layer by laminating an intermediate layer consisting of an olefin copolymer and an antifogging agent and an inner layer consisting of an ethylene-α-olefin copolymer having a specific density and an antifogging agent,
An agricultural film that induces the bleed-out of the antifogging agent to the film surface on the inner surface side of the agricultural house by setting the density of the α-olefin copolymer to be the density of the ethylene-α-olefin copolymer used for the outer layer or less. Japanese Patent Publication No. 63-65026 and Japanese Patent Laid-Open No. 11-
In 20090, the outer layer side of the agricultural film is a linear low density polyethylene or a mixed resin of a branched low density polyethylene and a linear low density polyethylene, and the inner layer side is, for example, an ethylene-vinyl acetate copolymer. By using a resin composition containing a surfactant or an antifogging agent, an agricultural film for preventing the antifogging agent from bleeding out on the film surface on the outer surface side of the agricultural house is disclosed, and JP-A-2000-354426 discloses a linear low density polyethylene in an inner layer composed of a resin composition containing an ethylene-vinyl acetate copolymer having a specific vinyl acetate content and a specific amount of an antifogging agent. And by laminating an outer layer made of a resin composition containing a specific amount of an inorganic heat retaining agent, an antifogging agent is added to the film surface on the outer side of the agricultural house. Agricultural film that inhibits to have been disclosed.

However, even in the agricultural films disclosed in these publications, the antifogging agent still bleeds out to the film surface on the outer surface side of the agricultural house, so that the durability of the antifogging property is efficiently improved. It is hard to say what you are doing.

[0013]

In view of the above problems, the object of the present invention is to exhibit excellent weather resistance over a long period of time because it is less deteriorated by ultraviolet rays and has excellent pesticide resistance (acid resistance). And to provide an agricultural film which is excellent in antifogging property, transparency, mechanical properties and the like over a long period of time.

[0014]

An agricultural film according to the invention of claim 1 (hereinafter referred to as "present invention 1") has an outermost layer (A layer) and an inner layer (when spread on an agricultural house). b layer) and a laminated film,
The layer A is composed of a polyolefin resin composition containing 100 parts by weight of a polyolefin resin and 0.1 to 20 parts by weight of a layered silicate, and the layer b is a polyolefin resin substantially free of a layered silicate. It is characterized by comprising a composition.

The agricultural film according to the second aspect of the present invention (hereinafter referred to as "present invention 2") has a laminated outermost layer (A layer) and an inner layer (b layer) when spread on an agricultural house. The layer A comprises 100 parts by weight of a polyolefin resin and 0.1 to 20 layered silicate.
It is composed of a polyolefin resin composition containing 0.01 part by weight and 0.01 to 2 parts by weight of an ultraviolet absorber, and the layer b is composed of a polyolefin resin composition containing substantially no layered silicate. .

The agricultural film according to the invention described in claim 3 (hereinafter referred to as "present invention 3") has a laminated innermost layer (B layer) and an outer layer (a layer) when spread on an agricultural house. The layer B comprises 100 parts by weight of a polyolefin resin and 0.1 to 2 parts of a layered silicate.
The layer a comprises 100 parts by weight of a polyolefin resin and 0.01 to 5 parts by weight of a hindered amine light stabilizer, and is substantially composed of a layered silicate. It is characterized by comprising a polyolefin-based resin composition which is not contained in.

The agricultural film according to the invention of claim 4 (hereinafter referred to as "present invention 4") has an outermost layer (A layer) and an inner layer (b layer) when spread on an agricultural house. Is a laminated film, wherein the layer A comprises 100 parts by weight of a polyolefin resin and a layered silicate of 0.1 to 0.1 parts by weight.
The layer b comprises 100 parts by weight of a polyolefin resin and 0.02 to 3 parts by weight of a nonionic surfactant, and is composed of a layered silicate. It is characterized by comprising a polyolefin-based resin composition that is not contained in the composition.

In the agricultural film of Invention 1, Invention 2, or Invention 4, the outermost layer (A layer) preferably has a thickness of 50% or less of the total thickness. When the thickness of the outermost layer (A layer) exceeds 50% of the total thickness, mechanical properties such as flexibility and elongation required as an agricultural film may be insufficient.

Further, in the agricultural film of the present invention 3, the thickness of the innermost layer (B layer) is preferably 50% or less of the total thickness. When the thickness of the innermost layer (B layer) exceeds 50% of the total thickness, mechanical properties such as flexibility and elongation required as an agricultural film may be insufficient.

The polyolefin resin used in the agricultural film of the present invention is not particularly limited, but examples thereof include branched low density polyethylene, linear low density polyethylene, medium density polyethylene, and high density polyethylene. Polyethylene resin, ethylene-propylene copolymer, ethylene-α-olefin copolymer, ethylene-vinyl acetate copolymer, ethylene- (meth) acrylic acid copolymer, ethylene- (meth) acrylic acid ester copolymer And the like, which are preferably used. These polyolefin resins may be used alone or in combination of two or more kinds. In addition, a polyolefin resin that constitutes the outermost layer (A layer) and the inner layer (b layer) of the agricultural film according to the present invention 1, the invention 2, and the invention 4, and the innermost layer of the agricultural film according to the invention 3 ( B layer) and outer layer (a
The polyolefin-based resins constituting the layers may be the same polyolefin-based resin or different polyolefin-based resins. Furthermore, the inner layer (b layer) of the agricultural film according to the present invention 1, the present invention 2, and the present invention 4, and the outer layer (a layer) of the agricultural film according to the present invention 3,
It may be formed by laminating a plurality of different polyolefin resin compositions. The (meth) acrylic referred to in the present invention means acrylic or methacrylic.

The above-mentioned α-olefin is not particularly limited, but for example, butene and 4-methyl-1.
-Pentene, hexene, octene and the like are mentioned and are preferably used. These α-olefins may be used alone or in combination of two or more kinds.

In the present invention, among the above-mentioned polyolefin resins, a polyethylene resin having a density of 0.930 g / cm ³ or less and an ethylene-vinyl acetate copolymer having a bilni acetate content of 25% by weight or less are particularly preferable. Used. The polyethylene resin and the ethylene-vinyl acetate copolymer may be used alone or in combination.

The density of the polyethylene resin is 0.930.
If it exceeds g / cm ³ , the transparency of the obtained agricultural film may be lowered, or the layered silicate described below may be poorly dispersed. Further, if the vinyl acetate content of the ethylene-vinyl acetate copolymer exceeds 25% by weight, the obtained agricultural film may have tackiness (stickiness) and may cause blocking during storage or transportation.

The layered silicate used in the agricultural film of the present invention means a silicate mineral having an exchangeable cation between layers.

The layered silicate is not particularly limited, but examples thereof include montmorillonite, saponite, hectorite, beidellite, stevensite,
Smectite-based clay minerals such as nontronite, vermiculite, halloysite, swelling mica, and the like are mentioned and are preferably used. In the present invention, among the above layered silicates, montmorillonite and / or swelling mica is particularly preferably used. The layered silicate may be a natural product or a synthetic product. Further, these layered silicates may be used alone or in combination of two or more kinds.

As the layered silicate, it is preferable to use smectites or swelling mica having a large shape anisotropy effect defined by the following relational expression (1). By using a layered silicate having a large shape anisotropy effect such as smectites and swelling mica, the weather resistance of the obtained agricultural film becomes remarkably excellent. Shape anisotropy effect = area of crystal surface (A) / area of crystal surface (B) (1) In the above equation, crystal surface (A) means layer surface, and crystal surface (B) is It means the layer side.

The shape of the layered silicate is not particularly limited, but preferably has an average length of 0.01 to 3 μm, a thickness of 0.001 to 1 μm, and an aspect ratio of 20 to 500, More preferably, the average length is 0.0
The thickness is 5 to 2 μm, the thickness is 0.01 to 0.5 μm, and the aspect ratio is 50 to 200.

The exchangeable cations existing between the layers of the layered silicate are metal ions such as sodium and calcium existing on the crystal surface of the layered silicate, and these metal ions are cationic. Since it has a cation exchange property with a substance, various substances having a cation property can be inserted (intercalated) between the crystal layers of the layered silicate.

The cation exchange capacity of the layered silicate is not particularly limited, but is 50 to 200 milliequivalent /
It is preferably 100 g. If the cation exchange capacity of the layered silicate is less than 50 milliequivalents / 100 g, the amount of the cationic substance intercalated between the crystal layers of the layered silicate due to cation exchange is small, so that the crystal layer May not be sufficiently depolarized, and conversely, if the cation exchange capacity of the layered silicate exceeds 200 milliequivalents / 100 g, the bonding force between the crystal layers of the layered silicate becomes too strong, and the crystal flakes become thin. May become difficult to peel off.

Since the polyolefin resin used in the present invention has a low polarity, it is preferable that the layers of the layered silicate be cation-exchanged with a cationic surfactant in advance to make them hydrophobic. By preliminarily hydrophobizing the layers of the layered silicate, the affinity between the layered silicate and the polyolefin resin is increased, and the layered silicate can be more finely dispersed in the polyolefin resin.

The cationic surfactant is not particularly limited, but examples thereof include a quaternary ammonium salt and a quaternary phosphonium salt, which are preferably used. In the present invention, among the above-mentioned cationic surfactants, the quaternary ammonium salt having an alkyl chain having 6 or more carbon atoms (having 6 or more carbon atoms) can be sufficiently depolarized between the crystal layers of the layered silicate. Alkyl ammonium salt)
Are particularly preferably used.

The quaternary ammonium salt is not particularly limited, and examples thereof include lauryl trimethyl ammonium salt, stearyl trimethyl ammonium salt, trioctyl ammonium salt, distearyl dimethyl ammonium salt, di-hardened tallow dimethyl ammonium salt, Distearyl dibenzylammonium salt, N-polyoxyethylene-N-lauryl-N, N-dimethylammonium salt, etc. are mentioned and used suitably. These quaternary ammonium salts may be used alone or 2
More than one kind may be used in combination.

The quaternary phosphonium salt is not particularly limited, but for example, dodecyltriphenylphosphonium salt, methyltriphenylphosphonium salt, lauryltrimethylphosphonium salt, stearyltrimethylphosphonium salt, trioctylphosphonium salt. , Distearyl dimethyl phosphonium salt, distearyl dibenzyl phosphonium salt and the like, which are preferably used. These quaternary phosphonium salts may be used alone or in combination of two or more kinds.

The above quaternary ammonium salt and the above quaternary phosphonium salt may be used alone or in combination.

The layered silicate used in the present invention can be improved in dispersibility in the polyolefin resin by the chemical treatment as described above.

The above chemical treatment is not limited to the cation exchange method using a cationic surfactant (hereinafter referred to as "chemical modification (1) method"), and for example, various chemical treatment methods shown below. Can also be implemented by. The layered silicate whose dispersibility in the polyolefin resin is improved by the various chemical treatment methods described below, including the chemical modification (1) method, is hereinafter referred to as “organized layered silicate”.

(2) Chemical modification A functional group capable of chemically bonding a hydroxyl group present on the crystal surface of the organically modified layered silicate chemically treated by the method (1), or chemically without the chemical bond. A method of chemically treating with a compound having one or more functional groups having a high affinity at a molecular end (hereinafter, referred to as "Chemical modification (2)
Law ").

(3) Chemical modification A functional group capable of chemically bonding a hydroxyl group present on the crystal surface of the organically modified layered silicate chemically treated by the method (1), or chemically without the chemical bond. A method of chemically treating with a compound having one or more functional groups and reactive functional groups having high affinity at the molecular end (hereinafter,
"Chemical modification (3) method".

(4) Chemical Modification (1) The method of chemically treating the crystal surface of the organically modified layered silicate chemically treated by the method (hereinafter, referred to as “chemical modification (4) method”). ]).

(5) Chemical modification In the method (4), a chemical treatment is carried out with a compound having one or more reactive functional groups other than the anionic site in the molecular chain of the compound having anionic surface activity (hereinafter, referred to as "Chemical modification (5) method").

(6) The organically modified layered silicate chemically treated by any one of the above-mentioned chemical modification (1) to chemical modification (5) is further used, for example, maleic anhydride-modified polyolefin resin. Method of using a composition containing a polymer having a functional group capable of reacting with a layered silicate (hereinafter,
"Chemical modification (6) method") and the like. These chemical modification methods may be used alone or in combination of two or more.

In the above-mentioned chemical modification (2), the functional group capable of chemically bonding with a hydroxyl group or the functional group having a large chemical affinity even if it is not chemically bonded is not particularly limited. , Alkoxy groups, epoxy groups, carboxyl groups (including dibasic acid anhydrides), hydroxyl groups, isocyanate groups, aldehyde groups, and other functional groups, and other functional groups with high chemical affinity for hydroxyl groups. To be

The compound having a functional group capable of chemically bonding with a hydroxyl group or a functional group having a high chemical affinity even if not chemically bonded is not particularly limited, but for example, the functional groups exemplified above. Group-containing silane compounds, titanate compounds, glycidyl compounds, carboxylic acids, alcohols and the like are mentioned and are preferably used. These compounds may be used alone or in combination of two or more kinds.

The silane compound is not particularly limited, but for example, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, γ-aminopropyltrimethoxysilane, γ-amino. Propylmethyldimethoxysilane, γ-aminopropyldimethylmethoxysilane, γ-
Aminopropyltriethoxysilane, γ-aminopropylmethyldiethoxysilane, γ-aminopropyldimethylethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, trimethylmethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, N-β- (Aminoethyl) γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) γ-aminopropyltriethoxysilane, N-β- (aminoethyl) γ-aminopropylmethyldimethoxysilane, octadecyltrimethoxysilane, octadecyl Triethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypro Le triethoxysilane and the like, is preferably used. These silane compounds may be used alone or in combination of two or more kinds.

Further, the chemical modification (4) method and the chemical modification (5)
In the method, as the compound having anionic surface activity and / or the compound having anionic surface activity and having one or more reactive functional groups other than the anionic site in the molecular chain, ionic interaction Any compound may be used as long as it can chemically treat the layered silicate with, but is not particularly limited, for example, sodium laurate, sodium stearate, sodium oleate,
A higher alcohol sulfuric acid ester salt, a secondary higher alcohol sulfuric acid ester salt, an unsaturated alcohol sulfuric acid ester salt, etc. are mentioned and used suitably. These compounds may be used alone or in combination of two or more kinds.

The layered silicate used in the present invention has a wide angle X
It is preferable that the layered silicate has an average inter-layer distance of 3 nm or more on the (001) plane measured by a line diffraction measurement method, and part or all of which is dispersed in 5 layers or less.
More preferably, it is a layered silicate in which the average interlayer distance is 6 nm or more and a part or all of which is dispersed in 5 layers or less. In addition, the average interlayer distance of the layered silicate referred to in the present invention means the average interlayer distance when the fine flaky crystals of the layered silicate are formed into a layer, and by X-ray diffraction peak and transmission electron microscope photography, That is, it can be calculated by the wide-angle X-ray diffraction measurement method. Further, the observation of the dispersed state of the layered silicate can be performed by photographing with a transmission electron microscope at a magnification of 50,000 to 100,000 times.

When the average interlayer distance of the layered silicate is 3 nm or more and a part or the whole is dispersed in 5 layers or less, the energy of ultraviolet rays can be effectively absorbed, and the layered silicate can be formed. The agricultural film of the present invention obtained by adding and dispersing it in a polyolefin resin exhibits excellent weather resistance for a long period of time.

When the average interlaminar distance of the layered silicate is 3 nm or more, and part or all of which is dispersed in 5 layers or less, the agricultural film on the inner surface side of the agricultural house is produced due to the baffle effect. Agricultural film of the present invention has excellent pesticide resistance because acidic substances such as pesticides from the layer (inner layer) are less likely to migrate to all layers of the film, and decomposition of the hindered amine light stabilizer by the acidic substances is suppressed. (Acid resistance), and thus excellent weather resistance over a long period of time.

Further, the average interlayer distance of the layered silicate is 3 nm.
If the above is the case and a part or all of them are dispersed in 5 layers or less, the nonionic surfactant (anti-fog agent) will not be wastefully transferred to the outer layer of the agricultural film due to the baffle effect. The agricultural film of the present invention exhibits excellent antifogging property for a long period of time.

The fact that the average interlayer distance of the layered silicate is 3 nm or more means that the layers of the layered silicate are split to 3 nm or more, and part or all of the layered silicate is cleaved. Dispersed in 5 layers or less means
This means that a part or all of the layered silicate laminate is peeled and widely dispersed, which means that the interaction between the layered silicate layers is weakened. The effect can be obtained.

Particularly, the average interlayer distance of the layered silicate is 6 nm.
The above is the agricultural film of the present invention obtained by adding and dispersing a layered silicate in a polyolefin resin,
It exhibits extremely excellent weather resistance, pesticide resistance (acid resistance), and antifogging property over a long period of time.

When the average interlayer distance of the layered silicate is 3 nm or more, preferably 6 nm or more, the crystal thin layer of the layered silicate is separated into layers, and the interaction between the layered silicate layers can be almost ignored. Since it is weakened to such an extent, there is an advantage that the dispersion state of the crystal flakes constituting the layered silicate in the polyolefin resin progresses toward the stabilization of crushing.

Further, the fact that part or all of the layered silicate is dispersed in 5 layers or less means that, specifically, 10% or more of the number of the layered silicate is dispersed in 5 layers or less. Is preferable, and more preferably 20% or more of the number of the layered silicate is dispersed in 5 layers or less.

The number of laminated layered silicates is preferably divided into 5 layers or less, whereby the above effect can be obtained, but more preferably 3 or less. It is particularly preferable that the thin film is formed into a single layer.

The method of dispersing the layered silicate in the polyolefin resin is not particularly limited, but for example, the method using the organically modified layered silicate, the method using a dispersant, and the dispersion by physical energy are used. And the like. By using these dispersion methods, the layered silicate can be more uniformly and finely dispersed in the polyolefin resin.

The method of dispersing with the above-mentioned physical energy is not particularly limited, but for example, a method of converting the shearing force by a kneader into the dispersion energy of the layered silicate can be mentioned. The method of converting the shearing force by the kneading machine into the dispersion energy of the layered silicate is not particularly limited, for example, a method of using a kneading machine having a large shearing force, a polyolefin resin composition constituting an agricultural film. Examples thereof include a method of kneading in a state where the melt viscosity of the product is high, a method of simultaneously adding and kneading an inorganic compound of a different type from the layered silicate to be used, and any method may be adopted. Further, these methods may be used alone or in combination of two or more kinds.

The ultraviolet absorber used in the agricultural film of the present invention 2 may be a commonly used ultraviolet absorber and is not particularly limited, but for example,
Benzophenone-based UV absorbers, benzotriazole-based UV absorbers, salicylic acid ester-based UV absorbers, cyanoacrylate-based UV absorbers, and the like are mentioned and are preferably used. These ultraviolet absorbers may be used alone or in combination of two or more kinds.

Specific examples of the above-mentioned benzophenone type ultraviolet absorber are not particularly limited, but for example,
2,4-dihydroxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 2-hydroxy-4
-Dodecyloxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2,2'-hydroxy-4,4'-dimethoxybenzophenone, 2-hydroxy-4-methoxy-5-sulfobenzophenone and the like are preferable. Used for. These benzophenone-based UV absorbers may be used alone or in combination of two or more.

Specific examples of the benzotriazole type ultraviolet absorber are not particularly limited, but for example, 2- (2'-hydroxy-5'-tert-butylphenyl) benzotriazole and 2- (2 '-Hydroxy-5'-methylphenyl) benzotriazole, 2-
(2'-hydroxy-3'-tert-butyl-5'-
Methylphenyl) -5-chlorobenzotriazole, 2
-(2'-hydroxy-3 ', 5'-di-tert-butylphenyl) -5-chlorobenzotriazole, 2-
(2′-Hydroxy-3 ′, 5′-di-tert-amylphenyl) -5-chlorobenzotriazole and the like can be mentioned, and they are preferably used. These benzotriazole-based UV absorbers may be used alone or in combination of two or more.

The salicylic acid ester-based ultraviolet absorber is not particularly limited, but examples thereof include phenyl salicylate, p-tert-butylphenyl salicylate, and p-octylphenyl salicylate, which are preferably used. These salicylic acid ester-based ultraviolet absorbers may be used alone or in combination of two or more.

The cyanoacrylate-based UV absorber is not particularly limited, but may be, for example, 2-
Ethylhexyl-2-cyano-3,3'-diphenyl acrylate, ethyl-2-cyano-3,3'-diphenyl acrylate and the like can be mentioned, and they are preferably used. These cyanoacrylate-based ultraviolet absorbers may be used alone or in combination of two or more.

The hindered amine-based light stabilizer used in the agricultural film of the present invention 3 may be a commonly used hindered amine-based light stabilizer and is not particularly limited, but for example, bis (2 , 2, 6, 6-
Tetramethyl-4-piperidyl) sebacate, dimethyl-1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine polycondensate, tetrakis (2,2,6,6) -Tetramethyl-4-
Piperidyl) -1,2,3,4-butane tetracarboxylate, 2,2,6,6-tetramethyl-4-piperidinyl benzoate, bis- (1,2,6,6-tetramethyl-4- Piperidinyl) -2-n-butyl malonate, bis (N-methyl-2,2,6,6-tetramethyl-4-piperidinyl) sebacate, 1,1 ′-(1,2
-Ethanediyl) bis (3,3,5,5-tetramethylpiperazinone), (mixed 2,2,6,6-tetramethyl-4-piperidyl / tridecyl) -1,2,3,3
4-butane tetracarboxylate, (mixed 1,
2,2,6,6-Pentamethyl-4-piperidyl / tridecyl) -1,2,3,4-butanetetracarboxylate, mixed {2,2,6,6-tetramethyl-4
-Piperidyl / β, β, β ', β'-tetramethyl-3
-9- [2,4,8,10-tetraoxaspiro (5,
5) undecane] diethyl} -1,2,3,4-butanetetracarboxylate, mixed {1,2,2
6,6-pentamethyl-4-piperidyl / β, β,
β ′, β′-tetramethyl-3-9- [2,4,8,1
0-Tetraoxaspiro (5,5) undecane] diethyl} -1,2,3,4-butanetetracarboxylate, N, N'-bis (3-aminopropyl) ethylenediamine-2-4-bis [N- Butyl-N- (1,2,
2,6,6-Pentamethyl-4-piperidyl) amino]
-6-chloro-1,3,5-triazine condensate, N,
A condensation product of N′-bis (2,2,6,6-tetramethyl-4-piperidyl) hexamethylenediamine and 1,2-dibromoethane, [N- (2,2,6,6-tetramethyl- 4-piperidyl) -2-methyl-2- (2,2,
6,6-Tetramethyl-4-piperidyl) imino] propionamide, poly {[6-[(1,1,3,3-tetramethylbutyl) amino] -1,3,5-triazine-
2,4-diyl] [(2,2,6,6-tetramethyl-
4-piperidyl) imino] hexamethylene [(2,2,
6,6-Tetramethyl-4-piperidyl) imino]} and the like are preferably used. These hindered amine light stabilizers may be used alone or in combination of two or more kinds.

The nonionic surfactant used as an antifogging agent in the agricultural film of the present invention 4 is a partial ester of a polyhydric alcohol and a fatty acid. The polyhydric alcohol is not particularly limited, but for example, sorbitol, sorbitan, glycerin, diglycerin, polyglycerin, polyethylene glycol, polypropylene glycol, pentaerythritol, trimethylolpropane, and the like, addition of ethylene oxide thereof. Compounds or propylene oxide adducts and the like, which are preferably used. These polyhydric alcohols may be used alone or in combination of two or more kinds. The fatty acid is not particularly limited, for example, saturated fatty acids such as capric acid, myristic acid, palmitic acid, stearic acid, behenic acid, oleic acid, linoleic acid, linolenic acid, erucic acid, etc. Unsaturated fatty acids and the like are preferably used. These fatty acids may be used alone or in combination of two or more.

Specific examples of the above nonionic surfactants are not particularly limited, but include, for example, sorbitol monostearate, sorbitol monooleate, sorbitol monopalmitate, sorbitol monobehenate, sorbitan monostearate. , Sorbitan monooleate, sorbitan monopalmitate, sorbitan monobehenate, glycerin monostearate, glycerin monooleate, glycerin monopalmitate, diglycerin monostearate, diglycerin monooleate, diglycerin monopalmitate, diglycerin monobehe Nate, diglycerin monocaprylate, diglycerin monolaurate, polyglycerin monostearate, polyglycerin monooleate, polyglycerin monopalmitate, polyglyce Monobehenate, polyethylene glycol monostearate, polyethylene glycol monooleate, polyethylene glycol monopalmitate, polyethylene glycol monobehenate, pentaerythritol monostearate, pentaerythritol monooleate, pentaerythritol monopalmitate, pentaerythritol monobehenate, polyoxy In addition to monoesters such as ethylene sorbitan monostearate and polyoxyethylene sorbitan monooleate, and the above monoesters, sesquiesters (monoester: diester = 1: 1 by weight ratio), diesters, polyesters, and the like can be mentioned. It is preferably used. These nonionic surfactants may be used alone or in combination of two or more.

The polyolefin resin composition constituting the outermost layer (A layer) of the agricultural film of the present invention 1, the invention 2 and the invention 4, and the innermost layer (layer B) of the agricultural film of the invention 3 The polyolefin resin composition constituting the above is based on 100 parts by weight of the above-mentioned polyolefin resin, and the above-mentioned layered silicate (including the above-mentioned organically modified layered silicate).
It is necessary to add 0.1 to 20 parts by weight, preferably 0.2 to 10 parts by weight of layered silicate,
It is more preferably 0.5 to 5 parts by weight of layered silicate.

In the above polyolefin-based resin composition, if the amount of the layered silicate added is less than 0.1 parts by weight relative to 100 parts by weight of the polyolefin-based resin, the resulting agricultural film has weather resistance and pesticide resistance (acid resistance). Material properties), antifogging properties, and the effect of improving the sustainability thereof cannot be sufficiently obtained, and conversely, when the amount of the layered silicate added to 100 parts by weight of the polyolefin resin exceeds 20 parts by weight, the obtained agriculture is obtained. The film for use will have a high elastic modulus, and the flexibility and elongation will be insufficient, and the spreading workability will be reduced.

The polyolefin resin composition constituting the outermost layer (A layer) of the agricultural film of the present invention 2 is 0.1 to 20 parts by weight of the above layered silicate with respect to 100 parts by weight of the polyolefin resin. In addition to the above, it is necessary to add 0.01 to 2 parts by weight of the above-mentioned ultraviolet absorber.

In the above polyolefin resin composition, if the amount of the ultraviolet absorber added is less than 0.01 parts by weight relative to 100 parts by weight of the polyolefin resin, the weather resistance and the durability thereof due to the addition of the ultraviolet absorber will be improved. The improvement effect cannot be obtained sufficiently, and conversely, the polyolefin resin 1
If the amount of the ultraviolet absorber added to 00 parts by weight exceeds 2 parts by weight, the bleed-out of the ultraviolet absorber to the surface of the obtained agricultural film becomes remarkable, and the transparency of the agricultural film decreases.

The polyolefin resin composition which constitutes the inner layer (layer b) of the agricultural film of the present invention 1, the invention 2 and the invention 4, and the outer layer (a) of the agricultural film of the invention 3
It is necessary that the polyolefin resin composition constituting the layer) does not substantially contain the layered silicate.

The term "substantially free of layered silicate" as used in the present invention means that the content is within a range that does not substantially affect mechanical properties such as elastic modulus and elongation of the obtained agricultural film. It means that the layered silicate is 0.05% based on 100 parts by weight of the polyolefin resin.
It is preferable that the content is not more than parts by weight.

The outer layer (a) of the agricultural film of the present invention 3 is also used.
In addition to the fact that the polyolefin-based resin composition constituting the layer) does not substantially contain the layered silicate, the hindered amine-based light stabilizer described above is added to 0.01 to 100 parts by weight of the polyolefin-based resin. It is necessary to add 5 parts by weight.

In the above polyolefin resin composition, if the amount of the hindered amine light stabilizer added is less than 0.01 parts by weight based on 100 parts by weight of the polyolefin resin, the weather resistance and the resistance to the addition of the hindered amine light stabilizer will be improved. If the effect of improving the sustainability is not sufficiently obtained, and conversely the addition amount of the hindered amine light stabilizer is more than 5 parts by weight based on 100 parts by weight of the polyolefin resin, the hindered amine light stabilizer on the surface of the obtained agricultural film is stabilized. Bleedout of the agent becomes remarkable, and the transparency of the agricultural film is reduced.

Furthermore, in addition to the fact that the polyolefin resin composition constituting the inner layer (layer b) of the agricultural film of the present invention 4 does not substantially contain the layered silicate, 100 wt. It is necessary to add 0.02 to 3 parts by weight of the above-mentioned nonionic surfactant as an antifogging agent to the parts.

In the above polyolefin-based resin composition, if the amount of the nonionic surfactant added is less than 0.02 parts by weight per 100 parts by weight of the polyolefin resin, the nonionic surfactant is prevented from being added. If the effect of improving the cloudiness and its persistence cannot be obtained sufficiently, and conversely, the amount of the nonionic surfactant added to 100 parts by weight of the polyolefin resin exceeds 3 parts by weight, the formability of the agricultural film will be poor. Become.

The polyolefin-based resin composition constituting the agricultural film of the present invention contains, for example, an antifog agent, an inorganic filler, an antioxidant (aging agent) as necessary as long as the achievement of the object of the present invention is not impaired. Inhibitor), heat stabilizer, light stabilizer other than hindered amine light stabilizer, softener (plasticizer),
1 of various additives such as lubricants, antistatic agents, flame retardants, and colorants
One kind or two or more kinds may be added.

The anti-fog agent is not particularly limited, but for example, a fluorine-based surfactant having a perfluoroalkyl group or a ω-hydrofluoroalkyl group, a silicone-based surfactant having an alkylsiloxane group, etc. Examples thereof include agents and the like, and they are preferably used. These antifog agents may be used alone or in combination of two or more kinds.

As the fluorine-containing surfactant, a nonionic fluorine-containing surfactant, an anionic fluorine-containing surfactant,
Examples include cationic fluorosurfactants and amphoteric fluorosurfactants, and any of these ionic fluorosurfactants may be used. Further, these fluorine-based surfactants may be used alone or in combination of two or more kinds.

Specific examples of the nonionic fluorine-containing surfactant are not particularly limited, but for example, general formulas Rf-OH, Rf (CH ₂ ) _n- OH and Rf (C
_{H 2) n -COOH, Rf-} B-N (R ') (C 2 H 4
The compounds represented by O) _n H and the like are mentioned and are preferably used. These nonionic fluorosurfactants may be used alone or in combination of two or more.

Specific examples of the anionic fluorine-based surfactant are not particularly limited, but for example, general formulas Rf-COO-M and Rf-BN (R ') CH ₂ CO.
OM, Rf-B-N ( R ') C 2 H 4 O-SO 3 M, R
The compound represented by the f-SO ₃ M and the like, is preferably used. These anionic fluorochemical surfactants are
They may be used alone or in combination of two or more.

Specific examples of the cationic fluorine-based surfactant are not particularly limited, but for example, the general formula Rf-B-NH (C ₂ H ₄ ) N ⁺ (CH ₃ ) ₂ -X is used. ^-
And the like. These cationic fluorosurfactants may be used alone or in combination of two or more.

Specific examples of the amphoteric fluorine-based surfactant are not particularly limited, but for example, general formula R
_{f-B-NH (C 2} H 4) N + (R ') 2 C 2 H 4 CO
Compounds represented by O ^{− and the} like can be mentioned, and they are preferably used. These amphoteric fluorochemical surfactants may be used alone or in combination of two or more kinds.

In the above general formula, Rf is 1 to 2 carbon atoms.
0 represents a fluorinated aliphatic group or a fluorinated aromatic group, and the aliphatic group may be linear, branched or cyclic. B represents a divalent linking group such as —SO ₂ — and —CO—, and R ′ represents a hydrogen atom or a carbon number of 1 to 20.
Represents an alkyl group, M represents a hydrogen atom, an alkali metal or —NH ₄ , X represents a halogen atom, and n represents
An integer of 1 to 50 is shown.

The silicone-based surfactant is not particularly limited, but examples thereof include polyether-modified silicone oil, carboxyl-modified silicone oil, amino-modified silicone oil, and the like, which are preferably used. These silicone-based surfactants may be used alone or in combination of two or more kinds.

The amount of the above-mentioned fog preventive agent added to the polyolefin resin composition is not particularly limited,
Anti-fog agent is added to 100 parts by weight of polyolefin resin.
It is preferably 005 to 3 parts by weight.

When the addition amount of the antifog agent is less than 0.005 part by weight relative to 100 parts by weight of the polyolefin resin, the effect of improving the antifog property and its durability by adding the antifog agent can be sufficiently obtained. On the contrary, if the amount of the fog-preventing agent added to 100 parts by weight of the polyolefin resin exceeds 3 parts by weight, the moldability of the agricultural film may be deteriorated.

The above-mentioned inorganic filler is not particularly limited, but for example, a hydrotalcite compound represented by the following general formula (1) and a lithium aluminum composite represented by the following general formula (2). Hydroxide salts, magnesium carbonate, magnesium silicate, silicon oxide, aluminum oxide, aluminum hydroxide, magnesium hydroxide and the like are preferably used. Among them, hydrotalcites have a high heat retention effect. Compounds and lithium aluminum complex hydroxide salts are more preferably used. These inorganic fillers may be used alone or in combination of two or more kinds. From the viewpoint of transparency, these inorganic fillers preferably have a particle size of 10 μm or less and a refractive index of 1.45 to 1.55. Further, these inorganic fillers may be surface-treated with, for example, a higher fatty acid or an alkali metal salt of a higher fatty acid in order to improve dispersibility.

[0087]   (M²⁺)_1-xAl_x(OH)₂(A₁ ^n-)_{x / n}・ MH₂O type (1) In the formula, M²⁺Is selected from the group consisting of Mg, Ca and Zn
Represents a divalent metal ion, and x is 0 <x <0.5.
Indicates a satisfying numerical value, and m is a numerical value satisfying 0 ≦ m ≦ 2
Indicates. Also, A₁ ^n-Indicates an n-valent anion, for example
For example, Cl^-, Br^-, I^-, NO₃ ^-, ClO_Four ^-, S
O_Four ^2-, CO₃ ^2-, SiO₃ ^2-, HPO_Four ^3-, HBO_Four
^3-, PO_Four ^3-, Fe (CN)_Four ^3-, Fe (CN)_Four ^Four-,
CH₃COO ^-, C₆H_Four(OH) COO^-, (CO
O)₂ ^2-, Terephthalate ion, naphthalene sulfonic acid
Examples include ions.

[0088]   Li⁺(Al³⁺)₂(OH^-)₆・ (A₂ ^n-)_{1 / n}・ MH₂O type (2) In the formula, m represents a numerical value satisfying 0 ≦ m ≦ 3. Also, A
₂ ^n-Represents an n-valent anion, for example, Cl^-, Br
^-, I^-, NO₃ ^-, ClO_Four ^-, SO_Four ^2-, C
O₃ ^2-, SiO₃ ^2-, HPO_Four ^3-, HBO_Four ^3-, PO_Four
^3-, Fe (CN)_Four ^3-, Fe (CN)_Four ^Four-, CH₃CO
O^-, C₆H_Four(OH) COO^-, (COO)₂ ^2-, Te
Examples include lephthalate ion and naphthalene sulfonate ion.
You can

As the above-mentioned antioxidant (antiaging agent),
Although not particularly limited, for example, hindered phenol-based antioxidants, phosphorus-based antioxidants and the like can be mentioned and are preferably used. These antioxidants may be used alone or in combination of two or more kinds.

The method for producing the polyolefin-based resin composition that constitutes the agricultural film of the present invention is not particularly limited, but, for example, the polyolefin-based resin and the layered silicate, the ultraviolet absorber, which are the essential components, Directly blending each specified amount of a hindered amine light stabilizer and a nonionic surfactant with each specified amount of one or more kinds of various additives that are added as necessary at room temperature or under heating. Kneading method (direct kneading method), or a masterbatch prepared by previously mixing a predetermined amount of layered silicate with a part of a predetermined amount of a polyolefin resin and kneading the masterbatch and the polyolefin resin. A predetermined amount of the balance (remaining amount), a predetermined amount of each of the ultraviolet absorber, the hindered amine-based light stabilizer, and the nonionic surfactant, and each added as necessary. And one or two or more predetermined amounts of additives, a method of kneading under room temperature or under heating (master batch method), and the like, any method may be employed.

The concentration of the layered silicate in the masterbatch is not particularly limited, but is preferably 1 to 500 parts by weight of the layered silicate with respect to 100 parts by weight of the polyolefin resin, and more preferably 5 parts by weight. ~ 300
Parts by weight.

In the above masterbatch, the concentration of the layered silicate was 1 with respect to 100 parts by weight of the polyolefin resin.
If it is less than parts by weight, the convenience as a masterbatch that can be diluted to an arbitrary concentration may be lost, and conversely, if the concentration of the layered silicate exceeds 500 parts by weight with respect to 100 parts by weight of the polyolefin resin, The dispersibility of the masterbatch itself, and particularly the dispersibility of the layered silicate when diluted to a predetermined addition amount, may deteriorate due to the balance (remaining amount) of the polyolefin resin.

The specific method for producing the polyolefin resin composition by the direct kneading method or the masterbatch method is not particularly limited, but for example, an extruder,
Using a kneader such as a two-roll or Banbury mixer,
One kind of each predetermined amount of polyolefin resin, layered silicate, ultraviolet absorber, hindered amine light stabilizer, nonionic surfactant constituting the polyolefin resin composition, and various additives added as necessary. Alternatively, a method of kneading two or more kinds of respective predetermined amounts at room temperature or under heating, or a predetermined amount of each of a polyolefin resin, a layered silicate, an ultraviolet absorber, a hindered amine light stabilizer, and a nonionic surfactant, Examples include a method of kneading one kind or two or more kinds of respective predetermined amounts of various additives added as needed in a solvent in which these can be dissolved or dispersed, and removing the solvent as necessary, Either method may be adopted.

The method for producing the agricultural film of the present invention may be a known film production method and is not particularly limited. For example, an inflation method, a T-die method,
A calendar method, a casting method and the like can be mentioned, and any method may be adopted. The agricultural film of the present invention is a multi-layer film in which two or more layers are laminated. The laminating method for forming the multilayer film is not particularly limited, but examples thereof include a coextrusion method and a laminating method, and any method may be adopted.

The total thickness of the agricultural film of the present invention thus obtained is not particularly limited, but the transparency,
From the viewpoint of mechanical properties, spreading workability, high-speed moldability, etc.,
It is preferably 0.03 to 0.3 mm.

[0096]

When the agricultural film of the present invention 1 is spread on an agricultural house, a specific amount of highly dispersed layered silicate is contained in the polyolefin resin composition constituting the outermost layer A. Therefore, it is possible to effectively prevent deterioration due to ultraviolet rays, and to exhibit excellent weather resistance.
Further, since the layered silicate does not bleed out on the surface of the agricultural film, it is possible to effectively prevent the deterioration of ultraviolet rays for a long period of time, and the durability of weather resistance becomes excellent.

When the agricultural film of the present invention 2 is spread on an agricultural house, a specific amount of highly dispersed layered silicate and a specific amount of the polyolefin resin composition forming the outermost layer A are used. Since the ultraviolet absorber is contained, the weather resistance and its durability are further improved.

The agricultural film of the present invention 3 contains a specific amount of highly dispersed layered silicate in the polyolefin resin composition constituting the innermost layer B when spread on an agricultural house. Therefore, it is possible to effectively prevent acidic substances such as agricultural chemicals from migrating to the agricultural film for a long period of time, and it is contained in the polyolefin-based resin composition that constitutes the outer layer a. The decrease in efficacy of the hindered amine light stabilizer can be effectively suppressed for a long period of time, and the weather resistance and its sustainability are further improved.

Further, the agricultural film of the present invention 4 contains a specific amount of highly dispersed layered silicate in the polyolefin resin composition constituting the outermost layer A when spread on an agricultural house. Therefore, it is possible to effectively prevent the nonionic surfactant contained in the polyolefin-based resin composition forming the inner layer b layer from migrating to the layer A for a long period of time. And exhibits excellent anti-fogging property and its durability.

[0100]

BEST MODE FOR CARRYING OUT THE INVENTION The following examples are given to illustrate the present invention in more detail, but the present invention is not limited to these examples. In addition, "part" in an Example means a "weight part."

(Example 1) Small extruder (trade name "TEX"
30 ", manufactured by Japan Steel Works, Ltd., and an ethylene-vinyl acetate copolymer (hereinafter," EV ") as a polyolefin resin.
A)) {trade name "Evatate D2045", vinyl acetate content: 5% by weight, melt flow rate (MF
R): 1.0 g / 10 minutes (190 ° C.), manufactured by Sumitomo Chemical Co., Ltd.} 98 parts, and swellable fluorine mica organically treated with distearyldimethyl quaternary ammonium salt as a layered silicate (trade name “ Somasif MAE-100 ", manufactured by Cope Chemical Co., Ltd.) is fed, melt-kneaded at a preset temperature of 160 ° C. and extruded into a strand, and the extruded strand is pelletized by a pelletizer, and the outermost layer (A
Pellets of the polyolefin-based resin composition for layer) were prepared.

Next, the polyolefin resin composition (pellets) obtained above was used as the outermost layer (A layer), and EVA was used.
{Product name "Evatate H2020", vinyl acetate content: 15% by weight, melt flow rate (MFR): 1.
5g / 10 minutes (190 ° C), manufactured by Sumitomo Chemical Co., Ltd.} is an intermediate layer, and EVA "Evatate D2045" is an innermost layer. It was manufactured by the method.
The layer thickness ratio of each layer was outermost layer (A layer) / intermediate layer / innermost layer = 1/3/1.

Example 2 In the production of a polyolefin resin composition for the outermost layer (A layer), ethylene and 1-octene were used as a polyolefin resin in place of 98 parts of EVA “Evatate D2045” as a metallocene catalyst. Linear low-density polyethylene copolymerized by using {trade name "Elite 5100", density: 0.920 g / cm ³ ,
MFR: 1.0 g / 10 minutes (190 ° C.), manufactured by Dow Chemical Co., Ltd.} The same as in Example 1 except that 98 parts were used, the total thickness of the three-layer structure was 0.1 mm,
The layer thickness ratio of each layer is as follows: outermost layer (A layer) / intermediate layer / innermost layer = 1
A 3/1 agricultural film was produced.

(Example 3) EVA "Evatate D" was used as a polyolefin resin in a small extruder "TEX30".
2045 ", 98 parts, 1.5 parts of swellable fluoromica" Somasif MAE-100 ", which is organically treated with distearyldimethyl quaternary ammonium salt as a layered silicate, and a benzotriazole-based ultraviolet absorber (trade name" Tinubin "). 327 ", manufactured by Ciba Specialty Chemicals).
Five parts were fed, melt-kneaded at a preset temperature of 160 ° C., extruded in a strand shape, and the extruded strand was pelletized by a pelletizer to prepare pellets of the polyolefin resin composition for the outermost layer (A layer).

Then, the polyolefin resin composition (pellets) obtained above was used as the outermost layer (A layer), and EVA was used.
A polyolefin-based resin composition comprising 99.5 parts of "Evatate H2020" and 0.5 part of benzotriazole-based ultraviolet absorber "Tinuvin 327" was used as an intermediate layer, and EVA was used.
Agricultural product having a total thickness of 0.1 mm, which has a three-layer structure including a polyolefin resin composition including 99.5 parts of "Evatate D2045" and 0.5 part of benzotriazole-based ultraviolet absorber "Tinuvin 327" as an innermost layer. The film was produced by the inflation method. The layer thickness ratio of each layer was outermost layer (A layer) / intermediate layer / innermost layer = 1/3/1.

Example 4 In the preparation of the polyolefin resin composition for the outermost layer (A layer), the swelling fluoromica “Somasif MAE-100” was used as the layered silicate.
The total thickness of the three-layer structure was the same as in Example 3 except that 1.5 parts of montmorillonite (trade name "Clayton HY", manufactured by Southern Clay Co., Ltd.) was added instead of 1.5 parts. The agricultural film was 0.1 mm, and the layer thickness ratio of each layer was the outermost layer (A layer) / intermediate layer / innermost layer = 1/3/1.

(Comparative Example 1) EVA "Evatate D2045" was prepared from the polyolefin resin composition for the outermost layer (A layer).
70 parts and swelling fluoromica "Somasif MAE-10"
The total thickness of the three-layer structure is 0.1 mm, and the layer thickness ratio of each layer is the outermost layer (A layer) / intermediate layer / Innermost layer = 1/3
/ 1 agricultural film was produced.

Comparative Example 2 Polyolefin resin composition (pellet) for outermost layer (A layer) prepared in Example 1
Is an outer layer and EVA "Evatate D2045" is an inner layer, and the total thickness is 0.1 mm. The layer thickness ratio of each layer is the outer layer / inner layer = 3/2. Manufactured by.

Comparative Example 3 In the production of the polyolefin resin composition for the outermost layer (A layer), calcium carbonate (average particle diameter: 10 μm) was used instead of 2 parts of the swelling fluoromica “Somasif MAE-100”. In the same manner as in Example 1 except that 2 parts were added, the total thickness of the three-layer structure was 0.1 mm, and the layer thickness ratio of each layer was the outermost layer (A layer) / intermediate layer / maximum layer. An agricultural film having an inner layer of 1/3/1 was produced.

(Comparative Example 4) The same as Example 1 except that the swelling fluoromica "Somasif MAE-100" was not added in the preparation of the polyolefin resin composition for the outermost layer (A layer). And the total thickness of the three-layer structure is 0.1 mm, and the layer thickness ratio of each layer is the outermost layer (A
Layer) / middle layer / innermost layer = 1/3/1 to produce an agricultural film.

(Comparative Example 5) In the preparation of the polyolefin resin composition for the outermost layer (A layer), calcium carbonate (average particle diameter: average particle diameter: was added) instead of 1.5 parts of the swelling fluoromica "Somasif MAE-100". 10 μm) In the same manner as in Example 3 except that 1.5 parts was added, the total thickness of the three-layer structure was 0.1 mm, and the layer thickness ratio of each layer was
The outermost layer (A layer) / intermediate layer / innermost layer = 1/3/1 was produced.

(Comparative Example 6) A polyolefin resin composition for the outermost layer (A layer) was manufactured by EVA "Evatate D2045".
99.5 parts and UV absorber "Tinuvin 327" 0.5
The total thickness of the three-layer structure is 0.1 mm, and the layer thickness ratio of each layer is as follows: outermost layer (A layer) / intermediate layer / innermost layer = A 1/3/1 agricultural film was produced.

Performance of the agricultural films obtained in Examples 1 to 4 and Comparative Examples 1 to 6 (average interlayer distance of layered silicate, transparency, elastic modulus, tensile breaking strength, tensile breaking) The elongation and weather resistance) were evaluated by the following methods. The results are shown in Table 1.

Average interlaminar distance of layered silicate: Using an X-ray diffractometer (trade name "RINT2400", manufactured by Rigaku), the X-ray incident angle was kept constant at 10 degrees, and a curved PSPC (position sensitive) was used as a detector. By using a proportional counter, it was possible to measure the average interlayer distance of layered silicates in thin agricultural films. That is, 2 of the diffraction peak obtained from the diffraction of the laminated surface of the layered silicate in the agricultural film.
θ was measured, the (001) plane spacing (d) of the layered silicate was calculated by the following Bragg diffraction formula, and the obtained d was taken as the average interlayer distance (nm). λ = 2 dsin θ (where λ: 1.54, d: interplanar spacing of layered silicate, θ:
Diffraction angle)

Transparency: The haze value (%) of the agricultural film was measured according to JIS K-7105 "Method for testing optical properties of plastics".

Elastic Modulus, Tensile Rupture Strength and Tensile Rupture Elongation: In accordance with JIS K-7127 "Plastic-Test method for tensile properties", the elastic modulus, tensile rupture strength and tensile rupture strength of the agricultural film in the machine direction and the transverse direction. The tensile elongation at break was measured.

Weather resistance: JIS K-7350-2 "Plastics-Exposure test method by laboratory light source (Part 2:
Xenon arc light source) ", ultraviolet irradiation was performed from the outermost layer (A layer) of the agricultural film, and the elongation retention rate (%) after 1000 hours was calculated by the following formula. Elongation retention rate (%) = 100 × (tensile rupture elongation after irradiation for 1000 hours) / (tensile rupture elongation before irradiation)

[0118]

[Table 1]

As is clear from Table 1, in all of the agricultural films of Examples 1 to 4 according to the present invention, the layered silicate was highly dispersed at an average interlayer distance of 3 nm or more,
It was excellent in transparency, balance of mechanical properties, and weather resistance.

On the other hand, in the polyolefin resin composition for the outermost layer (A layer), the polyolefin resin 1
The agricultural film of Comparative Example 1 in which the amount of the layered silicate added to 00 parts by weight exceeded 20 parts by weight had poor transparency and poor balance of mechanical properties. Further, the agricultural film of Comparative Example 2 in which the intermediate layer was not provided had a poor balance of mechanical properties. In addition, in the polyolefin resin composition for the outermost layer (A layer), the agricultural film of Comparative Example 3 in which calcium carbonate was added instead of the layered silicate had poor weather resistance, and had poor transparency and mechanical properties. The balance was poor. Comparative Example 4 in which the layered silicate was not added to the polyolefin resin composition for the outermost layer (A layer)
The agricultural film of No. 1 had extremely poor weather resistance. Furthermore,
In the polyolefin resin composition for the outermost layer (A layer), calcium carbonate was added instead of the layered silicate in the agricultural film of Comparative Example 5 and the polyolefin resin composition for the outermost layer (A layer). The agricultural films of Comparative Example 6 to which the layered silicate was not added were all inferior in weather resistance, had a low elastic modulus, and had a too large tensile elongation at break.

Example 5 Polyolefin resin composition (pellet) for the outermost layer (A layer) produced in Example 1
As the innermost layer (layer B), EVA "Evatate H202
0 "99.6 parts and 0.4 parts of a hindered amine light stabilizer (trade name" Kimasolve 944LD ", manufactured by Ciba Specialty Chemicals) as a middle layer, and a linear low-density polyethylene". The total thickness is 0.1 mm and the total thickness is 0.1 mm. The outermost layer is a polyolefin resin composition composed of 0.4 part of Elite 5100 "99.6 parts and hindered amine light stabilizer" Kimasolve 944LD "0.4 part. An agricultural film having a layer thickness ratio of innermost layer (B layer) / intermediate layer / outermost layer = 1/3/1 was produced by an inflation method.

Example 6 In the preparation of the polyolefin resin composition for the innermost layer (B layer), the swelling fluoromica “Somasif MAE-100” 2 was used as the layered silicate.
Instead of the section, Montmorillonite "Clayton HY" 2
In the same manner as in Example 5 except that parts were added,
The total thickness of the three-layer structure is 0.1 mm, and the layer thickness ratio of each layer is as follows: innermost layer (B layer) / intermediate layer / outermost layer = 1/3/1
Agricultural film was manufactured.

(Comparative Example 7) In the production of the polyolefin resin composition for the innermost layer (B layer), hydrotalcite (trade name "DHT4A") was used instead of 2 parts of the swelling fluorine mica "Somasif MAE-100". Manufactured by Kyowa Chemical Co., Ltd.)
As in Example 5, except that 2 parts were added, the total thickness of the three-layer structure was 0.1 mm, and the layer thickness ratio of each layer was as follows: innermost layer (B layer) / intermediate layer / maximum layer. Outer layer = 1/3
/ 1 agricultural film was produced.

Comparative Example 8 In the production of the polyolefin resin composition for the innermost layer (B layer), calcium carbonate (average particle diameter: 10 μm) was used instead of 2 parts of the swelling fluoromica “Somasif MAE-100”. As in Example 5, except that 2 parts were added, the total thickness of the three-layer structure was 0.1 mm, and the layer thickness ratio of each layer was as follows: innermost layer (B layer) / intermediate layer / maximum layer. An agricultural film having an outer layer of 1/3/1 was produced.

(Comparative Example 9) In the preparation of the polyolefin resin composition for the innermost layer (B layer), the swelling fluoromica "Somasif MAE-100" as the layered silicate was not added. Similar to the case of 5,
The total thickness of the three-layer structure is 0.1 mm, and the layer thickness ratio of each layer is as follows: innermost layer (B layer) / intermediate layer / outermost layer = 1/3/1
Agricultural film was manufactured.

Examples 5 and 6, and Comparative Example 7
~ Average interlayer distance, transparency, elastic modulus, tensile breaking strength and tensile breaking elongation of the layered silicate of the agricultural film obtained in Comparative Example 9 are evaluated by the above methods, and the pesticide resistance is evaluated by the following method. It was evaluated by. The results are shown in Table 2.

Agrochemical resistance: A 0.1 N aqueous solution of sulfite was put into a bag-shaped agricultural film by heat-sealing the surroundings, and the mixture was allowed to stand at room temperature for 7 days. Then JI
According to SK-7350-2, ultraviolet irradiation was performed from the outermost layer of the agricultural film, and the elongation retention rate (%) after 1000 hours was calculated by the following formula. Elongation retention rate (%) = 100 × (tensile rupture elongation after irradiation for 1000 hours) / (tensile rupture elongation before irradiation)

[0128]

[Table 2]

As is clear from Table 2, in the agricultural films of Examples 5 and 6 according to the present invention, the layered silicate was highly dispersed at an average interlayer distance of 3 nm or more, and the transparency and mechanical properties were high. It was excellent in the balance of physical properties and pesticide resistance.

On the other hand, in the polyolefin resin composition for the innermost layer (B layer), instead of the layered silicate,
The agricultural film of Comparative Example 7 containing hydrotalcite had a poor balance of mechanical properties and poor pesticide resistance. Further, in the polyolefin resin composition for the innermost layer (B layer), the agricultural film of Comparative Example 8 in which calcium carbonate was added instead of the layered silicate had poor pesticide resistance. Furthermore, the agricultural film of Comparative Example 9 in which the layered silicate was not added to the polyolefin resin composition for the innermost layer (B layer) had poor balance of mechanical properties and pesticide resistance.

(Embodiment 7) EVA "Evatate D" was used as a polyolefin resin in a small extruder "TEX30".
2045 "96 parts and 4 parts of swellable fluorine mica" Somasif MAE-100 "which has been treated with distearyl dimethyl quaternary ammonium salt as layered silicate are fed and melt-kneaded at a set temperature of 160 ° C to form strand And extruded strands were pelletized by a pelletizer to prepare pellets of the polyolefin resin composition for the outermost layer (A layer).

Then, the polyolefin resin composition (pellets) obtained above was used as the outermost layer (A layer), and EVA was used.
A EVA resin "Evatate D20" was prepared by using 98.5 parts of "Evatate H2020" and 1.5 parts of sorbitan stearate added with 1 mol of ethylene oxide as a nonionic surfactant as an intermediate layer.
45 "98.5 parts and a total thickness of a three-layer structure having a polyolefin-based resin composition consisting of 1.5 parts of sorbitan stearate with 1 mol of ethylene oxide added as a nonionic surfactant as an innermost layer. A 0.1 mm agricultural film was produced by the inflation method.
The layer thickness ratio of each layer was outermost layer (A layer) / intermediate layer / innermost layer = 1/3/1.

(Example 8) In the production of the polyolefin resin composition for the outermost layer (A layer), a linear low-density polyethylene "Elite 510" was used as the polyolefin resin instead of 96 parts of EVA "Evatate D2045".
The total thickness of the three-layer constitution is 0.1 mm, and the layer thickness ratio of each layer is the outermost layer (A layer) / intermediate layer in the same manner as in Example 7 except that 96 parts of "0" is used. / Innermost layer = 1 /
A 3/1 agricultural film was produced.

Comparative Example 10 In the production of the polyolefin resin composition for the outermost layer (A layer), calcium carbonate (average particle diameter: 10 μm) was used instead of 4 parts of the swelling fluoromica “Somasif MAE-100”. In the same manner as in Example 7 except that 4 parts was added, the total thickness of the three-layer constitution was 0.1 mm, and the layer thickness ratio of each layer was the outermost layer (A layer) / intermediate layer / maximum layer. An agricultural film having an inner layer of 1/3/1 was produced.

(Comparative Example 11) A three-layer structure was prepared in the same manner as in Example 7 except that the layered silicate was not added to the polyolefin resin composition for the outermost layer (A layer). An agricultural film having a thickness of 0.1 mm and a layer thickness ratio of each layer of outermost layer (A layer) / intermediate layer / innermost layer = 1/3/1 was produced.

(Comparative Example 12) In the production of the polyolefin resin composition for the outermost layer (A layer), the linear low density polyethylene "Elite 5100" was used as the polyolefin resin instead of EVA "Evatate D2045".
Was used, and the total thickness of the three-layer constitution was 0.1 mm, and the layer thickness ratio of each layer was the same as in Example 7 except that the layered silicate was not added. (A layer)
Agricultural film of / middle layer / innermost layer = 1/3/1 was produced.

Examples 7 and 8 and Comparative Example 1
0 to the average interlaminar distance, transparency, elastic modulus, tensile breaking strength, tensile breaking elongation and weather resistance of the layered silicate of the agricultural film obtained in Comparative Example 12, as well as the antifogging property. Was evaluated by the following method.
The results are shown in Table 3.

Persistence of anti-fog property: Water is put in a 15 cm square water bath and an agricultural film is spread on the upper surface.
It was placed in a refrigerator with temperature programming. The water temperature of the water bath is fixed at 15 ° C, and the temperature of the refrigerator is −
The temperature was programmed so that the temperature was repeatedly changed at a cycle of 5 ° C. for 4 hours and 25 ° C. for 2 hours. After the test was continued for 3 months under the above conditions, the state of adhesion of water droplets on the surface of the agricultural film was visually observed, and the persistence of the antifogging property was evaluated according to the following four criteria. [Judgment Criteria] 1 ... A water film was formed on the entire surface, and no water droplets were attached. 2 ... A slight drop of water was observed, but it was flowing without dripping. 3 ... A large water drop partially adhered and fell off. 4 ... Water droplets were attached to the entire surface.

[0139]

[Table 3]

As is clear from Table 3, in the agricultural films of Examples 7 and 8 according to the present invention, the layered silicate was highly dispersed at the average interlayer distance of 3 nm or more, and the transparency and mechanical properties were high. It was excellent in all of the balance of physical properties, weather resistance and durability of anti-fogging property.

On the other hand, in the polyolefin resin composition for the outermost layer (A layer), instead of the layered silicate,
The agricultural film of Comparative Example 10 to which calcium carbonate was added had poor transparency, weather resistance, and antifogging durability.
Further, Comparative Examples 11 and 1 in which the layered silicate was not added to the polyolefin resin composition for the outermost layer (A layer).
Each of the agricultural films of No. 2 had poor transparency and antifogging persistence, and had extremely poor weather resistance.

[0142]

As described above, since the agricultural film of the present invention is less deteriorated by ultraviolet rays and is excellent in pesticide resistance (acid resistance), it exhibits excellent weather resistance for a long period of time. Moreover, since it is also excellent in antifogging property, transparency, mechanical properties, etc. for a long period of time, it is suitably used as a covering material for agricultural greenhouse houses, tunnels, curtains and the like.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2B024 DA05 DB01 EB01                 2B029 EB03 EC02 EC09 EC14 EC19                 4F100 AA03A AK03A AK03B AK06A                       AK06B AK68A AK68B AL05A                       BA02 BA27 CA07A CA18B                       EH20 GB01 JL07 JL09 JN01                       YY00A

Claims (10)

[Claims] 1. A laminated film comprising an outermost layer (A layer) and an inner layer (b layer) which are laminated when spread on an agricultural house, wherein the A layer is a polyolefin resin 100.
Characterized in that it comprises a polyolefin resin composition containing 0.1 to 20 parts by weight of a layered silicate, and the layer b is composed of a polyolefin resin composition containing substantially no layered silicate. Agricultural film. 2. A laminated film in which an outermost layer (A layer) and an inner layer (b layer) are laminated when spread on an agricultural house, wherein the A layer is a polyolefin resin 100.
A polyolefin resin composition containing 0.1 to 20 parts by weight of a layered silicate and 0.01 to 2 parts by weight of an ultraviolet absorber, and the layer b is a polyolefin substantially free of a layered silicate. An agricultural film comprising a resin composition. 3. A laminated film, which is formed by laminating an innermost layer (B layer) and an outer layer (a layer) when spread on an agricultural house, wherein the B layer is a polyolefin resin 100.
And a layered silicate of 0.1 to 20 parts by weight, and the a layer contains 100 parts by weight of a polyolefin resin and 0.01 to 5 parts by weight of a hindered amine light stabilizer. And an agricultural film comprising a polyolefin-based resin composition containing substantially no layered silicate. 4. A laminated film obtained by laminating an outermost layer (A layer) and an inner layer (b layer) when spread on an agricultural house, wherein the A layer is a polyolefin resin 100.
And a layered silicate in an amount of 0.1 to 20 parts by weight. The layer b contains 100 parts by weight of the polyolefin resin and 0.02 to 3 parts by weight of a nonionic surfactant. An agricultural film comprising a polyolefin-based resin composition which contains and does not substantially contain layered silicate. 5. The outermost layer (A layer) has a total thickness of 50.
% Or less, The agricultural film according to claim 1, claim 2 or claim 4. 6. The innermost layer (B layer) has a thickness of 50% of the total thickness.
% Or less, The agricultural film of Claim 3 characterized by the above-mentioned. 7. The polyolefin resin has a density of 0.93.
The agricultural film according to any one of claims 1 to 6, which is a polyethylene resin having a content of 0 g / cm ³ or less or an ethylene-vinyl acetate copolymer having a vinyl acetate content of 25% by weight or less. 8. The layered silicate is montmorillonite and / or
Or it is swelling mica, The agricultural film in any one of Claims 1-7 characterized by the above-mentioned. 9. The agricultural film according to claim 1, wherein the layered silicate is a layered silicate containing an alkylammonium ion having 6 or more carbon atoms. 10. A layered silicate in which the layered silicate has an average interlayer distance of 3 nm or more on the (001) plane measured by a wide-angle X-ray diffractometry and a part or all of which is dispersed in 5 layers or less. It is salt, The agricultural film in any one of Claims 1-9.