JPH09183193A - Multilayred film for agriculture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a film from sticking on equipment when the film is prepared, to provide excellent secondary processability such as sticking preventive property beyween each film, connection in the width or length directions and to provide excellent anti-fogging durability ad anti-dust properties (a characteristics by which the outer face of a house is hardly stained) when the film is extended for a house and a tunnel. SOLUTION: A multilayered film for agriculture wherein an inner layer B consisting of an olrfin resin and an outer layer B' consisting of an olefin resin are laminated on the inner and outer faces of an intermediate layer A consisting of an olefin resin and the contact X1 of an anti-fogging agent in the intermediate layer A is 1<=X1<=10wt.% and the anti-fogging agent is not compounded in the inner layer B or the content X2 of the anti-fogging agent in the inner layer B is 0.05<=X2<X1wt.%, is provided.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an agricultural multilayer film for covering a house or a tunnel. More specifically, during film production, it is excellent in adhesion prevention to equipment, adhesion prevention between films, excellent secondary processability such as width joints and length joints,
The present invention also relates to an agricultural multi-layer film having excellent anti-fogging property when spread in a house or tunnel and having a property (dust-proof property) that the outer surface of the house is unlikely to be soiled.

[0002]

2. Description of the Related Art A large amount of plastic films are used as covering materials for facility horticulture such as agricultural houses and tunnels. Representative examples thereof include polyvinyl chloride films (hereinafter referred to as agricultural plastics) and polyethylene films (hereinafter referred to as agricultural plastics). Polyethylene) and ethylene vinyl acetate copolymer film (hereinafter referred to as agricultural vinegar). Of these, agricultural vinegar has heat retention, transparency, toughness, anti-fogging properties, house adhesion, and economy. It has excellent properties and is used most often. But,
Agricultural plastics are poor in workability and dust resistance due to the plasticizer contained in the film bleeding out and stickiness on the surface, and recently, various problems such as generating harmful gas at the time of incineration disposal are occurring, An alternative is desired.

On the other hand, although agricultural poly and agricultural vinegar have advantages over agricultural vinyl in terms of workability, dustproofness, and disposal, they have antifogging persistence, transparency, toughness, and house adhesion. There was a problem that was inferior. Agricultural poly, which is made of an ethylene polymer, has a problem in imparting antifogging property and antifogging sustainability because it has no polar group. In general, when an agricultural film without anti-fogging property is used as a covering material for a house or tunnel, the water in the soil evaporates and the water content condenses on the inner surface of the film to form water droplets. However, since the film is clouded by the water drops and a part of the sun rays is reflected, the amount of light rays passing through the film is reduced, so that the temperature increasing effect in the house or the tunnel is reduced. Further, the water droplets condensed on the inner surface of the film have a bad influence such as falling on the cultivated crops, damaging the shoots and seedlings, and causing a disease.
Against these adverse effects, a film in which a surfactant having an action of an antifogging agent is kneaded is used, and this antifogging agent prevents evaporated water from staying as a water drop on the film surface, It has the function of spreading water droplets in a film shape and causing them to flow down along the inner surface of the film. In the agricultural film having antifogging property, the kneaded antifogging agent diffuses and leaches from the inside of the film along the surface and is coordinated on the film surface to exert a surface activating effect. However, since the antifogging agent coordinated to the film surface is washed away by water drops during use, it is necessary to always transfer the antifogging agent from the inside of the film toward the surface in order to maintain the antifogging property of the film. . It is apparent that the longer the antifogging effect, that is, the more durable the antifogging effect is, the more practically the antifogging film is. In order to produce such a film having a long anti-fogging effect, generally, a large amount of anti-fogging agent is added at the time of film production, or an anti-fogging agent having a slow migration rate from the inside of the film to the surface after film formation is used. Attempts have been made to make selective use. However, the former, that is, a method of adding a large amount of anti-fogging agent during film production is effective for maintaining anti-fogging, but the amount transferred to the surface immediately after film formation is severe, and transparency due to whitening of the anti-fogging agent There are problems such as deterioration and adhesion between films, and it is actually difficult to increase it beyond a certain amount, and the latter method also has an antifogging effect, and this antifogging effect is long. No anti-fogging agent has been found in practice to last for a period of time.

In view of such a situation, the inventors of the present invention have a structure in which an antifogging agent is added to at least one of an inner layer and an intermediate layer of an olefin-based multilayer film, as seen in Japanese Patent Application No. 06-302775. By adding a specific amount of elastic copolymer to the inner and outer layers, it has excellent anti-fog properties and anti-fog durability,
In addition, they have invented an agricultural film having excellent dust resistance. However, as a result of various investigations, by adding a large amount of antifogging agent to the intermediate layer from the inner layer, the inner layer controls the permeation of the antifogging agent contained in the intermediate layer over time, which has been a problem until now. Avoiding the problem of adhesion of anti-fog agents to rolls and adhesion of films to each other during manufacturing.Due to surface migration of anti-fog agents due to secondary processability such as width-spreading and length-splicing of films. Decrease in fusion bond strength Even if a large amount of antifogging agent is added to the intermediate layer, the antifogging agent does not abruptly migrate to the film surface due to the selection of the resin for the inner layer. The inventors have completed the present invention by finding that the antifogging property can be maintained for a long period of time while solving the problem during processing.

[0005]

Means for Solving the Problems The present invention has the following configurations. (1) An inner layer B made of an olefin resin and an outer layer B ′ made of an olefin resin are laminated on the inner and outer surfaces of an intermediate layer A made of an olefin resin, and the content X1 of the antifogging agent in the middle layer A is 1 ≦ X1. ≦ 10% by weight, and the inner layer B does not contain an antifogging agent, or the content of the antifogging agent in the inner layer B is X2.
A multi-layer film for agriculture, in which 0.05 ≦ X2 <X1% by weight. (2) The agricultural multilayer film as described above, wherein the inner layer B has a thickness tb of 5 μm ≦ tb ≦ 30 μm, and the outer layer B ′ has a thickness tb ′ of tb ≦ tb ′. (3) The main component used for the olefin resin of the intermediate layer A is either ethylene / vinyl acetate copolymer resin or low density polyethylene, and the main component used for the olefin resin of the inner layer B is ethylene / vinyl acetate copolymer. The polymer resin, low density polyethylene, high density polyethylene, or polypropylene, and the main component used for the olefin resin of the outer layer B'is either low density polyethylene, high density polyethylene, or polypropylene. The agricultural multilayer film described. (4) Main component of the intermediate layer A is vinyl acetate content 10% by weight
The above-mentioned multi-layered agricultural film, which is the ethylene / vinyl acetate copolymer resin, wherein the main component of the inner layer B is the ethylene / vinyl acetate copolymer resin having a vinyl acetate content of less than 10% by weight. (5) Inner layer B and outer layer B'using low-density polyethylene, high-density polyethylene or polypropylene in combination with a low-crystalline olefin polymer, and the content Y1 of the low-crystalline olefin polymer into the inner layer B is Y1. And the content Y2 in the outer layer B'is 5 <Y1 <40% by weight and 0 <Y2, respectively.
<The agricultural multilayer film as described above, wherein Y is 1% by weight.

The present invention will be described in detail below. The agricultural multilayer film in the present invention is an agricultural film made of an olefin resin in which an inner layer B and an outer layer B ′ are laminated on the inner and outer surfaces of an intermediate layer A, and the inner layer is an intermediate film containing a large amount of antifogging agent. The layers stacked in layers indicate the layers in contact with the atmosphere inside the house or the tunnel, and the outer layers indicate the layers in contact with the atmosphere outside the house or outside the tunnel. It should be noted that a resin layer may be laminated between the inner layer and the intermediate layer, between the intermediate layer and the outer layer, and further on the outer surface side of the outer layer, etc., within a range that does not impair the effects of the present invention, to form a multilayer film of four or more layers. Further, the agricultural multilayer film of the present invention holds a large amount of antifogging agent in the intermediate layer A, and the outer layer surface is
It is an agricultural film that does not easily emit an anti-fog agent and continuously exudes on the inner layer surface.

The olefin-based resin used in the intermediate layer A is a homopolymer of α-olefin or a copolymer with a different monomer containing α-olefin as a main component, such as propylene homopolymer or Ethylene, 1-butene, 1
-Pentene, a propylene-based polymer which is a copolymer with 1-hexene, an ethylene homopolymer, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1
-Ethylene-based polymers, which are copolymers with octene and vinyl acetate, can be mentioned. Even if these resins are used alone, 2
Mixtures of more than one species may be used. Among them, ethylene / vinyl acetate copolymer resin and low density polyethylene are preferable.

These ethylene-based polymers are suitably used because they have appropriate flexibility and transparency. In particular, in the present invention, ethylene-vinyl acetate copolymer is preferably used in the intermediate layer because of its high ability to retain antifog agents, the vinyl acetate content is 30 wt% or less 10 wt% or more, the melt index Is preferably 0.1 g / 10 minutes or more and 5 g / 10 minutes or less. When the vinyl acetate content is in this range, the processability is excellent, the retaining ability of the antifogging agent is maintained, and the continuous antifogging property is excellent. Further, those having a melt index in this range are preferable because they are excellent in workability and maintain strength.

As the olefin-based resin constituting the inner layer B and the outer layer B ′ laminated on the inner and outer surfaces of the intermediate layer A, a homopolymer of α-olefin or a different type containing α-olefin as a main component is used as in the intermediate layer. A copolymer with a monomer, for example, propylene homopolymer or ethylene, 1-butene,
1-pentene, a propylene-based polymer which is a copolymer with 1-hexene, an ethylene homopolymer, 1-butene, 1-
Pentene, 1-hexene, 4-methyl-1-pentene,
1-octene, an ethylene-based polymer which is a copolymer with vinyl acetate can be mentioned, and even if these resins are used alone,
Two or more kinds may be used as a mixture. Above all, the inner layer B permeates while controlling the antifogging agent contained in the intermediate layer over time.
(= Permeation control) Select an olefin resin that
Further, for the outer layer B ′, it is preferable to select an olefin resin that does not allow the antifogging agent contained in the intermediate layer to permeate.

As the component of the inner layer B, ethylene / vinyl acetate copolymer resin, low density polyethylene, high density polyethylene, or polypropylene is preferable, and the ethylene / vinyl acetate copolymer resin has a vinyl acetate content of less than 10% by weight. Is preferably used. When the vinyl acetate content is less than 10% by weight, the antifogging agent contained in the intermediate layer is appropriately permeated and the durability of the antifogging property is good. Further, by reducing the vinyl acetate content of the inner layer B to be lower than the vinyl acetate content of the intermediate layer A, a large amount of antifogging agent is retained in the intermediate layer A, and the antifogging agent transferred to the inner layer B is exuded while continuing. be able to.
As a component of the inner layer B, low density polyethylene, high density polyethylene, polypropylene or the like can be used for the inner layer by using a low crystalline olefin polymer in combination.
Low crystalline olefin polymer with a density of 0.85 g / cm ³ or more
Less than 0.90 g / cm ³ , density as low density polyethylene
Those 0.900~0.935g / cm ^3, can be used as density 0.940~0.965g / cm main component and polypropylene also of possible transmission control inner layer of ³ as a high-density polyethylene.

As the low crystalline olefin polymer,
Known olefinic elastic copolymers such as ethylene-propylene copolymer, ethylene-butylene copolymer, polybutadiene polymer, styrene-butadiene copolymer, styrene-ethylene-butylene copolymer, propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-
Pentene, a copolymer of ethylene with α-olefins such as 1-octene and a density of 0.880 to 0.900 g / cm ³ , such as ultra low density polyethylene and ethylene-based polymers polymerized with a homogeneous catalyst. You can These low crystalline olefin polymers may be used alone or in combination of two or more. The amount Y1 of the low crystalline olefin polymer added to the inner layer B is preferably 5 to 40% by weight. Within this range, antifogging sustainability can be obtained, and the strength of the film can be maintained and the adhesion between the films can be improved. There is no poor workability.

[0012] As the component of the outer layer B ', low density polyethylene, or preferably high density polyethylene or polypropylene, in particular low density polyethylene having a density of 0.900~0.935g / cm ^3, the density of 0.940~0.965g / cm ³ Examples thereof include high-density polyethylene and polypropylene, and the above-mentioned low crystalline olefin polymer may be used together if necessary. The content Y2 of the low crystalline olefin polymer in the outer layer B'is preferably smaller than the content Y1 of the low crystalline olefin polymer in the inner layer B. When Y2 is equal to or less than Y1, The antifogging agent is less likely to permeate the outer layer located on the outer surface of the house, effective antifogging sustainability is obtained on the inner surface, and the dustproof effect on the outer surface of the film does not deteriorate.

Examples of the antifogging agent used in the present invention include nonionic surfactants, cationic surfactants, anionic surfactants, and amphoteric surfactants, among which, compared with olefin resins. Nonionic surfactants with high compatibility are preferably used, but cationic surfactants and anionic surfactants are also used in combination for the purpose of modifying the antifogging property at the initial and low temperatures. To be Nonionic surfactants include polyethylene glycol ethers such as polyethylene glycol nonyl phenyl ether and polyethylene glycol stearyl ether, polyethylene glycol stearate, polyethylene glycol carboxylic acid esters such as polyethylene glycol dilaurate, glycerin monostearate and sorbitan. Partial carboxylic acid esters of polyhydric alcohols such as monopalmitate and sorbitan tristearate, polyoxyethylene derivatives of sorbitan monostearate,
Polyoxyethylene derivatives of partial carboxylic acid esters of polyhydric alcohols such as polyoxyethylene derivatives of sorbitan monolaurate, N, N-di- (hydroxyethyl) -laurylamide, N- (2-hydroxypropyl) -stearoamide, etc. Amide derivatives and the like. Examples of the cationic surfactant include lauryl trimethyl ammonium chloride, N, N-dimethyl-N-
Quaternary ammonium salts such as (hydroxyethyl) -3- (stearoamido) -propylammonium nitrate, imidazoline derivatives such as 2-octadecyl- (hydroxyethyl) -2-imidazoline, N, N-diethyl- (stearoamide) -methyl Examples thereof include amines such as amine hydrochloride and polyoxyethylene stearylamine. As anionic surfactants, sodium lauryl phosphate, phosphates such as polyoxyethylene-sodium lauryl phosphate, sodium lauryl sulfate, sulfates such as sodium salt of sulfated oleic acid, sodium stearyl sulfonate, And sulfonic acid salts such as dodecylbenzenesulfonic acid triethanolamine salt and sodium salt of dioctylsulfosuccinate.

The antifogging agent added to the agricultural multilayer film of the present invention has a content X1 of 1 ≦ X1 ≦ 10 in the intermediate layer A.
% By weight and no antifogging agent is added to the inner layer B, or the content X2 of the antifogging agent in the inner layer B is added to be less than the addition amount X1 to the intermediate layer. By making the addition amount X2 of the antifogging agent to the inner layer smaller than the addition amount X1 of the antifogging agent to the intermediate layer, there is little seepage of the antifogging agent to the inner layer surface during film formation, and the antifogging agent to the roll There is no trouble caused by the adhesion of the adhesive, and the opening property at the time of unraveling and the fusion processing at the time of secondary processing such as width joints and length joints become good. The amount of antifogging agent added to the intermediate layer is 1% by weight or more and 10
It is in the range of less than wt%, and when it is in this range, the antifogging property is sufficiently exhibited, the spreadability at the time of melting is sufficient, the problem such as foaming is small, and the film forming property is good. In order to make the antifogging durability last, it is sufficient to add as many antifogging agents within these ranges as possible. Further, by adding no anti-fog agent to the inner layer and the outer layer, or by adding a small amount thereof, it is possible to reduce the above-mentioned problems at the time of production and secondary processing, etc. For the purpose of preventing static electricity during film formation, a small amount of surfactant may be added as long as the effect of the present invention is not impaired.

In the production of the agricultural multilayer film according to the present invention, a heat retaining agent such as hydrotalcite or aluminum silicate, an antifog agent, a heat stabilizer, an antioxidant, a hindered amine weather resistance improver, an ultraviolet absorber, You may add various additives, such as a slip agent.

The agricultural multilayer film of the present invention can be produced by known lamination techniques such as coextrusion molding by the inflation method or T-die method, wet lamination, dry lamination, hot melt lamination, extrusion coating lamination, etc. Co-extrusion molding by the inflation method or T-die method, which has excellent properties, is generally used. Further, after the film is formed, the effect of exhibiting anti-fogging property may be improved by corona discharge treatment or the like.

The thickness of the agricultural multilayer film of the present invention is
Generally depends on the place of use and service life, etc.
A diameter of about 0.20 mm is preferably used. Further, it is desirable that the thickness tb of the inner layer B is 5 μm to 30 μm, and the thickness of the outer layer is equal to or thicker than the thickness of the inner layer. As a result, the antifogging agent contained in the intermediate layer permeates to the inner layer side, the desired performance is obtained, and the antifogging property is exhibited. By thickening the outer layer tb ', the antifogging agent contained in the intermediate layer is less likely to migrate to the outer surface of the house, resulting in excellent dustproof property and continuous antifog property.

[0018]

EXAMPLES Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited thereto. The melt flow rate (MFR) shown in Examples and Comparative Examples was a value measured by a method specified in JIS-K-7210. Anti-fog persistence (45 ℃) is 10
The film sample was fixed to the skylight of a water bath having a skylight with a diameter of 3 inches so that the inner layer surface of the film sample was facing down, and the water temperature was kept at 45 ° C and allowed to stand in a constant temperature room at 23 ° C for 24 hours. The period until the antifogging property of the layer surface was maintained was evaluated. From the perspective of obstacles to crops and light transmittance,
It is preferable that the antifogging durability is long. Dust resistance is measured by measuring the haze value H1 of a film sample fixed on a frame of 30 cm in length × 50 cm in width × 30 cm in height in an outdoor field after 3 months, and the difference ΔH (= It was evaluated by H1-H0). The smaller ΔH is, the more excellent the dustproof property is, and the easier it is to maintain the light transmittance to the inside of the house or the like, which is preferable. Heat seal strength, which is an index of secondary processability, was measured using a test sealer heat sealer, and after 3 months of film formation, the seal temperature was 140, 150, 160, 170, 180 ° C, the seal time was 1 second, and the seal was 1 second. Under the condition of a pressure of 1.0 kgf / cm ² , heat sealing and peeling strength measurements were performed on the inner surface and the outer surface, and the maximum peeling strength (N / 15 mm width) was shown under each sealing temperature condition. The heat-sealing strength decreases as the amount of the antifogging agent transferred to the surface increases, and if the heat-sealing strength greatly decreases, it becomes a problem because it peels off due to wind and rain when it is spread on a house or the like. Regarding the film forming workability, the first time after forming the film for 2 hours
Observing the degree of adhesion of the antifogging agent to the pinch rolls, A (no adhesion of the antifogging agent is observed at all), B (slightly observed), C (a considerable amount of the antifogging agent is observed, film Was adhered) was evaluated in 3 ranks. Regarding the dismantling workability, when opening the inflation film 3 months after film formation, A (easy opening), B (slightly sticky film surface and slightly poor opening property), C (film surface The stickiness was severe and it was difficult to open).

Examples 1 to 3 MFR (190 ° C., 2.16) using a 3-layer blown film molding apparatus (rip clearance 2 mm) capable of molding a 3-kind 3-layer film having one 65φ extruder and two 40φ extruders. kgf)
= 1.0 g / 10 min, density ρ = 0.94 g / cm ³ , vinyl acetate content =
An antifogging agent comprising 15% by weight of an ethylene-vinyl acetate copolymer as a main component, 45% by weight of sorbitan monopalmitate, 45% by weight of glycerin sesquistearate and 10% by weight of diethanollaurylamine.
1,3,5% by weight, hydrotalcite compound 5% by weight, anti-fog agent 0.1% by weight, hindered amine weathering agent 0.2% by weight,
0.1% by weight of phenolic stabilizer, 0.1% by weight of phosphorus stabilizer
Into a 65φ extruder and the intermediate layer A
And MFR (190 ℃, 2.16kgf) = 0.5g / 10min, density ρ = 0.
93 g / cm ³ , vinyl acetate content = 5 wt% ethylene-vinyl acetate copolymer as the main component, hindered amine weathering agent 0.2 wt%, phenolic stabilizer 0.1 wt%, phosphorus stabilizer 0.1 wt% The contained resin composition was charged into one 40φ extruder to form the inner layer B, and MFR (190 ° C, 2.16kgf) = 1.0
Resin containing g / 10 min, low density polyethylene of density ρ = 0.92 g / cm ³ as the main component, 0.2% by weight of hindered amine weathering agent, 0.1% by weight of phenolic stabilizer and 0.1% by weight of phosphorus stabilizer. The composition was charged into the other 40φ extruder to form an outer layer B ′, and the inner layer B (thickness 2) was formed on the inner surface of the intermediate layer A (thickness 60 μm).
0 μ), a multilayer film having a total thickness of 100 μ and a three-layer structure having an outer layer B ′ (thickness 20 μ) laminated on the outer surface was obtained under the condition of a blow ratio of 2.5.

Example 4 MFR (190 ° C., 2.16 kgf) = 0.5 g / 10 minutes, density ρ = 0.92 g / cm
^{As a} main component of linear low-density polyethylene of ³ , ethylene-propylene elastic copolymer as a low crystalline olefin polymer (Moonie viscosity 24ML _{1 + 4} (100 ℃), propylene content 26% by weight, density 0.86 g / cm ³ , trade name; EP02P, manufactured by Japan Synthetic Rubber Co., Ltd.) 20% by weight, hindered amine weathering agent
The resin composition containing 0.2% by weight, 0.1% by weight of a phenolic stabilizer and 0.1% by weight of a phosphorus-based stabilizer was used as the inner layer B, and MF was used.
R (190 ℃, 2.16kgf) = 0.5g / 10min, density ρ = 0.92g / cm ³ linear low density polyethylene as the main component, hindered amine weathering agent 0.2% by weight, phenolic stabilizer 0.1% by weight The same procedure as in Example 2 was carried out except that the resin composition containing 0.1% by weight of the phosphorus-based stabilizer was used as the outer layer B ′.

Example 5 An ethylene-propylene elastic copolymer (Mooney viscosity 24 ML _{1 + 4} (100 ° C.), propylene content 26% by weight,
Density 0.86g / cm ³ , trade name; EP02P, Japan Synthetic Rubber Co., Ltd.
Manufactured in the same manner as in Example 4 except that 20% by weight was added.

Example 6 MFR (190 ° C., 2.16 kgf) = 0.5 g / 10 minutes, density ρ = 0.92 g / cm
Main component is linear low-density polyethylene ( ³ ), ethylene-propylene elastic copolymer (Moonie viscosity 24 ML _{1+ 4} (100
℃), propylene content 26% by weight, density 0.86 g / cm ³ , trade name; EP02P, manufactured by Nippon Synthetic Rubber Co., Ltd.) 30% by weight, sorbitan monopermitate 45% by weight, glycerin sesquistearate 45% by weight And 3% by weight of antifogging agent consisting of 10% by weight of diethanollaurylamine, 0.2% by weight of hindered amine weathering agent, 0.1% of phenolic stabilizer
Example 4 was carried out in the same manner as in Example 4, except that the resin composition containing 1% by weight and 0.1% by weight of a phosphorus-based stabilizer was used as the intermediate layer A.

Examples 7 to 9 Example 4 was repeated except that the thickness of the inner layer B was set to 5, 30, 40 μm.
Was performed in the same manner as described above.

Examples 10 to 12 To the inner layer B, 0.1, 0.5 and 1.0% by weight of an antifog agent comprising 45% by weight of sorbitan monopermitate, 45% by weight of glycerin sesquistearate and 10% by weight of diethanol laurylamine is added. Except for this, the same procedure as in Example 4 was performed.

Example 13 MFR (190 ° C., 2.16 kgf) = 0.45 g / 10 minutes, density ρ = 0.945 g /
cm ³ of high-density polyethylene as a main component, the ethylene-propylene elastic copolymer (trade name; EP02P, manufactured by Nippon Synthetic Rubber Co., Ltd.) 10% by weight, hindered amine weatherproofing agent
2% by weight, phenolic stabilizer 0.1% by weight, phosphorus stabilizer
The resin composition containing 0.1% by weight was used as the outer layer B ′, and the same high-density polyethylene as the outer layer B ′ was used as the main component, and the ethylene-propylene elastic copolymer (trade name; EP02P, manufactured by Nippon Synthetic Rubber Co., Ltd.) 20% by weight, 0.2% by weight of a hindered amine weathering agent, 0.1% by weight of a phenolic stabilizer, and 0.1% by weight of a phosphorus stabilizer as the outer layer B ′, except that a resin composition is used. It was carried out.

Example 14 MFR (230 ° C., 2.16 kgf) = 6.0 g / 10 minutes, density ρ = 0.90 g / cm
³ of ethylene and butene as a main component of polypropylene ternary random copolymer and comonomer, the ethylene - propylene elastic copolymer (trade name; EP02P, manufactured by Japan Synthetic Rubber Co.) 10 wt% hindered amine A resin composition containing 0.2% by weight of a weather-resistant agent, 0.1% by weight of a phenolic stabilizer, and 0.1% by weight of a phosphorus-based stabilizer is used as an outer layer B ′.
20% by weight of the above-mentioned ethylene-propylene elastic copolymer (trade name; EP02P, manufactured by Nippon Synthetic Rubber Co., Ltd.), 0.2% by weight of a hindered amine weathering agent, and a phenolic stabilizer. Example 2 was carried out in the same manner as in Example 2 except that the resin composition containing 0.1% by weight and 0.1% by weight of the phosphorus-based stabilizer was used as the outer layer B '.

Comparative Example 1 The same procedure as in Example 1 was carried out except that 1% by weight of an antifogging agent consisting of 50% by weight of sorbitan monopalmitate and 50% by weight of glycerin sesquistearate was added to the inner layer B and the intermediate layer A. did.

COMPARATIVE EXAMPLE 2 To the inner layer B and the intermediate layer A, 1% by weight each of an antifogging agent consisting of 45% by weight of sorbitan monopalmitate, 45% by weight of glycerin sesquistearate and 10% by weight of diethanollaurylamine was added. Was carried out in the same manner as in Example 2.

Comparative Example 3 Except for adding 2.25% by weight of an antifogging agent consisting of 45% by weight of sorbitan monopalmitate, 45% by weight of glycerin sesquistearate and 10% by weight of diethanollaurylamine to the inner layer B and the intermediate layer A, respectively. Was carried out in the same manner as in Example 2.

Comparative Example 4 The inner layer B, the outer layer B'and the intermediate layer A were mixed with sorbitan monopermeate 4
Example 2 was carried out in the same manner as in Example 2 except that 0.8% by weight of an antifogging agent consisting of 5% by weight, 45% by weight of glycerin sesquistearate and 10% by weight of diethanollaurylamine was added.

Comparative Example 5 The inner layer B, the outer layer B'and the intermediate layer A were mixed with sorbitan monopermeate 4
Example 2 was carried out in the same manner as in Example 2 except that 1.8% by weight of an antifogging agent consisting of 5% by weight, 45% by weight of glycerine sesquistearate and 10% by weight of diethanollaurylamine was added.

Comparative Examples 6 to 7 The procedure of Example 2 was repeated except that the antifogging agent added to the intermediate layer was 0.5 or 10% by weight. With 10 wt% added, foam cells were observed in the middle layer of the obtained film,
It was inferior in film forming property.

Comparative Examples 8-10 2.25% by weight of an antifogging agent consisting of 45% by weight of sorbitan monopalmitate, 45% by weight of glycerin sesquistearate and 10% by weight of diethanollaurylamine were added to the inner layer B and the intermediate layer A, respectively. The same procedure as in Example 8, Example 13 and Example 14 was carried out except that the above was carried out.

Comparative Examples 11 to 12 45% by weight of sorbitan monopermitate as the inner layer B and glycerin sesquistearate
Same as Example 8 and Example 13 except that 3% by weight of an antifogging agent consisting of 45% by weight and 10% by weight of diethanollaurylamine was added, and the addition amount of the antifogging agent to the intermediate layer A was 0% by weight. Carried out. From November 7, 1995 to November 22, 1995, Examples 1 to 14 and Comparative Examples 1 to 6 were performed at an outdoor farm house in Ichihara City, Chiba Prefecture.
And the samples of Comparative Examples 8 to 12 (300 mm square) were spread and the initial antifogging properties were observed. As a result, all the samples except Comparative Example 1 had good initial antifogging properties (water film was uniform). The sample of Comparative Example 1 had an insufficient initial anti-fogging property, the water film was non-uniform, and water droplets were generated.

[0035]

EFFECTS OF THE INVENTION The agricultural multilayer film of the present invention has an antifogging agent by adding a large amount of the antifogging agent to the intermediate layer rather than the inner layer and controlling the permeation of the antifogging agent contained in the intermediate layer over time. The durability and dust resistance are maintained for a long period of time, while the problems of adhesion of anti-fogging agent to the rolls and adhesion of films to each other, which have been problems in the past, are avoided. The secondary workability such as seam processing eliminates the decrease in fusion strength due to the migration of the antifogging agent to the surface, and thus it was suitable for use as an agricultural coating material for houses and tunnels.

[0032]

[Table 1]

[0033]

[Table 2]

[0034]

[Table 3]

[0035]

[Table 4]

[0036]

[Table 5]

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Claims (5)

[Claims] 1. An inner layer B made of an olefin resin and an outer layer B'made of an olefin resin are laminated on the inner and outer surfaces of an intermediate layer A made of an olefin resin, and the antifogging agent content X1 of the intermediate layer A is 1. A multi-layer film for agriculture, wherein ≦ X1 ≦ 10% by weight, and the inner layer B is not blended with an antifogging agent, or the content X2 of the antifogging agent in the inner layer B is 0.05 ≦ X2 <X1% by weight. 2. The thickness tb of the inner layer B is 5 μm ≦ tb ≦ 30 μm
And the thickness tb ′ of the outer layer B ′ is tb ≦ tb ′. 3. The main component used for the olefin resin of the intermediate layer A is either ethylene / vinyl acetate copolymer resin or low density polyethylene, and the main component used for the olefin resin of the inner layer B is ethylene / acetic acid. Either vinyl copolymer resin, low density polyethylene, high density polyethylene, or polypropylene, and the main component used for the olefin resin of the outer layer B'is either low density polyethylene, high density polyethylene, or polypropylene. The multilayer film for agriculture according to claim 1. 4. The main component of the intermediate layer A is a vinyl acetate content of 10
2. The agricultural multilayer film according to claim 1, wherein the ethylene / vinyl acetate copolymer resin is at least wt% and the main component of the inner layer B is an ethylene / vinyl acetate copolymer resin having a vinyl acetate content of less than 10 wt%. 5. An inner layer B and an outer layer B'combining any one of low-density polyethylene, high-density polyethylene, and polypropylene with a low-crystalline olefin polymer, and containing a low-crystalline olefin polymer in the inner layer B. The ratio Y1 and the content Y2 in the outer layer B ′ are 5 <Y1 ≦ 40% by weight and 0, respectively.
The agricultural multilayer film according to claim 1, wherein ≦ Y2 <Y1% by weight.