JP2002065075A - Multilayer film for agriculture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multilayer film for agriculture, excellent in toughness, having an Elmendorf tear strength good in balance in the machine direction(MD) and the transverse direction(TD), hardly being broken by strong wind or the like, and excellent in transparency. SOLUTION: This multilayer film for the agriculture consists of at least an inner layer A, an intermediate layer B and an outer layer C. The inner layer A and the outer layer C are composed of a compound of a polyolefin- based resin, and the intermediate layer is composed of a specific compound of a polypropylene-based copolymer composition (X).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multilayer agricultural film used as a covering material for a house or a tunnel. More specifically, the present invention relates to a multilayer film for agricultural use which is hardly broken by strong wind or the like and has excellent transparency.

[0002]

2. Description of the Related Art Various plastic films have been used as covering materials for horticulture such as agricultural houses and tunnels. Typical examples thereof include a polyvinyl chloride film (hereinafter, referred to as agricultural plastic), a polyethylene film (hereinafter, referred to as agricultural plastic), an ethylene vinyl acetate copolymer film (hereinafter, referred to as agricultural plastic). it can.

[0003] Above all, agricultural rice has heat retention, transparency, toughness,
Mostly used because it is excellent in anti-fog properties, house adhesion and economics, but because of insufficient Elmendorf tear strength, the film easily tears due to strong winds,
The plasticizer contained in the film gradually oozes out to the film surface, so that dust easily adheres to the film, and there is a problem in that the transparency decreases due to the adhesion of the dust. There is also a problem that, for example, harmful gases are generated when incinerated for disposal after use. Therefore, there is a demand for agricultural viable alternatives that do not generate harmful gases.

On the other hand, agricultural poly and agricultural vinegar are superior to agricultural virgin in terms of dust resistance and ease of disposal, and the Elmendorf tear strength is better than agricultural virgin but not sufficient. Improvements in heat retention, toughness, antifogging properties, and the like have been demanded because they are inferior to agricultural rice.

[0005] Japanese Patent Application Laid-Open No. Sho 60-104141 discloses a technique for adding a specific filler to improve the heat retaining property of these agricultural poly and agricultural vinegar. In order to improve toughness and anti-fogging property, Japanese Patent Application Laid-Open No. 58-90960 discloses an outer layer (a layer in contact with the atmosphere outside a house or a tunnel).
Linear low-density polyethylene, ethylene-vinyl acetate copolymer or olefin-vinyl alcohol copolymer in the intermediate layer, and linear low-density polyethylene or ethylene-vinyl acetate copolymer in the inner layer (layer in contact with the atmosphere inside the house or tunnel). Agricultural laminated films using polymers have been proposed.

[0006] These techniques have made it possible to bring the antifogging property and the heat retention of agricultural poly and agricultural vinegar close to those of agricultural plastic, but the transparency and toughness were insufficient.

On the other hand, in recent years, conventional multi-site catalysts have been replaced.
Alternatively, ethylene-α-ole using a single-site catalyst
Development of linear low-density polyethylene, a fin copolymer
Further, Japanese Patent Application Laid-Open No. 09-052332 discloses a density of 0.
925 to 0.940 g / cm ^ThreeOf ethylene-α-olef
Outer layer made of a vinyl copolymer, having a density of 0.880 to 0.9
10g / cm^ThreeEthylene-α-olefin copolymer?
Intermediate layer having a density of 0.905 to 0.930 g / c
m^ThreeFrom an ethylene-α-olefin copolymer consisting of
Agricultural laminated film in which the inner layer is laminated,
JP 08-276542 discloses ethylene-vinyl acetate.
Copolymer as the middle layer, single site in the inner and outer layers
Using a catalytic ethylene-α-olefin copolymer
Agricultural multilayer films have been proposed.

[0008] These agricultural multilayer films improve the toughness, but have a poor balance of the Elmendorf tear strength in the longitudinal (MD) and transverse (TD) directions, so that they are easily torn in the longitudinal direction of the film. Remained unsolved.

[0009]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an Elmendorf tear having excellent toughness and a well-balanced longitudinal (MD) and transverse (TD) direction, which is hardly broken by strong winds or the like. An object of the present invention is to provide an agricultural multilayer film having excellent transparency.

[0010]

Means for Solving the Problems The present inventors have conducted intensive studies to improve the problems of the prior art, and as a result, have found that an agricultural multilayer film comprising at least an inner layer A, an intermediate layer B and an outer layer C has been obtained. It has been found that an agricultural multilayer film in which the inner layer A and the outer layer C are composed of a blend of a polyolefin-based resin and the intermediate layer B is composed of a blend of a specific polypropylene-based copolymer composition can improve the above-mentioned problems. Based on this finding, the present invention has been completed.

The present invention comprises the following. (1) An agricultural multilayer film comprising at least an inner layer A, an intermediate layer B and an outer layer C, wherein the inner layer A and the outer layer C are composed of a blend of a polyolefin resin, and the intermediate layer B
Comprises a propylene-α-olefin random copolymer (E) having a propylene content of 90% by weight or more and a propylene-α-olefin random copolymer (F) having a propylene content of 55% to 90% by weight. an intrinsic viscosity [eta] _F of the propylene -α- olefin random copolymer (F) is 1.3~3.5dl / g, propylene -α- olefin copolymer intrinsic viscosity (E) [eta _E
When the intrinsic viscosity ratio [η] _F / [η] _E is 0.5 to
1.3, and propylene -α- olefin copolymer weight (E) and W _E, when the propylene -α- olefin copolymer the weight of (F) was W _F, these weight W _E / W _F and the intrinsic viscosity ratio [η] _F / [η] product of _{E ([η] F / [} η] E) × (W E / W F) is 1.0 to 4.5
The agricultural multilayer film comprised from the blend of the propylene-based copolymer composition (X) in the range of the above.

(2) The polyolefin resin used for the inner layer A and the outer layer C has a density of 0.88 to 0.92 g / cm
³ of low density polyethylene, linear low density polyethylene, high density polyethylene having a density of 0.94~0.97g / cm ^3, ethylene - vinyl acetate copolymer, and density 0.88, which is polymerized using a single site catalyst ~ 0.92g /
The agricultural multilayer film according to the above (1), which is one or a mixture of two or more members selected from the group consisting of an ethylene-α-olefin copolymer having a cm ³ .

(3) The tensile strength of the multilayer film in the machine direction (MD) and the transverse direction (TD) is 30 N / mm ^2.
The Elmendorf tear strength in the longitudinal (MD) direction and the transverse (TD) direction is 100 N / mm or more, respectively, and the Elmendorf tear strength ratio in the longitudinal (MD) direction and the transverse (TD) direction (longitudinal / lateral). The agricultural multilayer film according to the above (1) or (2), wherein is 1.5 to 0.6.

(4) The composition constituting the inner layer A and the outer layer C contains 1 to 10% by weight of an inorganic filler having a BET specific surface area of 5 to 50 m ² / g. The agricultural multilayer film according to any one of the above items (1) to (3), comprising 1 to 20% by weight of an inorganic filler.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the agricultural multilayer film according to the present invention will be described in detail.

The polyolefin resin used in the composition for forming the inner layer A and the outer layer C in the present invention is not particularly limited, but may be a low-density polyethylene having a density of 0.88 to 0.92 g / cm ^3, a linear low-density polyethylene. , Density 0.94 ~
0.97 g / cm ³ high density polyethylene, ethylene-
Vinyl acetate copolymer, ethylene-vinyl acetate copolymer having a vinyl acetate content of 10% by weight or less, and a density of 0.88 to 0.92 g / polymerized using a single-site catalyst.
An ethylene-α-olefin copolymer of cm ³ is suitably used in terms of transparency and cost.

In particular, the polyolefin resin is produced using a single-site catalyst such as a metallocene catalyst, ethylene having a density of 0.88 to 0.92 g / cm ³ and α- having a carbon number of 3 to 20. When it is a random copolymer with an olefin, the resulting agricultural multilayer film has good transparency and flexibility. The density is 0.88 g / cm
If it is less than ³ , the film-forming processability is poor and the melting point is low, so that heat may be stored and fused by sunlight. If it exceeds 0.92 g / cm ³ , sufficient flexibility tends not to be obtained.

The polyolefin resin used in the composition of the inner layer A and the outer layer C in the present invention can be produced by a known method, and can be selected from commercially available products having desired specifications. Can be used

In the polypropylene copolymer composition (X) used for the composition constituting the intermediate layer B in the present invention, the polypropylene-α-olefin random copolymer (E) has a polypropylene content of 90% by weight. More than 98
Wt% or less, more preferably 94 wt% or more and 98 wt%
The following random copolymer is shown. Propylene content of 9
If the amount is less than 0% by weight, heat resistance during film formation may be insufficient.

In the polypropylene-α-olefin random copolymer (E), the α-olefin to be copolymerized with propylene is not particularly limited, but specific examples thereof include ethylene, 1-butene, 1-pentene and 1-pentene. -Hexene, 1-octene, 1-decene, 1-dodecene, 4-
Methyl-1-pentene, 3-methyl-1-pentene and the like can be mentioned. These α-olefins may be used alone or in combination of two or more. Of these, the use of ethylene is preferred in terms of production cost.

In the polypropylene copolymer composition (X) used in the composition constituting the intermediate layer B in the present invention, the propylene-α-olefin random copolymer (F) has a propylene content of 55 to 90. % By weight, preferably 55 to 85% by weight of the random copolymer. When the propylene content is 90% or more, the impact properties and flexibility at low temperatures are insufficient, and when the propylene content is 55% by weight or less, the transparency decreases.

In the propylene-α-random copolymer (F), the α-olefin to be copolymerized with propylene is not particularly limited, but specific examples thereof include ethylene, 1-butene, 1-pentene and 1-pentene. Hexene, 1-octene, 1-decene, 1-dodecene, 4-methyl-1-
Penten, 3-methyl-1-pentene and the like can be mentioned. These α-olefins may be used alone or in combination of two or more. Of these, the use of ethylene is preferred in terms of production cost.

The propylene-α-olefin random copolymer (F) has an intrinsic viscosity [η] _F measured in tetralin at 135 ° C. of 1.3 to 3.5 dl / g, more preferably 1.5 to 3.5 dl / g. The intrinsic viscosity ratio [η] _F / [η] _{E of} 3.0 dl / g and intrinsic viscosity [η] _E measured in tetralin at 135 ° C. of the propylene-α-olefin random copolymer (E). Is 0.5 to 1.3, preferably 0.1.
6 to 1.2.

The intrinsic viscosity [η] _F affects the transparency of the propylene-based copolymer composition (X), and the intrinsic viscosity ratio [η] _F / [η] _E is defined as propylene-α-olefin random. This affects the dispersibility of the copolymer (F) in the propylene-α-olefin random copolymer (E). The lower the intrinsic viscosity [η] _{F of the} propylene-α-olefin random copolymer (F), the higher the productivity of the agricultural multilayer film is, and the intrinsic viscosity ratio [η] _F / [η] _E is within the above range. If so, the transparency is excellent.

In the propylene copolymer composition (X) used in the present invention, the weight ratio of the propylene-α-olefin random copolymer (E) to the propylene-α-olefin random copolymer (F) W _E / W _F is the product of the intrinsic viscosity ratio [η] _F / [η] _E ([η] _F / [η] _E ) ×
(W _E / W _F) is 1.0 to 4.5. If the product of the intrinsic viscosity ratio and the weight ratio is less than 1.0, the moldability of the propylene-based copolymer composition (X) is reduced, and if it exceeds 4.5, the impact resistance of the obtained agricultural multilayer film is increased. And the surface smoothness may be reduced.

The specific composition of the propylene copolymer composition (X) used in the present invention is such that the propylene-α-olefin random copolymer (F) is 10% based on the above composition.
５０50% by weight. When the propylene-α-olefin random copolymer (F) is in this range, the propylene-based copolymer composition (X) and the resulting agricultural multilayer film will have excellent transparency, flexibility, and toughness.

The propylene copolymer composition (X) has a melt flow rate (230 ° C., a load of 21.18 N, hereinafter M
FR) is preferably from 0.1 to 50 g / 10 min, more preferably from 0.2 to 20 g, from the viewpoint of the moldability of the propylene-based copolymer composition (X) and the appearance of the obtained agricultural multilayer film.
/ 10 minutes is more preferred. The MFR is 0.1 g / 10
If the amount is less than 50 minutes, the formability is reduced. If the amount exceeds 50 g / 10 minutes, the surface smoothness of the agricultural multilayer film is reduced, and the transparency and toughness may be insufficient.

The agricultural multi-layer film of the present invention is obtained by using the propylene-based copolymer composition (X) as a raw material for producing the composition for the intermediate layer (B).
Tensile strength in the transverse and transverse (TD) directions is 30 N / m each
toughness of at least m ² and Elmendorf tear strengths in the longitudinal (MD) and transverse (TD) directions of 100 N / mm, respectively.
As described above, the Elmendorf tear strength ratio (vertical / horizontal) in the longitudinal (MD) direction and the transverse (TD) direction is 1.5 to 0.6, which makes it difficult to break against strong winds and the like due to the good balance between the longitudinal and lateral directions. And excellent transparency.

The propylene copolymer composition (X) used in the present invention may be produced by any method as long as the above-mentioned various properties are satisfied. Of course, the propylene-α-olefin random copolymer (E) and the propylene-α-olefin copolymer (F) which are separately produced and used in the present invention are mixed using a mixing apparatus, and the propylene-based copolymer is mixed. Although the composition (X) may be produced, preferably, the composition of International Publication W
O97 / 19135, JP-A-10-316810
Propylene-α-olefin random copolymer (E) is produced by using a supported titanium-containing solid catalyst and an organoaluminum compound using an olefin polymerization catalyst, and then propylene-α -Propylene in the presence of olefin random copolymer (E)-
That is, an α-olefin random copolymer (F) is produced, and a propylene-based copolymer composition (X) is produced continuously. The propylene-based copolymer composition (X) can be produced by the above-described method, or can be used by selecting a product having desired specifications from commercial products.

When the propylene-α-olefin random copolymer (E) and the propylene-α-olefin random copolymer (E) are continuously produced to obtain the propylene-based copolymer composition (X) Since the intrinsic viscosity [η] _F of the propylene-α-olefin random copolymer (F) in the propylene-based copolymer composition (X) cannot be directly measured, the propylene-α-olefin random copolymer which can be directly measured is used. from the weight% W _F of the intrinsic viscosity [eta] _E and propylene copolymer composition (X) across the intrinsic viscosity [η] _{W HOLE} and copolymers coalescence (E), is obtained by the following formula (1) . _{[Η] F = {[η} ] WHOLE - (1-W F / 100) [η] E} / (W F / 100) (1)

An inorganic filler can be added to the composition constituting the inner layer A, the intermediate layer B and the outer layer C of the agricultural multilayer film of the present invention for the purpose of improving the heat retention of the agricultural multilayer film. Examples of the inorganic filler added to the composition constituting the agricultural multilayer film include silicate compounds such as silicon oxide, magnesium silicate, aluminum silicate, and calcium silicate; and aluminosilicates such as calcium aluminosilicate, sodium aluminosilicate, and potassium aluminosilicate. Compounds, alumina, sodium aluminate, potassium aluminate, calcium aluminate and other aluminate compounds, calcium carbonate, lithium-aluminum composite hydroxide salts represented by the following formulas (2) and (3), and the following formula (4) ), One or more inorganic fillers selected from the group of hydrotalcites and the like.

[Al ₂ Li (OH) ₆ ] ₂ (A ⁿ⁻ ) · mH ₂ O (2) (wherein, A ⁿ⁻ is an n-valent anion, and m is a number of 3 or less.)

[Al ₂ (Li _(1-x) · M ²⁺ _x ) (OH) ₆ ] ₂ · (Si _y O _{2y + 1} ² ) _{1 + x} · mH ₂ O (3) M ²⁺ is a divalent metal, m is a number in the range of 0 ≦ m <5, x is a number in the range of 0 ≦ x <1, and y is 2 ≦ y ≦ 4
Indicates a number in the range. )

M ²⁺ _1-x Al _x (OH) ₂ (A ⁿ⁻ ) _{x / 2} · mH ₂ O (4) (where M ²⁺ is Mg ²⁺ , Ca ²⁺ , and Zn ²⁺ Represents at least one divalent metal ion selected from the group consisting of: A ⁿ⁻ is an n-valent anion, x and m are the following conditions, and 0 <x <0.
5, 0 ≦ m ≦ 2 is satisfied. )

As the inorganic filler, JIS Z
BET specific surface area measured according to 8830 is 5-50
Those having m ² / g, preferably 5 to ²⁰ m ² / g are suitably used. When the BET specific surface area exceeds 50 m ² / g, the antifogging agent and the antifog agent are adsorbed by the inorganic filler and are not easily transferred to the film surface, so that the antifogging performance and the antifogging performance may not be obtained. If it is less than 5 m ² / g, the anti-fogging agent and anti-fog agent are not adsorbed to the inorganic filler and transfer to the film surface proceeds promptly, and the film becomes sticky, and the anti-fog and anti-fog properties are persistent. Becomes insufficient.

The addition ratio of the inorganic filler to the composition constituting the inner layer A and the outer layer C is preferably 1 to 10% by weight.
When the addition ratio is less than 1% by weight, the heat retention is insufficient,
If it exceeds 10% by weight, the transparency may be reduced. The addition ratio of the inorganic filler to the composition constituting the intermediate layer B is preferably 1 to 20% by weight, and the addition amount is 1% by weight.
If it is less than 30%, the heat retention is insufficient, and if it exceeds 20% by weight, transparency and mechanical properties may be reduced.

In the present invention, a compound constituting the inner layer A, the intermediate layer B and the outer layer C may be added with a modifying resin or an additive usually used for agricultural films as long as the object of the present invention is not impaired. Can be blended. Examples of the additive include a hindered amine-based weathering agent, an ultraviolet absorber, an anti-mist agent (fluorinated surfactant), an antistatic agent, a lubricant, an antioxidant, a heat stabilizer, an antibacterial agent, a coloring agent and a coloring agent. be able to.

As a method for obtaining the compounds constituting the inner layer A, the intermediate layer B and the outer layer C, the above-mentioned additives are added to the polymer used for each layer, and the mixture is stirred at high speed with a Henschel mixer (trade name). Examples thereof include a method of mixing with a normal compounding device such as a machine-mounted mixer, a ribbon blender, and a tumbler mixer, and a method of pelletizing using a general single-screw extruder or a twin-screw extruder.

The thickness of the agricultural multilayer film of the present invention varies depending on the place where it is used, the service life thereof, and the like.
Those having a thickness of about 05 to 0.3 mm are preferably used. The thickness T _a of the inner layer A, the thickness of the intermediate layer B T _b and the thickness T _c of the outer layer C
Is not particularly limited, but _Ta : _Tb : _Tc = 1
~ 5: 1 ~ 5: 1 ~ 5 is preferred.

The agricultural multi-layer film of the present invention can be produced by a known technique such as an inflation method or a T-die method using the above-mentioned composition. In addition to the intermediate layer B, a heat insulating property is imparted. It may be a multilayer film of four or more layers in which an intermediate layer D, an intermediate layer G for improving anti-fogging properties, an intermediate layer H containing recycled materials, and the like are laminated. Furthermore,
A dust-proof coating agent or an anti-fogging coating agent may be applied and dried to form a coating film on the surface.

The agricultural multilayer film of the present invention may be transparent or satin-finished, and may be used for mulching or bagging other than for covering agricultural houses (greenhouses) and tunnels.

[0042]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples and Comparative Examples, but the present invention is not limited thereto. In addition, evaluation of the agricultural multilayer film in an Example and a comparative example was implemented by the following method.

1) Total light transmittance and haze; JIS K
According to 7105, it was measured using a color computer “HGM-2K” manufactured by Suga Test Instruments Co., Ltd. The smaller the numerical value of the haze, the better the transparency.

2) Tensile strength (toughness): JIS K6
According to 732, tensile cutting loads in the longitudinal (MD) direction and the transverse (TD) direction were obtained, and the resulting value was divided by the cross-sectional area (mm ² ) of the film to obtain a tensile strength.

3) Elmendorf tear strength; JIS K
The Elmendorf tear load in the machine direction (MD) and the transverse (TD) direction of the film was determined according to 6732, and a value obtained by dividing the result by the thickness (mm) of the film was defined as Elmendorf tear strength.

4) Tensile modulus (flexibility: Young's modulus);
The length (M) of the film sample according to STM D 882
The tensile modulus in the direction D) and the tensile modulus in the transverse (TD) direction were measured, and the average value of both was shown.

5) Density: measured according to JIS K 7112.

6) Melt flow rate; JIS K7
The measurement was performed at 190 ° C. and 21.18 N (polyethylene resin) or 230 ° C. and 21.18 N (polypropylene resin) in accordance with No. 210.

7) Intrinsic viscosity; using tetralin (tetrahydronaphthalene) as a solvent under a temperature environment of 135 ° C.
Automatic Viscometer (AVS2, Mitsui Toatsu Chemicals, Inc.)
), The intrinsic viscosity [η] _{E of} the propylene-α-olefin random copolymer (E) extracted from the middle of the polymerization process, and then the intrinsic viscosity [η] of the propylene-based copolymer composition “X”. _WHOLE was measured directly. Propylene-α
-Intrinsic viscosity [η] of olefin random copolymer (F)
_F was calculated from the following equation using the values of [η] _E and [η] _WHOLE . _{[Η] F = ([η} ] WHOLE / W F) - ([η] E × W E /
W _F) W _E: generation amount W _F propylene -α- olefin random copolymer (E): Propylene -α- olefin random copolymer produced amount of (F) [η] _WHOLE: propylene copolymer composition Viscosity of product (X)

8) Propylene content: 1760X manufactured by Perkin-Elmer Co., Ltd.
It measured with the FT-IR apparatus.

9) Weight of propylene-α-olefin random copolymers (E) and (F); Mg content in the polymer obtained in the polymerization step was determined by high frequency inductively coupled plasma emission spectroscopy (ICP method). The weights of the random copolymers (E) and (F) were calculated from the polymer yield per unit weight of the catalyst.

Examples 1 to 10 and Comparative Examples 1 to 8 In accordance with the composition of each layer of the multilayer film shown in Tables 1 and 2 and the formulation of the fixed composition described later, a composition for each layer was prepared. Using the obtained compound, one 65 mmφ extruder and 4
Using a three-type three-layer T-die extruder having two 5 mmφ extruders, a multilayer film having a thickness of 0.1 mm was formed at a molding temperature of 210 ° C. The thickness ratio of each layer of the laminated film is outer layer: intermediate layer: inner layer = 1: 3: 1.

The symbols and contents of the resins used in the compounds constituting each layer of the multilayer film shown in Tables 1 and 2 are as follows. LDPE: low density polyethylene, NUC8505 (manufactured by Nippon Unicar Co., Ltd.), MFR (190 ° C.) = 0.8 g /
10 minutes, density = 0.92 g / cm ³ LLDPE: linear low density polyethylene, TUF206
0 (manufactured by Nippon Unicar Co., Ltd.), MFR (190 ° C.) = 1.
0 g / 10 min, density = 0.92 g / cm ³ EVA (15%): an ethylene-vinyl acetate copolymer having a vinyl acetate content of 15% by weight, NUC8452D (manufactured by Nippon Unicar Co., Ltd.), MFR (190 ° C.) = 1.0 g / 10
Min, density = 0.94 g / cm ³ EVA (5%): ethylene-vinyl acetate copolymer having a vinyl acetate content of 5% by weight, NUC3250 (manufactured by Nippon Unicar Co., Ltd.), MFR (190 ° C.) = 1 0.5 g / 10 minutes,
Density = 0.93 g / cm ³ M-PE: single-site catalyst-based ethylene-α-olefin copolymer, Elite 5400 (manufactured by Dow Chemical Co., Ltd.), MFR (190 ° C.) = 1.0 g / 10 minutes, Density = 0.92 g / cm ³ PP: polypropylene, XF1810 (Chisso Corporation)
MFR (230 ° C.) = 1.8 g / 10 min, density =
0.90 g / cm ³ PP copolymer (X): NHF5014 (Chisso Corporation)
_{Ltd.), W E / W F =} 3.95, intrinsic viscosity [η] _WHOLE =
2.1 dl / g, intrinsic viscosity ratio [η] _F / [η] _E = 1.
_{0, ([η] F /} [η] E) × (W E / W F) = 3.95,
MFR (230 ° C.) = 2.2 g / 10 minutes

The resin and hydrotalcite (weight% in the table) of each of the multilayer films shown in Tables 1 and 2 were used.
Is a numerical value based on the formulation. )) Is 0.5% by weight of hindered amine-based weathering agent and 0.05% of ultraviolet absorber in the outer layer A on the basis of the composition.
Wt%, phenol stabilizer 0.1 wt%, phosphorus stabilizer 0.1 wt%, antiblocking agent 0.05 wt%
In the middle layer B, 1.8% by weight of an antifogging agent, 0.5% by weight of a hindered amine-based weathering agent, 0.05% by weight of an ultraviolet absorber, 0.2% by weight of a fluorine-based surfactant, and 0% of a phenol-based stabilizer 0.1% by weight, phosphorus-based stabilizer 0.1% by weight, hindered amine-based weathering agent 0.5% by weight, ultraviolet absorber 0.05% by weight, fluorine-based surfactant 0.2% by weight in inner layer C Phenol-based stabilizer 0.1% by weight, phosphorus-based stabilizer 0.1% by weight, antiblocking agent 0.0
5%.

[0055]

[Table 1]

[0056]

[Table 2]

[0057]

The multilayer film for agricultural use of the present invention is excellent in toughness and transparency, so that it is not easily broken by wind or the like when used as a covering material for a house or a tunnel.
In addition, if an inorganic filler is used, the heat retention of the film is improved without impairing toughness and transparency, so that the growth of the cultivated crop is good even at a low temperature.

Continuing from the front page (72) Inventor Koichi Fukuda 5-1, Goi Kaigan, Ichihara-shi, Chiba F-term (reference) in the Processed Products Development Laboratory of Petrochemical Co., Ltd. 2B024 DA07 DB07 DB07 2B029 EB03 EC02 EC09 EC18 EC19 EC20 RA03 4F100 AA01A AA01C AK03A AK03C AK04A AK04C AK06A AK06C AK62A AK62C AK63A AK63C AK66B AK68A DK68C AL05A AL05B AL05C BA03 BA06 BA10A BA10C CA23A CA23C GB01 JA06B JA13A JJ02 YK00B01 JJ02 YK00B 001

Claims (4)

[Claims] An agricultural multilayer film comprising at least an inner layer A, an intermediate layer B and an outer layer C, wherein the inner layer A and the outer layer C are composed of a blend of a polyolefin resin, and the intermediate layer B has a propylene content. Is 90% by weight or more and a propylene-α-olefin random copolymer (E) having a propylene content of 55% to 90% by weight.
the propylene-α-olefin random copolymer (F) has an intrinsic viscosity [η] _F of 1.3 to 3.5 dl / g, and is composed of an α-olefin random copolymer (F). copolymer (E) an intrinsic viscosity ratio of the intrinsic viscosity [eta] when the _E of _{[η] F / [η]} E is 0.5 to 1.3, and propylene -α- olefin copolymer The weight of (E) is defined as W _E, and propylene-α-
When olefin copolymer weight (F) was W _F, these weight ratios W _E / W _F and the intrinsic viscosity ratio [η] _F / [η] product of _{E ([η] F / [} η] _{E) × (W E / W} F) is 1.0
Propylene copolymer composition (X) in the range of 4.5
Agricultural multi-layer film composed of the following compound. 2. The polyolefin resin used for the inner layer A and the outer layer C is a low-density polyethylene having a density of 0.88 to 0.92 g / cm ^3, a linear low-density polyethylene, and a density of 0.
94-0.97 g / cm ³ of high-density polyethylene, ethylene-vinyl acetate copolymer, and ethylene-α-olefin copolymer having a density of 0.88-0.92 g / cm ³ polymerized using a single-site catalyst The agricultural multilayer film according to claim 1, which is one or a mixture of two or more members selected from the group consisting of coalescence. 3. The multilayer film has a tensile strength in a longitudinal (MD) direction and a transverse (TD) direction of 30 N / mm ² or more, respectively, and an Elmendorf tear strength in a longitudinal (MD) direction and a transverse (TD) direction. Is 100 N / mm or more, and the vertical (M
The Elmendorf tear strength ratio (longitudinal / horizontal) in the D) direction and the transverse (TD) direction is 1.5 to 0.6.
The multilayer film for agricultural use according to the above. 4. A composition for forming the inner layer A and the outer layer C, wherein B
An inorganic filler having an ET specific surface area of 5 to 50 m ² / g
The agricultural multilayer film according to any one of claims 1 to 3, wherein the inorganic filler is contained in an amount of 10 to 20% by weight, and the composition constituting the intermediate layer B contains 1 to 20% by weight of the inorganic filler.