JP2002360081A - Agricultural coating film - Google Patents

Abstract

(57) [Abstract] [Problem] It is excellent in toughness and easily adapts to the shape of the drainage groove of the water supply bed, that is, it has excellent adaptability, there is no occurrence of wrinkles at the time of spreading, and there is no fusion of films. To provide an agricultural covering film having excellent molding stability and less moss generation. A melt flow rate polymerized using a single-site catalyst has a density of 0.3 to 5.0 and a density of 0.85.
A layer in which a white pigment is blended with 5 to 50% by weight of an ethylene / α-olefin copolymer of 0 to 0.910 g / cc, and a melt flow rate polymerized using a single-site catalyst of 0.3 to 0.3%; 5.0 and density 0.850-0.
A layer formed by mixing 1 to 20% by weight of a black pigment with an ethylene / α-olefin copolymer of 910 g / cc is laminated so as to form a white layer 10, a black layer 11, and a white to light black layer 12, respectively. A coated film for agriculture characterized by comprising:

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an agricultural covering film, and more particularly, to an agricultural covering film which improves the fusing and unwinding properties of films, which has been a problem at high temperatures.

[0002]

2. Description of the Related Art With the rapid development of economic growth, the outflow of agricultural population to other industries and the aging of agricultural workers, cultivation that can save labor and automate cultivation management has attracted attention.
For example, the present situation is that an automatic irrigation system is being introduced even for irrigation that requires a large amount of labor.

Then, a garden pot or the like is placed on the water supply bed,
The bottom water supply system for cultivation by supplying water to the water supply bed is also recognized for its practicality in large-scale production and labor-saving production, and there is no inconvenience that the soil is gradually hardened by watering from above the crop. This has the advantage of avoiding various problems such as cultivation soil scattered on the leaf surface of the crop and becoming dirty and lowering the commercial value, and the quality of cultivated plants produced thereby has been recognized in the market, It is becoming popular.

In this bottom water supply system, for example, as shown in FIGS. 2 and 3, a garden pot 2 is placed on a tray-shaped water supply bed 1, and water is supplied to a water level at which the bottom of the garden pot 2 is submerged. Cultivation. On the upper surface of the water supply bed 1, the stagnant water after the end of the water supply is drained smoothly, and the bottom of the garden pot 2 is exposed to the air and dried to prevent the occurrence of diseases such as root rot due to the stagnant water at the root. So that
A drain groove 3 is formed.

The water supply bed 1 is generally made of a synthetic resin, especially a foamed synthetic resin, in a block shape in order to make it lightweight and inexpensive, and a plurality of blocks of the water supply bed 1 are formed according to the number of garden pots 2 to be cultivated. The water supply bed 1 to which a plurality of blocks have been joined is provided with a synthetic resin film 4 in order to secure the water stopping performance of the joints and the like. Laying and water bed 1
To cover the surface.

[0006] Such a coating film has toughness capable of resisting rubbing caused by the bottom of a garden pot, weather resistance that does not decrease in strength even when exposed to the ultraviolet rays of sunlight, and reflection of sunlight to form a water supply bed. Various performances such as prevention of temperature rise are required.

In order to satisfy these requirements, conventionally,
A film (hereinafter, referred to as a conventional film) is used in which a high-strength synthetic resin such as polyethylene is used as a base resin and an additive such as a weather-resistant stabilizer is added to the base resin.

[0008] The film 4 must be laid along the surface shape of the water supply bed 1. In particular, in order to improve the drainage of stagnant water after the end of water supply, the film 4 is laid so as to adhere to the drain groove 3. Although it is necessary to use a conventional film, although the film strength is high, it is hard and hard to stretch, so it is difficult to adjust to the shape of the drainage groove of the water supply bed, and since there are many wrinkles at the time of expansion, smooth drainage is hindered, and water supply There was a drawback that the drainage of stagnant water after completion was inferior.

In order to solve such a drawback, the present inventor has focused on an ethylene / α-olefin copolymer polymerized using a single-site catalyst having high flexibility in order to make it easy to adjust to the shape of the drainage groove of the water supply bed. However, it is difficult to form into a film and lacks molding stability, and even if it can be formed into a film, it is difficult to secure toughness against rubbing by the bottom of a garden pot or the like as it is. Was.

A film using linear low-density polyethylene (LLDPE), which is excellent in molding stability, was also studied. However, it was difficult to conform to the shape of the drainage groove of the water supply bed, and the conformability was poor, and wrinkles occurred during spreading. However, there was a problem that the toughness was not sufficient.

Furthermore, in addition to the above-mentioned problems, the film for covering a water supply bed has a problem of moss generation, and a film free of such a problem is desired.

Therefore, the inventor of the present invention has excellent toughness, excellent in conformability that is easily adapted to the shape of a drainage groove of a water supply bed, no wrinkles at the time of spreading, excellent in molding stability, and excellent in moss generation. No Agricultural Coated Film First
No. 0518.

[0013]

SUMMARY OF THE INVENTION However, Japanese Patent Application No.
The agricultural coating film described in No. 220518 is a two-layer black / white material having a low melting point. Therefore, when the black layer is exposed to the sun during storage or installation work, the temperature rises and a new problem to be solved arises. I knew there was.

Therefore, the present invention is excellent in toughness and easily conforms to the shape of a drainage groove of a water supply bed, that is, excellent in conformability, does not generate wrinkles at the time of expansion, and does not cause fusion between films. An object of the present invention is to provide an agricultural covering film having excellent molding stability and less moss generation.

[0015]

Means for Solving the Problems The present inventors have conducted intensive studies on a coating film for agricultural use which satisfies the above-mentioned problems, and as a result, by increasing the reflectance on the back side, the amount of heat applied to the film when exposed to sunlight. And found that a softening agent can be added at a high concentration to prevent blocking.

That is, according to the first aspect of the present invention, the melt flow rate polymerized using a single-site catalyst is reduced.
0.3-5.0 with density 0.850-0.910 g / c
c) an ethylene / α-olefin copolymer containing 5 to 50% by weight of a white pigment and a melt flow rate polymerized using a single-site catalyst of 0.3 to
A black pigment is added to an ethylene / α-olefin copolymer having a density of 5.0 and a density of 0.850 to 0.910 g / cc.
The layers containing 20% by weight are respectively white layer, black layer, white
An agricultural covering film characterized by being laminated so as to form a thin black layer.

According to the second aspect of the present invention, the white layer has a reflectance of 7
0% or more highly reflective layer, white to light black layer reflectivity 30%
The agricultural covering film according to claim 1, characterized in that:

According to a third aspect of the present invention, there is provided the agricultural coated film according to the first or second aspect, wherein the white layer and the white to light black layers contain 1 to 40% by weight of a softening agent. .

The invention according to claim 4 is characterized in that the melt flow rate polymerized using a single site catalyst is 0.3.
A white pigment is added to an ethylene / α-olefin copolymer having a density of 0.850 to 0.910 g / cc and a white pigment of 5 to 5.0.
A layer composed of 50% by weight is mixed with an ethylene / α-olefin having a melt flow rate of 0.3 to 5.0 and a density of 0.850 to 0.910 g / cc polymerized using a single-site catalyst. A layer in which a black pigment is mixed with a polymer in an amount of 1 to 20% by weight, and a melt flow rate polymerized using a single-site catalyst is 0.3 to 5.0 and a density is 0.850 to 0.910 g / cc. Ethylene / α-
A layer formed by mixing 0 to 50% of a white pigment and 0.5 to 10% of a silver pigment in an olefin copolymer is laminated to form a white layer, a black layer, and a white to silver layer, respectively. It is a coating film for agriculture characterized by the above.

According to a fifth aspect of the present invention, the white layer has a reflectance of 7
0% or more high reflection layer, white to silver layer 30% reflectance
The above is the agricultural covering film according to claim 4, characterized in that:

The invention according to claim 6 is the agricultural coated film according to claim 4 or 5, characterized in that the white layer and the white-silver layer contain 1 to 40% by weight of a softening agent. .

[0022]

Embodiments of the present invention will be described below.

The ethylene / α-olefin copolymer polymerized using the single-site catalyst used in the present invention (hereinafter referred to as the copolymer of the present invention) is disclosed in JP-A-58-19.
309, JP-A-59-95292, JP-A-60-35005, JP-A-60-35006, JP-A-60-35007, and JP-A-60-35
008, JP-A-60-35009, JP-A-60-130341, JP-A-3-163030, European Patent Application No. 4,204,436,
U.S. Pat. No. 5,055,438 and International Publication WO9
1/04257, etc., a single-site catalyst, particularly a metallocene / alumoxane catalyst, or
For example, using a metallocene compound as described in International Patent Publication WO92 / 01723 and a catalyst comprising a compound that reacts with the metallocene compound to form stable ions, ethylene as the main component and α as the subcomponent are used. -Obtained by copolymerizing with an olefin.

As the α-olefin used for copolymerization with ethylene, it is preferable to use an α-olefin having 4 to 12 carbon atoms from the viewpoint of productivity and physical properties. For example, an α-olefin having 4 to 12 carbon atoms is used. 1-butene, 1-pentene, 1-hexene, 1-octene, 1-heptene, 4-
Methylpentene-1,4-methylhexene-1,4,4
-Dimethylpentene-1 and the like. Further, those having 6 to 8 carbon atoms are more preferable.

It is preferable to copolymerize 2 to 60% by weight, preferably 5 to 50% by weight of these α-olefins and 40 to 98% by weight, preferably 50 to 95% by weight of ethylene.

Examples of the method for polymerizing ethylene and α-olefin include a gas phase method, a slurry method, a solution method, and a high pressure ionic polymerization method. Among these, a solution method and a high-pressure ion polymerization method are preferably used. The high pressure ionic polymerization method is described in JP-A-56-18607 and JP-A-58-22.
As described in the publications of US Pat.
00 kg / cm ² or more, preferably 300 to 2000 k
g / cm ² , the temperature is 125 ° C. or higher, preferably 130 to
This is a continuous method for producing an ethylene-based polymer, which is carried out under a reaction condition of 250 ° C, particularly 150 to 200 ° C.

As the copolymer of the present invention, the ethylene / α-olefin copolymer polymerized using the above-mentioned single-site catalyst can be used alone or in an appropriate combination of two or more.

The copolymer of the present invention has a density of 0.85
It is important to use a material having a low density of 0 to 0.910 g / cc. The preferred density is 0.860-0.90
It is in the range of 5 g / cc. If the density exceeds 0.910 g / cc, the conformability is poor, the problem of generation of wrinkles is not solved, and the toughness is insufficient.

The melt flow rate of the copolymer of the present invention (hereinafter abbreviated as “MFR” as necessary) is from 0.3 to 5.0.
It is. If the melt flow rate is lower than this range, the flexibility is poor, and if the melt flow rate is high, the molding stability is poor. Further, the MFR is more preferably 0.8 to 3.0.

The embodiment of the agricultural covering film of the present invention includes the two embodiments shown in FIGS. 1A and 1B, and the embodiment shown in FIG. Black layer 1
1, a layer structure composed of white to light black layer 12, and FIG.
The embodiment shown in Fig. 1 has a layer configuration including a white layer 10, a black layer 11, and a white to silver layer 13.

The white layer 10 is a layer comprising the copolymer of the present invention and a white pigment in an amount of 5 to 50% by weight. When the addition amount of the white pigment is less than 5% by weight, the molding stability is slightly inferior, and there is a problem that the temperature rises due to solar radiation.
If the amount exceeds 0% by weight, the molding stability is considerably deteriorated, the toughness is deteriorated, the film becomes harder, the drainage property deteriorates, and there is a problem that moss is generated. The amount of the white pigment added to the copolymer of the present invention is preferably in the range of 10 to 40% by weight.

As the white pigment, titanium dioxide (TiO 2)
₂ ) Zinc white (ZnO), calcium carbonate (CaCO ₃ ) or the like containing a part or all of them are used. Among them, TiO ₂ is preferably used from the viewpoint of improving coloring power, hiding power, heat resistance and weather resistance.

In the present invention, the reflectance of the white layer is 70%.
The above is preferable, and a so-called high reflection layer is preferable. The more preferred reflectance of the white layer is 80% or more.

The black layer 11 is a layer comprising the copolymer of the present invention and a black pigment in an amount of 1 to 20% by weight. When the addition amount of the black pigment is less than 1% by weight, light shielding is insufficient, and when it exceeds 20% by weight, there is a problem that molding stability is lacking. The preferred addition amount is in the range of 2 to 10% by weight.

In the present invention, as the black pigment, a pigment containing carbon black is preferably used.

In the embodiment shown in FIG. 1A, the white to light black layer 12 is a layer formed in white to light black by adjusting the blending amount of a white pigment or a black pigment to the copolymer of the present invention. Yes, more preferably a layer adjusted to have a reflectance of 30% or more.

In the embodiment shown in FIG. 1B, the white-silver layer 13 is formed by adding a white pigment to the above-mentioned copolymer of the present invention in an amount of 0 to 50.
% By weight, and 0.5 to 10% by weight of a silver pigment. Preferably, the layer is adjusted to have a reflectance of 30% or more. When a white to silver layer is used instead of the white to light black layer, there is an effect that radiant heat radiated from the film itself can be suppressed.

As the silver pigment, aluminum, silver,
A method in which a metal such as tin, nickel, and stainless steel is formed into a metal foil by a rolling method and finely pulverized, or a fine powder formed by an electrolytic production method or the like can be used. Above all, finely pulverized aluminum foil is industrially used in various fields, and can be preferably used in terms of productivity and practicality.

In the present invention, the reflectance is Hitachi U-321.
Measure the spectral reflectance with a 0-type spectrophotometer and measure the wavelength to 420 nm.
Can be measured by reading the reflectance.

The white pigment or black pigment can be added to the copolymer of the present invention by melt-kneading the copolymer of the present invention using a kneader or a twin-screw kneading extruder.

In the present invention, white layer 10, white to light black layer 1
2 and the amount of the softening agent blended in the white to silver layer 13 is 1 to
Preferably it is 40% by weight. If it is less than this range, the anti-fusing properties will be insufficient, and if it is too large, the characteristic of this film being soft will be lost.

As softening agents, silica, alumina,
Fine powder such as zeolite and the like can be mentioned.

In the white layer, the black layer, the white-thin black layer and the white-silver layer, a weather resistance stabilizer, an antioxidant, a lubricant, a bactericide, a fungicide and the like can be added as required. .
Examples of weather stabilizers include benzophenone-based, benzotriazole-based ultraviolet absorbers, hindered amine-based light stabilizers, and the like, and examples of antioxidants include hindered amine-based antioxidants, phosphorus-based antioxidants, and the like. Examples thereof include fatty acid amides, polyethylene waxes, metal soaps, and the like, and bactericides include zinc ion-substituted zeolites, silver ion-substituted zeolites, and copper ion-substituted zeolites. A safe thing such as a fungicide is used.

In the film according to the present invention, between the white layer and the black layer, or between the black layer and the white to light black layer,
As the intermediate layer, another layer such as a transparent layer or a silver layer may be interposed.

In the present invention, the white layer, the black layer and the white
The thickness of each layer of the light black layer or the white to silver layer is 3 to 100 μm.
Is preferably within the range.

The film according to the present invention can be formed by using a coextrusion inflation molding method or a coextrusion T-die molding method.

The film thus formed includes:
Processing such as surface treatment such as corona treatment can be performed as necessary.

The agricultural coating film of the present invention can be applied to general film coating, but a typical example is an embodiment in which the film is laid on a water supply bed in a bottom water supply system.

As a method of laying such a laminated film on a water supply bed in a bottom water supply system,
In a preferred embodiment, the white layer is laid on the upper surface side.

In this way, the white layer on the front side reflects the sunlight, lowers the film surface temperature, and blocks the sunlight with the black layer to prevent the temperature rise of the water supply bed and the generation of moss. By using a white to light black layer that reflects light, fusing can be prevented, and further, blocking during storage is prevented.

[0051]

The present invention will now be described by way of examples, which should not be construed as limiting the invention.

Example 1 Ethylene / α having a melt flow rate (MFR) of 2.0 and a density of 0.903 polymerized using a single-site catalyst
-Olefin copolymer (Kernel K, manufactured by Nippon Polychem Co., Ltd.)
F260) (hereinafter referred to as the copolymer of the present invention) and 20 wt% of a black pigment “MB” (manufactured by Tokyo Ink Co., containing 40% by weight of carbon black), and a white pigment added to the same copolymer of the present invention. "MB" (Tokyo Ink, TiO ₂
A raw material in which 50% by weight of the white pigment “MB” was blended in the same copolymer and a raw material in which the white pigment “MB” was blended in 20% by weight were prepared. 10% by weight of nepheline syenite (average particle size: 5μ) is blended, and each blended raw material is co-extruded with a three-layer co-extrusion inflation molding machine to form a three-layer structure of white layer / black layer / white layer. To obtain films having a thickness of 40 μ / 20 μ / 10 μ, respectively. The 10 μm white layer became a light black color due to the effect of the intermediate black layer.

Example 2 Ethylene / α having a melt flow rate (MFR) of 2.2 and a density of 0.880 polymerized using a single-site catalyst
-Olefin copolymer (Kernel K, manufactured by Nippon Polychem Co., Ltd.)
S240) A raw material obtained by blending 5% by weight of a black pigment “MB” (manufactured by Tokyo Ink Co., containing 40% by weight of carbon black) with (hereinafter referred to as the present invention copolymer) and a white pigment in the same present invention copolymer "MB" (Tokyo ink Co., Ltd., TiO ₂ 6
0% by weight) is prepared,
20 wt% of a softening agent (nepheline syenite: average particle size of 5 μm) is further blended with the raw material containing the white pigment MB, and each blended raw material is co-extruded and molded by a three-layer co-extrusion blow molding machine. Thus, a film having a three-layer structure of white layer / black layer / white layer and a thickness of 80 μ / 30 μ / 20 μ was obtained.

Example 3 Ethylene / α having a melt flow rate (MFR) of 2.2 and a density of 0.880 polymerized using a single-site catalyst
-Olefin copolymer (Kernel K, manufactured by Nippon Polychem Co., Ltd.)
S240) A raw material in which a black pigment “MB” (manufactured by Tokyo Ink Co., containing 40% by weight of carbon black) is mixed with 20% by weight of a black pigment “MB” (hereinafter referred to as the present invention copolymer), and a white pigment is added to the same copolymer of the present invention. "MB" (Tokyo Ink, TiO ₂
A raw material containing 40% by weight (containing 60% by weight) was prepared, and a softening agent (nepheline syenite: average particle size of 5μ) was further added to the raw material containing the white pigment MB in an amount of 20% by weight.
Each compounding material was co-extruded and molded by a three-layer co-extrusion inflation molding machine to obtain a film having a three-layer structure of white layer / black layer / white layer and a thickness of 25 μ / 5 μ / 5 μ, respectively. The 5 μm white layer became light black due to the effect of the black layer of the intermediate layer.

Example 4 The procedure of Example 2 was repeated, except that the white pigment in the white layer having a thickness of 20 μm in Example 2 was changed to a silver pigment (finely pulverized aluminum foil: average diameter 7 μm) and the weight was changed to 2% by weight. Thus, a three-layer film of white layer / black layer / silver layer was obtained.

Comparative Example 1 The same copolymer of the present invention as in Example 1 was coextruded by a three-layer co-extrusion blow molding machine alone without blending a coloring pigment to form a three-layer film. However, when the tube swelled out of the die, the tube was sagged, and could not be molded due to poor stability.

Comparative Example 2 LLDPE manufactured by Nippon Polychem (“Novatech LL UF
230 ", MFR 1.0, density 0.920), a white pigment and a black pigment were blended in the same blending amount as in Example 1 and co-extruded with a three-layer co-extrusion inflation molding machine, and molded.
A three-layer film consisting of a white layer, a black layer and a light black layer was obtained.

Comparative Example 3 Among the raw materials in Example 1, 20 black pigment "MB" (manufactured by Tokyo Ink Co., containing 40% by weight of carbon black) was used.
₂ % by weight of a raw material blended with 50% by weight of a raw material blended with 50% by weight of a raw material blended with white pigment “MB” (manufactured by Tokyo Ink Co., Ltd., containing 60% by weight of TiO ₂ ). It is co-extruded with an extrusion inflation molding machine and molded into a two-layer structure of white layer / black layer, each having a thickness of 40 μ / 20.
A film of μ was obtained.

Comparative Example 4 A three-layer film was obtained in the same manner as in Example 1 except that the amount of the white pigment was changed to 55% by weight.

Comparative Example 5 A three-layer film was obtained in the same manner as in Example 2 except that the amount of the white pigment was changed to 4% by weight.

Comparative Example 6 A three-layer film was obtained in the same manner as in Example 1, except that the black pigment in Example 1 was changed to 0.8% by weight.

Table 1 shows the composition of each film described above.

(Evaluation) Each of the films of the above Examples and Comparative Examples was spread on a 2 m × 15 m water supply bed and covered.
On the upper surface, 100 No. 3 pots planted with cyclamen were juxtaposed, cultivation was performed by water supply from the bottom surface, and the following items were evaluated. The toughness and the occurrence of moss were evaluated by visual observation one month after the cultivation.

Table 2 shows the results.

A three-layer film consisting of a white layer / black layer / white to light black (or white to silver) layer or a two-layer film consisting of white layer / black layer is stretched such that the white layer is on the upper surface side. did.

The molding state during the process of forming the molding stability film was visually observed and evaluated according to the following evaluation method. ◎: Very good ○: Good △: Somewhat bad ×: Moldable but bad

The fixed state of the film when a fixed temperature (50 ° C.) is applied to the fused film is visually evaluated. ◎: Not at all ○: Not present △: Slightly present ×: Pretty present

Familiarity The degree of familiarity when laid along the surface shape of the water supply bed was visually evaluated according to the following evaluation method. The better the conformability, the more flexible the film. ◎: very good ○: good △: slightly poor ×: bad

Generation of Wrinkles The degree of generation of wrinkles when spread on a water-supply bed was visually evaluated according to the following evaluation method. ◎: No wrinkles were generated at all ○: Wrinkles were hardly generated △: Some wrinkles were generated ×: Many wrinkles were generated

The degree of scratching due to the rubbing of the bottom surface of the tough bowl was visually evaluated according to the following evaluation method. ◎: No damage at all ○: Almost no damage △: Somewhat scratches ×: Many scratches

The occurrence of moss was evaluated by visual observation according to the following evaluation method. ◎: No moss generated ○: Little moss generated △: Some moss generated ×: Many moss generated

[0072]

[Table 1]

[0073]

[Table 2]

As is clear from Table 2, the film of Example 1 is excellent in stability and toughness during film formation, excellent in anti-fusing property, and wrinkles are generated even when it is spread on a water supply bed. Without having to do so, it was well adapted to the surface shape and could be laid along the drainage groove shape of the water supply bed. Further, the film according to the present invention could be used favorably without generation of moss.

[0075]

According to the present invention, the white layer on the front side reflects sunlight, lowers the film surface temperature, blocks the sunlight with the black layer to prevent the formation of moss, and the white layer on the front side reflects the sunlight. To reduce the surface temperature of the film, block the sunlight with a black layer to prevent the formation of moss, and use a white-light black layer or a white-silver layer that reflects light on the back side to prevent fusing. Can be prevented, and blocking during storage can be prevented.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a layer configuration example of a film of the present invention.

FIG. 2 is an explanatory view showing a bottom water supply system.

FIG. 3 is a partial sectional view of a water supply bed.

[Explanation of symbols]

 1: water supply bed 2: garden pot 3: drain ditch 4: film 10: white layer 11: black layer 12: white to light ink layer 13: white to silver layer

Continuation of the front page (51) Int.Cl. ⁷ Identification code FI Theme coat II (reference) C08F 210/16 C08F 210/16 (72) Inventor Kazuyo Inaba 1-4, 2298 Junwell Chojahara, Ichihara-shi, Chiba Pref. In-house F-term (reference) 2B024 DA01 DA02 DB01 2B029 EB03 EC02 EC09 EC12 EC20 KB01 LA01 RA03 4F100 AC06A AK62A AK62B BA02 BA08 BA16 BA26 BA27 CA13A CA13B GB01 JA06A JA06B JA13A JA13B JK01 JL08A JL08BJA AJJBJA04 AA17Q AA19Q DA13 DA43 DA61 DA64 FA10 JA64

Claims (6)

[Claims] 1. A polymer having a melt flow rate of 0.3 to 5.0 and a density of 0.850 by polymerization using a single-site catalyst.
A layer in which a white pigment is blended with 5 to 50% by weight of an ethylene / α-olefin copolymer having a melt flow rate of 0.3 to 5; 0.0 and density 0.850-0.
A layer in which a black pigment is blended in an amount of 1 to 20% by weight with an ethylene / α-olefin copolymer of 910 g / cc, and a white layer, a black layer, and a white to light black layer are laminated. An agricultural coated film characterized by the following. 2. The agricultural covering film according to claim 1, wherein the white layer is a highly reflective layer having a reflectance of 70% or more, and the white to light black layers have a reflectance of 30% or more. 3. A softening agent is added to the white layer and the white to light black layer.
The agricultural covering film according to claim 1 or 2, which contains 40% by weight. 4. A polymer having a melt flow rate of 0.3 to 5.0 and a density of 0.850 obtained by polymerization using a single-site catalyst.
A layer in which a white pigment is blended with 5 to 50% by weight of an ethylene / α-olefin copolymer having a melt flow rate of 0.3 to 5; 0.0 and density 0.850-0.
A layer in which a black pigment is blended in an amount of 1 to 20% by weight with an ethylene / α-olefin copolymer of 910 g / cc, and a melt flow rate polymerized using a single site catalyst of 0.3 to 5.0. 0.850 ~ 0.910g density
/ Cc of an ethylene / α-olefin copolymer containing 0 to 50% of a white pigment and 0.5 to 10% of a silver pigment are respectively a white layer, a black layer, and a white to silver layer. An agricultural covering film characterized by being laminated in such a manner that: 5. The agricultural covering film according to claim 4, wherein the white layer is a highly reflective layer having a reflectance of 70% or more, and the white-silver layer has a reflectance of 30% or more. 6. A softening agent is added to the white layer and the white-silver layer in the form of a softener.
The agricultural covering film according to claim 4 or 5, which contains 40% by weight.