JP4694041B2 - Agricultural coating film - Google Patents

Description

【００７３】
【表２】

【００７４】
表２から明らかなように、実施例１のフィルムは、フィルム成形時の安定性、強靭性に優れ、融着防止性に優れ、また給水ベッド上に展張した際にも皺が発生することなく、その表面形状によく馴染み、給水ベッドの排水溝形状に添って敷設することができるものであった。また、本発明に係るフィルムは、苔の発生もなく良好に使用できるものであった。
【００７５】
【発明の効果】
本発明によれば、表側の白色層が太陽光を反射させ、フィルム表面温度を下げ、黒色層で太陽光を遮断させ苔の発生を防止し、表側の白色層が太陽光を反射させ、フィルム表面温度を下げ、黒色層で太陽光を遮断させ苔の発生を防止し、また、裏側に光を反射する白〜薄墨色層、白〜銀色層を用いることにより、融着を防止することができ、更に、保管時のブロッキングを防止する。
【図面の簡単な説明】
【図１】本発明のフィルムの層構成例を示す断面図
【図２】底面給水システムを示す説明図
【図３】給水ベッドの部分断面図
【符号の説明】
１：給水ベッド
２：園芸鉢
３：排水溝
４：フィルム
１０：白色層
１１：黒色層
１２：白〜薄墨色層
１３：白〜銀色層[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an agricultural coating film, and more particularly to an agricultural coating film that improves film-to-film fusion and unwinding properties, which have been problematic at high temperatures.
[0002]
[Prior art]
Due to the rapid development of economic growth and the outflow of agricultural population to other industries and the aging of farmers, cultivation that can save labor and automate cultivation management has attracted attention. An automatic irrigation system is being introduced for irrigation.
[0003]
A bottom-side water supply system in which a garden pot or the like is placed on a water supply bed and water is supplied to the water supply bed for cultivation is recognized for its practical use in large-scale production and labor-saving production, and water is sprayed from above the crop. By doing so, there is no inconvenience that the soil will gradually harden, and there are advantages such as avoiding various problems such as the soil being sprinkled on the leaves of the crops due to watering and soiling, thereby reducing the value of the product. Quality has gained recognition in the market and has become rapidly popular in recent years.
[0004]
For example, as shown in FIGS. 2 and 3, the bottom surface water supply system places a garden pot 2 on a tray-shaped water supply bed 1, and cultivates by supplying water up to a water level at which the bottom surface of the garden pot 2 is submerged. Is. On the upper surface of the water supply bed 1, the stagnant water after the end of the water supply is smoothly drained, and the bottom surface 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. In order to do so, drainage grooves 3 are formed.
[0005]
The water supply bed 1 is generally formed in a block shape from a synthetic resin, in particular, a foamed synthetic resin, in order to manufacture the water supply bed 1 at a light weight and at a low cost. The blocks of the plurality of water supply beds 1 are appropriately joined according to the number of garden pots 2 to be cultivated. The water supply bed 1 in which a plurality of blocks are joined in this way is provided with a synthetic resin film 4 in order to ensure the water-stopping performance of the joined portion and the like. The surface of the water supply bed 1 is covered.
[0006]
Such a coating film has toughness that can resist rubbing by the bottom of a garden pot, etc., weather resistance that does not decrease even when exposed to sunlight ultraviolet rays, and temperature rise of the water supply bed by reflecting sunlight. Various performances such as prevention are required.
[0007]
In order to satisfy these requirements, conventionally, a film (hereinafter referred to as a conventional film) in which a synthetic resin having a high strength such as polyethylene is used as a base resin and an additive such as a weather resistance stabilizer is added thereto is used. Yes.
[0008]
The film 4 needs to be laid along the surface shape of the water supply bed 1, and in particular, it should be laid so as to faithfully follow the drainage groove 3 in order to improve the drainage of stagnant water after the completion of water supply. However, with conventional films, although the film strength is high, it is hard and difficult to stretch, so it is difficult to adjust to the shape of the drainage groove of the water supply bed, and there are also many wrinkles at the time of expansion, so smooth drainage is hindered and after the water supply ends There was the fault that the drainage of stagnant water was inferior.
[0009]
In order to solve such a drawback, the present inventor paid attention to an ethylene / α-olefin copolymer polymerized using a flexible single-site catalyst in order to easily adapt to the shape of the drain groove of the water supply bed. It was difficult to form into a film and lacked molding stability, and even if it could be formed into a film, it was difficult to ensure toughness against rubbing due to the bottom of the garden pot or the like.
[0010]
We also examined a film using linear low-density polyethylene (LLDPE), which has excellent molding stability, but it is difficult to adapt to the shape of the drainage groove of the water supply bed, and it is inferior to familiarity. There was a problem that the toughness was not sufficient.
[0011]
Further, the water supply bed covering film has a problem of moss generation in addition to the above-described problems, and a film without such problems is desired.
[0012]
Therefore, the present inventor has excellent toughness, is easy to adjust to the shape of the drainage groove of the water supply bed, etc., is free of wrinkles at the time of spreading, has excellent molding stability, and has no moss generation The coating film was previously proposed as Japanese Patent Application No. 11-220518.
[0013]
[Problems to be solved by the invention]
However, since the agricultural coating film described in Japanese Patent Application No. 11-220518 is a low-melting-point material with two layers of white / black, when the black layer is exposed to the sun during storage or installation work, the temperature rises and is fused. It turns out that there are new issues to be solved.
[0014]
Therefore, the present invention is excellent in toughness, easy to adapt to the shape of the drainage groove of the water supply bed, etc., i.e., excellent adaptability, no generation of wrinkles during stretching, and no fusion between films, molding stability An object of the present invention is to provide a coating film for agriculture that is excellent in moss and has little moss generation.
[0015]
[Means for Solving the Problems]
As a result of intensive studies on the agricultural coating film that satisfies the above-mentioned problems, the present inventor has found that the amount of heat applied to the film when exposed to sunlight can be reduced by increasing the reflectance on the back side. It has been found that blocking agent can be prevented by adding a high concentration of the agent.
[0016]
That is, the invention according to claim 1 is 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 white layer formed by blending 5 to 50% by weight of a white pigment with a copolymer, a melt flow rate of 0.3 to 5.0 and a density of 0.850 to 0.910 g polymerized using a single site catalyst A black layer formed by blending 1 to 20% by weight of a black pigment with an ethylene / α-olefin copolymer of / cc, and a melt flow rate polymerized using a single site catalyst is 0.3 to 5.0 A white to light ink color layer formed in white to light ink color by adjusting the blending amount of a white pigment or a black pigment in an ethylene / α-olefin copolymer having a density of 0.850 to 0.910 g / cc , the white layer and the black color layer and the white to color Usuzumi That formed by the laminated in this order is agricultural covering film characterized.
[0017]
According to a second aspect of the invention, the white color layer is highly reflective layer of 70% or more reflectivity, agricultural of claim 1, wherein the white-Usuzumi color layer is the reflectance of 30% or more It is a coating film.
[0018]
According to a third aspect of the invention, the white color layer and the white-Usuzumi color layer, an agricultural covering film according to claim 1 or 2, wherein the containing softening agent 40 wt%.
[0019]
The invention according to claim 4 is an ethylene / α-olefin copolymer 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 white layer formed by blending 5 to 50% by weight of a white pigment into the coalescence, 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. A black layer obtained by blending 1 to 20% by weight of a black pigment with an ethylene / α-olefin copolymer, a melt flow rate polymerized using a single site catalyst is 0.3 to 5.0, and a density is A white to silver layer formed by blending 0 to 50% of a white pigment and 0.5 to 10% of a silver pigment in an ethylene / α-olefin copolymer of 0.850 to 0.910 g / cc is a white layer. product in the order of, black color layer and the white to silver layer An agricultural covering film, characterized by comprising a.
[0020]
The invention according to claim 5, white color layer is highly reflective layer of 70% or more reflectivity, white to silver layers agricultural covering according to claim 4, characterized in that the reflectance of 30% or more It is a film.
[0021]
The invention according to claim 6, white color layer and the white-silver layer, an agricultural covering film according to claim 4 or 5, wherein the containing softening agent 40 wt%.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below.
[0023]
An ethylene / α-olefin copolymer (hereinafter referred to as a copolymer of the present invention) polymerized using a single site catalyst used in the present invention is disclosed in JP-A-58-19309 and JP-A-59-95292. JP, 60-35005, JP 60-35006, JP 60-35007, JP 60-35008, JP 60-35209, JP Single site described in Japanese Patent Application Laid-Open No. 60-130341, Japanese Patent Application Laid-Open No. 3-163088, European Patent Application Publication No. 4,204,436, US Patent No. 5,055,438, International Publication No. WO 91/04257, etc. A catalyst, in particular a metallocene / alumoxane catalyst, or a metallocene compound as described, for example, in WO 92/01723 Obtained by copolymerizing a main component of ethylene and minor component α- olefins using a catalyst comprising a compound which reacts with the metallocene compound a stable ion.
[0024]
The α-olefin used for copolymerization with ethylene is preferably an α-olefin having 4 to 12 carbon atoms from the viewpoint of productivity and physical properties, for example, 1-butene having 4 to 12 carbon atoms. 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 preferred.
[0025]
It is preferable to copolymerize 2 to 60% by weight of these α-olefins, preferably 5 to 50% by weight, and 40 to 98% by weight of ethylene, preferably 50 to 95% by weight.
[0026]
Examples of the polymerization method of ethylene and α-olefin include a gas phase method, a slurry method, a solution method, and a high pressure ion polymerization method. Among these, the solution method and the high pressure ion polymerization method are preferably used. As described in JP-A-56-18607 and JP-A-58-225106, the high-pressure ion polymerization method is a pressure of 200 kg / cm ² or more, preferably 300 to 2000 kg / cm ² , This is a continuous process for producing an ethylene polymer carried out under reaction conditions of a temperature of 125 ° C. or higher, preferably 130 to 250 ° C., particularly 150 to 200 ° C.
[0027]
As the copolymer of the present invention, ethylene / α-olefin copolymers polymerized using the above-mentioned single site catalyst can be used alone or in appropriate combination of two or more.
[0028]
As the copolymer of the present invention, it is important to use a low-density one having a density of 0.850 to 0.910 g / cc. A preferred density is in the range of 0.860-0.905 g / cc. When the density exceeds 0.910 g / cc, the familiarity is inferior, the problem of wrinkles is not solved, and the toughness is insufficient.
[0029]
The melt flow rate (hereinafter abbreviated as “MFR” if necessary) of the copolymer of the present invention is 0.3 to 5.0. When the melt flow rate is lower than this range, the flexibility is inferior, and when it is higher, the molding stability is inferior. Further, the MFR is more preferably 0.8 to 3.0.
[0030]
The embodiment of the agricultural coating film of the present invention includes two embodiments shown in FIGS. 1A and 1B, and the embodiment shown in FIG. 1A includes the white layer 10 and the black layer 11 from the upper layer. a layer structure consisting of white to Usuzumi color layer 12, the embodiment shown in FIG. 1 (B) is a white layer 10, black layer 11 is a layer structure consisting of white to silver layer 13.
[0031]
The white layer 10 is a layer formed by blending 5 to 50% by weight of a white pigment with the above-described copolymer of the present invention. When the amount of the white pigment added is less than 5% by weight, the molding stability is slightly inferior, and there is a problem of temperature rise due to solar radiation. When it exceeds 50% by weight, the molding stability is considerably inferior and the toughness is low. Inferior, the film becomes harder and drainage becomes worse, and there is a problem of moss formation. The amount of white pigment added to the copolymer of the present invention is preferably in the range of 10 to 40% by weight.
[0032]
As the white pigment, those containing part or all of titanium dioxide (TiO ₂ ), zinc white (ZnO), calcium carbonate (CaCO ₃ ) and the like are used. Among these, TiO ₂ is preferably used from the viewpoint of improving coloring power, hiding power, heat resistance, and weather resistance.
[0033]
In the present invention, the reflectance of the white layer is preferably 70% or more, and is preferably a so-called highly reflective layer. A more preferable reflectance of the white layer is 80% or more.
[0034]
The black layer 11 is a layer formed by adding 1 to 20% by weight of a black pigment to the above-described copolymer of the present invention. When the added 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 insufficient. A preferable addition amount is in the range of 2 to 10% by weight.
[0035]
In the present invention, as the black pigment, a pigment containing carbon black is preferably used.
[0036]
In the embodiment shown in FIG. 1 (A), white to Usuzumi color layer 12 may be a layer formed by adjusting the amount of the white pigment and a black pigment to the present invention copolymer of the white-Usuzumi color More preferably, it is a layer adjusted to reflectivity of 30% or more.
[0037]
In the embodiment shown in FIG. 1B, the white to silver layer 13 is a layer formed by blending 0 to 50% by weight of white pigment and 0.5 to 10% by weight of silver pigment in the copolymer of the present invention. It is. Preferably, it is a layer adjusted to reflectivity of 30% or more. If a white to silver color layer is used instead of the white to light ink color layer, the radiant heat radiated from the film itself can be suppressed.
[0038]
As the silver pigment, it is possible to use a powder made of a metal such as aluminum, silver, tin, nickel, stainless steel or the like by pulverizing into a metal foil by a rolling method, an electrolytic manufacturing method, or the like. Of these, finely pulverized aluminum foil is industrially used in various fields, and can be preferably used from the viewpoint of productivity and practicality.
[0039]
The reflectance in the present invention can be measured by measuring the spectral reflectance with a Hitachi U-3210 spectrophotometer and reading the reflectance at a wavelength of 420 nm.
[0040]
In order to add a white pigment or a black pigment to the copolymer of the present invention, it can be added by melt-kneading the copolymer of the present invention using a kneader, a twin-screw kneading extruder or the like.
[0041]
In the present invention, the white color layer 10, softening agent amount to be blended in white to Usuzumi color layer 12 and the white-silver layer 13 is preferably 1 to 40 wt%. If it is less than this range, the anti-fusing property will be insufficient, and if it is more, the characteristic that this film is soft will be lost.
[0042]
Examples of the softening agent include fine powders such as silica, alumina, and zeolite.
[0043]
In the white layer, black layer, white to light ink color layer, and white to silver color layer, a weather resistance stabilizer, an antioxidant, a lubricant, a disinfectant, an antifungal agent and the like can be appropriately added as necessary. Examples of weathering stabilizers include benzophenone-based, benzotriazole-based ultraviolet absorbers, hindered amine-based light stabilizers, etc., and examples of antioxidants include hindered amine-based antioxidants, phosphorus-based antioxidants, etc. Fatty acid amides, polyethylene waxes, metal soaps, and the like. Examples of bactericides include zinc ion-substituted zeolite, silver ion-substituted zeolite, copper ion-substituted zeolite, and antifungal agents include benzimidazole-based antibacterial agents. Safe molds are used.
[0044]
In the film according to the present invention, another layer such as a transparent layer or a silver layer may be interposed as an intermediate layer between the white layer and the black layer, or between the black layer and the white to light ink color layer. .
[0045]
In the present invention, a white layer, the thickness of each layer of the black layer and white to Usuzumi color layer or white to silver layers is preferably in the range of 3～100Myu.
[0046]
The film according to the present invention can be formed by using a coextrusion inflation molding method or a coextrusion T-die molding method.
[0047]
The film thus formed can be subjected to processing such as surface treatment such as corona treatment as necessary.
[0048]
Although the agricultural covering film of the present invention can be applied to film covering in general, a typical aspect is an aspect in which the agricultural covering film is used by being laid on a water supply bed in a bottom surface water supply system.
[0049]
As a method of laying and using such a laminated film on a water supply bed in a bottom surface water supply system, it is preferable to lay the white film on the upper surface side.
[0050]
In this way, to reflect sunlight front white color layer, lower the film surface temperature was blocked sunlight in black color layer to prevent temperature increase and moss water bed, also on the back side By using a white to light ink color layer that reflects light, fusion can be prevented, and further blocking during storage can be prevented.
[0051]
【Example】
Examples of the present invention will be described below, but the present invention is not limited to such examples.
[0052]
Example 1
A melt flow rate (MFR) of 2.0 and a density of 0.903 ethylene / α-olefin copolymer (kernel KF260 manufactured by Nippon Polychem Co., Ltd.) (hereinafter referred to as the present invention copolymer) polymerized using a single site catalyst. And a black pigment “MB” (manufactured by Tokyo Ink Co., Ltd., containing 40% by weight of carbon black) and 20 wt% of the raw material, and the same copolymer of the present invention with the white pigment “MB” (manufactured by Tokyo Ink Co., TiO ₂ 60). A raw material containing 50% by weight), a raw material containing 20% by weight of the white pigment “MB” in the same copolymer, and a softener (霞) stone syenite average particle size: 5 [mu]) were compounded 10% by weight, by shaping coextruding each mixed material to a three-layer co-extrusion inflation molding machine, the white color layer / black color layer / white color layer 3 Thickness with layer structure A film having a thickness of 40 μ / 20 μ / 10 μ was obtained. White layer of 10μ became Usuzumi color under the influence of the black color layer of the intermediate layer.
[0053]
Example 2
Melt flow rate (MFR) 2.2 and density 0.880 ethylene / α-olefin copolymer (kernel KS240 manufactured by Nippon Polychem Co., Ltd.) (hereinafter referred to as the present invention copolymer) polymerized using a single site catalyst And a black pigment “MB” (manufactured by Tokyo Ink Co., Ltd., containing 40% by weight of carbon black) and the same copolymer of the present invention as a raw material containing 5% by weight of white pigment “MB” (manufactured by Tokyo Ink Co., Ltd., TiO ₂ 60). Material containing 25% by weight), and a material containing white pigment MB is further blended with 20% by weight of a softening agent (nepheline feldspar: average particle size 5μ). mixed material was molded coextruded three layer co-extrusion inflation molding machine to give a film thickness of a three-layer structure comprising a white color layer / black color layer / white color layer is respectively 80 [mu] / 30.mu. / 20 [mu] .
[0054]
Example 3
Melt flow rate (MFR) 2.2 and density 0.880 ethylene / α-olefin copolymer (kernel KS240 manufactured by Nippon Polychem Co., Ltd.) (hereinafter referred to as the present invention copolymer) polymerized using a single site catalyst And a black pigment “MB” (manufactured by Tokyo Ink Co., Ltd., containing 40% by weight of carbon black) and 20 wt% of the raw material, and the same copolymer of the present invention with the white pigment “MB” (manufactured by Tokyo Ink Co., TiO ₂ 60). Material containing 40% by weight), and a material containing white pigment MB is further blended with 20% by weight of a softening agent (nepheline feldspar: average particle size 5μ). mixed material was molded coextruded three layer co-extrusion inflation molding machine to give a film thickness of a three-layer structure comprising a white color layer / black color layer / white color layer is respectively 25.mu. / 5 [mu] / 5 [mu] . White layer of 5μ became Usuzumi color under the influence of the black color layer of the intermediate layer.
[0055]
Example 4
EXAMPLE white pigment silver pigment white color layer having a thickness of 20μ in 2: Change to (aluminum foil pulverized average diameter 7 microns), 2% by weight with other than the in the same manner as in Example 2 White color layer / to obtain a three-layer film of black color layer / silver layer.
[0056]
Comparative Example 1
The same copolymer of the present invention as in Example 1 was co-extruded by itself with a three-layer coextrusion inflation molding machine without blending a color pigment, but it was tried to form a three-layer film. When the tube swelled, the tube dropped, and the stability was poor, making it impossible to mold.
[0057]
Comparative Example 2
Nippon Polychem LLDPE ("Novatech LL UF230", MFR1.0, density 0.920) was blended with white pigment and black pigment in the same blending amounts as in Example 1 and coextruded with a three-layer coextrusion inflation molding machine. Thus, a three-layer film composed of a white layer, a black layer, and a light black color layer was obtained.
[0058]
Comparative Example 3
Among the raw materials in Example 1, a raw material containing 20% by weight of black pigment “MB” (manufactured by Tokyo Ink Co., Ltd., containing 40% by weight of carbon black) and white pigment “MB” (manufactured by Tokyo Ink Co., Ltd., 60% by weight of TiO ₂ ). % content) using two ingredients were blended 50% by weight, likewise blended with softening agent molded by coextrusion of two layers co-extrusion inflation molding machine, the white color layer / black color layer 2 Films having a layer structure and a thickness of 40 μ / 20 μm were obtained.
[0059]
Comparative Example 4
A three-layer film was obtained in the same manner as in Example 1 except that the white pigment in Example 1 was changed to 55% by weight.
[0060]
Comparative Example 5
A three-layer film was obtained in the same manner as in Example 2 except that the white pigment in Example 2 was changed to 4% by weight.
[0061]
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.
[0062]
The above film compositions are shown in Table 1.
[0063]
(Evaluation)
Each film of the above examples and comparative examples is spread and covered on a 2 m × 15 m water supply bed, and 100 pieces of No. 3 pots planted with cyclamen are juxtaposed on the top surface to carry out cultivation by water supply from the bottom. The following items were evaluated. The toughness and moss generation were evaluated by visual observation after one month of cultivation.
[0064]
The results are shown in Table 2.
[0065]
The two-layer film consisting of the white color layer / black color layer / white to Usuzumi color (or white to silver) three layers consisting of layer film or white color layer / black color layer, so that the white color layer becomes the upper surface It was extended.
[0066]
Molding stability The molding state in the process of molding the film was visually observed and evaluated according to the following evaluation methods.
◎: Very good ○: Good △: Slightly poor ×: Moldable but defective [0067]
Fusing property The state of fixation of the film is visually evaluated when a certain temperature (50C) is applied to the folded film.
◎: None at all ○: None △: Slightly present ×: Remarkable [0068]
Familiarity Familiarity when laid along the surface shape of the water supply bed was visually evaluated according to the following evaluation method. The better the familiarity, the more flexible the film.
◎: Very good ○: Good △: Somewhat bad ×: Bad
Generation of wrinkles The occurrence of wrinkles when spread on a water supply bed was visually evaluated according to the following evaluation method.
◎: No soot is generated. ○: Almost no soot is generated. Δ: Some soot is generated.
Toughness The degree of scratching due to rubbing of the bottom surface of the bowl was visually evaluated according to the following evaluation method.
◎: No damage at all ○: Almost no damage △: Slightly scratched ×: Many scratches [0071]
Occurrence of moss The occurrence of moss on the water supply bed under film coating was evaluated by visual observation according to the following evaluation method.
◎: Moss is not generated at all ○: Moss is generated less △: Moss is generated a little more ×: Moss is generated a lot [0072]
[Table 1]

[0073]
[Table 2]

[0074]
As is apparent from Table 2, the film of Example 1 is excellent in stability during film forming, toughness, excellent in anti-fusing properties, and without wrinkles when spread on a water supply bed. The surface shape was well adapted to the surface and could be laid along the shape of the drainage groove of the water supply bed. In addition, the film according to the present invention can be used satisfactorily without generation of moss.
[0075]
【The invention's effect】
According to the present invention, by reflecting sunlight front white color layer, lower the film surface temperature to prevent the generation of moss is blocked sunlight in black color layer, the front side of the white color layer reflect sunlight is to lower the film surface temperature to prevent the generation of moss is blocked sunlight in black color layer, white to Usuzumi color layer for reflecting light to the back side, by using a white-silver layer, fusion Further, blocking during storage can be prevented.
[Brief description of the drawings]
1 is a cross-sectional view showing an example of the layer structure of a film of the present invention. FIG. 2 is an explanatory view showing a bottom water supply system. FIG. 3 is a partial cross-sectional view of a water supply bed.
1: Water bed 2: horticultural pot 3: drainage grooves 4: Film 10: White Color layer 11: black color layer 12: White ~ Usuzumi color layer 13: white to silver layer

Claims (6)

5-50 wt.% Of white pigment on an ethylene / α-olefin copolymer polymerized using a single site catalyst with a melt flow rate of 0.3-5.0 and a density of 0.850-0.910 g / cc. % Blended white layer and ethylene / α-olefin copolymer 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 black layer formed by blending 1 to 20% by weight of a black pigment into the coalescence, 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. in a ethylene / alpha-olefin copolymer by adjusting the amount of white pigment, a black pigment and a white to Usuzumi color formed white to Usuzumi color layer, a white layer and black color layers, white to Usuzumi color Japanese that are laminated in this order of layers Agricultural covering film to be. White color layer is highly reflective layer of 70% or more reflectivity, agricultural covering film of claim 1, wherein the white-Usuzumi color layer is the reflectance of 30% or more. White color layer and the white-Usuzumi color layer, agricultural covering film according to claim 1 or 2, wherein the containing softening agent 40 wt%. 5-50 wt.% Of white pigment on an ethylene / α-olefin copolymer polymerized using a single site catalyst with a melt flow rate of 0.3-5.0 and a density of 0.850-0.910 g / cc. % Blended white layer and ethylene / α-olefin copolymer 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 black layer formed by blending 1 to 20% by weight of a black pigment into the coalescence, 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 / alpha-olefin copolymer white pigment 0-50% is, white to silver layer formed by blending the silver pigment 0.5% to 10% and is white layer and black color layers and white-silver layer and characterized in that formed by the laminated in this order Agricultural covering film that. White color layer is highly reflective layer of 70% or more reflectivity, agricultural covering film according to claim 4, wherein the white-silver layer is reflectivity of 30% or more. White color layer and the white-silver layer, agricultural covering film according to claim 4 or 5, wherein the containing softening agent 40 wt%.

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