JP2020062041A - Agricultural film - Google Patents

Abstract

To provide an agricultural film capable of effectively achieving a highly shadowless environment.SOLUTION: An agricultural film 1 of the present invention comprises a lamination of a light scattering agent dispersion film layer 3 on one surface of a transparent resin film layer 2. The light scattering agent dispersion film layer 3 is formed by dispersing and blending of at least a large diffused light agent 30 for converting incident light which has transmitted the transparent resin film layer 2 into first diffused light, and a small diffused light agent 31 for generating second diffused light by further diffusing the first diffused light in multiple directions. The diffused lights are emitted in multiple directions from a surface and an inner surface of the light scattering agent dispersion film layer 3, forming a highly shadowless environment in a house or in a tunnel.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an agricultural film, and more particularly, to an agricultural film that can preferably realize a high degree of shadow-free environment.

  The diffuser film not only scatters the sun rays that penetrate through the film to make it soft, but also diffuses the rays to reach the places where the sun rays usually do not reach the shadows. (Patent Document 1).

Japanese Patent No. 3763380

  In the conventional light-scattering film, a part that becomes a shadow may still be generated even when sunlight is scattered, and there is room for improvement in providing a so-called shadow-free environment.

  Then, the subject of this invention is providing the agricultural film which can implement | achieve a high-level shadowless environment suitably.

  Other problems of the present invention will be clarified by the following description.

  The above problems can be solved by the following inventions.

(Claim 1)
On one side of the transparent resin film layer, a diffuser dispersion film layer is laminated,
The diffuser-dispersed film layer is a large diffuser that converts light transmitted through the transparent resin film layer and incident into first scattered light, and the first scattered light is further scattered in multiple directions. And a small diffuser that produces a second scattered light, at least dispersedly blended,
An agricultural film, wherein scattered light is emitted in multiple directions from the surface or the inner surface of the diffuser-dispersed film layer to form a highly shadowless environment in a house or a tunnel.
(Claim 2)
2. The agricultural film according to claim 1, wherein the light-diffusing agent-dispersed film layer is used while being spread toward the side of the agricultural products grown in the house or in the tunnel.
(Claim 3)
The light-dispersing agent-dispersed film layer imparts antifogging property,
On the surface of the diffuser-dispersed film layer, a large convex surface is formed by a large diffuser that generates the first scattered light, and the first scattered light is provided around the large diffuser that forms the large convex surface. Further, a small convex surface is formed by a small diffuser that scatters light to generate second scattered light,
An agricultural film characterized by being used when heat retention is required.

  According to the present invention, it is possible to obtain the effect of providing an agricultural film capable of suitably realizing a high degree of shadowless environment.

The figure which explains notionally the layer constitution of the agricultural film of this invention. The figure which explains notionally the light scattering by the agricultural film of this invention. The figure explaining the test method of an Example. The figure which shows the result of an Example

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

FIG. 1 is a diagram conceptually illustrating the layer structure of the agricultural film of the present invention.
The agricultural film 1 comprises a transparent resin film layer 2 and a diffuser dispersion film layer 3.

  As the transparent resin used in the transparent resin film layer 2 and the diffuser-dispersed film layer 3, polyolefins such as ethylene-based polymers and propylene-based polymers, and vinyl chloride can be used. Among them, low-density polyethylene, linear low-density polyethylene, and ethylene / vinyl acetate copolymer are preferable from the viewpoints of stain resistance and durability.

  In the present invention, transparent, opaque or translucent means whether or not sunlight goes straight through the film without being scattered, and does not mean whether or not sunlight passes through.

  The resin forming the transparent resin film layer 2 and the resin forming the diffuser-dispersed film layer 3 may be different resins, but the resin having the same chemical composition is used to obtain the adhesiveness of both layers. Is also preferable.

  The large diffuser 30 and the small diffuser 31 are dispersed in the diffuser-dispersed film layer 3. One particle is shown in the figure as the large light diffuser 30, and the small light diffuser 31 is dispersed around or near the large light diffuser 30.

  The large light diffuser 30 has a particle size of 1 μm to 10 μm, preferably 2 μm to 4 μm, and the compounding amount thereof is 3 wt% to 15 wt%, preferably 5 wt% to 10 wt% with respect to the total weight of the light diffuser dispersion film layer 3. .

  The small diffuser 31 has a particle size of 0.1 μm to 0.9 μm, preferably 0.2 μm to 0.6 μm, and the compounding amount thereof is 0.3 wt% to 2 wt% with respect to the total weight of the diffuser dispersion film layer 3. , Preferably 0.5 wt% to 1.2 wt%.

  The blending amount of the small diffuser 31 is smaller than that of the large diffuser 30 in terms of weight. However, the volume (proportional to the cube of the particle size) of the small diffuser 31 is significantly smaller than that of the large diffuser 30, and at this time, there is no great difference in specific gravity, and therefore the amount of the small diffuser 31 mixed with the large diffuser 30 is large. The ratio will be significantly greater.

  In the present invention, the compounding quantity ratio of the small diffuser 31 to the large diffuser 30 is preferably 60 times to 100 times. As a result, a large convex surface derived from the large diffuser 30 is formed on the surface of the diffuser-dispersed film layer 3, and a small convex surface formed by the small diffuser 31 is further formed on the surface of the large convex surface.

  Next, referring to FIG. 2, light scattering by the agricultural film 1 will be conceptually described. FIG. 2 shows an enlarged area A surrounded by a dotted line in FIG.

  In FIG. 2, the light that has passed through the transparent resin film layer 2 (not shown) and is incident on the diffuser dispersion film layer 3 is first converted into the first scattered light by the large diffuser 30, and then the first scattered light. Generates second scattered light that is further scattered in multiple directions by the small diffuser 31. As a result, scattered light is emitted from the surface (inner surface) of the diffuser-dispersed film layer 3 in multiple directions, and a highly shadowless environment is formed.

  Examples of the large light diffuser 30 include alkali orthoclase, silicon oxide, and various natural or synthetic silicates. Among them, it is preferable to use alkali orthoclase made of nepheline or nepheline syenite (nepheline syenite). it can. As a commercially available product, "MINEX 7" manufactured by Unimin Co. can be used.

Hydrotalcites are used as the small diffuser 31. Hydrotalcite has the formula _{^{M 2+ 1-x Al 3+ x}} - a _{^{2 (A 1 n-) x /}} n · mH compound represented by the ₂ O ^_(OH). In the above formula, M ²⁺ represents a divalent metal ion selected from the group consisting of Mg ²⁺ , Ca ²⁺ and Zn ²⁺ , A ₁ ⁿ⁻ is an n-valent anion, and x is 0 <x <0. 5 is a number in the range of 5, m is a number in the range of 0 ≦ m ≦ 2, and n is a number in the range of 1 ≦ n ≦ 3. As the hydrotalcites, for example, DHT (manufactured by Kyowa Chemical Co., Ltd.) and the like can be preferably used.

  In the example of tomato cultivation using such an agricultural film, dead leaves were not confirmed so much. The volume of dead leaves was less than 10% of the volume of grown leaves. No burnt tomatoes were found after the rainy season.

  Furthermore, it was confirmed that the height of all the stocks inside the house was almost constant. This is also the effect of the shadowless environment. When the shadow occurs, the leaves existing there are withered, and the stems grow to attach the leaves to the places where photosynthesis is possible. This will result in tall stocks.

  In the film of the present invention, since there was no such high strain, all strains showed similar growth. As a result of the above, vegetative growth was suppressed and energy was spent on reproductive growth, so that the yield of tomatoes can be increased.

  The thickness of the transparent resin film layer 2 can be set arbitrarily, but is 5 μm or more, preferably 10 μm or more, and generally 10 to 150 μm. When the film thickness is thinner than 5 μm, it becomes difficult to smooth the film surface, and the transparency is lowered. The film thickness of the diffuser-dispersed film layer 3 can be arbitrarily set, but is generally 5 to 200 μm, preferably 10 to 100 μm.

  That is, the total film thickness of the agricultural film 1 is preferably 15 to 300 μm, and more preferably 50 to 200 μm.

  The method for laminating the transparent resin film layer 2 and the diffuser dispersion film layer 3 is not particularly limited. For example, the diffuser-dispersed film layer 3 may be formed in advance, and the transparent resin film layer 2 may be laminated thereon by extrusion laminating. Alternatively, the transparent resin film layer 2 may be formed in advance and the diffuser-dispersed film layer 3 may be formed thereon. May be laminated by extrusion laminating. Alternatively, the resin compositions of both layers may be simultaneously extruded by inflation molding and laminated within the die or immediately after being extruded from the die.

  The diffuser-dispersed film layer 3 is preferably oriented on the side (inside) of the crop. By using the diffuser-dispersed film layer 3 as the inner side, the transparent resin film layer 2 becomes the outer layer of the film, so that the outer surface of the film becomes smooth and the diffuser-dispersed film layer 3 becomes the inner layer of the film. As a result, a textured surface having fine irregularities is formed on the inner surface of the film, and shadowlessness can be favorably realized.

  Further, the surface of the diffuser-dispersed film layer 3 may be provided with antifogging property. As a method for imparting antifogging property, a method of kneading a compound having a hydrophilic group such as a surfactant into the diffuser-dispersed film layer 3 can be adopted. A clouding agent can also be applied.

  As the antifogging agent when kneading into the diffuser dispersion film layer 3, a nonionic, anionic or cationic surfactant can be used. Examples of these compounds include polyoxyalkylene ethers, polyhydric alcohol partial esters, polyhydric alcohol alkylene oxide adduct partial esters, higher alcohol sulfuric acid ester alkali metal salts, alkylaryl sulfonates, quaternary ammonium, and fatty acid amine derivatives. Can be mentioned. Among them, nonionic surfactants containing an ester of a fatty acid having 14 to 22 carbon atoms and a polyhydric alcohol such as sorbitan, sorbitol, glycerin, propylene glycol or the like and an alkylene oxide adduct thereof as a main component are preferable.

  As the anti-fogging agent which is applied to the light-scattering agent dispersion film layer 3 to impart anti-fogging property, those containing inorganic fine particles and a surfactant are desirable, and as the inorganic fine particles, inorganic particles having a particle size of about 5 to 100 nm are used. Hydrophilic colloidal substances can be used. Specifically, colloidal silica, colloidal alumina, colloidal iron hydroxide, tin hydroxide, titanium oxide, barium sulfate, lithium silicate and the like can be used.

  The antifogging agent may be applied before being stretched on the tunnel aggregate or the cultivation house frame, or may be applied at any time after tensioning on these.

  The agricultural film 1 thus obtained becomes opaque or semi-transparent in a dry state, and becomes transparent when the surface of the diffuser-dispersed film layer 3 is wet.

  In addition, in the agricultural film 1 of the present invention, the transparent resin film layer 2 may be a single layer or a laminated film layer. Therefore, the agricultural film 1 of the present invention may have a structure of three or more layers.

  Then, to each layer, various ultraviolet absorbers, light stabilizers (improvement of weather resistance), heat retaining agents, infrared absorbers, etc. may be appropriately added within a range that does not impair the effects of the present invention to impart various functions. it can.

  When the agricultural film 1 of the present invention is used, it is used and constructed in the same manner as the conventional one except that the surface of the diffuser-dispersed film layer 3 is stretched so as to be the inner surface of the film (inside of a tunnel or a house). It is stretched over the frame of a tunnel or a house where crops are cultivated.

  When cultivation is performed using the agricultural film 1, cultivation is carried out in a state where a house or a tunnel is closed when heat retention is required in winter or the like. When cultivating with the house or tunnel closed, the cultivation temperature can be kept high and the internal humidity rises so that the moisture adheres to the surface of the diffuser dispersion film layer 3 of the agricultural film 1. The adhered water becomes a water film on the surface of the diffuser dispersion film layer 3 due to the action of the antifogging agent. As a result, the agricultural film 1 becomes transparent, and direct sunlight is applied to the crop.

  On the other hand, after April-May in the spring, especially in the summer when the temperature is high and the sunlight is strong, the agricultural film 1 is partially pulled up and ventilated. When the inside of the tunnel or the house is ventilated, the inside is dried and the water film on the inner surface of the agricultural film 1 disappears. As a result, the agricultural film 1 becomes opaque or semi-transparent, and direct sunlight is dispersed to become soft light, which is applied to the crop. Therefore, it is possible to prevent high temperature damage such as burning from occurring in the crops, and it can be used for cultivation of many crops such as vegetables, fruit crops and flowers.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

1. Production of Film An inflation-forming method was used to produce an agricultural film (laminated film) having a transparent resin film layer and a diffuser-dispersed film layer having the following respective constitutions.
The transparent resin film layer and the diffuser-dispersed film layer were each a single layer.

<Transparent resin film layer>
It was formed with 100 parts by weight of an ethylene-vinyl acetate copolymer (MI: 0.5, vinyl acetate content 15%). The thickness was 100 μm.

<Diffusing agent dispersion film layer>
To 100 parts by weight of an ethylene-vinyl acetate copolymer (MI: 0.5, vinyl acetate content 15%) which is a transparent resin, 7 parts by weight of the following large diffuser and 0.8 parts by weight of the following small diffuser are added. Blended and mixed. The thickness of the diffuser-dispersed film layer is 30 μm.
Large diffuser: Nepheline syenite ("MINEX 7" manufactured by Unimin Co., Ltd.), particle size 3.5 μm
Small diffuser: Hydrotalcite (“DHT-4A” manufactured by Kyowa Chemical Industry Co., Ltd.), particle size 0.4 μm

2. Cultivation test As shown in FIG. 3, the obtained film 1 was spread on a house (height 3.6 m) provided at Mikado Kako Co., Ltd. Honda farm, and 50 cm below the film 1 (P1) and 1 m below ( P2), 2 m down (P3), 3 m down (P4), the house inner ground (P5), and the house outer ground (P6) diffused light arrival amount to each position were measured as an average illuminance for each time period. The results are shown in Fig. 4.

<Evaluation>
First, as shown by the dotted line in FIG. 4A, in a transparent film (comparative) that does not contain a large light diffusing agent and a small light diffusing agent, the illuminance usually decreases from the film toward the ground in the house.

  On the other hand, in the film of the present invention, as shown in the bar graph of FIG. 4 (a), in the time zone of 10:00 to 11:00, the transparent film ( It can be seen that a larger illuminance than that of (Comparison) is measured.

  In particular, it can be seen that the illuminance is larger in the area 1 m to 2 m below the film than immediately below the film (50 cm below the film). From these, it is understood that the film of the present invention can suitably realize a high degree of shadowless environment.

Further, as shown in the bar graph of FIG. 4B, it can be seen that the illuminance in the region from 1 m to 3 m below the film is slightly reduced in the time zone from 12:00 to 13:00. Therefore, according to the film of the present invention, in addition to the above-described shadow-eliminating effect, it is possible to obtain an effect of preventing the plants in the house from being irradiated with excessive light during a time period when the elevation angle of the sun is large.

  Furthermore, as shown in the bar graph of FIG. 4 (c), in the time zone from 14:00 to 13:00, the illuminance in the region 1 m to 3 m below the film is lower than that immediately below the film (50 cm below the film). It can be seen that the value becomes large and that a high-level shadowless environment can be suitably realized.

1: Agricultural film 2: Transparent resin film layer 3: Diffusing agent dispersion film layer 30: Large diffusing agent 31: Small diffusing agent

Claims (3)

On one side of the transparent resin film layer, a diffuser dispersion film layer is laminated,
The diffuser-dispersed film layer is a large diffuser that converts the light that has entered through the transparent resin film layer into first scattered light, and the first scattered light is further scattered in multiple directions. And a small diffuser that produces a second scattered light, at least dispersedly blended,
An agricultural film, characterized in that scattered light is emitted in multiple directions from the surface or the inner surface of the light-diffusing agent-dispersed film layer to form a highly shadowless environment in a house or a tunnel.   2. The agricultural film according to claim 1, wherein the diffuser-dispersed film layer is used by spreading it toward the side of the agricultural products grown in the house or in the tunnel. The light-dispersing agent-dispersed film layer imparts antifogging property,
On the surface of the diffuser-dispersed film layer, a large convex surface is formed by the large diffuser that generates the first scattered light, and the first scattered light is provided around the large diffuser that forms the large convex surface. Further, a small convex surface is formed by a small diffuser that scatters light to generate second scattered light,
An agricultural film characterized by being used when heat retention is required.

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