JP3763380B2 - Crop cultivation coating film and method of using the same - Google Patents

Description

【００５０】
２．比較例１フィルム：単層フィルム １３０μｍ
本発明１フィルムにおいて、無機粉体含有フィルム層を設けない以外は同様の単層フィルムを得た。フィルム表面粗さはＲa＝０．０８（ＪＩＳ Ｂ−０６０１−８２準拠）であった。
【００５１】
３．本発明２フィルム：
本発明１フィルムにおいて、無機粉体含有フィルム層に用いた無機粉体をケイ酸アルミニウム粉末（添加量１０ｗｔ％平均粒径４．０μｍ、屈折率１．５３）に代えた以外は同様にして本発明２フィルムを得た。この積層フィルムの無機粉体含有フィルム層の表面粗さはＲa＝０．5（ＪＩＳ Ｂ−０６０１−８２準拠）であった。
【００５２】
（栽培実験）
上記のフィルムを用い、千葉県市原市のみかど化工（株）圃場に構築された幅４．５ｍ、長さ２０ｍ、高さ２．５ｍのハウス用骨組み４基にそれぞれのフィルムを張設し、平成９年３月の定植から９月の収穫終了までの間トマトを栽培し た。
【００５３】
３月１５日に定植し、５月２５日より収穫を開始した。５月中旬以降晴天日の日中はハウスサイドの換気を開始した。被覆用フィルムの引上げ幅は天候を勘案しながら２０〜１００ｃｍとした。
【００５４】
比較例１の単層フィルムを用いたハウスは、６月下旬梅雨明け以降トマトに焼け症状が発生した。日中直射光の当たる位置は果実が発育段階に関係なく大きな被害を受け、直射光の当たり難い日陰にあるトマトが助かるのみであった。このため、商品となるトマトの収穫率が大幅に低下した。
【００５５】
これに対し、本発明のフィルム１，２の積層フィルムは、換気によって半透明となり作物には柔らかい日光が当たり高温障害は極めて少なかった。
【図面の簡単な説明】
【図１】本発明の作物栽培用の被覆フィルムの断面図
【符号の説明】
１：ハウス用フィルム
２：透明樹脂フィルム層
３：無機粉体含有フィルム層[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cover film for crop cultivation used for house or tunnel cultivation in the cultivation of crops and a method for using the same, and more particularly, for controlling cultivation and suitable for yearly cultivation of a tunnel or house, capable of adjusting heat retention and light transmission. The present invention relates to a coating film and a method for using the same.
[0002]
[Prior art]
In recent years, tunnel cultivation and house cultivation in which a transparent synthetic resin film is stretched are widely used for cultivation of vegetables, fruit crops, and flower crops.
[0003]
These crop cultivation tunnels or houses are required to keep warm in the winter when the temperature is low and to irradiate the crop with sunlight as much as possible because the sunlight is weak.
[0004]
However, when the tunnel or house is closed and heat is maintained, the humidity rises due to moisture inside the tunnel or house, and the moisture adheres to the inner surface of the coating film as water droplets. For this reason, there is a problem that sunlight is irregularly reflected by water droplets, the sunlight irradiated to the tunnel or the house is scattered outside the tunnel or the house, the incident light is reduced, and particularly direct sunlight is not irradiated to the crop.
[0005]
For this reason, an antifogging property is imparted to the inner side surface of the coating film to spread the water droplets to form a water film, thereby preventing irregular reflection due to the water droplets and transmitting direct sunlight.
[0006]
On the other hand, after the spring season (April to May) when the sun rays become strong, the temperature rises excessively when the cultivated crops are exposed to direct sunlight, causing damage to the crops. When cultivating in a tunnel or house using the treated coating film, there was a problem that high temperature damage such as burning occurred on leaves and fruits after spring.
[0007]
Furthermore, in order to control the temperature in the tunnel or house for cultivation on a fine day, ventilation is performed by opening the side of the tunnel or house, the ceiling, or the valley of the multi-storey house. When ventilation is performed, moisture is removed, so that water droplets on the coating film surface disappear. For this reason, direct sunlight enters through the coating film and the temperature rises, and even if ventilation is performed, the temperature in the tunnel or house often exceeds 30 ° C. and is close to 40 ° C., causing a problem of high temperature failure. . For this reason, crops are conventionally covered with a cold chill or the like after spring, especially in the summer. However, it has been troublesome to stretch the cold cocoon, which increases the cost and causes a shortage of light.
[0008]
In order to solve this problem, the inventor is made of a transparent resin in which inorganic powder having a refractive index of 1.37 to 1.63 and an average particle size of 1.0 to 20 μm is dispersed on one side of the transparent resin film layer. For crop cultivation in which an inorganic powder-containing film layer is laminated, and the surface on the inorganic powder-containing film layer side is a textured surface with an average roughness Ra = 0.1 to 5.0 μm and is provided with antifogging properties It has been found that the method of transmitting sunlight can be adjusted by the covering film, and that it is possible to grow an efficient crop that does not require a sun cover even in the summer when the sunlight is strong, and has led to the present invention. Is.
[0009]
Conventionally, the resin layer is made to contain an inorganic filler and both sides of the film are made into a satin finish. When sunlight is required, even if the inner surface of the house is painted and a water film is formed, the outer surface remains satin, so that sunlight is scattered, resulting in a shortage of light. Furthermore, since the outer surface is a concavo-convex structure, fine dirt and organic substances are easily deposited and deposited, resulting in a significant shortage of light.
[0010]
Conventionally, the refractive index of an inorganic substance is made similar to the refractive index of a resin to maintain the transparency of the resin (see JP-A-55-151043), but the transparency is imparted. The film is convenient for use in winter, but if it is used until summer, the incident sunlight is too strong, which is inconvenient for crop cultivation. For this reason, films with different characteristics were used for winter and summer, but this would be expensive.
[0011]
Then, development of the cultivation film which can carry out house cultivation with the same film is desired also in anniversary cultivation, and it is the film of this invention that implement | achieved this.
[0012]
[Problems to be solved by the invention]
Then, the subject of this invention is the crop film covering film which can adjust the method of permeation | transmission of sunlight, and enables cultivation of the efficient crop which does not require a sunshade also in the sunlight strong summer Is to provide.
[0013]
Moreover, the other subject of this invention is providing the usage method of the coating film for crop cultivation suitable for the anniversary cultivation of a tunnel or a house.
[0014]
The other subject of this invention becomes clear by the following description.
[0015]
[Means for Solving the Problems]
This invention is made | formed as a result of earnestly examining in order to solve this subject, Comprising: The invention of Claim 1 has a refractive index of 1.37 to 1.63, average on one side of the transparent resin film layer. An inorganic powder-containing film layer made of a transparent resin in which inorganic powder having a particle diameter of 1.0 to 20 μm is dispersed is laminated, and the surface on the inorganic powder-containing film layer side has an average roughness Ra = 0.1 to 5.0 μm. It is a covering film for crop cultivation characterized by being made into a pear ground and having an antifogging property.
[0016]
In the invention according to claim 2, the transparent resin of the transparent resin film layer and the transparent resin of the inorganic powder-containing resin film layer are both made of polyolefin resin, and the refractive index of the inorganic powder is in the range of 1.41-1.59. The cover film for crop cultivation according to claim 1, wherein the surface on the inorganic powder-containing film layer side is a pear ground having an average roughness Ra = 0.1 to 3.0 μm.
[0017]
The invention according to claim 3 is characterized in that the surface on the inorganic powder-containing film layer side is a pear ground having an average roughness Ra = 0.1 to 1.0 μm. Coating film.
[0018]
The invention according to claim 4 is characterized in that the antifogging property is imparted by applying an antifogging agent containing inorganic fine particles and a surfactant. The covering film for crop cultivation as described in 2.
[0019]
The invention according to claim 5 which solves the above-mentioned problem covers the film according to claims 1 to 4 so that the pear ground is located on the inner surface of the tunnel or house, and the year of the tunnel or house from winter to summer. It is the usage method of the cover film for crop cultivation characterized by using for cultivation.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
As shown in FIG. 1, the covering film 1 used for crop cultivation according to the present invention has a transparent film layer 2 and an inorganic powder-containing film layer 3 in which an inorganic powder is blended.
[0021]
As the transparent resin used for the transparent film layer 2 and the inorganic powder-containing film layer 3, polyolefins such as ethylene polymers and propylene polymers, vinyl chloride, and the like can be used. Of these, low-density polyethylene, linear low-density polyethylene, and ethylene / vinyl acetate copolymer are preferred in terms of antifouling properties, durability, and cost.
[0022]
In the present invention, transparent, opaque, or translucent means whether or not sunlight travels straight through the film and does not mean whether or not sunlight is transmitted. The resin that forms the transparent film layer 2 and the resin that forms the inorganic powder-containing film layer 3 may be different resins, but the same type of resin should be used in order to obtain adhesion between the two layers. Is desirable.
[0023]
As the inorganic powder added to the inorganic powder-containing film layer 3, one having a refractive index in the range of 1.37 to 1.63 can be used. However, as the transparent resin, low density polyethylene or ethylene / vinyl acetate copolymer is used. When coalescence is used, the refractive index of the inorganic powder is preferably in the range of 1.41-1.59. When the refractive index exceeds the range of 1.41 to 1.59, the internal scattering in the film is large, so that a so-called whitened film is obtained, the light transmission is remarkably reduced, and it is not suitable for crop cultivation particularly in winter. There are drawbacks.
[0024]
The average particle size of the inorganic powder is 1.0 to 20 μm, preferably 2 to 10 μm, more preferably 3 to 6 μm. If the average particle size is less than 1.0 μm, the surface roughness becomes small, and it is difficult to make the coating film opaque even in summer, and the satin effect is low. On the other hand, when the thickness exceeds 20 μm, film forming troubles and quality troubles such as film strength are likely to occur, and it becomes difficult to become transparent in winter.
[0025]
As the inorganic substance constituting the inorganic powder, when low density polyethylene or ethylene / vinyl acetate copolymer is used as a transparent resin, silicon oxide such as quartz, silica gel, diatomaceous earth, etc., various natural or synthetic Silicates such as talc, zeolite, feldspar, calcium silicate, glass, natural or synthetic hydrotalcite compounds, etc. can be used. These can be used in any combination. In addition, famous white pigments such as titanium oxide and zinc oxide having a refractive index of 2.0 or more are not suitable in the present invention. In addition, aluminum oxide, calcium carbonate, magnesium oxide and the like having a refractive index exceeding 1.63 are not preferable in the present invention.
[0026]
In general, in order to increase the heat retention in winter as a film characteristic, it is necessary that the coating film 1 absorbs infrared rays having a wavelength of about 5.0 to 30 μm, and contains an inorganic powder that absorbs infrared rays in this range. Although it is known that it is desirable, all of the inorganic powders have a function of absorbing infrared rays and function as a heat retention improving agent for the coating film.
[0027]
When low-density polyethylene or ethylene / vinyl acetate copolymer is used as the transparent resin, it satisfies the particle size, refractive index, and infrared absorption ability, and considering the film quality and cost, silicon oxide or silica Inorganic powder made of acid aluminum salt is desirable.
[0028]
The blending amount of the inorganic powder is 2 to 20% by weight, preferably about 3 to 15% by weight with respect to the composition of the inorganic powder-containing film layer 3. If it exceeds 20% by weight, foaming troubles are likely to occur during molding, leading to a decrease in film strength and durability. If it is less than 2% by weight, the satin effect is low.
[0029]
The film thickness of the transparent film layer 2 is 5 μm or more, preferably 10 μm or more, and generally 10 to 150 μm. When the film thickness is less than 5 μm, it is difficult to smooth the film surface, and transparency is lowered.
[0030]
The film thickness of the inorganic powder-containing film layer 3 can be arbitrarily set, but is generally 5 to 200 μm, preferably 10 to 100 μm.
[0031]
Lamination of the transparent film layer 2 and the inorganic powder-containing film layer 3 may be carried out by forming the inorganic powder-containing film layer 3 in advance and then laminating the transparent film layer 2 by extrusion lamination. The film layer 2 may be formed and the inorganic powder-containing film layer 3 may be laminated thereon by extrusion lamination. It is also possible to extrude both layers of the resin composition at the same time and laminate them in the die or immediately after being extruded from the die.
[0032]
By laminating the transparent film layer 2 and the inorganic powder-containing film layer 3, the surface on the transparent film layer 2 side becomes a smooth surface, and the surface on the inorganic powder-containing film layer 3 side is formed with a textured surface with minute irregularities. The
[0033]
In the present invention, the pear ground has an average surface roughness Ra (based on JIS B-0601-82) in the range of 0.1 to 5.0 μm, preferably 0.1 to 3.0 μm, more preferably 0.8. It is in the range of 1 to 1.0 μm. When the average surface roughness Ra is less than 0.1 μm, it cannot be made opaque or translucent even in the summer, and when it is greater than 5.0 μm, the transparency is deteriorated even in the winter.
[0034]
The total film thickness of the cover film 1 for crop cultivation is 15 to 300 μm, preferably 50 to 200 μm.
[0035]
Further, the surface of the inorganic powder-containing film layer 3 is given antifogging properties. As a method for imparting antifogging properties, a method of kneading a compound having a hydrophilic group such as a surfactant into the inorganic powder-containing film layer 3 can be employed. It is also possible to apply an antifogging agent.
[0036]
As an antifogging property imparting agent when kneading into the inorganic powder-containing film layer 3, a nonionic, anionic or cationic surfactant can be used. These compounds include polyoxyalkylene ethers, partial esters of polyhydric alcohols, partial esters of polyhydric alcohol alkylene oxide adducts, higher alcohol sulfate alkali metal salts, alkylaryl sulfonates, quaternary ammonium, fatty acid amine derivatives. Is mentioned.
[0037]
Among these, nonionic surfactants mainly composed of esters of fatty acids having 14 to 22 carbon atoms and polyhydric alcohols such as sorbitan, sorbitol, glycerin and propylene glycol or adducts thereof with alkylene oxide are preferred.
[0038]
The antifogging agent that is applied to the inorganic powder-containing film layer 3 to impart antifogging properties is preferably one containing inorganic fine particles and a surfactant, and the inorganic fine particles have an average particle size of about 5 to 100 nm. Inorganic hydrophilic colloidal materials can be used.
[0039]
Specifically, colloidal silica, colloidal alumina, colloidal iron hydroxide, tin hydroxide, titanium oxide, barium sulfate, lithium silicate, or the like can be used.
[0040]
As the surfactant, the aforementioned anionic surfactants and nonionic surfactants can be used.
[0041]
The anti-fogging agent may be applied before being laid on a tunnel aggregate or a cultivation house framework, or may be applied as needed after being laid on these.
[0042]
The coated film 1 thus obtained becomes opaque or translucent in the dry state, and becomes transparent when the surface of the inorganic powder-containing film layer 3 is wet.
[0043]
In the coated film 1 of the present invention, the transparent film layer 2 may be a single layer or a laminated film layer. Therefore, the coated film 1 of the present invention can also have a structure of three or more layers. Various layers can be provided with various functions by appropriately adding various ultraviolet absorbers, light stabilizers (weather resistance improvement), heat insulating agents, infrared absorbers and the like.
[0044]
When the coated film 1 of the present invention is used, it is used in the same manner as in the past except that the surface of the inorganic powder-containing film layer 3 is placed inside the tunnel or house. It is stretched and crops are cultivated inside.
[0045]
When cultivating using the coated film of the present invention, cultivation is carried out with the house or tunnel closed when it is necessary to keep warm in winter or the like. When cultivating with the house or tunnel closed, the cultivation temperature can be increased by keeping the house or tunnel, and the internal humidity rises, and the moisture adheres to the surface of the film layer 3 of the coated film 1 containing the inorganic powder. The attached water forms a water film on the surface of the inorganic powder-containing film layer 3 by the action of the antifogging agent. As a result, the covering film 1 becomes transparent and direct sunlight is irradiated to the crop.
[0046]
On the other hand, from April to May in spring, especially during summer when the temperature is high and the sunlight is strong, the covered film 1 is partially lifted for ventilation. When the tunnel or house is ventilated, the interior is dried and the water film on the inner surface of the covering film 1 disappears. As a result, the covering film 1 becomes opaque or translucent, and the direct sunlight is dispersed to become soft light, which is irradiated to the crop. Therefore, it is possible to prevent the occurrence of high-temperature damage such as burning in the crop, and it can be used for the cultivation of many crops such as vegetables, fruit crops and flower buds.
[0047]
【Example】
Examples of the present invention will be described below, but the present invention is not limited to such examples.
[0048]
(Film used)
1. Invention 1 film: Laminated film A laminated film having the following composition in which an antifogging agent (glycerin monostearate) was kneaded with the following inorganic powder-containing film layer was used. The surface roughness of the film layer containing the inorganic powder of this laminated film was Ra = 0.3 (according to JIS B-0601-82).
[0049]

[0050]
2. Comparative Example 1 Film: Single layer film 130 μm
In the present invention 1 film, a similar single layer film was obtained except that the inorganic powder-containing film layer was not provided. The film surface roughness was Ra = 0.08 (based on JIS B-0601-82).
[0051]
3. Invention 2 film:
In the present invention 1 film, the present invention is the same except that the inorganic powder used in the inorganic powder-containing film layer is replaced with aluminum silicate powder (added amount: 10 wt%, average particle size: 4.0 μm, refractive index: 1.53). Invention 2 A film was obtained. The surface roughness of the inorganic powder-containing film layer of this laminated film was Ra = 0.5 (conforms to JIS B-0601-82).
[0052]
(Cultivation experiment)
Using the above films, each film was stretched on 4 frames of a house with a width of 4.5m, a length of 20m, and a height of 2.5m constructed in Mikado Kako Co., Ltd., Ichihara City, Chiba Prefecture. Tomatoes were cultivated from planting in March 1997 to the end of harvesting in September.
[0053]
Planted on March 15 and started harvesting on May 25. After mid-May, house side ventilation was started during the day with fine weather. The pulling width of the covering film was set to 20 to 100 cm in consideration of the weather.
[0054]
In the house using the single layer film of Comparative Example 1, burnt symptoms occurred in the tomato after the end of the rainy season in late June. The position of direct sunlight during the day was greatly damaged by the fruit regardless of the stage of development, and only the tomatoes in the shade that were difficult to hit by direct light were saved. As a result, the yield of tomato products was greatly reduced.
[0055]
On the other hand, the laminated films of the films 1 and 2 of the present invention became translucent when ventilated, and the crops were exposed to soft sunlight and there were very few high-temperature obstacles.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a cover film for crop cultivation according to the present invention.
1: Film for house 2: Transparent resin film layer 3: Film layer containing inorganic powder

Claims (5)

An inorganic powder-containing film layer made of a transparent resin in which an inorganic powder having a refractive index of 1.37 to 1.63 and an average particle diameter of 1.0 to 20 μm is dispersed is laminated on one surface of the transparent resin film layer. A covered film for crop cultivation, characterized in that the surface on the side of the containing film layer has a pear surface having an average roughness Ra = 0.1 to 5.0 μm and is provided with antifogging properties. Both the transparent resin of the transparent resin film layer and the transparent resin of the inorganic powder-containing resin film layer are made of polyolefin resin, and the refractive index of the inorganic powder is in the range of 1.41-1.59, and the inorganic powder-containing film layer The coated film for crop cultivation according to claim 1, wherein the side surface is a pear ground having an average roughness Ra = 0.1 to 3.0 µm. The coated film for crop cultivation according to claim 2, wherein the surface on the inorganic powder-containing film layer side is a pear ground having an average roughness Ra = 0.1 to 1.0 µm. The coating film for crop cultivation according to any one of claims 1 to 3, wherein the antifogging property is imparted by applying an antifogging agent containing inorganic fine particles and a surfactant. A film for crop cultivation, characterized in that the film according to claim 1 is coated so that the pear ground is located on the inner surface of the tunnel or house, and used for year-round cultivation of the tunnel or house from winter to summer. How to use.

Images