JP2008278758A - Agricultural greenhouse with pneumatic film structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an agricultural greenhouse with pneumatic film structure excellent for crop cultivation in protected horticulture, capable of achieving great reduction of heating fuel consumption, and excellent in heat retaining property, translucency, antifog property, dust resistance, strength, antifuse property, durability and economic efficiency. <P>SOLUTION: This agricultural greenhouse with pneumatic film structure is such that in the structure of at least a ceiling part of the agricultural greenhouse, air is pressed in with a blower between a translucent polyolefin-based laminated film on the upper surface and a translucent polyolefin-based laminated film on the lower surface. The greenhouse includes using, as for a resin component of at least the external surface film layer forming each of the upper and lower translucent polyolefin-based laminated films, an olefin-based resin composition comprising composition mixed with ≥50 wt.% of an ethylene-α olefinic copolymer resin which is synthesized using a metallocene catalyst with a density of a range of 905-930 kg/m<SP>3</SP>. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to an agricultural air film structure house, and more specifically, an agricultural air film structure house excellent in heat retention, translucency, anti-fogging, dust resistance, strength, fusion resistance, durability, and economy. About.

  Until now, the temperature in the house during the period from autumn to winter, the night in the early spring and the morning in the morning has been severely refrigerated due to the drastic decrease in the outside temperature. In order to have an adverse effect, it is common practice to take measures against hot air heating by installing and operating a heating boiler using fuel oil or kerosene as fuel. However, in response to the recent increase in fuel prices, recently, the aim was to improve the heat retention of agricultural houses as a way to reduce the cost of fuel costs for heavy oil and light oil by reducing the operation of heating boilers. Various methods have been devised and put into practical use, such as the use of a high thermal insulation performance covering material and the combined use of an outer covering material and an inner covering material.

  Among them, as one of the most effective methods for improving the heat retention of agricultural houses, in order to improve the form of new agricultural houses, that is, heat retention at night and temperature rise during the day, A house with an air film structure has been devised in which a cover is installed using a double transparent plastic film on the ceiling, and air is blown and pressed into the gap. However, practical development has been promoted (Patent Documents 1 to 4).

Japanese Patent Laid-Open No. 52-81242 Japanese Utility Model Publication No. 56-55360 Japanese Patent Laid-Open No. 1-300831 JP-A-6-141688

  At that time, a method of adopting a plastic hard film typified by a polyester film, a fluorine film or the like having excellent durability and extremely good translucency as a covering material may be considered. However, in that case, the covering material itself is very expensive, and there are the following problems due to restrictions on the fixing method of the covering material to the agricultural house aggregate.

  That is, as the structure of an agricultural house that can be adopted, an inexpensive simple house that is most popular as an agricultural house, that is, without using a foundation, a pipe bent at the shoulder is inserted into the ground, The so-called steel-reinforced pipe type, in which two pipes are connected in a so-called underground push-in type pipe house or a concrete independent foundation, using a bending pipe on the roof and reinforced in combination with a steel frame A so-called steel frame that cannot be covered with a house (hereinafter referred to as “pipe-type house”), has an independent foundation, and has a roof-type steel structure that is the same type as a glass greenhouse. There are structural and economic problems of the house that are limited to covering the roof type house. For this reason, even now, it is actually deployed and utilized only in some special markets.

  On the other hand, taking advantage of the features that can be applied to both pipe-type houses and roof-type houses as a covering material, a double-layer coating is performed using a polyolefin-based laminated film, and air is blown and pressed into the gap. A structural house is also conceivable, but has the following problems.

  In other words, in the case of an agricultural air film structure house that employs a general-purpose polyolefin-based laminated film that is used as a covering material for the exterior of a conventional agricultural house, a double plastic film is placed on the ceiling of the house. Since it has an extended structure, it tends to exhibit poor growth due to lack of sunshine due to a part of the sunlight (particularly the visible light region) necessary for the growth of crops reaching the house.

  For example, a method of changing the coating film thickness to a thin coating material having a thickness of 0.04 mm or less can be considered. However, in a conventional agricultural air film structure house using a polyolefin-based laminated film, its durability It is extremely difficult to develop performance that extends for 2 to 3 years or more.

  In addition, the above-mentioned agricultural air-film house is generally used during autumn and winter, at night during the spring season, and in the morning when the house is severely chilled to prevent the temperature in the house from decreasing and crops. It is used for the purpose of promoting growth. Therefore, the air film structure is unnecessary in the period such as summer, and the operation of the blower for forming the air film in the period is wasteful economically. Therefore, in general, in the summer period, the operation of the blower is stopped and the two film covering materials are deflated and used as an agricultural house as a rain protection covering material.

  However, at this time, in the case of an agricultural air film structure house that employs a general-purpose polyolefin-based laminated film, two deflated film covering materials are melted from the film temperature rise due to the radiation energy of sunlight. As a result, when the blower is operated again in the autumn and later and used as an air film structure house, the two film covering materials may cause problems without partially expanding.

  The present invention has been made in view of the above circumstances, and its purpose is good for crop cultivation in facility horticulture, and can achieve significant savings in fuel consumption for heating, heat retention, translucency, anti-fogging. An object of the present invention is to provide an agricultural air film structure house having excellent properties, dust resistance, strength, fusion resistance, durability and economy.

That is, the gist of the present invention is an agriculture in which the structure of at least the ceiling portion of an agricultural house is formed by air being press-fitted by a blower between the translucent polyolefin-based laminated film on the upper surface and the translucent polyolefin-based laminated film on the lower surface. A metallocene catalyst having a density in the range of 905 to 930 kg / m ³ as a resin component of at least the outer surface film layer constituting each of the polyolefin-based laminated films on the upper surface and the lower surface. An agricultural air film structure house characterized by comprising a composition in which 50% by weight or more of an ethylene-α-olefin copolymer resin synthesized by use is blended.

  According to the present invention, in an agricultural house, it is good for crop cultivation, can achieve further saving of heating fuel, heat retention, translucency, antifogging, dustproof, strength, anti-fusing property, An agricultural air film structure house excellent in durability and economy can be provided.

  Hereinafter, the present invention will be described in detail. The agricultural air membrane structure house of the present invention is such that at least the ceiling structure of the agricultural house is press-fitted by a blower between the translucent polyolefin laminated film on the upper surface and the translucent polyolefin laminated film on the lower surface. It is of the structure which consists of. The layer structure of each of the polyolefin-based laminated films on the upper surface and the lower surface may be a structure of two or more layers, specifically, two types, two layers, two types, three layers, three types, three layers, three types, five layers, Examples of the film configuration include four types, four layers, four types, five layers, and five types, five layers.

The agricultural air film structure house of the present invention is characterized in that the density is in the range of 905 to 930 kg / m ³ as a resin component of at least the outer surface film layer constituting each polyolefin-based laminated film on the upper surface and the lower surface. The point is to use an olefin-based resin composition having a composition in which 50% by weight or more of an ethylene-α-olefin copolymer resin synthesized using a metallocene catalyst is blended. Thereby, the outstanding translucency, dustproofness, intensity | strength, fusing resistance, and durability can be expressed.

  Examples of the α-olefin used in the production of the ethylene-α-olefin copolymer resin (A) include propylene, butene-1, pentene-1, hexene-1, 4-methylpentene-1, octene-1, and decene. -1 and the like, and α-olefins having 4 to 8 carbon atoms are particularly preferable.

  As said metallocene catalyst component, what is called a metallocene olefin polymerization catalyst containing the metallocene catalyst component described in Unexamined-Japanese-Patent No. 6-9724, Unexamined-Japanese-Patent No. 6-136195, etc. is used, for example. Such a polymerization catalyst is usually a metallocene catalyst component (a) composed of a transition metal compound of Group IVB of the periodic table having at least one ligand having a cyclopentadienyl skeleton, an organoaluminum oxy compound catalyst component ( b), a particulate carrier (c), and the like.

  An ethylene-α-olefin copolymer resin obtained by copolymerizing ethylene and the above α-olefin in the presence of a metallocene catalyst component is a conventional Ziegler-based catalyst-synthesized ethylene-α-olefin copolymer resin. In comparison, the molecular weight distribution as a resin is extremely narrow and the composition distribution has a very narrow molecular structure. Therefore, when compared with resin compositions having the same density, the film using the metallocene catalyst-synthesized ethylene-α-olefin copolymer resin has excellent strength, transparency, and blocking resistance.

The density of the ethylene-α olefin copolymer resin (A) is required from the viewpoint of physical properties such as required translucency, dust resistance, strength, fusion resistance, durability, stickiness resistance, and flexibility. usually in the range of 905~930kg / ^{m 3,} preferably in the range of 910~925kg / ^{m 3.} The density of less than 905 kg / ^{m 3,} strength, melt contamination resistance is not preferable because the physical properties poor, such as resistance to stickiness, whereas, when the density exceeds 930 kg / ^{m 3,} translucent, properties such as flexibility Is inferior because it is inferior. Said density is the value measured by the method based on ASTM D1505.

  The MFR of the ethylene-α olefin copolymer resin (A) is not particularly limited, but is usually in the range of 0.2 to 20 g / 10 minutes, preferably 0.5 to 5 g / 10 minutes. If the MFR is less than 0.2 g / 10 min, the physical properties such as film moldability and translucency are inferior. On the other hand, if it exceeds 20 g / 10 min, the physical properties such as film moldability and strength are inferior. . The above MFR is a value measured by a method based on ASTM D1238.

  When using said ethylene-alpha olefin copolymer resin (A) as a composition with another olefin resin, content of ethylene-alpha olefin copolymer resin (A) is 50 weight% or more. However, it is preferably 60% by weight or more. When the content of the ethylene-α-olefin copolymer resin (A) is less than 50% by weight, the physical properties such as translucency, dustproof property, strength, anti-fusing property and durability are covering materials for agricultural air film structure houses It is not preferable because it does not reach the required level. In this case, as other olefin resins, conventional general-purpose Ziegler catalyst synthesis ethylene-α olefin copolymer resins, high-pressure polyethylene resins, high-density polyethylene resins in low-pressure methods, ethylene-vinyl acetate copolymer resins , Polypropylene resin, propylene-α olefin copolymer resin, polybutene resin and the like.

  The thickness of the polyolefin-based laminated film used in the present invention is usually 0.04 to 0.18 mm, preferably 0.05 to 0.17 mm. If the thickness is less than 0.04 mm, the target strength and durability cannot be obtained as a covering material for an agricultural air film structure house, and if the thickness exceeds 0.18 mm, the target translucency is obtained. I can't.

  Further, the translucency of the polyolefin-based laminated film is usually 75% or more, preferably 77% or more, as film direct light transmittance (light wavelength region: 555 nm, measurement method: conforming to ASTM D1003). When the translucency is less than 75%, when used as a covering material for an air film structure house for agriculture, sunlight reaching the house necessary for growing the crop is insufficient, which is not preferable.

  Furthermore, the ratio (F / D) of tensile breaking strength (F (unit: N / 10 mm width)) to the thickness (D (unit: mm)) of the polyolefin-based laminated film is usually 280 or more, preferably 290 or more. When F / D is less than 280, the desired balance of physical properties of translucency, strength and durability cannot be expressed, which is not preferable. The value of the film tensile strength at break is a value measured by a method based on ASTM D882.

  Further, in the two translucent polyolefin-based laminated films constituting the structure of the ceiling part, an antifogging agent composition composed of a silica-based inorganic material or an alumina-based inorganic material on at least one side corresponding to the house inner surface side of the film surface on the upper surface The object is preferably applied.

  As a prescription that expresses anti-fogging property on one side corresponding to the house inner surface side of the film surface, a method of melt kneading a conventionally known organic compound surfactant into a resin at the time of film forming is also assumed, but in that case, for agricultural use When used as a coating material for an air film structure house, the organic compound surfactant may excessively migrate to the film surface and impair the transparency of the film surface. It is extremely difficult to develop surface antifogging performance. Therefore, the above method is preferable as a prescription that exhibits long-term antifogging sustainability without inhibiting transparency on one side corresponding to the house inner surface side of the film surface. In such a method, an antifogging agent composition composed of a colloidal silk-based inorganic material or alumina-based inorganic material described in JP-A-7-52343, JP-A-8-319476 or the like is employed. Is preferred. In that case, the anti-fogging agent coating layer component includes, in addition to the above-mentioned silica-based inorganic material or alumina-based inorganic material, an inorganic binder component, an organic binder resin component, a crosslinking agent component, an organic surfactant. An agent component or the like can be appropriately blended.

  The two translucent polyolefin-based laminated films described above are for the purpose of enhancing durability and slipperiness as a covering material for agricultural air film structure houses, such as translucency, dust resistance, and fusion resistance of the film. An appropriate amount of various additives such as antioxidants, ultraviolet absorbers, weathering stabilizers, lubricants (organic and inorganic) can be contained within the range that does not impair the performance of the above. Furthermore, for the purpose of enhancing the heat retention as a coating material, an inorganic oxide containing at least one atom selected from the group consisting of Mg, Al, Ca and Si within a range that does not impair the translucency and strength of the film. A proper amount of heat-retaining agent components such as products, inorganic hydroxides and hydrotalcites can be contained.

The two translucent polyolefin-based laminated films do not have to be exactly the same, and the resin component of the film layer on at least the outer surface side of the translucent polyolefin-based laminated film has a density of 905 to 930 kg / As long as an olefin-based resin composition composed of 50% by weight or more of an ethylene-α-olefin copolymer resin synthesized using a metallocene catalyst in the range of m ³ is used, the agricultural air membrane structure house Excellent physical properties such as translucency, dust resistance, strength, fusion resistance, and durability as a coating material can be exhibited. The film thickness, film direct light transmittance, and film strength are preferably within the above ranges. Usually, in the two translucent polyolefin laminated films, the upper translucent polyolefin laminated film is directly exposed to the harsh environment outside the house. In comparison, in particular, a higher performance of durability as a coating material is required, and therefore, a film having a relatively equal or greater thickness may be used.

  As an installation method of the agricultural air membrane structure house of the present invention, any of an underground push-in pipe type house, a steel reinforced pipe type house, and a steel roof type house may be adopted. In that case, the method of fixing the translucent polyolefin-based laminated film can be the same as the fixing method of ordinary vinyl chloride film or polyolefin-based film, and the film is pressed onto the house-dedicated fixing rail via a dedicated spring. By doing so, the house body can be stretch-coated. The extension work procedure can usually be performed in the following manner.

  In other words, after pressing the translucent polyolefin laminated film on the lower surface to the fixed rail via a dedicated spring, the upper transparent translucent polyolefin laminated film is overlapped using the same fixed rail and then another dedicated spring. The film is covered with two films by pressing the film through a special spring to a separate fixed rail installed in parallel with it, and then covering the film with two films. I can do it. Separately from this, the ends of the two translucent polyolefin-based laminated films are sealed in a bag shape by a heat seal method or the like in advance, and then the house is pressed into the fixed rail via a dedicated spring. The body can be stretch-coated. At this time, with respect to the house form of the agricultural air film structure house, any house form can be adopted, and in particular, the economics of the house itself, and the translucent polyolefin-based laminated film for the air film structure Considering the ease of fixing work and the heat retaining property of the air film structure, it is preferable to employ an agricultural house having a pipe type structure such as an underground push-in pipe type house or a steel reinforced pipe type house.

  In the agricultural air film structure house of the present invention, the constituent part having the air film structure may include a house wife face part or a side part in addition to the ceiling part of the house. In order to form the film, the air press-fitted by the blower can be formed by connecting to each constituent part in a serial or parallel relationship with the blower via the connection hose.

  At that time, the higher the ratio of the area of the air film structure location to the total covered area of the agricultural house, the higher the heat insulation performance of the agricultural air film structure house. To alleviate a significant temperature rise in the house, open the side, skylight, and some ceilings of the house at a certain time during the day to introduce outside air into the house for ventilation. Since it is necessary, an air film structure house for agriculture of a type that adopts an air film structure on the ceiling part excluding the skylight part or the wife face part excluding the entrance door together with the ceiling part is preferable as a form.

In addition, the structure, specifications and performance of the blower used are not particularly limited, but the air inside the house or the air outside the house uses a fan with a conventional bladed fan structure, sirocco fan structure, or air pump structure. In addition, air is blown continuously or intermittently to the air film structure portion constituted by the two translucent polyolefin laminated films. At that time, the air membrane structure composed of the two translucent polyolefin laminated films does not have a complete airtight structure, but the blown air uses two coating materials for the agricultural air membrane structure. There is a tendency to gradually leak out from the minute gap between the special fasteners fixed to the house and the covering, and the end of the two translucent polyolefin-based laminated films is pre-heated by heat sealing method etc. Even when used as an agricultural air film structure house sealed in a bag shape, there is almost no air leakage from the seal part, but the appropriate internal pressure of the air film structure part is adjusted while taking into account the amount of leakage at other points. In any case, the preferable air film internal pressure is preferably in the range of 1 to 20 mmH ₂ O with respect to the outside. If the air film internal pressure is too low, the air film structure part is sufficient. Inflated like a balloon In some cases, wrinkles of the coating material may occur in the air film structure, causing a flicker phenomenon of the coating material due to the external wind, causing problems in heat retention, translucency, strength, durability, etc. On the other hand, when the air film internal pressure is too high, there is a problem that the covering material is strongly stretched by the internal pressure, which may cause a problem in durability.

  In addition, it is preferable that the air to be blown is sent from the air in the house to the air membrane structure through the connection hose using the air in the house having a temperature higher than that of the outside air from the viewpoint of heat retention. Because the air in the house has a higher relative humidity and absolute humidity than the outside air, it may exhibit condensation over time inside the air film structure, so the air film structure of the translucent polyolefin-based laminated film In order to maintain the daytime translucency on the inner surface side of the part, it is necessary to select a covering material having further antifogging performance.

  In the air film structure house for agriculture obtained in this way, it is good for crop cultivation, can achieve further saving of heating fuel, heat retention, translucency, antifogging, dustproof, strength, It is possible to exhibit performance excellent in fusion resistance, durability, and economy.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example, this invention is not limited to a following example, unless the summary is exceeded.

  The breakdown of the olefinic resins used in the examples of the present invention is as shown in Table 1. Using these resins, the layer constitution and composition constitution shown in Table 2 were used, and the thickness was 0.10 to 0.15 mm. The base film was molded under the following conditions, and then the antifogging agent composition described in Table 3 was applied to obtain a desired laminated film (detailed configuration is described in Table 2).

(1) Preparation of substrate film:
Using three extruders of 90 mmΦ and a three-layer die of 1300 mmΦ, film outer layer / intermediate layer / inner layer = 20/60 / at a molding temperature of 200 ° C., a blow ratio of 2.0, and a take-off speed of 10 m / min. A base film having a three-layer structure having a layer ratio of 20 (the outer surface layer is a film surface that becomes the outer surface of the house when the house is stretched and corresponds to the inner layer side during film formation) was obtained.

(2) Application of anti-fogging agent composition:
Using the above-mentioned base film, a corona treatment discharge is applied to the film inner layer (corresponding to the film outer layer at the time of film formation), and the film wetting index (measuring method: conforming to JIS-K6768) is 42 dyn / cm or more After the surface modification was performed, the antifogging agent composition shown in Table 3 was applied by a gravure coating method and kept in a warm air drying furnace adjusted to a temperature of 80 ° C. for 1 minute to obtain a liquid dispersion solvent Were dispersed to form an antifogging agent film. The coating amount (solid content) of the antifogging coating film was 1 g / m ² in all cases.

  In addition, the direct light transmittance of the laminated film in the examples of the present invention, the measuring method of tensile breaking strength, the measuring method of anti-fusing property, the construction method of the agricultural air film structure house, and the agricultural air film structure house The following are the methods for cultivating these crops and the method for evaluating the degree of kerosene fuel consumption of the heater installed in the agricultural air film structure house.

(3) Measuring method of direct light transmittance:
The obtained laminated film was irradiated with light from the outer surface layer side of the laminated film in accordance with ASTM D1003 using a spectrophotometer (manufactured by Hitachi, Ltd .: U3500 type), and a light wavelength range of 555 μm. The direct light transmittance (unit:%) of was measured.

(4) Measurement method of tensile strength at break:
Using the tensile test apparatus (manufactured by Toyo Seiki Seisakusho Co., Ltd.), the obtained laminated film was measured in accordance with ASTM D882 at a measurement temperature of 23 ° C. and a tensile speed of 300 mm / min. (MD) and the transverse direction (TD) tensile fracture strength (unit: N / 10 mm width) were measured, and the average value was measured.

(5) Fusing resistance evaluation method:
Assuming the summer environment with the deflated state of the laminated film on the upper surface and the laminated film on the lower surface of the agricultural air film structure house, in the obtained laminated film, the outer surface side of one laminated film and the other After laminating the inner surface side of the laminated film with a thin water film formed and leaving it in an oven set at 80 ° C. for 5 hours with a load of 20 g / cm ² applied to the film surface, It returned to room temperature and the presence or absence of the fusion | melting phenomenon of the two laminated | stacked laminated films was observed.

(6) Agricultural air-film house construction method:
The above-mentioned laminated film is used as a covering material for the lower surface on the entire ceiling part (width 2.7m, depth 10m) of an underground push-in pipe type house with a frontage of 4.5m, depth of 10m, and height of 3m. After pressing down on a fixed rail (Toto Kogyo Co., Ltd .: Binipet) attached in parallel with the part via a dedicated spring (Toto Kogyo Co., Ltd .: Soft Spring), the top laminated film is stacked and the same Double-stretching and covering by pressing the fixed rail through another special spring (Toto Kogyo Co., Ltd .: soft spring). At that time, with a blower (manufactured by Nepon Co., Ltd .: EBM400S2M type) using a dedicated connection hose, insert the air in the house air film coating layer of the above, to adjust the output of the blower so that air film pressure is generally in the range of 3~7mmH 2 _O , It was set-up the agricultural air membrane structure house for the purpose. The house face and side portions were covered with a laminated film (A) to seal the house (agricultural air membrane structure house location: Ureshinogawa Kitamachi, Matsusaka City, Mie Prefecture).

(7) Cultivation method of crops in agricultural air film house:
In the above air film structure house for agriculture, soil cultivation of tomatoes was cultivated from the beginning of December 2006 to the end of March 2007, and the growth management of the crops was performed by appropriately irrigating and fertilizing. At that time, as a temperature management method for cultivation, when the temperature in the house during the day exceeds 25 ° C, the side of the house is hoisted and ventilated to suppress a significant temperature rise in the house during the day, On the other hand, if the house temperature falls at night or in the morning, or if the house temperature under cloudy weather does not reach the specified temperature during the daytime, the temperature of the house should be moderated by operating the hot air heater below. The temperature was controlled so as to maintain the temperature.

(8) Method for evaluating the degree of kerosene fuel consumption of a heater installed in an agricultural air film structure house:
A hot air type heater using kerosene fuel (manufactured by Nepon Co., Ltd .: KA125 type) is installed in the air film structure house for agriculture, and when the temperature in the house becomes 16 ° C. or less, the heater is operated. When the temperature exceeded 20 ° C., temperature control management was performed so that the heater stopped. The kerosene fuel consumption during the cultivation period of the crop was measured.

  Table 4 shows the results of each example and each comparative example as an agricultural air membrane structure house using the combination of laminated films described in Table 2 above.

Claims (4)

An agricultural air film structure house in which air is press-fitted by an air blower between a translucent polyolefin laminated film on the upper surface and a translucent polyolefin laminated film on the lower surface of at least the ceiling portion of the agricultural house. The ethylene-α synthesized using a metallocene catalyst having a density in the range of 905 to 930 kg / m ³ as a resin component of at least the outer surface film layer constituting each of the polyolefin-based laminated films on the upper surface and the lower surface. An agricultural air film structure house comprising a composition containing 50% by weight or more of an olefin copolymer resin.   The thickness of the translucent polyolefin-based laminated film is 0.04 to 0.18 mm, the direct light transmittance (light wavelength region: 555 nm) is 75% or more, and the film relative to the film thickness (D (unit: mm)) The agricultural air film structure house of Claim 1 whose tensile fracture strength (F (unit: N / 10mm width)) ratio (F / D) is 280 or more.   In the translucent polyolefin-based laminated film, an antifogging agent composition composed of a silica-based inorganic material or an alumina-based inorganic material is applied to at least one side surface corresponding to the house inner surface side of the film surface on the upper surface. Agricultural air membrane structure house as described in.   The agricultural air film structure house according to any one of claims 1 to 3, wherein the agricultural air film structure house has a structure of an underground push-in pipe type house or a steel reinforced pipe type house.