JP2020068684A - Agricultural film - Google Patents

Abstract

To provide an agricultural film capable of giving light quality balance ideal for plants.SOLUTION: An agricultural film whose transmission characteristics satisfy the following conditions: R/B ratio (an average value of the total light transmittance from 600 to 700nm/an average value of the total light transmittance from 400nm to 500nm) is larger than 1.05; R/G ratio (an average value of the total light transmittance from 600 to 700nm/an average value of the total light transmittance from 500nm to 600nm) is larger than 1.1; G/B ratio (an average value of the total light transmittance from 500 to 600nm/an average value of the total light transmittance from 400nm to 500nm) is larger than 1.05; an average value of the total light transmittance from 400 to 700nm is larger than 60%; an average value of the total light transmittance from 300 to 400nm is larger than 0%; an average value of the total light transmittance from 400 to 500nm is larger than 30%; an average value of the total light transmittance from 500 to 600nm is larger than 70%; and an average value of the total light transmittance from 600 to 700nm is larger than 80%.

Description

  The present invention relates to an agricultural film in which the average value of R / B ratio, R / G ratio, G / B ratio, and transmittance in each wavelength region is adjusted, and more specifically, these optical properties are adjusted. Involved in agricultural polyolefin resin films.

  In recent years, the domestic agricultural population has been declining steadily with the aging of the population, and there is a need for a new mechanism for agricultural production to obtain stable income. From the perspective of food security, it is necessary to improve agricultural production methods, increase the yield per unit area, and build a system that enables stable and efficient agricultural production.

  Under such circumstances, the so-called fully-controlled plant factory, in which an agricultural light source that irradiates an artificial light source to cultivate a crop in a building, has been receiving attention. In a fully controlled plant factory, since the yield per unit area is increased, a multi-stage cultivation method is adopted, which makes it difficult to grow tall crops, and the initial investment amount is enormous. Due to such constraints, leaf vegetables have been used mainly for short cultivation periods and high turnover rates. In this cultivation mode, crop cultivation can be done in an extremely short period of time by optimal environmental management such as temperature and humidity, light environment, and nutrient solution, but the cultivated crops are very limited, and it cannot be used for fruits and flowers. .. In addition, once a pest has occurred, there has been a problem that enormous effort and cost are required for its control. For this reason, it is necessary to prepare expensive equipment such as an air shower so that the cause of the pest may not be brought into a sterile facility.

  On the other hand, cultivation forms by institutional horticulture using resin films and the like have evolved in accordance with cultivation forms of various crops because stable agricultural income can be obtained as compared with open-field cultivation. Increasing the yield per unit area is effective in increasing the size of agricultural houses from the viewpoints of work efficiency and cultivating environment management, and many film spreading operations to cover such large houses with film. It is becoming more labor intensive. However, as the number of farmers is decreasing year by year and the population is aging, it is not easy to secure manpower for the expansion work every year. In view of such a situation, as a film to be spread on a house used in a solar-powered plant factory, a film that is easy to spread and has a long service life until it is replaced, in other words, has a long life of 2 years or more. In addition to the development of high-performance agricultural coating materials that can retain their initial performance over a long period of time, it is also required that long-term use of lining materials used internally, for example, is required due to deterioration protection of internal materials. Is coming.

  In addition, attempts have been made to reduce pesticides by suppressing the growth of disease-causing bacteria and molds and imparting pest control properties to the environment inside the greenhouse. Botrytis cinerea and sclerotium disease are typical diseases that occur in greenhouses, and cause damage such as death of stems, leaves, flowers, and fruits of various agricultural crops. Whitefly, Whitefly, Thrips palmi Lentil, and Thrips palmi L. are typical pests of crops widely cultivated in greenhouses such as tomatoes, cucumbers, melons, strawberries, and flowers. In addition, it causes a great deal of damage such as the transmission of soybean bacterium parasitic on excrement and viral diseases such as tomato yellow necrosis virus disease. Due to the recent demand for safety of agricultural products, a specific method for suppressing these pests and diseases is desired for the cultivation with reduced pesticides, and the control of these pests and diseases is a very important problem in institutional horticulture.

  On the other hand, as a method of reducing the quality risk and increasing the yield per unit area, a method of supplementing the light amount required for photosynthesis by supplementing light in cloudy weather has been attracting attention. For example, an incandescent light bulb, a fluorescent lamp, a high-pressure sodium lamp, a halogen lamp, a light emitting diode (LED), or the like may be used as a lighting device for compensating for the lack of sunshine in cultivation. Compared with, the illuminance is often low, a large amount of energy is required to obtain the illuminance, and there is a demerit that economic efficiency deteriorates. Further, since the light from the light source is locally irradiated, it is difficult to exert the irradiation effect on the plant bodies over the entire cultivation area. On the other hand, if the number of irradiation devices is increased in order to irradiate the entire cultivated crop, the efficiency of the devices themselves causes inefficiency, which is a problem.

  As a means for solving such a problem of electric energy cost and a problem of local irradiation, for example, a wavelength conversion film as disclosed in JP-A-7-123870 (Patent Document 1) is mentioned. These wavelength conversion films use a fluorescent substance to convert high-energy light having a short wavelength into light having a long wavelength, which is absorbed by a photoreceptor at the time of photosynthesis, with the aim of improving cultivability. is there. Among them, there are many examples of study of increasing red light of 600 to 700 nm, and the amount of light accumulated by wavelength conversion is extremely small compared to the case of using a light supplement device, but the irradiation area is conversely used by the light supplement device. Since it is significantly larger than that in the case of the whole plant, the magnitude of the effect of use in the whole plant depends on how high and long-lasting the wavelength conversion efficiency is. However, the wavelength conversion film using the conventional technology, even if it has been commercialized, does not have sufficient wavelength conversion effect, and the wavelength conversion effect disappears in about 4 months, and the effect continues despite the high unit price of the film. Not doing was a problem. In addition, a similar wavelength conversion material is proposed in Japanese Patent Laid-Open No. 2007-135583 (Patent Document 2), but in reality, the perylene-based wavelength conversion substance used in the examples has a low effect persistence. In addition, although it is compatible with the polyester resin, it is not compatible with the polyolefin resin and there is a practical problem such that a wide film cannot be produced. Further, like the wavelength conversion substance described in JP 2011-115073 A (Patent Document 3), although it is compatible with a polyolefin resin to some extent, it is water-soluble, so that it may be washed out of the film system, and may be resistant to ultraviolet rays. There is a problem in that the durability is low, the sustainability of the effect is insufficient, and the sustainability of the performance when added to an agricultural film is insufficient.

JP-A-7-123870 JP, 2007-135583, A JP, 2011-115073, A

  An object of the present invention is to provide an agricultural film capable of giving an ideal light quality balance for plants.

The present inventors, by using a light adjustment film whose main component of an additive pigment is other than a fluorescent pigment, without using a means of wavelength conversion that absorbs light of a short wavelength and emits light of a long wavelength, By maintaining the transmittance of the wavelength range and the ratio of the average value of the transmittance of the specific wavelength range to a specific value or higher, the cultivation productivity improvement effect can be maintained for a long period of time without using expensive fluorescent pigments. The inventors have found out what can be done and have completed the present invention.
That is, by using the light adjusting film of the present invention, light having a short wavelength and high energy (for example, blue light) is absorbed to suppress the elongation suppression reaction of the morphogenesis reaction, and to secure the amount of light necessary for photosynthesis. However, by transmitting longer wavelength light (red light of 600 to 700 nm), elongation and growth are promoted by a morphogenic reaction, and more wavelengths effective for photosynthesis for plants are introduced into the house.
Such effects on plant growth in each wavelength range have been studied in cultivation using artificial light, but which wavelength range is specifically determined by light adjustment by a covering material using sunlight. How to control the R / B ratio, R / G ratio, and G / B ratio by setting the transmittance as described above has not been properly examined, and the specific setting values have not been clarified. .. The present invention, based on a detailed examination of what kind of transmittance setting of the light-conditioning film can sustain high cultivability for a long period of time by using a pigment having high durability, and technical characteristics are clarified. By doing so, an agricultural film that exhibits good cultivability for a long period of time as compared with conventional materials has been completed.

That is, the present invention is
[1] An agricultural film that satisfies the following characteristics.
・ R / B ratio (average value of total light transmittance of 600 to 700 nm / average value of total light transmittance of 400 nm to 500 nm) is larger than 1.05 ・ R / G ratio (total light transmittance of 600 to 700 nm) Average value / total average light transmittance of 500 nm to 600 nm) is larger than 1.1 G / B ratio (average total light transmittance of 500 to 600 nm / average total light transmittance of 400 nm to 500 nm) Value) is greater than 1.05 ・ Average value of total light transmittance of 400 to 700 nm is greater than 60% ・ Average value of total light transmittance of 300 to 400 nm is greater than 0% ・ Total light transmittance of 400 to 500 nm The average value of the transmittance is greater than 30%. The average value of the total light transmittance of 500 to 600 nm is greater than 70%. The average value of the total light transmittance of 600 to 700 nm is 80. Greater than and,
[2] An agricultural film that satisfies the following characteristics.
・ R / B ratio (total light transmittance at 660 nm / total light transmittance at 460 nm) is larger than 1.1 ・ R / G ratio (total light transmittance at 660 nm / total light transmittance at 555 nm) is 1.0 Greater than G / B ratio (total light transmittance of 555 nm / total light transmittance of 460 nm) is greater than 1.02. Average value of total light transmittance of 400 to 700 nm is greater than 60%. 300 to 400 nm The average value of total light transmittance is greater than 0%. The average value of total light transmittance of 400 to 500 nm is greater than 30%. The average value of total light transmittance of 500 to 600 nm is greater than 70%. 600 to 700 nm. The average value of the total light transmittance of is greater than 80%.

According to one embodiment of the present invention, it is possible to provide an agricultural film in which, in addition to the R / B ratio, the R / G ratio, the G / B ratio, and the light transmittance average value in each wavelength region are adjusted.
The agricultural film of the present invention absorbs light having a short wavelength and high energy (for example, blue light), suppresses the elongation suppression reaction of the morphogenic reaction, and secures the amount of light required for photosynthesis, while By transmitting light of a wavelength (red light of 600 to 700 nm), growth growth is promoted by a morphogenic reaction, and more wavelengths effective for photosynthesis for plants can be introduced into the house, and for plants, It is possible to give an ideal light quality balance.

  Hereinafter, the present invention will be described in detail.

  The material for the agricultural film (base resin) that can be used in the present invention generally has a film-forming ability that can be melt-molded at about 150 to 250 ° C., and is generally used for an agricultural coating material. Any of the above can be used, but vinyl chloride resins such as polyvinyl chloride, polyolefin resins, polyester resins such as polyethylene terephthalate, and fluororesins are preferable.

  In the present invention, the vinyl chloride resin means not only polyvinyl chloride but also a copolymer whose main component is vinyl chloride. Examples of the monomer compound which can be copolymerized with vinyl chloride include vinylidene chloride, ethylene, propylene, acrylonitrile, maleic acid, itaconic acid, acrylic acid, methacrylic acid and vinyl acetate. These vinyl chloride resins may be produced by any of conventionally known production methods such as emulsion polymerization method, suspension polymerization method, solution polymerization method and bulk polymerization method.

  Further, in the present invention, as the vinyl chloride resin, those having an average degree of polymerization of 1000 or more and 2500 or less, preferably 1100 or more and 2000 or less can be used, but two types having different average degree of polymerization are mixed. May be. As this mixing method, a method of mixing two kinds of resins at the time of forming a film is generally used, but two kinds of resins having different apparent degrees of polymerization are apparently obtained by controlling the polymerization conditions at the time of polymerization of vinyl chloride resin. It may be a mixed method.

  In order to impart flexibility to the vinyl chloride resin film, 30 to 60 parts by weight, preferably 40 to 55 parts by weight, of a plasticizer is added to 100 parts by weight of the resin. If it is less than 30 parts by weight, the flexibility at low temperature is poor, and sufficient low temperature physical properties cannot be obtained. On the other hand, if the amount exceeds 60 parts by weight, the handling property at room temperature (stickiness etc.) is deteriorated and the workability at the time of film forming is deteriorated, which is not preferable.

  Examples of the plasticizer that can be used include phthalic acid derivatives such as di-n-octyl phthalate, di-2-ethylhexyl phthalate, dibenzyl phthalate and diisodecyl phthalate; isophthalic acid derivatives such as dioctyl phthalate; di-n-butyl adipate. , Adipic acid derivatives such as dioctyl adipate; maleic acid derivatives such as di-n-butyl maleate; citric acid derivatives such as tri-n-butyl citrate; itaconic acid derivatives such as monobutyl itaconate; oleic acid such as butyl oleate Derivatives; ricinoleic acid derivatives such as glycerin monoricinolate; epoxidized soybean oil, epoxy resin-based plasticizers and the like. Further, in order to impart flexibility to the resin film, it is not limited to the above-mentioned plasticizer, and for example, thermoplastic polyurethane resin, polyvinyl acetate or the like can be used.

  Also, as the vinyl chloride resin, a blend of polyvinyl chloride and chlorinated polyethylene can be used. As the chlorinated polyethylene, polyethylene as a raw material is homopolymerized with ethylene or has 12 or less (preferably 3 to 9) carbon atoms of 30% by weight or less (preferably 20% by weight or less) of ethylene. Those obtained by copolymerizing the α-olefin of are preferable.

  Specific examples of the α-olefin include propylene, 1-butene, 1-hexene, 4-methyl-1-pentene and the like. As the raw material polyolefin, one obtained by homopolymerizing ethylene is particularly preferable. As the chlorinated polyethylene, a method of chlorinating polyethylene powder or particles in an aqueous suspension or chlorinating polyethylene dissolved in an organic solvent is adopted.

  The amount of chlorinated polyethylene mixed with the vinyl chloride resin is usually 0.5 to 20 parts by weight, preferably 0.5 to 10 parts by weight. The melt index of chlorinated polyethylene can be appropriately selected within the range of 0.5 to 150 g / 10 minutes.

As the polyolefin resin, an α-olefin-based homopolymer, a copolymer of a heteromonomer having an α-olefin as a main component, an α-olefin and a polyunsaturated compound such as a conjugated diene or a non-conjugated diene, Examples thereof include copolymers with acrylic acid, methacrylic acid, vinyl acetate, etc., for example, high density, low density or linear low density polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-butene copolymer, ethylene. Examples include -4-methyl-1-pentene copolymer, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer and the like. Among these, low-density polyethylene having a density of 0.910 to 0.935 g / cm ^3, an ethylene-α-olefin copolymer, and an ethylene-vinyl acetate copolymer having a vinyl acetate content of 30% by weight or less are transparent. It is preferable as an agricultural film from the viewpoints of properties, weather resistance and price. Further, in the present invention, an ethylene-α-olefin copolymer resin obtained by copolymerizing with a metallocene catalyst can be used as at least one component of the polyolefin resin.

  This is usually referred to as metallocene polyethylene, and is a copolymer of ethylene and an α-olefin such as butene-1, hexene-1, 4-methylpentene-1, octene. Method A) (JP-A-58-19309, JP-A-59-95292, JP-A-60-35005, etc.) and (B-method) (JP-A-6-9724, JP-A-6-924). 136195, JP-A-6-136196, etc.).

  Without being bound by the above methods (A) and (B) in that good initial transparency and transparency sustainability of the film can be obtained, a polyolefin resin polymerized using a metallocene compound, that is, metallocene polyethylene is used. Can be used.

  Polyethylene resins including these metallocene polyethylenes are classified by temperature rising elution fractionation (TREF: Temperature Rising Elution Fractionation), MFR, density, molecular weight distribution, and other measurements of various physical properties. The measurement of the elution curve by temperature rising elution fractionation (TREF) is performed by "Journal of Applied Polymer Science. Vol 126, 4, 217-4, 231 (1981)", "Proceedings of the 9th Political Debate, C. No. 9". 1988) ”and other principles.

The ethylene-α-olefin copolymer used as at least one component of the polyolefin resin used in the present invention has an MFR measured according to JIS-K7210 of 0.01 to 10 g / 10 minutes, preferably 0.1 to 10. The value is 5 g / 10 minutes. When the MFR is larger than this range, the film meanders during molding and is not stable. If the MFR is smaller than this range, the resin pressure at the time of molding increases and a load is applied to the molding machine. Therefore, it is necessary to reduce the production amount and suppress the increase in pressure, which is not practical. The ethylene-α-olefin copolymer used as at least one component of the polyolefin resin used in the present invention has a density of 0.880 to 0.930 g / cm ³ , preferably measured according to JIS-K7112. A value of 0.880 to 0.920 g / cm ³ is shown. If the density is higher than this range, the transparency will deteriorate. On the other hand, if the density is lower than this range, the film surface becomes sticky and causes blocking, resulting in poor practicability. The ethylene-α-olefin copolymer used as at least one component of the polyolefin resin used in the present invention has a molecular weight distribution (weight average molecular weight / number average molecular weight) determined by gel permeation chromatography (GPC). ) Indicates a value of 1.5 to 3.5, preferably 1.5 to 3.0. When the molecular weight distribution is larger than this range, the mechanical strength is lowered, which is not preferable. If the molecular weight distribution is smaller than this range, the film will meander during molding and will not be stable.

  The ethylene-vinyl acetate copolymer resin having a vinyl acetate content of usually 10 to 25% by weight, preferably 12 to 20% by weight can be used. If the vinyl acetate content is less than this range, the resulting film becomes hard and wrinkles and slack are likely to occur when it is spread on the house, and the antifogging property is adversely affected, resulting in poor practicability. If it is larger than the range, the melting point of the resin is low, so that the film is slackened at high temperature in the summer when the house is extended, and the film is apt to be broken by rubbing with the wind and the house structure, which is not practical.

  One embodiment of the present invention, the average value of the transmittance of a specific wavelength range, and the ratio of the average value of the transmittance in a specific wavelength range and the average value of the transmittance of a specific wavelength range is a specific value or more. It is an agricultural film set. While setting blue light, green light, and red light to be transmitted at a specific ratio, it is possible to set a high cultivation productivity improving effect by adjusting the R / B ratio, R / G ratio, and G / B ratio. Become.

In the present specification, the R / B ratio of blue light and red light is the average value of the total light transmittance of 600 to 700 nm / the average value of the total light transmittance of 400 nm to 500 nm (hereinafter referred to as “R / B ratio (1 ) ”) Or the ratio of the total light transmittance at 660 nm to the total light transmittance at 460 nm (hereinafter also referred to as“ R / B ratio (2) ”). The ratio of the average values of the transmittances in the specific wavelength range is 1.05, or the ratio of the transmittances in the specific wavelength is larger than 1.1.
In the agricultural film of the present invention, the R / B ratio (1) is preferably larger than 1.05, more preferably larger than 1.15, and further preferably larger than 1.25. The R / B ratio (1) is preferably smaller than 1.35.
Further, in the agricultural film of the present invention, the R / B ratio (2) is preferably larger than 1.1, more preferably larger than 1.15, and further preferably larger than 1.2. The R / B ratio (2) is preferably smaller than 1.35.

In the present specification, the R / G ratio of green light and red light means the average value of the total light transmittance of 600 to 700 nm / the average value of the total light transmittance of 500 nm to 600 nm (hereinafter referred to as “R / G ratio (1 ) ”) Or the ratio of the total light transmittance at 660 nm to the total light transmittance at 555 nm (hereinafter also referred to as“ R / G ratio (2) ”). The ratio of the average transmittance values in the specific wavelength region or the transmittance ratio in the specific wavelength region is greater than 1.0.
In the agricultural film of the present invention, the R / G ratio (1) and the R / G ratio (2) are preferably larger than 1.1, more preferably larger than 1.15, and further preferably 1.2. large. Further, the R / G ratio (1) and the R / G ratio (2) are preferably smaller than 1.25.

In the present specification, the G / B ratio of blue light and green light means the average value of the total light transmittance of 500 to 600 nm / the average value of the total light transmittance of 400 nm to 500 nm (hereinafter referred to as “G / B ratio”). (1) "or total light transmittance of 555 nm / total light transmittance of 460 nm (hereinafter also referred to as" G / B ratio (2) "), and each value is greater than 1.02 And
In the agricultural film of the present invention, the G / B ratio (1) and the G / B ratio (2) are preferably larger than 1.05, more preferably larger than 1.1, and further preferably 1.15. large. Further, the G / B ratio (1) and the G / B ratio (2) are preferably smaller than 1.20.

  In the agricultural film of the present invention, the average value of the total light transmittance from 400 to 700 nm is larger than 60%. The average value of the total light transmittance of 400 to 700 nm of the present invention is preferably larger than 60%, more preferably larger than 65%, and further preferably larger than 70%. The average value of the total light transmittance of 400 to 700 nm is preferably less than 85%.

  In the agricultural film of the present invention, the average value of the total light transmittance at 300 to 400 nm is characterized by being larger than 0%. The average value of the total light transmittance of 300 to 400 nm of the present invention is preferably larger than 0%, more preferably larger than 40%, and further preferably larger than 65%. The average value of the total light transmittance of 300 to 400 nm is preferably less than 70%.

  In the agricultural film of the present invention, the average value of the total light transmittance at 400 to 500 nm is larger than 30%. The average value of the total light transmittance of 400 to 500 nm of the present invention is preferably larger than 33%, more preferably larger than 35%, further preferably larger than 40%, and particularly preferably larger than 50%. Further, the average value of the total light transmittance of 400 to 500 nm is preferably less than 70%.

  In the agricultural film of the present invention, the average value of the total light transmittance at 500 to 600 nm is greater than 70%. The average value of the total light transmittance of 500 to 600 nm of the present invention is preferably more than 70%, more preferably more than 73%, and further preferably more than 75%. The average value of the total light transmittance of 500 to 600 nm is preferably less than 100%.

  In the agricultural film of the present invention, the average value of the total light transmittance from 600 to 700 nm is larger than 80%. The average value of the total light transmittance of 600 to 700 nm of the present invention is preferably larger than 80%, more preferably larger than 83%, and further preferably larger than 85%. The average value of the total light transmittance of 600 to 700 nm is preferably less than 100%.

In the agricultural film of the present invention, the main component of the additive pigment is other than the fluorescent pigment. When the main component is other than the fluorescent pigment, it is possible to use a known organic or inorganic pigment other than the fluorescent substance such as the wavelength conversion substance as the main component of the additive pigment.
In addition, in the agricultural film of the present invention, use of a fluorescent pigment other than the main component is not excluded as long as the effect of the present invention is not impaired.

  Examples of the pigment that can be used in the present invention include isoindolinone pigment and dioxazine violet (8,18-dichloro-5,15-diethyl-5,15-dihydrodiindolo [3,2-b: 3 ′, 2′- m] triphenodioxazine) and the like. By including isoindoline and dioxazine violet, it becomes possible to adjust the R / G ratio and the G / B ratio in addition to adjusting the R / B ratio.

  In cultivation experiments using LEDs and colored fluorescent lamps, it is becoming clear that the extreme enhancement of red light does not necessarily lead to improvement in growth, and that red light, green light and blue light must be balanced. In particular, in an experiment using a fluorescent lamp, it is becoming clear that the presence of blue light and green light to some extent is preferable in the cultivation environment even in an environment where red light is strong, and usually R tends to be noticed. Not only the / B ratio, but also the R / G ratio and the G / B ratio have been increasing in interest. From such a situation, in addition to high R / B ratio, improvement of cultivability in a light environment having R / G ratio and R / G ratio higher than that of sunlight, and in a form that can withstand practical use, In addition, there has been a long-awaited demand for a method of setting the transmittance of each wavelength region to obtain such a light environment. The invention of this embodiment has a high cultivability by setting the specific R / B ratio, R / G ratio, G / B ratio, and the transmittance in a specific wavelength region to the values described in the present invention or more. The effect is sustainable.

  In the agricultural film of the present invention, for example, the content of dioxazine violet is 0.005 to 1.0% by weight, preferably 0.01 to 0.75% by weight, based on the weight of the entire agricultural film. More preferably, it is 0.02 to 0.5% by weight. Further, in the agricultural film of the present invention, for example, the content of the isoindolinone pigment is 0.01 to 3.0% by weight, preferably 0.05 to 2.0% by weight, based on the weight of the entire film. , And more preferably 0.1 to 1.5% by weight. By setting the content of the dioxazine violet or isoindolinone pigment in the above range, the R / G ratio, the R / G ratio, and the G / B ratio can be set in the above preferable ranges, and the visible light range ( (400 to 700 nm), the average value of the transmittance in each wavelength range described in the present invention can be set while ensuring high light transmittance.

In the agricultural film of the present invention, the additive pigment may be added to all layers, or may be added to a part of layers (intermediate layer, or intermediate and outer layers, etc.).
In addition, in the agricultural film of the present invention, a plurality of pigments may be added to all layers, or may be added separately to some layers (intermediate layer, or intermediate and outer layers, etc.).

  In the agricultural film and the agricultural polyolefin film of the invention, various additives usually used for agricultural films can be blended. Examples of these additives include anti-fog agents, anti-fog agents, weather resistance improvers (hindered amine light stabilizers, ultraviolet absorbers, etc.), weather resistance agents, infrared absorbers, heat retaining agents, fillers, metal organics. Oxidation of acid salts, basic organic acid salts and overbased organic acid salts, hydrotalcite compounds, epoxy compounds, β-diketone compounds, polyhydric alcohols, halogen oxyacid salts, sulfur compounds, phenol compounds and phosphite compounds. Examples include an inhibitor, a heat stabilizer, a lubricant, an antistatic agent, a colorant, an antiblocking agent, and the like.

  Examples of the antifogging agent include various known nonionic surfactants, anionic surfactants, cationic surfactants, and other polyhydric alcohol partial ester systems composed of polyhydric alcohols and higher fatty acids. Those of silicone type, silicone type surfactant and fluorine type surfactant are preferable. Specific examples of such an antifogging agent include, for example, nonionic surfactants such as sorbitan monostearate, sorbitan monomyristate, sorbitan monopalmitate, sorbitan monobehenate, condensate of sorbitan and alkylene glycol and fatty acid. Glycerin monopalmitate, glycerin monostearate, glycerin monolaurate, diglycerin monopalmitate, glycerin dipalmitate, glycerin distearate, diglycerin monopalmitate monostearate , Triglycerin monostearate, triglycerin distearate or glycerin-based surfactants such as alkylene oxide adducts thereof, polyethylene glycol monostearate, polyethylene glycol Polyethylene glycol-based surfactants such as coal monopalmitate and polyethylene glycol alkyl phenyl ether, and other trimethylolpropane-based surfactants such as trimethylolpropane monostearate and pentaerythritol monopalmitate, pentaerythritol monostearate and other penta Erythritol-based surfactant, alkylene oxide adduct of alkylphenol; ester of sorbitan / glycerin condensate with fatty acid, sorbitan / alkylene glycol condensate with fatty acid; diglycerindiolate sodium lauryl sulfate, dodecylbenzene sulfonic acid Sodium, cetyltrimethylammonium chloride, dodecylamine hydrochloride, lauric acid laurylamide ethyl phosphate Can be exemplified triethylammonium cetyl ammonium iodide, oleyl amino diethylamine hydrochloride, and those containing dodecyl pyridinium salts, etc. and their isomers.

  As the anti-fog agent, a fluorine-based surfactant, specifically, a surfactant in which a part or all of F is substituted for H bonded to C of the hydrophobic group of a normal surfactant, Surfactants containing perfluoroalkyl or perfluoroalkenyl groups can be used. Examples of the fluorine-containing compound having a perfluoroalkyl group include anionic fluorine-containing surfactants, cationic fluorine-containing surfactants, amphoteric fluorine-containing surfactants, nonionic fluorine-containing surfactants and fluorine-containing oligomers. can give.

  As the hindered amine light stabilizer, a hindered amine light weathering agent that is usually blended for agriculture can be used. For example, a hindered amine compound having at least two piperidine ring structures in a molecule and having a molecular weight of 500 or more ( Hereinafter, a "piperidine ring-containing hindered amine compound" can be preferably used.

  Examples of the piperidine ring-containing hindered amine compound include bis (1,2,2,6,6-pentamethyl-4-piperidyl) -2-butyl-2- (3,5-di-tert-butyl-4-hydroxybenzyl). ) Malonate, tetra (2,2,6,6-tetramethyl-4-piperidyl) butanetetracarboxylate, tetra (1,2,2,6,6-pentamethyl-4-piperidyl) butanetetracarboxylate, bis ( 2,2,6,6-Tetramethyl-4-piperidyl) .di (tridecyl) butanetetracarboxylate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) .di (tridecyl) butanetetra Carboxylate, 3,9-bis [1,1-dimethyl-2- {tris (2,2,6,6-tetramethyl-4-piperidyloxy Rubonyloxy) butylcarbonyloxy} ethyl] -2,4,8,10-tetraoxaspiro [5.5] undecane, 3,9-bis [1,1-dimethyl-2- {tris (1,2,2) , 6,6-Pentamethyl-4-piperidyloxycarbonyloxy) butylcarbonyloxy} ethyl] -2,4,8,10-tetraoxaspiro [5.5] undecane, 1,5,8,12-tetrakis [4 , 6-bis {N- (2,2,6,6-tetramethyl-4-piperidyl) butylamino} -1,3,5-triazin-2-yl] -1,5,8,12-tetraaza Dodecane, 1- (2-hydroxyethyl) -2,2,6,6-tetramethyl-4-piperidinol / dimethyl succinate condensate, 2-tertiary octylamino-4,6-dichloro-s-triazine N, N'-bis (2,2,6,6-tetramethyl-4-piperidyl) hexamethylenediamine condensate, N, N'-bis (2,2,6,6-tetramethyl-4-piperidyl) Examples include hexamethylenediamine / dibromoethane condensate.

  In addition, commercially available hindered amine compounds, TINUVIN770, TINUVIN780, TINUVIN144, TINUVIN622LD, TINUVIN NOR 371, CHIMASSORB119FL, CHIMASSORB944 (above, manufactured by Ciba-Geigy), Sanor LS-765 (Sankyo LS, R-A, Sankyo (R), Sankyo (A-R), Sankyo (A-L), A). -68, MARK LA-68, MARK LA-62, MARK LA-67, MARKLA-57, LA-900, LA-81, NO-Alkyl-1 (above, manufactured by ADEKA), UV-3346, UV-3529. , UV-3581, UV-3853 (above, manufactured by Cytec), Hostabin N20, Hostabin N24, Hostabin N30, Hostabin 845, Hostabin NOW, Sandubo. A PR-31, Nairostab S-EED (above, Clariant Japan KK), UVINUL5050H (above, BASF Japan KK) and the like can be used. These piperidine ring-containing hindered amine compounds are used alone or in combination of two or more.

  The content of the hindered amine compound is 0.001 to 5% by weight, preferably 0.01 to 1% by weight, based on 100% by weight of the base resin of the agricultural film. If the content is less than 0.001% by weight, a sufficient effect cannot be obtained, and if it is more than 5% by weight, the effect is not improved, and the physical properties of the film are deteriorated.

Further, a copolymer of ethylene (A) and a cyclic aminovinyl compound (B) represented by the following formula (1) can be added to the agricultural film of the present invention.
In formula (1), R1 and R2 each independently represent a hydrogen atom or a methyl group, R3 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and preferably R1 and R2 are each a methyl group. And R3 is a hydrogen atom.

  The vinyl compound (B) represented by the formula (1) can be synthesized by a known method, for example, the method described in JP-B-47-8539, JP-A-48-65180 and the like.

Representative examples of the vinyl compound (B) represented by the formula (1) include 4-acryloyloxy-2,2,6,6-tetramethylpiperidine and 4-acryloyloxy-1,2,2,6,6. -Pentamethylpiperidine, 4-acryloyloxy-1-ethyl-2,2,6,6-tetramethylpiperidine, 4-acryloyloxy-1-propyl-2,2,6,6-tetramethylpiperidine, 4-acryloyl Oxy-1-butyl-2,2,6,6-tetramethylpiperidine, 4-methacryloyloxy-2,2,6,6-tetramethylpiperidine, 4-methacryloyloxy-1,2,2,6,6- Pentamethylpiperidine, 4-methacryloyloxy-1-ethyl-2,2,6,6-tetramethylpiperidine, 4-methacryloyloxy-1-butyl 2,2,6,6-tetramethylpiperidine, 4-crotonoyloxy-2,2,6,6-tetramethylpiperidine, 4-crotonoyloxy-1-propyl-2,2,6,6-tetramethyl Examples thereof include piperidine.

  The ethylene / cyclic aminovinyl compound copolymer is preferably such that the ratio of the (B) to the sum of the ethylene (A) and the cyclic aminovinyl compound (B) is 0.0005 to 0.85 mol%, It is more preferably 0.001 to 0.55 mol%. That is, the preferable thing of this copolymer has high light stability although the content of the vinyl monomer (cyclic amino vinyl compound (B)) which has a hindered amine group in a side chain is small. When the concentration of the cyclic aminovinyl compound (B) is 0.0005 mol%, the light stabilizing effect is sufficiently exhibited, while when it exceeds 0.85 mol%, it tends to be substantially uneconomical.

  Further, in the ethylene / cyclic aminovinyl compound copolymer, two or more (B) do not continuously exist in the copolymer, and the proportion of isolated (B) is 83% or more based on the total amount of (B), It is preferably 90% or more.

  The content of the ethylene / cyclic aminovinyl compound copolymer is preferably 0.5 to 15 parts by weight, particularly preferably 0.5 to 10 parts by weight, based on 100 parts by weight of the resin constituting the film. If the content is less than the above range, the weather resistance will be poor, so that it is not preferable, and if it exceeds the above range, it is not preferable in terms of economy.

  Examples of commercially available ethylene / cyclic aminovinyl copolymers that can be used include Novatec LD.XJ100H (manufactured by Nippon Polychem Co., Ltd.).

  In the present invention, by containing an ultraviolet absorber, it is possible to maintain a preferable light quality balance for a long period of time by substantially cutting off ultraviolet rays, and it can be expected to have a pest control effect.

As the ultraviolet absorber, for example, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 5,5′-methylenebis (2-hydroxy-4-methoxybenzophenone), etc. 2-hydroxybenzophenones; 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2- (2′-hydroxy-3 ′, 5′-ditertiarybutylphenyl) benzotriazole, 2- ( 2'-Hydroxy-3 ', 5'-di-tert-butylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3'-tert-butyl-5'-methylphenyl) -5-chlorobenzo Triazole, 2- (2'-hydroxy-5'-tertiary octylphenyl) benzotriazole, 2- (2'-hydroxy-3 ' 2- [2'-hydroxyphenyl) benzotriazoles such as 5'-dicumylphenyl) benzotriazole and 2,2'-methylenebis (4-tertiaryoctyl-6-benzotriazolyl) phenol; 2- [ 5-chloro (2H) -benzotriazol-2-yl] -4-methyl-6- (tert-butyl) phenol, 2- [5-chloro (2H) -benzotriazol-2-yl] -4,6- Benzotriazole type UV absorbers such as di (tert-pentyl) phenol; phenyl salicylate, resorcinol monobenzoate, 2,4-di-tert-butylphenyl-3 ', 5'-di-tert-butyl-4'-hydroxybenzoate, 2,4-Ditertiary amylphenyl-3 ', 5'-ditertiary butyl-4'-hydroxybenzoate, hexadecyl-3,5-ditertiary Benzoates such as tyl-4-hydroxybenzoate; Substituted oxanilides such as 2-ethyl-2'-ethoxyoxanilide and 2-ethoxy-4'-dodecyloxanilide; Ethyl-α-cyano-β, β- Cyanoacrylates such as diphenyl acrylate and methyl-2-cyano-3-methyl-3- (p-methoxyphenyl) acrylate; 2- (4,6-diphenyl-1,3,5-triazin-2-yl)- Triazines such as 5-[(hexyl) oxy] -phenol and 2- [4,6-bis (2,4-dimethylphenyl) -1,3,5-triazin-2-yl] -5- (octyloxy) phenol Kind and the like. These ultraviolet absorbers are used alone or in combination of two or more.
In the present invention, in particular, (2- [5-chloro (2H) -benzotriazol-2-yl] -4,6-di (tert-pentyl) phenol) alone or 2- [5-chloro By using it in combination with (2H) -benzotriazol-2-yl] -4-methyl-6- (tert-butyl) phenol, while imparting bleed-out resistance, it is preferable to provide a favorable light quality balance and pest control for a long period of time. You can expect an effect.

  The ultraviolet absorber can be added in an amount of preferably more than 0.001% by weight and less than 2% by weight, more preferably 0.01 to 1% by weight, based on 100% by weight of the base resin of the agricultural film. If the content is less than the above range, the effect of improving the weather resistance is low, and if it exceeds the above range, there is a problem such as a decrease in transparency due to bleed-out.

  By adding an infrared absorber to the agricultural film of the present invention, good heat retention can be imparted. As the infrared absorber, an inorganic compound (inorganic oxide, inorganic hydroxide, hydrotalcite, etc.) containing at least one atom of Mg, Ca, Al, Si and Li effective as a heat retaining agent can be used.

In particular, when a hydrotalcite-type infrared absorber represented by the following formula (2) is used, an inexpensive film having good moldability can be obtained.
Mg4.5Al2 (OH) 13CO3 ・ 3.5H2O (2)

Especially, when an infrared absorber represented by the following formula (3) is used, a film which is inexpensive and has good moldability can be obtained.
[Al2 (Li (1-x) .M (x + y)) (OH) 6 + y] 2 (An-) 2 (1 + x) /n.mH2O (3)
(In the formula, M is Mg and / or Zn, A is an n-valent anion, m is 0 or a positive number, and x and y are in the range of 0 ≦ x <1 and 0 ≦ y ≦ 0.5. )

  The method for obtaining the infrared absorbing agent (heat retaining agent) represented by the above formula (3) is not particularly limited, and commercially available ones can be used. For example, DHT4A, DHT6A, SYHT-3 (Kyowa Chemical Co., Ltd.) Manufactured by Sakai Chemical Industry Co., Ltd., Optima (manufactured by Toda Kogyo Co., Ltd.), Mizukarak (manufactured by Mizusawa Chemical Co., Ltd.) and the like.

  The infrared absorbing agent (heat retaining agent) is an inorganic fine particle having an infrared absorbing ability, and these can be used alone or in combination of two or more kinds. The inorganic fine particles that can be used are not particularly limited, but an inorganic compound containing at least one atom selected from the components: Si, Al, Mg, Ca can be used. For example, magnesium oxide, calcium oxide, aluminum oxide, silicon oxide, lithium hydroxide, magnesium hydroxide, calcium hydroxide, aluminum hydroxide, magnesium carbonate, calcium carbonate, calcium sulfate, magnesium sulfate, aluminum sulfate, lithium phosphate, calcium phosphate. , Magnesium silicate, calcium silicate, aluminum silicate, calcium aluminate, magnesium aluminate, sodium aluminosilicate, potassium aluminosilicate, calcium aluminosilicate, kaolin, clay, talc, mica, zeolite, hydrotalcite compounds and the like. These may be dehydrated water of crystallization.

  The inorganic fine particles may be natural products or synthetic products. Further, the above-mentioned inorganic fine particles can be used without being limited by their crystal structure, crystal particle size, and the like.

  The content of the inorganic fine particles is preferably more than 0.1% by weight and less than 15% by weight, and more preferably 1 to 12% by weight, based on 100% by weight of the base resin of the agricultural film. If the content is less than the above range, the effect of improving heat retention is low, and if the content exceeds the above range, there is a problem such as deterioration of transparency.

  Examples of the metal species constituting the organic acid salts, basic organic acid salts and overbased organic acid salts of the above metals include Li, Na, K, Ca, Ba, Mg, Sr, Zn, Cd, Sn, Cs, Examples of the organic acid include Al and organic Sn, and examples of the organic acid include carboxylic acid, organic phosphoric acids, and phenols.

  Examples of the filler include a silica, talc, aluminum hydroxide, hydrotalcite, calcium sulfate, calcium silicate, calcium hydroxide, and hydroxide for suppressing stickiness of the film or for further improving heat retention. Magnesium, kaolin clay, mica, alumina, magnesium carbonate, sodium aluminate, conductive zinc oxide, lithium phosphate, etc. are used. These fillers may be used alone or in combination of two or more.

  Examples of the phenolic antioxidant include 2,6-di-tert-butyl-p-cresol, 2,6-diphenyl-4-octadecyloxyphenol, stearyl (3,5-di-tert-butyl-4-). Hydroxyphenyl) -propionate, distearyl (3,5-di-tert-butyl-4-hydroxybenzyl) phosphonate, thiodiethylene glycol bis [(3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 1,6 -Hexamethylene bis [(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] and the like.

  Examples of the sulfur-based antioxidant include dialkyl thiodipropionates such as dilauryl thiodipropionate, dimyristyl and distearyl, and β-alkylmercapto polyols such as pentaerythritol tetra (β-dodecylmercaptopropionate). Examples include propionic acid esters.

  Examples of the phosphite-based antioxidant include trisnonylphenyl phosphite, tris (2,4-ditertiary butylphenyl) phosphite, tris [2-tertiary butyl-4- (3-tertiary butyl-). 4-hydroxy-5-methylphenylthio) -5-methylphenyl] phosphite and the like can be mentioned.

  Examples of the colorant include phthalocyanine blue, phthalocyanine green, Hansa yellow, alizarin lake, titanium oxide, zinc white, ultramarine blue, permanent red, quinacridone, and carbon black.

  The agricultural film of the present invention may contain the above-mentioned components in combination, and may further contain the following optional components as required. Optional components include other stabilizers, impact resistance improvers, cross-linking agents, fillers, foaming agents, antistatic agents, nucleating agents, anti-plateout agents, surface treatment agents, flame retardants, fluorescent agents, antifungal agents. Examples thereof include agents, bactericides, metal deactivators, release agents, pigments and processing aids.

  In order to mix various additives, the agricultural film of the present invention is weighed in a necessary amount, and a blending machine such as a ribbon blender, a Banbury mixer, a Henschel mixer, a super mixer, a single-screw or twin-screw extruder, and a roll is kneaded. A known compounding machine or mixing machine may be used. The resin composition thus obtained can be formed into a film by a method known per se, for example, a melt extrusion molding method (including a T die method and an inflation method), a calendering process, a roll processing, an extrusion molding process, Blow molding, inflation molding, melt casting method, pressure molding processing, paste processing, powder molding and the like can be preferably used.

  The thickness of the agricultural film of the present invention is preferably 0.01 to 1 mm, more preferably 0.05 to 0.5 mm, still more preferably 0.05 to 0 in terms of strength and cost. It is 0.2 mm. When the thickness is within this range, it is possible to obtain an agricultural film that does not have problems of strength and molding workability in terms of molding.

When the agricultural film of the present invention is an agricultural polyolefin resin film, it can be a multi-layer film having 3 to 5 layers. The layer ratio of the three-layer film is preferably 1 / 0.5 / 1 to 1/5/1 in terms of moldability, transparency and strength, and 1/2/1 to 1/4/1. Is more preferable. Further, the ratio of the outer layer to the inner layer is not particularly specified, but it is preferable to set the same ratio in view of the curl property of the obtained film.
In the case of a polyolefin resin multilayer film, various additives such as the above-mentioned weather resistance improver (hindered amine light stabilizer, ultraviolet absorber, etc.), weather resistance, infrared absorber, heat retaining agent, etc. are added to all layers. Alternatively, it may be added to a part of layers (intermediate layer, or intermediate and outer layers, etc.).

  Further, the agricultural film of the present invention can form an antifogging coating film and other coating films. For example, when the house is covered with the agricultural film, an antifogging coating may be formed on the inner surface and a dustproof coating may be formed on the outer surface.

  Examples of the antifogging coating film include a composition containing an inorganic colloid sol and / or a binder resin such as a thermoplastic resin as a main component. Preferably, an antifogging coating film containing an inorganic colloid substance and a hydrophilic organic compound as main components and an antifogging coating film containing an inorganic colloid substance and an acrylic resin as main components can be used. Further, the binder resin may not be added, and an inorganic substance such as colloidal silica or colloidal alumina may be laminated.

  As the inorganic colloidal sol, inorganic aqueous colloidal particles such as silica, alumina, water-insoluble lithium silicate, iron hydroxide, tin hydroxide, titanium oxide, barium sulfate are dispersed in water or a hydrophilic medium by various methods. , And an aqueous sol. Of these, silica sol and alumina sol are preferably used, and these may be used alone or in combination.

  As the inorganic colloidal sol, it is preferable to select an average particle size in the range of 5 to 100 nm, and in this range, two or more kinds of colloidal sols having different average particle sizes may be used in combination. By setting the average particle diameter within this range, the coating does not become white and devitrification is obtained, and the stability of the inorganic colloid sol is also good.

  The amount of the inorganic colloid sol to be compounded is preferably 0.2 or more and 5 or less, more preferably 0.5 or more and 4 or less in terms of solid content weight ratio with respect to the total solid content weight of the binder resin composition. That is, if the blending amount is too small, the sufficient antifogging effect may not be exhibited, while if the blending amount is too large, not only is the antifogging effect difficult to improve in proportion to the blending amount, but also coating There is a phenomenon that the coating film formed later becomes cloudy and the light transmittance of the film is lowered, and the coating film is rough and fragile, which is not preferable.

  Examples of the binder resin include acrylic resins, epoxy resins, urethane resins, polyester resins and the like. When the base material film is a polyolefin film, it is particularly preferable to use an acrylic resin and / or a urethane resin from the compatibility with the polyolefin film, and more preferably (a) a hydrophilic acrylic resin described below. Those composed of a united product, (c) composed of a hydrophobic acrylic resin, and (e) composed of a hydrophobic acrylic resin and a polyurethane emulsion have respective characteristics and are preferable.

  As the acrylic resin, (a) a hydrophilic acrylic polymer, (b) a block copolymer containing a hydrophobic molecular chain block and a hydrophilic molecular chain block in one molecule, (c) ) Those made of a hydrophobic acrylic resin can be mentioned. When the base film is a polyolefin-based film, (a) is particularly preferable because it is excellent in compatibility with the base film because of early early anti-fogging wetness, while (c) is preferable with the base film. It is excellent in compatibility and is preferable.

  Examples of the hydrophilic acrylic polymer (a) include a hydroxyl group-containing vinyl monomer component as a main component (preferably 60% by weight to 99.9% by weight, more preferably 65% by weight to 95% by weight), an acid. Examples thereof include a copolymer containing 0.1 to 30% by weight of a group-containing vinyl monomer component, a partially neutralized product or a completely neutralized product thereof. Examples of the hydroxyl group-containing vinyl monomer component include hydroxyalkyl (meth) acrylates, such as hydroxymethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, and 2-hydroxyethyl (meth) acrylate. Examples include, but are not limited to, hydroxypropyl (meth) acrylate. These may be homopolymers, or may be copolymers containing these hydroxyalkyl (meth) acrylates as main components and other monomers copolymerizable with them.

  Examples of the acid group-containing monomer copolymerizable with these hydroxyalkyl (meth) acrylates include carboxylic acids, sulfonic acids, and phosphonic acids, and (meth) acrylic acid belonging to carboxylic acid is particularly preferable.

  Examples of other copolymer components include styrene, vinyltoluene, vinyl chloride, vinylidene chloride, vinyl oxide, (meth) acrylic acid esters, N, N-dimethylaminoethyl (meth) acrylamide, vinylpyridine and the like. ..

  The hydrophobic acrylic resin (c) includes at least 60% by weight of a monomer composed of alkyl esters of acrylic acid or methacrylic acid, or a single monomer of an alkyl ester of acrylic acid or methacrylic acid and an alkenylbenzene. The monomer mixture and 0-40% by weight of the copolymerizable α, β-ethylenically unsaturated monomer are emulsion polymerized in an aqueous medium according to the usual polymerization conditions, for example in the presence of an emulsifier. The water-dispersible polymer or copolymer obtained can be mentioned.

  Examples of the alkyl ester of acrylic acid or methacrylic acid used for producing the hydrophobic acrylic resin include acrylic acid methyl ester, acrylic acid ethyl ester, acrylic acid-n-propyl ester, acrylic acid isopropyl ester, acrylic acid-n- Examples thereof include butyl ester, and generally, an acrylic acid alkyl ester having an alkyl group having 1 to 20 carbon atoms and / or a methacrylic acid alkyl ester having an alkyl group having 1 to 20 carbon atoms is used. Examples of the alkenylbenzenes include styrene, α-methylstyrene, vinyltoluene and the like.

  Α, β-ethylenically unsaturated monomer used to obtain the hydrophobic acrylic resin, α, such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, crotonic acid, itaconic acid, β-ethylenically unsaturated carboxylic acids; α, β-ethylenically unsaturated sulfonic acids such as ethylene sulfonic acid; 2-acrylamido-2-methylpropanoic acid; α, β-ethylenically unsaturated phosphonic acids; acrylic acid or methacrylic acid Hydroxy group-containing vinyl monomers such as hydroxyethyl acid; acrylonitriles; acrylamides; glycidyl esters of acrylic acid or methacrylic acid. These monomers may be used alone or in combination of two or more, and are preferably used in the range of 0 to 40% by weight. If the amount used is too large, the antifogging performance may be deteriorated, which is not preferable.

  The acrylic resin is a known emulsifier, for example, one or more selected from anionic surfactants, cationic surfactants and nonionic surfactants in the presence of an aqueous medium, It can be obtained by an emulsion polymerization method, a polymerization method using a reactive emulsifier, a polymerization method based on the oligo soap theory without containing an emulsifier.

  Examples of the polymerization initiator preferably used for producing the acrylic resin include persulfates such as ammonium persulfate and potassium persulfate. These can be used in the range of 0.1 to 10% by weight based on the total amount of the charged monomers.

  It is particularly preferable to use a hydrophobic acrylic resin having a glass transition temperature of 35 to 80 ° C. If the glass transition temperature is too low, the inorganic colloidal particles are likely to aggregate several times to form a non-uniform dispersion state, and if it is too high, it tends to be difficult to obtain a transparent and uniform coating film.

  The hydrophobic acrylic resin is preferably used as an aqueous emulsion. An aqueous emulsion obtained by polymerizing each monomer in an aqueous medium may be used as it is, or may be diluted by adding a liquid dispersion medium to this, or produced by the above-mentioned polymerization. Alternatively, the polymer may be separately collected and redispersed in a liquid dispersion medium to give an aqueous emulsion.

  On the other hand, as the urethane resin (d), an aqueous composition of a polyether-based, polyester-based, or polycarbonate-based anionic polyurethane, or an emulsion may be mentioned. When the base film is a polyolefin film, a polycarbonate-based anionic polyurethane emulsion is preferable in terms of adhesion to the base film of the anti-fog coating film, water resistance and scratch resistance, and further anti-fog coating. A polycarbonate type anionic polyurethane emulsion containing a silanol group is more preferable from the viewpoints of improving the water resistance and scratch resistance of the film, the time until the antifogging property is exhibited, and the antifogging durability. These may be used alone or in combination of two or more.

  The polycarbonate type anionic polyurethane emulsion containing a silanol group comprises a polyurethane resin containing at least one silanol group in the molecule and a strongly basic tertiary amine as a curing catalyst. Means a silanol group-containing polyurethane resin and the strongly basic tertiary amine dissolved in an aqueous phase, or a colloidal dispersion type (emulsion) in which the silanol group-containing polyurethane resin is dispersed in the form of fine particles.

  The polyurethane aqueous composition is preferably blended in a solid content weight ratio of 0.01 or more and 2 or less, more preferably 0.01 or more and 1 or less with respect to the hydrophobic acrylic resin. If it is less than 0.01, it is difficult to improve the scratch resistance, and it takes a long time to develop the antifogging property, and it is difficult to exhibit a sufficient antifogging effect. Further, when it is too large, not only scratch resistance is difficult to improve in proportion to the blended amount, but also the coating film formed after coating becomes turbid and the light transmittance is likely to be lowered, and it is also disadvantageous in terms of cost. Not preferable.

  When preparing an antifogging agent composition for forming an antifogging coating, an interface such as an anionic surfactant, a cationic surfactant, a nonionic surfactant, a polymer surfactant, etc. Activators can be added. The following surfactants can be used.

  Examples of the anionic surfactant include fatty acid salts such as sodium oleate and potassium oleate; higher alcohol sulfates such as sodium lauryl sulfate and ammonium lauryl sulfate; alkylbenzene sulfone such as sodium dodecylbenzenesulfonate and sodium alkylnaphthalenesulfonate. Acid salts and alkylnaphthalene sulfonates; naphthalene sulfonic acid formalin condensates; dialkyl sulfosuccinates; dialkyl phosphate salts; polyoxyethylene sulfate salts such as sodium polyoxyethylene alkyl ether sulfate and sodium polyoxyethylene alkylphenyl ether sulfate. Can be mentioned.

  Examples of the cationic surfactant include ethanolamines; laurylamine acetate, triethanolamine monostearate formate; amine salts such as stearamidoethyldiethylamine acetate; lauryltrimethylammonium chloride, stearyltrimethylammonium chloride, dilauryldimethyl. Examples thereof include quaternary ammonium salts such as ammonium chloride, distearyldimethylammonium chloride and lauryldimethylbenzylammonium chloride.

  Nonionic surfactants include polyoxyethylene higher alcohol ethers such as polyoxyethylene lauryl alcohol, polyoxyethylene lauryl ether, and polyoxyethylene oleyl ether; polyoxyethylene such as polyoxyethylene octylphenol and polyoxyethylene nonylphenol. Alkyl aryl ethers; Polyoxyethylene acyl esters such as polyethylene glycol monostearate; Polypropylene glycol ethylene oxide adducts; Sorbitan fatty acid esters such as sorbitan monostearate, sorbitan monopalmitate, sorbitan monobenzoate; Diglycerin monopalmi Diglycerin fatty acid esters such as tate and diglycerin monostearate; glycerin monostearate Fatty acid esters such as pentaerythritol monostearate; pentaerythritol fatty acid esters such as pentaerythritol monostearate; dipentaerythritol monopalmitate; dipentaerythritol fatty acid esters; sorbitan monopalmitate half adipate, diglycerin monostearate half Sorbitan such as glutamic acid ester and diglycerin fatty acid / dibasic acid ester; or condensate thereof with alkylene oxide such as ethylene oxide and propylene on oxide, such as polyoxyethylene sorbitan monolaurate and polyoxypropylene sorbitan monostearate Etc .; polyoxyethylene stearylamine, polyoxyethylene oleylamine, polyoxyethylene stearic acid amide, etc. Carboxymethyl ethylene alkyl amine fatty acid amides; sugar esters.

  Examples of the polymer surfactant include polyacrylic acid salts, polymethacrylic acid salts, cellulose ethers and the like.

  The addition of a surfactant can easily and quickly uniformly disperse the binder resin and the inorganic colloid sol, and when used in combination with the inorganic colloid sol, imparts hydrophilicity to the surface of the hydrophobic polyolefin resin film. Perform a function. The addition amount of the surfactant may be selected in the range of 0.1 to 50 parts by weight with respect to 100 parts by weight of the solid content of the resin. If the addition amount of the surfactant is too small, it takes time for the resin and the inorganic colloid sol to be sufficiently dispersed, and the antifogging effect in combination with the inorganic colloid sol cannot be sufficiently exerted, while the surfactant is used. If too much is added, the transparency of the coating will decrease due to the bleed-out phenomenon formed on the surface of the coating after application, and if remarkable, the blocking resistance of the coating may deteriorate and the water resistance of the coating may decrease. ..

  A cross-linking agent can be added when preparing an antifogging composition for forming an antifogging coating. The cross-linking agent is particularly effective in cross-linking acrylic resins with each other and improving the water resistance of the coating film. Examples of the cross-linking agent include phenol resins, amino resins, amine compounds, aziridine compounds, azo compounds, isocyanate compounds, epoxy compounds, silane compounds and the like, but particularly amine compounds and aziridine compounds. , Epoxy compounds can be preferably used.

  A liquid dispersion medium can be added to the antifogging agent composition used in the present invention, if necessary. The liquid dispersion medium includes a hydrophilic or water-miscible solvent containing water, water; monohydric alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol, etc .; polyhydric alcohols such as ethylene glycol, diethylene glycol, glycerin, etc. Examples thereof include cyclic alcohols such as benzyl alcohol; cellosolve acetates; ketones. These liquid dispersion media may be used alone or in combination.

  If necessary, the antifog composition can be mixed with conventional additives such as a defoaming agent, a plasticizer, a film-forming aid, a viscosity-improving agent, a pigment, and a pigment dispersant. Further, as the binder component other than the acrylic resin, for example, a polyether-based, polycarbonate-based, polyester-based water-dispersible urethane resin or the like may be mixed.

  In order to form an antifogging coating film on the surface of a substrate film, generally, a solution or dispersion of an antifogging composition is doctor blade coating method, roll coating method, dip coating method, spray coating method, rod coating method, respectively. A coating method known per se such as a bar coating method, a knife coating method, a brush coating method, etc. may be employed, and the coating may be dried. As a drying method after coating, either a natural drying method or a forced drying method may be adopted. When the forced drying method is adopted, it is usually dried at a temperature range of 50 to 250 ° C, preferably 70 to 200 ° C. Good. For the heating and drying, a hot air drying method, an infrared drying method, a far infrared ray drying method, an ultraviolet curing method, or the like may be appropriately used. Considering the drying speed and stability, it is advantageous to use the hot air drying method. is there.

  The thickness of the anti-fog coating film may be selected to be 1/10 or less of the base film, but is not necessarily limited to this range. If the thickness of the coating film is more than 1/10 of that of the base film, there is a difference in flexibility between the base film and the base film, and the phenomenon such as peeling of the base film from the base film is likely to occur. Moreover, a phenomenon that cracks are generated in the coating film and the strength of the base film is lowered occurs, which is not preferable.

  Further, when the adhesion between the base film and the coating film derived from the antifogging composition is not sufficient, the base film may be surface-treated. Examples of the surface treatment method include corona discharge treatment, sputter etching treatment, sodium treatment, and sandblast treatment. In the corona discharge treatment method, discharge is performed between a needle-shaped or knife-edge electrode and a counter electrode, and a sample is placed between them to perform treatment, and the film surface contains oxygen such as aldehyde, acid, alcohol peroxide, ketone, and ether. This is a process of generating a functional group. In the sputter etching treatment, a sample is put between electrodes under low-pressure glow discharge, and a large number of fine projections are formed on the film by the impact of positive ions generated by the glow discharge. The sandblast treatment is to spray fine sand on the film surface to form a large number of fine irregularities on the surface. Among these surface treatments, the corona discharge treatment is preferable in terms of adhesion to the coating layer, workability, safety, cost and the like.

  Hereinafter, the present invention will be described in more detail based on Examples and Comparative Examples, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded.

(1) Preparation of polyolefin-based resin multilayer film As a three-layer inflation molding device, 100 mmφ (manufactured by Pla Koken Co., Ltd.) was used for a three-layer die, and the extruder had two tube inner and outer layers of 30 mmφ (manufactured by Pla Giken Co., Ltd.) The intermediate layer is 40 mmφ (manufactured by Pla Giken Co., Ltd.), the outer and inner layer extruder temperature is 180 ° C., the intermediate layer extruder temperature is 170 ° C., the die temperature is 180 to 190 ° C., the blow ratio is 2.0 to 3.0, and the take-up is A three-layer laminated film composed of the components shown in Table 1 was obtained at a speed of 3 to 7 m / min and a thickness of 0.10 mm. Since these films are used by cutting open the ends of the tubes during the extension of the house, the outer layer of the tube during film formation when expanded becomes the inner layer (inner surface) of the house during extension.
The composition of the base material is shown in Table 1.

[Blending] The addition amount is as described in each table.
HP-LDPE: Branched polyethylene produced by a high pressure radical method catalyst (MFR: 0.7 g / 10 min, density 0.924) Novatec LD “LF240” manufactured by Nippon Polychem
Metallocene PE: Ethylene / α-olefin copolymer produced with metallocene catalyst (MFR: 2.0 g / 10 min, density 0.913) Kernel “KF270” manufactured by Nippon Polychem
EVA1: Ethylene / vinyl acetate copolymer (vinyl acetate content 15% by weight, MFR 2 g /
10 minutes)

Kimasorb 944: Light stabilizer synthetic hydrotalcite manufactured by Ciba Specialty Chemicals A: “DHT4A” manufactured by Kyowa Chemical Co., Ltd.
Ethylene / Cyclic Amino Vinyl Copolymer: “Novatech LD / XJ1” manufactured by Nippon Polychem Co., Ltd.
00H ”MFR = 3 g / 10 minutes (190 ° C., JIS-K6760) Density = 0.931 g
/ Cm3 (JIS-K6760) Cyclic aminovinyl compound content = 5.1% by weight (0.7 mol%) Proportion of cyclic aminovinyl compound present independently = 90 mol% Melting point = 111 ° C

Pigment masterbatch A: GT3637 (A): PE-based masterbatch (manufactured by Dainichiseika Kogyo Co., Ltd.)
Pigment masterbatch B: 13N7796A: PE masterbatch (manufactured by Dainichiseika Kogyo Co., Ltd.)
Pigment masterbatch C: PEX 3BG080: PE-based masterbatch (manufactured by Tokyo Ink Co., Ltd.)
Fluorescent pigment A: SMART LIGHT RL1000: wavelength conversion fluorescent substance (manufactured by BASF)
UV absorber A: seedsorb 740: UV absorber (manufactured by Cipro Kasei Co., Ltd.)
UV absorber B: tinuvin 326: UV absorber (manufactured by BASF)

(2) Surface treatment of film The outer layer surface of the obtained tubular film was subjected to corona discharge treatment at a discharge voltage of 120 V, a discharge current of 4.7 A and a line speed of 10 m / min, and the "wetting index" according to JIS-K6768 was measured. And confirmed its value.

(3) Formation of anti-fog coating film (anti-fog coating film coating type)
The main components (silica sol and / or alumina sol) shown in Table 1, a thermoplastic resin, a crosslinking agent and a liquid dispersion medium were blended to obtain an antifogging composition.
The composition of the antifogging composition was as follows.
Inorganic colloid sol (colloidal silica) 4.0
Thermoplastic resin (Sunmor SW-131) 3.0
Cross-linking agent (TAZM) 0.1
Dispersion medium (water / ethanol = 3/1) 93
(Note) The compounding amount of the inorganic colloid sol is shown by the amount of the inorganic particles, and the compounding amount of the thermoplastic resin is shown by the polymer solid content.
Colloidal silica: Snowtex 30 manufactured by Nissan Chemical Co., Ltd., average particle size 15 mμ
Sanmor SW-131: Acrylic emulsion T.S. manufactured by Sanyo Kasei. A. Z. M: The above antifogging agent composition was applied onto the surface of the substrate film surface-treated with the aziridine compound (2) manufactured by Mutual Yaku Co., Ltd. using a # 5 bar coater. The coated film was kept in an oven at 80 ° C. for 1 minute to volatilize the liquid dispersion medium to form an antifogging coating film. The thickness of the coating film of each obtained film was about 1 μm.

  This time, the test was conducted using a type provided with an antifogging coating (film thickness 100 μm), but the same effect can be obtained with a type in which an antifogging agent is kneaded. In addition, the same effects can be obtained even with a combination other than the resins and additives used this time, or with a film thickness different from this time, unless the gist thereof is changed.

[Example 1]
The multilayer film of Example 1 was prepared by adding 5% by weight of the pigment masterbatch A to the intermediate layer and 1% by weight of the pigment masterbatch B to the intermediate layer in the formulation of the multilayer film shown in Table 1.

[Example 2]
In the formulation of the multilayer film shown in Table 1, 3.5% by weight of pigment masterbatch A was added to the intermediate layer and 0.7% by weight of pigment masterbatch B was added to the intermediate layer to prepare the multilayer film of Example 2. did.

[Example 3]
In the formulation of the multilayer film shown in Table 1, the pigment masterbatch C was 1% by weight in the intermediate layer, the ultraviolet absorber A was 1.2% by weight in the intermediate layer, and the ultraviolet absorber B was 0.3% in the intermediate layer. %, And the multilayer film of Example 3 was prepared.

[Example 4]
In the formulation of the multilayer film shown in Table 1, the pigment masterbatch C was 2.5% by weight in the intermediate layer, the ultraviolet absorber A was 1.2% by weight in the intermediate layer, and the ultraviolet absorber B was 0% in the intermediate layer. The multilayer film of Example 4 was prepared by adding 0.3%.

[Comparative Example 1]
In the composition of the multilayer film shown in Table 1, 2.5% by weight of the fluorescent pigment A was added to the intermediate layer to prepare the multilayer film of Example 5.

[Comparative example 2]
In the formulation of the multilayer film shown in Table 1, 5% by weight of pigment masterbatch A was added to the intermediate layer to prepare a multilayer film of Comparative Example 6.

[Comparative Example 3]
In the formulation of the multilayer film shown in Table 1, 1.2% by weight of the ultraviolet absorber A in the intermediate layer and 0.3% of the ultraviolet absorber B in the intermediate layer were added to the intermediate layer. A film was prepared.

  The following optical characteristic measurements were performed on each sample.

(1) Total Light Transmittance A multi-layer film obtained by three-layer inflation molding (after forming (coating) an anti-fog coating film on the surface of the inner layer of the house) is a spectrophotometer (Shimadzu Corporation UV-2450 type: The value at each wavelength is shown. Further, using the measurement data, the total light transmittance of 400 to 700 nm, the total light transmittance of 300 to 400 nm, the total light transmittance of 400 to 500 nm, the total light transmittance of 500 to 600 nm, the total light transmittance of 600 to 700 nm. Transmittance, R / B ratio (2) (total light transmittance of 660 nm / total light transmittance of 460 nm), R / B ratio (1) (average value of total light transmittance of 600 to 700 nm / 400 to 500 nm Average of total light transmittance), R / G ratio (2) (total light transmittance of 660 nm / total light transmittance of 555 nm), R / G ratio (1) (average of all light transmittance of 600 to 700 nm) Value / average value of total light transmittance of 500 to 600 nm), G / B ratio (2) (total light transmittance of 555 nm / total light transmittance of 460 nm), G / B ratio (1) (500 to 600 nm) An average value) of the total light transmittance of the mean / 400 to 500nm of the total light transmittance was measured.

  Table 2 shows the optical characteristic values of Examples 1 to 4 and Comparative Examples 1 to 3, presence / absence of fluorescent pigment, cultivability, weather resistance (change in transmittance after 2 years of use), and presence / absence of extraordinary length. . From Table 2, it can be seen that the multilayer films of Examples 1 to 4 according to the present invention have good cultivability and weather resistance.

Table 3 shows the cultivation data for Comparative Examples 1 to 3. The ratio is shown based on Comparative Example 3.
From Table 3, it can be seen that the cultivability of Comparative Examples 1 and 2 is almost the same as that of Comparative Example 3.
The cultivation test was carried out in June 2011 in a field in Kyoto prefecture.
Variety: Spinach'Active '
Seeding: 2011.5.19
Thinning: 2011.5.30
Measurement date: 2011.23 (35 days after sowing)

Table 4 shows the cultivation data for Comparative Example 3 and Examples 1, 3, and 4. The ratio is shown based on Comparative Example 3.
From Table 4, it can be seen that the cultivability of Examples 1, 3 and 4 is improved as compared with Comparative Example 3.
The cultivation test was carried out in a field in Kyoto prefecture by cultivation from September to October 2016.
Variety: Spinach'Duel '
Sowing: 2016.9.15
Harvesting survey: 2016.10.26 (41 days after sowing)

Table 5 shows the cultivability data for Comparative Example 3 and Examples 1, 2, and 3. The ratio is shown based on Comparative Example 3.
From Table 5, it can be seen that the cultivability of Examples 1, 2, and 3 is improved as compared with Comparative Example 3.
The cultivation test was carried out in a field in Kyoto prefecture by cultivation from November 2017 to February 2018.
Variety: Spinach'try '
Seeding: 2017.11.10
Decimation: 2017.12.12
Harvest: 2018.2.7 (89 days after sowing)

The weather resistance evaluation was judged by the following method.
For each sample spread in a farm field in Kyoto Prefecture in April 2015, sampling was performed in March 2018 and measured by the spectrophotometer, and averaged in each wavelength range of 400 to 500 nm, 500 to 600 nm, 600 to 700 nm. The transmittance was calculated.
The results were classified according to the following criteria (Table 2).
⊚: Change in average transmittance in each wavelength range is less than 5% compared to that before spreading ×: Some average transmittance in each wavelength range is 5% or more compared to before expansion

As shown in the above Examples, it is understood that the agricultural polyolefin resin films (Examples 1 to 4) having the optical properties described in the present application have good cultivability and weather resistance.
Therefore, by using the agricultural film of the present invention, as in the case of using the wavelength conversion film, it is possible to obtain a light environment with high sunlight contrast, R / B ratio and R / G ratio, which is ideal for plants. In addition to providing a good light quality balance, it is possible to provide a long-term cultivation improvement effect as compared with the wavelength conversion film.

Claims (4)

Agricultural film that meets the following characteristics.
・ R / B ratio (average value of total light transmittance of 600 to 700 nm / average value of total light transmittance of 400 nm to 500 nm) is larger than 1.05 ・ R / G ratio (total light transmittance of 600 to 700 nm) Average value / total average light transmittance of 500 nm to 600 nm) is larger than 1.1 G / B ratio (average total light transmittance of 500 to 600 nm / average total light transmittance of 400 nm to 500 nm) Value) is greater than 1.05 ・ Average value of total light transmittance of 400 to 700 nm is greater than 60% ・ Average value of total light transmittance of 300 to 400 nm is greater than 0% ・ Total light transmittance of 400 to 500 nm The average value of the transmittance is greater than 30%. The average value of the total light transmittance of 500 to 600 nm is greater than 70%. The average value of the total light transmittance of 600 to 700 nm is 80. Larger than Agricultural film that meets the following characteristics.
・ R / B ratio (total light transmittance at 660 nm / total light transmittance at 460 nm) is larger than 1.1 ・ R / G ratio (total light transmittance at 660 nm / total light transmittance at 555 nm) is 1.0 Greater than G / B ratio (total light transmittance of 555 nm / total light transmittance of 460 nm) is greater than 1.02. Average value of total light transmittance of 400 to 700 nm is greater than 60%. 300 to 400 nm The average value of total light transmittance is greater than 0%. The average value of total light transmittance of 400 to 500 nm is greater than 30%. The average value of total light transmittance of 500 to 600 nm is greater than 70%. 600 to 700 nm. Average value of total light transmittance of is greater than 80%   The agricultural film according to claim 1, further comprising a pigment other than a fluorescent pigment as a main component of the additive pigment.   The agricultural film according to claim 1, wherein the base resin is a polyolefin resin.