JP2013000960A - Agricultural polyolefin based multilayer film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an agricultural film formed of a polyolefin based resin which can maintain its wavelength conversion effect even when it is stretched out at outdoor for a long period of time and in which a fluorescent substance is properly dispersed.SOLUTION: The agricultural multilayer film has a laminated structure with three or more layers having at least an outer layer, an intermediate layer and an inner layer and is formed of a polyolefin based resin composition. It contains a specific fluorescent substance of 0.1-5 wt.% in terms of the polyolefin based resin composition in the whole layers of the film. In the agricultural multilayer film, when the content rate (wt.%) of the fluorescent substance in the intermediate layer is X, the content rate (wt.%) of the fluorescent substance in the inner layer is Y and the content rate (wt.%) of the fluorescent substance in the outer layer is Z, X>Y and X>Z.

Description

  The present invention relates to an agricultural multilayer film comprising a polyolefin resin composition containing a specific fluorescent material capable of emitting a visible light component having a wavelength component of at least 600 to 700 nm. The agricultural multilayer film of the present invention has good transparency, high wavelength conversion efficiency, and excellent wavelength conversion effect sustainability.

  In recent years, the domestic agricultural population has been declining with the aging of the population, and there is a need for a mechanism that enables new leaders of agricultural production to obtain stable income. From the viewpoint of food security, there is an urgent need to improve the agricultural production method, increase the yield per unit area, and build a mechanism that enables stable and efficient agricultural production.

  The cultivated form by the horticulture using resin film or the like has evolved according to the cultivated forms of various crops in order to stably obtain agricultural income as compared with the open field cultivation. To increase the yield per unit area, it is effective to increase the size of agricultural houses from the viewpoint of work efficiency and cultivation environment management. It has become necessary to work manually. However, the number of farmers is decreasing year by year and aging is progressing, and it is not easy to secure manpower for the annual expansion work. In view of such a situation, as a film for house extension used in an agricultural house, a film that is easy to extend and has a long period of use until re-covering as much as possible, in other words, has a long life of 2 years or more and is long There has been a demand for the development of high-performance agricultural covering materials that can maintain the initial performance over a period of time.

  Further, as a method for increasing the yield per unit area while reducing the quality risk, a method of supplementing the amount of light necessary for photosynthesis by supplementary light has been attracting attention during cloudy weather. For example, incandescent bulbs, fluorescent lamps, high-pressure sodium lamps, halogen lamps, light-emitting diodes (LEDs), and the like may be used as lighting devices to compensate for the lack of sunshine during cultivation. Compared with, the illuminance is often low, and in order to obtain the illuminance, a large amount of energy is required, and there is a demerit that the economic efficiency deteriorates. Furthermore, since the light from the light source is locally irradiated, it is difficult to exert the irradiation effect on the plant body over the entire cultivation area. On the other hand, if the number of irradiation devices is increased to irradiate the entire cultivated crop, it becomes inefficient due to the influence of the devices themselves, which is a problem.

  As means for solving such problems of electric energy cost and local irradiation, for example, a wavelength conversion film as disclosed in JP-A-7-123870 has been proposed. These wavelength conversion films aim to improve cultivation characteristics by using fluorescent materials to convert light with high energy at short wavelengths into light with long wavelengths, especially light that is absorbed by the photoreceptor during photosynthesis. Is. In particular, there are many studies for 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 an auxiliary light device. Therefore, the magnitude of the use effect when viewed from the whole plant depends on how high and long-lasting the wavelength conversion efficiency is. However, even if the wavelength conversion film using the prior art is commercialized, the wavelength conversion effect is not sufficient, and the wavelength conversion effect disappears in about 4 months, and the effect does not continue even though the film unit price is high. Was a problem. In addition, a similar wavelength conversion material has been proposed in Japanese Patent Application Laid-Open No. 2007-135583, but the perylene wavelength conversion material used in the examples is actually low in durability and has a polyester resin. However, they are incompatible with polyolefin resins and have practical problems such as the inability to produce wide films.

  In addition, the use of the fluorescent material represented by the formula (1) for agricultural films as a material that converts near-ultraviolet light into longer-wavelength fluorescence has been studied. Since dispersibility in resins, particularly polyolefin-based resins, is inferior, which causes poor transparency and increases in cost, improvement thereof has been a problem. In order to improve this point, for example, as a method for uniformly dispersing a pigment having poor dispersibility, there is a general method of microencapsulation, which is not only very disadvantageous in terms of cost but also shearing in the molten resin. Therefore, it is difficult to add in a normal resin processing apparatus, and a dispersion method that can be practically used for general industrial products has been demanded.

JP 7-123870 A JP 2007-135583 A

  The present inventors have studied an agricultural polyolefin film containing a specific fluorescent material capable of emitting light containing a visible light component of at least 600 to 700 nm as a wavelength component. The conversion effect was not sustained, and the cause was that the fluorescent substance was extracted from the film and escaped, and it was confirmed that voids were formed after the fluorescent substance was extracted. In addition, the fluorescent substance itself has a problem that it is inferior in dispersibility in a polyolefin resin and the transparency is lowered, and a method for solving this without requiring an additional step has not yet been found. . Therefore, the present inventors have studied for the purpose of providing an agricultural film made of a polyolefin resin in which the wavelength conversion effect is sustained even when extended outdoors for a long time and the fluorescent material is well dispersed. However, the present invention has been completed.

（式中、Ｒ１〜Ｒ２は、それぞれ独立して水素原子、又は炭素数１〜１０のアルキル基を表す。）
また、式（１）の蛍光物質のポリオレフィン系樹脂との分散性を高めるべく鋭意検討したところ、当該蛍光物質を無機フィラーと組み合わせて配合することにより分散性が良好となり、透明性も向上することも見出された。 That is, this invention adjusts the quantity which adds the said fluorescent substance in each layer in the agricultural multilayer film which consists of a polyolefin-type resin composition containing 0.1-5 weight% of fluorescent substances represented by Formula (1). And the sustainability of the wavelength conversion effect is improved by increasing the compounding quantity to an intermediate | middle layer.

(In formula, R1-R2 represents a hydrogen atom or a C1-C10 alkyl group each independently.)
In addition, as a result of intensive studies to increase the dispersibility of the fluorescent substance of formula (1) with the polyolefin resin, the dispersibility is improved and the transparency is improved by blending the fluorescent substance in combination with an inorganic filler. Was also found.

（式中、Ｒ１〜Ｒ２は、それぞれ独立して水素原子、又は炭素数１〜１０のアルキル基を表す。）
（２）フィルム全層中の蛍光物質の添加量の８０％以上が中間層に含有されていることを特徴とする（１）に記載の農業用多層フィルム、
（３）外層および内層には蛍光物質を含有せず、中間層のみに蛍光物質を含有することを特徴とする（１）に記載の農業用多層フィルム、
（４）少なくとも中間層に無機フィラーが含有されていることを特徴とする（１）〜（３）のいずれか１に記載に農業用多層フィルム、
（５）無機フィラーがハイドロタルサイト類及び／またはその焼成体であることを特徴とする（１）〜（４）のいずれか１に記載の農業用多層フィルム、及び
（６）少なくとも中間層に分散剤が含有されていることを特徴とする（１）〜（５）のいずれか１に記載の農業用多層フィルム。
との構成を有する。 Thus, the present invention
(1) An agricultural multilayer film comprising a polyolefin-based resin composition having a laminated structure of three or more layers having at least an outer layer, an intermediate layer, and an inner layer, wherein the formula ( 1) containing 0.1 to 5% by weight of the fluorescent substance represented by 1), the fluorescent substance content (wt%) in the intermediate layer is X, the fluorescent substance content (wt%) in the inner layer is Y, and the outer layer is A multilayer film for agriculture, wherein X> Y and X> Z, where Z is the fluorescent substance content (% by weight) of

(In formula, R1-R2 represents a hydrogen atom or a C1-C10 alkyl group each independently.)
(2) Agricultural multilayer film according to (1), wherein 80% or more of the added amount of the fluorescent substance in the entire film layer is contained in the intermediate layer,
(3) The agricultural multilayer film according to (1), wherein the outer layer and the inner layer do not contain a fluorescent material, and only the intermediate layer contains the fluorescent material,
(4) The agricultural multilayer film according to any one of (1) to (3), wherein an inorganic filler is contained in at least the intermediate layer,
(5) The agricultural multilayer film according to any one of (1) to (4), wherein the inorganic filler is hydrotalcite and / or a fired body thereof, and (6) at least in the intermediate layer The agricultural multilayer film according to any one of (1) to (5), wherein a dispersant is contained.
It has the composition with.

  The agricultural multilayer film of the present invention is very preferable because it has a good transparency, a high wavelength conversion efficiency, and an excellent sustainability of the wavelength conversion effect. The agricultural material of the present invention can be suitably used as agricultural films and nets for house, tunnel, mulching, bag hanging and the like.

Graph of measurement results at 500 to 700 nm with a spectroradiometer using a reflamp Measurement results with a spectroradiometer using a reflex lamp (integrated values at 400 to 700 nm and values at 640 nm)

  Hereinafter, the present invention will be described in detail.

（式中、Ｒ１〜Ｒ２は、それぞれ独立して水素原子、又は炭素数１〜１０のアルキル基を表す。）
中でも、Ｒ１、Ｒ２はメチル基であるのが好ましい。 The agricultural multilayer film of the present invention is characterized by comprising a polyolefin resin composition containing a fluorescent material represented by the following formula (1).

(In formula, R1-R2 represents a hydrogen atom or a C1-C10 alkyl group each independently.)
Among these, R1 and R2 are preferably methyl groups.

The compound of the formula (1) can be synthesized by a known method. For example, Chemistry Letters 2000, P1426 “Synthesis and Nonlinear Optical Properties of
It can also be synthesized by the method described in “p- (Dimethylamino) benzylidene Dyes Containing Different Acceptors”. In that case, the compound of following formula (2) may be produced | generated as a by-product.

(Wherein R8 to R9 each independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms)
In that case, the ratio of the formula (1) / the formula (2) is preferably 60% or more, preferably 80% or more, more preferably 90% or more from the viewpoint of compatibility with the polyolefin resin.

  In the agricultural multilayer film of the present invention, the fluorescent material represented by the formula (1) is 0.1 to 5% by weight, preferably 0.5 to 3% by weight, based on the polyolefin resin composition in the entire film. %contains.

  The agricultural multilayer film of the present invention has a laminated structure of three or more layers having at least an outer layer, an intermediate layer, and an inner layer. Here, the outer layer corresponds to the outer surface of the house when it is used as an outer film for a house. Moreover, the agricultural multilayer film of this invention may have a layer further between the outer layer and the intermediate | middle layer, and the inner layer and the intermediate | middle layer.

  The agricultural multilayer film of the present invention contains 0.1 to 5% by weight of the fluorescent material represented by the formula (1) with respect to the polyolefin resin composition in the entire film, and the fluorescent material in the intermediate layer X> Y and X> Z, where X is the content (wt%), Y is the phosphor content (wt%) in the inner layer, and Z is the phosphor content (wt%) in the outer layer. It is preferable. In the present invention, it is more preferable that 80% or more of the added amount of the fluorescent substance in the entire film layer is contained in the intermediate layer. Furthermore, in the present invention, it is more preferable that the outer layer and the inner layer do not contain a fluorescent substance, and only the intermediate layer contains a fluorescent substance. By including the fluorescent material in the multilayer film in this way, it is possible to suppress the escape from the film due to extraction of the fluorescent material, and to increase the sustainability of the wavelength conversion effect.

  In the present invention, it is preferable that an inorganic filler is contained in at least the intermediate layer. Since the fluorescent substance represented by the formula (1) has low compatibility with the polyolefin resin, the dispersibility in the film made of the polyolefin resin composition is inferior, and as a result, the transparency is lowered and the wavelength is reduced. There was a problem of poor conversion efficiency. The present inventors thought that the decrease in dispersibility may be attributed to the high cohesive force derived from the structure of the fluorescent material, and when variously studied, by adding an inorganic filler in combination with the fluorescent material, It has been found that the dispersibility of the fluorescent substance in the polyolefin resin composition can be improved.

  The inorganic filler that can be added to the agricultural multilayer film of the present invention can be used alone or in combination of two or more. As the inorganic filler that can be used, an inorganic compound containing at least one atom selected from the components: Si, Al, Mg, Ca, Li can be used as long as the effects of the present invention are not impaired. 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 compound, lithium aluminum composite Hydroxides, aluminum / lithium / magnesium composite carbonate compounds, aluminum / lithium / magnesium composite silicate compounds, magnesium / aluminum Um silicon composite hydroxide, magnesium aluminum silicon composite sulfate compounds, magnesium aluminum silicon composite carbonate compound, a metal complex hydroxide salt containing more anions. These may be obtained by dehydrating crystal water.

The inorganic filler may be a natural product or a synthetic product. The inorganic filler can be used without being limited by its crystal structure, crystal particle diameter, etc., as long as the effects of the present invention are not impaired. From the viewpoint of suppressing the above, a hydrotalcite compound or a fired product thereof can be preferably used. Here, the hydrotalcites are compounds represented by the general formula M ²⁺ _1-x Al ³⁺ _x (OH ⁻ ) ₂ (A ₁ ⁿ⁻ ) _{x / n} · mH ₂ O. In the above general formula, M ²⁺ represents a divalent metal ion selected from the group consisting of Mg ²⁺ , Ca ²⁺ and Zn ²⁺ , A ₁ ⁿ⁻ is an n-valent anion, and x is 0 < A number in the range of x <0.5, m is a number in the range of 0 ≦ m ≦ 2, and n is a number in the range of 1 ≦ n ≦ 3. Even when other inorganic fillers are used, it is possible to suppress the reactivity with the fluorescent material by lowering the processing temperature, but processing appearance defects such as melt fracture are likely to occur due to low temperature resin molding. It is necessary to select a resin composition appropriately.

  The method for obtaining the inorganic filler is not particularly limited, and commercially available products can be used. For example, hydrotalcites and fired products thereof include DHT4A (manufactured by Kyowa Chemical Co., Ltd.), MHTPD (Kyowa Chemical Co., Ltd.). Manufactured), Alkamizer (manufactured by Kyowa Chemical Co., Ltd.), HT-P (manufactured by Sakai Chemical Co., Ltd.) and the like can be preferably used. On the other hand, examples of the lithium / aluminum composite hydroxide include Mizukarak (manufactured by Mizusawa Chemical Co., Ltd.). Examples of the aluminum / lithium / magnesium composite silicate compound include Optima-LSA (manufactured by Toda Kogyo Co., Ltd.).

  In addition, the inorganic filler has a surface of higher fatty acid such as stearic acid, higher fatty acid metal salt such as alkali metal oleate, organic sulfonic acid metal salt such as alkali metal dodecylbenzenesulfonate, higher fatty acid amide, higher fatty acid. Those coated with an ester or wax can also be used.

  The said inorganic filler can be used individually or in combination of 2 or more types. The average particle diameter is preferably in the range of 0.05 to 15 μm, more preferably 0.1 to 10 μm. If the average particle size of the inorganic filler is smaller than the above range, the dispersibility in the resin is inferior, and the appearance of the film is deteriorated and the appearance of the film is deteriorated. The handling is severely inferior. On the other hand, if the average particle size of the infrared absorber (heat retention agent) is larger than the above range, the transparency is inferior, and clogging occurs in the extruder breaker screen, resulting in poor productivity.

The content of the inorganic filler is preferably 0.1% by weight or more and 50% by weight or less, more preferably 1 to 20% by weight, and more preferably 1 to 10% by weight with respect to 100% by weight of the polyolefin resin in the entire film layer. %. If the content is less than the above range, the effect of improving dispersibility is low, and if it exceeds the above range, there are problems such as a decrease in transparency. In the present invention, since the inorganic filler is added in combination with the fluorescent substance, it is added at least to the intermediate layer, but can be added to other layers as long as the effects of the present invention are not impaired. When the content is about 20% by weight or more, foaming may occur due to the reaction between the fluorescent substance and the inorganic filler, but the reaction can be suppressed by lowering the film forming temperature. In this case, it is necessary to appropriately select the composition in the polyolefin-based resin composition so as not to cause problems due to resin molding at low temperatures (occurrence of poor processing appearance such as melt fracture).
In the present invention, when the hydrotalcite compound or a fired product thereof is contained in at least an intermediate layer in an amount of 1 to 5% by weight based on 100% by weight of the polyolefin resin in the entire film layer, A multilayer film excellent in wavelength conversion efficiency can be obtained without any restriction on the resin composition, and is particularly preferable.

  In the agricultural multilayer film of the present invention, the dispersibility of the fluorescent substance can be further improved by including a dispersant in at least the intermediate layer. Examples of the dispersant that can be added to the agricultural multilayer film of the present invention include surfactants (including fluorosurfactants), antifoggants, metal organic acid salts, and modified waxes.

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

  The above-mentioned fluorosurfactant is a surfactant in which a part or all of the surfactant is substituted with F instead of H bonded to C of the hydrophobic group of a normal surfactant, and particularly a perfluoroalkyl group or perfluoroalkenyl. A surfactant containing a group. The above various additives can be used alone or in combination of two or more. Examples of the fluorine-containing compound having a perfluoroalkyl group include an anionic fluorine-containing surfactant, a cationic fluorine-containing surfactant, an amphoteric fluorine-containing surfactant, a nonionic fluorine-containing surfactant, and a fluorine-containing oligomer. can give.

  Examples of the metal species constituting the organic acid salt, basic organic acid salt and overbased organic acid salt of the metal include Li, Na, K, Ca, Ba, Mg, Sr, Zn, Cd, Sn, Cs, Examples of the organic acid include carboxylic acid, organic phosphoric acid, and phenol. Examples of the carboxylic acid include acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, Caprylic acid, neodecanoic acid, 2-ethylhexylic acid, pelargonic acid, capric acid, undecanoic acid, lauric acid, tridecanoic acid, myristic acid, palmitic acid, isostearic acid, stearic acid, 12-hydroxystearic acid, behenic acid, montanic acid, Elaidic acid, oleic acid, linoleic acid, linolenic acid, thioglycolic acid, mercaptopropionic acid, octyl mercapto Lopionic acid, benzoic acid, monochlorobenzoic acid, p-tert-butylbenzoic acid, dimethylhydroxybenzoic acid, 3,5-ditert-butyl-4-hydroxybenzoic acid, toluic acid, dimethylbenzoic acid, ethylbenzoic acid, cumin Acids, n-propylbenzoic acid, acetoxybenzoic acid, salicylic acid, p-tertiary octylsalicylic acid and other monovalent carboxylic acids, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid , Divalent carboxylic acids such as sebacic acid, maleic acid, fumaric acid, citraconic acid, metaconic acid, itaconic acid, aconitic acid, thiodipropionic acid, phthalic acid, isophthalic acid, terephthalic acid, oxyphthalic acid, chlorophthalic acid, etc. Monoester or monoamide compound, butanetricarboxylic acid, butane Examples thereof include di- or triester compounds of trivalent or tetravalent carboxylic acids such as tracarboxylic acid, hemimellitic acid, trimellitic acid, merophanic acid, and pyromellitic acid, and examples of the organic phosphoric acid include mono- or dioctylphosphoric acid. Acid, mono or didodecyl phosphoric acid, mono or dioctadecyl phosphoric acid, mono or di- (nonylphenyl) phosphoric acid, phosphonic acid nonylphenyl ester, phosphonic acid stearyl ester, etc., and the phenols include phenol, cresol , Xylenol, methylpropylphenol, methyl tertiary octylphenol, ethylphenol, isopropylphenol, tertiary butylphenol, n-butylphenol, diisobutylphenol, isoamylphenol, diamylphenol, isohexylphenol Enol, octylphenol, isooctylphenol, 2-ethylhexylphenol, tertiary octylphenol, nonylphenol, dinonylphenol, tertiary nonylphenol, decylphenol, dodecylphenol, octadecylphenol, cyclohexylphenol, phenylphenolphenol, cresol, ethylphenol, cyclohexylphenol, nonylphenol And dodecylphenol.

In the agricultural multilayer film of the present invention, when at least the intermediate layer contains a dispersant, the dispersibility of the fluorescent material can be further improved. Preferred types of dispersant include perfluoroalkyl polyethylene oxide addition reaction product, polyglycerin stearate ester, polyoxyethylene (2) sorbitan stearate ester, polyglycerin oleate ester, polyoxyethylene sorbitan palmitate, monoglycerin mono Examples include stearate and diglycerin distearate.
When a dispersant is added together with a fluorescent material, the dispersion state of the fluorescent material in the film changes depending on the type, amount, and added layer of the dispersant, and the concealability of the film increases and the wavelength conversion effect decreases. It is known that antagonism occurs due to the cause of the above (see Japanese Patent Application No. 2009-273984 by the present inventors), but the amount of the dispersant is 0.01 to 2 times the fluorescent pigment in the entire film layer When added in an amount of preferably 0.01 to 1 times, more preferably 0.01 to 0.5 times, the antagonistic action does not occur, and the dispersibility of the fluorescent substance can be improved.

  Examples of the polyolefin resin used in the present invention include an α-olefin homopolymer, a copolymer of a different monomer mainly containing an α-olefin, an α-olefin and a conjugated diene or a non-conjugated diene, etc. And polyunsaturated compounds, acrylic acid, methacrylic acid, copolymers with vinyl acetate, etc., such as high density, low density or linear low density polyethylene, polypropylene, ethylene-propylene copolymer, ethylene- Examples include butene copolymer, ethylene-4-methyl-1-pentene copolymer, ethylene-vinyl acetate copolymer, and ethylene-acrylic acid copolymer. Among these, low density polyethylene having a density of 0.910 to 0.935, an ethylene-α-olefin copolymer, and an ethylene-vinyl acetate copolymer having a vinyl acetate content of 30% by weight or less have transparency and weather resistance. It is preferable in terms of sex and price.

  Moreover, in this invention, it is preferable to use the ethylene-alpha-olefin copolymer resin obtained by copolymerizing with a metallocene catalyst as at least one component of 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. It can be obtained by (Method A) or (Method B).

  (Method A) JP-A-58-19309, JP-A-59-95292, JP-A-60-35005, JP-A-60-35006, JP-A-60-35007, JP-A-60-35008 , JP-A-60-35009, JP-A-61-130314, JP-A-3-163088, European Patent Application No. 420436, US Pat. No. 5,555,438 and International Publication WO91. The method described in US Pat. No. 04247, for example, a metallocene catalyst, particularly a metallocene / alumoxane catalyst, or a metallocene compound and a metallocene compound as disclosed in, for example, International Publication No. WO92 / 01723 A catalyst comprising a compound that reacts with the compound to form stable ions, or further, JP-A-5-295020, JP-A-5-2 Using a catalyst in which a metallocene compound is supported on an inorganic compound, as described in No. 5022, etc., a copolymer obtained from ethylene as a main component and an α-olefin having 4 to 20 carbon atoms as a subcomponent is obtained. In this method, copolymerization is performed so that the density of the polymer is 0.880 to 0.930 g / cm 3. Examples of the polymerization method include a high-pressure ion polymerization method, a solution method, a slurry method, and a gas phase method. In these, it is preferable to manufacture by a high pressure ion polymerization method.

The high-pressure ion polymerization method is described in JP-A-56-18607 and JP-A-58-25106, but the pressure is 100 kg / cm ² or more, preferably 300 to 1500 kg / cm. ^{2 and produced} at a temperature of 125 ° C. or higher, preferably 150 to 200 ° C. by a high pressure ion polymerization method.

(Method B) Metallocene catalyst component and organoaluminum oxy compound catalyst component described in JP-A-6-9724, JP-A-6-136195, JP-A-6-136196, and JP-A-6-207057 In the presence of an olefin polymerization catalyst, various conditions in the gas phase, slurry, or solution liquid phase, including a particulate carrier, and optionally an organoaluminum compound catalyst component and an ionized ionic compound catalyst component And ethylene and an α-olefin, specifically, an α-olefin having 3 to 20 carbon atoms, are copolymerized so that the density of the resulting copolymer is 0.900 to 0.930 g / cm ³ cm ³ . Method.

  A polyolefin resin polymerized by using a metallocene compound, that is, a metallocene polyethylene, is not limited to the above methods (A) and (B) in that good initial transparency and transparency persistence of the film can be obtained. Can be used.

  The ethylene-vinyl acetate copolymer resin used in the present invention has a vinyl acetate content in the range of 10 to 25% by weight, preferably in the range of 12 to 20% by weight. If the vinyl acetate content is less than this range, the resulting film will be hard and will tend to wrinkle and sag when stretched in a house, which will have a negative effect on anti-fogging properties. If it is larger than the range, since the melting point of the resin is low, the film is slackened at the high temperature in summer during house extension, flutters due to wind and the like, and is easily broken due to rubbing with the house structure.

  In the agricultural multilayer film of the present invention, the outer layer, the intermediate layer and the inner layer are preferably made of a polyolefin resin, but further, as the resin composition suitable for low-temperature molding, the outer layer and the inner layer are made of low density polyethylene and the intermediate layer is made of By using an ethylene vinyl acetate copolymer, it is possible to avoid appearance defects during processing such as melt fracture. In that case, linear low-density polyethylene can be added to the outer layer and the inner layer for the purpose of improving the strength.

  In the present invention, an agricultural multilayer film having excellent long-term weather resistance, bleed-out resistance, and the like can be obtained by blending an ethylene / cyclic aminovinyl compound copolymer with a polyolefin resin composition. Compared with hindered amine weathering agents used for general agricultural films, the ethylene / cyclic aminovinyl compound copolymer not only provides an effect as a light stabilizer that significantly improves long-term weather resistance, but also prevents it. It plays the role of improving the adhesion to the surface of the coating including the cloudy coating.

The ethylene / cyclic aminovinyl compound copolymer that can be used in the present invention is a copolymer of ethylene (A) and a cyclic aminovinyl compound (B), or a copolymer of ethylene (A) and a vinyl compound of the following formula (3). Coalescence can be used. By adding a large amount of the ethylene / cyclic aminovinyl compound copolymer, the surface properties (waterdrop contact angle, etc.) of the polyolefin film can be changed.

  In said formula (3), R1 and R2 represent a hydrogen atom or a methyl group each independently, and R3 represents a hydrogen atom or a C1-C4 alkyl group. Preferably, R1 and R2 are each a hydrogen atom or a methyl group, and R3 is a hydrogen atom.

The vinyl compound (B) represented by the formula (3) is known and can be synthesized by a known method, for example, a method described in JP-B-47-8539, JP-A-48-65180, or the like. it can.
Representative examples of the vinyl compound (B) represented by the formula (3) include 4-acryloyloxy-2,2,6,6-tetramethylpiperidine, 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 include piperidine.

As the preferred ethylene / cyclic aminovinyl compound copolymer, the ratio of (B) to the sum of ethylene (A) and cyclic aminovinyl compound (B) is 0.0005 to 0.85 mol%, More preferably, it is 0.001 to 0.55 mol%. That is, the preferred copolymer is one having a high light stability for a low content of the vinyl monomer having a hindered amine group in the side chain (cyclic aminovinyl compound (B)). When the concentration of the cyclic aminovinyl compound (B) is 0.0005 mol%, a sufficient light stabilizing effect is exhibited. On the other hand, when it exceeds 0.85 mol%, it tends to be substantially uneconomical.
The presence of the cyclic aminovinyl compound (B) is confirmed as follows, as described in JP-A-4-80215. In 13C-NMR (for example, JNM-GSX270 Spectrometer manufactured by JEOL Ltd.), according to a known method (for example, Chemical Doujinshi "Electrical Analyzes (1)" pages 53 to 56 (1985)), Ethyl acrylate (see "Analytical bookstore," Polymer Analysis Handbook ", page 969 (1985)) and ethylene-hydroxyethyl acrylate copolymer (Eur. Poly. J. 25, 4, 411-418 (1989)) The 22.9 ppm peak in the TMS standard is attributed to the methylene group at the α-position from the branch point of the isolated vinyl compound (B), and the 35.7 ppm peak is two consecutive vinyls. It was attributed to the methylene group sandwiched between the branch points of the compound (B). Using these two signals, the proportion of the vinyl compound (B) present in isolation in the copolymer of ethylene (A) and vinyl compound (B) can be calculated by the following formula.

  The proportion of the vinyl compound (B) -derived structural unit derived from the vinyl compound (B) having a hindered amine group in the side chain estimated as described above is not continuous but is present in an isolated manner relative to the total amount of the vinyl compound (B) in the copolymer. It is preferably 83% or more. If the proportion of vinyl monomers having hindered amine groups in the side chain is less than 83% without two or more vinyl monomers having hindered amine groups in the side chain, the light stability is relatively high In some cases, the feature of having

  The MFR (value measured according to JIS-K6760 (190 ° C., 2.16 kg load)) of the ethylene / cyclic aminovinyl compound copolymer is 0.1 to 200 g / 10 min, preferably 0.5 to 20 g / 10 minutes, more preferably 1-5 g / 10 minutes. When the MFR is less than the above range, the compatibility with the polyolefin resin is poor, and when blended, it causes visible defects in film applications such as fish eyes and boots. On the other hand, if the MFR exceeds the above range, even a copolymer having a large molecular weight may cause bleeding or blooming phenomenon due to diffusion loss or decrease in strength of the resulting multilayer film.

  Further, the ethylene / cyclic aminovinyl compound copolymer is expressed by a ratio of the weight average molecular weight to the number average molecular weight determined by preparing a calibration curve with monodisperse polystyrene using GPC. The value is preferably in the range of 3 to 120. A particularly preferred range is 5-20.

The ethylene / cyclic aminovinyl compound copolymer is produced by subjecting required monomers to copolymerization conditions, but can be produced by a high-pressure low-density polyethylene production apparatus. Usually produced by radical polymerization, the catalyst used is a free radical generator, such as dialkyl peroxides, diacyl peroxides, peroxyesters, ketone peroxides, peroxyketals, hydroperoxides, azo Compounds and the like are useful.
As the polymerization apparatus, a continuous stirring tank reactor or a continuous tube reactor generally used in the high-pressure radical polymerization method of ethylene can be used. The polymerization pressure is about 1000 to 5000 kg / cm ² , and the polymerization temperature is about 100 to 400 ° C.

  In the present invention, the content of the ethylene / cyclic aminovinyl compound copolymer in the polyolefin resin composition is 2 to 10 parts by weight, preferably 2 to 8 parts by weight with respect to 100 parts by weight of the polyolefin resin. . If this content is less than the above range, the weather resistance is inferior because it is inferior.

  In the present invention, from the viewpoint of cost, the ethylene / cyclic aminovinyl compound copolymer to be used is not necessarily contained in all layers of the multilayer film, and may be contained in at least one layer. Further, the ethylene / cyclic aminovinyl compound copolymer can be used in combination with one or more hindered amine weathering agents usually used for agriculture. Further, one or two or more hindered amine weathering agents which are usually used can be used for the layer not containing the ethylene / cyclic aminovinyl compound copolymer. For example, it can be contained in the inner layer and the outer layer, and the other layer can contain a hindered amine light stabilizer usually blended for agricultural use.

  In the agricultural multilayer film of the present invention, various additives usually used for synthetic resins can be used in combination. These additives include, for example, ultraviolet absorbers, weathering agents, hindered amine compounds other than the ethylene / cyclic aminovinyl compound copolymer, infrared absorbers (heat retention agents), antifogging agents, fillers, and 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-based, phenol-based and phosphite-based compounds Examples thereof include an inhibitor, a heat stabilizer, a lubricant, an antistatic agent, a colorant, and an antiblocking agent.

  Examples of hindered amine compounds that can be used in the present invention include bis (1,2,2,6,6-pentamethyl-4-piperidyl) -2-butyl-2- (3,5-ditert-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) Butanetetracarboxylate, 3,9-bis [1,1-dimethyl-2- {tris (2,2,6,6-tetramethyl-4-piperidylo Cycarbonyloxy) 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-tetra Azadodecane, 1- (2-hydroxyethyl) -2,2,6,6-tetramethyl-4-piperidinol / dimethyl succinate condensate, 2-tert-octylamino-4,6-dichloro-s-tria / N, N′-bis (2,2,6,6-tetramethyl-4-piperidyl) hexamethylenediamine condensate, N, N′-bis (2,2,6,6-tetramethyl-4- Piperidyl) hexamethylenediamine / dibromoethane condensate.

  Examples of commercially available hindered amine compounds that can be used in the present invention and are usually used for agricultural purposes include TINUVIN 770, TINUVIN 780, TINUVIN 144, TINUVIN 622LD, TINUVIN NOR 371, CHIMASSORB 119FL, CHIMASSORB 944 (manufactured by Ciba Geigy Corp.), Sanol L 76 (Sankyo Co., Ltd.), MARK LA-63, MARK LA-68, MARK LA-68, MARK LA-62, MARK LA-67, MARK LA-57, LA-900, T-1167L (above, Asahi Denka) (Manufactured by Co., Ltd.), UV-3346, UV-3529, UV-3581, UV-3853 (above, manufactured by Cytec Corporation) and the like. These piperidine ring-containing hindered amine compounds are used alone or in combination of two or more.

  Content of the said piperidine ring containing hindered amine type compound is 0.001 to 5 weight% with respect to 100 weight% of polyolefin resin, Preferably it is 0.01 to 1 weight%. When the content is less than 0.001% by weight, a sufficient effect cannot be obtained, and when the content is more than 5% by weight, the effect is not improved, and the physical properties of the film are deteriorated.

  From the viewpoint of cost, the hindered amine compound used in the present invention is not necessarily contained in all layers of the multilayer film, and may be contained in at least one layer. For example, when an anti-fogging coating film is formed on a multilayer film, the influence on the coating film extends from additives transferred to and transferred from other layers in addition to the additive added to the layer in contact with the coating film. Therefore, the added layer is preferably the whole layer or the inner and outer layers, but may be the inner layer only, the intermediate layer only, the outer layer only, or any combination thereof.

Examples of the ultraviolet absorber include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, and 5,5′-methylenebis (2-hydroxy-4-methoxybenzophenone). 2-hydroxybenzophenones such as 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2- (2′-hydroxy-3 ′, 5′-ditert-butylphenyl) benzotriazole, 2- (2′-hydroxy-3 ′, 5′-ditert-butylphenyl) -5-chlorobenzotriazole, 2- (2′-hydroxy-3′-tert-butyl-5′-methylphenyl) -5-chloro Benzotriazole, 2- (2′-hydroxy-5′-tert-octylphenyl) benzotriazole, 2- (2′-hydroxy 2- (2′-hydroxyphenyl) benzotriazoles such as 3′.5′-dicumylphenyl) benzotriazole, 2,2′-methylenebis (4-tert-octyl-6-benzotriazolyl) phenol; phenyl Salicylate, resorcinol monobenzoate, 2,4-ditert-butylphenyl-3 ′, 5′-ditert-butyl-4′-hydroxybenzoate, 2,4-ditert-amylphenyl-3 ′, 5′-di Benzoates such as tert-butyl-4'-hydroxybenzoate and hexadecyl-3,5-ditert-butyl-4-hydroxybenzoate; 2-ethyl-2'-ethoxyoxanilide, 2-ethoxy-4'-dodecyl Substituted oxanilides such as oxanilide; ethyl-α-cyano-β, β-diphenyl acrylate, methyl-2-cyano-3-methyl-3 Cyanoacrylates such as (p-methoxyphenyl) acrylate; 2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5-[(hexyl) oxy] -phenol, 2- [4 , 6-bis (2,4-dimethylphenyl) -1,3,5-triazin-2-yl] -5- (octyloxy) phenol and the like. These ultraviolet absorbers are used alone or in combination of two or more.

Especially, a triazine type ultraviolet absorber can be preferably used from a viewpoint of the sustainability of an ultraviolet cut effect. In particular, when the triaryltriazine-type ultraviolet absorber is a triaryltriazine-type ultraviolet absorber described in the following general formula (4), the absorption wavelength is shorter than that of the benzotriazole-type ultraviolet absorber. This is very preferable because it does not affect not only the control effect but also the flower color development (particularly, inhibition of anthocyanin pigment expression) in the cultivation of flowers such as roses.

(Wherein R3 to R7 each independently represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms.)
In the film used in the present invention, more preferably from the viewpoint of compatibility and the like, when R3 in the formula (4) is an octyl group and R4 to R7 are methyl groups, and R3 in the formula (4) is Examples thereof include a hexyl group, and R4 to R7 are hydrogen atoms.

  The content of the ultraviolet absorber is more than 0.001% and less than 2% by weight, preferably 0.01 to 1% by weight, more preferably 0.01 to 0.8% by weight, based on 100% by weight of the polyolefin resin. It is. If the content is less than the above range, the effect of improving weather resistance is low, and if it exceeds the above range, there are problems such as a decrease in transparency due to bleeding out.

  When using the ultraviolet absorber represented by the general formula (4) in the present invention, from the viewpoint of cost, for example, when used in a multilayer film, it is not necessarily contained in all layers of the multilayer film, It is sufficient that at least one layer is contained. Moreover, the ultraviolet absorber represented by the general formula (4) can be used in combination with one or more other ultraviolet absorbers.

  In addition to the inorganic filler described above, the agricultural multilayer film according to the present invention can contain an infrared absorber (heat retention agent) (inorganic fine particles having infrared absorbing ability) in the outer layer and / or the inner layer. These inorganic fine particles can be used alone or in combination of two or more. The inorganic fine particles that can be used are not particularly limited, but inorganic compounds containing at least one atom selected from the components: Si, Al, Mg, Ca, Li 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 compound, lithium aluminum composite Hydroxides, aluminum / lithium / magnesium composite carbonate compounds, aluminum / lithium / magnesium composite silicate compounds, magnesium / aluminum Um silicon composite hydroxide, magnesium aluminum silicon composite sulfate compounds, magnesium aluminum silicon composite carbonate compound, a metal complex hydroxide salt containing more anions. These may be obtained by dehydrating crystal water.

  The infrared absorber (heat retention agent) may be a natural product or a synthetic product. The inorganic fine particles can be used without being limited by the crystal structure, crystal particle diameter, and the like.

  The method for obtaining the infrared absorber (heat retention agent) is not particularly limited, and commercially available products can be used. For example, DHT4A (manufactured by Kyowa Chemical Co., Ltd.), HT-P (manufactured by Sakai Chemical Co., Ltd.) , Optima (manufactured by Toda Kogyo Co., Ltd.) and Mizukarak (manufactured by Mizusawa Chemical Co., Ltd.).

  In addition, the infrared absorber (heat retention agent) has a surface of higher fatty acid such as stearic acid, higher fatty acid metal salt such as alkali metal oleate, organic sulfonic acid metal salt such as alkali metal dodecylbenzenesulfonate, Those coated with fatty acid amides, higher fatty acid esters or waxes can also be used.

  The said infrared absorber (heat retention agent) can be used individually or in combination of 2 or more types. The average particle diameter is preferably in the range of 0.05 to 15 μm, more preferably 0.1 to 10 μm. If the average particle size of the infrared absorber (heat retention agent) is smaller than the above range, the dispersibility in the resin is poor and the appearance of the film (inorganic secondary agglomerates) is deteriorated and the film appearance is deteriorated. The powdering at the time is intense and the handling is inferior. On the other hand, if the average particle size of the infrared absorbing agent (heat insulating agent) is larger than the above range, the transparency is inferior or the extruder breaker screen is clogged, and the productivity is deteriorated.

  The above infrared absorber (heat retention agent) can be added to any layer, but when it is added to the outer layer and / or inner layer, when it is in contact with condensed water for a long time at the hoisting part in the ventilation part of an agricultural house Therefore, the content of the outer layer and / or the inner layer can be arbitrarily set to such an extent that no water turbidity occurs.

The metal species constituting the organic acid salt, basic organic acid salt and overbased organic acid salt used as the additive include Li, Na, K, Ca, Ba, Mg, Sr, Zn, Cd, Examples thereof include Sn, Cs, Al, and organic Sn. Examples of the organic acid include carboxylic acid, organic phosphoric acid, and phenol. Examples of the carboxylic acid include acetic acid, propionic acid, butyric acid, valeric acid, and caproic acid. , Enanthic acid, caprylic acid, neodecanoic acid, 2-ethylhexylic acid, pelargonic acid, capric acid, undecanoic acid, lauric acid, tridecanoic acid, myristic acid, palmitic acid, isostearic acid, stearic acid, 12-hydroxystearic acid, behenic acid , Montanic acid, elaidic acid, oleic acid, linoleic acid, linolenic acid, thioglycolic acid, mercaptopropionic acid, o Tilmercaptopropionic acid, benzoic acid, monochlorobenzoic acid, p-tert-butylbenzoic acid, dimethylhydroxybenzoic acid, 3,5-ditert-butyl-4-hydroxybenzoic acid, toluic acid, dimethylbenzoic acid, ethylbenzoic acid , Cumic acid, n-propylbenzoic acid, acetoxybenzoic acid, salicylic acid, monovalent carboxylic acid such as p-tert-octylsalicylic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, Divalent carboxylic acids such as azelaic acid, sebacic acid, maleic acid, fumaric acid, citraconic acid, metaconic acid, itaconic acid, aconitic acid, thiodipropionic acid, phthalic acid, isophthalic acid, terephthalic acid, oxyphthalic acid, chlorophthalic acid Alternatively, these monoesters or monoamide compounds, butanetrica Examples thereof include di- or triester compounds of trivalent or tetravalent carboxylic acids such as boric acid, butanetetracarboxylic acid, hemimellitic acid, trimellitic acid, merophanic acid, and pyromellitic acid. Mono or dioctyl phosphoric acid, mono or didodecyl phosphoric acid, mono or dioctadecyl phosphoric acid, mono or di- (nonylphenyl) phosphoric acid, phosphonic acid nonylphenyl ester, phosphonic acid stearyl ester, etc., and the phenols , Phenol, cresol, xylenol, methylpropylphenol, methyl tert-octylphenol, ethylphenol, isopropylphenol, tert-butylphenol, n-butylphenol, diisobutylphenol, isoamylphenol, diamylphenol , Isohexylphenol, octylphenol, isooctylphenol, 2-ethylhexylphenol, tertiary octylphenol, nonylphenol, dinonylphenol, tertiary nonylphenol, decylphenol, dodecylphenol, octadecylphenol, cyclohexylphenol, phenylphenolphenol, cresol, ethylphenol, cyclohexyl Phenol, nonylphenol, dodecylphenol and the like can be mentioned.

  Examples of the filler include silica, talc, aluminum hydroxide, hydrotalcite, calcium sulfate, calcium silicate, calcium hydroxide, and hydroxide in order to suppress stickiness of the film or to further increase the heat retention. Magnesium, kaolin clay, mica, alumina, magnesium carbonate, sodium aluminate, conductive zinc oxide, lithium phosphate and the like are used. One type of these fillers may be used, or two or more types may be used in combination.

  Examples of the phenol-based antioxidant include 2,6-ditert-butyl-p-cresol, 2,6-diphenyl-4-octadecyloxyphenol, stearyl (3,5-ditert-butyl-4- Hydroxyphenyl) -propionate, distearyl (3,5-ditert-butyl-4-hydroxybenzyl) phosphonate, thiodiethylene glycol bis [(3,5-ditert-butyl-4-hydroxyphenyl) propionate], 1,6 -Hexamethylene bis [(3,5-ditert-butyl-4-hydroxyphenyl) propionate], 1,6-hexamethylene bis [(3,5-ditert-butyl-4-hydroxyphenyl) propionic acid amide] 4,4′-thiobis (6-tert-butyl-m-cresol), 2,2′-methylenebis (4-methyl-6- Tributylphenol), 2,2′-methylenebis (4-ethyl-6-tert-butylphenol), bis [3,3-bis (4-hydroxy-3-tert-butylphenyl) butyric acid] glycol ester, 4, 4'-butylidenebis (6-tert-butyl-m-cresol), 2,2'-ethylidenebis (4,6-ditert-butylphenol), 2,2'-ethylidenebis (4-secondarybutyl-6- Tert-butylphenol), 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, bis [2-tert-butyl-4-methyl-6- (2-hydroxy-3) -Tert-butyl-5-methylbenzyl) phenyl] terephthalate, 1,3,5-tris (2,6-dimethyl-3-hydroxy-4-tert-butylbenzyl) isocyanurate 1,3,5-tris (3,5-ditert-butyl-4-hydroxylbenzyl) isocyanurate, 1,3,5-tris (3,5-ditert-butyl-4-hydroxybenzyl) 2,4,6-trimethylbenzene, 1,3,5-tris [(3,5-ditert-butyl-4-hydroxyphenyl) propionyloxyethyl] isocyanurate, tetrakis [methylene-3- (3,5 -Di-tert-butyl-4-hydroxyphenyl) propionate] methane, 2-tert-butyl-4-methyl-6- (2-acryloyloxy-3-tert-butyl-5-methylbenzyl) phenol, 3,9- Bis [1,1-dimethyl-2-{(3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy} ethyl] -2,4,8,10-tetraoxaspiro [5. ] Undecane, triethylene glycol bis [(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate], n-octadecyl 3- (3 ', 5'-di-t-butyl-4'-hydroxyphenyl) ) Propionate, tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyloxymethyl] methane and the like.

  Examples of the sulfur-based antioxidant include dialkylthiodipropionates such as dilauryl thiodipropionate, dimyristyl, and distearyl, and β-alkyl mercapto of polyols such as pentaerythritol tetra (β-dodecyl mercaptopropionate). And propionic acid esters.

  Examples of the phosphite-based antioxidant include trisnonylphenyl phosphite, tris (2,4-ditert-butylphenyl) phosphite, tris [2-tert-butyl-4- (3-tert-butyl- 4-hydroxy-5-methylphenylthio) -5-methylphenyl] phosphite, tridecyl phosphite, octyl diphenyl phosphite, di (decyl) monophenyl phosphite, monodecyl diphenyl phosphite, mono (dinonylphenyl) Bis (nonylphenyl) phosphite, di (tridecyl) pentaerythritol diphosphite, distearyl pentaerythritol diphosphite, di (nonylphenyl) pentaerythritol diphosphite, bis (2,4-ditertiarybutylphenyl) penta Erythritol diphosphie Bis (2,6-ditert-butyl-4-methylphenyl) pentaerythritol diphosphite, tetra (tridecyl) isopropylidenediphenol diphosphite, tetra (tridecyl) isopropylidenediphenol diphosphite, tetra (C 12-15 mixed alkyl) -4,4′-n-butylidenebis (2-tert-butyl-5-methylphenol) diphosphite, hexa (tridecyl) -1,1,3-tris (2-methyl-4-hydroxy-) 5-tert-butylphenyl) butanetriphosphite, tetrakis (2,4-ditert-butylphenyl) biphenylene diphosphonite, 2,2′-methylenebis (4,6-ditert-butylphenyl) (octyl) phosphite , Tetrakis (2,4-di-t-butylphenyl) 4,4′-biphenylene-di Phosphonites, 2,2-methylenebis (4,6-di -t- butyl phenyl) octyl phosphite, and the like.

  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.

  As the anti-blocking agent that can be used in the present invention, inorganic fine particles, organic fine particles and the like can be used. An inorganic filler containing at least one selected from Si, Mg, Al, Li, and Ca can be used as a constituent element component of the inorganic fine particles. Among these, diatomaceous earth, natural silica, synthetic silica, talc, mica, zeolite, and the like that can be usually used as an antiblocking agent can be suitably used. As the organic fine particles, for example, polymer beads mainly composed of a thermoplastic resin can be used. Among them, acrylate, methacrylate, styrene, nylon polymers and / or copolymers thereof can be preferably used.

  Further, for the purpose of imparting an antifogging effect to the agricultural multilayer film of the present invention, surfactants (including fluorosurfactants) are used as long as they do not exert an antagonistic action with the fluorescent substance of formula (1). Can be added.

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

  The above-mentioned fluorosurfactant is a surfactant in which a part or all of the surfactant is substituted with F instead of H bonded to C of the hydrophobic group of a normal surfactant, and particularly a perfluoroalkyl group or perfluoroalkenyl. A surfactant containing a group. The above various additives can be used alone or in combination of two or more. Examples of the fluorine-containing compound having a perfluoroalkyl group include an anionic fluorine-containing surfactant, a cationic fluorine-containing surfactant, an amphoteric fluorine-containing surfactant, a nonionic fluorine-containing surfactant, and a fluorine-containing oligomer. can give.

  In the agricultural multilayer film of the present invention, the above-described components are combined with the fluorescent substance of formula (1) and the polyolefin-based resin, and the following optional components can be further contained as necessary. Optional ingredients include other stabilizers, impact resistance improvers, crosslinking agents, fillers, foaming agents, antistatic agents, nucleating agents, plate-out preventing agents, surface treatment agents, flame retardants, other fluorescent agents, Examples include antifungal agents, bactericides, metal deactivators, mold release agents, pigments, processing aids, and the like.

  As a method of blending various additives into the agricultural multilayer film of the present invention, each required amount is weighed, and blender such as a ribbon blender, a Banbury mixer, a Henschel mixer, a super mixer, a single or twin screw extruder, a roll, A kneader or other conventionally known blender or mixer may be used. In order to form the resin composition thus obtained into a film, a method known per se, for example, a melt extrusion molding method (including a T-die method and an inflation method), calendar processing, roll processing, extrusion molding processing, Blow molding, inflation molding, melt casting, pressure molding, paste processing, powder molding, and the like can be suitably used.

  When the resin composition containing the fluorescent substance represented by the formula (1) is thermally decomposed to form a multilayer film, the strength of the film and the transparency may be reduced due to foaming. Therefore, the resin temperature is 230 ° C or lower, preferably 180 ° C or lower, more preferably 160 ° C or lower. For example, at a molding temperature of 160 ° C., appearance defects such as melt fracture may be a problem, but this can be avoided by appropriately selecting the resin composition.

  In the agricultural multilayer film of the present invention, a layer made of an antifogging agent composition mainly composed of inorganic fine particles and / or a synthetic resin binder can be formed on the multilayer film. Examples of the layer made of the antifogging agent composition include an antifogging film described in JP-A-2001-89751, a type disclosed in JP-A-2005-96430 without a binder resin, and JP-A-2007-282625 and JP-A-2008. A multilayer antifogging film as described in -67645 can also be used preferably. Furthermore, a dry coating method called vapor deposition or effect fine particle deposit is also applicable.

  As the inorganic fine particles, metals, metal oxides, metal hydroxides, metal sulfates, metal carbonates, etc., metal composite hydroxides, etc., known ones can be used as long as they do not impair hydrophilicity to the film surface. I can do it.

  As the inorganic fine particles, an inorganic colloidal substance can be preferably used in the case of wet coating. As inorganic colloidal substances, inorganic aqueous colloidal particles such as silica, alumina, water-insoluble lithium silicate, zinc oxide, zirconium oxide, iron hydroxide, tin hydroxide, titanium oxide, antimony oxide, barium sulfate, zinc antimonate, Aqueous sols dispersed in water or hydrophilic media in various ways are mentioned. Of these, colloidal silica and colloidal alumina are preferably used, and these may be used alone or in combination. Of these, inorganic fine particles with strong photocatalytic action can be used in combination with other inorganic fine particles to reduce the substantial addition concentration, or by applying surface treatment within a range that does not impair hydrophilicity, to base materials and synthetic resin binders. It is necessary to reduce the influence of.

  The inorganic colloidal substance can be subjected to a surface treatment within a range that does not inhibit the imparting of hydrophilicity to the film surface in order to improve the adhesion between the inorganic colloidal sols during drying or between the inorganic colloidal sol and the synthetic resin binder. As a method for surface treatment on the colloidal silica surface, known methods can be used, and among them, a silane compound such as a silane coupling agent can be preferably used.

  Examples of the binder resin used for the synthetic resin binder in the present invention include acrylic resins, epoxy resins, urethane resins, polyester resins, and the like, particularly from compatibility with multilayer films made of polyolefin resins, It is preferable to use an acrylic resin and / or a urethane resin, and more preferably (a) a hydrophilic acrylic resin, (c) a hydrophobic acrylic resin, and (e) a hydrophobic property, which will be described later. An acrylic resin and a polyurethane emulsion are preferred from the following characteristics.

  As the acrylic resin, (a) a hydrophilic acrylic resin, (b) a block copolymer containing a hydrophobic molecular chain block and a hydrophilic molecular chain block in one molecule, (c) Examples include those composed of hydrophobic acrylic resins. In particular, (a) is preferable in terms of early antifogging and wettability, but it tends to be washed away. Must be granted. On the other hand, (c) is excellent in water resistance and preferable in terms of antifogging durability, but the ratio of the binder resin and the inorganic colloidal substance is adjusted in order to suppress surface hydrophobicization by the hydrophobic acrylic resin. There is a need.

  The hydrophilic acrylic resin (a) has a hydroxyl group-containing vinyl monomer component as a main component (preferably 60 wt% to 99.9 wt%, more preferably 65 wt% to 95 wt%), and an acid group. Examples thereof include a copolymer containing 0.1 to 30% by weight of a 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, 2- Hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxypentyl (meth) acrylate, 6-hydroxyhexyl (meth) An acrylate etc. are mention | raise | lifted. These may be homopolymers, or may be copolymers of these hydroxyalkyl (meth) acrylates as main components and other monomers that can be copolymerized therewith.

  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 acids is particularly preferred.

  Examples of other copolymer components include styrene, vinyl terene, vinyl chloride, vinylidene chloride, vinyl oxide, (meth) acrylic acid esters, N, N-dimethylaminoethyl (meth) acrylamide, vinyl pyridine, and the like. In addition to these, a monomer containing a crosslinking site is copolymerized and an appropriate crosslinking agent is reacted at an appropriate crosslinking temperature, whereby the crosslinking density can be improved and the water resistance can be improved.

  As the hydrophobic acrylic resin (c), at least a total of 60% by weight of a monomer comprising an alkyl ester of acrylic acid or methacrylic acid, or a single unit of an alkyl ester of acrylic acid or methacrylic acid and an alkenylbenzene. A monomer mixture and 0 to 40% by weight of a copolymerizable α, β-ethylenically unsaturated monomer are obtained by emulsion polymerization in an aqueous medium, for example, in the presence of an emulsifier, under normal polymerization conditions. And water dispersible polymers or copolymers.

  Examples of alkyl esters of acrylic acid or methacrylic acid used in the production of hydrophobic acrylic resins include acrylic acid methyl ester, acrylic acid ethyl ester, acrylic acid-n-propyl ester, acrylic acid isopropyl ester, acrylic acid-n- Butyl ester, acrylic acid-2-ethylhexyl ester, acrylic acid decyl ester, methacrylic acid methyl ester, methacrylic acid ethyl ester, methacrylic acid-n-propyl ester, methacrylic acid isopropyl ester, methacrylic acid-n-butyl ester, methacrylic acid- 2-ethylhexyl ester, methacrylic acid decyl ester, and the like. Generally, an alkyl alkyl group having 1 to 20 carbon atoms and / or a methyl group having 1 to 20 carbon atoms is used. Acrylic acid alkyl esters are used. Examples of alkenylbenzenes include styrene, α-methylstyrene, vinyltoluene and the like.

  Examples of α, β-ethylenically unsaturated monomers used to obtain hydrophobic acrylic resins include α, β such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, crotonic acid, and itaconic acid. -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 Hydroxyl group-containing vinyl monomers such as hydroxyethyl; acrylonitriles; acrylic amides; glycidyl esters of acrylic acid or methacrylic acid, and the like. 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 lowered, which is not preferable.

  The acrylic resin is a known emulsifier, for example, an anionic surfactant, a cationic surfactant, or a nonionic surfactant, in the presence of one or more kinds in an aqueous medium. It can be obtained by a method of emulsion polymerization, a method of polymerization using a reactive emulsifier, a method of polymerizing based on an oligo soap theory without containing an emulsifier. In the case of a polymerization method in the presence of an emulsifier, these emulsifiers are used in the range of 0.1 to 10% by weight with respect to the total amount of charged monomers. It is preferable from the viewpoint of stability.

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

  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 agglomerated several times and tend to be in a non-uniform dispersion state. If it is too high, it is difficult to obtain a transparent uniform coating.

  The hydrophobic acrylic resin is preferably used as an aqueous emulsion. An aqueous emulsion obtained by polymerization of each monomer in an aqueous medium may be used as it is, or may be diluted by adding a liquid dispersion medium to this, and also produced by the above polymerization. A polymer may be collected separately and re-dispersed in a liquid dispersion medium to form an aqueous emulsion.

  On the other hand, examples of the urethane-based resin that can be used in the present invention include polyether-based, polyester-based, and polycarbonate-based anionic polyurethane aqueous compositions and emulsions. Polycarbonate-based anionic polyurethane emulsions are preferred in terms of adhesion to the resin multilayer film, water resistance and scratch resistance, and further increase the water resistance, scratch resistance and antifogging properties of the antifogging coating. A polycarbonate-based anionic polyurethane emulsion containing a silanol group is more preferable in terms of time and antifogging durability. These may be used alone or in combination of two or more.

  A polycarbonate-based 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. Refers to a colloidal dispersion system (emulsion) in which the silanol group-containing polyurethane resin and the strongly basic tertiary amine are dissolved in the aqueous phase, or a colloidal dispersion system in which fine particles are dispersed.

  It is preferable that the amount of the polyurethane aqueous composition is 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 in terms of solid content by weight. When it is less than 0.01, it is difficult to improve the scratch resistance, and it takes a long time until the antifogging property is exhibited, and it is difficult to exhibit a sufficient antifogging effect. In addition, when it is too much, not only the scratch resistance is difficult to improve in proportion to the blending amount, but the coating film formed after coating tends to become cloudy and lower the light transmittance, which is also disadvantageous in terms of cost. It is not preferable.

  An anionic surfactant, a cationic surfactant, a nonionic surfactant, and a polymeric surfactant, as long as the effect of the present invention is not impaired when the antifogging agent composition of the present invention is prepared. A surfactant such as can be added.

  Anionic surfactants include fatty acid salts such as sodium oleate and potassium oleate; higher alcohol sulfates such as sodium lauryl sulfate and ammonium lauryl sulfate; alkylbenzene sulfones such as sodium dodecylbenzenesulfonate and sodium alkylnaphthalenesulfonate Acid salt and alkyl naphthalene sulfonate salt; naphthalene sulfonic acid formalin condensate; dialkyl sulfosuccinate salt; dialkyl phosphate salt; polyoxyethylene sulfate salt such as sodium polyoxyethylene alkyl ether sulfate, sodium polyoxyethylene alkyl phenyl ether sulfate, etc. Can be mentioned.

  Cationic surfactants include: ethanolamines; laurylamine acetate, triethanolamine monostearate formate; amine salts such as stearamide ethyl diethylamine acetate; lauryltrimethylammonium chloride, stearyltrimethylammonium chloride, dilauryldimethyl And quaternary ammonium salts such as ammonium chloride, distearyldimethylammonium chloride, lauryldimethylbenzylammonium chloride, and the like.

  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. Alkylaryl 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 Diglycerol fatty acid esters such as tate and diglycerol monostearate; glycerol monostearate Glycerin fatty acid esters such as pentaerythritol monostearate; pentaerythritol fatty acid esters such as dipentaerythritol monopalmitate; dipentaerythritol fatty acid esters such as dipentaerythritol monopalmitate; sorbitan monopalmitate half adipate, diglycerin monostearate half Sorbitan such as glutamate and diglycerin fatty acid / dibasic acid esters; or condensates 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 stearamide, etc. Carboxymethyl ethylene alkyl amine fatty acid amides; sugar esters.

  Examples of the polymer surfactant include polyacrylate, polymethacrylate, and cellulose ethers.

  By adding these surfactants, the binder resin and the inorganic colloid sol can be easily and quickly uniformly dispersed, and when used in combination with the inorganic colloid sol, hydrophilicity is imparted to the surface of the hydrophobic polyolefin resin film. Fulfills the function of The addition amount of the surfactant is preferably 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.

  When preparing the anti-fogging agent composition according to the present invention, a crosslinking agent can be added. The crosslinking agent is particularly effective in crosslinking acrylic resins to improve the water resistance of the coating. Examples of the crosslinking agent include phenolic resins, amino resins, carbodiimide compounds, amine compounds, aziridine compounds, azo compounds, isocyanate compounds, epoxy compounds, silane compounds, etc., but particularly amine compounds. Aziridine compounds and epoxy compounds can be preferably used.

  Examples of amine compounds include aliphatic polyamines such as diethylenetriamine, triethylenepentamine and hexamethylenediamine; alicyclic amines such as 3,3′-dimethyl-4,4′-diaminocyclohexylmethane and isophoronediamine; 4-4 Aromatic amines such as' -diaminodihenylmethane and m-phenylenediamine are used. Examples of the aziridine compounds include tris-2,4,6- (1-aziridinyl) -1,3,5-triazine, trimethylolpropane-tri-β-aziridinylpropionate, tris [1- (2- Methyl) -aziridinyl] phosphine oxide, hexa [1- (2-methyl) -aziridinyl] triphosphatriazine and the like are used.

  Epoxy compounds include reaction products of bisphenol A or bisphenol F and epichlorohydrin, epoxidized novolak resins, epichlorohydrin and aliphatics produced by the reaction of a resin reaction product of phenol (or substituted phenol) and formaldehyde with epichlorohydrin. Resin-like reaction products produced from polyhydric alcohols such as glycerol, 1,4-butanediol, poly (oxypropylene) glycol or similar polyhydric alcohol components, and resins obtained by epoxidation using peracetic acid are used. The Epoxy compounds can be used in combination with tertiary amines or quaternary ammonium salts as catalysts. These crosslinking agents can be used in an amount of 0.1 to 30% by weight based on the acrylic resin solid content.

  A liquid dispersion medium can be mix | blended with the anti-fogging agent composition in this invention as needed. Such a liquid dispersion medium includes a hydrophilic or water-miscible solvent containing water, water; monohydric alcohols such as methyl alcohol, ethyl alcohol, and isopropyl alcohol; polyhydric alcohols such as ethylene glycol, diethylene glycol, and glycerin. Examples: cyclic alcohols such as benzyl alcohol; cellosolve acetates; ketones and the like. These liquid dispersion media may be used alone or in combination.

  In the antifogging agent composition of the present invention, pigments, pigment dispersants, fillers, anti-settling agents, anti-sagging agents, antifoaming agents, leveling agents, anti-repelling agents, and adhesiveness that can be incorporated into ordinary paints An improver, an antiseptic, an algae, a fungicide, a deodorant, an ultraviolet absorber, a weathering agent, a plasticizer, a film-forming aid, a thickener, a coupling agent, and other various additives can be blended. The addition amount is not particularly limited, and may be appropriately selected within a range that does not affect the effects of the present invention.

  Although the mixing method of the antifogging agent composition in this invention is not specifically limited, It is preferable to mix uniformly and the temperature at the time of mixing | blending and the mixing method can select a suitable method suitably.

  Moreover, when the adhesiveness of the multilayer film which is a base material and the layer which consists of an anti-fogging agent composition is not enough, you may surface-treat to a multilayer film. Examples of the treatment method applied to the surface of the multilayer film include corona discharge treatment, sputter etching treatment, sodium treatment, and sandblast treatment. In the corona discharge treatment method, discharge is performed between a needle-like or knife-edge electrode and a counter electrode, and a sample is placed between the electrodes and the treatment is performed, and the film surface contains oxygen such as aldehyde, acid, alcohol peroxide, ketone, ether, etc. This is a process for generating a functional group. Sputter etching is a process in which a sample is placed between electrodes performing low-pressure glow discharge, and a large number of fine protrusions are formed on the film by the impact of positive ions generated by the glow discharge. In the sandblasting process, fine sand is sprayed on the film surface to form a large number of fine irregularities on the surface. Among these surface treatments, corona discharge treatment is preferable from the viewpoints of adhesion to the coating layer, workability, safety, cost, and the like.

  In the present invention, in order to form a layer composed of the antifogging agent composition on the outermost surface of the multilayer film, a known wet or dry coating method can be arbitrarily selected. Wet coating with simple construction equipment is preferably used. In the case of wet coating, generally the solution or dispersion of the anti-fogging agent composition is applied to the doctor blade coating method, roll coating method, dip coating method, spray coating method, rod coating method, bar coating method, knife coating method, brush coating, respectively. A known coating method such as a method may be adopted and dried after coating.

  As a drying method after coating, either a natural drying method or a forced drying method may be employed. When the forced drying method is employed, it is usually 50 to 200 ° C., preferably 70 to 180 ° C., more preferably 70 to What is necessary is just to dry in the temperature range of 150 degreeC. When the drying temperature is higher than 200 ° C., even when the drying time is short, the fluorescent material in the base material may be thermally deteriorated, which may cause deformation problems such as melting of the base film and heat shrinkage. For heating and drying, an appropriate method such as a hot air drying method, an infrared drying method, a far infrared drying method, and an ultraviolet curing method may be employed, and it is advantageous to adopt the hot air drying method in consideration of the drying speed and stability. is there.

In the case of wet drying, the coating amount of the antifogging composition is not particularly limited, but is preferably 0.01 to 10 g / m ² , more preferably 0.1 as the coating amount per unit area at the time of drying. ˜5 g / m ² . Below this range, it is difficult to obtain good antifogging properties, and exceeding this range causes a decrease in transparency due to whitening, which is not preferable.

  The thickness of the layer composed of the antifogging agent composition in the case of wet drying (also referred to as “antifogging coating”) may be selected based on 1/10 or less of the multilayer film, but is not necessarily limited to this range. It is not a thing. If the total thickness of the anti-fogging coating is greater than 1/10 of the multilayer film, there is a difference in flexibility between the base film and the coating, so that the coating tends to peel off from the base film. Moreover, the phenomenon that a crack occurs in the coating and the strength of the multilayer film is reduced is not preferable.

  The agricultural multilayer film of the present invention can form other coatings in addition to the antifogging coating. For example, an antifogging film may be formed on the inner surface of the house and a dustproof film may be formed on the outer surface of the house. In that case, the anti-blocking effect may be further improved by the dust-proof coating film.

  About the thickness of the agricultural multilayer film of this invention, the thing of the range of 0.01-1 mm is preferable at the point of intensity | strength or cost, The thing of 0.05-0.5 mm is more preferable, More preferably, 0.05- 0.2 mm. If it is less than this range, there is a problem in strength, and if it exceeds this range, molding is difficult and there is a problem in stretch workability.

  Moreover, as the layer ratio constituting the three-layer film of the agricultural multilayer film of the present invention, a range of 1 / 0.5 / 1 to 1/5/1 is preferable in terms of moldability, transparency, and strength, The range of 1/2/1 to 1/4/1 is more preferable. Further, the ratio between the outer layer and the inner layer is not particularly specified, but it is preferable that the ratio is approximately the same because of the curl property of the obtained film.

  When the agricultural multilayer film according to the present invention is actually used, it is preferably stretched so that the side on which the antifogging coating is provided becomes the inside of the house or tunnel.

  The agricultural polyolefin-based multilayer film of the present invention has good transparency, high wavelength conversion efficiency, and excellent sustainability of the wavelength conversion effect.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail using an Example and a comparative example, this invention is not limited to these at all.

Example 1
A polyolefin-based three-layer film (inner layer / intermediate layer / outer layer thickness ratio = 1/3/1, total thickness: 150 μm) having the following composition was prepared by three-layer inflation molding.
The main composition of the film was as follows. Although not specifically described, commercially available additives (additives such as anti-blocking agents and antioxidants) necessary for constituting agricultural films were used in usual amounts.

House inner and outer layers: Metallocene PE = ethylene / α-olefin copolymer produced with metallocene catalyst (MFR: 2 g / 10 min, density: 0.912)
House intermediate layer: EVA = ethylene-vinyl acetate copolymer (vinyl acetate content 15% by weight, MFR 2 g / 10 min)
As a fluorescent substance, SMART LIGHT RL1000 (manufactured by Ciba Specialty Chemicals) (compound in which R1 = R2 = methyl group in Formula (1)) is 1.5% with respect to the resin composition in the entire film layer. Thus, it added only to the intermediate layer.
Further, as an inorganic filler, MHT-PD (Mg—Al hydroxide carbonate) was added only to the intermediate layer so as to be 15% with respect to the resin composition in the entire film layer.
Using the above polyolefin resin composition, three-layer inflation molding was performed with the die temperature set to 190 ° C. and the extruder temperature set to 180 ° C.

Comparative Example 1
Polyolefin was added in the same manner as in Example 1 except that the fluorescent material was added in an inner layer of 1.5%, an intermediate layer of 1.5%, and an outer layer of 1.5% with respect to the resin composition in the entire film layer. A three-layer film was prepared.

Comparative Example 2
A polyolefin-based three-layer film was prepared in the same manner as in Example 1 except that the fluorescent material was added to the resin composition in the entire film layer at an inner layer of 2.25% and an outer layer of 2.25%. .

The total film excess rate at 450 nm after the multilayer films prepared in Example 1, Comparative Example 1 and Comparative Example 2 were spread outdoors for 15 months was measured, and the results were judged according to the following criteria. In Example 1 and Comparative Examples 1 and 2, the house was sealed and the test film was stretched. In Reference Example 1, the test film was stretched without being sealed.
◎: 65% or less, ○: 75% or less, ×: Greater than 75%

  From Table 1, the multilayer film of Example 1 in which the fluorescent material was added only to the intermediate layer was compared with the case where the fluorescent material was added to all layers (Comparative Example 1) and the case where it was added to the inner and outer layers (Comparative Example 2). The sustainability of wavelength conversion efficiency is excellent.

Example 2
A polyolefin-based three-layer film (inner layer / intermediate layer / outer layer thickness ratio = 1/3/1, total thickness: 150 μm) having the following composition was prepared by three-layer inflation molding.
The main composition of the film was as follows. Although not specifically described, commercially available additives (additives such as anti-blocking agents and antioxidants) necessary for constituting agricultural films were used in usual amounts.
House inner and outer layers: Metallocene PE = ethylene / α-olefin copolymer produced with metallocene catalyst (MFR: 2 g / 10 min, density: 0.912)
House intermediate layer: EVA = ethylene-vinyl acetate copolymer (vinyl acetate content 15% by weight, MFR 2 g / 10 min)
As a fluorescent material, SMART LIGHT RL1000 was added only to the intermediate layer so as to be 1.25% with respect to the resin composition in the entire film layer. The polyolefin resin composition was subjected to three-layer inflation molding at a die temperature of 190 ° C. and an extruder temperature of 180 ° C.

Example 3
In the blending of the polyolefin resin composition of Example 2, the intermediate layer was such that DHT-4A (Mg—Al hydroxide carbonate) as an inorganic filler was 2% with respect to the resin composition in the entire film layer. A multilayer film was prepared under the same molding conditions as in Example 2.

Example 4
In the formulation of the polyolefin resin composition of Example 3, the fluorosurfactant (DS403N) was added only to the intermediate layer so as to be 0.4% with respect to the resin composition in the entire film layer. A multilayer film was prepared under the same molding conditions as in Example 2.

Example 5
In blending the polyolefin resin composition of Example 2, SMART
LIGHT RL1000 was added only to the intermediate layer so as to be 2.5% with respect to the resin composition in the entire film layer. Using the above polyolefin resin composition, three-layer inflation molding was performed with the die temperature set to 190 ° C. and the extruder temperature set to 180 ° C.

Example 6
In the blending of the polyolefin resin composition of Example 5, DHT4A (Mg-Al hydroxide carbonate) as an inorganic filler was added only to the intermediate layer so as to be 2% with respect to the resin composition in the entire film layer. A multilayer film was prepared under the same molding conditions as in Example 5.

Example 7
In the formulation of the polyolefin resin composition of Example 6, the fluorosurfactant (DS403N) was added only to the intermediate layer so as to be 0.4% with respect to the resin composition in the entire film layer. A multilayer film was prepared under the same molding conditions as in Example 5.

Example 8
In blending the polyolefin resin composition of Example 7, SMART
A multilayer film was prepared in the same manner as in Example 7 except that LIGHT RL1000 was added only to the intermediate layer so as to be 0.63% with respect to the resin composition in the entire film layer.

Example 9
In the blending of the polyolefin resin composition of Example 2, MHT-PD (Mg-Al hydroxide carbonate) as an inorganic filler is an intermediate layer so as to be 2% with respect to the resin composition in the entire film layer. In addition, DS403N was added only to the intermediate layer so as to be 0.4% with respect to the resin composition in the entire film layer, and a multilayer film was prepared under the same molding conditions as in Example 2. .

Example 10
House inner and outer layers: LDPE (low temperature molding PE resin; MFR: 2.8 g / 10 min, density: 0.925)
House intermediate layer: EVA = ethylene-vinyl acetate copolymer (vinyl acetate content 15% by weight, MFR 2 g / 10 min)
As a fluorescent substance, SMART LIGHT RL1000 is added only to the intermediate layer so as to be 2.5% with respect to the resin composition in the entire film layer, and DHT4A is added as an inorganic filler to the resin composition in the entire film layer. A polyolefin resin composition in which DS403N is added only to the intermediate layer so as to be 12% and DS403N is added only to the intermediate layer so as to be 0.4% with respect to the resin composition in the entire film layer is used. Three-layer inflation molding was performed with the die temperature set at 150 ° C. and the extruder temperature set at 150 ° C.

Comparative Example 3
In blending the polyolefin resin composition of Example 2, SMART
A multilayer film was prepared under the same molding conditions as in Example 2 except that LIGHT RL1000 was not added.

Foaming was evaluated according to the following criteria for the polyolefin-based three-layer films obtained in the above-mentioned Examples and Comparative Examples.
Foaming: The presence or absence of foaming was visually observed.

Moreover, about these multilayer films, it measured with the following method with the spectroradiometer which used the reflex lamp.
Measurement with a spectroradiometer using a reflex lamp:
The light source was a National (current Panasonic) photographic reflex lamp PRF-500W (Flood 500W), measured with a spectroradiometer MS-720 manufactured by Eihiro Seiki Co., Ltd., and the data was analyzed on a personal computer as data every 1 nm. .

  Table 2 shows the evaluation results of foaming of each three-layer film. Moreover, about Example 5, Example 7, and Comparative Example 3, the graph of the measurement result in 500-700 nm by the spectroradiometer which uses a reflex lamp is shown in FIG. Moreover, about the Example 2-10, the comparative example 3, and the blank (only light source), using the result obtained by the measurement by the spectroradiometer which used the reflex lamp, the integrated value in 400-700 nm and the value in 640 nm are obtained. The plotted graph is shown in FIG. Here, the integrated value of 400 to 700 nm represents the transparency of the film in the visible light region, and the higher this value, the better the transparency. The value of 640 nm represents the degree of the amount of light that is wavelength-converted by the fluorescent material, and the higher this value, the higher the wavelength conversion efficiency. Table 2 also shows the integrated values of 400 to 700 nm and the values of 640 nm.

  Table 2 shows that the multilayer films obtained in Examples 2 to 10 are good in foaming and visual appearance. 2 and 3, the three-layer film containing the fluorescent material in the intermediate layer has good wavelength conversion efficiency, and when the fluorescent material and the inorganic filler are further combined with a dispersant, the transparency and the wavelength are high. It shows that a film having excellent conversion efficiency can be obtained.

  From the above results, the agricultural polyolefin-based multilayer film of the present invention can emit a visible light component of at least 600 to 700 nm as a wavelength component, has good transparency, and excellent sustainability of the wavelength conversion effect. Therefore, it is very preferable because a high cultivatability improvement effect can be obtained for a long time.

Claims (6)

An agricultural multilayer film comprising a polyolefin-based resin composition having a laminate structure of at least three layers having at least an outer layer, an intermediate layer, and an inner layer, wherein the polyolefin-based resin composition in the entire film is represented by the formula (1) 0.1 to 5% by weight of the fluorescent material represented, the fluorescent material content rate (% by weight) in the intermediate layer is X, the fluorescent material content rate (% by weight) in the inner layer is Y, and the fluorescent material in the outer layer An agricultural multilayer film, wherein X> Y and X> Z, where Z is the content (% by weight).

(In formula, R1-R2 represents a hydrogen atom or a C1-C10 alkyl group each independently.)   The agricultural multilayer film according to claim 1, wherein 80% or more of the amount of the fluorescent substance added in the entire film layer is contained in the intermediate layer.   The agricultural multilayer film according to claim 1, wherein the outer layer and the inner layer do not contain a fluorescent material, and only the intermediate layer contains the fluorescent material.   The agricultural multilayer film according to any one of claims 1 to 3, wherein an inorganic filler is contained in at least the intermediate layer.   The agricultural multilayer film according to any one of claims 1 to 4, wherein the inorganic filler is hydrotalcite and / or a fired body thereof.   The agricultural multilayer film according to any one of claims 1 to 5, wherein a dispersant is contained in at least the intermediate layer.

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