JP5756603B2 - Agricultural film - Google Patents

Description

  The present invention relates to an agricultural film that is excellent in long-term weather resistance, durability, and agrochemical resistance and hardly discolors. In addition, the present invention is excellent in coating film adhesion, antifogging properties and durability when coated with an antifogging coating, and after long-term stretching, particularly under acidic conditions including acid rain and agricultural chemicals. The present invention relates to an agricultural film in which the antifogging properties and the antifogging coating film adhesion strength are less reduced.

  In recent years, semi-forcing or suppressing cultivation of agricultural crops to increase their marketability and productivity, agricultural vinyl chloride film (hereinafter referred to as agricultural bi), polyethylene, ethylene-vinyl acetate copolymer, and polyolefin So-called house cultivation and tunnel cultivation are actively carried out to grow useful plants under the covering with agricultural covering materials such as agricultural polyolefin-based resin films (hereinafter referred to as agricultural poly and agricultural vinegar) mainly composed of resin. Yes. Among them, agricultural polyolefin-based resin film mainly composed of polyolefin-based resin is light because its density is smaller than that of vinyl chloride resin, and generates little toxic gas even when incinerated. Wide films that do not require adhesive processing can be provided at low cost, and are being actively used.

  Now, such an agricultural house is getting larger year by year, and the film expansion work for covering the house with a film requires a lot of manpower. On the other hand, the number of farmers is declining year by year and aging is progressing, and it is not easy to secure manpower for annual expansion work. In view of such a situation, the film to be spread in the house is a film that is easy to stretch and has a long use period until re-covering as much as possible, in other words, has a long life of 2 years or more and can maintain the initial performance over a long period of time. There is a need to develop high performance agricultural films.

  In response to such demands, the properties that the film should have include weather resistance, agricultural chemical resistance, and the like. Among these performances, the technology that has been regarded as the most difficult so far is imparting pesticide resistance, and many studies have been conducted in the past. In conventional agricultural applications, methods for imparting pesticide resistance to polyolefin films have been proposed, such as a method of combining a hindered amine compound having a general structure and hydrotalcite, or a method of using a weathering agent having a special structure. Yes.

  A resin composition containing a hindered amine compound as a weathering agent in a base film of an agricultural film is widely used. For example, a hindered amine having two or more piperidine rings in one molecule and a molecular weight of 500 or more. The system weathering agent can be mentioned. Already, as disclosed in, for example, JP-A-59-86645 and JP-A-2-167350, a hindered amine-based weathering agent can be added to a resin in a small amount to improve the weather resistance of the polyolefin-based resin. It is preferably used because it is remarkably improved, its effect is maintained for a long time, and changes in gloss and color tone of the polyolefin resin film are remarkably suppressed. However, molded articles obtained from such hindered amine-based weathering agent-containing resin compositions are significantly reduced in their effects when used, for example, under conditions exposed to acid rain and pesticides, and are required to have acid resistance and pesticide resistance. However, it could not be used satisfactorily for applications such as agricultural films.

  On the other hand, various hindered amine compounds have been proposed for the purpose of improving acid resistance. For example, compounds such as those disclosed in JP-A-11-80569 can improve acid resistance by addition, but various performances to be provided as an agricultural film, for example, under conditions other than acidic conditions Specific description for obtaining long-term weather resistance, anti-fogging durability, or long-term adhesion of the anti-fogging coating film under acidic conditions was lacking.

  On the other hand, agricultural films (for example, JP-A-5-127725 and JP-A-5-124161) to which an ethylene / cyclic aminovinyl compound copolymer is added have been devised for the purpose of sustaining further effects. Yes. This ethylene / cyclic aminovinyl compound copolymer is clearly distinguished from ordinary hindered amine weathering agents from the production method and molecular structure (for example, Japanese Patent No. 2695971 and Japanese Patent No. 2695975). However, this ethylene copolymer has high compatibility with the resin, and although the weather resistance improvement effect by the addition, especially the weather resistance improvement effect in the long term is recognized, it is expensive, so the addition amount can be increased. There are problems such as difficulties. When the addition amount is low, since the ratio of hindered amine groups in the total weight of the compound is low compared to ordinary hindered amine weathering agents, the effect of improving weatherability per added weight is low, and it is not necessarily used in general. I could not say.

  Japanese Patent Application Laid-Open No. 2001-2842 proposes a resin composition to which an ethylene copolymer having a triazine ultraviolet absorber and a hindered amine in the side chain is added. However, even when an agricultural film was prepared with the addition amount described in the present application, the weather resistance under acidic conditions was still insufficient.

  On the other hand, agricultural films, especially agricultural polyolefin-based resin films, are hydrophobic on the surface. Therefore, depending on conditions such as temperature and humidity, the film surface may become cloudy, resulting in poor transmission of sunlight. Slow growth of the larvae, or the water droplets generated by the collection of cloudy fine water droplets falling on the cultivated plant may damage the young buds or cause disease. In order to solve this problem, it is known that antifogging properties may be imparted to the surface of agricultural films including polyolefin resins. In order to impart antifogging properties to the surface of these agricultural films, a method of kneading and mixing a hydrophilic substance such as a surfactant with a polyolefin resin, or after forming a film, the surface thereof, for example, an interface with silica or alumina. Various methods of applying a mixture with an active agent have been proposed.

  However, in the former method, the hydrophilic substance kneaded and mixed with the resin is blown out and coordinated on the surface of the film to impart antifogging properties to the film. The antifogging property disappears within a short period of time. On the other hand, even in the latter method, since the adhesion with the polyolefin resin film is particularly poor, the formed coating film falls off with the passage of time.

  As another method for imparting antifogging properties, it has also been proposed to provide an antifogging coating mainly composed of an inorganic colloidal sol such as acrylic and colloidal silica after film formation. However, the conventionally proposed combination of an anti-fogging coating and a base film is exposed to the outside air for a long period of time, and agricultural films exposed to acidic conditions such as acid rain and agricultural chemicals are used for ventilation in the house. In addition, the antifogging coating film may be peeled off while the film is wound around the pipe and wound up or down, resulting in a problem that various antifogging performances are lowered. In particular, when exposed to acidic conditions such as acid rain and agricultural chemicals, there is a problem that the surface of the anti-fogging coating film is cracked, the coating film and the base film are easily peeled off, and the anti-fogging durability is also reduced. there were.

  In other words, not only during normal use, but also in an environment exposed to acidic conditions such as acid rain and agricultural chemicals, the anti-fogging coating surface is hard to crack, the durability of the anti-fogging performance, and the adhesion of the anti-fogging coating, It was difficult to obtain a film having good durability and pesticide resistance.

  With respect to such a problem, by including a hindered amine compound having a piperidine ring structure having a specific structure in at least one layer of the substrate film, excellent pesticide resistance can be imparted, and such a substrate is provided. When an anti-fogging coating film is applied to a film, for example, the adhesion of the anti-fogging coating film under acidic conditions is good, and the film is spread outdoors for a long time and exposed to acidic conditions such as acid rain and agricultural chemicals. It has been found that it is possible to provide an agricultural film that is often used (Japanese Patent Laid-Open No. 2003-199437).

  However, although the use of such a specific hindered amine compound can remarkably improve the pesticide resistance and the adhesion of the antifogging coating film, there is a problem that the film tends to be colored due to the inherent color of the hindered amine compound. If you come. Moreover, although the molding film-forming process of the base film containing these compounds is performed at a high temperature, there is also a problem that odor is generated at the time of molding or after molding due to partial volatilization of the compounds.

  The object of the present invention is to provide an agricultural film that is excellent in long-term weather resistance, durability, and pesticide resistance, hardly colored, and has no problem of odor, and when an anti-fogging coating film is applied to a base film In addition, it has excellent antifogging properties and long-term antifogging durability, and also has good antifogging properties, long-term antifogging properties, and weather resistance even under acidic conditions such as agricultural chemicals and acid rain. In addition, the present invention is to provide an agricultural film in which the bleeding out of a weathering agent is suppressed, the long-term weatherability is not deteriorated, and there is no problem of coloration or odor.

Japanese Patent Laid-Open No. 11-80569 JP 2001-2842 A JP 2003-199437 A

  As a result of intensive studies, the present inventor has included a hindered amine compound having a specific structure in a base film made of a thermoplastic resin (particularly a polyolefin-based resin), and is equivalent to the prior application (Patent Document 3). It has been found that it has the pesticide resistance and can solve the problems of coloration and odor. In addition, by applying an anti-fogging coating film having a specific composition to a base film containing such a hindered amine compound, the coating film adhesion, anti-fogging properties and durability are excellent, and coloration and odor problems. The present invention has been completed by finding out that an agricultural film free from the problem can be provided.

  The present invention has been made based on the above findings, and is an addition in which a thermoplastic resin (particularly, polyolefin resin) and a compound represented by the following general formula (1) are added to a polymer having an average molecular weight of 300 or more. Agricultural film comprising a multi-layer or single-layer base film having at least one layer containing at least one kind of hindered amine compound, wherein n represents an integer of 1 to 4 , R1 and R1 ′ may be the same or different and each represents a hydrogen atom or an arbitrary substituent.

  Moreover, this invention can further improve anti-fogging coating-film adhesiveness by containing at least 1 sort (s) of an ultraviolet absorber in at least 1 layer in the said base film.

  In addition, the present invention can improve the heat retaining property by containing at least one infrared absorber in at least one layer of the above-described base film, and is effective in suppressing the bleedout of the weathering agent. It can be made.

  The ultraviolet absorber in the present invention provides an agricultural film having better weather resistance and excellent bleed-out resistance by using a triaryltriazine type ultraviolet absorber described in the following formula (2).

（式中、Ｒ２〜Ｒ６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。）

(In formula, R2-R6 represents a hydrogen atom or a C1-C10 alkyl group each independently.)

  The infrared absorber in the present invention provides an agricultural film that is inexpensive and has good moldability by using an inorganic compound represented by the chemical formula of the following formula description (3).

  The present invention is excellent in bleed-out resistance by having at least one layer containing a copolymer of ethylene (A) and a cyclic aminovinyl compound (B) represented by the following formula (4). Providing agricultural films with good long-term weather resistance and good coating film adhesion.

（式中、Ｒ７及びＲ８は、それぞれ独立して水素原子又はメチル基を表し、Ｒ９は水素原子又は炭素数１〜４のアルキル基を表す。）

(In the formula, R7 and R8 each independently represent a hydrogen atom or a methyl group, and R9 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.)

  The present invention also provides an agricultural film characterized in that a coating layer of an antifogging paint mainly comprising a synthetic resin binder and an inorganic colloid sol is provided on the surface of the base film.

  The present invention also provides an agricultural film characterized in that the inorganic colloidal sol of the antifogging coating used for the antifogging layer provided on the surface of the base film described above is colloidal silica and / or colloidal alumina.

  The present invention also provides an agricultural film characterized in that the base film described above contains substantially no antifogging agent and an antifogging film is formed on the inner surface of the house.

  The ultraviolet absorber according to the present invention provides an agricultural film having excellent bleed-out resistance and chemical stability particularly when R2 in the formula (2) is an octyl group and R3 to R6 are methyl groups. .

  The ultraviolet absorber according to the present invention provides an agricultural film that is particularly excellent in bleed-out resistance and chemical stability when R2 in the formula (2) is a hexyl group and R3 to R6 are hydrogen atoms. .

  In the copolymer of ethylene (A) and the cyclic aminovinyl compound (B) represented by the above formula (4) in the present invention, R7 and R8 in the following formula (4) are each a methyl group, and R9 is hydrogen. Provided is an agricultural film having excellent bleed-out resistance and long-term weather resistance particularly when it is an atom.

  The present invention includes at least one layer containing an ethylene copolymer having a hindered amine in the side chain obtained by copolymerizing ethylene and a cyclic aminovinyl compound as described above, and / or a part of the components. All have at least one layer containing an ultraviolet absorber component which is a triazine compound having a specific structure according to the present invention, and 100 parts by weight of the thermoplastic resin in the entire film, the above formula (2) There is provided an agricultural multilayer film comprising less than 2 parts by weight of the triaryltriazine type ultraviolet absorber represented.

(Embodiment of the Invention)
Hereinafter, the present invention will be described in detail. As the thermoplastic resin constituting the substrate film of the present invention, a vinyl chloride resin, a polyolefin resin such as polyethylene and ethylene-vinyl acetate copolymer, and a polyester resin such as polyethylene terephthalate, which are usually used for agricultural films, are used. In particular, in the present invention, it is preferable to use a polyolefin-based resin because the effects of the present invention can be exhibited well. Examples of polyolefin resins include α-olefin homopolymers, copolymers of different monomers mainly containing α-olefins, polyunsaturated compounds such as α-olefins and conjugated dienes or nonconjugated dienes, Examples include copolymers with acrylic acid, methacrylic acid, vinyl acetate, and the like, such as high density, low density or linear low density polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-butene copolymer, ethylene. Examples include -4-methyl-1-pentene copolymer, ethylene-vinyl acetate copolymer, 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 as an agricultural film from the viewpoint of properties and price. In the present invention, an ethylene-α-olefin copolymer resin obtained by copolymerization with a metallocene catalyst can be used as at least one component of the polyolefin resin.

This is usually referred to as metallocene polyethylene, and is a copolymer of ethylene and an α-olefin such as butene-1, hexene-1, 4-methylpentene-1, octene. 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 metallocene catalyst, in particular, the metallocene / alumoxane catalyst, or the metallocene compound disclosed in, for example, International Publication WO92 / 01723, and the metallocene. A catalyst comprising a compound that reacts with a compound to form a stable ion, or further disclosed in JP-A-5-295020 and JP-A-5 Using a catalyst in which a metallocene compound is supported on an inorganic compound as described in No. 295022, etc., the main component ethylene and the secondary component α-olefin having 4 to 20 carbon atoms can be obtained. This is a method of copolymerizing 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 In which 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. . 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.

  Polyethylene resins including these metallocene polyethylenes are classified by temperature rising elution fractionation (TREF), MFR, density, molecular weight distribution, and various other physical property measurements.

Measurement of elution curve by temperature rising elution fractionation (TREF) The elution curve measurement by temperature rising elution fractionation (TREF) is described in “Journal of Applied Polymer Science. Vol 126, 4, 217-4, 231 (1981)”. ”,“ Polymer debate proceedings 2P1C09 (Showa 63) ”and the like. That is, first, the target polyethylene is completely dissolved once in a solvent. Thereafter, it is cooled to produce a thin polymer layer on the surface of the inert carrier. Such a polymer layer is formed easily on the inner side (side closer to the surface of the inert carrier), and on the outer side is difficult to crystallize. Next, by elevating the temperature continuously or stepwise, first, at a low temperature, the polymer is eluted from an amorphous portion in the target polymer, that is, from a polymer having a high degree of short-chain branching. As the elution temperature rises, the one with a little branching degree is gradually eluted, and finally the linear part without branching is eluted to complete the measurement. The concentration of the elution component at each temperature is continuously detected, and the composition distribution of the polymer can be measured by the peak of the graph (elution curve) drawn by the elution amount and elution temperature.

  The ethylene-α-olefin copolymer used as at least one component of the polyolefin resin of the present invention preferably exhibits the following physical properties.

Melt flow rate (MFR)
The MFR measured according to JIS-K7210 is 0.01 to 10 g / 10 min, preferably 0.1 to 5 g / 10 min. If the MFR is larger than this range, the film meanders during molding and is not stable. On the other hand, if the MFR is too smaller than this range, the resin pressure at the time of molding increases and a load is applied to the molding machine. Therefore, the increase in pressure must be suppressed by reducing the production amount, which is not practical.

Density The density measured by JIS-K7112 is 0.880 to 0.930 g / cm ³ , preferably 0.880 to 0.920 g / cm ³ . When the density is larger than this range, the transparency is deteriorated. On the other hand, if the density is smaller than this range, blocking occurs due to stickiness of the film surface, resulting in poor practicality.

Molecular weight distribution The molecular weight distribution (weight average molecular weight / number average molecular weight) determined by gel permeation chromatography (GPC) is 1.5 to 3.5, preferably 1.5 to 3.0. . When the molecular weight distribution is larger than this range, the mechanical strength is lowered, which is not preferable. If the molecular weight distribution is smaller than this range, the film meanders during molding and is not stable.

  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, the melting point of the resin is low, so that the film loosens at high temperatures in summer during house extension, and is easily broken by wind and flapping with the house structure.

  As a preferred embodiment of the agricultural film in the present invention, a base film made of a polyolefin-based resin composition is a multilayer film composed of at least three layers of an outer layer, an intermediate layer, and an inner layer that are outer when stretched, and an outer layer that is outer when stretched Alternatively, as the resin component of the outer layer and the inner layer, a resin containing an ethylene-α-olefin copolymer resin obtained by copolymerization with a metallocene catalyst in an amount of 45 wt% to 100 wt%, preferably 55 wt% to 95 wt% Using the composition, a resin composition containing 45 wt% to 100 wt%, preferably 55 wt% to 98 wt% ethylene-vinyl acetate copolymer in the intermediate layer or in the intermediate layer and the inner layer is used. Is preferred.

  The agricultural film in the present invention has at least one layer containing at least one hindered amine compound that is an adduct obtained by adding a compound represented by the following general formula (1) to a polymer having an average molecular weight of 300 or more. Agricultural film characterized by comprising a multi-layer or single-layer substrate film (wherein n represents an integer of 1 to 4, R1 and R1 ′ may be the same or different, and each represents a hydrogen atom or any Of the substituent.

  In the hindered amine compound in the present invention, a nitroxy group is added to the polymer, and when a radical is generated due to deterioration of the polyolefin resin of the base film, the nitroxy group is detached from the polymer and acts as a radical scavenger. It expresses weather resistance. Therefore, in the hindered amine compound of the formula (1), the R1 and R1 ′ groups located on the opposite side of the nitroxy group are involved in the mobility and compatibility in the resin, but are not effective in the expression of weather resistance. Therefore, R1 and R1 ′ should be appropriately selected in combination with the resin equipment blending or additive blending, and may be a hydrogen atom or an arbitrary substituent.

  Examples of the optional substituent include alkyl group, vinyl group, allyl group, aryl group, acyl group, hydroxy group, alkoxy group, amino group, hydroxylamino group, cycloalkyl group, cycloalkylcarbonyl group, heterocyclic group, aryl Examples thereof include, but are not limited to, an oxy group and a halogen atom. These substituents may further have a substituent. One or more carbon atoms in the cycloalkyl group or cyclocarbonyl group may be substituted with one or more heteroatoms such as oxygen, nitrogen, sulfur, phosphorus or silicon. Further, the optional substituent of R1 may be a bond representing carbonyl oxygen or imino group (= NR '), and in this case, the group of -R1' does not exist.

  When n = 2 or more, R1 is a group that bridges two or more nitroxy groups such as —O—CO— (CH2) x—CO—O— (x is an integer of 1 or more). There may be.

Examples of the polymer having a molecular weight of 300 or more include polymers having unsaturated bonds such as polyolefins such as polypropylene, high density polyethylene, low density polyethylene, and linear low density polyethylene when a polyolefin resin is used as a base material. It can be preferably used. In addition to so-called polymers, the polymer in the present invention includes long-chain alkanes such as natural or synthetic waxes. Preferred waxes include polyolefin waxes such as polyethylene wax and polypropylene wax. In the present invention, the long-chain alkane of the polyolefin wax may be linear or branched, and two or more main chains may be crosslinked.
Moreover, the hindered amine compound of Formula (1) can also be added by forming a carbon-carbon double bond in the polyolefin wax molecule. Moreover, the hindered amine compound of Formula (1) can be added by forming a carbon-carbon double bond in the polyolefin wax molecule and further converting the double bond into a reactive group.

As such a hindered amine compound, an adduct obtained by adding the compound represented by the general formula (1) to a polymer having a molecular weight of 300 or more (preferably a molecular weight of 2000 or more), for example, ADK STAB LA-900 (manufactured by Asahi Denka Co., Ltd.) ). Moreover, as an adduct obtained by adding the compound represented by the general formula (1) to a polyethylene wax having a molecular weight of 300 or more, for example, HostavinNOW manufactured by Clariant is mentioned.
The compound represented by the general formula (1) can be added to a polyethylene wax having a molecular weight of 300 or more by a known method. As the polyethylene wax to be used, a thermal decomposition method or a Ziegler catalyst is used. Any type of metallocene catalyst can be used. Examples of those using metallocene catalysts include polyolefin wax such as EXELEX manufactured by Mitsui Chemicals, Inc., which has features such as low molecular weight, high hardness, and easy introduction of reactive groups. The cost tends to be slightly higher.

  Content of the said hindered amine compound in the resin composition of the agricultural film of this invention is 0.001-10 weight part with respect to 100 weight part of said thermoplastic resins (especially polyolefin resin), Preferably it is 0.01. -5 parts by weight, more preferably 0.1-4 parts by weight.

  From the viewpoint of cost, for example, when the hindered amine compound used in the present invention is used in a multilayer film, it is not necessarily required to be contained in all layers of the multilayer film, and it may be contained in at least one layer. For example, in the case of 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. Although a layer or an inner / outer layer is preferable, only an inner layer, only an intermediate layer, only an outer layer, or any combination thereof may be used.

  The hindered amine compound can be used in combination with one or two or more other hindered amine weathering agents that are usually used. Furthermore, the 1 type, or 2 or more types of hindered amine type weathering agent normally used can also be used with respect to the layer which does not contain the said hindered amine compound. Of course, the hindered amine compound may be contained in all layers, but for example, it may be contained in the house intermediate layer, and the other layers may contain hindered amine weathering agents that are usually blended for agricultural use. Moreover, the hindered amine compound and the hindered amine type weathering agent normally mix | blended for agriculture can also be contained in the same layer. In that case, the cost becomes more advantageous than the case where the hindered amine compound is used in all layers.

Other than the specific hindered amine compound that is a feature of the invention of the present application, the hindered amine weathering agent that is usually blended for agricultural use can have at least a piperidine ring structure represented by the following formula (5) in the molecule. A hindered amine compound having two or more and a molecular weight of 500 or more (hereinafter also referred to as “piperidine ring-containing hindered amine compound”). When the number of piperidine rings in the piperidine ring-containing hindered amine compound is less than 2, sufficient weather resistance cannot be obtained, and when the molecular weight is less than 500, volatilization tends to occur and long-term weather resistance cannot be obtained. The number of piperidine rings in the piperidine ring-containing hindered amine compound is preferably 2 to 50, and the molecular weight is preferably 750 or more.

  Examples of the piperidine ring-containing hindered amine compound that can be used in combination 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-piperi) Ruoxycarbonyloxy) 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- Tetraazadodecane, 1- (2-hydroxyethyl) -2,2,6,6-tetramethyl-4-piperidinol / dimethyl succinate condensate, 2-tert-octylamino-4,6-dichloro-s- Liazine / 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 combination include TINUVIN 765, TINUVIN 770, TINUVIN 780, TINUVIN 144, TINUVIN 622LD, CHIMASSORB119FL, CHIMASSORB944 (above, manufactured by Ciba Geigy), Sanol LS-765 (manufactured by Sankyo R, Inc., 63, MA-R) MARKLA-68, MARK LA-68, MARK LA-62, MARK LA-67, MARK LA-57 (manufactured by Adeka Argus), CYASORBUV-3346, CYASORBUV-3529, CYASORBUV-3582, CYASORB UV-3853, etc. Is mentioned. These piperidine ring-containing hindered amine compounds are used alone or in combination of two or more.

  The agricultural film in the present invention can obtain good weather resistance by adding an ultraviolet absorber, and in particular, at least one of triaryltriazine type ultraviolet absorbers represented by the following formula (2) is used. If this is the case, a better effect can be obtained.

  Usable ultraviolet absorbers usually used for agriculture are, for example, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 5,5′-methylenebis ( 2-hydroxybenzophenones such as 2-hydroxy-4-methoxybenzophenone); 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2- (2′-hydroxy-3 ′, 5′-dithane) Tributylphenyl) benzotriazole, 2- (2′-hydroxy-3 ′, 5′-ditert-butylphenyl) -5-chlorobenzotriazole, 2- (2′-hydroxy-3′-tert-butyl-5) '-Methylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-5'-tertiary octyl fe 2) 2 such as benzotriazole, 2- (2′-hydroxy-3′.5′-dicumylphenyl) benzotriazole, 2,2′-methylenebis (4-tert-octyl-6-benzotriazolyl) phenol -(2'-hydroxyphenyl) benzotriazoles; phenyl salicylate, resorcinol monobenzoate, 2,4-ditert-butylphenyl-3 ', 5'-ditert-butyl-4'-hydroxybenzoate, 2,4- Benzoates such as ditertiary amylphenyl-3 ′, 5′-ditertiarybutyl-4′-hydroxybenzoate, hexadecyl-3,5-ditertiarybutyl-4-hydroxybenzoate; 2-ethyl-2′- Substituted oxanilides such as ethoxyoxanilide and 2-ethoxy-4′-dodecyloxanilide; ethyl-α-cyano-β Cyanoacrylates such as β-diphenyl acrylate and methyl-2-cyano-3-methyl-3- (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, etc. And triazines. These ultraviolet absorbers are used alone or in combination of two or more.

  A particularly effective ultraviolet absorber is a triaryltriazine type ultraviolet absorber represented by the following formula (2).

（式中、Ｒ２〜Ｒ６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。）

(In formula, R2-R6 represents a hydrogen atom or a C1-C10 alkyl group each independently.)

  Here, in Formula (2), R2 to R6 each independently represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. More preferably, R2 is an alkyl group having 6 to 10 carbon atoms, particularly preferably an alkyl group having 6 to 8 carbon atoms, and R3 to R6 are a hydrogen atom or an alkyl group having 1 to 2 carbon atoms, particularly preferably hydrogen. An atom or a methyl group.

  In the above formula (2), if the carbon number of R2 is less than the above range, bleeding out tends to occur, which is not preferable, and if it exceeds the above range, weather resistance is inferior, which is not preferable. If the number of carbon atoms in R3 to R6 is less than the above range, bleeding out tends to occur, which is not preferable, and if it exceeds the above range, weather resistance is inferior. In particular, the ultraviolet absorber in the present invention is the case where R2 in the formula (2) is an octyl group and R3 to R6 are methyl groups, or the ultraviolet absorber in the present invention is R2 in the formula (3). Is a hexyl group, and when R3 to R6 are hydrogen atoms, an agricultural film particularly excellent in bleed-out resistance and chemical stability can be obtained.

  The method for obtaining the triaryltriazine-based ultraviolet absorber represented by the above formula (2) is not particularly limited, and commercially available products can be used. For example, UV1164 (made by Cytec), TINUVIN1577FF (made by Ciba Specialty Chemicals), etc. can be mentioned.

  The content of the triaryltriazine type ultraviolet absorber represented by the above formula (2) in the agricultural film of the present invention is less than 5 parts by weight, preferably 0.001 to 3 parts per 100 parts by weight of the thermoplastic resin. Part by weight, more preferably 0.005 to 1 part by weight. 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.

  From the viewpoint of cost, the triaryltriazine type ultraviolet absorber used in the present invention does not necessarily need to be contained in all layers of the multilayer film, for example, when used in a multilayer film, and is contained in at least one layer. It only has to be. Moreover, this triaryl triazine type | mold ultraviolet absorber can be used in combination with the 1 type, or 2 or more types of other ultraviolet absorber normally used. Further, one or more commonly used ultraviolet absorbers can be used for the layer not containing the triaryltriazine type ultraviolet absorber. Of course, the triaryltriazine-type ultraviolet absorber may be contained in all layers, but for example, it may be contained in the house intermediate layer, and the other layers may contain an ultraviolet absorber usually blended for agriculture. Moreover, the triaryltriazine type ultraviolet absorber and the ultraviolet absorber usually blended for agricultural use can be contained in the same layer. In that case, it becomes more advantageous in terms of cost than the case of using a triaryltriazine type ultraviolet absorber in all layers.

The triaryltriazine type ultraviolet absorber used in the present invention is characterized by good bleeding out properties, but when added to a multilayer film, the bleeding out properties can be further improved. As a method for adding excellent bleed-out resistance, the content of UV absorber X per unit volume in the intermediate layer X> the content Y of UV absorber per unit volume in the inner layer, and X> per unit volume in the outer layer Agricultural multilayer film with UV absorber content Z, agricultural multilayer film in which 80% or more of UV absorber added in all films is contained in the intermediate layer, and other than the surface layer of the multilayer film (house inner layer An agricultural multilayer film obtained by adding a UV absorber to a layer other than the outer layer of the house (intermediate layer).

  In the present invention, an agricultural film having excellent long-term weather resistance and bleed-out resistance can be obtained by using an ethylene / cyclic aminovinyl compound copolymer. The ethylene / cyclic aminovinyl compound copolymer has an effect as a light stabilizer that significantly improves long-term weather resistance as compared with a hindered amine weathering agent used in general agricultural films.

  The thermoplastic resin composition of the present invention is represented by ethylene (A) and the following formula (5) as a light stabilizer in addition to the triaryltriazine type ultraviolet absorber represented by the above formula (2). A copolymer with the cyclic aminovinyl compound (B) (hereinafter referred to as “ethylene / cyclic aminovinyl compound copolymer”) can be contained. The ethylene / cyclic aminovinyl compound copolymer is also difficult to bleed out, and by using this in combination with the ultraviolet absorber represented by the above formula (2), extremely high weather resistance is obtained while suppressing bleed out. be able to.

  In said formula (4), R7 and R8 represent a hydrogen atom or a methyl group each independently, and R9 represents a hydrogen atom or a C1-C4 alkyl group. Preferably, R7 and R8 are each a methyl group and R9 is a hydrogen atom.

  The vinyl compound (B) represented by the formula (4) 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 represented by the formula (4) include 4-acryloyloxy-2,2,6,6-tetramethylpiperidine, 4-acryloyloxy-1,2,2,6,6-pentamethyl. Piperidine, 4-acryloyloxy-1-ethyl-2,2,6,6-tetramethylpiperidine, 4-acryloyloxy-1-propyl-2,2,6,6-tetramethylpiperidine, 4-acryloyloxy-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, , 6,6-tetramethylpiperidine, 4-crotonoyloxy-2,2,6,6-tetramethylpiperidine, 4-crotonoyloxy-1-propyl-2,2,6,6-tetramethylpiperidine and the like. Can be mentioned.

  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.

  Further, the ethylene / cyclic aminovinyl compound copolymer is such that (B) is not continuous in two or more in the copolymer, and the ratio of being isolated is 83% or more based on the total amount of (B), Preferably it is 90% or more.

  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, see Chemical Doujinshi "Tekiki no Tebiki (1)" pages 53-56 (1985)) Ethyl acid (see “Polymer Analysis Handbook” published by Asakura Shoten, page 969 (1985)) and ethylene-hydroxyethyl acrylate copolymer (Eur. Poly. J. Vol. 25, No. 4, pages 411 to 418 (1989)) ), The 32.9 ppm peak in the TMS standard is attributed to the methylene group at the α-position from the branch point of the isolated vinyl monomer (B), and the 35.7 ppm peak is two consecutive vinyl monomers. It was attributed to a methylene group sandwiched between the branch points of (B). Using these two signals, the ratio of the vinyl monomer (B) present in isolation in the copolymer of ethylene (A) and vinyl monomer (B) can be calculated by the following formula.

  The proportion of the hindered amine group-containing vinyl monomers having two or more hindered amine groups that are estimated as described above is not continuous but is present in an isolated state of 83% or more based on the total amount of vinyl monomers (B) in the copolymer. Is preferred. 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. If the MFR is less than the above range, the compatibility with the thermoplastic 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 if the copolymer has a large molecular weight, bleeding or blooming due to diffusion loss occurs, or when it is blended with a thermoplastic resin, it causes a decrease in strength of the resulting resin composition. It becomes.

  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.

  The content of the ethylene / cyclic aminovinyl compound copolymer in the thermoplastic resin composition of the present invention is 2 to 10 parts by weight, preferably 2 to 6 parts by weight with respect to 100 parts by weight of the thermoplastic resin. If this content is less than the above range, the weather resistance is inferior because it is inferior.

  From the viewpoint of cost, the ethylene / cyclic aminovinyl compound copolymer 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. Further, the ethylene / cyclic aminovinyl compound copolymer can be used in combination with one or two or more hindered amine weathering agents that are usually used. 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. Of course, the ethylene / cyclic aminovinyl compound copolymer may be contained in all layers, for example, it is contained in the innermost layer and the outermost layer (outer surface of the house), and the other layers are usually formulated for agriculture as described above. A hindered amine light stabilizer may also be included. Moreover, the hindered amine light stabilizer normally mix | blended for agricultural use can also be contained in the same layer with an ethylene-cyclic amino vinyl compound copolymer. In this case, the cost becomes more advantageous than the case where an ethylene / cyclic aminovinyl compound copolymer is used for all layers.

  The agricultural film in this invention can provide favorable heat retention by adding an infrared absorber. As the infrared absorber, an inorganic compound (inorganic oxide, inorganic hydroxide, hydrotalcite, etc.) containing at least one atom of Mg, Ca, Al, Si and Li that is effective as a heat retaining agent can be used.

  Especially, when the hydrotalcite infrared absorber represented by the following formula (3) is used, a film that is inexpensive and has good moldability can be obtained.

  The method for obtaining the infrared absorber (heat retention agent) represented by the above formula (3) is not particularly limited, and commercially available products can be used, and examples thereof include DHT4A (manufactured by Kyowa Chemical Co., Ltd.). .

  The infrared absorbent (heat retention agent) according to the present invention is inorganic fine particles having infrared absorbing ability, and these 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, and Ca can be used. For example, magnesium oxide, calcium oxide, aluminum oxide, silicon oxide, lithium hydroxide, magnesium hydroxide, calcium hydroxide, aluminum hydroxide, magnesium carbonate, calcium carbonate, calcium sulfate, magnesium sulfate, aluminum sulfate, lithium phosphate, calcium phosphate , Magnesium silicate, calcium silicate, aluminum silicate, calcium aluminate, magnesium aluminate, sodium aluminosilicate, potassium aluminosilicate, calcium aluminosilicate, kaolin, clay, talc, mica, zeolite, hydrotalcite 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 fine particles may be natural products or synthetic products. The inorganic fine particles can be used without being limited by the crystal structure, crystal particle diameter, and the like.

  The surface of the inorganic fine particles is 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 metal composite hydroxide salts can be used alone or in combination of two or more. 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 fine particles 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 inorganic fine particles is larger than the above range, the transparency is inferior or clogging occurs in the extruder breaker screen, and the productivity deteriorates.

  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 merca Topropionic acid, benzoic acid, monochlorobenzoic acid, p-tert-butylbenzoic acid, dimethylhydroxybenzoic acid, 3,5-ditert-butyl-4-hydroxybenzoic acid, toluic acid, dimethylbenzoic acid, ethylbenzoic acid, Monovalent carboxylic acids such as cumic acid, n-propylbenzoic acid, acetoxybenzoic acid, salicylic acid, p-tert-octylsalicylic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelain Divalent carboxylic acids such as 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, etc. These monoester or monoamide compounds, butanetricarboxylic acid, butane And tetracarboxylic acid, hemimellitic acid, trimellitic acid, merophanic acid, pyromellitic acid and the like tri- or tetravalent carboxylic acid di- or triester compounds, and the organic phosphoric acids include mono- or dioctyl. Phosphoric acid, mono- or dododecyl phosphoric acid, mono- or di-octadecyl 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 tert-octylphenol, ethylphenol, isopropylphenol, tert-butylphenol, n-butylphenol, diisobutylphenol, isoamylphenol, diamylphenol, isohexyl Ruphenol, octylphenol, isooctylphenol, 2-ethylhexylphenol, tertiary octylphenol, nonylphenol, dinonylphenol, tertiary nonylphenol, decylphenol, dodecylphenol, octadecylphenol, cyclohexylphenol, phenylphenolphenol, cresol, ethylphenol, cyclohexylphenol, Nonylphenol, dodecylphenol and the like can be mentioned.

  Moreover, in the agricultural film of this invention, the various additives normally used for a synthetic resin can be used together. Examples of these additives include metal organic acid salts, basic organic acid salts and overbased organic acid salts, hydrotalcite compounds, epoxy compounds, β-diketone compounds, polyhydric alcohols, halogen oxyacid salts, Examples thereof include sulfur-based, phenol-based and phosphite-based antioxidants, heat stabilizers, lubricants, antistatic agents, coloring agents, antiblocking agents, antifogging agents, and antifogging agents.

  Although there is no restriction | limiting in particular about the said anti-fogging agent, It consists of polyhydric alcohol and higher fatty acids including well-known various nonionic surfactant, anionic surfactant, cationic surfactant, etc. A polyhydric alcohol partial ester type is preferred. 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.

  Examples of the anti-fogging agent include a fluorine-based surfactant and a silicone-based surfactant. Specific examples of the fluorine-based surfactant include, instead of H bonded to C of the hydrophobic group of a normal surfactant. In addition, a surfactant having a part or all thereof substituted with F, particularly a surfactant containing a perfluoroalkyl group or a perfluoroalkenyl 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.

  The amount of the fluorine-containing compound having a perfluoroalkyl group is preferably 0.001 to 10 parts by weight, more preferably 0.01 to 5 parts by weight with respect to 100 parts by weight of the thermoplastic resin. If the amount of the fluorine-containing compound used is less than 0.001 part by weight, the antifogging effect is hardly exhibited, and if it exceeds 10 parts by weight, the effect is saturated, which is not preferable.

  In addition, as a filler, for example, silica, talc, aluminum hydroxide, hydrotalcite, calcium sulfate, calcium silicate, calcium hydroxide, water, in order to suppress stickiness of the film or to further improve heat retention Magnesium oxide, 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-ditert-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 .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, distearylpentaerythritol diphosphite, di (nonylphenyl) pentaerythritol diphosphite, bis (2,4-ditertiarybutylphenyl) penta Erythritol diphosphie Bis (2,6-ditert-butyl-4-methylphenyl) pentaerythritol diphosphite, tetra (tridecyl) isopropylidene diphenol diphosphite, tetra (tridecyl) isopropylidenediphenol diphosphite, tetra (C12 -15 mixed alkyl) -4,4'-n-butylidenebis (2-tert-butyl-5-methylphenol) diphosphite, hexa (tridecyl) -1,1,3-tris (2-methyl-4-hydroxy-5) -Tertiarybutylphenyl) butanetriphosphite, tetrakis (2,4-ditertiarybutylphenyl) biphenylenediphosphonite, 2,2'-methylenebis (4,6-ditertiarybutylphenyl) (octyl) phosphite, Tetrakis (2,4-di-t-butylphenyl) 4,4'-biphenyl Down - di - phosphonite, 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.

  Examples of the anti-blocking agent include diatomaceous earth, synthetic silica, talc, mica and zeolite. These anti-blocking agents can be used alone or in combination of two or more, and the range of usually 0.01 to 0.5% by weight is preferred.

  The agricultural film of the present invention contains the above-described components in combination, and can further contain the following optional components that can be contained in the thermoplastic resin film of the present invention, if necessary. Optional components include other stabilizers, impact resistance improvers, cross-linking agents, fillers, foaming agents, antistatic agents, nucleating agents, plate-out preventing agents, surface treatment agents, flame retardants, fluorescent agents, anti-glare agents Agents, bactericides, metal deactivators, mold release agents, pigments, processing aids and the like.

  The agricultural film of the present invention is each weighed in a necessary amount for blending various additives, and blending machines such as a ribbon blender, a Banbury mixer, a Henschel mixer, a super mixer, a single or twin screw extruder, a roll, and a kneading machine. Any other known blending machine or mixing machine 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.

  About the film thickness for agriculture 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.

  The agricultural film of the present invention may be a single layer or multiple layers. In the case of multiple layers, 3 to 5 layers are easy to balance each layer. The layer ratio constituting the three-layer film is preferably in the range of 1 / 0.5 / 1 to 1/5/1 in terms of moldability, transparency and strength, and 1/2/1 to 1/4/1. The range of 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.

  The agricultural film of the present invention is also characterized in that an antifogging film is formed in contact with the innermost layer of the thermoplastic resin film substrate. At this time, when a large amount of an antifogging agent is contained in the film in contact with the antifogging coating film, it is difficult to form the antifogging coating film due to the spraying of the antifogging agent onto the non-uniform film surface. There is. However, when used as a master batch in which various additives are concentrated and blended in advance with the base resin of each layer, the object of the present invention is as an anti-adhesive agent during kneading or as a surface modifier when forming an antifogging film. A small amount can be used as long as it is not impaired.

  Moreover, the agricultural film of this invention can form a coating film other than that. For example, a dust-proof coating film may be formed on the outer surface of the house. In that case, the effect of improving the adhesion of the coating film, which is the effect of the present invention, may be obtained for the dust-proof coating film.

  Examples of the anti-fogging coating film in the present invention include compositions composed mainly of an inorganic colloidal sol such as silica sol and / or alumina sol, and a binder resin such as a thermoplastic resin. Preferably, an antifogging coating film mainly composed of an inorganic colloid material and a hydrophilic organic compound or an antifogging coating film mainly composed of an inorganic colloid material and an acrylic resin can be used.

  The inorganic colloid sol used in the present invention has a function of imparting hydrophilicity to the surface of the film, particularly by applying it to the surface of a hydrophobic polyolefin resin film. As the inorganic colloidal sol, inorganic aqueous colloidal particles such as silica, alumina, water-insoluble lithium silicate, iron hydroxide, tin hydroxide, titanium oxide, barium sulfate were dispersed in water or a hydrophilic medium by various methods. And aqueous sols. Among these, silica sol and alumina sol are preferably used, and these may be used alone or in combination.

  As the inorganic colloid sol, it is preferable to select an average particle size in the range of 5 to 100 nm. In this range, two or more colloid sols having different average particle sizes may be used in combination. If the average particle size is too large, the coating may be devitrified in white, and if the average particle size is too small, the stability of the inorganic colloidal sol may be unfavorable. The amount of the inorganic colloidal sol is preferably 0.2 to 5 and preferably 0.5 to 4 in terms of the weight ratio as the solid content with respect to the total solid weight of the binder resin composition. That is, when the blending amount is too small, a sufficient antifogging effect may not be exhibited. On the other hand, when the blending amount is too large, the antifogging effect is not easily improved in proportion to the blending amount. The film formed later becomes cloudy and causes a phenomenon that the light transmittance of the film is lowered, and the film may be coarse and brittle, which is not preferable.

  Examples of the binder resin include acrylic resins, epoxy resins, urethane resins, polyester resins, and the like, in particular from the viewpoint of compatibility with the thermoplastic resin substrate film of the present invention, acrylic resins and / or urethanes. It is preferable to use a resin, more preferably (a) a hydrophilic acrylic polymer, (c) a hydrophobic acrylic resin, (e) a hydrophobic acrylic resin, and a polyurethane emulsion. Those having each characteristic are preferable.

  Examples of the acrylic resin include (a) one made of a hydrophilic acrylic polymer, (b) one made of a block copolymer containing a hydrophobic molecular chain block and a hydrophilic molecular chain block in one molecule, (c ) Among those composed of a hydrophobic acrylic resin, (a) is particularly preferable because it is excellent in compatibility with the base film of the present invention in terms of early antifogging wetness, while (c) is preferred. It is excellent in compatibility with the substrate film of the present invention and is preferable.

  As the hydrophilic acrylic polymer (a), a hydroxyl group-containing vinyl monomer component is a main component (preferably 60 wt% to 99.9 wt%, more preferably 65 wt% to 95 wt%), acid Examples thereof include a copolymer containing 0.1 to 30% by weight of a group-containing vinyl monomer component, a partially neutralized product thereof, 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 preferable.

  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.

  Examples of anti-fogging coatings mainly composed of an inorganic colloid material and a hydrophilic organic compound that can be used in the present invention include, for example, Japanese Patent Publication No. 63-45432, Japanese Patent Publication No. 63-45717, Japanese Patent Publication No. 64-2158, and patents. And compounds shown in No. 3094296.

  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 used in the present invention 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 (d) urethane-based resin include polyether-based, polyester-based, and polycarbonate-based anionic polyurethane aqueous compositions and emulsions. The antifogging coating has adhesion to the base thermoplastic resin film, water resistance, and the like. The anionic polyurethane emulsion based on polycarbonate is preferable in terms of water resistance and scratch resistance, and silanol in terms of water resistance of the further antifogging coating, improvement in scratch resistance, time to develop antifogging properties and antifogging durability A polycarbonate-based anionic polyurethane emulsion containing a group is more preferred. 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.

  Further, as a preferred antifogging film of the present invention, an embodiment using an emulsion prepared by mixing (e) the above-mentioned (c) hydrophobic acrylic resin and (d) an aqueous polyurethane composition is suitable from the viewpoint of compatibility with the substrate. It is preferable from the standpoint of satisfying both the expression speed of fogging and the antifogging sustainability in a well-balanced manner and scratch resistance.

  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.

  When preparing the antifogging agent composition for forming the antifogging film of the present invention, an anionic surfactant, a cationic surfactant, a nonionic surfactant, a polymer surfactant, etc. A surfactant 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 and sodium polyoxyethylene alkylphenyl ether sulfate 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, etc .; 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 rapidly dispersed uniformly, and when used in combination with the inorganic colloid sol, hydrophilicity is imparted to the surface of the hydrophobic thermoplastic 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 resin solid content. If the amount of the surfactant added is too small, it takes time to sufficiently disperse the resin and the inorganic colloid sol, and the antifogging effect in combination with the inorganic colloid sol cannot be sufficiently exhibited. If the amount added is too large, the transparency of the coating will decrease due to the bleed-out phenomenon on the coating surface formed after coating, and if it is noticeable, it may cause deterioration of the blocking resistance of the coating or decrease the water resistance of the coating. .

  When preparing the anti-fogging agent composition for forming the anti-fogging film of this 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 phenol resins, amino resins, amine compounds, aziridine compounds, azo compounds, isocyanate compounds, epoxy compounds, silane compounds, etc., but particularly amine compounds and aziridine compounds. 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 used for 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.

  The anti-fogging agent composition prepared in the present invention is further mixed with conventional additives such as an antifoaming agent, a plasticizer, a film-forming aid, a thickening agent, a pigment, and a pigment dispersant as necessary. be able to. Further, as a binder component other than the acrylic resin, for example, a polyether-based, polycarbonate-based, or polyester-based water-dispersible urethane resin may be mixed.

  In order to form an antifogging film on the surface of a base film, generally a solution or a dispersion of an antifogging composition is respectively applied to a doctor blade coating method, a roll coating method, a dip coating method, a spray coating method, a rod coating method, a bar coating method. A known coating method such as a coating method, a knife coating method, or a brush coating method may be employed 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, the drying method is usually 50 to 250 ° C., preferably 70 to 200 ° C. Good. 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 present invention, the thickness of the coating film formed on the surface of the substrate film may be selected by using 1/10 or less of the substrate film as a guide, but is not necessarily limited to this range. If the thickness of the coating is larger than 1/10 of the base film, there is a difference in flexibility between the base film and the coating, so that a phenomenon such as peeling of the coating from the base film is likely to occur, and the coating is cracked. This is not preferable because a phenomenon occurs in which the strength of the base film is lowered.

  When the adhesion between the base film and the coating derived from the coating composition is not sufficient, the base film may be subjected to a surface treatment. Examples of the treatment method applied to the surface of the laminated film of the present invention 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 film surface contains oxygen such as aldehyde, acid, alcohol peroxide, ketone, ether, etc. This is a process for generating a functional group. In the sputter etching process, a sample is placed between electrodes that are 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.

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

  The agricultural film of the present invention maintains antifogging properties and its properties over a long period of time. Good antifogging properties and antifogging coating film adhesion even under acidic conditions including agricultural chemicals and acid rain, In addition to excellent weather resistance, it has a well-balanced performance to be provided as an agricultural film. In particular, when the ultraviolet absorber having the structure according to the present invention and / or the ethylene / cyclic aminovinyl compound copolymer according to the present invention is used, the weather resistance, the agricultural chemical resistance, and the bleed out resistance are excellent. The effect of the present invention is particularly exerted, and when an anti-fogging coating film is provided on the film, bleed out is suppressed and adhesion to the substrate is not lowered, which is preferable. The agricultural film of the present invention may be transparent, satin, or semi-pear, and is an agricultural film for house, tunnel, mulching, bag hanging, etc. (so-called agricultural bi, agricultural poly, agricultural sacbi, agricultural PO, hard film) Etc.).

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

(1) Preparation of laminated film (both antifogging agent kneading type and antifogging coating application type)
As a three-layer inflation molding device, a 100 mmφ (made by Pla Koken Co., Ltd.) was used for a three-layer die. Manufactured by Giken Co., Ltd.) Outer inner layer extruder temperature 180 ° C., intermediate layer extruder temperature 170 ° C., die temperature 180-190 ° C., blow ratio 2.0-3.0, take-off speed 3-7 m / min, thickness 0 A three-layer laminated film composed of the components shown in Table-1 to Table-4 was obtained at a thickness of .10 to 0.15 mm. These films are
Since the end of the tube is cut open when the house is stretched, the tube outer layer at the time of film formation becomes the inner layer (inner surface) of the house when the film is stretched.

[Composition] Addition amounts are as described in each table.
HP-LDPE: Branched polyethylene produced with a high-pressure radical catalyst (MFR: 1.1 g / 10 min, density 0.920) Novatec LD “YF30” manufactured by Nippon Polychem
Metallocene PE: An ethylene / α-olefin copolymer produced with a metallocene catalyst (MFR: 2 g / 10 min, density 0.907) Kernel “KF270” manufactured by Nippon Polychem

EVA (1): ethylene-vinyl acetate copolymer (vinyl acetate content 5% by weight, MFR 2 g / 10 min)
EVA (2): ethylene-vinyl acetate copolymer (vinyl acetate content 15% by weight, MFR 2 g / 10 min)

Synthetic _{hydrotalcite: Mg 4.5 Al 2 (OH)} 13 CO 3 · 3.5H 2 O
Light stabilizer A: Light stabilizer “ADK STAB LA-900” manufactured by Asahi Denka Co., Ltd. A hindered amine compound obtained by graft-adding the compound represented by the general formula (1) to polyethylene having an average molecular weight of about 100,000. It has at least two structures of the general formula (1).
Light stabilizer B: Light stabilizer “Tinuvin NOR371 FF” manufactured by Ciba Specialty Chemicals Co., Ltd. 2,2,6,6-tetramethylpiperidine derivative having a triazine skeleton, molecular weight of about 3600
Light stabilizer C: Light stabilizer Kimasorb 944 manufactured by Ciba Specialty Chemicals Co., Ltd. A hindered amine compound in which a hydrogen atom is bonded to the nitrogen atom of the piperidine ring, and does not have the structure described in the general formula (1). Molecular weight of about 2000 to 3000.
Light stabilizer D: Light stabilizer manufactured by Cytec Corporation CYASORB UV-3529 A hindered amine compound in which a methyl group is bonded to the nitrogen atom of the piperidine ring, and does not have the structure described in the general formula (1). Average molecular weight about 1700.

(2) Film surface treatment (anti-fogging coating type)
The surface of the outer layer of the obtained tubular film was subjected to corona discharge treatment at a discharge voltage of 120 V, a discharge current of 4.7 A, and a line speed of 10 m / min, and the “wetting index” according to JIS-K6768 was measured and confirmed.

(3) Formation of anti-fogging coating film (anti-fogging coating type)
The main component (silica sol and / or alumina sol) shown below, a thermoplastic resin, a crosslinking agent and a liquid dispersion medium were blended to obtain an antifogging agent composition. The antifogging agent composition was blended as follows.
<Anti-fog coating type>
Inorganic colloidal sol (colloidal silica) 4.0
Thermoplastic resin (Sanmor SW-131: hydrophobic binder resin) 3.0
Cross-linking agent (TAZM) 0.1
Dispersion medium (water / ethanol = 3/1) 93
(Note) The amount of inorganic colloidal sol is indicated by the amount of inorganic particles, and the amount of thermoplastic resin is indicated by the solid content of the polymer.
Colloidal silica: Snowtex 30 manufactured by Nissan Chemical Co., Ltd., average particle size 15 nm, Sunmol SW-131: acrylic emulsion manufactured by Sanyo Kasei Co., Ltd. A. Z. M: Aziridine compound manufactured by Mutual Yakugyo Co., Ltd. (Note) The amount of inorganic colloid sol is indicated by the amount of inorganic particles, and the amount of thermoplastic resin is indicated by the solid amount of polymer.
The antifogging agent composition was applied to the surface of the base film surface-treated in (2) using a # 5 bar coater. The applied film was kept in an oven at 80 ° C. for 1 minute to volatilize the liquid dispersion medium to form an antifogging coating film. The thickness of the coating film of each obtained film was about 1 μm.

  The following physical properties were measured for each film provided with an antifogging coating film (film thickness 100 μm), but the gist was changed even with combinations other than the resin and additives used this time, or with different film thicknesses. As long as it is not, the same effect can be obtained. The following tests were conducted for each sample used this time. Each measuring method in an Example and a comparative example is shown below.

Performance evaluation (1) Initial coating film adhesion (coating peelability: after itch test)
The stagnation test was carried out with a UF stagnation tester FT-501 manufactured by Ueshima Seisakusho. A film cut to a width of 2 cm and a length of 7 cm was allowed to stand in a thermostatic chamber at 23 ° C. for 60 minutes, and then a sag test was performed 10 times under the conditions of a load of 500 g, a sag width of 2 cm, and a stagnation speed of 120 times / min. Then, the coating film adhesion of the anti-fogging layer in the stagnation width portion was visually evaluated according to the following criteria.

A: peeling area 0 to 10%
○: peeling area 10-20%
Δ: Peeling area 20-50%
×: peeling area> 50%

(2) Coating film adhesion after 800 hours of agricultural chemical resistance test The film was stretched in a pipe house constructed in the above-mentioned field in Isshi-gun, Mie Prefecture so as to be in a sealed state. Moreover, the sulfur was fumigated for 8 hours during the day by heating it with a commercially available sulfur fumigator (trade name: Shinkoden) in the pipe house. The film that had been stretched and fumigated for about 4 months from mid-April 2001 to mid-August 2001 was exposed to a weather resistance tester (manufactured by TheQ-PANELCOMPANY). The coating film adhesion of these films after the elapse of 800 hours was measured according to the method for measuring the initial coating film adhesion.

(3) Initial anti-fogging property The surface of the pipe house in the field of Isshi-gun, Mie Prefecture was stretched so that the surface with the anti-fogging coating formed inside the house. The antifogging property on the inner surface of the stretched film was visually evaluated. The evaluation criteria are as follows.

A: Water droplets adhering to the film surface (the one facing the inside of the house, hereinafter the same) are combined to spread in a thin film, and the area of this thin film portion extends over 2/3 of the film surface.
○: Although coalescence of water droplets adhering to the film surface is recognized, the area of this thin film-like portion is less than 2/3 of the film surface and 1/2 or more.
Δ: Coalescence of water droplets adhering to the film surface is observed, but the area of the thin film portion is less than 1/2 of the film surface.
X: A combination of water droplets adhering to the film surface is not recognized.

(4) Anti-fogging property after 800 hours of agricultural chemical resistance test The film was stretched in a pipe house constructed in the above-mentioned field in Isshi-gun, Mie Prefecture so as to be in a sealed state. Moreover, the sulfur was fumigated for 8 hours during the day by heating it with a commercially available sulfur fumigator (trade name: Shinkoden) in the pipe house. The film that had been stretched and fumigated for about 4 months from mid-April 2001 to mid-August 2001 was exposed to a weather resistance tester (manufactured by TheQ-PANELCOMPANY). The antifogging property after the lapse of 800 hours was measured in accordance with the initial antifogging measuring method (difference: the size of the sample is 15 cm wide and 30 cm long).

(5) Agrochemical weather resistance (tensile strength)
The film was spread on the pipe house constructed in Isshi-gun, Mie Prefecture, in a sealed state. Moreover, the sulfur was fumigated for 8 hours during the day by heating it with a commercially available sulfur fumigator (trade name: Shinkoden) in the pipe house. The film that had been stretched and fumigated for about 4 months from mid-April 2001 to mid-August 2001 was exposed to a weather resistance tester (manufactured by TheQ-PANELCOMPANY). The strength at break in the machine direction (resin flow direction) of these films at each time was measured by a tensile test (based on JIS-K6732). (Evaluation of pesticide resistance)

(6) Color resistance The produced film was punched into a 10 cm square with a punching machine and stacked so as to have a thickness of 2 cm, and the color tone was evaluated by a sensory test.
Evaluation standard is reddish ...
No redness ...

(7) Odor A film having a folded diameter of 30 cm width × 8 m length was prepared, put in a plastic bag, sealed, placed in a 50 ° C. oven for 48 hours, and then taken out. Immediately after removal, the odor in the plastic bag was evaluated by a sensory test.
Evaluation criteria There is an irritating odor ...
No pungent odor ...

[Example 1, Comparative Examples 1-3]
With the above blending, a 100 μm film (antifogging agent kneaded and antifogging coating coating type) was prepared by a processing method. Various tests were carried out under the above conditions using the film obtained here. Table 1 shows the results of the evaluation tests for (1) to (5).

[Examples 2 and 3]
A laminate film as described in (1) above, wherein Hostavin NOW (Clariant) was added in an amount of 0.4 parts by weight to each of the inner layer, intermediate layer and outer layer, and 6 parts by weight of synthetic hydrotalcite was added to the intermediate layer. (Example 2). Further, a laminated film was produced in the same manner as in Example 2 with each addition amount of HostavinNOW added to the inner layer, intermediate layer, and outer layer as 4.0 parts by weight (Example 3). The resulting laminated film was evaluated for color resistance and odor. The results are shown in Table 2 together with the evaluation results of color resistance and odor of the laminated films of Example 1 and Comparative Examples 1 to 3 (before application of the antifogging coating film).

  As is clear from the above results, the agricultural film according to the present invention is excellent in pesticide resistance, adhesion of the antifogging coating film, excellent antifogging durability, coloration, and odor. there is no problem.

  Accordingly, the agricultural film of the present invention may be transparent, satin or semi-satin, and is used for farming films for house, tunnel, mulching, bag hanging, etc. It can be suitably used for applications such as a hard film, and can provide good workability during film forming.

Claims (10)

A multilayer having at least one layer comprising at least one kind of hindered amine compound which is an adduct obtained by adding a thermoplastic resin and a compound represented by the following general formula (1) to a polymer having an average molecular weight of 300 or more Agricultural film characterized by comprising a single-layer substrate film (wherein n represents an integer of 1 to 4, R1 and R1 ′ may be the same or different, and each represents a hydrogen atom or an arbitrary substitution) Wherein the polymer having an average molecular weight of 300 or more is a polyolefin wax .

The agricultural film according to claim 1, wherein the polyolefin wax may be linear or branched, and two or more main chains may be crosslinked. The substrate film has at least one layer containing at least one ultraviolet absorber, and the ultraviolet absorber is a triaryltriazine type ultraviolet absorber described in the following general formula (2). The agricultural film according to claim 1 or 2.

(In formula, R2-R6 represents a hydrogen atom or a C1-C10 alkyl group each independently.) The base film has at least one layer containing at least one infrared absorber, and the infrared absorber is an inorganic compound represented by the chemical formula of the following description (3), Item 4. The agricultural film according to any one of Items 1 to 3.

The base film has at least one layer containing a copolymer of ethylene (A) and a cyclic aminovinyl compound (B) represented by the following formula (4): The agricultural film according to any one of 4.

(In the formula, R7 and R8 each independently represent a hydrogen atom or a methyl group, and R9 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.)   At least one layer containing an ethylene-based copolymer having a hindered amine in a side chain obtained by copolymerizing ethylene and a cyclic aminovinyl compound according to claim 5, and a part / all of the components are It has at least one layer containing an ultraviolet absorber component which is a triazine compound represented by the formula (2) according to claim 3, and the above formula (2) with respect to 100 parts by weight of the thermoplastic resin in the entire film. And a triaryltriazine type ultraviolet absorber represented by the formula (2) in an amount of less than 2 parts by weight.   The agricultural film according to any one of claims 1 to 6, wherein a coating layer of an anti-fogging coating mainly comprising a synthetic resin binder and an inorganic colloid sol is provided on the surface of the base film.   The agricultural film according to claim 7, wherein the synthetic resin binder is an acrylic resin and / or a urethane resin.   The agricultural film according to claim 7 or 8, wherein the inorganic colloidal sol is colloidal silica and / or colloidal alumina.   The agricultural film according to any one of claims 7 to 9, wherein the base film does not substantially contain an antifogging agent and an antifogging film is formed on the inner surface of the house.