JP2009202350A - Agricultural film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an agricultural film having an excellent antifogging property, preventing the lowering of the cultivation property due to the insufficiency of the amount of light that is caused by the light scattering by water droplets and preventing the occurrence of the disease damage due to the falling of the water droplets, and besides excellent in transparency, hard to cause the whitening of creases and good in the adhesion of the antifogging coat. <P>SOLUTION: The agricultural film is formed by coating at least one surface of a base film with an antifogging agent composition which contains, as predominant components, an inorganic colloidal substance and a synthetic resin binder and which, as the inorganic colloidal substance, contains an inorganic colloidal substance having a particle size of ≤20 nm. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to the antifogging property on the inner layer side of the house, and with the excellent antifogging property, prevents the deterioration of cultivation due to light quantity shortage due to light scattering of water droplets on the film surface and the occurrence of diseases caused by water droplet dropping, The present invention relates to an agricultural film that has good transparency and is easy to process during coating.

  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 Agricultural polyolefin-based resin film (hereinafter referred to as agricultural poly, agricultural vinegar), and agricultural polyethylene terephthalate resin film mainly composed of biaxially stretched polyethylene terephthalate resin. So-called house cultivation and tunnel cultivation, where useful plants are cultivated, are actively carried out. 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-width films that do not require adhesive processing have been actively used because they can be provided at low cost, and have come to be used in a form that replaces traditionally used agricultural bean.

  When cultivating plants inside the house as a form of use of these agricultural films, if the anti-fogging property inside the house is low, the cultivatability deteriorates due to lack of translucency (light quantity inside the house) due to condensation inside the house, and drops of water drops Since various problems such as the occurrence of diseases due to the occurrence of the disease, it is one of the important performances required for agricultural films to maintain better anti-fogging properties for a long period of time.

  Among these agricultural films, the type in which the antifogging paint is coated on the surface of the house inner layer side film can impart antifogging properties over a longer period than the type in which the antifogging agent is kneaded into the base material. Currently, research is actively underway. In particular, the coating type in which a hydrophilic inorganic component is mixed with a binder resin component is less likely to be washed away and the hydrophilic property can be maintained for a long period of time. It has an excellent balance of performance and has been actively researched. In this way, as the transition from anti-fogging agent kneading type, in which hydrophilic components are washed away in a short period of time, to anti-fogging paint coat type that can impart anti-fogging properties for a long period of time, There is a growing demand for further improvements.

  As the structure of such an antifogging coating film, it is known that the antifogging performance is improved when a large amount of hydrophilic components are present on the surface. However, the anti-fogging coating film using the hydrophilic inorganic component decreases in water resistance (anti-fogging durability) and durability (folding whitening property, coating adhesion) as the ratio of the inorganic component to the binder resin increases. There is a tendency. The cause is that if the binder component that adheres the hydrophilic inorganic component to the base material or the inorganic component does not exist to some extent, the hydrophilic component is removed from the coating surface by the condensed water flowing down the surface of the anti-fogging coating during use. This is because the anti-fogging coating film is lost due to external force due to runoff or insufficient adhesion.

  On the other hand, when the ratio of the binder resin to the inorganic component is high, the binder resin having a certain degree of water resistance often contains a large amount of hydrophobic components, so it depends on the hydrophobic component of the binder resin present on the surface of the antifogging coating film. Due to the partial hydrophobization, a high level of antifogging property beyond a certain level was not obtained.

  Also, if there is no binder resin component as an adhesive component, the film-forming property is inferior, or even if it is formed into a film, the adhesion between inorganic components cannot be secured, and whitening or anti-fogging coating film peeling due to folding wrinkles There was a case that became a problem, and the improvement was demanded.

  In such a background, various types of anti-fogging coatings have been studied in order to make the hydrophilic component present at a high concentration on the surface. For example, a binderless coating surface as disclosed in JP-A-11-10783. Are proposed in which two layers of silica and hydrophilic polysaccharide are applied, or two layers of silica and hydrophilic resin are applied on the surface of a binderless coating as disclosed in JP-A-11-240112. I came. However, since these anti-fogging coatings have a layer that does not contain a binder resin, the adhesion to the substrate and the followability of the coatings are not sufficient, and the crease whitening property tends to be inferior.

  On the other hand, in order to allow a hydrophilic component to be present on the surface while having a binder resin layer, for example, an anti-fogging coating film having a multilayer structure as disclosed in JP-A-2007-282625 has been proposed. However, such a multi-layer coating involves a coating process and a drying process a plurality of times, so that the process is complicated and the cost tends to be disadvantageous.

  When a hydrophilic component is present on the surface and a binder component is present at the substrate interface in a single layer coat, it can be considered to form an inclined structure, but a specific method has been sought.

  Against this background, analytical methods such as cryo-SEM have recently been developed in which the coating film is instantly frozen in the drying process and observed with an electron microscope, and research on particle behavior during coating film drying has been reported. Yes. A research group at the University of Minnesota has reported that the formation of a gradient structure is suggested using two types of latex with different particle sizes and glass transition points (Progress in Organic Coating 52 (2005) 46-62). Even in single-layer coating, by designing the coating drying process well, it is possible to obtain a gradient structure in which the composition distribution is different between the base resin interface and the coating film surface, which could not be obtained without conventional multilayer coating. Is becoming possible.

  Although there are only a few reports on gradient-structured coatings that use differences in resin compatibility and solubility in solvents, those that use particle behavior in the drying process as described above are practical. There were no reports at the level, and basic research remained. In particular, there has been no report or teaching so far regarding a specific base material and antifogging paint combination when used in an antifogging coating film for agricultural use.

  The present inventor has intensively studied to obtain an antifogging coating film having an inclined structure by single layer coating, which is a very simple process compared to multilayer coating, while using a binder resin component. As a result, surprisingly, it was found that inorganic colloids with a small particle size of 20 nm or less tend to accumulate near the surface of the coating film during the drying process, and succeeded in obtaining an antifogging coating film having both high antifogging properties and water resistance. The present invention has been completed.

  The present invention has been made on the basis of the above findings, and contains an anti-fogging agent composition containing an inorganic colloidal substance and a synthetic resin binder as main components, and an inorganic colloidal substance having a particle size of 20 nm or less as the inorganic colloidal substance. An agricultural film characterized in that is applied to at least one side of a base film.

  Hereinafter, the present invention will be described in detail.

  The agricultural film of the present invention contains an anti-fogging agent composition containing an inorganic colloidal substance and a synthetic resin binder as main components, and an inorganic colloidal substance having a particle size of 20 nm or less as the inorganic colloidal substance. It is characterized by being applied to. In the present invention, the antifogging composition essentially contains an inorganic colloidal substance having a particle size of 20 nm or less as an inorganic colloidal substance. Further, in the present invention, by combining an inorganic colloidal material having a particle size of 20 nm or less and an inorganic colloidal material having a different particle size, high antifogging property, long-term antifogging durability, and anti-folding wrinkle whitening resistance can be imparted. It is. In particular, it contains an inorganic colloidal substance and a synthetic resin binder as main components, and includes an inorganic colloidal substance A and an inorganic colloidal substance B having a particle diameter of 20 nm or less as the inorganic colloidal substance, An anti-fogging agent composition in which the particle size ratio of the inorganic colloidal substance B is twice or more, an inorganic colloidal substance and a synthetic resin binder as main components, and an inorganic colloid having a particle diameter of 20 nm or less as the inorganic colloidal substance The ratio of the particle size of the inorganic colloidal material B to the particle size of the inorganic colloidal material A is at least twice as large as the inorganic colloidal material A. When an antifogging agent composition in which the ratio of the particle size of the inorganic colloidal substance C to the particle size is 4 times or more is used, Good effect is high and can be suitably used. More specifically, it contains an inorganic colloidal substance and a synthetic resin binder as main components, and includes an inorganic colloidal substance having a particle size of 20 nm or less and an inorganic anticoldant having a particle diameter of 40 nm or more as the inorganic colloidal substance. A composition, an inorganic colloidal substance, and a synthetic resin binder as main components, an inorganic colloidal substance having a particle diameter of 20 nm or less, an inorganic colloidal substance having a particle diameter of 20 to 60 nm, and a particle diameter of 60 nm or more. By using an antifogging agent composition containing an inorganic colloidal substance, high antifogging property, long-term antifogging durability, and anti-folding whitening resistance can be obtained. Here, the “main component” means that it becomes a main component in the components of the antifogging agent composition excluding the dispersion medium.

  As the antifogging coating film of the present invention, particularly when the inorganic colloidal material is colloidal silica and / or colloidal alumina, not only high hydrophilicity is obtained, but also in terms of cost, it is preferable to use it. I can do it.

  The inorganic colloidal substance used in the antifogging agent composition of the present invention can be used alone or in combination of two or more. The inorganic colloidal material of the present invention can impart good antifogging properties when used as an antifogging coating, and further functions to prevent blocking by a resin binder or the like on the coating film surface. . As the inorganic fine particles, metals, metal oxides, metal hydroxides, metal sulfates, metal carbonates, etc., metal composite hydroxides, etc., known ones can be used as long as they do not impair hydrophilicity to the film surface. I can do it.

  Examples of the inorganic colloidal substance include inorganic aqueous colloidal particles such as silica, alumina, water-insoluble lithium silicate, zinc oxide, zirconium oxide, iron hydroxide, tin hydroxide, titanium oxide, antimony oxide, barium sulfate, and zinc antimonate. And aqueous sols dispersed in water or hydrophilic media in various ways. Of these, colloidal silica and colloidal alumina are preferably used, and these may be used alone or in combination. Among these, inorganic fine particles with strong photocatalytic action may have an effect on the synthetic resin binder by reducing the substantial addition concentration by combining with other inorganic fine particles, or by applying surface treatment in a range that does not inhibit hydrophilicity. It is necessary to reduce it.

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

  In the present invention, the use of an inorganic colloidal substance having a particle size of 20 nm or less has a high accumulation effect on the coating film surface during drying and can impart high antifogging properties. . Here, one kind or two or more kinds of inorganic colloidal substances having a particle diameter of 20 nm or less can be used. Furthermore, in addition to the inorganic colloidal material having a particle size of 20 nm or less, by using a material having a particle size larger than 20 nm, not only high antifogging properties but also antifogging durability and anti-folding whitening resistance are imparted. It becomes possible. If the particle size is too large, the coating may be white and devitrified, and a colloidal silica particle having a particle size of 100 nm or less can be preferably used. In particular, when an inorganic colloidal material having a particle size of 20 to 60 nm and an inorganic colloidal material having a particle size of 60 nm or more are used in combination, the antifogging coating film excellent in antifogging property, antifogging durability, and anti-folding wrinkle whitening property Can be obtained. The particle size of the inorganic colloidal sol can be measured by a known method such as a laser diffraction method, a BET method, a dynamic scattering method, or a Sears method, and the formed antifogging coating film is observed by an electron microscope with a TEM or the like. Can also be measured.

  When the inorganic colloidal substance having a particle diameter of 20 nm or less of the present invention is added, the surface concentration is increased during drying. Although depending on the drying conditions, the addition amount is 1% or more, preferably 10% or more, as the weight concentration during drying in the inorganic colloidal substance added to the antifogging agent composition applied at one time. Preferably it is 20% or more. The amount of the inorganic colloidal substance can be confirmed from the image data obtained by observing the formed anti-fogging coating film with an electron microscope or the like, and the addition amount can also be estimated from the area ratio in the image. it can.

  The inorganic colloidal substance having a particle diameter of 20 to 100 nm used in the present invention has a low surface accumulation effect at the time of drying, so that depending on the drying conditions, the addition amount may be an antifogging agent composition applied at a time. The dry weight concentration in the inorganic colloidal substance added therein is 10% or more, preferably 20% or more, more preferably 30% or more for each particle size range described above.

  The amount of the inorganic colloidal substance used in the present invention is 0.1 to 10 with respect to the synthetic resin binder resin component as a ratio of the weight concentration during drying in the antifogging coating film applied at one time. , Preferably 0.5 or more and 5 or less, more preferably 1 or more and 3 or less.

  In the agricultural film of the present invention, it is sufficient that the antifogging coating film according to the present invention is formed on the surface on the inner side of the house, and in some cases, the antifogging coating film is applied to another coating layer (undercoat). Layer). In this case, although it is disadvantageous in terms of processing cost, it may be possible to add the functionality of the undercoat layer to the antifogging coating film according to the present invention. For example, under the antifogging coating film according to the present invention, by applying an antifogging agent composition mainly composed of one or more synthetic resin binders and / or inorganic colloidal sol to the base film in advance. Good antifogging properties can be obtained. Although this is disadvantageous in terms of cost, it is particularly effective when the surface of the base film is hydrophobic, and it is possible to maintain good antifogging properties for a long time as the film thickness can be increased. .

  Examples of the binder resin used for the synthetic resin binder in the present invention include acrylic resins, epoxy resins, urethane resins, polyester resins, and the like, particularly from the compatibility with the base film made of synthetic resins, It is preferable to use an acrylic resin and / or a urethane resin, and more preferably (i) a hydrophilic acrylic polymer, (ii) a hydrophobic acrylic resin, and (iii) hydrophobic, which will be described later. The acrylic acrylic resin and the polyurethane emulsion are preferable because they have respective characteristics. Also, (iv) a copolymer resin of a monomer used for the resin can be preferably used. Examples of (iv) include urethane-modified polyester urethane.

  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 hydrophobic acrylic resins, (a) is preferable in terms of early antifogging and wettability. However, since it tends to be washed away, the coating film has a certain water resistance due to a crosslinking reaction or the like. It is necessary to impart sex. On the other hand, (c) is excellent in water resistance and preferable in terms of anti-fogging durability, but it is necessary to adjust the ratio of the binder resin and the inorganic colloidal substance in order to suppress surface hydrophobization by hydrophobic acrylic. is there.

  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 preferred.

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

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

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

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

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

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

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

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

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

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

  It is preferable that the amount of the polyurethane aqueous composition is 0.01 or more and 2 or less, more preferably 0.01 or more and 1 or less with respect to the hydrophobic acrylic resin in terms of solid content by weight. When it is less than 0.01, it is difficult to improve the scratch resistance, and it takes a long time until the antifogging property is exhibited, and it is difficult to exhibit a sufficient antifogging effect. In addition, when it is too much, not only the scratch resistance is difficult to improve in proportion to the blending amount, but the coating film formed after coating tends to become cloudy and lower the light transmittance, which is also disadvantageous in terms of cost. It is not preferable.

  When preparing the antifogging agent composition according to the present invention, a surfactant such as an anionic surfactant, a cationic surfactant, a nonionic surfactant, or a polymer surfactant is added. be able to.

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

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

  Nonionic surfactants include polyoxyethylene higher alcohol ethers such as polyoxyethylene lauryl alcohol, polyoxyethylene lauryl ether and polyoxyethylene oleyl ether; polyoxyethylene such as polyoxyethylene octylphenol and polyoxyethylene nonylphenol. Alkyl aryl ethers; polyoxyethylene acyl esters such as polyethylene glycol monostearate; polypropylene glycol ethylene oxide adducts; sorbitan fatty acid esters such as sorbitan monostearate, sorbitan monopalmitate, sorbitan monobenzoate; diglycerin monopalmi 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 quickly uniformly dispersed, and when used in combination with the inorganic colloid sol, hydrophilicity is imparted to the surface of the hydrophobic polyolefin resin film. Fulfills the function of The addition amount of the surfactant is preferably selected in the range of 0.1 to 50 parts by weight with respect to 100 parts by weight of the solid content of the resin. 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. .

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

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

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

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

  In the antifogging agent composition according to the present invention, pigments, pigment dispersants, fillers, anti-settling agents, anti-sagging agents, antifoaming agents, leveling agents, anti-repelling agents that can be incorporated into ordinary paints, Adhesion improvers, antiseptics, algae inhibitors, antibacterial agents, deodorants, UV absorbers, weathering agents, plasticizers, film-forming aids, thickeners, coupling agents, and various other additives I can do it. The addition amount is not particularly limited, and may be appropriately selected within a range that does not affect the effects of the present invention.

  The blending method of the antifogging agent composition according to the present invention is not particularly limited, but it is preferably mixed uniformly, and the temperature and blending method at the time of blending can be appropriately selected as appropriate.

  Moreover, when the adhesiveness between the base film and the antifogging coating film 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.

  In the present invention, in order to form an antifogging coating film on the surface of a substrate film, generally a solution or dispersion of an antifogging agent composition is respectively applied to a doctor blade coating method, a roll coating method, a dip coating method, a spray coating method, a rod. A known coating method such as a coating method, a bar coating method, a knife coating method, or a brush coating method may be employed, and drying may be performed after coating.

  As the drying method after coating, either natural drying or forced drying may be employed. When the forced drying method is employed, it is usually 50 to 200 ° C., preferably 70 to 180 ° C. Good. When the drying temperature is higher than 200 ° C., a film using a synthetic resin for the base material may exceed the melting point of the base material, which may cause deformation problems such as melting and heat shrinkage. For heating and drying, an appropriate method such as a hot air drying method, an infrared drying method, a far infrared drying method, and an ultraviolet curing method may be employed, and it is advantageous to adopt the hot air drying method in consideration of the drying speed and stability. is there.

The coating amount of the anti-fogging agent composition according to the present invention is not particularly limited, but is preferably 0.01 to 10 g / m ² , more preferably 0 as the coating amount per unit area of the laminated portion during drying. .1 to 5 g / m ² . Below this range, it is difficult to obtain good antifogging properties, and exceeding this range causes a decrease in transparency due to whitening, which is not preferable.

  The coating thickness of the antifogging coating film according to the present invention may be selected with 1/10 or less of the base film as a guide, but is not necessarily limited to this range. If the total thickness of the coating film is larger than 1/10 of the base film, there is a difference in flexibility between the base film and the coating film, so that a phenomenon such as peeling of the coating film from the base film is likely to occur. The phenomenon that the coating film is cracked and the strength of the base film is lowered is not preferable.

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

  As a base film used for this invention, what mixed the additive with the well-known resin used for an agricultural film can be used.

  As the resin, vinyl chloride resin, low density polyethylene, linear low density polyethylene, high density polyethylene, linear low density polyethylene having a long chain branch, ethylene-vinyl acetate copolymer, ethylene-propylene copolymer, A single layer or multilayer film mainly composed of a polyolefin resin such as polyethylene terephthalate, a polyester resin such as polyethylene terephthalate, or the like can be used. When applied to a base resin film mainly composed of polyethylene terephthalate resin, polyolefin resin, and fluorine resin, the effect is remarkable and preferable. In particular, when a polyolefin resin is used, a wide and highly flexible film is obtained, which is preferable.

Examples of the polyolefin resin used for the base film in the present invention include an α-olefin homopolymer, a copolymer with a different monomer mainly containing an α-olefin, an α-olefin and a conjugated diene, or a non-diene. Examples thereof include polyunsaturated compounds such as conjugated dienes, 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-4-methyl-1-pentene copolymer, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, and the like. Among these, low density polyethylene having a density of 0.910 to 0.935, 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 method described in US Pat. No. 04247, that is, a metallocene catalyst, particularly a metallocene-alumoxane catalyst, or a metallocene compound as disclosed in, for example, International Publication No. WO92 / 01723, and a 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 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 based on temperature rising elution fractionation (TREF), MFR, density, molecular weight distribution, and other various physical properties.

Measurement of elution curve by temperature rising elution fractionation (TREF) The measurement of elution curve 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 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.

  The present invention uses an ethylene / cyclic aminovinyl compound copolymer to provide excellent long-term weather resistance, bleed-out resistance, good antifogging coating adhesion, and poor antifogging due to coating peeling. Film can be obtained. Compared with hindered amine weathering agents used for general agricultural films, the ethylene / cyclic aminovinyl compound copolymer not only provides an effect as a light stabilizer that significantly improves long-term weather resistance, but also prevents it. It plays a role in improving the adhesion to the surface of the coating including the cloudy coating.

  The copolymer of ethylene (A) and cyclic aminovinyl compound (B) of the present invention (hereinafter referred to as “ethylene / cyclic aminovinyl compound copolymer”) is composed of ethylene (A) and the compound of formula (1). Copolymers can be used. When the ethylene / cyclic aminovinyl compound copolymer is added in a large amount, the surface properties (waterdrop contact angle, etc.) of the polyolefin film of the film can be changed, and can be suitably used for the purpose of the present invention.

  In said formula (2), R1 and R2 represent a hydrogen atom or a methyl group each independently, and R3 represents a hydrogen atom or a C1-C4 alkyl group. Preferably, R1 and R2 are each a hydrogen atom or a methyl group, and R3 is a hydrogen atom.

  The vinyl compound (B) represented by the formula (2) is known and can be synthesized by a known method, for example, a method described in JP-B-47-8539, JP-A-48-65180, or the like. it can.

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

  As the preferred ethylene / cyclic aminovinyl compound copolymer, the ratio of (B) to the sum of ethylene (A) and cyclic aminovinyl compound (B) is 0.0005 to 0.85 mol%, More preferably, it is 0.001 to 0.55 mol%. That is, the preferred copolymer is one having a high light stability for a low content of the vinyl monomer having a hindered amine group in the side chain (cyclic aminovinyl compound (B)). When the concentration of the cyclic aminovinyl compound (B) is 0.0005 mol%, a sufficient light stabilizing effect is exhibited. On the other hand, when it exceeds 0.85 mol%, it tends to be substantially uneconomical.

  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 13 C-NMR (for example, JNM-GSX270 Spectrometer manufactured by JEOL Ltd.), according to a known method (for example, refer to “Chemistry Dossier (1)” pages 53 to 56 (1985)) Polyethyl acrylate (see Asakura Shoten "Polymer Analysis Handbook", page 969 (1985)) and ethylene-hydroxyethyl acrylate copolymer (Eur. Poly. J. 25, 4, 411-418 (1989) ))), The 32.9 ppm peak in the TMS standard is attributed to the methylene group in the α position from the branch point of the isolated vinyl monomer (B), and the 35.7 ppm peak It was attributed to the methylene group sandwiched between the branch points of the vinyl monomer (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. When the MFR is less than the above range, the compatibility with the polyolefin resin is poor, and when blended, it causes visible defects in film applications such as fish eyes and boots. On the other hand, if the MFR exceeds the above range, even if the copolymer has a large molecular weight, bleeding or blooming due to diffusion loss occurs, or when it is blended with a polyolefin 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 generating initiator such as dialkyl peroxide, diacyl peroxide, peroxy ester, ketone peroxide, peroxy ketal, hydroperoxide, 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 polyolefin 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 polyolefin 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, but it is, for example, contained in the innermost layer and the outermost layer (outer surface of the house), and the other layers are hindered amines usually blended for agricultural use. A light stabilizer can also be contained. 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.

  In the thermoplastic resin base film used in the present invention, various additives usually used for synthetic resins can be used in combination. These additives include, for example, ultraviolet absorbers, weathering agents, hindered amine compounds, infrared absorbers, heat retention agents, surfactants (including fluorosurfactants), antifoggants, fillers, and metal organic acids. Antioxidation of salt, basic organic acid salt and overbased organic acid salt, hydrotalcite compound, epoxy compound, β-diketone compound, polyhydric alcohol, halogen oxyacid salt, sulfur-based, phenol-based and phosphite-based Agents, heat stabilizers, lubricants, antistatic agents, colorants, antiblocking agents, and the like.

  Examples of hindered amine compounds that can be used 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-piperidyloxycarbonyl) Xyl) 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-triazine / N, N ' Bis (2,2,6,6-tetramethyl-4-piperidyl) hexamethylenediamine condensate, N, N′-bis (2,2,6,6-tetramethyl-4-piperidyl) hexamethylenediamine / dibromo Examples include ethane condensate.

  Examples of commercially available hindered amine compounds that can be used include TINUVIN 770, TINUVIN 780, TINUVIN 144, TINUVIN 622LD, TINUVIN NOR 371, CHIMASSORB 119FL, CHIMASSORB 944 (above, manufactured by Ciba Geigy), Sanol LS-765 (Sankyo R / K) -63, MARK LA-68, MARK LA-68, MARK LA-62, MARK LA-67, MARK LA-57, LA-900, T-1167L (above, manufactured by Asahi Denka Co., Ltd.), UV-3346, UV-3529, UV-3581, UV-3853 (above, manufactured by Cytec Corporation) and the like. These piperidine ring-containing hindered amine compounds are used alone or in combination of two or more.

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

  From the viewpoint of cost, 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.

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

  The content of the ultraviolet absorber is preferably more than 0.001% by weight and less than 2% by weight, more preferably 0.01-1% by weight, based on 100% by weight of the polyolefin resin. 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, for example, when used in a multilayer film, the ultraviolet absorber used in the present invention does not necessarily need to be contained in all the layers of the multilayer film, and may be contained in at least one layer. Moreover, a ultraviolet absorber can be used in combination with the 1 type, or 2 or more types of other ultraviolet absorber normally used.

  The said infrared absorber (heat retention agent) is an inorganic fine particle which has infrared absorptivity, and these can be used combining 1 type (s) or 2 or more types. The inorganic fine particles that can be used are not particularly limited, but inorganic compounds containing at least one atom selected from the components: Si, Al, Mg, Ca, and Li can be used. For example, magnesium oxide, calcium oxide, aluminum oxide, silicon oxide, lithium hydroxide, magnesium hydroxide, calcium hydroxide, aluminum hydroxide, magnesium carbonate, calcium carbonate, calcium sulfate, magnesium sulfate, aluminum sulfate, lithium phosphate, calcium phosphate , Magnesium silicate, calcium silicate, aluminum silicate, calcium aluminate, magnesium aluminate, sodium aluminosilicate, potassium aluminosilicate, calcium aluminosilicate, kaolin, clay, talc, mica, zeolite, hydrotalcite compound, lithium aluminum composite Hydroxides, aluminum / lithium / magnesium composite carbonate compounds, aluminum / lithium / magnesium composite silicate compounds, magnesium / aluminum Um silicon composite hydroxide, magnesium aluminum silicon composite sulfate compounds, magnesium aluminum silicon composite carbonate compound, a metal complex hydroxide salt containing more anions. These may be obtained by dehydrating crystal water.

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

  The method for obtaining the infrared absorber (heat retention agent) represented by the above formula (4) is not particularly limited, and commercially available products can be used. For example, DHT4A (manufactured by Kyowa Chemical Co., Ltd.), HT-P (Manufactured by Sakai Chemical Co., Ltd.), Optima (manufactured by Toda Kogyo Co., Ltd.), Mizukarak (manufactured by Mizusawa Chemical Co., Ltd.)

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

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

  The content of the infrared absorber (heat retention agent) is preferably more than 0.1% by weight and less than 15% by weight, and more preferably 1 to 12% by weight with respect to 100% by weight of the polyolefin resin. If the content is less than the above range, the effect of improving heat retention is low, and if it exceeds the above range, there are problems such as a decrease in transparency.

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

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

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

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

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

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

  Examples of the phosphite-based antioxidant include trisnonylphenyl phosphite, tris (2,4-ditert-butylphenyl) phosphite, tris [2-tert-butyl-4- (3-tert-butyl- 4-hydroxy-5-methylphenylthio) -5-methylphenyl] phosphite, tridecyl phosphite, octyl diphenyl phosphite, di (decyl) monophenyl phosphite, monodecyl diphenyl phosphite, mono (dinonylphenyl) Bis (nonylphenyl) phosphite, di (tridecyl) pentaerythritol diphosphite, distearylpentaerythritol diphosphite, di (nonylphenyl) pentaerythritol diphosphite, bis (2,4-ditertiarybutylphenyl) penta Erythritol diphosphite 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) butane triphosphite, tetrakis (2,4-ditertiarybutylphenyl) biphenylene diphosphonite, 2,2'-methylenebis (4,6-ditertiarybutylphenyl) (octyl) phosphite, Tetrakis (2,4-di-t-butylphenyl) 4,4'-biphenylene-di- Suhonaito, 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.

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

  The thermoplastic resin base film used in the present invention contains the above-mentioned components in combination, and can contain the following optional components as 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.

  In order to mix various additives, the required amounts are weighed, ribbon blenders, Banbury mixers, Henschel mixers, super mixers, single or twin screw extruders, rolls and other compounding machines and kneaders, and so on. What is necessary is just to use a blender and a mixer. 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.

  The substrate film thickness of the present invention is preferably in the range of 0.01 to 1 mm, more preferably 0.05 to 0.5 mm, still more preferably 0.05 to 0.2 mm in terms of strength and cost. It is. 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.

  When the substrate film of the present invention is a polyolefin multilayer film, 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.

  When the agricultural film according to the present invention is actually used, the film provided with the anti-fogging coating is preferably spread so as to be inside the house or tunnel.

  The agricultural film of the present invention has a very good antifogging property on the inner layer side of the house, prevents deterioration in cultivation due to insufficient light quantity due to light scattering by water droplets, and prevents the occurrence of diseases caused by water droplet falling, This is an agricultural film that prevents blocking, and not only provides good anti-fogging properties when extended by farmers, but it can also be suitably stored in warehouses in areas and times where condensation tends to occur during distribution. It has a good balance of performance to be provided as an agricultural film. The agricultural film of the present invention may be transparent, pear or semi-pear. Agricultural films for house, tunnel, mulching, bag hanging, etc. (so-called agricultural poly, agricultural sacbi, agricultural PO, agricultural PET (polyethylene terephthalate) ) 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 PO film 100 mmφ (made by Pla Koken Co., Ltd.) is used as a three-layer die as a three-layer inflation molding device, and the extruder has two inner tube outer layers of 30 mmφ (made by Pla Giken Co., Ltd.), intermediate layer Is 40 mmφ (manufactured by Pla Giken Co., Ltd.), outer 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— A three-layer laminated film composed of the components shown in Table-1 to Table-3 was obtained at 7 m / min and a thickness of 0.15 mm. Since these films are used with the end of the tube cut open when the house is stretched, the tube outer layer during film formation becomes the inner layer (inner surface) of the house when stretched when unfolded.

[Formulation] Addition amounts are as shown in Table 1.
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
EVA1: Ethylene / vinyl acetate copolymer (vinyl acetate content 5% by weight, MFR 2 g / 10 min)
EVA2: Ethylene / vinyl acetate copolymer (vinyl acetate content 15% by weight, MFR 2 g / 10 min)
UV absorber A: Cytec's triaryltriazine UV absorber "UV1164"
Synthetic hydrotalcite A: “DHT4A” manufactured by Kyowa Chemical Co., Ltd.
Light Stabilizer A: Light Stabilizer “chimassorb 944” manufactured by Ciba Specialty Chemicals
Light stabilizer A: Light stabilizer “Tinuvin NOR 371 FF” manufactured by Ciba Specialty Chemicals
Ethylene / Cyclic aminovinyl copolymer: “Novatech LD · XJ100H” manufactured by Nippon Polyethylene Co., Ltd. MFR = 3 g / 10 min (190 ° C., JIS-K6760) Density = 0.931 g / cm ³ (JIS-K6760) Cyclic amino Vinyl compound content = 5.1% by weight (0.7 mol%) Percentage of cyclic aminovinyl compound present in isolation = 90 mol% Melting point = 111 ° C.

(2) Surface treatment of film The surface corresponding to the house inner layer side of the obtained base 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 “wetting index” according to JIS-K6768. Was measured and confirmed.

(3) Preparation of antifogging agent composition An inorganic colloidal sol, a thermoplastic resin (binder component), a crosslinking agent, a crosslinking aid, a liquid dispersion medium and the like shown below were blended to obtain a coating composition.
The antifogging agent composition was formulated as shown in Tables 2-3.
(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.

The additives used are as follows (catalog values are used for the particle size).
Inorganic colloidal sol A: Colloidal silica "Snowtex ZL" manufactured by Nissan Chemical Industries, Ltd.
(Particle size 70-100nm)
Inorganic colloidal sol B: Colloidal silica “Snowtex 20L” manufactured by Nissan Chemical Industries, Ltd.
(Particle size: 40-50 nm)
Inorganic colloidal sol C: Colloidal silica “Snowtex 20” manufactured by Nissan Chemical Industries, Ltd.
(Particle size: 10-20 nm)
Inorganic colloidal sol E: Colloidal silica "Snowtex S" manufactured by Nissan Chemical Industries, Ltd.
(Particle size: 8-11 nm)
Inorganic colloidal sol F: Colloidal silica “Cataloid S-SA” manufactured by Catalyst Kasei Kogyo Co., Ltd.
(Particle size: 10-14 nm)
Thermoplastic resin A: “GD88” (hydrophobic acrylic resin) manufactured by NSC Japan
Thermoplastic resin B: “A-612” (hydrophobic acrylic resin) manufactured by NSC Japan
Thermoplastic resin C: Anionic polycarbonate polyurethane emulsion “WS-4000” manufactured by Takeda Pharmaceutical Co., Ltd.
Crosslinking aid A: Japan NSC “EB10”
Crosslinking agent A: Japan NSC "EA55"

(4) Formation of coating film Each of the above antifogging agent coating liquid compositions was applied to the surface of the base film surface-treated in (2) using a # 8 bar coater. The coated film was held in an oven at 80 ° C. for 1 minute to volatilize the liquid dispersion medium to form a lower layer coating film, and then the thickness of each coating film obtained was confirmed.

  Although the following physical property measurement was performed for each sample produced by the above method, the same effect can be obtained even in combinations other than those used this time, as long as the gist is not changed. The following tests were conducted for each sample used this time. Each measuring method in an Example and a comparative example is shown below.

(Evaluation methods)
Water Drop Contact Angle A water drop contact angle at 23 ° C. was measured for each sample shown in Table 2 using Kyowa Interface Science Co., Ltd. solid-liquid interface analysis system “DM-700”. The water droplet contact angle was measured at 10 points for each sample, and the average value was displayed.

Transparency The straight light transmittance at a wavelength of 555 nm of the film after forming (coating) an antifogging coating film was measured with a spectrophotometer (manufactured by Hitachi, U3500 type), and the value was shown.

Haze value (HAZE)
The HAZE value (cloudiness value) of the film after forming (coating) the antifogging coating film was measured with a haze meter (Tokyo Denshoku Co., Ltd .: TC-H3DP), and the value was shown.

Coating film adhesion In the film after forming (coating) the anti-fogging coating film, the cellophane tape is adhered to the surface of the molded product on which the coating film has been formed. Observed with the naked eye. The evaluation criteria are as follows.
○: The coating film without any peeling, completely remaining ones ○ _△: those more than two-thirds of the coating film remained without peeling △: × those more than two-thirds of the coating film was peeled off: The coating film Completely peeled

Wrinkle whitening property After forming (coating) an anti-fogging coating film, pinch the center of a molded product cut to 10 cm x 10 cm with a finger and twist it three times, then open the film and generate wrinkles at that time The width of the whitened portion (the widest portion of the sample) to be measured was measured and determined based on the following criteria.
The evaluation criteria are as follows.
○: The width of the whitened portion from the folded crease is narrower than 1 mm ×: The width of the whitened portion from the folded crease is 1 mm or more

Coating appearance The appearance of the transparent molded product was observed with the naked eye.
The evaluation criteria are as follows.
(Double-circle): Compared with the molded article which does not apply | coat an anti-fogging agent composition, what was applied has better transparency.
○: Transparency is almost the same as that of the molded product to which the antifogging agent composition is not applied.
○ _× : A slight decrease in transparency is observed.
Δ: A considerable decrease in transparency is observed.
X: The deterioration of transparency is very severe and cannot be practically used.

Antifogging Observation conditions based on the time until water droplets start to flow under conditions where condensation does not occur as a standard The observation condition based on the antifogging criterion The surface on which the coating film of the molded product is formed is placed inside the water tank. The air temperature is kept at 12 ° C and the water temperature inside the water tank is kept at 22 ° C. The speed of the anti-fogging property is observed with the naked eye when a predetermined time has passed, and the time until the water droplets start to flow is shown. It was.
Also, the antifogging property was evaluated according to the following evaluation criteria depending on the time until water droplets started to flow.
A: The time until water droplets start to flow is shorter than 60 minutes.
○: Time until the water droplet starts flowing is shorter than 60 minutes and shorter than 150 minutes.
X: Time until a water droplet starts flowing is 150 minutes or more.
Load test conditions Placed on the top of the water tank containing the water, the surface on which the coating film of the molded product is formed is placed inside the water tank, the outside air temperature is kept at 23 ° C, and the water temperature inside the water tank is kept at 50 ° C. The speed of appearance of antifogging at the time point was observed with the naked eye according to the above conditions, and the time until water droplets started to flow was shown.

[Examples 1 and 2 and Comparative Examples 1 to 3]
With the above formulation, a polyolefin three-layer film (base film) with a film thickness of 150 μm and a layer ratio of 1/3/1 is prepared, and an antifogging agent composition (hydrophobic acrylic resin + inorganic colloid sol) is applied to one side of the base film. Thus, a film on which an antifogging coating film was formed was prepared. The water droplet contact angle was measured by the above method. The results are shown in Table 2. From these results, it can be seen that the anti-fogging coating using colloidal silica having a particle size of 20 nm or less has higher hydrophilicity than the anti-fogging coating using silica having a particle size larger than 20 nm.

[Examples 3 to 5, Comparative Example 4, Reference Example 1]
By the above formulation, a polyolefin three-layer film (base film) having a film thickness of 150 μm and a layer ratio of 1/3/1 was prepared, and an antifogging agent composition (hydrophobic acrylic resin + urethane resin + inorganic colloid sol was formed on one side of the base film. ) Was applied to form a film having an antifogging coating film. Evaluation of anti-fogging properties under the above conditions was carried out under the conditions of transparency, haze value, coating film adhesion, crease whitening, appearance, and resistance to condensation. The results are shown in Table 3. From these results, the polyolefin film coated with the antifogging agent composition according to the present invention has a good crease whitening property, good coating film adhesion, and a commercially available polyolefin film for agriculture ( It can be seen that it has extremely high anti-fogging properties even when compared to “Super Solar Mutex S” manufactured by Mitsubishi Chemical MKV Co., Ltd.).

  As is apparent from the above results, an agricultural film characterized by applying an anti-fogging agent composition containing an inorganic colloidal material having a particle size of 20 nm or less and a synthetic resin binder as main components according to the present invention. Has very good antifogging properties. In particular, in an anti-fogging coating film in which a combination of colloidal silica having a specific particle size is used in combination with a synthetic resin binder, a very high anti-fogging performance can be maintained for a long period of time, and performance to be provided as an anti-fogging coating film ( (Transparency, coating film adhesion, anti-folding wrinkle whitening, etc.) are well-balanced and are extremely excellent as an anti-fogging coating film for agricultural films (Examples 1 to 5). The effect of such a combination is considered that the silica component and the binder resin component are moderately separated, and the silica / binder ratio in the film depth direction of the antifogging coating film is optimized.

  Further, in the present invention, by adding an ethylene-cyclic aminovinyl compound to the side in contact with the antifogging coating film, the adhesion of the antifogging coating film is not impaired as described in JP-A-2001-161180. Can be further improved, which is preferable.

  When an inorganic colloidal substance having a particle size of 20 nm or less is lacking, there is a problem that the water droplet contact angle, which is a measure of antifogging property, is inferior to that of the antifogging coating film according to the present invention (Comparative Example 1, 2, 4).

  Further, when only the inorganic fine particles are used without the synthetic resin binder component, even if the surface is subjected to corona treatment, it does not form a film and does not function as an antifogging coating film (Comparative Example 3).

That is, when the constituent elements in the present invention are lacking, it cannot be said that the performance to be provided as an agricultural film is provided in a balanced manner.
(The invention's effect)

  The present invention has excellent anti-fogging properties, prevents deterioration in cultivation due to insufficient light quantity due to light scattering by water droplets, and prevents the occurrence of diseases caused by dropping water droplets, and also has high transparency and is difficult to whiten folds. Another object is to provide an agricultural film having good antifogging coating adhesion. The agricultural film of the present invention may be transparent, satin or semi-satin, and can be suitably used for agricultural film applications such as house, tunnel, mulching and bag hanging.

Claims (9)

  An antifogging agent composition containing an inorganic colloidal substance and a synthetic resin binder as main components and containing an inorganic colloidal substance having a particle size of 20 nm or less as an inorganic colloidal substance is applied to at least one surface of a base film. Agricultural film.   An inorganic colloid containing an inorganic colloidal substance and a synthetic resin binder as main components, including an inorganic colloidal substance A and an inorganic colloidal substance B having a particle diameter of 20 nm or less as the inorganic colloidal substance, and corresponding to the particle diameter of the inorganic colloidal substance A An agricultural film comprising an antifogging agent composition having a particle size ratio of twice or more of the particulate material B applied to at least one surface of a base film.   An inorganic colloidal substance A containing an inorganic colloidal substance and a synthetic resin binder as main components, and including an inorganic colloidal substance A, an inorganic colloidal substance B, and an inorganic colloidal substance C having a particle size of 20 nm or less as the inorganic colloidal substance The ratio of the particle size of the inorganic colloidal material B to the particle size of the inorganic colloidal material B is 2 times or more, and the ratio of the particle size of the inorganic colloidal material C to the particle size of the inorganic colloidal material A is 4 times or more. An agricultural film comprising an article coated on at least one side of a base film.   An antifogging agent composition comprising an inorganic colloidal substance and a synthetic resin binder as main components, an inorganic colloidal substance having a particle size of 20 nm or less as an inorganic colloidal substance, and an inorganic colloidal substance having a particle diameter of 20 to 100 nm. An agricultural film characterized by being applied to at least one side of a base film.   It contains an inorganic colloidal substance and a synthetic resin binder as main components, and as an inorganic colloidal substance, an inorganic colloidal substance having a particle diameter of 20 nm or less, an inorganic colloidal substance having a particle diameter of 20 to 60 nm, and a particle diameter of 60 nm or more An agricultural film comprising an antifogging agent composition containing an inorganic colloidal substance applied to at least one surface of a base film.   The agricultural film according to any one of claims 1 to 5, wherein the inorganic colloidal substance used is colloidal silica and / or colloidal alumina.   The agricultural film according to any one of claims 1 to 6, wherein the synthetic resin binder is an acrylic resin and / or a urethane resin.   The agricultural film according to claim 1, wherein the base film is a polyolefin-based resin. The base film is characterized in that the layer containing a copolymer of ethylene (A) and a cyclic aminovinyl compound (B) represented by the following formula (1) is at least one layer including a house outer layer. Item 9. The agricultural film according to Item 8.

(In the formula, R 1 and R 2 each independently represent a hydrogen atom or a methyl group, and R 3 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.)