WO2019004007A1 - Coating-type antifogging agent for films for agricultural use, and film for agricultural use - Google Patents

Abstract

The present invention provides an antifogging agent which is capable of imparting a film for agricultural use with long-term antifogging properties. A coating-type antifogging agent for films for agricultural use, which contains (A) colloidal inorganic fine particles, (B) a water-soluble alkali metal silicate salt and (C) a synthetic resin. This coating-type antifogging agent for films for agricultural use is configured such that, with respect to 100 parts by mass of the solid content of the colloidal inorganic fine particles (A), the solid content of the water-soluble alkali metal silicate salt (B) is 30-150 parts by mass and the solid content of the synthetic resin (C) is 30-150 parts by mass.

Description

Coating film type antifogging agent for agricultural film and agricultural film

The present invention relates to an antifogging agent to be used by applying to a film for agricultural use, and a film having an antifogging property which is sustained for a long time by applying the antifogging agent.

BACKGROUND ART In recent years, cultivation of crops under films (hereinafter referred to as "synthetic resin films") made of synthetic resins as raw materials, such as house cultivation and tunnel cultivation, has been actively performed. With regard to the film, the film surface becomes clouded or water droplets adhere due to water vapor transpiration from the soil or crops, etc., leading to a decrease in the cultivatability of crops due to a lack of sunshine power and disease occurrence of crops due to water drops. It is known that.
Therefore, development of the technique which provides antifogging property to the synthetic resin film (henceforth "agricultural film") used for cultivation of agricultural products conventionally is tried.

As a technology for imparting antifogging properties to agricultural films, an antifogging agent composition containing an aqueous emulsion of a specific acrylic resin and an inorganic colloidal sol in a specific amount (Patent Document 1), an aqueous dispersion of a specific acrylic resin, inorganic matter Method of preparing an anti-fogging agent composition containing a specific amount of a colloidal sol and a surfactant (Patent Document 2), (A) at least one selected from anionic polyurethane emulsions of polyester type and polycarbonate type (B A composition for forming an antifogging coating film comprising a specific ratio of colloidal silica particles of a specific average particle size and at least one selected from colloidal alumina particles (Patent Document 3), An antifogging coating layer comprising a synthetic resin binder and chain-like colloidal silica is provided on one side of a synthetic resin-coated material base layer, which has good storage stability. Antifogging agricultural coating material (Patent Document 4), characterized by containing a (meth) acrylic acid copolymer and a hydrophilic substance produced using an emulsifier having a specific reactive polymerization group. Antifogging paint composition (Patent Document 5), a monomer mixture containing at least (A) (meth) acrylic acid alkyl ester and (meth) acrylic acid as monomers in the presence of a reactive nonionic emulsifier A film-forming resin composition containing a (meth) acrylic copolymer obtained by emulsion polymerization, (B) inorganic colloid sol, (C) aliphatic alcohol having 1 to 10 carbon atoms, and (D) water Composition containing a component and having a minimum film forming temperature of -25.degree. C. or more and 20.degree. C. or less (Patent Document 6), necklace-like colloidal silica in which primary particles of colloidal silica are bound cyclically, primary particles of colloidal silica Form a chain The chain colloidal silica, and antifogging composition characterized by containing a binder resin in a specific ratio (Patent Document 7), and the like have been disclosed.

However, although the above-mentioned prior art temporarily prevents fogging of the agricultural film, the coating film may be detached from the surface of the film after a certain period of time, and the antifogging property may not be maintained. Therefore, there has been a demand for an antifogging agent which can impart long-lasting antifogging properties (hereinafter referred to as "long-term antifogging property").

JP-A-62-246984 Japanese Patent Application Laid-Open No. 63-150369 Unexamined-Japanese-Patent No. 6-122851 Japanese Patent Application Laid-Open No. 7-327522 JP, 2006-16578, A JP, 2008-50492, A JP, 2015-168692, A

An object of the present invention is to provide an antifogging agent capable of imparting long-term antifogging properties to agricultural films. Another object of the present invention is to provide an agricultural film to which a long-term antifogging property is imparted by applying the antifogging agent.

As a result of intensive studies to solve the above problems, the present inventors have made it possible to obtain an antifogging agent comprising an inorganic inorganic fine particle, a water-soluble alkali metal silicate and a synthetic resin in a specific ratio to an agricultural film. It discovered that the said subject was solved by apply | coating. The present inventors have further studied based on these findings to complete the present invention.
That is, the present invention comprises the following (1) and (2).
(A) Colloidal inorganic fine particles, (B) Water soluble alkali metal silicate, and (C) Coating type antifogging agent for agricultural films containing synthetic resin, wherein (A) Colloidal inorganic fine particles (B) 30 to 150 parts by mass of a water-soluble alkali metal silicate and (C) 30 to 150 parts by mass of a synthetic resin relative to 100 parts by mass of the solid content of Mold antifog agent.
(2) An agricultural film formed by applying the coating type antifogging agent of the above (1) on at least one surface of a synthetic resin film surface.
The present invention also includes the following inventions and the like.
(3) A method of producing a film (agricultural film) having an antifogging property (antifogging layer) by applying the coating type antifogging agent of the above (1) on at least one surface of a synthetic resin film surface.
(4) A method of applying the coating type antifogging agent of the above (1) on at least one surface of a synthetic resin film surface to impart antifogging properties (or forming an antifogging layer) on a synthetic resin film (agricultural film) .
(5) The film or method according to any one of the above (2) to (4), wherein the coating amount (solid content conversion) is 0.1 to 2 g / m ² .

By applying the coating type antifogging agent for agricultural films of the present invention (hereinafter referred to as "the antifogging agent of the present invention") to an agricultural film, the film has an initial antifogging property (immediate effect of antifogging effect) As well as long-term anti-fog can be imparted. In addition, the agricultural film coated with the antifogging agent of the present invention has the transparency required for the agricultural film.

Evaluation box for evaluating anti-fogging property and thermostatic water tank. 1: Evaluation box 2: Window of evaluation box 3: 3: Constant-temperature water tank. A constant temperature water tank equipped with an evaluation box for evaluating the antifogging property. 1: Evaluation box 3: 3: Constant-temperature water tank 4: 4: A film attached to the window of the evaluation box.

The (A) colloidal inorganic fine particles (hereinafter also referred to as “component (A)”) used for the antifogging agent of the present invention are inorganic fine particles. Examples of the inorganic substance include silica, alumina, titanium oxide, iron hydroxide, tin hydroxide or barium sulfate and the like, with preference given to silica or alumina. These inorganic substances may be used alone or in combination of two or more. There is no particular limitation on the average particle size of the fine particles, and it is preferably 5 to 100 nm. The shape of the fine particles is not particularly limited, and examples thereof include chains, spheres, and necklaces.

Commercially available (A) colloidal inorganic fine particles include, for example, silica sol (trade name: Snowtex; solid content 20% by mass; Nissan Chemical Industries, Ltd.) or alumina sol (trade name: AS-520; solid) 20% by mass (manufactured by Nissan Chemical Industries, Ltd.) and the like, and these can be used in the present invention.

The (B) water-soluble alkali metal silicate (hereinafter also referred to as “component (B)”) used for the antifogging agent of the present invention is a compound represented by M ₂ O · nSiO ₂ . Examples of M include Li (lithium), Na (sodium), K (potassium) and the like, preferably Li (lithium) or Na (sodium), and particularly preferably Li (lithium). The above n means SiO ₂ / M ₂ O (molar ratio), and the numerical value is not particularly limited as long as the alkali metal silicate becomes water soluble, but in the case where M is Li (lithium) , Preferably 3.5 to 7.5, when M is Na (sodium), preferably 2.0 to 4.0, and when M is K (potassium), preferably 2.0 to 4.0. It is. In addition, since (B) water-soluble alkali metal silicate is water-soluble, it is distinguished from colloidal inorganic fine particles.

(B) Examples of the water-soluble alkali metal silicate include lithium silicate, sodium silicate and potassium silicate, preferably lithium silicate or sodium silicate, particularly preferably silicic acid. It is lithium.

As a commercially available (B) water-soluble alkali metal silicate, for example, an aqueous solution of lithium silicate [trade name: lithium silicate 45; SiO ₂ / Li ₂ O (molar ratio) = 4.5; solid) Min. 26 mass%; Nissan Chemical Industries, Ltd.] or sodium silicate aqueous solution [trade name; SiO ₂ / Na ₂ O (molar ratio) = 2.2; solid content 55 mass%; Wako Pure Chemical Industries, Ltd. These can be used in the present invention.

The (C) synthetic resin (hereinafter also referred to as "(C) component") used for the antifogging agent of the present invention is particularly limited as long as it is a resin capable of bringing the antifogging agent of the present invention into close contact with agricultural films. However, water-insoluble synthetic resins or water-soluble synthetic resins can be used alone or in combination.

Examples of the water-insoluble synthetic resin include acrylic resin, acrylic styrene resin, vinyl acetate resin, vinyl acetate acrylic resin, vinyl acetate beige resin, ethylene vinyl acetate resin, urethane resin, epoxy resin, epoxy resin, phenol resin, alkyd resin or polyester resin or These copolymer resins, hybrid resins, modified resins, etc. are mentioned, Preferably they are an acrylic resin or a urethane resin. These water-insoluble synthetic resins may be used alone or in combination of two or more.

Examples of the acrylic resin include polymers or copolymers of acrylic acid monomers, and copolymers of acrylic acid monomers and other monomers.

As said acrylic acid type monomer, acrylic acid, acrylic acid ester, methacrylic acid, methacrylic acid ester, maleic acid, maleic anhydride, fumaric acid, crotonic acid, itaconic acid, ethylenesulfonic acid, 2-acrylamido-2-, for example Methylpropanoic acid, hydroxyl group-containing vinyl monomer of acrylic acid derivative, hydroxyl group-containing vinyl monomer of methacrylic acid derivative, acrylonitriles, acrylamides, glycidyl (meth) acrylate, glycidyl esters of acrylic acid or glycidyl of methacrylic acid Esters etc. are mentioned.

Examples of the other monomers include vinyl acetate, N-vinyl pyrrolidone or a derivative thereof, N-vinyl acetamide, ethylene-vinyl acetate and the like.

The urethane resin is a polymer compound obtained by reacting polyisocyanate and polyol. Examples of the polyisocyanate include aliphatic isocyanates such as hexamethylene diisocyanate and isophorone diisocyanate, and examples of polyols include polyether polyols such as polyethylene glycol or polypropylene glycol, and polyesters such as polyethylene adipate glycol or polybutylene adipate glycol. Polyol or polycarbonate polyol such as polybutylene carbonate diol or polyhexamethylene carbonate diol, etc. may be mentioned.

The water-insoluble synthetic resin is preferably used in the form of an emulsion in which the water-insoluble synthetic resin is dispersed in the form of particles in water and / or a water-soluble dispersion medium. Examples of commercially available emulsions of water-insoluble synthetic resins include acrylic resin emulsions (trade name: NeoCryl A-6057; solid content 35% by mass; Kushimoto Chemical Co., Ltd.) or urethane resin emulsions (trade name: NeoRez) R-986; solid content 35% by mass; manufactured by Kushimoto Chemical Co., Ltd.) and the like, and these can be used in the present invention.

Examples of the water-soluble synthetic resin include polyvinyl alcohol, polyethylene oxide, polyacrylic acid, polyvinyl pyrrolidone, carboxymethyl cellulose, methyl cellulose, hydroxyethyl cellulose, carboxyvinyl polymer and the like, with preference given to polyvinyl alcohol or polyethylene oxide. These water-soluble synthetic resins may be used alone or in combination of two or more.

As a commercially available water-soluble synthetic resin, for example, polyvinyl alcohol (trade name: KL-03; manufactured by Nippon Synthetic Chemical Co., Ltd.) or polyethylene oxide (trade name: L-6; manufactured by Meisei Chemical Industry Co., Ltd.), etc. These can be used in the present invention.

The antifogging agent of the present invention may contain (D) a solvent or a dispersion medium (hereinafter simply referred to as "solvent etc.").
As the (D) solvent and the like (hereinafter also referred to as "(D) component") used for the antifogging agent of the present invention, the (A) to (C) components contained in the antifogging agent of the present invention can be dissolved and dispersed. There is no particular limitation as long as it is a thing, for example, water, monohydric alcohols such as methyl alcohol, ethyl alcohol or isopropyl alcohol, polyhydric alcohols such as ethylene glycol, diethylene glycol or glycerin, cyclic alcohols such as benzyl alcohol And cellosolve acetates, ketones and the like, and from the environmental point of view, water is preferred. These solvents may be used alone or in combination of two or more.
When the component (D) contains water, the ratio of water to the entire component (D) is, for example, 10% by mass or more (for example, 20% by mass or more), preferably 30% by mass or more (for example, 40% by mass) More preferably, it may be about 50 mass% or more (for example, 60 mass% or more), or more than 70 mass% (for example, 75 mass% or more, 80 mass% or more, 85 mass% or more, 90 mass%) The above may be 95% by mass or more.

The antifogging agent of the present invention may contain any additive which is generally used for a coating type antifogging agent as long as the object of the present invention is not impaired. For example, antifoaming agent, plasticizer, coalescent agent Agents, thickeners, pigments, pigment dispersants, weatherability improvers, heat stabilizers, leveling agents, crosslinking agents, dispersants and the like.

As the compounding amount of the components (A) to (C) contained in the antifogging agent of the present invention, (B) water soluble alkali metal silicate relative to 100 parts by mass of solid content of (A) colloidal inorganic fine particles The solid content of the (C) synthetic resin is 30 to 150 parts by mass, preferably 50 to 150 parts by mass, and the solid content of the synthetic resin (C) is 30 to 150 parts by mass, preferably 60 to 150 parts by mass. The compounding amount of the solvent (D) and the like contained in the antifogging agent of the present invention is not particularly limited as long as it can dissolve and disperse the components (A) to (C). The total solid concentration of the components (A) to (C) in 100% by mass of the clouding agent is adjusted so as to be usually 0.5 to 10% by mass, preferably 1 to 5% by mass. The solid content in the present invention is the residual amount when a 10 mg sample is heated at 105 ° C. for 2 hours under a nitrogen atmosphere using a residual amount thermogravimeter (model: TGA 55; manufactured by TA Instruments). By measuring

The antifogging agent of the present invention can be obtained by uniformly mixing each component [at least (A) to (C) components, such as (A) to (D) components]. There is no restriction | limiting in particular in the method to mix, A well-known stirrer, a mixer, etc. can be used. The mixing conditions are not particularly limited as long as each component [for example, the components (A) to (D)] can be uniformly mixed, but, for example, a method of mixing at 25 to 60 ° C. for 180 to 360 minutes Can be mentioned.

An agricultural film formed by applying the antifogging agent of the present invention on at least one surface of a synthetic resin film surface is also one of the embodiments of the present invention.

The synthetic resin used for the above synthetic resin film is not particularly limited, and examples thereof include polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-butene copolymer, ethylene-4-methyl-1-pentene copolymer, etc. Polyolefin resins, ethylene-vinyl acetate copolymers, ethylene-acrylic acid copolymers, polyvinyl chloride and the like may be mentioned, and one or more of these may be used in combination.

The above-mentioned synthetic resin film may contain, in addition to the above-mentioned synthetic resin, any additive generally used in the synthetic resin film. For example, an antioxidant, a weathering agent, an ultraviolet absorber, an infrared absorber, a lubricant, Antiblocking agents, antifog agents, heat retaining agents, pigments and the like can be mentioned.

The synthetic resin film is not particularly limited as long as the synthetic resin or the synthetic resin composition in which the additive is blended into the synthetic resin is molded into a film, and, for example, an inflation molding method, a T-die molding method, etc. What was shape | molded to a film shape by the method of, etc. are mentioned. The synthetic resin film may be a single layer or a multilayer.

The thickness of the synthetic resin film is not particularly limited as long as it is a thickness suitable for agricultural use, but in consideration of film strength, weight and the like, it is usually 50 to 200 μm, preferably 80 to 150 μm.

The surface of the synthetic resin film is preferably subjected to pretreatment such as plasma discharge treatment and corona discharge treatment in advance in order to improve the coating properties and adhesion of the antifogging agent of the present invention.

In the agricultural film of the present invention, for example, the antifogging agent of the present invention containing a solvent or the like is applied to at least one surface of a synthetic resin film surface, and the solvent or the like in the antifogging agent is removed An antifogging layer is formed on at least one surface of the synthetic resin film surface.

The coating method is not particularly limited, and examples thereof include blade coating method, roll coating method, dip coating method, bar coating method, spray coating method, rod coating method, knife coating method and brush coating method.

The coating amount of the antifogging agent of the present invention on the synthetic resin film is usually 0.1 to 2 g / l converted to the amount of the antifogging layer from which the solvent (D) and the like have been removed after application to the synthetic resin film surface. m ² , preferably 0.2 to 1 g / m ² .

As a method of removing the said (D) solvent etc., the method of drying is mentioned. The drying method is not particularly limited, and examples thereof include a natural drying method or a forced drying method such as a hot air drying method, an infrared drying method or a far infrared drying method. In the case of the forced drying method, the drying temperature is usually 50 to 120 ° C. , Preferably 55 to 75 ° C.

The invention will now be described by way of example, which is merely illustrative of the invention and is not limiting.

<Production of coating type antifogging agent for agricultural films>
(1) Raw materials 1) Silica sol (trade name: Snowtex; solid content 20% by mass; Nissan Chemical Industries, Ltd.)
2) Alumina sol (trade name: AS-520; solid content 20% by mass; Nissan Chemical Industries, Ltd.)
3) Lithium silicate aqueous solution (trade name: lithium silicate 45; SiO ₂ / Li ₂ O (molar ratio) = 4.5; solid content 26 mass%; manufactured by Nissan Chemical Industries, Ltd.)
4) Sodium silicate aqueous solution (trade name; SiO ₂ / Na ₂ O (molar ratio) = 2.2; solid content 55% by mass; manufactured by Wako Pure Chemical Industries, Ltd.)
5) Acrylic resin emulsion (trade name: NeoCryl A-6057; solid content 35% by mass; manufactured by Kushimoto Chemical Co., Ltd.)
6) Urethane resin emulsion (trade name: NeoRez R-986; solid content 35% by mass; manufactured by Enomoto Chemical Co., Ltd.)
7) Polyvinyl alcohol (Brand name: KL-03; manufactured by Nippon Synthetic Chemical Industry Co., Ltd.)
8) Polyethylene oxide (trade name: L-6; manufactured by Meisei Chemical Industry Co., Ltd.)
9) Water (ion-exchanged water)

(2) Formulations Formulations of coating type antifogging agents (hereinafter simply referred to as "antifogging agents") 1 to 13 for agricultural films produced using the above-mentioned raw materials are shown in Tables 1 to 5. Here, the antifogging agents 1 to 9 are examples of the present invention, and the antifogging agents 10 to 13 are comparative examples to them. In Tables 1 to 5, (A) colloidal inorganic fine particles, (B) water-soluble alkali metal silicate, (C) synthetic resin and (D) solvent, etc. are simply referred to as (A), (B), It described as (C) and (D).

(3) Preparation method of anti-fogging agent The equal volume raw materials listed in Tables 1 to 5 are charged in a beaker, and magnetic stirrer (type: SR-356; using a normal type stirrer; manufactured by ADVANTEC) at 30 ° C., 300 Stirring and mixing for 1 minute made antifogging agents 1-13.

<Production of agricultural films>
(1) Molding of synthetic resin film 1000 g of ethylene-vinyl acetate copolymer (trade name: Suntec EF 0925; manufactured by Asahi Kasei Chemicals Corporation) using a Labo Plastomill (type: 4C-150; manufactured by Toyo Seiki Seisakusho Co., Ltd.) After melting and kneading at a temperature of 170 ° C. and a rotational speed of 200 rpm, the kneaded product is formed into a 100 μm thick film by inflation molding, and then the film is treated with a corona processor (type: ASA-4; corona treatment) Corona treatment was performed using an intensity of 36 dyne (manufactured by Shinko Electric Instruments Co., Ltd.).

(2) Application of Antifogging Agent After applying the antifogging agents 1 to 13 on one side of a synthetic resin film using a bar coater (number No. 07: manufactured by Daiichi Rika Co., Ltd.), a gear of 75.degree. An agricultural film 1 to 13 dried in an oven (type: GPHH-201; ESPEC) for 1 minute to form an antifogging layer on one side (the amount of the antifogging layer is equivalent to 0.5 g / m ² ) Obtained. In addition, the film for agriculture which does not add an antifogging agent was made into the film 14 for agriculture.

<Evaluation of agricultural films>
(1) Evaluation of initial antifogging property (immediate effect of antifogging effect) A window (2 in FIG. 1) provided on the upper surface of an evaluation box (1 in FIG. 1) with an inclination of 15 ° The film for agriculture 1 to 14 (11 × 11 cm) (4 in FIG. 2) is stretched (the film for agriculture 1 to 13 is stretched so that the antifogging layer is inside) to cover the window and the film The evaluation box with a tension of 30 ° C. is placed on a thermostatic water bath (3 in FIG. 1) with a half volume of water, and the thermostat water bath (FIG. 2) in which the evaluation box is installed is a constant temperature with an atmosphere temperature of 25 ° C. The container was placed in the tank and the initial antifogging property was evaluated.
As the initial antifogging property, the state of agricultural films 1 to 14 was visually observed, and the time until the film surface was uniformly wet (water became thin and water was not removed) was measured. The measured time was symbolized by the following evaluation criteria. The results are shown in Table 6. In addition, it can be said that it is excellent in initial stage antifogging property that a result is (circle), and it can be said that it is especially excellent if it is (double-circle).
:: Less than 15 minutes ○: More than 15 minutes, less than 30 minutes Δ: More than 30 minutes, less than 45 minutes ×: More than 45 minutes

(2) Evaluation of long-term antifogging film 1 to 14 (Agricultural films obtained) in the window (2 in FIG. 1) provided on the upper surface of the evaluation box (1 in FIG. 1) having a slope of 15 ° 11 × 11 cm) (4 in FIG. 2) (the agricultural film 1 to 13 is stretched so that the antifogging layer is on the inside), the window is covered and the evaluation box with the film stretched at 40 ° C. The water bath is placed on a thermostatic water tank (3 in Fig. 1) stretched about a half volume, and the thermostatic water tank (Fig. 2) provided with the evaluation box is placed in the chamber of a thermostatic bath having an atmosphere temperature of 25 ° C. The long-term antifogging property was evaluated.
As long-term antifogging properties, the condition after 1 day, 14 days, 28 days and 56 days of the agricultural film was visually observed and evaluated according to the following evaluation criteria. The results are shown in Table 6. In addition, it can be said that it is excellent in long-term antifogging property that a result is (circle), it is further excellent that it is (circle) +, and it can be said that it is the best if it is *.
:: adhesion of water droplets not found in agricultural film + +: adhesion of water droplets less than 15% of area of agricultural film :: adhesion of water droplets 15% or more and less than 30% of area of agricultural film :: 30% or more and less than 50% of the area of the agricultural film for which the water droplets are attached ×: 50% or more of the area of the agricultural films for which the water droplets are adhered

(3) Transparency By using a turbidimeter (model: NDH 2000; Nippon Denshoku Kogyo Co., Ltd.) according to the measurement method in accordance with JIS K7136, leave films 1 to 14 for agriculture at 20 ° C. × 65% RH 7 The turbidity after the day was measured and evaluated for transparency according to the following criteria. The results are shown in Table 6. In addition, it can be said that it is excellent in transparency that a result is (circle), and it can be said that it is especially excellent in being (double).
:: The turbidity is less than 15.0 〇: The turbidity is 15.0 to 17.0
:: The turbidity is 17.0 to 19.0
×: turbidity is 19.0 or more

As is clear from the results in Table 6, agricultural films 1 to 9 coated with the antifogging agents 1 to 9, which are examples of antifogging agents, have not only initial antifogging properties but also long-term antifogging properties. Was. Moreover, it had transparency suitable as an agricultural film. On the other hand, agricultural films 10 and 11 coated with antifogging agents 10 and 11 which are comparative examples had initial antifogging properties but did not have long-term antifogging properties. Further, the agricultural films 12 and 13 coated with the antifogging agents 12 and 13 not only did not have long-term antifogging properties, but also did not have initial antifogging properties.

According to the present invention, novel antifogging agents and the like can be provided.

Claims (2)

(A) Colloidal inorganic fine particles, (B) Water soluble alkali metal silicate, and (C) Coating type antifogging agent for films for agricultural use comprising a solid content of (A) Colloidal inorganic fine particles Coating-type antifogging for agricultural films whose solid content of (B) water-soluble alkali metal silicate is 30 to 150 parts by mass and solid content of (C) synthetic resin is 30 to 150 parts by mass with respect to 100 parts by mass. Agent. An agricultural film formed by applying the coating type antifogging agent according to claim 1 on at least one surface of a synthetic resin film surface.

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