Coating agent composition for polymer membrane, modified membrane using same, and method for producing coating agent composition for polymer membrane

Abstract

The invention provides a coating agent composition for a polymer film, a modified film using the same, and a method for producing the coating agent composition for the polymer film. The coating agent composition for the polymer film can form a coating part with excellent transparency and dripping property on the polymer film. The coating agent composition for a polymeric membrane is characterized by containing inorganic particles and a surfactant, and the inorganic particles include alumina particles (A) described below and alumina particles (B) described below. Aluminum oxide particles (A): aluminum oxide particles having a primary particle diameter of 5 nm or more but less than 11 nm; aluminum oxide particles (B): aluminum oxide particles having a primary particle diameter of 14-40 nm.

Description

Technical Field

[0001] The present invention relates to a polymer film coating composition, a modified film using the same, and a method for producing the polymer film coating composition. Background Art

[0002] In the past, as a film for agricultural greenhouses, transparent polymer films made of resins such as polyethylene were widely used. However, the surface of the polymer film is generally hydrophobic, so when used in agricultural greenhouses, it is easy to attach fine water droplets on its surface and produce condensation and fog due to changes in temperature and humidity. As a result, the transmittance of sunlight decreases, which may lead to poor development of crops. In addition, since the water droplets attached to the film fall on the plants in the agricultural greenhouse, it may also become the cause of plant diseases, etc. In addition, when the polymer film is used in the agricultural greenhouse, it is difficult for air to circulate in the greenhouse, and there is evaporation from the crops and evaporation of water from the soil surface, so it is easy to become a high humidity environment compared to the outdoors. Under such a high humidity environment, as the use time passes, the composition coated on the film easily flows away with the water droplets. Therefore, for the film used in the agricultural greenhouse, in addition to transparency, it is also necessary to maintain excellent dripping for a long time.

[0003] In order to improve the transparency and dripping properties of polymer films, it is widely practiced to coat a composition that imparts transparency and dripping properties on a polymer film as a substrate. As such a composition, for example, Patent Document 1 discloses a defogging composition comprising the following three components: (A) two inorganic sols with different average particle sizes that show two peaks when represented by a particle size frequency curve and have an average particle size ratio in the range of 40 to 2; (B) a surfactant; and (C) a liquid dispersion medium. However, in the defogging composition of Patent Document 1, no research has been conducted on transparency in a high humidity environment.

[0004] In addition, Patent Document 2 discloses a thermoplastic polymer film coating composition, characterized in that, relative to 100 parts by mass of an inorganic cationic sol calculated on a solid content basis, 10 to 50 parts by mass of a polyether-modified silicone is contained, 2 to 30 parts by mass of a polyoxyalkylene derivative is contained, and 45 to 75 parts by mass of an ethylene oxide-propylene oxide block polymer having a number average molecular weight of 1000 to 9800 is contained, wherein the inorganic cationic sol contains 20 to 100% by mass of a cationic alumina sol calculated on a solid content basis and 0 to 80% by mass of a polyol calculated on a solid content basis (the total amount calculated on a solid content basis is 100% by mass). The polyoxyalkylene derivative is composed of at least one selected from the group consisting of a compound to which ethylene oxide is added in a ratio of 3 to 100 moles per mole of a starting compound, a compound to which ethylene oxide and propylene oxide are randomly added in a ratio of 3 to 100 moles per mole of a starting compound, and a compound to which ethylene oxide and propylene oxide are block-added in a ratio of 3 to 100 moles per mole of a starting compound, wherein the starting compound is composed of at least one selected from the group consisting of aliphatic alcohols having 8 to 22 carbon atoms, fatty acids having 8 to 22 carbon atoms, alkylphenols having 8 to 22 carbon atoms in the alkyl group, and monoalkylamines having 8 to 22 carbon atoms. However, in the thermoplastic polymer film coating composition of Patent Document 2, dripping properties were evaluated after 1 day and 30 days, but whether dripping properties persist for a long period of about 1 year was not studied.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 60-69181

[0008] Patent Document 2: Japanese Patent Application Publication No. 2018-127546 Summary of the invention

[0009] Therefore, an object of the present disclosure is to provide a polymer film coating composition capable of forming a coating portion having excellent transparency and dripping properties on a polymer film, a modified film using the same, and a method for producing the polymer film coating composition.

[0010] The present invention adopts the following means to solve the above-mentioned problems.

[0011] [1] A polymer film coating composition comprising inorganic particles and a surfactant, wherein the inorganic particles include the following aluminum oxide particles (A) and the following aluminum oxide particles (B).

[0012] Alumina particles (A): Alumina particles having a primary particle size of 5 nm or more and less than 11 nm Alumina particles (B): Alumina particles having a primary particle size of 14 nm to 40 nm

[0013] [2] The polymer film coating composition according to [1], wherein the aluminum oxide particles (A) are contained in a ratio of 20 to 90 parts by mass, and the aluminum oxide particles (B) are contained in a ratio of 10 to 80 parts by mass, when the total content ratio of the aluminum oxide particles (A) and the aluminum oxide particles (B) is set to 100 parts by mass.

[0014] [3] The polymer film coating composition according to [1], wherein, when the content of the inorganic particles is 100% by mass, the total content of the aluminum oxide particles (A) and the content of the aluminum oxide particles (B) is 60% by mass or more.

[0015] [4] The polymer film coating composition according to [1], wherein the oil absorption of the inorganic particles is 70 ml / 100 g or more.

[0016] [5] The polymer film coating composition according to [1], wherein the surfactant is a nonionic surfactant.

[0017] [6] A modified film comprising a base film portion and a coating portion, wherein the base film portion is formed of a synthetic resin film, and the coating portion is provided on at least a portion of a surface and comprises the polymer film coating composition according to any one of [1] to [5].

[0018] [7] A production method, characterized in that it is the production method for a polymer film coating composition according to any one of [1] to [5],

[0019] The method comprises the step of mixing the inorganic particles including the alumina particles (A) and the alumina particles (B) with the surfactant,

[0020] The aluminum oxide particles (A) and the aluminum oxide particles (B) are supplied from different supply sources.

[0021] In addition, in this specification, the numerical range shown by "○○ to △△" means a range including the upper limit and the lower limit. That is, "○○ to △△" means "≥○○ and △△".

[0022] According to the present invention, there can be provided a polymer film coating composition capable of forming a coating portion having excellent transparency and dripping properties on a polymer film, a modified film using the same, and a method for producing the polymer film coating composition. DETAILED DESCRIPTION

[0023] 《Coating agent composition for polymer film》

[0024] The polymer film coating composition of the present invention (hereinafter, also referred to as "coating composition") contains inorganic particles and surfactants described later. The inorganic particles include the following aluminum oxide particles (A) and aluminum oxide particles (B). It should be noted that, within the scope of not hindering the effect of the present invention, the inorganic particles may also contain inorganic particles other than aluminum oxide particles (A) and aluminum oxide particles (B). Thus, the coating composition can impart excellent transparency and dripping properties (initial dripping properties, mid-term dripping properties, and long-term dripping properties) to the polymer film.

[0025] Alumina particles (A): Alumina particles having a primary particle size of 5 nm or more and less than 11 nm

[0026] Alumina particles (B): Alumina particles with a primary particle size of 14 nm to 40 nm

[0027] <Inorganic particles>

[0028] As long as the inorganic particles can be dispersed in the coating composition, conventionally known inorganic particles can be used. Examples of inorganic particles include silica (silicon oxide) particles, alumina (Aluminium Oxide) particles, zirconium oxide particles, cerium dioxide particles, titanium dioxide particles, calcium carbonate particles, kaolin particles, crystalline glass fillers, talc particles, silica-alumina composite oxide particles, and barium sulfate particles. The shape of the inorganic particles is spherical, irregular, needle-shaped, plate-shaped, etc., and is not particularly limited. One or more inorganic particles can be used.

[0029] <Alumina particles>

[0030] There is no particular limitation on the alumina particles, and they can be appropriately selected from the conventionally known alumina particles. Alumina constituting the alumina particles include alumina hydrate, α-alumina, γ-alumina, θ-alumina, δ-alumina, and the like. The alumina particles can be natural or synthetic. In addition, they can be appropriately selected from commercially available products, or they can be the desired alumina particles prepared by heat treatment, pulverization, and the like.

[0031] <Alumina particles (A)>

[0032] The alumina particles (A) contained in the inorganic particles are alumina particles having a primary particle size of 5 nm or more and less than 11 nm. The purpose of including alumina particles (A) having a small primary particle size in the coating composition is to impart transparency. Alumina particles having a small primary particle size are difficult to scatter light. Therefore, by using a coating composition containing alumina particles (A), the transmittance is improved and the transparency of the film becomes higher. It should be noted that the particle size distribution of the inorganic particles in the present invention is obtained by measuring the particle sizes of 20 inorganic particles using an electron microscope photograph.

[0033] <Alumina particles (B)>

[0034] The alumina particles (B) contained in the inorganic particles are alumina particles having a primary particle size of 14 nm to 40 nm. The purpose of including alumina particles (B) having a large primary particle size in the coating composition is to improve dripping properties. By using alumina particles (B) having a large primary particle size, the pore volume becomes larger. Therefore, the surfactant described later can enter between the alumina particles (B) more. That is, by using alumina particles (B) having a large primary particle size, the oil absorption becomes higher. Therefore, as the use time passes, the surfactant flows out little by little together with the water droplets, and the inorganic particles containing the alumina particles (B) can retain the surfactant for a long time. Therefore, by using a coating composition containing alumina particles (B), dripping properties can be maintained for a long time.

[0035] <Oil absorption of inorganic particles>

[0036] The oil absorption in the present invention is determined by measuring the amount of surfactant absorbed by inorganic particles according to JIS K 5101-13-1: 2004. From the viewpoint of imparting excellent long-term dripping properties, the oil absorption of the inorganic particles is preferably 70 ml / 100 g or more, more preferably 80 ml / 100 g or more.

[0037] <Compounding ratio of coating composition>

[0038] The mixing ratio of the aluminum oxide particles (A) and the aluminum oxide particles (B) in the coating composition is not particularly limited. When the total content of the aluminum oxide particles (A) and the aluminum oxide particles (B) is 100 parts by mass, it is preferred that the aluminum oxide particles (A) be contained in a ratio of 20 to 90 parts by mass, and the aluminum oxide particles (B) be contained in a ratio of 10 to 80 parts by mass. Furthermore, it is more preferred that the aluminum oxide particles (A) be contained in a ratio of 40 to 90 parts by mass, and the aluminum oxide particles (B) be contained in a ratio of 10 to 60 parts by mass.

[0039] As mentioned above, from the viewpoint of transparency, since the aluminum oxide particles with a small primary particle size are difficult to scatter light, the transparency of the film coated with the coating agent composition becomes higher by being included in the coating agent composition. On the other hand, since the aluminum oxide particles with a large primary particle size scatter light easily, the film coated with the coating agent composition whitish by being included in the coating agent composition. From the viewpoint of long-term dripping, the higher the oil absorption of the inorganic particles, the more the surfactant can be kept for a long time, and the long-term dripping becomes good, and the aluminum oxide particles with a small primary particle size have a low oil absorption due to a small pore volume. On the other hand, the aluminum oxide particles with a large primary particle size have a high oil absorption due to a large pore volume. Therefore, in order to take into account excellent transparency and long-term dripping, it is preferably set to the mixing ratio of the above-mentioned coating agent composition.

[0040] Alumina particles having a primary particle diameter between the primary particle diameter of the alumina particles (A) and the primary particle diameter of the alumina particles (B) are referred to as alumina particles (C) described below.

[0041] Alumina particles (C): Alumina particles having a primary particle size of 11 nm or more and less than 14 nm

[0042] When the total content of the aluminum oxide particles (A), the aluminum oxide particles (B) and the aluminum oxide particles (C) is 100 parts by mass, the content of the aluminum oxide particles (C) is preferably 0 to 10 parts by mass. This is because the smaller the content of the aluminum oxide particles (C), the easier it is to obtain the effect of the two aluminum oxide particles (A) and (B) having different particle sizes.

[0043] <Surfactant>

[0044] As the surfactant, there is no particular limitation, and conventionally known surfactants can be used. Examples include nonionic surfactants, anionic surfactants, cationic surfactants, amphoteric surfactants, and the like. Among these, nonionic surfactants are preferred from the viewpoint of the dispersibility of the inorganic particles. These surfactants can be used alone or in combination of two or more. The surfactant is preferably 5 to 200 parts by mass, more preferably 5 to 100 parts by mass, relative to 100 parts by mass of the inorganic particles.

[0045] <Nonionic surfactant>

[0046] The nonionic surfactant is not particularly limited, and any conventionally known nonionic surfactant may be appropriately selected for use. For example, polyether-modified silicone, polyoxyethylene stearyl ether, polyoxyethylene stearate, nonylphenol polyoxyethylene ether, polyoxyethylene polyoxypropylene oleate, polyoxyethylene polyoxypropylene lauryl ether, etc. may be cited. In addition, (1) compounds obtained by adding an alkylene oxide having 2 to 4 carbon atoms to an organic acid, an organic alcohol, an organic amine and / or an organic amide, for example, polyoxyethylene dilaurate, polyoxyethylene oleate, polyoxyethylene oleic acid diester, polyoxyethylene octyl ether, polyoxyethylene lauryl ether, polyoxyethylene lauryl ether methyl ether, polyoxypropylene lauryl ether methyl ether, polyoxyethylene oleyl ether, polyoxybutylene oleyl ether, polyoxyethylene polyoxypropylene nonyl ether, polyoxypropylene nonyl ether, polyoxyethylene polyoxypropylene octyl ether, ethylene oxide adduct of 2-hexylhexanol, polyoxyethylene 2-ethyl-1-hexyl ether, polyoxyethylene isononyl ether, polyoxyethylene dodecyl ether, compounds obtained by adding ethylene oxide to secondary dodecanol, polyoxyethylene tridecyl ether, polyoxyethylene (1) ether-type nonionic surfactants such as polyoxyethylene tetradecyl ether, polyoxyethylene lauryl amino ether, polyoxyethylene lauramide ether, and polyoxyalkylene tristyrenated phenyl ether; (2) polyoxyalkylene sorbitan trioleate, polyoxyalkylene coconut oil, polyoxyalkylene castor oil, polyoxyalkylene hydrogenated castor oil, polyoxyalkylene hydrogenated castor oil trioctanoate, and polyoxyalkylene hydrogenated castor oil maleate, stearate, or oleate; (3) alkylamide-type nonionic surfactants such as stearic acid diethanolamide and diethanol monolauramide; (4) polyoxyalkylene fatty acid amide-type nonionic surfactants such as polyoxyethylene diethanolamine monooleamide, polyoxyethylene lauramine, and polyoxyethylene tallow amine. These nonionic surfactants can be used alone or in combination of two or more. Among these nonionic surfactants, polyethers are more preferred.

[0047] <Anionic surfactant>

[0048] The anionic surfactant is not particularly limited, and any conventionally known anionic surfactant may be appropriately selected and used. For example, (1) fatty alcohol phosphates such as lauryl phosphate, cetyl phosphate, octyl phosphate, oleyl phosphate, and stearyl phosphate; (2) phosphates obtained by adding at least one alkylene oxide selected from ethylene oxide and propylene oxide to fatty alcohols such as polyoxyethylene lauryl ether phosphate, polyoxyethylene oleyl ether phosphate, and polyoxyethylene stearyl ether phosphate; (3) aliphatic sulfonates or aromatic sulfonates such as lauryl sulfonate, myristyl sulfonate, cetyl sulfonate, oleyl sulfonate, stearyl sulfonate, tetradecane sulfonate, dodecylbenzene sulfonate, and secondary alkyl sulfonic acid (C13-15) salts; (4) sulfates of fatty alcohols such as lauryl sulfate, oleyl sulfate, and stearyl sulfate; (5) polyoxyethylene lauryl ether sulfate, polyoxyalkylene (polyoxyethylene, polyoxypropylene) lauryl ether sulfate, polyoxyethylene (6) fatty acid sulfates of castor oil fatty acid sulfates, sesame oil fatty acid sulfates, tall oil fatty acid sulfates, soybean oil fatty acid sulfates, rapeseed oil fatty acid sulfates, palm oil fatty acid sulfates, lard fatty acid sulfates, tallow fatty acid sulfates, whale oil fatty acid sulfates, etc.; (7) fat sulfates of castor oil sulfates, sesame oil sulfates, tall oil sulfates, soybean oil sulfates, rapeseed oil sulfates, soybean oil sulfates, lard sulfates, tallow sulfates, whale oil sulfates, etc.; (8) fatty acid salts such as laurate, oleate, stearate, etc.; (9) sulfosuccinate salts of fatty alcohols such as dioctyl sulfosuccinate, etc. These anionic surfactants may be used alone or in combination of two or more.

[0049] <Cationic surfactant>

[0050] There are no particular restrictions on the cationic surfactant, and it can be appropriately selected from the cationic surfactants known in the past. For example, dodecyl trimethyl ammonium chloride, hexadecyl trimethyl ammonium chloride, stearyl trimethyl ammonium chloride, behenyl trimethyl ammonium chloride, didecyl dimethyl ammonium chloride, 1,2-dimethyl imidazole, triethanolamine, etc. can be cited. These cationic surfactants can be used alone or in combination of two or more.

[0051] <Amphoteric surfactant>

[0052] The amphoteric surfactant is not particularly limited, and any conventionally known amphoteric surfactant may be appropriately selected and used. For example, betaine-type amphoteric surfactants may be mentioned.

[0053] <Other additives>

[0054] Other known additives can be added to the coating composition according to the purpose. As such additives, for example, adhesives, colorants, antioxidants, light stabilizers, flame retardants, antistatic agents, mildew inhibitors, antibacterial agents, antifouling agents, ultraviolet light absorbers, preservatives, lubricants, etc. can be enumerated.

[0055] 《Modified membrane》

[0056] The modified film of the present invention comprises a base film portion composed of a synthetic resin film and a coating portion containing a coating composition on at least a portion of the surface of the base film portion. The coating portion of the modified film may be formed only on one side of the base film portion or on both sides.

[0057] <Basement membrane>

[0058] The base film portion is not particularly limited as long as it is composed of a synthetic resin film. The base film portion may be any of a thermoplastic resin film and a thermosetting resin film, and a thermoplastic resin film is preferred in the present invention. Examples of thermoplastic resins include olefin resins, polyester resins, vinyl chloride resins, vinylidene chloride resins, ethylene-vinyl acetate copolymers, ethylene-methacrylate alkyl ester copolymers, ethylene-vinyl alcohol copolymers, polyvinyl alcohol, cyclic olefin resins, acrylic resins, aromatic vinyl resins, polyamide resins, and polyurethane resins. In addition, the base film portion may be a single layer or a multilayer.

[0059] As olefin resins, homopolymers of ethylene or α-olefins having 3 or more carbon atoms, ethylene·α-olefin copolymers, copolymers of two or more α-olefins, etc. can be cited. It should be noted that as α-olefins, propylene, 1-butene, 1-pentene, 1-hexene, 3-methyl-1-butene, 3-methyl-1-pentene, 4-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-pentene, 4-ethyl-1-hexene, 3-ethyl-1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, etc. can be cited. The above-mentioned olefin resin is preferably an ethylene·1-butene copolymer, an ethylene·1-hexene copolymer, an ethylene-vinyl acetate copolymer, polyethylene, or an ethylene·propylene copolymer. The polyolefin resin can also be used by mixing two or more polyolefin resins.

[0060] Examples of the polyester resin include polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, etc. Examples of the vinyl chloride resin include polyvinyl chloride, vinyl chloride-ethylene copolymers, and vinyl chloride-vinyl acetate copolymers.

[0061] For the base film portion, other conventionally known resin additives may be added according to the purpose. Such additives include, for example, antioxidants, weathering agents, ultraviolet absorbers, infrared absorbers, lubricants, anti-blocking agents, defogging agents, anti-fogging agents, heat-retaining agents, colorants, etc.

[0062] The base film used in the modified film may be surface treated by corona discharge treatment, atmospheric pressure plasma treatment, flame treatment, etc., or may have a surface on which a primer layer is formed. The thickness of the base film is not particularly limited.

[0063] The method of providing the coating portion containing the coating composition on the base film portion is not particularly limited, and a conventionally known method can be used. For example, a gravure coating method, a spray coating method, a dip coating method, a roller coating method, a scraper coating method, a wire rod coating method, an air knife coating method, etc. can be used. The coating amount of the coating composition of the base film portion and the thickness of the coating film are not particularly limited, and the coating film after the coating film is dried is preferably 0.05 to 3.0 g / m 2 , more preferably 0.1 to 2.0 g / m 2 .

[0064] The modified film can be dried after the coating composition is applied to the base film portion, if necessary, by natural drying, cold air drying, hot air drying, infrared drying, or a combination of these.

[0065] The modified membrane of the present invention is not particularly limited in its use, but is particularly preferably used in agricultural greenhouses because water droplets adhering to the surface of the membrane can flow down along the modified membrane by unfolding the modified membrane with the surface of the membrane portion inclined and facing the ground.

[0066] 《Method for producing coating composition》

[0067] The method for manufacturing a coating composition comprises a step of mixing inorganic particles containing aluminum oxide particles (A) and aluminum oxide particles (B) with a surfactant, and there is no particular limitation as long as the aluminum oxide particles (A) and the aluminum oxide particles (B) are supplied from different supply sources. For example, aluminum oxide particles (A) are mixed and stirred in a liquid solvent so that the aluminum oxide particles (A) are dispersed in the liquid solvent, and then aluminum oxide particles (B) are added and mixed and stirred so that the aluminum oxide particles (B) are dispersed in the liquid solvent, and a surfactant is further added and mixed and stirred to manufacture. Alternatively, a surfactant may be added to a liquid solvent and mixed and stirred, and aluminum oxide particles (A) and aluminum oxide particles (B) are further added and mixed and stirred to manufacture. Alternatively, aluminum oxide particles (A), aluminum oxide particles (B), surfactants and other raw material components may be mixed together.

[0068] The polymer film coating composition of the present invention is suitable for coating of synthetic resin films, and even when a coating portion is formed on a substrate composed of a metal or an inorganic compound or a composite substrate having a layer formed on the surface of the substrate, an article having a coating portion excellent in transparency and dripping properties can be formed.

[0069] Example

[0070] The following examples and comparative examples are provided to make the configuration and effects of the present disclosure more specific, but the present disclosure is not limited to these examples. It should be noted that in the following examples and comparative examples, "parts" and "%" are based on mass. Table 1 shows the raw material components of the coating composition used in each example and each comparative example and the oil absorption of the inorganic particles.

[0071] 《Raw materials for coating composition》

[0072] The raw materials used in the production of the coating composition are as follows.

[0073] <Alumina particles (A)>

[0074] A-1: Plate-shaped alumina sol with a primary particle size of 5 nm or more and less than 11 nm

[0075] A-2: Feather-shaped alumina sol with a primary particle size of 5 nm or more and less than 11 nm

[0076] <Alumina particles (B)>

[0077] B-1: Plate-shaped alumina sol with a primary particle size of 14nm to 30nm

[0078] B-2: Bulk alumina sol with primary particle size of 14nm to 30nm

[0079] <Other>

[0080] C-1: Alumina-modified silica sol with a primary particle size of 10nm to 20nm

[0081] C-2: Alumina modified silica sol with primary particle size of 40nm to 60nm

[0082] C-3: Silica sol with primary particle size of 10nm to 20nm

[0083] C-4: Silica sol with primary particle size of 40nm to 60nm

[0084] C-5: Plate-shaped alumina sol with a primary particle size of 11 nm or more and less than 14 nm

[0085] <Surfactant>

[0086] D-1: Main chain / side chain = 50 / 50 (mass ratio), ethylene oxide / propylene oxide = 100 / 0 (molar ratio), kinematic viscosity at 25°C: 600 mm 2 / s polyether modified silicone

[0087] D-2: ethylene oxide 20 mole adduct of stearyl alcohol

[0088] D-3: 12 mole adduct of stearic acid with ethylene oxide

[0089] D-4: Nonylphenol ethylene oxide 10 mole adduct

[0090] D-5: Random adduct of oleic acid with 9 moles of ethylene oxide and 9 moles of propylene oxide

[0091] D-6: Lauryl alcohol ethylene oxide 9 mol propylene oxide 9 mol block adduct

[0092] 《Preparation of coating composition and determination of oil absorption》

[0093] A coating composition was prepared using the above raw materials, and the oil absorption of the inorganic particles of the obtained coating composition was measured.

[0094] <Coating agent composition X-1>

[0095] 500 parts of aluminum oxide particles (A) (A-1: solid content 15%) and 167 parts of aluminum oxide particles (B) (B-1: solid content 15%) were added to 6790 parts of water, and stirred and mixed for more than 30 minutes to completely disperse them in water. 50 parts of surfactant (D-1) were added, and stirred and mixed for more than 30 minutes to prepare a coating composition (X-1) with a pure component concentration of 2%.

[0096] <Coating agent compositions X-2 to X-11 and x-1 to x-10>

[0097] In the same manner as in the coating composition X-1, coating compositions (X-2) to (X-11) and (X-1) to (X-10) having the compositions shown in Table 1 below were prepared.

[0098] <Measurement of oil absorption of inorganic particles>

[0099] Next, each of the obtained coating compositions X-1 to X-11 and X-1 to X-10 was vacuum dried at 40°C, and then the surfactant was extracted from the obtained dried product using chloroform to obtain inorganic particles. The inorganic particles were pulverized in a mortar, and the oil absorption per 100 g of the inorganic particles was measured by a method based on JIS K 5101-13-1:2004. The results are shown in Table 1.

[0100] [Table 1]

[0101]

[0102] 《Production of basement membrane》

[0103] Next, a base film to which the coating composition is applied is prepared.

[0104] <Preparation example 1>

[0105] Ethylene-1-butene copolymer (ethylene unit content: 95%, density: 0.920 g / cm 3 , MFR: 2.1 g / 10 minutes) was subjected to blow molding (resin extrusion temperature: 200°C, BUR=1.8) with a mold having a diameter of 75 mm and a lip gap of 3 mm to obtain an olefin resin film having a thickness of 150 μm. Next, the surface of the olefin polymer film was subjected to corona discharge treatment to obtain a surface-treated olefin resin film (hereinafter referred to as "base film (F-1)"). The wetting tension of the corona discharge treated surface was measured by a method in accordance with JIS K 6768, and the result was 44 mN / m.

[0106] <Preparation example 2>

[0107] Ethylene-1-hexene copolymer (ethylene unit content: 96%, density: 0.930 g / cm 3 , MFR: 1.0 g / 10 min) was used instead of the ethylene-1-butene copolymer, and the same operation as in Preparation Example 1 was performed to obtain a surface-treated olefin resin film (hereinafter referred to as "base film (F-2)"). The wetting tension of the corona discharge treated surface was 40 mN / m.

[0108] <Preparation example 3>

[0109] A surface-treated olefin resin film (hereinafter referred to as "base film (F-3)") was obtained by the same operation as in Preparation Example 1 except that ethylene-vinyl acetate copolymer (ethylene unit content: 93%, MFR: 1.5 g / 10 minutes) was used instead of ethylene-1-butene copolymer. The wetting tension of the corona discharge treated surface was 42 mN / m.

[0110] <Preparation example 4>

[0111] Use polyethylene (density: 0.927g / cm 3 , MFR: 4.0 g / 10 min) was used instead of the ethylene-1-butene copolymer, and the same operation as in Preparation Example 1 was performed to obtain a surface-treated olefin resin film (hereinafter referred to as "base film (F-4)"). The wetting tension of the corona discharge treated surface was 44 mN / m.

[0112] <Preparation example 5>

[0113] Ethylene-propylene copolymer (ethylene unit content: 4%, density: 0.90 g / cm 3 , MFR: 8.0 g / 10 min) was used instead of the ethylene-1-butene copolymer, and the same operation as in Preparation Example 1 was performed to obtain a surface-treated olefin resin film (hereinafter referred to as "base film (F-5)"). The wetting tension of the corona discharge treated surface was 43 mN / m.

[0114] 《Production and evaluation of modified membranes》

[0115] A modified film was prepared using the above-mentioned coating composition and base film. Then, the transparency and dripping property of the film surface of the obtained modified film were evaluated by the following methods.

[0116] <Example 1-1>

[0117] The coating composition (X-1) was applied to the corona discharge treated surface of the base film (F-1) by dipping so that the absolute dry coating amount was 0.3 g / m 2 , and dried at 70°C using a hot air dryer to obtain a modified film (M-1) having a coating portion containing the coating composition (X-1) on the corona discharge treated surface side of the base film (F-1). Next, the modified film (M-1) was evaluated by the following (1) and (2). The results are shown in Table 2 below.

[0118] <Example 1-2 to Example 1-11 and Comparative Examples 1-1 to 1-10>

[0119] Modified films M-2 to M-11 and m-1 to m-10 were obtained in the same manner as in Example 1-1 using the coating composition and base film shown in Table 2 below. Next, the obtained modified films were evaluated in the following (1) and (2). The results are shown in Table 2 below.

[0120] (1) Transparency

[0121] The film was humidified at 20°C and 65% relative humidity for 24 hours. The haze value was then measured using a haze meter (trade name (NDH-5000) manufactured by Nippon Denshoku Industries) according to JIS K 7136: 2000. The transparency of the film was evaluated according to the following criteria.

[0122] ◎: Less than 12% (very excellent transparency)

[0123] ○: 12% or more and less than 14% (excellent transparency)

[0124] ×: 14% or more (poor transparency)

[0125] (2) Drip

[0126] 1m 2 The modified film was attached to a test greenhouse with an inclination of 15 degrees relative to the horizontal, and the water droplet adhesion conditions were visually observed after 1 day (initial dripping), 1 month (mid-term dripping), and 1 year (long-term dripping), and evaluated according to the following criteria.

[0127] ◎: Water droplet adhesion area is less than 10% (very good dripping resistance)

[0128] ○: The adhesion area of ​​water droplets is 10% or more and less than 30% (excellent dripping property)

[0129] ×: The adhesion area of ​​water droplets is 30% or more (poor dripping property)

[0130]

[0131] The coating compositions of Examples 1-1 to 1-11 have excellent transparency, initial dripping, mid-term dripping, and long-term dripping because they contain aluminum oxide particles (A) and aluminum oxide particles (B). On the other hand, Comparative Examples 1-1 to 1-10 do not contain either or both of the aluminum oxide particles (A) and aluminum oxide particles (B), and therefore have poor transparency, initial dripping, mid-term dripping, and long-term dripping.

Claims

1. A polymer film coating composition, characterized in that A polymer film coating composition containing inorganic particles and a surfactant, The inorganic particles include the following aluminum oxide particles A and the following aluminum oxide particles B, Alumina particles A: Alumina particles having a primary particle size of 5 nm or more and less than 11 nm, Alumina particles B: Alumina particles having a primary particle size of 14 nm to 40 nm.

2. The polymer film coating composition according to claim 1, wherein When the total content of the aluminum oxide particles A and the aluminum oxide particles B is 100 parts by mass, the aluminum oxide particles A are contained in a ratio of 20 to 90 parts by mass, and the aluminum oxide particles B are contained in a ratio of 10 to 80 parts by mass.

3. The polymer film coating composition according to claim 1, wherein When the content of the inorganic particles is 100 mass %, the total of the content of the aluminum oxide particles A and the content of the aluminum oxide particles B is 60 mass % or more.

4. The polymer film coating composition according to claim 1, wherein The oil absorption of the inorganic particles is greater than 70 ml / 100 g.

5. The polymer film coating composition according to claim 1, wherein The surfactant is a nonionic surfactant.

6. A modified membrane, characterized in that: The invention comprises a base film portion and a coating portion, wherein the base film portion is composed of a synthetic resin film, and the coating portion is provided on at least a part of a surface of the base film portion and comprises the polymer film coating composition according to any one of claims 1 to 5.

7. A manufacturing method, characterized in that: A method for producing a polymer film coating composition according to any one of claims 1 to 5, The method comprises the step of mixing the inorganic particles including the aluminum oxide particles A and the aluminum oxide particles B with the surfactant, The aluminum oxide particles A and the aluminum oxide particles B are supplied from different supply sources.

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