Agricultural synthetic resin film coating agent composition and modified film using the same and method for manufacturing the same

Abstract

The present invention provides an agricultural synthetic resin film coating agent composition capable of forming a coated film portion on a film having excellent flow drop properties and wet rub resistance. An agricultural synthetic resin film coating agent composition characterized by being an agricultural synthetic resin film coating agent composition containing inorganic particles, a binder resin, and a surfactant, the inorganic particles comprising inorganic particles (A) described below. Inorganic particles (A): colloidal silica that is a single colloidal silica and has an average particle diameter of 60 to 90 nm measured by a dynamic light scattering method and a CV value calculated from the following formula 1 of 35 to 55%. CV value (%) = (standard deviation) ÷ (average particle diameter) × 100··· (Formula 1).

Description

Technical Field

[0001] This invention relates to synthetic resin film coating compositions for agricultural use, modified films using the same, and methods for manufacturing the same. Background Technology

[0002] Previously, transparent films made of synthetic resins such as polyethylene were widely used in agricultural greenhouses. However, the surface of synthetic resin films is generally hydrophobic, so when used in agricultural greenhouses, fine water droplets easily adhere to their surface, causing condensation and fogging due to changes in temperature and humidity. As a result, the transmittance of sunlight is reduced, sometimes leading to poor crop development. Furthermore, water droplets adhering to the film falling onto the crops inside the greenhouse can sometimes contribute to crop diseases. Therefore, films used in agricultural greenhouses require anti-fogging properties (dripping properties) that prevent water droplets adhering to the inner surface of the film from falling onto the crops and instead allow them to flow down the inner surface of the film.

[0003] As a method for imparting such properties to agricultural films, it is known to form a coating composed of a modifier on a synthetic resin film. For example, Patent Document 1 discloses an anti-fogging composition adjusted by mixing and stirring an adhesive resin, at least two types of colloidal silica with different average primary particle sizes, and a surfactant with a dispersant, and an anti-fogging film using the same. Furthermore, Patent Document 2 discloses an agricultural film obtained by coating an anti-fogging agent composition containing an inorganic colloidal substance and a synthetic resin adhesive as main components, and including an inorganic colloidal substance with a particle size of 20 nm or less as the inorganic colloidal substance, onto a substrate film.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2018-065990

[0007] Patent Document 2: Japanese Patent Application Publication No. 2009-202350 Summary of the Invention

[0008] Typically, agricultural greenhouses are isolated spaces from the outside, where air tends to stagnate and temperatures rise due to sunlight, creating a humid environment for crop cultivation. It is known that in such a humid environment, if the unfolded film repeatedly comes into contact with the greenhouse frame, the film coating can easily peel off due to friction. Furthermore, if the film coating peels off, the anti-fogging (drip) properties of that section decrease. Therefore, modified films used in agricultural greenhouses require excellent resistance to abrasion under humid conditions (wet abrasion resistance). However, conventional modified films for agriculture do not possess sufficient resistance to wet abrasion.

[0009] Therefore, the object of the present invention is to provide an agricultural synthetic resin film coating composition capable of forming a coating portion on a film with excellent drip-proof and wet abrasion resistance, as well as a modified film using the same and a method for manufacturing the same.

[0010] To address the aforementioned issues, the present invention employs the following approach.

[0011] [1] An agricultural synthetic resin film coating composition, characterized in that it is an agricultural synthetic resin film coating composition containing inorganic particles, adhesive resin and surfactant, wherein the inorganic particles include the following inorganic particles (A).

[0012] Inorganic particles (A): Colloidal silica with an average particle size of 60–90 nm as determined by dynamic light scattering and a CV value of 35–55% calculated by Equation 1 below.

[0013] CV value (%) = (standard deviation) ÷ (average particle size) × 100 ... (Equation 1)

[0014] [2] The agricultural synthetic resin film coating composition according to [1], wherein the inorganic particles further comprise the following inorganic particles (B),

[0015] When the total proportion of the inorganic particles (A) and the inorganic particles (B) is set to 100 parts by mass, the inorganic particles (A) are contained in a proportion of 5 to 30 parts by mass, and the inorganic particles (B) are contained in a proportion of 70 to 95 parts by mass.

[0016] Inorganic particles (B): Colloidal silica with an average particle size greater than 90 nm and less than 160 nm as determined by dynamic light scattering.

[0017] [3] According to the agricultural synthetic resin film coating composition of [2], when the total proportion of the inorganic particles (A) and the inorganic particles (B) is set to 100 parts by mass, the adhesive resin is contained in a proportion of 10 to 50 parts by mass, and the surfactant is contained in a proportion of 1 to 15 parts by mass.

[0018] [4] A manufacturing method, characterized in that it is a method for manufacturing the agricultural synthetic resin film coating composition of any one of [1] to [3],

[0019] It includes a process of mixing the inorganic particles (A) with the adhesive resin.

[0020] [5] A modified film, characterized in that it comprises a base film portion made of a synthetic resin film and a coating portion comprising an agricultural synthetic resin film coating composition of any one of [1] to [3] on at least a portion of the surface of the base film portion.

[0021] It should be noted that the numerical range represented by "○○~△△" in this specification includes both its upper and lower limits. That is, "○○~△△" means "above ○○ and below △△".

[0022] According to the present invention, an agricultural synthetic resin film coating composition capable of forming a coating portion on a film with excellent drip-proof and wet abrasion-resistant properties can be provided, as well as a modified film using the same and a method for manufacturing the same. Detailed Implementation

[0023] Compositions for agricultural synthetic resin film coating agents

[0024] The agricultural synthetic resin film coating composition of the present invention (hereinafter also referred to as the "coating composition") contains inorganic particles, adhesive resin and surfactant described later. Thus, the coating composition can impart excellent drip properties (initial dripping and dripping persistence) and resistance to wet abrasion to agricultural synthetic resin films.

[0025] <Inorganic Particles>

[0026] The inorganic particles include inorganic particles (A), and more preferably inorganic particles (B). It should be noted that the inorganic particles may also include inorganic particles other than inorganic particles (A) and inorganic particles (B), to a extent that does not impair the effects of the present invention.

[0027] <Inorganic Particles (A)>

[0028] The inorganic particles (A) can be any colloidal silica that is a single colloidal silica with an average particle size of 60-90 nm as determined by dynamic light scattering and a CV value of 35-55% calculated by Equation 1 below. Previously known inorganic particles can be used.

[0029] CV value (%) = (standard deviation) ÷ (average particle size) × 100 ... (Equation 1)

[0030] It should be noted that in this specification, the "average particle size" and "CV value" of inorganic particles refer to the "average particle size" and "CV value" of the silica contained in the colloidal silica within the inorganic particles. Furthermore, the "average particle size" and "CV value" of the inorganic particles are calculated based on the particle size distribution of the inorganic particles measured using a dynamic light scattering particle size distribution measuring device (HORIBA, nanoPartica SZ-100V2 Series) on a volume basis via dynamic light scattering.

[0031] <Colloidal Silica>

[0032] Colloidal silica is a colloid obtained by dispersing silica (silica) or its hydrate in a dispersion medium such as water. Examples of colloidal silica include colloidal silica in which primary particles of spherical silica are dispersed in a liquid to form a colloid; chain-like colloidal silica in which primary particles of silica are linked in a chain-like manner; spherical colloidal silica in which primary particles of silica are aggregated in a spherical shape; and beaded colloidal silica in which primary particles of silica are linked in a beaded manner. The type of colloidal silica contained in the coating composition of the present invention is not particularly limited.

[0033] Here, "single colloidal silica" refers to colloidal silica manufactured as a colloid (dispersion). Therefore, a substance obtained by mixing multiple colloidal silicas is not equivalent to "single colloidal silica" in this specification. Therefore, colloidal silica that satisfies at least one of the following conditions—an average particle size of 60–90 nm as determined by dynamic light scattering and a CV value of 35–55% calculated by Formula 1 above—is not included in the "single colloidal silica with an average particle size of 60–90 nm as determined by dynamic light scattering and a CV value of 35–55% calculated by Formula 1" in this specification. Furthermore, from another perspective, "single colloidal silica" generally refers to colloidal silica with a single peak in its particle size distribution as determined by dynamic light scattering.

[0034] <Inorganic Particles (B)>

[0035] The inorganic particles (B) can be any colloidal silica with an average particle size exceeding 90 nm and less than 160 nm as determined by dynamic light scattering. Conventionally known inorganic particles can be used. Furthermore, colloidal silica with an average particle size of 110–140 nm is more preferred. One or more types of inorganic particles (B) can be used. By including inorganic particles (B) in the coating composition, excellent resistance to wet abrasion can be imparted while maintaining drip-proof properties.

[0036] When the coating composition of the present invention comprises inorganic particles (A) and inorganic particles (B), the inorganic particles (A) are contained in a ratio of 5 to 30 parts by mass and the inorganic particles (B) are contained in a ratio of 70 to 95 parts by mass relative to a total of 100 parts by mass of the inorganic particles (A) and inorganic particles (B). If the proportions of inorganic particles (A) and inorganic particles (B) are within the above range, excellent resistance to wet abrasion can be achieved while maintaining excellent dripping properties.

[0037] <Adhesive Resin>

[0038] The adhesive resin can be either a hydrophilic or a hydrophobic adhesive resin, and conventionally known adhesive resins can be used. For example, in agricultural films, if the adhesive resin flows out due to water adhering to the surface under high temperature and humidity, the colloidal silica will detach. Therefore, to suppress the detachment of colloidal silica, a hydrophobic adhesive resin is preferred.

[0039] Examples of hydrophilic adhesive resins include polyvinyl alcohol, ethylene-vinyl alcohol copolymers, vinyl acetate-based water-soluble resins, polyethylene oxide, acylated cellulose, polyethylene glycol, polyvinylpyrrolidone, polyacrylamide, polyvinyl butyral, polyether ester amide, poly(N-hydroxymethylacrylamide), hydroxyethyl cellulose, methyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose and other modified celluloses, water-soluble polyester resins, water-soluble polyvinyl acetal, poly-N-vinyl acetamide, polyacrylamide, polyacryloylmorpholine, polyhydroxyacrylate, polyacrylic acid, polyether-based materials, etc.

[0040] Examples of hydrophobic adhesive resins include acrylic resins, urethane resins, epoxy resins, and polyester resins. When the substrate film is a polyolefin film, acrylic resins are particularly preferred from the perspective of compatibility with polyolefin films. In addition, acrylic resins have excellent heat resistance and are readily available and inexpensive; therefore, from this point of view, they are also preferred as base resins.

[0041] Examples of the aforementioned acrylic resins include, for instance, individual or copolymeric (meth)acrylic monomers, and copolymers of (meth)acrylic monomers with other copolymerizable monomers. It should be noted that in this specification, "(meth)acrylic monomer" is a general term for both acrylic monomers and methacrylic monomers, and the same applies to other terms such as "(meth)acrylic acid" or "(meth)acrylate".

[0042] Specifically, examples of the aforementioned (meth)acrylate monomers include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, tert-butyl methacrylate, isobutyl methacrylate, n-hexyl methacrylate, n-octyl methacrylate, 2-ethylhexyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, phenyl methacrylate, nonyl methacrylate, decyl methacrylate, dodecyl methacrylate, stearyl methacrylate, and other alkyl methacrylates; acrylic acid or its neutralized salts, methacrylic acid or its neutralized salts, maleic acid or its neutralized salts, maleic anhydride or... This includes functionalized (meth)acrylates such as salts, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, glyceryl mono(meth)acrylate, and glycidyl (meth)acrylate; polyfunctional (meth)acrylates such as divinylbenzene, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, allyl (meth)acrylate, and trimethylolpropane tri(meth)acrylate; and functionalized (meth)acrylamides such as N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, and N-hydroxymethyl(meth)acrylamide, as well as dimethylol(meth)acrylamide. These monomers can be used alone or in combination of two or more.

[0043] Hydrophobic acrylic resins are preferably used in the form of aqueous emulsions. Aqueous emulsions obtained by polymerizing the monomers in an aqueous medium can be used directly, or they can be diluted by adding a liquid dispersion medium. Alternatively, the polymers produced by polymerization as described above can be separated, collected, and redispersed in a liquid dispersion medium to prepare aqueous emulsions.

[0044] <surfactants>

[0045] There are no particular restrictions on the surfactants used; conventionally known surfactants can be used. Examples include nonionic surfactants, anionic surfactants, cationic surfactants, and amphoteric surfactants. Among these, nonionic surfactants are preferred from the viewpoint of dispersibility of inorganic particles. These surfactants can be used alone or in combination of two or more.

[0046] Nonionic Surfactants

[0047] As a nonionic surfactant, there are no particular restrictions, and conventionally known nonionic surfactants can be appropriately selected. For example, (1) compounds obtained by adding 2 to 4 carbon atoms of an epoxide to an organic acid, organic alcohol, organic amine, and / or organic amide, such as polyoxyethylene dilaurate, polyoxyethylene oleate, polyoxyethylene oleate diester, p-nonylphenol, lauryl alcohol, oleyl alcohol, polyoxyethylene octyl ether, polyoxyethylene lauryl ether, polyoxyethylene lauryl ether methyl ether, polyoxyethylene polyoxypropylene lauryl ether, polyoxypropylene lauryl ether methyl ether, polyoxyethylene oil-based ether, polyoxybutylene oil-based 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, and compounds obtained by adding ethylene oxide to a dodecyl alcohol. The nonionic surfactants include: (1) ether-type nonionic surfactants such as polyoxyethylene tridecyl ether, polyoxyethylene tetradecyl ether, polyoxyethylene lauryl amino ether, polyoxyethylene lauramide ether, and polyoxyethylene tristyrene phenyl ether; (2) polyoxyethylene polyol fatty acid ester-type nonionic surfactants such as polyoxyethylene sorbitan trioleate, polyoxyethylene coconut oil, polyoxyethylene castor oil, polyoxyethylene hydrogenated castor oil, polyoxyethylene hydrogenated castor oil trioctyl ester, polyoxyethylene hydrogenated castor oil maleate, stearate, or oleate; (3) alkylamide-type nonionic surfactants such as stearic acid diethanolamide and diethanolamine monolauramide; and (4) polyoxyethylene fatty acid amide-type nonionic surfactants such as polyoxyethylene diethanolamine monooleamide, polyoxyethylene laurylamine, and polyoxyethylene tallow amine. These nonionic surfactants can be used alone or in combination of two or more.

[0048] Anionic Surfactants

[0049] As an anionic surfactant, there are no particular restrictions, and previously known anionic surfactants can be appropriately selected. Examples include (1) phosphate salts of aliphatic alcohols such as lauryl phosphate, cetyl phosphate, octyl phosphate, oleyl phosphate, and stearyl phosphate; (2) phosphate salts of compounds obtained by adding at least one epoxide selected from ethylene oxide and propylene oxide to aliphatic 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) sulfate salts of aliphatic alcohols such as lauryl sulfate, oleyl sulfate, and stearyl sulfate; and (5) polyoxyethylene lauryl ether sulfate and polyoxyethylene (polyoxyethylene, polyoxypropylene) lauryl ether sulfate. Sulfate salts of compounds obtained by adding ester salts, polyoxyethylene oleyl ether sulfate salts, etc., to aliphatic alcohols via the addition of at least one epoxide selected from ethylene oxide and propylene oxide; (6) sulfate salts of fatty acids such as castor oil fatty acid sulfate salt, sesame oil fatty acid sulfate salt, tall oil fatty acid sulfate salt, soybean oil fatty acid sulfate salt, rapeseed oil fatty acid sulfate salt, palm oil fatty acid sulfate salt, lard fatty acid sulfate salt, tallow fatty acid sulfate salt, and whale oil fatty acid sulfate salt; (7) sulfate salts of oils such as castor oil sulfate salt, sesame oil sulfate salt, tall oil sulfate salt, soybean oil sulfate salt, rapeseed oil sulfate salt, palm oil sulfate salt, lard sulfate salt, tallow sulfate salt, and whale oil sulfate salt; (8) fatty acid salts such as laurate, oleate, and stearate; and (9) sulfosuccinate salts of aliphatic alcohols such as dioctyl sulfosuccinate. These anionic surfactants can be used alone or in appropriate combinations of two or more.

[0050] Cationic Surfactants

[0051] As cationic surfactants, there are no particular restrictions, and conventionally known cationic surfactants can be appropriately selected. Examples include lauryltrimethylammonium chloride, hexadecyltrimethylammonium chloride, stearyltrimethylammonium chloride, docosyltrimethylammonium chloride, dialcyldimethylammonium chloride, 1,2-dimethylimidazole, and triethanolamine. These cationic surfactants can be used alone, or two or more can be used in combination.

[0052] Amphoteric Surfactants

[0053] As an amphoteric surfactant, there are no particular restrictions, and conventionally known amphoteric surfactants can be appropriately selected. For example, betaine-type amphoteric surfactants can be cited.

[0054] <Formulation ratio of coating composition>

[0055] In the coating composition, the proportions of inorganic particles (A), adhesive resin, and surfactant can be arbitrarily set. When the coating composition further contains inorganic particles (B), the coating composition preferably contains adhesive resin in a proportion of 10 to 50 parts by mass and surfactant in a proportion of 1 to 15 parts by mass relative to a total of 100 parts by mass of inorganic particles (A) and inorganic particles (B). More preferably, the coating composition contains adhesive resin in a proportion of 20 to 40 parts by mass and surfactant in a proportion of 3 to 10 parts by mass.

[0056] <Other Additives>

[0057] Other known additives may be added to the coating composition as needed. Examples of such additives include colorants, antioxidants, light stabilizers, flame retardants, antistatic agents, mildew inhibitors, antibacterial agents, antifouling agents, UV absorbers, preservatives, and lubricants.

[0058] Method for manufacturing coating compositions

[0059] The method for manufacturing the coating composition is not particularly limited as long as it includes the step of mixing inorganic particles (A) with the adhesive resin. For example, the inorganic particles (A) are mixed and stirred in a liquid solvent in which the adhesive resin is dissolved or dispersed to disperse the inorganic particles (A) in the liquid solvent, and then a surfactant is added and mixed and stirred. Alternatively, a surfactant may be added to the liquid solvent and mixed and stirred, and then a mixture of inorganic particles (A) and adhesive resin may be added and mixed and stirred. Alternatively, other raw material components such as inorganic particles (A), adhesive resin, and inorganic particles (B) may be mixed together. When the coating composition contains other additives, it is preferable to disperse the inorganic particles in the liquid solvent before mixing them with the other components.

[0060] Modified membranes

[0061] The modified film of the present invention comprises a base film portion made of a synthetic resin film, and a coated portion comprising a coating agent composition on at least a portion of the surface of the base film portion. The coated portion of the modified film may be formed only on one side of the base film portion, or it may be formed on both sides.

[0062] <Basement Membrane Section>

[0063] There are no particular limitations as long as the base film is composed of a synthetic resin film. The base film can be either a thermoplastic resin film or a thermosetting resin film, but a thermoplastic resin film is preferred in this invention. Examples of thermoplastic resins include olefin resins, polyester resins, vinyl chloride resins, vinylidene chloride resins, ethylene-vinyl acetate copolymers, ethylene-alkyl methacrylate copolymers, ethylene-vinyl alcohol copolymers, polyvinyl alcohol, cyclic olefin resins, acrylic resins, aromatic vinyl resins, polyamide resins, and polyurethane resins. Furthermore, the base film can be a single layer or multiple layers.

[0064] Examples of olefin-based resins include homopolymers of ethylene or α-olefins with 3 or more carbon atoms, ethylene-α-olefin copolymers, and copolymers of two or more α-olefins. It should be noted that examples of α-olefins include 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, and 1-eicosene. Preferably, the above-mentioned olefin-based resins are ethylene-1-butene copolymers, ethylene-1-hexene copolymers, ethylene-vinyl acetate copolymers, polyethylene, or ethylene-propylene copolymers. Polyolefin-based resins can also be used by mixing two or more polyolefin-based resins.

[0065] Examples of polyester resins include polyethylene terephthalate, polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate. Examples of vinyl chloride-based resins include polyvinyl chloride, vinyl chloride-ethylene copolymer, and vinyl chloride-vinyl acetate copolymer.

[0066] Other known resin additives may be added to the base film as needed. Examples of such additives include antioxidants, weathering agents, ultraviolet absorbers, infrared absorbers, lubricants, anti-blocking agents, anti-fogging agents, defogging agents, heat-insulating agents, and colorants.

[0067] The base film portion used in the modified film can be surface-treated by corona discharge, atmospheric pressure plasma treatment, flame treatment, etc., or it can have a surface with an undercoating layer. The thickness of the base film portion is not particularly limited.

[0068] The method for forming the coating portion containing the coating composition in the base film portion is not particularly limited, and conventionally known methods can be used. For example, gravure coating, spray coating, dip coating, roller coating, doctor blade coating, wire rod coating, and air knife coating can be employed. The coating amount and film thickness are not particularly limited, but as the coating after drying, a thickness of 0.05–3.0 g / m² is preferred. 2 More preferably, it is 0.1–2.0 g / m 2 .

[0069] The synthetic resin film coating composition of the present invention is suitable for coating synthetic resin films, but even when forming a coated portion on a substrate made of metal or inorganic compound, or a composite substrate having a layer formed on the surface of the substrate, an article with a coated portion having excellent drip-proof and wet scratch resistance can be formed.

[0070] Example

[0071] The present invention will now be described in more detail with reference to examples and comparative examples, but the present invention is not limited to these examples. It should be noted that in the following examples and comparative examples, "parts" and "%" are mass measurements.

[0072] Raw materials for coating compositions

[0073] The raw materials used in the manufacture of the coating composition are as follows.

[0074] <Inorganic Particles (A)>

[0075] A-1: Colloidal silica with an average particle size of 77 nm and a CV value of 36% (50% solids).

[0076] A-2: Colloidal silica with an average particle size of 65 nm and a CV value of 38% (40% solid content).

[0077] A-3: Colloidal silica with an average particle size of 58 nm and a CV value of 31% (40% solid content).

[0078] A-4: Colloidal silica with an average particle size of 16 nm and a CV value of 20% (40% solids content).

[0079] A-5: Colloidal silica with an average particle size of 87 nm and a CV value of 25% (40% solid content).

[0080] <Inorganic Particles (B)>

[0081] B-1: Colloidal silica with an average particle size of 128 nm (40% solids)

[0082] B-2: Colloidal silica with an average particle size of 115 nm (40% solids)

[0083] B-3: Colloidal silica with an average particle size of 100 nm (40% solids)

[0084] B-4: Colloidal silica with an average particle size of 303 nm (40% solids)

[0085] <Adhesive Resin>

[0086] C-1: Aqueous acrylic emulsion manufactured by NIPPON CARBIDE INDUSTRIES CO.,INC., Nikasol FT-4683 (34% solids).

[0087] C-2: DIC-based water-based acrylic emulsion, Voncoat 40-418EF (55% solids).

[0088] <surfactants>

[0089] D-1: 10-molar adduct of p-nonylphenol into ethylene oxide

[0090] D-2: The 6-molar adduct of lauryl alcohol into ethylene oxide

[0091] D-3: 14-molar adduct of oleyl alcohol and ethylene oxide

[0092] [Calculation of average particle size and CV value]

[0093] Each colloidal silica (A-1 to A-5, B-1 to B-4) was diluted 10-fold with ion-exchanged water (IEW), and the particle size distribution on a volume basis was determined using a dynamic light scattering particle size distribution measuring device (HORIBA, nanoPartica SZ-100V2 Series) via dynamic light scattering. Based on the measured particle size distribution, the average particle size and CV value were calculated. It should be noted that the CV value was calculated using the following formula 1.

[0094] CV value (%) = (standard deviation) ÷ (average particle size) × 100 ... (Equation 1)

[0095] Preparation of Coating Compositions

[0096] The above-mentioned raw materials are used to prepare a coating composition.

[0097] <Example 1-1>

[0098] 88 parts of adhesive resin (C-1: 34% solids) were mixed with 6414 parts of water and stirred. Then, 30 parts of inorganic particles (A) (A-1: 50% solids) and 213 parts of inorganic particles (B) (B-1: 40% solids) were slowly added and stirred for at least 30 minutes to ensure complete dispersion of inorganic particles (A) and (B) in the water. Next, 5 parts of surfactant (D-1: 100% solids) were added and stirred for at least 30 minutes to prepare a coating composition (X-1) with a purity concentration of 2%.

[0099] <Examples 1-2 to 1-6, Comparative Examples 1-1 to 1-4>

[0100] The same procedure was followed as in Examples 1-1 to prepare coating compositions (X-2) to (X-10) with the compositions shown in Table 1 below.

[0101] Table 1

[0102] Table 1. Examples of preparation of coating compositions

[0103]

[0104] Fabrication of the base film

[0105] Next, a base film for coating the coating agent composition is prepared.

[0106] <Preparation example 1>

[0107] Ethylene-1-butene copolymer (ethylene unit weight: 95%, density: 0.920 g / cm³) 3 The resin (MFR: 2.1 g / 10 min) was used for blow molding (resin extrusion temperature: 200 °C, BUR = 1.8) with a die fitted with a 75 mm diameter mold and a 3 mm die lip gap to obtain an olefin resin film with a thickness of 150 μm. Next, the surface of this 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-treated surface was measured using a method based on JIS K 6768, and the result was 44 mN / m.

[0108] <Preparation example 2>

[0109] Ethylene-1-hexene copolymer (ethylene unit weight: 96%, density: 0.930 g / cm³) was used. 3 The ethylene-1-butene copolymer was replaced with MFR (1.0 g / 10 min), and the same procedure as in 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.

[0110] <Preparation example 3>

[0111] Using ethylene-vinyl acetate copolymer (ethylene unit weight: 93%, MFR: 1.5 g / 10 min) instead of ethylene-1-butene copolymer, the same procedures as in Example 1 were performed to obtain a surface-treated olefin resin film (hereinafter referred to as "base film (F-3)"). The wetting tension of the corona discharge treated surface was 42 mN / m.

[0112] <Preparation example 4>

[0113] Polyethylene (density: 0.927 g / cm³) was used. 3 The ethylene-1-butene copolymer was replaced with MFR (4.0 g / 10 min), and the same procedure as in 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.

[0114] <Preparation example 5>

[0115] Ethylene-propylene copolymer (ethylene unit weight: 4%, density: 0.90 g / cm³) was used. 3 The ethylene-1-butene copolymer was replaced with an MFR of 8.0 g / 10 min, and the same procedure as in 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.

[0116] Production and Evaluation of Modified Membranes

[0117] The modified film was prepared using the above-described coating composition and base film, and then evaluated by the following test methods.

[0118] <Example 2-1>

[0119] The coating composition (X-1) was prepared by impregnation to achieve an absolute dry coating weight of 0.2 g / m. 2 The coating was applied to the corona discharge treated surface of the base film (F-1) and dried at 70°C using a warm air dryer to obtain a modified film (M-1) having a coated portion composed of the coating agent composition (X-1) on the corona discharge treated surface of the base film (F-1). Next, the modified film (M-1) was used to conduct the following tests (1) to (3). The results are shown in Table 2 below.

[0120] <Examples 2-2 to 2-6 and Comparative Examples 2-1 to 2-4>

[0121] Using the coating composition, base film, and absolute dry coating amount shown in Table 2, except as in Example 2-1, modified films M-2 to M-10 were obtained. Then, the following tests (1) to (3) were performed using each modified film. The results are shown in Table 2.

[0122] (1) Initial dripping

[0123] Above a constant-temperature water bath at 60°C, the modified membrane is positioned with the coated portion facing the warm water bath and tilted at a 15-degree angle relative to the horizontal. The condition of water vapor in contact with the coated portion forming water droplets and adhering to the membrane is visually observed. The time required until the adhering area of ​​the water droplets is less than 10% is measured, and the initial dripping performance is evaluated according to the following criteria.

[0124] ◎: Less than 15 minutes (excellent initial dripping properties).

[0125] ○: 15 minutes or more but less than 30 minutes (excellent initial dripping properties).

[0126] ×: After 30 minutes or more, the surface area of ​​water droplets is more than 10% (poor initial dripping properties).

[0127] (2) Dripping persistence

[0128] Following the same procedure as in (1) above, visually observe the adhesion state of water droplets after the modified membrane has been continuously prepared for 7 days, and evaluate the droplet persistence according to the following criteria.

[0129] ◎: No water droplets adhere (dripping performance is excellent).

[0130] ○: The adhesion area of ​​water droplets is less than 10% (excellent drip persistence).

[0131] ×: The surface area of ​​the water droplets is more than 10% (poor drip persistence).

[0132] (3) Resistance to wet abrasion

[0133] With a load of 300g applied to the friction surface of the arm of the Daiei Scientific Precision Machinery Co., Ltd. vibration mode dyeing fastness tester, the modified film, which was sprayed with water and became wet just before the experiment, was rubbed back and forth 30 times. The rubbed modified film was placed above a constant temperature water layer in the same manner as described in (1) above, and exposed to water vapor for 1 hour.

[0134] After 1 hour, observe the degree of peeling of the coated part from the base film, and evaluate the resistance to wet abrasion according to the following criteria.

[0135] ◎: The area of ​​the coated part peeling off from the base film is less than 10% (excellent resistance to wet abrasion).

[0136] ○: The area of ​​the coated portion peeling off from the base film is more than 10% and less than 50% (resistance to wet abrasion is of practical grade).

[0137] ×: The area of ​​the coated portion peeling off from the base film is more than 50% (poor resistance to wet abrasion).

[0138] Table 2

[0139] Table 2】Evaluation of the Example

[0140]

[0141] The modified films of Examples 2-1 to 2-6 exhibit excellent initial dripping properties, dripping persistence, and resistance to wet abrasion. On the other hand, the modified film of Comparative Example 2-1 has poor initial dripping properties and resistance to wet abrasion because the coating composition used contains inorganic particles (A) with small average particle size and CV value, and inorganic particles (B) with large average particle size. The modified film of Comparative Example 2-2 has poor initial dripping properties because the coating composition used contains only inorganic particles (B) and not inorganic particles (A). The modified film of Comparative Example 2-3 has poor initial dripping properties because the coating composition used contains inorganic particles (A) with small average particle size and CV value. The modified film of Comparative Example 2-4 has poor initial dripping properties because the coating composition used contains inorganic particles (A) with an average particle size in the range of 60-90 nm but a small CV value.

Claims

1. An agricultural synthetic resin film coating composition, characterized in that it is An agricultural synthetic resin film coating composition containing inorganic particles, adhesive resin, and surfactant, wherein the inorganic particles comprise inorganic particles A and inorganic particles B as described below. Inorganic particles A: Colloidal silica with a single particle size of 60–90 nm as determined by dynamic light scattering and a CV value of 35–55% calculated by Equation 1. CV value (%) = (standard deviation) ÷ (average particle size) × 100 ・・・ (Equation 1). Inorganic particles B: Colloidal silica with an average particle size exceeding 90 nm and below 160 nm, as determined by dynamic light scattering.

2. The agricultural synthetic resin film coating composition according to claim 1, wherein, When the total proportion of inorganic particles A and inorganic particles B is set to 100 parts by mass, inorganic particles A is contained in a proportion of 5 to 30 parts by mass, and inorganic particles B are contained in a proportion of 70 to 95 parts by mass.

3. The agricultural synthetic resin film coating composition according to claim 2, wherein, When the total content ratio of the inorganic particles A and the inorganic particles B is set to 100 parts by mass, the adhesive resin is included in a ratio of 10 to 50 parts by mass, and the surfactant is included in a ratio of 1 to 15 parts by mass.

4. A manufacturing method, characterized in that, The method for manufacturing the agricultural synthetic resin film coating composition according to any one of claims 1 to 3 It includes a step of mixing the inorganic particles A with the adhesive resin.

5. A modified membrane, characterized in that, The product comprises a base film portion made of a synthetic resin film and a coating portion comprising, at least a portion of the surface of the base film portion, the agricultural synthetic resin film coating composition according to any one of claims 1 to 3.

Images