Multilayer film

Abstract

[Problem] To provide a film that exhibits the good physical properties of both water repellency and oil repellency while maintaining adhesion to a resin substrate film. [Solution] Provided is a laminated film having, on a resin substrate film, a coating layer that contains: a binder resin; and fine particles the surfaces of which are hydrophobicized and lipophobicized, wherein the laminated film has a fluorine atom ratio of at least 20 at% in terms of atomic composition ratio, in a region where the depth from the surface of the coating layer of the laminated film is 10 nm, as measured by an X-ray photoelectron spectrometer (ESCA).

Description

Technical Field

[0001] The present invention relates to a laminated film. More specifically, it relates to a coated laminated film having water and oil repellency.

Background Art

[0002] Materials that exhibit water and oil repellency on the surface are industrially important in fields where antifouling properties are required. To achieve antifouling properties, it is necessary to reduce the interaction between contaminants and the material surface, and this is generally achieved by making the material surface water-repellent or oil-repellent.

[0003] Conventionally, methods for producing films excellent in water and oil repellency by using silica fine particles having voids or fine particles having voids by forming aggregates are known (see, for example, Patent Documents 1 and 2). However, generally, coating methods for imparting water and oil repellency to the film surface have a problem that the adhesiveness to the substrate is low and the coating layer easily peels off, and it has been difficult to achieve both sufficient water and oil repellency and adhesion to the substrate.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

[0005] The present invention has been made in view of such problems of the prior art. That is, an object of the present invention is to provide a film that exhibits good physical properties in both water repellency and oil repellency while maintaining adhesion to a resin substrate film.

Means for Solving the Problems

[0006] As a result of intensive studies to achieve such an object, the present inventors have found that the above problems can be solved by the means described below, and have reached the present invention. That is, the present invention has the following configuration. 1. A laminated film having a coating layer containing a binder resin and fine particles whose surfaces are hydrophobized and oleophobized on a resin base film, wherein when the atomic composition ratio is determined for a depth region of 10 nm from the surface of the coating layer by measurement with an X-ray photoelectron spectrometer (ESCA), the ratio of fluorine atoms is 20 at% or more. 2. The laminated film according to the first item above, wherein the resin base film is a polyethylene terephthalate film or a polyethylene naphthalate film. 3. The laminated film according to the first or second item above, wherein the average primary particle diameter of the fine particles whose surfaces are hydrophobized is 30 nm to 1 μm. 4. The laminated film according to any one of the first to third items above, wherein the binder resin is an acid-modified polyolefin resin or a polyester resin.

Effect of the Invention

[0007] The laminated film of the present invention exhibits high water and oil repellency because the ratio of fluorine atoms is 20 at% or more when the atomic composition ratio is determined for a depth region of 10 nm from the surface of the coating layer.

Mode for Carrying Out the Invention

[0008] Hereinafter, the present invention will be described in detail. The present invention provides a laminated film having excellent water and oil repellency on the surface of the coating layer and adhesiveness between the coating layer and the resin base film.

[0009] (Resin Base Film) The laminated film in the present invention has a resin base film. The material of this resin base film is not particularly limited, but a resin film is preferable from the viewpoint of handleability such as flexibility. Examples of the resin constituting the resin film include polyolefins such as polyethylene, polypropylene, polystyrene and diene polymers, polyesters such as polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyamides such as nylon 6, nylon 6,6, nylon 6,10, nylon 12, acrylate resins such as polymethyl methacrylate, polymethacrylic acid esters, polymethyl acrylate, polyacrylic acid esters, polyacrylic acid resins, polymethacrylic acid resins, polyurethane resins, cellulose resins such as cellulose acetate, ethyl cellulose, polyarylate, aramid, polycarbonate, polyphenylene sulfide, polyphenylene oxide, polysulfone, polyethersulfone, polyetheretherketone, polyetherimide, polyimide, polyamideimide, polybenzimidazole, polybenzoxazole, polybenzothiazole and other aromatic hydrocarbon polymers, fluorine resins such as polytetrafluoroethylene, polyvinylidene fluoride, epoxy resins, phenol resins, novolak resins, benzoxazine resins and the like. Among these, from the viewpoints of transparency and dimensional stability, a film made of a polyester resin or an acrylate resin is preferable. Specific examples of the polyester resin include polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polyethylene naphthalate and the like. Among these, from the viewpoint of physical properties, polyethylene terephthalate and polyethylene naphthalate are preferable, and from the viewpoint of the balance between physical properties and cost, polyethylene terephthalate is particularly preferable.

[0010] The resin base film may be single-layered or may have two or more layers laminated thereon. When two or more layers are laminated, the same or different types of films can be laminated. Also, a resin composition may be laminated on the resin base film. Further, within the range where the effects of the present invention are achieved, various additives can be contained in the resin base film as necessary. Examples of the additives include antioxidants, light-resistant agents, anti-gelling agents, organic wetting agents, antistatic agents, ultraviolet absorbers, surfactants, and the like. When the resin base film is composed of two or more layers, additives can also be contained according to the functions of each layer. In order to improve the handling properties such as the slipperiness and winding property of the resin base film, inert particles may be contained in the resin base film.

[0011] In the present invention, the thickness of the resin base film is not particularly limited, but it is preferably 5 μm or more and 300 μm or less. More preferably, it is 10 μm or more and 280 μm or less, and even more preferably, it is 12 μm or more and 260 μm or less. When it is 5 μm or more, it is easy to coat during the lamination of the coating layer, and when it is 300 μm or less, it is advantageous in terms of cost.

[0012] As the surface of the resin base film, it may be used untreated, but those subjected to surface treatments such as plasma treatment, corona treatment, flame treatment, or those coated with a primer layer can also be used.

[0013] (Fine particles with a hydrophobized surface) The laminated film in the present invention has a coating layer directly on the resin base film or via another layer, and the coating layer contains fine particles with a hydrophobized and oleophobicized surface. The type of the fine particles is not particularly limited. For example, at least one of silica (silicon dioxide), alumina, titania, zirconia, etc. can be used. These may be synthesized via any compound or known or commercially available ones may be used. In particular, silica (silicon dioxide) fine particles are preferable because the subsequent hydrophobization and oleophobicization of the surface are easy.

[0014] The microparticles have a hydrophobic and oleophobic surface, but the method of hydrophobization is not particularly limited. For example, hydrophilic oxide microparticles hydrophobized by surface treatment may be used. That is, surface treatment can be performed on the hydrophilic oxide microparticles with an arbitrary reagent such as a silane coupling agent to hydrophobize the surface, and the hydrophobized surface can be used.

[0015] As the method for hydrophobizing microparticles typified by silica microparticles, surface treatment with various known reagents such as silicone oil, silane coupling agents, and silazanes is preferably used. In particular, from the viewpoint of exhibiting excellent water and oil repellency, fluorine-based functional groups typified by 1H,1H,2H,2H-perfluorooctyl group, 1H,1H,2H,2H-perfluorodecyl group, 1H,1H,2H,2H-perfluorohexyl group, 3,3,3-trifluoropropyl group, etc., alkyl groups typified by methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, octyl group, etc., alkenyl groups, alkynyl groups, vinyl groups, cyclohexyl groups, styryl groups, phenyl groups, trimethylsilyl groups, etc. are more preferably introduced. Among these, hydrophobic and oleophobic oxide microparticles with a 1H,1H,2H,2H-perfluorooctyl group introduced are preferred because they exhibit more excellent water and oil repellency (oleophobicity), and hydrophobic and oleophobic silica with a 1H,1H,2H,2H-perfluorooctyl group introduced is particularly preferred.

[0016] The primary particle diameter of the fine particles in the present invention is preferably 5 nm or more and 2 μm or less, more preferably 20 nm or more and 1.5 μm or less, and still more preferably 30 nm or more and 1 μm or less. When it is 5 nm or more, it is easy to form irregularities on the surface layer of the coating layer, and it is preferable because it is easy to increase the contact angle described later. On the other hand, when it is 2 μm or less, it is preferable because it is difficult for the fine particles to fall off from the coating layer, and it is also easy to maintain the transparency of the resin base film, so it is preferable. In the present invention, the size of the primary particle average diameter can be determined from the results of morphological observation using a microscope such as a scanning electron microscope or a transmission electron microscope. Specifically, in these microscopic observations, the average of the diameters of 20 arbitrarily selected fine particles is taken as the primary particle average diameter. The primary particle average diameter of amorphous fine particles can be calculated as an equivalent circle diameter. The equivalent circle diameter is a value obtained by dividing the area of the observed fine particles by π, calculating the square root, and doubling the result.

[0017] In the present invention, as an index of the water and oil repellency on the surface of the coating layer of the laminated film, that is, as an index of the modification rate by a functional group having water and oil repellency on the surface of the fine particles whose surface is hydrophobized and oleophobicized, the measurement results by an X-ray photoelectron spectrometer (ESCA) can be used. Specifically, the atomic composition ratio can be determined for a depth region of about 10 nm, and the ratio of a specific atom constituting a functional group having water and oil repellency, for example, a fluorine atom, can be compared. In the present invention, from the viewpoint of exhibiting excellent water and oil repellency, for example, in the case of hydrophobic and oleophobic silica into which a 1H,1H,2H,2H-perfluorooctyl group or the like is introduced, the ratio of fluorine atoms is preferably 20 at% or more. When the fluorine atom ratio is 20 at% or more, good liquid repellency can be obtained even for substances with low surface tension. More preferably, it is 25 at% or more. Although there is no upper limit for the fluorine atom ratio, it is preferably 50 at% or less, and preferably 40 at% or less, from the viewpoint of adhesion to the substrate and the like.

[0018] (Binder resin) The binder resin in the present invention is not particularly limited as long as it can be well adhered to the resin base film. For example, it is preferable to use a polyester resin, an acid-modified polyolefin resin, a polyurethane resin, an epoxy resin, an acrylic resin, etc. Further, from the viewpoint of adhesion to the resin base film, it is preferable to use a polyester resin or an acid-modified polyolefin resin for the first coating layer, and it is particularly preferable to use a polyester resin, an acid-modified polyolefin resin, or an acrylic silicone resin for the second coating layer from the viewpoint of preventing a decrease in water and oil repellency.

[0019] As the acid-modified polyolefin resin, those in which at least a part is a polyolefin or an unsaturated carboxylic acid-modified polyolefin are preferable, more preferably unsaturated carboxylic acid-modified polypropylene or unsaturated carboxylic acid-modified polyethylene, and most preferably unsaturated carboxylic acid-modified polypropylene.

[0020] As the unsaturated carboxylic acid, maleic acid, fumaric acid, acrylic acid, methacrylic acid, and acid anhydrides thereof are preferable, and maleic anhydride and maleic acid are most preferable. It can be said that a coating layer with high adhesion to the resin base film can be formed by these.

[0021] The acid value of the acid-modified olefin resin is preferably 2 mgKOH / g or more and 35 mgKOH / g or less, more preferably 5 mgKOH / g or more and 35 mgKOH / g or less, and still more preferably 5 mgKOH / g or more and 25 mgKOH / g. If it is less than the above, the adhesion to the resin base film decreases, and if it is more than the above, it leads to a decrease in water and oil repellency. When the acid value is larger than the lower limit, the adhesion to the resin or the resin base film is good, and when the acid value is smaller than the upper limit, the water and oil repellency of the resin itself is utilized for the liquid repellency of the coating layer, which is preferable.

[0022] The polyester resin used as the binder resin of the coating layer is not particularly limited, but polyester resins of the BYRON series manufactured by Toyobo Co., Ltd. are preferably used.

[0023] The binder resin may be used after being mixed with a curing agent and crosslinked. Preferred curing agents to be used include isocyanate, epoxy, melamine, and carboxylic acid, with epoxy and melamine being more preferred. It is possible to form a coating layer containing silica fine particles while maintaining the transparency of the resin base film by using these.

[0024] (Other components in the coating layer) The coating layer in the present invention may contain components other than the above fine particles. Specifically, binder components, antioxidants, curing agents, light-resistant agents, anti-gelling agents, organic wetting agents, antistatic agents, ultraviolet absorbers, surfactants, etc. may be mentioned, and these components can be appropriately contained as needed.

[0025] Note that the thickness of the entire coating layer is preferably 5 nm or more from the viewpoint of satisfying the adhesion between the coating layer and the resin base film, more preferably 10 nm or more, still more preferably 30 nm or more, and particularly preferably 50 nm or more. Also, the thickness of the entire coating layer is preferably 3 μm or less, more preferably 2 μm or less, still more preferably 1.5 μm or less, and particularly preferably 1.2 μm or less in consideration of the water and oil repellency of the coating layer surface and economy.

[0026] The solid content of the coating liquid is preferably 0.5% by mass or more and 20% by mass or less, more preferably 1% by mass or more and 15% by mass or less, and still more preferably 3% by mass or more and 10% by mass or less. Being within the above range is preferable because the unevenness of the fine particles is likely to appear on the coating surface layer and the coatability is also good.

[0027] The mixing ratio (binder resin: fine particles) of the fine particles to the binder resin preferably ranges from 90:10 to 5:95, more preferably from 70:30 to 5:95, and still more preferably from 50:50 to 5:95. Being within the above range is preferable because the unevenness of the fine particles appears on the surface but a state where peeling from the binder hardly occurs can be formed.

[0028] (Solvent) The solvent used for coating is not particularly limited. For example, organic solvents such as water, alcohols, ketones, normal hexane, cyclohexane, toluene, butyl acetate, and glycols are preferred, organic solvents such as toluene, cyclohexane, and hexane are more preferred, and toluene is most preferred. These can enhance the solubility of the binder resin and produce a uniform coating solution.

[0029] (Primary particle diameter of the hydrophobized fine particles) It can be determined based on the results of morphological observation by a microscope using a scanning electron microscope, a transmission electron microscope, etc. Specifically, in these microscope observations, the average of the diameters of 20 arbitrarily selected particles is taken as the primary particle average diameter.

[0030] (Method for measuring acid value) The acid value (mgKOH / g-resin) in the present invention refers to the amount of KOH required to neutralize 1 g of the acid-modified polyolefin and was measured according to the test method of JIS K0070 (1992). Specifically, after dissolving 1 g of the acid-modified polyolefin in 100 g of xylene adjusted to a temperature of 100°C, titration was performed with a 0.1 mol / L potassium hydroxide ethanol solution [trade name "0.1 mol / L ethanolic potassium hydroxide solution", manufactured by Wako Pure Chemical Industries, Ltd.] using phenolphthalein as an indicator at the same temperature. At this time, the amount of potassium hydroxide required for titration was converted to mg to calculate the acid value (mgKOH / g).

[0031] (Water and oil repellency) The water and oil repellency of the laminated film according to the present invention can be evaluated by known methods. Specifically, the water repellency can be evaluated by measuring the contact angle with water, and the oil repellency can be evaluated by measuring the contact angle with iodine methane and decane. The preferable range of the contact angle with respect to water in the present invention is 100 degrees or more, more preferably 120 degrees or more. The larger the contact angle with respect to water, the better, and the upper limit is not particularly limited, but realistically, it is about 170 degrees. A contact angle with respect to water of 100 degrees or more is preferable because it exhibits excellent water repellency, and 120 degrees or more is more preferable because it exhibits water repellency equal to or better than that of a conventional fluororesin sheet typified by polytetrafluoroethylene (PTFE). Further, the preferable range of the contact angle with respect to iodine methane in the present invention is 60 degrees or more, more preferably 90 degrees or more. The larger the contact angle with respect to iodine methane, the better, and the upper limit is not particularly limited, but realistically, it is about 160 degrees. A contact angle with respect to iodine methane of 60 degrees or more is preferable from the viewpoint of imparting oil repellency capable of suppressing oil stains and the like, and 90 degrees or more is more preferable because it exhibits oil repellency equal to or better than that of a conventional fluororesin sheet. The preferable range of the contact angle with respect to decane in the present invention is 30 degrees or more, more preferably 40 degrees or more. The larger the contact angle with respect to decane, the better, and the upper limit is not particularly limited, but realistically, it is about 150 degrees. A contact angle with respect to decane of 40 degrees or more is preferable because it exhibits excellent oil repellency, and more than 40 degrees is more preferable because it exhibits oil repellency equal to or better than that of a conventional fluororesin sheet typified by polytetrafluoroethylene (PTFE).

[0032] (Manufacturing process of laminated film) In the production of the laminated film of the present invention, the coating method is not particularly limited. For example, it can be produced according to known methods such as roll coating, gravure coating, bar coating, doctor blade coating, spin coating, spray coating, and brush coating. The solvent used when coating by these methods is not particularly limited, and for example, water, alcohols, ketones, normal hexane, cyclohexane, toluene, butyl acetate, organic solvents such as glycols can be appropriately selected and used. These solvents may be used alone or in combination of a plurality. The content of the hydrophobized fine particles with respect to the solvent can be selected at any ratio at which a uniform dispersion can be obtained. The drying method after coating may be either natural drying or heat drying, but from the viewpoint of industrial production, heat drying is more preferable. The drying temperature is not particularly limited as long as it does not affect the components contained in the resin base film or the coating layer, but usually 150 °C or lower is preferable, and 50 °C or higher and 140 °C or lower is more preferable. The drying method is not particularly limited, and known methods for drying the film such as a hot plate or a hot air oven can be used. The drying time is appropriately selected according to other conditions such as the drying temperature, but it is sufficient as long as it does not affect the components contained in the resin base film or the coating layer. Further, the coating step may be a so-called offline coating method in which it is performed in a separate step after the formation of the resin base film, or a so-called inline coating method in which a coating solution is applied to an unstretched sheet or a uniaxially stretched film in the production process of the resin base film and stretched at least in one axial direction.

Example

[0033] Hereinafter, the present invention will be further described with specific examples, but the present invention is not limited to the embodiments of these examples. First, the evaluation method adopted in the present invention will be described.

[0034] (Contact angle measurement) The contact angle with respect to a solvent was measured for the coating layer surface of the fabricated laminated film. For the contact angle measurement, a contact angle meter CA-X manufactured by Kyowa Interface Science Co., Ltd. was used. As the measurement solvents, pure water, diiodomethane, and decane were used. The contact angle of water was measured 10 seconds after dropping 1.8 μL of water droplets. The contact angle of diiodomethane was measured 10 seconds after dropping 0.9 μL of diiodomethane droplets, and the contact angle of decane was measured 10 seconds after dropping 0.5 μL of decane droplets.

[0035] (Adhesion measurement) The adhesion between the film and the coating layer was determined by a visual test using cellophane tape. A cellophane tape with a width of 24 mm was attached to the coating surface, strongly pressed with a finger, and then the presence or absence of peeling of the coating layer was visually confirmed when it was forcefully peeled off. 〇: No peeling is observed ×: No peeling is observed

[0036] (Measurement of the average primary particle diameter) The average primary particle diameter of the hydrophobized fine particles was determined from the results of observations using a scanning electron microscope or a transmission electron microscope. Specifically, in these microscope observations, the average of the diameters of 20 arbitrarily selected fine particles was taken as the average primary particle diameter. The average primary particle diameter of amorphous fine particles can be calculated as the equivalent circle diameter. The equivalent circle diameter is a value obtained by dividing the area of the observed fine particles by π, calculating the square root, and doubling the result.

[0037] (ESCA measurement of fine particles whose surface is hydrophobized and oleophobicized) A dispersion of fine particles whose surface was hydrophobized and oleophobicized was dropped onto a clean aluminum foil, dried, and a thin film of hydrophobized fine particles was formed on the aluminum foil. At this time, it was dried as quickly as possible so that surface contamination would not occur as much as possible, and immediately sampled for surface composition analysis. The apparatus used was K-Alpha +(Manufactured by Thermo Fisher Scientific) was used. The details of the measurement conditions are shown below. In the analysis, background removal was performed by the Shirley method. The surface composition ratio was taken as the average value of the measurement results at three or more sites where Al in the resin base film was not detected. · Measurement conditions Excitation X-ray: Monochromated AlKα ray X-ray output: 12 kV, 6 mA Photoelectron escape angle: 90 degrees Spot size: 400 μmΦ Pass energy: 50 eV Step: 0.1 eV

[0038] (ESCA measurement of the coating layer of the laminated film) Composition analysis was performed on the depth region of 10 nm from the surface of the coating layer of the laminated film. The device used was K-Alpha + (Manufactured by Thermo Fisher Scientific) was used. The details of the measurement conditions are shown below. In the analysis, background removal was performed by the Shirley method. The surface composition ratio was taken as the average value of the measurement results at three or more sites. · Measurement conditions Excitation X-ray: Monochromated AlKα ray X-ray output: 12 kV, 6 mA Photoelectron escape angle: 90 degrees Spot size: 400 μmΦ Pass energy: 50 eV Step: 0.1 eV

[0039] The following are the reagents used during the study of the examples. · BYRON (registered trademark) RV-280 (polyester resin manufactured by Toyobo) · MS-001 (methylated melamine resin manufactured by Sanwa Chemical) · p-Toluenesulfonic acid monohydrate (manufactured by Tokyo Chemical Industry) · YD128 (epoxy resin manufactured by Nippon Steel Chemical & Material) ·TETRAD (registered trademark)-X (a multifunctional epoxy resin manufactured by Mitsubishi Gas Chemical)

[0040] <Production Example of Acid-Modified Polyolefin> Into a 1 L autoclave, 100 parts by mass of polypropylene, 150 parts by mass of toluene, 8.5 parts by mass of maleic anhydride, and 4 parts by mass of di-tert-butyl peroxide were added. After heating the temperature to 140 °C, it was further stirred for 1 hour. After the reaction was completed, the reaction solution was poured into a large amount of methyl ethyl ketone to precipitate the resin. This resin was further washed several times with methyl ethyl ketone to remove unreacted maleic anhydride. By drying the obtained resin under reduced pressure, maleic anhydride-modified polypropylene (acid value 12.7 mgKOH / g, weight average molecular weight 60,000, Tm 80 °C), which is an acid-modified polyolefin, was obtained.

[0041] <Production Example of Acid-Modified Polyolefin Solution A-1> 10 parts by mass of the acid-modified polyolefin was weighed into a reaction vessel, and 90 parts by mass of toluene was added thereto, and it was stirred for 1 hour or more to obtain an acid-modified polyolefin solution A-1 having a solid content concentration of 10% by mass.

[0042] <Production Example of Acid-Modified Polyolefin Solution A-2> 23 parts by mass of the acid-modified polyolefin solution A-1, 27 parts by mass of toluene, 0.2 parts by mass of YD128 as a crosslinking agent, and 0.02 parts by mass of TETRAD (registered trademark)-X as a crosslinking catalyst were added to a sample bottle, and it was stirred at room temperature for 5 minutes to obtain an acid-modified polyolefin solution A-2 having a solid content concentration of 5% by mass.

[0043] <Production Example of Polyester Solution B-1> 20 parts by mass of BYRON (registered trademark) RV280 (a polyester resin manufactured by Toyobo Co., Ltd.), 90 parts by mass of toluene, and 90 parts by mass of methyl ethyl ketone were added to a sample bottle, and it was stirred at room temperature for 1 hour to prepare a polyester solution B-1 (solid content concentration 10% by mass).

[0044] <Production Example of Polyester Solution B-2> 23 parts by mass of polyester solution B-1, 27 parts by mass of toluene, 0.2 part by mass of melamine resin MS-001 as a crosslinking agent, and 0.02 part by mass of p-toluenesulfonic acid (PTS) as a crosslinking catalyst were added to a sample bottle and stirred at room temperature for 5 minutes to prepare polyester solution B-2 (solid content concentration: 5% by mass).

[0045] <Synthesis method of silica particle dispersion D-1> 100 parts by mass of tetraethoxysilane and 439 parts by mass of ethanol were mixed in reaction vessel 1. 179 parts by mass of ethanol, 13 parts by mass of aqueous ammonia (25%), and 26 parts by mass of deionized water were mixed in reaction vessel 2, and then the content of reaction vessel 2 was dropped into and transferred to reaction vessel 1. At this time, in order to prevent a rapid reaction, it was dropped over 10 minutes. After the dropping was completed, the reaction solution was left standing at 20 °C for 48 hours. Then, ammonia and water were distilled off to prepare a silica particle dispersion (average primary particle diameter: 35 nm). Then, 7.5 parts by mass of 1H,1H,2H,2H-perfluorooctyltrichlorosilane and 7.5 parts by mass of aqueous ammonia (25%) were added, and heated at 65 °C for 2 days to prepare silica particle dispersion D-1 modified with 1H,1H,2H,2H-perfluorooctyl groups. In order to confirm the solid content concentration of the silica particle dispersion, 5 grams of the silica particle dispersion was weighed into an aluminum cup (1.3 grams), and ethanol and water as residual solvents were removed by heating in an oven at 150 °C for 24 hours or more. When the aluminum cup after removal was weighed, it was 1.55 grams. Therefore, the solid content in 5 grams of the silica particle dispersion could be calculated as 0.25 grams, and the solid content concentration of the silica particle dispersion was confirmed to be 5% by mass. Then, when preparing the coating solution, ethanol in the silica particle dispersion was removed and the same amount of toluene as the removed ethanol was added, and it was carried out as a toluene dispersion. The results of the ESCA analysis of the surface-modified silica particles were C: 17.8 at% and F: 31.9 at%.

[0046] <Synthesis method of particle dispersion D-2> 100 parts by mass of tetraethoxysilane and 49 parts by mass of ethanol were mixed in reaction vessel 1. After 60 parts by mass of ethanol, 13 parts by mass of aqueous ammonia (25%), and 536 parts by mass of deionized water were mixed in reaction vessel 2, the content of reaction vessel 2 was dropped and transferred to reaction vessel 1. At this time, in order to prevent a rapid reaction, the dropping was carried out over 30 minutes. After the completion of dropping, the reaction solution was left standing at 20 °C for 48 hours. Then, ammonia and water were distilled off to prepare a silica fine particle dispersion (average primary particle diameter: 800 nm). Then, 7.5 parts by mass of 1H,1H,2H,2H-perfluorooctyltrichlorosilane and 7.5 parts by mass of aqueous ammonia (25%) were added, and heating was carried out at 65 °C for 2 days to prepare a silica fine particle dispersion D-2 modified with a 1H,1H,2H,2H-perfluorooctyl group. In order to confirm the solid content concentration of the silica fine particle dispersion, 5 grams of the silica fine particle dispersion was measured into an aluminum cup (1.3 grams), and ethanol and water as the residual solvent were removed by heating in an oven at 150 °C for 24 hours or more. When the aluminum cup after removal was weighed, it was 1.55 grams. Therefore, the solid content in 5 grams of the silica fine particle dispersion could be calculated as 0.25 grams, and the solid content concentration of the silica fine particle dispersion was confirmed to be 5% by mass. Then, when preparing the coating solution, ethanol in the silica fine particle dispersion was removed and the same amount of toluene as the removed ethanol was added, and it was carried out as a toluene dispersion. The results of the ESCA analysis of the surface-modified silica fine particles were C: 14.7 at% and F: 30.7 at%.

[0047] <Synthesis method of silica fine particle dispersion D-3> 100 parts by mass of tetraethoxysilane and 439 parts by mass of ethanol were mixed in the reaction vessel 1. After mixing 179 parts by mass of ethanol, 13 parts by mass of aqueous ammonia (25%), and 26 parts by mass of deionized water in the reaction vessel 2, the content of the reaction vessel 2 was dropped into the reaction vessel 1 and transferred. At this time, in order to prevent a rapid reaction, it was dropped over 10 minutes. After the dropping was completed, the reaction solution was left at 20 °C for 48 hours. Then, ammonia and water were distilled off to prepare a silica fine particle dispersion (average primary particle diameter 35 nm). Then, 150 parts by mass of hexamethyldisilazane was added and heated at 65 °C for 2 days to prepare a silica fine particle dispersion D-3 modified with trimethylsilyl groups. In order to confirm the solid content concentration of the silica fine particle dispersion, 5 grams of the silica fine particle dispersion was measured into an aluminum cup (1.3 grams), and ethanol and water as residual solvents were removed by heating in an oven at 150 °C for 24 hours or more. When the aluminum cup after removal was weighed, it was 1.55 grams. Therefore, the solid content in 5 grams of the silica fine particle dispersion could be calculated as 0.25 grams, and the solid content concentration of the silica fine particle dispersion was confirmed to be 5% by mass. Then, when preparing the coating solution, ethanol in the silica fine particle dispersion was removed and the same amount of toluene as the removed ethanol was added, and it was carried out as a toluene dispersion. The results of the ESCA analysis of the silica fine particles surface-modified with trimethylsilyl groups were that C was 8.5 at% and F was less than 0.1 at%.

[0048] <Production Example of Coating Liquid E-1> 40 parts by mass of an acid-modified polyolefin solution A-1 (solid content concentration 10% by mass), 40 parts by mass of a silica fine particle dispersion D-1 (solid content concentration 5% by mass), 44 parts by mass of toluene, 0.2 parts by mass of an epoxy curing agent YD128 (solid content concentration 100% by mass), and 0.02 parts by mass of a catalyst TETRAD-X (solid content concentration 100% by mass) were added to a sample bottle and mixed to prepare a coating liquid E-1 (solid content concentration 5% by mass).

[0049] Except for compounding each substance as shown in Table 1 below, coating liquids E-2 to E-9 for the second coating layer were produced in the same manner as coating liquid E-1. Table 1 shows the compositions of coating liquids E-1 to E-9.

[0050]

Table 1

[0051] <Production of Coating Film> (Example 1) On the corona-treated surface of a film of polyethylene terephthalate (hereinafter sometimes referred to as PET film), Toyobo Ester (registered trademark) film (product number: E5100, thickness: 75 μm), polyester solution B-2 was coated using a bar coater #5, and then dried at 120 °C for 10 minutes to produce a first coating layer (the film thickness after drying of the first coating layer was 0.6 μm). Thereafter, coating liquid E-1 produced by the method described in the production example of the above coating liquid was coated with a bar coater #5, and then dried at 110 °C for 60 minutes to produce a second coating layer, thereby obtaining a coating film (the film thickness after drying of the second coating layer was 0.6 μm).

[0052] (Examples 2 to 12) Hereinafter, by changing the coating liquids of the first coating layer and the second coating layer as shown in Table 2, coating films of Examples 2 to 12 were obtained.

[0053] (Example 13) A coating film of Example 13 was obtained in exactly the same manner as Example 1 except that the resin base film to be used was changed to Teonex (registered trademark) film (product number: Q51, thickness 38 μm) which is a film made of polyethylene naphthalate.

[0054] (Comparative Example 1) After applying the acid-modified polyolefin solution A-2 to the corona-treated surface of the PET film E5100 using a bar coater #5, the coating film was obtained by drying at 120°C for 1 minute.

[0055] (Comparative Example 2) A coating film was obtained in the same manner as in Example 1 except that the second coating layer was changed to the coating solution E-9. The evaluation results of each example and comparative example are summarized in Table 2.

[0056]

Table 2

Industrial Applicability

[0057] According to the present invention, it is possible to provide a laminated film having excellent water and oil repellency and exhibiting antifouling properties. The laminated film according to the present invention can be applied to uses such as packaging, coating, and release materials, and is useful.

Claims

1. A laminated film having a coating layer on a resin substrate film, the coating layer containing a binder resin and fine particles whose surfaces have been rendered hydrophobic and oleophobic, wherein the total thickness of the coating layer is 3 μm or less, the coating layer having a first coating layer on the resin substrate film, the first coating layer containing a binder resin and a curing agent, and a second coating layer on the first coating layer, the second coating layer containing a binder resin, a curing agent, and fine particles whose surfaces have been rendered hydrophobic and oleophobic, and wherein, when the atomic composition ratio is determined in a region 10 nm deep from the surface of the coating layer by measurement using an X-ray photoelectron spectroscopy (ESCA), the laminated film has a ratio of fluorine atoms of 20 at% or more.

2. 2. The laminated film according to claim 1, wherein the resin substrate film is a polyethylene terephthalate film or a polyethylene naphthalate film.

3. 3. The laminated film according to claim 1, wherein the fine particles having hydrophobic surfaces have an average primary particle diameter of 30 nm to 1 μm.

4. 4. The laminated film according to claim 1, wherein the binder resin is an acid-modified polyolefin resin or a polyester resin.

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