laminate

Abstract

(assignment) The present invention provides a laminate that is capable of mass production and has a water-repellent and / or oil-repellent layer that is difficult to peel off or detach. (Solution) The present invention relates to a laminate having a porous functional layer comprising a thermoplastic resin and a three-dimensional network structure formed by fine particles having water-repellent and / or oil-repellent properties adhering to each other on a substrate film, wherein the porous functional layer is characterized in that, in the thickness direction therein, the porosity is 1 volume% or more and 50 volume% or less in the region between the bottom surface of the porous functional layer and 50% thickness, and the porosity is 50 volume% or more and 99 volume% or less in the region between the bottom surface of the porous functional layer and beyond 50% thickness to the surface of the porous functional layer.

Description

Technology Field

[0001] The present invention relates to a laminate having water-repellent and oil-repellent properties. Background Technology

[0002] Water-repellent or oil-repellent technologies have been widely studied for anti-adhesion and release applications. In particular, for food, beverages, pharmaceuticals, and cosmetics, products are being developed that have undergone superhydrophobic treatment, which exhibits a contact angle with water of 150° or more, or superoleophobic treatment, which exhibits a contact angle with oil of 150° or more, for the purpose of reducing the adhesion of contents to packaging materials. Generally, superhydrophobicity and superoleophobicity are realized by modifying chemical properties through coating or modifying physical properties by imparting fine irregularities.

[0003] For example, Patent Document 1 discloses a method of forming a water-repellent layer with excellent durability by forming a metal thin film on a substrate surface, then depositing hydrophobic microparticles on the surface using an organosilicon compound CVD method, and exposing the metal film to an atmosphere containing the same organosilicon compound to bond the metal film and the hydrophobic microparticles or the hydrophobic microparticles to each other.

[0004] In addition, Patent Document 2 proposes a technology in which a water-repellent layer containing hydrophobic microparticles and a binder (metal alkoxide) is treated to form a highly durable water-repellent layer in which the hydrophobic microparticles do not easily lose their water-repellent properties, and a heat seal is made possible by treating the adhesive layer with the water-repellent layer.

[0005] According to Patent Documents 3 and 4, a water-repellent surface with excellent durability is formed by imparting fine irregularities to the surface of a substrate surface through a nano-imprint method (UV curing method, thermal curing method). Patent Document 3 proposes a method of forming convex fillers with a pitch of several hundred nanometers by using a UV curing method to press a mold having a concave structure with a pitch of several hundred nanometers against a UV-curing resin and curing the resin by irradiating UV. Patent Document 4 proposes a method of forming convex fillers by using a thermal curing method to press a mold having a concave structure with a pitch of several hundred nanometers against a thermoplastic resin and then cooling. Prior art literature

[0006] Patent Document 1: Japanese Patent Publication No. 2014-152389 Patent Document 2: Japanese Patent Publication No. 2017-100778 Patent Document 3: Japanese Patent Publication No. 2018-187767 Patent Document 4: Japanese Patent Publication No. 2018-95799 The problem to be solved

[0007] However, the method of Patent Document 1 has a problem in that it requires large-scale facilities and is difficult to mass-produce because a process for depositing and growing hydrophobic microparticles is required after forming a metal thin film.

[0008] In addition, in the technology of Patent Document 2, a superhydrophobic layer is formed by mixing hydrophobic microparticles with tetraethoxysilane (metal alkoxide) as a binder, but the adhesion strength between the superhydrophobic layer and the substrate is weak, so there is a risk that the superhydrophobic layer itself may peel off relatively easily.

[0009] In the methods of Patent Documents 3 and 4, a superhydrophobic layer is formed by a nanoimprint method, but the nanoimprint method has low productivity compared to surface modification by coating, so it is not suitable for production on an industrial scale.

[0010] Therefore, the main objective of the present invention is to provide a laminate that is capable of mass production and has a water-repellent and / or oil-repellent layer that is difficult to peel off or detach. means of solving the problem

[0011] The inventors, taking into account the problems of the prior art, conducted extensive research and discovered that the above objective could be achieved by adopting a specific layer structure, thereby completing the present invention.

[0012] That is, the present invention relates to the following laminate.

[0013] 1. A laminate having a porous functional layer comprising a thermoplastic resin and a three-dimensional network structure formed by fine particles having water-repellent and / or oil-repellent properties adhering to each other, formed on a substrate film,

[0014] The porous functional layer has, in the thickness direction, a porosity of 1 volume% or more and 50 volume% or less in the region between the bottom surface of the porous functional layer and 50% thickness, and a porosity of 50 volume% or more and 99 volume% or less in the region between the bottom surface of the porous functional layer and beyond 50% thickness to the surface of the porous functional layer.

[0015] A laminate characterized by the following.

[0016] 2. A laminate described in claim 1, wherein a thermoplastic resin is filled into the pores of a three-dimensional network structure in the region between the bottom surface of the porous functional layer and 50% of its thickness.

[0017] 3. A laminate described in claim 1 or 2, wherein a portion of the porous functional layer is inserted into a substrate film.

[0018] 4. A laminate described in any one of claims 1 to 3, wherein the average primary particle diameter of the above-mentioned fine particles is 5 to 50 nm.

[0019] 5. A laminate described in any one of claims 1 to 4, wherein the mass ratio of the fine particles to the thermoplastic resin is 50:50 to 80:20.

[0020] 6. The above thermoplastic resin is a laminate described in any one of claims 1 to 5, comprising a polyolefin resin.

[0021] 7. A method for manufacturing a laminate having water-repellent and / or oil-repellent properties, wherein

[0022] (1) A process of applying a coating solution containing fine particles having water-repellent and / or oil-repellent properties and a thermoplastic resin to a substrate film, and

[0023] (2) A process of heat-treating the coating film obtained above

[0024] A method for manufacturing a laminate characterized by including

[0025] 8. The manufacturing method described in claim 7 above, wherein the coating solution is a dispersion formed by dispersing water-repellent and / or oil-repellent fine particles, thermoplastic resin particles, and a solvent. Effects of the invention

[0026] According to the present invention, a laminate can be provided that is capable of mass production and has a water-repellent and / or oil-repellent layer that is difficult to peel off or detach.

[0027] In particular, the laminate of the present invention comprises a porous functional layer comprising a thermoplastic resin, wherein functional particles form a three-dimensional network structure, and the porous functional layer has a non-uniform structure (preferably a gradient structure) in which the porosity of the porous functional layer is lower closer to the substrate film and higher near the surface of the porous functional layer. By adopting such a structure, the adhesion between the substrate film and the porous functional layer is enhanced, and since both take on an integrated structure, the peeling or detachment of the porous functional layer from the substrate film can be effectively suppressed or prevented. Consequently, it can exhibit a certain level of durability even under relatively strong frictional forces. Furthermore, such a laminate can be formed using a predetermined coating solution, for example, as described below. As a result, it becomes possible to more efficiently provide a laminate capable of effectively maintaining desired water repellency and / or oil repellency. Brief explanation of the drawing

[0028] FIG. 1 is a schematic diagram (image) showing an example of the layer configuration of a laminate of the present invention. FIG. 2 is an image of the layer structure of the laminate fabricated in Example 1, observed using a scanning electron microscope. FIG. 3 is a 3D image of a porous functional layer created using FIB-SEM in the laminate of Example 1. Figure 4 shows the analysis of the porous functional layer extracted from Figure 3. Specific details for implementing the invention

[0029] 1. Laminate

[0030] The laminate of the present invention (the laminate of the present invention) is a laminate having a porous functional layer comprising a thermoplastic resin and a three-dimensional network structure formed by fine particles having water-repellent and / or oil-repellent properties adhering to each other on a substrate film.

[0031] The porous functional layer has, in the thickness direction, a porosity of 1 volume% or more and 50 volume% or less in the region between the bottom surface of the porous functional layer and 50% thickness, and a porosity of 50 volume% or more and 99 volume% or less in the region between the bottom surface of the porous functional layer and beyond 50% thickness to the surface of the porous functional layer.

[0032] It is characterized by the fact that.

[0033] FIG. 1 is a schematic diagram showing an example of the layer configuration of a laminate of the present invention. As shown in FIG. 1, a porous functional layer (12) is formed on a substrate film (11) of the laminate (10) of the present invention. This porous functional layer (12) is supported by being fixed (adhered) to the substrate film (11). The porous functional layer (12) comprises a three-dimensional network structure formed by adhering to each other fine particles (hereinafter also referred to as "functional particles" unless otherwise specified) (13) having water-repellent and / or oil-repellent properties, and a thermoplastic resin (14). In the laminate (10) of the present invention, the thermoplastic resin (14) may be contained in either the outer circumference or the interior of the three-dimensional network structure, but as shown in FIG. 1, it is preferable that it be contained in at least the pores of the three-dimensional network structure.

[0034] In the thickness (t) direction, the porous functional layer (12) has a porosity of 1 volume% or more and 50 volume% or less in the region between the bottom surface (12a) of the porous functional layer and the 50% thickness (t / 2) (hereinafter also referred to as "region (B)"), and also has a porosity of 50 volume% or more and 99 volume% or less in the region between the bottom surface (12a) of the porous functional layer and the surface (12b) of the porous functional layer beyond the 50% thickness (t / 2). That is, the porous functional layer (12) has a structure in which the density of functional particles and thermoplastic resin is high in the region (B) closer to the substrate film, and the density is low in the region (A) closer to the surface of the porous functional layer. By doing so, it is possible to increase the strength of fixing the porous functional layer to the substrate film. As a result, it is possible to maintain water repellency and oil repellency for a longer period.

[0035] In addition, in the present invention, the thickness (t) of the porous functional layer is calculated by the following formula based on the position of the bottom surface (11a) of the base film (11), with the horizontal position of the functional particle at the lowest position of the three-dimensional network structure as shown in FIG. 1 being the bottom surface (12a) of the porous functional layer and the horizontal position of the functional particle at the highest position of the three-dimensional network structure being the surface (12b) of the porous functional layer.

[0036] Thickness (t) of the porous functional layer = (distance (difference in height) from the bottom surface (11a) to the surface (12b) of the porous functional layer) - (distance (difference in height) from the bottom surface (11a) to the bottom surface (12a) of the porous functional layer)

[0037] In addition, as shown in FIG. 1, in the laminate (10) of the present invention, it is preferable that a portion of the porous functional layer (12) (in particular, a three-dimensional network structure) is inserted into the substrate film (11). By doing so, the adhesion of the porous functional layer to the substrate film can be increased.

[0038] In the following, in addition to each layer constituting the laminate of the present invention, the materials constituting each layer, etc., will be described separately.

[0039] (Substrate film)

[0040] The base film functions as a supporting layer that supports the porous functional layer in the laminate of the present invention. Therefore, as long as it has such a function, the material is not particularly limited, and examples include resins (e.g., synthetic resins such as polyester, polyethylene, and polypropylene), fibrous materials (e.g., paper, synthetic paper, nonwoven fabric, woven fabric, wood board, etc.), metals or alloys (e.g., metal foil such as aluminum foil), glass (glass board), composite materials, laminated materials, etc., in addition to solid materials.

[0041] In particular, in the present invention, at least one type of resin film, such as a polypropylene-based film, a polyethylene-based film, and a polyester-based film, can be suitably used as a base film.

[0042] In addition, especially when the substrate film is a resin film, the resin film may be either a stretched film or an unstretched film. Also, the stretched film may be either a uniaxially stretched film or a biaxially stretched film. Furthermore, as for the resin film, various types of resin films that have undergone surface treatment, such as corona treatment, may also be used as the substrate film.

[0043] The thickness of the base film is not limited, but can be appropriately set according to the material of the base film, the use of the laminate of the present invention, etc. Generally, it can be appropriately set within a range of about 20 to 80 μm, but is not limited thereto.

[0044] The substrate film may have a surface treatment applied to its surface (especially the surface on which the porous functional layer is laminated). By doing so, the adhesion (adhesion) between the substrate film and the porous functional layer can be further enhanced. Examples of such surface treatments include surface treatment using additives (preferably filler particles) or surface treatment using embossing. Although the height of the surface is not limited, it is particularly desirable to have it of about 5 to 60 μm, and among them, it is more desirable to have it of 20 to 50 μm.

[0045] In addition, the base film may be either a single layer or a multilayer. For example, a laminated film formed by laminating a heat seal layer on at least one surface of a resin film may be used as the base film.

[0046] In this case, as a heat seal for forming a heat seal layer, in addition to the components of a known or commercially available sealant film, a component used in known or commercially available adhesives such as a lacquer-type adhesive, an easy-peel adhesive, or a hot-melt adhesive may be employed.

[0047] The main components constituting the heat seal layer are not particularly limited, and include, for example, low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear (linear) low-density polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ionomer resin, ethylene-acrylic acid copolymer, vinyl chloride-vinyl acetate-acrylic acid ester copolymer, ethylene-ethyl acrylate copolymer, ethylene-methacrylic acid copolymer, ethylene-methyl methacrylate copolymer, ethylene-propylene copolymer, methylpentene polymer, polybutene polymer, acid-modified polyolefin resin obtained by modifying polyolefin resins such as polyethylene or polypropylene with unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, and itaconic acid, polyvinyl acetate resin, poly(meth)acrylic resin, and polyacrylonitrile resin. In addition to polyvinyl chloride resins and other heat-sealable resins, blend resins thereof, copolymers comprising combinations of monomers constituting them, modified resins, etc., may be used.

[0048] In addition, other components may be included in the substrate film within a range that does not impede the effects of the present invention. Examples include tackifiers, anti-blocking agents, coloring agents, thickeners, etc. In particular, an anti-blocking agent may be suitably used in the present invention. As for the anti-blocking agent, there are no particular limitations, and at least one type such as polyethylene wax, polypropylene wax, silica, inorganic particles, or synthetic resin particles may be suitably added.

[0049] (Porous functional layer)

[0050] The porous functional layer in the laminate of the present invention is a layer having water-repellent and / or oil-repellent properties. The porous functional layer comprises a three-dimensional network structure formed by functional particles adhering to each other and a thermoplastic resin.

[0051] Functional particles (group of particles) form a three-dimensional network structure by fixing individual functional microparticles in contact with each other. In particular, the three-dimensional network structure is porous (aggregated) and has pores formed between the functional particles. These pores may be isolated pores, continuous pores, or a combination of isolated and continuous pores.

[0052] The present invention is characterized by the fact that, when comparing region (A) and region (B), the porosity of the porous functional layer is relatively higher in region (A). That is, the functional particles and thermoplastic resin are more densely concentrated on the substrate film side of the functional layer. Due to this pore distribution (density distribution), the adhesion of the porous functional layer to the substrate film is further enhanced in conjunction with the presence of the thermoplastic resin, and furthermore, the high porosity of the surface of the functional layer (presence of surface irregularities and air layers) can contribute to the long-term maintenance of high water repellency and / or oil repellency.

[0053] The amount of the porous functional layer can be appropriately set according to the type of thermoplastic resin used, such as the desired water repellency and / or oil repellency, and it is desirable to set it within the range of the amount of functional particles shown below. For example, it can be within the range of about 0.6 to 5 g / m² (especially 1 to 3 g / m²), but is not limited thereto.

[0054] In addition, regarding the degree of water repellency and / or oil repellency of the porous functional layer, it is desirable to have the following physical properties, although they are not limited. Regarding water repellency, it is desirable that the contact angle with water be 150° or more (so-called superhydrophobic). In addition, regarding oil repellency, it is desirable that the contact angle with oil be 150° or more (so-called superoil-repellent).

[0055] The thickness of the porous functional layer is not particularly limited, but is usually within the range of about 1 to 20 μm, and is particularly desirable to be 1 to 5 μm. By keeping it within this range, even higher water repellency or oil repellency can be obtained.

[0056] The functional particles constituting the porous functional layer are not particularly limited as long as they have water-repellent and / or oil-repellent properties. For example, hydrophobic oxide microparticles, etc., can be suitably used.

[0057] As hydrophobic oxide fine particles, at least one type of particle (powder) such as silicon oxide, titanium oxide, aluminum oxide, or zinc oxide can be used. Among these, it is preferable that the particles be silicon oxide.

[0058] The hydrophobic oxide microparticles preferably have an average primary particle diameter of 5 to 50 nm, and particularly preferably 7 to 30 nm. In addition, the measurement of the above average primary particle diameter can be performed using a transmission electron microscope or a scanning electron microscope. More specifically, the average primary particle diameter can be obtained by taking a photograph with a transmission electron microscope or a scanning electron microscope, measuring the diameters of 200 or more particles in the photograph, and calculating the arithmetic mean value.

[0059] Nano-level oxide microparticles as described above may be used if they are known or commercially available. For example, as silica, examples include the product names "AEROSIL R972," "AEROSIL R972V," "AEROSIL R972CF," "AEROSIL R974," "AEROSIL RX200," and "AEROSIL RY200" (all products of NIPPON AEROSIL CO., LTD.), "AEROSIL R202," "AEROSIL R805," "AEROSIL R812," and "AEROSIL R812S" (all products of Evonik Degussa), and "SYLOPHOBIC 100," "SYLOPHOBIC 200," and "SYLOPHOBIC 603" (all products of FUJI SILYSIA CHEMICAL LTD.). Examples of titania include the product name "AEROXIDE TiO2T805" (product of Evonik Degussa). Examples of alumina include fine particles with a hydrophobic surface made by treating the product name "AEROXIDE Alu C" (product of Evonik Degussa) with a silane coupling agent.

[0060] Among these, hydrophobic silica microparticles can be suitably used. In particular, hydrophobic silica microparticles having trimethylsilyl groups on their surface are preferred in that they can obtain even better non-adhesion. Examples of commercially available products corresponding to this include the above-mentioned "AEROSIL R812" and "AEROSIL R812S" (both products of Evonik Degussa).

[0061] As for particles having oil-repellent properties, for example, composite particles in which a surface treatment is performed to impart oil-repellent properties to the oxide fine particles serving as the core can be suitably used.

[0062] The oxide fine particles serving as the core may use at least one type of particle (powder) such as silicon oxide, titanium oxide, aluminum oxide, or zinc oxide. Among these, it is preferable that the particles be silicon oxide.

[0063] In addition, commercially available oxide fine particles may be used as the core. Examples of silicon oxide include the product name "AEROSIL 200" ("AEROSIL" is a registered trademark; hereinafter the same), "AEROSIL 130", "AEROSIL 300", "AEROSIL 50", "AEROSIL 200FAD", and "AEROSIL 380" (all products of Nippon Aerosil Co., Ltd.). Examples of titanium oxide include the product name "AEROXIDE TiO2T805" (product of Evonik Degussa). Examples of aluminum oxide include the product name "AEROXIDE Alu C 805" (product of Evonik Degussa).

[0064] The method for preparing the above composite particles is not particularly limited, and for example, a polyfluoroalkyl methacrylate resin may be used as a coating material for metal oxide particles (powder) to form a coating layer according to known coating methods, assembly methods, etc. More specifically, the composite particles can be suitably prepared by a manufacturing method comprising a process (coating process) of coating oxide particles with a coating solution in which a liquid polyfluoroalkyl methacrylate resin is dissolved or dispersed in a solvent.

[0065] In the above manufacturing method, a polyfluoroalkyl methacrylate resin that is in a liquid state at room temperature (25°C) and under atmospheric pressure can be suitably used. As the polyfluoroalkyl methacrylate resin, for example, a copolymer of polyfluorooctyl methacrylate, 2-N,N-diethylaminoethyl methacrylate, 2-hydroxyethyl methacrylate, and 2,2'-ethylenedioxydiethyldimethacrylate can be suitably used. As such a polyfluoroalkyl methacrylate resin, commercially available products may also be used.

[0066] The solvent used in the coating solution is not particularly limited, and organic solvents such as alcohol and toluene may be used in addition to water, but in the present invention, it is preferable to use water. That is, it is preferable to use a coating solution in which a polyfluoroalkyl methacrylate resin is dissolved and / or dispersed in water.

[0067] The content of polyfluoroalkyl methacrylate resin in the above coating solution is not particularly limited, but generally it is about 10 to 80 weight%, particularly 15 to 70 weight%, and among them, it is more preferable to set it within the range of 20 to 60 weight%.

[0068] The method of coating the coating solution onto the surface of oxide particles may follow known methods, and any of the following may be applied:, for example, the spray method, the immersion method, or the stirring method. In particular, in the present invention, coating by the spray method is particularly preferred due to its excellent uniformity.

[0069] After coating with a coating solution, composite particles can be obtained by removing the solvent through heat treatment. The heat treatment temperature is typically around 150 to 250°C, and is particularly preferably 180 to 200°C. Although the atmosphere for heat treatment is not limited, an inert gas (non-oxidizing) atmosphere, such as nitrogen gas or argon gas, is preferred. Additionally, for example, if necessary, a series of processes consisting of a coating process and a heat treatment process can be performed one or more times. By doing so, it becomes possible to appropriately control the coating amount.

[0070] The surface of the composite particle obtained in this way contains a polyfluoroalkyl methacrylate resin. By including this resin, a strong coating layer with relatively high adhesion can be formed on the particle surface because of its excellent affinity with oxide particles, and furthermore, higher water repellency or oil repellency can be expressed.

[0071] The amount of functional particles attached (weight after drying) should be sufficient to form a three-dimensional network structure, but it is generally preferable to have it in an amount of 0.01 to 10 g / m², more preferably 0.2 to 1.5 g / m², and most preferably 0.2 to 1 g / m².

[0072] (Thermoplastic resin)

[0073] In the laminate of the present invention, the thermoplastic resin included in the porous functional layer primarily performs the function of strengthening the adhesion between the porous functional layer and the substrate film, as well as the adhesion between the functional particles within the porous functional layer.

[0074] The type of thermoplastic resin is not particularly limited as long as it exhibits adhesion to the substrate film. For example, various resins such as polyolefin resins, polyamide resins, polyester resins, urethane resins, and acrylic resins may be used.

[0075] In particular, for example, when the base film is a polypropylene film, a polyolefin resin (particularly a polypropylene-based resin or a modified polypropylene-based resin) may be suitably employed as the thermoplastic resin. Additionally, for example, when the base film is a polyethylene terephthalate (PET) film, acrylic resins, polyester resins, etc., may be suitably used as the thermoplastic resin. In this way, by selecting a thermoplastic resin that adheres more closely to the base film used, it becomes possible to further enhance the adhesion between the porous functional layer and the base film.

[0076] The softening point of the thermoplastic resin used is not particularly limited, but it is usually good to set it to about 60 to 150°C.

[0077] The content of the thermoplastic resin is not particularly limited, but if the total of the functional particles and the thermoplastic resin is 100 mass%, it is preferable to have a ratio of functional particles:thermoplastic resin = 50 mass%:50 mass% to 80 mass%:20 mass%. By doing so, the adhesion between the substrate film and the porous functional layer can be further increased, and at the same time, it is possible to obtain even better water repellency or oil repellency.

[0078] 2. Method for manufacturing a laminate

[0079] The laminate of the present invention can be suitably manufactured, for example, by the following method. That is, as a method for manufacturing a laminate having water-repellent and / or oil-repellent properties, a manufacturing method comprising (1) a process of applying a coating solution containing fine particles having water-repellent and / or oil-repellent properties and a thermoplastic resin to a substrate film (coating film formation process), and (2) a process of heat-treating the coating film obtained above (heat treatment process) can be suitably employed.

[0080] Coating film formation process

[0081] In the coating film formation process, a coating solution containing fine particles having water-repellent and / or oil-repellent properties and a thermoplastic resin is applied to a substrate film.

[0082] The coating solution typically comprises functional particles, a thermoplastic resin, and a solvent. The types of functional particles and thermoplastic resin, and the ratio of the two, are as described above. Furthermore, the solvent is not limited and can be appropriately selected depending on the type of thermoplastic resin used. For example, it can be appropriately selected from organic solvents such as alcohol-based solvents (ethanol, methanol, isopropyl alcohol (IPA), hexyl alcohol, etc.), ketone-based solvents (acetone, ketone, methyl ethyl ketone (MEK), etc.), hydrocarbon-based solvents (cyclohexane, normal pentane, normal hexane, methylcyclohexane (MCH), etc.), aromatic-based solvents (toluene, etc.), and glycol-based solvents (propylene glycol, hexylene glycol, butyl diglycol, pentamethylene glycol, etc.).

[0083] Regarding the coating solution, a thermoplastic resin or the like may be dissolved in a solvent to form a solution, but it is particularly preferable that it be in the form of a dispersion in which functional particles and thermoplastic resin particles are dispersed in a solvent. Accordingly, when the coating solution is applied to a substrate film, the functional particles and thermoplastic resin particles are applied homogeneously, so the adhesion between the functional particles and the porous functional layer and the substrate film can be increased while maintaining the characteristics of the functional particles. Furthermore, when this dispersion solution is applied to the substrate film, most of the functional particles and thermoplastic resin particles move downward (in the direction of gravity), so the porosity of the porous functional layer decreases in the region (B) close to the substrate film of the porous functional layer, and increases in the region (A). In this way, a porous functional layer having a sloped structure can be effectively formed.

[0084] The application method is not particularly limited, and known methods such as roll coating, various gravure coatings, bar coaters, doctor blade coatings, comma coaters, spray coatings, and brush coatings can be appropriately employed.

[0085] After application, a drying process may be performed as needed. The drying method is not particularly limited and may be either natural drying or heat drying. In the case of heat drying, the temperature is usually set to about 60 to 100°C, and it is particularly preferable to set it to 80 to 90°C. The heating time may be set appropriately according to the heating temperature, etc., and can usually be set to about 3 to 30 seconds, but is not limited thereto.

[0086] Heat treatment process

[0087] In the heat treatment process, the coating film obtained from the above coating film formation process is heat-treated. Through heat treatment, the functional particles and the thermoplastic resin are bonded within the porous functional layer, and the thermoplastic resin is bonded with the base film, thereby obtaining a laminate with excellent adhesion between the base film and the porous functional layer. Furthermore, since it is possible to insert a portion of the functional particles and / or the thermoplastic resin into the base film during the heat treatment process, higher adhesion can be obtained, allowing the base film and the porous functional layer to be formed into an integrated structure more effectively.

[0088] It is desirable to set the heat treatment temperature to a temperature lower than the heat resistance temperature of the base film and also to a temperature range higher than the temperature at which the thermoplastic resin included in the porous functional layer softens. Accordingly, for example, if the heat resistance temperature of the base film is 150°C and the softening temperature of the thermoplastic resin is 120°C, the heat treatment temperature can be set to approximately 120 to 145°C (also, for example, approximately 125 to 140°C).

[0089] In addition, regarding the heat treatment time, it should be sufficient to obtain the desired adhesion, for example, 10 seconds to 10 minutes, but is not limited to this.

[0090] 3. Use of laminates

[0091] The laminate of the present invention can be used for various applications requiring, for example, anti-adhesion performance, antifouling properties, water repellency, and / or oil repellency. For example, it can be suitably used as a packaging material for packaging or sealing food, pharmaceuticals, cosmetics, etc. For example, a sealed packaged product can be provided by loading various contents into a packaging pouch formed using the laminate of the present invention, with the porous functional layer positioned on the inside.

[0092] (Example)

[0093] The features of the present invention will be explained in more detail below by presenting examples and comparative examples. However, the scope of the present invention is not limited to the examples.

[0094] Example 1

[0095] As a base film, a commercially available film with a thickness of 40 μm (biaxially stretched polypropylene film (OPP)) was used.

[0096] A coating solution was prepared to form a porous functional layer. After adding hydrophobic oxide microparticles with water-repellent properties (product name "AEROSIL R812S," manufactured by Evonik Degussa, BET specific surface area: 200 m² / g, average primary particle diameter 7 nm) and a thermoplastic resin (modified polyolefin resin, product name "ZAIKTHENE A," manufactured by Sumitomo Seika Chemicals Company, Limited.) to ethanol, the mixture was stirred using a stirrer at 2000 rpm × 5 minutes. In this way, a coating solution was obtained. The mass ratio of the hydrophobic oxide microparticles to the thermoplastic resin in the coating solution was set to 50:50, and the total solid content of the hydrophobic oxide microparticles and the thermoplastic resin in the coating solution was set to 5 mass%.

[0097] The obtained coating solution was applied to the above film using a bar coater, and a porous functional layer was formed by drying under conditions of 120°C × 60 seconds. The coating amount of the porous functional layer after drying was set to 2.5 g / m². In this way, a laminate with a porous functional layer formed on the surface of a substrate film was produced.

[0098] Example 2

[0099] A laminate was fabricated by the same method as in Example 1, except that surface-modified silica microparticles obtained according to the following procedure were used instead of hydrophobic oxide microparticles.

[0100] 5g of hydrophilic silica particles (product name "AEROSIL 200", manufactured by Nippon Aerosil Co., Ltd., BET specific surface area: 200 m² / g, average primary particle diameter 12 nm) were placed in a reaction vessel, and 500g of a commercially available surface treatment agent was sprayed while stirring under a nitrogen gas atmosphere, and then the mixture was stirred at 200°C for 30 minutes and then cooled. By this, a powder of surface-modified silica fine particles (oxide composite fine particles) was obtained. In addition, as the above surface treatment agent, an aqueous dispersion (solid content concentration: 20 mass%) of a copolymer of polyfluorooctyl methacrylate, 2-N,N-diethylaminoethyl methacrylate, 2-hydroxyethyl methacrylate, and 2,2'-ethylenedioxydiethyldimethacrylate was used.

[0101] Example 3

[0102] A laminate was produced by the same method as in Example 1, except that a vinyl acetate copolymer resin (product name "SEPOLSION VA", manufactured by Sumitomo Seika Co., Ltd.) (polyolefin A) was used instead of a modified polyolefin resin as the thermoplastic resin.

[0103] Example 4

[0104] A laminate was produced by the same method as in Example 2, except that a vinyl acetate copolymer resin (product name "Sepolzone VA", manufactured by Sumitomo Seika Co., Ltd.) (polyolefin A) was used instead of a modified polyolefin resin as the thermoplastic resin.

[0105] Example 5

[0106] As the base film, a commercially available film with a thickness of 25 μm (biaxially stretched polyethylene terephthalate film (PET)) was used. In addition, instead of the modified polyolefin resin, a copolymer polyester resin (product name "Sepolzone ES", manufactured by Sumitomo Seika Co., Ltd.) (polyester) was used. Except for this, the laminate was manufactured by the same method as in Example 1.

[0107] Example 6

[0108] A laminate was prepared by the same method as in Example 5, except that surface-modified silica microparticles described in Example 2 were used instead of hydrophobic oxide microparticles.

[0109] Example 7

[0110] As the base film, a commercially available film (low-density polyethylene film (LDPE)) with a thickness of 30 μm was used. In addition, instead of the modified polyolefin resin, a polyolefin resin (product name "Sepolzone G", manufactured by Sumitomo Seika Co., Ltd.) (polyolefin B) was used. Except for this, the laminate was manufactured by the same method as in Example 1.

[0111] Example 8

[0112] A laminate was prepared by the same method as in Example 7, except that surface-modified silica microparticles described in Example 2 were used instead of hydrophobic oxide microparticles.

[0113] Example 9

[0114] As a base film, a commercially available film with a thickness of 40 μm (biaxially stretched polypropylene film (OPP)) was used.

[0115] A dispersion was prepared by mixing 10 parts by weight of high-density polyethylene particles (HDPE, average particle size (D50): 12㎛, melting point: 136℃, density: 0.94g / cm³) with 100 parts by weight of a commercially available polyolefin resin coating agent (heat seal coating agent). The obtained dispersion was applied to the corona-treated surface of the film using a bar coater and dried under conditions of 80℃ × 10 seconds to form a heat seal layer containing filler particles and heat seals. The adhesion amount of the heat seal layer after drying was set to 3.0g / m².

[0116] Next, a coating solution was prepared to form a porous functional layer. After adding hydrophobic oxide microparticles with water-repellent properties (product name "AEROSIL R812S", manufactured by Evonik Degussa, BET specific surface area: 200 m² / g, average primary particle diameter 7 nm) and a thermoplastic resin (modified polyolefin resin, product name "Zyxen A", manufactured by Sumitomo Seika Corp.) to ethanol, the mixture was stirred using a stirrer at 2000 rpm × 5 minutes. In this way, a coating solution was obtained. The mass ratio of the hydrophobic oxide microparticles to the thermoplastic resin in the coating solution was set to 50:50, and the total solid content of the hydrophobic oxide microparticles and the thermoplastic resin in the coating solution was set to 5 mass%.

[0117] After applying the obtained coating solution onto the heat seal layer using a bar coater, a porous functional layer was formed by drying under conditions of 120°C × 60 seconds. The coating amount of the porous functional layer after drying was set to 2.5 g / m².

[0118] Example 10

[0119] A laminate was prepared by the same method as in Example 9, except that surface-modified silica microparticles described in Example 2 were used instead of hydrophobic oxide microparticles.

[0120] Comparative Example 1

[0121] A laminate was prepared by the same method as in Example 1, except that the mass ratio of hydrophobic oxide microparticles and modified polyolefin resin in the coating solution was set to 90:10.

[0122] Comparative Example 2

[0123] A laminate was prepared by the same method as in Example 2, except that the mass ratio of surface-modified silica microparticles and modified polyolefin resin in the coating solution was 90:10.

[0124] Comparative Example 3

[0125] A laminate was prepared by the same method as in Example 1, except that the mass ratio of hydrophobic oxide microparticles and modified polyolefin resin in the coating solution was 40:60.

[0126] Comparative Example 4

[0127] A laminate was prepared by the same method as in Example 2, except that the mass ratio of surface-modified silica microparticles and modified polyolefin resin in the coating solution was 40:60.

[0128] Comparative Example 5

[0129] A laminate was manufactured by the same method as in Example 1, except that the amount of coating solution applied after drying was 10.0 g / m².

[0130] Comparative Example 6

[0131] A laminate was manufactured by the same method as in Example 2, except that the amount of coating solution applied after drying was 10.0 g / m².

[0132] Comparative Example 7

[0133] A laminate was manufactured by the same method as in Example 1, except that the amount of coating solution applied after drying was 0.3 g / m².

[0134] Comparative Example 8

[0135] A laminate was produced by the same method as in Example 2, except that the amount of coating solution applied after drying was 0.3 g / m².

[0136] Comparative Example 9

[0137] A laminate was prepared by the same method as in Example 1, except that a polyester resin was used instead of a modified polyolefin resin.

[0138] Comparative Example 10

[0139] A laminate was prepared by the same method as in Example 2, except that a polyester resin was used instead of a modified polyolefin resin.

[0140] Comparative Example 11

[0141] A laminate was prepared by the same method as in Example 1, except that a vinyl chloride-vinyl acetate copolymer resin was used instead of a modified polyolefin resin.

[0142] Comparative Example 12

[0143] A laminate was prepared by the same method as in Example 2, except that a vinyl chloride-vinyl acetate copolymer resin was used instead of a modified polyolefin resin.

[0144] Comparative Example 13

[0145] A laminate was prepared by the same method as in Example 1, except that a copolymerized amide resin was used instead of a modified polyolefin resin.

[0146] Comparative Example 14

[0147] A laminate was prepared by the same method as in Example 2, except that a copolymerized amide resin was used instead of a modified polyolefin resin.

[0148] Comparative Example 15

[0149] As a base film, a commercially available film with a thickness of 40 μm (biaxially stretched polypropylene film (OPP)) was used.

[0150] A dispersion was prepared by adding oil-repellent metal oxide composite particles (product name "AEROSIL 200", manufactured by Nippon Aerosil Co., Ltd., BET specific surface area: 200 m² / g, average primary particle diameter 12 nm) to ethanol. The solid content in the dispersion was set to 5 mass%.

[0151] The above dispersion was applied onto the above film using a bar coater, and an oil-repellent layer was formed by drying under conditions of 120°C × 60 seconds. The amount of coating applied after drying the oil-repellent layer was set to 2.5 g / m².

[0152] Test Example 1 (Cross-sectional observation and measurement of occupancy rate)

[0153] (1) Cross-sectional observation

[0154] For the obtained laminate, a smooth cross-section was prepared at any location in the planar view by irradiating an Ar ion beam using an ion milling device, and the formation of a porous functional layer containing a three-dimensional network structure was confirmed by observing the treated sample with a scanning electron microscope (SEM). As a representative example, the cross-sectional view of the laminate of Example 1 is shown in FIG. 2.

[0155] (2) Measurement of market share

[0156] For the laminate, a porous functional layer at any location when viewed from a planar view was observed using a FIB-SEM (Hitachi High-Technologies Corporation product, “NX5000”) under conditions of electron emission current of 21,900 nA, working distance of 4.0 mm, and magnification of 15,000 times, and observed at 50 nm pitches in the thickness direction to create a total of 100 observation images. The observation images were read using commercially available image analysis software (“Image Pro+3D Module” (product of Media Cybernetics, USA), threshold conditions: smart analysis dark color, automatic) to create a 3D image of size 5 μm × 5 μm × 7 μm, and then the occupancy rate of functional particles in region (A) and region (B) was analyzed. More specifically, a 3D image was sliced ​​every 400 nm in the thickness direction from the surface of the porous functional layer, and the ratio of the area of ​​the pore portion to the total area of ​​the sliced ​​image was defined as the porosity. The above area ratio was calculated using the image analysis software from the color tone (shade) of each sliced ​​image. The sliced ​​images were created by slicing up to regions where the porosity is 0% and 100%. As an example, a 3D image of the porous functional layer created using FIB-SEM for the laminate of Example 1 is shown in FIG. 3. In addition, FIG. 4 shows an analysis image of a location where only the porous functional layer exists in the above 3D image.

[0157] Test Example 2 (Water-repellent and oil-repellent properties)

[0158] Water and olive oil were used to evaluate water and oil repellency. The water and oil-repellent surface of each sample was used as the test surface, and water or olive oil was applied dropwise to check the condition of the droplets. Specifically, the sample was placed on an inclined surface at a 10° angle with the test surface facing upward, and 1 mL of water or olive oil was applied dropwise. It was marked as “○” if the droplet slid off, “△” if it slid off but a small amount remained, and “×” if it did not slid off. The results are shown in Tables 1 and 2. Pure water was used. For the olive oil, the commercially available “AJINOMOTO Olive Oil” (edible olive oil) (a product of Ajinomoto Co., Inc.) was used.

[0159] Test Example 3 (Wear Resistance)

[0160] For the durability evaluation, a Gakushin-Type friction fastness tester (YASUDA SEIKI SEISAKUSHO, LTD.) was used. Each sample was cut to a size of 15 mm × 150 mm, and a stainless steel surface was brought into contact with the sample. A durability test was conducted under the conditions of a load of 4.9 N, a friction distance of 100 mm, and a speed of 30 reciprocating cycles / min. It was determined as “○” if water and oil repellency were maintained after 100 reciprocating cycles, “△” if the water and oil repellency effect was lost between 50 and 100 reciprocating cycles, and “×” if the water and oil repellency effect was lost in less than 50 reciprocating cycles. The results of the durability are shown in Tables 1 and 2.

[0161]

[0162]

[0163] As clearly shown in the results of Tables 1 and 2, in Examples 1 to 10, when the porosity of the outermost surface side of the porous functional layer (region (A)) is 50% or more and 99% or less, and the porosity of the substrate film side (region (B)) is 1% or more and 50% or less, it can be seen that a superhydrophobic layer and a superoil-repellent layer with excellent durability can be obtained because the porous functional layer is strongly adhered to the substrate film and the outermost surface side retains pores.

[0164] In contrast, Comparative Examples 1 to 4 show that sufficient performance cannot be obtained when the mixing ratio of functional microparticles and thermoplastic resin is changed. Specifically, it can be seen that increasing the proportion of functional microparticles worsens the adhesion between the substrate film and the porous functional layer, and increasing the proportion of thermoplastic resin does not allow for the performance of the porous functional layer to be achieved.

[0165] In Comparative Examples 5 to 8, it can be seen that when the amount of the mixed solution applied after drying was changed, the adhesion strength between the porous functional layer and the substrate film was sufficient, but the water and oil repellency performance could not be achieved. It can be seen that if the amount of application is excessively large, a uniform film cannot be formed during the drying process, and the pores are small. Furthermore, it can be seen that if the amount of application is excessively small, the performance of the functional agent itself is not exhibited.

[0166] In Comparative Examples 7 to 11, it can be seen that when a thermoplastic resin with poor adhesion to the substrate film (OPP) is selected, the performance as a porous functional layer is exhibited, but the adhesion to the substrate film is low.

Claims

Claim 1 A laminate comprising a porous functional layer including a thermoplastic resin and a three-dimensional network structure formed by fine particles having water-repellent and / or oil-repellent properties adhering to each other, wherein, in the thickness direction, the porous functional layer has a porosity of 1 volume% or more and 50 volume% or less in the region between the bottom surface of the porous functional layer and 50% thickness, and a porosity of 50 volume% or more and 99 volume% or less in the region between the bottom surface of the porous functional layer and beyond 50% thickness to the surface of the porous functional layer. is, (1) The above-described film is at least one type of resin film, such as a polypropylene-based film, a polyethylene-based film, and a polyester-based film, and (2) The above-mentioned microparticles are at least one type of a) hydrophobic oxide microparticles and b) composite particles in which a surface treatment is performed to impart oleophobicity to the core oxide microparticles, and (3) The amount of the above fine particles attached is 0.01 to 10 g / m², and (4) The above thermoplastic resin is a polyolefin resin, a polyamide resin, a polyester resin, a urethane resin, or an acrylic resin, and (5) The content of the thermoplastic resin is such that when the total of the fine particles and the thermoplastic resin is 100 mass%, the fine particles:thermoplastic resin = 50 mass%:50 mass% to 80 mass%:20 mass%. A laminate characterized by the following. Claim 2 A laminate according to claim 1, wherein a thermoplastic resin is filled in the pores of a three-dimensional network structure in the region between the bottom surface of the porous functional layer and 50% thickness. Claim 3 A laminate according to claim 1 or 2, wherein a portion of the porous functional layer is inserted into a substrate film. Claim 4 Paragraph 1 or Paragraph 2 In the above, a laminate having an average primary particle diameter of the fine particles of 5 to 50 nm. Claim 5 Paragraph 1 or Paragraph 2 A laminate in which the mass ratio of the fine particles to the thermoplastic resin is 50:50 to 80:

20. Claim 6 Paragraph 1 or Paragraph 2 In this case, the thermoplastic resin is a laminate comprising a polyolefin resin. Claim 7 As stated in paragraph 1 A method for manufacturing a laminate, comprising: (1) a process of applying a coating solution containing fine particles having water-repellent and / or oil-repellent properties and a thermoplastic resin to a substrate film; and (2) a process of heat-treating the coating film obtained above. Claim 8 In paragraph 7, the coating solution comprises fine particles having water-repellent and / or oil-repellent properties and thermoplastic resin particles go A manufacturing method comprising a dispersion formed by dispersion in a solvent.

Images