Barrier Film

Abstract

To provide a barrier film in which an aluminum vapor-deposited film and a barrier coat layer are sufficiently adhered, and which can maintain the close contact state for a long term.SOLUTION: A barrier film 10 comprises: a film base material layer 11; a vapor-deposited layer 12 comprising aluminum formed on the film base material layer 11; and a barrier coat layer 13 formed on the vapor-deposited layer 12 and containing a water-soluble polymer, and metal alkoxide or its hydrolysate. In the vapor-deposited layer 12, a peak area value of aluminum (Al-O) bonded with oxygen in XPS analysis of a surface at a barrier coat layer 13 side is two times or less of a peak area value of non-oxidized aluminum (Al).SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a barrier film, and more particularly to a barrier film suitable for a laminate for a vacuum insulation material. This application claims priority to Japanese Patent Application No. 2018-231560, filed on December 11, 2018, the contents of which are incorporated by reference. [Background technology]

[0002] 2. Description of the Related Art In recent years, efforts to reduce greenhouse gas emissions have been promoted to prevent global warming, and there is a demand for energy-saving electrical appliances, vehicles, equipment, buildings, and the like. In particular, from the viewpoint of reducing power consumption, vacuum insulation materials are being increasingly adopted for various items used in electrical appliances, vehicles, buildings, etc. By providing these items with vacuum insulation materials, it is possible to improve the insulation performance of the item as a whole, and energy reduction effects are expected.

[0003] Vacuum insulation material is an insulation material that has improved insulating performance by wrapping a core material in a laminate, creating a vacuum around the core material, and reducing the thermal conductivity of the gas to as close to zero as possible.

[0004] Vacuum insulation materials are generally formed by thermally welding the edges of two opposing exterior materials (hereinafter also referred to as a "pair of exterior materials") to form a bag, placing a core material such as a foamed resin or fibrous material inside it, evacuating the air to create a vacuum inside, and sealing the opening of the bag to seal it. Since the inside of the vacuum insulation material is in a high vacuum state, heat transfer due to air convection inside is blocked, allowing the material to exhibit high insulating performance.

[0005] In order to maintain the heat insulating performance of the vacuum insulation material for a long period of time, it is necessary to maintain the internal vacuum state. Therefore, the packaging material used for the vacuum insulation material is required to have various functions such as gas barrier properties to prevent gas from passing through from the outside and thermal adhesive properties to cover and seal the core material, and a laminate having multiple functional layers that have these functions is usually used as the packaging material.

[0006] For example, Patent Documents 1 to 3 disclose packaging materials in which a heat-sealing layer, a single-layer or multi-layer gas barrier layer, and a single-layer or multi-layer protective layer are laminated in this order from the core side of a vacuum insulation material. Furthermore, these functional layers constituting the packaging material are usually laminated via an interlayer adhesive layer. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2010-255938 [Patent Document 2] Japanese Patent Publication No. 2011-89740 [Patent Document 3] Japanese Patent Application Publication No. 2006-194297 Summary of the Invention [Problem to be solved by the invention]

[0008] Vacuum insulation materials are sometimes used for long periods of time in high-temperature environments of around 100°C. If the exterior material has low heat resistance, the vacuum state inside the vacuum insulation material cannot be maintained due to the deterioration of the exterior material. As a result, the problem of not being able to maintain the insulation performance for a long period of time arises.

[0009] In order to improve the heat insulation performance, aluminum vapor deposition films are often used in the above-mentioned exterior materials. In this case, a barrier coat layer may be formed on the aluminum vapor deposition film to further improve the barrier properties of the aluminum vapor deposition film. However, there are cases where the aluminum vapor deposition film and the barrier coat layer do not adhere sufficiently, or the laminate strength decreases over time, causing delamination in the laminate. The inventors have discovered the cause of this, the details of which will be described later.

[0010] An object of the present invention is to provide a barrier film in which an aluminum vapor deposition film and a barrier coat layer are sufficiently adhered to each other and the adhered state can be maintained for a long period of time. [Means for solving the problem]

[0011] The present invention is a barrier film comprising a film substrate layer, an aluminum vapor deposition layer formed on the film substrate layer, and a barrier coat layer formed on the aluminum vapor deposition layer and containing a water-soluble polymer and a metal alkoxide or a hydrolysate thereof. In an XPS analysis of the aluminum vapor deposition layer on the barrier coat layer side, the peak area value of aluminum bonded to oxygen (Al-O) is less than twice the peak area value of unoxidized aluminum (Al). Effect of the Invention

[0012] In the barrier film of the present invention, the aluminum vapor deposition layer and the barrier coat layer are sufficiently adhered to each other, and the adhered state can be maintained for a long period of time. [Brief description of the drawings]

[0013] [Figure 1] 1 is a schematic cross-sectional view of a vacuum insulation material according to one embodiment of the present invention. [Diagram 2] 1 is a partial cross-sectional schematic diagram of a vacuum insulation material laminate according to one embodiment of the present invention. [Diagram 3] FIG. 1 is a partial cross-sectional schematic diagram of a barrier film according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, the embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to these examples.

[0015] FIG. 1 is a schematic cross-sectional view illustrating a vacuum insulation material according to one embodiment of the present invention. The core material (3) is covered and enclosed with the vacuum insulation laminate (2), and the whole constitutes the vacuum insulation material (1). At this time, the inside is degassed and in a vacuum state. The vacuum insulation laminate (2) is formed into a bag shape by stacking two sheets with the heat-sealing layers facing each other and heat-sealing them.

[0016] FIG. 3 is a schematic cross-sectional view illustrating one embodiment of a barrier film that constitutes a part of the vacuum insulation material laminate (2). The barrier film (10) forms a gas barrier layer, and is configured by laminating a deposition layer (12) on a film base layer (11), and further laminating a barrier coat layer (13) on top of that to maintain the protective barrier function.

[0017] 2 is a partial cross-sectional schematic diagram of a laminate for vacuum insulation material (2). In this embodiment, a polyamide film is used as a substrate (4) of the laminate for vacuum insulation material (2). The substrate (4) becomes the outermost layer of the vacuum insulation material (1).

[0018] A gas barrier layer (9) is laminated on the substrate (4). In this embodiment, two films are used as the gas barrier layer (9): a barrier-coated aluminum-deposited polyethylene terephthalate (hereinafter referred to as "barrier VM-PET") film (5) and an aluminum-deposited ethylene-vinyl alcohol copolymer (hereinafter referred to as "VM-EVOH") film (6). The barrier VM-PET film (5) is bonded to the substrate (4) by a dry laminate layer (8). The VM-EVOH film (6) is bonded to the barrier VM-PET film (5) by a dry laminate layer (8).

[0019] A heat-sealing layer (7) is formed on the VM-EVOH film (6). The heat-sealing layer (7) is bonded to the VM-EVOH film (6) by a dry laminate layer (8). Any of various adhesives used in dry lamination can be appropriately selected and used as the dry laminate layer 8. Instead of dry lamination, non-solvent lamination using a solvent-free adhesive may be used.

[0020] The barrier VM-PET film (5) shown in Fig. 2 has three layers, a film base layer (11), a deposition layer (12), and a barrier coat layer (13), like the barrier film (10) shown in Fig. 3. The deposition layer (12) is an aluminum deposition layer having a thickness of 10 nm to 100 nm. The VM-EVOH film (6) has a two-layer structure obtained by removing the barrier coat layer (13) from the barrier film (10). There is no particular restriction on the number of layers in the gas barrier layer (9), and it is sufficient that the gas barrier layer (9) has at least one layer that exhibits barrier properties. The layer structure and material of the gas barrier layer (9) can be appropriately determined in consideration of the application of the vacuum insulation material.

[0021] (base material) Next, each component of the vacuum insulation material laminate (2) will be described. A plastic film made of a polymeric material can be used for the substrate (4). The polymeric film is a film made of a polymeric resin composition, and can be selected appropriately according to the application, such as polyolefin (polyethylene, polypropylene, etc.), polyester (polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, etc.), polyamide (nylon-6, nylon-66, etc.), polyimide, etc. For example, the embodiment shown in FIG. 2 is an example in which a polyamide film is used, which is preferable in terms of strength as the material for the outermost layer that covers the vacuum insulation material.

[0022] The laminate for vacuum insulation material (2) is required to have gas barrier properties in order to maintain the internal vacuum state. For this purpose, a gas barrier layer is provided in the layers constituting the laminate to impart gas barrier properties. As the gas barrier layer, a metal foil such as aluminum can be used, or a gas barrier film with a gas barrier layer provided on the surface can be used.

[0023] (Barrier film) The barrier film (10) is formed, for example, by using a film substrate layer (11) made of a plastic material and providing a vapor deposition layer on one side of it, but it may also be formed by sequentially laminating a vapor deposition layer (12) and a barrier coat layer (13). Examples of plastic materials that can be used include polyester films such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyolefin films such as polyethylene and polypropylene, polystyrene films, polyamide films, polycarbonate films, polyacrylonitrile films, polyimide films, ethylene-vinyl alcohol copolymer (EVOH) films, and polyvinyl alcohol (PVA) films. These may be stretched or unstretched as long as they have mechanical strength and dimensional stability. Usually, these are processed into a film for use. In particular, from the viewpoint of heat resistance, etc., polyethylene terephthalate film, polyamide film, and polypropylene film that are arbitrarily stretched in biaxial directions are preferably used.

[0024] The surface of the film opposite to the surface on which the deposition layer is formed may contain various well-known additives and stabilizers, such as antistatic agents, ultraviolet protection agents, plasticizers, lubricants, etc. In order to improve adhesion to the deposition layer, the lamination surface of the substrate may be pretreated by any of corona treatment, low-temperature plasma treatment, ion bombardment treatment, chemical treatment, solvent treatment, etc.

[0025] The thickness of the film is not particularly limited, and in consideration of suitability as a film, a film formed by laminating films having different properties other than a single film can also be used. In consideration of processability, the thickness is preferably in the range of 3 to 200 μm, and more preferably 6 to 30 μm.

[0026] In addition, in consideration of mass productivity, it is preferable to form each layer in a continuous long film.

[0027] (deposited layer) Next, the deposition layer (12) is made of, for example, an aluminum deposition film, and has gas barrier properties against oxygen, water vapor, and the like.

[0028] The optimum thickness of the deposition layer varies depending on the type and composition of the compound used, but is preferably within the range of 10 to 100 nm, and the thickness can be selected appropriately. However, if the thickness is less than 10 nm, a uniform film cannot be obtained, and the thickness cannot be said to be sufficient.

[0029] The deposition layer can be formed on the film by a normal vacuum deposition method. Other thin film formation methods such as sputtering, ion plating, and plasma chemical vapor deposition (PCVD) can also be used. Considering productivity, the vacuum deposition method is currently the most superior. As a heating means for the vacuum deposition method, it is preferable to use either an electron beam heating method, a resistance heating method, or an induction heating method. In order to improve the adhesion between the deposition layer and the substrate and the density of the deposition layer, the deposition can also be performed using a plasma assisted method or an ion beam assisted method.

[0030] (Barrier coat layer) Additionally, a coating barrier coat layer (13) is described that can be applied over the deposition layer to form a gas barrier layer. The barrier coat layer is formed using a coating agent whose main component is an aqueous solution or water / alcohol mixed solution containing a water-soluble polymer and at least one of (a) one or more alkoxides or their hydrolysates, or both, or (b) tin chloride. For example, a solution is prepared by dissolving a water-soluble polymer and tin chloride in an aqueous (water or water / alcohol) solvent, or by mixing this with a metal alkoxide directly or after hydrolysis or other treatment. This solution is coated on the deposition layer (12) made of an inorganic oxide, and then heated and dried to form the barrier coat layer.

[0031] Examples of water-soluble polymers used in coating agents include polyvinyl alcohol, polyvinylpyrrolidone, starch, methyl cellulose, carboxymethyl cellulose, and sodium alginate. In particular, polyvinyl alcohol (PVA) has the best gas barrier properties. This PVA is generally obtained by saponifying polyvinyl acetate, and includes, but is not limited to, so-called partially saponified PVA, in which several tens of percent of acetate groups remain, and complete PVA, in which only a few percent of acetate groups remain.

[0032] The tin chloride used in the coating agent is stannous chloride (SnCl 2 ), stannic chloride (SnCl 4 ), or a mixture thereof. These tin chlorides may be either anhydrous or hydrated.

[0033] Furthermore, metal alkoxides used in coating agents are generally represented by the formula M(OR)n (M: metals such as Si, Ti, Al, and Zr, R: CH 3 ,C 2 H 5 Specifically, tetraethoxysilane [Si(OC 2 H 5 ) 4 〕, triisopropoxyaluminum [Al(O-2'-C 3 H 7 ) 3 Among these, tetraethoxysilane and triisopropoxyaluminum are preferred because they are relatively stable in aqueous solvents after hydrolysis.

[0034] Known additives such as an isocyanate compound, a silane coupling agent, a dispersant, a stabilizer, a viscosity adjuster, a colorant, etc. may be added as necessary within a range that does not impair the gas barrier property of the coating agent.

[0035] For example, the isocyanate compound added to the coating agent is preferably one having two or more isocyanate groups in its molecule, such as monomers such as tolylene diisocyanate, triphenylmethane triisocyanate, and tetramethylxylene diisocyanate, as well as their polymers and derivatives.

[0036] The coating agent can be applied by a conventional method such as dipping, roll coating, screen printing, spraying, or gravure printing. The thickness of the coating varies depending on the type of coating agent, the processing machine, and the processing conditions. If the thickness after drying is 0.01 μm or less, it is not preferable because a uniform coating film cannot be obtained and sufficient gas barrier properties cannot be obtained. If the thickness exceeds 50 μm, there is a problem because the film is prone to cracking. Therefore, the thickness is preferably in the range of 0.01 to 50 μm, and more preferably in the range of 0.1 to 10 μm.

[0037] In addition, it is also possible to provide a further vapor deposition layer or barrier coat layer on the vapor deposition layer or barrier coat layer in the same manner, and a plurality of layers can be laminated as necessary.

[0038] The method of laminating each layer constituting the gas barrier layer (9) of the vacuum insulation laminate can be, for example, a dry lamination method using a two-component curing urethane adhesive, a non-solvent lamination method using a solvent-free adhesive, or an extrusion lamination method, but is not particularly specified.

[0039] (Heat-sealing layer) The material of the heat-sealing layer 7 contains a polyolefin resin. The heat-sealing layer 7 is usually a layer that serves as the outermost layer on one side of the lamination direction of the vacuum insulation material laminate of the present invention.

[0040] The heat-sealing layer (7) can be made of, in particular, linear polyethylene resin, medium-density polyethylene resin, high-density polyethylene resin, or polypropylene resin, and in a vacuum insulation material using the vacuum insulation material laminate of the present invention, the adhesion of the ends of the vacuum insulation material can be strengthened.

[0041] The thickness of the heat-sealing layer may be any thickness that can provide the desired adhesive strength, and is, for example, within the range of 20 μm to 100 μm, preferably within the range of 25 μm to 90 μm, and particularly preferably within the range of 30 μm to 80 μm. If the thickness of the heat-sealing layer is greater than the above range, the gas barrier properties and appearance of the vacuum insulation material laminate as a whole may deteriorate, while if the thickness is smaller than the above range, the desired adhesive strength may not be obtained, and peeling may occur during long-term use at high temperatures.

[0042] The heat-sealing layer may be a commercially available film or sheet, or may be formed by applying a composition for the heat-sealing layer to the surface of a layer that comes into contact with the heat-sealing layer.

[0043] In the vacuum insulation material of this embodiment, the laminate for the vacuum insulation material is disposed so that the heat-sealing layer is in contact with the core material. The laminate for vacuum insulation material, which is disposed so as to cover the core material and bonded by heat fusion, exhibits excellent heat resistance, and therefore, even if the vacuum insulation material is exposed to a high-temperature environment for a long period of time, peeling or deterioration at the edge of the vacuum insulation material or between layers of the laminate for vacuum insulation material can be suppressed, and a high vacuum state can be maintained inside the vacuum insulation material for a long period of time.

[0044] (Vacuum insulation material) In the vacuum insulation material of this embodiment, the core material (3) is disposed between a pair of opposing laminates for vacuum insulation material as shown in Fig. 1, and is sealed by sealing the peripheral portions of the laminates for vacuum insulation material. As the material for the core material (3), a material generally used as the core material for vacuum insulation material can be used. For example, a porous body such as a powder of silica or the like, a foam of urethane polymer or the like, or a fiber body such as glass wool can be mentioned. These porous bodies preferably have a porosity of 50% or more, and more preferably 90% or more. As the porosity increases, the thermal conductivity of the core material decreases.

[0045] The core material (3) may contain a getter agent for absorbing a small amount of gas entering from the outside. For example, silica, alumina, zeolite, activated carbon, etc. can be used as the getter agent.

[0046] The thickness of the core material (3) is not particularly limited as long as it can exhibit the desired heat insulating effect, but it is preferable that it is within the range of 1 mm to 30 mm after the pressure is reduced.

[0047] The degree of vacuum inside the vacuum insulation material is preferably 5 Pa or less, because this can block air convection inside the vacuum insulation material and improve the insulation performance.

[0048] The thermal conductivity (initial thermal conductivity) of the vacuum insulation material of this embodiment is, for example, 10 mW m -1 ·K -1 It can be used with less than 5mW m -1 ·K -1 Less than 3mW m is preferable. -1 ·K -1 The following is more preferable. When the vacuum insulation material is less likely to conduct heat to the outside, the heat insulating effect is improved. The above thermal conductivity is a value measured by a heat flow meter method using a thermal conductivity measuring device (HC-074 manufactured by Eiko Seiki Co., Ltd.) in accordance with JIS-A-1412-3.

[0049] The method for manufacturing the vacuum insulation material of this embodiment is not particularly limited as long as it is a method that can enclose a core material using a laminate of the above-mentioned configuration in at least one of a pair of opposing vacuum insulation material laminates, degas the inside to create a vacuum state, and seal it, and any known method can be used.

[0050] The vacuum insulation material of this embodiment can be used anywhere that requires insulation, such as a vacuum insulation material for electrical appliances, a vacuum insulation material for buildings, a vacuum insulation material for cold and warm insulation boxes, a vacuum insulation material for automobiles, etc.

[0051] In the course of developing a laminate for a vacuum insulation material in which a barrier film having a barrier coat layer formed on an aluminum vapor deposition layer is used as a gas barrier layer (9), the inventors noticed that, despite the use of films having the exact same layer structure, some laminates are prone to delamination at the interface between the vapor deposition layer and the barrier coat layer, while others are not. As a result of further investigation, it was found that delamination was unlikely to occur in a laminate using a barrier film on which a barrier coat layer was formed immediately after the formation of an aluminum vapor deposition layer during production. On the other hand, delamination was likely to occur in a laminate using a barrier film on which a certain amount of time had passed between the formation of the aluminum vapor deposition layer and the formation of the barrier coat layer. Through further investigation, the inventors have found that oxidation of aluminum on the surface of the aluminum vapor deposition layer is involved in the increase in delamination.

[0052] Based on the above-mentioned new findings, in the laminate for vacuum insulation material (2) of this embodiment, the barrier coat layer is formed soon after the aluminum vapor deposition layer is formed, so that the aluminum vapor deposition layer is covered with the barrier coat layer before the oxidation of aluminum on the surface of the aluminum vapor deposition layer progresses. As a result, in the surface of the aluminum vapor deposition layer in contact with the barrier coat layer, the peak area of ​​aluminum bonded to oxygen (Al-O) by XPS analysis is less than twice the peak area of ​​unoxidized aluminum (Al). Due to the above-mentioned configuration, in the laminate for vacuum insulation material of this embodiment, the aluminum vapor deposition layer and the barrier coat layer are well adhered to each other immediately after production, and the good adhesion state is maintained for a long period of time even when the vacuum insulation material is used in a high-temperature environment. The peak area values ​​of Al-O and Al are determined based on a graph of the results of X-ray photoelectron spectroscopy, and can be easily calculated and obtained using a general XPS analyzer (e.g., Quantum2000 manufactured by ULVAC-PHI).

[0053] The inventors' investigation confirmed that the Al-O peak area can be made two times or less than the Al peak area if the aluminum vapor deposition layer is covered with a barrier coat layer within 60 hours after the aluminum vapor deposition layer is formed. This is a condition under an oxygen-containing atmosphere, and if the film after the aluminum vapor deposition layer is formed is stored in an oxygen-free environment such as under vacuum or inert gas, the Al-O peak area can be made two times or less than the Al peak area even if the barrier coat layer is formed more than 60 hours after the aluminum vapor deposition layer is formed.

[0054] The inventors' investigations have revealed that in addition to the degree of oxidation of the aluminum vapor-deposited layer surface, carbon present on the aluminum vapor-deposited layer surface is involved in delamination. When the proportion of carbon on the aluminum vapor-deposited layer surface is 5% or less according to XPS analysis, the adhesion between the aluminum vapor-deposited layer and the barrier coat layer is good. This carbon is thought to be due to hydrocarbons such as methane present in the air, and it is believed that the adhesion of the hydrocarbons to the surface of the aluminum vapor deposition layer reduces the adhesion between the barrier coat layer and the aluminum vapor deposition layer.

[0055] In the laminate for vacuum insulation material of this embodiment, two or more pairs of aluminum vapor deposition layers and barrier coat layers may be provided. This can further improve the gas barrier properties. In this case, since there are the number of interfaces between the aluminum vapor deposition layers and the barrier coat layers, by satisfying the above conditions in each of them, delamination can be suitably suppressed. EXAMPLES

[0056] The laminate for a vacuum insulation material and the vacuum insulation material according to the present embodiment will be further described using examples and comparative examples. The present invention is not limited to the specific contents of the examples and comparative examples.

[0057] <Example 1> A polyamide (NY) film (manufactured by Kojin Film & Chemicals Co., Ltd., product name: Bonyl RX) having a thickness of 25 μm was used as the substrate (4). A 12 μm thick VM-PET film (5) was laminated on the substrate (4) via a dry laminate layer (8). A urethane adhesive was used for the dry laminate layer (8). The aluminum vapor deposition layer on the VM-PET film (5) was 70 nm thick, and a barrier coat layer was formed on the aluminum vapor deposition layer using a coating agent mainly composed of tetraethoxysilane (TEOS) and polyvinyl alcohol (PVA). A VM-EVOH film (6) (product name: VM-XL, manufactured by Kuraray Co., Ltd.) having a thickness of about 12 μm was laminated on the VM-PET film (5) via a dry laminate layer (8). The thickness of the aluminum vapor deposition layer in the VM-EVOH film (6) was 40 nm. Furthermore, a 50 μm thick linear polyethylene film (manufactured by Mitsui Chemicals Tocello Inc., product name: FCS) was laminated on the VM-EVOH film (6) via a dry laminate layer (8) as a heat-sealing layer (7), thereby obtaining an exterior material for vacuum insulation material according to Example 1. The dry laminate layer (8) was made of a urethane adhesive.

[0058] Two sheets of the vacuum insulation packaging material of Example 1 were stacked with the heat-sealing layers (7) facing each other, and the three sides were joined by heat fusion to form a bag. Glass fiber was enclosed inside as the core material (3), and one unjoined side was sealed by heat fusion while the pressure inside the bag was maintained at 1.0 Pa in a vacuum packaging device. By the above procedure, the vacuum insulation material according to Example 1 was obtained.

[0059] <Example 2> The vacuum insulation packaging material and vacuum insulation material of Example 2 were obtained in the same manner as in Example 1, except that a VM-PET film (5) was used instead of the VM-EVOH film (6) and two pairs of an aluminum vapor deposition layer and a barrier coat layer were provided.

[0060] <Example 3> The vacuum insulation packaging material and vacuum insulation material of Example 3 were obtained in the same manner as in Example 2, except that another VM-PET film (5) was layered on top and three pairs of aluminum vapor deposition layer and barrier coat layer were provided.

[0061] <Example 4> Except for using a 15 μm thick aluminum-deposited biaxially stretched polypropylene (OPP) film (VM-OPP) instead of the VM-PET film (5) and using the VM-PET film (5) instead of the VM-EVOH film (6), the vacuum insulation packaging material and vacuum insulation material according to Example 4 were obtained in the same manner as in Example 1. VM-OPP is obtained by co-extrusion of polypropylene and EVOH, and depositing aluminum on the EVOH surface of the stretched base film. In the base film, the thicknesses of the EVOH and polypropylene are 2.0 μm and 13.0 μm, respectively, and the thickness of the aluminum deposition layer is 40 nm.

[0062] <Example 5> The same substrate (4) as in Example 1 was laminated on the barrier coat layer of the VM-PET film (5) via a dry laminate layer (8), and a VM-PET film (5) was further laminated on the substrate (4) via the dry laminate layer (8). Furthermore, the same heat-sealing layer (7) as in Example 1 was laminated on the VM-PET film (5) via a dry laminate layer (8) to obtain an packaging material for vacuum insulation materials according to Example 5. The packaging material for vacuum insulation materials according to Example 5 has two pairs of an aluminum vapor deposition layer and a barrier coat layer. The vacuum insulation material of Example 5 was obtained in the same manner as in Example 1.

[0063] <Example 6> An exterior packaging material for a vacuum insulation material and a vacuum insulation material according to Example 6 were obtained in the same manner as in Example 1, except that the VM-PET film (5-2) was used instead of the VM-PET film (5). In the VM-PET film (5-2), a second aluminum vapor-deposited layer (70 nm thick) is formed on the barrier coat layer, and a second barrier coat layer is further formed on the second aluminum vapor-deposited layer. The composition of the second barrier coat layer is the same as that of the barrier coat layer. The vacuum insulation packaging material according to Example 6 has two pairs of an aluminum vapor deposition layer and a barrier coat layer.

[0064] <Example 7> The vacuum insulation packaging material and vacuum insulation material of Example 7 were obtained in the same manner as in Example 6, except that the substrate (4) was placed between the VM-PET film (5-2) and the VM-EVOH film (6). The vacuum insulation packaging material according to Example 7 has two pairs of an aluminum vapor deposition layer and a barrier coat layer.

[0065] <Example 8> An exterior material for vacuum insulation and a vacuum insulation material according to Example 8 were obtained in the same manner as in Example 6, except that the VM-PET film (5) was used instead of the VM-EVOH film (6). The vacuum insulation packaging material according to Example 8 has three pairs of an aluminum vapor deposition layer and a barrier coat layer.

[0066] <Example 9> An exterior packaging material for vacuum insulation material and a vacuum insulation material according to Example 9 were obtained in the same manner as in Example 7, except that the VM-PET film (5) was used instead of the VM-EVOH film (6). The vacuum insulation packaging material according to Example 9 has three pairs of an aluminum vapor deposition layer and a barrier coat layer.

[0067] <Example 10> Except for using the substrate (4-2) instead of the substrate (4), the vacuum insulation packaging material and the vacuum insulation material according to Example 9 were obtained in the same manner as in Example 5. The substrate (4-2) was a multilayer coextruded film having a three-layer structure of polyamide, EVOH, and polyamide with a total thickness of 17 μm.

[0068] <Example 11> An exterior material for a vacuum insulation material and a vacuum insulation material according to Example 9 were obtained in the same manner as in Example 2, except that the substrate (4-2) was used instead of the substrate (4).

[0069] <Comparative Example 1> An exterior packaging material for a vacuum insulation material and a vacuum insulation material according to Comparative Example 1 were obtained in the same manner as in Example 1, except that a VM-PET film (5-Oxy) was used instead of the VM-PET film (5). The time it takes for the barrier coat layer to be formed after the aluminum vapor deposition layer is formed differs between VM-PET film (5) and VM-PET film (5-2) and VM-PET film (5-Oxy). For VM-PET film (5) and VM-PET film (5-2), the barrier coat layer is formed within 24 hours after the aluminum vapor deposition layer is formed, whereas for VM-PET film (5-Oxy), the barrier coat layer is formed more than 96 hours after the aluminum vapor deposition layer is formed.

[0070] <Comparative Example 2> The vacuum insulation packaging material and vacuum insulation material of Comparative Example 2 were obtained in the same manner as in Example 2, except that a VM-PET film (5-Oxy) was used instead of the VM-PET film (5) closest to the substrate 4.

[0071] <Comparative Example 3> An exterior packaging material for vacuum insulation material and a vacuum insulation material for Comparative Example 3 were obtained in the same manner as in Example 3, except that a VM-PET film (5-Oxy) was used instead of the VM-PET film (5) closest to the substrate 4.

[0072] <Comparative Example 4> An exterior packaging material for a vacuum insulation material and a vacuum insulation material according to Comparative Example 4 were obtained in the same manner as in Example 4, except that a VM-PET film (5-Oxy) was used instead of the VM-PET film (5).

[0073] <Comparative Example 5> An exterior packaging material for vacuum insulation material and a vacuum insulation material according to Comparative Example 5 were obtained in the same manner as in Example 5, except that both VM-PET films (5) were changed to VM-PET films (5-Oxy).

[0074] <Comparative Example 6> An exterior packaging material for a vacuum insulation material and a vacuum insulation material according to Comparative Example 6 were obtained in the same manner as in Example 6, except that a VM-PET film (5-2Oxy) was used instead of the VM-PET film (5-2). The VM-PET film (5-2Oxy) has the same layer structure as the VM-PET film (5-2), but both of the two barrier coat layers were formed 96 hours or more after the formation of the aluminum vapor deposition layer.

[0075] <Comparative Example 7> An exterior packaging material for a vacuum insulation material and a vacuum insulation material according to Comparative Example 7 were obtained in the same manner as in Example 7, except that a VM-PET film (5-2Oxy) was used instead of the VM-PET film (5-2).

[0076] <Comparative Example 8> An exterior packaging material for vacuum insulation materials and a vacuum insulation material according to Comparative Example 8 were obtained in the same manner as in Example 8, except that a VM-PET film (5-2Oxy) was used instead of the VM-PET film (5-2).

[0077] <Comparative Example 9> An exterior packaging material for a vacuum insulation material and a vacuum insulation material according to Comparative Example 9 were obtained in the same manner as in Example 9, except that a VM-PET film (5-2Oxy) was used instead of the VM-PET film (5-2).

[0078] <Comparative Example 10> An exterior packaging material for vacuum insulation material and a vacuum insulation material for Comparative Example 10 were obtained in the same manner as in Example 10, except that both VM-PET films (5-2) were changed to VM-PET films (5-2Oxy).

[0079] <Comparative Example 11> An exterior packaging material for vacuum insulation material and a vacuum insulation material for Comparative Example 11 were obtained in the same manner as in Example 11, except that both VM-PET films (5-2) were changed to VM-PET films (5-2Oxy).

[0080] The following evaluations were carried out using the vacuum insulation packaging material and the vacuum insulation material of each example. (Analysis of aluminum vapor deposition surface) An X-ray photoelectron spectrometer (XPS) (Quantum2000, manufactured by ULVAC-PHI) was used to obtain the Al-O peak area, Al peak area, and carbon ratio on the surface of the aluminum vapor deposition layer that was in contact with the barrier coat layer. In cases with multiple pairs of aluminum vapor deposition layers and barrier coat layers, all of the relevant surfaces were analyzed. However, in the case of VM-PET film (5-2) and VM-PET film (5-2Oxy), the side of the aluminum vapor deposition layer facing the film base layer, which is farther from the film base layer, is also in contact with the barrier coat layer, but this side was not analyzed. This is because this side comes into contact with the barrier coat layer the moment the aluminum is vapor-deposited, and therefore no oxidation problems occur.

[0081] (Laminate strength measurement) Measurements were performed using a Tensilon universal material testing machine RTF series (manufactured by A&D Co., Ltd.) in accordance with JIS-K-6854. The laminate strength was measured for each interface of the substrate, the barrier film, and the heat-sealing layer by preparing a plurality of test pieces.

[0082] (Measurement of thermal conductivity) The vacuum insulation materials of each example were kept at a temperature of 90° C. for 8 weeks. Measurements were made in accordance with JIS-A-1412-3 using a thermal conductivity measuring device (HC-074, manufactured by Eiko Seiki Co., Ltd.) at three points: before storage, after 4 weeks, and after 8 weeks. The results of the examples are shown in Table 1, and the results of the comparative examples are shown in Table 2. Table 1 shows the measured laminate strength at each interface, but since the number of layers differs in each example, the values ​​for the interface with the heat-sealing layer are all listed in the "heat-sealing layer" column. For VM-PET film (5-2) and VM-PET film (5-2Oxy), the values ​​for each aluminum vapor deposition layer surface are shown.

[0083] [Table 1]

[0084] [Table 2]

[0085] As shown in Table 1, in each of the Examples, the peak area ratio between AL-O and AL on the aluminum vapor deposition layer surface in contact with the barrier coat layer was 2 or less. In contrast, the peak area ratios of the VM-PET film (5-2Oxy) and VM-PET film (5-Oxy) barrier films used in each of the Comparative Examples exceeded 2. In addition, the carbon ratio was 5% or less in each of the Examples, whereas it exceeded 10% in both of the VM-PET film (5-2Oxy) and VM-PET film (5-Oxy) in the Comparative Examples. The laminate strength of each vacuum insulation material in each Example was high, at around 3.0 N / 15 mm, but in each Comparative Example, the laminate strength at the interface on the aluminum vapor deposition layer side of the VM-PET film (5-2Oxy) and VM-PET film (5-Oxy) was 0.2 or less, making delamination prone to occur. In this study, the barrier film in contact with the heat-sealing layer had a film base layer facing the heat-sealing layer, so the lamination strength at the interface with the heat-sealing layer was good in both the examples and the comparative examples. However, when forming an exterior material for a vacuum insulation material, it is quite conceivable that the barrier coat layer is laminated facing the heat-sealing layer depending on the material of the core material and the device to which the vacuum insulation material is applied. In such a case, if the adhesion between the barrier coat layer and the aluminum vapor deposition layer is not sufficient, there is a concern that delamination will occur between the gas barrier layer and the heat-sealing layer, but this can be suitably prevented by applying the exterior material for a vacuum insulation material of the present invention. That is, in the vacuum insulation packaging material of the present invention, either side of the barrier film may face the heat-sealing layer.

[0086] In each of the Examples, the thermal conductivity before storage was favorably maintained for up to 8 weeks when stored at 90° C. On the other hand, in each of the Comparative Examples, although the value before storage was similar to that of the Examples, the thermal conductivity significantly decreased over time.

[0087] A structure in which multiple pairs of aluminum vapor deposition layers and barrier coat layers are provided, such as the VM-PET film (5-2), is often adopted for the purpose of improving gas barrier performance. However, the findings of the present invention have revealed that unless the surface of the aluminum vapor deposition layer is maintained in a specified state, a dilemma arises in that the risk of delamination increases with the number of pairs of aluminum vapor deposition layers and barrier coat layers. The vacuum insulation packaging material of the present invention does not encounter this dilemma, and can improve barrier performance while suppressing delamination.

[0088] An embodiment of the present invention and examples have been described above, but the specific configuration is not limited to this embodiment, and configuration changes and combinations that do not deviate from the gist of the present invention are also included. [Industrial Applicability]

[0089] The application of the barrier film according to the present invention is not limited to the above-mentioned vacuum insulation packaging material, and the barrier film alone can be used for a variety of purposes. [Explanation of symbols]

[0090] 10. Barrier Film 11 Film base layer 12 Deposited layer 13 Barrier coat layer

Claims

1. A film base layer; an aluminum vapor deposition layer formed on the film substrate layer; a barrier coat layer formed on the aluminum vapor deposition layer and containing a water-soluble polymer and a metal alkoxide or a hydrolysate thereof; Equipped with In an XPS analysis of the aluminum vapor deposition layer on the barrier coat layer side, the peak area value of aluminum bonded to oxygen (Al-O) is not more than twice the peak area value of non-oxidized aluminum (Al). Barrier film.

2. The carbon content in the XPS analysis is 5% or less. The barrier film of claim 1 .

3. The thickness of the aluminum vapor deposition layer is within the range of 10 to 100 nm. The barrier film according to claim 1 or 2.

4. The thickness of the barrier coat layer is within the range of 0.01 to 50 μm. The barrier film according to claim 1 .

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