JP2014113737A - Laminated gas barrier film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reflective laminated gas barrier film which has superior water wetting durability and is suitably used for a jacket material for a vacuum heat insulating material.SOLUTION: The laminated gas barrier film comprises: a film (A) formed by providing a metal layer on one face of a substrate film; an aromatic crosslinking resin adhesive layer (B) containing 1-20 mass% of zeolite; and a film (C) formed by providing a metal layer on one face of a substrate film. The film (A), the layer (B) and the film (C) are laminated so that each of the metal layers of the film (A) and the film (C) comes in contact with the layer (B).

Description

  The present invention relates to a laminated gas barrier film for external coating of a vacuum heat insulating material used as a heat insulating material for a refrigerator, a house wall and the like.

  Glass wool and polyurethane foam were well known as heat insulating materials, but in recent years, vacuum heat insulating materials are said to have a heat insulating effect of 10 times or more, and refrigerators using vacuum heat insulating materials are energy-saving home appliances. Vacuum insulation is attracting attention because it can be expected to have a large energy-saving effect, such as reducing the power consumption of air conditioners and the like, as well as increasing the insulation of houses with vacuum insulation on the outer wall. The vacuum heat insulating material is a heat insulating material that is sealed by covering the porous core material with an outer bag and then reducing the pressure inside. Since the contribution of gas conductivity is almost zero, excellent heat insulation performance can be obtained.

  Initially, a metal-plastic laminate film in which an aluminum foil and a sealant film such as a polyolefin film were laminated was used as the exterior bag (Patent Document 1). However, this has the disadvantage that metals such as aluminum foil have a very high thermal conductivity, heat is easily transmitted from the closing portion of the bag, and heat insulation performance is poor. Therefore, at present, outer packaging materials using a vapor deposition film obtained by vapor deposition on one side of a plastic film are mainly used. For example, a plastic film made of an ethylene vinyl alcohol copolymer resin with excellent gas barrier properties is used for the gas barrier layer, and aluminum deposition is performed on one side of the plastic film, and the surface on which the aluminum deposition is performed is disposed on the heat welding layer side. Has been proposed (Patent Document 2). However, since this ethylene vinyl alcohol copolymer is hydrophilic, this film swells by adsorbing moisture from the surface on the side of the non-deposited heat-fusing layer, and the deposited layer peels off, reducing the heat insulation performance. There was a problem to do. In order to solve this disadvantage, a laminate film of a bag is composed of a heat-welded layer, a gas barrier layer, and a scratch-preventing layer, and the gas barrier layer is a plastic composed of an ethylene vinyl alcohol copolymer resin. Aluminum vapor deposition, alumina vapor deposition, or silica vapor deposition is performed on one side of the film, and the surface on which the vapor deposition is performed is disposed on the heat welding side. Vapor deposition, alumina vapor deposition, or silica vapor deposition is performed, and the surface on which this vapor deposition is performed is arranged on the gas barrier layer side (PTL 3). The heat insulation performance of this is 50 ° C., 80% RH, and does not deteriorate with time at 6 days. However, when used outdoors and exposed to rain, the ethylene vinyl alcohol copolymer is attributed to the hydrophilicity of the ethylene vinyl alcohol copolymer. Subsequent studies revealed that the resin adsorbs moisture and therefore increases the heat transfer coefficient. Also, the vapor deposition film surface of the composite film in which the vapor deposition film of inorganic oxide or metal is formed on at least one surface of the non-hygroscopic resin layer is another non-hygroscopic resin layer surface or another composite film via an adhesive layer. A multilayer film having a total number of layers (n) of 2 to 8 of the deposited films laminated adjacent to the adhesive layer is prepared. It is also known that a moisture-proof multilayer film having a high degree of moisture-proof performance and appropriate flexibility and flexibility can be obtained by heat-treating the film for a long time at a relatively low temperature of less than 140 ° C. ( Patent Document 4). However, since moisture moves from outside to the film through the adhesive layer, there is a problem that the heat insulation performance of the vacuum heat insulating material using the exterior film deteriorates with time.

Japanese Patent Laid-Open No. 61-153481 JP-A-10-122477 JP 2012-77864 A JP 2000-318081 A

  The problem to be solved by the present invention is to provide a laminated gas barrier film for a vacuum insulation material having good water resistance.

  As a result of intensive investigations to solve the above problems, the present inventors have made the following invention. That is, the present invention is a film (A) in which a metal layer is provided on one side of a base film, an aromatic cross-linked resin adhesive layer (B) containing 1 to 20% by mass of zeolite, and one side of the base film. A film (C) provided with a metal layer is a laminated gas barrier film in which the metal layers (A) and (C) are laminated with the (B) side facing each other.

  Moreover, since the said laminated gas barrier film can provide the toughness of a laminated gas barrier film that the base film of a film (A) and the base film of a film (C) are biaxially-stretched polyester films, it is preferable.

  Further, the laminated gas barrier film is preferably such that the aromatic crosslinked resin adhesive layer (B) is a layer made of an aromatic polyepoxy resin or a layer made of an aromatic urethane resin.

According to the present invention, sunlight is reflected, etc., and has a water vapor barrier performance of 0.2 g / (m ² · day) or less and an oxygen barrier performance of 0.1 cc / (m ² · day · atm) or less, A water-resistant laminated gas barrier film can be realized. As a result, it is possible to provide a laminated gas barrier film that is particularly useful as an exterior film of a vacuum heat insulating material having excellent water resistance.

FIG. 1 is an example of the laminated gas barrier film of the present invention.

  The present invention will be described in detail below.

  FIG. 1 shows an example of the laminated gas barrier film of the present invention. The laminated gas barrier film of the present invention is an aromatic film containing 1 to 20% by mass of a film (A) (7) having a metal layer (2) provided on one side of a base film (1) and zeolite (3). Film (C) (9) in which a metal layer (5) is provided on one surface of a base film (6), an adhesive layer (B) (8) comprising the cross-linked resin (4) of the film (A) and It is a laminated gas barrier film laminated with each metal layer of the film (C) facing the (B) side.

  Both the film (A) and the film (C) are films in which a metal layer is provided on one side of the base film. The metal layer can represent materials such as aluminum, silicon, magnesium, zinc, indium and tin, but is not limited thereto. These metal layers are formed by a known method such as a method of directly heating and evaporating and depositing a metal, ion plating, sputtering, chemical vapor deposition or the like. By providing a metal layer, it is useful for suppressing thermal conductivity by reflecting sunlight or the like.

  As the base film of the film (A) and the film (C), a known film such as a polyester film, a polyolefin film such as polyethylene or polypropylene (may be abbreviated as PP), a polycarbonate film, or a polystyrene film can be used. The water absorption is more preferably less than 1.0%. This is because, if the water absorption is 1.0% or more, when the vacuum heat insulating material is submerged, it absorbs moisture, lowers the gas barrier property, and increases the thermal conductivity. Among them, a biaxially stretched polyester film that is excellent in mechanical strength, heat resistance, and chemical stability and excellent in gas barrier performance of the base film itself is preferable, and in particular, biaxially stretched polyethylene terephthalate (may be abbreviated as PET). A film, a biaxially stretched polyethylene naphthalate (may be abbreviated as PEN) film, and the like are preferred because they are easily available on a commercial basis. The thickness of these substrate films is selected in the range of 9 to 125 μm depending on the purpose from the viewpoint of film handling and economy.

  Further, when the laminated gas barrier film of the present invention is used as an exterior material, if any one of the base films of the film (A) and the film (C) has thermal adhesiveness, the outer bag can be formed only by the outer jacket material. Can be formed. As a base film for this purpose, an unstretched polypropylene film can be raised, the unstretched polypropylene film surfaces can be firmly heat-bonded to each other, and the polypropylene film has excellent water vapor barrier performance. Water vapor barrier performance can also be exhibited.

Either the film (A) or the film (C) has an oxygen transmission rate of 3.0 cc / (m ² · day · atm) or less, or a water vapor transmission rate of 3.0 g / (m ² · day) or less, or Having both of these properties is preferable because the gas barrier performance of the laminated gas barrier film can be expressed. The gas barrier performance of the laminated gas barrier film is preferably such that the water vapor transmission rate is 0.2 g / (m ² · day) or less or the oxygen transmission rate is 0.1 cc / (m ² · day · atm) or less. Is preferably satisfied. From the viewpoints of water absorption and strength, the film (A) and the film (C) are particularly preferably biaxially stretched polyester films, because the strength of the film is high and the film is not easily broken and is not easily deformed. In addition, it is preferable that the film (A) and the film (C) are the same, in the case where they are laminated, the laminate does not curl.

  The adhesive layer (B) is an adhesive layer made of an aromatic crosslinked resin containing 1 to 20% by mass of zeolite. The aromatic system means that the main chain portion of the resin has an aromatic ring, that is, a benzene ring, and this structure restrains the thermal motion of the molecular chain and improves the gas barrier performance.

  On the other hand, a cross-linked resin is a type of resin that is cured by mixing components consisting of a main agent and a curing agent and carrying out a cross-linking reaction. By cross-linking, the thermal motion of molecular chains is still constrained and gas barrier performance is improved. To do. As the cross-linked resin, a main component is a prepolymer having an epoxy group at the end (epoxy resin), a polyepoxy resin typically composed of amines as a curing agent, or various polyols as a main component, and diisocyanate as a curing agent. The urethane resin to be used is preferable from the viewpoint of the function as an adhesive and the gas barrier performance.

  It is important for the polyepoxy resin as the aromatic cross-linked resin that the prepolymer chain as the main agent is aromatic. The prepolymer (epoxy resin) as the main agent containing a benzene ring includes an epoxy resin having a glycidylamine moiety derived from metaxylylenediamine, and a glycidylamine derived from 1,3-bis (aminomethyl) cyclohexane. Epoxy resin having a glycidylamine moiety derived from diaminodiphenylmethane, an epoxy resin having a glycidylamine moiety derived from paraaminophenol, an epoxy resin having a glycidyl ether moiety derived from bisphenol A, bisphenol F Epoxy resins having glycidyl ether moieties derived from phenol, epoxy resins having glycidyl ether moieties derived from phenol novolac, and glycidyl derived from resorcinol Resin such as epoxy resin having a Jill ether moiety and the like. Among these, an epoxy resin having a glycidylamine moiety derived from metaxylylenediamine is particularly preferable.

  The amine of the curing agent is preferably an aromatic amine such as metaphenylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone.

  With the urethane resin as the aromatic cross-linked resin, it is necessary that either the polyol as the main agent or the curing agent is aromatic. Examples of the polyol include polyester polyol, polyether polyol, polycarbonate polyol, polycaprolactone polyol, ethylenediamine polyol, trimethylolpropane polyol, and acrylic polyol. A prepolymer obtained by crosslinking a part of these polyols with an isocyanate can also be used. Among them, polyester polyols are preferable from the viewpoint of gas barrier performance, and aromatic polyester polyols include polycarboxylic acids such as isophthalic acid, terephthalic acid, adipic acid, and succinic acid, and polyhydric alcohols such as ethylene glycol, diethylene glycol, 1 , 4-butanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, polyester polyol obtained by reaction with glycerin and the like.

  The curing agent for urethane resin is hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), diphenylmethane diisocyanate (MDI), dicyclohexylmethane 4,4′-diisocyanate (HMDI), tolylene diisocyanate (TDI), m-xylylene. Examples thereof include range isocyanate (XDI), and a prepolymer obtained by crosslinking a part of these isocyanate groups (NCO groups) with a polyol can also be used. MDI, TDI, and XDI have a benzene ring structure. Among them, XDI is more preferable because it has a low molecular weight, a high crosslinking density, and a higher barrier property.

  These cross-linked resin adhesives are prepared by dissolving a main agent and a curing agent in an arbitrary diluting solvent such as ethyl acetate, methyl ethyl ketone, methanol, and the like by a known coating method such as a gravure method on one of the films (A) and (C) After the solvent is dried, it is bonded to the other film and cured by aging. In this process, moisture mixed in the coating liquid, residual diluted solvent, carbon dioxide gas due to curing reaction The monomer of the adhesive component is gasified. In order to adsorb these gases and suppress the generation of bubbles, zeolite is contained in the adhesive layer (B).

  Zeolite in the present invention is a general term for crystalline aluminosilicates. A regular porous body with a crystal structure in which four oxygens are regularly and three-dimensionally connected around Si and Al. It has nano-level pores, moisture and odor in gases and solvents, and molecules of trace components. It is known to have a function of adsorbing. Since Al (+3 valence) and Si (+4 valence) share oxygen (-2 valence) with each other, the periphery of Si is electrically neutral, and the periphery of Al is −1. In order to compensate for this negative charge, cations are retained in the pores. As the crystal structure of zeolite, mordenite type, A type, X type, Y type, beta type, ferrierite, L type, ZSM-5 type and the like are representative, and the cation in the pore is potassium, Sodium, calcium, ammonium, hydrogen, lithium and the like. The size of the molecule that can be adsorbed in the pore is determined by the pore diameter and the ionic radius of the cation supported in the pore, and the supported cation attracts the negative charge of the polar molecule, so polar molecules such as moisture and carbon dioxide It is effective for adsorption. Since the bubbles in the adhesive layer are reduced due to the adsorption effect and oxygen and water vapor hardly pass through, it is effective for improving the barrier property. Moreover, since water vapor is adsorbed by the water adsorption effect of zeolite, the barrier property is improved.

In the present invention, the adhesive layer (B) needs to contain 1 to 20% by mass of zeolite with respect to the mass of the aromatic crosslinked resin. If the content is less than 1% by mass, the bubble suppression effect is small. When it contains more than 20 mass%, the adhesive force of a film (A) and a film (C) falls and it becomes a problem. More preferably, it is 1-10 mass%.
As the solvent for the adhesive, any solvent such as ethyl acetate, methyl ethyl ketone, and methanol can be used, but it is preferable to select a solvent having a low boiling point because the residual solvent is reduced and the bubble suppression effect is enhanced.

  The thickness of the adhesive layer (B) is preferably 1 to 10 μm, more preferably 2 to 7 μm. When the thickness of the adhesive layer (B) is 1 μm or more, sufficient gas barrier performance is obtained, and when the thickness is 10 μm or less, the solvent in the adhesive layer (B) is easily volatilized, so that the bubble suppression effect is enhanced.

  In the adhesive layer (B) in the present invention, additives such as a silane coupling agent, an antistatic agent, an ultraviolet absorber, a stabilizer, an antioxidant, a plasticizer, a lubricant, a filler, etc. What was added within the range which is not impaired can also be used.

  The laminated gas barrier film of the present invention is applied with an adhesive coating mixed with zeolite on the metal film-forming surface of the film (A), and the film (C) with the metal film-forming surface facing the adhesive layer (B). By laminating together, a laminated gas barrier film useful as an exterior film for a vacuum heat insulating material that requires extremely high gas barrier performance can be produced.

  Hereinafter, the present invention will be described in more detail with reference to examples. In addition, the physical property in an Example and a comparative example was measured as follows.

(1) Water vapor transmission rate (g / (m ² · day))
The laminated gas barrier film of the present invention was measured twice based on a differential pressure method using a water vapor permeability measuring device (model name, DELTAPERRM type) manufactured by Technolox under the conditions of a temperature of 40 ° C. and a humidity of 90% RH. The average value was calculated.

(2) Oxygen permeability (cc / (m ² · day · atm))
Method B described in JIS K7126 (2000 version) using an oxygen permeability measuring device (model name, OXTRAN2 / 21MH type) manufactured by MOCON under conditions of a temperature of 23 ° C. and a humidity of 40% RH on the laminated gas barrier film The average value measured twice based on (isobaric method) was calculated.

(3) Adhesive layer thickness (μm)
A cross section of the film is cut out with a microtome, and the cross section is magnified 1000 times using a field emission scanning electron microscope (S-4800, manufactured by Hitachi High-Technologies Corporation). The length in the thickness direction was measured, and the thickness of the adhesive layer was determined by calculating backward from the magnification. In determining the thickness of the adhesive layer, a total of five cross-sectional photometers arbitrarily selected from different measurement visual fields were used, and the average value thereof was calculated.

(4) The water absorption film piece was immersed in water and measured by mass change (JISK 7209: 2000 compliant).

(5) Evaluation of heat insulating performance of vacuum heat insulating material A laminated gas barrier film and a non-stretched polypropylene film having a thickness of 60 μm (“Torphan” (registered trademark) ZK207 manufactured by Toray Film Processing Co., Ltd.) were laminated by dry lamination to obtain an exterior material. .
Cut out two 20cm x 20cm laminate pieces from this exterior material, stack them so that the polypropylene film is on the inside, create a bag by fusing the three sides by heat sealing, cut into 9cm thickness x 10cm x 10cm Glass wool insulation (Asahi Fiber Glass Co., Ltd., high-performance glass wool “ACRYL WOOL” ACW) and calcium oxide (Oe Chemical Co., Ltd. “Lime” (registered trademark) P9), 100 g as an adsorbent. Then, using a vacuum packaging machine, it was held at 2.0 Pa or less for 30 minutes and then heat-sealed to form a vacuum heat insulating material.
The heat insulation performance of the vacuum heat insulating material using this exterior bag was evaluated by thermal conductivity. The thermal conductivity was measured using a rapid thermal conductivity meter QTM-500 manufactured by Kyoto Electronics Industry Co., Ltd.
Initial performance of vacuum insulation material (after 1 day at room temperature), aging after 6 days at 50 ° C. and 80% RH, after 1 day at room temperature, immersed in boiling water at 90 ° C. for 30 minutes, 6 at 50 ° C. and 80% RH The deterioration with time after the day was observed.

Example 1
4.9 parts by mass of "Maxive" M-100 (solid content concentration 100%) manufactured by Mitsubishi Gas Chemical Co., Ltd., an epoxy resin having a glycidylamine moiety, which is a copolymer of metaxylylenediamine and epichlorohydrin Curing agent C-93 (solid content concentration 65%) 16.0 parts by mass, A-type crystalline zeolite “Zeoram” A-3 powder type 0.17 parts by mass containing potassium ions manufactured by Tosoh Corporation, 28.7 parts by mass of methanol was stirred for 10 minutes to prepare an adhesive coating solution having a solid concentration of 31%. The content of zeolite was 1.1% by mass.
The film (A) has a water vapor transmission rate of 1.5 g / (m ² · day) and an oxygen transmission rate of 1.5 cc / (m ² · day · atm). Direct gravure using a dry laminator machine (DL-130) manufactured by Okazaki Machinery Co., Ltd. on the deposition surface of polyethylene terephthalate film BR-PET1012 (12 μm, water absorption 0.3%). And dried at 80 ° C. for 20 seconds to form a 3.0 μm thick adhesive layer. As a film (C), the vapor-deposited surface of BR-PET1012 was also overlapped so as to face the adhesive layer, and bonded together using a dry laminator machine (DL-130) manufactured by Okazaki Kikai Kogyo. This laminated film was aged in an oven heated to 40 ° C. for 2 days to produce a laminated gas barrier film of film (A) / adhesive layer (B) / film (C).

(Example 2)
In Example 1, lamination was performed in the same manner as in Example 1 except that the zeolite of the adhesive coating solution was changed to A-type crystalline zeolite “Zeoram” A-4 powder type containing sodium ions manufactured by Tosoh Corporation. A gas barrier film was obtained.

(Example 3)
In Example 1, lamination was performed in the same manner as in Example 1 except that the zeolite of the adhesive coating solution was changed to A-type crystalline zeolite “Zeolam” A-5 powder type containing calcium ions manufactured by Tosoh Corporation. A gas barrier film was obtained.

Example 4
In Example 1, a laminated gas barrier film was obtained in the same manner as in Example 1 except that ZEOLAM A-3 powder type was 3.8 parts by mass as a prescription for the adhesive coating solution. The content of zeolite was 20% by mass.

(Example 5)
In Example 1, a laminated gas barrier film was obtained in the same manner as in Example 1 except that “Zeoram” A-3 powder type was 1.7 parts by mass as the formulation of the adhesive coating solution. The content of zeolite was 10% by mass.

(Example 6)
In Example 1, the adhesive coating agent was changed to a polyurethane adhesive. 51.3 parts by mass of polyester polyol LX-510 (solid content 50%), which is a main component of urethane adhesive manufactured by DIC Corporation, partially crosslinked with aliphatic diisocyanate, and manufactured by DIC Corporation A laminated gas barrier film was prepared in the same manner as in Example 1 except that 5.7 parts by mass of the curing agent KW-75 (solid content concentration 75%) and 42.85 parts by mass of ethyl acetate were used as aromatic isocyanate TDI. Obtained.

(Example 7)
In Example 1, a biaxially stretched polyethylene naphthalate film “Teonex” Q51 (16 μm, water absorption 0.3%) manufactured by Teijin DuPont Films Ltd. was used as a base film for the films (A) and (C). Aluminum metal was evaporated by a resistance heating type evaporation source with a roll type vapor deposition machine manufactured by Co., Ltd. to form an aluminum film having a thickness of 20 nm. An aluminum / polyethylene naphthalate film having a water vapor transmission rate of 1.0 g / (m ² · day) and an oxygen transmission rate of 2.0 cc / (m ² · day · atm) was obtained. A laminated gas barrier film was obtained in the same manner as in Example 1 except that this aluminum-deposited polyethylene naphthalate film was changed to film (A) and film (C).

(Example 8)
In Example 1, an unstretched polypropylene film “Torphan” (registered trademark) NO9021T (25 μm, water absorption 0.3%) manufactured by Toray Film Processing Co., Ltd. was used as the base film of the film (C). Similarly, an aluminum film was formed by vapor deposition. An aluminum / unstretched polypropylene film having an oxygen transmission rate of 10 cc / (m ² · day · atm) and a water vapor transmission rate of 0.5 g / (m ² · day) was obtained. A laminated gas barrier film was obtained in the same manner as in Example 1 except that BR-PET1012 was used as the film (A) and the above film was used as the film (C).

Example 9
In Example 1, a laminated gas barrier film was obtained in the same manner as in Example 1 except that the thickness of the adhesive layer (B) was 0.8 μm.

(Example 10)
In Example 1, a laminated gas barrier film was obtained in the same manner as in Example 1 except that the thickness of the adhesive layer (B) was 12.0 μm.

(Example 11)
In Example 1, the film (A) and the film (C) have a water vapor transmission rate of 0.7 g / (m ² · day) and an oxygen transmission rate of 1.9 cc / (m ² · day · atm). Axial stretched ethylene-vinyl alcohol copolymer (EVOH) resin film, “EVAL” (registered trademark) EF-CR (15 μm, water absorption 8.2%) manufactured by Kuraray Co., Ltd. The aluminum metal was evaporated by a resistance heating type evaporation source using a machine to form an aluminum film having a thickness of 20 nm. An aluminum / EVOH film having a water vapor transmission rate of 0.01 g / (m ² · day) and an oxygen transmission rate of 0.01 cc / (m ² · day · atm) was obtained. A laminated gas barrier film was obtained in the same manner as in Example 1 except that this aluminum-deposited EVOH film was changed to film (A) and film (C).

(Example 12)
In Example 1, a biaxially stretched nylon film as a base film for the film (A) and the film (C), “Emblem” ON (15 μm, water absorption 8.0%) manufactured by Unitika Ltd., ULVAC, Inc. Aluminum metal was evaporated by a resistance heating type evaporation source with a winding type vapor deposition machine to form an aluminum film having a thickness of 20 nm. An aluminum / nylon film having a water vapor transmission rate of 1.0 g / (m ² · day) and an oxygen transmission rate of 2.0 cc / (m ² · day · atm) was obtained. A laminated gas barrier film was obtained in the same manner as in Example 1 except that this aluminum-deposited nylon film was changed to film (A) and film (C).
(Example 13)
In Example 1, as a base film of the film (A) and the film (C), a polyimide film, “UPILEX” (registered trademark) -25S (25 μm, water absorption 1.4%) manufactured by Ube Industries, Ltd. Aluminum metal was evaporated by a resistance heating type evaporation source with a roll type vapor deposition machine manufactured by Co., Ltd. to form an aluminum film having a thickness of 20 nm. An aluminum / polyimide film having a water vapor transmission rate of 1.0 g / (m ² · day) and an oxygen transmission rate of 0.6 cc / (m ² · day · atm) was obtained. A laminated gas barrier film was obtained in the same manner as in Example 1 except that this aluminum-deposited polyimide film was changed to film (A) and film (C).

(Comparative Example 1)
In Example 1, a laminated gas barrier film was obtained in the same manner as in Example 1 except that the adhesive layer (B) did not contain zeolite.

(Comparative Example 2)
A laminated gas barrier film was obtained in the same manner as in Example 1, except that 5.1 parts by mass of “Zeoram” A-3 powder type was used as the formulation for the adhesive coating solution. The content of zeolite was 25% by mass.

(Comparative Example 3)
In Example 1, as film (A) and film (C), the water vapor transmission rate is 55.2 g / (m ² · day), and the oxygen transmission rate is 152 cc / (m ² · day · atm). Polyethylene terephthalate film A laminated gas barrier film was obtained in the same manner as in Example 1 except that “Lumirror” (registered trademark) P60 (12 μm) manufactured by Toray Industries, Inc. was used.

(Comparative Example 4)
Example 1 is the same as Example 1 except that the silica sol “OSCAL” (particle size: 5 nm) manufactured by JGC Catalysts & Chemicals Co., Ltd. is used instead of zeolite and the solid content of the silica sol is 1.1% by mass. Thus, a laminated gas barrier film was obtained.

(Comparative Example 5)
In Example 1, a laminated gas barrier film was obtained in the same manner as in Example 1 except that instead of zeolite, fumed silica “AEROSIL” 380 manufactured by Nippon Aerosil Co., Ltd. was changed to 1.7 parts by mass. The content of fumed silica was 10% by mass.

(Comparative Example 6)
In Example 1, the adhesive coating agent was changed to an aliphatic polyurethane adhesive. 27 parts by mass of a polyester polyol LX-500 (solid content 60%) obtained by partially crosslinking an aliphatic polyester polyol, which is a main component of a urethane adhesive manufactured by DIC Corporation, with an aliphatic diisocyanate, and an aliphatic product manufactured by DIC Corporation A laminated gas barrier film was obtained in the same manner as in Example 1 using 5 parts by mass of the system curing agent KO-55 (solid content concentration 55%) and 69.25 parts by mass of ethyl acetate.

  The evaluation results of these examples and comparative examples are shown in Table 1. In Comparative Example 2, the thermal conductivity performance was good, but the film (A) and the film (C) tended to peel off when the exterior was rubbed with a finger after the measurement. This is probably because the amount of zeolite added was too large and the adhesive strength of the adhesive layer was lowered. From Comparative Example 4 and Comparative Example 5, it can be seen that unlike zeolite, silica sol and fumed silica have a low ability to prevent the movement of moisture in the adhesive layer. From Comparative Example 6, it can be seen that when the curing agent is an aliphatic isocyanate, the adhesive layer does not have an aromatic crosslinked resin structure, and the gas barrier performance is inferior to that of the aromatic system. From Example 11, Example 12, and Example 13, when the water absorption of the film (A) and the film (C) is 1.4% or more, the thermal conductivity after 6 days of boiling water treatment at 50 ° C. and 80% RH It turns out that it tends to rise.

The laminated gas barrier film of the present invention is reflective, has a water vapor barrier performance of 0.2 g / (m ² · day) or less, and an oxygen barrier performance of 0.1 cc / (m ² · day · atm) or less, water A laminated gas barrier film having wet durability can be realized. As a result, it is possible to provide a laminated gas barrier film that is particularly useful as an exterior film for a vacuum heat insulating material.

1, 6 Base film 2, 5 Metal oxide layer 3 Zeolite 4 Aromatic crosslinked resin 7, 9 Film (A) or film (C)
8 Adhesive layer (B)

Claims (4)

Film (A) provided with a metal layer on one side of the base film, aromatic cross-linked resin adhesive layer (B) containing 1 to 20% by mass of zeolite, and metal layer provided on one side of the base film The laminated gas barrier film, wherein the obtained film (C) is laminated with the respective metal layers of the film (A) and the film (C) facing the aromatic crosslinked resin adhesive layer (B) side . The laminated gas barrier film according to claim 1, wherein the base film of the film (A) and the base film of the film (C) are biaxially stretched polyester films. The laminated gas barrier film according to claim 1 or 2, wherein the aromatic cross-linked resin adhesive layer (B) is a layer made of an aromatic polyepoxy resin. The laminated gas barrier film according to claim 1 or 2, wherein the aromatic crosslinked resin adhesive layer (B) is a layer made of an aromatic urethane resin.

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