JP2015193141A - Gas barrier film and gas barrier laminate body using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas barrier film excellent in long term heat insulation properties, and a gas barrier laminate body suitably usable to a vacuum heat insulation material application using the gas barrier film.SOLUTION: Provided is a gas barrier film in which a first inorganic layer, a gas barrier resin layer and a second inorganic layer are laminated at least on one side of a base material in this order, and in which the gas barrier resin layer is composed of the main agent composed of a copolymer using the three components of (a) unsaturated nitrile, (b) an unsaturated compound having a hydroxyl group and (c) unsaturated carboxylic ester as monomers and a curing agent composed of a compound having an isocyanate group.

Description

  The present invention relates to a gas barrier film and a gas barrier laminate using the same, and in particular, to a gas barrier film excellent in long-term heat resistance of gas barrier performance, and external coating of vacuum heat insulating materials such as refrigerators, vending machines, and residential walls. The present invention relates to a gas barrier laminate that can be suitably used.

  In recent years, as a measure against global warming, a movement to promote energy saving has been active, and vacuum heat insulating materials having excellent heat insulation performance have attracted attention from the viewpoint of effectively utilizing heat. Glass heat insulation and polyurethane foam are common as heat insulation materials, but vacuum heat insulation materials are said to have a heat insulation effect of 10 times or more compared to them. A highly insulated house with a wall installed on the outer wall is expected to have a significant energy saving effect as it can reduce the power consumption of air conditioners and the like. The vacuum heat insulating material is a heat insulating material in which a core material having a porous structure is covered with an outer bag and then the inside is decompressed and sealed. Since the contribution of gas conductivity is almost zero, excellent heat insulation performance can be obtained.

  The exterior bag in the above-mentioned application needs to have a function of maintaining a vacuum for a long time, and a metal / plastic laminate film in which an aluminum foil and a sealant film such as a polyolefin film are laminated is used (Patent Document 1). However, aluminum has a very high thermal conductivity, heat is easily transmitted from the closing portion of the bag, and there is a disadvantage that the heat insulation performance is poor. For this reason, an exterior bag using a vapor-deposited film on which a plastic film is vapor-deposited has attracted attention. For example, an aluminum vapor-deposited resin film having excellent gas barrier properties is subjected to aluminum vapor deposition, and the surface on which this aluminum vapor-deposition is applied. Has been proposed (Patent Document 2). This film has very good gas barrier performance, but since ethylene / vinyl alcohol copolymer is hydrophilic, it absorbs moisture from the non-deposited side and swells, causing the vapor deposition layer to peel off and heat insulation performance There was a problem of lowering.

  Further, as a vapor deposition film excellent in gas barrier performance, there is known a gas barrier film in which a metal oxide, an organic ultrathin film layer, a metal or a metal oxide layer are laminated in this order on a plastic film substrate (Patent Document 3). These vapor-deposited gas barrier films are processed into vacuum insulation packaging bags and placed on the exterior walls of refrigerators or houses. When exposed to high temperatures over a long period of time, the gas barrier performance gradually decreases. Since the adhesive force between the film substrate and the vapor deposition layer is reduced and peeling occurs, the vacuum heat insulating material cannot be maintained in a vacuum state, and there is a problem that the heat insulating performance is greatly reduced.

Japanese Patent Laid-Open No. 61-153481 JP-A-10-122477 JP-A-4-14440

  The problem to be solved by the present invention is to provide a gas barrier film excellent in long-term heat insulation and a gas barrier laminate that can be suitably used for a vacuum heat insulating material application using the gas barrier film.

  In order to solve the above problems, the present invention has the following configuration.

  A first invention is a gas barrier film in which a first inorganic layer, a gas barrier resin layer, and a second inorganic layer are laminated in this order on at least one surface of a base film, and the gas barrier resin layer is (a) Curing composed of a main component composed of a copolymer comprising three components of a saturated nitrile, (b) an unsaturated compound having a hydroxyl group, and (c) an unsaturated carboxylic acid ester, and a compound having an isocyanate group It is a gas barrier film comprised with an agent.

  In the second invention, the weight fraction of the component (a), the component (b), and the component (c) in the copolymer is 10 to 30% by weight, 30 to 70% by weight, and 20 to 60% by weight, respectively. %, Which is a gas barrier film.

  A third invention is characterized in that the first inorganic layer and the second inorganic layer are each formed of at least one selected from aluminum, aluminum oxide, silicon oxide, silicon oxynitride, and a mixture thereof. It is a gas barrier film.

  A fourth invention is a gas barrier film, wherein the component (a) is acrylonitrile.

  5th invention is a gas-barrier film characterized by the said (b) component being 2-hydroxyethyl methacrylate.

  A sixth invention is a gas barrier film, wherein the component (c) is methyl methacrylate.

  According to a seventh aspect of the present invention, there is provided a gas barrier laminate characterized by laminating a surface base film on the second inorganic layer side of the gas barrier film according to any one of the above and a heat fusion film on the base film side. Is the body.

  The eighth invention is the gas barrier laminate, wherein the heat-sealing film is an unstretched polypropylene film or a linear low-density polyethylene film.

  A ninth invention is a gas barrier laminate characterized in that the surface base film is any one of a polyethylene terephthalate film, a nylon film, and a polypropylene film.

  According to the present invention, there are provided a gas barrier film excellent in long-term heat insulation and a gas barrier laminate that can be suitably used for a vacuum heat insulating material using the gas barrier film.

It is sectional drawing which shows the structure of the gas barrier film of this invention. It is sectional drawing which shows the structure of the gas barrier laminate of this invention.

  The present invention will be described in detail below.

  The gas barrier film of the present invention is a gas barrier film in which a first inorganic layer, a specific gas barrier resin layer, and a second inorganic layer are laminated on at least one surface of a base film.

  By laminating and infiltrating the specific gas barrier resin layer in the present invention into the first inorganic layer, the base film, the first inorganic layer and the gas barrier resin layer are integrated. Furthermore, by laminating the second inorganic layer, deterioration of each layer can be suppressed under a long-term high-temperature atmosphere, gas barrier performance can be maintained, and adhesion between the layers can be maintained.

  In either case where only the first inorganic layer is formed on the base film, or where the first inorganic layer and the resin layer are formed on the base film, the gas barrier performance is insufficient. In order to maintain the gas barrier performance and adhesion for a long time under a high temperature atmosphere, it is essential to form the first inorganic layer, the specific gas barrier resin layer and the second inorganic layer in the present invention on the base film. Further, when the resin layer and / or the inorganic layer are further laminated beyond the layer structure of the present invention, the cost increases and it is not practical.

  The first and second inorganic layers are preferably made of at least one selected from the group consisting of aluminum, aluminum oxide, silicon oxide, silicon oxynitride, and mixtures thereof. These inorganic layers can be obtained by directly evaporating and vapor-depositing metals, reactive vapor deposition methods that form oxides and nitrides by the reaction of vaporized metal with oxygen and nitrogen, and direct heating and vapor deposition of inorganic oxides. , Ion plating, sputtering, and chemical vapor deposition.

  The thickness of the first inorganic layer and the second inorganic layer is preferably 5 to 200 nm, more preferably 5 to 100 nm. If the thickness is less than 5 nm, it may be difficult to maintain the form of the inorganic layer, and it may be difficult to develop gas barrier performance. Even if the thickness is greater than 200 nm, the gas barrier performance is not greatly improved, and the metal oxide In the case of metal nitride, cracks are generated during handling, which may cause the gas barrier performance to be lowered, and the cost may be increased, which is not practical.

  As the base film, a known film such as a polyester film, a polyolefin film such as polyethylene or polypropylene, a polycarbonate film, a polyamide film, a polyimide film, or a polystyrene film can be used, among which mechanical strength, heat resistance, and chemical stability are used. A biaxially stretched polyester film excellent in gas barrier performance of the base film itself is preferable. Particularly, a biaxially stretched polyethylene terephthalate film, a biaxially stretched polyethylene naphthalate film, a biaxially stretched polylactic acid film, etc. are on a commercial basis. It is easy to obtain and preferable. 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.

A biaxially stretched polyethylene terephthalate film is more preferable from the viewpoint of strength, heat resistance, and economy as a base film of a gas barrier film for a vacuum heat insulating material.
In the present invention, the gas barrier resin layer is a copolymer composed of three components of (a) an unsaturated nitrile, (b) an unsaturated compound having a hydroxyl group, and (c) an unsaturated carboxylic acid ester. It is comprised with the comprised main ingredient and the hardening | curing agent comprised with the compound which has an isocyanate group. As described in the background art, a gas barrier film in which a metal oxide, an organic ultrathin film layer, a metal or a metal oxide layer are laminated in this order on a plastic film substrate is well known as a film having excellent gas barrier performance. However, the gas barrier resin layer between the first inorganic layer and the second inorganic layer greatly affects the gas barrier performance and the long-term durability of the gas barrier performance.

  Factors that determine the gas barrier properties of the thin film layer formed of the resin include cohesive energy density, free volume, crystallinity, orientation, and the like. These factors are often attributed to side chain functional groups in the polymer structure. That is, polymer chains containing functional groups capable of intermolecular interaction such as hydrogen bonding or electrostatic interaction in the structure tend to strongly aggregate using the interaction force as a driving force. As a result, the cohesive energy density and orientation are increased, the free volume is decreased, and the gas barrier property is improved. On the other hand, when the polymer structure contains a sterically bulky functional group, it is considered that the gas barrier property is lowered because the aggregation of the polymer is prevented and the free volume is increased. Furthermore, it can be considered that as the number of intermolecular interactions formed increases, the aggregation force increases and the driving force for reducing the free volume space increases, and as a result, the aggregation density of the polymer increases.

  The gas barrier resin layer in the present invention is described in detail below.

(Main ingredient: component (a))
As the unsaturated nitrile which is the main component (a), acrylonitrile is preferable. Acrylonitrile has a nitrile group in its molecular structure, and has a strong ability to form hydrogen bonds because the nitrile group is a highly polarized functional group. That is, a gas barrier property is imparted to a coating film formed of a copolymer containing acrylonitrile as a constituent component due to a large contribution of the nitrile group of acrylonitrile. The gas barrier property expressed by the acrylonitrile content varies.

  The blending amount of the unsaturated nitrile needs to be 10 to 30% by weight in the copolymer, and preferably 10 to 25% by weight. When the blending amount of the component (a) is less than 10% by weight, a sufficient number of hydrogen bonds are not formed in the coating film, and the gas barrier property is not sufficiently exhibited. On the other hand, when the blending amount of component (a) is more than 30% by weight, the solubility of the copolymer resin in the organic solvent is lowered, which not only prevents an increase in molecular weight during polymerization but also makes it difficult to form a coating. Become. Furthermore, it becomes impractical because the film-forming property of the coating film is lowered.

(Main ingredient: component (b))
The component (b) is an unsaturated compound having a hydroxyl group.

As described above, it is preferable to increase the content of the component (a) in the copolymer from the viewpoint of improving the gas barrier performance. However, polyacrylonitrile has a high glass transition temperature of about 300 ° C., and a high temperature is required to form a film. In order to solve this problem, means for copolymerizing the component (a) and the unsaturated compound is effective. Furthermore, in order to form a crosslinked structure with the curing agent for the purpose of expressing the strength of the coating film in order to strongly adhere to the inorganic layer as in the present invention, a hydroxyl group is contained in the main resin structure. Is preferred. That is, as the component (b) to be copolymerized with the component (a) of the main agent, for example, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 2-hydroxybutyl acrylate And monomers of unsaturated compounds such as 2-hydroxybutyl methacrylate, 2-hydroxyvinyl ether, polyethylene glycol methacrylate, polypropylene glycol monoacrylate, and polypropylene glycol monomethacrylate. These unsaturated compounds having a hydroxyl group can be selected singly or in combination of two or more. Of these unsaturated compounds having a hydroxyl group, 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate is preferable because good polymerization stability is obtained and reactivity with an isocyanate group is good. Ethyl methacrylate is particularly preferred.

  In the copolymer, the film-forming property and gas barrier performance of the gas barrier resin layer vary depending on the content of the component (b). The blending amount of the component (b) is required to be 30 to 70% by weight in the copolymer, and more preferably 50 to 70% by weight. When the blending amount of the component (b) is less than 30% by weight, the cohesive force between the resin chains derived from the hydroxyl group may not work sufficiently, and the gas barrier performance may not be improved. The number of crosslinking points formed by the progress of the crosslinking reaction between the hydroxyl group and the curing agent may not be sufficient, and the heat resistance of the resin layer may not be sufficiently exhibited. On the other hand, when the amount is more than 70% by weight, the number of hydroxyl groups in the copolymer resin is increased, so that it is necessary to increase the amount of the curing agent. At the same time, isocyanate groups in the curing agent are likely to remain unreacted, and blocking, etc. May be a problem.

  As a weight ratio in the copolymer of (a) unsaturated nitrile and (b) unsaturated compound having a hydroxyl group, (a) :( b) is preferably 1: 7 to 1: 1. More preferably, it is 2: 5 to 3: 5.

(Main ingredient (c) component)
In the present invention, the component (c) constituting the main agent is an unsaturated carboxylic acid ester.

  Examples of unsaturated carboxylic acid esters that can be used include methyl methacrylate, methyl acrylate, ethyl acrylate, ethyl methacrylate, n-propyl acrylate, n-propyl methacrylate, isopropyl acrylate, isopropyl methacrylate, n-butyl acrylate, n-butyl methacrylate, isobutyl acrylate, Examples include isobutyl methacrylate, t-butyl acrylate, t-butyl methacrylate, 2-ethylhexyl acrylate, and 2-ethylhexyl methacrylate. Of unsaturated carboxylic acid esters, methyl methacrylate and methyl acrylate are particularly preferable, and methyl methacrylate is more preferable.

The compounding amount of the component (c) is required to be 20 to 60% by weight in the copolymer, and more preferably 25 to 40% by weight. When the blending amount of the component (c) is less than 20% by weight, the film forming property of the coating film is not sufficiently improved, and it becomes difficult to finish the coating film surface smoothly and transparently. . On the other hand, when the amount of the component (c) is more than 60% by weight, the relative amount of the component (a) and the component (b) in the copolymer resin decreases, and the gas barrier property is not sufficiently developed. There arises a problem that the coating film strength and heat resistance due to the lack of structure are insufficient.

(Manufacture of copolymer)
The above components (a), (b), and (c) are blended and copolymerized using a known technique to produce a copolymer resin (main agent). The copolymer resin (main agent) is dissolved, for example, in a propyl acetate / propylene glycol monomethyl ether / n-propyl alcohol mixed solution and mixed with a curing agent described later.

(Other additives)
A silane coupling agent may be added to the copolymer resin (main agent) coating liquid. The silane coupling agent has an organic functional group and a hydrolyzable functional group in the molecule, and has an effect of improving the adhesion between the inorganic substance and the organic substance. Therefore, when a silane coupling agent is added, the adhesion between the inorganic oxide vapor deposition layer and the gas barrier resin layer can be strengthened to such an extent that it can withstand long-term thermal effects. Examples of silane coupling agents that can be used include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and the like. These silane coupling agents may be used alone or in combination of two or more.

  The addition amount of the silane coupling agent is preferably about 0.1 to 2 parts by weight with respect to 100 parts by weight of the sum of the main agent and the curing agent used for forming the gas barrier resin layer. In the case of an addition amount of 0.1 parts by weight or less, the effect of the silane coupling agent is thin and sufficient adhesion cannot be obtained. On the other hand, when more than 2 parts by weight is added, the silane coupling agent functions like a plasticizer in the gas barrier resin layer, so that the gas barrier performance of the coating film is lowered.

  Further, the copolymer resin (main agent) coating liquid according to the present invention includes a heat stabilizer, an antioxidant, a reinforcing agent, a pigment, a deterioration preventing agent, a weathering agent, a flame retardant, and a plasticizer, as long as the characteristics are not impaired. , Mold release agents, lubricants and the like may be added.

  Examples of heat stabilizers, antioxidants and deterioration inhibitors that can be used include hindered phenols, phosphorus compounds, hindered amines, sulfur compounds, copper compounds, alkali metal halides, and mixtures thereof.

  Examples of reinforcing agents that can be used include clay, talc, calcium carbonate, zinc carbonate, wollastonite, silica, alumina, magnesium oxide, calcium silicate, sodium aluminate, sodium aluminosilicate, magnesium silicate, glass balloon, carbon black, and oxidation. Examples include zinc, zeolite, hydrotalcite, metal fiber, metal whisker, ceramic whisker, potassium titanate whisker, boron nitride, graphite, glass fiber, and carbon fiber.

  An inorganic layered compound may be mixed in the copolymer resin (main agent) coating liquid according to the present invention. Preferable examples of the inorganic layered compound include montmorillonite, beidellite, saponite, hectorite, saconite, vermiculite, fluoric mica, muscovite, paragonite, phlogopite, leoprite, margarite, clintonite, anandite, etc. Swellable fluoromica or montmorillonite is particularly preferred. These inorganic layered compounds may be naturally occurring, artificially synthesized or modified, or those treated with an organic material such as an onium salt.

(Curing agent)
In this invention, a hardening | curing agent is used in order to bridge | crosslink the copolymer resin which is a main ingredient. When the copolymer resin used as the main agent is applied alone, it exhibits gas barrier properties, but physical properties such as coating strength and heat resistance cannot be obtained. Therefore, a compound having an isocyanate group that reacts with a hydroxyl group that the copolymer resin as the main agent has as a side chain is used as a curing agent. Since a crosslinked structure is generated by the addition of the crosslinking agent, a gas barrier resin layer having physical properties such as gas barrier properties, coating film strength, and heat resistance is formed.

  Examples of the compound having an isocyanate group include aromatic diisocyanates, araliphatic diisocyanates, alicyclic diisocyanates, and aliphatic diisocyanates.

  Examples of aromatic diisocyanates that can be used include m- or p-phenylene diisocyanate, 4,4'-diphenyl diisocyanate, 1,5-naphthalene diisocyanate (NDI), 4,4'-, 2,4'- or 2, Examples include 2'-diphenylmethane diisocyanate (MDI), 2,4- or 2,6-tolylene diisocyanate (TDI), 4,4'-diphenyl ether diisocyanate, and the like.

  Examples of the araliphatic diisocyanate that can be used include 1,3- or 1,4-xylylene diisocyanate (XDI), 1,3- or 1,4-tetramethylxylylene diisocyanate (TMXDI), and the like.

  Examples of alicyclic diisocyanates that can be used include 1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate, 3-isocyanate methyl-3,5,5-trimethylcyclohexyl isocyanate (isophorone diisocyanate; IPDI), 4,4 ′. -, 2,4'- or 2,2'-dicyclohexylmethane diisocyanate (hydrogenated MDI), methyl-2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate, 1,3- or 1,4-bis (Isocyanate methyl) cyclohexane (hydrogenated XDI) and the like can be exemplified.

  Examples of the aliphatic diisocyanate that can be used include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), pentamethylene diisocyanate, 1,2-propylene diisocyanate, 1,2-, 2,3-, or 1,3- Examples include butylene diisocyanate, 2,4,4- or 2,2,4-trimethylhexamethylene diisocyanate.

  Furthermore, you may use the partial condensate of the isocyanate compound illustrated above, the compound etc. which have a hydroxyl group, 1 type of various derivatives, or these 2 or more types. For example, a wide range of diols from various low molecular weight diols to oligomers, and partial condensates with trifunctional or higher functional polyols as required.

  Considering the gas barrier performance of the gas barrier resin layer formed by the crosslinking reaction product of the main agent and the curing agent composed of a copolymer, among these compounds having an isocyanate group, 1,3- or 1,4-xylyl Range isocyanate (XDI) and its partial condensates are preferred. The three-dimensional structure of the crosslinked product greatly affects the gas barrier property. In order to develop gas barrier properties, it preferably has a xylylene diisocyanate skeleton. These compounds have a xylylene diisocyanate skeleton.

  The blending amount of the curing agent is the number of hydroxyl groups contained in the main copolymer resin (generally expressed by OH number) and the number of isocyanate groups contained in the curing agent resin (generally represented by NCO rate). Is preferably equivalent. The effect of the invention is not lost even if the amount of the curing agent is increased or decreased by about 15% by weight of the main copolymer resin. When the amount of the curing agent is increased, a coating film having particularly excellent coating film strength and heat resistance to the substrate film may be formed.

(Manufacture of gas barrier resin layer)
A predetermined amount of the copolymer resin (main agent) solution and a curing agent are blended and dissolved in a solvent to obtain a coating solution for the resin layer. Solvents that can be used include toluene, xylene, ethyl acetate, butyl acetate, acetone, methyl ethyl ketone, methyl isobutyl ketone, tetrahydrofuran, dimethylformamide, dimethylacetamide, methanol, ethanol, water and the like.

  In the present invention, the mixing ratio of the main agent and the curing agent constituting the gas barrier resin layer is not particularly limited, but if the amount of the curing agent is too small, the crosslinking reaction occurring between the main agent and the main agent becomes insufficient. However, not only does it cause curing failure, but the coating film strength does not sufficiently develop, and heat resistance, adhesion to the substrate, and the like are insufficient. Moreover, when there are too many compounding quantities of a hardening | curing agent, it not only becomes a cause which produces blocking, but it may produce inconvenience in post-processing etc. because an excess isocyanate compound transfers to another layer.

  There is no restriction | limiting in particular as a method to manufacture the gas barrier resin layer concerning this invention, It can manufacture by the method according to a base film. For example, printing methods such as offset printing method, gravure printing method, silk screen printing method, roll coating method, dip coating method, bar coating method, die coating method, knife edge coating method, gravure coating method, kiss coating method, spin coating method The coating liquid may be coated using a method such as a combination of these.

  In the present invention, when the gas barrier resin layer is formed and laminated on the first inorganic layer by coating, the temperature is preferably 70 ° C. or higher, more preferably 90 ° C. or higher, although it depends on the solvent used for the coating liquid. It is preferable to dry with. When the drying temperature is lower than 70 ° C., the coating film is not sufficiently dried, and it becomes difficult to obtain a gas barrier film having sufficient gas barrier performance. Moreover, an aging process can also be performed after the coating in order to sufficiently advance the crosslinking reaction between the main agent and the curing agent. By the aging treatment, the crosslinking reaction further proceeds, and sufficient coating strength, gas barrier performance, and heat resistance are easily developed.

  The thickness of the gas barrier resin layer is preferably 0.1 to 10 μm, more preferably 0.2 to 5 μm. When the thickness of the resin layer is 0.1 μm or more, the gas barrier property can be sufficiently improved, the processability at the time of coating can be improved, and a gas barrier resin layer free from defects such as film breakage and repellency can be formed. . On the other hand, when the thickness of the gas barrier resin layer is 10 μm or less, the solvent is sufficiently dried even when the drying conditions at the time of coating are low temperature and for a short time. This is preferable because it does not cause problems such as high costs.

  The gas barrier film of the present invention can be used as a gas barrier laminate in which a surface base film is laminated on the second inorganic layer side and a heat fusion film is laminated on the base film side.

  The heat-sealing film is for heat-sealing with the above gas barrier laminates or other materials, and is not particularly limited, but is not an unstretched polypropylene film or a linear low-density polyethylene film. It is preferable from the viewpoint of ease of heat fusion.

  The front substrate film is a film that is laminated on the outermost layer of the above-mentioned subbarrier laminate and has a function of mechanically protecting the gas barrier film of the present invention, and is not particularly limited, but a polyethylene terephthalate film, nylon From the object of the present base film, it is preferable that it is either a film or a polypropylene film. As a method for forming these films, a dry laminating method in which a two-component reaction curable adhesive is used, a non-solvent laminating method in which a non-solvent adhesive is used, a plastic material is heated and melted and extruded into a curtain shape, Any of the lamination methods such as extrusion lamination can be laminated by a known method.

The gas barrier performance of the gas barrier laminate using the gas barrier film of the present invention can achieve a water vapor transmission rate of less than 0.1 g / m ² 24 hr, or an elementary transmission rate of less than 0.1 cc / m ² 24 hr · atm. Satisfying both can also be achieved.

  In the present invention, the long-term heat resistance of the gas barrier performance is evaluated as the degree of oxygen permeability deterioration and the degree of water vapor permeability deterioration after long-term storage. The oxygen permeability deterioration degree and the water vapor permeability deterioration degree are values obtained by dividing the respective transmittances after long-term storage by the initial respective transmittances, and are preferably 10 or less. Moreover, the laminate strength deterioration degree after long-term storage is evaluated as a value obtained by dividing the laminate strength after long-term storage by the initial laminate strength, and is preferably 0.5 or more.

  EXAMPLES Examples will be given below to describe the present invention in detail, but the present invention is not limited to the examples. In the examples, “parts” means “parts by weight” unless otherwise specified. In addition, the physical property in an Example and a comparative example was measured as follows.

(1) Water vapor transmission rate (g / m ² 24 hr)
An average measured twice based on a differential pressure method using a water vapor permeability measuring device (DELTATAPRM type) manufactured by Technolox under the conditions of a temperature of 40 ° C. and a relative humidity of 100% on a laminate using a gas barrier film. Values were used. The initial value (before heat treatment) of water vapor permeability was less than 0.1 g / m ² 24 hr, and the degree of deterioration after long-term heat treatment was 10 or less.

(2) Oxygen permeability (cc / m ² 24 hr · atm)
A laminate using a gas barrier film is described in JIS K7126 (2000 version) using an oxygen transmission rate measuring device (OXTRAN2 / 21MH type) manufactured by MOCON under the conditions of a temperature of 23 ° C. and a relative humidity of 90%. The average value measured twice based on the B method (isobaric method) was used. The initial value (before heat treatment) of oxygen permeability was less than 0.1 cc / m ² 24 hr · atm, and the degree of deterioration after long-term heat treatment was 10 or less.

(3) Laminate strength (N / 15mm)
The laminate was cut into a width of 15 mm, and the laminate strength was measured with a tensile tester at a peeling angle of T type and a crosshead speed of 300 mm / min. The initial value (before heat treatment) of the laminate strength was 2N / 15 mm or more, and the deterioration degree after long-term heat treatment was 0.5 or more.

(4) Evaluation after long-term heat treatment The gas barrier film and the members described in Examples and Comparative Examples were laminated by dry lamination to obtain a gas barrier laminate.

  Two 20cm x 20cm laminates are cut out from the gas barrier laminate, stacked with the sealant film on the inside, and the three sides are fused by heat sealing to produce a bag, 9cm thick x 10cm x A glass wool insulation material (Asahi Fiber Glass Co., Ltd. high-performance glass wool “Aklia Wool” ACW) cut into 10 cm was put, and air was removed and heat-sealed to produce a vacuum insulation material.

  The vacuum heat insulating material was put in an oven at 80 ° C., taken out after 100 days, the bag was disassembled, and the water vapor permeability, oxygen permeability, and laminate strength of the gas barrier laminate were measured.

(Example 1)
First, the coating liquid for the gas barrier resin layer was adjusted by the following method.

  Acrylonitrile (AN), 2-hydroxyethyl methacrylate (2-HEMA), and methyl methacrylate (MMA) monomers are blended at 20 wt%, 50 wt%, and 30 wt%, respectively, and copolymerized by a known technique for copolymerization. A polymer resin was obtained. That is, a reactor equipped with a stirrer, a nitrogen gas introduction tube, a rectification tube, and a water separator is charged so as to have the above-mentioned quantity, and gradually heated so that the rectification tube upper temperature does not exceed 100 ° C The internal temperature was kept at 220 ° C. The reaction was terminated when the acid value became 1 mgKOH / g or less to obtain a copolymer resin. The obtained copolymer resin was dissolved in a mixed solvent of propyl acetate, propylene glycol monomethyl ether and n-propyl alcohol to obtain a copolymer resin solution having a solid content concentration of 30% by weight.

  Copolymer resin solution 10.0 parts, Dainippon Ink & Chemicals, Inc. isocyanate curing agent “Dick Dry” X-75 (XDI: xylylene diisocyanate) 2.5 parts and methyl ethyl ketone 28.1 parts were stirred for 30 minutes. Thus, a coating solution for a gas barrier resin layer having a solid content concentration of 12% by weight was prepared.

  Using polyethylene terephthalate having a thickness of 12 μm (“Lumirror” (registered trademark) P60, manufactured by Toray Industries, Inc.) as the base film, as the first inorganic layer, oxygen oxide was deposited at the time of aluminum deposition so that the thickness was 10 nm. After production by reactive vapor deposition, a resin layer having a dry thickness of 0.6 μm was formed using the above coating solution. On top of that, as a second inorganic material layer, aluminum was vacuum-deposited to a thickness of 180 nm to produce a gas barrier film.

  It is a second inorganic layer of the gas barrier film using a polyester-based adhesive (DIC Co., Ltd., main agent: registered trademark “Dick Dry” LX-500, curing agent: registered trademark “Dick Dry” KO-55). The adhesive was applied onto the aluminum layer so as to have an adhesive thickness of 4 μm, and bonded to a biaxially stretched nylon film (Unitika Co., Ltd. “OMNU Film”) having a thickness of 15 μm by a dry lamination method. Similarly, a linear low density polyethylene film (Tosero Co., Ltd. “FCS film”) having a thickness of 50 μm was laminated on the side opposite to the second inorganic layer side by dry lamination to produce a laminate.

(Example 2)
Except for forming aluminum as the first inorganic layer to a thickness of 185 nm, forming the gas barrier resin layer to a thickness of 0.4 μm, and forming the second inorganic layer to have a thickness of 100 nm, A gas barrier film and a laminate were produced in the same manner as in Example 1.

(Example 3)
Except that silicon oxide is formed as the first inorganic layer so that the thickness is 20 nm, the thickness of the gas barrier resin layer is 5 μm, and aluminum oxide is formed in the second inorganic layer so that the thickness is 7 nm. A gas barrier film and a laminate were produced in the same manner as in Example 1.

Example 4
Except that silicon oxide was formed as a first inorganic layer to a thickness of 25 nm, the gas barrier resin layer was formed to a thickness of 5 μm, and aluminum was formed to a thickness of 40 nm in the second inorganic layer. A gas barrier film and a laminate were produced in the same manner as in Example 1.

(Example 5)
A gas barrier film and a laminate were produced in the same manner as in Example 1 except that the monomers AN, 2-HEMA, and MMA of the copolymer resin were changed to 30 wt%, 30 wt%, and 40 wt%, respectively.

(Example 6)
A gas barrier film and a laminate were produced in the same manner as in Example 1 except that the monomers AN, 2-HEMA, and MMA of the copolymer resin were changed to 10% by weight, 70% by weight, and 20% by weight, respectively.

(Comparative Example 1)
Titanium oxide was formed as the first inorganic layer so as to have a thickness of 210 nm, the thickness of the gas barrier resin layer was 12 μm, and the second inorganic layer was not formed. The gas barrier film and laminate of Comparative Example 1 were produced. All of oxygen permeability, water vapor permeability, and laminate strength were insufficient from the initial values.

(Comparative Example 2)
Example 1 except that the first inorganic layer was not formed, the gas barrier resin layer was applied directly to the base film at a thickness of 0.07 μm, and copper was formed thereon as the inorganic layer at a thickness of 220 nm. A gas barrier film and a laminate were produced by various methods. All of oxygen permeability, water vapor permeability, and laminate strength were insufficient from the initial values.

(Comparative Example 3)
The first inorganic layer was formed to have a thickness of 2 nm, the gas barrier resin layer was not formed, and the indium oxide was formed to a thickness of 4 nm as the second inorganic layer. A gas barrier film and a laminate were produced by the method. All of oxygen permeability, water vapor permeability, and laminate strength were insufficient from the initial values. Any laminate strength was insufficient from the initial value.

(Comparative Example 4)
As a coating liquid for gas barrier resin layer, Toyobo Co., Ltd. organic solvent-soluble amorphous polyester resin ("Byron" GK640) is dissolved in methyl ethyl ketone and coated with a direct gravure method with a solid content concentration of 12%. Then, a gas barrier film and a laminate of Comparative Example were produced in the same manner as in Example 1 except that the gas barrier resin layer was 0.6 μm. The initial values of oxygen permeability, water vapor permeability, and laminate strength were good, but all deteriorated rapidly after long-term heat treatment.

(Comparative Example 5)
For the gas barrier resin layer coating solution, a copolymer polyester resin ("Chemit" (registered trademark) K-1294 (trade name)) manufactured by Toray Industries, Inc. is dissolved in NMP, and the solid content concentration is 12%. A gas barrier film of comparative example and a laminate were produced in the same manner as in comparative example 4 except that. The initial values of oxygen permeability, water vapor permeability, and laminate strength were good, but all deteriorated rapidly after long-term heat treatment.

In all the results shown in the examples, the initial oxygen permeability is less than 0.1 cc / m ² 24 hr · atm, the initial water vapor permeability is less than 0.1 g / m ² 24 hr, and the initial laminate strength is 2 N / 15 mm. As described above, the oxygen permeability deterioration degree after long-term heat treatment is 10 or less, the water vapor permeability deterioration degree is 10 or less, and the laminate strength deterioration degree is 0.5 or more.

According to the gas barrier film of the present invention, a gas barrier having a water vapor barrier performance of 0.1 g / m ² 24 hr or less, an oxygen barrier performance of 0.1 cc / m ² 24 hr · atm or less, and long-term heat resistance of these gas barrier performances. Can be realized. As a result, it can be used as a gas barrier laminate that can be suitably used as an outer packaging bag of a vacuum heat insulating material.

1: Base film
2: First inorganic layer
3: Gas barrier resin layer
4: Second inorganic layer 5: Gas barrier film 6: Front substrate film 7: Thermal fusion film

Claims (9)

A gas barrier film in which a first inorganic layer, a gas barrier resin layer, and a second inorganic layer are laminated in this order on at least one surface of a base film, wherein the gas barrier resin layer is (a) an unsaturated nitrile, (b) Consists of an unsaturated compound having a hydroxyl group, (c) a main agent composed of a copolymer comprising three components of unsaturated carboxylic acid ester as a monomer, and a curing agent composed of a compound having an isocyanate group. Gas barrier film. The weight fractions of the component (a), the component (b), and the component (c) in the copolymer are 10 to 30% by weight, 30 to 70% by weight, and 20 to 60% by weight, respectively. The gas barrier film according to claim 1. The first inorganic layer and the second inorganic layer are each formed of at least one selected from aluminum, aluminum oxide, silicon oxide, silicon oxynitride, and a mixture thereof. The gas barrier film according to the description. The gas barrier film according to any one of claims 1 to 3, wherein the component (a) is acrylonitrile. The gas barrier film according to claim 1, wherein the component (b) is 2-hydroxyethyl methacrylate. The gas barrier film according to claim 1, wherein the component (c) is methyl methacrylate. A gas barrier laminate, wherein the gas barrier film according to any one of claims 1 to 6 is laminated with a surface base film on the second inorganic layer side and a heat fusion film on the base film side. . The gas barrier laminate according to claim 7, wherein the heat-sealing film is an unstretched polypropylene film or a linear low-density polyethylene film. The gas barrier laminate according to claim 7 or 8, wherein the front substrate film is any one of a polyethylene terephthalate film, a nylon film, and a polypropylene film.

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