JP2013075442A - Metal-deposited multilayer high barrier film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metal-deposited multilayer high barrier film capable of reducing a laminate frequency or a base material used, and further having a combination of an excellent gas barrier property and pinhole resistance while reducing costs, and a vacuum insulation material which is obtained using the multilayer high barrier film and can maintain a high vacuum.SOLUTION: The metal-deposited multilayer high barrier film has a coextruded composite stretched film having a gas barrier layer as an inner layer and thermoplastic resin layers as surface layers formed at both sides of the gas barrier layer. At least one side of the surface layers of the coextruded composite stretched film is subjected to surface treatment and includes a metal vacuum-deposited thereon. The vacuum insulation material uses the metal-deposited multilayer high barrier film.

Description

  The present invention relates to a metal-deposited multilayer high barrier film that is excellent in gas barrier properties and pinhole resistance and enables cost reduction, and particularly relates to a multilayer high barrier film that is suitably used for a vacuum heat insulating material that can maintain a high degree of vacuum.

In order to maintain a higher degree of vacuum in vacuum insulation materials used for heat insulation structures such as refrigerators, freezers, rice cookers, desktop pots, cooler boxes, residential building materials, automobiles, and railway vehicles, polyethylene has conventionally been used as a barrier material. Transparent vapor-deposited polyethylene terephthalate (PET) film in which inorganic silica is vapor-deposited on terephthalate film, ethylene-vinyl alcohol resin film (EVOH film), EVOH film in which aluminum is vapor-deposited, films with barrier properties such as aluminum foil, etc. Was used. These barrier materials are not usually used in a single layer, and have been utilized by increasing the quality by laminating a base material that compensates for insufficient properties. Examples of supplemental properties include gas barrier properties, pinhole resistance, and sealing properties. For example, Patent Document 1 illustrates the configuration of ONY // aluminum-deposited EVOH // LLDPE. And sealability is imparted by LLDPE.
On the other hand, in the configuration of ONY // silica-deposited PET // LLDPE, which is an example of the transparent vapor-deposited PET film on which silica is vapor-deposited, ONY and LLDPE have similar functions, but such films are bent or the like. In some cases, it may be difficult to use as an excellent barrier material, such as cracks in the deposited layer and failure to satisfy the required barrier performance. Therefore, the barrier property required can be satisfied and can be used in a situation where bending or the like does not occur.

As described above, the high barrier film is required to have gas barrier properties and further to pinhole resistance. Usually, in order to impart pinhole resistance, it is common to laminate and use an ONY film. It has become a structure.
As an example in which an ONY film is not used, Patent Document 2 discloses a protective layer, a gas barrier layer, and a heat layer made of a coextruded stretched film in which a nylon resin, an ethylene-vinyl alcohol copolymer, and a nylon resin are laminated in this order. The case of having a fusion layer is described. In this case, although an ONY film is not used, since aluminum foil is used as a barrier layer, the number of times of lamination increases, and the cost of the aluminum foil has been regarded as a problem.

Japanese Patent No. 4642265 International Publication 2011-068148 Pamphlet

As described above, in the prior art, pinhole resistance is required in order to maintain gas barrier properties. For this reason, an ONY film (biaxially stretched film) is required, and this is mostly used after being laminated. It was. In the case of such a barrier film, the number of times of lamination increases or the ONY film has to be purchased separately, which complicates the process and imposes cost constraints.
Also, even when using a nylon / EVOH / nylon coextrusion stretched film, if an aluminum foil is used to improve the barrier properties, an ONY film need not be used. In addition, there are problems such as an increase in the number of laminations and an increase in the purchase cost of aluminum foil. Also, aluminum foil and films laminated with aluminum foil are flexible, so pinhole resistance is not always sufficient when subjected to bending, etc., and it is necessary to increase the thickness of the aluminum foil, which is economical There were disadvantages to this.

  Therefore, the present invention was devised to eliminate the conventional drawbacks, and can reduce the number of times of lamination and the base material to be used, and further has excellent gas barrier properties and pinhole resistance, and cost. It is an object of the present invention to provide a metal-deposited multilayer high barrier film that can be reduced, and a vacuum heat insulating material that is obtained using the metal-deposited multilayer high barrier film and that can maintain a high degree of vacuum.

  The present invention has a coextruded composite stretched film having a gas barrier layer as an inner layer and a thermoplastic resin layer as a surface layer provided on both sides of the gas barrier layer, and at least one of the surface layers of the coextruded composite stretched film The present invention relates to a metal-deposited multilayer high barrier film, wherein a metal is vacuum-deposited on the side, and a vacuum heat insulating material obtained using the metal-deposited multilayer high barrier film.

  According to the present invention, it is possible to provide a metal-deposited multilayer high barrier film that has excellent gas barrier properties and pinhole resistance and enables cost reduction, and a vacuum heat insulating material that can maintain a high degree of vacuum.

  The present invention is described in further detail below. However, the scope of the present invention is not limited to the embodiments described below.

[Metal-deposited multilayer high barrier film]
<Thermoplastic resin layer as surface layer>
The metal-deposited multilayer high barrier film of the present invention has surface layers on both sides of the gas barrier layer which is an inner layer, and a thermoplastic resin layer is used as each of the surface layers.
The thermoplastic resin layer as the surface layer is preferably a resin layer made of a resin composition containing a polyamide resin from the viewpoint of pinhole resistance, and the resin composition containing a polyamide resin is an effect of the present invention. In the range which does not impair the resin, it may contain a resin other than the polyamide-based resin, an additive or the like, or may be a multilayer body formed by laminating a thermoplastic resin layer made of a resin other than the polyamide-based resin.

  Although it does not specifically limit as a polyamide-type resin, It is preferable to use what has a 3-membered ring or more lactam, the superposition | polymerization omega-amino acid, diamine, and dicarboxylic acid as a main component (50 mol% or more). When the polyamide resin is a copolymer, the polyamide component is preferably contained in an amount of 80 mol% or more, more preferably 85 mol% or more, and further preferably 90 mol% or more.

  The polyamide resin is not particularly limited, and may be any of a polymer of lactams having three or more members, a polymer of ω-amino acids, a polycondensate of dicarboxylic acids and diamines, and the like. Specifically, for example, polymers of lactams such as γ-butyrolactam, δ-valerolactam, ε-caprolactam, enantolactam, ω-lauryllactam, 6-aminocaproic acid, 7-aminoheptanoic acid, 8-aminooctane Polymers of amino acids such as acid, 9-aminononanoic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, fats such as ethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, octamethylenediamine, decamethylenediamine Group diamine, 1,3- or 1,4-bis (aminomethyl) cyclohexane Diamines such as cycloaliphatic diamines such as xane and bis (p-aminocyclohexylmethane), aromatic diamines such as m- or p-xylylenediamine, glutaric acid, adipic acid, β-methyladipic acid, pimelic acid , Suberic acid, azelaic acid, sebacic acid, decamethylene dicarboxylic acid, aliphatic dicarboxylic acid such as dodecamethylene dicarboxylic acid, cycloaliphatic dicarboxylic acid and other alicyclic dicarboxylic acids, terephthalic acid, isophthalic acid and other aromatic dicarboxylic acids, etc. Examples thereof include polycondensates with dicarboxylic acids and copolymers thereof, and are preferably aliphatic polyamides, aromatic polyamides, or a mixture thereof because they have sufficient strength and are inexpensive.

  The aliphatic polyamide is preferably made of nylon 6, the aromatic polyamide is preferably made of polymetaxylylene adipamide, and is obtained by ring-opening polymerization of ε-caprolactam, etc., and has a melting point of about 220 to 225 ° C. It is particularly preferable to use the polyamide 6 as a main component. These polyamide resins may be homopolymers, copolymers or mixtures thereof.

In the present invention, the polyamide resin is preferably contained in the thermoplastic resin layer constituting the surface layer in an amount of 70% by mass or more, more preferably 75% by mass or more, and further preferably 80% by mass or more. .
In addition, 5-40 mass% of polymetaxylylene adipamide can be mixed with a polyamide-type resin layer for extending | stretching improvement. However, when the polyamide resin layer contains a polyamide other than the polyamide resin, the melting point of the polyamide is preferably 250 ° C. or less.

In addition, resins such as polyolefins, polyamide elastomers, and polyester elastomers can be added to the surface layer for the purpose of imparting flexibility, impact resistance, and the like.
In the present invention, the surface layer may be composed of two or more layers. Although there is no restriction | limiting in particular about the thickness of each said surface layer, It is preferable that it is 1-10 micrometers from viewpoints, such as a softness | flexibility and impact resistance, More preferably, it is 3-7 micrometers.

<Gas barrier layer as inner layer>
The metal-deposited multilayer high barrier film of the present invention has a gas barrier layer as an inner layer. In the present invention, the gas barrier layer is preferably made of ethylene-vinyl acetate copolymer saponified product (EVOH), aromatic polyamide or the like from the viewpoint of coextrusion processability and gas barrier property.
The ethylene content in EVOH is not particularly limited, but is preferably 5 mol% or more, more preferably 23 mol% or more, still more preferably 27 mol% or more, from the viewpoint of film formation stability. From the viewpoint of gas barrier properties, it is preferably 60 mol% or less, more preferably 38 mol% or less, still more preferably 32 mol% or less. Further, the saponification degree of EVOH is preferably 90% or more, more preferably 96% or more, and further preferably 99 mol% or more. In the present invention, by maintaining the ethylene content and saponification degree in EVOH within the above ranges, good oxygen barrier properties can be maintained, and coextrusion properties and film strength can be improved. .

  In addition to the saponified product of ethylene and vinyl acetate binary copolymer, the EVOH contains a small amount of an α-olefin such as propylene, isobutene, α-octene, α-dodecene, α-octadecene as a copolymer component; It may contain saturated carboxylic acids, or salts thereof, partial alkyl esters, fully alkyl esters, nitriles, amides, anhydrides, unsaturated sulfonic acids, salts thereof, etc., and other resins, specifically A mixture of a thermoplastic resin such as a polyamide resin, a polyolefin resin, or a polyester resin may be used.

In the present invention, the aromatic polyamide used for the gas barrier layer can be the same as that used for the surface layer described above, and polymetaxylylene adipamide is preferable from the viewpoint of coextrusion processability and gas barrier properties. . In addition, additives such as polyolefins, polyamide elastomers, and polyester elastomers can be blended in the gas barrier layer for the purpose of flexibility, impact resistance, and the like.
In the present invention, the EVOH or aromatic polyamide is preferably contained in the gas barrier layer in an amount of 90% by mass or more, more preferably 93 to 98% by mass.
The thickness of the gas barrier layer as the inner layer is preferably 1 to 10 μm, more preferably 3 to 7 μm, from the viewpoint of coextrusion processability and gas barrier properties.

<Co-extrusion composite stretched film>
In the present invention, the coextruded composite stretched film has the surface layer and the inner layer.
The coextruded composite stretched film in the present invention can be produced by a conventionally known method. First, as a raw material, a thermoplastic resin such as a polyamide-based resin for a surface layer, EVOH for a gas barrier layer, or the like is used. A laminated unstretched film). The production of this laminated unstretched film is, for example, by melting the above raw materials with 2 to 5 extruders, extruding from a flat die or an annular die, and then rapidly cooling to form a flat or annular laminated unstretched film and The coextrusion method is preferably employed.

Next, the above-mentioned laminated unstretched film is usually at least twice, preferably 2.0 to 5.0 times in at least one direction in the film flow direction (longitudinal direction) and the direction perpendicular thereto (lateral direction). More preferably, the film is stretched in the range of 2.5 to 4.5 times, more preferably 2.5 to 4.0 times in the longitudinal and transverse biaxial directions. If the draw ratios in the longitudinal and transverse biaxial stretching directions are each 2.0 times or more, the stretching effect is sufficient and the film has excellent strength, and the stretching ratio in the biaxial stretching direction. Is 5.0 times or less, the laminated film does not tear or break during stretching.
As the biaxial stretching method, conventionally known stretching methods such as tenter-type sequential biaxial stretching, tenter-type simultaneous biaxial stretching, and tubular simultaneous biaxial stretching can be adopted as long as the gist of the present invention is not exceeded.

For example, in the case of the tenter-type sequential biaxial stretching method, the laminated unstretched film is heated to a temperature range of 50 to 110 ° C. and stretched 2.0 to 5.0 times in the longitudinal direction by a roll type longitudinal stretching machine. Subsequently, the film is stretched 2.0 to 5.0 times in the transverse direction within a temperature range of 60 to 140 ° C. by a tenter type transverse stretching machine.
In the case of the tenter simultaneous biaxial stretching or the tubular simultaneous biaxial stretching method, for example, in the temperature range of 60 to 130 ° C., the film is stretched 2.0 to 5.0 times in each axial direction at the same time in the vertical and horizontal directions. Can be manufactured.

  The stretched laminated biaxially stretched film is preferably subsequently heat-set (heat treated). Thereby, dimensional stability at room temperature can be imparted. The heat treatment temperature in this case is preferably selected within a range where 110 ° C. is the lower limit and the temperature is 2 ° C. lower than the melting point of each polyamide. Thereby, the stretched film which is excellent in normal temperature dimensional stability and has an arbitrary heat shrinkage rate can be obtained. The laminated biaxially stretched film that has been sufficiently heat-set by the heat treatment operation can be cooled and wound by a conventional method.

  The coextruded composite stretched film obtained by heat treatment preferably has a hot water shrinkage of 0.5 to 5.0% in both the longitudinal and transverse directions at 95 ° C. for 5 minutes. When the hot water shrinkage is 0.5% or more, the heat treatment temperature is appropriate, and the mechanical strength of the coextruded composite stretched film is maintained. In addition, if the hot water shrinkage is 5.0% or less, the heat treatment temperature is sufficient, and the shrinkage does not occur due to heat applied in post-processing such as metal vapor deposition, so that laminating wrinkles and Does not cause distortion. The hot water shrinkage is preferably 0.8 to 4.5%, more preferably 1.0 to 4.0%.

  The thickness of the coextruded composite stretched film in the present invention is preferably 5 to 40 μm. If the total thickness is 5 μm or more, the oxygen gas barrier property and the bending pinhole property are excellent in balance, and the wear resistance is sufficient, which is suitable for packaging applications. Moreover, if it is 40 micrometers or less, the softness | flexibility of a film is maintained, and also when a sealant layer is bonded together, the whole film does not become thick and is suitable for a flexible packaging use. From the above viewpoint, the thickness of the coextruded composite stretched film is more preferably 10 to 30 μm, still more preferably 12 to 27 μm, from the viewpoint of film processability and the like.

  When performing metal vapor deposition on the co-extruded composite stretched film, surface treatment such as corona discharge treatment should be applied to the surface of the co-extruded composite stretched film on which metal vapor deposition is performed in order to improve the metal adhesion strength to the film. Is preferred. Preferred examples of the surface treatment include corona treatment, plasma treatment, flame treatment, and the like. From the above viewpoint, corona treatment is preferred. As for the degree of treatment, the wetting tension index measured by the wetting tension test method (JIS K6768) is preferably 42 mN / m or more, more preferably 50 mN / m or more if there is a wetting tension index. It is preferable to secure an adhesion strength of 150 gf / 15 mm width or more.

  The thickness ratio of the resin layer (including the gas barrier layer) other than the surface layer in the coextruded composite stretched film is preferably more than 0% and preferably 10% or more. The thickness ratio is preferably 50% or less, more preferably 45% or less, and further preferably 40% or less. By setting the thickness of the resin layer other than the surface layer in such a range, it is possible to further improve characteristics such as oxygen barrier properties and impact resistance without impairing the transparency and moisture resistance of the multilayer film of the present invention. it can.

<Metal vapor deposition layer>
In the present invention, on at least one side of the surface layer of the coextruded composite stretched film, for example, using a vacuum deposition apparatus, the film thickness is preferably 200 to 1000 mm, more preferably 300 to 800 mm, and still more preferably 400 to A 700-nm metal vapor deposition layer is formed. As the metal of the metal vapor deposition layer, metals such as aluminum, chromium, zinc, gold, silver, platinum, nickel and the like are used, and aluminum is preferable from the viewpoint of cost and vapor deposition workability. If the film thickness of a metal vapor deposition layer is in the said range, gas barrier property and water vapor permeability are favorable and preferable.

<Thermoplastic resin layer having heat sealability>
In addition to the coextruded composite stretched film and the metal vapor deposition layer, the metal vapor deposition multilayer high barrier film of the present invention is further provided with a thermoplastic resin layer having heat sealability on at least one surface of the surface layer, preferably the inner side. Hereinafter, it may be referred to as “heat-sealable resin layer”. The resin used for the heat-sealable resin layer is not limited as long as it is a heat-sealable thermoplastic resin, and is appropriately determined in consideration of the material of the adherend. Examples of heat-sealable thermoplastic resins include olefin resins, styrene resins, ester resins, ethylene resins having adhesion to ester resins, styrene resins, or adhesion to styrene resins. The olefin resin is preferably used from the viewpoint of ease of handling such as sealing strength.

  Examples of olefin resins include ethylene resins such as very low density polyethylene (VLDPE), low density polyethylene (LDPE), medium density polyethylene (MDPE) or high density polyethylene (HDPE), and linear low density polyethylene (LLDPE); Ethylene-vinyl acetate copolymer (EVA), ethylene-methyl methacrylate copolymer (EMMA), ethylene-ethyl acrylate copolymer (EEA, ethylene-methyl acrylate copolymer (EMA), ethylene-ethyl acrylate-anhydrous Ethylene copolymers such as maleic acid copolymer (E-EA-MAH), ethylene-acrylic acid copolymer (EAA), ethylene-methacrylic acid copolymer (EMAA); ethylene-acrylic acid copolymer Metal neutralized product, ethylene-methacrylic acid copolymer metal Japanese products (for example, those in which at least 10 mol%, preferably 10 to 60 mol% of the carboxyl groups are neutralized with ions of metals such as sodium and zinc); ionomer, homopolypropylene, block copolymer or Random copolymer type polypropylene resin, ethylene-propylene copolymer, polybutene-1, ethylene-butene-1 copolymer, propylene-butene-1 copolymer, ethylene-propylene-butene-1 copolymer, ethylene -Vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-ethyl acrylate copolymer, ethylene-ethyl methacrylate copolymer and the like.

Examples of the styrenic resin include styrene copolymers in which a small amount of rubber and other vinyl monomers are copolymerized with styrene monomers in addition to polystyrene. Examples of other vinyl monomers include styrene monomers such as α-methylstyrene and p-methylstyrene, acrylonitrile, methyl acrylate, methyl methacrylate, acrylic acid, methacrylic acid, and maleic anhydride. Can be mentioned. Moreover, the usage-amount of a rubber part is 0.1-20 mass% normally with respect to a styrene-type copolymer, and the usage-amount of another vinyl-type monomer is 0.1-30 mass% normally. Preferred examples of the styrene resin include polystyrene and high impact polystyrene (HIPS) which is a copolymer of diene rubber and styrene.
In addition, these resin can be used individually or in mixture. The heat-sealable resin layer may be composed of two or more layers made of different resins as necessary.

  The thickness of the heat-sealable resin layer is preferably 10 μm or more, more preferably 20 μm or more, further preferably 30 μm or more, preferably 100 μm or less, more preferably 75 μm or less, and even more preferably 50 μm or less. If the thickness of the heat-sealable resin layer is 10 μm or more, it is preferable because a decrease in seal strength can be suppressed.

<Metal vapor deposition multilayer high barrier film>
The metal-deposited multilayer high barrier film of the present invention has the coextruded composite stretched film having the surface layer and the inner layer, and a metal is vacuum deposited on at least one side of the surface layer of the coextruded composite stretched film. It is what.
If the metal vapor deposition multilayer high barrier film of this invention has the said structure, there will be no restriction | limiting in particular in the layer structure, Specifically, the following structures can be mentioned.
(1) Metal vapor deposition layer / surface treatment surface layer / inner layer / surface layer // heat seal resin layer (2) Surface layer / inner layer / surface treatment surface layer / metal vapor deposition layer // heat seal resin layer (3) Metal vapor deposition layer / Surface treatment surface layer / Inner layer / Surface treatment surface layer / Metal deposition layer // Heat seal resin layer (4) Surface treatment surface layer / Inner layer / Surface treatment surface layer / Metal deposition layer // Heat seal resin layer Metal of the present invention The total thickness of the vapor-deposited multilayer high barrier film is preferably 5 to 40 μm, more preferably 10 to 30 μm, and still more preferably 12 to 27 μm.

The metal-deposited multilayer high barrier film of the present invention preferably has an oxygen permeability of 2 ml / m ² · day · MPa [25 ° C. × 80% RH] or less. In particular, considering the thermal conductivity of the vacuum heat insulating material, the value is more preferably 1.5 ml / m ² · day · MPa [25 ° C. × 80% RH] or less, and 1.0 ml / m ² · More preferably, it is not more than day · MPa [25 ° C. × 80% RH]. The water vapor permeability is preferably 0.3 g / (m ² · d) [40 ° C. × 90% RH] or less. In particular, considering the thermal conductivity of the vacuum heat insulating material, the value is preferably 0.25 g / (m ² · d) [40 ° C. × 90% RH] or less.

[Vacuum insulation]
The metal-deposited multilayer high barrier film of the present invention is preferably used for a vacuum heat insulating material from the viewpoint of having sufficient gas barrier properties and pinhole resistance and enabling cost reduction.
Specifically, the vacuum heat insulating material is obtained using the metal-deposited multilayer high barrier film of the present invention. For example, the two metal-deposited multilayer high barrier films having the heat-sealable resin layer are used to heat each other. Combine the sealing layers and make a bag by heat sealing, and put the material that can develop a heat insulation effect into the resulting bag, and then heat seal the interior preferably with a vacuum of 100 Pa or less. Are preferably mentioned.
Examples of materials that can exhibit a heat insulating effect include fine powders such as silica and calcium silicate, and molded products such as glass wool, rock wool, styrene foam, and polyurethane foam. In order to draw out, it is more preferable that it is 50 Pa or less, and the more suitable vacuum degree is 1-3 Pa.

  The vacuum heat insulating material of the present invention has the above-mentioned sufficient gas barrier property and pinhole resistance, and enables cost reduction, from the refrigerator, freezer, rice cooker, desktop pot, cooler box, residential building material, automobile, and It is preferably used for a heat insulating structure selected from railway vehicles. From the above viewpoint, it is more preferable to use for items that are expected to have a great effect on heat insulation.

  EXAMPLES Hereinafter, although the content and effect of this invention are demonstrated in detail by an Example, this invention is not limited to the following examples. In the following examples, the obtained film was evaluated by the following method.

(1) AL vapor-deposited layer adhesion strength Urethane-based two-pack type adhesive (manufactured by Toyo Morton Co., Ltd., AD900 / RT5) was used for the metal vapor-deposited multilayer high barrier film obtained by the method described in each of the following examples. Then, an unstretched polyethylene film (Mitsui Chemicals Tosero Co., Ltd., FCS, thickness 50 μm) was dry laminated to prepare a laminated film. Next, after this laminated film was aged at 40 ° C. for 3 days, the laminate strength of the AL-deposited multilayer high barrier film and the unstretched polyethylene film was measured with a tensile tester [manufactured by Shimadzu Corporation, Autograph AG-I]. Was measured. The measurement conditions were a laminate film having a width of 15 mm, peeled from the AL vapor deposition surface, and measured the AL adhesion strength in the direction perpendicular to the flow direction (TD) with T-type peeling and a peeling speed of 20 mm / min.
The AL adhesion strength was 150 gf / 15 mm width or more, and the strength lower than 150 gf / 15 mm width was insufficient.

(2) Resistance to bending pinholes [number of pinholes / 497 cm ² (= 77 inch ² )]
The barrier film cut to a size of 20.3 m × 27.9 cm was conditioned at 23 ° C. in a 50% RH atmosphere for 24 hours or longer, and gelboflex tester (“No.901 type” manufactured by Rigaku Corporation). (Compliant with MIL-B-131C standard)), the bending test is repeated as follows, and the number of pinholes is measured.
The rectangular test film is formed into a cylindrical shape having a length of 20.3 cm, and one end of the wound cylindrical film is placed on the outer periphery of the disk-shaped fixed head of the tester, and the other end is placed on the outer periphery of the tester disk-shaped movable head. Respectively. While the movable head is made to approach 8.9 cm along the axis of both heads facing in parallel to the direction of the fixed head (the fixed head and the movable head are opposed to each other by 17.8 cm), 440 Rotate. Subsequently, a straightening test is performed in which the straight line travels 6.4 cm without rotating, and then reverses these operations, and the stroke until the movable head is returned to the initial position is one cycle. 3000 cycles are performed continuously at a rate of 40 cycles per minute. Thereafter, the number of pinholes generated in a portion within 17.8 cm × 27.9 cm (7 inch × 11 inch = 77 inch ² = 496 cm ² ) excluding the fixed head of the tested film and the portion fixed to the outer periphery of the movable head, Measurement is performed by applying a voltage of 1 KV with a pinhole tester (“TRD type” manufactured by Sanko Electronics Laboratory).
The number of pinholes of 20 or less was considered good, and the number of pinholes exceeding 20 was considered insufficient.

(3) Oxygen permeability Using an OXY-TRAN100 type oxygen permeability measuring device manufactured by Modern Control Co., Ltd., the barrier film was measured at 23 ° C. × 50% RH to obtain oxygen permeability.
The oxygen permeability was 2.0 [ml / m ² · day · MPa] or less. Further, it was considered insufficient to exceed 2.0 [ml / m ² · day · MPa].

(4) Water vapor transmission rate Based on JIS K7129B, the water vapor transmission rate of the barrier film was measured in an atmosphere of 40 ° C. and 90% RH using PERMATRAN W 3/31 manufactured by MOCON. A water vapor permeability of 0.3 g / (m ² · 24 hours · MPa) or less was regarded as acceptable.

(5) Cost Indicates the production cost, ○: cheap (good), Δ: normal, ×: high (insufficient).

<Materials used>
[Polyamide resin]
Polyamide-1: Product name Novamid 1022C6 (polyamide 6) manufactured by DM Japan Engineer Plastics Co., Ltd.
Polyamide-2: Mitsubishi Gas Chemical Co., Ltd. trade name MX nylon S6007 (polyamide MXD6, metaxylenediamine / adipic acid = 50.5 / 49.5 mol%)

[Saponified ethylene-vinyl acetate copolymer]
Product name Soarnol DC3203 manufactured by Nippon Synthetic Chemical Industry Co., Ltd. (EVOH, ethylene content: 32 mol%)
[Aluminum foil]
Japanese foil 1N30 material 7μm, 12μm
[LLDPE film]
Mitsui Chemicals Tosero Co., Ltd. Tosero T.U.X.FCS 50μm
[EVOH aluminum evaporated film]
Kuraray Co., Ltd. Eval Film VM-XL 15μm
[ONY film]
Made by Mitsubishi Plastics Co., Ltd. Biaxially stretched nylon film Santonyl SNR 15μm
[Silica-deposited PET]
Transparent high gas barrier film manufactured by Mitsubishi Plastics Co., Ltd. Tech Barrier HX12μm

Example 1
The raw material for layer (A) is polyamide-1 mixed with 2% silica AB agent masterbatch, and the raw material for layer (B) is EVOH [Nippon Synthetic Chemical Co., Ltd. “Soarnol DC3203”, ethylene content 32 mol %], And polyamide-1 was used as a raw material for the layer (C). Then, using three φ65 mm extruders, the raw materials were melted separately, and the polyamide-1 of the layer (A) and the polyamide-1 of the layer (C) were divided into approximately half by the distribution block, respectively. It is laminated in an extrusion T-die, extruded as a laminated film having a five-layer structure, and each layer thickness is 35 μm / 20 μm in a layer (A) / layer (C) / layer (B) / layer (C) / layer (A) configuration. A melted film comprising / 40 μm / 20 μm / 35 μm was obtained, and then rapidly cooled on a cooling roll at 30 ° C. to obtain an unstretched laminated film having a thickness of 150 μm.

  Next, after heating and heating the unstretched laminated film to 50 ° C., the film was stretched three times in the machine direction by a roll-type longitudinal stretching machine at this temperature condition, and further heated to 120 ° C. and then tenter-type lateral stretching. The film was stretched by 3.3 times in the transverse direction. Subsequently, the obtained biaxially stretched film was heat-treated at 215 ° C. for 6 seconds to obtain a stretched laminated film having a total thickness of 15 μm. Furthermore, the corona treatment of 50 mN / m or more was performed on both the AL deposition surface side and the opposite side by an in-line corona treatment apparatus. As a subsequent process, AL was vapor-deposited with a film thickness of 330 mm using a vacuum vapor deposition apparatus. Furthermore, the product name TM-329 manufactured by Toyo Morton Co., Ltd. as the main agent as an adhesive on the opposite side of the AL vapor deposition surface of the film. The product name CAT-8B manufactured by Toyo Morton Co., Ltd. as a curing agent, and ethyl acetate as a diluent solvent, TM-329, CAT-8B, and ethyl acetate were mixed in a mass ratio of 13.8 / 13.8. /72.4 After mixing, gravure coating, drying at 70 ° C. to remove ethyl acetate, the adhesive coating thickness is 0.005 mm, LLDPE 50 μm is laminated, and aged at 40 ° C. for 48 hours. A multilayer barrier film of Example 1 was obtained.

Examples 2-4
A multilayer barrier film of Example 2-4 was obtained in the same manner as in Example 1, except that the thickness of 330 mm of the AL deposited layer by the vacuum deposition apparatus was changed to 500 mm, 650 mm, and 800 mm, respectively.

Example 5
In Example 1, except that the AL vapor deposition layer thickness 330 mm by the vacuum vapor deposition apparatus was changed to 500 mm, and the vacuum vapor deposition apparatus was used twice, and an AL vapor deposition layer having a thickness of 500 mm was provided on both sides of the stretched laminated film. In the same manner, a multilayer barrier film of Example 5 was obtained.

Example 6
As a raw material for the layer (A), polyamide-1 mixed with 2% of a silica AB agent master batch, polyamide-2 was used as a raw material for the layer (B), and polyamide-1 was used as a raw material for the layer (C). Then, using three φ65 mm extruders, the raw materials were separately melted. Further, the polyamide AB of the silica AB agent-containing layer (A) and the polyamide-1 of the layer (C) were each approximately half in the distribution block. Divided and laminated in a coextrusion T-die, extruded as a laminated film with a five-layer structure, each layer thickness in the layer (A) / layer (C) / layer (B) / layer (C) / layer (A) configuration The melted films each consisting of 35 μm / 20 μm / 40 μm / 20 μm / 35 μm were obtained, and then rapidly cooled on a cooling roll at 30 ° C. to obtain an unstretched laminated film having a thickness of 150 μm.

  Next, after heating and heating the unstretched laminated film to 50 ° C., the film was stretched three times in the longitudinal direction by a roll-type longitudinal stretching machine at this temperature condition, and further heated to 120 ° C. and then tenter-type lateral stretching. The film was stretched by 3.3 times in the transverse direction. Subsequently, the obtained biaxially stretched film was heat-treated at 215 ° C. for 6 seconds to obtain a stretched laminated film having a total thickness of 15 μm. The following post-process was performed in the same manner as in Example 1 to obtain a multilayer barrier film of Example 6.

Comparative Example 1
In Example 3, the multilayer barrier film of Comparative Example 1 was obtained in the same manner except that the corona treatment was not performed on the AL vapor deposition surface of the stretched laminated film having a total thickness of 15 μm using an in-line corona treatment apparatus.

Comparative Example 2
Three types of ONy (15 μm), EVOH aluminum vapor-deposited film (Kuraray VM-XL) 15 μm and LLDPE 50 μm film are used in this order as the main agent, product name TM-329 manufactured by Toyo Morton Co., Ltd., and as a curing agent manufactured by Toyo Morton Co., Ltd. The product name CAT-8B and ethyl acetate as a diluent solvent, TM-329, CAT-8B, and ethyl acetate were mixed at a mixing mass ratio of 13.8 / 13.8 / 72.4, After gravure coating, drying was performed at 70 ° C. to remove ethyl acetate, and the adhesive coating thickness was set to 0.005 mm, respectively, and the laminate was aged at 40 ° C. for 48 hours to obtain a multilayer barrier film of Comparative Example 2. .

Comparative Example 3
Three types of ONY film (15 μm), silica-deposited PET (Tech Barrier HX) 12 μm, and LLDPE film 50 μm were dry laminated in this order in the same manner as in Comparative Example 2 to obtain a multilayer barrier film composition of Comparative Example 3.

Comparative Example 4
The multilayer barrier film of Comparative Example 4 was obtained by dry-laminating three types of stretched laminated film having a total thickness of 15 μm obtained in Example 1, AL foil 7 μm, and LLDPE 50 μm film in this order as in Comparative Example 2.

Comparative Example 5
A multilayer barrier film of Comparative Example 5 was obtained in the same manner as Comparative Example 4 except that the thickness of the AL foil of Comparative Example 4 was changed from 7 μm to 12 μm.

The film structure obtained in each of Examples 1-5 and Comparative Examples 1-5 is shown below.
Example 1 [AL deposition 330 mm] [with corona treatment Ny / EVOH / Ny with corona treatment] // LLDPE 50 μm
Example 2 [AL vapor deposition 500 mm] [with corona treatment Ny / EVOH / Ny with corona treatment] // LLDPE 50 μm
Example 3 [AL evaporation 650 mm] [with corona treatment Ny / EVOH / Ny with corona treatment] // LLDPE 50 μm
Example 4 [AL vapor deposition 800 mm] [with corona treatment Ny / EVOH / Ny with corona treatment] // LLDPE 50 μm
Example 5 [AL vapor deposition 500 mm] [with corona treatment Ny / EVOH / Ny corona treatment] [AL vapor deposition 500 mm] // LLDPE 50 μm
Example 6 [AL vapor deposition 330 mm] [with corona treatment Ny / MXD6 / with Ny corona treatment] // LLDPE 50 μm
Comparative Example 1 [AL vapor deposition 650 mm] [Ny / EVOH / Ny corona treatment without corona treatment] // LLDPE 50 μm
Comparative Example 2 ONy (15 μm) // [AL vapor deposition] EVOH 15 μm (Kuraray VM-XL) /// LLDPE 50 μm
Comparative Example 3 ONY (15 μm) // silica-deposited PET 12 μm // LLDPE 50 μm
Comparative Example 4 Ny / EVOH / Ny // AL foil 7 μm // LLDPE 50 μm
Comparative Example 5 Ny / EVOH / Ny // AL foil 12 μm // LLDPE 50 μm

Table 1 shows the results of measuring the physical properties of the films obtained in each Example and Comparative Example.

  According to Table 1, each of Examples 1 to 6 having the configuration of the present invention was excellent in adhesion strength, gas barrier property, and pinhole resistance, and allowed cost reduction. On the other hand, Comparative Example 1 in which the stretched laminated film was not subjected to corona treatment was inferior in adhesion strength, gas barrier property, and pinhole resistance, and Comparative Examples 2 to 5 having no layer structure of the present invention were all in pinhole property. It was inferior and costly.

Claims (17)

  It has a coextruded composite stretched film having a gas barrier layer as an inner layer and a thermoplastic resin layer as a surface layer provided on both sides of the gas barrier layer, and surface treatment is performed on at least one side of the surface layer of the coextruded composite stretched film And a metal-deposited multilayer high barrier film, wherein the metal is vacuum-deposited.   The metal-deposited multilayer high barrier film according to claim 1, wherein the metal is aluminum.   The metal-deposited multilayer high barrier film according to claim 1 or 2, wherein the thickness of the metal-deposited layer is 200 to 1000 mm.   The surface treatment applied to the coextruded composite stretched film is a corona treatment, and the wetting index measured by the surface wetting tension test method (JIS K6768) is 42.0 mN / m or more. The metal-deposited multilayer high barrier film according to claim 1.   The metal-deposited multilayer high barrier film according to claim 1, wherein the thermoplastic resin constituting each of the surface layers is made of a polyamide-based resin.   The metal-deposited multilayer high barrier film according to claim 5, wherein the polyamide-based resin is an aliphatic polyamide, an aromatic polyamide, or a mixture thereof.   The metal-deposited multilayer high barrier film according to claim 6, wherein the aromatic polyamide is polymetaxylylene adipamide.   The metal-deposited multilayer high barrier film according to claim 6, wherein the aliphatic polyamide is made of nylon 6.   The metal-deposited multilayer high barrier film according to any one of claims 1 to 8, wherein the gas barrier layer comprises an ethylene-vinyl acetate copolymer saponified resin or an aromatic polyamide.   The metal-deposited multilayer high barrier film according to claim 9, wherein the ethylene-vinyl acetate copolymer saponified resin has an ethylene content of 5 to 60 mol% and a saponification degree of 90% or more.   The metal-deposited multilayer high barrier film according to any one of claims 1 to 10, wherein the coextruded composite stretched film is a stretched film stretched at least twice in a uniaxial direction.   Furthermore, the metal vapor deposition multilayer high barrier film in any one of Claims 1-11 which has the thermoplastic resin layer which has heat-sealability in at least one surface of a surface layer. The metal-deposited multilayer high barrier film according to any one of claims 1 to 12, which has an oxygen permeability of 2 ml / m ² · day · MPa [25 ° C x 80% RH] or less. The metal vapor-deposited multilayer high barrier film according to any one of claims 1 to 13, which has a water vapor permeability of 0.3 g / (m ² · d) [40 ° C x 90% RH] or less.   The vacuum heat insulating material using the metal vapor deposition multilayer high barrier film in any one of Claims 1-14.   A bag is formed using the metal-deposited multilayer high barrier film according to any one of claims 12 to 14, and a material that exhibits a heat insulating effect is put into the bag, and then heat sealed under a vacuum degree of 100 Pa or less. Item 16. The vacuum heat insulating material according to Item 15.   The vacuum heat insulating material of Claim 15 or 16 used for the heat insulation structure of the product chosen from a refrigerator, a freezer, a rice cooker, a desktop pot, a cooler box, a housing building material, a motor vehicle, and a railway vehicle.