KR102484868B1 - Gas barrier aluminum deposited film and laminated film using the same - Google Patents

Abstract

On at least one side of the surface of the base film, a vapor deposition layer whose composition is continuously changed from an aluminum metal layer with a film thickness of 25 nm or more to an aluminum oxide layer with a film thickness of 5 nm or more is formed, and a gas barrier number with a film thickness of 0.1 to 4 μm is formed thereon. A gas barrier aluminum deposited film characterized in that the gas barrier resin layer is made of a gas barrier composition obtained by polycondensation of a vinyl alcohol resin and an organosilicon compound having an alkoxy group. A gas barrier aluminum deposited film having excellent oxygen and water vapor barrier performance and laminate strength, bending resistance and tensile resistance, and a laminated film using the same are provided.

Description

Gas barrier aluminum deposited film and laminated film using the same

The present invention relates to a gas barrier aluminum deposited film having excellent oxygen and water vapor barrier performance and having laminate strength, bending resistance and tensile resistance.

Packaging materials using aluminum foil have light blocking properties and excellent gas barrier performance in addition to design due to metallic luster, so they are used for packaging materials including packaging materials for retort foods, and for vacuum insulation materials such as insulation materials for refrigerators and insulation panels for houses. It is used as an outer layer packaging material. However, since pinholes tend to occur in packaging materials using aluminum foil, handling of the aluminum foil is difficult, and there is a problem that the load on the incinerator is large due to residues after incineration.

In order to solve the problem of the aluminum foil, an aluminum deposition film using a physical vapor deposition method such as a vacuum deposition method on a thermoplastic film such as a polyester film is used as an aluminum foil substitute. However, the aluminum deposited film has insufficient gas barrier performance for boil-retort food applications, and the vapor-deposited aluminum layer disappears during boil-retort sterilization, greatly deteriorating the gas barrier performance. it wasn't

Disclosed is a gas barrier film in which a vapor deposition layer composed of an inorganic oxide or inorganic nitride and a specific resin layer are laminated on at least one surface of a plastic film as a gas barrier film for use in boil-retort food (for example, See Patent Document 1).

In addition, in order to improve the alkali boiling resistance and acetic acid retort resistance of the aluminum-deposited film and suppress the change in appearance of the aluminum-deposited layer, the substrate (a), the metal-deposited layer (b), and the protective layer (c) are formed in this order. It is a laminate formed by laminating, and it is disclosed that the protective layer (c) contains a specific dimer acid-based polyamide resin (see Patent Document 2, for example).

On the other hand, the thermal conductivity of aluminum is about 200 W/m K, which is larger than the thermal conductivity of polyethylene terephthalate, which is a typical packaging material, of about 0.14 W/m K, and the thermal conductivity of air, about 0.02 W/m K. , Insulators in which aluminum foil is laminated have a problem that a heat bridge in which heat moves along the aluminum foil portion is generated, and the heat insulation performance of the vacuum insulator is significantly reduced. In addition, the film for vacuum insulators is required to have excellent gas barrier performance in order to prevent infiltration of gas (air) from the outside and maintain a vacuum state for a long period of time. In addition, recently, the fin part (welded and sealed part) around the vacuum insulator has lower heat insulating performance than the part containing the core material, so the fin part is bent to maintain the overall heat insulating performance, and the vacuum insulator itself also has a complicated shape ( For example, when used in a circular arc shape or a rectangular shape), it is deformed according to the shape of the storage space. From the above, it is also requested|required that the gas barrier performance does not fall at the time of bending or deformation|transformation of the film for vacuum insulators.

In order to solve the problem of aluminum foil in this vacuum insulation application, that is, to achieve both heat bridge reduction and gas barrier improvement of the vacuum insulation material, a vapor deposition layer composed of an inorganic oxide or inorganic nitride and a specific resin layer are laminated. A vacuum insulating material in which a gas barrier film is laminated has been developed (see Patent Document 3, for example). Further, a film for a vacuum insulator in which two transparent barrier films are bonded together by extrusion lamination using a polyolefin resin has been proposed (see Patent Document 4, for example).

Japanese Unexamined Patent Publication No. 2010-131756 Japanese Unexamined Patent Publication No. 2012-210744 Japanese Unexamined Patent Publication No. 2005-132004 Japanese Unexamined Patent Publication No. 2007-290222

However, the gas barrier film according to Patent Document 1 is a transparent gas barrier film and does not replace the aluminum foil.

The laminate according to Patent Literature 2 did not have sufficient gas barrier performance.

The vacuum insulating material according to Patent Literature 3 is a transparent gas barrier film, and the infrared reflectance is not sufficient because heat is transmitted as infrared rays to radiation during heat conduction, and heat is conducted even in vacuum.

The film for a vacuum insulator according to Patent Literature 4 had a problem that the vapor barrier property deteriorated due to deterioration of the vapor deposition layer due to the heat of the polyolefin resin extruded to the transparent barrier film.

An object of the present invention is to provide a gas barrier aluminum deposited film having excellent oxygen and water vapor barrier performance and laminate strength, bending resistance and tensile resistance, and a laminated film using the same.

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

(1) On at least one surface of the surface of the base film, a vapor deposition layer whose composition is continuously changed from an aluminum metal layer with a film thickness of 25 nm or more to an aluminum oxide layer with a film thickness of 5 nm or more is formed, and thereon, a film thickness of 0.1 to 4 μm. A gas barrier aluminum deposited film characterized in that a gas barrier resin layer is laminated, and the gas barrier resin layer is made of a gas barrier composition obtained by polycondensation of a vinyl alcohol resin and an organosilicon compound having an alkoxy group.

(2) The above gas barrier aluminum deposited film, wherein the film thickness of the aluminum metal layer is in the range of 40 to 125 nm, and the film thickness of the aluminum oxide layer is in the range of 10 to 25 nm.

(3) The gas barrier aluminum deposited film having an adhesion strength between the deposited layer and the gas barrier resin layer of 3.0 N/15 mm or more.

(4) The gas barrier aluminum deposited film having a water vapor transmission rate of 0.1 g/m 2 24 hr or less and an oxygen transmission rate of 0.1 cc/m 2 24 hr atm or less after 5% stretching.

(5) The above gas barrier aluminum deposited film having a water vapor transmission rate of 0.5 g/m2·24 hr or less and an oxygen transmission rate of 0.2 cc/m2·24 hr·atm or less after a flexural fatigue test.

(6) The gas barrier aluminum deposited film having an infrared reflectance of 60% or more when measured using an infrared spectrophotometer at a relative reflection angle of 12 degrees of a reflector.

(7) A laminated film characterized in that a sealant film, a gas barrier film and a plastic film are laminated in this order, and the gas barrier film is made of the gas barrier aluminum deposited film according to any one of the above.

According to the present invention, a gas barrier aluminum deposited film having excellent oxygen and water vapor barrier performance, laminate strength, bending resistance and tensile resistance, and a laminated film using the same can be obtained.

Below, this invention is demonstrated in detail.

In the gas barrier aluminum deposited film of the present invention, on at least one side of the surface of the base film, a deposited layer whose composition is continuously changed from an aluminum metal layer with a film thickness of 25 nm or more to an aluminum oxide layer with a film thickness of 5 nm or more is formed, and a film is formed thereon. A gas barrier resin layer having a thickness of 0.1 to 4 μm is laminated, and the gas barrier resin layer is characterized in that it is made of a gas barrier composition obtained by polycondensation of a vinyl alcohol resin and an organosilicon compound having an alkoxy group.

As described above in the background art, the gas barrier performance of the aluminum deposited film according to the prior art is insufficient compared to that of the aluminum foil, but by providing a deposited layer continuously changing composition from an aluminum metal layer to an aluminum oxide layer and a specific gas barrier resin layer, , In addition to supplementing the incomplete gas barrier performance of the aluminum metal layer, the aluminum oxide deposition layer exhibits the effect of an adhesion enhancement layer between the deposition layer and the gas barrier resin layer, and the gas barrier performance originally possessed by the resin constituting the gas barrier resin layer exert

[Base film]

As a base film in the gas barrier aluminum deposited film of the present invention, there are no particular restrictions as long as characteristics such as chemical resistance, mechanical strength (elasticity of the film, abrasion from the outside, puncture strength), heat resistance, and weather resistance are considered depending on the application. However, for example, a polyethylene terephthalate film, a polypropylene film, a nylon film, etc. are used. Preferably, a polyethylene terephthalate film is practical.

The base film may be an unstretched film, but a film that is normally stretched (uniaxially or biaxially) is excellent in mechanical properties and thickness uniformity, and a biaxially oriented film is more preferable. As the stretching method, conventional stretching methods such as roll stretching, roll stretching, belt stretching, tenter stretching, tube stretching, and stretching in combination thereof can be applied.

The thickness of the base film is not particularly limited, but it is practical to be about 6 μm to 30 μm in the case of a polyethylene terephthalate film, about 20 μm to 40 μm in the case of a polypropylene film, and about 10 μm to 30 μm in the case of a nylon film.

[Deposited layer continuously changing composition from aluminum metal layer to aluminum oxide layer]

In the present invention, a deposition layer whose composition is continuously changed from an aluminum metal layer to an aluminum oxide layer is formed on the base film. A deposited layer whose composition continuously changes from an aluminum metal layer to an aluminum oxide layer is a deposited layer having an inclined structure in which an aluminum metal layer is formed at the beginning of deposition and changes to aluminum oxide as the film grows. By the way, in the aluminum deposited layer, a thin natural oxide film is formed on the surface of the aluminum metal film at the stage of being taken out to the air after deposition, but this natural oxide film is at most about 3 nm, and the aluminum oxide layer in the present invention is 5 nm according to the analysis method described later. more than Preferably it is 10-25 nm. When it exceeds 25 nm, the appearance of the metal strip of an aluminum metal layer may be damaged and infrared reflectance may fall.

It is important that the film thickness of the aluminum metal layer is 25 nm or more. If it is less than 25 nm, the gas barrier performance may be insufficient and the appearance of the metal bath may also be insufficient. In addition, in the use of a vacuum insulator, the infrared reflectance may be less than 60%, resulting in insufficient thermal insulation performance. Preferably it is 40-125 nm. Even if it exceeds 125 nm, the gas barrier performance reaches a limit, the cohesive energy during deposition of the aluminum metal layer increases, the base film is deformed by heat, and the appearance may not withstand practical use.

It is preferable that the total film thickness of the vapor deposition layer which continuously changes composition from an aluminum metal layer to an aluminum oxide layer is 30-150 nm. If the film thickness is less than 30 nm, it becomes difficult to express the target oxygen barrier performance and water vapor barrier performance. At 150 nm or more, the cohesive force of the deposited layer is lowered, peeling is caused by cohesive failure in the deposited layer, and the apparent laminate strength is lowered. In addition, the cohesive energy during vapor deposition increases, and the substrate film is deformed by heat, resulting in a state in which the appearance does not stand up to practical use in some cases.

A method for forming a deposited layer whose composition continuously changes from an aluminum metal layer to an aluminum oxide layer is preferably a method in which a deposited layer whose composition changes continuously from an aluminum metal layer to an aluminum oxide layer is formed in a vacuum chamber. The method for vapor deposition may be performed by a known method such as vapor deposition or sputtering, but a method by vapor deposition is preferable from the point of view of productivity, and methods such as resistance heating, high-frequency heating, and electron beam heating are applied for heating and evaporation of aluminum for that purpose. can do. In these methods by vapor deposition, it is preferable to form a vapor deposition layer whose composition changes continuously from an aluminum metal layer to an aluminum oxide layer by reactive vapor deposition. That is, the base film is generally long, supplied in a roll shape, unwound from the roll in a vacuum chamber, deposited, and then wound into a roll shape again, but a normal aluminum metal layer is formed in the early stage of deposition, and the latter part of the deposition It is said that oxygen is introduced into and aluminum oxide is formed by the reaction of metal aluminum and oxygen. Oxygen introduced in the latter part of the deposition diffuses from the winding side of the base film toward the unwinding side, so the metal aluminum layer and the aluminum oxide layer are not strictly separated and formed, but the position of the deposition zone through which the base film passes Accordingly, the reaction of oxygen continuously proceeds from the aluminum metal layer to the aluminum oxide layer, forming an inclined structure in which the composition continuously changes in the film thickness direction.

[Gas Barrier Resin Layer]

In the present invention, the gas barrier resin layer is formed by applying a gas barrier resin obtained by polycondensation of a vinyl alcohol-based resin and an organosilicon compound having an alkoxy group. This protects the aluminum deposition layer serving as the base layer and improves gas barrier properties. That is, the deposited layer made of aluminum metal and aluminum oxide may have defects such as pinholes, cracks, grain boundaries, etc., and there is a risk that gas barrier properties may be deteriorated thereby, and the gas barrier resin layer compensates for these defects of the deposited layer. In addition, the gas barrier performance itself can be enhanced.

A specific method for forming the gas barrier resin layer is based on a vinyl alcohol-based resin having a high affinity for the deposition layer, and an aqueous solution or an alcohol mixed aqueous solution containing either an organosilicon compound having an alkoxy group or a hydrolyzate thereof. is formed by

The vinyl alcohol-based resin as the main agent for forming the gas barrier resin layer is not particularly limited as long as it is, for example, a vinyl alcohol-based resin such as polyvinyl alcohol, ethylene/vinyl alcohol copolymer, or modified polyvinyl alcohol. Among them, when polyvinyl alcohol is used for the coating agent of the present invention, it is more preferable since it has excellent gas barrier properties. The polyvinyl alcohol referred to herein is generally obtained by saponifying polyvinyl acetate, and may be partially saponified or completely saponified obtained by saponifying a part of the acetic acid groups, and is not particularly limited. An organosilicon compound having an alkoxy group is further added to the coating agent forming the gas barrier resin layer. An alkoxy group has a structure of RO- in which an alkyl group R is bonded to oxygen, and is changed to a silanol group through a dealcoholization reaction by hydrolysis, and a representative example is a methoxy group or an ethoxy group. These silicon compounds having an alkoxy group include, specifically, tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, and n-propyltrimethoxysilane. , n-propyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane and the like, among which tetraethoxysilane is preferable because it is relatively stable in an aqueous solvent after hydrolysis.

The mixing ratio of the organosilicon compound having an alkoxy group to the vinyl alcohol-based resin is preferably in the range of vinyl alcohol-based resin/organosilicon compound = 15/85 to 85/15 in terms of mass ratio of the organosilicon compound as SiO ₂ , and 40 The range of /60 - 60/40 is more preferable. The mass ratio in terms of SiO ₂ is obtained by converting the number of moles of silicon atoms in the organosilicon compound to the mass of SiO ₂ , and is expressed as vinyl alcohol-based resin/organosilicon compound (mass ratio). When this value exceeds 85/15, the vinyl alcohol-based resin cannot be immobilized and the gas barrier performance may decrease. On the other hand, if the ratio is less than 15/85, the ratio of the organosilicon compound increases and the gas barrier resin layer solidifies, so bending resistance and tensile performance may decrease.

In the present invention, the gas barrier resin layer is formed using a coating agent composed of an aqueous solution containing the vinyl alcohol-based resin, at least one of the organosilicon compound having an alkoxy group and at least one of a hydrolyzate thereof, or an alcohol mixed aqueous solution. . The vinyl alcohol-based resin alone exhibits excellent barrier performance against gases such as oxygen and nitrogen because the hydroxyl groups in the molecular chains bind to each other through hydrogen bonds during the process of solidifying as a coating film, but the molecular chains are restrained and exhibit excellent barrier performance against gases such as oxygen and nitrogen. Since the bonds are plasticized, barrier performance cannot be expressed. By forming a resin composition composed of a vinyl alcohol-based resin and an organosilicon compound having an alkoxy group, an inorganic structure having a siloxane bond polycondensed by the organic silicon compounds as a backbone, and a hydrogen bond through mutual hydroxyl groups of the vinyl alcohol-based resin, Furthermore, a so-called organic-inorganic hybrid structure having a covalent bond of Si-O- through oxygen appears due to dehydration. In such a structure, the restraint of the molecular chain is stronger than that of a single vinyl alcohol-based resin, and water vapor barrier performance can be expressed. Furthermore, since a dense structure can be formed by bonding with hydroxyl groups on the surface of the deposited film to improve adhesion, and by filling and reinforcing defects such as pinholes, cracks, and grain boundaries in the deposited layer, gas barrier performance during bending or deformation is improved. deterioration can be suppressed.

[Formation of Gas Barrier Resin Layer]

There is no restriction|limiting in particular as a method of forming the gas barrier resin layer in this invention, It can form by the method according to a base film. For example, printing methods such as offset printing, gravure printing, silk screen printing, roll coating, dip coating, bar coating, die coating, knife edge coating, gravure coating, kiss coating, spin What is necessary is just to coat a coating liquid using the coating method etc. or the method of combining these.

The film thickness of the gas barrier resin layer provided on the deposited layer continuously changing composition from the aluminum metal layer to the aluminum oxide layer needs to be 0.1 to 4 μm, more preferably 0.2 to 1 μm.

When the film thickness of the gas barrier resin layer is 0.1 μm or less, the gas barrier performance may not be expressed. On the other hand, when the film thickness of the gas barrier resin layer exceeds 4 μm, the cohesive force of the gas barrier resin layer decreases, peeling is caused by cohesive failure in the gas barrier resin layer, and the apparent laminate strength is lowered. In addition, the coating drying conditions are required for a high temperature and a long time, and the problem that manufacturing cost rises also arises.

[Laminate Film]

A laminated film prepared using the gas barrier aluminum vapor-deposited film of the present invention is formed by laminating a sealant film as a heat-sealing layer, a gas barrier film, and a plastic film as a surface protective layer in this order.

The sealant film is not particularly limited as long as characteristics such as chemical resistance, mechanical strength (elasticity of the film, abrasion from the outside, puncture strength), heat resistance, and weather resistance are considered depending on the application, but polypropylene film, polyethylene film, etc. are used. do. Preferably, a polyethylene film is practical, and a linear low-density polyethylene film is particularly preferable.

The gas barrier aluminum deposited film, which is a gas barrier film, may have a deposition surface on the plastic film side or the sealant film side, and is selected depending on the design. Further, as necessary, the gas barrier film may be a laminate of a plurality of gas barrier aluminum deposited films, and in that case, the deposition surfaces may be bonded together, or the substrate film surfaces may be bonded together, and the deposition surface and the base material may be bonded together. The film surfaces may be bonded together. Even when a plurality of these gas barrier aluminum deposited films are laminated, a sealant film is laminated on one surface of the laminate and a plastic film is laminated on the other surface to constitute the laminated film of the present invention.

The plastic film is not particularly limited as long as chemical resistance, mechanical strength (elasticity of the film, abrasion from the outside, puncture strength), heat resistance, and weather resistance are considered depending on the purpose, but examples include polyethylene terephthalate film, poly Propylene film, nylon film and the like are used. It may be an unstretched film, but a film normally stretched (uniaxially or biaxially) has excellent mechanical properties and thickness uniformity, and a biaxially stretched film is more preferable. The thickness is not particularly limited, but practical is about 6 μm to 30 μm for a polyethylene terephthalate film, about 20 μm to 40 μm for a polypropylene film, and about 10 μm to 30 μm for a nylon film.

A laminate of a plurality of these plastic films may be used as a surface protective layer as required.

A dry lamination method using a two-component curing type urethane-based adhesive or an extrusion lamination method can be employed as a method for preparing a laminated film prepared using the gas barrier aluminum-deposited film of the present invention, but is not particularly limited.

Example

Hereinafter, examples are given to explain the present invention in detail, but the present invention is not limited to the examples.

(Assessment Methods)

(1) Adhesion strength between the deposition layer and the gas barrier resin layer (N/15 mm)

On the deposition surface of the gas barrier film, a 40 μm-thick linear low-density polyethylene film is applied as a sealant film through an adhesive composed of a polyester urethane base material (manufactured by DIC Corporation, LX500) and an aromatic isocyanate curing agent (manufactured by DIC Corporation, KW75). were laminated by the dry lamination method to prepare a laminated film. Next, the laminated film is cut to a width of 15 mm and a length of 150 mm to prepare a cut sample, and using a tensile tester (Tensilon), the interface between the gas barrier film and the linear low-density polyethylene film is used, and the T-peel method is applied to the tensile test. Peel strength (laminate strength) was measured at a speed of 50 mm/min to evaluate the adhesion strength between the deposited layer and the gas barrier resin layer. As for the value of adhesion strength, 3.0 N/15 mm or more was regarded as a pass.

(2) Oxygen permeability (cc/m² 24hr atm)

The gas barrier film was tested under conditions of a temperature of 23 ° C. and a humidity of 0% RH, using an oxygen permeability meter (OXTRAN 2/20) manufactured by Mocon Inc., USA, based on the isobaric method described in JIS K7126-2: 2006, oxygen Transmittance was measured. As for the value of oxygen permeability, 0.1 cc/m<2>*24hr*atm or less was considered pass.

(3) Moisture vapor transmission rate (g/m² 24hr)

Based on the infrared sensor method described in JIS K7129: Annex B of JIS K7129: 2008 using an oxygen transmission rate meter (PERMATRAN W3/31) manufactured by Mocon Inc., USA, the gas barrier film is subjected to conditions of a temperature of 40 ° C. and a humidity of 90% RH. The water vapor transmission rate was measured. As for the value of the water vapor transmission rate, 0.1 g/m 2 24 hr or less was regarded as a pass.

(4) Infrared reflectance (%)

Using an infrared spectrophotometer (Hitachi High-Technologies Corporation, U-4000), the reflected light intensity of the gas barrier film was measured in a wavelength range of 240 nm to 2600 nm including the infrared wavelength range at a relative reflection angle of 12 degrees of the reflector. did. Among these, regarding the reflected light intensity at three points of wavelengths 1500 nm, 2000 nm and 2500 nm, the ratio of the reflected light intensity of the gas barrier film to the reflected light intensity of the aluminum vapor deposition flat mirror used as a reference is referred to as infrared reflectance (%), and the three points calculated the average value of The closer this value is to 100%, the better the reflection characteristics, and the value of the infrared reflectance of 60% or more was considered acceptable.

(5) Oxygen permeability and water vapor permeability after 5% stretching

Oxygen permeability and water vapor permeability were measured using a test piece stretched 5% (7 mm) at a rate of 5 mm/min from both ends of the 90 mm side of a 140 mm × 90 mm test piece of the gas barrier film.

(6) Oxygen permeability and water vapor permeability after flexural fatigue test

Bonding both ends of the 300 mm side of a 200 mm × 300 mm test piece of gas barrier film, rounding it into a cylindrical shape, holding both ends of the tubular test piece with a fixed head and a drive head, while applying a twist of 440 degrees, the fixed head and drive head The gap between the heads is narrowed from 7 inches to 3.5 inches, and the gap between the heads is narrowed to 1 inch while applying a twist, then the gap between the heads is widened to 3.5 inches, and the gap between the heads is increased to 7 inches while reversing the twist. Oxygen permeability and water vapor permeability were measured using test pieces before and after the flexural fatigue test in which reciprocating motion was performed three times at a rate of 40 times/min.

(7) Measurement of puncture strength (N)

A 40 μm thick linear low-density polyethylene film (Mitsui Chemicals Tohcello, Inc. T.U.X FC-S), a 15 μm-thick biaxially oriented nylon film (ONUM manufactured by Unitika Ltd.) as a plastic film, and a gas barrier film by dry lamination so that the deposition surface is on the plastic film side. Laminated by lamination to produce a laminated film. Next, the puncture strength of the laminated film was measured using a tensile tester (Tensilon) for a sample piece of 50 mm x 50 mm, based on the method described in JIS Z1707-1997.

(8) Deposited film thickness measurement

Compositional analysis in the depth direction was performed with a scanning type Auger electron spectrometer (SAM-670 manufactured by ULVAC-PHI, Inc.), and the film structure of aluminum oxide/metal aluminum was confirmed by the depth profile. Deposition of aluminum oxide when data is collected while paying attention to the Al concentration and the O concentration, and performing Ar ion etching from the surface layer of the deposited film, and the depth at which the concentration ratio of the Al concentration to the O concentration is 50:50 is defined as the interface. The film thickness of the layer and the aluminum vapor deposition layer was calculated. Separately, a metal aluminum film whose film thickness was known from cross-section observation with a transmission electron microscope was etched by the same etching method, and the etching time of the data was converted into an absolute value of the etching depth by calculating the etching rate.

(Example 1)

Using a biaxially stretched polyethylene terephthalate film (Toray Industries, Inc. "Lumiror" (registered trademark) P60) with a film thickness of 12 µm as the base film, a crucible method of high-frequency induction heating by a roll-to-roll vacuum evaporator Using an aluminum evaporation source, an aluminum metal layer was continuously formed to a thickness of 40 nm and an aluminum oxide layer to a thickness of 10 nm. On the base film, films of the composition according to the position are sequentially formed in the thickness direction within a zone of a certain width in the direction in which the base film travels on a cooled rotary drum. By supplying oxygen from the position where the vapor deposition is last received, a vapor deposition layer continuously changing from an aluminum metal layer to an aluminum oxide layer was formed.

Next, on the deposited layer obtained above, an aqueous solution having the following composition was applied by a gravure coating method and dried to form a gas barrier resin layer having a film thickness of 0.3 μm to prepare a gas barrier aluminum deposited film. In addition, the mixing ratio (% by weight) of the following composition with (liquid A)/(liquid B) was 35/65.

(Aqueous solution for forming gas barrier resin layer)

(Liquid A): Hydrochloric acid (0.1 N) was added to tetraethoxysilane (TEOS), stirred for 120 minutes to hydrolyze, and Liquid A was prepared (solid content: 30% by weight: in terms of SiO ₂ ).

(Liquid B): A 10% by weight aqueous solution of polyvinyl alcohol (PVA, degree of polymerization 1,700, degree of saponification 98.5%) and methyl alcohol were blended at a ratio of 35/65 (weight ratio) and stirred to prepare Liquid B.

(Example 2)

A gas barrier aluminum deposited film was obtained in the same manner as in Example 1, except that the deposition layer was made so that the thickness of the aluminum metal layer was 25 nm and the thickness of the aluminum oxide layer was 5 nm.

(Example 3)

A gas barrier aluminum deposited film was obtained in the same manner as in Example 1, except that the deposition layer was made so that the thickness of the aluminum metal layer was 80 nm and the thickness of the aluminum oxide layer was 20 nm.

(Example 4)

A gas barrier aluminum deposited film was obtained in the same manner as in Example 1, except that the thickness of the gas barrier resin layer was 0.1 μm.

(Comparative Example 1)

A gas barrier aluminum deposited film was obtained in the same manner as in Example 1 except that the film thickness was 50 nm only with the aluminum metal layer without supplying oxygen to the deposited layer.

(Comparative Example 2)

A gas barrier aluminum deposited film was obtained in the same manner as in Example 1, except that metallic aluminum was evaporated while oxygen gas was supplied to the entire surface of the deposited layer, and the film thickness was 10 nm only with the aluminum oxide layer.

(Comparative Example 3)

A gas barrier aluminum deposited film was obtained in the same manner as in Example 1, except that the thickness of the gas barrier resin layer was 5 μm.

(Comparative Example 4)

A gas barrier aluminum deposited film was obtained in the same manner as in Example 1, except that the thickness of the gas barrier resin layer was 0.05 μm.

(Comparative Example 5)

A gas barrier aluminum deposited film was obtained in the same manner as in Example 1 except that the gas barrier resin layer was coated with an aqueous solution having the following composition by the gravure coating method and dried to obtain a gas barrier resin layer having a film thickness of 0.3 μm. In addition, the mixing ratio (% by weight) of the following composition with (liquid A)/(liquid B) was 20/80.

(Aqueous solution for forming gas barrier resin layer)

(Liquid A): each monomer of acrylonitrile (AN), 2-hydroxyethyl methacrylate (HEMA), and methyl methacrylate (MMA) was blended at a ratio of 20/50/30% by weight, respectively, and acetic acid Liquid A was prepared by dissolving in a mixed solvent of propyl, propylene glycol monomethyl ether, and n-propyl alcohol (solid content: 30% by weight).

(Liquid B): Liquid B was prepared by blending and stirring xylylene diisocyanate and methyl ethyl ketone at a ratio of 10/90.

Table 1 shows the constitution and characteristics of the films prepared in Examples and Comparative Examples.

(Reference Example 1)

An aluminum metal layer and an aluminum oxide layer were deposited under the same conditions as in Example 1 using a 12 μm thick ethylene-vinyl alcohol copolymer film ("EVAL (registered trademark)" film VMXL manufactured by Kuraray Co., Ltd.) , which did not provide a gas barrier resin layer on the vapor deposition layer was prepared. The water vapor transmission rate was 2.0 g/m 2 ·24 hr, which was insufficient.

(Reference example 2)

A 6 μm-thick aluminum foil was used as the gas barrier film, and a 40 μm-thick linear low-density polyethylene film as a sealant film and a 15 μm-thick biaxially oriented nylon film as a plastic film were dry laminated as in Example 1. It was laminated according to the method to obtain a laminated film. The puncture strength was 9 N, and it became a small value compared with the laminated film of the Example of this invention.

As is clear from the results of each of the above examples, the gas barrier aluminum deposited film of the present invention is excellent in oxygen barrier performance and water vapor barrier performance, and can maintain these gas barrier properties even in tension or bending. It was a good thing.

On the other hand, in Comparative Example 1, the laminate strength deteriorates because the adhesion between the aluminum layer and the gas barrier resin layer is low, in Comparative Example 2, the infrared reflectance deteriorates because there is no aluminum layer, and in Comparative Example 3, because the gas barrier resin layer is thick, Peeling occurred due to cohesive failure in the gas barrier resin layer, and the adhesion strength between the vapor deposition layer and the gas barrier resin layer became low. In Comparative Example 4, the gas barrier resin layer was thin and the barrier properties deteriorated, and in Comparative Example 5, since the gas barrier resin layer was not a vinyl alcohol-based resin and an organosilicon compound having an alkoxy group, oxygen after 5% tension and flex fatigue test Barrier performance and water vapor barrier properties deteriorated.

Since the gas barrier aluminum deposited film of the present invention has excellent oxygen barrier performance and water vapor barrier performance, it is also useful as a vacuum insulator packaging material requiring high gas barrier properties.

Claims (7)

On at least one side of the surface of the base film, a vapor deposition layer whose composition is continuously changed from an aluminum metal layer with a film thickness of 25 nm or more to an aluminum oxide layer with a film thickness of 5 nm or more is formed, and a gas barrier number with a film thickness of 0.1 to 4 μm is formed thereon. Base layers are laminated, and the gas barrier resin layer is made of a gas barrier composition obtained by polycondensation of a vinyl alcohol resin and an organosilicon compound having an alkoxy group, using an infrared spectrophotometer, at a relative reflection angle of 12 degrees of a reflector. A gas barrier aluminum deposited film, characterized in that the measured infrared reflectance is 60% or more. According to claim 1,
A gas barrier aluminum deposited film wherein the film thickness of the aluminum metal layer is in the range of 40 to 125 nm, and the film thickness of the aluminum oxide layer is in the range of 10 to 25 nm. According to claim 1 or 2,
A gas barrier aluminum deposited film, characterized in that the adhesion strength between the deposited layer and the gas barrier resin layer is 3.0 N / 15 mm or more. According to claim 1 or 2,
A gas barrier aluminum deposited film characterized by having a water vapor transmission rate of 0.1 g/m 2 24 hr or less and an oxygen transmission rate of 0.1 cc/m 2 24 hr atm or less after 5% stretching. According to claim 1 or 2,
A gas barrier aluminum deposited film characterized by having a water vapor transmission rate of 0.5 g/m2·24 hr or less and an oxygen transmission rate of 0.2 cc/m2·24 hr·atm or less after a flexural fatigue test. A laminated film characterized in that a sealant film, a gas barrier film and a plastic film are laminated in this order, and the gas barrier film is made of the gas barrier aluminum deposited film according to claim 1 or 2. According to claim 1,
The aluminum metal layer is a gas barrier aluminum deposited film, characterized in that the appearance of the metal bath.