JP5664341B2 - Gas barrier film - Google Patents

Description

  The present invention relates to a transparent gas barrier film excellent in high gas barrier properties and transparency.

  Conventionally, physical vapor phase such as vacuum deposition, sputtering, ion plating, etc., using inorganic materials (including inorganic oxides) such as aluminum oxide, silicon oxide, magnesium oxide on the surface of polymer film substrate The inorganic substance using a growth method (PVD method) or a chemical vapor deposition method (hereinafter referred to as a CVD method) such as a plasma chemical vapor deposition method, a thermal chemical vapor deposition method, or a photochemical vapor deposition method. A transparent gas barrier film formed by forming a vapor-deposited film is used as a packaging material for foods and pharmaceuticals that needs to block various gases such as water vapor and oxygen, and as an electronic device member such as a thin-screen TV and a solar cell. .

  As a gas barrier property improving technique, for example, a gas containing an organic silicon compound vapor and oxygen is used to form a main component of silicon oxide on a substrate by a plasma CVD method, and at least one of carbon, hydrogen, silicon and oxygen. A method of improving transparency and gas barrier properties by using a contained compound is used (Patent Document 1). Further, as a gas barrier property improving technique other than the plasma CVD method, a catalytic CVD method is used in which a silicon nitride film is formed on the film surface by catalytically decomposing silane gas, ammonia gas, and hydrogen gas with a tungsten wire heated at a high temperature ( Patent Document 2).

JP-A-8-142252 JP 2006-57121 A

However, in the method of forming a silicon oxide thin film by a plasma CVD method using a gas containing an organic silicon compound vapor and oxygen as described above, the formed silicon oxide thin film has a very dense film quality. When the base material is a plastic material having a low melting point, when the silicon oxide thin film is formed as a single layer, the base material is used in a high temperature and high humidity environment such as a temperature of 85 ° C. or higher and a humidity of 85% RH or higher. There was a problem that the silicon oxide thin film could not follow the thermal deformation of the film, cracks were generated in the film, and the gas barrier property was lowered.

  On the other hand, the method of forming a silicon nitride film by the catalytic CVD method is a process in which the catalyst body such as tungsten or platinum wire is heated to 1000 ° C. or higher, so that the substrate is greatly damaged by the radiant heat of the catalyst body, and the polymer film There was a problem that the base material was warped due to heat loss and the workability was deteriorated in the post-processing. In view of the background of such prior art, the present invention provides a gas barrier film having a transparent and high gas barrier property that reduces the warpage of the film due to film formation and does not deteriorate the gas barrier property even in a high temperature and high humidity environment. It is to be provided.

The above object of the present invention is achieved by the following configuration. That is,
(1) At least one mixed thin film layer using ZnS and SiO ₂ is formed on one or both surfaces of a polymer film substrate, and at least one silicon-based thin film layer is laminated on the mixed thin film layer. The composition ratio of the mixed thin film layer is expressed by M _X L _(1-X) where ZnS is M and SiO ₂ is L, and the mixed thin film layer is mixed. A gas barrier film in which the physical film thickness of the thin film layer is in the range of 5 nm to 500 nm, and the physical film thickness of the silicon-based thin film layer is in the range of 5 nm to 300 nm;
0.7 ≦ X ≦ 0.9 (Formula 1)
(2) The gas barrier film according to (1), wherein the silicon-based thin film layer includes one or more selected from the group consisting of silicon oxide, silicon nitride, and silicon carbide.
(3) The gas barrier film according to (1) or (2), wherein the mixed thin film layer and the silicon thin film layer are alternately laminated,
(4) The mixed thin film layer has a refractive index of 2.1 to 2.4 at a wavelength of 550 nm, and the silicon thin film layer has a refractive index of 1.4 to 2.1 at a wavelength of 550 nm. ) Gas barrier film according to any one of
(5) The gas barrier film according to any one of (1) to (4), wherein the silicon-based thin film layer has a surface roughness Ra of 2 nm or less,
(6) The gas barrier film according to any one of (1) to (5), wherein a resin layer is further laminated on the outermost layer of the silicon-based thin film layer,
It is.

  Since the present invention is a gas barrier film having high gas barrier properties, transparency, and heat resistance against oxygen gas, water vapor, etc., it is useful as a packaging material for foods, pharmaceuticals, etc., and as an electronic device member for thin televisions, solar cells, etc. A gas barrier film can be provided.

It is sectional drawing which showed the structure of the gas barrier film of this invention. It is the schematic which shows typically the winding-type sputtering apparatus for manufacturing the gas barrier film of this invention. It is the schematic which shows typically the batch type CVD apparatus for manufacturing the gas barrier film of this invention.

Embodiments of the present invention will be described below. FIG. 1 is a cross-sectional view showing the structure of the gas barrier film of the present invention. As shown in FIG. 1, the gas barrier film of the present invention is obtained by sequentially laminating a mixed thin film layer 2 and a silicon-based thin film layer 3 in the thickness direction on the surface of a polymer film 1.
The polymer film substrate used in the present invention is not particularly limited as long as it is a film made of an organic polymer compound. For example, polyolefin such as polyethylene or polypropylene, polyester such as polyethylene terephthalate or polyethylene naphthalate, polyamide, polycarbonate Films made of various polymers such as polystyrene, polyvinyl alcohol, saponified ethylene vinyl acetate copolymer, polyacrylonitrile, polyacetal and the like can be used. A film made of polyethylene terephthalate is preferable. The polymer constituting the polymer film may be either a homopolymer or a copolymer, and may be used alone or blended.

  Further, as the polymer film substrate, a single layer film, a film having two or more layers, for example, a film formed by a coextrusion method, a film stretched in a uniaxial direction or a biaxial direction, and the like can be used. . Furthermore, on the surface on the side where the mixed thin film layer is formed, an anchor coat layer made of corona treatment, ion bombardment treatment, solvent treatment, surface roughening treatment, organic matter, inorganic matter or a mixture thereof is arranged to improve adhesion. It does not matter.

  The thickness of the polymer film substrate used in the present invention is not particularly limited, but is preferably 500 μm or less from the viewpoint of ensuring flexibility, and preferably 5 μm or more from the viewpoint of ensuring strength against tension or impact. Furthermore, 10 μm or more and 200 μm or less are more preferable because of the ease of processing and handling of the film.

  In the polymer film substrate used in the present invention, for example, additives such as an antistatic agent, an ultraviolet absorber, a plasticizer, a lubricant, and a filler are added within the range that does not impair the effects of the present invention. A film or the like added in step 1 can also be used.

As a result of inventor's earnest study, when a mixed thin film layer composed mainly of ZnS and SiO ₂ is laminated, it is possible to form a gas barrier film with good gas barrier properties and excellent flexibility against mechanical bending caused by external stress. It became clear that. Here, the main component means 60% by mass or more of the entire mixed thin film layer. The reason why the gas barrier property is good is not clear, but probably the crystal size of ZnS, which tends to produce microcrystals, is suppressed by mixing the crystalline component contained in ZnS with the vitreous component of SiO ₂ Therefore, it is considered that the film quality becomes dense and the permeation of oxygen and water vapor is suppressed. In addition, a mixed thin film layer containing ZnS with suppressed crystal growth is more flexible than a thin film formed only of an inorganic oxide or a metal oxide, so that cracks are not caused by heat or external stress. It is unlikely to occur, and it is considered that the gas barrier property can be suppressed from decreasing.

The method of forming the mixed thin film layer on the polymer film substrate is not particularly limited. For example, it is formed by using a mixed sintered material of ZnS and SiO ₂ by a vacuum deposition method, a sputtering method, an ion plating method, or the like. can do. When a single material of ZnS and SiO ₂ is used, it can be formed by the binary simultaneous film formation of the method described above. Among these methods, the method for forming the mixed thin film layer used in the present invention is more preferably a sputtering method using a mixed sintered material from the viewpoint of gas barrier properties and composition reproducibility of the formed film.

In addition, since the composition of the mixed thin film layer is formed with a composition almost the same as the mixed sintered material used at the time of film formation, the mixed thin film layer can be easily formed by using a mixed sintered material having a composition suitable for the purpose. Composition adjustment is possible. The composition analysis of the mixed thin film layer is performed by ICP emission spectroscopic analysis. Based on this value, each element can be quantitatively analyzed by using Rutherford backscattering method to know the composition ratio of ZnS and SiO ₂ . The ICP emission spectroscopic analysis can simultaneously measure multiple elements from the emission spectrum generated when the sample is introduced into the plasma light source unit together with the argon gas, and the composition analysis of the investigation sample can be performed. In Rutherford backscattering method, a charged particle accelerated by a high voltage is irradiated on a sample, and the number of charged particles bounced from the sample and the element are identified and quantified from the energy, and the composition ratio of each element can be known. When an inorganic layer or a resin layer is laminated on the mixed thin film layer, the laminated film is removed by ion etching or chemical treatment as necessary, and then analyzed by ICP emission spectroscopic analysis and Rutherford backscattering method. it can.

As a result of intensive studies by the inventors, the mixed thin film layer in the present invention is preferably formed of ZnS and SiO ₂ from the viewpoints of gas barrier properties and transparency.

As the composition of the mixed thin film layer of the present invention, when the molar fraction X of ZnS occupying the entire mixture of ZnS and SiO ₂ is larger than 0.9, the oxide that suppresses the crystal growth of ZnS is insufficient, so the void portion In other words, the number of defective portions increases and a predetermined gas barrier property cannot be obtained. In addition, when the molar fraction X of ZnS occupying the whole is smaller than 0.7, the glassy component of SiO ₂ inside the film increases and the flexibility of the film decreases, so the flexibility to mechanical bending decreases. Problems occur. In particular, as in the present invention, in the case of a configuration in which two or more thin films are laminated, since the film stress of the entire gas barrier film increases and cracks are likely to occur in the film, the molar fraction X of ZnS is set to It is necessary to make it 0.7 or more. Therefore, from the viewpoint of gas barrier properties and flexibility, the molar fraction X of ZnS is preferably 0.7 or more and 0.9 or less, and more preferably 0.75 or more and 0.85 or less.

  The film thickness of the mixed thin film layer used in the present invention is 5 nm or more and 500 nm or less as the film thickness at which the gas barrier property of the mixed thin film layer is manifested. When the film thickness is less than 5 nm, there are places where sufficient gas barrier properties cannot be ensured, causing problems such as variations in gas barrier properties within the substrate surface. Further, when the film thickness is greater than 500 nm, the film stress of the mixed thin film layer increases, so that a crack occurs in the mixed thin film layer in a high temperature and high humidity environment, resulting in a problem that the gas barrier property is lowered. Therefore, the thickness of the mixed thin film layer is preferably 5 nm or more and 500 nm or less, and more preferably 10 nm or more and 300 nm or less from the viewpoint of ensuring flexibility.

The gas barrier film of the present invention requires that at least one silicon-based thin film layer is laminated on the mixed thin film layer. As a result of intensive studies by the inventors, the gas barrier property has been dramatically improved while ensuring flexibility by laminating at least one silicon-based thin film layer on a mixed thin film layer made of ZnS and SiO ₂ . It has been found that a film can be formed. The reason why the gas barrier property is improved is not clear, but since the silicon-based thin film is probably filled in the defective part existing on the surface of the mixed thin film layer, the film quality of the surface layer becomes denser than the mixed thin film layer alone, resulting in a gas barrier property. It is thought to improve.

  Further, the product of the present invention can further improve the gas barrier property as a structure in which mixed thin film layers and silicon-based thin film layers are alternately laminated.

  As a result of intensive studies by the inventors, the silicon-based thin film layer in the present invention preferably forms silicon oxide, silicon nitride, and silicon carbide from the viewpoint of gas barrier properties, and more preferably silicon oxide from the viewpoint of transparency.

The film thickness of the silicon-based thin film layer used in the present invention is 5 nm or more and 300 nm or less as a film thickness that exhibits gas barrier properties. When the film thickness is less than 5 nm, defects in the surface layer of the mixed thin film layer are not sufficiently filled, and there may be a problem that the gas barrier property is not improved. It is presumed that a uniform silicon-based thin film layer cannot be obtained when the mixed thin-film layer is not sufficiently filled with defects and when the silicon-based thin film layer is in the initial growth stage. On the other hand, when the thickness of the silicon-based thin film layer is greater than 300 nm, the gas barrier property is improved because the silicon-based thin film is uniform, but the flexibility of the silicon-based thin film with respect to bending is reduced. Cracks occur in the mixed thin film layer, resulting in a problem that the gas barrier property is lowered. Therefore, the film thickness of the silicon-based thin film layer is preferably 5 nm or more and 300 nm or less, and more preferably 10 nm or more and 300 nm or less from the viewpoint of ensuring flexibility.
The surface roughness Ra of the silicon-based thin film layer used in the present invention is preferably 2 nm or less. If the surface roughness Ra exceeds 2 nm, the mixed thin film layer has a large particle size, so that it is not dense and the permeation of oxygen and water vapor may increase (gas barrier properties may decrease). On the other hand, it is presumed that the lower the surface roughness Ra is, the smaller the particle diameter of the mixed thin film layer becomes, and the denser the film, so that the effect of suppressing permeation of oxygen and water vapor is further improved. However, if the surface roughness Ra is excessively small, such as 0.1 nm or less, cracks are likely to occur due to external stress or bending, and stable physical properties may not be obtained. . From such a viewpoint, it is preferable that the surface roughness Ra is 0.3 nm or more because it is easy to balance gas barrier properties and crack resistance.

  The method for forming the silicon-based thin film layer on the mixed thin film layer is not particularly limited, and can be formed by, for example, a CVD method, a vacuum deposition method, a sputtering method, an ion plating method, or the like. Among these methods, the method for forming a silicon-based thin film layer used in the present invention is a monomer gas of a silicon-based organic compound as a method for efficiently filling defects on the surface of a mixed thin film layer and dramatically improving gas barrier properties. A CVD method in which a silicon-based thin film layer is formed by polymerization reaction and activated by plasma is more preferable.

  The silicon-based organic compound is a compound containing silicon in the molecule, for example, silane, methylsilane, dimethylsilane, trimethylsilane, tetramethylsilane, ethylsilane, diethylsilane, triethylsilane, tetraethylsilane, propoxysilane, Dipropoxysilane, tripropoxysilane, tetrapropoxysilane, dimethyldisiloxane, tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetramethyldisiloxane, hexamethyldisiloxane, tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, Hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, undecamethylcyclohexasiloxane, dimethyl Silazane, trimethyldisilazane, tetramethyldisilazane, hexamethyldisilazane, hexamethylcyclotrisilazane, octamethylcyclotetrasilazane, decamethylcyclopentasiloxane silazane, such undecapeptide methyl cyclohexasilane La disilazane and the like. Of these, hexamethyldisiloxane and tetraethoxysilane are preferable in terms of safety in handling.

  The refractive index of the mixed thin film layer used in the present invention varies depending on the composition and formation conditions. For example, in the case of the composition of the formula 1 of the present invention described above, the refractive index at a wavelength of 550 nm is preferably 2.1 to 2.4. More preferably, it is 2.2 to 2.3. When the refractive index is smaller than 2.1, the grain boundary of the mixed thin film layer has a large grain quality, so that a gas and water vapor can easily pass through, resulting in a problem that the gas barrier property is lowered. Further, when the refractive index is larger than 2.4, there are cases where the fine crystal part of ZnS increases inside the mixed thin film layer, cracks are likely to occur in the film itself, and the flexibility is lowered. .

  Although the refractive index of the silicon-based thin film layer used in the present invention varies depending on the forming conditions, the refractive index is lower than that of the mixed thin film layer from the viewpoint of reducing light reflection by the mixed thin film layer and improving the light transmittance of the gas barrier film. Is preferred. For example, the refractive index at a wavelength of 550 nm is preferably 1.4 to 2.1, and more preferably 1.45 to 1.8. If the refractive index is less than 1.4, the grain boundary of the mixed thin film layer is large, as is the case with the mixed thin film layer, so that the gas and water vapor can easily pass through, and the gas barrier property is reduced. May occur. On the other hand, when the refractive index is larger than 2.1, the light reflection of the silicon-based thin film layer itself is increased, which may cause a problem that the permeability of the gas barrier film is lowered.

  In the present invention, it is preferable to form a resin layer as the outermost layer from the viewpoint of surface protection of the laminated mixed thin film layer and silicon thin film layer. For example, in the present invention, when a silicon-based thin film layer is formed on a mixed thin film layer, a resin layer is preferably formed on the silicon-based thin film layer formed as the outermost layer as a configuration that realizes a high gas barrier property. . The thickness of the resin layer is preferably 0.01 μm or more and 5 μm or less, more preferably 0.05 μm or more and 3 μm or less, from the viewpoints of adhesion and gas barrier properties.

  The method for forming the resin layer used in the present invention is not particularly limited, but a dry coating method in which a mixed thin film layer and a resin layer are continuously formed in a vacuum film forming machine, and a polymer in which the mixed thin film layer is formed in advance. It is formed using a wet coating method in which only a resin layer is applied and formed off-line on a film.

  In the case of the dry coating method, as long as the raw material of the resin layer is heated and evaporated in a vacuum, a method of heating with a dot-like or thin slit-like nozzle and evaporation / spraying can be used. The method for curing the resin layer is not particularly limited, but can be achieved by using high-temperature heating, ultraviolet irradiation, electron beam irradiation, plasma irradiation, or the like.

  The material of the resin layer used in the dry coating method is not particularly limited, but is selected from silicone oils, acrylic monomers, oligomers or mixtures thereof. For example, examples of the silicone oil include dimethylpolysiloxane, methylphenylsilicone oil, and methylphenyldimethylpolysiloxane. Examples of the acrylic material include polyester-based, polyether-based, urethane-based, epoxy-based, and silicon-based acrylate.

  In addition, in the case of the wet coating method, it is possible to apply at high speed, so that a solution in which the constituent components of the coating film are dispersed in various solvents is a gravure coat, reverse coat, spray coat, kiss coat, comma coat, die coat. A knife coat, an air knife coat or a metering bar coat is preferred. As a method for drying the coating film, a hot roll contact method, a heating medium (air, oil, etc.) contact method, an infrared heating method, a microwave heating method, or the like can be used.

  The gas barrier resin used in the wet coating method is not particularly limited as long as it does not impair the properties such as gas barrier property and transparency. For example, polyester resin, polyvinyl alcohol resin, polyurethane resin, A phenol resin, a polyvinyl chloride resin, a polyvinylidene chloride resin, a polyacrylic resin, a polyacrylonitrile resin, or the like can be arbitrarily selected and used.

  The gas barrier resin used in the present invention is preferably a two-component curable resin from the viewpoint of solvent resistance, and more preferably a polyester resin, a urethane resin, or an acrylic resin is used as a main agent from the viewpoint of gas barrier properties and water resistance. The curing agent is not particularly limited as long as it does not impair the properties such as gas barrier properties and transparency, and general curing agents such as isocyanate and epoxy can be used.

  The resin layer of the present invention may contain various additives as long as the gas barrier property or the adhesion with the mixed thin film layer is not impaired. As the various additives, known weathering agents, heat stabilizers, ultraviolet absorbers, colorants and the like can be used. At the same time, inorganic or organic particles may be included as long as the gas barrier property or the adhesion with the mixed thin film layer is not impaired. Examples include calcium carbonate, titanium oxide, silicon oxide, calcium fluoride, lithium fluoride, alumina, barium sulfate, zirconia, calcium phosphate, and crosslinked polystyrene-based particles.

  Although the method of obtaining a laminated body using the gas barrier film obtained with the manufacturing method of this invention is not specifically limited, For example, it manufactures preferably with the following method.

  The surface of the gas barrier film obtained in the present invention, if necessary, after pretreatment such as corona treatment, ozone treatment, flame treatment, etc., polyester-based, isocyanate-based (urethane-based), polyethyleneimine-based, Known packaging materials using anchor coating agents such as polybutadiene and organic titanium, or polyurethane, polyacryl, polyester, epoxy, polyvinyl acetate, cellulose, and other adhesives for laminating A laminated body can be produced by a method of laminating the film. Here, the laminating method is not particularly limited. For example, wet lamination method, dry lamination method, solventless dry lamination method, extrusion lamination method, T-die extrusion molding method, co-extrusion lamination method, inflation method, co-extrusion inflation method. Other methods can be used.

  For example, the gas barrier film of the present invention can be arbitrarily combined with functional members formed from other resin films, paper base materials, metal materials, synthetic paper, cellophane, and other materials, and laminated to produce various laminates. can do. In addition to the high gas barrier properties, heat resistance, and high transparency that are the characteristics of the product of the present invention, these laminates can be provided with weather resistance, electrical conductivity, decorative properties, and the like, so that, for example, It can be used as packaging for foods, pharmaceuticals, electronic parts, etc., thin displays such as liquid crystal displays, organic EL displays, electronic papers, and electronic device members such as solar cells.

  Next, an example is given and the present invention is explained concretely. The film characteristics were measured under the following conditions.

A) Method for measuring water vapor transmission rate A water vapor transmission rate measuring device (model name: PERMATRAN (registered trademark)) manufactured by MOCON, USA under the conditions of a temperature of 40 ° C., a humidity of 90% RH, and a measurement area of 50 cm ^2. W3 / 31). The number of measurements was 10 times, and the average value was the water vapor transmission rate.

B) Bending test A specimen having a length of 10 cm and a width of 10 cm was cut out and repeatedly bent 100 times at a bending radius of 5 mm and a bending angle of 130 °. The water vapor transmission rate of the test piece before and after the bending test was measured. As for the number of tests, a bending test was performed on three test pieces of each level.

C) Film thickness measurement method A sample for cross-sectional observation was prepared by the FIB method using a microsampling system (Hitachi FB-2000A). Using a transmission electron microscope (H-9000UHRII, manufactured by Hitachi), the cross section of the observation sample was observed at an acceleration voltage of 300 kV, and the film thicknesses of the mixed thin film layer and the silicon thin film layer were measured.

D) Composition analysis of the mixed thin film layer The composition analysis of the mixed thin film layer was performed by ICP emission spectroscopic analysis (manufactured by Seiko Denshi Kogyo Co., Ltd., SPS4000). Based on this value, Rutherford backscattering method (Nisshin High Voltage ( Each element is quantitatively analyzed by using AN-2500), and the composition ratio of ZnS and SiO ₂ is determined. When an inorganic layer or a resin layer is laminated on the mixed thin film layer, the laminated film is removed by ion etching or chemical treatment as necessary, and then analyzed by ICP emission spectroscopic analysis and Rutherford backscattering method.

E) Refractive Index Measurement Method The refractive index of a thin film is obtained by measuring the polarization state of light reflected from the thin film using a high-speed spectroscopic ellipsometer (M-2000 manufactured by JAWoollam). The refractive index of the mixed thin film layer is measured by cutting a sample 3 cm long by 3 cm wide from the roll after forming the mixed thin film layer. Further, the refractive index of the silicon-based thin film layer is measured by cutting a sample 3 cm long by 3 cm wide after forming the silicon thin film layer on the mixed thin film layer. The number of measurements was 5 each, and the average value was taken as the refractive index.
F) Surface roughness Ra measuring method The surface roughness Ra of the silicon-based thin film layer was measured using an atomic force microscope under the following specifications and conditions.
System: NanoScopeIII / MMAFM (manufactured by Digital Instruments)
Scanner: AS-130 (J-Scanner)
Probe: NCH-W type, single crystal silicon (manufactured by Nanoworld)
Scanning mode: Tapping mode Scanning range: 10 μm × 10 μm
Scanning speed: 0.5Hz
Measurement environment: temperature 23 ° C., relative humidity 65%, in air.

Example 1
A biaxially stretched polyethylene terephthalate film (Lumirror (registered trademark) manufactured by Toray Industries, Inc.) having a thickness of 100 μm and a surface centerline surface roughness Ra of 30 nm is used, using a winding type sputtering apparatus having the apparatus structure shown in FIG. Using a sputtering target (Mitsubishi Materials Corp. target, ST-IV series) which is a mixed sintered material formed of ZnS and SiO ₂ as a base material, sputtering with argon gas plasma was performed, and the film thickness was One ZnS · SiO ₂ film, which is a mixed thin film layer, was provided so that the composition was 300 nm and the molar fraction X of ZnS was 0.85. FIG. 2 is an apparatus configuration diagram showing an outline of a winding type sputtering apparatus for carrying out a manufacturing method for forming a mixed thin film layer. First, in the take-up chamber 5 of the take-up type sputtering apparatus 4, the polymer film 1 is set on the take-up roll 6, unwound, and passed through the cooling drum 10 through the guide rolls 7, 8, 9. The plasma electrode 11 is provided with a sputtering target having a ZnS / SiO ₂ molar composition ratio of 85/15, and is turned on by a high frequency power source with argon gas introduced so that the degree of vacuum is 2 × 10 ⁻¹ Pa. When power of 500 W is applied, argon gas plasma is generated and sputtering is started, so that a ZnS / SiO ₂ film, which is a mixed thin film layer, is formed on the surface of the polymer film 1. A ZnS · SiO ₂ film was formed on the substrate using this apparatus. Thereafter, the polymer film 1 on which the mixed thin film layer was formed was wound around a winding roll 15 through guide rolls 12, 13, and 14.

Next, a single wafer CVD apparatus shown in FIG. 3 was used, and one layer of SiO ₂ film was provided on the mixed thin film layer so that the film thickness was 200 nm. FIG. 3 is an apparatus configuration diagram showing an outline of a single wafer CVD apparatus for carrying out a manufacturing method for forming a silicon-based thin film layer. First, it cuts out into a sheet form from the roll in which the mixed thin film layer was formed, and sets it to the sample holder 17. Next, when hexamethyldisiloxane is introduced at 70 cc / min from an argon gas 0.5 L / min and a silicon-based organic compound vaporizer and an input power of 500 W is applied to the plasma electrode from a high frequency power source, silicon-containing plasma is generated, A SiO ₂ film is formed on the mixed thin film layer. Using this, one layer of SiO ₂ film was provided so as to have a film thickness of 200 nm.

  Subsequently, using the obtained gas barrier film, the surface roughness Ra of the silicon-based thin film layer was measured. Next, 10 cm long and 10 cm wide test pieces were cut out from the obtained gas barrier film, and after measuring the water vapor transmission rate (water vapor transmission rate before the bending test), the bending test was carried out, and the water vapor transmission rate after the bending test. Was measured. The results are shown in Table 1.

(Example 2)
In Example 1, a gas barrier film was obtained in the same manner as in Example 1 except that one layer of ZnS · SiO ₂ film was provided so that the film thickness was 50 nm.

Example 3
In Example 1, a gas barrier film was obtained in the same manner as in Example 1 except that one SiO ₂ film as a silicon-based thin film layer was provided so that the film thickness was 50 nm.

Example 4
In Example 1, using a sputtering target having a ZnS / SnO ₂ molar composition ratio of 70/30, ZnS · SnO ₂ is a mixed thin film layer so that the molar fraction X of ZnS becomes a composition of 0.70. A gas barrier film was obtained in the same manner as in Example 1 except that one film was provided.

(Example 5)
In Example 1, a gas barrier film was obtained in the same manner as in Example 1 except that one SiO ₂ film as a silicon-based thin film layer was provided so that the refractive index was 1.43.

(Example 6)
In Example 1, a gas barrier film was obtained in the same manner as in Example 1 except that a SiN film having a thickness of 200 nm was formed on the silicon-based thin film layer instead of the SiO ₂ film.

(Example 7)
On the silicon-based thin film layer of the gas barrier film obtained in Example 1, one mixed thin film layer having a composition with a ZnS molar fraction X of 0.85 was formed so as to have a film thickness of 150 nm. Furthermore, one silicon-based thin film layer was laminated so that the film thickness was 100 nm to obtain a gas barrier film.

(Comparative Example 1)
In Example 1, a sputtering target having a ZnS / SiO ₂ molar composition ratio of 95/5 was used, and ZnS · SiO ₂ , which was a mixed thin film layer, had a ZnS molar fraction X of 0.95. A gas barrier film was obtained in the same manner as in Example 1 except that one film was provided.

(Comparative Example 2)
In Example 1, using a sputtering target having a ZnS / SiO ₂ molar composition ratio of 50/50, ZnS · SiO ₂ is a mixed thin film layer so that the molar fraction X of ZnS is 0.50. A gas barrier film was obtained in the same manner as in Example 1 except that one film was provided.

(Comparative Example 3)
A gas barrier film was obtained in the same manner as in Example 1 except that one SiO ₂ film, which is a silicon-based thin film layer, was provided so that the film thickness was 500 nm.

(Comparative Example 4)
In Example 1, a gas barrier film was obtained in the same manner as in Example 1 except that one layer of ZnS · SiO ₂ film as a mixed thin film layer was provided so that the film thickness was 600 nm.

(Comparative Example 5)
In Example 1, a gas barrier film was obtained in the same manner as in Example 1 except that one ZnS · SiO ₂ film as a mixed thin film layer was provided so that the refractive index was 2.00 and the film thickness was 600 nm.

(Comparative Example 6)
In Example 1, a gas barrier film was prepared in the same manner as in Example 1 except that the refractive index of the mixed laminated film was 2.20, the film thickness was 100 nm, and the silicon thin film was changed to Al ₂ O ₃ as shown in Table 1. Got.

(Comparative Example 7)
In Example 1, a gas barrier film was obtained in the same manner as in Example 1 except that no mixed thin film layer was formed and one SiO ₂ film, which is a silicon-based thin film layer having a thickness of 500 nm, was provided on the film.

(Comparative Example 8)
In Example 1, a gas barrier film was obtained in the same manner as in Example 1 except that no mixed thin film layer was formed and one SiO ₂ film, which is a silicon-based thin film layer having a thickness of 200 nm, was provided on the film.

(Comparative Example 9)
In Example 1, a gas barrier film was formed in the same manner as in Example 1 except that one ZnS / SiO ₂ film, which was a mixed thin film layer, was provided so that the film thickness was 1000 nm, and no silicon-based thin film layer was provided thereon. Got.

About the gas-barrier film obtained in Examples 1-7 and Comparative Examples 1-9, the water-vapor-permeation rate before and behind a bending test was measured. Table 1 shows the measurement results of water vapor permeability before and after the bending test. Here, from the comparison between Examples 1 and 2 and Comparative Examples 1 and 2, if the molar fraction X of the ZnS / SiO ₂ mixed target is in the range of 0.7 to 0.9, both before and after the bending test It can be seen that the water vapor barrier property is not more than 0.01 g / (m ² · day), which is the lower limit value measured by the water vapor transmission rate meter, and is excellent. From the comparison between Examples 1 to 3 and Comparative Example 3, if the film thickness of the silicon-based thin film layer is in the range of 5 nm to 300 nm or less, the water vapor barrier property before and after the bending test is the lower limit value of 0 measured by the water vapor permeability meter. .01 g / (m ² · day) or less, which shows that it is very excellent. From the comparison between Examples 1 and 2 and Comparative Example 4, when the thickness of the ZnS · SiO ₂ film is increased to 600 nm, the water vapor barrier property before the bending test is excellent, but the water vapor barrier property may deteriorate after the test. Recognize. From Example 1 and Comparative Example 6, by forming a silicon-based thin film on the mixed thin film layer, the water vapor barrier property before and after the bending test is 0.01 g / (m ² · day) It is the following and it turns out that it is very excellent. From Example 1 and Comparative Example 8, by forming a mixed thin film layer, the water vapor barrier property was 0.01 g / (m ² · day) or less before and after the bending test. It turns out that it is excellent in. Further, in Examples 1 to 7 and Comparative Examples 3 to 5 and 9, since the surface roughness Ra is 2 nm or less, a uniform silicon-based thin film layer is obtained, and the mixed thin film layer surface layer is sufficiently filled with defects. It can be said that it is possible. On the other hand, in Comparative Examples 3 to 5 and 9, flexibility is not ensured, and the water vapor transmission rate after the bending test is remarkably deteriorated. As is clear from the comparison between the examples and the comparative examples, the product of the present invention forms a mixed thin film layer composed of at least one layer of ZnS and SiO _{2 on} one side or both sides of the polymer film base material. By laminating at least one silicon-based thin film thereon, a gas barrier film having a high gas barrier property that does not deteriorate the gas barrier property even in a bending test.

Since the present invention has high gas barrier properties, transparency, and heat resistance against oxygen, water vapor, etc., it can contribute to the electronic device industry such as flat-screen TVs and solar cells that require advanced characteristics. is there.

1: Polymer film 2: Mixed thin film layer 3: Silicon-based thin film layer 4: Winding type sputtering apparatus 5: Winding chamber 6: Unwinding roll 7, 8, 9: Unwinding side guide roll 10: Cooling drum 11: Sputtering electrode 12, 13, 14: Winding side guide roll 15: Winding roll 16: Single wafer type CVD device 17: Sample holder 18: Plasma electrode 19: Gas barrier film 20: Vaporizer for silicon organic compound 21: Silicon -Based organic compound introduction nozzle

Claims (6)

Gas barrier properties in which at least one mixed thin film layer using ZnS and SiO ₂ is formed on one or both sides of a polymer film substrate, and at least one silicon-based thin film layer is laminated on the mixed thin film layer The composition ratio of the mixed thin film layer is in the range of (Formula 1) where M is ZnS as M and SiO ₂ is L and expressed as M _X L _(1-X) . A gas barrier film having a physical film thickness of 5 nm or more and 500 nm or less and a silicon-based thin film layer having a physical film thickness of 5 nm or more and 300 nm or less.
0.7 ≦ X ≦ 0.9 (Formula 1) The gas barrier film according to claim 1, wherein the silicon-based thin film layer is one or more selected from the group consisting of silicon oxide, silicon nitride, and silicon carbide. The gas barrier film according to claim 1 or 2, wherein the mixed thin film layer and the silicon thin film layer are alternately laminated. The refractive index at a wavelength of 550 nm of the mixed thin film layer is 2.1 to 2.4, and the refractive index at a wavelength of 550 nm of the silicon thin film layer is 1.4 to 2.1. The gas barrier film according to the description. The gas barrier film according to any one of claims 1 to 4, wherein the silicon-based thin film layer has a surface roughness Ra of 2 nm or less. The gas barrier film according to any one of claims 1 to 5, wherein a resin layer is further laminated on the outermost layer of the silicon-based thin film layer.

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