JP2016124219A - Stacked inorganic film, and barrier film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stacked inorganic film having high transparency, high gas barrier properties and excellent ultraviolet ray cuttability.SOLUTION: A stacked inorganic film 13 includes: a first inorganic film 13a the refractive index of which is changed continuously from n1 to n2 (n1<n2) from the one-side principal surface toward the other-side principal surface; a second inorganic film 13b which is stacked on such the principal surface of the first inorganic film 13a that the refractive index is n2 and the refractive index of which is n3; and a third inorganic film 13c which is stacked on the second inorganic film 13b and the refractive index of which is changed continuously from n4 to n5 (n5<n4) from the one-side principal surface, which is contacted with the second inorganic film 13b, toward the other-side principal surface. A difference between n2 and n3 and that between n3 and n4 are equal to or smaller than 0.1 respectively. Each of the first and third inorganic films 13a, 13c is formed from the compound oxide containing: at least one of Si and Al; Zn; and Sn.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a laminated inorganic film capable of suppressing permeation of water vapor and oxygen and a barrier film using the laminated inorganic film.

  In a flexible device that is lightweight and can be bent freely, an organic substance such as a resin is used for a base material or an element itself. In a so-called flexible device using a flexible substrate made of a resin or the like as a substrate, a barrier film having flexibility as well as gas barrier properties and transparency is required as a sealing member.

  Patent Document 1 discloses a plastic film in which an aluminum film is deposited in order to impart gas barrier properties. Moreover, in patent document 2, in order to make gas barrier property and transparency compatible, the plastic film in which the silicon oxide film was vapor-deposited is disclosed.

JP 2004-1888 A JP 1999-240102 A

  However, since the aluminum vapor deposition film as in Patent Document 1 cannot obtain sufficient transparency, it has been difficult to use it as a display or solar cell application. Moreover, the silicon oxide film vapor deposition film as disclosed in Patent Document 2 has poor UV cut property, and the gas barrier property is not sufficient as compared with the aluminum vapor deposition film.

  An object of the present invention is to provide a laminated inorganic film having high transparency and gas barrier properties and excellent UV cut property, and a barrier film using the laminated inorganic film.

  The laminated inorganic film according to the present invention includes a first inorganic film in which the refractive index continuously changes from n1 to n2 (n1 <n2) from the main surface on one side to the main surface on the other side. The first inorganic film is laminated on the main surface on the side where the refractive index is n2, and the second inorganic film whose refractive index is n3 and the second inorganic film are laminated. The third inorganic material has a refractive index continuously changing from n4 to n5 (n5 <n4) from the main surface on one side in contact with the second inorganic film to the main surface on the other side. A difference between n2 and n3 and a difference between n3 and n4 is 0.1 or less, respectively, and the first and third inorganic films are at least one of Si and Al, respectively. On the other hand, it is formed of a double oxide containing Zn and Sn.

  In a specific aspect of the laminated inorganic film according to the present invention, at least one of the first inorganic film and the third inorganic film is formed of a complex oxide containing Si, Zn, and Sn. Preferably, in the double oxide containing Si, Zn and Sn, the ratio Xs of Sn to the total sum of Zn and Sn satisfies 70> Xs> 0.

  In another specific aspect of the laminated inorganic film according to the present invention, at least one of the first inorganic film and the third inorganic film is formed of a double oxide containing Al, Zn, and Sn. .

  In another specific aspect of the laminated inorganic film according to the present invention, the first inorganic film is formed of a double oxide containing Al, Zn, and Sn, and the third inorganic film is Si, Zn. And a double oxide containing Sn.

  In still another specific aspect of the laminated inorganic film according to the present invention, the refractive index n3 of the second inorganic film is in the range of 1.9 to 2.0.

  In still another specific aspect of the laminated inorganic film according to the present invention, the second inorganic film is formed of a double oxide containing Zn and Sn.

  In another specific aspect of the laminated inorganic film according to the present invention, the thickness of the second inorganic film is in a range of 50 to 250 nm. Preferably, the thickness of the second inorganic film is in the range of 100 to 200 nm.

  The barrier film according to the present invention includes a base material and the laminated inorganic film laminated on the base material, the main surface of the first inorganic film having a refractive index n1 and the base material. The refractive index n0 of the base material satisfies the relationship of n0 ≦ n1.

  In a specific aspect of the barrier film according to the present invention, the barrier film includes a resin layer provided on the third inorganic film, and a refractive index n6 of the resin layer satisfies a relationship of n6 ≦ n5.

  The laminated inorganic film according to the present invention has the above-described configuration, that is, a first inorganic film whose refractive index is continuously increased from n1 to n2, and a laminated film on the first inorganic film. A second inorganic film having a refractive index of n3, and a third inorganic film laminated on the second inorganic film and having a refractive index continuously decreasing from n4 to n5, and n2 And the difference between n3 and n3 and n4 are 0.1 or less, respectively.

  Therefore, reflection due to a difference in refractive index is suppressed, and a decrease in light transmittance can be prevented. That is, it becomes possible to provide a laminated inorganic film having high transparency. Further, by inserting a second inorganic film having a high absorption effect in the short wavelength region, UV cutability can be imparted while maintaining transparency in the long wavelength region.

  In the laminated inorganic film according to the present invention, since the first and third inorganic films are formed of a complex oxide containing at least one of Si and Al, Zn, and Sn, gas barrier properties. Is excellent.

It is sectional drawing which shows the barrier film using the laminated inorganic film which concerns on one Embodiment of this invention. It is sectional drawing which shows the refractive index of each layer of the barrier film shown in FIG. It is a figure which shows the structure of an example of the apparatus used in order to form the barrier film of this invention.

  Hereinafter, details of the present invention will be described with reference to the drawings.

  A barrier film using a laminated inorganic film according to an embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, a barrier film 1 is configured by laminating and integrating a planarizing layer 12 made of an organic material, first to third inorganic films 13 a to 13 c, and a resin layer 14 in this order on a base material 11. Has been. Here, the first to third inorganic films 13a to 13c constitute the laminated inorganic film 13 according to the present embodiment.

  As shown in FIG. 2, in the first inorganic film 13a, the refractive index of the main surface in contact with the second inorganic film 13b is from the refractive index n1 of the main surface in contact with the planarization layer 12. It continuously increases monotonously to n2. The second inorganic film 13b has a refractive index of n3 and is constant. Note that the second inorganic film is a high refractive index layer.

  In the third inorganic film 13c, the refractive index of the main surface on the side in contact with the second inorganic film 13b is continuously changed from n4, which is the refractive index of the surface on the side in contact with the resin layer 14, to n5. It has decreased monotonously. Here, the refractive indexes of the refractive index gradient layers are n1 <n2 and n4> n5. Further, the refractive index n2 and the refractive index n4 are equal in the present embodiment, and the relationship of n2 = n3 = n4 is satisfied with respect to the refractive index n3.

  However, even if the relationship of n2 = n3 = n4 is not satisfied, the difference between n2 and n3 is 0.1 or less, and the difference between n3 and n4 may be 0.1 or less. In that case, a change in refractive index at the interface between the first inorganic film 13a and the second inorganic film 13b, and between the second inorganic film 13b and the third inorganic film 13c can be reduced. Thereby, reflection caused by the difference in refractive index can be suppressed, and a decrease in light transmittance can be suppressed. That is, the barrier film 1 is excellent in transparency. From the viewpoint of further enhancing the transparency, the difference between n2 and n4 is also preferably 0.1 or less.

  The first inorganic film 13a, the second inorganic film 13b, and the third inorganic film 13c are functional films. In this embodiment, a high gas barrier property is expressed as a function. Here, the gas barrier property has a characteristic of sufficiently reducing the permeation of gases such as carbon dioxide, oxygen, and water vapor.

  In the present embodiment, the first inorganic film 13a and the third inorganic film 13c have a structure in which the refractive index continuously changes as described above. At the interface between the first inorganic film 13a and the second inorganic film 13b and at the interface between the third inorganic film 13c and the second inorganic film 13b, the refractive index difference between them is somewhat high, but there is a difference in refractive index. As small as 0.1 or less. Therefore, reflection caused by the difference in refractive index can be suppressed. In addition, the gas barrier property can be sufficiently developed near the interface having a relatively high refractive index.

  On the other hand, the refractive index is low on the side opposite to the interface, that is, on the outer surfaces of the first inorganic film 13a and the third inorganic film 13c. Therefore, sufficient light transmittance is ensured.

  The laminated inorganic film 13 is formed by laminating the first and third inorganic films 13a and 13c and the second inorganic film 13b whose functions such as gas barrier properties increase as the refractive index increases as described above. . Therefore, the gas barrier property can be effectively enhanced at the portion where the refractive index is high. And since the difference of n2 and n3 and the difference of n3 and n4 are 0.1 or less, the fall of the light transmittance in both interface can also be suppressed.

  As described above, the combination of the inorganic materials constituting the first inorganic film 13a and the third inorganic film 13c whose gas barrier properties increase as the refractive index increases is not particularly limited as long as such a function is exhibited. Examples thereof include silicon oxide and zinc tin oxide, silicon oxide and aluminum zinc oxide, and aluminum oxide and zinc tin oxide.

  The second inorganic film 13b has a high refractive index and UV absorption. Therefore, the laminated inorganic film 13 has UV cut properties. As described above, the second inorganic film 13b is not particularly limited as long as it has a high refractive index and UV absorption. The second inorganic film 13b is preferably a complex oxide containing Zn and Sn. In addition to these materials, for example, oxides or oxynitrides of In, Ti, Mg, Zr, Ni, Ta, W, Cu, or alloys containing two or more of these may be included.

  The difference between the refractive index of the second inorganic film 13b and the refractive index of the interface between the first or third inorganic films 13a and 13c is preferably less than 0.1, and more preferably less than 0.05. preferable. The film thickness of the second inorganic film 13b is preferably 50 to 250 nm, and more preferably 100 to 200 nm, from the viewpoint of effectively enhancing the UV cut property and transparency.

  In the barrier film 1, the planarization layer 12, the first inorganic film 13 a, the second inorganic film 13 b, the third inorganic film 13 c, and the resin layer 14 are laminated on the base material 11 in this order. Therefore, a steep change in refractive index between the respective layers can be eliminated. Therefore, reflection due to the difference in refractive index can be prevented. This antireflection effect can improve the light transmittance of the laminate.

  Refractive index change rates per film thickness of the first and third inorganic films 13a and 13c are expressed as refractive index change ratios A = (n3−n2) / t1 [t1 = first inorganic film thickness, unit: nm] and refractive index change rate B = (n4-n5) / t2 [t2 = thickness of second inorganic film, unit: nm], the refractive index change rate X is 0 ≦ X <0.01. / Nm is preferably satisfied. The refractive index change rate X more preferably satisfies 0 ≦ X <0.006 / nm. Here, when the refractive index change rate X, which is a change in refractive index per unit film thickness, exceeds 0.01 / nm, optical interference due to a sudden change in the refractive index occurs, which is a sufficient transmittance improvement effect. May not be obtained.

  When the film thickness of the barrier film 1 is t, the range of the value of the film thickness t is not particularly limited, but from the viewpoint of further enhancing the gas barrier properties, it is preferably 30 nm ≦ t ≦ 3000 nm, and 50 nm ≦ t More preferably, it is ≦ 1000 nm.

  Hereinafter, each layer of the barrier film according to the present invention will be described in more detail.

(Base material)
The material constituting the base material of the barrier film is not particularly limited. For example, acrylic resins such as polymethyl methacrylate, polyethyl methacrylate, and polybutyl acrylate, polyethylene terephthalate, polybutylene terephthalate, isophthalate copolymer Examples thereof include polyester resins such as coalescence, polyolefin resins such as polyethylene resins and polypropylene resins. In addition, only 1 type may be used for a synthetic resin, and 2 or more types may be used together.

  When the base material is in contact with the main surface on the refractive index n1 side of the first inorganic film, the refractive index n0 of the base material preferably satisfies the relationship of n0 ≦ n1. In that case, the light transmittance is less likely to be lowered, and the transparency of the barrier film can be further enhanced.

(Flattening layer)
In the barrier film according to the present invention, a planarizing layer that is an organic layer may be formed on a substrate. The material constituting the planarization layer is not particularly limited as long as it can obtain surface smoothness, and includes, for example, an alkoxysilane having a radical polymerizable group, an alkoxysilane not having a radical polymerizable group, and water. It is obtained by irradiating the applied composition with active energy rays after preparing the composition and applying the composition.

  The thickness of the planarization layer is preferably 0.01 to 100 μm, more preferably 0.1 to 50 μm, and particularly preferably 1 to 10 μm. If the thickness is less than 0.01 μm, sufficient gas barrier properties may not be obtained. Moreover, in the planarization layer whose thickness exceeds 100 micrometers, there exists a possibility that rigidity may become high too much and the handleability of a gas barrier film may be reduced.

(Laminated inorganic film)
The laminated inorganic film according to the present invention includes the following first to third inorganic films.

A first inorganic film;
The first inorganic film has 1) a refractive index gradient structure in which the refractive index continuously monotonously increases in the film thickness direction, and 2) the base material or the flattening layer at the interface with the base material or the flattening layer. And the refractive index n1 of the surface in contact with the substrate or the flattening layer satisfies the condition of n0 ≦ n1. 3) As described above, the difference between the refractive index n2 and the refractive index n3 is 0.1 or less. I just need it.

  The material constituting the first inorganic film is not particularly limited as long as it is a complex oxide containing at least one of Si and Al, Zn, and Sn. In addition to these materials, for example, oxides or oxynitrides of In, Ti, Mg, Zr, Ni, Ta, W, Cu, or alloys containing two or more of these may be included. From the viewpoint of matching the refractive index with the planarizing layer, the first inorganic film 13a is preferably made of a double oxide containing Si, Al, Zn, and Sn.

  The value of n1 is preferably 1.7 or less, and more preferably 1.6 or less, from the viewpoint of reducing the difference in refractive index from n0 and further enhancing transparency. Further, the value of n2 is not particularly limited, but is preferably larger than 1.7, more preferably 1.8 or more, from the viewpoint of further enhancing the gas barrier property.

A second inorganic membrane;
The material constituting the second inorganic film is not particularly limited as long as it is a double oxide containing Zn and Sn. In addition to these materials, for example, oxides or oxynitrides of In, Ti, Mg, Zr, Ni, Ta, W, Cu, or alloys containing two or more of these may be included.

  The difference between the refractive index n3 of the second inorganic film and the refractive index n2 of the first inorganic film and the refractive index n4 of the third inorganic film is 0.1 or less. Further, the refractive index n3 of the second inorganic film is preferably in the range of 1.9 to 2.0 from the viewpoint of further effectively increasing the UV cut property, and 1.95 to 1.97. It is more preferable to be within the range.

A third inorganic membrane;
The third inorganic film has 1) a refractive index gradient structure in which the refractive index continuously monotonously decreases in the film thickness direction, and 2) when the above-described resin layer is provided on the third inorganic film, the resin layer 3), the refractive index n5 of the surface in contact with the refractive index n6 of the resin layer satisfies the condition of n5 ≧ n6. 3) As described above, the difference between the refractive index n4 and the refractive index n3 is Each may be 0.1 or less.

  The material constituting the third inorganic film is not particularly limited as long as it is a complex oxide containing at least one of Si and Al, Zn, and Sn. In addition to these materials, for example, oxides or oxynitrides of In, Ti, Mg, Zr, Ni, Ta, W, Cu, or alloys containing two or more of these may be included. From the viewpoint of matching the refractive index with the planarizing layer, the third inorganic film is preferably made of a complex oxide containing Si, Al, Zn, and Sn. The value of n4 is preferably 1.7 or less, and more preferably 1.6 or less, from the viewpoint of reducing the difference in refractive index from the refractive index n5 of the resin layer. In addition, the 1st inorganic film 13a and the 3rd inorganic film 13c may be comprised with the same material, and may be comprised with a different material.

(Resin layer)
As described above, a resin layer may be formed on the third inorganic film. It does not specifically limit as a resin layer, What is necessary is just to be comprised with organic substance. Examples of the function of the resin layer include planarization, stress relaxation, adhesion improvement, and lamination with other members. Examples of the resin constituting the resin layer include ethylene-unsaturated carboxylic acid-acrylic acid ester copolymer, ethylene-unsaturated carboxylic acid-methacrylic acid ester copolymer, thermoplastic elastomer, low-density polyethylene, ethylene-acetic acid. Vinyl copolymer, polyvinylidene chloride, ionomer, vinyl chloride-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, nitrocellulose, cellulose acetate, silicone, polyether polyurethane which is a condensate of diisocyanate and polyether polyol, Examples thereof include polyurethane resins such as polyester polyurethane which is a condensate of diisocyanate and polyester polyol. In addition, only 1 type may be used for the said resin and 2 or more types may be used together.

(Production method)
Next, a method for manufacturing a laminated inorganic film will be described. The method for forming the first to third inorganic films constituting the laminated inorganic film is not particularly limited. For example, physical vapor deposition (PVD) such as sputtering, vapor deposition, ion plating, And chemical vapor deposition (CVD). In these film forming methods, the film forming conditions may be changed so that the refractive index continuously changes. Thereby, the first to third inorganic films having a refractive index gradient structure can be formed. The first to third inorganic film formation methods may be the same method or different methods.

  In the present invention, as described above, in the first and third inorganic films, the refractive index is inclined so that the refractive index increases from the outside toward the interface with the second inorganic film. Sufficient light transmission can be ensured by a low refractive index. In addition, since the difference between n2 and n4 and the difference between n3 and n4 are small and the refractive indexes n2, n3, and n4 themselves are high, an excellent UV-cutting property can be exhibited and a decrease in light transmittance can be suppressed. .

  As the first inorganic film and the third inorganic film, the SiZnSnO film is inclined so that the refractive index increases from the outside toward the interface with the second inorganic film, that is, in the SiZnSnO film. The Si content can be changed so as to continuously decrease toward the interface with the second inorganic film. In addition, a ZnSnO film can be formed as the second inorganic film.

  In the SiZnSnO film, the weight ratio Xs of Sn to the total sum of Zn and Sn preferably satisfies 70> Xs> 0, and satisfies 50 ≧ Xs> 0 from the viewpoint of obtaining even higher gas barrier properties. More preferably, it is more preferable that 30> Xs ≧ 5 is satisfied, and it is particularly preferable that 10 ≧ Xs ≧ 5 is satisfied.

  In addition, as the first inorganic film and the third inorganic film, the AlZnSnO film is inclined so that the refractive index increases from the outside toward the interface with the second inorganic film, that is, in the AlZnSnO film. The Al content can be changed so as to continuously decrease toward the interface with the second inorganic film. Even in that case, a ZnSnO film can be formed as the second inorganic film.

  In the AlZnSnO film, the weight ratio Xs of Sn to the total sum of Zn and Sn preferably satisfies 50 ≧ Xs> 0 and satisfies 50> Xs> 0 from the viewpoint of obtaining even higher gas barrier properties. More preferably, it is more preferable that 30 ≧ Xs> 0 is satisfied, and it is particularly preferable that 30 ≧ Xs ≧ 10 is satisfied.

  In the present invention, an AlZnSnO film may be used for the first inorganic film, and a SiZnSnO film may be used for the third inorganic film. In that case, the refractive index is inclined so that the refractive index increases from the outside toward the interface with the second inorganic film, that is, the Si content in the SiZnSnO film or the Al content in the AlZnSnO film is It was made to change so as to decrease continuously toward the interface with the second inorganic film. However, in the present invention, a SiZnSnO film may be used for the first inorganic film, and an AlZnSnO gas barrier film may be used for the third inorganic film.

  Next, examples of the present invention will be described. The present invention is not limited to the following examples.

Example 1
As a base material of the barrier film, a PET film (trade name “Lumirror 50T60” manufactured by Toray Industries, Inc.) was used.

≪Formation of planarization layer≫
In a composition containing 80 parts by weight of 3-methacryloxypropyltrimethoxysilane, 53 parts by weight of tetraethoxysilane, 30 parts by weight of titanium tetrabutoxide and 4.9 parts by weight of water, 2-methyl-1 [4- (methylthio) phenyl] -2-Morifolinopropan-1-one (product name “Irgacure 907” manufactured by Ciba Specialty Chemicals Co., Ltd.) 0.1 part by weight was added and irradiated with ultraviolet rays for 15 minutes using a 9 W ultraviolet lamp. Prepolymerization was performed. This composition was applied to one surface of the substrate by a gravure coater, and the applied composition was subjected to an accelerating voltage of 175 kV and an irradiation dose of 150 kGy using an electron beam irradiation apparatus (manufactured by ESI, model number “EC300 / 165/800”). A polyethylene terephthalate film having a composition subjected to electron beam irradiation on one side after radical polymerization of 3-methacryloxypropyltrimethoxysilane to form a radical polymer by irradiation with an electron beam under the conditions of 45 A dehydration condensate of tetraethoxysilane that crosslinks between the main chains of the radical polymer is formed by accelerating hydrolysis and dehydration condensation reaction by leaving it in an environment of ℃ and relative humidity 65% RH for 1 hour. A chemical layer (thickness 8 μm) was obtained.

<< Formation method of inorganic film >>
A gas barrier layer was formed using an RtoR sputtering apparatus 31 shown in FIG. This apparatus includes an unwinding / winding chamber 32 and a film forming chamber 40. The unwinding / winding chamber 32 is provided with an unwinding shaft 33, a winding shaft 34, guide rolls 35 and 36, and a can roll 37, and is evacuated by a vacuum pump 38 to be in a reduced pressure state. The unwinding shaft 33 is attached with a film original film as a base material, and the base film 30 unwound from the film original film is wound on the winding shaft 34 through the guide roll 35, the can roll 37 and the guide roll 36. It is done. The film forming chamber 40 includes targets 41 and 42 and is connected to a bipolar power source 43. This bipolar power supply 43 can alternately supply pulse power to the target 41 and the target 42. Further, an argon gas supply line 44 and an oxygen gas supply line 45 are connected to the film forming chamber 40, and argon gas and oxygen gas can be supplied into the film forming chamber 40. A vacuum pump 39 is also connected to the film forming chamber 40 so that the inside of the film forming chamber 40 can be depressurized. After depressurizing the film formation chamber 40, argon gas and oxygen gas are supplied at a predetermined flow rate, and further, power is supplied to the target 41 and the target 42, so that plasma is generated in the space between the targets 41 and 42 and the can roll 37. Can be formed. The material constituting the target 41 and the target 42 is ejected from the surfaces of the targets 41 and 42 by this plasma. Then, the ejected material is deposited on the surface of the base material passing over the surface of the can roll 37 to form a thin film. The bipolar power supply 43 can arbitrarily control the pulse number ratio supplied to the target 41 and the target 42. By controlling the pulse number ratio, the ratio of the amount of material ejected from the surface of the target 41 and deposited on the substrate film 30 and the amount of material ejected from the surface of the target 42 and deposited on the substrate film 30 is controlled. Can do. When different materials are selected for the target 41 and the target 42, the composition of the double oxide deposited on the base film 30 can be controlled by controlling the pulse number ratio. More specifically, in this example, a laminated inorganic film including the first to third inorganic films was formed by the following method.

<< Formation of first inorganic film >>
A base film having a flattened layer formed on one side is set on the unwinding shaft 33 shown in FIG. 3, and Si is used as the target 41, and a ZnSn alloy (Zn: Sn = 70: 30 wt%) target is attached as the target 42. It was. The RtoR sputtering apparatus 31 was evacuated by the vacuum pump 38 and the vacuum pump 39, and the pressure was reduced to 3.0 × 10 ⁻⁴ Pa. Thereafter, the substrate film 30 is transported in the direction from the unwinding shaft 33 to the winding shaft 34 through the guide roll 35, the can roll 37, and the guide roll 36. A SiZnSnO thin film having a thickness of 150 nm is formed on the flattening layer, and the refractive index from the main surface on the side in contact with the flattening layer of the first inorganic film toward the other main surface as shown in Table 1 below. A first inorganic film having a gradually increasing height was obtained.

(Film formation condition A)
Substrate conveyance speed: 0.1 m / min, tension 100 N, can roll cooling temperature: 10 ° C.
Argon gas flow rate: 80 sccm, oxygen gas flow rate: 80 sccm
Power output: 5 kW, power pulse ratio: target 41: target 42 = 3: 1

<< Formation of second inorganic film >>
Next, the film on which the first inorganic film was formed was set on the unwinding shaft 33, and a ZnSn alloy (Zn: Sn = 70: 30 wt%) target was attached as the target 41 and the target 42. While conveying the installed film in the direction from the unwinding shaft 33 to the winding shaft 34, a ZnSnO film was formed on the surface of the first inorganic film under the conditions shown in the film forming condition B. A second inorganic film having a high refractive index was obtained.

(Film formation condition B)
Substrate conveyance speed: 0.2 m / min, tension 100 N, can roll cooling temperature: 10 ° C.
Argon gas flow rate: 80 sccm, oxygen gas flow rate: 80 sccm
Power output: 3 kW, power pulse ratio: target 41: target 42 = 1: 1

<< Formation of third inorganic film >>
Next, the film on which the second inorganic film was formed was set on the take-up shaft 34, and Si as the target 41 and a ZnSn alloy (Zn: Sn = 70: 30 wt%) target as the target 42 were attached. A SiZnSnO film having a thickness of 150 nm is formed on the surface of the second inorganic film on the surface of the second inorganic film while transporting the installed film in the direction from the winding shaft 34 to the unwinding shaft 33, as shown in Table 1 below. In this way, a third inorganic film having a refractive index that gradually decreases from the main surface of the third inorganic film in contact with the second inorganic film toward the other main surface is obtained.

≪Formation of resin layer≫
A pressure-sensitive adhesive (manufactured by Sekisui Chemical Co., Ltd., trade name “Double Tack Tape”, product number: 5405A, thickness 50 μm) was attached to the surface of the third inorganic film to obtain a resin layer.

≪Bonding of weather resistant resin base material≫
After pasting with an adhesive, a gas barrier film 1 was prepared by pasting with an ETFE (tetrafluoroethylene and ethylene copolymer) film (manufactured by Asahi Glass Co., Ltd., trade name “Aflex”, thickness 100 μm).

(Example 2)
A gas barrier film 2 was produced in the same manner as in Example 1 except that the transport speed was adjusted so that the thickness was 200 nm in the film formation condition B for the second inorganic film.

Example 3
A gas barrier film 3 was produced in the same manner as in Example 1 except that the conveyance speed was adjusted so that the thickness was 50 nm in the film formation condition B for the second inorganic film.

Example 4
A gas barrier film 4 was produced in the same manner as in Example 1 except that the transport speed was adjusted so that the thickness was 250 nm in the film formation condition B for the second inorganic film.

(Comparative Example 1)
A base film having a flattening layer formed on one side is set on the unwinding shaft 33, and a Si target is further attached as a target 41 and a target 42, and a SiO film is formed on the flattening layer under the film forming condition B. A gas barrier film 6 having only the second inorganic film as a film was produced.

(Comparative Example 2)
A base film having a flattening layer formed on one side is set on the unwinding shaft 33, and a ZnSn target is attached as the target 41 and the target 42, and a ZnSnO film is formed on the flattening layer under the film forming condition B. A gas barrier film 7 having only the second inorganic film as a film was produced.

[Evaluation results]
(Light transmittance)
About evaluation of the light transmittance of visible light and UV, it measured with the spectrophotometer (The Hitachi High-Tech make, brand name "U-4100"). As the value of visible light, the light transmittance at an average value of wavelengths of 400 to 800 nm was measured. For UV, the light transmittance at a wavelength of 350 nm was measured. In addition, the evaluation criteria of the light transmittance of visible light and UV are shown below.

Visible light average;
◎ ・ ・ ・ Light transmittance is 91% or more ○ ・ ・ ・ Light transmittance is 90% or more and less than 91% × ・ ・ ・ Light transmittance is less than 90%

UV;
A light transmittance at 350 nm is less than 30% A light transmittance at 350 nm is 30% or more and less than 33% A light transmittance at 350 nm is 33% or more

(Water vapor transmission rate)
In order to evaluate the gas barrier property of the obtained gas barrier film, using a differential pressure type moisture permeability measuring device (product number “GTR-300XASC” manufactured by GTR Tech Co., Ltd.), temperature: 40 ° C., humidity: 90%, The water vapor transmission rate was measured. In addition, the evaluation criteria of water vapor permeability are shown below.

○: Water vapor transmission rate is less than 5.0 × 10 ⁻³ × ... Water vapor transmission rate is 5.0 × 10 ⁻³ or more

  The evaluation results of light transmittance (visible light, UV) and water vapor transmittance are shown in Table 1 below.

DESCRIPTION OF SYMBOLS 1 ... Barrier film 11 ... Base material 12 ... Planarization layer 13 ... Laminated inorganic film 13a ... 1st inorganic film 13b ... 2nd inorganic film 13c ... 3rd inorganic film 14 ... Resin layer 30 ... Base film 31 ... RtoR sputtering apparatus 32 ... unwinding take-up chamber 33 ... unwinding shaft 34 ... take-up shaft 35 ... guide roll 36 ... guide roll 37 ... can roll 38 ... vacuum pump 39 ... vacuum pump 40 ... deposition chamber 41 ... target 42 ... Target 43 ... Bipolar power supply 44 ... Argon gas supply line 45 ... Oxygen gas supply line

Claims (11)

A first inorganic film having a refractive index continuously changing from n1 to n2 (n1 <n2) from one main surface to the other main surface;
A second inorganic film having a refractive index of n3, the first inorganic film being laminated on the principal surface on the side where the refractive index is n2, and
It is laminated on the second inorganic film, and the refractive index is changed from n4 to n5 (n5 <n4) from the main surface on one side in contact with the second inorganic film to the main surface on the other side. A third inorganic film that is continuously changing;
The difference between n2 and n3 and the difference between n3 and n4 are 0.1 or less, respectively.
A laminated inorganic film in which the first and third inorganic films are each formed of a complex oxide containing at least one of Si and Al, Zn, and Sn.   2. The laminated inorganic film according to claim 1, wherein at least one of the first inorganic film and the third inorganic film is formed of a double oxide containing Si, Zn, and Sn.   3. The laminated inorganic film according to claim 2, wherein in the double oxide containing Si, Zn, and Sn, a ratio Xs of Sn to a total sum of Zn and Sn satisfies 70> Xs> 0.   The laminated inorganic film according to claim 1, wherein at least one of the first inorganic film and the third inorganic film is formed of a double oxide containing Al, Zn, and Sn.   The first inorganic film is formed of a double oxide containing Al, Zn, and Sn, and the third inorganic film is formed of a double oxide containing Si, Zn, and Sn. The laminated inorganic film according to any one of 1 to 4.   The laminated inorganic film according to any one of claims 1 to 5, wherein the refractive index n3 of the second inorganic film is in a range of 1.9 to 2.0.   The laminated inorganic film according to any one of claims 1 to 6, wherein the second inorganic film is formed of a double oxide containing Zn and Sn.   The laminated inorganic film according to claim 1, wherein a thickness of the second inorganic film is in a range of 50 to 250 nm.   The laminated inorganic film according to claim 8, wherein the thickness of the second inorganic film is in a range of 100 to 200 nm. A substrate and a laminated inorganic film according to any one of claims 1 to 9 laminated on the substrate,
The main surface on the side where the refractive index of the first inorganic film is n1 is in contact with the base material,
A barrier film in which a refractive index n0 of the substrate satisfies a relationship of n0 ≦ n1.   The barrier film according to claim 10, comprising a resin layer provided on the third inorganic film, wherein a refractive index n6 of the resin layer satisfies a relationship of n6 ≦ n5.

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