WO2023054177A1

WO2023054177A1 - Gas barrier film, method for producing same, polarizing plate equipped with gas barrier layer, and image display device

Info

Publication number: WO2023054177A1
Application number: PCT/JP2022/035426
Authority: WO
Inventors: 一裕中島; 帆奈美伊藤; 智剛梨木
Original assignee: 日東電工株式会社
Priority date: 2021-09-30
Filing date: 2022-09-22
Publication date: 2023-04-06
Also published as: TW202330253A

Abstract

A gas barrier film (10) comprises a transparent film substrate (11) and a gas barrier layer (12). The gas barrier layer (12) has a first layer (13) that contains silicon, oxygen, and carbon as constituent elements and a second layer (14) that contains silicon, oxygen, and nitrogen as constituent elements. The first layer (13) is, in the gas barrier layer (12), the layer disposed furthest from the transparent film substrate (11). The second layer (14) is in contact with the main surface (13a) of the first layer (13) on the transparent film substrate (11) side. The content of the oxygen in the second layer (14) is not less than 15 at%, where the total of the silicon, oxygen, and nitrogen in the second layer (14) is 100 at%.

Description

GAS BARRIER FILM, METHOD FOR MANUFACTURING THE SAME, POLARIZING PLATE WITH GAS BARRIER LAYER, AND IMAGE DISPLAY DEVICE

The present invention relates to a gas barrier film, a method for producing the same, a polarizing plate with a gas barrier layer, and an image display device.

As image display devices become lighter, thinner, and more flexible, resin film substrates are being used instead of glass substrates. Since resin films have higher permeability to gases such as water vapor and oxygen than glass, it has been proposed to use a gas barrier film having a gas barrier layer for the purpose of suppressing element deterioration caused by these gases. .

Organic EL elements may have defects called "dark spots" due to the infiltration of even a small amount of moisture, and high gas barrier properties (water vapor blocking properties) are required. Silicon nitride (SiN) and silicon oxynitride (SiON) are known as materials having excellent gas barrier properties.

For example, Patent Document 1 proposes a gas barrier film including a silicon nitride layer and a silicon oxide layer as a gas barrier film with excellent transparency and flexibility.

WO2019/187978

In a gas barrier film using a nitrogen-containing layer (more specifically, a silicon nitride layer, a silicon oxynitride layer, etc.) as a gas barrier layer, ammonia (ammonia gas) can be generated from the nitrogen-containing layer in a humidified environment. This has been clarified by the studies of the inventors. Ammonia generated from the nitrogen-containing layer reacts with, for example, moisture in the air to produce ammonium ions and hydroxide ions, which may corrode the device.

With only the technology disclosed in Patent Document 1, it is difficult to obtain a gas barrier film that is excellent in transparency while ensuring gas barrier properties and that can suppress the generation of ammonia.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a gas barrier film that is excellent in transparency while ensuring gas barrier properties and that can suppress the generation of ammonia, a method for producing the same, and a method for producing the gas barrier film. An object of the present invention is to provide a polarizing plate with a gas barrier layer and an image display device.

<Aspect of the present invention>
The present invention includes the following aspects.

[1] A gas barrier film comprising a transparent film substrate and a gas barrier layer disposed directly or indirectly on at least one main surface of the transparent film substrate,
The gas barrier layer has a first layer containing silicon, oxygen and carbon as constituent elements, and a second layer containing silicon, oxygen and nitrogen as constituent elements,
The first layer is a layer located farthest from the transparent film substrate in the gas barrier layer,
The second layer is in contact with the main surface of the first layer on the transparent film substrate side,
The gas barrier film, wherein the oxygen content in the second layer is 15 atomic % or more when the total of silicon, oxygen and nitrogen in the second layer is 100 atomic %.

[2] The above-mentioned [1], wherein the oxygen content in the second layer is 50 atomic % or less when the total of silicon, oxygen and nitrogen in the second layer is 100 atomic %. gas barrier film.

[3] The gas barrier film according to [1] or [2] above, wherein the first layer has a thickness of 30 nm or more and 250 nm or less.

[4] The gas barrier film according to any one of [1] to [3], wherein the second layer has a thickness of 20 nm or more and 120 nm or less.

[5] The content of carbon in the first layer is 1 atomic % or more and 10 atomic % or less when the total of silicon, oxygen and carbon in the first layer is 100 atomic %. ] The gas barrier film according to any one of [4].

[6] The gas barrier film according to any one of [1] to [5], further comprising a hard coat layer disposed between the transparent film substrate and the gas barrier layer.

[7] A method for producing a gas barrier film according to any one of [1] to [6],
introducing trisilylamine, nitrogen and oxygen into a chamber of a film forming apparatus to form the second layer by a chemical vapor deposition method;
A method for producing a gas barrier film, comprising introducing an organosilicon compound and oxygen into a chamber of a film forming apparatus to form the first layer by a chemical vapor deposition method.

[8] A polarizing plate with a gas barrier layer, comprising the gas barrier film according to any one of [1] to [6] above and a polarizer.

[9] An image display device comprising the gas barrier film according to any one of [1] to [6] and an image display cell.

[10] An image display device comprising the polarizing plate with a gas barrier layer according to [8] and an image display cell.

[11] The image display device according to [9] or [10], wherein the image display cell includes an organic EL element.

According to the present invention, it is possible to provide a gas barrier film that is excellent in transparency while ensuring gas barrier properties and that can suppress the generation of ammonia, a method for producing the same, and a polarizing plate with a gas barrier layer and an image display device using the gas barrier film. .

1 is a cross-sectional view showing an example of a gas barrier film according to the present invention; FIG. FIG. 4 is a cross-sectional view showing another example of the gas barrier film according to the present invention; FIG. 4 is a cross-sectional view showing another example of the gas barrier film according to the present invention; FIG. 4 is a cross-sectional view showing another example of the gas barrier film according to the present invention; BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows an example of the polarizing plate with a gas barrier layer which concerns on this invention. It is a sectional view showing an example of an image display device concerning the present invention.

A preferred embodiment of the present invention will be described below. First, the terms used in this specification will be explained. The number average primary particle diameter of the particles is the circle of 100 primary particles measured using a scanning electron microscope and image processing software (e.g., "ImageJ" manufactured by the National Institutes of Health), unless otherwise specified. It is a number average value of equivalent diameters (Heywood diameter: diameter of a circle having the same area as the projected area of primary particles).

Layered material (more specifically, transparent film substrate, gas barrier layer, first layer, second layer, silicon oxynitride layer, silicon oxycarbide layer, hard coat layer, adhesive layer, polarizer, etc.) "Plane" refers to a plane perpendicular to the thickness direction of the layered product. The numerical value for the "thickness" of the layered material is the "average thickness". The average thickness of the layered material is obtained by observing a cross section of the layered material cut in the thickness direction with an electron microscope, randomly selecting 10 measurement points from the cross-sectional image, and measuring the thickness of the selected 10 measurement points. Arithmetic mean of 10 measurements obtained.

"Refractive index" refers to the refractive index for light with a wavelength of 550 nm in an atmosphere at a temperature of 23°C.

The flow rate unit "sccm (Standard Cubic Centimeter per Minute)" is the flow rate unit "mL/min" under standard conditions (temperature: 0°C, pressure: 101.3 kPa).

In the following, "system" may be added after the name of the compound to generically refer to the compound and its derivatives. When the polymer name is expressed by adding "system" after the compound name, it means that the repeating unit of the polymer is derived from the compound or its derivative. Acryl and methacryl may be collectively referred to as "(meth)acryl".

The drawings referred to in the following description mainly show each component schematically for the sake of easy understanding. It may be different from the actual from above. Also, for convenience of description, in the drawings described later, the same components as those in the drawings described earlier may be denoted by the same reference numerals, and the description thereof may be omitted.

<First Embodiment: Gas Barrier Film>
A gas barrier film according to a first embodiment of the present invention has a transparent film substrate and a gas barrier layer directly or indirectly arranged on at least one main surface of the transparent film substrate. The gas barrier layer has a first layer containing silicon, oxygen and carbon as constituent elements and a second layer containing silicon, oxygen and nitrogen as constituent elements. A 1st layer is a layer arrange|positioned farthest from a transparent film base material in a gas barrier layer. The second layer is in contact with the main surface of the first layer on the side of the transparent film substrate. The oxygen content in the second layer is 15 atomic % or more when the total of silicon, oxygen and nitrogen in the second layer is 100 atomic %.

Hereinafter, a layer containing silicon, oxygen and carbon as constituent elements may be referred to as a "silicon oxycarbide layer". A layer containing silicon, oxygen, and nitrogen as constituent elements is sometimes referred to as a "silicon oxynitride layer." Further, the content of oxygen in the second layer (or silicon oxynitride layer) when the total of silicon, oxygen and nitrogen in the second layer (or silicon oxynitride layer) is 100 atomic % is defined as "second content of oxygen in the layer (or silicon oxynitride layer)". Further, the content of carbon in the first layer (or silicon oxycarbide layer) when the total of silicon, oxygen and carbon in the first layer (or silicon oxycarbide layer) is 100 atomic % is defined as "first The content of carbon in the layer (or silicon oxycarbide layer)". Unless otherwise specified, the elemental composition of the silicon oxycarbide layer is the elemental composition at the central portion in the thickness direction of the silicon oxycarbide layer (when 1/2 of the total etching time of the silicon oxycarbide layer, which will be described later, has elapsed). . Unless otherwise specified, the elemental composition of the silicon oxynitride layer is the elemental composition at the central portion in the thickness direction of the silicon oxynitride layer (when 1/2 of the total etching time of the silicon oxynitride layer, which will be described later, has elapsed). . The method for measuring the elemental composition of the silicon oxycarbide layer and the method for measuring the elemental composition of the silicon oxynitride layer are both the same method as in Examples described later or a method based thereon.

Since the gas barrier film according to the first embodiment has the above configuration, it is possible to suppress the generation of ammonia while ensuring gas barrier properties and excellent transparency. The reason is presumed as follows.

In general, silicon oxynitride layers tend to have higher gas barrier properties as the nitrogen ratio increases, and the higher the oxygen ratio, the less visible light is absorbed and the more transparent they tend to be. The gas barrier film according to the first embodiment has excellent transparency because the silicon oxynitride layer, which is the second layer, has an oxygen content of 15 atomic % or more.

Further, since the gas barrier film according to the first embodiment has a silicon oxycarbide layer as the first layer in addition to the silicon oxynitride layer, even if the oxygen content in the silicon oxynitride layer is 15 atomic % or more, gas barrier properties can be ensured regardless of

In the gas barrier film according to the first embodiment, since the outermost layer of the gas barrier layer is the silicon oxycarbide layer (first layer), the ammonia gas is released from the silicon oxynitride layer (second layer) in contact with the silicon oxycarbide layer. Even if it occurs, the diffusion of ammonia gas is blocked by the silicon oxycarbide layer. Therefore, according to the gas barrier film according to the first embodiment, it is possible to suppress the generation of ammonia (especially the generation of ammonia in a humidified environment).

In the first embodiment, in order to obtain a gas barrier film with more excellent transparency, the oxygen content in the second layer is preferably 18 atomic % or more, more preferably 19 atomic % or more, More preferably 20 atomic % or more, 21 atomic % or more, 22 atomic % or more, 23 atomic % or more, 24 atomic % or more, 25 atomic % or more, 26 atomic % or more, 27 atomic % or more, 28 atomic % or more , 29 atomic % or more, or 30 atomic % or more.

In the first embodiment, in order to obtain a gas barrier film with more excellent gas barrier properties, the oxygen content in the second layer is preferably 50 atomic % or less, more preferably 47 atomic % or less, It is more preferably 45 atomic % or less, and even more preferably 43 atomic % or less.

In the first embodiment, the thickness of the first layer is preferably 30 nm or more and 250 nm or less, more preferably 40 nm or more and 220 nm, in order to obtain a gas barrier film that is more excellent in gas barrier properties and transparency and can further suppress the generation of ammonia. It is more preferably 50 nm or more and 200 nm or less, even more preferably 60 nm or more and 200 nm or less, 70 nm or more and 200 nm or less, 80 nm or more and 200 nm or less, 90 nm or more and 200 nm or less, or 100 nm or more and 200 nm or less. may be

In the first embodiment, the thickness of the second layer is preferably 20 nm or more and 120 nm or less, more preferably 25 nm or more and 110 nm, in order to obtain a gas barrier film that is more excellent in gas barrier properties and transparency and can further suppress the generation of ammonia. It is more preferably 30 nm or more and 100 nm or less, even more preferably 30 nm or more and 90 nm or less, and may be 30 nm or more and 80 nm or less, 30 nm or more and 70 nm or less, or 30 nm or more and 60 nm or less. .

In the first embodiment, in order to obtain a gas barrier film that is more excellent in gas barrier properties and transparency and can further suppress the generation of ammonia, the carbon content in the first layer is 1 atomic % or more and 10 atomic % or less. It is preferably 2 atomic % or more and 7 atomic % or less, and still more preferably 3 atomic % or more and 5 atomic % or less.

Hereinafter, when the composition analysis in the thickness direction of the silicon oxycarbide layer (specifically, the first layer, etc.) is performed using an X-ray photoelectron spectrometer, the carbon content (the total of silicon, oxygen and carbon is The carbon content at the point where the carbon content at 100 atomic %) is the maximum value is sometimes referred to as the "maximum carbon content." In order to obtain a gas barrier film with better gas barrier properties, the maximum carbon content is preferably 10 atomic % or less, more preferably 9 atomic % or less, and even more preferably 7 atomic % or less. It is even more preferably 5 atomic % or less, and particularly preferably 3 atomic % or more and 5 atomic % or less. For example, when forming a silicon oxycarbide layer by the CVD method described later, the maximum carbon content is at least one of the introduction amount (flow rate) of the silicon source, the introduction amount (flow rate) of the oxygen source, and the applied power. can be adjusted by changing the

In the first embodiment, in order to obtain a gas barrier film that is more excellent in gas barrier properties and transparency and can further suppress the generation of ammonia, it is preferable to satisfy the following condition 1, and more preferably to satisfy the following condition 2. It is more preferable to satisfy condition 3 below.
Condition 1: The oxygen content in the second layer is 18 atomic % or more and 50 atomic % or less, and the thickness of the first layer is 30 nm or more and 250 nm or less.
Condition 2: Condition 1 above is satisfied, and the thickness of the second layer is 20 nm or more and 120 nm or less.
Condition 3: Condition 2 above is satisfied, and the maximum carbon content of the first layer is 5 atomic % or less.

The first embodiment will be described in detail below with reference to the drawings. FIG. 1 is a cross-sectional view showing an example of the gas barrier film according to the first embodiment. A gas barrier film 10 shown in FIG. 1 is a laminate having a transparent film substrate 11 and a gas barrier layer 12 directly disposed on one main surface 11 a of the transparent film substrate 11 . The gas barrier layer 12 has a first layer 13 (silicon oxycarbide layer) containing silicon, oxygen and carbon as constituent elements, and a second layer 14 (silicon oxynitride layer) containing silicon, oxygen and nitrogen as constituent elements. . The first layer 13 is the layer located farthest from the transparent film substrate 11 in the gas barrier layer 12 . The second layer 14 is in contact with the main surface 13a of the first layer 13 on the transparent film substrate 11 side. The oxygen content in the second layer 14 is 15 atomic % or more when the total of silicon, oxygen and nitrogen in the second layer 14 is 100 atomic %.

The configuration of the gas barrier film according to the first embodiment is not limited to the configuration of the gas barrier film 10 shown in FIG. For example, in the gas barrier film according to the first embodiment, a silicon oxycarbide layer may be arranged as a third layer between the silicon oxynitride layer and the transparent film substrate. In addition, in the gas barrier film according to the first embodiment, the gas barrier layer may include two or more silicon oxynitride layers, for example, two silicon oxynitride layers and three silicon oxycarbide layers. Alternating laminates may also be used. The gas barrier layer may have a laminate structure of four layers or a laminate structure of six or more layers. For example, the gas barrier layer having a four-layer structure may be an alternate laminate in which silicon oxynitride layer/silicon oxycarbide layer/silicon oxynitride layer/silicon oxycarbide layer are arranged in this order from the transparent film substrate side. The gas barrier layer may be an alternately laminated body composed of 3 silicon oxynitride layers and 4 silicon oxycarbide layers, a total of 7 layers, or may be an alternately laminated body composed of 8 or more layers. In order to obtain a gas barrier film with better transparency, the gas barrier layer preferably has a two-layer or three-layer laminate structure, and more preferably has a two-layer laminate structure like the gas barrier film 10 shown in FIG. preferable.

Further, in the gas barrier film according to the first embodiment, the gas barrier layer may be indirectly arranged on the main surface of the transparent film substrate. For example, the gas barrier film 20 shown in FIG. 2 has a hard coat layer 21 arranged between the transparent film substrate 11 and the gas barrier layer 12 (second layer 14). In the gas barrier film 20 , the gas barrier layer 12 is indirectly arranged on the main surface of the transparent film substrate 11 . The hard coat layer 21 is a layer that enhances mechanical properties such as hardness and elastic modulus of the gas barrier film 20 . If the main surface of the hard coat layer 21 on the side of the gas barrier layer 12 is smooth, the gas barrier properties of the gas barrier layer 12 formed thereon are enhanced, and the water vapor transmission rate tends to decrease. The arithmetic mean height Sa of the main surface of the hard coat layer 21 on the side of the gas barrier layer 12 may be 1.5 nm or less or 1.0 nm or less. The arithmetic mean height Sa is calculated according to ISO 25178 from the three-dimensional surface profile of the range of 1 μm×1 μm measured by an atomic force microscope (AFM).

The hard coat layer 21 may contain particles with a number average primary particle diameter of less than 1.0 μm (hereinafter sometimes referred to as "nanoparticles"). For example, when the hard coat layer 21 contains nanoparticles, fine irregularities are formed on the surface of the hard coat layer 21, and adhesion between the hard coat layer 21 and the gas barrier layer 12 tends to be improved.

In addition, the gas barrier film according to the first embodiment may be provided with gas barrier layers on both main surfaces of the transparent film substrate in order to further improve gas barrier properties. For example, the gas barrier film 30 shown in FIG. and In the gas barrier film according to the first embodiment, a gas barrier layer having a laminated structure of three or more layers may be provided on each of both main surfaces of the transparent film substrate.

The configuration of the gas barrier layer 31 may be the same as or different from the configuration of the gas barrier layer 12 . That is, the gas barrier layer 31 may have the silicon oxynitride layer 33 and the silicon oxycarbide layer 32 in this order from the transparent film substrate 11 side, and the oxygen content in the silicon oxynitride layer 33 is 15 atomic %. or more. Also, the gas barrier layer 31 may not have at least one of the silicon oxynitride layer 33 and the silicon oxycarbide layer 32 . In order to obtain a gas barrier film with more excellent transparency while further improving the gas barrier property, the gas barrier layer 31 has a silicon oxynitride layer 33 and a silicon oxycarbide layer 32 in this order from the transparent film substrate 11 side, and It is preferable that the oxygen content in the silicon nitride layer 33 is 15 atomic % or more. In addition, in order to obtain a gas barrier film that is more excellent in gas barrier properties and transparency and can further suppress the generation of ammonia, the carbon content in the silicon oxycarbide layer 32 should be 1 atomic % or more and 10 atomic % or less. is preferred.

In addition, the gas barrier film according to the first embodiment may further have an adhesive layer. For example, a gas barrier film 40 shown in FIG. 4 has an adhesive layer 41 in addition to the configuration of the gas barrier film 30 . In the gas barrier film 40, the adhesive layer 41 is arranged on the main surface 13b of the first layer 13 opposite to the transparent film substrate 11 side.

A release liner (not shown) may be temporarily attached to the main surface of the pressure-sensitive adhesive layer 41 opposite to the first layer 13 side. The release liner protects the surface of the pressure-sensitive adhesive layer 41, for example, until the gas barrier film 40 is attached to the polarizing plate 101 (see FIG. 5), which will be described later. Plastic films made of acrylic, polyolefin, cyclic polyolefin, polyester or the like are preferably used as the constituent material of the release liner. The thickness of the release liner is, for example, 5 μm or more and 200 μm or less. The surface of the release liner is preferably subjected to release treatment. Examples of release agent materials used in release treatment include silicone-based materials, fluorine-based materials, long-chain alkyl-based materials, fatty acid amide-based materials, and the like.

The configuration of the gas barrier film according to the first embodiment has been described above with reference to the drawings. Next, elements of the gas barrier film according to the first embodiment will be described.

[Transparent film substrate 11]
The transparent film substrate 11 is a layer that serves as a base for forming the gas barrier layer. The transparent film substrate 11 may have flexibility. By using a flexible film as the base material, the gas barrier layer can be formed by a roll-to-roll method, so the productivity of the gas barrier layer can be improved. A gas barrier film in which a gas barrier layer is provided on a flexible film also has the advantage of being applicable to flexible devices and foldable devices.

The visible light transmittance of the transparent film substrate 11 is preferably 80% or higher, more preferably 90% or higher. The thickness of the transparent film substrate 11 is not particularly limited, but from the viewpoint of strength, handleability, etc., it is preferably 5 μm or more and 200 μm or less, more preferably 10 μm or more and 150 μm or less, and 30 μm or more and 100 μm or less. is more preferred.

As the resin material that constitutes the transparent film substrate 11, a resin material that is excellent in transparency, mechanical strength and thermal stability is preferable. Specific examples of resin materials include cellulose resins such as triacetyl cellulose, polyester resins, polyethersulfone resins, polysulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, (meth) Examples include acrylic resins, cyclic polyolefin resins (more specifically, norbornene resins, etc.), polyarylate resins, polystyrene resins, polyvinyl alcohol resins, and mixtures thereof.

Corona treatment, plasma treatment, flame treatment, ozone treatment, glow treatment, saponification treatment, and coupling agent are applied to the main surface of the transparent film substrate 11 on which the gas barrier layer is formed, for the purpose of improving adhesion with the gas barrier layer. Surface modification treatment such as treatment with may be applied.

The surface layer of the transparent film substrate 11 on which the gas barrier layer is formed may be a primer layer (not shown). When the surface layer on which the gas barrier layer is formed is the primer layer, the adhesion between the transparent film substrate 11 and the gas barrier layer tends to be high. Examples of materials constituting the primer layer include metals (or semi-metals) such as silicon, nickel, chromium, tin, gold, silver, platinum, zinc, indium, titanium, tungsten, aluminum, zirconium, and palladium; alloys (or metalloids); oxides, fluorides, sulfides or nitrides of these metals (or metalloids); The thickness of the primer layer is, for example, 1 nm or more and 20 nm or less, preferably 1 nm or more and 15 nm or less, and more preferably 1 nm or more and 10 nm or less.

[Second layer 14]
The second layer 14 is a layer mainly having a gas barrier function in the gas barrier layer, and is a silicon oxynitride layer made of a material containing silicon, oxygen and nitrogen as main constituent elements. The second layer 14 may contain a small amount of elements such as hydrogen, carbon, etc. taken in from the raw material at the time of film formation, the transparent film substrate 11 and the external environment. When the second layer 14 contains carbon, the carbon content in the second layer 14 is preferably lower than that in the first layer 13 .

The composition of silicon oxynitride contained in the second layer 14 is represented by the general formula SiO _x N _y . Hereinafter, x in the general formula SiO _x N _y may be simply referred to as "x". Also, y in the general formula SiO _x N _y may be simply described as "y". The silicon oxynitride contained in the second layer 14 may have a stoichiometric composition or may be a non-stoichiometric composition deficient in oxygen or nitrogen. Stoichiometric silicon oxynitride has x/2+3y/4=1. The value of (x/2+3y/4) is preferably 0.70 or more and 1.10 or less. Theoretically, the upper limit of (x/2+3y/4) is 1, but it may show a value greater than 1 due to excessive intake of oxygen or nitrogen. If (x/2+3y/4) is 0.70 or more, transparency and gas barrier properties tend to be enhanced.

In order to obtain a gas barrier film with better transparency, x is preferably 0.3 or more. In order to obtain a gas barrier film with more excellent gas barrier properties, x is preferably 1.2 or less. In order to obtain a gas barrier film with more excellent gas barrier properties, y is preferably 0.4 or more. In order to obtain a gas barrier film having excellent transparency while further suppressing the generation of ammonia, y is preferably 0.8 or less.

In the second layer 14, the content of elements other than silicon, oxygen, and nitrogen is preferably 5 atomic % or less, more preferably 3 atomic % or less, and 1 atomic % or less. More preferred. Among the elements constituting the second layer 14, the total content of silicon, oxygen and nitrogen is preferably 90 atomic % or more, more preferably 95 atomic % or more, and 97 atomic % or more. is more preferable, and may be 99 atomic % or more, 99.5 atomic % or more, or 99.9 atomic % or more.

The refractive index of the second layer 14 is generally 1.50 or more and 2.20 or less, preferably 1.55 or more and 2.00 or less, and may be 1.60 or more and 1.90 or less. 0.85 or less, 1.80 or less, 1.75 or less, or 1.70 or less. The second layer 14 having a refractive index within this range can achieve both excellent gas barrier properties and transparency. Further, when the refractive index is 2.00 or less, there is a tendency for the light transmittance to be improved. The second layer 14 tends to have a higher refractive index as the nitrogen ratio increases.

The density of the second layer 14 is preferably 2.10 g/cm ³ or more. The higher the density of the second layer 14, the higher the gas barrier properties tend to be. The second layer 14 tends to have a higher density as the nitrogen ratio increases.

A method for forming the second layer 14 is not particularly limited, and may be a dry coating method or a wet coating method. A dry process such as a sputtering method, an ion plating method, a vacuum deposition method, or a chemical vapor deposition method (CVD method) is preferable because a film having a high film density and a high gas barrier property can be easily formed. A CVD method is preferable, and a plasma CVD method is more preferable, because a film having small film stress and excellent bending resistance can be easily formed.

When a flexible film is used as the transparent film substrate 11 and a gas barrier layer (for example, the second layer 14) is formed (film-formed) on the flexible film, CVD film-forming is performed by a roll-to-roll method. Therefore, productivity can be improved. In a roll-to-roll type CVD film forming apparatus, a film forming roll constitutes one or both electrodes of a pair of opposed electrodes, and a thin film is formed on the film when the film runs on the film forming roll. be. When two film-forming rolls constitute a pair of opposing electrodes, a thin film is formed on each of the film-forming rolls, so the film-forming speed can be doubled. In addition, the expression "above" when explaining the film forming method by the CVD method has no relation to the direction in the CVD film forming apparatus, and has the same meaning as "in contact with".

Examples of the silicon supply source (silicon source) when forming the second layer 14 by the CVD method include silicon hydride (more specifically, silane, disilane, etc.) and silicon halide (more specifically, , dichlorosilane, etc.) Si-containing gas such as hexamethyldisilazane, hexamethyldisiloxane, 1,1,3,3-tetramethyldisiloxane, tetramethylsilane, vinyltrimethoxysilane, vinyltrimethylsilane, dimethyldimethoxy Silicon compounds such as silane, tetramethoxysilane, methyltrimethoxysilane, dimethyldiethoxysilane, trimethylmethoxysilane, tetraethoxysilane, diethyldiethoxysilane, methyldimethoxysilane, methyldiethoxysiloxane, monosilylamine, disilylamine, and trisilylamine is mentioned. Among these, trisilylamine is preferable because it has low toxicity, a low boiling point, and can form a highly transparent and high-density film.

In order to form the second layer 14, normally, in addition to the silicon source, a nitrogen source and an oxygen source gas are introduced. Nitrogen sources include nitrogen and ammonia. Oxygen sources include oxygen, carbon monoxide, carbon dioxide, and the like. Nitrogen (nitrogen gas) is preferable as the nitrogen source, and oxygen (oxygen gas) is preferable as the oxygen source, from the viewpoint of reducing hydrogen and carbon taken into the film.

In general, a silicon nitride film formed by a CVD method by introducing a nitrogen source together with trisilylamine as a silicon source has a _large amount of hydrogen in the film, and a wave number of 2140 cm ^{− 1} (range of 2120 cm ⁻¹ to 2150 cm ⁻¹ ). In addition, in general, a silicon oxynitride film formed by a CVD method by introducing nitrogen and oxygen together with trisilylamine as a silicon source shifts the infrared absorption peak to the high wave number side, and is 2160 cm ⁻¹ to 2280 cm It exhibits an infrared absorption peak in the range of ^-1 or less, and exhibits transparency superior to that of silicon nitride films. Oxygen has a strong bonding force with silicon, so it is presumed that the introduction of oxygen suppresses the uptake of hydrogen into the film, which is one of the reasons for the improvement in transparency.

By changing the introduction amount of at least one of the nitrogen source and the oxygen source with respect to the silicon source, the composition of the second layer 14 can be appropriately adjusted. When nitrogen is used as the nitrogen source and oxygen is used as the oxygen source, from the viewpoint of achieving both transparency and gas barrier properties, the amount of oxygen to be introduced is set to 0.05 by volume with respect to the amount of nitrogen to be introduced. It is preferably 0.1 times or more and 5 times or less, more preferably 0.03 times or more and 2 times or less, further preferably 0.04 times or more and 1.5 times or less, and 0.04 times or more and 1 0 times or less, or 0.04 times or more and 0.5 times or less. If the amount of oxygen introduced is excessively small, the amount of oxygen introduced into the film tends to be small and the light transmittance of the film tends to decrease. If the amount of oxygen introduced is excessively large, the amount of nitrogen incorporated into the film tends to be small, resulting in insufficient gas barrier properties.

A gas other than the silicon source, the nitrogen source, and the oxygen source may be used as the introduced gas when forming the film by the CVD method. For example, when using a liquid such as trisilylamine, a carrier gas may be used to vaporize the liquid and introduce it into the chamber (vacuum chamber). Also, a nitrogen source or an oxygen source may be mixed with a carrier gas and introduced into the vacuum chamber, or a discharge gas may be used to stabilize the plasma discharge. Carrier gas and discharge gas include rare gases such as helium, argon, neon, and xenon, and hydrogen. A rare gas is preferable from the viewpoint of reducing the amount of hydrogen taken into the film and increasing the transparency.

Various conditions in the plasma CVD method can be set as appropriate. The substrate temperature (temperature of the surface of the film-forming roll) is set, for example, within the range of -20°C or higher and 500°C or lower. The substrate temperature (film substrate temperature) when forming a gas barrier layer (for example, the second layer 14) on the film substrate is preferably 150° C. or less from the viewpoint of the heat resistance of the film substrate. , 100° C. or lower. The pressure in the film forming chamber (inside the vacuum chamber) is, for example, 0.001 Pa or more and 50 Pa or less. An AC power supply, for example, is used as the power supply for plasma generation. The frequency of the power supply in roll-to-roll CVD film formation is generally in the range of 50 kHz to 500 kHz. The applied power in roll-to-roll CVD film formation is generally 0.1 kW or more and 10 kW or less.

The density of the second layer 14 formed by the CVD method is, for example, 2.10 g/cm ³ or more and 2.50 g/cm 3 or less, 2.15 g/cm ³ ^or more and 2.45 g/cm ³ or less, or 2.20 g/cm 3 or more. /cm ³ or more and 2.40 g/cm ³ or less, or 2.25 g/cm ³ or more and 2.35 g/cm ³ or less.

[First layer 13]
The first layer 13 is a layer that blocks the diffusion of ammonia gas from the second layer 14 while having a gas barrier function together with the second layer 14, and is made of a material containing silicon, oxygen and carbon as main constituent elements. Silicon layer. The first layer 13 may contain a small amount of elements such as hydrogen, nitrogen, etc. taken in from the raw material at the time of film formation, the transparent film substrate 11 and the external environment. When the first layer 13 contains nitrogen, the nitrogen content in the first layer 13 is preferably lower than that in the second layer 14 . In the first layer 13, the content of elements other than silicon, oxygen, and carbon is preferably 3 atomic % or less, more preferably 1 atomic % or less, and 0.5 atomic % or less. is more preferred. Among the elements constituting the first layer 13, the total content of silicon, oxygen and carbon is preferably 90 atomic % or more, more preferably 95 atomic % or more, and 97 atomic % or more. is more preferable, and may be 99 atomic % or more, 99.5 atomic % or more, or 99.9 atomic % or more.

The composition of silicon oxycarbide contained in the first layer 13 is represented by the general formula SiO _a C _b . Hereinafter, a in the general formula SiO _a C _b may be simply referred to as "a". In addition, _b in the general formula _SiOaCb may be simply described as "b".

In order to obtain a gas barrier film that is more excellent in gas barrier properties and transparency and can further suppress the generation of ammonia, a is 1.5 or more and 2.5 or less, and b is 0.01 or more and 0.5 or less. is preferred.

A method for forming the first layer 13 is not particularly limited, and may be a dry coating method or a wet coating method. When the second layer 14 is formed by the CVD method, the first layer 13 is also preferably formed by the CVD method from the viewpoint of productivity.

Examples of the silicon source and the oxygen source for forming the first layer 13 by the CVD method include those exemplified above regarding the formation of the second layer 14 . As the silicon source, organosilicon compounds are preferred because they have low toxicity and can suppress incorporation of nitrogen into the film. methylsilane, vinyltrimethoxysilane, vinyltrimethylsilane, dimethyldimethoxysilane, tetramethoxysilane, methyltrimethoxysilane, dimethyldiethoxysilane, trimethylmethoxysilane, tetraethoxysilane, diethyldiethoxysilane, methyldimethoxysilane, and methyldimethoxysilane. More preferably, one or more selected from the group consisting of ethoxysiloxane. Among these organosilicon compounds, hexamethyldisiloxane is particularly preferred because it can suppress incorporation of impurities into the film and can form a film with high transparency and gas barrier properties. Although the organosilicon compound as the silicon source also serves as a carbon source, an organic compound containing no silicon may be used as the carbon source in addition to the organosilicon compound. Oxygen gas is preferable as the oxygen source from the viewpoint of reducing the amount of hydrogen in the film.

When the first layer 13 is formed by a CVD method using hexamethyldisiloxane and oxygen, the amount of oxygen introduced is preferably 10 times or more by volume the amount of hexamethyldisiloxane (gas) introduced. , 15 times or more, or 20 times or more. From the viewpoint of appropriately maintaining the film formation rate, the amount of oxygen introduced is preferably 200 times or less, and preferably 100 times or less or 50 times or less, the volume ratio of the amount of hexamethyldisiloxane (gas) introduced. good too.

The composition of the first layer 13 can be appropriately adjusted by changing the introduction amount of the oxygen source (or the oxygen source and the carbon source) with respect to the silicon source.

A carrier gas or a discharge gas may be introduced in the CVD film formation of the first layer 13 . Various conditions such as substrate temperature, pressure, power supply frequency, and applied power may be appropriately adjusted in the same manner as in the film formation of the second layer 14 .

From the viewpoint of contributing to the improvement of gas barrier properties of the first layer 13, the density of the first layer 13 is preferably 1.80 g/cm ³ or more, more preferably 1.90 g/cm ³ or more. 00 g/cm ³ or more and 2.40 g/cm ³ or less, 2.05 g/cm ³ or more and 2.35 g/cm ³ or less, or 2.10 g/cm ³ or more and 2.30 g/cm ³ or less.

The gas barrier layer may include layers (other layers) other than the second layer 14 and the first layer 13. Examples of "other layers" include inorganic thin films made of ceramic materials such as metal or semi-metal oxides, nitrides or oxynitrides. Oxides, nitrides or oxynitrides of Si, Al, In, Sn, Zn, Ti, Nb, Ce or Zr are preferred because they have both low moisture permeability and transparency.

From the viewpoint of achieving both high gas barrier properties and transparency, the total thickness of the gas barrier layer is preferably 50 nm or more and 1000 nm or less, more preferably 80 nm or more and 500 nm or less.

[Hard coat layer 21]
The hard coat layer 21 contains, for example, a binder resin and nanoparticles. As the binder resin, curable resins such as thermosetting resins, photocurable resins and electron beam curable resins are preferably used. Types of curable resins include polyester resins, acrylic resins, urethane resins, acrylic urethane resins, amide resins, silicone resins, silicate resins, epoxy resins, melamine resins, and oxetane resins. mentioned. One or more curable resins can be used. Among these, one or more selected from the group consisting of acrylic resins, acrylic urethane resins, and epoxy resins are preferable because they have high hardness and can be photocured, and acrylic resins and acrylic urethane resins. More preferably, one or more selected from the group consisting of

The number average primary particle size of the nanoparticles contained in the hard coat layer 21 is preferably 15 nm or more, more preferably 20 nm or more, from the viewpoint of enhancing dispersibility in the binder resin. From the viewpoint of forming fine irregularities that contribute to improved adhesion, the number average primary particle diameter of the nanoparticles contained in the hard coat layer 21 is preferably 90 nm or less, more preferably 70 nm or less. It is more preferably 50 nm or less.

Inorganic oxides are preferable as materials for nanoparticles. Examples of inorganic oxides include metal (or metalloid) oxides such as silica, titanium oxide, aluminum oxide, zirconium oxide, niobium oxide, zinc oxide, tin oxide, cerium oxide, and magnesium oxide. The inorganic oxide may be a composite oxide of multiple (semi)metals. Among the exemplified inorganic oxides, silica is preferable because it has a high adhesion improving effect. That is, silica particles (nanosilica particles) are preferable as the nanoparticles. A functional group such as an acrylic group or an epoxy group may be introduced into the surface of the inorganic oxide particles as nanoparticles for the purpose of enhancing adhesion and affinity with the resin.

The amount of nanoparticles in the hard coat layer 21 is preferably 5 parts by weight or more, 10 parts by weight or more, 20 parts by weight or more, or 30 parts by weight or more with respect to 100 parts by weight of the total amount of the binder resin and the nanoparticles. may be If the amount of nanoparticles is 5 parts by weight or more, the adhesion to the gas barrier layer formed on the hard coat layer 21 can be improved. The upper limit of the amount of nanoparticles in the hard coat layer 21 is, for example, 90 parts by weight, preferably 80 parts by weight, and preferably 70 parts by weight with respect to 100 parts by weight of the total amount of the binder resin and the nanoparticles. good too.

The thickness of the hard coat layer 21 is not particularly limited, but is preferably 0.5 μm or more, more preferably 1.0 μm or more, in order to improve the adhesion to the gas barrier layer while achieving high hardness. It is more preferably 2.0 μm or more, and even more preferably 3.0 μm or more. On the other hand, the thickness of the hard coat layer 21 is preferably 20 μm or less, more preferably 15 μm or less, and even more preferably 12 μm or less in order to suppress a decrease in strength due to cohesive failure.

(Method for forming hard coat layer 21)
The hard coat layer 21 is formed by applying the hard coat composition onto the transparent film substrate 11 and, if necessary, removing the solvent and curing the resin. The hard coat composition contains, for example, the above binder resin and nanoparticles, and optionally contains a solvent capable of dissolving or dispersing these components. When the resin component in the hard coat composition is a curable resin, the hard coat composition preferably contains an appropriate polymerization initiator. For example, when the resin component in the hard coat composition is a photocurable resin, the hard coat composition preferably contains a photopolymerization initiator.

In addition to the above components, the hard coat composition includes particles (microparticles) having a number average primary particle diameter of 1.0 μm or more, leveling agents, viscosity modifiers (thixotropic agents, thickeners, etc.), antistatic agents, blocking agents, Additives such as inhibitors, dispersants, dispersion stabilizers, antioxidants, UV absorbers, antifoaming agents, surfactants and lubricants may be included.

As a method for applying the hard coat composition, any suitable method such as bar coating, roll coating, gravure coating, rod coating, slot orifice coating, curtain coating, fountain coating, comma coating, etc. can be used. can be adopted.

[Adhesive layer 41]
As a constituent material of the adhesive layer 41, an adhesive having a high visible light transmittance is preferably used. Examples of adhesives constituting the adhesive layer 41 include acrylic polymers, silicone polymers, polyesters, polyurethanes, polyamides, polyvinyl ethers, vinyl acetate-vinyl chloride copolymers, modified polyolefins, epoxy resins, and fluorine resins. , natural rubber, synthetic rubber or the like as a base polymer can be appropriately selected and used. The thickness of the adhesive layer 41 is preferably 5 μm or more and 100 μm or less. The refractive index of the adhesive layer 41 is, for example, 1.4 or more and 1.5 or less.

[Characteristics of gas barrier film]
The water vapor transmission rate of the gas barrier film is preferably 3.0×10 ⁻² g/m ² ·day or less, more preferably 2.0×10 ⁻² g/m ² ·day or less. It is more preferably 0×10 ⁻² g/m ² ·day or less. From the viewpoint of suppressing deterioration of the protection object such as the organic EL element, the lower the water vapor transmission rate, the better. Although the lower limit of the water vapor transmission rate of the gas barrier film is not particularly limited, it is generally 1.0×10 ⁻⁵ g/m ² ·day. Water vapor transmission rate (WVTR) is measured according to the differential pressure method (Pressure Sensor Method) described in ISO 15106-5 under conditions of a temperature of 40° C. and a relative humidity of 90%.

The light transmittance of the gas barrier film is preferably 75% or higher, more preferably 80% or higher. Light transmittance is the Y value of the CIE tristimulus values specified in JlS Z8781-3:2016.

The amount of ammonium ions extracted per 1 cm ² of the gas barrier film is preferably 0.30 μg or less, more preferably 0.15 μg or less, even more preferably 0.12 μg or less, and 0.11 μg or less. It is even more preferred to have The method for measuring the extracted amount of ammonium ions is the same method as in Examples described later or a method based thereon.

<Second Embodiment: Method for Producing Gas Barrier Film>
Next, a method for manufacturing a gas barrier film according to the second embodiment of the present invention will be described. The method for manufacturing the gas barrier film according to the second embodiment is a suitable method for manufacturing the gas barrier film according to the first embodiment described above. Therefore, descriptions of components that overlap with those of the above-described first embodiment may be omitted. In the method for producing a gas barrier film according to the second embodiment, trisilylamine, nitrogen and oxygen are introduced into a chamber (vacuum chamber) of a film forming apparatus to form the second layer 14 by chemical vapor deposition. and a step of introducing an organosilicon compound and oxygen into a chamber of a film forming apparatus to form the first layer 13 by chemical vapor deposition.

In the second embodiment, for example, by using a CVD film forming apparatus (not shown) and adopting the conditions of the plasma CVD method illustrated in the explanation of the gas barrier film according to the first embodiment, Such a gas barrier film can be easily produced. For example, when producing the gas barrier film according to the first embodiment using a CVD film forming apparatus (not shown) in which a pair of film forming rolls constitutes a pair of opposed electrodes, the second layer 14 is formed. While supplying a film-forming gas (more specifically, trisilylamine, oxygen, nitrogen, etc.) to the vacuum chamber, plasma discharge is generated between a pair of film-forming rolls, so that the film-forming gas is It is decomposed by plasma, and the second layer 14 is formed on the transparent film substrate 11, for example. Next, plasma discharge is generated between a pair of film-forming rolls while supplying a film-forming gas (more specifically, an organic silicon compound, oxygen, etc.) for forming the first layer 13 into the vacuum chamber. As a result, the deposition gas is decomposed by plasma, and the first layer 13 is formed on the second layer 14 .

<Third Embodiment: Polarizing Plate with Gas Barrier Layer>
Next, a polarizing plate with a gas barrier layer according to a third embodiment of the present invention will be described. A polarizing plate with a gas barrier layer according to the third embodiment includes the gas barrier film according to the first embodiment and a polarizer. FIG. 5 is a cross-sectional view showing an example of a polarizing plate with a gas barrier layer according to the third embodiment. The polarizing plate 100 with a gas barrier layer shown in FIG. 5 has the gas barrier film 40 and the polarizing plate 101 described above. In the gas barrier layer-attached polarizing plate 100, the polarizing plate 101 is arranged on the main surface 41a of the adhesive layer 41 opposite to the first layer 13 side. That is, the polarizing plate 101 and the first layer 13 are bonded together with the adhesive layer 41 interposed therebetween. Although the polarizing plate 100 with a gas barrier layer shown in FIG. For example, it may be the gas barrier film 10 or the gas barrier film 20 .

The polarizing plate 101 includes a polarizer (not shown), and generally transparent protective films (not shown) as polarizer protective films are laminated on both main surfaces of the polarizer. A transparent protective film may not be provided on one principal surface or both principal surfaces of the polarizer. As a polarizer, for example, a hydrophilic polymer film such as a polyvinyl alcohol film is uniaxially stretched after adsorbing a dichroic substance such as iodine or a dichroic dye.

As the transparent protective film, a transparent resin film composed of a cellulose resin, a cyclic polyolefin resin, an acrylic resin, a phenylmaleimide resin, a polycarbonate resin, or the like is preferably used. A gas barrier film may be used as the transparent protective film.

The polarizing plate 101 may include an optical functional film laminated on one or both main surfaces of a polarizer via an appropriate adhesive layer or pressure-sensitive adhesive layer as necessary. Examples of the optical functional film include retardation plates, viewing angle widening films, viewing angle limiting (peep prevention) films, brightness improving films, and the like.

Since the polarizing plate with a gas barrier layer according to the third embodiment includes the gas barrier film according to the first embodiment, it has excellent transparency while ensuring gas barrier properties, and can suppress the generation of ammonia.

<Fourth Embodiment: Image Display Device>
Next, an image display device according to a fourth embodiment of the invention will be described. An image display device according to the fourth embodiment includes the gas barrier film according to the first embodiment or the polarizing plate with a gas barrier layer according to the third embodiment, and an image display cell.

FIG. 6 is a cross-sectional view showing an example of an image display device according to the fourth embodiment. An image display device 200 shown in FIG. 6 includes a gas barrier layer-attached polarizing plate 100 having a gas barrier film 40 and an image display cell 202 . The image display cell 202 includes a substrate 203 and display elements 204 provided on the substrate 203 . In the image display device 200 , the gas barrier layer 31 and the display element 204 are bonded together with the adhesive layer 201 interposed therebetween. Although the image display device 200 shown in FIG. 6 has the gas barrier film 40 (gas barrier film 30), the gas barrier film of the image display device according to the fourth embodiment is not limited to the gas barrier film 40. For example, the gas barrier film 10 or gas barrier film 20 .

As the adhesive constituting the adhesive layer 201, for example, the same adhesives as those exemplified as the adhesive constituting the adhesive layer 41 described above can be used. The adhesive that forms the adhesive layer 201 and the adhesive that forms the adhesive layer 41 may be of the same type or of different types.

The preferable range of the thickness of the adhesive layer 201 is, for example, the same as the preferable range of the thickness of the adhesive layer 41 described above. The thickness of the adhesive layer 201 and the thickness of the adhesive layer 41 may be the same or different.

A glass substrate or a plastic substrate is used as the substrate 203 . When the image display cell 202 is of the top emission type, the substrate 203 does not have to be transparent, and a highly heat-resistant film such as a polyimide film may be used as the substrate 203 .

Examples of the display element 204 include an organic EL element, a liquid crystal element, an electrophoretic display element (electronic paper), and the like. A touch panel sensor (not shown) may be arranged on the viewing side of the image display cell 202 .

When the display element 204 is an organic EL element, the image display cell 202 is, for example, top emission type. The organic EL element includes, for example, a metal electrode (not shown), an organic light emitting layer (not shown), and a transparent electrode (not shown) in this order from the substrate 203 side.

The organic light-emitting layer may include an electron-transporting layer, a hole-transporting layer, etc. in addition to the organic layer that itself functions as a light-emitting layer. The transparent electrode is a metal oxide layer or a metal thin film and transmits light from the organic light emitting layer. A back sheet (not shown) may be provided on the back side of the substrate 203 for the purpose of protecting and reinforcing the substrate 203 .

　The metal electrode of the organic EL element is light reflective. Therefore, when external light enters the inside of the image display cell 202, the light is reflected by the metal electrodes, and the reflected light is visually recognized as a mirror surface from the outside. By arranging a circularly polarizing plate as the polarizing plate 101 on the viewing side of the image display cell 202, the re-emission of light reflected by the metal electrode to the outside is prevented, and the visibility and design of the screen of the image display device 200 are improved. can improve sexuality.

The circularly polarizing plate has, for example, a retardation film on the main surface of the polarizer on the image display cell 202 side. The transparent protective film arranged adjacent to the polarizer may be a retardation film. Further, the transparent film substrate 11 of the gas barrier film 40 may be a retardation film. Lamination of the polarizer and the retardation film when the retardation film has a retardation of λ / 4 and the angle formed by the slow axis direction of the retardation film and the absorption axis direction of the polarizer is 45 ° The body functions as a circular polarizer for suppressing re-emission of reflected light from the metal electrode. The retardation film that constitutes the circularly polarizing plate may be a laminate of two or more layers of films. For example, by laminating a polarizer, a λ/2 plate and a λ/4 plate so that their optical axes form a predetermined angle, a broadband circularly polarizing plate that functions as a circularly polarizing plate over a wide band of visible light is obtained. can get.

The image display cell 202 may be of a bottom emission type in which a transparent electrode, an organic light emitting layer and a metal electrode are laminated in this order on a substrate. In the bottom emission type image display cell 202, a transparent substrate is used, and the transparent substrate is arranged on the viewing side. A gas barrier film may be used as the transparent substrate.

Since the image display device according to the fourth embodiment includes the gas barrier film according to the first embodiment, it is possible to suppress deterioration of the display element caused by gas (for example, water vapor).

Examples of the present invention will be described below, but the present invention is not limited to the following examples.

<Production of gas barrier film>
The methods for producing the gas barrier films of Examples 1 to 8 and Comparative Examples 1 to 6 are described below. In the preparation of the gas barrier films of Examples 1 to 8 and Comparative Examples 1 to 6, a roll-to-roll CVD film forming apparatus was used for film formation of each layer constituting the gas barrier layer.

[Example 1]
A 40 μm-thick cyclic polyolefin film (“Zeonor (registered trademark) film ZF-14” manufactured by Nippon Zeon Co., Ltd.) as a transparent film substrate was set in a film forming apparatus, and the pressure in the vacuum chamber was reduced to 1×10 ⁻³ Pa. . Next, while the film was running, a silicon oxynitride layer having a thickness of 60 nm was formed on the film by CVD, and then a silicon oxycarbide layer having a thickness of 200 nm was formed by CVD on the silicon oxynitride layer. As a result, a gas barrier film having a gas barrier layer having a silicon oxynitride layer and a silicon oxycarbide layer was obtained. For both the deposition of the silicon oxynitride layer and the deposition of the silicon oxycarbide layer, the substrate temperature was set to 12° C., the frequency of the power source for plasma generation was set to 80 kHz, and the discharge was performed under the conditions of an applied power of 1.0 kW. A film was formed at a pressure of 1.0 Pa by introducing a film forming gas between the film forming rolls (between the electrodes) in the vacuum chamber. When forming the silicon oxynitride layer, trisilylamine (TSA) (flow rate: 30 sccm), nitrogen (flow rate: 500 sccm), and oxygen (flow rate: 100 sccm) were used as deposition gases. When forming the silicon oxycarbide layer, hexamethyldisiloxane (HMDSO) (flow rate: 25 sccm) and oxygen (flow rate: 700 sccm) were used as deposition gases. Both TSA and HMDSO were vaporized by heating and introduced into the vacuum chamber.

[Example 2]
A gas barrier film of Example 2 was produced in the same manner as in Example 1, except that the thickness of the silicon oxycarbide layer was changed to 100 nm.

[Example 3]
A gas barrier film of Example 3 was produced in the same manner as in Example 1, except that the thickness of the silicon oxycarbide layer was changed to 50 nm.

[Example 4]
A gas barrier film of Example 4 was produced in the same manner as in Example 1, except that the thickness of the silicon oxynitride layer was changed to 30 nm.

[Example 5]
A gas barrier film of Example 5 was produced in the same manner as in Example 1, except that the thickness of the silicon oxynitride layer was changed to 100 nm.

[Example 6]
A gas barrier film of Example 6 was produced in the same manner as in Example 1, except that the flow rate of nitrogen was set to 550 sccm and the flow rate of oxygen was set to 50 sccm when forming the silicon oxynitride layer.

[Example 7]
The gas barrier film of Example 7 was prepared in the same manner as in Example 1 except that the flow rate of HMDSO was 15 sccm, the flow rate of oxygen was 420 sccm, and the applied power was 0.6 kW when forming the silicon oxycarbide layer. was made.

[Example 8]
A gas barrier film of Example 8 was produced in the same manner as in Example 1, except that the nitrogen flow rate was set to 575 sccm and the oxygen flow rate was set to 25 sccm when forming the silicon oxynitride layer.

[Comparative Example 1]
A gas barrier film of Comparative Example 1 was produced in the same manner as in Example 1, except that the silicon oxycarbide layer was not formed.

[Comparative Example 2]
In forming the silicon oxynitride layer, the same method as in Example 1 was used except that the flow rate of nitrogen was set to 525 sccm and the flow rate of oxygen was set to 75 sccm, and the silicon oxycarbide layer was not formed. A gas barrier film of Comparative Example 2 was produced.

[Comparative Example 3]
In forming the silicon oxynitride layer, the same method as in Example 1 was used, except that the flow rate of nitrogen was set to 550 sccm and the flow rate of oxygen was set to 50 sccm, and the silicon oxycarbide layer was not formed. A gas barrier film of Comparative Example 3 was produced.

[Comparative Example 4]
In forming the silicon oxynitride layer, the same method as in Example 1 was used except that the flow rate of nitrogen was set to 575 sccm and the flow rate of oxygen was set to 25 sccm, and the silicon oxycarbide layer was not formed. A gas barrier film of Comparative Example 4 was produced.

[Comparative Example 5]
Comparison was performed by the same method as in Example 1 except that the nitrogen flow rate was 600 sccm, oxygen was not introduced, and the silicon oxycarbide layer was not formed when forming the silicon oxynitride layer. A gas barrier film of Example 5 was prepared.

[Comparative Example 6]
A comparative example was prepared in the same manner as in Example 1, except that after forming a silicon oxycarbide layer on the film, a silicon oxynitride layer was formed on the silicon oxycarbide layer (the order of film formation was changed). No. 6 gas barrier film was produced.

<Measurement of Elemental Composition of Silicon Oxynitride Layer and Silicon Oxycarbide Layer>
For each of the gas barrier films of the above Examples and Comparative Examples, an X-ray photoelectron spectrometer equipped with an Ar ion gun (“Quantera SXM” manufactured by ULVAC-Phi, Inc.) was used to examine the side of the gas barrier layer opposite to the transparent film substrate side. Composition analysis in the thickness direction of the gas barrier layer (specifically, the silicon oxycarbide layer and the silicon oxynitride layer) was performed by X-ray photoelectron spectroscopy (XPS) while etching the gas barrier layer from the main surface of the film under the following conditions. Then, the content of each element (Si, O, N, and C) in the central portion of the silicon oxycarbide layer in the thickness direction (when 1/2 of the total etching time of the silicon oxycarbide layer has elapsed), and the silicon oxycarbide The maximum carbon content of the layer and the content of each element (Si, O, N and C) in the central portion of the silicon oxynitride layer in the thickness direction (when 1/2 of the total etching time of the silicon oxynitride layer has elapsed) rate was calculated. In addition, the “total etching time of the silicon oxycarbide layer” means the time from the start to the end of etching when etching the silicon oxycarbide layer. The "total etching time of the silicon oxynitride layer" means the time from the start to the end of etching when etching the silicon oxynitride layer. Peaks corresponding to the binding energies of 2p of Si, 1s of O, 1s of N, and 1s of C obtained from the wide scan spectrum were used to calculate the content of each element. Detailed measurement conditions are shown below.

[Measurement condition]
X-ray source: monochrome AlKα
X-ray focal size: 100 μmφ (15 kV, 25 W)
Photoelectron extraction angle: 45° with respect to the sample surface
Correction of bond energy: Correction of the peak derived from CC bond to 285.0 eV (only the outermost surface of the gas barrier layer)
Charge neutralization conditions: combined use of electron neutralization gun and Ar ion gun (neutralization mode) Acceleration voltage of Ar ion gun: 1 kV
Ar ion gun raster size: 1mm x 1mm
Etching rate of Ar ion gun: 5 nm/min (in terms of _SiO2 )
Elemental composition measurement interval: 60 seconds (5 nm)

<Method for evaluating gas barrier film>
[Light transmittance]
The light transmittance (Y value) of the gas barrier film was measured with a spectrophotometer ("U4100" manufactured by Hitachi High-Tech Science). When the light transmittance was 75% or more, it was evaluated as "excellent in transparency". On the other hand, when the light transmittance was less than 75%, it was evaluated as "not excellent in transparency".

[Water vapor transmission rate]
According to the differential pressure method (Pressure Sensor Method) described in ISO 15106-5, using a water vapor transmission rate measuring device "Deltaperm (registered trademark)" manufactured by Technolox, under the conditions of a temperature of 40 ° C. and a relative humidity of 90%, The water vapor transmission rate (WVTR) of the gas barrier film was measured. When the WVTR was 1.0×10 ⁻² g/m ² ·day or less, it was evaluated as “gas barrier property is ensured”. On the other hand, when WVTR exceeded 1.0×10 ⁻² g/m ² ·day, it was evaluated as “gas barrier properties cannot be ensured”.

[Extraction amount of ammonium ions]
First, the gas barrier film was cut into a size of 60 mm×60 mm to obtain a sample for measurement. Next, after putting the obtained sample into a container made of polypropylene, 100 mL of ultrapure water was put into the container. Next, the container containing the sample and ultrapure water was placed in a dryer set at a temperature of 120° C. for 1 hour, and then the liquid (extract) in the container was filtered through a membrane filter with a pore size of 0.2 μm. Then, using ion chromatography (IC method), the amount of ammonium ions (extracted amount) in the resulting filtrate was quantified under the following conditions. A commercially available ammonium ion standard solution (manufactured by Kanto Kagaku Co., Ltd.) was used for quantification. When the amount of extracted ammonium ions per 1 cm ² of the sample was 0.11 μg or less, it was evaluated as “ammonia generation can be suppressed”. On the other hand, when the amount of extracted ammonium ions per 1 cm ² of the sample exceeded 0.11 µg, it was evaluated as "the generation of ammonia cannot be suppressed."

(Measurement conditions for the IC method)
Analyzer: Thermo Fisher Scientific "Dionex (registered trademark) ICS-6000"
Separation column: Thermo Fisher Scientific "Dionex (registered trademark) IonPac CS16 (3 mm × 250 mm)"
Guard column: Thermo Fisher Scientific "Dionex (registered trademark) IonPac CG16 (3 mm × 50 mm)"
Suppressor: Thermo Fisher Scientific "Dionex (registered trademark) CDRS 600 (external mode)"
Detector: Conductivity detector Eluent: Methanesulfonic acid aqueous solution (concentration of methanesulfonic acid: 25 mmol/L)
Eluent flow rate: 0.36 mL/min Injection volume of sample (filtrate): 5 μL

<Analysis results and evaluation results>
Table 1 shows details of the gas barrier layers for Examples 1 to 8 and Comparative Examples 1 to 6. Table 2 shows the light transmittance, WVTR, and the amount of extracted ammonium ions per 1 cm ² of the sample for Examples 1 to 8 and Comparative Examples 1 to 6. The maximum carbon content of the first layer (silicon oxycarbide layer) of Examples 1 to 6 was 9 atomic %. The maximum carbon content of the first layer (silicon oxycarbide layer) of Example 7 was 4 atomic %.

In addition, the "first layer" in Table 1 means the layer arranged farthest from the transparent film substrate in the gas barrier layer. "Second layer" in Table 1 means a layer in contact with the main surface of the first layer on the side of the transparent film substrate (the layer closest to the transparent film substrate in the gas barrier layer). When the gas barrier layer has a single layer structure, Table 1 assumes that the gas barrier layer has a single layer structure consisting of the first layer. In Table 1, "-" means that the second layer was not deposited.

In addition, the content of each element (Si, O, N and C) in Table 1 is the thickness direction central portion of the measured layer (either the silicon oxycarbide layer or the silicon oxynitride layer) (1 /2), and the total of Si, O, N and C was calculated as 100 atomic %. The "NH ₄ ⁺ extraction amount" in Table 2 is the extraction amount of ammonium ions per 1 cm ² of the sample.

As shown in Table 1, in Examples 1 to 8, the gas barrier layer had a first layer containing silicon, oxygen and carbon as constituent elements and a second layer containing silicon, oxygen and nitrogen as constituent elements. was In Examples 1 to 8, the oxygen content in the second layer was 15 atomic % or more when the total of silicon, oxygen and nitrogen in the second layer was 100 atomic %.

As shown in Table 2, in Examples 1 to 8, the light transmittance was 75% or more. Therefore, the gas barrier films of Examples 1 to 8 were excellent in transparency. In Examples 1 to 8, the WVTR was 1.0×10 ⁻² g/m ² ·day or less. Therefore, the gas barrier films of Examples 1 to 8 were able to secure gas barrier properties. In Examples 1 to 8, the amount of ammonium ions extracted per 1 cm ² of the sample was 0.11 μg or less. Therefore, the gas barrier films of Examples 1 to 8 were able to suppress the generation of ammonia.

As shown in Table 1, in Comparative Examples 1 to 5, the gas barrier layer had a single layer structure consisting of the first layer. In Comparative Example 6, the gas barrier layer had a first layer containing silicon, oxygen and nitrogen as constituent elements and a second layer containing silicon, oxygen and carbon as constituent elements.

As shown in Table 2, in Comparative Example 5, the light transmittance was less than 75%. Therefore, the gas barrier film of Comparative Example 5 was not excellent in transparency. In Comparative Examples 1 and 6, WVTR exceeded 1.0×10 ⁻² g/m ² ·day. Therefore, the gas barrier films of Comparative Examples 1 and 6 could not ensure gas barrier properties. In Comparative Examples 1 to 6, the amount of extracted ammonium ions per 1 cm ² of sample exceeded 0.11 μg. Therefore, the gas barrier films of Comparative Examples 1 to 6 could not suppress the generation of ammonia.

From the above results, it was shown that according to the present invention, it is possible to provide a gas barrier film that is excellent in transparency while ensuring gas barrier properties, and that can suppress the generation of ammonia.

10, 20, 30, 40 gas barrier film 11

transparent film substrate

12, 31 gas barrier layer 13 first layer 14 second layer 21 hard coat layer 100 polarizing plate with gas barrier layer 101 polarizing plate 200 image display device 202 image display cell

Claims

A gas barrier film comprising a transparent film substrate and a gas barrier layer disposed directly or indirectly on at least one main surface of the transparent film substrate,
The gas barrier layer has a first layer containing silicon, oxygen and carbon as constituent elements, and a second layer containing silicon, oxygen and nitrogen as constituent elements,
The first layer is a layer located farthest from the transparent film substrate in the gas barrier layer,
The second layer is in contact with the main surface of the first layer on the transparent film substrate side,
The gas barrier film, wherein the oxygen content in the second layer is 15 atomic % or more when the total of silicon, oxygen and nitrogen in the second layer is 100 atomic %.
The gas barrier film according to claim 1, wherein the oxygen content in the second layer is 50 atomic % or less when the total of silicon, oxygen and nitrogen in the second layer is 100 atomic %.
The gas barrier film according to claim 1 or 2, wherein the first layer has a thickness of 30 nm or more and 250 nm or less.
The gas barrier film according to claim 1 or 2, wherein the second layer has a thickness of 20 nm or more and 120 nm or less.
3. According to claim 1 or 2, wherein the carbon content in the first layer is 1 atomic % or more and 10 atomic % or less when the total of silicon, oxygen and carbon in the first layer is 100 atomic %. The gas barrier film described.
The gas barrier film according to claim 1 or 2, further comprising a hard coat layer arranged between the transparent film substrate and the gas barrier layer.
A method for producing the gas barrier film according to claim 1 or 2,
introducing trisilylamine, nitrogen and oxygen into a chamber of a film forming apparatus to form the second layer by a chemical vapor deposition method;
A method for producing a gas barrier film, comprising introducing an organosilicon compound and oxygen into a chamber of a film forming apparatus to form the first layer by a chemical vapor deposition method.
A polarizing plate with a gas barrier layer, comprising the gas barrier film according to claim 1 and a polarizer.
An image display device comprising the gas barrier film according to claim 1 and an image display cell.
An image display device comprising the gas barrier layer-attached polarizing plate according to claim 8 and an image display cell.
11. The image display device according to claim 9, wherein said image display cell includes an organic EL element.