TW202122262A - Laminated film - Google Patents

Abstract

An embodiment of the present invention provides a laminated film exhibiting an excellent warpage suppression effect, and preferably having high gas barrier properties as a result of including a highly dense inorganic thin-film layer. An embodiment of the present invention provides a laminated film including a base material layer with a flexible base material contained therein, an organic layer, and an inorganic thin-film layer in the stated order, wherein after a laminate composed of the base material layer and the organic layer is heated for 30 minutes at a temperature of 130°C or higher and then left to cool for 10 minutes at 25°C, the measured internal stress of the organic layer is 0.2 GPa or more.

Description

Laminated film

The present invention relates to a laminated film (film), which sequentially includes a substrate layer including a flexible substrate, an organic layer, and an inorganic thin film layer.

The laminated film imparted with gas barrier properties is widely used for packaging purposes such as food, industrial products, and pharmaceuticals (for example, Patent Document 1). In recent years, in flexible substrates for electronic devices such as solar cells, organic electro-luminescence (EL) displays, organic EL lighting, etc., more improved gas barrier properties are required compared to the food applications. The laminated film. In order to improve the gas barrier properties of such laminated films, a laminated film has been developed in which an organic layer is laminated on a flexible substrate containing polyethylene terephthalate (PET) and a thin film layer is laminated. (For example, Patent Document 2). [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2016-68267 [Patent Document 2] Japanese Patent Laid-Open No. 2016-68383

[The problem to be solved by the invention] In general, laminated films used for electronic devices and the like are required to have higher gas barrier properties than laminated films used for food and pharmaceutical applications. In response to this requirement, for example, the laminated film described in Patent Document 2 is realized by laminating a denser thin film layer compared with the inorganic layer constituting the existing gas barrier laminated film as described in Patent Document 1. High gas barrier properties. However, according to the research conducted by the inventors of the present invention, in a thin film layer with high density, high compressive stress is likely to occur in the layer, and there is a tendency to warp the entire laminated film due to the compressive stress generated in the thin film layer. problem. In particular, in laminated films using flexible substrates, due to changes in the expansion and contraction of the flexible substrate during the manufacturing process, the warpage of the entire laminated film tends to become greater, and it is necessary to ensure high In the case of compactness, it is a technology to suppress the warpage of the laminated film.

Therefore, an object of one aspect of the present invention is to provide a laminated film having an excellent warpage suppression effect, and preferably including a highly dense inorganic thin film layer and having high gas barrier properties. [Means to solve the problem]

The present inventors have made diligent studies to solve the above-mentioned problems, and as a result, they have completed the present invention. That is, one aspect of the present invention provides the following preferable aspects.

[1] A laminated film comprising in this order: a substrate layer including a flexible substrate, an organic layer, and an inorganic thin film layer, and the laminated body including the substrate layer and the organic layer is heated at a temperature of 130°C or higher. The internal stress of the organic layer measured after heating for 30 minutes at 25° C. for 10 minutes is 0.2 GPa or more. [2] The laminated film according to the above [1], wherein a laminated body including the base material layer and the inorganic thin film layer directly laminated on the base material layer is heated at a temperature of 130°C or higher for 30 minutes, The internal stress of the inorganic thin film layer measured when left to cool at 25°C for 10 minutes is 2.0 GPa or more. [3] The laminated film according to [1] or [2], wherein a laminated body including the base material layer, the organic layer, and the inorganic thin film layer is heated at a temperature of 130° C. or higher for 30 minutes Thereafter, the internal stress of the laminated film including the organic layer and the inorganic thin film layer measured by leaving to cool at 25° C. for 10 minutes was 0.030 GPa or less. [4] The laminated film according to any one of [1] to [3], wherein the laminated body including the base material layer and the organic layer is heated at 180°C for 30 minutes, and then heated at 25°C The internal stress of the organic layer measured when left to cool for 10 minutes is 0.8 GPa or more. [5] The laminated film according to any one of [1] to [4], wherein the laminated body including the base layer and the inorganic thin film layer directly laminated on the base layer is heated at 180°C After heating for 30 minutes, the internal stress of the inorganic thin film layer measured by leaving to cool at 25° C. for 10 minutes is 3.0 GPa or more. [6] The laminated film according to any one of [1] to [5], wherein the inorganic thin film layer is only present on one side of the base layer. [7] The laminated film according to any one of [1] to [6], wherein the surface of the base layer opposite to the organic layer further includes an organic layer. [8] The laminated film according to any one of [1] to [7], wherein the inorganic thin film layer is a layer formed by a plasma chemical vapor deposition method. [9] The multilayer film according to any one of [1] to [8], wherein the inorganic thin film layer contains silicon atoms, oxygen atoms, and carbon atoms. [10] The multilayer film as described in [9], wherein the number of carbon atoms relative to the total number of silicon atoms, oxygen atoms, and carbon atoms contained in the inorganic thin film layer is greater than the thickness direction of the inorganic thin film layer Change continuously in more than 90% of the area. [11] The laminated film according to any one of [1] to [10], which has gas barrier properties. [Effects of the invention]

According to one aspect of the present invention, it is possible to provide a laminated film having an excellent warpage suppression effect and having high gas barrier properties by including an inorganic thin film layer with high density.

Hereinafter, an embodiment of the present invention will be described in detail. In addition, the scope of the present invention is not limited to the embodiment described here, and various changes can be made without departing from the gist of the present invention.

[Laminated film] The laminated film of the present invention includes, in order, a substrate layer including a flexible substrate (hereinafter also referred to as a "substrate layer"), an organic layer, and an inorganic thin film layer. In the present invention, the laminate comprising the base material layer and the organic layer constituting the laminate film is heated at a temperature of 130°C or higher for 30 minutes, and then left to cool at 25°C for 10 minutes. The internal stress is 0.2 GPa or more. In an inorganic thin film layer with improved compactness in order to improve gas barrier properties, the surface on which the inorganic thin film layer is formed tends to be convexly warped due to the high compressive stress generated in the layer. In one aspect of the present invention, the internal stress of the organic layer (hereinafter also referred to as "organic layer") is measured by heating the laminated body including the substrate layer and the organic layer constituting the laminated film to 130°C or higher. Internal stress A”) is set to 0.2 GPa or more, and the organic layer existing between the base layer and the inorganic thin film layer is given a moderate tensile stress that can eliminate the warpage caused by the high compressive stress generated in the inorganic thin film layer As a result, the warpage of the entire laminated film can be suppressed. If the internal stress A of the organic layer is less than 0.2 GPa, it is difficult to sufficiently suppress the warpage of the inorganic thin film layer when the inorganic thin film layer has high compressive stress. The structure of the laminated film of the inorganic thin film layer with high performance and excellent gas barrier properties. The internal stress A of the organic layer is preferably 0.25 GPa or more, more preferably 0.3 GPa or more. Generally, the higher the internal stress A of the organic layer, the higher the effect of eliminating the compressive stress generated in the inorganic thin film layer. The internal stress A of the organic layer can be appropriately adjusted according to the compressive stress of the inorganic thin film layer constituting the laminated film, but from the viewpoint of the ease of adjustment of warpage during the formation of the inorganic thin film layer and the suppression of cracks in the inorganic thin film layer The upper limit is usually 7.5 GPa or less, preferably 5.0 GPa or less.

The internal stress A of the organic layer is measured in a laminate that constitutes the target laminate film and includes a base layer and an organic layer. In the case where the laminated film of one aspect of the present invention has organic layers on both sides of the base layer, the internal stress A of the organic layer refers to the organic layer including the base layer and the organic layer located on the side of the inorganic thin film layer to be laminated ( In the case where the inorganic thin film layer exists on both sides, the internal stress of the laminate located between the base layer and one of the inorganic thin film layers). In addition, when there are multiple organic layers between the base layer and the inorganic thin film layer, the internal stress A of the organic layer includes the base layer and all that exists between the base layer and the inorganic thin film layer. Internal stress of a laminate of organic layers. In the case where the organic layer and the inorganic thin film layer are respectively present on both sides of the base layer, the organic layer laminated on at least one side of the base layer only needs to have the internal stress in the above-mentioned range. The organic layer laminated on each side as the center has internal stress (tensile stress) sufficient to eliminate warpage caused by the compressive stress generated in the inorganic thin film layer laminated on the layer, and it can be balanced with the base layer as the center In order to exhibit a warpage suppressing effect, it is preferable that the laminate including the organic layer and the base material layer on each side has an internal stress in the above-mentioned range.

In one aspect of the present invention, the laminated film is preferably the internal stress of the organic layer measured by heating the laminated body including the base layer and the organic layer at 130°C for 30 minutes and then cooling it at 25°C for 10 minutes (below Also known as "organic layer internal stress A (130°C)") is 0.2 GPa or more. If the internal stress A (130°C) of the organic layer is 0.2 GPa or more, it is easy to ensure a sufficiently high tensile stress in the organic layer that can eliminate the warpage of the inorganic thin film layer caused by high compressive stress, thereby suppressing the build-up Warpage of the film as a whole. The internal stress A (130°C) of the organic layer is preferably 0.25 GPa or more, more preferably 0.3 GPa or more. In addition, from the viewpoint of ease of warpage adjustment during formation of the inorganic thin film layer and suppression of cracks in the inorganic thin film layer, The upper limit is usually 7.5 GPa or less, preferably 5.0 GPa or less.

In another aspect of the present invention, the laminated film is preferably the internal stress of the organic layer measured by heating the laminated body including the base layer and the organic layer at 180°C for 30 minutes and then cooling it at 25°C for 10 minutes ( Hereinafter, also referred to as "organic layer internal stress A (180°C)") is 0.8 GPa or more. If the internal stress A (180°C) of the organic layer is 0.8 GPa or more, it is easy to ensure a sufficiently high tensile stress in the organic layer to eliminate the warpage of the inorganic thin film layer caused by high compressive stress, thereby suppressing the build-up Warpage of the film as a whole. The internal stress A (180°C) of the organic layer is preferably 0.9 GPa or more, more preferably 1.0 GPa or more. In addition, from the viewpoint of ease of warpage adjustment during formation of the inorganic thin film layer and suppression of cracks in the inorganic thin film layer, The upper limit is usually 7.5 GPa or less, preferably 5.0 GPa or less.

In addition, in another aspect of the present invention, it is preferable that the internal stress A (130°C) of the organic layer is 0.2 GPa or more, and the internal stress A (180°C) of the organic layer is 0.8 GPa or more, more preferably the inside of the organic layer The stress A (130°C) and the internal stress A (180°C) of the organic layer each have an internal stress within the range described in the previous paragraph. If the internal stress A (130°C) of the organic layer and the internal stress A (180°C) of the organic layer are within the above ranges, it is easier to ensure that the warpage of the inorganic thin film layer caused by high compressive stress can be eliminated in the organic layer. With a sufficiently high tensile stress, the warpage suppression effect of the laminated film can be more effectively improved.

The internal stress A of the organic layer can be selected by appropriately selecting the composition of the organic layer, the structure of the substrate layer, the type of flexible substrate, the thickness of the organic layer and/or the substrate layer, the coating method when forming the organic layer, and the tension. -Drying conditions such as temperature-residence time, temperature-curing conditions such as ultraviolet (UV) irradiation conditions, etc. are controlled.

The heating temperature of the laminate when measuring the internal stress A of the organic layer was 130°C or higher. Generally speaking, when the laminated film is used by bonding electronic devices such as solar cells, organic EL displays, and organic EL lighting, it is necessary to remove moisture adsorbed on the surface of the laminated film, or the adhesive or adhesive used during bonding. The sheet is dehydrated, for example, sometimes exposed to a high temperature environment above 130°C. In the case of large warpage during this step, when bonding to electronic devices, bubbles, wrinkles, cracks and other poor bonding may occur. . When the laminate including the organic layer is heated to 130°C or higher, if the laminate has the internal stress of the organic layer in the above range, the laminate film will be exposed to the step of exposing to a high temperature environment of 130°C or higher. In the medium, a high warpage suppression effect can also be expected. Therefore, the heating temperature only needs to be 130°C or higher, preferably 130°C or higher and 200°C or lower, more preferably 130°C or 180°C, which is 130°C in one aspect of the present invention, and in another aspect In the sample, it is 180°C.

In one aspect of the present invention, the internal stress A of the organic layer may be based on heating a laminate including a substrate layer and an organic layer as a measurement object at room temperature (25°C) to 130°C or higher for 30 minutes Calculate the amount of deformation of the laminate when left to cool at 25°C for 10 minutes. Specifically, a laminated body to be measured cut into a quadrilateral of an appropriate size is heated at a temperature of 130°C or higher for 30 minutes, then left to cool at 25°C for 10 minutes, and placed on a horizontal surface, and the distance from the horizontal surface to the four corners is measured. (Height), calculate the radius of curvature based on the average value of these. In addition, when the laminated body after cooling is cylindrical, the diameter of the inside of the cylinder is measured, and the radius of curvature is calculated. According to the calculated radius of curvature, the thickness of the base layer and the organic layer, the Young's modulus and Poisson's ratio of the base layer, according to the following formula (1): Inside the organic layer Stress A (GPa) = Eh ² /6 (1-v) Rt (1) [In the formula, t represents the thickness of the organic layer (m), R represents the radius of curvature (m), and h represents the thickness of the base layer (m) ), E represents the Young's modulus (Pa) of the base layer, and v represents the Passon's ratio of the base layer] to calculate the internal stress of the organic layer. In more detail, the internal stress A of the organic layer can be measured and calculated in accordance with the method described in Examples described later, for example.

In one aspect of the present invention, a laminate comprising a base material layer and an inorganic thin film layer directly laminated on the base material layer constituting the laminate film is heated at 130°C for 30 minutes and then cooled at 25°C for 10 minutes. The measured internal stress of the inorganic thin film layer is preferably 2.0 GPa or more. The internal stress of the inorganic thin film layer (hereinafter also referred to as “inorganic thin film layer”) is measured when a laminate comprising a base material layer and an inorganic thin film layer directly laminated on the base material layer constituting the laminate film is heated to 130°C or higher. If the internal stress B” of the thin film layer is 2.0 GPa or more, it is easy to sufficiently increase the density of the inorganic thin film layer, and it is easy to realize the high gas barrier properties of the laminated film. The internal stress B of the inorganic thin film layer is more preferably 2.1 GPa or more, and still more preferably 2.2 GPa or more. Generally, the higher the internal stress B of the inorganic thin film layer, the higher the density of the inorganic thin film layer and the higher the gas barrier properties. The internal stress B of the inorganic thin film layer usually varies according to the structure of the inorganic thin film layer to ensure the desired gas barrier properties. However, as a range in which sufficient density of the inorganic thin film layer can be ensured and excessive compressive stress is not easily generated, the above The limit is usually 15 GPa or less, preferably 10 GPa or less. Furthermore, the internal stress B of the inorganic thin film layer is usually a compressive stress.

In one aspect of the present invention, the laminated film is preferably a laminated body comprising a substrate layer and an inorganic thin film layer directly laminated on the substrate layer, heated at 130°C for 30 minutes, and then cooled at 25°C for 10 minutes The measured internal stress of the inorganic thin film layer (hereinafter also referred to as "inorganic thin film layer internal stress B (130°C)") is 2.0 GPa or more. If the internal stress B (130° C.) of the inorganic thin film layer is 2.0 GPa or more, the density of the inorganic thin film layer can be sufficiently improved, and the high gas barrier properties of the laminated film can be easily achieved. The internal stress B (130°C) of the inorganic thin film layer is more preferably 2.1 GPa or more, and still more preferably 2.2 GPa or more. In addition, from the viewpoint of ensuring sufficient density of the inorganic thin film layer and suppressing the generation of excessive compressive stress, The upper limit is usually 10 GPa or less, preferably 15 GPa or less.

In another aspect of the present invention, the laminated film is preferably a laminated body comprising a substrate layer and an inorganic thin film layer directly laminated on the substrate layer, heated at 180°C for 30 minutes, and then cooled at 25°C. The internal stress of the inorganic thin film layer (hereinafter also referred to as "inorganic thin film layer internal stress B (180°C)") measured in minutes is 3.0 GPa or more. If the internal stress B (180°C) of the inorganic thin film layer is 3.0 GPa or more, it is easy to sufficiently increase the density of the inorganic thin film layer, and it is easy to realize the high gas barrier properties of the laminated film. The internal stress B (180°C) of the inorganic thin film layer is more preferably 3.2 GPa or more, and still more preferably 3.5 GPa or more. In addition, from the viewpoint of ensuring sufficient density of the inorganic thin film layer and suppressing the generation of excessive compressive stress, The upper limit is usually 15 GPa or less, preferably 10 GPa or less.

In addition, in another aspect of the present invention, it is preferable that the internal stress B (130°C) of the inorganic thin film layer is 2.0 GPa or more, and the internal stress B (180°C) of the inorganic thin film layer is 3.0 GPa or more, more preferably inorganic The internal stress B (130° C.) of the thin film layer and the internal stress B (180° C.) of the inorganic thin film layer each have an internal stress within the range described in the previous paragraph. If the internal stress B (130°C) of the inorganic thin film layer and the internal stress B (180°C) of the inorganic thin film layer are within the above ranges, it is easier to improve the density of the inorganic thin film layer, and the gas barrier properties of the laminated film can be more effective To improve.

The internal stress B of the inorganic thin film layer can be determined by appropriately selecting the composition of the inorganic thin film layer, the distribution (density) of the inorganic materials/compounds constituting the inorganic thin film layer, the structure of the substrate layer, the type of flexible substrate, the inorganic thin film layer, and the /Or the thickness of the base layer, the film forming conditions when forming the inorganic thin film layer, etc. are controlled.

The internal stress B of the inorganic thin film layer is measured in a laminate comprising a base material layer and an inorganic thin film layer directly laminated on the base material layer, which constitutes the target laminated film. In one aspect of the present invention, the laminate film includes an organic layer between the base layer and the inorganic thin film layer. Therefore, the internal stress B of the inorganic thin film layer is measured, for example, in the following laminate for measurement. In the laminate, the inorganic thin film layer is formed on the same base layer as the laminate film to be measured by the same method as the inorganic thin film layer constituting the laminate film to be measured. In the case where there are inorganic thin film layers on both sides of the base layer, the internal stress B of the inorganic thin film layer refers to the inside of the laminate including the base layer and the inorganic thin film layer laminated on one side of the base layer stress. In the case where the laminate film has inorganic thin film layers on both sides of the base layer, the internal stress B of the inorganic thin film layers of the two inorganic thin film layers may be the same or different from each other, preferably at least one of the inorganic thin film layers The thin film layer has an internal stress in the stated range.

In one aspect of the present invention, the internal stress B of the inorganic thin film layer may be based on heating a laminate including a substrate layer and an organic layer as a measurement object at room temperature (25°C) to 130°C or higher for 30 minutes After that, the amount of deformation of the laminate when left to cool at 25°C for 10 minutes was calculated. Specifically, in accordance with the same method as the previously described method for measuring the internal stress A of the organic layer, the layered body to be measured cut into a rectangular shape of an appropriate size is heated at a temperature of 130°C or higher for 30 minutes, and then at 25°C. After cooling down for 10 minutes, place it on a horizontal surface, measure the distance (height) from the horizontal surface to the four corners, and calculate the radius of curvature based on the average value of these. In addition, when the laminated body after cooling is cylindrical, the diameter of the inside of the cylinder is measured, and the radius of curvature is calculated. According to the calculated radius of curvature, the thickness of the substrate layer and the inorganic thin film layer, the Young's modulus and the Passon ratio of the substrate layer, according to the following formula (2): Inorganic thin film layer internal stress B (GPa) = Eh ² /6(1-v)Rt' (2) [In the formula, t'represents the thickness of the inorganic thin film layer (m), R represents the radius of curvature (m), h represents the thickness of the substrate layer (m), E Represents the Young's modulus (Pa) of the base layer, and v represents the Passon's ratio of the base layer] to calculate the internal stress of the inorganic thin film layer.

The heating temperature of the laminate when measuring the internal stress B of the inorganic thin film layer was 130°C or higher. The heating temperature only needs to be 130°C or higher, preferably 130°C or higher and 200°C or lower, more preferably 130°C or 180°C, 130°C in one aspect of the present invention, and in another aspect It is 180°C. For the warpage of the inorganic thin film layer caused by the internal stress (compressive stress) generated in the inorganic thin film layer, the internal stress (tensile stress) generated in the organic layer located between the inorganic thin film layer and the base material layer Elimination can increase the warpage suppression effect of the laminated film. Therefore, it is preferable that the inorganic thin film layer internal stress B in the specific range is generated at the same temperature as the internal stress A of the organic layer in the inorganic thin film layer. Therefore, the heating temperature when measuring the internal stress B of the inorganic thin film layer is preferably the same temperature as the heating temperature applied when measuring the internal stress A of the organic layer of the organic layer to be measured. More specifically, the internal stress B of the inorganic thin film layer can be measured and calculated in accordance with, for example, the method described in Examples described later.

In the laminated film of one aspect of the present invention, the organic layer preferably has an internal stress A (130°C) of 8% or more of the internal stress B (130°C) of the inorganic thin film layer, and more preferably has an internal stress A (130°C) of 10% or more. , More preferably, the internal stress A (130°C) of the organic layer of 12% or more. In addition, in one aspect of the present invention, the organic layer preferably has an organic layer internal stress A (180°C) of 15% or more of the inorganic thin film layer internal stress B (180°C), more preferably 20% or more, More preferably, it is 25% or more of the internal stress A (180°C) of the organic layer. If the internal stress A of the organic layer is more than the above lower limit with respect to the internal stress B of the inorganic thin film layer, it can be suitable for suppressing the warping of the inorganic thin film layer due to the internal stress (compressive stress) generated in the inorganic thin film layer. The organic layer of the song. Generally, the thickness of the organic layer is designed to be larger than that of the inorganic thin film layer. Therefore, in the laminated film of one aspect of the present invention, the internal stress A of the organic layer is preferably smaller than the internal stress B of the inorganic thin film layer. The upper limit of the internal stress A relative to the internal stress B of the inorganic thin film layer is usually 50% or less, preferably 40% or less.

In one aspect of the present invention, the laminated film has relatively high internal stress A of the organic layer, even when it contains an inorganic thin film layer with high density and excellent gas barrier properties, it is suppressed from the inorganic thin film layer. The warpage caused by the high compressive stress is also excellent. Therefore, in the laminated film of one aspect of the present invention, it is preferable to heat a laminated body including a base layer, an organic layer, and an inorganic thin film layer that constitutes the laminated film at a temperature of 130°C or higher for 30 minutes, and then cool it at 25°C. The internal stress of the laminated film including the organic layer and the inorganic thin film layer (hereinafter also referred to as "the internal stress C of the laminated film") measured for 10 minutes is 0.030 GPa or more. If the internal stress C of the laminated film is 0.030 GPa or less, it is considered that the organic layer with a specific range of internal stress suppresses the warpage of the inorganic film layer due to high compressive stress, and the denseness of the inorganic film layer is high. A laminated film that ensures excellent gas barrier properties and suppresses warpage as a laminated film as a whole. The internal stress C of the laminated film is more preferably 0.025 GPa or less, and still more preferably 0.020 GPa or less. Generally, the smaller the value of the internal stress C of the laminated film, the higher the warpage suppression effect of the laminated film. Therefore, the lower limit of the internal stress C of the laminated film is not particularly limited, and may be 0 GPa. Furthermore, in the case where the laminated film includes a base layer, an organic layer, and/or a plurality of organic layers or other layers between the organic layer and the inorganic thin film layer, the internal stress C of the laminated film includes the base layer, The internal stress of all layers included between the base material layer and the inorganic thin film layer and the laminate of the inorganic thin film layer located on the side where the inorganic thin film layer is to be laminated.

In one aspect of the present invention, the laminated film is preferably formed by heating a laminated body comprising a substrate layer, an organic layer, and an inorganic thin film layer constituting the laminated film at 130°C for 30 minutes, and then cooling at 25°C for 10 minutes. When measured, the internal stress of the laminated film including the organic layer and the inorganic thin film layer (hereinafter also referred to as "the internal stress of the laminated film C (130°C)") is 0.030 GPa or more. If the internal stress C (130°C) of the laminated film is 0.030 GPa or less, it is easy to obtain a laminated film that has high density of the inorganic thin film layer, ensures excellent gas barrier properties, and suppresses warpage as a laminated film as a whole. The internal stress C (130°C) of the laminated film is more preferably 0.025 GPa or less, and still more preferably 0.020 GPa or less, and its lower limit may be 0 GPa.

In another aspect of the present invention, the laminated film is preferably a laminated body comprising a substrate layer, an organic layer, and an inorganic thin film layer constituting the laminated film, after being heated at 180°C for 30 minutes, and then cooled at 25°C for 10 minutes As measured, the internal stress of the laminated film including the organic layer and the inorganic thin film layer (hereinafter also referred to as "the internal stress of the laminated film C (180°C)") is 0.020 GPa or more. If the internal stress C (180°C) of the laminated film is 0.020 GPa or less, it is easy to obtain a laminated film that has high density of the inorganic thin film layer, ensures excellent gas barrier properties, and suppresses warpage as a whole of the laminated film. The internal stress C (180°C) of the laminated film is more preferably 0.015 GPa or less, and still more preferably 0.010 GPa or less, and its lower limit may be 0 GPa.

In addition, in another aspect of the present invention, it is preferable that the internal stress C (130°C) of the laminated film is 0.030 GPa or more, and the internal stress C (180°C) of the laminated film is 0.020 GPa or more, more preferably the internal stress of the laminated film. The stress C (130°C) and the internal stress C (180°C) of the laminated film each have an internal stress below the upper limit described in the previous paragraph. If the internal stress C (130°C) of the multilayer film and the internal stress C (180°C) of the multilayer film are each below the upper limit, the density of the inorganic thin film layer is high, excellent gas barrier properties are ensured, and the multilayer film warps The effect of suppressing kinks can be further improved.

In one aspect of the present invention, the internal stress C of the laminated film may be based on heating the laminated body as the measurement object at room temperature (25°C) to 130°C or higher for 30 minutes, and then cooling at 25°C for 10 minutes Calculate the amount of deformation of the laminate at the time. Specifically, a laminated body to be measured cut into a quadrilateral of an appropriate size is heated at a temperature of 130°C or higher for 30 minutes, then left to cool at 25°C for 10 minutes, and placed on a horizontal surface, and the distance from the horizontal surface to the four corners is measured. (Height), calculate the radius of curvature based on the average value of these. In addition, when the laminated body after cooling is cylindrical, the diameter of the inside of the cylinder is measured, and the radius of curvature is calculated. According to the calculated radius of curvature, the thickness of the substrate layer, the total thickness of the organic layer and the inorganic film layer, the Young's modulus and the Passson ratio of the substrate layer, the following formula (3) can be used: Internal stress C of the laminated film (GPa)=Eh ² /6(1-v)Rt” (3) [In the formula, t” represents the total thickness of the organic layer and the inorganic thin film layer (m), R represents the radius of curvature (m), and h represents The thickness (m) of the substrate layer, E represents the Young's modulus (Pa) of the substrate layer, and v represents the Passon's ratio of the substrate layer] to calculate the internal stress of the laminated film.

The heating temperature of the laminate when measuring the internal stress C of the laminate film was 130°C or higher. The heating temperature only needs to be 130°C or higher, preferably 130°C or higher and 200°C or lower, more preferably 130°C or 180°C, 130°C in one aspect of the present invention, and in another aspect It is 180°C. The heating temperature when measuring the internal stress C of the laminated film is preferably the same temperature as the heating temperature applicable when measuring the internal stress A of the organic layer and the internal stress B of the inorganic thin film of the laminated film to be measured. More specifically, the internal stress C of the laminated film can be measured and calculated in accordance with the method described in Examples described later, for example.

In one aspect of the present invention, the laminated film is preferably transparent when observed by visual observation. Specifically, the total light transmittance (Tt) of the laminated film is preferably 78.0% or more, more preferably 80.0% or more, still more preferably 83.0% or more, particularly preferably 85.0% or more, and extremely preferably 87.0% or more. In one aspect of the present invention, if the total light transmittance of the laminated film is equal to or higher than the lower limit, it is easy to ensure sufficient visibility when the film is assembled in electronic devices such as image display devices. In one aspect of the present invention, the upper limit of the total light transmittance of the laminated film is not particularly limited, as long as it is 100% or less.

In one aspect of the present invention, the haze of the laminated film is preferably 5.0% or less, more preferably 3.0% or less, and even more preferably 2.0% or less. In one aspect of the present invention, if the haze of the laminated film is equal to or less than the upper limit, it is easy to ensure sufficient visibility when the film is assembled in electronic devices such as image display devices. Furthermore, in one aspect of the present invention, the lower limit of the haze of the laminated film is not particularly limited, but is usually 0% or more. From the viewpoint of visibility, the smaller the value of the haze, the better. In addition, it is preferable that the laminated film after being exposed to an environment of 60° C. and a relative humidity of 90% for 250 hours still has a haze in the above-mentioned range.

For example, the total light transmittance and haze can be measured using a haze computer. After measuring the background without the laminated film, the laminated film is set in a sample holder to measure, and the total light of the laminated film can be calculated Transmittance and haze value.

In one aspect of the present invention, the thickness of the laminated film may be appropriately determined according to the application. From the viewpoint of good handling properties of the laminated film and easy improvement of bending characteristics while ensuring a moderate surface hardness, for example, it may be 5 μm to 550 μm, preferably 10 μm to 250 μm, and more preferably 15 μm to 200 μm. In addition, the thickness of the laminated film can be measured with a film thickness meter.

In a laminate film having an inorganic thin film layer that produces relatively high compressive stress due to high density, for example, by providing inorganic thin film layers with the same degree of compressive stress on both sides of the base layer, the spacer is The two inorganic thin film layers existing in the material layer cancel each other's internal stresses, thereby suppressing the warpage of the laminated film. However, in general, in order to improve the gas barrier properties of the laminated film, the inorganic material needs to be present in the inorganic thin film layer at a high density, and a laminated film with such dense inorganic thin film layers on both sides of the base material layer is produced. The viewpoints of performance and production cost are sometimes not fully satisfied. In contrast, in one aspect of the present invention, in the laminated film, the organic layer existing between the base layer and the inorganic thin film layer has enough to eliminate the warpage caused by the internal stress generated in the inorganic thin film layer. Therefore, even when the inorganic thin film layer is only present on one side of the substrate layer, the effect of suppressing the warpage of the laminated film is excellent, and as long as the inorganic thin film layer is formed on only one side of the substrate layer, that is Yes, it can be advantageous in terms of productivity or production cost. Therefore, in a preferred aspect of the present invention, the laminated film has an inorganic thin film layer only on one side of the substrate layer.

Hereinafter, each component of the laminated film of one aspect of the present invention will be described in detail.

〔Substrate layer〕 The base material layer which comprises the laminated film of this invention contains a flexible base material. The flexible substrate refers to a substrate that can maintain the flexibility of the inorganic thin film layer. For example, a resin film containing at least one resin as a resin component can be used. The flexible substrate is preferably a transparent resin substrate.

Examples of resins that can be used in the flexible substrate include: polyester resins such as polyethylene naphthalate (PEN); polyethylene (PE), polypropylene (PP), Polyolefin resins such as cyclic polyolefins; polyamide resins; polycarbonate resins; polystyrene resins; polyvinyl alcohol resins; saponified ethylene-vinyl acetate copolymers; polyacrylonitrile resins; acetal resins; poly Imide resin; polyether sulfide (PES), polyethylene terephthalate (PET) with biaxial stretching and thermal annealing treatment. As the flexible substrate, one kind of the above-mentioned resins may be used, or two or more kinds of resins may be used in combination. Among these, in terms of easy control of the internal stress A of the organic layer or the internal stress B of the inorganic thin film layer of the obtained laminated film, the viewpoint of easily improving the warpage suppression effect, the viewpoint of having high transparency, etc., it is preferable to use the optional The resin selected from the group consisting of polyester resins and polyolefin resins is more preferably a resin selected from the group consisting of PEN and cyclic polyolefins, and more preferably PEN is used.

The flexible substrate can be an unstretched resin substrate, or it can be uniaxially extended, tenter-sequential biaxial extension, tenter-type simultaneous biaxial extension, tubular (tubular) simultaneous biaxial extension A known method such as stretching, in which an unstretched resin substrate is stretched in the direction of flow of the resin substrate (MD direction) and/or in a direction perpendicular to the direction of flow of the resin substrate (TD direction). . The flexible base material may be a laminate in which two or more layers of the resin are laminated.

From the viewpoint of the heat resistance of the laminated film, the glass transition temperature (Tg) of the flexible substrate is preferably 100°C or higher, more preferably 130°C or higher, and still more preferably 150°C or higher. In addition, the upper limit of the glass transition temperature is preferably 250°C or less. Furthermore, the glass transition temperature (Tg) can be measured using a dynamic viscoelasticity measurement (Dynamic mechanical analysis (DMA)) device or a differential scanning calorimeter (Differential Scanning Calorimeter, DSC).

The thickness of the flexible substrate can be appropriately set in consideration of the stability during the production of the laminated film, etc. However, from the viewpoint of facilitating the transportation of the flexible substrate in vacuum in the production step of the laminated film, it is preferably 5 μm～500 μm. Furthermore, in the case of forming the inorganic thin film layer by the plasma chemical vapor deposition method (Plasma Chemical Vapor Deposition method, plasma CVD method) as described later, the thickness of the flexible substrate is more preferably 10 μm~ 200 μm, more preferably 15 μm to 150 μm. Furthermore, the thickness of the flexible substrate can be measured with a film thickness meter.

The flexible substrate may also be a retardation film in which the refractive indices of two orthogonal components in the plane are different from each other, such as a λ/4 retardation film and a λ/2 retardation film. Examples of materials for the retardation film include: cellulose resins, polycarbonate resins, polyarylate resins, polyester resins, acrylic resins, polyether resins, polyether resins, and cyclic olefins. Alignment hardening layer of resin, liquid crystal compound, etc. As the film forming method, a solvent casting method, a precision extrusion method that can reduce the residual stress of the film, or the like can be used. In terms of uniformity, a solvent casting method can be preferably used. The stretching method is not particularly limited, and longitudinal uniaxial stretching between rolls, tentering and lateral uniaxial stretching, etc., which can obtain uniform optical characteristics can be applied.

When the flexible substrate is a λ/4 retardation film, the in-plane retardation Re (550) at a wavelength of 550 nm is usually 100 nm to 180 nm, preferably 110 nm to 170 nm, and more preferably 120 nm to 160 nm.

When the flexible substrate is a λ/2 retardation film, the in-plane retardation Re (550) at a wavelength of 550 nm is usually 220 nm to 320 nm, preferably 240 nm to 300 nm, and more preferably 250 nm to 280 nm.

When the flexible substrate is a retardation film, it can show the reverse wavelength dispersion that the retardation value increases according to the wavelength of the measurement light, and it can also show that the retardation value changes according to the wavelength of the measurement light. The small positive wavelength dispersion characteristics can also show flat wavelength dispersion characteristics in which the retardation value hardly changes with the wavelength of the measurement light.

When the flexible substrate is a retardation film exhibiting reverse wavelength dispersion, when the retardation at the wavelength λ of the flexible substrate is expressed as Re(λ), the flexible substrate can satisfy Re(450)/Re(550)<1 and Re(650)/Re(550)>1.

From the viewpoint of allowing light to pass through or absorb, the flexible substrate is preferably colorless and transparent. More specifically, the total light transmittance is preferably 80% or more, more preferably 85% or more. In addition, the haze is preferably 5% or less, more preferably 3% or less, and still more preferably 1% or less. The total light transmittance and haze of the flexible substrate can be measured by the same method as described previously as the method of measuring the total light transmittance and haze of the laminated film.

From the viewpoint that it can be used as a substrate for an organic device or an energy device, the flexible substrate is preferably insulating, and the resistivity is preferably 10 ⁶ Ωcm or more.

From the viewpoint of the adhesiveness with the organic layer, etc., the surface of the flexible substrate may be subjected to a surface active treatment for washing the surface. Examples of such surface active treatments include corona treatment, plasma treatment, and flame treatment.

The flexible substrate may be annealed or not, but from the viewpoint of easy control of the internal stress A of the organic layer or the internal stress B of the inorganic thin film layer and the improvement of the warpage suppression effect of the laminated film, it is preferably Perform annealing treatment. Annealing treatment can include: heating the flexible substrate at a temperature above the upper limit temperature (for example, 200°C) while biaxially stretching the flexible substrate; after biaxially stretching the flexible substrate, passing the upper limit temperature (for example, 200℃) or higher temperature heating furnace medium. Furthermore, the flexible substrate may be annealed, or the substrate layer in a state in which the undercoat layer or the like described later is laminated on one side or both sides may be annealed.

In one aspect of the present invention, the base material layer constituting the laminated film may include only the flexible base material, and in addition to the flexible base material, it may also include a single side formed on the flexible base material. Or primer on both sides. By having the primer layer, the adhesion between the flexible substrate and the organic layer can be improved. In addition, when the flexible substrate has primer layers on both sides, and there is no layer outside the primer layer on one side, that is, in the case where the primer layer is the outermost layer, the primer layer serves as a build-up layer The protective layer of the film functions and also functions to improve sliding properties during manufacturing and prevent blocking. Furthermore, in one aspect of the present invention, the laminated film may have a further primer layer laminated on other parts in addition to the primer layer present in contact with the flexible substrate.

When the base layer includes an undercoat layer, the undercoat layer preferably has a softening temperature of 130°C or higher. By having such a softening temperature, even in a high-temperature environment, the flexible base material and the organic layer can be sufficiently adhered, and it is easy to sufficiently improve the warpage suppression effect of the laminated film. The softening temperature of the undercoat layer is preferably 130°C or higher, more preferably 160°C or higher, and still more preferably 180°C or higher. If the softening temperature of the primer layer is more than the above lower limit, the warpage suppression effect can be further improved. In addition, the upper limit of the softening temperature of the primer layer is usually 250°C or less.

The primer layer preferably contains at least one selected from the group consisting of urethane resin, acrylic resin, polyester resin, epoxy resin, melamine resin, and amino resin. Among these, it is more preferable to contain a polyester resin as a main component.

In addition to the resin, the undercoat layer may also contain additives. As the additives, well-known additives for forming the undercoat layer can be used. Examples include silica particles, alumina particles, calcium carbonate particles, magnesium carbonate particles, barium sulfate particles, aluminum hydroxide particles, titanium dioxide particles, and oxide particles. Inorganic particles such as zirconium particles, clay, and talc. Among these, from the viewpoint of the warpage suppression effect of the laminated film, silicon dioxide particles are preferred.

In the case where the undercoat layer contains silicon dioxide particles, the average primary particle size is preferably 5 nm or more, more preferably 10 nm or more, further preferably 15 nm or more, particularly preferably 20 nm or more, and more preferably It is 100 nm or less, more preferably 80 nm or less, still more preferably 60 nm or less, and particularly preferably 40 nm or less. If the average primary particle diameter of the silicon dioxide particles is within the above range, the aggregation of the silicon dioxide particles can be suppressed, and the transparency and warpage suppression effect of the laminated film can be improved. In addition, when the undercoat layer becomes the outermost layer, if the average primary particle size of the silicon dioxide particles is within the above range, the sliding properties of the laminated film during production can be further improved and blocking can be effectively prevented. Furthermore, the average primary particle size of the silicon dioxide particles can be measured by the Brunauer-Emmett-Teller (BET) method or the transmission electron microscope (TEM) observation of the particle profile.

The content of the silicon dioxide particles relative to the mass of the undercoat layer is preferably 1% by mass to 50% by mass, more preferably 1.5% by mass to 40% by mass, and still more preferably 2% by mass to 30% by mass. If the content of the silicon dioxide particles is greater than or equal to the lower limit, it is easy to increase the warpage suppression effect of the laminated film. If the content of silicon dioxide particles is below the upper limit, it is easy to improve optical properties such as low haze or high total light transmittance.

The thickness of the undercoat layer is preferably 1 μm or less, more preferably 500 nm or less, still more preferably 200 nm or less, and preferably 10 nm or more, more preferably 20 nm or more, and still more preferably 30 nm or more. If the thickness of the undercoat layer is in the above range, it is easy to improve the adhesion between the undercoat layer and the organic layer and the warpage suppression effect of the laminated film. Furthermore, the thickness of the primer layer can be measured with a film thickness meter. In the case where primers are present on both sides of the flexible substrate, the thickness of these may be the same or different. However, from the viewpoint of easily improving the warpage suppression effect of the laminated film, the two primers The thickness is preferably the same. Furthermore, in one aspect of the present invention, when the laminated film has three or more undercoat layers, it is preferable that each undercoat layer has the above-mentioned thickness.

The undercoat layer can be obtained by coating a resin composition containing a resin, a solvent, and optional additives on a flexible substrate, and drying the coating film to form a film. When there are primer layers on both surfaces of the flexible substrate, the order of forming these is not particularly limited.

The solvent is not particularly limited as long as it can dissolve the resin. Examples include alcohol solvents such as methanol, ethanol, 2-propanol, 1-butanol, and 2-butanol; diethyl ether and diisopropyl alcohol. Ether solvents such as propyl ether, tetrahydrofuran, 1,4-dioxane, and propylene glycol monomethyl ether; ketone solvents such as acetone, 2-butanone, and methyl isobutyl ketone; N,N-dimethylformamide , N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, dimethyl sulfide and other aprotic polar solvents; methyl acetate, Ester solvents such as ethyl acetate and n-butyl acetate; nitrile solvents such as acetonitrile and benzonitrile; hydrocarbon solvents such as n-pentane, n-hexane, n-heptane, octane, cyclohexane, and methylcyclohexane; Aromatic hydrocarbon solvents such as benzene, toluene, xylene and mesitylene; halogenated hydrocarbon solvents such as dichloromethane, chloroform, carbon tetrachloride, 1,2-dichloroethane, monochlorobenzene, dichlorobenzene, etc. The solvent can be used alone or in combination of two or more.

As a method of applying the primer layer to the flexible substrate, various coating methods used previously, such as spray coating, spin coating, bar coating, curtain coating, dipping method, Air knife method, slide coating, hopper coating, reverse roll coating, gravure coating, extrusion coating and other methods.

As a method of drying the coating film, for example, a natural drying method, an air drying method, a heat drying method, and a reduced pressure drying method can be cited, and heat drying can be preferably used. The drying temperature also depends on the type of resin or solvent, but is usually about 50°C to 350°C, and the drying time is usually about 30 seconds to 300 seconds.

As mentioned above, the primer layer can be formed on one or both sides of the flexible substrate, but it is also possible to use a commercially available film with a primer layer on one or both sides of the flexible substrate, such as Teijin Film Solution "Teonex (registered trademark)" manufactured by TEIJIN Film Solution.

When the substrate layer has an undercoat layer, the undercoat layer may be a single layer or a multilayer of two or more layers. In addition, when the flexible substrate has primer layers on both sides, the two primer layers may include the same composition or different compositions, but it is easy to improve the warpage suppression effect of the laminated film. From a viewpoint, it is preferable to include a layer of the same composition. In addition, in one aspect of the present invention, when the laminated film has a further primer layer, the plurality of primer layers may be layers including the same or different compositions.

As long as the substrate layer includes a flexible substrate, it may be a single layer or a multilayer of two or more layers. In the present invention, when other layers such as a primer layer are present on the flexible substrate, the layer between the flexible substrate and the organic layer closest to the flexible substrate It is a layer constituting the substrate layer. In the case where other layers such as an undercoat layer are formed on both sides of the flexible substrate, the substrate layer for measuring the internal stress A of the organic layer or the internal stress B of the inorganic thin film layer is included in the flexible substrate. The layer existing between the material and the inorganic thin film layer, to the organic layer closest to the flexible substrate, and the same layer (undercoat or asymmetric) that exists symmetrically or asymmetrically between the flexible substrate The other layers). That is, for example, in FIG. 3, the substrate layer 1 includes a flexible substrate 1-1 and two undercoat layers 1-2 adjacent to both surfaces of the flexible substrate 1-1. In the case where the base material layer contains other layers in addition to the flexible base material, it is difficult to affect the internal stress of the organic layer and the internal stress of the inorganic thin film layer, and from the viewpoint that the warpage suppression effect of the laminated film is excellent, the base material The total thickness of the layer may be, for example, 5 μm to 550 μm, preferably 10 μm to 250 μm, and more preferably 15 μm to 200 μm.

〔Organic layer〕 The laminated film of the present invention has an organic layer (hereinafter also referred to as “first organic layer”) that is located between the base layer and the inorganic thin film layer and has the specific internal stress A of the organic layer. In addition, in one aspect of the present invention, the laminated film further has an organic layer (hereinafter also referred to as a “second organic layer”) on the surface of the base layer opposite to the first organic layer. By having the second organic layer, for example, it is easy to suppress the precipitation of the resin component of the flexible substrate or the deformation of the flexible substrate, so even if the laminated film is exposed to a high temperature environment, it can be expected to suppress the haze Rise and other effects.

In one aspect of the present invention, in the case where the laminated film includes the first organic layer and/or the second organic layer, the first organic layer and the second organic layer may each be a layer having a function as a planarization layer, It may be a layer having a function as an anti-blocking layer, or a layer having the functions of both. In particular, in a laminated film in which the inorganic thin film layer is only present on one side of the base layer, it is preferable that the second organic layer without the laminated inorganic thin film layer has the function of The function of the anti-blocking layer is to improve the gas barrier properties brought about by the homogenization of the inorganic thin film layer and to ensure the sliding property during film transport. It is more preferable that the first organic layer has a function as a planarizing layer. , And the second organic layer has a function as an anti-adhesion layer.

In one aspect of the present invention, when the laminated film includes the first organic layer and the second organic layer, as long as the first organic layer satisfies the internal stress A of the organic layer in the specified range described above, the second organic layer The value of the internal stress A of the organic layer is not particularly limited, but when there is no inorganic thin film layer on the side of the second organic layer opposite to the base layer, the lower the internal stress of the organic layer of the second organic layer, the more good. In addition, each of the first organic layer and the second organic layer may be a single layer, or may be a multilayer of two or more layers. In addition, the first organic layer and the second organic layer may be layers including the same composition, or may be layers including different compositions, but from the viewpoint of easily improving the warpage suppression effect of the laminated film, it is preferable to include the same composition的层。 The layer. In addition, in one aspect of the present invention, in the case where the laminated film has organic layers other than the first organic layer and the second organic layer, the plurality of organic layers may be layers including the same composition, or may include different layers. Composition of layers. Hereinafter, in the description of the organic layer in this specification, unless otherwise specified, the "organic layer" means both the first organic layer and the second organic layer.

The composition of the organic layer is not particularly limited as long as it is a layer containing an organic compound and satisfies the specific internal stress A of the organic layer described above. For example, it can be formed by containing a photocurable compound having a polymerizable functional group. The composition is coated on the substrate layer and hardened to form it. Examples of the photocurable compound contained in the composition for forming the organic layer include ultraviolet curable or electron beam curable compounds. Examples of such compounds include those having one or more polymerizable functional groups in the molecule. The compound is, for example, a compound having a polymerizable functional group such as a (meth)acryloyl group, a vinyl group, a styryl group, and an allyl group. The composition for forming the organic layer (hereinafter also referred to as the "composition for forming an organic layer") may contain one type of photocurable compound, or two or more types of photocurable compounds. By curing the photocurable compound having a polymerizable functional group contained in the composition for forming an organic layer, the photocurable compound is polymerized to form an organic layer containing a polymer of the photocurable compound.

From the viewpoint of easy improvement of the appearance quality, the reaction rate of the polymerizable functional group of the photocurable compound having the polymerizable functional group in the organic layer is preferably 70% or more, more preferably 75% or more, and still more preferably More than 80%. The upper limit of the reaction rate is not particularly limited, but from the viewpoint of easy improvement of appearance quality, it is preferably 95% or less, and more preferably 90% or less. If the reaction rate is equal to or higher than the lower limit, it is easy to become colorless and transparent. In addition, if the reaction rate is not more than the above upper limit, it is easy to improve the bending resistance. The reaction rate becomes higher as the polymerization reaction of a photocurable compound having a polymerizable functional group progresses. Therefore, for example, when the photocurable compound is an ultraviolet curable compound, the intensity of the irradiated ultraviolet light can be increased or extended. The irradiation time can be increased. By adjusting the curing conditions as described above, the reaction rate can be made within the above-mentioned range.

Regarding the reaction rate, a total reflection type Fourier transform infrared can be used for the coating film before curing obtained by coating the composition for forming an organic layer on the substrate and drying as necessary and the coating film after curing the coating film. A spectrometer (Fourier Transform-Infrared Spectrometer, FT-IR) measures the infrared absorption spectrum from the surface of the coating film, and measures it based on the amount of change in the intensity of the peak derived from the polymerizable functional group. For example, when the polymerizable functional group is a (meth)acryloyl group, the C=C double bond part in the (meth)acryloyl group is a group that participates in the polymerization, and the reaction rate becomes higher as the polymerization occurs, The intensity of the peak derived from the C=C double bond decreases. On the other hand, the C=O double bond part of the (meth)acrylic acid group does not participate in the polymerization, and the intensity of the peak derived from the C=O double bond does not change before and after polymerization. _{Therefore, the intensity (I CC1} ) of the peak derived from the C=C double bond in the (meth)acrylic acid group in the infrared absorption spectrum measured on the coating film before curing is compared with that derived from the C=O double bond. the ratio of the peak bond strength (I _CO1) of (I _CC1 / I _CO1), derived from the infrared spectrum measured after curing the coating film absorbing (meth) Bing Xixi group of C = C double bond The ratio (I _CC2 /I _CO2 ) of the intensity of the peak (I _CC2 ) to the intensity of the peak derived from the C=O double bond (I _CO2 ) can be used to calculate the reaction rate. In this case, the reaction rate is calculated by formula (4): Reaction rate [%]=[1-(I _CC2 /I _CO2 )/(I _CC1 /I _CO1 )]×100 (4). Furthermore, the infrared absorption peak derived from the C=C double bond is usually in the range of 1350 cm ^-1 to 1450 cm ^-1 , for example ^{, it is observed around 1400 cm -1} , and the infrared absorption peak derived from the C=O double bond is usually It is observed ^{in the range of 1700 cm -1} to 1800 cm ^-1 , for example, around 1700 cm ^-1.

In the infrared absorption spectrum of the organic layer, ^{the intensity of the infrared absorption peak in the range of 1000 cm -1} to 1100 cm ^-1 _{is set to I a} , and the intensity of the infrared absorption peak in the range of ^{1700 cm -1} to 1800 cm ^-1 is set to In the case of I _b , I _a and I _b preferably satisfy the formula (5): 0.05≦I _b /I _a ≦1.0 (5). Here, it is considered that ^{the infrared absorption peak in the range of 1000 cm -1} to 1100 cm ^-1 is derived from the compound and polymer contained in the organic layer (for example, a photocurable compound having a polymerizable functional group and/or its polymer The infrared absorption peak derived from the Si-O-Si bond in the siloxane, the infrared absorption peak ^{in the range of 1700 cm -1} to 1800 cm ^-1 is derived from the compounds and polymers contained in the organic layer (For example, a photocurable compound having a polymerizable functional group and/or a polymer thereof) the infrared absorption peak of the C=O double bond present. Furthermore, it is considered that the ratio of the intensities of these peaks (I _b /I _a ) represents the relative ratio of the C=O double bond in the organic layer to the Si-O-Si bond derived from siloxane. When the peak intensity ratio (I _b /I _a ) is within the above-mentioned predetermined range, the uniformity of the organic layer is easily improved, and the adhesion between the layers, especially the adhesion under a high-humidity environment, is easily improved. The peak intensity ratio (I _b /I _a ) is preferably 0.05 or more, more preferably 0.10 or more, and still more preferably 0.20 or more. When the peak intensity ratio is equal to or higher than the lower limit, the uniformity of the organic layer can be easily improved. It is presumed that the reason is that although it is not limited by the following mechanism, if the Si-O-Si bond derived from siloxane in the compound and polymer contained in the organic layer becomes excessive, it will be present in the organic layer In this case, agglomerates are generated to cause layer embrittlement, and the present invention is easy to reduce the generation of such agglomerates. The peak intensity ratio (I _b /I _a ) is preferably 1.0 or less, more preferably 0.8 or less, and still more preferably 0.5 or less. When the peak intensity ratio is equal to or less than the upper limit, it is easy to improve the adhesiveness of the organic layer. It is presumed that the reason is that although it is not limited by the following mechanism, the Si-O-Si bond derived from siloxane exists in the compound and polymer contained in the organic layer at a certain amount or more, and the organic layer can be moderately reduced. The hardness. The infrared absorption spectrum of the organic layer can be measured by a Fourier transform infrared spectrophotometer (manufactured by JASCO Corporation, FT/IR-460Plus) equipped with an attachment (PIKE MIRacle) of Attenuated Total Reflection (ATR).

The photocurable compound contained in the composition for forming an organic layer is a compound that starts polymerization by ultraviolet rays or the like and is cured to become a resin as a polymer. From the viewpoint of curing efficiency, the photocurable compound is preferably a compound having a (meth)acryloyl group. The compound having a (meth)acryloyl group may be a monofunctional monomer or oligomer, or a multifunctional monomer or oligomer. In addition, in this specification, the so-called "(meth)acryloyl group" means an acrylic group and/or methacryloyl group, and the so-called "(meth)acryloyl group" means an acrylic group and/or a methyl group. Acrylic based.

Examples of the compound having a (meth)acryloyl group include (meth)acrylic compounds, and specific examples include alkyl (meth)acrylate, urethane (meth)acrylate, and ester (Meth) acrylate, epoxy (meth) acrylate, and their polymers and copolymers. Specifically, examples include: methyl (meth)acrylate, butyl (meth)acrylate, methoxyethyl (meth)acrylate, butoxyethyl (meth)acrylate, and (meth)acrylic acid Phenyl ester, ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, ethylene glycol di(meth)acrylate (Meth)acrylate, propylene glycol di(meth)acrylate, and pentaerythritol tri(meth)acrylate, and their polymers and copolymers.

The photocurable compound contained in the composition for forming an organic layer is preferably substituted for the compound having a (meth)acryloyl group, or in addition to the compound having a (meth)acryloyl group, it contains, for example, four Methoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, isopropyltrimethoxysilane, isopropyltrimethoxysilane Butyltrimethoxysilane, cyclohexyltrimethoxysilane, n-hexyltrimethoxysilane, n-octyltriethoxysilane, n-decyltrimethoxysilane, phenyltrimethoxysilane, dimethyldimethyl dimethyl Oxysilane, diisopropyldimethoxysilane, trimethylethoxysilane, triphenylethoxysilane, etc. Alkoxysilanes other than these can also be used.

Examples of photocurable compounds other than the photocurable compounds having polymerizable functional groups described above include polyester resins, isocyanate resins, ethylene vinyl alcohol resins, vinyl modified resins, and epoxy resins that are polymerized. Monomers or oligomers of resins, phenol resins, urea melamine resins, styrene resins, and alkyl titanates.

The composition for forming an organic layer may contain the inorganic particles described as the inorganic particles that can be contained in the undercoat layer, preferably silicon dioxide particles. The average primary particle size of the silicon dioxide particles contained in the composition for forming an organic layer is preferably 5 nm to 100 nm, more preferably 5 nm to 75 nm. If inorganic particles are contained, it is easy to increase the warpage suppression effect of the laminated film.

The content of inorganic particles, preferably silica particles, is preferably 20% to 90%, and more preferably 40% to 85% relative to the mass of the solid content of the composition for forming an organic layer. If the content of the inorganic particles is within the above range, it is easy to further increase the warpage suppression effect of the laminated film. In addition, the solid content of the composition for forming an organic layer means a component excluding volatile components such as a solvent contained in the composition for forming an organic layer.

From the viewpoint of the curability of the organic layer, the composition for forming an organic layer may contain a photopolymerization initiator. From the viewpoint of improving the curability of the organic layer, the content of the photopolymerization initiator is preferably 2% to 15%, more preferably 3% to 11% relative to the mass of the solid content of the composition for forming the organic layer .

From the viewpoint of coatability, the composition for forming an organic layer may contain a solvent. As the solvent, a solvent capable of dissolving the photocurable compound having a polymerizable functional group can be appropriately selected according to the type of the photocurable compound, and examples thereof include solvents previously described as the solvents that can be used by the user when forming the primer layer. The solvent can be used alone or in combination of two or more.

In addition to the photocurable compound having a polymerizable functional group, the inorganic particles, the photopolymerization initiator, and the solvent, if necessary, a thermal polymerization initiator, antioxidant, ultraviolet absorber, Plasticizers, leveling agents, curl inhibitors and other additives.

By appropriately selecting the type, compounding amount, and combination of the photocurable compound or inorganic particles, photopolymerization initiator, solvent, etc., constituting the composition for forming the organic layer, the inside of the organic layer obtained can be controlled Stress A. For example, when forming an organic layer, by increasing the temperature at which the coating film formed from the composition for forming an organic layer is dried, or by extending the drying time of the coating film, or when the coating film is cured by UV irradiation Increasing the amount of UV irradiation or the like increases the degree of hardening of the composition for forming an organic layer, and the internal stress A of the organic layer tends to increase. On the other hand, due to the low temperature and short residence time when the organic layer is formed, the solvent remains in the organic layer, or when the coating film is cured by UV irradiation, the UV illuminance or the cumulative amount of UV light is small, so that the organic layer If the degree of hardening cannot be increased sufficiently, the internal stress A of the organic layer tends to decrease.

For example, a composition for forming an organic layer (photocurable composition) containing a photocurable compound can be applied to the substrate layer, dried as necessary, and then irradiated with ultraviolet rays or electron beams to make the photocurable compound It hardens to form an organic layer.

As a coating method, the same method as the method of coating the said undercoat layer on a flexible base material is mentioned.

When the organic layer functions as a planarization layer, the organic layer may contain (meth)acrylate resin, polyester resin, isocyanate resin, ethylene vinyl alcohol resin, vinyl modified resin, epoxy resin, phenol Resin, urea melamine resin, styrene resin, alkyl titanate, etc. The organic layer may contain one kind of these resins or a combination of two or more kinds of these resins.

When the organic layer functions as a planarization layer, the organic layer is preferably used to test the surface of the organic layer by a rigid pendulum type physical property testing machine (such as RPT-3000W manufactured by A&D Co., Ltd.) In the case of evaluating the temperature change of the coefficient of elasticity of the organic layer, the temperature at which the coefficient of elasticity of the surface of the organic layer decreases by 50% or more is 150° C. or more.

When the organic layer functions as a planarization layer, the surface roughness measured by observing the organic layer with a white light interference microscope is preferably 3 nm or less, more preferably 2 nm or less, and still more preferably 1 nm or less . If the surface roughness of the organic layer is less than or equal to the upper limit, the inorganic thin film layer laminated on the organic layer has fewer defects, and there is an effect of further improving the gas barrier properties. The surface roughness can be measured by observing the organic layer with a white light interference microscope and forming interference fringes based on the unevenness of the sample surface.

When the organic layer functions as an anti-blocking layer, the organic layer particularly preferably contains the above-mentioned inorganic particles.

In one aspect of the present invention, the thickness of the first organic layer and the second organic layer can be appropriately adjusted according to the application, and are preferably 0.1 μm to 15 μm, more preferably 0.5 μm to 12 μm, and even more preferably 0.7 μm～10 μm. The thickness of the organic layer can be measured with a film thickness meter. If the thickness is greater than or equal to the lower limit, it is easy to increase the surface hardness of the laminated film. In addition, if the thickness is equal to or less than the above upper limit value, the bending resistance is likely to be improved. The thickness of the first organic layer and the second organic layer may be the same or different. When the laminated film of one aspect of the present invention has three or more organic layers, it is preferable that each organic layer has the above-mentioned thickness.

〔Inorganic thin film layer〕 The laminated film of the present invention has an inorganic thin film layer at least on the surface of the first organic layer opposite to the base layer. By having an inorganic thin film layer, excellent gas barrier properties can be imparted to the laminated film. In one aspect of the present invention, inorganic thin film layers may be provided on both sides of the base material layer constituting the laminated film. In one aspect of the present invention, the organic layer existing between the base material layer and the inorganic thin film layer has a laminated film sufficient to eliminate the internal stress caused by the internal stress generated in the inorganic thin film layer, even if When the inorganic thin film layer exists only on one side of the substrate layer, the effect of suppressing the warpage of the laminated film is also excellent. Therefore, by forming the inorganic thin film layer on only one side of the substrate layer, it is effective in productivity or production. The cost aspect is favorable. Furthermore, in one aspect of the present invention, when the laminated film has two or more inorganic thin film layers on both sides of the base layer, the inorganic thin film layers may have the same structure or Different structures.

The inorganic thin film layer is preferably configured to satisfy the specific internal stress B of the inorganic thin film layer described above, and it is preferably a layer that has high density that can express the internal stress B of the inorganic thin film layer and functions as a gas barrier layer. . Such an inorganic thin film layer having gas barrier properties is not particularly limited as long as it is a layer of an inorganic material having gas barrier properties, and a layer of a known inorganic material having gas barrier properties can be suitably used. Examples of inorganic materials include metal oxides, metal nitrides, metal oxynitrides, metal oxycarbides, and mixtures containing at least two of these. The inorganic thin film layer may be a single-layer film, or may be a multilayer film formed by stacking two or more layers including at least the inorganic thin film layer.

From the viewpoints of easy development of higher gas barrier properties (especially water vapor transmission prevention properties), bending resistance, ease of manufacturing, and low manufacturing costs, the inorganic thin film layer preferably contains at least silicon atoms (Si ), oxygen atom (O) and carbon atom (C).

In this case, the inorganic thin film layer may contain a compound represented by the _{general formula SiO α} C _{β as the main component.} In the formula, α and β each independently represent a positive number less than 2. Here, the "main component" means that the content of the component is 50% by mass or more, preferably 70% by mass or more, and more preferably 90% by mass or more relative to the mass of all components of the material. Inorganic thin film layer may contain a compound of the general formula _SiO α _C β represented by two or more compounds of general formula _SiO α _C β may also contain represented. The α and/or β in the general formula may be a constant value in the film thickness direction of the inorganic thin film layer, or may change.

Furthermore, the inorganic thin film layer may also contain elements other than silicon atoms, oxygen atoms, and carbon atoms, such as hydrogen atoms, nitrogen atoms, boron atoms, aluminum atoms, phosphorus atoms, iodine atoms, fluorine atoms, and chlorine atoms. atom.

Regarding the inorganic thin film layer, when C/Si is used to express the average atomic ratio of carbon atoms (C) to silicon atoms (Si) in the inorganic thin film layer, the density is improved and fine voids or cracks are reduced. From the viewpoint of defects, the range of C/Si preferably satisfies formula (6): 0.02<C/Si<0.50 (6). From the same viewpoint, C/Si is more preferably in the range of 0.03<C/Si<0.45, more preferably in the range of 0.04<C/Si<0.40, and particularly preferably in the range of 0.05<C/Si< Within the range of 0.35.

In addition, regarding the inorganic thin film layer, when O/Si is used to express the average atomic ratio of oxygen atoms (O) to silicon atoms (Si) in the inorganic thin film layer, the density is improved and the fine voids or fine spaces are reduced. From the viewpoint of defects such as cracks, it is preferably in the range of 1.50<O/Si<1.98, more preferably in the range of 1.55<O/Si<1.97, and still more preferably in the range of 1.60<O/Si<1.96 Within the range, it is particularly preferable to be in the range of 1.65<O/Si<1.95.

Furthermore, regarding the average atomic number ratio C/Si and the average atomic number ratio O/Si, X-ray photoelectron spectroscopy (XPS) depth profile measurement can be performed under the following conditions, according to The obtained distribution curves of silicon atoms, oxygen atoms, and carbon atoms are used to obtain the average atomic concentration of each atom in the thickness direction, and then calculate it as the average atomic ratio C/Si and the average atomic ratio O/Si. <XPS depth profiling measurement> Etching ion species: Argon (Ar ⁺ ) Etching rate (SiO ₂ thermal oxide film conversion value): 0.027 nm/sec Sputtering time: 0.5 minutes X-ray photoelectron spectroscopy device: Alfaco Fain (ULVAC -Manufactured by PHI (stock), model name "Quantera SXM" X-ray irradiation: single crystal AlKα (1486.6 eV) X-ray spot and its size: 100 μm Detector: pass energy (Pass Energy) 69 eV, step size (Step size) 0.125 eV Charge correction: neutralization electron gun (1 eV), low-speed Ar ion gun (10 V)

In the case of infrared spectroscopy (ATR method) on the surface of the inorganic thin film layer, the peak intensity (I ₁ ^{) existing in 950 cm -1} ～1050 cm ^-1 and the peak intensity (I 1) existing in 1240 cm ^-1 ～1290 cm -1 are preferred. The intensity ratio (I ₂ /I ₁ ) of the peak intensity (I ₂ ) in cm ⁻¹ satisfies the formula (7): 0.01≦I ₂ /I ₁ <0.05 (7).

It is considered that the peak intensity ratio I ₂ /I ₁ calculated by infrared spectroscopy (ATR method) represents the relative ratio of Si-CH ₃ to Si-O-Si in the inorganic thin film layer. The inorganic thin film layer that satisfies the relationship represented by the formula (7) has high density and is easy to reduce defects such as fine voids and cracks, and therefore it is considered that it is easy to improve gas barrier properties and impact resistance. From the standpoint that it is easy to keep the density of the inorganic thin film layer high, the peak intensity ratio I ₂ /I _{1 is more} preferably in the range of 0.02≦I ₂ /I ₁ <0.04.

When the inorganic thin film layer satisfies the _{range of the peak intensity ratio I 2} /I ₁ , in one aspect of the present invention, the laminated film is easy to slide moderately and is easy to reduce blocking. If the peak strength ratio I ₂ /I _{1 is} too large, it means that there is too much Si-C. In this case, there is a tendency that bending resistance is poor and sliding is difficult. In addition, if the peak strength is _{too small than I 2} /I ₁ , there is a tendency for the bending resistance to decrease due to the too small amount of Si-C.

The infrared spectrophotometric measurement of the surface of the inorganic thin film layer can be performed by, for example, a Fourier transform infrared spectrophotometer (manufactured by JASCO Corporation, FT/IR- 460Plus) to determine.

In the case of infrared spectroscopy (ATR method) on the surface of the inorganic thin film layer, the peak intensity (I ₁ ^{) existing in 950 cm -1} to 1050 cm ^-1 and the peak intensity (I 1) existing in 770 cm ^-1 to 830 cm -1 are preferred. The intensity ratio (I ₃ /I ₁ ) of the peak intensity (I ₃ ) in cm ^-1 satisfies the formula (8): 0.25≦I ₃ /I ₁ ≦0.50 (8).

It is considered that the peak intensity ratio I ₃ /I ₁ calculated by infrared spectroscopy (ATR method) represents the relative ratio of Si—C, Si—O, etc., to Si—O—Si in the inorganic thin film layer. The inorganic thin film layer that satisfies the relationship represented by the formula (8) maintains high density and introduces carbon, and therefore it is considered that it is easy to improve the bending resistance and also easy to improve the impact resistance. From the viewpoint of maintaining the balance between the density of the inorganic thin film layer and the bending resistance, the peak strength ratio I ₃ /I _{1 is} preferably in the range of 0.25≦I ₃ /I ₁ ≦0.50, and more preferably 0.30≦I ₃ / I ₁ ≦0.45.

Regarding the inorganic thin film layer, when infrared spectroscopy (ATR method) is performed on the surface of the inorganic thin film layer, it is preferable that the peak intensity (I ₃ ^{) existing in 770 cm -1} to 830 cm ^-1 and the peak intensity (I 3) existing in The intensity ratio of the peak intensity (I ₄ ) in 870 cm ^-1 to 910 cm ^-1 satisfies the formula (9): 0.70≦I ₄ /I ₃ <1.00 (9).

It is considered that the peak intensity ratio I ₄ /I ₃ calculated by infrared spectroscopy (ATR method) represents the ratio of the peaks associated with Si-C in the inorganic thin film layer. The inorganic thin film layer that satisfies the relationship represented by the formula (9) maintains high density and introduces carbon, and therefore it is considered that it is easy to improve the bending resistance and also easy to improve the impact resistance. Regarding the range of the peak intensity ratio I ₄ /I ₃ , from the viewpoint of maintaining the balance between the density of the inorganic thin film layer and the bending resistance, the range is preferably 0.70≦I ₄ /I ₃ <1.00, and more preferably 0.80 The range of ≦I ₄ /I ₃ <0.95.

The thickness of the inorganic thin film layer can be appropriately adjusted according to the application, and is preferably 5 nm to 3000 nm, more preferably 10 nm to 2000 nm, and still more preferably 50 nm to 1000 nm. The thickness of the inorganic thin film layer can be measured with a film thickness meter. If the thickness is greater than or equal to the lower limit, the gas barrier properties are likely to be improved. In addition, if the thickness is equal to or less than the upper limit, the bending resistance is likely to be improved. In particular, in the case of forming an inorganic thin film layer by a plasma CVD method using glow discharge plasma as described later, the inorganic thin film layer is formed while discharging through the substrate. It is preferably 10 nm to 2000 nm, and more preferably 50 nm to 1000 nm.

The inorganic thin film layer may preferably have a high average density of ^{1.8 g/cm 3 or more.} Here, the "average density" of the inorganic thin film layer can be obtained by the following method: According to the number of silicon atoms, the number of carbon atoms, and the number of carbon atoms obtained by Rutherford Backscattering Spectrometry (RBS) The number of oxygen atoms and the number of hydrogen atoms determined by the hydrogen forward scattering spectrometry (HFS) are used to calculate the weight of the inorganic thin film layer in the measurement range, and divide by the volume of the inorganic thin film layer in the measurement range ( The product of the irradiation area of the ion beam and the film thickness). If the average density of the inorganic thin film layer is equal to or higher than the lower limit, it has a structure that has high density and is easy to reduce defects such as fine voids and cracks, which is preferable. In a preferred aspect of the present invention where the inorganic thin film layer contains silicon atoms, oxygen atoms, carbon atoms, and hydrogen atoms, the average density of the inorganic thin film layer is preferably less than 2.22 g/cm ³ .

In a preferred aspect of the present invention where the inorganic thin film layer contains at least silicon atoms (Si), oxygen atoms (O), and carbon atoms (C), the distance from the inorganic thin film layer in the thickness direction of the inorganic thin film layer The curve of the relationship between the distance of the layer surface and the atomic ratio of silicon atoms in each distance is called the silicon distribution curve. Here, the surface of the inorganic thin film layer refers to the surface that becomes the surface of the laminated film of the present invention. Similarly, a curve showing the relationship between the distance from the surface of the inorganic thin film layer in the film thickness direction and the atomic ratio of oxygen atoms in each distance is referred to as an oxygen distribution curve. In addition, a curve showing the relationship between the distance from the surface of the inorganic thin film layer in the film thickness direction and the atomic ratio of carbon atoms in each distance is referred to as a carbon distribution curve. The atomic ratio of silicon atoms, the atomic ratio of oxygen atoms, and the atomic ratio of carbon atoms refer to the ratio of the respective atomic numbers to the total number of silicon atoms, oxygen atoms, and carbon atoms contained in the inorganic thin film layer.

From the viewpoint of easily suppressing the decrease in gas barrier properties caused by bending, it is preferable that the number of carbon atoms relative to the total number of silicon atoms, oxygen atoms, and carbon atoms contained in the inorganic thin film layer is more than The inorganic thin film layer continuously changes in an area of 90% or more in the film thickness direction. Here, the term “atomic ratio of carbon atoms” continuously changes in the film thickness direction of the inorganic thin film layer, for example, means that the carbon distribution curve does not contain carbon at which the atomic ratio changes discontinuously.

From the viewpoint of bending resistance and gas barrier properties of the laminated film, it is preferable that the carbon distribution curve of the inorganic thin film layer has eight or more extreme values.

From the viewpoint of bending resistance and gas barrier properties of the laminated film, it is preferable that the silicon distribution curve, oxygen distribution curve, and carbon distribution curve of the inorganic thin film layer satisfy the following conditions (i) and (ii). (I) The atomic ratio of silicon, the atomic ratio of oxygen, and the atomic ratio of carbon satisfy the condition represented by the following formula (10) in a region where 90% or more of the thickness direction of the inorganic thin film layer; and (Atomic ratio of oxygen)>(Atomic ratio of silicon)>(Atomic ratio of carbon) (10) (Ii) The carbon distribution curve has preferably at least one extreme value, more preferably at least eight extreme values.

The carbon distribution curve of the inorganic thin film layer is preferably substantially continuous. The term "carbon distribution curve is substantially continuous" means that there is no part where the atomic ratio of carbon in the carbon distribution curve changes discontinuously. Specifically, it is preferable that when the distance from the surface of the inorganic thin film layer in the film thickness direction is x [nm] and the atomic ratio of carbon is C, the formula (11) is satisfied: |dC/dx|≦0.01 (11).

In addition, the carbon distribution curve of the inorganic thin film layer preferably has at least one extreme value, and more preferably has eight or more extreme values. The extreme value described here is the maximum value or the minimum value of the atomic ratio of each element with respect to the distance from the surface of the inorganic thin film layer in the film thickness direction. The extreme value is the value at which the atomic ratio of the element rotates to a point at which the atomic ratio of the element changes to a decrease or the point where the atomic ratio of the element rotates to increase when the distance from the surface of the inorganic thin film layer in the thickness direction is changed. The extreme value can be determined based on, for example, atomic ratios measured at a plurality of measurement positions in the film thickness direction. The measurement position of the atomic ratio is set so that the interval in the film thickness direction is, for example, 20 nm or less. The position showing the extreme value in the film thickness direction can be obtained by the following method: For a discrete data group including the measurement results at each measurement position, for example, the measurement results at three or more measurement positions that are different from each other Compare them and find the position where the measurement result turns from an increase to a decrease or where the measurement result turns from a decrease to an increase. The position showing the extreme value can also be obtained, for example, by differentiating the approximate curve obtained from the discrete data group. Depending on the position where the extreme value is displayed, when the section where the atomic ratio monotonously increases or decreases, for example, 20 nm or more, the atomic ratio at the position that moves only 20 nm in the film thickness direction from the position where the extreme value is displayed The absolute value of the difference from the extreme value is, for example, 0.03 or more.

As described above, the inorganic thin film layer formed to satisfy the condition that the carbon distribution curve has an extreme value of preferably at least one, and more preferably eight or more extremes, compared with the case where the condition is not satisfied, the gas after bending is permeated The increase in the gas permeability relative to the gas permeability before bending becomes smaller. That is, by satisfying the above conditions, the effect of suppressing the decrease in gas barrier properties due to bending can be obtained. When the inorganic thin film layer is formed so that the number of extreme values of the carbon distribution curve becomes two or more, the increase is smaller than when the number of extreme values of the carbon distribution curve is one. In addition, when the inorganic thin film layer is formed so that the number of extreme values of the carbon distribution curve becomes three or more, the increase is smaller than when the number of extreme values of the carbon distribution curve is two. In the case where the carbon distribution curve has two or more extreme values, the distance from the surface of the inorganic thin film layer in the film thickness direction at the position where the first extreme value is shown is the same as the second extreme value adjacent to the first extreme value. The absolute value of the difference in the distance from the surface of the inorganic thin film layer in the film thickness direction at the value position is preferably in the range of 1 nm or more and 200 nm or less, and more preferably in the range of 1 nm or more and 100 nm or less.

In addition, the absolute value of the difference between the maximum value and the minimum value of the atomic ratio of carbon in the carbon distribution curve of the inorganic thin film layer is preferably greater than 0.01. The inorganic thin film layer formed so as to satisfy the above conditions has a smaller increase in the gas permeability after bending relative to the gas permeability before bending than when the above conditions are not satisfied. That is, by satisfying the above conditions, the effect of suppressing the decrease in gas barrier properties due to bending can be obtained. If the absolute value of the difference between the maximum value and the minimum value of the atomic ratio of carbon is 0.02 or more, the effect is increased, and if it is 0.03 or more, the effect is further increased.

The lower the absolute value of the difference between the maximum value and the minimum value of the atomic ratio of silicon in the silicon distribution curve, the more the gas barrier properties of the inorganic thin film layer tend to be improved. From this point of view, the absolute value is preferably less than 0.05 (less than 5 at%), more preferably less than 0.04 (less than 4 at%), particularly preferably less than 0.03 (less than 3 at%) ).

In addition, in the oxygen-carbon distribution curve, when the sum of the atomic ratio of oxygen atoms and the atomic ratio of carbon atoms in each distance is set as the "total atomic ratio", there is an absolute difference between the maximum and minimum values of the total atomic ratio. The lower the value, the more the gas barrier properties of the inorganic thin film layer tend to improve. From this viewpoint, the total atom ratio is preferably less than 0.05, more preferably less than 0.04, and particularly preferably less than 0.03.

In the inner direction of the inorganic thin film layer, if the inorganic thin film layer is made to have substantially the same composition, the gas barrier properties of the inorganic thin film layer can be made uniform and improved. The so-called substantially the same composition refers to the number of extreme values existing in the film thickness direction at any two points on the surface of the inorganic thin film layer in the oxygen distribution curve, carbon distribution curve, and oxygen-carbon distribution curve. The absolute value of the difference between the maximum value and the minimum value of the atomic ratio of carbon in the respective carbon distribution curves is the same or the difference is within 0.05.

The inorganic thin film layer formed to satisfy the above-mentioned conditions can exhibit, for example, gas barrier properties required for flexible electronic devices using organic EL elements and the like.

In a preferred aspect of the present invention in which the inorganic thin film layer contains at least silicon atoms, oxygen atoms, and carbon atoms, from the viewpoint that it is easy to improve the density and easily reduce defects such as fine voids or cracks, such atoms are included. The layer of inorganic material is preferably formed by a chemical vapor deposition method (CVD method), and among them, it is more preferable to use a plasma chemical vapor deposition method (Plasma Enhanced Chemical Vapor Deposition method, PECVD method) using glow discharge plasma or the like. Law) to form.

An example of the raw material gas used in the chemical vapor deposition method is an organosilicon compound containing silicon atoms and carbon atoms. Examples of such organosilicon compounds are hexamethyldisiloxane, 1,1,3,3-tetramethyldisiloxane, vinyl trimethylsilane, methyltrimethylsilane, hexamethyldisiloxane Silane, methyl silane, dimethyl silane, trimethyl silane, diethyl silane, propyl silane, phenyl silane, vinyl triethoxy silane, vinyl trimethoxy silane, tetramethoxy silane, Tetraethoxysilane, phenyltrimethoxysilane, methyltriethoxysilane, octamethylcyclotetrasiloxane. Among these organosilicon compounds, from the viewpoints of the handling properties of the compound and the gas barrier properties of the obtained inorganic thin film layer, hexamethyldisiloxane, 1,1,3,3-tetra Methyl disiloxane. As the raw material gas, one of these organosilicon compounds may be used alone, or two or more of them may be used in combination.

In addition, with respect to the source gas, a reaction gas that can react with the source gas to form an inorganic compound such as oxide and nitride can be appropriately selected and mixed. As the reaction gas for forming oxides, for example, oxygen gas and ozone (ozone) can be used. In addition, as the reaction gas for forming nitrides, for example, nitrogen gas and ammonia gas can be used. These reaction gases may be used alone or in combination of two or more. For example, in the case of forming oxynitride, a reaction gas for forming an oxide and a reaction gas for forming a nitride may be used in combination. The flow rate ratio of the raw material gas and the reaction gas can be appropriately adjusted according to the atomic ratio of the inorganic material for film formation.

In order to supply the raw material gas into a vacuum chamber, a carrier gas may be used as needed. Furthermore, in order to generate plasma discharge, a gas for discharge can also be used as needed. As such carrier gas and discharge gas, known ones can be suitably used. For example, inert gases such as helium, argon, neon, and xenon; hydrogen can be used.

In addition, the pressure (vacuum degree) in the vacuum chamber can be appropriately adjusted according to the type of raw material gas, etc., and is preferably set to a range of 0.5 Pa to 50 Pa.

For example, the internal stress B of the inorganic thin film layer can be controlled by controlling the degree of vacuum during film formation, the substrate temperature during film formation, the film formation power, and the magnetic field in the electrode. For example, the internal stress B of the inorganic thin film layer tends to increase by reducing the degree of vacuum, increasing the substrate temperature during film formation, increasing the film formation power, or increasing the magnetic field density. On the other hand, by increasing the degree of vacuum, lowering the substrate temperature during film formation, lowering the film formation power, or lowering the magnetic field density, the internal stress B of the inorganic thin film layer tends to decrease.

The structure of one aspect of the laminated film of the present invention will be explained based on FIG. 1. The laminated film 4 of one aspect of the present invention is formed by laminating a base material layer 1, an organic layer 2, and an inorganic thin film layer 3 in this order. If the laminated film of the present invention has a substrate layer, an organic layer, and an inorganic thin film layer in this order, as long as it does not affect the effect of the present invention, it may have other layers between the layers or the outermost layer. However, in one aspect of the present invention In this way, the substrate layer, the organic layer, and the inorganic thin film layer are present next to each other in order. Examples of other layers include: further organic layers and inorganic thin film layers, protective layers, slippery layers, hard coat layers, transparent conductive film layers, color filter layers, easy bonding layers, curl adjustment layers, and stress relaxation layers , Heat-resistant layer, scratch-resistant layer, pressure-resistant layer, etc.

As a laminated film including other layers, for example, in the laminated film 4 shown in FIG. 2 which is another aspect of the present invention, a first organic layer 2-1 and an inorganic thin film are layered on one of the areas of the base layer 1 In layer 3, there is a second organic layer 2-2 on an area of the substrate layer 1 opposite to the first organic layer 2-1. In the laminated film 4 described in FIG. 2, the laminated body when the internal stress A of the organic layer of one aspect of the present invention is measured is a laminated body including the base layer 1 and the first organic layer 2-1. In addition, the laminate when measuring the internal stress B of the inorganic thin film layer of one aspect of the present invention is a laminate including the base material layer 1 and the inorganic thin film layer 3 directly formed on the base material layer 1.

Furthermore, the laminated film 4 of one aspect of this invention shown in FIG. 3 contains the base layer 1 which has the primer layer 1-2 on both surfaces of the flexible base material 1-1. In the laminated film 4, a first organic layer 2-1 is laminated on one of the undercoat layers 1-2, and the inorganic thin film layer 3 is formed on the first organic layer 2-1 and the undercoat layer 1-2. Opposite face side. In addition, the undercoat layer 1-2 on the side of the flexible substrate 1-1 opposite to the undercoat layer 1-2 on which the first organic layer 2-1 is laminated, and the flexible substrate 1-1 The area layer on the opposite side has a second organic layer 2-2. In the laminated film 4 described in FIG. 3, the laminated body when the internal stress A of the organic layer of one aspect of the present invention is measured is a laminated body including a base material layer 1 and a first organic layer 2-1, the base material The layer 1 includes a flexible substrate 1-1 and a primer layer 1-2 laminated on both sides of the flexible substrate 1-1. In addition, the laminate when measuring the internal stress B of the inorganic thin film layer of one aspect of the present invention is a laminate including a base material layer 1 and an inorganic thin film layer 3 directly formed on the base material layer 1. The base material layer 1 Contains a flexible substrate 1-1 and a primer layer 1-2 laminated on both sides of the flexible substrate 1-1.

[Manufacturing method of laminated film] The manufacturing method of the laminated film of the present invention is not particularly limited as long as the layers can be formed in the stated order. As an example, an organic layer may be formed on one side of a substrate layer including a flexible substrate, and then applied to the organic layer. The method of forming an inorganic thin film layer on the layer. In the case where the substrate layer has a primer layer, after the primer layer is formed on one side of the flexible substrate, an organic layer can be formed on the primer layer. In addition, when the laminated film of one aspect of the present invention further includes an organic layer (second organic layer) on the surface of the base layer opposite to the organic layer (first organic layer), The second organic layer is formed on the surface of the base layer opposite to the first organic layer in the same manner as in the above method. Furthermore, the laminated film of one aspect of the present invention may be manufactured by laminating the layers after each layer is formed separately.

From the standpoint of easily improving the density of the inorganic thin film layer and easily reducing defects such as fine voids or cracks, the inorganic thin film layer is preferably formed by using a glow discharge plasma as described above and forming a film by a well-known vacuum such as the CVD method. Method and formed on the organic layer. The inorganic thin film layer is preferably formed by a continuous film-forming process. For example, it is more preferable to continuously form the inorganic thin film layer on the long layered body while continuously conveying it. Specifically, the inorganic thin film layer can be formed while conveying the layered body from the delivery roller to the winding roller. After that, the delivery roller and the winding roller are reversed to convey the laminate in the reverse direction, thereby further forming an inorganic thin film layer.

Since the laminated film of one aspect of the present invention is excellent in the warpage suppression effect of the laminated film and has high gas barrier properties, it is suitable for use in electronic devices requiring high gas barrier properties, for example. Examples of electronic devices include flexible electronic devices (flexible displays) such as liquid crystal display elements, solar cells, organic EL displays, organic EL microdisplays, organic EL lighting, and electronic paper that require high gas barrier properties. The laminated film of one aspect of the present invention can be preferably used as a flexible substrate of the flexible electronic device. When the laminated film is used as a flexible substrate, the device can be directly formed on the laminated film, or after the device is formed on another substrate, the laminated film may be superimposed from above with an adhesive layer or an adhesive layer interposed therebetween. [Example]

Hereinafter, one aspect of the present invention will be described in more detail based on examples. As long as there is no special description, "%" and "parts" in the examples are mass% and mass parts.

1. Example 1 Biaxially stretched polyethylene naphthalate film (manufactured by Teijin Film Solutions (stock), Q65HWA, 100 μm in thickness) with primer coatings on both sides of a flexible substrate as a substrate A single side with a width of 350 mm, as a composition for forming an organic layer for forming an organic layer, was coated with coating composition 1 (Nippon Chemical Co., Ltd., TOMAX (registered trademark) FA-) by gravure coating. 3376-2). After the coating film was dried at 100°C for 1 minute, a high-pressure mercury lamp was used ^{to irradiate ultraviolet rays under the condition of a cumulative light amount of 500 mJ/cm 2} to laminate an organic layer with a thickness of 4 μm to obtain a substrate with an organic layer.

In accordance with the method for producing an inorganic thin film layer described below, an inorganic thin film layer (thickness 400 nm) was layered on the surface area of the organic layer side of the obtained substrate with an organic layer to obtain a laminate layer consisting of a substrate layer/organic layer/inorganic thin film layer膜1。 Film 1.

In addition, regarding the thickness of each of the base layer, organic layer, and inorganic thin film layer of the laminated film 1, a film thickness meter (manufactured by Kosaka Research Institute (Stock): Surfcorder ET200) was used for no film formation. The level difference between the part and the film-forming part was measured, and the film thickness (T) of each layer was obtained.

[Method of Manufacturing Inorganic Thin Film Layer] Using a manufacturing apparatus as shown in FIG. 4, an inorganic thin film layer was laminated on a substrate with an organic layer. Specifically, in a manufacturing apparatus as shown in FIG. 4 installed in a vacuum chamber, the organic layered base film 18 is mounted on the delivery roll 10, and the vacuum chamber is 1×10 ^-3 After Pa or less, while transporting the base film 18 by the transport roller 11, an inorganic thin film layer is formed on the organic layer laminated on the base film. In a plasma CVD apparatus for forming an inorganic thin film layer, the substrate film 18 with an organic layer is brought into close contact with the surfaces of a pair of roller electrodes including the film forming roller 12 and the film forming roller 13, respectively, while being transported , A plasma is generated between a pair of electrodes, and the raw material is decomposed in the plasma to form an inorganic thin film layer on the organic layer. The pair of roller-shaped electrodes are equipped with magnets inside the electrodes to increase the magnetic flux density on the surface of the electrodes and the substrate with the organic layer being transported. When plasma is generated, the electrodes and the organic layer The plasma on the substrate is constrained by high density. When the inorganic thin film layer is formed, hexamethyldisiloxane (HMDSO) gas and oxygen are introduced into the space between the electrodes (the film forming roller 12 and the film forming roller 13) that become the film forming area, and the electrode roller AC power is supplied and discharged to generate plasma. Next, after adjusting the exhaust gas volume so that the pressure around the exhaust port in the vacuum chamber becomes 1 Pa, a dense inorganic thin film layer is formed on the substrate with an organic layer by the plasma CVD method, and by winding The roll 17 is wound into a roll shape.

＜Film-forming conditions 1＞ Supply volume of raw material gas: 50 sccm (Standard Cubic Centimeter per Minute, 0°C, 1 barometric basis) Oxygen supply: 500 sccm Vacuum degree in the vacuum chamber: 1 Pa Applied power from power supply 15 for plasma generation: 0.8 kW Frequency of power supply for plasma generation: 70 kHz Film transport speed: 0.6 m/min Pass times: 2 times

For the obtained laminated film 1, the flatness, internal stress, moisture permeability, etc. were measured and/or evaluated in accordance with the following methods.

[Evaluation of the flatness of laminated film] The laminated film 1 was cut into a square of 50 mm×50 mm to obtain a sample for measurement. Then, the sample for measurement was heated from room temperature (25°C) to 130°C or 180°C and kept at room temperature (25°C) for 30 minutes in a hot air circulating oven, and then left to cool at room temperature (25°C) for 10 minutes. Next, the sample is placed on the horizontal surface, the center of the measurement sample is in contact with the horizontal surface, the distances (heights) from the horizontal surface to the four corners are measured, and the average value is calculated from the four obtained distances. The calculated value is described in Table 1 as the value of warpage.

[Measurement of the internal stress of the organic layer and the internal stress of the inorganic thin film layer] Using a biaxially stretched polyethylene naphthalate film (manufactured by Teijin Film Solutions Co., Ltd.) with primer layers formed on both sides of a flexible substrate, Q65HWA, thickness 100 μm) was used as the substrate layer. According to the example 1, an organic layer formed of coating composition 1 (Nippon Chemical Co., Ltd., TOMAX FA-3376-2) was laminated on the substrate. Layer to obtain a laminate for measuring the internal stress of the organic layer. In the same manner as the above-mentioned flatness evaluation method, the sample for measurement is heated from room temperature (25°C) to 130°C or 180°C and held for 30 minutes in a hot air circulating oven, and then left to cool at room temperature (25°C) for 10 minutes. The amount of deformation of the resulting laminate was measured (the average value of the distances from the horizontal plane to the four corners, in the case of a cylindrical shape, the diameter of the cylindrical interior). Using the radius of curvature calculated from the measured amount of deformation, the film thickness of the organic layer, the thickness of the substrate, the Young’s modulus of the substrate, and the Passon’s ratio of the substrate, the organic layer’s Internal stress. In the biaxially stretched polyethylene naphthalate film used as the substrate, the Young's modulus E of the substrate is 6.1×10 ⁹ Pa, and the Passon's ratio v of the substrate is 0.33. Furthermore, instead of the base material with an organic layer, the biaxially stretched polyethylene naphthalate film without an organic layer was transported as a base material. Otherwise, the same as described in Example 1 was used. The formation method of the inorganic thin film layer was carried out in the same manner, and the inorganic thin film layer was directly laminated on the substrate layer to produce a laminate for measuring the internal stress of the inorganic thin film layer. In the same way as the method of measuring and calculating the internal stress of the organic layer, the internal stress of the inorganic thin film layer is calculated by using the amount of deformation of the obtained laminate.

Internal stress (GPa) = Eh ² /6 (1-v) Rt (12) [In formula (11), t is the thickness of the organic layer or inorganic film layer (m), R is the radius of curvature (m), and h is The thickness of the substrate (m), E is the Young's modulus (Pa) of the substrate, and v is the Passon's ratio of the substrate]

In the laminate for measuring the internal stress of the organic layer corresponding to the laminate film 1, the internal stress of the organic layer was calculated in accordance with the above-mentioned measurement method. The radius of curvature after heating to 130°C is 11.8 mm, and the internal stress is 0.32 GPa. In addition, the radius of curvature after heating to 180°C was 3.6 mm, and the internal stress was 1.05 GPa.

In the laminate for measuring the internal stress of the inorganic thin film layer corresponding to the laminate film 1, the internal stress of the inorganic thin film layer was calculated in accordance with the above-mentioned measurement method. The radius of curvature after heating to 130°C is 17.0 mm, and the internal stress is 2.23 GPa. In addition, the radius of curvature after heating to 180°C was 9.8 mm, and the internal stress was 3.89 GPa.

[Measurement of the internal stress of the laminated film] The internal stress of the laminated film (the laminated film including the organic layer and the inorganic thin film layer of the laminated film 1) is the same as the above-mentioned flatness evaluation method, and the measurement sample is taken from the chamber using a hot air circulation oven After heating to 130°C or 180°C at temperature (25°C) and keeping it for 30 minutes, let it cool at room temperature (25°C) for 10 minutes, and measure the deformation of the resulting laminated film 1 (average value of each distance from the horizontal plane to the four corners) , In the case of a cylindrical shape, the diameter of the cylindrical interior). Using the radius of curvature calculated from the measured amount of deformation, the total film thickness of the organic layer and the inorganic thin film layer, the thickness of the substrate, the Young’s modulus of the substrate, and the Passon’s ratio of the substrate, the following formula (13 ) Calculate the internal stress of the laminated film. In the biaxially stretched polyethylene naphthalate film used as the substrate, the Young's modulus E of the substrate is 6.1×10 ⁹ Pa, and the Passon's ratio v of the substrate is 0.33.

Internal stress (GPa) = Eh ² /6 (1-v) Rt (13) [In formula (13), t is the total film thickness of the organic layer and the inorganic thin film layer (m), R is the radius of curvature (m), h is the thickness of the substrate (m), E is the Young's modulus (Pa) of the substrate, and v is the Passon's ratio of the substrate]

In the laminated film 1, the radius of curvature after heating to 130°C is 200 mm, and the internal stress is 0.017 GPa. In addition, the radius of curvature after heating to 180°C was 417 mm, and the internal stress was 0.0083 GPa.

[X-ray photoelectron spectroscopy in the thickness direction of the inorganic thin film layer] A scanning X-ray photoelectron spectrometer (manufactured by ULVAC PHI Co., Ltd., Quantera SXM) is used. In X-ray photoelectron spectroscopy, the atomic ratio of the inorganic thin film layer of the multilayer film 1 in the film thickness direction is measured in accordance with the following measurement conditions. As the X-ray source, AlKα rays (1486.6 eV, X-ray spot 100 μm) were used, and for charging correction during measurement, a neutralization electron gun (1 eV) and a low-speed Ar ion gun (10 V) were used. The analysis after the measurement is performed by using MultiPak V6.1A (ULVAC-PHI (stock)) for spectral analysis, using the 2p, equivalent to Si obtained from the wide scan spectrum of the measurement. The binding energy peaks of O 1s, N 1s, and C 1s respectively, calculate the surface atomic ratio of C to Si (C/Si) and the surface atomic ratio of O to Si (O/ Si). As the surface atomic number ratio, the average value of the values obtained by five measurements is used. Based on this result, a carbon distribution curve is prepared. <XPS depth profiling measurement conditions> Etching ion species: Argon (Ar ⁺ ) Etching rate (SiO ₂ thermal oxide film conversion value): 0.027 nm/sec Sputtering time: 0.5 minutes X-ray photoelectron spectroscopy device: Afak Fain ( Manufactured by ULVAC-PHI, model name "Quantera SXM" X-ray irradiation: single crystal AlKα (1486.6 eV) X-ray spot and size: 100 μm Detector: Pass Energy 69 eV, Step size 0.125 eV Charge correction: neutralization electron gun (1 eV), low speed Ar ion gun (10 V)

According to the results of the XPS depth profiling measurement, it was confirmed that in the region of 90% or more of the thickness direction of the inorganic thin film layer of the obtained laminated film 1, the ones with the larger atomic number ratio were oxygen, silicon, and carbon in this order. In addition, after obtaining the average atomic concentration of each atom in the thickness direction from the obtained distribution curves of silicon, oxygen and carbon atoms, the average atomic number ratio C/Si and the average atomic number ratio O/Si were calculated, and the results were confirmed To the average atomic ratio C/Si=0.30, O/Si=1.73. Furthermore, the number of carbon atoms with respect to the total number of silicon atoms, oxygen atoms, and carbon atoms contained in the inorganic thin film layer continuously changes in a region over 90% of the thickness direction of the inorganic thin film layer.

[Infrared spectroscopy measurement of the surface of the inorganic thin film layer (ATR method)] A Fourier transform infrared spectrophotometer (manufactured by JASCO Corporation, FT/IR-460Plus) with an ATR accessory (PIKE MIRacle) using germanium crystals in the 稜鏡 was used to perform infrared spectroscopy on the surface of the inorganic thin film layer of the multilayer film 1. Determination.

Obtained by the infrared absorption spectrum obtained in the presence of 950 cm ^-1 ~ 1050 cm ^-1 is a peak intensity (I ₁₎ present in the 1240 cm ^-1 ~ 1290 cm ^-1 is a peak intensity (I ₂₎ of the absorption intensity When the ratio is (I ₂ /I ₁ ), I ₂ /I ₁ =0.03. Further absorption intensity obtained in the presence of ~ 1050 cm ^-1 to the peak intensity in 950 cm ^-1 (I ₁₎ present in the 770 cm ^-1 ~ 830 cm ^-1 is a peak intensity (I ₃₎ ratio (I ₃ /I ₁ ), I ₃ /I ₁ = 0.36. Further absorption intensity obtained in the presence of 770 cm ^-1 ~ 830 cm ^-1 is a peak intensity (I ₃₎ present in the 870 cm ^-1 ~ 910 cm ^-1 is a peak intensity (I ₄₎ ratio (I ₄ /I ₃ ), I ₄ /I ₃ =0.84.

[Water vapor permeability of laminated film] The water vapor permeability is measured under the conditions of a temperature of 40°C and a humidity of 90%RH in accordance with the International Standardization Organization (ISO)/WD 15106-7 (Annex C) and the Ca corrosion test method.

^{The resulting laminated film 1 had a water vapor permeability of 3.5×10 -3} g/(m ² ·day) under the conditions of a temperature of 40° C. and a humidity of 90% RH.

2. Comparative example 1 A biaxially stretched polyethylene naphthalate film (manufactured by Teijin Film Solutions Co., Ltd., Q65HA, thickness 100 μm, width 350 mm) with a primer layer on one side of a flexible substrate is used as the substrate layer Using the same method as in Example 1, a single-area inorganic thin film layer (400 nm) of the film was used to obtain a laminated film 2 including a base layer/inorganic thin film layer.

With respect to the obtained laminated film 2, the internal stress of the inorganic thin film layer was calculated by the same method as in Example 1. The radius of curvature after heating to 130°C is 17.0 mm, and the internal stress is 2.23 GPa. In addition, the radius of curvature after heating to 180°C was 9.8 mm, and the internal stress was 3.89 GPa. In addition, in the laminated film 2, since the sample for measurement after heating and cooling is cylindrical, the diameter of the cylindrical interior is measured as the radius of curvature.

In addition, the flatness of the laminated film 2 was evaluated in the same manner as in Example 1, and the diameter inside the tube obtained was described in Table 1 as the value of warpage.

3. Comparative Example 2 Biaxially stretched polyethylene naphthalate film (manufactured by Teijin Film Solutions (stock), Q65HWA, thickness 100 μm) with primer layers on both sides of a flexible substrate as a base layer , A width of 350 mm) on one side, as the organic layer forming composition used to form the organic layer, the coating composition 2 is applied by the gravure coating method (Nippon Chemical Co., Ltd., TOMAX FA-3298-1 ). After the coating film was dried at 100°C for 1 minute, a high-pressure mercury lamp was used ^{to irradiate ultraviolet rays under the condition of a cumulative light amount of 500 mJ/cm 2} to laminate an organic layer with a thickness of 4 μm to obtain an organic layer substrate. By the same method as in Example 1, on the surface area layer inorganic thin film layer (400 nm) on the organic layer side of the obtained organic layer substrate, a laminate film 3 containing substrate layer/organic layer/inorganic thin film layer was obtained. .

With respect to the obtained laminated film 3, the water vapor permeability was measured by the same method as in Example 1. As a result, it was 3.7×10 ^-3 g/(m ² ·day) under the conditions of a temperature of 40° C. and a humidity of 90% RH.

Use a biaxially stretched polyethylene naphthalate film (manufactured by Teijin Film Solutions Co., Ltd., Q65HWA, thickness 100 μm) with primer layers formed on both sides of a flexible substrate as the substrate layer. In Example 3, an organic layer formed of the coating composition 2 (Nippon Chemical Co., Ltd., TOMAX FA-3298-1) was laminated on the substrate to obtain a laminate for measuring the internal stress of the organic layer. In the laminate for measuring the internal stress of the organic layer corresponding to the laminate film 3, the internal stress of the organic layer was calculated in accordance with the same measurement method as in Example 1. The radius of curvature after heating to 130°C is 23.8 mm, and the internal stress is 0.16 GPa. In addition, the radius of curvature after heating to 180°C is 7.5 mm, and the internal stress is 0.51 GPa.

The laminated body for measuring the internal stress of the inorganic thin film layer corresponding to the laminated film 3 is the same as the laminated body for measuring the internal stress of the inorganic thin film layer of Example 1. The radius of curvature after heating to 130° C. is 17.0 mm, and the internal stress is 2.23 GPa. In addition, the radius of curvature after heating to 180°C was 9.8 mm, and the internal stress was 3.89 GPa.

In addition, the flatness of the laminated film 3 was evaluated in the same manner as in Example 1, and the average value of the distance (height) to the four corners obtained was described in Table 1 as the value of warpage.

[Table 1] Internal stress after heating at 130℃ Warpage Internal stress after heating at 180℃ Warpage Organic layer Inorganic thin film layer Laminated film Organic layer Inorganic thin film layer Laminated film (GPa) (GPa) (GPa) (Mm) (GPa) (GPa) (GPa) (Mm) Example 1 0.32 2.23 0.017 1.6 1.05 3.89 0.008 0.8 Comparative example 1 - 2.23 2.23 Φ34.0 (cylinder shape) - 3.89 3.89 Φ19.5 (tube shape) Comparative example 2 0.16 2.23 0.035 3.1 0.51 3.89 0.045 4.0

As shown in Table 1, the laminated film obtained in Example 1 has an inorganic thin film layer with high density and high internal stress. However, the internal stress of the organic layer is high, and it is heated at any temperature of 130°C and 180°C. In all cases, the effect of suppressing the warpage of the laminated film is excellent. On the other hand, in the laminated film obtained in Comparative Example 1 and Comparative Example 2 in which the organic layer was not contained or the internal stress of the organic layer was insufficient, large warpage of the laminated film occurred under any temperature condition.

1: Substrate layer 1-1: Flexible substrate 1-2: Primer 2: Organic layer 2-1: The first organic layer 2-2: Second organic layer 3: Inorganic thin film layer 4: Laminated film 10: Delivery roller 11: Conveying roller 12, 13: Film forming roller 14: Gas supply pipe 15: Power supply for plasma generation 16: Magnetic field generator 17: Winding roller 18: Base film

Fig. 1 is a schematic cross-sectional view showing an example of a laminated film of one aspect of the present invention. Fig. 2 is a schematic cross-sectional view showing another example of the laminated film of one aspect of the present invention. Fig. 3 is a schematic cross-sectional view showing another example of the laminated film of one aspect of the present invention. Fig. 4 is a schematic diagram showing a manufacturing apparatus of a laminated film used in Examples and Comparative Examples.

no.

Claims (11)

A laminate film, including in this order: a substrate layer including a flexible substrate, an organic layer, and an inorganic thin film layer, and the laminate including the substrate layer and the organic layer is heated at a temperature of 130° C. or higher for 30 Minutes later, the internal stress of the organic layer measured by leaving it to cool at 25°C for 10 minutes was 0.2 GPa or more. The laminated film according to claim 1, wherein the laminated body including the base material layer and the inorganic thin film layer directly laminated on the base material layer is heated at a temperature of 130°C or higher for 30 minutes and then placed at 25°C The internal stress of the inorganic thin film layer measured after cooling for 10 minutes is 2.0 GPa or more. The laminated film according to claim 1 or 2, wherein the laminated body including the base material layer, the organic layer, and the inorganic thin film layer is heated at a temperature of 130°C or higher for 30 minutes, and then heated at 25°C. The internal stress of the laminated film including the organic layer and the inorganic thin film layer measured when it is left to cool down for 10 minutes is 0.030 GPa or less. The laminated film according to any one of claims 1 to 3, wherein the laminated body including the base material layer and the organic layer is heated at 180°C for 30 minutes and then cooled at 25°C for 10 minutes. The internal stress of the organic layer measured is 0.8 GPa or more. The laminated film according to any one of claims 1 to 4, wherein a laminated body including the base material layer and the inorganic thin film layer directly laminated on the base material layer is heated at 180°C for 30 minutes The internal stress of the inorganic thin film layer measured at 25°C for 10 minutes is 3.0 GPa or more. The laminated film according to any one of claims 1 to 5, wherein the inorganic thin film layer is only present on one side of the substrate layer. The laminated film according to any one of claims 1 to 6, wherein the surface of the base layer opposite to the organic layer further includes an organic layer. The laminated film according to any one of claims 1 to 7, wherein the inorganic thin film layer is a layer formed by a plasma chemical vapor deposition method. The laminated film according to any one of claims 1 to 8, wherein the inorganic thin film layer contains silicon atoms, oxygen atoms, and carbon atoms. The laminated film according to claim 9, wherein the number of carbon atoms relative to the total number of silicon atoms, oxygen atoms, and carbon atoms contained in the inorganic thin film layer is 90% or more in the thickness direction of the inorganic thin film layer Change continuously in the area. The laminated film according to any one of claims 1 to 10, which has gas barrier properties.

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