JP2021169185A - Laminate, method for producing laminate, optical laminate and flexible display - Google Patents

Abstract

To provide a laminate that has high-level gas barrier properties despite its low-cost, simple structure, and also has high sterilization performance and high light transmittance.SOLUTION: A laminate has, on at least one side of a base material 1, A layer 2 containing silicon, a metal element and oxygen. The laminate has a spectral absorption rate of 15% or less at a wavelength 300 nm as measured with a spectrophotometer.SELECTED DRAWING: Figure 1

Description

The present invention relates to packaging materials for foods, pharmaceuticals and medical products that require high gas barrier properties, and laminates for protecting electronic components such as solar cells, electronic paper, and organic electroluminescence (EL) displays.

Organic electroluminescence (organic EL) elements, pharmaceuticals, etc. cause functional deterioration (deterioration of light emitting characteristics and decomposition of materials) when they come into contact with water vapor. It has been proposed to seal with an adhesive sheet) (Patent Documents 1 to 3).

The above patent document describes a plastic film having a moisture-proof property as a base material, and a plastic film in which an inorganic film such as a copper foil, an aluminum foil, and a silicon oxide film is laminated.

Japanese Unexamined Patent Publication No. 2013-54985 Japanese Unexamined Patent Publication No. 2015-122170 Japanese Unexamined Patent Publication No. 2016-186042

However, the plastic film of the above patent document has a problem that the light transmittance in the ultraviolet region is low, and when it is used as a packaging material for medicines and medical treatments, the sterilization / sterilization effect using ultraviolet rays becomes poor. rice field.

Further, an inorganic film made of silicon oxide or the like is well known as a moisture-proof layer, but the thickness of the inorganic film made of silicon oxide needs to be increased in order to sufficiently reduce the water vapor transmittance. There are problems that cracks are likely to occur and the cost is high. From the above viewpoint, none of the above-mentioned patent documents simultaneously satisfy bactericidal properties, low water vapor permeability, low crack generation, and low cost.

An object of the present invention is to provide a laminate having a high gas barrier property, a high sterilization performance, and a high light transmittance even with a low cost and a simple configuration in view of the background of the prior art.

The present invention employs the following means in order to solve such a problem. That is, it is as follows.

(1) A laminate having a layer A containing silicon, a metal element and oxygen on at least one surface of a base material, and having a spectral absorption rate of 15% or less at a wavelength of 300 nm measured by a spectrophotometer.

According to the present invention, it is possible to provide a laminate having a high gas barrier property and a high sterilizing performance even with a low cost and a simple structure.

It is sectional drawing which showed an example of the laminated body of this invention. It is sectional drawing which showed an example of the laminated body of this invention. It is the schematic which shows typically the winding type electron beam vapor deposition apparatus for manufacturing the laminated body of this invention. It is a figure which shows typically the material arrangement for manufacturing the laminated body of this invention from the upper part. It is a figure which shows typically the material arrangement for manufacturing the laminated body of this invention from the side. It is the schematic which shows typically the winding type sputtering apparatus. It is sectional drawing which showed an example of the optical laminated body of this invention. It is sectional drawing which showed an example of the optical laminated body of this invention.

The details of the present invention will be described below.

A preferred embodiment of the laminate of the present invention has an A layer containing silicon, a metal element and oxygen on at least one surface of the base material, and has a spectral absorption rate of 15% or less at a wavelength of 300 nm measured by a spectrophotometer. It is a laminate.

With such an embodiment, it is possible to provide a laminate having a high gas barrier property, a high sterilization performance, and a high light transmittance even with a low cost and a simple configuration. In the present invention, the metal element is a metal element other than silicon.

The metal element contained in the layer A is preferably at least one selected from the group consisting of magnesium, calcium, aluminum, and gallium from the viewpoint of gas barrier properties and optical properties, and at least one selected from magnesium and calcium. Is more preferable, and magnesium is further preferable from the viewpoint of film forming property.

The morphology of silicon and metal elements contained in layer A is not limited to oxides, nitrides, nitride nitrides, carbides, etc., but from the viewpoint of forming an amorphous film and gas barrier properties, oxides and nitrides , Preferably contained as at least one compound selected from the group consisting of oxides, nitrides and carbides, and contained as at least one compound selected from the group consisting of oxides, nitrides and nitrides. Is more preferable. Among them, it is more preferable to contain magnesium oxide and silicon oxide. As long as the layer A contains silicon, a metal element, and oxygen, other inorganic compounds may be contained.

The fact that layer A contains oxygen means that when evaluated by X-ray photoelectron spectroscopy (XPS), _{the equivalent thickness of the SiO 2} film is from the outermost surface of layer A to the position where the thickness of layer A is halved. It means that the content ratio of oxygen atoms is 10.0 atm% or more at the place where argon ion etching is performed. From the viewpoint of transparency and density, the oxygen atom content ratio is preferably 20.0 atm% or more, and more preferably 40.0 atm% or more. The outermost surface of the A layer refers to the surface opposite to the surface where the A layer is closest to the base material.

In the present invention, it is preferable that the spectral absorption rate at a wavelength of 300 nm measured by a spectrophotometer is 15% or less. When the spectral absorption rate at a wavelength of 300 nm is 15% or less, the transmittance in the ultraviolet region becomes good. From the viewpoint of enhancing the bactericidal and sterilizing effect of the internal substance sealed with the laminate, the spectral absorption rate is preferably 15% or less, more preferably 10% or less, and 8%. The following is more preferable.

In the present invention, the spectral transmittance measured by the spectrophotometer is preferably 60% or more at a wavelength of 300 nm, 85% or more at a wavelength of 550 nm, and 80% or more at a wavelength of 780 nm. By satisfying the above, the transmittance of ultraviolet rays becomes good, and the sterilizing / sterilizing effect of the internal substance sealed with the laminate becomes good.

From the viewpoint of improving the light extraction efficiency when the laminate of the present invention is used for an organic element such as a flexible display, the spectral transmittance is 70% or more at a wavelength of 300 nm, 88% or more at a wavelength of 550 nm, and 85% or more at a wavelength of 780 nm. The spectral transmittance is more preferably 80% or more at a wavelength of 300 nm, 90% or more at a wavelength of 550 nm, and 90% or more at a wavelength of 780 nm. In particular, it is preferable that the spectral transmittance at a wavelength of 550 nm and a wavelength of 780 nm is good as the transmittance in the visible light region.

The A layer of the present invention has an average lifetime of 0 as measured by the positron beam method (measurement of positron annihilation lifetime for thin films) (see "Science of positron measurement" (Japan Radioisotope Association), Chapter I, Section 1, Section V, Section 2). It is preferably .935 ns or less. The positron beam method is one of the methods for measuring the positron annihilation lifetime, and measures the time (several hundred ps to several tens of ns order) from when a positron is incident on a sample until it disappears. This is a non-destructive evaluation method for information on the size, number concentration, and size distribution of pores of 1 to 10 nm. ^{The point that a positron beam is used instead of a radioisotope (22} Na) as a positron radiation source is significantly different from the usual positron annihilation method, and it is possible to measure a thin film with a thickness of several hundred nm formed on a silicon or quartz substrate. This is a possible method. From the obtained measured values, the average pore radius and the number concentration of pores can be obtained by the nonlinear least squares program POSITRONFIT. Those corresponding to sub-nm order pores and basic skeletons can be obtained by analyzing the average lifetimes of the third component and the fourth component.

Here, the third component means the average life obtained by selecting the analysis for the three components as the measurement condition of the average life by the positron beam method, and the fourth component means the measurement of the average life by the positron beam method. It refers to the average life obtained by selecting the analysis for 4 components as a condition. When the analysis is performed by POSITRONFIT, the number of components of POSITRONFIT is determined from the number of peaks obtained by the pore radius distribution curve calculated by using the distribution analysis program CONTIN based on the inverse Laplace transform method. It is judged that the analysis is valid when the average pore radius calculated from POSITRONFIT and the peak position of the pore radius distribution curve of CONTIN match. The average life of the third component as used in the present invention refers to the average life of the third component.

When the average life is 0.935 ns or less, the layer A is dense and high gas barrier properties can be exhibited. From the viewpoint of gas barrier property, the average lifetime measured by the positron beam method is preferably 0.912 ns or less, more preferably 0.863 ns or less. The lower limit of the average life is not particularly limited, but is preferably 0.542 ns or more. When the average life is 0.542 ns or more, the flexibility can be made sufficient.

In order for the average lifetime measured by the positron beam method of layer A specified in the present invention to be 0.935 ns or less, for example, a composite oxide film is placed on a substrate having an arithmetic mean roughness Ra of 3.0 nm or less. Is achieved by densely forming with a suitable composition ratio. The term "densely formed" as used herein means a state in which each oxide is mixed at the atomic level to form a dense network.

In the layer A of the present invention, the half width of the peak of oxygen atoms (O1s) measured by X-ray photoelectron spectroscopy is preferably 3.25 eV or less. FWHM, if the maximum value of the peak was F _max, the intensity of the peak refers to the peak width when the F _{max / 2.} The narrower the half width of the peak of O1s, the more uniformly bonded network structure is formed, so that a dense film is likely to be formed. From the viewpoint of bond uniformity and barrier property, 3.00 eV or less is more preferable, and 2.75 eV or less is further preferable. The lower limit is not particularly limited, but is preferably 1.65 eV or higher.

It is preferable that the layer A in the present invention is a laminated body having a refractive index of 2.0 or less. Refractive index refers to the refractive index at a wavelength of 550 nm. When the refractive index of the A layer is 2.0 or less, reflection and absorption in the ultraviolet-visible region are reduced, and transparency can be improved. From the same viewpoint, the refractive index of the A layer is preferably 1.90 or less, and more preferably 1.80 or less.

The A layer of the present invention contains magnesium oxide and silicon oxide, and has a magnesium (Mg) atomic concentration of 5 to 50 (atm%) and a silicon (Si) atomic concentration measured by (XPS) by X-ray photoelectron spectroscopy. It is preferably a laminate having 2 to 30 (atm%) and an oxygen (O) atom concentration of 45 to 70 (atm%). In addition, ~ represents the above and the following.

The composition ratio of layer A can be measured by X-ray photoelectron spectroscopy (XPS). By argon ion etching, the A layer is removed to a position where the thickness of the A layer is halved, and the content ratio of each element is measured.

The magnesium atom concentration is preferably 50 atm% or less, and / or the silicon atom concentration is preferably 2 atm% or more from the viewpoint of preventing the A layer from becoming a crystal layer and easily cracking. It is preferable that the magnesium atom concentration is 5 atm% or more and / or the silicon atom concentration is 30 atm% or less from the viewpoint of making the ratio of silicate bonds in the layer A sufficient, improving the denseness and exhibiting gas barrier properties. .. The silicate bond is a bond between silicon (Si) and a metal (M) via oxygen (O), and can be described as Si—OM. The oxygen atom concentration is preferably 45 atm% or more from the viewpoint of suppressing the decrease in light transmittance due to insufficient oxidation of magnesium and silicon. Further, it is preferable that the oxygen atom concentration is 70 atm% or less from the viewpoint of suppressing excessive intake of oxygen and increasing voids and defects and exhibiting gas barrier properties.

From the above viewpoint, the composition of the A layer of the present invention has a magnesium atom concentration of 8 to 35 (atm%), a silicon atom concentration of 6 to 25 (atm%), and an oxygen atom concentration of 50 to 65 (atm%). More preferably, the magnesium atom concentration is 15 to 30 (atm%), the silicon atom concentration is 8 to 20 (atm%), and the oxygen atom concentration is 50 to 65 (atm%).

Regarding the composition of the A layer of the present invention, the atomic concentration (atm%) ratio Mg / (Mg + Si) of magnesium (Mg) atom and silicon (Si) atom is preferably 0.45 to 0.80. When the atomic concentration (atm%) ratio is Mg / (Mg + Si) ≥ 0.45, the ratio of silicate bonds in the layer A can be made sufficient, the density can be improved, and gas barrier properties can be exhibited. can. When the atomic concentration (atm%) ratio is Mg / (Mg + Si) ≦ 0.80, it is possible to suppress the presence of a crystal portion in the A layer and prevent cracks from easily forming. From the same viewpoint, the atomic concentration (atm%) ratio Mg / (Mg + Si) is more preferably 0.50 to 0.78, and even more preferably 0.55 to 0.76.

The thickness of layer A in the present invention can be obtained by evaluation by a transmission electron microscope (TEM) and an X-ray reflectivity method (XRR method). The thickness of the A layer is preferably 5 nm or more, more preferably 10 nm or more. If the thickness is thinner than 5 nm, a region that is not formed as a layer may occur, and sufficient gas barrier properties may not be ensured. The thickness of the A layer is preferably 500 nm or less, more preferably 300 nm or less. If the thickness of the layer A is thicker than 500 nm, cracks may easily occur and the bending resistance and stretchability may decrease.

The laminate of the present invention preferably has a water vapor transmission rate of ^{less than 5.0 × 10-2} g / m ² / day. From the viewpoint of being used in organic devices and flexible display applications that require high gas barrier properties, the water vapor transmission rate of the laminate of the present invention is more preferably less than ^{1.0 × 10-2} g / m ^{2 / day.} .. The lower limit of the water vapor transmission rate is not particularly limited, but if the film becomes denser than necessary, cracks are likely to occur. Therefore, the water vapor transmission rate of the laminate of the present invention is 1.0 × 10 ^-4 g / m ² /. It is preferably day or more.

[Manufacturing method of layer A]
The method for forming the A layer is not particularly limited, and is a vacuum deposition method, a sputtering method, a reactive sputtering method, a molecular beam epitaxy method, a cluster ion beam method, an ion plating method, an atomic layer deposition method, a plasma polymerization method, and a large method. A pressure plasma polymerization method, a plasma CVD method, a laser CVD method, a thermal CVD method, a coating method and the like can be used. From the viewpoint of manufacturing cost, environmental load, gas barrier property, etc., it is preferable to use the vacuum deposition method.

An example of the method of forming the A layer by the take-up type vapor deposition apparatus (FIG. 3) is shown. A compound thin film of materials B and C is provided as a layer A on the surface of the base material 1 by an electron beam (EB) vapor deposition method. First, as the vapor deposition material, granular material B and material C having a size of about 2 to 5 mm are alternately arranged as shown in FIGS. 4 and 5. The area ratio when the layers are alternately arranged is arranged according to the target film composition of the A layer, the EB irradiation method, and the like. At that time, the width of each material to be arranged is preferably 10 to 100 mm. If it is larger than 100 mm, the composition ratio and the film quality in the width direction of the materials B and C tend to vary greatly. If it is less than 10 mm, workability when arranging the material may decrease. It is more preferably 20 to 80 mm from the viewpoint of composition ratio in the width direction, variation in film quality, workability, and the like. Further, the vapor deposition material is not limited to granules, and a molded body such as a square or tablet may be used. Further, a composite material obtained by pre-sintering the material B and the material C may be used. If the vapor-deposited material absorbs moisture, the moisture in the material may be taken into the layer A, and the desired film composition and physical properties may not be obtained. Therefore, the material may be dehydrated by heating before use. preferable. In the take-up chamber 4, the unwinding roll 5 is set so that the surface of the base material 1 on which the A layer is provided faces the hearth liner 10, and the unwinding roll is unwound via the guide rolls 6, 7, and 8. , Pass through the main drum 9. Next, the pressure inside the vapor deposition apparatus 60 is reduced by a vacuum pump ^{to obtain 5.0 × 10 -3} Pa or less. The ultimate vacuum ^{is preferably 5.0 × 10 -3} Pa or less. If the ultimate vacuum degree is ^{larger than 5.0 × 10 -3} Pa, residual gas may be taken into the A layer, and the desired film composition and physical properties may not be obtained. The temperature of the main drum 9 is set to −15 ° C. as an example. From the viewpoint of preventing heat loss of the base material, the temperature is preferably 20 ° C. or lower, more preferably 0 ° C. or lower. Next, one electron gun (hereinafter, EB gun) 12 is used as a heating source to uniformly heat the surfaces of the materials B and C. The EB gun forms an A layer on the surface of the base material 1 by EB vapor deposition at an acceleration voltage of 10 kV. The thickness of the A layer is adjusted by the acceleration current of the EB gun and the film transport speed. After that, it is wound on the winding roll 17 via the guide rolls 14, 15 and 16.

[Base material]
The base material used in the present invention preferably has a film form from the viewpoint of ensuring flexibility.

Examples of the material of the base material used in the present invention include polyester, acrylic, polycarbonate, cellulose ester, olefin, cyclic olefin, polypropylene, polyethylene and the like. In order to satisfy the aspect of the present invention, it is preferable to use a base material having low UV absorption. Specifically, it is preferable that the spectral absorption rate at a wavelength of 300 nm measured by the spectrophotometer of the substrate used in the present invention is 15% or less. From the same viewpoint, it is more preferable that the spectral absorption rate at a wavelength of 300 nm is 10% or less. From such a viewpoint, the base material is preferably olefin, cyclic olefin, polypropylene, or polyethylene. Cyclic olefins are more preferable from the viewpoint of gas barrier properties and use in display applications.

The cyclic olefin resin film is a resin film containing a cyclic olefin resin (COP) or a cyclic olefin copolymer resin (COC) as a main component. Here, the main component means that the composition ratio of COP or COC among the resin components constituting the resin film is 50% by mass or more, preferably 60% by mass or more, more preferably. Is 80% by mass or more, more preferably 90% by mass or more, and particularly preferably 95% by mass or more.

The surface of the base material on the side forming the A layer is composed of corona treatment, plasma treatment, ultraviolet treatment, ion bombard treatment, solvent treatment, organic or inorganic substances, or a mixture thereof in order to improve adhesion and smoothness. Pretreatment such as formation treatment of an anchor coat layer may be performed. Further, on the opposite side of the side forming the A layer, a coating layer of an organic substance, an inorganic substance, or a mixture thereof is laminated for the purpose of improving the slipperiness when winding the base material and the scratch resistance of the base material. You may.

The thickness of the base material used in the present invention is not particularly limited, but is preferably 500 μm or less from the viewpoint of ensuring flexibility, and preferably 5 μm or more from the viewpoint of ensuring strength against tension and impact. Further, the thickness of the base material is more preferably 10 μm or more and 150 μm or less from the viewpoint of ease of processing and handling of the film.

[Anchor coat layer]
The laminate of the present invention may have an anchor coat layer. It is preferable that one surface of the anchor coat layer is in contact with the base material and the other surface is in contact with the A layer. Further, it is more preferable that the anchor coat layer contains a structure obtained by cross-linking a polyurethane compound having an aromatic ring structure. If there are defects such as protrusions and scratches on the base material, pinholes and cracks may also occur in the A layer laminated on the base material starting from the above defects, and the gas barrier property and bending resistance may be impaired. Therefore, it is preferable to provide an anchor coat layer. Further, even when the difference in thermal dimensional stability between the base material and the layer A is large, the gas barrier property and the flexibility may be lowered, so that an anchor coat layer may be provided.

The thickness of the anchor coat layer is preferably 200 nm or more and 4,000 nm or less, more preferably 300 nm or more and 2,000 nm or less, and further preferably 500 nm or more and 1,000 nm or less. If the thickness of the anchor coat layer is thinner than 200 nm, it may not be possible to suppress the adverse effects of defects such as protrusions and scratches existing on the base material. When the thickness of the anchor coat layer is thicker than 4,000 nm, the smoothness of the anchor coat layer is lowered, the uneven shape of the surface of the A layer laminated on the anchor coat layer is also increased, and the vapor deposition film to be laminated becomes dense. It is difficult, and it may be difficult to obtain the effect of improving the gas barrier property. Here, the thickness of the anchor coat layer can be measured from a cross-sectional observation image by a transmission electron microscope (TEM).

The arithmetic average roughness Ra of the anchor coat layer is preferably 10 nm or less. When Ra is set to 10 nm or less, a homogeneous layer A is easily formed on the anchor coat layer, and the reproducibility of gas barrier properties is improved, which is preferable. When Ra on the surface of the anchor coat layer is larger than 10 nm, the uneven shape of the surface of the A layer on the anchor coat layer also becomes large, the vapor-deposited film is difficult to become dense, and the effect of improving the gas barrier property may be difficult to obtain. In addition, cracks are likely to occur due to stress concentration in a portion having many irregularities, which may cause a decrease in reproducibility of gas barrier properties. Therefore, in the present invention, the Ra of the anchor coat layer is preferably 10 nm or less, more preferably 5 nm or less. Ra of the anchor coat layer in the present invention can be measured using an atomic force microscope (AFM) or the like.

When the anchor coat layer is applied to the laminate of the present invention, it is applied by, for example, a reverse coating method, a gravure coating method, a rod coating method, a bar coating method, a die coating method, a spray coating method, a spin coating method, or the like. Is preferable.

[Optical laminate]
The optical laminate of the present invention is preferably an optical laminate including a laminate, a λ / 4 retardation film, and a linear polarizer layer.

A λ / 4 retardation film is a film that functions as a λ / 4 plate, that is, gives a phase difference of π / 2 (= λ / 4) between the phase-advancing axis and the slow-phase axis with respect to incident light. be. The in-plane retardation Re (550) of the λ / 4 retardation film at a wavelength of 550 nm can be 100 nm to 180 nm, preferably 110 nm to 170 nm, and more preferably 120 nm to 160 nm. ..

The thickness of the λ / 4 retardation film can be set to best function as a λ / 4 plate. That is, the thickness can be set so as to obtain the desired in-plane phase difference. The thickness is preferably 1 μm to 80 μm, more preferably 10 μm to 60 μm, and even more preferably 30 μm to 50 μm.

Materials for the λ / 4 retardation film include cellulose-based resin, polycarbonate-based resin, polyarylate-based resin, polyester-based resin, acrylic-based resin, polysulfone, polyether sulfone, cyclic olefin polymer, and orientation-solidified layer of liquid crystal compound. Can be exemplified. Among them, a polycarbonate-based resin film is preferably used because it is inexpensive and a uniform film is available. As the film forming method, a solvent casting method or a precision extrusion method capable of reducing the residual stress of the film can be used, but the solvent casting method is preferably used from the viewpoint of uniformity. The stretching method is not particularly limited, and can be applied to roll-to-roll longitudinal uniaxial stretching and tenter horizontal uniaxial stretching in which uniform optical characteristics can be obtained.

The λ / 4 retardation film may exhibit an inverse wavelength dispersibility in which the retardation value increases according to the wavelength of the measurement light, and a positive wavelength dispersion characteristic in which the retardation value decreases according to the wavelength of the measurement light. It may be shown, or may show a flat wavelength dispersion characteristic in which the phase difference value hardly changes with the wavelength of the measurement light.

When the λ / 4 retardation film exhibits anti-wavelength dispersibility, there is an effect that the viewing angle compensation is improved. In this case, when the in-plane retardation of the λ / 4 retardation film at the wavelength λ is expressed as Re (λ), Re (450) / Re (550) <1 and Re (650) / Re (550). > 1 can be satisfied.

The linearly polarized light layer of the present invention is a film having a linearly polarized light function. Such a linear polarizer layer is, for example, a stretched film on which a dye having absorption anisotropy is adsorbed, or a film coated with a dye having absorption anisotropy. The dye having absorption anisotropy is, for example, a dichroic dye such as iodine, and the base material is, for example, a polyvinyl alcohol-based resin.

One example of a method for producing a stretched film in which a dye having absorption anisotropy is adsorbed is a step of uniaxially stretching a polyvinyl alcohol-based resin film, and dyeing the polyvinyl alcohol-based resin film with a bicolor dye to obtain the two colors. At least one of the polarizers produced through a step of adsorbing a sex dye, a step of treating a polyvinyl alcohol-based resin film on which a bicolor dye is adsorbed with a boric acid aqueous solution, and a step of washing with water after treatment with a boric acid aqueous solution. It is produced by sandwiching the surface with a transparent protective film via an adhesive.

The thickness of the linear polarizing element layer is preferably 5 to 40 μm, more preferably 5 to 30 μm. Further, from the viewpoint of protecting the linear polarizer layer, it is preferable that one side or both sides has a protective film such as triacetyl cellulose.

As a configuration for obtaining circularly polarized light, the λ / 4 retardation film and the linear polarizing element layer are provided so that the phase-advancing axis of the λ / 4 retardation film and the transmission axis of the linear polarizing element layer intersect at 45 °. It is preferable to arrange it.

In the optical laminate as shown in FIG. 7, in addition to the laminate having gas barrier properties, a function of converting linearly polarized light into circularly polarized light can be provided by a λ / 4 retardation film and a linearly polarizing element layer.

The optical laminate of the present invention is an optical laminate including a laminate and a λ / 2 retardation film. The λ / 2 retardation film is a film that functions as a λ / 2 plate, that is, gives a phase difference of π (= λ / 2) between the phase-advancing axis and the slow-phase axis with respect to the incident light. The in-plane retardation Re (550) of the λ / 2 retardation film at a wavelength of 550 nm is preferably 220 nm to 320 nm, more preferably 240 nm to 300 nm, and even more preferably 250 nm to 280 nm.

The thickness of the λ / 2 retardation film can be set to best function as a λ / 2 plate. That is, the thickness can be set so as to obtain the desired in-plane phase difference. Specifically, the thickness is preferably 1 μm to 80 μm, more preferably 10 μm to 60 μm, and even more preferably 30 to 50 μm.

The material and manufacturing method of the λ / 2 retardation film can be the same as that of the λ / 4 retardation film.

In the optical laminate as shown in FIG. 8, the inverse wavelength dispersibility can be imparted to the optical laminate by providing the λ / 2 retardation film at a predetermined angle.

[Encapsulating resin layer]
The sealing resin layer in the present invention is a layer containing at least a sealing resin. Such a sealing resin contains at least one resin selected from the group consisting of rubber-based polymers, polyolefin-based polymers, styrene-based thermoplastic elastomers, (meth) acrylic-based polymers, polyester-based polymers, and silicone-based polymers. Is preferable.

Among the sealing resins, it is preferable to contain at least one resin selected from the group consisting of rubber-based polymers, polyolefin-based polymers and styrene-based thermoplastic elastomers from the viewpoint of reducing the water vapor permeability.

The rubber-based polymer has rubber elasticity such as natural rubber or synthetic rubber. For example, natural rubber, butadiene homopolymer (butadiene rubber), chloroprene homopolymer (chloroprene rubber), isoprene homopolymer, acrylonitrile-butadiene copolymer (nitrile rubber), ethylene-propylene-non-conjugated diene ternary common weight. Combined, isobutylene-based polymers, or modified ones thereof can be mentioned. Among the rubber-based polymers, isobutylene-based polymers are preferable.

Isobutylene-based polymers refer to polymers having isobutylene-derived repeating units in the main chain and / or side chains. The content ratio of the repeating unit derived from isobutylene is preferably 50% by mass or more, more preferably 60% by mass or more, and particularly preferably 70% by mass or more. The upper limit content ratio is about 99% by mass.

Examples of isobutylene-based polymers include isobutylene homopolymers (polyisobutylene), isobutylene-isoprene copolymers (butyl rubber), isobutylene-n butene copolymers, isobutylene-butadiene copolymers, and bromination or bromination of these polymers. Examples thereof include a halogenated polymer obtained by chlorination. Among these, an isobutylene-isoprene copolymer (butyl rubber) is preferable.

The number average molecular weight (Mn) of the rubber-based polymer is preferably in the range of 50,000 to 3 million, more preferably in the range of 100,000 to 2 million, and particularly preferably in the range of 150,000 to 1.5 million. When the number average molecular weight (Mn) of the rubber-based polymer is within the above range, a sealing film having a low water vapor transmittance can be obtained.

The number average molecular weight (Mn) of the rubber-based polymer can be determined as a standard polystyrene-equivalent value by performing gel permeation chromatography using tetrahydrofuran as a solvent.

The polyolefin-based polymer is a polymer having a repeating unit derived from an olefin-based monomer in the main chain and / or side chain, and examples thereof include an olefin-based monomer homopolymer, a copolymer, or a modified product thereof.

Examples of such olefin-based monomers include α-olefins having 3 to 20 carbon atoms such as propylene, 1-butene, 4-methyl-1-pentene, 3-methyl-1-butene, 1-hexene and 1-octene, or cyclobutene. , Tetracyclododecene, norbornene and other cyclic olefins having 4 to 20 carbon atoms.

The styrene-based thermoplastic elastomer is a polymer having a repeating unit derived from styrene or a modified polymer. For example, a styrene-butadiene-styrene block copolymer and a hydrogen additive of the copolymer, a styrene-ethylene-butene-styrene block copolymer, a styrene-isoprene-styrene block copolymer, and hydrogen of the copolymer. Additives styrene-ethylene-propylene-styrene block copolymer, styrene-butadiene copolymer (styrene butadiene rubber), styrene-isoprene copolymer, styrene-isobutyrene block copolymer, styrene-isobutylene-styrene tri Block copolymers and the like can be mentioned.

A (meth) acrylic polymer is a polymer having a repeating unit derived from a (meth) acrylic monomer in the main chain and / or side chain. For example, homopolymers or copolymers of (meth) acrylic monomers, or modified ones thereof can be mentioned. Here, "(meth) acrylic" means acrylic or methacryl.

The content ratio of the repeating unit derived from the (meth) acrylic monomer in the (meth) acrylic polymer is preferably 50% by mass or more, more preferably 60% by mass or more, and particularly preferably 70 or more. The upper limit content ratio is about 99% by mass.

Examples of the (meth) acrylic monomer include alkyls such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate. Examples thereof include (meth) acrylic acid esters having 1 to 20 carbon atoms in the group, and (meth) acrylic monomers having reactive functional groups such as (meth) acrylic acid and hydroxymethyl (meth) acrylate.

The polyester-based polymer is a polymer obtained by polycondensation of a polyvalent carboxylic acid and a polyol, or a modified product thereof. Examples of such polyvalent carboxylic acids include phthalic acid, isophthalic acid, orthophthalic acid, succinic acid, adipic acid, sebacic acid, cyclohexanedicarboxylic acid, trimellitic acid and the like. Examples of the polyol include aliphatic alcohols such as ethylene glycol and propylene glycol, and polyether polyols such as polyethylene glycol and polypropylene glycol.

Silicone-based polymers are polymers having a (poly) siloxane structure in the main chain and / or side chains, or modified thereof. Examples of such silicone-based polymers include dimethylpolysiloxane, methylphenylpolysiloxane, and methylhydrogenpolysiloxane.

As the sealing resin layer, the above-mentioned sealing resins can be used alone or in combination of two or more. The content of the sealing resin in the sealing resin layer is preferably in the range of 25 to 90% by mass, more preferably in the range of 30 to 80% by mass, and more preferably 40, based on 100% by mass of the total solid content of the sealing resin layer. The range of ~ 70% by mass is particularly preferable.

The sealing resin layer preferably further contains a tackifier resin. Examples of such tackifier resins include alicyclic petroleum resins, alicyclic hydrogenated petroleum resins, aromatic petroleum resins, and rosin resins. Among these tackifier resins, alicyclic petroleum resins are preferable, and among alicyclic hydrogenated petroleum resins, hydrogenated terpene resins, hydrogenated ester resins, hydrogenated C5 petroleum resins, C9 A hydrogenated resin of a petroleum resin is preferable.

The content of the tackifier resin in the sealing resin layer is preferably in the range of 5 to 60% by mass, more preferably in the range of 10 to 50% by mass, based on 100% by mass of the total solid content of the sealing resin layer. The range of ~ 40% by mass is particularly preferable.

The mass ratio of the sealing resin to the tackifying resin (sealing resin / tackifying resin) is preferably 20/80 to 95/5, and more preferably 30/70 to 90/10.

The sealing resin layer may have a crosslinked structure. By forming the crosslinked structure, the sealing resin layer has a sufficient cohesive force, is excellent in adhesiveness, and has a lower water vapor permeability.

When forming a crosslinked structure in the sealing resin layer, a known crosslinked structure forming method such as an adhesive can be used. For example, when a sealing resin having a hydroxyl group or a carboxyl group is used, a crosslinked structure is formed by using a crosslinking agent such as an isocyanate-based crosslinking agent, an epoxy-based crosslinking agent, an aziridine-based crosslinking agent, or a metal chelate-based crosslinking agent. Can be done.

The sealing resin layer preferably further contains an epoxy resin. Examples of such epoxy resins include bisphenol A type epoxy resin, bisphenol F type epoxy resin, biphenyl type epoxy resin, biphenyl aralkyl type epoxy resin, naphthol type epoxy resin, naphthalene type epoxy resin, phosphorus-containing epoxy resin, and aromatic glycidyl amine. Type epoxy resin, alicyclic epoxy resin, aliphatic chain epoxy resin, phenol novolac type epoxy resin, phenol aralkyl type epoxy resin, cresol novolac type epoxy resin, bisphenol A novolac type epoxy resin, epoxy resin having dicyclopentadiene structure , Epoxy resin having a butadiene structure, diglycidyl etherified product of bisphenol, diglycidyl etherified product of naphthalene diol, glycidyl etherified product of phenols, diglycidyl etherified product of alcohols and the like.

Among the above epoxy resins, from the viewpoint of improving heat resistance, bisphenol A type epoxy resin, bisphenol F type epoxy resin, biphenyl aralkyl type epoxy resin, aromatic glycidylamine type epoxy resin, phenol novolac type epoxy resin, phenol aralkyl type Epoxy resins and epoxy resins having a dicyclopentadiene structure are preferably used.

The content of the epoxy resin in the sealing resin layer is preferably in the range of 0.1 to 20% by mass, more preferably in the range of 1 to 15% by mass, based on 100% by mass of the total solid content of the sealing resin layer. The range of 2 to 10% by mass is particularly preferable.

The sealing resin layer preferably further contains an inorganic filler. Examples of such inorganic fillers include silica, alumina, barium sulfate, talc, clay, mica powder, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, boron nitride, aluminum borate, barium titanate, and titanic acid. Examples thereof include strontium, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, barium titanate, and calcium zirconate. Among these, talc is particularly preferably used from the viewpoint of improving moisture permeability.

In addition, the sealing resin layer can further contain a hygroscopic metal oxide. Here, the "hygroscopic metal oxide" means a metal oxide having an ability to absorb water and chemically reacting with the absorbed water to become a hydroxide. Specifically, it is one selected from calcium oxide, magnesium oxide, strontium oxide, aluminum oxide, barium oxide and the like, or a mixture or solid solution of two or more. Among the above hygroscopic metal oxides, calcium oxide and magnesium oxide are preferable from the viewpoints of high hygroscopicity, cost, and stability of raw materials. In addition, the sealing resin layer can further contain an ultraviolet absorber, an antioxidant, an antistatic agent, a plasticizer, a filler, a flame retardant, a rust preventive, and the like.

The thickness of the sealing resin layer is preferably in the range of 5 to 150 μm, more preferably in the range of 10 to 100 μm, and particularly preferably in the range of 20 to 80 μm. Further, the sealing resin layer preferably has a water vapor transmittance of 40 g / m ² / day or less, ^{more preferably 30 g / m 2} / day or less, and 20 g / m ² / day or less. Is particularly preferable.

The sealing resin layer may be formed by applying it on the A layer of the laminated body, or once the sealing resin layer is applied to the release film, the surface of the sealing resin layer and the A layer of the laminated body are formed. You may stick it to the surface.

[Other layers]
An overcoat layer is formed on the outermost surface of the laminate of the present invention, that is, on the layer A, for the purpose of improving scratch resistance, chemical resistance, printability, etc. within a range in which the gas barrier property is not deteriorated. Alternatively, it may have a laminated structure in which a sealing resin layer or a film made of an organic polymer compound for bonding to an element or the like is laminated. Further, a low refractive index layer may be formed to improve the optical characteristics. The outermost surface here means the surface of the A layer after the A layer is laminated on the base material.

[Use of laminate]
Since the laminate of the present invention has high UV transparency and gas barrier properties, it can be suitably used as a packaging material for pharmaceutical products that require bactericidal properties. Further, from the viewpoint of achieving both high light transmittance and gas barrier property, it can be suitably used for organic elements such as organic EL elements and organic phototube elements. In addition, it can be suitably used for a flexible display described later.

[Flexible display]
A preferred embodiment of the flexible display of the present invention is a flexible display using the above-mentioned laminated body or optical laminated body. According to this aspect, the durability of the flexible display is high, and the appearance quality and color characteristics can be excellent.

Hereinafter, the present invention will be specifically described based on examples. However, the present invention is not limited to the following examples.

[Evaluation method]
(1) Thickness of each layer A sample for cross-section observation is used by the FIB method using a microsampling system (FB-2000A manufactured by Hitachi, Ltd.) (Specifically, "Polymer Surface Processing" (written by Akira Iwamori) p. . 118-119). With a transmission electron microscope (H-9000UHRII manufactured by Hitachi, Ltd.), the cross section of the observation sample was observed at an acceleration voltage of 300 kV at a magnification of 200,000, and the thickness of the A layer of the laminated body was measured.

(2) Composition of layer A The composition of layer A of the laminated body was analyzed by X-ray photoelectron spectroscopy (XPS). The content ratio of each element was measured at a position where etching was performed from the surface of the A layer to a position where the thickness of the A layer was halved to a thickness _{equivalent to SiO 2 by argon ion etching.} Peaks for use in analysis, magnesium 2s, silicon 2p, calcium _{2p 3/2,} zinc _{2p 3/2,} aluminum 2p, oxygen was 1s.

The XPS measurement conditions were as follows.
-Device: PHI5000 VersaProbeII (manufactured by ULVAC-PHI)
-Excited X-ray: monochromatic AlKα
・ Analysis range: φ100 μm
・ Photoelectron escape angle: 45 °
-Ar ion etching: 2.0 kV, raster size 2 x 2
The half width of the oxygen atom (O1s) peak was set to a value calculated by the analysis software Multipak attached to the measuring device.

(3) Moisture vapor transmission rate (g / m ² / day)
The water vapor transmission rate of the laminate is a water vapor transmission rate measuring device (model name: "DELTAPERM" (registered trademark) manufactured by Technolox, UK, under the conditions of a temperature of 40 ° C., a humidity of 90% RH, and a measurement area of 50 cm ^2. )) Was measured. The number of samples was 2 samples per level. The data obtained by measuring the two samples were averaged to two significant figures, the average value at the relevant level was obtained, and the value was defined as the water vapor transmission rate (g / m ² / day).

(4) Positron lifetime and pore radius distribution The positron lifetime and pore radius distribution were measured by the positron beam method (the positron annihilation lifetime measurement method for thin films). The sample to be measured was attached to a 15 mm × 15 mm square Si wafer and evacuated at room temperature, and then the measurement was performed. The measurement conditions are as follows.
・ Equipment: Small positron beam generator PALS200A manufactured by Fuji Invac
- positron source: ²² Na based positron beam-gamma ray detector: BaF ₂ manufactured scintillator + photomultiplier and equipment constants: 255~278ps, 24.55ps / ch
・ Beam intensity: 1 keV
・ Measurement depth: around 0 to 100 nm (estimated)
-Measurement temperature: Room temperature-Measurement atmosphere: Vacuum-Measurement count number: Approximately 5,000,000 counts The measurement results were analyzed with three or four components by the non-linear least squares program POSITRONFIT.

(5) Spectral characteristics (spectral transmittance / spectral absorption rate)
Spectrophotometer V-670 (manufactured by JASCO Corporation) and absolute reflectance measurement unit ARSN-
Using 733, the spectral transmittance and the spectral reflectance in the wavelength range of 300 to 800 nm were measured under the following conditions. The spectral absorption rate was calculated from the obtained data by a mathematical formula of 100- (transmittance + reflectance) (%).

Among the obtained data, the spectral absorption rates at wavelengths of 300 nm, 350 nm and 400 nm and the average spectral absorption rates at wavelengths of 300 nm to 400 nm were evaluated. Moreover, the spectral transmittance at wavelengths of 400 nm, 550 nm and 780 nm and the average spectral transmittance at wavelengths of 400 nm to 780 nm were evaluated.

-Incident angle: 5 ° (0 ° is perpendicular to the sample plane)
-Measurement wavelength: 300 nm to 800 nm
-Bandwidth: 5.0 nm
・ Data acquisition interval: 0.5 nm
-Scanning speed: 1,000 nm / min.

(Example 1)
Using a take-up type vapor deposition apparatus having the structure shown in FIG. 3, MgO + SiO ₂ layers as A layer were provided on the base material by an electron beam (EB) vapor deposition method aiming at a thickness of 200 nm. As the base material, a cyclic olefin resin film having a thickness of 50 μm (“Zeonor Film” (registered trademark) ZF14-050 of Nippon Zeon Corporation, spectroscopic absorption rate of 0.2% at 300 nm) was used.

The specific operation is as follows. First, as a vapor deposition material, granular magnesium oxide MgO (purity 99.9%) and silicon dioxide SiO ₂ (purity 99.99%) having a size of about 2 to 5 mm are heated in advance at 100 ° C. for 8 hours, respectively. went. Subsequently, each material was set in the carbon hearth liner 10 as shown in FIGS. 4 and 5. The area ratio of the material was set to MgO: SiO ₂ = 1: 1. In the take-up chamber 4, the unwinding roll 5 is set so that the surface of the base material 1 on which the A layer is provided faces the hearth liner 10, and the unwinding roll is unwound via the guide rolls 6, 7, and 8. , Passed through the main drum 9. At this time, the temperature of the main drum was controlled to −10 ° C. Next, the pressure inside the vapor deposition apparatus 60 was reduced by a vacuum pump ^{to obtain 5.0 × 10 -3} Pa or less. Next, using an electron gun (hereinafter, EB gun) 12 as a heating source, the heating ratio of MgO and SiO _{2 is such that the ratio of atomic concentration (atm%) is about Mg: Si = 2: 1.} Was controlled. The acceleration voltage of the EB gun was 10 kV, and the acceleration current and the film transfer speed were adjusted so that the thickness of the A layer to be formed was about 200 nm, and the A layer was formed on the surface of the base material 1. After that, it was wound on the winding roll 17 via the guide rolls 14, 15 and 16.

Subsequently, test pieces were cut out from the obtained laminate, and various evaluations were carried out. The results are shown in Tables 1-3.

(Example 2)
A laminate was obtained in the same manner as in Example 1 except that a cyclic olefin resin film having a thickness of 23 μm was used as the base material. The results are shown in Tables 1-3.

(Example 3)
In the formation of the MgO + SiO ₂ layer, which is the A layer, the heating ratio _{of MgO and SiO 2} was controlled so that the atomic concentration (atm%) ratio was about Mg: Si = 3: 2. A laminate was obtained in the same manner as in Example 1. The results are shown in Tables 1-3.

(Example 4)
In the formation of the MgO + SiO ₂ layer, which is the A layer, the heating ratio _{of MgO and SiO 2} was controlled so that the atomic concentration (atm%) ratio was about Mg: Si = 3: 1. A laminate was obtained in the same manner as in Example 1. The results are shown in Tables 1-3.

(Example 5)
As the vapor deposition material, granular calcium oxide CaO (purity 99.9%) having a size of about 2 to 5 mm and granular silicon oxide SiO ₂ (purity 99.9%) having a size of about 2 to 5 mm are used. In the formation of the CaO + SiO ₂ layer, which is the A layer, the heating ratio _{of CaO and SiO 2} was controlled so that the ratio of atomic concentration (atm%) was about Ca: Si = 3: 2. A laminate was obtained in the same manner as in Example 1. The results are shown in Tables 1-3.

(Example 6)
In the formation of the MgO + SiO ₂ layer, which is the A layer, the heating ratio _{of MgO and SiO 2} was controlled so that the atomic concentration (atm%) ratio was about Mg: Si = 6: 1. A laminate was obtained in the same manner as in Example 1. The results are shown in Tables 1-3.

(Example 7)
In the formation of the MgO + SiO ₂ layer, which is the A layer, the heating ratio _{of MgO and SiO 2} was controlled so that the atomic concentration (atm%) ratio was about Mg: Si = 1: 1. A laminate was obtained in the same manner as in Example 1. The results are shown in Tables 1-3.

(Comparative Example 1)
A laminate was prepared in the same manner as in Example 1 except that a polyethylene terephthalate film having a thickness of 50 μm (“Lumirror” (registered trademark) P60: 92.0% at 300 nm) having a thickness of 50 μm was used as a base material. Obtained. The results are shown in Tables 1-3.

(Comparative Example 2)
As the vapor deposition material, granular silicon dioxide SiO ₂ (purity 99.99%) having a size of about 2 to 5 mm is used, set in a carbon hearth liner without a partition, and the EB gun is formed with an acceleration voltage of 10 kV. A laminated body was obtained in the same manner as in Example 1 except that the A layer was formed by adjusting the acceleration current and the film transport speed so that the thickness of the A layer was about 200 nm. The results are shown in Tables 1-3.

(Comparative Example 3)
Using the take-up sputtering apparatus shown in FIG. 6, a composite oxide layer (ZnO + SiO ₂ + Al ₂ O ₃ layer) of zinc oxide, silicon dioxide, and aluminum oxide was formed as layer A on the substrate by a sputtering method with a thickness of 150 nm. It was set up with the aim. As the base material, a cyclic olefin resin film having a thickness of 50 μm (“Zeonor Film” (registered trademark) ZF14-050 of Nippon Zeon Corporation, spectroscopic absorption rate of 0.2% at 300 nm) was used. The specific operation is as follows.

First, it is wound in the winding chamber 20 of the winding type sputtering apparatus 70 in which a sputtering target sintered with a composition mass ratio of zinc oxide / silicon dioxide / aluminum oxide of 77/20/3 is installed on the sputtering electrode 26. The surface on the take-out roll 21 on which the A layer of the cyclic olefin resin film is provided is set so as to face the sputtering electrode 26, and is passed through the main drum 25 via the unwind-out side guide rolls 22, 23, 24. bottom. At this time, the temperature of the main drum was controlled to 25 ° C. Next, the pressure inside the take-up sputtering apparatus 70 was reduced by a vacuum pump to obtain 1.0 × 10 ^-3 Pa or less. Subsequently, argon gas and oxygen gas were introduced at a partial pressure of oxygen gas of 10% so as to have a decompression degree of 2 × 10 ^-1 Pa, and an input power of 2,000 W was applied by a DC power source to obtain an argon / oxygen gas plasma. Was generated to form the A layer. The thickness was adjusted by the film transport speed. After that, it was wound on the winding roll 30 via the winding side guide rolls 27, 28, 29. Subsequently, test pieces were cut out from the obtained laminate, and various evaluations were carried out. The results are shown in Tables 1-3.

In Examples 1 to 4, the A layer forms a dense composite oxide film of magnesium oxide and silicon dioxide, and the water vapor permeability is 1.0 × ^10-2 (g) even when the film composition and the base material thickness are different. It is good at less than / m ² / day), and the spectral absorption rate at a wavelength of 300 nm is good at 8% or less. Further, in Example 5, the layer A forms a composite oxide film of calcium oxide and silicon dioxide, and the water vapor permeability ^{is as good as 1.5 × 10-2} (g / m ² / day), and the wavelength is also good. The spectral absorption rate at 300 nm is as good as 8% or less. In Examples 6 and 7, the spectral absorption rate at a wavelength of 300 nm is as good as 8% or less, but since the half width of the O1s peak in XPS is as large as 2.87 eV or more, the bond in the layer A is non-uniform and the gas barrier. The sex is 7.6 × ^10-2 (g / m ² / day) or more.

In Comparative Example 1, since polyethylene terephthalate (PET) having absorption in the ultraviolet region was used as the base material, the spectral absorption rate at a wavelength of 300 nm was very large at 93.8%, and as a result, the spectral transmittance at a wavelength of 300 nm was very large. Is 0%. The water vapor transmission rate is also inferior to that when the cyclic olefin resin is used. Comparative Example 2 is _{a single material having two} layers of SiO, and has good spectral characteristics, but its water vapor transmission rate is inferior to that of Examples 1 to 7. Comparative Example 3 uses a _{ZnO + SiO 2 + Al 2 O} 3 layer on the A layer, while the water vapor permeability is very good, spectral absorption at a wavelength of 300nm is 18.2%, as a result, wavelength 300nm The spectral transmittance in is reduced.

Since the laminate of the present invention has high UV transparency and gas barrier properties, it can be suitably used as a packaging material for medical / pharmaceutical products that requires bactericidal properties. Further, from the viewpoint of achieving both high light transmittance and gas barrier property, it can be suitably used for organic elements such as organic EL elements and organic phototube elements, but the application is not limited to these.

1 Base material 2 A layer 3 Anchor coat layer 4, 20 Winding chamber 5, 21 Unwinding roll 6, 7, 8, 22, 23, 24 Unwinding side guide roll 9, 25 Main drum 10 Haas liner 11 Deposited material 12 Electron gun 13 Electron wire 14, 15, 16, 27, 28, 29 Winding side guide roll 17, 30 Winding roll 18 Deposited material B
19 Thin-film deposition material C
26 Sputtering electrode 31 Encapsulating resin layer 32 λ / 4 retardation film 33 Linear polarizer layer 34 λ / 2 retardation film 50 Laminated body 60 Rewind-type electron beam (EB) vapor deposition equipment 70 Rewind-type sputtering equipment 80 Optical lamination body

Claims (15)

A laminate having a layer A containing silicon, a metal element, and oxygen on at least one surface of a base material, and having a spectral absorption rate of 15% or less at a wavelength of 300 nm measured by a spectrophotometer. The laminate according to claim 1, wherein the spectral transmittance measured by a spectrophotometer is 60% or more at a wavelength of 300 nm, 85% or more at a wavelength of 550 nm, and 80% or more at a wavelength of 780 nm. The laminate according to claim 1 or 2, wherein the layer A has an average lifetime of 0.935 ns or less as measured by the positron beam method. The laminate according to any one of claims 1 to 3, wherein the layer A has a half-value width of a peak of oxygen atoms (O1s) measured by X-ray photoelectron spectroscopy of 3.25 eV or less. The laminate according to any one of claims 1 to 4, wherein the refractive index of the A layer is 2.0 or less. The laminate according to any one of claims 1 to 5, wherein the metal element of the layer A is at least one selected from the group consisting of magnesium, calcium, aluminum, and gallium. The layer A contains magnesium oxide and silicon oxide, and has a magnesium (Mg) atomic concentration of 5 to 50 (atm%) and a silicon (Si) atomic concentration of 2 to 30 (atm%) measured by X-ray photoelectron spectroscopy. The laminate according to any one of claims 1 to 6, wherein the oxygen (O) atomic concentration is 45 to 70 (atm%). The A layer is any one of claims 1 to 7, wherein the ratio Mg / (Mg + Si) of the atomic concentration (atm%) of magnesium (Mg) atom and silicon (Si) atom is 0.45 to 0.80. The laminate described in. The laminate according to any one of claims 1 to 7, wherein the spectral absorption rate at a wavelength of 300 nm measured by the spectrophotometer of the base material is 15% or less. The laminate according to any one of claims 1 to 9, wherein the base material is a cyclic olefin-based resin film. The method for producing a laminate according to any one of claims 1 to 10, wherein the method for forming the layer A is a vacuum vapor deposition method. An optical laminate comprising the laminate according to any one of claims 1 to 10, a λ / 4 retardation film, and a linear polarizer layer. The optical laminate according to claim 12, further comprising a λ / 2 retardation film. The optical laminate according to claim 12 or 13, which includes a sealing resin layer. A flexible display using the laminate according to any one of claims 1 to 10 or the optical laminate according to any one of claims 12 to 14.

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