TW202135359A - Method for producing optical film - Google Patents

Abstract

An embodiment of the present invention provides a method for producing an optical film having excellent appearance traits and optical properties as a result of accurate identification and/or removal of a film region containing tiny foreign matter, said optical film being less susceptible to appearance defects and reduced optical/emission properties in a layer further formed upon said film. This method for producing an optical film includes a) a step in which a foreign matter detection coating is formed on the surface of a starting film having optical properties, b) a step in which the film surface having the coating formed thereon is irradiated with light so as to detect foreign matter within and/or on said film and identify a film region containing foreign matter, and c) a step in which the film region is removed or the film region is marked and an optical film is obtained.

Description

Manufacturing method of optical film

One aspect of the present invention relates to a manufacturing method of an optical film.

Electronic devices such as organic electro-luminescence (EL) displays, lighting devices using organic EL elements, and the like are composed of optical laminates including various optical films having optical properties. In recent years, particularly in various devices using organic EL, the usefulness of optical films having gas barrier properties for preventing water vapor from entering the device has increased. As such optical films, for example, a laminated film has been developed. It is suitable for flexible substrates of electronic devices such as organic EL displays, and a thin film layer is laminated on a flexible substrate containing polyethylene terephthalate (PET) with an organic layer interposed therebetween (for example, Patent Document 1 ). [Prior Art Literature] [Patent Literature]

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

[The problem to be solved by the invention] Generally, high visibility and transparency are required for optical films or optical laminates constituting various devices. Therefore, regarding the decrease in visibility or transparency, there is a film area where there are external adherents such as dust or dust that may be the cause of appearance defects, or foreign materials such as gelled products of the liquid composition for film formation. Preferably, it is removed before assembling to the optical laminate, preferably during the manufacturing process of the optical film. In the conventional optical film manufacturing method, foreign matter is generally detected through a camera lens, and the film area where the foreign matter exists is removed. However, in conventional methods for detecting foreign objects passing through a camera lens, even if a foreign object having a size of several tens of micrometers (μm) can be detected, it is difficult to detect a foreign object less than 10 μm, for example, about 1 μm.

On the other hand, in recent years, electronic devices, lighting devices, and the like have tended to be thinner, and thickness reduction is also desired for each member constituting them. For example, if the thickness of each optical functional layer such as a retardation layer or a polarizing layer constituting an organic EL display becomes thinner, when these layers are formed, it is likely to be caused by smaller foreign matter present on the optical film as the base material. Coating unevenness or alignment defects may not only cause appearance defects such as visibility or transparency, but also may cause degradation of optical properties. In particular, the organic EL layer (organic EL element) is a very thin layer usually formed with a film thickness of about 50 nm to 500 nm. When forming an organic EL element, it can be an optical film that functions as a substrate (for example, it can be used as an optical film). In the barrier film of the flexible substrate of the electronic device, even foreign matter with a size of about several μm is likely to have a large impact on the organic EL element formed here, and problems such as uneven coating caused by this are likely to become Significant.

Therefore, there is a need for a technique for manufacturing an optical film, which accurately recognizes and/or removes the film area where such a minute foreign matter is present, thereby suppressing the appearance defect of the optical film caused by the foreign matter itself, and suppressing the film The presence of foreign matter on the surface may cause appearance defects such as uneven coating or degradation of optical/luminescent properties in various optical functional layers or organic EL elements to be formed on the film.

An object of one aspect of the present invention is to provide a method of manufacturing an optical film, which can accurately identify and/or remove film regions where extremely small foreign substances are present, thereby manufacturing an optical film having excellent appearance characteristics and optical characteristics, and In the optical film, even when a layer is further formed on the film, it is unlikely that the layer will have appearance defects or decrease in optical/luminescent 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 manufacturing method of an optical film, including: a) The step of forming a coating film for foreign matter detection on the surface of a raw film with optical properties; b) by irradiating the surface of the film on which the coating film is formed with light to detect foreign matter present on the film and/or inside the film, and determining the film area where the foreign matter exists; and c) The step of removing the film area or marking the film area to obtain an optical film. [2] The manufacturing method described in [1], wherein the coating film for detecting foreign matter contains at least one selected from the group consisting of fluorescent substances, colorants, high refractive index materials, and low refractive index materials . [3] The manufacturing method according to [1] or [2], wherein the coating film for detecting foreign matter has a refractive index of 3% or more and 50% in absolute value with respect to the refractive index of the raw material film forming the coating film. Refractive index below %. [4] The manufacturing method as described in any one of [1] to [3], including a step of removing the coating film for foreign matter detection by washing. [5] The manufacturing method as described in any one of [1] to [4], including a step of manufacturing a raw film having optical properties. [6] The production method as described in any one of [1] to [5], wherein the raw material film has a long strip shape. [7] The production method as described in any one of [1] to [6], which includes processing a long raw film or an optical film into a monolithic body. [8] The production method according to any one of [1] to [7], wherein the optical film includes a substrate and an inorganic thin film layer laminated on the substrate. [9] The production method according to the above [8], wherein the base material includes an organic layer. [10] The manufacturing method as described in [8] or [9], wherein the inorganic thin film layer is a layer formed by a plasma chemical vapor deposition method. [11] The manufacturing method according to any one of [8] to [10], wherein the inorganic thin film layer contains silicon atoms, oxygen atoms, and carbon atoms. [12] The production method according to [11], 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. [13] The production method according to any one of [1] to [12], wherein the optical film has gas barrier properties. [Effects of the invention]

According to an aspect of the present invention, a method of manufacturing an optical film can be provided, which can accurately identify and/or remove film regions where extremely small foreign matter is present, thereby manufacturing an optical film with excellent appearance characteristics and optical characteristics, and In the optical film, even when a layer is further formed on the film, it is unlikely that the layer will have appearance defects or decrease in optical/luminescent properties.

Hereinafter, embodiments 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.

The manufacturing method of an optical film of one aspect of the present invention includes: a) A step of forming a coating film for foreign matter detection on the surface of a raw film with optical properties (hereinafter also referred to as "coating film formation step"); b) The step of detecting foreign matter present on and/or inside the film by irradiating light on the film surface on which the coating film is formed, and identifying the film area where the foreign matter is present (hereinafter also referred to as "foreign matter detection step") ;as well as c) The step of removing the film area or marking the film area to obtain an optical film (hereinafter also referred to as "foreign matter removal step").

In one aspect of the present invention, the coating film for foreign matter detection in the step of forming the coating film can be formed, for example, by coating the surface of the raw material film that is the target of foreign matter detection. A composition of at least one component (hereinafter also referred to as a "composition for forming a coating film") for detecting the function of a foreign body, and drying and hardening as necessary. The coating film for foreign matter detection only needs to be formed on the surface of the raw material film on which the foreign matter is to be detected, and it may be formed on only one side of the raw material film or on both sides. For example, when the optical film obtained by one aspect of the manufacturing method of the present invention is used as an optical film for forming other layers such as organic EL elements, it is preferable to form at least on the surface where the layer is formed. Coating film for foreign body detection.

In one aspect of the present invention, the composition for forming a coating film is not particularly limited as long as the composition can form a coating film capable of detecting minute foreign substances present on the raw optical film. The coating film for foreign matter detection and the composition forming the coating film generally contain at least one component that can function for detecting foreign matter. As such a component, for example, uneven fluorescence or color unevenness in the film area where the foreign matter exists due to foreign matter when irradiated with light, iris unevenness due to optical interference caused by uneven coating film thickness, and Substances such as the effect of scattering light due to the difference in refractive index and appearing to be larger than the actual size of foreign objects, changes in internal haze, and changes in external haze caused by minute surface irregularities. Specifically, for example, fluorescent substances, colorants, high-refractive-index materials, low-refractive-index materials, etc. can be cited. In addition, high-flat materials, scratch-resistant materials, anti-fouling materials, fingerprint-resistant materials, antistatic materials, conductive materials, etc. can also be used. It can be configured not only as a coating film for foreign body detection, but also in optical films. The material of the film that functions as a functional layer. Among them, the coating film for foreign matter detection and/or the coating film forming composition preferably includes at least one selected from the group consisting of fluorescent substances, colorants, high-refractive-index materials, and low-refractive-index materials. Regardless of the composition of the raw optical film, it is easy to apply to a wide variety of optical films and to easily obtain a coating film for easy foreign matter detection. In one aspect of the present invention, the foreign matter detection coating film and/or the coating film The forming composition preferably contains a fluorescent substance or a coloring agent. Only one kind of these components may be used, or a plurality of kinds may be used in combination.

When the coating film for foreign body detection contains a fluorescent substance, the coating film forming composition containing the fluorescent substance tends to exist in a biased manner at the location where the foreign body exists. When light is irradiated, the coating film for foreign body detection causes fluorescence unevenness or The color is uneven, so it is easy to identify small foreign objects by visual inspection. As the fluorescent substance that can be used in the coating film for foreign body detection, those used in conventional fluorescent inks can be used without particular limitation. For example, basic dyes, acid dyes, disperse dyes, oil-soluble dyes, fluorescence enhancement can be used. Dye inks manufactured using white dyes, etc., or organic fluorescent pigment inks manufactured using the dyes, etc.

When the coating film for foreign matter detection contains a colorant, the coating film forming composition containing the colorant tends to be eccentrically present at the location where the foreign matter exists, and color unevenness occurs in the coating film for foreign matter detection when the It is easy to identify small foreign objects visually. As a coloring agent that can be used in the coating film for foreign matter detection, those used in conventional colored inks can be used without particular limitation. For example, inorganic and organic pigments, resin particle colorants containing pigments, and resin matrix can be used. Coloring latex colorants obtained by solid-solution of fluorescent dyes, etc., inks, etc., using silica or mica as a base material and multi-layer coating of iron oxide or titanium oxide on the surface. Specifically, examples include: channel black, furnace black, carbon black such as acetylene black, thermal black, black colorants such as spherical graphite particles, black iron oxide, black spherical resin particles, or colorful organic pigments, coloring Latex pigments, azo pigments, condensed azo pigments, phthalocyanine pigments, anthraquinone pigments, perylene pigments, perylene pigments, quinacridone pigments, dioxazine series, thioindigo series, Isoindolinone pigments, etc. These colorants can be used alone or in combination of two or more.

In one aspect of the present invention, the high-refractive index material refers to a material that is relatively high in refractive index compared to the surface of the raw material film that is the object to be detected for foreign matter. When the coating film for foreign body detection contains a high-refractive index material, when light is irradiated, the difference between the refractive index of the optical film and the refractive index of the coating film containing the high-refractive index material causes the light to scatter. Make the foreign matter look larger than the actual size, so that even the small foreign matter can be easily identified. As a high refractive index material that can be used as a coating film for foreign matter detection, for example, a sulfur-containing substituent, a halogen-containing substituent, an aromatic ring, etc., with a high atomic refractive index can be introduced into the polymer skeleton, or a metal oxide The fine particles and their alkoxides and complexes are dispersed in the polymer. Examples of metals specifically include Si, Zn, Ti, Zr, Ce, Hf, Nb, Al, Sn , etc., which can also be used as BaTiO ₃ composite oxide and the like. Examples of polymers that can be used to introduce substituents, etc., or to disperse metal oxide particles, etc. include polyvinylpyrrolidone, polyester, polystyrene, high-impact polystyrene, styrene copolymer, acrylonitrile, Butadiene copolymer, polyisobutylene, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polyacrylonitrile, polyacrylate, polymethacrylate, polybutadiene, ethylene vinyl acetate, polyvinyl acetate Amine, polyimide, polyoxymethylene, polysulfide, polyphenylene sulfide, melamine, vinyl ester, epoxy, polycarbonate, polyurethane, polyacetal, phenol, polyester carbonate, poly Ether, polyether ether, polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyarylate, polyarylene sulfide, polyketone, polyethylene, high Density polyethylene, polypropylene, rosin esters, cycloolefin polymers, cycloolefin copolymers, hydrocarbon resins, copolymers, grafts, blends and mixtures of these, or photocuring properties containing polymerizable functional groups Compound composition, composition containing thermosetting compound with polymerizable functional group, acrylic adhesive, rubber adhesive, silicone adhesive, polyester adhesive, urethane adhesive , Epoxy adhesives and polyether adhesives and other adhesives.

In one aspect of the present invention, the low-refractive index material refers to a material that is relatively low compared to the refractive index of the surface of the raw material film that is the object to be detected for foreign matter. When the coating film for foreign body detection contains a low-refractive index material, when the light is irradiated, the refractive index difference between the optical film and the coating film containing the low-refractive index material causes the light to scatter. Make the foreign matter look larger than the actual size, so that even the small foreign matter can be easily identified. As a low refractive index material that can be used as a coating film for foreign body detection, for example, fluorine can be introduced into polymer molecules, or fine particles with low refractive index can be dispersed in the polymer chain by introducing pores containing a crystal cage structure into the polymer chain. Obtained from materials. Specific examples of fine particles with a low refractive index include: silicon dioxide, zinc oxide, titanium oxide (titania), zirconium oxide (zirconium), cerium oxide (ceria), hafnium oxide, Porous structures such as niobium oxide, aluminum oxide, tin oxide, and barium titanate, or hollow particles. Examples of polymers that can be used to introduce fluorine or disperse fine particles with low refractive index include: polyvinylpyrrolidone, polyester, polystyrene, high-impact polystyrene, styrene copolymers, acrylonitrile, butylene Diene copolymer, polyisobutylene, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polyacrylonitrile, polyacrylate, polymethacrylate, polybutadiene, ethylene vinyl acetate, polyamide , Polyimide, polyoxymethylene, polyimide, polyphenylene sulfide, melamine, vinyl ester, epoxy, polycarbonate, polyurethane, polyacetal, phenol, polyester carbonate, polyether , Polyether sulfide, polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyarylate, polyarylene sulfide, polyketone, polyethylene, high density Polyethylene, polypropylene, rosin esters, cycloolefin polymers, cycloolefin copolymers, hydrocarbon resins, copolymers, grafts, blends and mixtures of these, or photocurable compounds containing polymerizable functional groups Compositions, compositions containing thermosetting compounds with polymerizable functional groups, acrylic adhesives, rubber-based adhesives, silicone-based adhesives, polyester-based adhesives, urethane-based adhesives, Adhesives such as epoxy-based adhesives and polyether-based adhesives.

In one aspect of the present invention, as a highly flat material, scratch resistant material, antifouling material, fingerprint resistant material, antistatic material, conductive material, etc., it can be configured to not only function as a coating film for foreign body detection, but also As the material of the film that can function as a functional layer in the optical film, generally used materials can be used without particular limitation according to the respective functions, but it is preferable to satisfy the adhesiveness, optical characteristics, and heat resistance required for the optical film. Of resistance, weather resistance, etc. These materials can be blended into the components (such as transparent resins, transparent adhesives, transparent adhesives, etc.) that are generally used as constituent materials of optical films as needed, and general methods are used to form each layer constituting the optical film. Form a coating film.

The content of the above-mentioned components capable of detecting foreign bodies (hereinafter also referred to as "foreign body detection functional components") in the composition for coating film formation should be based on the foreign body detection functional components used and the content of the coating film. The thickness, the film forming method, etc. may be appropriately determined. Regarding the content of the foreign matter detection functional component, it may be used in a state of 100 parts by mass of the solid content of the composition for forming a coating film, or it may be diluted with a solvent and used as a solution or dispersion. The solid content concentration of the coating film forming composition when used as a solution or dispersion may be adjusted to an appropriate viscosity according to the thickness of the coating film or the film forming method. By obtaining an appropriate thickness of the coating film, uneven fluorescence or color unevenness in the area where foreign matter exists, iris unevenness caused by optical interference due to uneven coating film thickness, and refractive index difference The effect of scattering light to look larger than the actual size of the foreign body, changes in internal haze, and changes in external haze caused by small surface irregularities, are likely to become significant, making it easy to detect foreign objects. In addition, in this specification, the solid content of the composition for coating film formation means all components except volatile components, such as an organic solvent, from the composition for coating film formation.

From the viewpoints of workability, ease of coating film formation, and productivity of optical films, the composition for coating film formation is preferably a liquid composition. Generally, the functional component for detecting foreign matter as described above is applied to the raw optical film in a state of being dissolved or dispersed in a solvent. Therefore, the composition for forming a coating film preferably contains a solvent. As the solvent, a solvent that can dissolve or disperse the foreign matter detection functional component as described above and that does not adversely affect the raw optical film of the coating film forming composition can be appropriately selected and used. As such a solvent, for example, alcohol-based solvents such as methanol, ethanol, 2-propanol, 1-butanol, and 2-butanol; diethyl ether, diisopropyl ether, dibutyl ether, tetrahydrofuran, 1,4- Ether solvents such as dioxane and propylene glycol monomethyl ether; ketone solvents such as acetone, 2-butanone, and methyl isobutyl ketone; N,N-dimethylformamide, N,N-dimethylethyl Aprotic polar solvents such as amide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, dimethyl sulfide, etc.; methyl acetate, ethyl acetate, n-butyl acetate, etc. Ester solvents; nitrile solvents such as acetonitrile and benzonitrile; hydrocarbon solvents such as n-pentane, n-hexane, n-heptane, octane, cyclohexane, methylcyclohexane, etc.; benzene, toluene, xylene, mesitylene Aromatic hydrocarbon solvents such as toluene; halogenated hydrocarbon solvents such as dichloromethane, chloroform, carbon tetrachloride, 1,2-dichloroethane, trichloroethane, monochlorobenzene, dichlorobenzene, water, etc. These solvents can be used alone or in combination of two or more.

The content of the solvent in the coating film formation composition may be appropriately determined according to the foreign matter detection functional component used, the size of the foreign matter to be detected, the coating method of the coating film formation composition, the thickness of the coating film, etc. . The coating film for foreign body detection is formed by swelling on the foreign body to cover the foreign body. If it is a thin and uniform film in the area where the foreign body is not present, it is caused by the foreign body detection functional component at the location where the foreign body is present when the light is irradiated. Fluorescence unevenness or color unevenness, iris unevenness caused by optical interference caused by uneven coating film thickness, and the effect of scattering light due to the difference in refractive index to appear larger than the actual size of foreign objects, internal Changes in coating film properties, such as haze changes and changes in external haze caused by minute surface irregularities, tend to become significant, making it easy to detect foreign matter. Such a coating film can detect foreign matter defects of a size exceeding the resolution of the camera, and can detect fine foreign matter of about 1 μm to 20 μm that cannot be normally detected.

In addition to the foreign body detection functional components and solvents, the coating film forming composition may also contain a dispersant or dispersion stabilizer, a free radical generator, an acid generator, a pH adjuster, a chelating agent, an ultraviolet absorber, and a viscosity adjuster , Dye dissolving agent, anti-fading agent, emulsion stabilizer, surface tension regulator, defoamer and other well-known additives. These can be used individually or in combination of multiple types.

As a method for coating the composition for forming a coating film on the raw optical film, various methods known in the past can be used, for example, spray coating, spin coating, bar coating, curtain coating, Die coating method, dipping method, air knife method, slide coating, hopper coating, reverse roll coating, gravure coating, extrusion Coating, inkjet coating and other methods. Among them, in the spin coating method in which the liquid coating film forming composition is spread from the center of the optical film as the object of foreign matter detection to the outside by centrifugal force, in the presence of foreign matter, the thickness of the coating film is The foreign matter changes as the starting point, leaving traces of the foreign matter as a tail on the coating film. Therefore, by irradiating light, it is easy to recognize the minute foreign matter under visual observation. It is used as a coating method for the composition for coating film formation. It is preferable, and it is especially preferable as a coating method in a single-piece raw optical film. The conditions (coating speed, etc.) when the coating film forming composition is applied to the raw optical film may be appropriately determined according to the composition of the coating film forming composition, the coating method, the size of the foreign object to be detected, etc. .

After coating the composition for forming a coating film, if necessary, the solvent is removed by drying or the like to form a dry coating film. As a drying method, natural drying method, ventilation drying method, heat drying, and reduced-pressure drying method etc. are mentioned. The drying conditions may be appropriately determined according to the composition or concentration of the coating film forming composition used, the type of solvent or additives, the thickness of the coating film to be obtained, and the like. For example, the drying temperature is usually 25°C to 200°C, preferably 50°C to 150°C. In addition, the drying time is usually 1 minute to 30 minutes, preferably 1 minute to 15 minutes.

The thickness of the coating film for foreign matter detection (thickness after drying) can be appropriately selected according to the material of the coating film for foreign matter detection. For example, when a fluorescent substance is used to detect foreign objects, the average in-plane thickness of the foreign object detection coating film in the area where there is no foreign object relative to the height (average height) of the foreign object to be detected is preferably 300% Below, it is more preferably 200% or less, and still more preferably 150% or less. If the thickness of the dry coating film is equal to or less than the upper limit value relative to the height of the foreign matter (average height), the change in the properties of the coating film at the location where the foreign matter is present is likely to become significant, making it easy to detect the foreign matter. From the viewpoints of ease of detection of foreign objects, productivity, and the like, the lower limit of the thickness of the dried coating film is preferably 30% or more, and more preferably 50% or more with respect to the height of the foreign object to be detected. In this specification, the "average in-plane thickness of the coating film for foreign matter detection" refers to the average in-plane thickness of the coating film for foreign matter detection in a region where no foreign matter is present in the short-side direction of the optical film. In addition, the “height of the foreign object (average height)” may be an imaginary value calculated from the minimum value and the maximum value of the height of the foreign object to be detected. The average in-plane thickness of the coating film or the height of the detected foreign matter can be measured, for example, using a stylus type shape measuring machine or the like.

If the coating film for foreign body detection has high transparency, the foreign body detection step will facilitate the detection of foreign bodies when irradiated with light. Therefore, the total light transmittance of the coating film for foreign body detection is preferably 80% or more, more preferably 83 % Or more, more preferably 85% or more. The upper limit of the total light transmittance of the coating film for foreign matter detection is not particularly limited, as long as it is 100% or less. The total light transmittance of the coating film for foreign matter detection can be measured in accordance with Japanese Industrial Standards (JIS) K 7361-1, for example.

In addition, the haze of the coating film for foreign matter detection is preferably 5.0% or less, more preferably 3.0% or less, and still more preferably 2.0% or less. If the haze of the coating film for foreign matter detection is equal to or less than the above upper limit value, the foreign matter detection step tends to be easier to detect foreign matter when irradiated with light. The lower limit of the haze of the coating film for foreign matter detection is not particularly limited, but is usually 0% or more. The haze of the coating film for foreign matter detection can be measured in accordance with JIS K 7136, for example.

The coating film for foreign body detection is preferably a coating film that can be easily removed after the foreign body detection step, or a coating film that does not affect the physical properties or characteristics of the optical film even if it is directly present as a constituent layer of the finally obtained optical film. For the film, it is preferable to select the components constituting the coating film for foreign matter detection so as to have any of the above-mentioned characteristics. For example, when the coating film for foreign matter detection is a coating film that produces a large refractive index difference at the location where the foreign matter is present, it is easy to directly exist as a constituent layer of the optical film after the foreign matter detection step without removing the coating film. Furthermore, since the cleaning process of the coating film for foreign matter detection mentioned later is not required, it is advantageous in terms of productivity and the possibility of reducing the possibility of optical film damage accompanying coating film cleaning.

In one aspect of the present invention, the refractive index of the coating film for foreign matter detection is preferably 3% or more in absolute value, more preferably 5% relative to the refractive index of the raw optical film forming the coating film. Above, more preferably 10% or more. In addition, it is preferably 50% or less, more preferably 30% or less, and still more preferably 20% or less. The refractive index of the coating film for foreign matter detection can be controlled, for example, by considering the refractive index of the raw optical film, and appropriately selecting the high refractive index material or the low refractive index material exemplified as the component constituting the coating film forming composition. The refractive index of the coating film for foreign matter detection and the raw optical film can be measured and calculated by, for example, an ellipsometer.

In the case where the coating film for foreign body detection can directly exist as a constituent layer of the finally obtained optical film, although it also depends on the use or function of the optical film, the coating film for foreign body detection is usually colorless and preferably has high Transparency. In one aspect of the present invention, the total light transmittance of the coating film for foreign matter detection is preferably 80% or more, more preferably 83% or more, and still more preferably 85% or more. If the total light transmittance of the coating film for foreign matter detection is greater than or equal to the lower limit, even when the coating film remains as a constituent layer of the optical film, the obtained optical film is assembled in an image display It is easy to ensure sufficient visibility for electronic devices such as devices. The upper limit of the total light transmittance of the coating film for foreign matter detection is not particularly limited, as long as it is 100% or less. In addition, the haze is preferably 5.0% or less, more preferably 3.0% or less, and still more preferably 2.0% or less. The lower limit is not particularly limited, but is usually 0% or more.

In the foreign matter detection step, light is irradiated to the surface of the film on which the foreign matter detection coating film is formed, foreign matter existing on and/or inside the film is detected, and the film area where the foreign matter exists is determined.

The light irradiated on the surface of the film may be appropriately selected according to the composition, absorption wavelength, fluorescence wavelength, visual sensitivity, etc. of the coating film for foreign matter detection. Examples include white light, blue light, green light, red light, ultraviolet light, and infrared light. Light and so on. As the light source of the irradiated light, for example, a light-emitting diode (LED) light source, a high-intensity light, a high color rendering light, a slit light source, a diffused light source, a crossed Nicol light source, and the like can be cited.

The light irradiation in the foreign matter detection step can be performed from either side of the optical film on which the foreign matter detection coating film is formed, but from the viewpoint of the ease of foreign matter detection, it is preferable to irradiate from the foreign matter detection coating film side. The light irradiation conditions may be appropriately determined according to the composition (kind) of the coating film for foreign body detection, the absorption wavelength, the fluorescence wavelength, and the size or kind of the foreign body to be detected.

In one aspect of the present invention, the detection of foreign matter can be performed by, for example, visual inspection, camera inspection, microscopic inspection, white interference inspection, etc. However, since the foreign matter detection coating film is formed to visualize the location of the foreign matter, Therefore, it is easy to identify small foreign objects by visual inspection or camera inspection. Therefore, in a preferred aspect of the present invention, the detection of foreign objects is performed by visual inspection or camera inspection. By using visual inspection or camera inspection to perform foreign matter detection, no special equipment or equipment is required, and it is possible to easily and efficiently identify the film area where foreign matter, particularly fine foreign matter is present.

The manufacturing method of an optical film of one aspect of the present invention can visualize foreign objects that are difficult to recognize visually by forming a coating film for foreign object detection, and therefore can provide a method that does not contain minute foreign objects that are difficult to detect even through a camera lens.的optical film. In the foreign matter detection step, foreign matter that can be attached and/or mixed in the general manufacturing process of the raw optical film is used as the detection target, but for example, even if it is less than 20 μm, preferably 15 μm or less, more preferably 10 A foreign object with a size of less than μm, more preferably 5 μm or less, and particularly preferably 3 μm or less (for example, about 1 μm) can also be used as a detection target by visual inspection. In addition, the size of the foreign matter here refers to the maximum width when the foreign matter existing on the surface or inside of the film is viewed from directly above. In addition, from the viewpoint of ensuring efficient foreign matter detection by the coating film for foreign matter detection, when the foreign matter is present on the surface of the raw optical film, the height is preferably 0.01 μm or more, more preferably 0.03 μm above. In this case, the upper limit of the height of the foreign matter is not particularly limited, as long as the height of the foreign matter can be attached and/or mixed in the general manufacturing process of the raw optical film, and it is preferably 20 μm or less, for example. It is 10 μm or less. The size and height of the foreign matter can be measured by, for example, a reflection electron microscope, a laser microscope, a white interference microscope, a linear interferometer, a stylus profiler, or the like.

In the foreign matter detection step, light is irradiated to the film surface on which the foreign matter detection coating film is formed, and it will be confirmed that the fluorescence unevenness or color unevenness caused by the foreign matter is caused by the optical interference caused by the unevenness of the coating film thickness. The effect of uneven iris shape, light scattering due to the difference in refractive index, and the effect that the size of foreign matter is larger than the actual size, internal haze change, external haze change caused by small surface unevenness, etc., is determined to be the presence of foreign matter膜区。 Membrane area. In this way, the film area to be removed or to be marked is determined in the foreign material removal step described later. In the determination of the film area where the foreign matter is present, by setting the screening criteria according to the type or use of the obtained optical film, etc., an optical film having a predetermined quality can be manufactured.

The foreign matter removal step is to remove or mark the film area where the foreign matter is determined in the foreign matter detection step, so as to obtain the optical film with the foreign matter removed or the film area where the foreign matter is determined. step. Generally, when the (raw material) optical film used in the foreign matter removal step is in the form of a short strip, such as a monolithic body, the film area where the foreign matter exists can be cut, or the short optical film in the area can be removed one by one. On the other hand, when the (raw material) optical film used in the foreign matter removal step is, for example, a long film roll wound into a roll, in order to identify and remove the film area where the foreign matter is present during use of the optical film, etc. For example, it is preferable to mark the film ends in the short-side direction of the long film.

The method of manufacturing an optical film of one aspect of the present invention may also include a step of removing the coating film for foreign matter detection by washing according to the composition or optical characteristics of the coating film for foreign matter detection. As a method for cleaning the coating film for foreign body detection, for example, high-pressure cleaning, ultrasonic cleaning, two-fluid cleaning, scrubbing cleaning, and cleaning by stirring the solvent while immersing the optical film containing the coating film for foreign body detection in the solvent can be used. The method of stirring and cleaning, using waste cloth, etc. to wipe the coating film for foreign matter detection wetted by the solvent, and ultraviolet (ultraviolet, UV) -O ₃ treatment or atmospheric piezoelectric plasma treatment, corona discharge treatment, excimer irradiation treatment, plasma Dry etching such as processing, ion beam processing, etc. These methods may be appropriately selected according to the shape of the optical film, the composition (kind), thickness, and the like of the coating film for foreign matter detection.

The solvent used for cleaning can be appropriately determined according to the composition of the coating film for foreign matter detection, the type, composition, and structure of the raw optical film, as long as it does not adversely affect the obtained optical film. Examples of the cleaning solvent include water, organic solvents such as methanol, ethanol, and isopropyl alcohol (IPA), acids, alkalis, and the like. Only one type of these solvents may be used, or two or more types may be used in combination.

After the washing step, a step of removing the solvent used in washing by drying may also be included. As a drying method, natural drying method, ventilation drying method, heat drying, and reduced-pressure drying method etc. are mentioned. The drying conditions are preferably appropriately selected according to the composition of the optical film, etc., so as not to affect the physical properties and/or characteristics of the optical film. For example, the drying temperature is usually 50°C to 200°C, preferably 70°C to 150°C. In addition, the drying time is usually 1 minute to 30 minutes, preferably 3 minutes to 15 minutes.

In one aspect of the present invention, the method of manufacturing an optical film may also include a step of manufacturing a raw material film (raw material optical film) having optical properties. In one aspect of the present invention, the raw optical film refers to a film with optical characteristics to be subjected to the coating film formation step, the foreign matter detection step, and the foreign matter removal step. In one aspect of the present invention, an optical film refers to a film that is incorporated in an electronic device such as an image display device or a lighting device, etc., and has various optical characteristics that can function to express the function of the device. These raw optical films can have a single-layer structure or a multi-layer structure. Specifically, for example, optically functional films such as polarizing film, retardation film, brightness enhancement film, anti-glare film, anti-reflection film, diffuser film, condensing film, polarizing plate, retardation film, etc., or having gas barrier properties The barrier film and so on.

The manufacturing process of the raw material optical film is not particularly limited as long as a film having desired optical properties and the like can be obtained, and it can be manufactured by a conventionally known method in the field. In addition, as a raw material film, a commercially available optical film can also be used.

The shape of the raw optical film is not particularly limited, and it may be a monolithic body or a long strip. In the case where the raw optical film is elongated, in one aspect of the present invention, the manufacturing method of the optical film may also include passing the elongated raw optical film or passing through a coating film forming step, a foreign matter detection step, and/or The optical film in the foreign matter removal step is processed into a single-piece body. The processing from the long film into a monolithic body can be carried out using existing well-known devices and/or methods in this field. Specifically, for example, cutting processing using Thomson type punches, super cutters, cross cutters, cut-off cutters, shear cutters, rotary die cutters, press cutters, etc. can be cited. Processing by ablation using various lasers, etc. Only one kind of these processing methods may be used, or two or more kinds of them may be combined.

Furthermore, the end surface of the processed film may be cut. As a method for cutting the processed end surface, for example, a method of cutting the outer peripheral end of an optical film with a rotating blade as disclosed in Japanese Patent Laid-Open No. 2001-54845, such as Japanese Patent Laid-Open No. 2003 The method of continuously cutting the outer peripheral end of the optical film by the fly-cut method as disclosed in the -220512 publication.

In one aspect of the present invention, the optical film manufacturing method can visualize minute foreign objects that are difficult to recognize by visual inspection, and is therefore suitable for manufacturing appearance defects or optical characteristics that are likely to cause significant uneven coating due to extremely small foreign objects. It can be an optical film that can function as a base material when the optical function layer is reduced. It is particularly suitable as a method for manufacturing an optical film that can function as a substrate when an organic EL element formed with a very thin film thickness compared to a general optical functional layer is formed. As such an optical film, the gas barrier film etc. which can be used as a flexible substrate of electronic devices, such as an organic electroluminescent image display apparatus, etc. are mentioned, for example.

Therefore, in one aspect of the present invention, the (raw material) optical film is preferably an optical film including a substrate and an inorganic thin film layer laminated on the substrate. The optical film having this structure can have gas barrier properties. Hereinafter, an optical film (hereinafter also referred to as a "gas barrier film") including the above-mentioned structure will be described.

〔Substrate〕 The base material constituting the gas barrier film preferably includes a flexible film. The flexible film refers to a film substrate that can maintain the flexibility of the inorganic thin film layer, and for example, a resin film containing at least one resin as a resin component can be used. The flexible film is preferably a transparent resin film.

Examples of resins that can be used in the flexible film include: polyester resins such as polyethylene naphthalate (PEN); polyethylene (PE), polypropylene (PP), ring Polyolefin resins such as polyolefins; polyamide resins; polycarbonate resins; polystyrene resins; polyvinyl alcohol resins; saponified ethylene-vinyl acetate copolymers; polyacrylonitrile resins; acetal resins; polyamides Imine resin; polyether sulfide (PES), polyethylene terephthalate (PET) with biaxial stretching and thermal annealing treatment. As the flexible film, one kind of the above-mentioned resins may be used, or two or more kinds of resins may be used in combination. Among these, from the viewpoints of heat resistance, transparency, and dimensional stability, it is preferable to use a resin selected from the group consisting of polyester resins and polyolefin resins, and more preferably to use resins selected from the group consisting of PEN and cyclic resins. It is more preferable to use PEN as the resin in the group consisting of polyolefin.

The flexible film can be an unstretched resin film, or it can be uniaxially stretched, tenter sequential biaxial stretching, tenter simultaneous biaxial stretching, tubular simultaneous biaxial stretching, etc. A known method is a stretched resin film obtained by stretching an unstretched resin film in the flow direction of the resin film (MD direction) and/or a direction perpendicular to the flow direction of the resin film (TD direction). The flexible film may be a laminate obtained by laminating two or more layers of the resin.

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

From the viewpoint of the adhesiveness with the organic layer or the like that can be adjacent thereto, the surface of the flexible film 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 substrate may also include a primer layer. From the viewpoint of easy improvement in adhesion, heat resistance, etc., the primer layer is preferably formed on at least one surface of the flexible film. For example, in the case where the base material includes the organic layer described later, and the flexible film, the undercoat layer, and the organic layer are laminated in this order, the undercoat layer can improve the adhesion between the flexible film and the organic layer. In addition, when an undercoat layer is formed on the surface of the flexible film opposite to the side on which the inorganic thin film layer is formed, and the undercoat layer is the outermost layer, the undercoat layer serves as a protective layer for the gas barrier film It functions as well as the function of improving sliding properties during manufacturing and preventing adhesion.

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, from the viewpoint of the heat resistance of the gas barrier film, the primer layer preferably contains 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 heat resistance of the gas barrier film, silicon dioxide particles are preferred.

The average primary particle size of the silicon dioxide particles that may be contained in the primer layer is preferably 5 nm or more, more preferably 10 nm or more, still more preferably 15 nm or more, particularly preferably 20 nm or more, and preferably 100 nm Hereinafter, it is 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 size of the silicon dioxide particles is in the above range, the aggregation of the silicon dioxide particles can be suppressed, and the transparency and heat resistance of the gas barrier film can be improved. In addition, in the case where the primer layer is the outermost layer, if the average primary particle size of the silicon dioxide particles is within the above range, the sliding properties of the gas barrier 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.

From the viewpoint of heat resistance and transparency of the gas barrier film, the content of silicon dioxide particles is preferably 1% by mass to 50% by mass, and more preferably 1.5% by mass to 40% by mass relative to the mass of the primer layer. %, more preferably 2% by mass to 30% by mass.

From the standpoint of easily improving the heat resistance of the gas barrier film and the adhesion between the primer layer and the organic layer, the thickness of the primer layer is preferably 1 μm or less, more preferably 500 nm or less, and even more preferably 200 nm Hereinafter, it is preferably 10 nm or more, more preferably 20 nm or more, and still more preferably 30 nm or more. Furthermore, the thickness of the primer layer can be measured with a film thickness meter. When the gas barrier film includes two or more primer layers, the thickness of each primer layer may be the same or different.

The primer layer can be obtained by applying a resin composition containing a resin, a solvent, and optional additives to a flexible film or the like, and drying the coating film to form a film. The order of forming the primer layer 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 film, etc., various coating methods previously used can be cited, such as spray coating, spin coating, bar coating, curtain coating, dipping, air knife, etc. Sliding 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 described above, for example, an undercoat layer can be formed on at least one side of the flexible film, but a commercially available film with an undercoat layer can also be used on both sides of the flexible film, such as Teijin Film Solution (TEIJIN Film Solution). ) "Teonex (registered trademark)" manufactured by the company.

The primer layer may be a single layer or multiple layers of two or more layers. In addition, when two or more primer layers are included, each primer layer may be a layer including the same composition, or may be a layer including a different composition.

The substrate may also include an organic layer. From the viewpoints of stabilizing the gas barrier properties due to the homogenization of the inorganic thin film layer and/or ensuring the sliding properties during film transport, the substrate preferably includes a flexible film and is formed on the flexible film. The organic layer on at least one side of the sexual film. In addition, when the undercoat layer is included on at least one surface of the substrate, it is preferable that an organic layer is formed on the undercoat layer.

The organic layer may be a layer having a function as a planarization layer, may be a layer having a function as an anti-blocking layer, or may be a layer having both functions. In addition, from the viewpoint of ensuring the sliding properties during film transport, it is preferable that the organic layer is an anti-blocking layer. In addition, the stabilization of the gas barrier properties due to the homogenization of the inorganic thin film layer and the securing of the film during transport From the viewpoint of the coexistence of sliding properties, the organic layer is preferably a planarization layer. In the case of forming organic layers on both sides of the flexible film, both organic layers can be anti-adhesion layers or planarization layers, or one of the organic layers can be an anti-adhesion layer and the other organic layer For the planarization layer. In addition, the organic layer may be a single layer, or multiple layers of two or more layers. In the case of forming two or more organic layers, the multiple organic layers may be layers with the same composition or layers with different compositions. .

The thickness of the organic layer can be appropriately adjusted according to the application, but from the viewpoint of easy improvement of the surface hardness or bending resistance of the gas barrier film, it is preferably 0.1 μm or more, more preferably 0.5 μm or more, and even more preferably 0.7 μm or more , And preferably 5 μm or less, more preferably 4 μm or less, and still more preferably 3 μm or less. When the gas barrier film has two or more organic layers, it is preferable that each organic layer has a thickness in the above-mentioned range, and the thickness of each organic layer may be the same or different. The thickness of the organic layer can be measured by a film thickness meter, for example, by the method described in the examples.

The organic layer can be formed, for example, by applying a composition containing a photocurable compound having a polymerizable functional group to the surface of a flexible film or an undercoat layer and curing 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. When the reaction rate is greater than or equal to the lower limit, it is easy to become colorless and transparent. In addition, when 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, the coating film before curing obtained by applying the composition for forming an organic layer to the surface of a flexible film or a primer layer and drying if necessary and the coating film after curing the coating film Measure the infrared absorption spectrum from the surface of the coating film using a total reflection Fourier Transform-Infrared Spectrometer (FT-IR), and measure 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, by comparing the intensity of the peak derived from the C=C double bond in the (meth)acrylic acid group (I _CC1 ) in the infrared absorption spectrum measured on the coating film before curing, the intensity (I CC1) of the peak derived from the C=O double bond The ratio of the bond peak intensity (I _{CO1 ) (I CC1} /I _CO1 ) and the ratio of the C=C double bond in the (meth)acryloyl group in the infrared absorption spectrum measured on the cured coating film The ratio of the intensity of the peak (I _{CC2 ) to the intensity (I CO2} ) of the peak derived from the C=O double bond _{(I CC2} /I _CO2 ) can be used to calculate the reaction rate. In this case, the reaction rate is calculated by the formula (1): Reaction rate [%]=[1-(I _CC2 /I _CO2 )/(I _CC1 /I _CO1 )]×100 (1). Furthermore, the infrared absorption peak derived from the C=C double bond is usually ^{observed in the range of 1350 cm -1} to 1450 cm ^-1 , for example, 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.

Let the intensity of the infrared absorption peak in the range ^{of 1000 cm -1} to 1100 cm ^-1 of the infrared absorption spectrum of the organic layer _{be I c} , and ^{the intensity of the infrared absorption peak in the range of 1700 cm -1} to 1800 cm ^-1 as When I _d , I _c and I _d preferably satisfy the formula (2): 0.05≦I _d /I _c ≦1.0 (2). 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 _d /I _c ) 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 _d /I _c ) 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 in a high-humidity environment, is easily improved. The peak intensity ratio (I _d /I _c ) 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 (I _d /I _c ) is more than the above lower limit, it is easy to improve the uniformity of the organic layer. It is considered that the reason is that although the present invention is not limited by the mechanism described later, if the Si-O-Si bond derived from siloxane in the compound and polymer contained in the organic layer becomes too large, organic Agglomerates are generated in the layer to cause embrittlement of the layer, and the present invention is easy to reduce the generation of such agglomerates. The peak intensity ratio (I _d /I _c ) 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 (I _d /I _c ) is equal to or less than the above upper limit, it is easy to improve the adhesiveness of the organic layer. It is considered that the reason is that the present invention is not limited by the mechanism described later, but the Si-O-Si bond derived from siloxane is present in the compound and polymer contained in the organic layer in a certain amount, which can be moderately reduced. The hardness of the organic layer. 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 those that can be blended in the undercoat layer, preferably silica 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, the heat resistance of the gas barrier film can be easily improved.

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. When the content of the inorganic particles is within the above range, the heat resistance of the gas barrier film is easily improved. 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 described as a user in 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.

As described above, for example, a composition for forming an organic layer (photocurable composition) containing a photocurable compound can be applied to the surface of a flexible film or an undercoat layer, and dried as necessary, and then irradiated with ultraviolet rays or The electron beam hardens the photocurable compound to form an organic layer.

As a coating method, the same method as the method of coating the said undercoat layer can be 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 and alkyl titanate, etc. The organic layer may contain one kind of these resins or a combination of two or more kinds of these resins.

In the case where the organic layer functions as a planarization layer, the planarization layer is preferably applied to the planarization layer by a rigid pendulum type physical property testing machine (for example, RPT-3000W manufactured by A&D Co., Ltd.) When the temperature change of the elastic coefficient of the surface is evaluated, the temperature at which the elastic coefficient of the surface of the flattened 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 planarization 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 . When the surface roughness of the planarization layer is less than or equal to the above upper limit, the defects of the inorganic thin film layer are reduced, and there is an effect of further improving the gas barrier properties. The surface roughness can be measured by observing the flattened 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.

The thickness of the substrate can be appropriately set in consideration of the stability during the production of the gas barrier film. However, from the viewpoint of facilitating the transportation of the substrate in vacuum, it is preferably 5 μm or more, more preferably 10 μm or more. It is more preferably 15 μm or more, more preferably 550 μm or less, more preferably 250 μm or less, and still more preferably 200 μm or less. Furthermore, the thickness of the substrate can be measured with a film thickness meter.

〔Inorganic thin film layer〕 The gas barrier film preferably includes an inorganic thin film layer laminated on a substrate. By having an inorganic thin film layer, gas barrier properties can be imparted to the film. In one aspect of the present invention, an inorganic thin film layer may be provided on at least one side or both sides of the base material constituting the gas barrier film. When there are two or more inorganic thin film layers on both sides of the substrate, the inorganic thin film layers may have the same structure or different structures.

The inorganic thin film layer is preferably a layer having high density and having a function 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 such as crack), the range of C/Si is preferably to satisfy formula (3): 0.02<C/Si<0.50 (3). 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, for example, X-ray photoelectron spectroscopy (XPS) depth profile measurement can be performed under the following conditions, Based on the obtained distribution curves of silicon atoms, oxygen atoms, and carbon atoms, the average atomic concentration of each atom in the thickness direction is calculated, and then calculated as the average atomic ratio C/Si and the average atomic ratio O/Si. The details are described in the section of Examples described later. <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 (4): 0.01≦I ₂ /I ₁ <0.05 (4).

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 (4) 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 gas barrier 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 (5): 0.25≦I ₃ /I ₁ ≦0.50 (5).

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 (5) 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 (6): 0.70≦I ₄ /I ₃ <1.00 (6).

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 (6) 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 or more, more preferably 10 nm or more, still more preferably 50 nm or more, in addition, preferably 3000 nm or less, more preferably 2000 nm or less, and still more preferably Below 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 above upper limit value, the bending resistance is likely to be improved. In particular, in the case of using a glow discharge plasma to form an inorganic thin film layer by a plasma CVD method 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: from 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 includes 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 gas barrier film. 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 the carbon atoms” continuously changes in the film thickness direction of the inorganic thin film layer, for example, means a portion where the atomic ratio of the carbon distribution curve that does not contain carbon changes discontinuously.

From the viewpoint of bending resistance and gas barrier properties of the gas barrier 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 gas barrier 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 (7) 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) (7) (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 (8) is satisfied: |dC/dx|≦0.01 (8).

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 film 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 viewpoint 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.

The manufacturing method of the gas barrier film is not particularly limited as long as the layers can be formed in any order. As an example, an organic layer is formed on one surface of the flexible film, and then an inorganic thin film layer is formed on the organic layer. Methods. In the case where there is an undercoat layer between the flexible film and the organic layer, after the undercoat layer is formed on one surface of the flexible film, an organic layer can be formed on the undercoat layer. In addition, in the case where the gas barrier film includes organic layers on both sides of the flexible film, organic layers can be formed on both sides of the flexible film in the same manner as the method described above. In addition, after each layer is produced separately, these can be laminated and produced.

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 substrate. 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 gas barrier film as described above has high gas barrier properties, it is suitable, for example, for electronic device applications that require high gas barrier properties. 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 gas barrier film can be preferably used as a flexible substrate of the flexible electronic device. In the case of using such a gas barrier film as a flexible substrate, after forming a component on another substrate, the gas barrier film can be superimposed from above with an adhesive layer or an adhesive layer, but it can be accurately The gas barrier film produced by the optical film manufacturing method of one aspect of the present invention that removes fine foreign matter is suitable for directly forming elements on the film.

The optical film obtained by the manufacturing method of an optical film of one aspect of this invention can be used as a film which has various optical functions, such as a retardation film, according to these optical characteristics. In addition, since the extremely small foreign matter on and/or in the film is also reduced or removed, it is also suitable as a substrate when forming the optical functional layer. As described above, the optical functional layer is likely to be significantly affected by extremely small foreign matter. Appearance defects such as uneven coating or degradation of optical properties occur. When an organic EL element or various optical functional layers are provided on the optical film obtained by one aspect of the manufacturing method of the present invention, the surface of the film after the foreign matter detection coating film is removed by washing or the like, Or instead of removing the coating film for foreign matter detection, a desired layer is formed on the coating film using a conventionally known method.

For example, in one aspect of the manufacturing method of the present invention, when the gas barrier film as described above is used as the raw optical film, foreign matter is formed on the inorganic thin film layer of other layers such as organic EL elements. The coating film for detection, and the detection and removal of foreign matter, can obtain a gas barrier film that is less likely to cause appearance defects or decrease in optical/luminescent properties in organic EL elements or other optical functional layers to be formed later. By directly forming an organic EL element on the inorganic thin film layer of the gas barrier film (optical film) obtained by using one aspect of the manufacturing method of the present invention, various electronic devices such as organic EL displays and organic EL lighting can be manufactured. At this time, the structure of the organic EL element and its production method are not particularly limited. [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. Production of optical film (1) Production of raw material optical film (i) Production of base material with organic layer on biaxially stretched polynaphthalic acid having primer layers on both sides of flexible film 101 as base material One side of ethylene glycol film (manufactured by Teijin Film Solutions (stock), Q65HWA, thickness 100 μm, width 350 mm, double-sided easy bonding process), using gravure as an organic layer forming composition for forming an organic layer Coating method to coat the coating composition (Nippon Chemical Co., Ltd., TOMAX FA-3292). 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 2.5 μm to obtain a substrate with an organic layer.

According to the method for producing the inorganic thin film layer described below, the inorganic thin film layer (thickness 700 nm) on the surface area of the organic layer side of the obtained organic layer substrate was obtained on the substrate (undercoat layer/flexible film/ A laminate film of an inorganic thin film layer is formed on the undercoat layer/organic layer.

In addition, regarding the thickness of each of the organic layer and the inorganic thin film layer of the laminated film, a film thickness meter (manufactured by Kosaka Laboratory Co., Ltd.: Surfcorder ET200) was used for the non-film forming part and the film forming part. Measure the level difference of each layer to obtain the film thickness (T) of each layer.

(Ii) Preparation of the inorganic thin film layer The inorganic thin film layer 103 is laminated on the base material using a manufacturing apparatus as shown in FIG. 1. Specifically, in a manufacturing apparatus as shown in FIG. 1 installed in a vacuum chamber, the substrate 18 with the organic layer 102 is mounted on the delivery roll 10 so that the vacuum chamber is 1×10 ^-3 After Pa or less, while transporting the base material 18 by the transport roller 11, an inorganic thin film layer is formed on the organic layer constituting the base material. In a plasma CVD apparatus for forming an inorganic thin film layer, the substrate 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 while being transported. A plasma is generated between a pair of electrodes, and the raw materials are 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: 0.4 kW Frequency of power supply for plasma generation: 70 kHz Film transport speed: 3.0 m/min Pass times: 28 times

(Iii) Analysis of laminated film The following analysis and evaluation were performed on the obtained laminated film.

[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 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> 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, model name "Quantera SXM" X-ray irradiation: single crystal AlKα (1486.6 eV) X-ray spot and its 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 in the thickness direction of the inorganic thin film layer of the obtained laminated film, 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)] The infrared spectrophotometric measurement of the surface of the inorganic thin film layer of the laminated film is performed using a Fourier transform infrared spectrophotometer (manufactured by JASCO Corporation, FT/IR-460Plus) with an ATR accessory (PIKE MIRacle) using germanium crystals in the film. conduct.

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 had a water vapor permeability of 5.0×10 -5} g/(m ² ·day) under the conditions of a temperature of 40° C. and a humidity of 90% RH.

(Iv) Formation of coating film for foreign matter detection The laminated film produced above was used as a raw material film. Prepare multiple 50 mm square samples cut from the laminated film, and drop 500 mg of fluorescent ink (fluorescent marker supplement ink made by Tombow Pencil) on the central part of the side surface of the inorganic thin film layer of each sample. For the composition for forming a coating film, the fluorescent ink was applied to the entire area of the sample surface by a spin coating method under the conditions of 3,000 rpm and 20 seconds. The coating film obtained was dried at room temperature (25°C) to form a coating film for foreign matter detection with a thickness of 300 nm on the inorganic thin film layer.

The film thickness of the coating film for foreign matter detection is measured using a laser microscope (Olympus (Stock): OLS4100), and the inorganic thin film of the laminated film exposed by the coating film forming part and wiping off the coating film The level difference of the layer surface is measured.

(V) Detection, inspection and removal of foreign objects Light (365 nm, 15 W) was irradiated to the surface of the foreign matter detection coating film side of the laminated film on which the foreign matter detection coating film was formed, and by visual observation, the foreign matter detection coating film containing fluorescent ink was coated. The portion where the cloth film thickness is uneven is determined as the film area where the foreign matter is present. The above-mentioned visual observation was performed on each sample, and the samples not containing the film area where the foreign matter existed and the samples containing the film area where the foreign matter existed were taken out one by one. In this step, foreign matter mainly having a size of about 5 μm to 30 μm and a height of mainly about 0.05 μm to 1.0 μm are removed. Furthermore, the size and height of the foreign matter are measured by directly observing the defect using a laser microscope (Olympus Co., Ltd.: OLS4100).

(Vi) Cleaning of coating film for foreign matter detection The coating film for foreign matter detection formed on the surface of the inorganic thin film layer of the sample that does not contain the film area where the foreign matter exists and the sample that contains the film area where the foreign matter exists is taken out by visual observation, respectively, using high-pressure water (25°C). , 0.6 MPa) for cleaning to remove it.

A sample that does not include a film region where foreign matter is present is used as the optical film 1 obtained by one aspect of the present invention, and a sample that includes a film region where foreign matter is present is used as an optical film for comparison, and an organic EL element is formed according to the following method 20. Evaluation of the optical film.

(Vii) Production of organic EL elements For the optical film 1 from which the coating film for foreign matter detection was removed and the comparative optical film, a metal shadow mask was used, respectively, and an indium tin oxide with a film thickness of 150 nm was formed on the inorganic thin film layer by a sputtering method ( Pattern formation of indium tin oxide (ITO) film. Furthermore, in this patterned film formation, as shown in FIGS. 2 and 3, the ITO film is patterned to form two regions on the surface of the optical film, and one of the regions is used as a cathode lead electrode ( The extraction electrode 203 (a)) of the second electrode uses the other area as an anode (ITO electrode) (first electrode 201). Next, a UV ozone cleaning device (manufactured by Technovision (stock), trade name: UV-312) was used to clean and surface-modify the surface of the optical film on which the ITO film was formed for 10 minutes. Next, the suspension of poly(3,4-ethylenedioxythiophene)/polystyrene sulfonic acid (manufactured by Heraeus Co., Ltd., trade name: AI4083) was filtered with a filter with a diameter of 0.2 μm The resulting filtrate was formed by spin coating on the surface of the optical film on which the ITO film was formed, and dried on a hot plate under atmospheric pressure at a temperature of 160°C for 60 minutes to form a thickness of 65 on the ITO film. nm hole injection layer.

Prepare a xylene solution in which a light-emitting material (polymer compound) is dissolved in xylene as an organic solvent. In addition, the light-emitting material (polymer compound) was prepared by the same method as the preparation method of the composition 1 described in Example 1 of JP 2012-144722 A. Next, under atmospheric pressure, the xylene solution was coated on the hole injection layer surface of the optical film formed with the ITO film and the hole injection layer by a spin coating method to make a thickness of 80 nm Coating film for light emitting layer. Thereafter, under a nitrogen atmosphere in which the oxygen concentration and the water concentration were controlled to be 10 vol ppm or less, the light-emitting layer was laminated on the hole injection layer by keeping it at a temperature of 130° C. for 10 minutes and drying it. After that, the hole injection layer and the light-emitting layer formed on the contact portion with the external electrode (portion of the extraction electrode for the anode and the cathode) are removed, and a part of it is exposed so that it can be in contact with the external electrode. Next, the optical film formed with the ITO film, the hole injection layer, and the light-emitting layer is moved to the vapor deposition chamber, and a cathode is laminated on the surface of the light-emitting layer in order to adjust (align) the position with the cathode mask. The cathode is electrically connected to the part where the cathode is drawn out to form a film. Therefore, the cathode is vapor deposited while the mask and the substrate are rotated. The cathode formed in this way has the following structure. First, sodium fluoride (NaF) is heated to vaporize at a vapor deposition rate of about 0.5 Å/sec until the thickness reaches about 4 nm, and then aluminum (Al) is vaporized at a vapor deposition rate of about 4 nm. It is deposited at about 4 Å/sec to a thickness of about 100 nm and layered.

Next, using a roll cutter, the electrolytic copper foil with a thickness of 35 μm was cut into a shape that, when it is laminated on the cathode and viewed from the cathode side, has a contact part that can cover the entire light-emitting layer and is in contact with the external electrode (The part of the lead electrode for the anode and the cathode) has a shape of a size that is exposed to the outside (refer to FIG. 3: As shown in FIG. 3, when the electrolytic copper foil (sealing substrate 4) is viewed from the top) The shape of the following size, which has a larger area than the cathode, does not see the size of the cathode, and is the contact part that contacts the outside formed on the gas barrier film (the lead electrode for the anode and the lead electrode for the cathode Part) (a part of the lead electrode 203(a) of the first electrode 201 and the second electrode) has a size that appears to be exposed to the outside of the electrolytic copper foil), and a sealing substrate is prepared. The sealing substrate containing the electrolytic copper foil prepared in this way has a length of 40 mm, a width of 40 mm, and a thickness of 35 μm.

In a nitrogen atmosphere, the sealing substrate (electrolytic copper foil) was heated at a temperature of 130° C. for 15 minutes to remove moisture adsorbed on the surface (drying treatment was performed). Next, a two-component epoxy adhesive 3 cured at room temperature (25°C) by mixing a main agent containing bisphenol A epoxy resin and a curing agent containing modified polyamide is used as a sealing material , The sealing material is applied to cover the light-emitting element part composed of the laminated structure including the ITO film/hole injection layer/light-emitting layer/cathode, and the sealing material is pasted on the layer of the sealing material so that the sealing substrate faces the cathode The sealing substrate is closed and sealed. That is, the sealing material (adhesive) is applied so as to cover the laminated structure part including the ITO film/hole injection layer/light-emitting layer/cathode The connection part (except for a part of the part where the electrode is drawn) is attached to the sealing substrate on the sealing material layer on the surface of the gas barrier film after the cathode is formed so that air bubbles do not enter into the nitrogen. This seals the light-emitting element part (the layered structure part of the ITO film/hole injection layer/light-emitting layer/cathode: except for a part of the extraction electrode) to manufacture an organic EL element. Furthermore, this organic EL element is flexible. This organic EL element has a structure in which a hole injection layer is further laminated on the light-emitting element portion 2 of the organic EL element shown in FIG. 2 (the light-emitting element portion 2 shown in FIG. The structure is different from the light-emitting element section, but otherwise the structure is basically the same as an organic EL element). Here, the thickness of the sealing material layer is 10 μm.

FIG. 3 shows a schematic diagram of the organic EL element 202 viewed from the sealing substrate side. In addition, as shown in FIG. 3, when the obtained organic EL element is viewed from the side of the sealing substrate 4, the gas barrier film and the part (connection part with the outside) leading to the outside of the anode (first electrode 201) can be confirmed: The extraction electrode), the connection portion between the cathode 203 and the outside (the extraction electrode 203 (a) of the second electrode), and the sealing substrate 4. As mentioned above, when using a sealing material and a sealing substrate, a part of the lead electrode of each electrode can be connected to the outside, and the light-emitting element part (including ITO film/hole injection layer/light-emitting layer/cathode The layered structure part) is sealed around. In addition, in the light-emitting element portion, the size of the light-emitting region (the area of the light-emitting portion) is 10 mm in length and 10 mm in width.

The organic EL element formed on the optical film 1 was made to emit light. As a result, it was confirmed that the entire surface of 10 mm in length and 10 mm in width was uniformly emitted. Next, the organic EL element was stored under accelerated test conditions at 60° C. and 90% RH. After storage for 100 hours, the area ratio of the non-light-emitting portion (dark spot) observed when emitting light again was determined. As a result, it was 0.5%.

Similarly, in a comparative optical film in which an organic EL element was formed, the organic EL element was allowed to emit light. As a result, five non-luminous points accompanied by foreign matter were observed. In addition, it was stored under accelerated test conditions of 60° C. and 90% RH. After storage for 100 hours, the area ratio of the non-light-emitting portion (dark spot) observed when light was re-emitted was 10%.

1: Optical film 2: Light-emitting element section 3: Adhesive 4: Sealing substrate 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: Substrate 20: Organic EL element 101: Flexible film 102: Organic layer 103: Inorganic thin film layer 201: first electrode 202: Organic EL layer 203: Cathode 203(a): Take-out electrode of the second electrode

Fig. 1 is a schematic diagram showing a manufacturing apparatus of an optical film used in Examples. 2 is a schematic cross-sectional view of an organic EL element laminated on an optical film manufactured by an aspect of the manufacturing method of the present invention. Fig. 3 is a schematic view of an organic EL element laminated on an optical film manufactured by an aspect of the manufacturing method of the present invention, viewed from the sealing substrate side.

Claims (13)

A method for manufacturing an optical film includes: a) The step of forming a coating film for foreign matter detection on the surface of a raw film with optical properties; b) by irradiating the surface of the film on which the coating film is formed with light to detect foreign matter present on the film and/or inside the film, and determining the film area where the foreign matter exists; and c) The step of removing the film area or marking the film area to obtain an optical film. The method of manufacturing an optical film according to claim 1, wherein the coating film for foreign matter detection includes at least one selected from the group consisting of a fluorescent substance, a colorant, a high refractive index material, and a low refractive index material. The method of manufacturing an optical film according to claim 1 or claim 2, wherein the refractive index of the coating film for foreign matter detection relative to the raw film forming the coating film has 3% or more and 50% or less in absolute value The refractive index. The method of manufacturing an optical film according to any one of claims 1 to 3 includes a step of removing the coating film for foreign matter detection by washing. The method of manufacturing an optical film according to any one of claims 1 to 4, including a step of manufacturing a raw film having optical properties. The method for manufacturing an optical film according to any one of claims 1 to 5, wherein the raw material film is a long strip. The method of manufacturing an optical film according to any one of claims 1 to 6, which includes processing a long raw film or an optical film into a single piece. The method for manufacturing an optical film according to any one of claims 1 to 7, wherein the optical film includes a substrate and an inorganic thin film layer laminated on the substrate. The method of manufacturing an optical film according to claim 8, wherein the base material includes an organic layer. The method of manufacturing an optical film according to claim 8 or claim 9, wherein the inorganic thin film layer is a layer formed by a plasma chemical vapor deposition method. The method for manufacturing an optical film according to any one of claims 8 to 10, wherein the inorganic thin film layer contains silicon atoms, oxygen atoms, and carbon atoms. The method of manufacturing an optical film according to claim 11, 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% in the thickness direction of the inorganic thin film layer. It changes continuously in the area above %. The method of manufacturing an optical film according to any one of claims 1 to 12, wherein the optical film has gas barrier properties.

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