JP2007269957A - Gas-barrier film, method for producing the same, and image display element using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a film having high gas-barrier performance, and excellent flexibility. <P>SOLUTION: The method for producing the gas-barrier film comprises a process of preparing a radiation-curable monomer layer on a base film, a process of treating the radiation-curable monomer layer with heat, and a process of curing the heat-treated radiation-curable monomer layer with a radiation. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a gas barrier film having excellent gas barrier performance. More specifically, the present invention relates to a gas barrier film that can be suitably used for various image display elements, and particularly useful as a substrate for flexible organic electroluminescence elements (hereinafter referred to as “organic EL elements”). And its manufacturing method, and an organic EL device.

  Conventionally, a gas barrier film in which a metal oxide thin film such as aluminum oxide, magnesium oxide, silicon oxide or the like is formed on the surface of a plastic substrate or film is used for packaging an article that requires blocking of various gases such as water vapor and oxygen, It is widely used in packaging applications to prevent the deterioration of food, industrial goods and pharmaceuticals. Recently, gas barrier films are being used in liquid crystal display elements, solar cells, EL, and the like in addition to packaging applications.

  In the development process of image display elements such as liquid crystal display elements and EL elements in recent years, long-term reliability and flexibility of shape are required for transparent base materials forming these elements in addition to the conditions of weight reduction and size increase. Advanced conditions such as high image quality and the ability to display curved surfaces are also required. As a transparent base material satisfying such advanced conditions, a plastic base material has begun to be adopted as a new base material that replaces a conventional glass substrate that is heavy, fragile and difficult to increase in area. In the case of a plastic substrate, not only the above conditions are satisfied, but it is possible to manufacture by a roll-to-roll method, so that the productivity is better than a glass substrate and it is advantageous in terms of cost reduction.

However, film substrates such as transparent plastics have the disadvantage that the gas barrier performance is inferior to that of glass substrates. If a base material with inferior gas barrier properties is used, water vapor or air will permeate, for example, causing deterioration of the liquid crystal in the liquid crystal cell, resulting in display defects and deterioration of display quality. In order to solve such problems, gas barrier films in which a metal oxide thin film is formed on a film substrate have been developed so far. For example, as gas barrier films used for packaging materials and liquid crystal display elements, those obtained by depositing silicon oxide on a plastic film (Patent Document 1) and those obtained by depositing aluminum oxide (Patent Document 2) are known. , Both have a water vapor barrier property of about 1 g / (m ² · day).

On the other hand, in large-sized liquid crystal displays and high-definition displays that have been developed in recent years, the gas barrier performance required for plastic film substrates is about 0.1 g / (m ² · day) in terms of water vapor barrier properties. Furthermore, recently, the development of organic EL displays, high-definition color liquid crystal displays, etc. has progressed, and while maintaining the transparency that can be used in these displays, it has a higher barrier performance, particularly 0.1 g / (m ² · day for a water vapor barrier. There is a need for transparent substrates with performance below.
In order to meet these demands, recently, as a means for expecting higher barrier performance, film formation by sputtering method or CVD method in which a thin film is formed using plasma generated by glow discharge under low pressure conditions has been studied. ing. In addition, an organic light emitting device in which a barrier film having an alternately laminated structure of organic layers / inorganic layers is produced by a vacuum deposition method has been proposed (Patent Document 3). However, since this device has insufficient bending resistance, it cannot be applied to a flexible image display element.

In order to provide the bending resistance necessary for application to a flexible image display element, a technique is disclosed in which a polymer obtained by polymerizing an acrylic monomer having a volume shrinkage rate of less than 10% is used in an organic layer (Patent Literature). 4). However, this technique has a problem that the gas barrier property is not sufficient.
Therefore, it has been desired to develop a plastic film having gas barrier properties and bending resistance that can be applied to flexible image display elements.
Japanese Examined Patent Publication No. 53-12953 (Example) JP 58-217344 A (Example) US Pat. No. 6,268,695 (page 4 [2-5] to page 5 [4-49]) JP 2003-53881 A (Page 3 [0006] to Page 4 [0008])

  The present invention has been made in view of the above problems, and a first object of the present invention is to provide a gas barrier film that can maintain excellent gas barrier properties even when bent. A second object of the present invention is to provide an image display element having excellent durability using the gas barrier film.

  As a result of earnestly examining the cause of occurrence of problems in the prior art, the present inventor may have insufficient adhesion between the organic layer formed on the base film and the adjacent inorganic layer or base film. I found that it contributed. Therefore, as a result of investigating increasing gas barrier properties and flex resistance while ensuring sufficient adhesion between the organic layer and inorganic layer and between the organic layer and the substrate film, it was identified as an organic layer. It has been found that the problem can be solved by adopting the resin layer produced by the above method. Based on such findings, the present inventor has provided the present invention described below.

  The first object of the present invention is to provide a step of providing a radiation-curable monomer layer on a substrate film, a step of heat-treating the radiation-curable monomer layer, and the radiation-curable monomer layer after the heat treatment by radiation. And a step of curing. The method is achieved by a method for producing a gas barrier film. The first object of the present invention is to provide a step of providing a radiation-curable monomer layer on an inorganic layer provided on a substrate film, a step of heat-treating the radiation-curable monomer layer, and the heat treatment. And a step of curing the subsequent radiation curable monomer layer by radiation.

In the production method of the present invention, the following step (1) may be further performed on the radiation-curable resin layer after the curing, and the following step (1) and step (2) are alternately performed at least 1 each. It may be done once.
Step (1): Step of providing an inorganic layer on the cured radiation curable resin layer Step (2): A radiation curable monomer layer is provided on the inorganic layer, and the radiation curable
The monomer layer is heat-treated, and the radiation-curable monomer after the heat treatment
Curing the layer with radiation

  In the manufacturing method of this invention, you may further perform the process of providing a transparent conductive layer on the inorganic layer which is the uppermost layer, or the radiation-curable resin layer after hardening. In addition, it is preferable to perform the heat processing in the manufacturing method of this invention by heating the said radiation-curable monomer layer to 50 degreeC or more. The inorganic layer preferably contains a metal oxide or metal nitride as a main component, and particularly contains a metal oxide such as silicon, aluminum, titanium, zirconium or tin, a nitride or a composite thereof. It is preferable that

The present invention also provides a gas barrier film produced by the above production method. The gas barrier film of the present invention has an oxygen permeability of 0.01 ml / (m ² · day · atm) or less at 38 ° C. and a relative humidity of 90%, and has a water vapor transmission rate of 0 at 38 ° C. and a relative humidity of 90%. It is preferably not more than 0.01 g / (m ² · day).

  The second object of the present invention is achieved by an image display device using the gas barrier laminate film. In particular, if the gas barrier laminate film is used for a flexible image display element or organic EL element, the features of the present invention can be exhibited more effectively.

  The gas barrier film of the present invention has high gas barrier performance and excellent bending resistance. The image display element of the present invention having a gas barrier film having such characteristics has high durability.

  Hereinafter, the gas barrier film of the present invention, its production method, and the image display element will be described in detail. The description of the constituent elements described below may be made based on typical embodiments of the present invention, but the present invention is not limited to such embodiments. In the present specification, a numerical range represented by using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.

[Method for producing gas barrier film]
(Steps constituting the manufacturing method)
The method for producing a gas barrier film of the present invention includes a step of providing a radiation curable monomer layer on a base film or an inorganic layer provided on the base film, and a step of heat-treating the radiation curable monomer layer. And a step of curing the radiation-curable monomer layer after the heat treatment with radiation.

The resin layer production step may be performed only once or a plurality of times in the method for producing a gas barrier film of the present invention. When performing several times, it is preferable to comprise so that an inorganic layer may be pinched | interposed between the resin layers to produce. Specifically, it is preferable that the following step (1) and step (2) are alternately performed at least once, and at least the steps of step (1), step (2), and step (1) are performed. Is more preferable.
Step (1): Step of providing an inorganic layer on the cured radiation curable resin layer Step (2): A radiation curable monomer layer is provided on the inorganic layer, and the radiation curable
The monomer layer is heat-treated, and the radiation-curable monomer after the heat treatment
Curing the layer with radiation

  If the manufacturing method of this invention includes the preparation process of said resin layer, it may further include the process of producing another layer, a surface treatment process, etc. Other layer types are not particularly limited. For example, a functional layer may be formed between the base film and the inorganic layer, between the base film and the resin layer, and between the inorganic layer and the resin layer. Examples of functional layers include optical functional layers such as antireflection layers, polarizing layers, color filters, and light extraction efficiency improving layers; mechanical functional layers such as hard coat layers and stress relaxation layers; antistatic layers and conductive layers An electric functional layer; an antifogging layer; an antifouling layer; a printing layer and the like.

At least the inorganic gas barrier layer, the resin layer, and the inorganic gas barrier layer are laminated in this order on the base film surface (opposite surface) opposite to the side having the inorganic layer and the resin layer containing a polymer having a phosphate ester group. A gas barrier laminate layer can be provided. By providing such a gas barrier laminate layer, water molecules can be prevented from entering from the opposite surface. As a result, the dimensional change of the gas barrier laminate film can be suppressed to prevent stress concentration and destruction on the inorganic layer (gas barrier layer), and as a result, the durability can be further enhanced.
Below, each layer produced with the manufacturing method of this invention is demonstrated in detail.

(Resin layer)
When forming the resin layer in the production method of the present invention, first, a layer containing a radiation curable monomer is formed.
A radiation curable resin is a resin that cures when irradiated with radiation such as ultraviolet rays and electron beams. Specifically, an unsaturated double molecule such as an acryloyl group, a methacryloyl group, or a vinyl group in a molecule or a single structure. A resin containing a bond. Among these, an acrylic resin containing an acryloyl group is particularly preferable. In the production method of the present invention, one type of resin may be used as the radiation curable resin, or two or more types of resins may be mixed and used. In the production method of the present invention, it is preferable to use an acrylic resin having two or more acryloyl groups in a molecule or unit structure. Examples of such a polyfunctional acrylate resin include urethane acrylate, ester acrylate, epoxy acrylate, and the like, but the polyfunctional acrylate resin that can be employed in the present invention is not limited to these.

  When an ultraviolet curing method is used when curing these radiation curable resins, an appropriate amount of a known photoreaction initiator is added to the radiation curable resin. Examples of the photoreaction initiator include IRGACURE series manufactured by Ciba Specialty Chemicals. The addition amount of the photoinitiator is preferably 0.1 to 10% by mass, and more preferably 1 to 5% by mass with respect to the total amount of the radiation curable monomer.

  In order to further strengthen the interaction with the polymer molecule, a hydrolyzate of alkoxysilane or a silane coupling agent may be mixed in the radiation curable resin. As the silane coupling agent, one having a hydrolyzable reactive group such as a methoxy group, an ethoxy group, or an acetoxy group and the other having an epoxy group, a vinyl group, an amino group, a halogen group, or a mercapto group. preferable. Particularly preferred are those having a vinyl group having the same reactive group for fixing to the main component resin, such as KBM-503, KBM-803 of Shin-Etsu Chemical Co., Ltd., A made by Nihon Unicar Co., Ltd. -187 or the like is used. These addition amounts are preferably 0.2 to 3% by mass with respect to the total amount of the radiation curable monomer.

  Examples of the method for forming the resin layer include a coating method and a vacuum film forming method. Although there is no restriction | limiting in particular as a vacuum film-forming method, Film-forming methods, such as vapor deposition and plasma CVD, are preferable, and the resistance heating vapor deposition method which is easy to control the film-forming rate of an organic substance monomer is more preferable. The method for crosslinking the monomer used in the present invention is not limited in any way, but crosslinking with an electron beam or ultraviolet ray by irradiation with active energy rays can be easily mounted in a vacuum chamber, and the high molecular weight by a crosslinking reaction is rapid. desirable.

  When the resin layer is formed by a coating method, various conventionally used coating methods such as roll coating, gravure coating, knife coating, dip coating, curtain flow coating, spray coating, and bar coating may be used. it can. Examples of the solvent for application include methyl ethyl ketone.

  After providing the radiation curable monomer layer, the radiation curable monomer layer is heat-treated. The heat treatment as used herein refers to heating to such an extent that the constituent material of the radiation curable monomer layer does not evaporate. The heating temperature is preferably 50 to 200 ° C, more preferably 50 to 150 ° C, and further preferably 50 to 100 ° C. The heating time is preferably 1 to 20 minutes, and preferably 5 to 10 minutes. The heating method is not particularly limited, and examples thereof include a heating method using a heating wire heater.

  After the heat treatment, the radiation curable monomer layer is cured by radiation. The term “radiation” as used herein means radiation capable of propagating energy by irradiation with ultraviolet rays, X-rays, electron beams, infrared rays, microwaves, and the like, and the type and energy can be arbitrarily selected according to the application. it can. The irradiation amount and irradiation time of the radiation are adjusted to a degree sufficient to cure the radiation curable monomer layer. The radiation is adjusted so as to irradiate the resin surface, but the surface opposite to the resin surface may be irradiated.

(Inorganic layer)
The inorganic layer produced in the method for producing a gas barrier film of the present invention is preferably a layer made of a metal oxide, nitride, or oxynitride such as silicon, aluminum, titanium, zirconium, tin, or a composite thereof. The layer which consists of may be sufficient.

  The inorganic layer can be formed by vapor deposition, physical vapor deposition (PVD) such as sputtering or ion plating, various chemical vapor deposition (CVD), or liquid phase such as plating or sol-gel. There is a growth method. Among these, chemical vapor deposition (CVD) and physical vapor deposition are effective in avoiding the effects of heat on the base film during inorganic layer formation, high production speed, and easy to obtain a uniform thin film layer. The method (PVD) is preferred. Moreover, it is also preferable to form an inorganic layer by a sol-gel method from the viewpoint that a thick film can be easily obtained. Here, the thick film refers to a film in the range of 100 nm to 1 μm.

  The thickness of the inorganic layer is preferably 30 nm to 1 μm, and more preferably 50 to 200 nm. When the thickness of the inorganic layer is in the range of 50 nm to 1 μm, it is difficult to be affected by defective portions or portions having low density between crystals, and high gas barrier properties can be obtained. Further, even when it is deformed, the destruction of the inorganic layer can be reduced, which is preferable in practice.

(Base film)
The base film used in the method for producing a gas barrier film of the present invention is preferably selected from materials having heat resistance so that it can be used as an image display element described later. A preferable base film is a transparent plastic film having a glass transition temperature (Tg) of 100 ° C. or higher and / or a linear thermal expansion coefficient of 40 ppm / ° C. or lower and high heat resistance. Tg and the linear expansion coefficient can be changed by an additive or the like.

  The polymer used for the substrate film may be either a thermoplastic polymer or a thermosetting polymer. The thermoplastic polymer preferably has a polymer Tg of 130 to 300 ° C, more preferably 160 to 250 ° C. Further, in order to achieve optical uniformity, an amorphous polymer is preferable. Examples of such thermoplastic resins include the following (in parentheses indicate Tg).

  Polycarbonate (PC: 140 ° C.), alicyclic polyolefin (for example, ZEONOR 1600: 160 ° C. manufactured by Nippon Zeon Co., Ltd.), polyarylate (PAr: 210 ° C.), polyethersulfone (PES: 220 ° C.), polysulfone (PSF: 190 ° C), cycloolefin copolymer (COC: compound of JP 2001-150584 A, 162 ° C.), fluorene ring-modified polycarbonate (BCF-PC: compound of JP 2000-227603 A: 225 ° C.), alicyclic modification Polycarbonate (IP-PC: compound of JP 2000-227603 A: 205 ° C.), acryloyl compound (compound of JP 2002-80616 A: 300 ° C. or higher). In particular, when transparency is required, it is preferable to use an alicyclic polyolefin or the like.

  Examples of the thermosetting polymer include epoxy resins and radiation curable resins. Examples of the epoxy resin include polyphenol type, bisphenol type, halogenated bisphenol type, and novolac type. A known curing agent can be used as the curing agent for curing the epoxy resin. Examples thereof include curing agents such as amines, polyaminoamides, acids and acid anhydrides, imidazoles, mercaptans, and phenol resins. Among them, from the viewpoints of solvent resistance, optical properties, thermal properties, etc., polymers or aliphatic amines containing acid anhydrides and acid anhydride structures are preferably used, and particularly preferred are acid anhydrides and acid anhydride structures. It is a polymer containing. Furthermore, it is preferable to add an appropriate amount of a known curing catalyst such as tertiary amines and imidazoles. Examples of the radiation curable resin are the same as those used for the resin layer.

  When the produced gas barrier film is used as an image display element such as a display, a transparent substrate film, that is, a base having a light transmittance of 80% or more, preferably 85% or more, more preferably 90% or more. It is preferable to use a material film. If the light transmittance of the base film is 80% or more, it can be suitably used as a base film of an organic EL element described later.

  It goes without saying that an opaque material can be used for applications that do not necessarily require transparency, such as when not used on the viewing side even when used for display applications, or for opaque packaging materials. Examples thereof include polyimide, polyacrylonitrile, and known liquid crystal polymers.

  The light transmittance used as a scale of transparency in this specification is determined by measuring the total light transmittance and the amount of scattered light using the method described in JIS-K7105, that is, using an integrating sphere light transmittance measuring device. It can be calculated by subtracting the diffuse transmittance from the light transmittance.

(Transparent conductive layer)
In the production method of the present invention, a transparent conductive layer can be laminated on at least one side of the film. A known metal film, metal oxide film, or the like can be applied as the transparent conductive layer. Among these, a metal oxide film having excellent transparency, conductivity, and mechanical properties is preferably used as the transparent conductive layer. The metal oxide film is, for example, a metal oxide film of indium oxide, cadmium oxide or tin oxide to which tin, tellurium, cadmium, molybdenum, tungsten, fluorine, zinc, germanium or the like is added as an impurity; an oxide to which aluminum is added as an impurity Examples thereof include metal oxide films such as zinc and titanium oxide. Among them, an indium oxide thin film mainly composed of tin oxide and containing 2 to 15% by mass of zinc oxide is excellent in transparency and conductivity, and is preferably used.

  The transparent conductive layer can be formed by any method as long as it can form a target thin film. For example, a vapor deposition method that forms a film by depositing a material from the vapor phase, such as sputtering, vacuum deposition, ion plating, plasma CVD, and Cat-CVD, is suitable. The film can be formed by the methods described in Japanese Patent Laid-Open Nos. 2002-322561 and 2002-361774. Among these, the sputtering method is preferable from the viewpoint that particularly excellent conductivity and transparency can be obtained.

  The preferred degree of vacuum of the sputtering method, vacuum deposition method, ion plating method, or plasma CVD method is 0.133 mPa to 6.65 Pa, preferably 0.665 mPa to 1.33 Pa. Before forming the transparent conductive layer, it is preferable to subject the base film to a surface treatment such as plasma treatment (reverse sputtering) or corona treatment. Moreover, you may heat up to 50-200 degreeC during providing the transparent conductive layer.

  The film thickness of the transparent conductive layer thus obtained is preferably 20 to 500 nm, and more preferably 50 to 300 nm.

  The surface electrical resistance of the transparent conductive layer measured at 25 ° C. and 60% relative humidity is preferably 0.1 to 200Ω / □, and more preferably 0.1 to 100Ω / □. More preferably, it is 0.5-60Ω / □. Moreover, the light transmittance of the transparent conductive layer is preferably 80% or more, more preferably 83% or more, and further preferably 85% or more.

[Gas barrier film]
The gas barrier film produced by the production method of the present invention has high gas barrier performance and excellent bending resistance. A preferable gas barrier film produced by the production method of the present invention has an oxygen permeability of 0.01 ml / (m ² · day · atm) or less at 38 ° C. and 90% relative humidity, and 38 ° C. and 90% relative humidity. % Water vapor transmission rate is 0.01 g / (m ² · day) or less. A more preferable gas barrier film produced by the production method of the present invention has an oxygen transmission rate of not more than 0.005 ml / (m ² · day · atm) at 38 ° C. and 90% relative humidity, and 38 ° C./relative humidity. The water vapor transmission rate at 90% is 0.005 g / (m ² · day) or less. In addition, the gas barrier film produced by the production method of the present invention can maintain high gas barrier properties even when it is repeatedly bent.

  The gas barrier film produced by the production method of the present invention can be effectively applied to a wide variety of articles and flexible articles that are required to block water vapor, oxygen and the like. For example, food packaging film, industrial product packaging film, pharmaceutical packaging film, flexible display substrate film, flat panel display substrate film, solar cell substrate film, touch panel substrate film, flexible circuit substrate film, optical disc protection It can be used for films, optical films, retardation films, polarizing plate protective films, transparent conductive films and the like.

[Image display element]
In particular, the gas barrier film of the present invention can be effectively used for an image display element. Here, the image display element refers to all elements having an image display function such as a circularly polarizing plate, a liquid crystal display element, an organic EL element, and electronic paper. In these image display elements, the gas barrier film of the present invention can be suitably used as a substrate or a sealing film. Since the gas barrier film of the present invention has excellent bending resistance, the characteristics can be effectively used when used in a flexible image display element. The term “flexible” as used herein means that the shape of the portion to which the gas barrier film is applied is not fixed and has a function capable of changing the shape according to the use mode. Specific examples of flexible image display elements include organic EL elements and electronic paper.
Below, the circularly-polarizing plate, liquid crystal display element, and organic EL element which can use the gas barrier film of this invention preferably are demonstrated in order.

(Circularly polarizing plate)
The circularly polarizing plate can be produced by laminating a λ / 4 plate and a polarizing plate on the gas barrier film of the present invention. In this case, the lamination is performed so that the slow axis of λ / 4 and the absorption axis of the polarizing plate are 45 °. As such a polarizing plate, it is preferable to use what is extended | stretched in the 45 degree direction with respect to the longitudinal direction (MD), For example, what is described in Unexamined-Japanese-Patent No. 2002-865554 can be used suitably.

(Liquid crystal display element)
Liquid crystal display devices can be broadly classified into reflective liquid crystal display devices and transmissive liquid crystal display devices.
The reflective liquid crystal display device has a configuration including a lower substrate, a reflective electrode, a lower alignment film, a liquid crystal layer, an upper alignment film, a transparent electrode, an upper substrate, a λ / 4 plate, and a polarizing film in order from the bottom. The gas barrier film of the present invention can be used as a transparent electrode and an upper substrate. When the reflective liquid crystal display device has a color display function, it is preferable to further provide a color filter layer between the reflective electrode and the lower alignment film, or between the upper alignment film and the transparent electrode.

  The transmissive liquid crystal display device includes a backlight, a polarizing plate, a λ / 4 plate, a lower transparent electrode, a lower alignment film, a liquid crystal layer, an upper alignment film, an upper transparent electrode, an upper substrate, a λ / 4 plate, and a polarization, in that order It has a structure consisting of a film. Among these, the gas barrier film of the present invention can be used as an upper transparent electrode and an upper substrate. Further, when the transmissive liquid crystal display device is provided with a color display function, it is preferable to further provide a color filter layer between the lower transparent electrode and the lower alignment film, or between the upper alignment film and the transparent electrode.

  The structure of the liquid crystal layer is not particularly limited. An OCB (Optically Compensated Bend) type or a CPA (Continuous Pinwheel Alignment) type is preferable.

(Organic EL device)
An organic EL element has a cathode and an anode on a substrate, and an organic compound layer including an organic light emitting layer (hereinafter sometimes simply referred to as “light emitting layer”) between both electrodes. In view of the properties of the light emitting element, at least one of the anode and the cathode is preferably transparent. The specific layer structure of the organic EL device includes anode / light emitting layer / transparent cathode, anode / light emitting layer / electron transport layer / transparent cathode, anode / hole transport layer / light emitting layer / electron transport layer / transparent cathode, anode / Hole transport layer / light emitting layer / transparent cathode, anode / light emitting layer / electron transport layer / electron injection layer / transparent cathode, anode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / electron injection layer / transparent cathode, etc. Is mentioned. The gas barrier film of the present invention having a transparent conductive layer can be used as a transparent electrode in these layer configurations.

  When the gas barrier film of the present invention is used for an organic EL or the like, JP-A-11-335661, JP-A-11-335368, JP-A-2001-192651, JP-A-2001-192652, JP-A-2001-192653. JP, 2001-335776, JP, 2001-247859, JP, 2001-181616, JP, 2001-181617, JP, 2002-181816, JP, 2002-181617, JP, 2002-056776, etc. It is preferable to use together with the content of each of these publications, and JP 2001-148291, JP 2001-221916, JP 2001-231443. That is, the gas barrier film of the present invention can be used as a base film and / or a protective film when forming an organic EL element.

  The features of the present invention will be described more specifically with reference to examples and comparative examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the specific examples shown below.

<Example 1>
(Preparation of base film)
After mixing 10 parts by mass of a synthetic mica [Coop Chemical Co., Ltd., Somasif MTE] with 100 parts by mass of cycloolefin polymer resin [manufactured by Nippon Zeon Co., Ltd., ZEONOR 1600R, Tg163 ° C.], a twin screw extruder [ A base film 1A having a film thickness of 200 μm was obtained by kneading and extruding at 270 ° C. using Rhemix 600P / PTW25] manufactured by Haake, Germany. The light transmittance at 550 nm of the base film 1A was 90%.

(Preparation of inorganic layer)
On the base film 1A, a reactive vapor deposition was performed under vacuum to form an alumina layer having a thickness of 60 nm as an inorganic layer by a sputtering method. This was designated as film 2A.

(Production of resin layer)
10 g of tripropylene glycol diacrylate as a photopolymerizable acrylate and 0.1 g of a photopolymerization initiator [Ciba Specialty Chemicals, IRGACURE907] were prepared and dissolved in 190 g of methyl ethyl ketone to obtain a coating solution. . This coating solution is applied onto the base film 1A using a wire bar, and heat-treated at 80 ° C. for 5 minutes under a nitrogen purge with an oxygen concentration of 0.1% or less, followed by 160 W / cm air cooling. Using a metal halide lamp (made by Eye Graphics Co., Ltd.), a resin layer having a film thickness of 300 nm is obtained by heating at 80 ° C. for 5 minutes while irradiating ultraviolet rays with an illuminance of 350 mW / cm ² and an irradiation amount of 500 mJ / cm ^2. Formed. This was designated as gas barrier film 2B.
A gas barrier film 2D formed on the base film 1A under the same conditions as the film 2B except that IRR-214K manufactured by Daicel Cytec Co., Ltd. was used instead of tripropylene glycol diacrylate as the photopolymerizable acrylate. It was. Further, the gas barrier films 2B and 2D which were not subjected to the heat treatment before UV curing were designated as gas barrier films 2C and 2E, respectively.
Further, the film 2A was used in place of the base film 1A, and the respective resin layers were formed on the film 2A by the same method as the gas barrier films 2B to 2E, which were designated as gas barrier films 3A to 3D, respectively.

(Preparation of inorganic layer)
On the resin layers of the gas barrier films 2B to 2E, an alumina layer having a film thickness of 60 nm was formed under the same conditions as described above, and the gas barrier films 3E to 3H were obtained.
Moreover, what formed the 60-nm-thickness alumina layer on the resin barrier of gas barrier film 3A-3D on the conditions similar to the above was made into gas barrier film 4A-4D, respectively.

(Preparation of transparent conductive layer)
The gas barrier film 4A was introduced into a vacuum chamber, and a transparent conductive layer (transparent electrode) made of an ITO thin film having a thickness of 200 nm was formed on the inorganic layer by DC magnetron sputtering using an ITO target. This was designated as a gas barrier film 5A.

<Test example>
(Adhesion test)
In order to evaluate the adhesion of the laminated film, a cross-cut test based on JIS K5400 was performed. The surface of the gas barrier films 2B to 2E and 3A to 3D on the resin layer side and the surface of the gas barrier films 3E to 3H and 4A to 4D on the inorganic layer side are each cut by 90 ° with respect to the film surface with a cutter knife. Were placed at 1 mm intervals to make 100 grids at 1 mm intervals. A 2 cm wide Mylar tape [manufactured by Nitto Denko, polyester tape (No. 31B)] was applied thereto, and the tape attached using a tape peeling tester was peeled off. Of the 100 grids on the film, the number of cells remaining without peeling was counted and evaluated. The results are shown in Table 1.

(Gas barrier property test during bending)
The gas barrier films 3E to 3H and 4A to 4D are cut into 20cm x 30cm, respectively, the ends on which the inorganic layer and the resin layer are formed are outside, and both ends are bonded to form a cylindrical shape. The film was rotated and conveyed at 30 cm / min while applying a tension of about 1 N between the film and the roller part so that the film and the roller part were in complete contact and the film did not slip. Each film was conditioned for 8 hours in an environment of 25 ° C. and a relative humidity of 60%, and the test was performed in a laboratory under the same conditions. After the above operation, the oxygen transmission rate and water vapor transmission rate were adjusted to 38 ° C. and relative humidity of 10% or 90% using the MOCON method (oxygen: MOCON OX-TRAN 2/20 L, water vapor: MOCON PERMATRAN-W (3) / 31). The results are shown in Table 2.

(Evaluation)
From Table 2, the gas barrier films 3E, 3G, 4A, and 4C that were heat-treated before the ultraviolet curing of the acrylate when forming the resin layer are the gas barrier films 3F that were not heat-treated before the ultraviolet curing. It can be seen from 3H, 4B, and 4D that the oxygen permeability and water vapor permeability during film bending are excellent. Furthermore, it can be seen that the gas barrier properties of the gas barrier films 4A and 4C in which a plurality of inorganic layers are provided as the first layer and the third layer on the base film are further improved. On the other hand, even when the inorganic layers were provided as the first layer and the third layer, the gas barrier films 4B and 4D that were not subjected to the heat treatment when the resin layer was formed had poor gas barrier properties when bent. From this, heat treatment is performed prior to UV curing when forming the resin layer, thereby strengthening the adhesion between the base film or inorganic layer and the resin layer, and suppressing delamination of the laminated film Became clear. Further, from Table 1, the gas barrier film that had been heat-treated prior to the UV curing of the acrylate when forming the resin layer had good adhesion between the resin layer and the inorganic layer and did not cause delamination. As a result, the gas barrier film of the present invention improves the adhesion at the interface by performing a heat treatment prior to UV curing of the acrylate when forming the resin layer, and provides a good gas barrier performance even when bent. I understand that

(Example 2)
In this example, a substrate and an organic EL device were produced and tested using the gas barrier film 5A of the present invention.
An aluminum lead wire was connected from the transparent electrode (ITO) of the gas barrier film 5A to form a laminated structure. The surface of the transparent electrode was spin-coated with an aqueous dispersion of polyethylene dioxythiophene / polystyrene sulfonic acid [BAYER, Baytron P: solid content: 1.3% by mass], and then vacuum-dried at 150 ° C. for 2 hours, A hole-transporting organic thin film layer having a thickness of 100 nm was formed. This was designated as substrate X.

On the other hand, using a spin coater, a coating solution for a light-emitting organic thin film layer having the following composition is formed on one surface of a temporary support made of polyethersulfone [Sumitomo Bakelite Co., Ltd., Sumilite FS-1300] having a thickness of 188 μm. By coating and drying at room temperature, a light-emitting organic thin film layer having a thickness of 13 nm was formed on the temporary support. This was designated as transfer material Y.
Polyvinylcarbazole 40 parts by mass (Mw = 63000, manufactured by Aldrich)
Tris (2-phenylpyridine) iridium complex 1 part by mass (orthometalated complex)
1,200 parts by mass of 1,2-dichloroethane

  The luminescent organic thin film layer side of the transfer material Y is superimposed on the upper surface of the organic thin film layer of the substrate X, and heated and pressurized at 160 ° C., 0.3 MPa, 0.05 m / min using a pair of heat rollers, and a temporary support Was peeled off to form a light-emitting organic thin film layer on the upper surface of the substrate X. This was designated as substrate XY.

A patterned mask (a mask with a light emitting area of 5 mm × 5 mm) is placed on one side of a polyimide film [UPILEX-50S, manufactured by Ube Industries, Ltd.] having a thickness of 50 μm cut into 25 mm square, and a film thickness of 250 nm is obtained by vapor deposition. Al was formed into a film, and LiF was formed into a film with a thickness of 3 nm by vapor deposition. A coating solution for an electron transporting organic thin film layer having the following composition is applied onto the obtained laminated structure using a spin coater coating machine, and vacuum dried at 80 ° C. for 2 hours, whereby an electron having a thickness of 15 nm is obtained. A transportable organic thin film layer was formed on LiF. Furthermore, an aluminum lead wire was connected from the Al electrode, and this was used as a substrate Z.
Polyvinyl butyral 2000L 10 parts by mass (Mw = 2000, manufactured by Denki Kagaku Kogyo Co., Ltd.)
1-butanol 3500 parts by mass An electron transporting compound having the following structure 20 parts by mass

  Using the substrates XY and Z, the electrodes are stacked so that the electrodes face each other with the light-emitting organic thin film layer interposed therebetween, and heated and pressurized at 160 ° C., 0.3 MPa, 0.05 m / min using a pair of heat rollers, The organic EL element was produced by bonding.

  When a direct voltage was applied to the obtained organic EL element using a source measure unit 2400 type (manufactured by Toyo Technica Co., Ltd.), the produced organic EL element emitted light well. The organic EL device was allowed to stand for 10 days at 25 ° C. and 10% and 90% relative humidity for 10 hours after the device was fabricated, and the device was allowed to emit light in the same manner, but no deterioration of the device was observed. As mentioned above, it turned out that the organic EL element of this invention shows high durability.

  The gas barrier film of the present invention has high gas barrier performance and excellent bending resistance. For this reason, it can be effectively applied to a wide variety of articles that need to block water vapor, oxygen, and the like, and flexible articles. Moreover, according to the present invention, it is possible to provide a high-definition image display element having high durability, and it can be preferably applied to a flexible high-definition display. Therefore, the present invention has high industrial applicability.

Claims (11)

  Including a step of providing a radiation-curable monomer layer on a base film, a step of heat-treating the radiation-curable monomer layer, and a step of curing the radiation-curable monomer layer after the heat treatment with radiation. A method for producing a gas barrier film.   A step of providing a radiation-curable monomer layer on an inorganic layer provided on a base film, a step of heat-treating the radiation-curable monomer layer, and curing the radiation-curable monomer layer after the heat treatment with radiation A gas barrier film manufacturing method comprising the steps of:   The method for producing a gas barrier film according to claim 1, further comprising a step of providing an inorganic layer on the radiation-curable resin layer after the curing. The gas barrier film according to claim 1 or 2, wherein the following steps (1) and (2) are alternately performed at least once each on the radiation-curable resin layer after the curing. Production method.
Step (1): Step of providing an inorganic layer on the cured radiation curable resin layer Step (2): A radiation curable monomer layer is provided on the inorganic layer, and the radiation curable
The monomer layer is heat-treated, and the radiation-curable monomer after the heat treatment
Curing the layer with radiation   The production of a gas barrier film according to any one of claims 1 to 4, further comprising a step of providing a transparent conductive layer on the inorganic layer which is the uppermost layer or the radiation curable resin layer after curing. Method.   The method for producing a gas barrier film according to claim 1, wherein the heat treatment is performed by heating the radiation curable monomer layer to 50 ° C. or more.   The gas barrier film manufactured by the manufacturing method as described in any one of Claims 1-6. The oxygen permeability at 38 ° C. and 90% relative humidity is 0.01 ml / (m ² · day · atm) or less, and the water vapor permeability at 38 ° C. and 90% relative humidity is 0.01 g / (m ² · day). The gas barrier film according to claim 7, wherein:   An image display device using the gas barrier film according to claim 7.   The image display element according to claim 9, wherein the image display element is flexible.   The image display element according to claim 9, wherein the image display element is an organic EL element.