JP5339045B2 - Gas barrier substrate for display element and display device - Google Patents

Description

  The present invention relates to a gas barrier substrate for a display element. More specifically, the present invention relates to a gas barrier substrate for a display element having ultraviolet cleaning resistance and a display device such as an organic electroluminescence display using the same.

  Recently, display devices such as organic electroluminescence displays, liquid crystal displays, and plasma displays are difficult to break as a substrate material to replace glass in order to meet the demand for larger, thinner, or flexible display devices. Plastics that are flexible and lightweight are drawing attention.

  However, the plastic film has higher permeability of oxygen, water vapor, and the like than glass, and the plastic film alone has insufficient gas barrier properties. In particular, in an organic electroluminescence display, a light-emitting element made of an organic compound is used as a display element, and the display element is easily affected by oxygen or water vapor, so that high gas barrier performance is required. Therefore, in a display element substrate, in order to provide gas barrier performance, a gas barrier inorganic compound layer is generally formed on a plastic film.

  A technique is also known in which a plurality of gas barrier inorganic compound layers are laminated on a plastic film, and an ultraviolet curable resin layer is provided between these gas barrier inorganic compound layers (Patent Document 1). . According to this technique, since the surface smoothness of the underlying inorganic compound layer is improved, defects in the inorganic compound layer laminated thereon can be reduced, and high gas barrier performance can be obtained. Moreover, since the adhesion between the layers is improved, when the plastic film is bent, it is possible to prevent the gas barrier performance from being deteriorated due to the occurrence of cracks or the like in the inorganic compound layer.

JP 2008-173838 A

  On the other hand, the factors that adversely affect the display element of the display device are not only oxygen and water vapor, but also when organic contaminants such as residual solvent adhere to the substrate surface in the manufacturing process of the display device, the voltage at the contaminated portion There is a problem that a change or wettability change occurs and the performance of the display device deteriorates. Therefore, organic contaminants are washed by repeatedly irradiating high-intensity and short-wavelength ultraviolet rays such as a xenon excimer lamp and a low-pressure mercury lamp in each step.

  However, when a gas barrier substrate having an ultraviolet curable resin layer provided between a plurality of formed gas barrier inorganic compound layers is used for a display device, if UV cleaning is performed in the manufacturing process of the display device, UV curing is performed by the irradiated ultraviolet light. The resin layer was destroyed and gasified, and as a result, cracks occurred in the inorganic compound layer, resulting in a problem that the gas barrier performance deteriorated.

  The present inventor presumed that the process in which cracks occur in the inorganic compound layer due to ultraviolet irradiation and the gas barrier performance deteriorates is as follows. In other words, the UV cleaning device is a device that cleans and removes organic substances adhering to the substrate surface. It has a high decomposing / cleaning power for organic substances, but has no ability to remove inorganic substances, and it can be removed on the inorganic film. It is suitably used for removing organic substances. However, while the detergency for organic substances is high, if the gas barrier inorganic compound layer has the property of transmitting ultraviolet rays, the ultraviolet curable resin layer under the inorganic film has a cleaning effect and the ultraviolet curable resin layer is decomposed. -Gasification will occur. At this time, in the configuration in which layers having high gas barrier properties are provided above and below the UV curable resin layer, the generated gas is gradually accumulated between the layers because there is no escape, but the amount of accumulated gas exceeds a certain limit amount. And destroys the inorganic film and diffuses it into the atmosphere.

  The present inventor previously found that the above problem can be solved by controlling the film thickness of the ultraviolet curable resin layer within a certain range (Patent Document 1). However, in the invention described in Patent Document 1, since the ultraviolet curable resin layer is provided between the inorganic compound layers having gas barrier properties, the generated gas cannot escape even slightly, and the interlayer Therefore, it cannot be denied that the adhesion between the layers is lowered. It has also been found that if the ultraviolet cleaning is repeated many times, the inorganic compound layer may eventually crack due to the gradually accumulated gas. Furthermore, if equivalent gas barrier properties can be obtained, it is clear that a smaller number of layers is preferable from the viewpoint of productivity and cost.

  The present invention has been made based on such circumstances, and an object of the present invention is to provide a gas barrier substrate for a display element that has both high gas barrier properties and UV cleaning resistance and is more cost effective than conventional ones. And providing a display device.

According to a first aspect of the present invention, an ultraviolet curable resin layer and a gas barrier inorganic compound layer are formed in this order on at least one surface of a plastic film, and the gas permeability of the plastic film is determined by the gas barrier inorganic compound layer. A gas barrier substrate for a display element , wherein the ultraviolet curable resin layer is made of a resin mainly composed of tricyclodecane (meth) acrylate, and the plastic film is a polyethylene naphthalate film. .

According to a second aspect of the present invention, an ultraviolet curable resin layer and a gas barrier inorganic compound layer are formed on at least one surface of the plastic film one by one in this order, and the gas permeability of the plastic film is determined by the gas barrier inorganic compound layer. The UV curable resin layer is made of a resin mainly composed of tricyclodecane (meth) acrylate and polyester (meth) acrylate oligomer, and the plastic film is a polyethylene naphthalate film. It is a gas barrier substrate for a display element.

According to a third invention, in the first invention or the second invention, the gas barrier inorganic compound layer is made of one or more materials selected from silicon oxide, silicon nitride, and silicon oxynitride. This is a gas barrier substrate for a display element.

A fourth invention is a display device using the gas barrier substrate for a display element according to any one of the first invention to the third invention.

  The ultraviolet curable resin layer mainly composed of tricyclodecane (meth) acrylate or the ultraviolet curable resin layer mainly composed of tricyclodecane (meth) acrylate and a polyester (meth) acrylate oligomer is a dense film. Therefore, the potential capability of gas barrier property and ultraviolet cleaning resistance is extremely high, and the gas barrier substrate for a display element of the present invention is excellent in ultraviolet cleaning resistance and high gas barrier property.

  In addition, in the case of an ultraviolet curable resin layer mainly composed of tricyclodecane (meth) acrylate and polyester (meth) acrylate oligomer, since the film is given flexibility, the gas barrier substrate for a display element of the present invention is , Bending resistance is improved and curling is reduced.

  Furthermore, in the gas barrier substrate for a display element of the present invention, since the inorganic compound layer having gas barrier properties is not formed between the plastic film and the ultraviolet curable resin layer, the ultraviolet curable resin is decomposed by the ultraviolet cleaning. The resulting gas can escape through the plastic film. Therefore, even if the ultraviolet cleaning is repeated, the occurrence of cracks is not seen, and the gas barrier performance can be stabilized.

  In addition, even when the number of laminated gas barrier inorganic compound layers is one, a high gas barrier property equivalent to the case where two or more layers are laminated can be obtained, and a low-cost display element that is more productive than conventional ones. A gas barrier substrate for use is provided.

  Furthermore, the display device of the present invention has good display performance because the gas barrier substrate for display elements has ultraviolet cleaning resistance and high gas barrier properties.

[Gas barrier substrate for display element]
Hereinafter, the gas barrier substrate for a display element and the method for producing the same according to the present invention will be described in detail.

  The gas barrier substrate for a display element of the present invention is a laminate in which an ultraviolet curable resin layer and a gas barrier inorganic compound layer are formed in this order on at least one surface of a plastic film. For the ultraviolet curable resin layer, a resin mainly composed of tricyclodecane (meth) acrylate or a resin mainly composed of tricyclodecane (meth) acrylate and a polyester (meth) acrylate oligomer is used. The plastic film is preferably a polyethylene naphthalate film or a polyethylene terephthalate film, and the gas barrier inorganic compound layer includes at least one material selected from silicon oxide, silicon nitride, and silicon oxynitride. It is preferably used.

  FIG. 1 is a cross-sectional view showing a configuration example of a gas barrier substrate of the present invention. A gas barrier substrate 4 of the present invention shown in FIG. 1 has a configuration in which an ultraviolet curable resin layer 2 and a gas barrier inorganic compound layer 3 are laminated on a plastic film 1 one by one in this order.

Since the gas permeability of the plastic film is higher than that of the gas barrier inorganic compound layer, the gas barrier substrate for display element has a gas permeability gradient due to the above configuration, and is caused by deterioration of the UV curable resin layer. The gas that escapes can escape from the plastic film. As a result, the generation of cracks in the inorganic compound layer can be prevented and the gas barrier performance can be maintained.
In addition, when two or more layers of the ultraviolet curable resin layer and the gas barrier inorganic compound layer are alternately laminated, the gas barrier inorganic compound layer is formed above and below the intermediate ultraviolet curable resin layer. The gas generated by the gas cannot escape and affects the gas barrier performance. Therefore, in the present invention, the ultraviolet curable resin layer and the gas barrier inorganic compound layer are formed only one layer at a time in this order on the plastic film.

  Examples of the method for producing a gas barrier substrate for a display device of the present invention include a composition mainly composed of tricyclodecane (meth) acrylate on a plastic film using a resin material described below, or tricyclodecane. A film composed of (meth) acrylate and polyester (meth) acrylate oligomer as main components is formed into a film by a coating method and then cured by irradiation with ultraviolet rays to form an ultraviolet curable resin layer once. Next, a gas barrier inorganic compound layer is formed once on the ultraviolet curable resin layer by a vacuum film forming method using an inorganic compound having a gas barrier property described below.

  Hereinafter, the plastic film, the ultraviolet curable resin layer, and the gas barrier inorganic compound layer constituting the gas barrier substrate for a display element of the present invention will be described in more detail.

(Plastic film)
As a polymer material used for a plastic film, a resin generally used as a base material for a gas barrier substrate for a display element can be appropriately selected. For example, polyolefins such as polypropylene and polyethylene, polyethylene terephthalate and polyethylene naphthalate are used. Examples thereof include polyester such as phthalate, polyarylate, polyethersulfone, polycarbonate, polyamide, and polyvinyl alcohol.

  Among these, the polyolefin film or the polyester film has many advantages in that it is relatively inexpensive and can be easily obtained because of its high versatility and processability.

  Furthermore, the polyester film can be preferably used in that it has appropriate physical strength and chemical resistance, good light transmittance in the visible light region, and good surface smoothness. The polyester film is obtained by copolymerizing an acid component and a glycol component. For example, a polyethylene terephthalate film (PET), a polytrimethylene terephthalate film, a polybutylene terephthalate film (PBT), a polyethylene naphthalate film ( PEN) or polytrimethylene naphthalate film.

  Polyethylene naphthalate film (PEN) is particularly preferred because of its high heat resistance and relatively high gas barrier properties. In the polyethylene naphthalate film, naphthalenedicarboxylic acid is used as the main dicarboxylic acid component, and ethylene glycol is used as the main diol component.

  Polyethylene terephthalate film (PET) has a lower gas barrier property than polyethylene naphthalate film (PEN), but the gas generated by decomposition of the UV curable resin by UV cleaning is likely to escape through the plastic film, so from the viewpoint of UV cleaning resistance. Are advantageous and particularly preferred. In the polyethylene terephthalate film, terephthalic acid is used as the main dicarboxylic acid component, and ethylene glycol is used as the main diol component.

  As an acid component of the polyester film, naphthalenedicarboxylic acid and terephthalic acid may be mixed and used. Thereby, it is possible to obtain a plastic film in which the good gas barrier property of the polyethylene naphthalate film (PEN) and the excellent ultraviolet washing resistance of the polyethylene terephthalate film (PET) are balanced. In the present invention, when the proportion of naphthalene dicarboxylic acid in the acid component is large, it is classified as a polyethylene naphthalate film, and when the proportion of terephthalic acid is large, it is classified as a polyethylene terephthalate film. (Equal amounts shall be classified as either).

  The plastic film may be unstretched, uniaxially stretched, or biaxially stretched, but is preferably biaxially stretched from the viewpoint of dimensional stability and mechanical properties. In addition, the plastic film may contain, as an additive, an ultraviolet ray inhibitor, an antioxidant, an antistatic agent, a surfactant, a lubricant, or the like as long as the transparency is not impaired.

  The thickness of the plastic film is usually 12 to 200 μm, more preferably 50 to 130 μm. If the thickness is too thin, the required mechanical strength cannot be obtained. On the other hand, if the thickness is too thick, the processability deteriorates and the cost increases.

  The plastic film may be subjected to some surface treatment in order to improve the adhesion of the surface of the plastic film. For example, corona discharge treatment, flame treatment, plasma treatment, glow discharge treatment, ultraviolet ozone treatment, chemical treatment and the like can be mentioned. Moreover, you may improve the adhesiveness of the surface of a plastic film by providing the undercoat layer using a polyester resin, a urethane resin, etc. The undercoat layer may contain an inorganic filler such as calcium carbonate for improving slipperiness and imparting film strength. In addition, you may perform the surface treatment of said plastic film or / and undercoat layer formation on the surface opposite to the surface in which the ultraviolet curable resin layer of the plastic film was formed.

(UV curable resin layer)
As a material used for the ultraviolet curable resin layer, a composition mainly composed of tricyclodecane (meth) acrylate or a composition mainly composed of tricyclodecane (meth) acrylate and a polyester (meth) acrylate oligomer is used as an ultraviolet ray. And obtained by curing. In the present specification, the term “(meth) acrylate” is a general term for both acrylate and methacrylate.

  Tricyclodecane (meth) acrylate is a tricyclodecane derivative having a polymerization-reactive acryloyl group or methacryloyl group, specifically, dimethylol tricyclodecane di (meth) acrylate, tricyclodecane di (meth). An acrylate etc. can be mentioned.

  The polyester (meth) acrylate oligomer is a saturated or unsaturated polyester oligomer having at least one polymerization-reactive acryloyl group or methacryloyl group in the molecule. This polyester oligomer is obtained by an esterification reaction between a polyhydric alcohol such as a glycol component or a triol component and a polybasic acid such as a dibasic acid or a tribasic acid component, and has a molecular weight of approximately 1,000 to 10. , 000. If necessary, an epoxy compound and an isocyanate compound may be used in combination to bind the glycol component and the polybasic acid component.

  Examples of the glycol include alkylene glycols represented by ethylene glycol, propylene glycol, butylene glycol, spiro glycol and the like, polyoxyalkylene glycols represented by diethylene glycol, polyoxyethylene glycol, dipropylene glycol, polyoxypropylene glycol and the like, There are addition reaction products of dihydric phenols typified by bisphenol A, bisphenol F, bisphenol S and the like and alkylene oxides typified by ethylene oxide and propylene oxide. Examples of the triol include glycerin, trimethylolpropane, trimethylolethane, 1,2,6-hexanetriol, and any of them can be used.

  Dibasic acids (anhydrides) include i-phthalic acid, o-phthalic acid, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, tetrachlorophthalic acid, malonic acid, succinic acid, adipic acid, maleic acid, maleic anhydride Examples of tribasic acids include trimellitic acid, acounitic acid, butanetricarboxylic acid, 6-carboxy-3-methyl 1,2,3,6 hexahydrophthalic acid and the like. Examples of tetrabasic acids include pyromellitic acid.

  When mixing tricyclodecane (meth) acrylate and polyester (meth) acrylate oligomer, blending of tricyclodecane (meth) acrylate (A) and polyester (meth) acrylate oligomer (B) in the main component of the composition The mass ratio (A / B) may be adjusted as appropriate, but a range of 40/60 to 60/40 is preferable from the viewpoint of obtaining good gas barrier properties. In addition, in this invention, a main component shall mean the component which comprises about 80 mass% or more of the whole composition.

  As the photopolymerization initiator used for curing the (meth) acrylate or / and (meth) acrylate oligomer, known ones such as benzoyl series and azo series can be used. For example, 1-hydroxy-cyclohexyl-phenyl-ketone, benzyl dimethyl ketal and the like can be used. Moreover, you may add a well-known additive as a subcomponent of a composition for the purpose of viscosity adjustment, coating property improvement, or the performance improvement of a gas-barrier board | substrate.

  Composition containing tricyclodecane (meth) acrylate and other components as required, or composition containing tricyclodecane (meth) acrylate, polyester (meth) acrylate oligomer, and other components as necessary The coating method is, for example, roll coating method, dip coating method, bar coating method, nozzle coating method, die coating method, spray coating method, spin coating method, curtain coating method, flow coating method, screen printing, gravure printing, or curved surface Various printing methods such as printing, or a combination of these can be used.

  Examples of the ultraviolet light source used for ultraviolet curing of the composition include light sources such as an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc lamp, a black light fluorescent lamp, and a metal halide lamp. As the wavelength of the ultraviolet light, a wavelength range of 190 to 380 nm can be used.

The film thickness of the ultraviolet curable resin layer is preferably 3.5 to 30 μm, more preferably 4 to 20 μm, and most preferably 4 to 10 μm. When the film thickness is less than 3.5 μm, the UV curable resin layer is damaged by UV cleaning, and when it exceeds 30 μm, the gas barrier substrate for display element is curled.
The ultraviolet curable resin layer is formed on at least one side of the plastic film.

(Gas barrier inorganic compound layer)
The material used for the gas barrier inorganic compound layer only needs to have transparency and gas barrier properties such as oxygen and water vapor. For example, magnesium, aluminum, calcium, titanium, zinc, indium, tin, etc. Mention may be made of oxides, nitrides or oxynitrides. These materials may be used alone or in combination of two or more. In particular, since it has excellent gas barrier properties, it is preferable to use one or more materials selected from silicon oxide, silicon nitride, and silicon oxynitride.

  As a method for forming the gas barrier inorganic compound layer, a vacuum film formation method such as a vacuum vapor deposition method, a reactive vapor deposition method, an ion beam assisted vapor deposition method, a sputtering method, an ion plating method, a plasma CVD method, or a thermal CVD method is used. The film thickness can be appropriately set in the range of 10 to 300 nm, more preferably 30 to 150 nm. If the film thickness is too thin, it is difficult to obtain a sufficient gas barrier property. On the other hand, if the film thickness is too thick, the time required for film formation may become long and the productivity may be impaired.

  The gas barrier inorganic compound layer is formed on at least one side of the plastic film. When the gas barrier inorganic compound layer is formed on both sides of the plastic film, the stress generated on one side is balanced with the stress generated on the other side, so that the gas barrier substrate for display element is warped (curled). Occurrence can be suppressed.

[Display device]
Hereinafter, the display device of the present invention will be described in detail.

  Examples of the display device include an organic electroluminescence display (hereinafter referred to as “EL”), a liquid crystal display, a plasma display, and the like. In the display device of the present invention, the gas barrier substrate for a display element described above is used as a substrate of a display element used in the display device.

Hereinafter, an EL display will be described as an example.
The EL display of the present invention has a laminated structure in which at least an EL display element and a sealing layer are laminated in this order on the gas barrier substrate for a display element. Among these, the sealing layer is provided for sealing the EL display element and imparting gas barrier properties. For example, the EL display element is provided with an epoxy resin thermosetting adhesive or an acrylic resin ultraviolet curing type. An adhesive can be formed by laminating a resin base material. In addition, when sufficient gas barrier property is securable with adhesive itself, it is not necessary to use a resin base material. On the contrary, when a sufficient gas barrier film cannot be secured even if a single resin base material is pasted, silicon oxide or the like may be deposited on the resin base material to provide gas barrier properties.

  The EL display element has a laminated structure in which an EL layer is mainly formed between an anode and a cathode. Of these, the material used for the anode is preferably a conductive material having a high work function (for example, indium tin oxide (ITO)) so that holes can be easily injected, and the material used for the cathode is injected with electrons. A conductive material having a small work function (for example, metallic calcium) is preferable so that it can be easily formed. These are usually formed so as to be adjacent to the EL layer by sputtering or vacuum deposition.

  The EL layer can have a laminated structure in which each element layer such as a hole transport layer, a light emitter layer, and an electron transport layer functions. An azo compound that is generally used as an EL layer can be used in the phosphor layer containing the organic phosphor. As the hole transport material, an aromatic amine derivative or the like can be used as the electron transport material, and a commonly used material such as an oxazole derivative or a triazole derivative can be used as the electron transport material. Each of these layers can be manufactured by applying a coating solution in which a polymer material is dissolved, and a manufacturing method applying a printing method on paper or a manufacturing method applying an ink jet method can be applied.

  An example is shown below and an example of the embodiment of the present invention is explained.

(Evaluation method of gas barrier property) The oxygen permeability of the gas barrier substrate is measured using an oxygen gas permeability measuring device (manufactured by MOCON, OXTRAN 2/20) at a temperature of 23 ° C., a humidity of 90% RH, and a background removal measurement. The measurement was performed under the condition with the individual zero measurement. Moreover, the water vapor transmission rate of the gas barrier substrate was measured using a water vapor transmission rate measuring device (manufactured by MOCON, PERMATRAN-W3 / 31) under the conditions of a temperature of 40 ° C. and a humidity of 100% RH.

(Evaluation method of UV cleaning resistance) The UV cleaning resistance of the gas barrier substrate was evaluated by the following procedure. First, a smooth iron plate (or SUS plate) having a length of 156 mm, a width of 156 mm, and a thickness of 2 mm was prepared, and resin foots having a height of 8 mm were provided on four sides of the iron plate. A measuring table was created by placing a glass plate having a length of 150 mm, a width of 150 mm and a thickness of 1 mm on the footrest. Next, an evaluation sample having a length of 150 mm and a width of 150 mm was placed on the glass plate of the measurement table. In addition, when the curl of the evaluation sample was large, four sides of the evaluation sample were fixed to a glass plate using a polyimide tape. Next, the measurement table on which the evaluation sample was placed was attached to an ultraviolet cleaning device (UV DRY PROCESSOR manufactured by Oak Manufacturing Co., Ltd.) using a low-pressure mercury lamp (120 W × 7 lamps), and irradiation for 15 minutes was repeated a predetermined number of times. . Next, about the evaluation sample taken out from the ultraviolet cleaning device, the surface appearance was visually observed and evaluated.
The evaluation criteria for visual appearance was ◯ when no crack or bubble-like defect occurred on the surface of the gas barrier substrate, and x when it occurred.

Example 1
First, as a plastic film, a polyethylene-2,6-naphthalene film (Q65F manufactured by Teijin DuPont Films Co., Ltd.) having a thickness of 100 μm and subjected to easy adhesion treatment on one side was used. On the untreated surface of this plastic film, the ultraviolet curable resin layer ink (1) adjusted to the following composition was applied by die coating, dried at 120 ° C. for 3 minutes, and then irradiated with ultraviolet rays under the condition of an integrated light quantity of 150 mJ. Irradiation was performed to form an ultraviolet curable resin layer (1) having a thickness of 10 μm.
<Composition of UV curable resin layer ink (1)>
Dimethylol tricyclodecane diacrylate (KAYARAD R-684, manufactured by Nippon Kayaku Co., Ltd.) 40 parts by weight toluene (solvent) 60 parts by weight 1-hydroxy-cyclohexyl-phenyl-ketone (photopolymerization initiator, Nippon Ciba-Geigy Co., Ltd.) Irgacure 184) 2 parts by weight

Next, in order to form the gas barrier inorganic compound layer, the plastic film on which the ultraviolet curable resin layer is formed is formed on the ultraviolet curable resin layer side in the chamber of a batch type sputtering apparatus (SPF-530H manufactured by Anelva Co., Ltd.). The film was installed in the direction of film formation and mounted in the chamber using silicon as a target material. The distance between the target and the plastic film (TS distance) was set to 50 mm. Nitrogen gas (manufactured by Taiyo Toyo Oxygen Co., Ltd., purity 99.9999% or more) and argon gas (manufactured by Taiyo Toyo Oxygen Co., Ltd., purity 99.9999% or more) were used as additive gases during film formation. The inside of the chamber was decompressed to an ultimate vacuum of 2.5 × 10 ⁻⁴ Pa with an oil rotary pump and a cryopump. Next, nitrogen gas was introduced into the chamber at a flow rate of 15 sccm, and argon gas was introduced at a flow rate of 20 sccm. Then, by controlling the opening / closing degree of the valve between the vacuum pump and the chamber, the RF pressure in the chamber is kept at 0.25 Pa and the RF magnetron sputtering method is used with an input power of 1.2 kW on the ultraviolet curable resin layer. A silicon oxynitride layer having a thickness of 80 nm was formed. Note that sccm is an abbreviation for standard cubic centimeter per minute.
Finally, a silicon oxide layer having a thickness of 80 nm was formed on the easy-adhesion treated surface of the plastic film by the same procedure as described above (however, nitrogen gas was not introduced into the chamber) to obtain a gas barrier substrate. The layer structure of the obtained gas barrier substrate is silicon oxide layer / (easy adhesion treated surface) polyethylene-2,6-naphthalene film (untreated surface) / ultraviolet curable resin layer (1) / silicon oxynitride layer. .

(Example 2)
A gas barrier substrate was obtained in the same procedure as in Example 1 except that the ultraviolet curable resin layer (2) was formed using the following ultraviolet curable resin layer ink (2) as the ultraviolet curable resin layer ink. .
<Composition of UV curable resin layer ink (2)>
30 parts by weight of polyester acrylate oligomer (Aronix M-8060, manufactured by Toagosei Co., Ltd.) 10 parts by weight Toluene (solvent) 60 parts by weight 1- 2 parts by weight of hydroxy-cyclohexyl-phenyl-ketone (photopolymerization initiator, Irgacure 184 manufactured by Ciba Geigy Japan)

(Example 3)
A gas barrier substrate was obtained in the same procedure as in Example 1 except that the ultraviolet curable resin layer (3) was formed using the following ultraviolet curable resin layer ink (3) as the ultraviolet curable resin layer ink. .
<Composition of UV curable resin layer ink (3)>
Dimethylol tricyclodecane diacrylate (KAYARAD R-684 manufactured by Nippon Kayaku Co., Ltd.) 20 parts by weight polyester acrylate oligomer (Aronix M-8060 manufactured by Toagosei Co., Ltd.) 20 parts by weight Toluene (solvent) 60 parts by weight 1- 2 parts by weight of hydroxy-cyclohexyl-phenyl-ketone (photopolymerization initiator, Irgacure 184 manufactured by Ciba Geigy Japan)

Example 4
A gas barrier substrate was obtained in the same procedure as in Example 1 except that the ultraviolet curable resin layer (4) was formed using the following ultraviolet curable resin layer ink (4) as the ultraviolet curable resin layer ink. .
<Composition of UV curable resin layer ink (4)>
Dimethylol tricyclodecane diacrylate (KAYARAD R-684, manufactured by Nippon Kayaku Co., Ltd.) 15 parts by weight polyester acrylate oligomer (Aronix M-8060, manufactured by Toagosei Co., Ltd.) 30 parts by weight Toluene (solvent) 55 parts by weight 1- 2 parts by weight of hydroxy-cyclohexyl-phenyl-ketone (photopolymerization initiator, Irgacure 184 manufactured by Ciba Geigy Japan)

(Comparative Example 1)
A gas barrier substrate was prepared in the same manner as in Example 1, except that a silicon oxide layer having a thickness of 80 nm was first formed on the untreated surface of the plastic film, and then an ultraviolet curable resin layer was formed on the silicon oxide layer. Got. The layer structure of the obtained gas barrier substrate was as follows: silicon oxide layer / (easy adhesion treated surface) polyethylene-2,6-naphthalene film (untreated surface) / silicon oxide layer / ultraviolet curable resin layer (1) / silicon oxynitride Layer.

(Comparative Example 2)
A gas barrier substrate was obtained in the same procedure as in Example 1 except that acrylate (UVT-302 manufactured by Toagosei Co., Ltd.) was used as the material for the ultraviolet curable resin layer.

(Comparative Example 3)
A gas barrier substrate was obtained in the same procedure as in Example 1 except that acrylate (RC-501 manufactured by Sanyo Chemical Co., Ltd.) was used as a material for the ultraviolet curable resin layer.

  Table 1 shows the evaluation results of the gas barrier substrates obtained in Examples 1 to 4 and Comparative Examples 1 to 3. In addition, the ultraviolet-ray washing tolerance was evaluated after performing ultraviolet irradiation for 15 minutes once and after repeating it three times. Moreover, the oxygen transmission rate and the water vapor transmission rate were measured before performing ultraviolet irradiation and after repeating 15 minutes of ultraviolet irradiation three times.

  The gas barrier substrates of Examples 1 to 4 had good visual appearance observation evaluation results even after repeated ultraviolet cleaning. Moreover, it showed a high initial gas barrier performance, and even when the UV cleaning was repeated, the gas barrier performance was not lowered (“>” in the table means that it was below the lower limit of measurement). In addition, the gas barrier board | substrate of Examples 2-4 had the curvature (curl) before ultraviolet irradiation smaller than the gas barrier board | substrate of Example 1. FIG. On the other hand, even if the gas barrier substrate of Comparative Example 1 had a high gas barrier performance, cracks and bubble-like defects were observed on the surface when the ultraviolet cleaning was repeated, resulting in a decrease in gas barrier performance. On the other hand, the gas barrier substrates of Comparative Examples 2 to 3 had low oxygen permeability and low gas barrier performance even though they had UV cleaning resistance.

It is sectional drawing which shows the structural example of the gas-barrier board | substrate of this invention.

Explanation of symbols

1: Plastic film 2: UV curable resin layer 3: Gas barrier inorganic compound layer 4: Gas barrier substrate for display element

Claims (4)

On at least one side of the plastic film, an ultraviolet curable resin layer and a gas barrier inorganic compound layer are formed one by one in this order,
The gas permeability of the plastic film is higher than that of the gas barrier inorganic compound layer,
The ultraviolet curable resin layer is made of a resin mainly composed of tricyclodecane (meth) acrylate,
The plastic film is a polyethylene naphthalate film;
A gas barrier substrate for a display element, characterized in that: On at least one side of the plastic film, an ultraviolet curable resin layer and a gas barrier inorganic compound layer are formed one by one in this order,
The gas permeability of the plastic film is higher than that of the gas barrier inorganic compound layer,
The ultraviolet curable resin layer is made of a resin mainly composed of tricyclodecane (meth) acrylate and polyester (meth) acrylate oligomer,
A gas barrier substrate for a display element, wherein the plastic film is a polyethylene naphthalate film.   3. The gas barrier for a display element according to claim 1, wherein the gas barrier inorganic compound layer is made of at least one material selected from silicon oxide, silicon nitride, and silicon oxynitride. Substrate.   A display device comprising the gas barrier substrate for a display element according to any one of claims 1 to 3.

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