JP4289116B2 - Gas barrier substrate, display device substrate and display device - Google Patents

Description

  The present invention relates to a gas barrier substrate, a display device substrate, and a display device.

  Conventionally, a gas / water vapor barrier film in which a thin film of a metal oxide such as aluminum, aluminum oxide, magnesium oxide, or silicon oxide is formed on the surface of a resin substrate or the like has been used for packaging of articles, food, Widely used in packaging applications to prevent alteration of industrial products and pharmaceuticals.

Such gas / water vapor barrier films are also used in liquid crystal display elements, solar cells, electroluminescence (EL) elements and the like in addition to packaging applications. In particular, transparent substrates, which are being applied to liquid crystal display elements, EL elements, etc., have recently been required to be lighter and larger, have long-term reliability and a high degree of freedom in shape, and can display curved surfaces. There are high demands such as being. In order to meet such demands, film substrates such as transparent resins have begun to be used in place of glass substrates that are heavy, easily broken, and difficult to increase in area.
Furthermore, a film substrate such as a transparent resin not only meets the above requirements, but also has an advantage in terms of productivity and cost reduction over a glass substrate in that it can be produced by a roll method.

  However, the film substrate has a problem that the gas barrier property is inferior to the glass substrate. If a base material with inferior gas barrier properties is used, oxygen or water vapor may 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, it is known to form a metal oxide thin film on a film substrate to form a gas barrier film substrate. For example, examples of the gas barrier film used for the packaging material and the liquid crystal display element include a film obtained by vapor-depositing silicon oxide on a resin substrate, a film obtained by vapor-depositing aluminum oxide, and the like (for example, see Patent Documents 1 and 2).
However, in recent years, with the development of large-size liquid crystal displays, high-definition displays, etc., higher barrier properties have also been required for film substrates.

JP-A-53-12953 JP 58-217344 A

An object of the present invention is to provide a substantially transparent gas barrier substrate having a high gas barrier property.
Moreover, the objective of this invention is providing the display device board | substrate which is excellent in performance, and a display device using the same, when it is set as a display device.

Such an object is achieved by the present invention described in the following (1) to (19).
(1) A substantially transparent gas barrier substrate having a first layer composed of a resin material and a second layer composed of an inorganic material provided on at least one side of the first layer. And
The melting point of the inorganic material constituting the second layer state, and are 1,500 ° C. or less,
And when the melting point of the inorganic material is [Tm] and the glass transition temperature of the first layer is [Tg],
A gas barrier substrate satisfying the relationship of 0 ° C. ≦ (Tm−Tg) ≦ 1,125 [° C.] .
(2) The gas barrier substrate according to (1) above, wherein the second layer is formed of two or more layers.
(3) The gas barrier substrate according to (1) or (2) above, wherein a third layer made of an organic material is further provided on at least one surface of the second layer.
(4) The gas barrier substrate according to any one of (1) to (3), wherein the second layer is substantially in an amorphous state.
(5) The gas barrier substrate according to any one of (1) to (4), wherein the glass transition temperature [Tg] of the first layer is 200 ° C. or higher.
(6) The gas barrier substrate according to any one of (1) to (5), wherein the resin material includes a polyethersulfone resin or an epoxy resin.
( 7 ) The gas barrier substrate according to any one of (1) to ( 6 ), wherein the inorganic material includes a plurality of metal oxides.
( 8 ) The gas barrier substrate according to any one of (1) to ( 7 ), wherein the metal oxide includes silicon oxide.
( 9 ) The gas barrier substrate according to any one of (1) to ( 8 ), wherein the metal oxide further contains aluminum oxide.
(10) The gas barrier substrate according to any one of (1) to (9), wherein the metal oxide further contains one or both of magnesium oxide and boron oxide.
(11) The gas barrier substrate according to any one of (1) to (10), wherein the surface of the second layer has an arithmetic average roughness of 10 nm or less.
(12) The water vapor permeability specified in JIS K7129B of the second layer is 0.1 [g / m ² / day / 40 ° C., 90% RH] or less, any of (1) to (11) above A gas barrier substrate according to any one of the above.
(13) The oxygen permeability defined in JIS K7126B of the second layer is 0.1 [cm ³ / m ² / day / 1 atm / 23 ° C.] or less, and any one of the above (1) to (12) A gas barrier substrate as described in 1.
(14) The gas barrier substrate according to any one of (1) to (13), wherein the light transmittance of the gas barrier substrate defined in JIS K7105 is 60% or more.
(15) The water vapor permeability specified in JIS K7129B of the gas barrier substrate is any one of the above (1) to (14), which is 0.1 [g / m ² / day / 40 ° C., 90% RH] or less. A gas barrier substrate as described in 1.
(16) The oxygen permeability specified in JIS K7126B of the gas barrier substrate is 0.1 [cm ³ / m ² / day / 1 atm / 23 ° C.] or less, and any one of (1) to (15) above The gas barrier substrate as described.
(17) The gas barrier substrate according to any one of the above (1) to (16), wherein the corrosion area ratio after treatment at a temperature of 50 ° C., a humidity of 95%, and 12 hours is 1% or less as evaluated by a calcium corrosion method.
(18) A display device substrate comprising the gas barrier substrate according to any one of (1) to (17).
(19) A display device comprising the display device substrate according to (18).

According to the present invention, a substantially transparent gas barrier substrate having a high gas barrier property can be obtained.
Moreover, according to this invention, when it is set as a display device, the board | substrate for display devices which is excellent in display quality, and a display device using the same can be obtained.
Further, when a specific resin is used as the resin of the layer composed of the resin material, the flexibility of the gas barrier substrate can be particularly improved.
Further, when the inorganic material contains a plurality of metal oxides, an amorphous and dense glass thin film can be formed, and the gas barrier property can be particularly improved.
Moreover, when using the gas barrier base material in which the corrosion area rate in a calcium corrosion method has a specific value, it is excellent in long-term reliability especially when it is set as the substrate for display devices.
Moreover, when using the gas barrier base material in which the corrosion location in a calcium corrosion method has a specific value, it is excellent in long-term reliability especially when it is set as the board | substrate for display devices.

Hereinafter, the gas barrier substrate, display device substrate and display device of the present invention will be described in detail.
The gas barrier substrate of the present invention is substantially transparent having a first layer made of a resin material and a second layer made of an inorganic material provided on at least one side of the first layer. It is a gas barrier base material, and the melting point of the inorganic material constituting the second layer is 1,500 ° C. or less.
In addition, the display device substrate of the present invention is characterized by having the above-mentioned gas barrier base material.
Moreover, the display device of the present invention is characterized by having the display device substrate described above.

First, the gas barrier substrate and display device substrate of the present invention will be described based on preferred embodiments.
FIG. 1 is a cross-sectional view schematically showing an example of a gas barrier substrate of the present invention.
In the gas barrier substrate 10, the second layer 2 made of an inorganic material is provided on the upper surface (upper side in FIG. 1) of the first layer 1 made of a resin material.
The resin material constituting the first layer 1 is not particularly limited as long as it is a transparent resin material. For example, a thermoplastic resin such as an acrylic resin, a polycarbonate resin, a polyethersulfone resin, or a cyclic polyolefin resin, bisphenol A Examples thereof include thermosetting resins such as epoxy resins, bisphenol type epoxy resins such as bisphenol F epoxy resin, novolac epoxy resins such as novolac epoxy resin and cresol novolac epoxy resin, and epoxy resins such as biphenyl type epoxy resin. Among these, one or more resins selected from polyethersulfone resins, cyclic polyolefin resins, and acrylic resins are preferable. Thereby, the flexibility of the gas barrier base material 10 can be improved.

  Although the glass transition temperature of the 1st layer 1 is not specifically limited, It is preferable that it is 200 degreeC or more, and 250-400 degreeC is especially preferable. If the glass transition temperature is less than the lower limit value, the effect of improving the gas barrier property may be reduced due to processing condition restrictions. If the glass transition temperature exceeds the upper limit value, it may be difficult to form the first layer. is there.

  Although the thickness of the 1st layer 1 is not specifically limited, 0.01-2 mm is preferable and 50-400 micrometers is especially preferable. When the thickness is less than the lower limit value, for example, the workability when processing from the gas barrier base material 10 to a display device substrate or the like may be reduced, and when the thickness exceeds the upper limit value, the flexibility of the gas barrier base material 10 is reduced. There is a case.

The inorganic material constituting the second layer 2 has a melting point of 1,500 ° C. or less. Thereby, when depositing the inorganic material by the vapor phase method, the second layer 2 (gas barrier layer) can be formed on the first layer 1 at a low temperature.
The melting point of the inorganic material is preferably 1,200 ° C. or less, and particularly preferably 400 to 1,000 ° C. If the melting point of the inorganic material exceeds the upper limit value, the effect of improving the gas barrier property may be reduced, and if it is less than the lower limit value, the rate of forming the second layer 2 may be reduced.
The melting point can be evaluated by, for example, a differential thermal analysis method, a thermomechanical analysis, or the like.

Conventionally, the melting point of the inorganic material constituting the gas barrier layer has been about 2,300 to 2,500 ° C. Such a gas barrier layer composed of an inorganic material having a high melting point was excellent in the gas barrier property of the material itself. However, when the gas barrier layer is used, the gas barrier property inherent to the material cannot be exhibited due to crystal defects formed by the inorganic material.
In contrast, in the present invention, the inorganic material constituting the gas barrier layer has a melting point of 1,500 ° C. or lower. Such a gas barrier layer composed of an inorganic material having a relatively low melting point is likely to be in an amorphous state and can improve a decrease in gas barrier properties due to crystal defects.

Examples of the inorganic material include at least one oxide selected from Si, Al, Ca, Na, B, Ti, Pb, Nb, Mg, P, Ba, Ge, Li, K, Zr, and the like, or two kinds Examples thereof include oxides, fluorides, nitrides, and oxynitrides of the above mixtures.
Among these, it is preferable to include a plurality of oxides, and glass including a plurality of oxides is particularly preferable. Thereby, since an amorphous and dense glass thin film is formed, gas barrier properties can be improved. Moreover, it becomes easy to make melting | fusing point 1500 degrees C or less by using a some oxide.

The plurality of oxides is not particularly limited, but preferably includes silicon oxide. Thereby, especially gas barrier property can be improved.
The plurality of oxides preferably further contain aluminum oxide. Thereby, the amorphous property of the second layer 2 can be particularly improved.
The plurality of oxides preferably further contain magnesium oxide or boron oxide. Thereby, the effect of lowering the melting point of the inorganic material can be improved.

  Although content of the said silicon oxide is not specifically limited, 20-70 mol% of the whole said inorganic material is preferable, and 30-60 mol% is especially preferable. Although content of the said aluminum oxide is not specifically limited, 5-50 mol% of the said whole inorganic material is preferable, and 10-40 mol% is especially preferable. The content of the magnesium oxide is not particularly limited, but is preferably 5 to 50 mol%, particularly preferably 10 to 40 mol%, based on the whole inorganic material. Furthermore, although content of the said boron oxide is not specifically limited, 5-50 mol% of the whole said inorganic material is preferable, and 10-40 mol% is especially preferable. When the content is within the above range, the gas barrier property is particularly excellent.

  The second layer 2 is not particularly limited, but is preferably substantially in an amorphous state. When the second layer 2 is in an amorphous state, the effect of improving the gas barrier property is particularly excellent. The substantially amorphous state means that a peak showing crystallinity does not appear by X-ray diffraction measurement, for example. In addition, the crystal part in the second layer 2 may be amorphized after or after the process of forming the second layer 2. Laser annealing, electron beam irradiation, ion beam irradiation, or the like can be used for the amorphization treatment step.

Although the arithmetic mean roughness of the surface of the 2nd layer 2 is not specifically limited, 10 nm or less is preferable and especially 0.1-5 nm is preferable. If the arithmetic average roughness exceeds the upper limit, the effect of improving the gas barrier properties may be reduced, and even if the arithmetic average roughness is less than the lower limit, further improvement of the effect cannot be expected.
The arithmetic average roughness can be evaluated using an atomic force microscope, for example, for a 20 μm × 20 μm square region.

The maximum height of the surface of the second layer 2 is not particularly limited, but is preferably 0.3 μm or less, and particularly preferably 0.02 to 0.2 μm. When the maximum height is within the above range, the gas barrier property is particularly excellent.
The maximum height can be evaluated using, for example, an atomic force microscope for a 20 μm × 20 μm square region.

Although the water vapor transmission rate prescribed | regulated to JISK7129B of the 2nd layer 2 is not specifically limited, It is preferable that it is 0.1 [g / m < ² > / day / 40 degreeC, 90% RH] or less. When the water vapor permeability is within the above range, the long-term reliability when the gas barrier substrate 10 is used as a display device substrate is excellent.

Although the oxygen permeability prescribed | regulated to JISK7126B of the 2nd layer 2 is not specifically limited, It is preferable that it is 0.1 [cm < ³ > / m < ² > / day / 1atm / 23 degreeC] or less. When the oxygen permeability is within the above range, the long-term reliability when the gas barrier substrate 10 is used as a display device substrate is excellent.

  The thickness of the second layer 2 is not particularly limited, but is preferably 10 to 1,000 nm, and particularly preferably 30 to 200 nm. If the thickness is less than the lower limit value, the gas barrier property may decrease, and if the thickness exceeds the upper limit value, the bending durability may decrease.

  The ratio between the thickness of the first layer 1 and the thickness of the second layer 2 is not particularly limited, but is preferably 10: 1 to 2,000: 1, and particularly preferably 250: 1 to 40,000: 3. . When the ratio is within the above range, the bending durability is particularly excellent.

  The glass transition temperature (Tg) of the first layer 1 and the melting point (Tm) of the inorganic material are not particularly limited, but satisfy the relationship of 0 ≦ (Tm−Tg) ≦ 1,125 [° C.]. In particular, it is preferable to satisfy the relationship of 300 ≦ (Tm−Tg) ≦ 900 [° C.]. When the above relationship is satisfied, the gas barrier property is particularly excellent.

The gas barrier substrate 10 is characterized by being substantially transparent. Here, the gas barrier substrate 10 being substantially transparent means that the light transmittance specified in JIS K7105 is 50% or more.
Actually, the light transmittance is preferably 60% or more, particularly preferably 80 to 99.5%. When the light transmittance is within the above range, it can be suitably used particularly for applications requiring high transparency such as a display device substrate (display substrate), other optical substrates, packaging films and the like.

  As a method of forming the second layer 2 on at least one side of the first layer 1, for example, a physical method such as a thermal evaporation method, a sputtering method, an ion plating method, a cluster ion beam method, a CVD method, or the like is used. Chemical methods can be used.

The water vapor transmission rate defined in JIS K7129B of the gas barrier substrate 10 is not particularly limited, but is preferably 0.1 [g / m ² / day / 40 ° C., 90% RH] or less. When the water vapor permeability is within the above range, the long-term reliability when the gas barrier substrate 10 is used as a display device substrate is particularly excellent.

Although the oxygen permeability prescribed | regulated to JISK7126B of the gas barrier base material 10 is not specifically limited, 0.1 [cm < ³ > / m < ² > / day / 1atm / 23 degreeC] or less is preferable. When the oxygen permeability is within the above range, the long-term reliability when the gas barrier substrate 10 is used as a display device substrate is particularly excellent.

The corrosion area ratio after treatment at a temperature of 50 ° C., a humidity of 95% and 12 hours is not particularly limited in the evaluation by the calcium corrosion method to be described later of the gas barrier substrate 10, but is preferably 1% or less, particularly 0.01 to 0.5. % Is preferred. When the corrosion area ratio is within the above range, the gas barrier substrate 10 is particularly excellent in long-term reliability when applied to applications requiring high barrier properties such as organic EL displays and high-definition color liquid crystal displays.
Here, the said corrosion area rate can be calculated | required with a following formula.
Corrosion area ratio (%) = (Area of calcium discolored due to corrosion / Area of calcium part) × 100

Further, the number of corrosion sites that grow to 50 μm or more within the range of 1 mm ^{2 in} the evaluation by the calcium corrosion method described later is not particularly limited, but is preferably 5 or less, and particularly preferably 3 or less. . When the corrosion location is within the above range, the gas barrier substrate 10 is particularly excellent in display quality when applied to applications requiring high barrier properties such as an organic EL display and a high-definition color liquid crystal display.

The evaluation by the calcium corrosion method can be evaluated by the following method.
1. For example, after forming a calcium layer that reacts with moisture and corrodes on the second layer 2 constituting the gas barrier substrate 10 shown in FIG. 1 by a vacuum process, the calcium layer is an aluminum layer that is impermeable to water vapor. Is sealed to form a water vapor barrier property evaluation cell. Here, the thickness of the calcium layer was 200 nm, and the thickness of the aluminum layer was 4 μm.
The surface roughness of the aluminum layer was an arithmetic average value of 4.6 nm, and the maximum height and the maximum depth were a maximum height of 70 nm and a maximum depth of 3 nm.

2. Next, when the upper layer of the aluminum layer is exposed to a temperature of 40 ± 0.5 ° C. and a relative humidity of 90 ± 2%, the mass change is an organic substance (1 mg / 24 hours or less at an exposed area of 50 cm ² ). Specifically, the mixture was sealed with beeswax and paraffin melted and mixed at a ratio of 1: 1. After that, it is treated for 12 hours at a temperature of 50 ° C. and a humidity of 95%, and the corrosion state of calcium that corrodes by reacting with moisture is evaluated by the discoloration of calcium, and the metal corrosion calculated from the corrosion area and corrosion thickness of calcium. The amount of water that reacts with the metal is evaluated from the volume of the object.

The reason why the water vapor permeability was evaluated by such a calcium corrosion method instead of the measurement of the water vapor permeability specified in JIS is as follows.
In the measurement of water vapor permeability specified in the conventional JIS, the measurement limit was 0.1 [g / m ² / day / 40 ° C., 90% RH]. However, in recent years, there is a high demand for water vapor permeability in applications that require high barrier properties, such as organic EL displays and high-definition color liquid crystal displays, and it is possible to evaluate water vapor permeability for these requirements. There wasn't.
On the other hand, in the present invention, since the gas barrier substrate 10 having a very low water vapor permeability compared with the conventional gas barrier substrate could be obtained, an excellent water vapor barrier that could not be evaluated by the conventional method. It was because sex could be evaluated.

As shown in FIG. 1, the gas barrier substrate 10 of the present invention includes a first layer 1 made of a resin material, and a second layer made of an inorganic material provided on at least one side of the first layer 1. And layer 2.
The gas barrier substrate 10 of the present invention can also be applied to a gas barrier substrate having a configuration other than that shown in FIG. Examples of the gas barrier base material having another configuration include those shown in FIGS. 2 and 3 are cross-sectional views of the gas barrier substrate 10 having other configurations. Hereinafter, the difference from the gas barrier substrate 10 shown in FIG. 1 will be mainly described.

FIG. 2 is a cross-sectional view showing an example of the gas barrier substrate 10 having the third layer 3. As shown in FIG. 2, the gas barrier base material 10 includes a third layer made of an organic material between a first layer 1 made of a resin material and a second layer 2 made of an inorganic material. 3 is provided.
As the third layer 3, one having various functions is used according to its purpose. For example, as shown in FIG. 2, the function as a smoothing layer which smoothes the 1st layer 1 is mentioned. Moreover, as a function of the 3rd layer 3, the function as an adhesive layer which improves adhesiveness, and the function as a barrier layer which further improves barrier property are mentioned.
The third layer 3 can also be provided on the upper side (the upper side in FIG. 1) of the second layer 2. In this case, the functions of the third layer 3 include those having a function as a protective layer of the second layer 2 and those having a function as an optical antireflection layer.

  Examples of the organic material constituting the third layer 3 include acrylic resins and vinylidene chloride resins. Specific examples of acrylic resins include epoxy acrylate, urethane acrylate, isocyanuric acid triacrylate, pentaerythritol acrylate, trimethylolpropane acrylate, ethylene glycol acrylate, polyester acrylate, norbornene acrylate, bisphenol A type epoxy diacrylate, and 4 bromination. Bisphenol A diepoxy diacrylate, novolac epoxy acrylate and the like can be mentioned. Among these, at least one selected from isocyanuric acid triacrylate, bisphenol A type epoxy diacrylate, tetrabrominated bisphenol A type diepoxy diacrylate, and novolac type epoxy acrylate is preferable. Thereby, the improvement of surface smoothness and the improvement of adhesiveness can be aimed at.

  Although the thickness of the 3rd layer 3 is not specifically limited, 0.1-10 micrometers is preferable and 0.3-6 micrometers is especially preferable. If the thickness is less than the lower limit, the effect of improving the smoothness may be reduced, and if the thickness exceeds the upper limit, the uniformity of the thickness may be reduced.

  As a method for forming the third layer 3, for example, a wet coating method in which a thermosetting or ultraviolet curing is performed after coating film formation using a kiss coating method, a bar coating method, a gravure coating method, a micro gravure coating method, or the like, Examples thereof include a transfer method in which a cured film is formed while contacting a polished solid substrate such as glass on the surface of the resin composition applied onto the first layer 1.

  In FIG. 3, two second layers 21 and 22 are formed. The third layer 3 is the same as in FIG. That is, the gas barrier substrate 10 is provided with the third layer 3, the second layer 21, and the second layer 22 adjacent to each other in this order on the upper side of the first layer 1. Thereby, gas barrier performance can be improved more.

  The thickness of the second layer 21 is not particularly limited, and is preferably 10 to 1,000 nm, and particularly preferably 30 to 200 nm. When the thickness is within the above range, the bending durability is particularly excellent.

The thickness of the second layer 22 is not particularly limited, and is preferably 10 to 1,000 nm, particularly preferably 30 to 200 nm. When the thickness is within the above range, the bending durability is particularly excellent.
The ratio of the thickness of the second layer 21 and the thickness of the second layer 22 is not particularly limited, but is preferably 100: 1 to 1: 100, and particularly preferably 20: 3 to 3:20. When the ratio is within the above range, the bending durability is excellent.

Although the 2nd layer 21 and the 2nd layer 22 may be comprised with the inorganic material of the same composition, you may be comprised with the inorganic material of a different composition.
Note that when the second layer 21 and the second layer 22 are made of an inorganic material having the same composition, the interface may or may not be clear.
Specifically, the second layer 21 is preferably made of silicon oxide, aluminum oxide, magnesium oxide, boron oxide, or the like. The second layer 22 is preferably made of silicon oxide, aluminum oxide, magnesium oxide, boron oxide, or the like. Thereby, the gas barrier property can be particularly improved.

Note that in this embodiment mode, two layers formed of an inorganic material are formed; however, the present invention is not limited to this, and two or more layers of three layers, four layers, or the like may be used.
Further, a third layer may be further provided between the second layer 21 and the second layer 22.

  Such a gas barrier substrate 10 is specifically a substrate for a flat panel display such as a liquid crystal display, an organic EL display, an inorganic EL display, or electronic paper, a substrate for a surface light emitter such as an organic EL backlight, an inorganic EL backlight, etc. It can be suitably used as a display device substrate. Furthermore, by using such a display device substrate, a display device having excellent display performance and long-term reliability can be obtained.

Next, a display device will be described based on a preferred embodiment. FIG. 4 is a cross-sectional view showing an example of the display device (organic EL display) of the present invention.
In the organic EL display 20, the electrode 51, the light emitting layer 6, and the electrode 52 are provided in this order adjacent to the gas barrier substrate 10 as described above.
The electrode 51, the light emitting layer 6, and the electrode 52 are covered with a sealing material 7 that surrounds them. The sealing material 7 is bonded to the second layer 2 with an adhesive 71. The sealing material 7 maintains the sealed state of the electrode 51, the light emitting layer 6, and the electrode 52.
The gas barrier substrate 10 is composed of the first layer 1 and the second layer 2 as described above.

As the electrode 51 and the electrode 52, for example, a transparent electrode or a translucent electrode formed of ITO, SnO ₂ , In ₂ O ₃ , ZnO, or a composite of these oxides can be used.
Further, as the electrode 52, when transparency is not particularly required, for example, an electrode composed of Mg, Ag, Al, or a composite of these metals can be used.

Examples of the material constituting the light emitting layer 6 include TPD, Alq _{3 and the} like.
Examples of the sealing material 7 include a metal can and glass.
Examples of the adhesive 71 include an ultraviolet curable epoxy resin adhesive, a two-part epoxy adhesive, and the like.

When electricity is applied between the electrodes 51 and 52 of the organic EL display 20, the light emitting layer 6 emits light. The light is directly or reflected and passes through the gas barrier substrate 10 and is irradiated to the first layer 1 side.
Since the novel gas barrier substrate 10 is used for the organic EL display 20, it has a sufficient water vapor barrier property. Therefore, there is no deterioration of the light emitting layer and the electrode layer due to the ingress of moisture, and the long-term reliability and display quality when the organic EL display 20 is obtained are excellent.

Next, another embodiment of the display device will be described.
FIG. 5 is a cross-sectional view showing a liquid crystal display device which is an example of the display device.
In the liquid crystal display device 30, the alignment films 12 are provided on both surfaces (upper and lower surfaces in FIG. 5) of the liquid crystal composition 5.
A transparent electrode 11 is provided adjacent to each alignment film 12, and a gas barrier substrate 10 composed of the second layer 2 and the first layer 1 is further provided. The compensator plate 9 and the polarizing plate 8 and the polarizing plate 8 and the counter substrate 14 are held together to obtain the liquid crystal display device 30.

  Since a new substrate is used for the liquid crystal display device 30, it has a sufficient gas barrier property. Therefore, there is no entry of oxygen or water vapor into the liquid crystal layer, and the long-term reliability as a display body is excellent.

  In addition, although demonstrated about the organic EL display and the liquid crystal display device about the display device, this invention is not limited to this, For example, it can use also about display devices, such as electronic paper.

EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example and a comparative example, this invention is not limited to this.
First, the gas barrier substrate will be described.

Example 1
1. Formation of First Layer Polyethersulfone (thickness 200 μm, glass transition temperature Tg = 223 ° C.) was used as the first layer composed of a resin material.

2.1 Formation of Second Layer of Second Layer As a second layer composed of an inorganic material, SiOx (50 mol%), AlOx (16 mol%), MgOx (13 mol%), and BOx (10 mol%) An inorganic material having a melting point of 1,080 ° C. composed of NaOx (5 mol%), CaOx (4 mol%), KOx (1 mol%), and C (1 mol%) was used.
A value obtained by subtracting the Tg of the first layer from the melting point of the inorganic material was 857.
Using the RF magnetron sputtering apparatus, the above-mentioned first layer was set in this apparatus, evacuated to a level of 10 ⁻⁴ Pa, and argon as a discharge gas was introduced at a partial pressure of 0.5 Pa. Discharge was started when the atmospheric pressure in the RF magnetron sputtering apparatus was stabilized, plasma was generated on the inorganic material as a sputtering target, and a sputtering process was started. When the process was stabilized, the shutter was opened and the formation of the second layer (a layer made of an inorganic material) on the first layer was started. The temperature of the first layer when forming the second layer was 177 ° C. When the 50 nm film was deposited, the shutter was closed to complete the film formation. As a result of measuring the second layer by X-ray diffraction, it was in an amorphous state.

3. Formation of third layer Next, the atmosphere was introduced into the vacuum chamber of the RF magnetron sputtering apparatus, and the first layer on which the second layer was formed was taken out.
A uniform mixed solution comprising 25 wt% of bifunctional epoxy acrylate, 48.5 wt% of diethylene glycol, 24 wt% of ethyl acetate, 1 wt% of silane coupling agent, and 1.5 wt% of photoinitiator is formed on the second layer. Was applied with a spin coater, heated and dried at 80 ° C. for 10 minutes, and further cured by UV irradiation to form a 2 μm third layer.

4. Formation of Second Layer as Second Layer On the third layer described above, SiOx (50 mol%), AlOx (16 mol%), MgOx (13 mol%), and BOx (10 mol%) are further added. And a second layer having a thickness of 50 nm using an inorganic material having a melting point of 1,080 ° C. composed of NaOx (5 mol%), CaOx (4 mol%), KOx (1 mol%), and C (1 mol%). The second layer was formed to obtain a substantially transparent gas barrier substrate. In addition, the formation method of the 2nd layer of the 2nd layer used RF magnetron sputtering apparatus similarly to the above-mentioned.

(Example 2)
Example 1 was used except that the following materials were used as the first layer resin material and the second layer inorganic material, and the thicknesses of the first layer and the second layer were as follows. .
Polyethersulfone (thickness 200 μm, Tg = 223 ° C.) was used as the resin material. Moreover, SiOx (55 mol%), AlOx (14 mol%), MgOx (11 mol%), BOx (9 mol%), NaOx (5 mol%), CaOx (4 mol%), and KOx (1 mol) as inorganic materials. %) And C (1 mol%) and having a melting point of 1,150 ° C. A value obtained by subtracting Tg of the first layer from the melting point of the inorganic material was 917. The thickness of the second layer was 100 nm each for the first layer and the second layer.

(Example 3 )
Example 1 was repeated except that the second layer was only one layer.

(Example 4 )
Example 2 was the same as Example 1 except that the following inorganic materials were used.
An inorganic material having a melting point of 1190 ° C. composed of SiOx (50 mol%), AlOx (20 mol%), MgOx (16 mol%), and BOx (14 mol%) was used. A value obtained by subtracting the Tg of the first layer from the melting point of the inorganic material was 967.

(Example 5 )
Example 1 was repeated except that the third layer was not formed.

(Example 6 )
The resin material constituting the first layer was the same as that of Example 1 except that the following materials were used.
Polyetherimide (thickness 100 μm, glass transition temperature Tg = 216 ° C.) was used as the resin material. The value obtained by subtracting the Tg of the first layer from the melting point of the inorganic material was 864.

(Reference Example 1)
Example 2 was the same as Example 1 except that the following inorganic materials were used.
An inorganic material having a melting point of 1,485 ° C. composed of Nb ₂ O ₅ was used. The inorganic material was formed using RF magnetron sputtering in the same manner as in Example 1. However, the target used during sputtering was Nb ₂ O _5, and the gas to be introduced was added to 0.5 Pa of argon, and oxygen 0 .003 Pa was also introduced. The value obtained by subtracting the Tg of the first layer from the melting point of the inorganic material was 1,262.
( Reference Example 2 )
It was the same as Reference Example 1 except that oxygen gas was not introduced when forming the second layer (sputtering film formation).

(Comparative Example 1)
Example 2 was the same as Example 1 except that the following inorganic materials were used.
As the inorganic material, Al ₂ O ₃ having a melting point of 2,050 ° C. was used. The value obtained by subtracting the Tg of the first layer from the melting point of the inorganic material was 1,827.

(Comparative Example 2)
Example 1 was performed except that the following inorganic materials were used for the second layer.
As the inorganic material, Al having a melting point of 660 ° C. was used. A value obtained by subtracting the Tg of the first layer from the melting point of the inorganic material was 437.

(Comparative Example 3)
Polyethersulfone (thickness 200 μm, glass transition temperature Tg = 223 ° C.) was used as the first layer composed of a resin material. On the first layer, a homogeneous mixed solution consisting of 25 wt% bifunctional epoxy acrylate, 48.5 wt% diethylene glycol, 24 wt% ethyl acetate, 1 wt% silane coupling agent, and 1.5 wt% photoinitiator is spun. It was coated with a coater, dried by heating at 80 ° C. for 10 minutes, and further cured by UV irradiation to form a 2 μm resin layer.

The following evaluation was performed about the gas barrier base material obtained by each Example , the reference example, and the comparative example. The evaluation items are shown below together with the contents. The obtained results are shown in Table 1.
1. Water vapor permeability specified in JIS K 7129B The water vapor permeability was evaluated according to JIS K 7129B.

2. Oxygen permeability specified in JIS K 7126B The oxygen permeability was evaluated according to JIS K 7126B.

3. Corrosion area ratio by calcium corrosion method Corrosion area ratio was evaluated by the calcium corrosion method described above. In addition, the corrosion area rate was made into the average value of the value measured about eight gas barrier base materials obtained by each Example , the reference example, and the comparative example.
Moreover, since the gas barrier base material of Comparative Example 2 was opaque, it was impossible to measure the corrosion area ratio.

4). Corrosion spots by the calcium corrosion method Corrosion spots were evaluated by the calcium corrosion method described above. In addition, the corrosion location was made into the average value of the value measured about eight gas barrier base materials obtained by each Example , the reference example, and the comparative example.

5. Light transmittance The light transmittance was evaluated according to JIS K 7105.

6). Flexibility Flexibility refers to whether the gas barrier substrate is bent to an angle of about 30 degrees or more by hand, and then the gas barrier substrate is visually checked for deterioration such as cracks, deformation, and abnormal appearance. evaluated.

7). Bending durability Bending durability was obtained by bending the obtained gas barrier base material along a metal cylinder having a diameter of 30 mm with the second layer made of an inorganic material facing outward. The gas barrier properties were evaluated before and after this treatment was performed once to evaluate whether there was any deterioration in the gas barrier performance.

8). Surface smoothness The surface smoothness was evaluated with respect to the arithmetic average roughness in the range of 20 μm × 20 μm with an atomic force microscope (AFM).

As is clear from Table 1, Examples 1 to 6 had high light transmittance, and low water vapor permeability and oxygen permeability. That is, Examples 1 to 6 were shown to be substantially transparent and excellent in gas barrier properties.
Moreover, Examples 1-6 showed that the corrosion area rate was low, there were few corrosion locations, and water vapor | steam barrier property was especially excellent.
Moreover, it was shown that Examples 1-6 are excellent also in flexibility and bending durability.

Next, examples of display device substrates and display devices , reference examples, and comparative examples will be described.
(Example 1A~ Example 6 A)
An anode electrode composed of an ITO layer having a thickness of 100 nm was formed on the gas barrier substrate obtained in Examples 1 to 6 , and a TPD (N, N′-bis (3- Methylphenyl) 1,1′-biphenyl-4,4′-diamine) and a light emitting layer composed of Alq ₃ (tris- (8-hydroxyquinoline) aluminum) with a thickness of 100 nm are formed, and the thickness is further increased. A cathode electrode composed of a 100 nm Mg—Ag deposition layer was formed. And it sealed with the metal can and the adhesive so that the electrode mentioned above and the light emitting layer might be covered, and the organic EL display was obtained.

(Reference Examples 1A, 2A)
The same procedure as in Example 1A was used, except that the gas barrier substrate obtained in Reference Examples 1 and 2 was used.
(Comparative Example 1A to Comparative Example 3A)
The same procedure as in Example 1A was used except that the gas barrier substrate obtained in Comparative Examples 1 to 3 was used.

The organic EL displays obtained in each of the examples , reference examples and comparative examples were subjected to continuous light emission at room temperature and normal pressure to evaluate long-term reliability.
Example 1A to Example 6 The organic EL displays obtained in A emitted light even after 500 hours, but the comparative example was significantly weak or did not emit light within 24 hours. Therefore, it was confirmed that the examples were excellent in long-term reliability.

It is sectional drawing which shows an example of the gas barrier base material of this invention. It is sectional drawing which shows an example of the gas barrier base material of this invention. It is sectional drawing which shows an example of the gas barrier base material of this invention. It is sectional drawing which shows an example of the board | substrate for display devices of this invention. It is sectional drawing which shows an example of the display device of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st layer comprised by resin material 2 2nd layer comprised by inorganic material 21 2nd layer comprised by inorganic material 22 2nd layer comprised by inorganic material 3 It comprised by organic material Third layer 5 Liquid crystal composition 6 Light emitting layer 7 Sealing material 71 Adhesive 8 Polarizing plate 9 Compensation plate 10 Gas barrier substrate 11 Transparent electrode 12 Alignment film 14 Counter substrate 20 Organic EL display 30 Liquid crystal display device 51 Electrode 52 Electrode

Claims (19)

A substantially transparent gas barrier substrate having a first layer composed of a resin material and a second layer composed of an inorganic material provided on at least one side of the first layer,
The melting point of the inorganic material constituting the second layer state, and are 1,500 ° C. or less,
And when the melting point of the inorganic material is [Tm] and the glass transition temperature of the first layer is [Tg],
A gas barrier substrate satisfying the relationship of 0 ° C. ≦ (Tm−Tg) ≦ 1,125 [° C.] .   The gas barrier substrate according to claim 1, wherein two or more of the second layers are formed.   The gas barrier substrate according to claim 1 or 2, wherein a third layer made of an organic material is further provided on at least one surface of the second layer.   The gas barrier substrate according to any one of claims 1 to 3, wherein the second layer is substantially in an amorphous state.   The gas barrier substrate according to any one of claims 1 to 4, wherein the glass transition temperature [Tg] of the first layer is 200 ° C or higher.   The gas barrier substrate according to any one of claims 1 to 5, wherein the resin material contains a polyethersulfone resin or an epoxy resin. The gas barrier substrate according to any one of claims 1 to 6 , wherein the inorganic material includes a plurality of metal oxides. The gas barrier substrate according to any one of claims 1 to 7 , wherein the metal oxide contains silicon oxide. The gas barrier substrate according to any one of claims 1 to 8 , wherein the metal oxide further contains aluminum oxide.   The gas barrier substrate according to any one of claims 1 to 9, wherein the metal oxide further contains one or both of magnesium oxide and boron oxide.   The gas barrier substrate according to any one of claims 1 to 10, wherein the arithmetic average roughness of the surface of the second layer is 10 nm or less. The gas barrier group according to any one of claims 1 to 11, wherein a water vapor transmission rate defined in JIS K7129B of the second layer is 0.1 [g / m ² / day / 40 ° C, 90% RH] or less. Wood. The gas barrier substrate according to any one of claims 1 to 12, wherein an oxygen permeability specified by JIS K7126B of the second layer is 0.1 [cm ³ / m ² / day / 1 atm / 23 ° C] or less. .   The gas barrier substrate according to any one of claims 1 to 13, wherein the light transmittance of the gas barrier substrate defined in JIS K7105 is 60% or more. The gas barrier base material according to any one of claims 1 to 14, wherein the gas barrier base material has a water vapor permeability defined by JIS K7129B of 0.1 [g / m ² / day / 40 ° C, 90% RH] or less. . The gas barrier substrate according to any one of claims 1 to 15, wherein an oxygen permeability specified by JIS K7126B of the gas barrier substrate is 0.1 [cm ³ / m ² / day / 1 atm / 23 ° C] or less.   The gas barrier substrate according to any one of claims 1 to 16, wherein the corrosion area rate after treatment at a temperature of 50 ° C and a humidity of 95% for 12 hours is 1% or less as evaluated by a calcium corrosion method.   A display device substrate comprising the gas barrier substrate according to claim 1.   A display device comprising the display device substrate according to claim 18.

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