KR101788501B1 - Gas barrier film and display device with the same - Google Patents

Abstract

A gas barrier comprising a buffer layer comprising Al ₂ O ₃ , formed of AlO _x formed on the substrate layer and containing X 1.35 to 1.45, and a barrier layer containing silicon dioxide (SiO ₂ ) formed on the buffer layer Film and a display device including the same.

Description

[0001] The present invention relates to a gas barrier film and a display device including the same,

The present invention relates to a gas barrier film and a display device comprising the same.

The use of gas barrier films as package materials for electronic devices or display devices has been expanded. The gas barrier film is required to have low water permeability and oxygen permeability and to secure transparency.

Although a large number of plate glasses have been used as display substrates for electrode substrates for liquid crystal display panels, plasma display devices, electroluminescence devices, fluorescent display tubes or light emitting diode devices, Which is a limitation on weight saving. Plastic films have been attracting attention as display substrates replacing plate glass. The plastic film is difficult to break due to its light weight, it can be thinned easily, and the roll-to-roll process can be applied, so productivity can be improved.

When a plastic film alone is applied to an electronic device or a display device as a display material or a packaging material, it is required to additionally have a function of preventing gas permeation due to its relatively high gas permeability as compared with a glass material. When the gas barrier property of the plastic film is weak, water vapor or air may penetrate the film encapsulating the pixel element of the display device to deteriorate the pixel element. As a result, display defects may be caused in the display device or the display quality may be degraded.

Japanese Patent Application No. 2004-0082598 discloses a method of using a multilayer gas barrier thin film made of an organic layer and an inorganic layer, and Japanese Patent Application No. 2007-237588 discloses a method of forming a polysilazane film by a wet process, Thereby forming a barrier layer. Nonetheless, in a multilayer thin film structure, cracks can be induced at the interface of several layers having different physical properties. When a part of the polysilazane film is changed to silica, cracks may also be induced in the polysilazane film. Many attempts have been made to develop a method for improving cracks, since induced cracks can provide a path through which moisture is imbibed.

The present invention intends to provide a gas barrier film structure in which cracking can be suppressed and a display device including the same.

According to one aspect of the present invention, A buffer layer comprising aluminum oxide represented by AlO _x formed on the base layer and having X of 1.35 to 1.45; And a barrier layer containing silicon dioxide (SiO ₂ ) formed on the buffer layer.

According to another aspect of the present invention, there is provided a liquid crystal display comprising pixel elements; And a display device including the gas barrier film covering the pixel elements.

According to the present invention, it is possible to provide a gas barrier film structure in which cracking can be suppressed and a display device including the same.

1 is a cross-sectional view for explaining a gas barrier film structure according to an embodiment of the present invention.
2 is a cross-sectional view illustrating a display device including a gas barrier film according to an embodiment of the present invention.

The barrier film according to embodiments of the present invention may include a buffer layer for improving the adhesion with the substrate layer and improving the gas barrier property. The gas barrier film may have a structure in which a buffer layer and a barrier layer are laminated on a base layer. The buffer layer may be formed of an oxide-based inorganic compound in order to block the influence of oxygen or water vapor. The buffer layer may be deposited including aluminum oxide. The buffer layer can prevent the occurrence of cracks in the barrier layer formed by wet coating thereon or reduce the possibility of peeling, and can prevent the degradation of the gas barrier property. In addition, the buffer layer can further improve the adhesion with the barrier layer which is wet-coated.

1 shows a gas barrier film structure according to one embodiment of the present invention.

Referring to FIG. 1, the gas barrier film 10 may include a buffer layer 120 and a barrier layer 130 on a substrate layer 110. The substrate layer 110 may be introduced into a flexible plastic substrate. In embodiments, the substrate layer 110 may comprise polyethylene terephthalate (PET). The substrate layer 110 may comprise, alone, or a mixture thereof, selected from the group consisting of polycarbonate, polyethersulfone, polyimide, polybutyl terephthalate, and polyethylene naphthalate.

When the substrate layer 110 is a member used in a display device, it can be introduced into a film having optical transparency. Optical transparency may be at least 80% or greater than 90% of the light transmittance of the substrate to visible light. The thickness of the base layer 110 may vary depending on the intended use, and may have a thickness of from about 5.0 μm to about 500 μm, for example, from 100 μm to 200 μm, or from 25 μm to 125 μm have.

The buffer layer 120 formed on the base layer 110 has a role of suppressing the occurrence of cracks and reducing the possibility of peeling, and can suppress the moisture permeation of moisture. The buffer layer 120 may include aluminum oxide (AlO _x ) as an inorganic layer which induces adhesion enhancement with respect to the base layer 110 and improvement of gas barrier properties. When aluminum oxide is represented by AlO _x , the ratio of oxygen O (O / Al), that is, X may be in the range of 1.35 to 1.45, for example, from 1.41 to 1.43 in comparison to aluminum Al. In the above range, it is possible to further improve the adhesiveness and improve the water vapor transmission rate (WVTR). The buffer layer 120 may be deposited to a thickness of 5 nm to 1,000 nm, or 10 nm to 300 nm, or 40 nm to 60 nm.

The barrier layer 130 may be formed on the buffer layer 120. The barrier layer 130 is derived from a polysilazane (polysilazane) system or a hydrogenated polysiloxane four jangye compound may include a silicon dioxide (SiO _2). The hydrogenated polysiloxazane may have a unit represented by the following formula (1), a unit represented by the following formula (2), and a terminal represented by the following formula (3).

≪ Formula 1 >

(2)

(3)

In formulas (1) and (2), R1 to R7 each independently represent hydrogen, a substituted or unsubstituted C1 to C30 alkyl group, a substituted or unsubstituted C3 to C30 cycloalkyl group, a substituted or unsubstituted C3 to C30 aryl group, A substituted or unsubstituted C3 to C30 arylalkyl group, a substituted or unsubstituted C3 to C30 heteroalkyl group, a substituted or unsubstituted C3 to C30 heterocycle alkyl group, a substituted or unsubstituted C3 to C30 alkenyl group, a substituted Or an unsubstituted alkoxy group, a substituted or unsubstituted carbonyl group, a hydroxy group, or a combination thereof.

The end of Formula 3 of the hydrogenated polysiloxazane can be included in an amount of 15 to 35% by weight based on the total amount of Si-H bonds in the hydrogenated polysiloxazane structure. In such a case, the SiH ₃ portion reacts with SiH ₄ and is prevented from being scattered during curing, while the oxidation reaction sufficiently occurs during curing after coating, so that shrinkage is more effectively prevented, cracks are generated in the barrier layer 130 It is possible to more effectively suppress the occurrence of the problem.

The hydrogenated polysiloxazane may have a weight average molecular weight (Mw) of 1000 to 5000 g / mol. In this range, dense barrier layer 130 can be induced by thin film coating while reducing evaporation components during heat treatment. More effectively, the weight average molecular weight (Mw) may be 1500 to 3500 g / mol.

The hydrogenated polysiloxazane may be included in an amount of about 0.1 to 50% by weight based on the total amount of the coating liquid. When included in such a range, an appropriate viscosity can be maintained and a flat and even coating can be performed without voids and gaps. The solvent may be any solvent that is capable of dissolving the hydrogenated polysiloxazane while being not reactive with the hydrogenated polysiloxazane. However, when the -OH group is contained, a solvent containing no -OH group can be used because it is reactive with the hydrogenated polysiloxazane. Examples of the solvent include hydrocarbon solvents such as aliphatic hydrocarbons, reductive hydrocarbons and aromatic hydrocarbons, halogenated hydrocarbon solvents, aliphatic ethers, and alicyclic ethers. Specific examples thereof include hydrocarbons such as pentane, hexane, cyclohexane, toluene, xylene, solvesso and tallow, halogen hydrocarbons such as methylene chloride and tricholoroethane, ethers such as dibutyl ether, dioxane and tetra- And so on. The solubility of the hydrogenated polysiloxazane and the evaporation rate of the solvent can be appropriately selected and a plurality of solvents can be mixed and used.

The gas barrier film 10 may have a water permeability of 0.0005 g / m ² / day to 0.08 g / m ² / day according to the ASTM F 1249 measurement method. The moisture permeability of the gas barrier film 10 may be 0.0005 g / m ² / day to 0.001 g / m ² / day.

Hereinafter, a gas barrier film according to another embodiment of the present invention will be described. The gas barrier film according to another embodiment of the present invention is a gas barrier film according to another embodiment of the present invention described above except that the barrier layer (130 in FIG. 1) further contains hydrogen (H) and nitrogen (N) May be substantially the same as the barrier layer according to < RTI ID = 0.0 > Accordingly, the barrier layer will be mainly described below.

The barrier layer according to the present embodiment 130, is derived from a polysilazane jangye or hydride polysiloxane jangye four compounds as in the one embodiment of the present invention described above may comprise a silicon dioxide (SiO _2). Further, the barrier layer may further include a hydrogen (H) atom and a nitrogen (N) atom. At this time, the concentration of hydrogen atoms in the barrier layer 130 may be 1 to 30 atomic%, and the concentration of nitrogen atoms may be 1 to 20 atomic%. Such a concentration of hydrogen and nitrogen atoms can secure the flexibility of the barrier layer without lowering the water permeability, and cracks may not be generated in the barrier layer. The concentration of hydrogen atoms can be measured using Hydrogen Forward Scattering Spectroscopy (HFS), and the concentration of nitrogen atoms can be measured using Rutherford backscattering spectroscopy (RBS).

Hereinafter, a method for producing a gas barrier film according to one embodiment of the present invention will be described. A method of manufacturing a gas barrier film according to one embodiment of the present invention includes forming a buffer layer 120 of aluminum oxide on a base layer 110 (FIG. 1), forming silicon dioxide (SiO ₂ ) on the buffer layer 120 To form a barrier layer (130) containing the barrier layer (130).

Specifically, aluminum oxide (AlO _x ) may be deposited on the base layer 110 by a sputtering process. The oxygen content in the aluminum oxide deposited can be controlled by controlling the flow of oxygen gas flowing into the deposition chamber when performing sputtering on the aluminum target. When aluminum oxide is represented by AlO _x , it can be deposited by controlling the flow rate of oxygen gas such that the ratio of oxygen O (O / Al), that is, X is in the range of 1.35 to 1.45, compared with aluminum Al. Specifically, the amount of the oxygen gas introduced into the chamber can be controlled at a flow rate of about 50 sccm to 60 sccm. Further, the temperature of the substrate can be maintained at room temperature (20 DEG C) by contact with a cooling roll in the chamber. The deposition process can be performed while maintaining the process pressure in the chamber between 1.5 mTorr and 2.5 mTorr.

The buffer layer 120 may be deposited to a thickness of 5 nm to 1,000 nm, in embodiments from 10 nm to 300 nm, or in embodiments, to a thickness of 40 nm to 60 nm.

A barrier layer 130 is formed on the buffer layer 120. The barrier layer 130 may be formed from a polysilazane-based or hydrogenated polysiloxane-based compound to include silicon dioxide (SO ₂ ). In the specific example, a coating solution prepared by dissolving 0.1 to 50% by weight of hydrogenated polysiloxazane in 50 to 99.9% by weight of a solvent is prepared, wet-coated on the buffer layer 120, and then the coated layer is cured to form the barrier layer 130 .

The coating solution may be coated on the buffer layer 120 by a roll coating, a spin coating, a dip coating, a flow coating, a spray coating, or the like. The barrier layer 130 formed by such a coating may be about 5 nm to 3 탆 thick. Or a thickness of 100 nm to 200 nm. In embodiments, it may have a thickness of 40 nm to 60 nm. Cracks can be further suppressed in this thickness range.

The barrier layer 130 can be formed by performing a modification treatment or a curing treatment by drying and ultraviolet irradiation. In addition to ultraviolet irradiation, the coating layer may be cured by plasma treatment or thermal curing, wet curing by drying at high humidity, or a mixture thereof. The modification or curing treatment can be understood as a process of changing the hydrogenated polysiloxazane into a layer containing silicon dioxide to ceramize it. In one embodiment, the coating layer can be cured by heat treatment. When curing is carried out by ultraviolet irradiation, ultraviolet irradiation can be carried out by using a vacuum ultraviolet irradiator at an irradiation intensity of 10 to 200 mW / cm 2 and an irradiation dose of 100 to 6000 mJ / cm 2.

The curing by the plasma treatment can be carried out at atmospheric pressure or in a vacuum environment. In the case of the atmospheric plasma treatment, a nitrogen gas, an oxygen gas or such a mixed gas, specifically oxygen gas, can be used as the plasma gas. In addition, the hydrogenated polysiloxazane can be cured by heat treatment under high humidity and low temperature conditions. In this case, the heat treatment temperature can be set at 40 to 350 DEG C and the relative humidity can be treated at 40 to 100% humidity.

Hereinafter, an apparatus of a display including a gas barrier film according to one embodiment of the present invention will be described.

Figure 2 shows a display device comprising a gas barrier film according to an embodiment of the present invention. The display device 20 includes the pixel elements 300 on the substrate 200 and may be provided with the gas barrier film 10 to cover and encapsulate the pixel elements 300. [ The substrate 200 may be introduced in substantially the same form as the gas barrier film 10. The pixel element 300 may be an organic light emitting diode (OLED) element. The pixel element 300 may include various display elements in addition to the OLED element.

Hereinafter, the present invention can be more specifically described by the embodiments and the comparative examples

Coating liquid

A coating solution for the barrier layer 130 coated on the buffer layer (120 in FIG. 1) was prepared. The interior of the 2 L reactor equipped with a stirrer and a temperature controller was replaced with dry nitrogen. 2.0 g of pure water was poured into 1,500 g of dry pyridine, and the mixture was thoroughly mixed. The mixture was kept in a reactor at 5 ° C. 100 g of dichlorosilane was gradually introduced into the reactor over 1 hour, and 70 g of ammonia was gradually injected over 3 hours while stirring. Dry nitrogen was injected for 30 minutes to remove ammonia remaining in the reactor. The resulting white slurry-like product was filtered through a 1 mu m teflon filter in a dry nitrogen atmosphere to obtain 1,000 g of a filtrate. 1,000 g of dry xylene was added thereto, and the operation of replacing the solvent with xylene in pyridine using a rotary evaporator was repeated three times in total to adjust the solid concentration to 20%, and the pore size ( pore size) was filtered with a 0.03 mu m teflon filter to obtain hydrogenated polysiloxazane. The oxygen content of the hydrogenated polysiloxazane measured by using FlashEA 1112 (manufactured by Thermo Fisher Scientific Inc.) was 0.5%, and the SiH 3 / SiH (total amount) measured using the proton NMR AC-200 (manufactured by Bruker) was 0.20 , And a weight average molecular weight of 2,000 g / mol was measured using GPC: HPLC P ump 1515, RI Detector 2414 (manufactured by Waters), and Colem: KF801, KF802, and KF803 (manufactured by Shodex).

Example 1

A substrate of HC PET (manufactured by KIMOTO) having a thickness of 125 탆 was loaded on a substrate layer (110 in FIG. 1) and a buffer layer (120 in FIG. 1) was sputter deposited on the vacuum deposition chamber of the sputtering apparatus. The preprocessing process was performed by preparing the vapor deposition substrate. The pre-treatment was performed by applying a power of 75 W under a chamber pressure of 1.8 mTorr using a magnetron plasma pre-treatment apparatus to remove impurities on the surface of the substrate and increase surface energy. In the deposition, an Ar gas of 270 sccm was introduced as a discharge gas into a chamber of a sputtering system, and an oxygen gas (O ₂ gas) as an oxidizing gas was introduced into a reactive gas, . The process chamber pressure was set to 1.8 mTorr, pulsed DC power was applied at 5 kW, and the flow rate of oxygen gas was adjusted using a plasma emission monitor (Plasma Emission Monitor, manufactured by Fraunhofer). An aluminum oxide thin film was deposited to a thickness of about 50 nm by sputtering at a set point of a plasma emission monitor of 2.5. By adjusting the set point of the plasma emission monitor, the amount of oxygen gas introduced into the chamber was adjusted from about 60 sccm to 50 sccm, and the injection amount of oxygen gas was adjusted to about 58 sccm.

A coating solution was spin-coated on the deposited aluminum oxide layer to form a layer having a thickness of 100 nm. Spin coating was performed at approximately 1000 rpm for 20 seconds and then primary dried in a convection oven at 80 캜 for 3 minutes. Using a SMT model CR403 as a vacuum UV irradiator, exposure was carried out at an irradiation intensity of 14 mW / cm ₂ for 143 seconds to a radiation dose of approximately 2000 mJ / cm ₂ and a secondary drying in a convection oven at 120 ° C for 1 hour To perform a curing reforming process.

Example 2

When the aluminum oxide layer was sputter deposited, the set point of the plasma discharge monitor for adjusting the flow rate of the oxygen gas into the vacuum deposition chamber of the sputtering apparatus was adjusted to 2.7, Lt; / RTI > to about 56 sccm. The procedure was carried out in substantially the same manner as in Example 1 except for this.

Example 3

Other procedures were performed in substantially the same manner as in Example 2 except that the coating liquid was spin-coated to form a coating layer having a thickness of 200 nm.

Example 4

When the aluminum oxide layer is sputter deposited, the set point of the plasma discharge monitor for controlling the flow rate of the oxygen gas into the vacuum deposition chamber of the sputtering apparatus is set to 2.9, sccm. The other procedures were carried out in substantially the same manner as in Example 2.

Comparative Example 1

When the aluminum oxide layer was sputter deposited, the set point of the plasma discharge monitor controlling the flow rate of the oxygen gas into the vacuum deposition chamber of the sputtering apparatus was adjusted to 2.0, and the flow rate of the oxygen to be injected was about 60 sccm. The procedure was carried out in substantially the same manner as in Example 1 except for this.

Comparative Example 2

When the aluminum oxide layer was sputter deposited, the set point of the plasma discharge monitor for adjusting the flow rate of the oxygen gas into the vacuum deposition chamber of the sputtering apparatus was adjusted to 3.0, About 50 sccm. The aluminum oxide layer was deposited to a thickness of about 80 nm. The procedure was carried out in substantially the same manner as in Example 3 except for this.

Comparative Example 3

Except for omitting the process of coating the coating liquid, the other procedures were carried out in substantially the same manner as in Example 2. Accordingly, the barrier layer 130 is omitted on the buffer layer (120 in FIG. 1).

Comparative Example 4

The process of spin-coating a coating solution other than omitting the sputtering process of the aluminum oxide layer was carried out in the same manner as in Example 3. Thus, the barrier layer 130 was directly coated on the base layer (110 in FIG. 1) without the buffer layer (120 in FIG. 1).

The above-described embodiments and comparative examples can be presented as shown in Table 1 below.

No. rescue O / Al AlOx film thickness
(nm) Wet Coating Thickness (nm) PEM
Set Point Example 1 AlOx / wet coating 1.43 50 100 2.5 Example 2 AlOx / wet coating 1.41 50 100 2.7 Example 3 AlOx / wet coating 1.41 50 200 2.7 Example 4 AlOx / wet coating 1.35 50 100 2.9 Comparative Example 1 AlOx / wet coating 1.48 50 100 2.0 Comparative Example 2 AlOx / wet coating 1.29 80 200 3.0 Comparative Example 3 AlOx 1.41 50 - 2.7 Comparative Example 4 Wet coating - - 200 -

The properties of the gas barrier films prepared by the examples and comparative examples shown in Table 1 were measured and presented in Table 2.

How to measure property

1. Adhesion:

According to the ASTM D3359 measurement method, the remaining number of 10 X 10 cuts with a knife in 1 mm increments with a 3M tape was confirmed by the classification criteria shown in the measurement method. "0B" is greater than 65% when "B" is classified as "5B", "0B" is less than 5%, "1B" is between 35 and 65%, and "0B" is greater than 65%.

2. Water Transmission (WVTR):

ASTM F 1249 method using a moisture permeability meter (AQUATRAN Model) manufactured by MOCOM. The prepared specimens were cut into a size of 100 mm x 100 mm and then inserted into a zig with an open center. The temperature was measured at 23 캜 and 100% relative humidity.

3. Crack:

The presence or absence of cracks in the coating layer of the specimen was confirmed by an optical microscope. The evaluation was carried out in three stages as described below, and the evaluation results are shown in the table.

* Excellent (indicated with a mark " x " in Table 2): No cracks were observed in the coating layer.

* Normal (marked with "Δ"): Part of the coating layer was cracked.

* Bad (In Table 2, marked with " o "): The cracks were seen throughout the coating layer.

4. Oxygen / Aluminum ratio (O / Al):

The aluminum oxide thin film was analyzed by XPS.

5. Light Transmittance:

UV Spectrometer Lambda 45 Model (manufactured by Perkin Elmer). Based on the transmittance at a wavelength of 550 nm.

division Example 1 Example 2 Example 3 Example 4 compare
Example 1 compare
Example 2 compare
Example 3 compare
Example 4 Attachment 5B 5B 4B 4B 1B 0B 5B 0B WVTR
(g / m ² / day) 0.001 0.0005 0.0007 0.001 0.03 0.08 0.09 4.5 crack × × × × × × × ○ O / Al 1.43 1.41 1.41 1.35 1.48 1.29 1.41 - Light transmittance (%) 92 92 90 83 90 52 83 90

The measurement results presented in Table 2 indicate that when water vapor permeability is introduced into the buffer layer 120 below the barrier layer (130 in FIG. 1) and aluminum oxide AlO _x is in the range of 1.35 to 1.43, water permeability 0.001 g / m < ² > / day or less. It is shown that the buffer layer of the aluminum oxide layer can inhibit cracking in the wet coating layer. In addition, when _X of AlO _X is in the range of 1.35 to 1.43, the adhesion is relatively excellent. Possession excellent properties in adhesion and moisture permeability even, AlO time of _X of X is 1.35 to 1.43 within the range, the gas barrier film (10 of FIG. 1) is shown at least 83% higher light transmittance, the X of AlO _X 1.41 To 1.43, the gas barrier film (10 in FIG. 1) shows a higher light transmittance of 90% to 92%.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be understood that the invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. It is therefore to be understood that the embodiments described above are in all respects illustrative and not restrictive.

10: gas barrier film, 20: display device,
110: substrate layer, 120: buffer layer,
130: barrier layer.

Claims (4)

A base layer;
A buffer layer formed directly on the substrate layer and comprising aluminum oxide represented by AlO _x and having X of 1.35 to 1.45; And
The gas barrier film comprising a barrier (barrier) layer containing silicon dioxide (SiO ₂₎ formed on said buffer layer,
The moisture permeability of the gas barrier film is 0.0005 g / m ² / day to 0.001 g / m ² / day,
The gas barrier film has an area of not less than 0% and less than 5% that is torn off according to ASTM D3359,
The buffer layer has a thickness of 10 nm to 60 nm,
Wherein the barrier layer further contains a hydrogen atom and a nitrogen atom in the silicon dioxide,
Wherein the barrier layer has a hydrogen atom concentration of 1 to 30 atomic% and a nitrogen atom concentration of 1 to 20 atomic%. The method according to claim 1,
The buffer layer
And an aluminum oxide layer represented by AlO _x and having X of 1.41 to 1.43. delete Pixel elements; And
The display device according to claim 1 or 2, wherein the gas barrier film covers the pixel elements.

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