KR20130128212A - Self-healable barrier substrate for flexible organic electronic device and method for manufacturing the same - Google Patents

Abstract

The present invention relates to a barrier substrate having self-healing properties and a manufacturing method thereof, and more particularly, to a barrier substrate having a core-shell type structure including a mineral acid oxide precursor in which hydrophilic polyurethane is formed, included in a base layer, mineral acid oxide layer formed on the base layer, and the mineral acid oxide. The barrier substrate, according to the present invention, has self-healing properties with the help of external oxygen and moisture when crack is created. Also, the barrier substrate can be manufactured through simplified processes compared to a conventional multilayer thin film structured barrier substrate. Especially, large area barrier substrates can be manufactured through a coaxial electro-spinning and roll-to-roll processes.

Description

A barrier substrate having self-healing and a method for manufacturing the same {SELF-HEALABLE BARRIER SUBSTRATE FOR FLEXIBLE ORGANIC ELECTRONIC DEVICE AND METHOD FOR MANUFACTURING THE SAME}

The present invention relates to a barrier substrate and a method of manufacturing the same.

Organic electronic devices, such as organic light emitting diodes (OLEDs), organic solar cells (OPVs), organic thin film transistors (OTFTs), etc., are easily influenced by external factors such as internal characteristics of organic semiconductors, or moisture, oxygen, ultraviolet rays, and manufacturing conditions of the devices. Deterioration may occur and the life may be shortened. thereafter. In the commercialization of organic electronic devices, packaging that protects the devices from external factors such as moisture and oxygen is recognized as an important factor.

Previously, a method of packaging an organic electronic device has been used to seal a substrate in which the organic electronic device is formed with a protective cap such as glass. There are limitations that cannot be applied to flexible devices.

In order to overcome this limitation, recently, a method of applying a barrier substrate of a thin film to an organic electronic device has been used, and a case of applying a barrier substrate of various materials has been reported, focusing on the development of a flexible device. have.

Among them, barrier substrates such as inorganic thin films or polymer films are generally used, and polymer films generally have a high moisture permeability of about 1 to 100 g / m 2 · day, and inorganic thin films have pin-holes due to their characteristics. There is a disadvantage that it is difficult to form a completely excluded thin film.

In order to overcome this problem, a barrier substrate having a multilayer structure in which an inorganic thin film, a polymer film, a film of a hybrid material, or the like is laminated in various combinations has been proposed. However, the barrier substrate of such a multilayer structure is only to delay the deterioration of the life of the device by bypassing the penetration path of oxygen or moisture, and also because the thin film is manufactured by stacking a plurality of thin films, the barrier substrate becomes thick and has low productivity. There is this.

In addition, when forming a polymer film on the inorganic thin film, due to the difference in stress characteristics such as the coefficient of thermal expansion between the film quality, a lot of cracks must be accompanied on the inorganic thin film, once generated cracks do not disappear on their own and continue to grow The lifetime of the device is reduced.

Accordingly, there is an urgent need for development of a barrier substrate suitable for a flexible organic electronic device while minimizing physical damage.

The present invention is to provide a barrier substrate capable of self-healing and recovering from physical damage.

The present invention also provides a method capable of continuously manufacturing the barrier substrate in a large area.

According to one embodiment of the invention,

A base layer;

An inorganic oxide layer formed on the base layer; And

Core-shell type structure including an inorganic oxide precursor contained in the inorganic oxide layer, the water-soluble polymer is formed on the surface

There is provided a barrier substrate comprising a.

Here, the core-shell type structure may be core-shell type particles or fibers.

In this case, the core-shell type particles or fibers may have a diameter of 10 to 100 ㎛.

In addition, the inorganic oxide layer may include titanium dioxide (TiO ₂ ), and the inorganic oxide precursor may be titanium tetrachloride (TiCl ₄ ).

In addition, the water-soluble polymer may be polyvinylpyrrolidone, polyvinyl alcohol or a mixture thereof.

Meanwhile, the base layer may include at least one polymer selected from the group consisting of polyolefin, polyethylene terephthalate, polycarbonate, polyether sulfone, and polysiloxane.

In addition, the thickness of the inorganic oxide layer may be 10 to 500 ㎛.

In addition, the barrier substrate according to the present invention may further include a polymer layer formed on the inorganic oxide layer.

In addition, in the barrier substrate according to the present invention, two or more inorganic oxide layers may be formed on the substrate layer.

The barrier substrate according to the present invention may be used for a flexible organic electronic device.

On the other hand, according to another embodiment of the present invention, forming an inorganic oxide layer on the base layer; And dispersing a core-shell-type structure including an inorganic oxide precursor having a water-soluble polymer formed on a surface thereof on the inorganic oxide layer.

In this case, the forming of the inorganic oxide layer may be performed by a method of sputtering deposition of an inorganic oxide on a base layer.

The method of manufacturing a barrier substrate according to the present invention may further include forming a core-shell type structure before the step of dispersing the core-shell type structure.

The forming of the core-shell type structure may be performed by forming a core-shell type particle or fiber by a coaxial electro-spinning method.

In addition, the method of manufacturing a barrier substrate according to the present invention may further include forming a polymer layer on the inorganic oxide layer.

The barrier substrate according to the present invention has excellent barrier properties due to self-healing by external oxygen or moisture when a crack is generated, and can be manufactured in a simplified process as compared with the barrier substrate of the previous multilayer thin film structure. In particular, large-area barrier substrates can be continuously produced using coaxial electro-spinning and roll-to-roll processes.

1 schematically illustrates a self-healing mechanism of a barrier substrate according to an embodiment of the present invention,
Figure 2 schematically shows a method of manufacturing a barrier substrate according to an embodiment of the present invention,
3 schematically illustrates a coaxial electrospinning method that may be included in a method of manufacturing a barrier substrate according to an embodiment of the present invention.

Hereinafter, a barrier substrate and a method of manufacturing the same according to embodiments of the present invention will be described.

Prior to this, some terms are defined as follows unless explicitly stated in the present specification and claims.

First, the 'core-shell type structure' refers to a structure in which a material forming a shell (or shell) surrounds a material forming a core (or center).

In addition, the term “core-shell type particles or fibers” includes a healing agent capable of exhibiting self-healing properties by reaction with oxygen or moisture in the core portion, and oxygen in the core portion and outside. Or a shell which blocks the contact with moisture to form particles or fibers surrounding the core portion.

In this case, in the 'core-shell type fiber', the core inside the shell may be continuous or discontinuous, and the portion where the core is discontinuous may be connected by the shell.

In addition, the inclusion of the core-shell type particles or fibers in the inorganic oxide layer is defined as meaning the state in which the core-shell type particles or fibers are dispersed in or on the surface of the inorganic oxide layer.

On the other hand, a barrier substrate for a flexible organic electronic device known in the art is generally a barrier substrate having a multilayer structure in which an inorganic thin film, a polymer film, or an inorganic thin film and a polymer film are laminated in various combinations.

However, the polymer film has a limitation in expressing sufficient moisture permeability due to the characteristics of the polymer, and the inorganic thin film has a disadvantage in that barrier properties are not sufficient such that it is difficult to form a thin film in which pinholes are completely excluded and cracks are easily generated by repeated bending. In addition, the barrier substrate having a multilayer structure including an inorganic thin film and a polymer film merely bypasses the penetration path of oxygen or moisture when a crack is generated, and thus a crack is generated continuously and thus, there is a limit in obtaining an ultimate barrier effect. The more layers are laminated, the thicker there is a limit to increasing the bending radius.

Accordingly, the inventors of the present invention, in the course of continuing the study of the barrier substrate, when the inorganic oxide layer includes the core-shell type particles or fibers including the inorganic oxide precursor, even if a crack occurs in the inorganic oxide layer, the external oxygen Or it can be seen that the self-healing properties by the moisture is excellent barrier properties, it was confirmed that it can be suitably used as a flexible barrier substrate for organic electronic device, to complete the present invention.

In particular, the barrier substrate according to an embodiment of the present invention, the water-soluble polymer constituting the shell of the core-shell-type structure is dissolved in contact with the oxygen or moisture of the outside, or the shell is directly destroyed by physical impact or the like In this case, the inorganic oxide precursor in the core portion is exposed to the outside, and the exposed inorganic oxide precursor is converted into the inorganic oxide by reacting with external oxygen or moisture, so that the crack may be cured. As described above, the barrier substrate according to the embodiment of the present invention may exhibit self-healing properties, thereby greatly reducing the permeability of oxygen or moisture, thereby realizing excellent barrier properties even at a thin thickness.

According to such an embodiment of the present invention, a base layer; An inorganic oxide layer formed on the base layer; And a core-shell-type structure included in the inorganic oxide layer and including an inorganic oxide precursor having a water-soluble polymer formed on a surface thereof.

Hereinafter, each configuration that can be included in the barrier substrate according to the present invention will be described.

First, the barrier substrate according to the present invention includes a base layer. The base layer is a base layer of the barrier substrate according to the present invention, and the kind thereof may be conventional in the art (hereinafter, referred to as 'the art') to which the present invention belongs.

However, preferably, the base layer may be a polymer film, and more preferably, made of polyolefin, polyethylene terephthalate, polycarbonate, polyether sulfone, and polysiloxane, so as to be suitable for a flexible substrate substrate for organic electronic devices. It may be one containing at least one polymer selected from the group.

In this case, the thickness of the substrate layer is not particularly limited, and may be appropriately adjusted according to the field to which the barrier substrate is applied. However, in order to ensure the minimum physical strength required for the barrier substrate, the base layer may have a thickness of 10 μm or more, preferably 10 to 500 μm, and more preferably 10 to 300 μm.

On the other hand, the barrier substrate according to the present invention is an inorganic oxide layer formed on the base layer; And a core-shell-type structure included in the inorganic oxide layer and including an inorganic oxide precursor having a water-soluble polymer formed on a surface thereof.

Since the substrate layer is an organic material layer, moisture or gas may be generated according to an external environment to deteriorate the organic electronic device. The inorganic oxide layer may have oxygen or moisture introduced from the substrate layer or the outside inside the organic electronic device. Prevents penetration into

However, in general, since the inorganic oxide layer is difficult to form a pin-hole free thin film, many cracks are accompanied in the process of use, and the cracks generated once do not disappear on their own and continue to grow. Done.

Accordingly, the present invention provides a barrier substrate that can recover itself when a crack occurs by applying a self-healing mechanism to the inorganic oxide layer.

That is, as shown in FIG. 1, the barrier substrate according to the present invention includes (a) a core-shell type structure including an inorganic oxide precursor having a water-soluble polymer formed on its surface or in the inorganic oxide layer. . Accordingly, when (b) the crack occurs in the inorganic oxide layer, (c) the inorganic oxide precursor in the core portion fills the cracked portion while the core-shell structure is destroyed. At this time, (d) the inorganic oxide precursor is converted to the inorganic oxide by causing a condensation reaction by the external oxygen or water, etc., (e) to repair the damage itself and to block the external water permeation.

In other words, the infiltration of external oxygen or moisture into the damaged portion of the inorganic oxide layer is a signal, and the self-healing property that damage of the inorganic oxide layer is self-repaired by the core-shell type structure including the inorganic oxide precursor. Will be displayed.

Accordingly, the barrier substrate according to the present invention has an advantage that the barrier substrate according to the present invention can exhibit self-healing while having a simpler structure and exhibit self-healing as compared to the previous barrier substrate in which the inorganic oxide layer and the polymer layer are laminated in multiple layers. There is this.

Herein, the inorganic oxide layer may include an inorganic oxide conventional in the art, and may be preferably determined in consideration of the characteristics of the inorganic oxide precursor to be described later, and more preferably include titanium dioxide (TiO ₂ ). Can be.

In addition, the core-shell-type structure included in the inorganic oxide layer includes a precursor of the above-described inorganic oxide in the core portion.

In this case, the inorganic oxide precursor may be converted into an inorganic oxide by causing a condensation reaction by oxygen or moisture, and more preferably, titanium tetrachloride (TiCl ₄ ).

In addition, the shell formed on the surface of the core may be a component that can be easily destroyed by physical stimulation such as cracks of the inorganic oxide layer, oxygen or moisture, preferably a water-soluble polymer, more preferably polyvinyl Pyrrolidone, polyvinyl alcohol, or mixtures thereof.

On the other hand, the core-shell-type structure is not particularly limited as long as the structure is a shell formed on the surface of the core, it may be preferably a core-shell-type particles or fibers.

Here, the core-shell type particles or fibers may have a diameter of 10 to 100 μm, preferably 10 to 90 μm, more preferably 10 to 80 μm. That is, the core-shell type particles or fibers are advantageously to have a diameter in the above range in order to secure the transparency of the substrate and to impart the minimum self-healing performance.

In this case, the core-shell type particles may be spherical particles or particles close to a spherical shape, and the diameter or longest diameter of the particles is regarded as the diameter of the particles.

In the core-shell type fiber, the core inside the shell may be continuous or discontinuous, and the portion where the core is discontinuous may be connected by the shell. In addition, the core-shell type fibers may have a spherical or near spherical figure in the cross section of the core and the shell, and the diameter of the cross section or the longest diameter is regarded as the diameter of the fiber.

In addition, according to one embodiment of the present invention, the core-shell type particles or fibers, the core having a diameter of 5 to 50 ㎛; And a shell having a thickness of 5 to 95 μm.

That is, in the core-shell type particles or fibers, the diameter of the core may be 5 to 50 ㎛. In order for the minimum self-healing mechanism required by the present invention to be expressed, it is advantageous for the core to have a diameter in this range.

In addition, the shell surrounding the core may be formed to a thickness of 5 to 95 ㎛. The thickness of the shell is measurable from the cross-section of the core-shell type particles or fibers, in order to ensure that the self-healing mechanism is sufficiently expressed while ensuring the minimum physical strength required for the shell, the shell is described above. It is advantageous to be formed in a range.

Such core-shell type particles or fibers may be prepared by a conventional method in the art, but preferably may be prepared by a coaxial electro-spinning method, a specific manufacturing method will be described later. .

On the other hand, the inorganic oxide layer including the core-shell-type structure as described above may be formed in a thickness of a range conventional in the art to which the present invention pertains, and is not particularly limited. However, according to the present invention, the thickness of the inorganic oxide layer may be 10 to 500 μm, preferably 50 to 500 μm, more preferably 150 to 500 μm.

As such, the barrier substrate according to the present invention includes a base layer; An inorganic oxide layer formed on the base layer; And a core-shell type structure included in the inorganic oxide layer.

In this case, the barrier substrate according to the present invention may be a polymer layer further formed on the inorganic oxide layer. The polymer layer is a layer for supplementing the physical performance of the substrate, or providing additional functionality such as antireflection performance or antistatic performance, and may be the same as or different from the above-described base layer, and the configuration thereof is not particularly limited.

In addition, the barrier substrate according to the present invention may be two or more inorganic oxide layers formed on the substrate layer, preferably a plurality of substrate layers and a plurality of inorganic oxide layers may be formed, more preferably the substrate The layer and the inorganic oxide layer may be a multi-layered structure alternately stacked.

However, the configuration of the barrier substrate according to the present invention is not limited thereto, and a configuration commonly adopted in the art may be further included.

As described above, the barrier substrate of the present invention has a simplified structure and, when cracks are formed in the inorganic oxide layer by repeated bending, can be self-repaired through a self-healing mechanism, particularly a flexible organic electronic device (organic light emitting device). Diode (OLED), organic solar cell (OPV), organic thin film transistor (OTFT) and the like) can be suitably used.

Meanwhile, according to another embodiment of the present invention,

Forming an inorganic oxide layer on the substrate layer; And

A method of manufacturing a barrier substrate is provided, comprising dispersing a core-shell-type structure including an inorganic oxide precursor having a water-soluble polymer formed on a surface thereof on the inorganic oxide layer.

As described above, the barrier substrate of the present invention is formed with an inorganic oxide layer having self-healing property on the substrate layer, and can be manufactured in a simplified process as compared with the barrier substrate having a multilayered thin film structure.

In particular, the method for manufacturing a barrier substrate according to the present invention can apply a roll-to-roll method to continuously manufacture a large area barrier substrate. Preferably, by applying a coaxial electro-spinning method to the process of manufacturing a core-shell-type structure included in the inorganic oxide layer, by applying the roll-to-roll method productivity of the barrier substrate Can be further improved.

Hereinafter, a method of manufacturing a barrier substrate according to the present invention will be described with reference to FIGS. 2 and 3.

First, the method for manufacturing a barrier substrate according to the present invention may perform the step of forming an inorganic oxide layer on the substrate layer.

That is, the polymer sheet for a base layer is continuously supplied from a plastic sheet roll, and an inorganic oxide layer is formed in the polymer sheet supplied.

Here, the thickness of the polymer sheet for the base layer may be 100 to 800 ㎛, specific details such as the type of the polymer sheet for the base layer is replaced with the above.

In this case, the forming of the inorganic oxide layer may be performed by a conventional method in the art, and preferably, the above-described inorganic oxide may be performed by sputter deposition on the polymer sheet for the base layer. The inorganic oxide layer may have a thickness of 10 to 500 μm, and specific details such as the type of the inorganic oxide are replaced with the above contents.

Subsequently, the method of manufacturing a barrier substrate according to the present invention may perform a step of dispersing a core-shell type structure including an inorganic oxide precursor having a water-soluble polymer formed on a surface thereof on the inorganic oxide layer. .

Particles or fibers of the core-shell type may be used previously formed in a separate process, it is advantageous in terms of productivity to continuously manufacture the core-shell-type structure together in the manufacturing process of the barrier substrate.

That is, preferably, the method of manufacturing the barrier substrate according to the present invention may include forming the core-shell type particles or fibers before the dispersing the core-shell type structure. More preferably, the forming of the core-shell type structure may be performed by forming a core-shell type particle or fiber by a coaxial electro-spinning method.

As shown in FIG. 3, the coaxial electrospinning method is a method of using an electrospinning device including a spinneret and a syringe pump including a capillary tube positioned on the same central axis as the spinneret, a voltage supply device, and a current collector plate.

The shell component is continuously radiated through the spinneret, and at the same time, the core component is radiated together through the capillary. In this case, the core-shell type particles or fibers may be manufactured by adjusting the amount of the core component supplied through the capillary, the feeding time, and whether the feeding is continuous. In addition, the type of the inorganic oxide precursor and the water-soluble polymer, the diameter of the core-shell type particles or fibers, etc. are replaced with the above description.

Thus prepared core-shell type particles or fibers can be produced by the barrier substrate of the present invention by the method of evenly dispersed on the inorganic oxide layer.

At this time, if necessary, a step of forming a polymer layer on the inorganic oxide layer on which the core-shell type particles or fibers are dispersed may be further performed. Since the step of forming the polymer layer can be performed by a conventional method in the art, the structure is not particularly limited, but preferably, as shown in Fig. 2, a resin composition containing a photo- And then photo-curing it. However, the manufacturing method of the present invention is not limited thereto.

Best Mode for Carrying Out the Invention Hereinafter, preferred embodiments are described to facilitate understanding of the present invention. However, the following examples are intended to illustrate the present invention without limiting it thereto.

Example

As shown in FIG. 2, the barrier substrate was manufactured using a roll-to-roll apparatus equipped with a plastic sheet roll, a sputter, a coaxial electrospinning apparatus, and a polymer coating apparatus.

First, the polymer sheet for a base material layer (polyethylene terephthalate sheet, thickness: 500 micrometers) was continuously supplied through the plastic sheet roll.

Subsequently, a titanium dioxide layer having a thickness of 200 μm was formed on the polymer sheet using a sputter. Subsequently, a core (titanium tetrachloride, about 10 μm in diameter) -shell (polyvinylpyrrolidone, about 10 μm in thickness) type of fiber was produced using a coaxial electrospinning device equipped with a plurality of coaxial spinnerets, and manufactured. The fibers were evenly dispersed on the titanium dioxide layer.

Thereafter, a polymer composition (composition comprising an acrylate-based compound and a photopolymerization initiator) was applied onto the titanium dioxide layer in which the core-shell type fibers were dispersed, and the thickness thereof was irradiated with UV of 150 mJ / cm 2. A barrier substrate was prepared by forming a polymer layer having a thickness of 200 μm.

Experimental Example

The physical properties of the barrier substrate obtained through the above example were evaluated as follows.

After forming a scratch by rubbing the surface of the barrier substrate using a steel wool (loaded with a 150g load), the degree of scratch recovery over about 48 hours was visually observed.

As a result of the experiment, the barrier substrate according to the embodiment almost disappeared at about 24 hours after the scratch was formed on the surface, it was confirmed that the substrate can effectively express the self-healing ability.

Claims (16)

A base layer;
An inorganic oxide layer formed on the base layer; And
Core-shell type structure including an inorganic oxide precursor contained in the inorganic oxide layer, the water-soluble polymer is formed on the surface
Barrier substrate comprising a.
The method of claim 1,
And the core-shell type structure is a core-shell type particle or fiber.
3. The method of claim 2,
The core-shell type particle or fiber has a diameter of 10 to 100 ㎛ barrier substrate.
The method of claim 1,
The inorganic oxide layer includes titanium dioxide (TiO ₂ ).
The method of claim 1,
The inorganic oxide precursor includes titanium tetrachloride (TiCl ₄ ).
The method of claim 1,
The water-soluble polymer is polyvinylpyrrolidone, polyvinyl alcohol, or a mixture thereof.
The method of claim 1,
The substrate layer comprises at least one polymer selected from the group consisting of polyolefin, polyethylene terephthalate, polycarbonate, polyether sulfone, and polysiloxane.
The method of claim 1,
The inorganic oxide layer has a thickness of 10 to 500 ㎛ barrier substrate.
The method of claim 1,
A barrier substrate further comprising a polymer layer formed on the inorganic oxide layer.
The method of claim 1,
A barrier substrate having at least two inorganic oxide layers formed on the substrate layer.
The method of claim 1,
Barrier substrates used in flexible organic electronic devices.
Forming an inorganic oxide layer on the substrate layer; And
Dispersing a core-shell type structure including an inorganic oxide precursor having a water-soluble polymer formed on a surface thereof on the inorganic oxide layer;
Method of manufacturing a barrier substrate comprising a.
13. The method of claim 12,
The forming of the inorganic oxide layer is performed by a method of sputtering deposition of an inorganic oxide on a substrate layer.
13. The method of claim 12,
Before dispersing the core-shell type structure,
Forming a core-shell type structure.
15. The method of claim 14,
The forming of the core-shell type structure is performed by forming a core-shell type particle or fiber by a coaxial electro-spinning method.
13. The method of claim 12,
The method of manufacturing a barrier substrate further comprising the step of forming a polymer layer on the inorganic oxide layer.

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