KR20180116042A - Multi-layered structure and manufacturing method thereof - Google Patents

Abstract

Various embodiments of the present invention relate to a multilayer structure and a method of manufacturing the same. In particular, the present invention provides a multilayer structure with high hardness, and a method of manufacturing the same, by forming an inorganic load-bearing layer on a flexible substrate by using a room temperature spray in vacuum technique; and forming an organic or organic/inorganic hybrid coating layer on a surface of the inorganic load-bearing layer by using a solution process technique. Disclosed in the present invention is a method of manufacturing a multilayer structure, which comprises the steps of: receiving ceramic powder form a powder supply unit and transferring the ceramic powder by using a transfer gas; crashing and pulverizing the transferred ceramic powder onto a flexible substrate inside a processing chamber at a speed of 100-500 m/s, to form a load-bearing layer; and forming an organic or organic/inorganic hybrid coating layer on a surface of the load-bearing layer by using a solution process.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a multi-

Various embodiments of the present invention relate to a multilayer film structure and a method of manufacturing the same.

In the display industry, white goods and automobile industries, organic materials such as polyimide (PI), polyethylene terephthalate (PET), polymethylmethacrylate (PMMA), polycarbonate, Or is under development. However, due to the nature of organic materials, the resistance to abrasion and scratches due to external stimuli is very weak, so it is essential to form a hard coat layer for surface protection.

Typically, the hard coating layer is formed by a single process such as physical vapor deposition (PVD), chemical vapor deposition (CVD), and solution process (i.e., solution-dry-cure) . The above-mentioned PVD and CVD processes are carried out under high vacuum, and expensive raw material gas and chemical gas are used. The above-mentioned solution process must use a chemical solvent. At this time, it is difficult to control the thickness and the characteristics are poor. In order to secure resistance against the external impact, the thickening is very weak. In particular, such a conventional method of producing a hard coat layer has various problems in surface coating of an organic substrate, has a high process temperature, and has a low adhesion.

The above-described information disclosed in the background of the present invention is only for improving the understanding of the background of the present invention, and thus may include information not constituting the prior art.

In various embodiments of the present invention, a load supporting layer of an inorganic material is formed on the surface of a flexible substrate by a room temperature vacuum injection technique, and a coating layer of organic or inorganic hybrid material is formed on the surface of the load supporting layer Thereby providing a multilayer film structure having a high surface hardness and a manufacturing method thereof.

The method for manufacturing a multilayer structure according to various embodiments of the present invention includes the steps of: receiving a ceramic powder from a powder supply unit and transferring the ceramic powder using a transfer gas; Colliding and crushing the transferred ceramic powder to a flexible substrate in a process chamber at a speed of 100 to 500 m / s to form a load supporting layer; And forming an organic or inorganic hybrid coating layer on the surface of the load supporting layer using a solution process.

The particle size range of the ceramic powder may be 100 nm to 3000 nm.

The ceramic powder may be pulverized by a dry or wet ball milling method and supplied to the powder feeder.

The ceramic powder may be selected from the group consisting of Al ₂ O ₃ , SiO ₂ , Si ₃ N ₄ , AlN, TiN, B ₄ C, ZrO _{2 ,} TiO ₂ , Y ₂ O ₃ -Al ₂ O ₃ Based compound, a yttrium-based compound, a yttrium-based compound, and a yttrium-based oxide.

The organic or organic hybrid coating layer may be formed of an epoxy or acrylic thermosetting or photo-curing resin.

The flexible substrate may be formed of PI, PET, PMMA, PC, or acrylic.

The multilayer structure according to various embodiments of the present invention includes a load supporting layer formed of a ceramic powder on a surface of a flexible substrate; And an organic or inorganic hybrid coating layer formed on the surface of the load supporting layer.

The multilayer structure according to various embodiments of the present invention includes a seed layer formed on the surface of a flexible substrate by ceramic powder by a vacuum injection process at room temperature; A water glass layer formed of a water glass by a solution process on the seed layer; And a top transparent coating layer formed on the surface of the water glass layer by ceramic powder by vacuum injection at room temperature.

In various embodiments of the present invention, a load supporting layer of an inorganic material is formed on the surface of a flexible substrate by a room temperature vacuum injection technique, and a coating layer of organic or inorganic hybrid material is formed on the surface of the load supporting layer Thereby providing a multilayer film structure having a high surface hardness and a manufacturing method thereof.

1 is a schematic diagram illustrating an apparatus for forming a load bearing layer of a multi-layer film structure according to various embodiments of the present invention.
FIG. 2 is a flowchart showing a method of forming a load supporting layer among multi-layer film structures according to various embodiments of the present invention.
3 is a graph showing the particle size distribution of powders for forming the load supporting layer in the multilayer structure according to various embodiments of the present invention.
4A is a cross-sectional view illustrating a case where an organic or inorganic hybrid coating layer is formed on an organic substrate, and FIG. 4B is a cross-sectional view illustrating a case where a load supporting layer and an organic or inorganic hybrid coating layer are formed on an organic substrate to form a hard coating .
5 is a scanning electron microscope (SEM) photograph of the multilayer structure according to various embodiments of the present invention.
FIG. 6A is a photograph of optical haze when only a load supporting layer is formed on a flexible substrate, FIG. 6B is a photograph showing a load supporting layer and an organic or inorganic hybrid coating layer on the flexible substrate according to various embodiments of the present invention And a photographed image of the light blur when it is formed.
7A and 7B are graphs showing light transmittance and light reflectance of a multilayer film structure according to various embodiments of the present invention.
8A and 8B are photographs of pencil hardness test and rubbing test result of the multilayer film structure according to various embodiments of the present invention.
9 is a photograph of a result of bending test of the multilayer structure according to various embodiments of the present invention.
10 is a cross-sectional view illustrating a multilayer film structure according to various embodiments of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Various embodiments of the present invention are provided to more fully describe the present invention to those skilled in the art, and the following various embodiments may be modified in various other forms, Is not limited to the following examples. Rather, these various embodiments are provided so that this disclosure will be more thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

In the following drawings, thickness and size of each layer are exaggerated for convenience and clarity of description, and the same reference numerals denote the same elements in the drawings. As used herein, the term "and / or" includes any and all combinations of one or more of the listed items. In the present specification, the term " connected "means not only the case where the A member and the B member are directly connected but also the case where the C member is interposed between the A member and the B member and the A member and the B member are indirectly connected do.

The terminology used herein is for the purpose of describing certain specific embodiments and is not intended to be limiting of the invention. As used herein, the singular forms "a," "an," and "the" include singular forms unless the context clearly dictates otherwise. Also, " comprise, " and / or "comprising, " when used in this specification, are intended to be interchangeable with the said forms, numbers, steps, operations, elements, elements and / And does not preclude the presence or addition of one or more other features, integers, operations, elements, elements, and / or groups.

Although the terms first, second, etc. are used herein to describe various elements, components, regions, layers and / or portions, these members, components, regions, layers and / It is obvious that no. These terms are only used to distinguish one member, component, region, layer or section from another region, layer or section. Thus, a first member, component, region, layer or section described below may refer to a second member, component, region, layer or section without departing from the teachings of the present invention.

It is to be understood that the terms related to space such as "beneath," "below," "lower," "above, But may be utilized for an easy understanding of other elements or features. Terms related to such a space are for easy understanding of the present invention depending on various process states or use conditions of the present invention, and are not intended to limit the present invention. For example, if an element or feature of the drawing is inverted, the element or feature described as "lower" or "below" will be "upper" or "above." Thus, "lower" is a concept encompassing "upper" or "lower ".

FIG. 1 is a schematic view showing an apparatus for forming a load supporting layer of a multi-layer film structure according to various embodiments of the present invention, and FIG. 2 is a flow chart showing a method of forming a load supporting layer in the multilayer film structure according to various embodiments of the present invention to be.

1, an apparatus 200 for forming a load supporting layer according to an embodiment of the present invention includes a transfer gas supply unit 210, a powder supply unit 220 for storing and supplying ceramic powder, a ceramic supply unit 220 for supplying ceramic from the powder supply unit 220, A transfer tube 222 for transferring the powder at high speed using a transfer gas, a nozzle 232 for coating / laminating or spraying the ceramic powder from the transfer tube 222 on the flexible substrate 231, And a process chamber 230 for allowing a load bearing layer to be formed by causing the ceramic powder of the ceramic substrate to collide, crush and / or crush the surface of the flexible substrate 231.

A method of forming a load supporting layer according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG.

The transfer gas stored in the transfer gas supply unit 210 may be one or two kinds of mixed gases selected from the group consisting of oxygen, helium, nitrogen, argon, carbon dioxide, hydrogen, and equivalents thereof. In the present invention, Is not limited. The transfer gas is directly supplied from the transfer gas supply unit 210 to the powder supply unit 220 through the pipe 211 and the flow rate and pressure thereof can be controlled by the flow rate regulator 250.

The powder supply part 220 stores and supplies a large amount of ceramic powder. By way of example, and not by way of limitation, the ceramic powder can be a ceramic powder such as Al ₂ O ₃ , SiO ₂ , Si ₃ N ₄ , AlN, TiN, B ₄ C, ZrO _{2 ,} TiO ₂ , Y ₂ O ₃ -Al ₂ O ₃ Based compound, a yttrium-based compound, a yttrium-based compound, and a yttrium-based oxide.

In addition, the ceramic powder may be, for example, but not limited to, feldspar having a far-infrared ray emission characteristic, such as feldspar, borax, boric acid, potassium carbonate, basic stone, alumina hydroxide, limestone, barium carbonate, lithium, zircon, ≪ / RTI > and mixtures thereof. Accordingly, when the load supporting layer according to the embodiment of the present invention is used for a touch screen or the like, a large amount of far infrared rays useful for the human body may be emitted.

Here, the present inventors have found that when the above-mentioned ceramic powder having a grain size range of approximately 100 nm to 3000 nm (having normal distribution characteristics) is used, the thickness of a predetermined load supporting layer (for example, 100 탆) was obtained.

In fact, when the particle size range of the ceramic powder (for example, the center particle diameter of the powder) is less than about 100 nm, it is difficult to store and supply the ceramic powder, and due to the coagulation phenomenon during storage and supply of the ceramic powder, There is a drawback in that it is easy to form a green compact in which particles smaller than 100 nm are aggregated at the time of jetting, collision, crushing, and / or pulverization, and formation of a large load supporting layer is also difficult.

Further, when the particle size range of the ceramic powder (for example, the center particle size of the powder) is larger than about 1000 nm, a sandblasting phenomenon in which the flexible ceramic powder is shaved off, crushed and / The load supporting layer structure becomes unstable and the porosity of the inside or the surface of the load supporting layer becomes large so that the inherent characteristics of the load supporting layer may not be exhibited .

The porosity (porosity) is relatively small (or the compactness is relatively large) when the ceramic powder has a particle size range (for example, the center particle size of the powder) of about 100 nm to 3000 nm, , A load supporting layer with easy control of the ceramic powder was obtained. In addition, when the ceramic powder had a particle diameter range of approximately 100 nm to 3000 nm, a load supporting layer having a relatively large lamination speed of the load supporting layer, (semi) transparent, easy to implement high hardness and low friction characteristics was obtained.

3 is a graph showing the particle size distribution of powders for forming the load supporting layer in the multilayer structure according to various embodiments of the present invention.

The particle size (grain size) analysis of the ceramic powder is performed using a laser diffraction technique. As an example of the apparatus for measuring the size of the ceramic powder, there is an analyzer such as Beckman Coulter's LS 13 320. Specifically, a method of analyzing particle size (particle size) of a powder is described. A powder is put in a solvent such as water and diluted with a suspension having a concentration of about 10% to prepare a slurry. Then, the slurry is uniformly dispersed in the powder using an ultrasonic wave or a rotor. Thereafter, the dispersed powder in the slurry state is circulated, the laser beam is incident on the ceramic powder in the dispersed slurry state, and the intensity of the laser beam scattered through the ceramic powder is measured to measure the particle size of the ceramic powder do. The analytical range of the ceramic powder by this analytical instrument is approximately 0.01 탆 to 2,000 탆, though it varies slightly from model to model.

As shown in Fig. 3, the particle size range of the ceramic powder may be approximately 100 nm to 3000 nm. Practically, there is a problem that it is difficult to obtain a load supporting layer having high surface hardness, low light reflectivity, high abrasion resistance, and high flexibility when the particle diameter range of the powder is out of the above range.

For example, when a load supporting layer is formed using only a ceramic powder having a particle diameter of less than about 100 nm, the ceramic powder itself has a small particle diameter, so that the surface hardness, light reflectivity, abrasion resistance and bending property of the load supporting layer are excellent , There is a problem that the rate of formation of the load supporting layer is too slow and the ceramic powder is aggregated and the powder is difficult to control.

As another example, when a load supporting layer is formed by using a ceramic powder having a particle diameter larger than about 1000 nm, since the ceramic powder itself has a large particle diameter range, the lamination speed of the load supporting layer as a whole is high and the porosity of the load supporting layer is high. There is a problem that the structure of the load supporting layer becomes unstable due to surface micro cracks.

On the other hand, in general, in case of a room temperature nano-coating process, there is a high possibility that the surface of the substrate is damaged by the high-speed collision of the ceramic powder with respect to the substrate material. Particularly, in the case of an organic substrate, the surface of the substrate is etched in severe cases. Therefore, in the embodiment of the present invention, the ceramic powder is stressed by the dry or wet ball milling method to induce microcracks to such an extent that the powder is not broken, thereby improving the coating property.

Here, the dry or wet ball milling method includes, for example, but not limited to, a method in which a drum is rotated while a ceramic powder and a grinding ball of approximately 1 to 10 탆 are filled in a drum, The powder is crushed by impact. At this time, the balls may be forged balls, chrome balls, SUS balls, alumina balls, zirconia balls, or the like. By such a dry or wet ball milling method, a ceramic powder having a particle size range of approximately 100 nm to 3000 nm is obtained.

By such a dry or wet ball milling method, the powder may be roughly spherical in favor of high-speed conveying, but the present invention is not limited to this form, and powder may have a multi-angle structure.

The method of forming the load supporting layer according to the present invention will be further described with reference to FIGS. 1 and 2. FIG.

The process chamber 230 maintains a vacuum during the formation of the load bearing layer, and a vacuum unit 240 may be further connected thereto. Specifically, the pressure of the process chamber 230 is approximately 1 pascal to 800 pascal, and the pressure of the ceramic powder conveyed by the rapid delivery pipe 222 may be approximately 500 pascals to 2000 pascals. However, in any case, the pressure of the high-speed transfer pipe 222 must be higher than the pressure of the process chamber 230.

In addition, the internal temperature range of the process chamber 230 is approximately 0 ° C to 30 ° C (ie, low or normal temperature), and thus there may be no member to increase or decrease the internal temperature of the separate process chamber 230 . That is, the transfer gas and / or the substrate may not be separately heated, but may be maintained at a temperature of 0 ° C to 30 ° C.

However, in some cases, the transfer gas and / or the flexible substrate may be heated to improve the deposition efficiency and density of the load supporting layer. That is, the transfer gas in the transfer gas supply unit 210 may be heated by a heater (not shown), or the flexible substrate 231 in the process chamber 230 may be heated by a heater (not shown). By the heating of the transfer gas and / or the flexible substrate, the stress applied to the powder at the time of forming the load supporting layer is reduced, so that a dense load bearing layer having a small porosity is obtained. When the temperature of the transfer gas and / or the flexible substrate is higher than about 1000 캜, the ceramic powder is melted to cause a rapid phase transition, and the porosity of the load supporting layer increases according to the difference in thermal expansion coefficient between the ceramic powder and the flexible substrate, The structure may become unstable. In addition, when the transferred gas and / or the flexible substrate is smaller than the temperature of about 300 캜, the stress applied to the ceramic powder may not decrease.

However, this temperature range is not limiting in the present invention, and depending on the characteristics of the flexible substrate on which the load bearing layer is to be formed, the internal temperature range of the transfer gas, the flexible substrate and / or the process chamber can be adjusted between approximately 0 ° C and 1000 ° C have.

Meanwhile, as described above, the pressure difference between the process chamber 230 and the high-speed transfer pipe 222 (or the transfer gas supply unit 210 or the powder supply unit 220) may be approximately 1.5 times to 2000 times. If the pressure difference is less than about 1.5 times, high-speed transfer of the ceramic powder may be difficult, and if the pressure difference is greater than about 2000 times, the surface of the flexible substrate may be excessively etched by the ceramic powder.

The ceramic powder from the powder supply unit 220 is injected through the transfer pipe 222 and transferred to the process chamber 230 at a high speed according to the pressure difference between the process chamber 230 and the transfer pipe 222.

In addition, a nozzle 232 connected to the transfer pipe 222 is provided in the process chamber 230 to collide the ceramic powder with the flexible substrate 231 at a speed of about 100 m / s to 500 m / s. That is, the ceramic powder through the nozzle 232 is fractured and / or crushed by the kinetic energy obtained during the transfer and the collision energy generated during high-speed collision, thereby forming a load supporting layer having a certain thickness on the surface of the flexible substrate 231.

More specifically, when a ceramic powder having a particle diameter in the above-described range and having a normal distribution characteristic is crushed and crushed by a flexible substrate at a speed of about 100 m / s to 500 m / s, . That is, the ceramic powder collides with the flexible substrate due to the transfer gas. In this collision, the ceramic powder cleans the surface of the flexible substrate, is crushed into very fine pieces, and a part of the kinetic energy is released as heat energy or the like . At this time, a part of the ground microfine chips are stuck to the flexible substrate and exhibit an anchoring effect. Furthermore, some of the pieces have strong bonds due to the new wavefront (new surface) formed after grinding. In this way, the new powder repeatedly collides with the wave front to form new microscopic pieces repeatedly, and the energy released during the collision promotes plastic deformation and mass transfer of the pieces to form a dense load supporting layer. Therefore, the compact load supporting layer can be formed without the need of separate heating or heat treatment process by the above-mentioned powder collision and crushing, bonding of very fine pieces, plastic deformation and mass transfer.

On the other hand, the flexible substrate may be formed of, for example, PI, PET, PMMA, PC, or acrylic, though it is not limited thereto. In addition, the flexible substrate may include ordinary resins, plastics, and the like, and the material thereof is not limited in the present invention. For example, the flexible substrate may be made of at least one selected from the group consisting of diacetylcellulose, triacetylcellulose, acetylcellulose butyrate, isobutylester cellulose, ethylene-vinyl acetate copolymer, propionylcellulose, butyrylcellulose, acetylpropionylcellulose , Polyesters, polystyrenes, polyamides, polyetherimides, polyacrylics, polyimides, polyether sulfone, polysulfone, polyethylene, polypropylene, polymethylpentene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyvinyl But may be any one selected from the group consisting of acetal, polyether ketone, polyether ether ketone, polyether sulfone, polybutylene terephthalate, polyethylene naphthalate, polyurethane and epoxy film.

On the other hand, an organic or inorganic hybrid coating layer is further formed on the load supporting layer to reduce the haze and improve the surface slip property after the load supporting layer of the inorganic material (ceramic) as described above is formed by the room temperature vacuum injection technique. The organic or inorganic hybrid coating layer can be formed by, for example, but not limited to, a solution process, and is typically formed by bar coating, spray coating, flow coating, . In addition, an organic or inorganic hybrid coating layer may be formed through a process such as inkjet, electro spray or gravure depending on the purpose or the form of the applied product.

Further, the organic or organic hybrid coating layer may be formed of, for example, an epoxy or acrylic thermosetting or photo-curing resin, though it is not limited thereto. For example, an epoxy or acrylic thermosetting resin is coated on the load supporting layer by the above-described method, and then thermosetting is performed in a temperature range of about 80 to 150 DEG C to form an organic or inorganic hybrid coating layer of a predetermined thickness . An epoxy or acryl-based photo-curable resin is coated on the load supporting layer by the above-described method, and then photo-cured by ultraviolet light for 1 second to 60 seconds to form an organic or inorganic hybrid coating layer having a predetermined thickness.

In addition, the organic or inorganic hybrid coating layer may contain, for example, Al ₂ O ₃ , SiO ₂ , Si ₃ N ₄ , AlN, TiN, B ₄ C, ZrO _{2 ,} TiO ₂ , Y ₂ O ₃ -Al ₂ O ₃ Based compound, yttrium-based compound, zirconium-based compound, yttrium-based compound, and a yttrium-based oxide may be further added. Of course, these powders may also have a particle size of approximately 100 nm to 3000 nm. In addition, such an organic or inorganic hybrid coating layer may also be formed to a thickness of, for example, but not limited to, approximately 1 μm to 10 μm.

FIG. 4A is a cross-sectional view illustrating a case where only an organic or inorganic hybrid coating layer is formed on an organic substrate, and FIG. 4B is a cross-sectional view illustrating a case where a hard coating is formed by forming a load supporting layer and an organic or inorganic hybrid coating layer on an organic substrate .

As shown in FIG. 4A, when the organic or inorganic hybrid coating layer 132 'is formed on the organic substrate 231', if the surface thereof is scratched by the pencil lead 234, the organic substrate 234 ' So that the organic substrate 234 'can be destroyed.

4B, when a load supporting layer 232 made of a ceramic material is formed on the organic substrate 231 and an organic or inorganic hybrid coating layer 233 is formed on the surface of the load supporting layer 232, The deformation of the organic substrate 231 is minimized due to the load supporting layer 232, and thus the destruction of the organic substrate 231 can be prevented. In the drawing, reference numeral HC denotes a hard coating layer including a load supporting layer 232 and an organic or inorganic hybrid coating layer 233. [

Here, the pencil hardness test is performed by observing whether or not scratches occur when a pencil tilted at approximately 45 ° is applied with a load of approximately 750 or 1000 g and the surface of the organic or inorganic hybrid coating layer formed on the load supporting layer is grasped.

The pencil hardness has a value of 6B-5B-4B-3B-2B-B-HB-FH-2H-3H-4H-5H-6H-7H-8H-9H, . In addition, this pencil hardness can be converted to the value (GPa) of the nanoindenter, and in the embodiment of the present invention, pencil hardness is observed at 8H (0.46 GPa).

The steel wool rubbing test was carried out by applying a load of 750 or 1000 g to a steel wool (# 0000) approximately 15 x 15 mm in size and applying a load of 50 or 1000 g on the surface of the organic or inorganic hybrid coating layer formed on the load- And it is performed by observing whether or not scratches occur when reciprocating motion is performed. No scratches were observed in the examples of the present invention.

The optical characteristic (UV-visible test) indicates the amount of light projected through a hard coating layer composed of a load supporting layer and an organic or inorganic hybrid coating layer by irradiating light having a certain wavelength (for example, visible light).

On the other hand, the flexural test was carried out by winding a film (i.e., a hard coat layer comprising a load supporting layer and an organic or inorganic hybrid coating layer) on a rod having a bending radius of approximately 1 to 5 mm. After the repeated bending test 10000 times), and the presence or absence of cracks in the hard coat layer is confirmed by visual observation and microscopic observation. In the examples of the present invention, cracks in the hard coat layer were not observed.

5 is a scanning electron microscope (SEM) photograph of the multilayer structure according to various embodiments of the present invention.

As shown in FIG. 5, in the embodiment of the present invention, a relatively thin alumina load supporting layer is formed on a flexible substrate of a PI material, and an overcoat layer having a relatively thicker thickness than the thickness of the load supporting layer is formed thereon. Or organic hybrid coating layer. Here, the load supporting layer was formed to have a thickness of less than about 1 mu m, and the organic or organic hybrid layer was formed to have a thickness of about 3 to 5 mu m.

FIG. 6A is a photograph of optical haze when only a load supporting layer is formed on a flexible substrate, FIG. 6B is a photograph showing a load supporting layer and an organic or inorganic hybrid coating layer on the flexible substrate according to various embodiments of the present invention And a photographed image of the light blur when it is formed.

As shown in FIG. 6A, when only a load supporting layer made of alumina is formed on a flexible substrate made of a PI material, the degree of optical fogging is about 19.3%. However, as shown in FIG. 6B, The optical haze is observed to be about 1.0%. Thus, when the overcoat layer as well as the load supporting layer is formed on the flexible substrate, the optical haze is improved.

7A and 7B are graphs showing light transmittance and light reflectance of a multilayer film structure according to various embodiments of the present invention.

As shown in FIG. 7A, when only a load supporting layer of alumina was formed on a flexible substrate of a PI material in a wavelength range of approximately 400 to 800 nm, the light transmittance was approximately 87 to 89%. However, When a load supporting layer and an overcoat layer made of alumina are formed, the light transmittance is observed to be about 91 to 92%, so that light transmittance is improved when an overcoat layer as well as a load supporting layer is formed on a flexible substrate.

In addition, as shown in FIG. 7B, when only a load supporting layer of alumina is formed on a flexible substrate of a PI material in a wavelength range of about 400 to 800 nm, the light reflectance is about 14 to 15% When the load supporting layer and the overcoat layer made of alumina are formed on the substrate, the light reflectance is observed to be about 9 to 12%, so that the light reflectance is improved when the overcoat layer as well as the load supporting layer is formed on the flexible substrate.

8A and 8B are photographs of pencil hardness test and rubbing test result of the multilayer film structure according to various embodiments of the present invention.

As shown in the left drawing of Fig. 8A, scratches were observed in the pencil hardness test in the PI substrate. However, as shown in the right drawing of Fig. 8A, the load supporting layer of alumina Scratches were not observed in the pencil hardness test when the coat layer was formed, and the scratch resistance was improved when the load supporting layer and the overcoat layer were formed on the flexible substrate.

As shown in the left drawing of FIG. 8B, scratches were observed in the rubbing test on the flexible substrate of the PI material. However, as shown in the right drawing of FIG. 8B, the load supporting layer of alumina When the overcoat layer was formed, no scratch was observed in the rubbing test, and it was found that the scratch resistance was improved when the load supporting layer and the overcoat layer were formed on the flexible substrate.

9 is a photograph of a result of bending test of the multilayer structure according to various embodiments of the present invention.

As shown in FIG. 9, the multilayer structure according to an embodiment of the present invention includes a load supporting layer formed on a flexible substrate made of a PI material, and an organic or inorganic hybrid coating layer. Moreover, despite this bending, no breakage phenomenon of the load bearing layer and / or the organic or inorganic hybrid coating layer was observed.

Thus, the present invention has the following features.

(1) Insertion of a load supporting layer using a high-density ceramic layer

In the case of hard coating using an organic material on the surface of an organic substrate material, the substrate material is deformed due to an external stimulus (load) and is vulnerable to scratches. Therefore, in order to impart resistance to an external load, in the embodiment of the present invention, a high-density ceramic layer is formed to insert a load supporting layer, thereby improving surface hardness.

(2) Reduction of light haze through refractive index matching

At room temperature, nano-coating is a process in which impacts and deposition of powders occur at the same time, and surface haze is reduced due to the roughness of the surface of the coating layer. In order to solve this problem, in the practice of the present invention, haze is reduced by coating a load supporting layer (ceramic coating layer) with an organic or inorganic hybrid coating layer capable of light refractive index matching very thinly.

(3) Reduced surface reflectance (AR) through refractive index matching and multilayering)

In the embodiment of the present invention, the light reflectance can be minimized by including the functions (1) and (2) and by multilayering for additional refractive index matching.

(4) Improved abrasion resistance through surface slip property

The external stimulus depends on the characteristics of the material surface. Therefore, slipperiness is imparted to the surface of the uppermost coating layer, and wear resistance is improved by improving the avoidance of external stimuli. Here, in order to impart the slip property, the functional additive may be mixed in the organic or inorganic hybrid coating layer. The functional additives may be selected from the group consisting of Al ₂ O ₃ , SiO ₂ , Si ₃ N ₄ , AlN, TiN, B ₄ C, ZrO _{2 ,} TiO ₂ , Y ₂ O ₃ -Al ₂ O ₃ Based compound, a yttrium-based compound, a zirconium-based compound, a yttrium-based compound, and a yttrium-based oxide.

(5) Flexibility by controlling thickness of load-bearing layer and organic or inorganic hybrid coating layer

The conventional organic hard coating technology has difficulty in ensuring flexibility due to thickness of the film for scratch and surface hardness, but it is difficult to insert the high density ceramic load supporting layer according to the embodiment of the present invention and the hardness through controlling the thickness of the organic or inorganic hybrid coating layer. The coating layer was able to secure the flexibility by inducing thickness reduction.

(6) Applied powder material Pretreatment method

In the case of a general room temperature nano-coating process (aerosol deposition), there is a possibility of damage to the substrate surface due to high-speed collision of the ceramic powder with respect to the substrate material. In the case of an organic substrate, an etching is generated on the surface of the substrate in severe cases. Therefore, in the embodiment of the present invention, stress is applied to the ceramic powder particles by the dry milling method to induce microcracks to the extent that they are not broken down to the particles, and the coating property is improved.

10 is a cross-sectional view illustrating a multilayer film structure according to various embodiments of the present invention.

The above-mentioned multi-layer film structure may be slightly exposed to the surface scratch resistance due to exposure of the organic or inorganic hybrid coating layer containing a part or a large amount of organic components through the top.

Therefore, the surface scratch resistance can be improved by a structure / method of forming a ceramic layer such as a load supporting layer at the top.

For example, as shown in FIG. 10, in order to form a transparent ceramic coating layer (having a thickness of about 1.0 to 2 μm) by a room-temperature vacuum injection process (or an AD process) at the top, a transparent ceramic coating layer is formed A coating layer is required which is stronger than the organic or inorganic hybrid material and can ensure flexibility, which is advantageously formed of an inorganic layer.

This inorganic layer is more advantageous in securing flexibility than an amorphous (amorphous) intermediate coating layer rather than a crystalline (crystalline or polycrystalline) inorganic layer.

As the coating material usable herein, it is most advantageous to use an amorphous solution coating material, for example sodium-, lithium-, potassium-silicate (approximately 0.5 to 5 탆 thick).

However, such water glass is a solution of a water base, and generally has poor wettability to a plastic surface, so that the coating is not smooth.

Therefore, the lower support layer provided in another embodiment of the present invention is formed into a seed layer (thickness of approximately 0.1 to 1.0 탆) by ultra-thinning the ceramic coating layer of the lower support layer by a room temperature vacuum spraying process, And at the same time, an anchor layer is formed between the room temperature vacuum spray coating layer and a plastic substrate (for example, an organic substrate such as PET or PI).

As a result, the seed layer formed by the normal-temperature vacuum spraying process or the AD process has a role of securing the wettability of the water glass layer in the form of an aqueous solution coating and forming an anchor layer at the interface with the flexible substrate such as a plastic film, . Further, the water glass layer plays a role of securing the coating property to the uppermost ceramic layer and also serves as a lower support layer. Further, the uppermost transparent ceramic coating layer formed by the room temperature vacuum spraying process or the AD process serves to improve the external scratch resistance.

It is to be understood that the present invention is not limited to the above-described various embodiments, and various modifications and changes may be made without departing from the scope of the present invention as set forth in the following claims It will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.

231; An organic substrate 232; Load bearing layer
233; Organic or inorganic hybrid coating layer

Claims (11)

Receiving ceramic powder from a powder supply part and transferring the ceramic powder using a transfer gas;
Colliding and crushing the transferred ceramic powder to a flexible substrate in a process chamber at a speed of 100 to 500 m / s to form a load supporting layer; And
And forming an organic or inorganic hybrid coating layer on the surface of the load supporting layer using a solution process. The method according to claim 1,
Wherein the ceramic powder has a particle diameter ranging from 100 nm to 3000 nm. The method according to claim 1,
Wherein the ceramic powder is pulverized by a dry or wet ball milling method and is supplied to the powder supply part. The method according to claim 1,
The ceramic powder may be selected from the group consisting of Al ₂ O ₃ , SiO ₂ , Si ₃ N ₄ , AlN, TiN, B ₄ C, ZrO _{2 ,} TiO ₂ , Y ₂ O ₃ -Al ₂ O ₃ Based compound, yttrium-based compound, yttrium-based compound, yttrium-based compound, and yttrium-based oxide. The method according to claim 1,
Wherein the organic or inorganic hybrid coating layer is formed of an epoxy or acryl based thermosetting or photocurable resin. The method according to claim 1,
Wherein the flexible substrate is formed of PI, PET, PMMA, PC, or acrylic. A load supporting layer formed of a ceramic powder on the surface of the flexible substrate; And
And an organic or inorganic hybrid coating layer formed on the surface of the load supporting layer. 8. The method of claim 7,
The ceramic powder may be selected from the group consisting of Al ₂ O ₃ , SiO ₂ , Si ₃ N ₄ , AlN, TiN, B ₄ C, ZrO _{2 ,} TiO ₂ , Y ₂ O ₃ -Al ₂ O ₃ Based compound, yttrium-based compound, yttrium-based compound, yttrium-based compound, and yttrium-based oxide. 8. The method of claim 7,
Wherein the organic or inorganic hybrid coating layer is formed of an epoxy or acrylic thermosetting or photocurable resin. 8. The method of claim 7,
Wherein the flexible substrate is formed of PI, PET, PMMA, PC, or acrylic. A seed layer formed on the surface of the flexible substrate by a ceramic powder by a vacuum injection step at room temperature;
A water glass layer formed of a water glass by a solution process on the seed layer; And
And a top transparent coating layer formed on the surface of the water glass layer by ceramic powder by vacuum injection at room temperature.

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