Method of manufacturing transparent resin layer and method of manufacturing display device including the same

Abstract

The invention relates to a method of preparing a transparent resin layer and a method of manufacturing a display device including the transparent resin layer. The method of preparing the transparent resin layer includes: forming a photocurable composition layer by applying a photocurable composition onto a substrate including a first region; performing (a) an exposure process of covering the first region of the photocurable composition layer with a mask and exposing the photocurable composition layer with a first light; and performing (b) an exposure process to expose the entire surface of the photocurable composition layer with a second light wherein the first light cures the photocurable composition layer more firmly than the second light.

Description

[0001] Cross - reference to related applications

[0002] This application claims the priority and benefit of Korean Patent Application No. 10 - 2024 - 0012445, filed with the Korean Intellectual Property Office on January 26, 2024, the entire content of which is incorporated herein by reference. Technical field

[0003] One or more embodiments of the present disclosure relate to a method of preparing a transparent resin layer and a method of manufacturing a display device including the transparent resin layer prepared by the method of preparing the transparent resin layer. Background art

[0004] Conventional display devices include: an emission unit on a substrate provided with thin - film transistors (TFTs); a display panel including a light control unit that controls light emitted from the emission unit; and a window unit on the display panel. Glass has been used for each of the substrate and the window unit of the display panel. However, recently, considering the flexible characteristics of some display panels and the like, display devices have been developed in which polyimide is used for the substrate of the display panel and a transparent resin layer is used instead of glass for the window unit. Here, the transparent resin layer is an outer coating formed on the light control unit. Summary of the invention

[0005] In order to replace glass with a transparent resin layer, a predetermined or specific hardness level should be used. However, considering the possibility of deterioration and / or bending of the light - emitting device on the opening part, etc., the hardness of the transparent resin layer should vary according to the region of the display panel. In this regard, one or more embodiments include a method of preparing a transparent resin layer capable of adjusting the hardness according to the region while using the same material, and a method of manufacturing a display device including the transparent resin layer.

[0006] Additional aspects of the embodiments will be set forth in part in the following description and in part will be apparent from the description, or may be learned by practice of the presented embodiments of the disclosure.

[0007] According to one or more embodiments, a method of preparing a transparent resin layer includes:

[0008] Forming a photocurable composition layer by applying a photocurable composition to a substrate including a first region,

[0009] Performing (a) an exposure process of covering the first region of the photocurable composition layer with a mask and exposing the photocurable composition layer with a first light, and

[0010] Performing (b) an exposure process of exposing the entire surface of the photocurable composition layer with a second light.

[0011] The first light can cure the layer of the photocurable composition more firmly (or more completely) than the second light.

[0012] In an embodiment, the first light can be light in a wavelength region shorter than that of the second light, or the first light can include light in a wavelength region shorter than that of the second light.

[0013] In an embodiment, the intensity of the first light can be greater than the intensity of the second light.

[0014] The (a) exposure process can be carried out after the (b) exposure process, or the (b) exposure process can be carried out after the (a) exposure process.

[0015] In an embodiment, the second light can be obtained by installing a band - pass filter on the light source of the exposure device that blocks or reduces the transmission in the short - wavelength region.

[0016] In an embodiment, the first light can have a wavelength in the ultraviolet region and the visible light region, and the second light can have a wavelength in the visible light region.

[0017] In an embodiment, the first light can have an emission peak in the region of about 200 nm to about 800 nm, and the second light can have an emission peak in the region of about 400 nm to about 700 nm.

[0018] The hardness of the transparent resin layer in the first region covered with the mask can be lower than the hardness of the transparent resin layer in the region not covered with the mask.

[0019] The average surface hardness of the transparent resin layer can be adjusted by adjusting the area ratio of the first region covered with the mask and the region not covered with the mask.

[0020] According to one or more embodiments, a method of manufacturing a display device includes:

[0021] Providing a display panel including a first region,

[0022] Forming a light - control unit on the display panel, and

[0023] Forming an outer coating on the light - control unit,

[0024] Wherein forming the outer coating includes:

[0025] Forming a layer of the photocurable composition by applying the photocurable composition to the light - control unit,

[0026] Performing an (a) exposure process, covering a first region of the layer of the photocurable composition with a mask and exposing the layer of the photocurable composition with the first light, and

[0027] Performing a (b) exposure process, exposing the entire surface of the layer of the photocurable composition with the second light,

[0028] The first light can cure the photocurable composition layer more firmly (or more completely) than the second light.

[0029] In an embodiment, the first light can be light in a wavelength region shorter than the wavelength region of the second light, or the first light can include light in a wavelength region shorter than the wavelength region of the second light.

[0030] In an embodiment, the intensity of the first light can be greater than the intensity of the second light.

[0031] The (a) exposure process can be performed after the (b) exposure process, or the (b) exposure process can be performed after the (a) exposure process.

[0032] In an embodiment, the first light can be obtained without a band - pass filter installed on the light source of the exposure device, and the second light can be obtained by installing a band - pass filter on the light source of the exposure device. The band - pass filter can block or reduce the transmission of a part of the short - wavelength region of the light source.

[0033] In an embodiment, the first light can have an emission peak in the region of about 200 nm to about 800 nm, and the second light can have an emission peak in the region of about 400 nm to about 700 nm.

[0034] The average surface hardness of the outer coating can be adjusted by adjusting the area ratio of the first region covered with the mask and the region not covered with the mask.

[0035] In an embodiment, the display panel can include a light - emitting region and a non - light - emitting region, and the first region can be the light - emitting region.

[0036] In an embodiment, the display panel can be a flexible panel, and the first region can be a bending region. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The above and other aspects and features of certain embodiments of the present disclosure will become more apparent from the following description in conjunction with the accompanying drawings, where:

[0038] Figure 1 is a flowchart for illustrating a method of forming a transparent resin layer according to an embodiment;

[0039] Figure 2 is a flowchart for illustrating a method of forming a transparent resin layer according to another embodiment;

[0040] Figures 3A - 3D are diagrams for sequentially illustrating a method of manufacturing a display device according to an embodiment;

[0041] Figures 4A - 4D are diagrams for sequentially illustrating a method of manufacturing a display device according to an embodiment;

[0042] Figure 5 Shows the emission spectra of the light sources of the band - pass filters that have passed through Test Example 1 to Test Example 4;

[0043] Figure 6 Shows the emission spectra of the light sources without the band - pass filters of Test Example 1 to Test Example 4 installed thereon;

[0044] Figures 7 - 10 Respectively are photographs of the surfaces of the outer coatings of the samples of Test Example 1 to Test Example 4 after performing wear tests on the samples of Test Example 1 to Test Example 4; and

[0045] Figures 11 - 12 Shows the measurement graphs of the light transmittance according to wavelength of the samples formed in the same manner as in Test Example 1 and Test Example 4 respectively. Detailed Description of the Invention

[0046] Embodiments of the present disclosure in the accompanying drawings will now be explained in more detail with reference to their examples, where the same reference numerals refer to the same elements throughout. In this regard, the present embodiments may have different forms and should not be construed as limited to the descriptions set forth herein. Accordingly, the embodiments are described below only by referring to the drawings to explain aspects of the embodiments of the present description. As used herein, the term "and / or" includes any and all combinations of one or more of the related listed items. Throughout the present disclosure, the expression "at least one of a, b, and c" indicates only a, only b, only c, both a and b, both a and c, both b and c, all of a, b, and c, or variations thereof.

[0047] Since the embodiments allow for various suitable changes and the present invention has many embodiments, exemplary embodiments will be illustrated in the drawings and described in more detail in the written description. When referring to the embodiments described with reference to the drawings, the effects and characteristics of the present disclosure and the methods for achieving them will be apparent. However, the subject matter of the present disclosure may be implemented in many different forms and should not be construed as limited to the embodiments set forth herein.

[0048] Hereinafter, embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings. The same or corresponding components will be denoted by the same reference numerals, and thus their repeated description will be omitted.

[0049] It will be understood that although terms such as "first", "second", etc. may be used herein to describe various components, these components should not be limited by these terms. These terms are only used to distinguish one component from another.

[0050] Expressions used for the singular cover the plural, unless the context clearly indicates otherwise.

[0051] It will be further understood that the terms “comprises” and / or “comprising” as used herein specify the presence of stated features or elements, but do not preclude the presence or addition of one or more other features or elements.

[0052] It will be understood that when a layer, region or component is referred to as being “on” or “onto” another layer, region or component, it can be directly or indirectly formed on the other layer, region or component. For example, there may be intervening layers, regions or components.

[0053] For ease of explanation, the dimensions of elements in the drawings may be enlarged. In other words, since the dimensions (e.g., thickness) of elements in the drawings can be arbitrarily interpreted for ease of explanation, the present invention is not limited to the following embodiments.

[0054] When implementing the embodiments differently, the specific process order may be different from the described order. For example, two processes described consecutively may be carried out substantially simultaneously, or may be carried out in an order opposite to the order in which they are described.

[0055] In the following examples, it will be understood that when a film, region or component is referred to as being “connected to” another film, region or component, the film, region or component can be not only directly connected to the other film, region or component, but also indirectly connected to the other film, region or component due to the presence of intervening films, regions or components. For example, in this specification, it will be understood that when a film, region or component is referred to as being “electrically connected to” another film, region or component, the film, region or component can be not only directly electrically connected to the other film, region or component, but also indirectly electrically connected to the other film, region or component due to the presence of intervening films, regions or components.

[0056] Method for forming a transparent resin layer

[0057] Figure 1 A flowchart for explaining a method for forming a transparent resin layer (also referred to as “method for preparing a transparent resin layer”) according to an embodiment. Refer to Figure 1 , a photocurable composition for forming a transparent resin layer can be applied to a substrate (step S110). The substrate is a substrate on which a transparent resin layer is to be formed, and can be, for example, a display panel including a light-emitting device thereon. The display panel can include a glass substrate and / or a plastic substrate (for example, taking a polyimide substrate as an example).

[0058] The photocurable composition is a composition that cures upon exposure to form a transparent resin layer. The photocurable composition may include a monomer containing a photopolymerizable functional group, a photoinitiator, and a solvent, and may further include additives (e.g., leveling agents and sensitizers) and / or inorganic particles for modulus control, etc. As the photocurable composition, any suitable photocurable composition commonly used in the art for forming a transparent resin layer can be used. The photocurable composition may be, for example, a composition for forming a poly(silsesquioxane) resin.

[0059] The photocurable composition can be applied to a substrate by using an appropriate or suitable method (e.g., spin coating method, inkjet printing method, and / or slot coating method, etc.) to form a photocurable composition layer. Due to the evaporation of the solvent during the application of the photocurable composition to the substrate, the photocurable composition can form a photocurable composition layer that is solvent-free or has a reduced solvent amount.

[0060] The photocurable composition layer can be exposed to first light using a mask (step S120). In an embodiment, the transparent resin layer to be formed has different hardnesses according to regions. For example, in an embodiment, the transparent resin layer has a low hardness in some regions to allow bending, and has a high hardness in other regions to not allow bending. For this reason, the regions with low hardness can be first covered, and the photocurable composition layer can be exposed to the first light. In an embodiment, the exposure can be performed by using an exposure device and a mask. The first light can be light having conditions capable of promoting the curing of the photocurable composition layer. For example, the first light can have conditions that enable the effective operation of the photoinitiator used in the photocurable composition. In the regions exposed to the first light (e.g., in the regions not covered by the mask), the photocurable composition layer can be firmly (or completely) cured. In an embodiment, the photocurable composition layer in the regions covered by the mask may not be cured.

[0061] Subsequently, the entire surface of the photocurable composition layer can be exposed to second light (step S130). By removing the mask, the photocurable composition layer in the regions that were not cured in step S120 can also be cured with the second light.

[0062] Compared to the first light, the second light can cure the photocurable composition layer less firmly (or less completely). For example, the second light can have conditions that make the photoinitiator used in the photocurable composition operate less efficiently. In an embodiment, by installing a bandpass filter on the light source of the exposure device that blocks or reduces the transmission in the short wavelength region and passes through the long wavelength region, the second light can mainly include light components in the low energy and long wavelength regions. In one or more embodiments, without installing the bandpass filter, the first light can include light in all short wavelength regions of the light source.

[0063] For example, a high-pressure mercury UV lamp can be used as a light source of an exposure device. The high-pressure mercury UV lamp can emit light in a region of about 200 nm to about 800 nm. When a band-pass filter is not installed on the light source of the exposure device, all the light in the short-wavelength region emitted from the high-pressure mercury UV lamp (for example, the light in the region of about 380 nm or less) can be used to cure the photocurable composition. Since light having a wide energy range including the short-wavelength region is used, the curing rate of the photocurable composition layer can be increased. When a band-pass filter is installed on the light source of the exposure device, light in a limited range in the low-energy region can be used, resulting in a lower curing rate of the photocurable composition layer than the case where the band-pass filter is not used. In an embodiment, the exposure energy can be, for example, in the range of dozens of mJ / cm 2 to 1 J / cm 2 and can vary according to process conditions and the like.

[0064] For example, the wavelength of the first light can include wavelengths in the ultraviolet region and the visible light region, and the wavelength of the second light can include only wavelengths in the visible light region. For example, the wavelength of the first light can include wavelengths in the ultraviolet region and the visible light region, and the wavelength of the second light can include only the long-wavelength region among the visible light regions. For example, the first light can have an emission peak in the region of about 200 nm to about 800 nm, and the second light can have an emission peak in the region of about 400 nm to about 700 nm. For example, the first light can have an emission peak in the region of about 300 nm to about 600 nm, and the second light can have an emission peak in the region of about 500 nm to about 600 nm.

[0065] In an embodiment, the intensity of the first light can be greater than the intensity of the second light. In an embodiment, the first light and the second light can be in the same wavelength range, and the intensity of the first light can be greater than the intensity of the second light. In one or more embodiments, the first light and the second light can have different wavelength ranges as described above, and the intensity of the first light can be greater than the intensity of the second light. The greater the intensity of the light, the more firmly (or completely) the photocurable composition layer can be cured.

[0066] In an embodiment, the region exposed with the first light can be repeatedly exposed by exposing the entire surface with the second light, resulting in more firmly (or completely) curing compared to the case of exposing only with the first light.

[0067] Therefore, a transparent resin layer having different hardnesses in different regions can be formed by sequentially exposing the photocurable composition with high-energy first light using a mask and then with low-energy second light without using a mask (step S140).

[0068] In an embodiment, by adjusting the size of the mask, the area ratio of the masked area of the photocurable composition layer to the unmasked area of the photocurable composition layer can be adjusted, and in this regard, the average surface hardness of the transparent resin layer formed by curing can be adjusted. For example, when the surface hardness of the transparent resin layer in the masked area is 3H, the surface hardness of the transparent resin layer in the unmasked area can be 8H, and during curing, the area ratio of the masked area to the unmasked area can be 3:7, the average surface hardness of the transparent resin layer can be roughly estimated to be 3H×0.3+8H×0.7=6.5H. In an embodiment, when the masked area and the unmasked area are uniformly (or substantially uniformly) mixed and distributed, the average surface hardness of the transparent resin layer can be effectively adjusted.

[0069] Figure 2 FIG. 1 is a flow chart illustrating a method for forming a transparent resin layer according to another embodiment. Figure 2 , forming a photocurable composition layer on the substrate (step S210) may be the same as the above-mentioned step S110. The method for forming a transparent resin layer of this embodiment differs from the previous embodiment only in that the order of curing with a mask and curing without a mask is reversed. For example, in this embodiment, the entire surface may be exposed with a second light without using a mask (step S220), and then exposed with a first light using a mask (step S230), thereby forming a transparent resin layer having different hardnesses in different areas (step S240). For the description of the first light, the second light, and the mask, reference may be made to the description of the first light, the second light, and the mask. Figure 1 The first light, the second light, and the mask are described.

[0070] Display device manufacturing method

[0071] Figures 3A - 3D The following are diagrams illustrating a method for manufacturing a display device (also referred to as a "method for manufacturing a display device") according to an embodiment. Figure 3A , a display panel 100 having a color filter layer 110 provided thereon may be provided. The display panel 100 may include a substrate and a driving device and a light-emitting device on the substrate, or may be composed of a substrate and a driving device and a light-emitting device on the substrate. The color filter layer 110 may include color filter patterns 115 (a red color filter pattern 115R, a green color filter pattern 115G, and a blue color filter pattern (not shown)) and isolation walls 111 separating the color filter patterns. In this embodiment, only the color filter layer 110 is shown, but the display device may further include a quantum dot color conversion layer below the color filter layer 110. The color filter layer 110 and the quantum dot color conversion layer may constitute a light converter.

[0072] In one or more embodiments, the display panel 100 may be provided without the color filter layer 110 thereon. In an embodiment, the transparent resin layer may be directly on the display panel 100.

[0073] Reference Figure 3B , the photocurable composition for forming the transparent resin layer can be applied onto the color filter layer 110 (see Figure 3A ) to form the photocurable composition layer 120p. The photocurable composition is a composition that can be cured by exposure to form the transparent resin layer. Thus, the transparent resin layer can be an outer coating. The outer coating can planarize the steps generated by the color filter layer 110 (see Figure 3A ) and protect the display device.

[0074] The photocurable composition can include monomers containing functional groups for photopolymerization, photoinitiators, and solvents, and can further include additives (such as, for example, leveling agents and sensitizers) and / or inorganic particles for modulus control, etc. As the photocurable composition, any suitable photocurable composition commonly used in the art for forming the transparent resin layer can be used. The photocurable composition can be, for example, a composition for forming a poly(silsesquioxane) resin. The photocurable composition can be applied onto the substrate by using an appropriate or suitable method (such as a spin coating method, an inkjet printing method, and / or a slot die coating method) to form the photocurable composition layer 120p. Due to the evaporation of the solvent during the application of the photocurable composition onto the substrate, the photocurable composition can form a photocurable composition layer 120p that is solvent-free or has a reduced solvent content.

[0075] Reference Figure 3C , a part of the photocurable composition layer 120p can be covered with a mask M1 and exposed to the first light. The area covered with the mask M1 can include the area where the light-emitting device at the bottom is exposed through the color filter pattern 115 (see Figure 3A ), that is, the so-called opening area. In one or more embodiments where the display device does not include the color filter layer 110 (see Figure 3A ), the area where the light-emitting device is directly provided at the bottom can be included, that is, the so-called opening area. The area not covered with the mask M1 can include the area where the light-emitting device is not exposed, that is, the so-called non-opening area.

[0076] The first light may be light capable of promoting the curing of the photocurable composition layer. For example, the first light may have a wavelength within a range under conditions where the photoinitiator contained in the photocurable composition acts effectively (e.g., in the short wavelength region in the ultraviolet region and / or in a wide range of wavelengths in the ultraviolet region and the visible light region). Also, the first light may have an intensity suitable for effective curing. Accordingly, the region 120mb of the photocurable composition layer not covered by the mask M1 can be firmly (or completely) cured with the first light. In an embodiment, the region 120ma of the photocurable composition layer covered by the mask M1 may not be (or may substantially not be) cured. When the light-emitting device is exposed to short wavelength light such as ultraviolet light, the material may deteriorate and the light-emitting device may be damaged. Since the light-emitting device located in the opening region is not exposed to the first light due to the mask M1, it will not (or will substantially not) be damaged when the light-emitting device is cured with the first light.

[0077] As a light source for an exposure apparatus for photocuring, for example, a mercury lamp (e.g., a high-pressure mercury UV lamp) and / or an LED lamp can be used, but not limited thereto. Any suitable light source having an appropriate or suitable wavelength range and an appropriate or suitable intensity can be used. In an embodiment, the entire wavelength range of the light source can be used for the first light without installing a band-pass filter on the light source. By using a wide range of wavelengths including short wavelengths as the first light for curing, the curing efficiency can be increased. In one or more embodiments, a band-pass filter passing through the short wavelength region and / or the ultraviolet region can be installed on the light source of the exposure apparatus so that only the wavelength range effective for curing can be used.

[0078] Reference Figure 3D , the entire surface of the photocurable composition layer 120m (see Figure 3C ) can be exposed to the second light. Since the mask M1 has been removed, even the region 120ma (see Figure 3C ) that was not cured in the first exposure process can be cured with the second light.

[0079] The second light may be light in a wavelength region longer than that of the first light and, for example, light in a low energy region. For example, the wavelength of the first light may include wavelengths in the ultraviolet region, and the wavelength of the second light may include wavelengths in the visible light region and not include wavelengths in the ultraviolet region.

[0080] In an embodiment, the second light may use the same light source as the light source of the first light. By installing a bandpass filter that blocks or reduces the transmission of the short wavelength region and passes the long wavelength region on the same light source as the exposure device, the second light may mainly include light components in the long wavelength region. For example, by using a bandpass filter to cut off light below 400nm from the first light, the first light may have an emission peak in the region of about 200nm to about 800nm, and the second light may have an emission peak in the region of about 400nm to about 700nm. For example, by using a bandpass filter to cut off, block or reduce the transmission of light below 500nm from the first light, the first light may have an emission peak in the region of about 300nm to about 600nm, and the second light may have an emission peak in the region of about 500nm to about 600nm.

[0081] When the photocurable composition layer 120m (see Figure 3C ) is cured by the second light, an outer coating layer 120 may be formed. The area 120a of the outer coating layer 120 cured only by the second light may have a lower hardness than the hardness of the area 120b of the outer coating layer 120 cured by both the first light and the second light. For example, the area 120a of the outer coating layer 120 may have a surface hardness of 3H to 4H, while the area (non-opening area) 120b of the outer coating layer 120 may have a surface hardness of 7H to 8H. In an embodiment, the average surface hardness of the outer coating layer 120 may be adjusted by adjusting the size of the mask. In an embodiment, a mask may be prepared to cover all opening areas, but the size of the mask may be different. For example, when the surface hardness of the outer coating layer in the masked area cured by the first light is 3H, the surface hardness of the outer coating layer in the unmasked area cured by the first light may be 8H, and the mask may be prepared so that the proportion of the masked area is 40%, the average surface hardness of the outer coating layer may be roughly estimated to be 3H×0.4+8H×0.6=6H. When the mask is prepared so that the ratio of the masked area is 30%, the average surface hardness of the outer coating layer can be roughly estimated to be 3H×0.3+8H×0.7=6.5H.

[0082] Figures 4A - 4D The following are diagrams illustrating a method for manufacturing a display device according to another embodiment. Figures 3A - 3D The difference between the embodiments is that the order of curing with a mask and curing without a mask is reversed. Figure 4A and Figure 4B For a description, see Figure 3A and Figure 3B description and can be found by reference Figures 3A - 3D The description of the first light, the second light, the mask M1 and other common reference numerals are understood.

[0083] refer to Figure 4C , the photocurable composition layer 120p (see Figure 3B) The entire surface can be exposed to the second light. The second light can be understood in combination with the second light described in the Figures 3A - 3D embodiment. By exposing the entire surface to the second light, a fully cured layer of the photocurable composition 120s can be formed (for example, although the layer of the photocurable composition is not fully or completely cured, at least a part of the entire layer of the photocurable composition is cured). The layer of the photocurable composition 120s can be cured to the same hardness as the region 120a of the layer of the photocurable composition described in the Figures 3A - 3D embodiment (see Figure 3D ).

[0084] Referring to Figure 4D , a part of the layer of the photocurable composition 120s can be covered with a mask M1 and exposed to the first light. The first light can be understood in combination with the first light described in the Figures 3A - 3D embodiment. Figures 4A - 4D The embodiment of Figures 3A - 3D is the same as the embodiment of Figure 4D in that the non-opening region 120b exposed by the mask M1 can be cured by both the first light and the second light, and the opening region 120a covered by the mask M1 can be cured only by the second light. However, Figures 3A - 3D the embodiment of Figure 4D is different from the embodiment of Figures 3A - 3D in that the non-opening region 120b in the embodiment of Figures 3A - 3D can be first cured by the second light and then cured by the first light, which is contrary to the embodiment of

[0085]

[0086] For a flexible display device, the hardness of the outer coating in the bending region should be lower than that of the outer coating in other regions. When the hardness of the outer coating in the bending region is too high, the outer coating may break during the bending operation. Although the method for manufacturing a display device for forming an outer coating with a low hardness in the opening region is described in the above embodiments, a display device can be manufactured by applying the same method to form an outer coating with a low hardness in the bending region. Examples

[0087] Test Example 1

[0088] On a display panel having a color filter pattern, a photocurable composition including a polyhedral oligomeric silsesquioxane resin for forming an outer coating is applied by inkjet printing to form a layer of the photocurable composition.

[0089] A display panel having a photocurable composition layer formed thereon is placed in an exposure apparatus, and irradiated with an exposure light source equipped with a band-pass filter at 0.5 J / cm 2 to expose the photocurable composition layer. A high-pressure mercury UV lamp is used as the light source of the exposure apparatus. The emission spectrum of the light source that has passed through the band-pass filter is shown in Figure 5 . Referring to Figure 5 , the light source has a main emission peak between 500 nm and 600 nm. The photocurable composition layer is cured by exposure to form an outer coating having a thickness of about 10 μm. Due to the steps generated by the color filter pattern, the thickness of the outer coating may vary according to the region.

[0090] Test Example 2

[0091] On a display panel having a color filter pattern thereon, a photocurable composition including a polyhedral oligomeric silsesquioxane resin for forming an outer coating is applied by inkjet printing to form a photocurable composition layer. In the same manner as in Test Example 1, the display panel having the photocurable composition layer formed thereon is placed in an exposure apparatus. Then, the photocurable composition layer is subjected to a first exposure process by irradiating the panel with a light source equipped with a band-pass filter at 0.5 J / cm 2 .

[0092] Subsequently, the color filter pattern is covered with a mask, and then irradiated with an exposure light source not equipped with a band-pass filter at 0.5 J / cm 2 to perform a second exposure process on the photocurable composition layer obtained by the first exposure process. The emission spectrum of the light source not equipped with a band-pass filter is shown in Figure 6 . Referring to Figure 6 , in addition to including an emission peak between 500 nm and 600 nm, the light source further includes an emission peak between 300 nm and 500 nm.

[0093] The photocurable composition layer is cured by the first exposure process and the second exposure process to form an outer coating having a thickness of about 10 μm. Here, the area covered by the mask is about 25% of the total area of the outer coating.

[0094] Test Example 3

[0095] An outer coating is formed in substantially the same manner as in Test Example 2, except that the mask is changed such that the area covered by the mask is about 40%.

[0096] Test Example 4

[0097] An outer coating is formed in substantially the same manner as in Test Example 1, except that no band-pass filter is installed on the exposure apparatus.

[0098] Hardness measurement results

[0099] For each of the outer coatings formed in Test Examples 1 to 4, the surface hardness was measured by using a pencil hardness measuring device (CT-PC2 manufactured by Coretech Corporation) and a wear tester, and the measurement results are shown in Table 1.

[0100] Referring to Table 1, the outer coating of Test Example 1 has the lowest pencil hardness of 3H, the outer coating of Test Example 4 has the highest pencil hardness of 8H, the outer coating of Test Example 2 has a pencil hardness of 7H, and the outer coating of Test Example 3 has a pencil hardness of 5.5H.

[0101] Figures 7 - 10 Photographs of the surfaces of the outer coatings of the samples of Test Examples 1 to 4 after the wear test was performed thereon. The wear test was performed by placing a heavy object on top of the outer coating and pressing downward with a force of about 1.5 kgf, and moving the steel wool #0000 back and forth 10 times from one side to the other side. Refer to Figures 7 - 10 and Table 1, severe linear scratches were generated in the moving direction of the steel wool in the outer coating of Test Example 1, and dot-shaped scratches were generated in the outer coatings of Test Examples 2 to 4. Here, the outer coating of Test Example 4 has the fewest scratches, and the outer coatings of Test Examples 2 and 3 have more scratches than the outer coating of Test Example 4 but much fewer scratches than the outer coating of Test Example 1.

[0102] Table 1

[0103]

[0104] Referring to the hardness measurement and wear test results of the samples of Test Examples 1 to 4, it can be seen that the hardness of the outer coating can be adjusted by two-step exposure.

[0105] Figure 11 A measurement graph of the light transmittance according to wavelength of a sample in which an outer coating is formed on a glass substrate in the same manner as in Test Example 1 instead of on a display panel on which a color filter pattern is formed. Figure 12 A measurement graph of the light transmittance according to wavelength of a sample in which an outer coating is formed on a glass substrate in the same manner as in Test Example 4 instead of on a display panel on which a color filter pattern is formed. Refer to Figure 11 and Figure 12 , the light transmittance curves in the two graphs are the same (or substantially the same). Accordingly, it can be seen that the light transmittance of the outer coating is not affected by whether a band-pass filter is used.

[0106] According to one or more embodiments, by adjusting the exposure wavelength and using a mask for two-step exposure, the hardness of the transparent resin layer can be adjusted according to the position while using the same material.

[0107] It should be understood that the embodiments described herein should be considered only in a descriptive sense and not for purposes of limitation. The description of features or aspects within each embodiment is generally to be considered applicable to other similar features or aspects in other embodiments. Although one or more embodiments have been described with reference to the accompanying drawings, those of ordinary skill in the art will understand that various suitable changes in form and detail can be made therein without departing from the spirit and scope of the claims and their equivalents.

Claims

1. A method for preparing a transparent resin layer, the method comprising: forming a photocurable composition layer by applying a photocurable composition to a substrate including a first region; performing (a) an exposure process, covering the first region of the photocurable composition layer with a mask and exposing the photocurable composition layer with a first light; and performing (b) an exposure process, exposing the entire surface of the photocurable composition layer with a second light, wherein the first light cures the photocurable composition layer more firmly than the second light.

2. The method according to claim 1, wherein the first light is light in a wavelength region shorter than the wavelength region of the second light, or the first light includes light in a wavelength region shorter than the wavelength region of the second light.

3. The method according to claim 1, wherein the first light has an intensity greater than that of the second light.

4. The method according to claim 1, wherein the (b) exposure process is performed after the (a) exposure process.

5. The method according to claim 1, wherein the (a) exposure process is performed after the (b) exposure process.

6. The method according to claim 1, wherein the second light is obtained by installing a band - pass filter that blocks or reduces the transmission of the short - wavelength region on the light source of the exposure device.

7. The method according to claim 1, wherein the first light has a wavelength in the ultraviolet region and the visible light region, and the second light has a wavelength in the visible light region.

8. The method according to claim 1, wherein the first light has an emission peak in the region of 200 nm to 800 nm, and the second light has an emission peak in the region of 400 nm to 700 nm.

9. The method according to claim 1, wherein the hardness of the transparent resin layer in the first region covered with the mask is lower than the hardness of the transparent resin layer in the region not covered with the mask.

10. The method according to claim 1, wherein the average surface hardness of the transparent resin layer is adjusted by adjusting the area ratio of the first region covered with the mask and the region not covered with the mask.

11. A method for manufacturing a display device, the method comprising: providing a display panel including a first region; forming a light - control unit on the display panel; and forming an outer coating on the light - control unit, wherein forming the outer coating includes: forming a photocurable composition layer by applying a photocurable composition to the light - control unit; performing (a) an exposure process, covering the first region of the photocurable composition layer with a mask and exposing the photocurable composition layer with a first light; and performing (b) an exposure process, exposing the entire surface of the photocurable composition layer with a second light, wherein the first light cures the photocurable composition layer more firmly than the second light.

12. The method according to claim 11, wherein the first light is light in a wavelength region shorter than the wavelength region of the second light, or the first light includes light in a wavelength region shorter than the wavelength region of the second light.

13. The method according to claim 11, wherein the first light has an intensity greater than that of the second light.

14. The method according to claim 11, wherein: the (b) exposure process is performed after the (a) exposure process, or the (a) exposure process is performed after the (b) exposure process.

15. The method according to claim 11, wherein: the first light is obtained without a band-pass filter being installed on a light source of an exposure apparatus, and the second light is obtained by installing the band-pass filter on the light source of the exposure apparatus.

16. The method according to claim 15, wherein the band-pass filter reduces the transmission of a part of a short-wavelength region of the light source.

17. The method according to claim 11, wherein the first light has an emission peak in a region of 200 nm to 800 nm, and the second light has an emission peak in a region of 400 nm to 700 nm.

18. The method according to claim 11, wherein the average surface hardness of the outer coating is adjusted by adjusting an area ratio of the first region covered with the mask and a region not covered with the mask.

19. The method according to claim 11, wherein the display panel includes a light-emitting region and a non-light-emitting region, and the first region is the light-emitting region.

20. The method according to claim 11, wherein: the display panel is a flexible panel, and the first region is a bent region.

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