Spacers for image display devices, methods for manufacturing the same, and image display devices including the same

Abstract

The present application provides a spacer wall for an image display device, a manufacturing method thereof, and an image display device including the spacer wall. In the spacer wall for the image display device, the line width at a 95% thickness from a lowermost end of the spacer wall with respect to the overall thickness of the spacer wall is A, the maximum line width at a 50% to 90% thickness from the lowermost end of the spacer wall is B, and the line width at a 10% thickness from the lowermost end of the spacer wall is C, and 0.8≤A / B<1.0 and 0.85≤C / B<1.0 are satisfied. The spacer wall for the image display device of the present application can be effectively applied to the manufacturing of color conversion pixels through an inkjet process, and the image display device including the spacer wall has excellent brightness and maintains high brightness when viewed from a side surface, thereby exhibiting the effect of excellent viewing angle characteristics.

Description

Technical Field

[0001] The present invention relates to a partition wall for an image display device, a method for manufacturing the partition wall, and an image display device comprising the partition wall. Background Technology

[0002] Conventional image display devices use color filters to form colors. In this case, when light emitted from a white backlight source passes through red, green, and blue color filters, specific wavelengths of light are absorbed and specific wavelengths of light are transmitted to display the desired color. Compared to the backlight source that generates the light, this transmitted light is separated into absorbed and transmitted light, thus resulting in a significant loss.

[0003] Recently, research has been conducted on image display devices using color conversion layers. For example, in a display structure consisting of a color conversion layer and a backlight source that generates blue light, blue pixels directly utilize the blue light from the backlight, thus enabling full use of the backlight's light. Furthermore, in a color conversion layer display, pixels displaying red to green convert blue light to red to green, resulting in less light loss and superior light efficiency compared to conventional color filters that use absorption and transmission. However, conventional image display devices using color conversion layers still fall short in terms of brightness and viewing angle characteristics.

[0004] On the other hand, the photolithography process, typically used to manufacture color conversion pixels for color conversion layers, has the advantages of simple process and mass production of identical products. However, it also suffers from the problem of generating a large amount of wastewater and the fact that the amount of material actually used is less than the amount consumed, with most of it being discarded. Recently, inkjet printing has been applied to the color conversion pixel process, which has the advantage of not generating wastewater and reducing the amount of discarded material.

[0005] This inkjet process requires spacers and ink. The spacers act as weirs, dividing the pixel areas into regions for ink injection. Ink is then filled into these pixel areas through nozzles. During the inkjet process, insufficient spreadability and wetting ability of the ink at the openings between the multiple spacers results in increased processing time and an increase in undesirable color-converting pixels.

[0006] In this regard, although Korean Patent Publication No. 10-2019-0090114 discloses a color conversion component with improved color reproduction and light efficiency, as well as an electronic device containing the same, it lacks viewing angle characteristics and does not recognize the problems when forming color conversion pixels through an inkjet process. Summary of the Invention

[0007] Technical issues

[0008] The present invention addresses the aforementioned problems of the prior art and aims to provide a spacer for an image display device that can improve brightness and viewing angle characteristics.

[0009] Furthermore, the present invention aims to provide a spacer for an image display device, wherein the color conversion ink in the multiple pixel regions defined by the spacer has excellent extensibility and wettability, and can be effectively applied to the inkjet process used to form color conversion pixels.

[0010] Furthermore, the present invention aims to provide a method for manufacturing a spacer for an image display device.

[0011] Furthermore, the object of the present invention is to provide an image display device including a spacer for an image display device.

[0012] Problem Solving Methods

[0013] The present invention provides a partition wall for an image display device, wherein, relative to the overall thickness of the partition wall, the line width at 95% of the thickness from the bottom end is A, the maximum line width at 50% to 90% of the thickness from the bottom end is B, and the line width at 10% of the thickness from the bottom end is C, the partition wall satisfies 0.8≤A / B<1.0 and 0.85≤C / B<1.0.

[0014] Furthermore, the present invention provides a method for manufacturing a spacer for an image display device, comprising the step of forming a spacer on a substrate, wherein, relative to the overall thickness of the spacer, the linewidth at 95% of the thickness of the spacer from the bottom end is A, the maximum linewidth at 50% to 90% of the thickness of the spacer from the bottom end is B, and the linewidth at 10% of the thickness of the spacer from the bottom end is C, the spacer satisfies 0.8≤A / B<1.0 and 0.85≤C / B<1.0.

[0015] Furthermore, the present invention provides an image display device comprising a spacer for an image display device.

[0016] Invention Effects

[0017] The image display device of the present invention, which includes a spacer for an image display device, has excellent brightness and maintains high brightness even when viewed from the side, thereby exhibiting excellent viewing angle characteristics.

[0018] Furthermore, the spacer for the image display device of the present invention is characterized in that the color conversion ink in the multiple pixel regions defined by the spacer has excellent extensibility and wettability, thereby being effectively applied to the manufacture of pixel portions by inkjet process.

[0019] Furthermore, by applying the spacer wall of the image display device of the present invention to the image display device, a high-quality image display device with excellent brightness and viewing angle and no pixel defects can be provided. Attached Figure Description

[0020] Figure 1 This is a cross-sectional view illustrating the shape of the spacer wall in an image display device according to an embodiment of the present invention.

[0021] Figure 2 This is a SEM photograph showing a cross-section of the spacer wall of the image display device according to Embodiment 1 of the present invention.

[0022] Figure 3 This is a SEM photograph showing a cross-section of the partition wall of the image display device of Comparative Example 2 of the present invention.

[0023] Figure 4 This is a SEM photograph showing a cross-section of the partition wall of the image display device of Comparative Example 3 of the present invention.

[0024] Figure 5 This is an evaluation standard used to evaluate inkjet characteristics in embodiments of the present invention. Detailed Implementation

[0025] The present invention provides a spacer for an image display device, wherein, relative to the overall thickness of the spacer, the line width at 95% of the thickness from the bottom end is A, the maximum line width at 50% to 90% of the thickness from the bottom end is B, and the line width at 10% of the thickness from the bottom end is C, the spacer satisfies 0.8≤A / B<1.0 and 0.85≤C / B<1.0.

[0026] Furthermore, the present invention provides a method for manufacturing a spacer for an image display device, which includes the step of forming a spacer on a substrate, wherein, relative to the overall thickness of the spacer, the linewidth at 95% of the thickness of the spacer from the bottom end is A, the maximum linewidth at 50% to 90% of the thickness of the spacer from the bottom end is B, and the linewidth at 10% of the thickness of the spacer from the bottom end is C, the spacer satisfies 0.8≤A / B<1.0 and 0.85≤C / B<1.0.

[0027] Furthermore, the present invention provides an image display device comprising a spacer for an image display device.

[0028] The present invention has been experimentally confirmed that when the shape of the spacer in the image display device of the present invention meets the above-mentioned specific conditions, it can improve the brightness and viewing angle characteristics of the image display device using the spacer and can be effectively applied to the inkjet process used to form color conversion pixels.

[0029] The advantages and features of the present invention, as well as the methods for implementing them, will become apparent from the following detailed description of the embodiments and in conjunction with the accompanying drawings. The present invention is not limited to the embodiments disclosed below and can be implemented in various ways. These embodiments are provided to make the disclosure of the present invention complete and to enable those skilled in the art to fully understand the scope of the invention.

[0030] The shapes, dimensions, proportions, angles, quantities, etc., disclosed in the accompanying drawings used to illustrate embodiments of the present invention are exemplary, and therefore the present invention is not limited to the matters illustrated. Throughout this specification, the same reference numerals denote the same constituent elements.

[0031] When describing this invention, detailed descriptions of known functions or configurations may be omitted if it is determined that such descriptions would unnecessarily obscure the spirit of the invention. When terms such as "comprising," "having," or "forming" are used in this specification, additional parts may be added unless "~only" is used.

[0032] When explaining constituent elements, in cases where positional relationships are described, such as when the positional relationship between two parts is described as “~above,” “~upper part,” “~lower part,” “~next to,” etc., unless “exactly” or “directly” is used, there may be more than one other constituent element located between the two parts.

[0033] The features of the various embodiments of the present invention can be partially or wholly combined or integrated with each other, and can be linked and driven in various technical ways. Furthermore, the embodiments can be implemented independently of each other or can be implemented together in a related manner.

[0034] The specific embodiments of the present invention will now be described with reference to the accompanying drawings. However, the drawings in this specification are for illustrating preferred embodiments of the present invention and, together with the above description, serve to further understand the technical concept of the present invention. Therefore, the present invention should not be construed as being limited to the matters described in these drawings.

[0035] <Spacer for image display device>

[0036] The present invention provides a spacer for an image display device.

[0037] In an image display device, each pixel represents color, thus requiring the formation of partitions to distinguish each pixel. In this invention, the partitions in the image display device can be formed in a way that defines pixel regions, that is, around pixel regions.

[0038] The aforementioned pixel area refers to the part of the pixel portion that forms the display color, specifically the part where a coloring composition such as red, green, or blue ink and luminescent material is sprayed, coated, or filled.

[0039] The image display device described above may include liquid crystal display devices, organic light-emitting diodes, flexible displays, etc., but the present invention is not limited thereto, and all display devices known in the art that can be applied can be exemplified.

[0040] Figure 1 This is a cross-sectional view illustrating the shape of the spacer wall in an image display device according to an embodiment of the present invention. The following will refer to... Figure 1 The shape of the spacer wall for the image display device of the present invention will be described in detail.

[0041] Figure 1 In this context, D represents the height from the lowermost end portion to the uppermost end portion of the spacer, i.e., the thickness of the spacer. The thickness (D) of the spacer is not particularly limited, but is preferably 8 μm to 12 μm, more preferably 9 μm to 11 μm. When the spacer in the image display device meets the above thickness range, it has the advantage of further improving light efficiency, thereby exhibiting superior performance of the color conversion pixels.

[0042] In this invention, A, B, and C represent the linewidth of the partition wall measured at a specific height. More specifically, A represents the linewidth at 95% of the thickness of the partition wall, i.e., a height of 0.95D. B represents the maximum linewidth at 50% to 90% of the thickness of the partition wall, preferably at 60% to 80% of the thickness of the partition wall. C represents the linewidth at 10% of the thickness of the partition wall, i.e., a height of 0.1D.

[0043] The partition wall for the image display device of the present invention is characterized in that it can satisfy 0.8≤A / B<1.0, and preferably satisfies 0.85≤A / B<1.0.

[0044] Furthermore, the partition wall for the image display device of the present invention is characterized in that it can satisfy 0.85≤C / B<1.0, and preferably satisfies 0.9≤C / B<1.0.

[0045] When the spacer in the image display device of the present invention satisfies the ranges of A / B and C / B above, a pixel region with an increased surface area can be formed compared to using a spacer where A, B, and C all have the same linewidth. Therefore, the light absorption rate incident from the light source to the pixel increases, resulting in excellent brightness, and as the angle at which light exits from the pixel improves, the decrease in brightness on the side is reduced, resulting in excellent viewing angle characteristics.

[0046] Furthermore, when the spacers in the image display device of the present invention satisfy the ranges of A / B and C / B above, a pixel region with an increased volume can be formed compared to using spacers where A, B, and C all have the same linewidth. As a result, more color composition can be accommodated in the pixel region, thus increasing the light conversion efficiency and enabling the display of superior brightness and color conversion characteristics.

[0047] On the other hand, during the formation of the spacer walls, components from the spacer wall forming composition that sublimate during the high-temperature heating process may fall into the pixel area, potentially causing contamination. Of this contamination, the contamination formed at the center of the pixel area is a major cause of hindering the spreadability and wettability of the color conversion ink when manufacturing color conversion pixels via an inkjet process. When the spacer walls for the image display device of the present invention satisfy the ranges of A / B and C / B above, the contamination generated during the spacer wall formation process adhering to the center of the pixel area can be reduced. Therefore, the color conversion ink exhibits excellent spreadability and wettability, and can thus be effectively applied to the manufacture of color conversion pixels via an inkjet process.

[0048] The spacer for the image display device of the present invention can be formed from a photosensitive resin composition for spacer formation.

[0049] <Photosensitive Resin Composition for Spacer Formation>

[0050] The photosensitive resin composition for spacer formation of the present invention may contain colorants, alkali-soluble resins, photopolymerizable compounds, photopolymerization initiators, and solvents, and may further contain additives if necessary, but the present invention is not limited thereto.

[0051] Colorant

[0052] The colorant contained in the photosensitive resin composition of the present invention may include a white pigment.

[0053] The white pigment is used to enhance the reflective properties of the spacers in an image display device; specifically, it can improve the reflectivity of the spacers. That is, brightness can be increased by reflecting light generated by the pixel that is directed towards the spacers.

[0054] The average particle size of the white pigment is preferably between 150 nm and 300 nm. When the average particle size is less than 150 nm, the reflectivity in the visible light region of 380 nm to 780 nm will be weakened. When the average particle size is greater than 300 nm, the dispersibility and storage stability will be reduced.

[0055] In this invention, the "average particle size" can be the number-average particle size, for example, obtained from images observed by field emission scanning electron microscopy (FE-SEM) or transmission electron microscopy (TEM). Specifically, it can be obtained by extracting multiple samples from the observed images of FE-SEM or TEM, measuring the diameters of these samples, and then arithmetically averaging them.

[0056] As the white pigment described above, white pigments known in the art can be used if the above conditions are met. In one or more embodiments, CI pigment white 4, 5, 6, 6:1, 7, 18, 18:1, 19, 20, 22, 25, 26, 27, 28, 32, etc. can be used. Considering the reflectance efficiency and whiteness, CI pigment white 6 or 22 is preferred, and CI pigment white 6 is more preferred.

[0057] They can be used alone or in combination of two or more.

[0058] Titanium dioxide (TiO2) contained in CI pigment white 6 is inexpensive and has a high refractive index and excellent reflectivity, so it can be used as an effective white colorant. From the perspective of whiteness, it is preferred to have a rutile structure.

[0059] Titanium dioxide (TiO2), the white pigment mentioned above, can be subjected to resin treatment, surface treatment using pigment derivatives that introduce acid or base groups, grafting treatment of the pigment surface using polymer compounds, micronization treatment using sulfuric acid micronization, cleaning treatment using organic solvents or water to remove impurities, or ion impurity removal treatment using ion exchange.

[0060] The aforementioned titanium dioxide (TiO2) can be titanium dioxide (TiO2) surface-treated using one or more of the group consisting of silicon dioxide (SiO2), aluminum oxide (Al2O3), zirconium oxide (ZrO2), and organic matter. Preferably, titanium dioxide surface-treated sequentially using silicon dioxide (SiO2), aluminum oxide (Al2O3), and zirconium oxide (ZrO2) can be used. More preferably, titanium dioxide obtained by treating the outermost surface of the surface-treated titanium dioxide (TiO2) with an organic matter is used. As for the aforementioned organic matter, there are no particular limitations as long as the surface treatment of titanium dioxide (TiO2) by coating it with a low-polarity monolayer reduces the energy required to disperse the titanium dioxide (TiO2) and prevents the titanium dioxide (TiO2) from compressing and agglomerating, it can be used. In one or more embodiments, stearic acid, trimethylpropane (TMP), pentaerythritol, etc., can be used.

[0061] By performing surface treatment on titanium dioxide (TiO2) as described above, the photocatalytic activity of titanium dioxide (TiO2) can be reduced and its reflectivity characteristics improved. In particular, according to a preferred embodiment of the surface treatment described above, it is beneficial in terms of improved reliability, such as heat resistance and chemical resistance. The surface treatment described above can be performed by coating.

[0062] The content of titanium oxide (TiO2) cores contained in the surface-treated titanium oxide (TiO2) is preferably 85% to 95% by weight relative to the total weight of the surface-treated titanium oxide (TiO2). When the surface of the titanium oxide (TiO2) cores is treated within the above range, it exhibits excellent whiteness and excellent reflectivity.

[0063] Commercially available titanium dioxide products include DuPont's "R-101", "R-102", "R-103", "R-104", "R-105", "R-350", "R-706", "R-794", "R-796", "TS-6200", "R-900", "R-902", "R-902+", "R-906", "R-931", "R-960" and "R-6200", Huntsman's "R-FC5", "TR81" and "TR88", and ISK's "CR-57".

[0064] The colorant of the present invention may further comprise one or more selected from black pigment, red pigment and orange pigment.

[0065] As the aforementioned black pigment, pigments known in the art can be used. In one or more embodiments, lactam black, perylene black, cyanine black, aniline black, carbon black, titanium black, etc., can be used, either alone or in combination of two or more.

[0066] The aforementioned black pigment can be surface-treated with resin as needed. There are no particular limitations on the surface treatment method; for example, it can be implemented by surface-treating the carbon black surface with compounds having OH groups, compounds having COOH groups, and / or silicone compounds. In one embodiment, as a main chain and / or rings capable of forming markings as needed, it is composed of (Si-O)... n The polysiloxane and / or the group bound to the oxygen-containing silane compound are represented by hydrogen, alkyl, vinyl, aryl, alkylaryl, aralkyl, etc.

[0067] Commercially available black pigments include Mitsubishi's "MA77", "MA7", "MA8", "MA11", "MA100", "MA100R", "MA100S", "MA230", "MA220" and "MA14", and BASF's "Paliogen Black L 0086", "Lumogen Black L 0087", "Lumogen Black L 0088", "Sicopal Black L 0095", "Paliogen Black L 0084" and "Irgaphor Black S 0100CF".

[0068] The aforementioned red pigment may be selected from one or more of the diketopyrrolopyrrole series, anthraquinone series, perylene series, and azo series. Specifically, it may be selected from one or more of the group consisting of CI Pigment Red 9, 97, 81, 105, 122, 123, 144, 149, 150, 155, 166, 168, 171, 175, 176, 177, 179, 180, 185, 192, 202, 208, 209, 214, 215, 216, 220, 222, 224, 242, 254, 255, 264, 269, 270, and 272, but there is no particular limitation.

[0069] The orange pigment mentioned above can be one or more selected from quinophthalone-based, isoindolinone-based, and diketopyrrolopyrrole-based pigments. Specifically, it can be one or more selected from the group consisting of CI pigment orange 13, 15, 31, 36, 38, 40, 42, 43, 51, 55, 59, 61, 64, 65 and 71, but there is no particular limitation.

[0070] The content of the colorant can be from 0.5% to 30% by weight, preferably from 1.0% to 20% by weight, relative to the total weight of the solid components in the photosensitive resin composition. When the content of the colorant is within the above range, it has the advantage of being able to further increase the light-blocking properties.

[0071] In this invention, the total weight of solid components in the photosensitive resin composition refers to the total weight of all components in the photosensitive resin composition except for the solvent.

[0072] Alkali-soluble resins

[0073] The aforementioned alkali-soluble resin serves the following functions: preventing pigment particles present in the photosensitive resin composition from dissolving in the solvent after coating, and preventing the increase in viscosity caused by the aggregation of pigment particles.

[0074] There are no particular limitations on the above-mentioned alkali-soluble resins, but they may include copolymers represented by the following chemical formula 1.

[0075] [Chemical Formula 1]

[0076]

[0077] (In the above chemical formula 1, R1 and R2 are each independently hydrogen or methyl, and the molar ratio of monomer a to monomer b is 1:20 to 20:1.)

[0078] In this invention, by using a copolymer of the above-mentioned chemical formula 1 containing epoxy groups as an alkali-soluble resin, solvent resistance, storage stability and residual film yield can be improved.

[0079] The weight-average molecular weight of the above-mentioned alkali-soluble resin is not particularly limited, but may be from 3,000 to 100,000, preferably from 3,000 to 50,000, and more preferably from 5,000 to 50,000.

[0080] The acid value of the above-mentioned alkali-soluble resin is 50 to 200 mg KOH / g based on the solid content. Within the above range, the dispersion stability of the pigment can be improved.

[0081] The alkali-soluble resin described above can be a copolymer of other monomers that can copolymerize with the copolymer represented by the above chemical formula 1.

[0082] Specific examples of monomers capable of copolymerizing with the aforementioned alkali-soluble resins according to Formula 1 include: styrene, vinyltoluene, α-methylstyrene, p-chlorostyrene, o-methoxystyrene, m-methoxystyrene, p-methoxystyrene, o-vinylbenzylmethyl ether, m-vinylbenzylmethyl ether, p-vinylbenzylmethyl ether, o-vinylbenzyl glycidyl ether, m-vinylbenzyl glycidyl ether, p-vinylbenzyl glycidyl ether, and other aromatic vinyl compounds; methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, etc. Alkyl methacrylates such as n-butyl methacrylate, isobutyl methacrylate, sec-butyl methacrylate, and tert-butyl methacrylate; alicyclic methacrylates such as cyclopentyl methacrylate, cyclohexyl methacrylate, 2-methylcyclohexyl methacrylate, tricyclo[5.2.1.0(2,6)]decane-8-yl methacrylate, 2-dicyclopentoxyethyl methacrylate, and isobornyl methacrylate; aryl methacrylates such as phenyl methacrylate and benzyl methacrylate. Aryl acrylates; 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, etc.; hydroxyalkyl (meth)acrylates; N-cyclohexylmaleimide, N-benzylmaleimide, N-phenylmaleimide, N-o-hydroxyphenylmaleimide, N-m-hydroxyphenylmaleimide, N-p-hydroxyphenylmaleimide, N-o-methylphenylmaleimide, N-m-methylphenylmaleimide, N-p-methylphenylmaleimide, N-o-methoxyphenylmaleimide, N-m-methoxyphenylmaleimide, N-p-methoxyphenylmaleimide N-substituted maleimide compounds such as amines; unsaturated amide compounds such as (meth)acrylamide and N,N-dimethyl(meth)acrylamide; unsaturated oxetane compounds such as 3-(methacryloyloxymethyl)oxetane, 3-(methacryloyloxymethyl)-3-ethyloxetane, 3-(methacryloyloxymethyl)-2-trifluoromethyloxetane, 3-(methacryloyloxymethyl)-2-phenyloxetane, 2-(methacryloyloxymethyl)oxetane, and 2-(methacryloyloxymethyl)-4-trifluoromethyloxetane.

[0083] The compounds listed above can be used individually or in combination of two or more.

[0084] The alkali-soluble resin of the present invention can be further mixed with various other known alkali-soluble resins commonly used in the art as needed.

[0085] The content of the alkali-soluble resin relative to the total weight of the solid components in the photosensitive resin composition can be from 20% to 70% by weight, preferably from 30% to 60% by weight. When the content of the alkali-soluble resin is within the above range, the pigment particles are uniformly dispersed, which can prevent the aggregation between pigment particles, thereby improving solvent resistance and storage stability.

[0086] Photopolymers

[0087] The aforementioned photopolymerizable compounds are compounds that can be polymerized by light and heat. As long as they can be polymerized by light and heat, there are no particular restrictions on the use of polymerizable compounds known in this technical field. Specifically, monofunctional monomers, difunctional monomers, and other polyfunctional monomers can be used.

[0088] There are no particular restrictions on the types of monofunctional, difunctional, and polyfunctional monomers mentioned above. For example, as polyfunctional monomers, trimethylolpropane tri(meth)acrylate, ethoxylated trimethylolpropane tri(meth)acrylate, propoxylated trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, ethoxylated dipentaerythritol hexa(meth)acrylate, propoxylated dipentaerythritol hexa(meth)acrylate, dipentaerythritol hexa(meth)acrylate, etc.

[0089] The content of the photopolymerizable compound can be from 5% to 50% by weight, preferably from 10% to 45% by weight, relative to the total weight of the solid components in the photosensitive resin composition. When the content of the photopolymerizable compound is within the above-mentioned range, it is preferable from the perspective of the strength or smoothness of the pixel portion.

[0090] Photopolymerization initiator

[0091] As the aforementioned photopolymerization initiator, photopolymerization initiators known in this art can be used without particular restriction. For example, acetophenone-based, benzophenone-based, triazine-based, thioxanone-based, oxime-based, benzoin-based, and biimidazole-based compounds can be used. As commercially available products, Ciba Specialty Chemicals' "OXE-01", "OXE-02", and "OXE-03" or BASF's IRGACURE OXE-03 can be used.

[0092] The above-mentioned photopolymerization initiators can be used alone or in combination of two or more.

[0093] The content of the photopolymerization initiator relative to the total weight of the solid components in the photosensitive resin composition can be from 0.01% to 15% by weight, preferably from 0.1% to 10% by weight. When the content of the photopolymerization initiator is within the above-mentioned range, the photopolymerization reaction rate is appropriate, preventing an increase in the total process time and preventing the photoreaction from causing a decrease in the physical properties of the final cured film, which is therefore preferred.

[0094] The photosensitive resin composition of the present invention may further include a photopolymerization initiation aid in the above-mentioned photopolymerization initiator. When the above-mentioned photopolymerization initiation aid and photopolymerization initiator are used together, the photosensitive resin composition becomes more sensitive, improving productivity, and is therefore preferred.

[0095] The aforementioned photopolymerization initiator is a compound used to promote the polymerization of photopolymerizable compounds initiated by the aforementioned photopolymerization initiator, and preferably uses one or more compounds selected from the group consisting of amines and carboxylic acid compounds.

[0096] Relative to 1 mole of the aforementioned photopolymerization initiator, the content of the aforementioned photopolymerization initiation aid is generally from 0.001 moles to 10 moles, preferably from 0.01 moles to 5 moles. When the content of the aforementioned photopolymerization initiation aid is within the above range, the effect of improving photopolymerization efficiency and thus increasing productivity can be expected.

[0097] solvent

[0098] There are no particular limitations on the use of the solvents described above, as long as they can effectively dissolve the other components contained in the photosensitive resin composition. Various organic solvents known in the field of photosensitive resin compositions can be used.

[0099] In one or more embodiments, the solvent may be a monoalkyl ether of ethylene glycol, such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, or ethylene glycol monobutyl ether; a dialkyl ether of diethylene glycol, such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, or diethylene glycol dibutyl ether; an alkyl ether acetate of ethylene glycol, such as methyl cellosolve acetate or ethyl cellosolve acetate; or a methyl ether acetate of propylene glycol, such as propylene glycol monoethyl ether. Alkyl diols and alkyl ether acetates such as ether acetate, propylene glycol monopropyl ether acetate, methoxybutyl acetate, and methoxypentyl acetate; aromatic hydrocarbons such as benzene, toluene, xylene, and mesitylene; ketones such as methyl ethyl ketone, acetone, methyl pentyl ketone, methyl isobutyl ketone, and cyclohexanone; alcohols such as ethanol, propanol, butanol, hexanol, cyclohexanol, ethylene glycol, and glycerol; esters such as ethyl 3-ethoxypropionate and methyl 3-methoxypropionate; and cyclic esters such as γ-butyrolactone.

[0100] From the perspective of coating properties and drying properties, the above-mentioned solvents can preferably be organic solvents with a boiling point of 100°C to 200°C, and more preferably propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, cyclohexanone, ethyl lactate, butyl lactate, ethyl 3-ethoxypropionate, methyl 3-methoxypropionate, etc.

[0101] The solvents described above can be used alone or in combination of two or more. The content of the solvents relative to the total weight of the photosensitive resin composition can be from 60% to 90% by weight, preferably from 70% to 85% by weight. When the solvent content is within the above range, it provides improved coatability when coating using coating equipment such as roller coaters, spin coaters, slot coaters, slot die coaters (die coaters), and inkjet printers, and is therefore preferred.

[0102] additive

[0103] The photosensitive resin composition of the present invention may also contain additives if necessary. The types of additives can be determined according to the user's needs. The present invention does not impose any particular restrictions on the types of additives.

[0104] In one or more embodiments, at least one selected from dispersants, wetting agents, silane coupling agents and anti-coagulants may be used.

[0105] Commercially available surfactants can be used as the dispersant. Examples of such surfactants include silicone surfactants, fluorinated surfactants, silicone surfactants containing fluorine atoms, and mixtures thereof.

[0106] Examples of silicone-based surfactants include surfactants with siloxane bonds. Commercially available products include "Toray Silicon DC3PA", "Toray Silicon SH7PA", "Toray Silicon DC11PA", "Toray Silicon SH21PA", "Toray Silicon SH28PA", "Toray Silicon 29SHPA", "Toray Silicon SH30PA", polyether-modified silicone oil "SH8400" (manufactured by Toray Silicone Co., Ltd.), "KP321", "KP322", "KP323", "KP324", "KP326", "KP340" and "KP341" (manufactured by Shin-Etsu Silicone), "TSF400", "TSF401", "TSF410", "TSF4300", "TSF4440", "TSF4445", "TSF-4446", "TSF4452" and "TSF4460" (manufactured by GE Toshiba Silicone Co., Ltd.), etc.

[0107] Examples of fluorinated surfactants include surfactants with fluorocarbon chains. Commercially available products include "Prolinate FC430", "Prolinate FC431" (manufactured by Sumitomo 3M Co., Ltd.), "Megapack F142D", "Megapack F171", "Megapack F172", "Megapack F173", "Megapack F177", "Megapack F183" and "Megapack R30" (manufactured by Dai Nippon Ink Chemical Co., Ltd.), "Ftop EF301", "Ftop EF303", "Ftop EF351", "Ftop EF352" (manufactured by Shin-Akita Kasei Co., Ltd.), "Suffron S381", "Suffron S382", "Suffron SC101", "Suffron SC105" (manufactured by Asahi Glass Co., Ltd.), and "E5844" (manufactured by Daikin Fine Chemicals Co., Ltd.). (Manufactured by the Institute of Chemicals), "BM-1000", "BM-1100" (trade name: manufactured by BMChemie Company), etc.

[0108] The aforementioned organosilicon surfactants containing fluorine atoms include surfactants with siloxane bonds and fluorocarbon chains. Commercially available products include "Megapack (trade name) R08", "Megapack BL20", "Megapack F475", "Megapack F477" and "Megapack F443" (manufactured by Dai Nippon Ink Chemical Industry Co., Ltd.).

[0109] Glycerin, diethylene glycol, and ethylene glycol can be used as the above-mentioned wetting agents, and they can be used alone or in combination of two or more.

[0110] As the aforementioned silane coupling agents, for example, aminopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, and γ-methacryloyloxypropyltrimethoxysilane can be used. As commercially available products, “SH6062” and “SZ6030” (manufactured by Toray-Dow Corning Silicon Co., Ltd.), “KBE903”, “KBM803”, and “KBM-9007” (manufactured by Shin-Etsu Silicone Co., Ltd.) can be used.

[0111] Sodium polyacrylate can be cited as an example of the aforementioned anti-condensing agent.

[0112] The photosensitive resin composition of the present invention can be manufactured by conventional methods known in the art, and there are no particular limitations in the present invention.

[0113] In one embodiment of the invention, the colorant is premixed with a solvent and dispersed using a beadmill or similar device. At this time, a pigment dispersant may be used as needed, and sometimes part or all of the alkali-soluble resin may be mixed in. To the resulting dispersion, the remaining alkali-soluble resin, photopolymerizable compound, photopolymerization initiator, and additives as needed are added, and further solvent is added as needed to reach a predetermined concentration, thereby obtaining the target photosensitive resin composition.

[0114] <Manufacturing Method of Spacer Wall for Image Display Device>

[0115] Furthermore, the present invention provides a method for manufacturing a spacer for an image display device.

[0116] The method for manufacturing a spacer for an image display device according to the present invention includes the step of forming a spacer on a substrate. When the linewidth of the spacer at 95% of its thickness from the bottom end relative to the overall thickness of the spacer is A, the maximum linewidth at 50% to 90% of its thickness from the bottom end is B, and the linewidth at 10% of its thickness from the bottom end is C, the spacer satisfies 0.8 ≤ A / B < 1.0 and 0.85 ≤ C / B < 1.0.

[0117] The meanings of A to C mentioned above, as well as the technical advantages when satisfying the ranges of A / B and C / B, are the same as those described above for the partition wall of the image display device.

[0118] The steps for forming spacers on a substrate may include: a coating formation step of applying a photosensitive resin composition to a substrate and then heating and drying it; an exposure step of irradiating the formed coating with ultraviolet light; a pattern formation step of contacting the exposed coating with a developer to develop it; and a post-curing step of curing the formed pattern.

[0119] First, the photosensitive resin composition of the present invention is coated onto a substrate and then heated and dried to remove volatile components such as solvents, thereby forming a smooth coating film.

[0120] As a coating method, coating can be performed using methods such as spin coating, flexible coating, roller coating, slit spin coating, or slit coating. After coating, heat drying (pre-baking) is performed to evaporate volatile components such as solvents. The thickness of the coating film after heat drying is typically about 7 μm to 15 μm. There are no particular limitations on the above heat drying, but it is preferable to perform it at 90°C to 100°C for 120 to 180 seconds. When the above heat drying temperature and time range are met, it has the advantage of easily manufacturing spacers for image display devices that meet A / B and C / B ranges.

[0121] The resulting coating is then irradiated with ultraviolet light through a mask used to form the target pattern. When irradiated with ultraviolet light, free radicals are formed at the irradiated area by a photopolymerization initiator, reacting with a polymerizable compound to achieve photocuring. In this case, it is preferable to use a device such as a mask aligner or a stepper to ensure that parallel light is uniformly irradiated across the entire exposure area and to achieve precise alignment between the mask and the substrate.

[0122] The aforementioned mask pattern may include a first pattern for integrally forming pixel portions and spacers, and a second pattern for forming only spacers. For example, the first pattern may be a pattern for integrally forming the pixel portion region to be integrally formed with the spacers and the region to be formed with adjacent spacers.

[0123] As the aforementioned ultraviolet light, gamma rays (wavelength 436 nm), h-rays, i-rays (wavelength 365 nm), etc., can be used. The amount of ultraviolet light irradiation can be appropriately selected as needed, and there is no limitation on this in the present invention.

[0124] Spacer walls are formed by dissolving unexposed areas in the photocured coating by contacting it with a developer for development. Here, the developer is not particularly limited to any developer commonly used in this art, but a developer with a conductivity of 1,100 s / m to 1,300 s / m can be used. Furthermore, the spacer wall pattern forming step is not particularly limited, but it is preferable to perform the process by spraying the developer at a pressure of 1.0 MPa to 1.3 MPa. When the conductivity and pressure range of the developer are satisfied, it has the advantage of easily manufacturing spacer walls for image display devices that meet the A / B and C / B ranges.

[0125] The resulting pattern shape can be hardened through a post-curing process. Here, the post-curing step is typically performed at 150°C to 250°C for 5 to 35 minutes, preferably at 200°C to 220°C for 30 to 35 minutes. When the post-curing temperature and time range are met, it has the advantage of easily manufacturing spacers for image display devices that meet A / B and C / B ranges.

[0126] <Image display device>

[0127] Furthermore, the present invention provides an image display device comprising the spacers described above for an image display device. In short, the image display device of the present invention may comprise spacers formed from the photosensitive resin composition for forming the spacers described above.

[0128] Specifically, in addition to the partition for image display devices of the present invention, the above-mentioned image display device may also include other components commonly included in image display devices, such as optical films, which are not limited in the present invention.

[0129] The aforementioned image display devices may specifically include liquid crystal displays (LCDs), organic EL displays (including organic EL displays, OLEDs and QLEDs), inorganic light-emitting diode (LED) displays, liquid crystal projectors, display devices for gaming, display devices for portable terminals such as mobile phones, display devices for digital cameras, display devices for car navigation, etc., but the present invention is not limited thereto.

[0130] When the above-described image display device includes the partition wall for the image display device of the present invention, it has the advantage of providing a high-quality image display device with excellent brightness and viewing angle and no defects in the pixel portion.

[0131] Implementation

[0132] The present invention will be described in more detail below based on embodiments, but the embodiments disclosed below are merely illustrative, and the scope of the invention is not limited to these embodiments. The scope of the invention is shown in the claims and includes all modifications in the meaning and scope equivalent to those set forth in the claims. Furthermore, unless otherwise stated, the terms “%” and “parts” used to indicate content in the following embodiments and comparative examples are based on mass.

[0133] <Example>

[0134] Manufacturing example: Manufacturing a photosensitive resin composition

[0135] The photosensitive resin composition is prepared according to the ingredients and contents listed in Table 1 below.

[0136] [Table 1]

[0137]

[0138] Example 1: Manufacturing a partition wall

[0139] A 5cm × 5cm glass substrate (Corning Corporation) was sequentially cleaned with a neutral detergent, water, and alcohol, and then allowed to dry. To form spacers, the photosensitive resin composition of Manufacturing Example 1 was spin-coated onto the glass substrate to a final film thickness of 10.0 μm, and pre-baked in a cleaning oven at 90°C for 150 seconds. After cooling the pre-baked substrate to room temperature, the spacing between it and the quartz glass photomask was set to 50 μm, and an exposure machine (TME-150RSK, Topcon Co., Ltd.) was used at 100 mJ / cm². 2 The light exposure is applied. The irradiation uses reflected light from an ultra-high pressure mercury lamp. In this case, a photomask with a pattern formed on the same plane is used. The mask used to form the spacers has a rectangular blocking portion (unexposed portion) inside, and a light-transmitting portion (pattern) with intersecting straight lines for forming the spacers. After light irradiation, a press-type developer (conductivity = 1100 S / m) is sprayed at a pressure of 1.0 MPa for the development process. The aqueous developer contains 0.12 wt% nonionic surfactant and 0.04 wt% potassium hydroxide. After rinsing with water, the spacers are baked in a cleaning oven at 210°C for 30 minutes to form the spacers.

[0140] Examples 2 to 10 and Comparative Examples 1 to 6: Manufacturing of spacer walls

[0141] The photosensitive resin composition and process conditions used in Example 1 were modified according to the composition and conditions described in Table 2 below, but otherwise the process was carried out in the same manner as in Example 1 to form a spacer wall.

[0142] [Table 2]

[0143]

[0144] Experimental Example

[0145] (1) Determine the shape of the septum wall

[0146] For the spacers manufactured according to Examples 1 to 10 and Comparative Examples 1 to 6 above, the shape of the spacers was photographed using a FE-SEM device (Regulus 8240, Hitachi), and the thickness (D) and linewidth (A to C) of each spacer at a specific thickness were measured. The results are shown in Table 3 below. Figures 2 to 4 .

[0147] The line width A represents the line width at 95% of the thickness from the bottom of the partition wall, the line width B represents the maximum line width at 50% to 90% of the thickness from the bottom of the partition wall, and the line width C represents the line width at 10% of the thickness from the bottom of the partition wall.

[0148] [Table 3]

[0149]

[0150] (2) Evaluation of brightness characteristics

[0151] For the spacers in Examples 1 to 10 and Comparative Examples 1 to 6 above, 20 drops (10 picoliters per drop) of red quantum dot ink* were injected into the pixel area defined by the spacer using an inkjet process to form a pixel. A blue light source was injected into the pixel at a power consumption of 30 mW to emit red light, and the luminance value was then measured using a CAS140CT (Instrument System Corporation). The ratio of the red light luminance value to the blue light luminance value (red light luminance value / blue light luminance value, %) was calculated and is shown in Table 4 below.

[0152] *Red Quantum Dot Ink: A red quantum dot ink composition containing red quantum dots, scattering material (TiO2), photopolymerizable compound (DPHA), and photopolymerization initiator (IRGACURE OXE-03).

[0153] (3) Evaluation perspective characteristics

[0154] Viewing angle is a very important evaluation factor in the characteristics of image display devices.

[0155] In this invention, for the pixels formed in “(2) Evaluation of brightness characteristics”, the brightness of the side surface is measured by gradually changing the angle with the front (0°) as the reference. The angle at which the brightness is measured up to 50% is confirmed with the brightness of the blue light source as the reference, thereby evaluating the viewing angle characteristics. The results are shown in Table 4 below.

[0156] The wider the viewing angle, the higher the brightness remains, even when viewed from the side surface, thus resulting in a high-quality image display device.

[0157] (4) Evaluate the characteristics of the inkjet process

[0158] For the spacers in Examples 1 to 10 and Comparative Examples 1 to 6 above, one drop (10 picoliters) of white ink* was dropped into the pixel area defined by the spacers using Omnijet 300 (UniJet Corporation), and the results were evaluated according to the following evaluation criteria and Figure 5 The standard evaluation criteria were used to assess the spreadability and wettability of ink within the pixel area. The results are shown in Table 4 below.

[0159] *White ink: A white ink composition containing a scattering substance (TiO2), a photopolymerizable compound (DPHA), and a photopolymerization initiator (IRGACURE OXE-03).

[0160] Evaluation Criteria for Inkjet Process Characteristics

[0161] ◎: When one drop is added, the ink wets the spacer wall.

[0162] ○○: When 1 drop is added, the size of the ink is greater than 30μm.

[0163] ○: When 1 drop is added, the size of the ink is greater than 20μm and less than 30μm.

[0164] Δ: When 1 drop is added, the size of the ink is greater than 10μm and less than 20μm.

[0165] ×: When 1 drop is added, the size of the ink is less than 10μm.

[0166] [Table 4]

[0167]

[0168] Referring to the results in Table 4 above, it can be confirmed that pixels formed using the spacers of Embodiments 1 to 10 of the present invention, which satisfy 0.8≤A / B<1.0 and 0.85≤C / B<1.0, exhibit excellent performance in terms of brightness, viewing angle, and inkjet process characteristics.

[0169] On the other hand, it can be confirmed that the brightness, viewing angle and inkjet process characteristics of pixels formed using spacers that do not satisfy 0.8≤A / B<1.0 and / or 0.85≤C / B<1.0 are reduced, especially the viewing angle and inkjet process characteristics are significantly reduced.

[0170] Industrial availability

[0171] The image display device of the present invention, which includes a spacer for an image display device, has excellent brightness and maintains high brightness when viewed from the side surface, thereby exhibiting excellent viewing angle characteristics.

Claims

1. A spacer for an image display device, said spacer being formed of a photosensitive resin composition comprising a colorant, an alkali-soluble resin, a photopolymerizable compound, a photopolymerization initiator, and a solvent. The colorant contains white pigment. When the line width of the partition wall is A at 95% of its thickness from the bottom end relative to the overall thickness of the partition wall, the maximum line width is B at 50% to 90% of its thickness from the bottom end, and the line width is C at 10% of its thickness from the bottom end, the partition wall satisfies 0.8 ≤ A / B < 0.92 and 0.85 ≤ C / B < 1.

0.

2. The partition wall for the image display device according to claim 1, wherein B is the maximum linewidth of the partition wall at a thickness of 60% to 80% from the lowest end.

3. The spacer for the image display device according to claim 1, wherein the spacer is formed in a manner that defines a plurality of pixel regions.

4. The spacer wall for the image display device according to claim 1, wherein the thickness of the spacer wall is 8 μm to 12 μm.

5. The spacer for the image display device according to claim 1, wherein, relative to the total weight of the solid components of the photosensitive resin composition, the photosensitive resin composition comprises: 0.5% to 30% by weight of a colorant; 20% to 70% by weight of an alkali-soluble resin; 5% to 50% by weight of a photopolymerizable compound; and 0.01% to 10% by weight of a photopolymerization initiator. Furthermore, the composition contains 60% to 90% by weight of solvent relative to the total weight of the photosensitive resin composition.

6. A method for manufacturing a spacer wall for an image display device, comprising the step of forming the spacer wall on a substrate. The spacer wall is formed of a photosensitive resin composition comprising a colorant, an alkali-soluble resin, a photopolymerizable compound, a photopolymerization initiator, and a solvent. The colorant contains white pigment. When the line width of the partition wall is A at 95% of its thickness from the bottom end relative to the overall thickness of the partition wall, the maximum line width is B at 50% to 90% of its thickness from the bottom end, and the line width is C at 10% of its thickness from the bottom end, the partition wall satisfies 0.8 ≤ A / B < 0.92 and 0.85 ≤ C / B < 1.

0.

7. The method for manufacturing a spacer wall for an image display device according to claim 6, wherein the step of forming the spacer wall comprises: The step of coating a photosensitive resin composition onto a substrate and then heating and drying it to form a coating film; The exposure step of irradiating the formed coating film with ultraviolet light; A pattern formation step in which the developing solution is brought into contact with the exposed coating to perform development; as well as A post-curing step is performed to solidify the formed pattern.

8. The method for manufacturing a spacer for an image display device according to claim 7, wherein the heating and drying in the coating formation step is performed at 90°C to 100°C for 120 to 180 seconds.

9. The method for manufacturing a spacer for an image display device according to claim 7, wherein in the pattern forming step, a developing solution having a conductivity of 1100 s / m to 1300 s / m is sprayed at a pressure of 1.0 MPa to 1.3 MPa.

10. The method for manufacturing a spacer for an image display device according to claim 7, wherein the post-curing step is performed at 200°C to 220°C for 30 to 35 minutes.

11. An image display device comprising a spacer for an image display device according to any one of claims 1-5.

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