Liquid-crystal display

Abstract

The present invention discloses a liquid crystal display in which the display-side polarizer has a first polyester protective film disposed on light exiting side and the backlight-side polarizer has a second polyester protective film disposed on light incident side, which can reduce stress patterns caused by uneven stress on both sides of the liquid crystal panel due to the residual stress of the polyester protective films, and when the birefringence difference of the first polyester protective film is between

Description

Technical Field

[0001] This invention relates to a liquid crystal display, which, when the display-side polarizing plate or the backlight-side polarizing plate has a polyester protective film, can not only reduce stress spots caused by uneven stress on both sides of the liquid crystal panel due to residual stress of the polyester protective film, but also simultaneously avoid interference rainbow patterns caused by different light sources such as backlight and ambient light at different viewing angles. Prior Technology

[0002] Liquid crystal displays (LCDs) consist of a liquid crystal panel, a display-side polarizer, and a backlight-side polarizer, and require a backlight source to provide image illumination. To further enhance the water vapor penetration resistance, temperature resistance, and mechanical strength of the display-side or backlight-side polarizers, current research suggests using crystalline polyester films instead of conventional triacetate cellulose (TAC) or polyacrylate (PMMA) films, which lack in-plane phase gradation, as the outer protective film for these polarizers. However, polyester films, such as the common polyethylene terephthalate (PET) film, contain highly crystalline benzene ring structures, resulting in a high inherent birefringence and shrinkage stress during stretching. Therefore, using a single polyester film as the protective film for one side of the display-side or backlight-side polarizer cannot comprehensively improve water vapor penetration resistance. Furthermore, with increasing LCD panel size, the strain caused by uneven residual stress increases with temperature changes, easily leading to stress spots. Furthermore, if both the display side polarizer and the backlight side polarizer have conventional polyester protective films, it will be even more difficult to simultaneously suppress the interference rainbow patterns formed between the film layers by different light sources, such as ambient light and backlight.

[0003] When a polyester film is used as the protective film for a conventional display side polarizer, the in-plane phase difference (R0) of the polyester film needs to be extremely high, for example, greater than or equal to 8000 nm. Therefore, it often needs to have a high birefringence difference (Δn) of 0.1 or higher and a certain thickness. The refractive index of the base coating, hard coating and polyester film are matched to overcome the problem of uneven rainbow and interference fringes caused by obliquely emitted backlight and excessively strong external obliquely reflected light on both sides of the polyester film when the screen is bright. Alternatively, the direction of reflected light can be changed by high scattering surface treatment, such as a surface functional layer with a haze of greater than or equal to 80%, to reduce the interference of oblique light on both sides of the polyester film. However, with the increasing demand for high brightness and high contrast images, the polarization and coherence of the backlight are also constantly improving. Therefore, optical films such as prism condensers and reflective polarizing brightness enhancement films are often used in backlights to improve collimation and the intensity of light at the positive viewing angle, thereby increasing the intensity and utilization of light entering the liquid crystal display. Therefore, even if the display-side polarizer uses the aforementioned high in-plane phase difference polyester film, or if the backlight-side polarizer's protective film also uses the same polyester film to improve water vapor penetration resistance and stress balance, it is still difficult to reduce the interference rainbow effect caused by the image light with high collimation, polarization, and coherence generated by the high-intensity backlight, which is clearly visible at a normal viewing angle. This still significantly affects the display quality of the monitor. The limitation to using only surface functional layers with excessively high haze also reduces the applicability of liquid crystal displays.

[0004] Therefore, a liquid crystal display (LCD) is needed that has polyester protective films on both the display-side polarizer and the backlight-side polarizer, and can maintain stress balance on both sides of the LCD panel and have optimal resistance to water vapor penetration even when it has a surface functional layer that has not undergone specific surface treatment. Furthermore, by combining the birefringence difference between the polyester protective film on the light-emitting side of the display-side polarizer and the polyester protective film on the light-incident side of the backlight-side polarizer, the interference of ambient light and its reflected light at the side viewing angle can be reduced, as can the interference rainbow pattern in the positive viewing angle direction caused by the high collimation, polarization, and coherence of the backlight source. In particular, it can provide good display effect for image light formed by polarized backlight sources. Summary of the Invention

[0005] One embodiment of the present invention provides a liquid crystal display, comprising: a liquid crystal panel having a display side and a backlight side opposite to each other; a backlight source disposed on the backlight side of the liquid crystal panel; and a display-side polarizing plate disposed on the display side of the liquid crystal panel, comprising a first polarizing layer, a first polyester protective film, and a surface functional layer, wherein the first polarizing layer has a first light-emitting side and a first light-receiving side opposite to each other, and the first polarizing layer is disposed on the display side of the liquid crystal panel via the first light-receiving side; the first polyester protective film is disposed on the first light-emitting side of the first polarizing layer; the surface functional layer is disposed on the first polyester protective film; and the birefringence difference of the first polyester protective film is between 0.003. The second polarizing plate is disposed on the backlight side of the liquid crystal panel and located between the liquid crystal panel and the backlight source. It includes a second polarizing layer and a second polyester protective film. The second polarizing layer has a second light-emitting side and a second light-incident side facing each other. The second light-incident side faces the backlight source. The second polarizing layer is disposed on the backlight side of the liquid crystal panel through the second light-emitting side. The second polyester protective film is disposed on the second light-incident side of the second polarizing layer. The birefringence difference of the second polyester protective film is between 0.030 and 0.080.

[0006] In a liquid crystal display according to an embodiment of the present invention, the in-plane phase difference of the first polyester protective film is ≤1500 nm, and the in-plane phase difference of the second polyester protective film is ≥2200 nm.

[0007] In another embodiment of the liquid crystal display of the present invention, the first polyester protective film has a first refractive index matching layer and a second refractive index matching layer on its two opposite sides, and the second polyester protective film has a third refractive index matching layer and a fourth refractive index matching layer on its two opposite sides. The first refractive index n1 of the first refractive index matching layer and the second refractive index n2 of the second refractive index matching layer are both less than the average refractive index np1 of the first polyester protective film, and the third refractive index n3 of the third refractive index matching layer and the fourth refractive index n4 of the fourth refractive index matching layer are both less than the average refractive index np2 of the second polyester protective film.

[0008] In another embodiment of the liquid crystal display of the present invention, the average refractive indices np1 and np2 of the first polyester protective film and the second polyester protective film are both between 1.60 and 1.70, and the first refractive index n1, the second refractive index n2, the third refractive index n3 and the fourth refractive index n4 are all between 1.51 and 1.65.

[0009] In another embodiment of the liquid crystal display of the present invention, the thicknesses of the first refractive index matching layer, the second refractive index matching layer, the third refractive index matching layer and the fourth refractive index matching layer are all between 0.1 μm and 0.3 μm.

[0010] In another embodiment of the liquid crystal display of the present invention, the thickness of the first polyester protective film is between 20 μm and 80 μm, and the thickness of the second polyester protective film is between 60 μm and 110 μm.

[0011] In another embodiment of the liquid crystal display of the present invention, the first polyester protective film and the second polyester protective film are uniaxially or biaxially extended polyester films.

[0012] In another embodiment of the liquid crystal display of the present invention, the first polarizing layer and the second polarizing layer are an iodine-based or dye-based extended polarizing layer or an iodine-based or dye-based coated polarizing layer.

[0013] In another embodiment of the liquid crystal display of the present invention, the surface functional layer is selected from one or a combination of the group consisting of a hard coating layer, an anti-glare layer, an anti-fouling layer, an antistatic layer, and an anti-reflective layer.

[0014] In another embodiment of the liquid crystal display of the present invention, the total haze of the surface functional layer is between 1% and 60%.

[0015] In another embodiment of the liquid crystal display of the present invention, the thickness of the surface functional layer is between 2 μm and 10 μm.

[0016] In another embodiment of the liquid crystal display of the present invention, the first polyester protective film and the second polyester protective film are selected from polyethylene terephthalate film, polyethylene terephthalate film or polyethylene terephthalate film.

[0017] In another embodiment of the liquid crystal display of the present invention, the backlight is a polarized backlight.

[0018] The foregoing summary is intended to provide a simplified overview of this disclosure, enabling the reader to gain a basic understanding. This summary is not a complete overview of the disclosure and is not intended to identify key elements of the embodiments or define the scope of the invention. Upon reviewing the following embodiments, those skilled in the art will readily understand the basic spirit of the invention and the technical means and implementation methods employed. Simple Explanation of the Diagram

[0019] Figure 1 illustrates a schematic diagram of one embodiment of the liquid crystal display of the present invention.

[0020] Figure 2 illustrates a schematic diagram of yet another embodiment of the liquid crystal display of the present invention. Implementation

[0021] To make the description of the present invention more detailed and complete, illustrative descriptions of embodiments and specific examples of the present invention are provided below; however, these are not the only forms of implementing or using the specific examples of the present invention. The various embodiments disclosed below can be combined or substituted with each other where advantageous, and other embodiments can be added to one embodiment without further description or explanation.

[0022] The advantages, features, and technical methods of this invention will be more readily understood by referring to exemplary embodiments. This invention may be implemented in different forms and should not be construed as limited to the embodiments set forth herein. Rather, the embodiments provided will make this disclosure more thorough, complete, and fully convey the scope of the invention to those skilled in the art. This invention will be defined only by the appended claims.

[0023] Unless otherwise defined, all terms (including technical and scientific terms) and proper nouns used below shall, in substance, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains, and those terms as defined in commonly used dictionaries shall be understood to have the same meaning as the content of the relevant field, and shall not be interpreted in an overly idealized or overly formal sense unless explicitly defined below.

[0024] In this article, the term "display side" refers to the side of the LCD panel facing the viewer in an LCD monitor, while "backlight side" refers to the side of the LCD panel adjacent to the backlight source.

[0025] The liquid crystal display disclosed in this invention includes a polyester protective film on both the first light-emitting side of the display-side polarizer and the second light-incident side of the backlight-side polarizer to provide the liquid crystal display with better resistance to water vapor penetration and mechanical strength. The simultaneous presence of a polyester protective film on both the first light-emitting side of the display-side polarizer and the second light-incident side of the backlight-side polarizer in the liquid crystal display of this invention maintains the stress balance on both sides of the liquid crystal panel, provides optimal resistance to water vapor penetration, achieves better light transmittance, and reduces interface reflection and backlight intensity loss. Furthermore, the liquid crystal display of this invention avoids interference patterns formed by oblique reflection of ambient light, and also avoids interference rainbow patterns that can be clearly observed and interfere with image quality, especially the uneven color spots or patterns caused by backlights with high coherence and collimation, after polarized positive viewing angle image light passes through the interfaces on both sides of the polyester protective film.

[0026] As shown in Figure 1, one embodiment of the present invention provides a liquid crystal display 100, which includes a liquid crystal panel 110 having a display side 110A and a backlight side 110B opposite to each other; a backlight 140 disposed on the backlight side 110B of the liquid crystal panel 110; and a display-side polarizing plate 120 disposed on the display side 110A of the liquid crystal panel 110, which includes a first polarizing layer 121, a first polyester protective film 122 and a surface functional layer 123. The first polarizing layer 121 has a first light-emitting side 121A and a first light-incident side 121B, and the first polarizing layer 121 is disposed on the display side 110A of the liquid crystal panel 110 via the first light-incident side 121B. The first polyester protective film 122 is disposed on the first light-emitting side 121A of the first polarizing layer 121, and the surface functional layer 123 is disposed on the first polyester protective film 122. The birefringence difference of the first polyester protective film 122 is between 0.003 and 0.015. A backlight-side polarizing plate 130 is disposed on the backlight side 110B of the liquid crystal panel 110, and includes a second polarizing layer 131 and a second polyester protective film 132. The second polarizing layer 131 has a second light-emitting side 131A and a second light-incident side 131B facing each other. The second light-incident side 131B faces the backlight 140. The second polarizing layer 131 is disposed on the backlight side 110B of the liquid crystal panel 110 via the second light-emitting side 131A. The second polyester protective film 132 is disposed on the second light-incident side 131B of the second polarizing layer 131. The birefringence difference of the second polyester protective film 132 is between 0.030 and 0.080.

[0027] Since the birefringence difference of polyester polymers increases with the increase of the number and orientation of high-refractive-index molecular chain segments, when the birefringence difference between the first polyester protective film 122 and the second polyester protective film 132 is less than 0.1, it can be obtained by a lower elongation process, making the shrinkage of the polyester protective film itself more consistent in the elongation direction (MD) and width direction (TD), and the shrinkage affected by the increase of temperature is also lower. Therefore, when the first polyester protective film 122 and the second polyester protective film 132 with low birefringence difference are used as protective films for the liquid crystal display 100, the stress on both sides of the liquid crystal display 100 can be better balanced, avoiding the appearance of stress patterns or uneven color spots in the polarized image light source generated by the light from the backlight 140 penetrating the second polarizing layer 131 and the first polarizing layer 121 due to uneven stress.

[0028] Furthermore, when the birefringence difference of the first polyester protective film 122 is lower than that of the second polyester protective film 132 (between 0.003 and 0.015), the ambient reflected light intensity at different viewing angles of the liquid crystal display 100 is more consistent, preventing the formation of interference patterns due to strong homogeneous reflected light in a specific direction. The slow axis direction of the first polyester protective film 122 does not need to be limited to a single direction, or consist of continuous or discontinuous multiple axial regions. Therefore, when forming the display-side polarizing plate 120 with the first polarizing layer 121, the slow axis of the first polyester protective film 122 and the absorption axis of the first polarizing layer 121 have better axial compatibility.

[0029] When the backlight 140 of the liquid crystal display 100 enters the second polyester protective film 132 of the second light-incident side 131B of the closest second polarizing layer 131, due to the fact that high-intensity light of different wavelengths with collimation and polarization penetrates the thin film with a non-zero phase difference in the in-plane, there are corresponding enhanced interference bands. This causes the image light that penetrates the two interfaces of the second polyester protective film 132 and enters the liquid crystal panel 110 to produce stronger and more clearly observable uneven color spots or rainbow patterns. By setting the birefringence difference of the second polyester protective film 132 to between 0.030 and 0.080, and adjusting the in-plane phase difference of the second polyester protective film 132 to ≥2200 nm, the interference fringe area and spacing width when viewed from the front and side can be further reduced. In addition, by adjusting the in-plane phase difference of the first polyester protective film 122 to ≤1500 nm, the light with interference fringe area can be further uniformly faded after passing through the first polyester protective film 122. Therefore, even when displaying a bright white screen, interference rainbow fringe interference caused by the image light passing through the liquid crystal panel 110 at the positive viewing angle can be avoided.

[0030] As shown in Figure 2, in another embodiment of the liquid crystal display 200 of the present invention, the two sides of the first polyester protective film 122 have a first refractive index matching layer 1221 and a second refractive index matching layer 1222, and the two sides of the second polyester protective film 132 have a third refractive index matching layer 1321 and a fourth refractive index matching layer 1322. The first refractive index n1 of the first refractive index matching layer 1221 and the second refractive index n2 of the second refractive index matching layer 1222 are both less than the average refractive index np1 of the first polyester protective film 122. The third refractive index n3 of the third refractive index matching layer 1321 and the fourth refractive index n4 of the fourth refractive index matching layer 1322 are both less than the average refractive index np2 of the second polyester protective film 132. By having the refractive index of the refractive index matching layer lower than the average refractive index of the polyester protective film, a lower interface reflectivity is obtained. This reduces interference caused by interface reflection light without affecting the light intensity of the backlight 140 after it passes through the polyester protective film 132. The first polyester protective film 122 and the second polyester protective film 132 obtained after stretching, for example, the average refractive index of the stretched polyethylene terephthalate (PET) is generally between 1.60 and 1.70, and the first refractive index n1, the second refractive index n2, the third refractive index n3 and the fourth refractive index n4 are all between 1.51 and 1.65.

[0031] In another embodiment of the liquid crystal display of the present invention, the first refractive index matching layer 1221, the second refractive index matching layer 1222, the third refractive index matching layer 1321, and the fourth refractive index matching layer 1322 comprise, but are not limited to, coatings formed of acetalized polyvinyl alcohol, polyurethane, urethane, polyether resin, polyacrylic resin, isocyanate, or combinations thereof, to reduce the refractive index difference between the polyester protective film and the air interface. They can also serve as easily adhesive layers between the first polarizing layer 121 or the second polarizing layer 131 for bonding with other optical films and layers. The refractive index can be selectively adjusted to a desired range by adding metal oxide particles, benzene ring compounds, etc., to the coating. The thickness of the first refractive index matching layer 1221, the second refractive index matching layer 1222, the third refractive index matching layer 1321, and the fourth refractive index matching layer 1322 is all between 0.1 μm and 0.3 μm. A refractive index matching layer within this thickness range can effectively change the refractive index difference between the two sides of the first polyester protective film 122 or the second polyester protective film 132 without significantly increasing the thickness of the polyester protective film, thus not affecting the stress distribution after the polarizing plate is formed.

[0032] In another embodiment of the liquid crystal display of the present invention, the thickness of the first polyester protective film 122 is between 20 μm and 80 μm, and the thickness of the second polyester protective film 132 is between 60 μm and 110 μm, so as to have a light transmittance of at least 85%, preferably more than 88%. Furthermore, an appropriate thickness contributes to its water resistance and mechanical strength, thereby providing good protection.

[0033] In another embodiment of the liquid crystal display of the present invention, the first polyester protective film 122 and the second polyester protective film 132 are uniaxially or biaxially stretched polyester films. In particular, they are uniaxially or biaxially stretched polyester films with low birefringence difference produced by a low elongation ratio process. Because the first polyester protective film 122 and the second polyester protective film 132 of the present invention are polyester films produced by a low elongation ratio process, they have better tensile strength and a more uniform heat shrinkage ratio in both the elongation and width directions. When used in a polarizing plate, whether combined with a high elongation ratio stretched polarizing layer or a coating polarizing layer that does not require elongation to form a display-side polarizing plate or a backlight-side polarizing plate, the stress distribution on both sides of the liquid crystal panel is more uniform, stress spots are less likely to occur, better protection is provided, and it is also beneficial for application in flexible display devices.

[0034] In another embodiment of the liquid crystal display of the present invention, the first polarizing layer 121 and the second polarizing layer 131 are iodine-based or dye-based extended polarizing layers or coated polarizing layers.

[0035] In another embodiment of the liquid crystal display of the present invention, the surface functional layer 123 of the display-side polarizing plate 120 is selected from one or a combination of the group consisting of a hard coating layer, an anti-glare layer, an anti-fouling layer, an antistatic layer, and an anti-reflective layer. The total haze of the surface functional layer 123 is between 1% and 60%. The surface functional layer 123 provides the liquid crystal display 100 with the haze, surface roughness, etc. required for visual taste, anti-glare, or other functional requirements. The thickness of the surface functional layer 123 is between 2 μm and 10 μm. In order to make the display anti-glare, for example, an acrylic adhesive resin mixed with microparticles can be coated onto a polyester protective film such as polyethylene terephthalate film, polyethylene terephthalate film, or polyethylene terephthalate film. By using microparticles of different particle sizes, shapes, or proportions, and by controlling their settling speed, a concave-convex microstructure or a difference in refractive index between particles can be formed on the surface to achieve the effect of controlling haze or surface roughness. The microparticles used can be organic microparticles, inorganic microparticles, or combinations thereof.

[0036] Suitable organic microparticles are combinations thereof, with particle sizes ranging from 0.3 µm to 6 µm, including polymethyl methacrylate resin microparticles, polystyrene resin microparticles, styrene-methyl methacrylate copolymer microparticles, polyethylene resin microparticles, epoxy resin microparticles, polysiloxane resin microparticles, polyvinylidene fluoride resin microparticles, polyvinyl fluoride resin microparticles, melamine resin microparticles, or the like. Suitable inorganic microparticles are combinations thereof, with particle sizes ranging from 0.01 µm to 3 μm, including aluminosilicates, talc, mica, silica, or the like.

[0037] To make a display anti-reflective, a surface functional layer can be formed by coating an anti-reflective coating onto a protective film. The anti-reflective coating is typically prepared by mixing an acrylic binder resin with nano-silica particles with a particle size between 0.02 µm and 0.3 μm, and then applying the solution to the protective film or layering it onto other surface functional layers with different functions to achieve the anti-reflective effect.

[0038] In another embodiment of the liquid crystal display of the present invention, the backlight 140 is a polarized backlight including optical films such as prism light-concentrating film and reflective polarizing brightness enhancement film, which increases the light intensity and utilization rate of the backlight side polarizing plate entering the liquid crystal display.

[0039] The following examples are provided to further illustrate the present invention, but the scope of the invention is not limited thereto.

[0040] Example

[0041] Preparation Example 1: Preparation of Acrylic Adhesive Resin (I)

[0042] 42 parts by weight of polyurethane acrylate oligomer (functionality 6, molecular weight approximately 2,600, viscosity approximately 62,000 cps (25°C), purchased from Miwon Specialty Chemical Co., Ltd, Korea), 4.5 parts by weight of pentaerythritol triacrylate (PETA), 12 parts by weight of dipentaerythritol hexaacrylate (DPHA), 3 parts by weight of isobornyl acrylate (IBOA), 4 parts by weight of photoinitiator (Chemcure-481, purchased from Heng Chiao Industry, Taiwan), 24.5 parts by weight of ethyl acetate (EAC), and 10 parts by weight of n-butyl acetate (nBAC) were mixed and stirred for 1 hour to form acrylate-based adhesive resin (I).

[0043] Preparation Example 2: Preparation of Acrylic Adhesive Resin (II)

[0044] 42 parts by weight of polyurethane acrylate oligomer (functionality 6, molecular weight about 1,600, viscosity about 36,000 cps (25°C), purchased from IGM, Taiwan), 4.5 parts by weight of pentaerythritol triacrylate (PETA), 12 parts by weight of dipentaerythritol hexaacrylate (DPHA), 3 parts by weight of cyclotrimethylolpropane methyl acetal acrylate (CTFA), 4 parts by weight of photoinitiator (Chemcure-481), 24.5 parts by weight of ethyl acetate (EAC), and 10 parts by weight of n-butyl acetate (nBAC) were mixed and stirred for 1 hour to form acrylate-based adhesive resin (II).

[0045] Preparation Example 3: Preparation of Acrylic Adhesive Resin (III)

[0046] 39 parts by weight of polyurethane acrylate oligomer (functionality 9, molecular weight approximately 2,400, viscosity approximately 266,000 cps (25°C), purchased from Tung-Asia Synthetic, Taiwan), 4.5 parts by weight of pentaerythritol triacrylate (PETA), 10.5 parts by weight of dipentaerythritol hexaacrylate (DPHA), 4.5 parts by weight of hexanediol diacrylate (HDDA), 1.5 parts by weight of 2-phenoxyethyl acrylate (PHEA), 3.5 parts by weight of photoinitiator (Chemcure-481), 0.5 parts by weight of photoinitiator (TR-PPI-one, purchased from Strong New Materials, Hong Kong), 24.5 parts by weight of ethyl acetate (EAC), and 10 parts by weight of n-butyl acetate (nBAC) were mixed and stirred for 1 hour to form acrylate-based adhesive resin (III).

[0047] Preparation Example 4: Surface Treatment Solution (I)

[0048] 152.7 parts by weight of acrylic adhesive resin (I), 1.6 parts by weight of polymethyl methacrylate microparticles (SSX-102, average particle size 2 μm, refractive index 1.49, purchased from Sekisui Chemicals Co., Ltd., Japan), 10.5 parts by weight of silica nanoparticle dispersion sol (MEK-ST-UP, solid content 20%, solvent: methyl ethyl ketone, purchased from Nissan Chemical, Japan) with an average primary particle size of 9 nm to 15 nm and a chain length of 40 nm to 100 nm, 5.8 parts by weight of acrylate-ether-based surfactant (BYK-UV3535, solid content 10%, solvent: ethyl acetate, purchased from BYK, Germany), and 2.1 parts by weight of silica nanoparticle dispersion sol (NanoBYK-3650, average primary particle size 20 nm to 100 nm) were prepared. The nanoparticles, with a solid content of 31%, were mixed and stirred for 1 hour to form a surface treatment solution (I), using propylene glycol methyl ether acetate / propylene glycol methyl ether (purchased from BYK, Germany), 44.3 parts by weight of ethyl acetate (EAC), and 81.8 parts by weight of n-butyl acetate (nBAC) as solvents.

[0049] Preparation Example 5: Surface Treatment Solution (II)

[0050] 152.7 parts by weight of acrylic adhesive resin (I), 11.2 parts by weight of methyl methacrylate and styrene copolymer microparticles (XX-49IK, average particle size 5 μm, refractive index 1.545, purchased from Sekisui Chemicals Co., Ltd., Japan), 2.9 parts by weight of methyl methacrylate and styrene copolymer microparticles (XX-50IK, average particle size 3.5 μm, refractive index 1.555, purchased from Sekisui Chemicals Co., Ltd., Japan), 4.2 parts by weight of polyether-modified polydimethylsiloxane leveling agent (BYK-333, solid content 10%, solvent ethyl acetate, purchased from BYK, Germany), and 11.4 parts by weight of silicon dioxide nanoparticle dispersion sol (NanoBYK-3650, average primary particle size 20 μm) were prepared. The nanoparticles, with a solid content of 31%, were mixed and stirred for 1 hour to form a surface treatment solution (II), using propylene glycol methyl ether acetate / propylene glycol methyl ether (purchased from BYK, Germany), 28.6 parts by weight of ethyl acetate (EAC), 57.2 parts by weight of n-propyl acetate (nPAC), and 28.6 parts by weight of propylene glycol methyl ether acetate (PGMEA) as solvents.

[0051] Preparation Example 6: Surface Treatment Solution (III)

[0052] 152.7 parts by weight of acrylic adhesive resin (II), 4.0 parts by weight of amorphous silica particles (Nipsil® SS-50B, average particle size 4.0 μm, refractive index 1.45~1.47, purchased from Tosoh Silicon Chemicals Co., Ltd., Japan), 1.5 parts by weight of block copolymer dispersion containing basic pigment affinity groups (DisperBYK-2150, solid content 5%, solvent ethyl acetate and propylene glycol methyl ether acetate, purchased from BYK, Germany), 4.7 parts by weight of polyether modified polydimethylsiloxane leveling agent (BYK-333, solid content 10%, solvent ethyl acetate, purchased from BYK, Germany), 68.3 parts by weight of ethyl acetate (EAC), and 191.1 parts by weight of n-butyl acetate (nBAC) were mixed and stirred for 1 hour to achieve uniform dispersion, thus forming a surface treatment solution (III).

[0053] Preparation Example 7: Surface Treatment Solution (IV)

[0054] The following components were prepared: 152.7 parts by weight of acrylic adhesive resin (III), 2.7 parts by weight of amorphous silica particles (Nipsil® SS-50B, average particle size 4.0 μm, refractive index 1.45~1.47, purchased from Tosoh Silicon Chemicals Co., Ltd., Japan), 5.4 parts by weight of polystyrene microparticles (SXX-302ABE, average particle size 2 μm, refractive index 1.595, purchased from Sekisui Chemicals Co., Ltd., Japan), 1.8 parts by weight of a block copolymer dispersion containing basic pigment affinity groups (DisperBYK-2150, solid content 5%, solvents ethyl acetate and propylene glycol methyl ether acetate, purchased from BYK, Germany), 3.3 parts by weight of polyether-modified polydimethylsiloxane leveling agent (BYK-333, solid content 10%, solvent ethyl acetate, purchased from BYK, Germany), and 57.9 parts by weight of ethyl acetate (EAC). Mix with 86.8 parts by weight of n-butyl acetate (nBAC) and stir for 1 hour to disperse it evenly, forming a surface treatment solution (IV).

[0055] Preparation Example 8: Surface Treatment Solution (V)

[0056] The following components were prepared: 152.7 parts by weight of acrylic adhesive resin (III), 16.8 parts by weight of polystyrene microparticles (XX-40IK, average particle size 3 μm, refractive index 1.595, purchased from Sekisui Chemicals Co., Ltd., Japan), 3.0 parts by weight of silica nanoparticle dispersion sol (MEK-ST-UP, solid content 20%, solvent: methyl ethyl ketone, purchased from Nissan Chemical, Japan) with an average primary particle size of 9 nm to 15 nm and a chain length of 40 nm to 100 nm, 11.7 parts by weight of silica nanoparticle dispersion sol (NanoBYK-3650, average primary particle size 20 nm, solid content 31%, solvent: propylene glycol methyl ether acetate / propylene glycol methyl ether, purchased from BYK, Germany), 30.9 parts by weight of ethyl acetate (EAC), and 86.6 parts by weight of n-propyl acetate (nPAC). Mix with 41.9 parts by weight of propylene glycol methyl ether acetate (PGMEA) and stir for 1 hour to disperse it evenly, forming a surface treatment solution (V).

[0057] Preparation Example 9: Surface Treatment Solution (VI)

[0058] 152.7 parts by weight of acrylic adhesive resin (II), 5.3 parts by weight of amorphous silica particles (Nipsil® SS-50B, average particle size 4.0 μm, refractive index 1.45~1.47, purchased from Tosoh Silicon Chemicals Co., Ltd., Japan), 2.6 parts by weight of block copolymer dispersion containing basic pigment affinity groups (DisperBYK-2150, solid content 5%, solvent ethyl acetate and propylene glycol methyl ether acetate, purchased from BYK, Germany), 4.7 parts by weight of polyether modified polydimethylsiloxane leveling agent (BYK-333, solid content 10%, solvent ethyl acetate, purchased from BYK, Germany), 62.8 parts by weight of ethyl acetate (EAC), and 189.6 parts by weight of n-butyl acetate (nBAC) were mixed and stirred for 1 hour to achieve uniform dispersion, thus forming a surface treatment solution (VI).

[0059] Preparation Example 10: Surface Treatment Solution (VII)

[0060] 152.7 parts by weight of acrylic adhesive resin (III), 5.7 parts by weight of amorphous silica particles (Nipsil® SS-50B, average particle size 4.0 μm, refractive index 1.45~1.47, purchased from Tosoh Silicon Chemicals Co., Ltd., Japan), 5.5 parts by weight of polystyrene microparticles (XX-40IK), 2.1 parts by weight of a block copolymer dispersion containing basic pigment affinity groups (Disper BYK-2150, solid content 5%, solvents ethyl acetate and propylene glycol methyl ether acetate, purchased from BYK, Germany), 4.7 parts by weight of polyether-modified polydimethylsiloxane leveling agent (BYK-333, solid content 10%, solvent ethyl acetate, purchased from BYK, Germany), 60.2 parts by weight of ethyl acetate (EAC), and 115.1 parts by weight of n-butyl acetate (nBAC) were mixed and stirred for 1 minute. After being evenly dispersed for hours, a surface treatment solution (VII) is formed.

[0061] Preparation Example 11: Preparation of Surface Treatment Solution (VIII)

[0062] The mixture consisted of 14 parts by weight of a fluorinated and acrylate-modified polysiloxane resin (X-12-2430C, purchased from Shigeobu Chemical, Japan), 14 parts by weight of a hexafunctional fluorinated polyurethane oligomer (LR6000, purchased from Miwon, South Korea), 1.7 parts by weight of a photoinitiator (KIP-160, purchased from IGM Resin, Netherlands), 103.5 parts by weight of a mixture of (meth)acrylic acid-modified organosilicon compounds with perfluoropolyether functional groups (X-71-1203E, solid content 20%, solvent: methyl ethyl ketone, purchased from Shigeobu Chemical, Japan), and 198 parts by weight of a hollow silica nanoparticle dispersion sol (Thrulya 4320, solid content 20%, average particle size 60 mm). nm, the solution is methyl isobutyl ketone, purchased from Nichibukai Chemicals, Japan), 1779 parts by weight of ethyl acetate (EAC) and 890 parts by weight of propylene glycol methyl ether acetate (PGMEA) are mixed and stirred for 10 minutes to form a surface treatment solution (VIII).

[0063] The different protective film substrates used in this invention are shown in Table 1. When the surface treatment solutions of Preparation Examples 4 to 11 are coated on the different substrates shown in Table 1, they can serve as protective films with surface functional layers for display-side polarizing plates. Alternatively, they can serve as light-incident side protective films for backlight-side polarizing plates without coating with the surface treatment solution.

[0064] Table 1 Substrate Substrate thickness (μm) The refractive index (n1) of the first refractive index matching layer The refractive index (n2) of the second refractive index matching layer substrate refractive index (np) Substrate birefringence difference (Δn) In-plane phase difference (R0, nm) PET-1 75 1.56 1.64 1.66 0.033 2475 PET-2 75 1.54 1.64 1.66 0.031 2353 PET-3 75 1.54 1.61 1.66 0.040 3037 PET-4 75 1.56 1.61 1.66 0.047 3496 PET-5 100 1.65 1.65 1.66 0.049 4930 PET-6 76 1.54 1.61 1.66 0.004 271 PET-7 50 1.56 1.61 1.66 0.008 407 PET-8 50 1.56 1.64 1.66 0.009 456 PET-9 66 1.54 1.61 1.66 0.011 713 PET-10 75 1.62 1.65 1.66 0.014 1080 PMMA 40 1.50 — 1.50 0.0000215 0.86 TAC 60 — — 1.48 0.0000162 0.97

[0065] Implementation Example 1

[0066] The surface treatment solution (I) of Example 4 was coated onto a 76 μm polyethylene terephthalate substrate (PET-6, model: QBN-0016, purchased from Mitsubishi Chemical Corporation, Japan). The thickness, refractive index, birefringence difference (Δn), in-plane phase difference, and refractive index of the refractive index matching layer of the substrate used for the protective film are shown in Table 1. After the surface treatment solution (I) was dried, it was photocured under a nitrogen atmosphere with a UV lamp with a radiation dose of 80 mJ / cm2 to form a first polyester protective film with an anti-glare surface and a thickness of 7.2 μm on the polyethylene terephthalate substrate.

[0067] A first polyester protective film with a surface functional layer was adhered to the light-emitting surface of the polarizing layer of a commercially available polarizing plate (model: RTT00015TH, BenQ Materials Corp.) after the existing surface protective film was removed, using a transparent optical adhesive to form a display-side polarizing plate. Different polyethylene terephthalate film substrates (PET-1, model: QBN-0008, purchased from Mitsubishi Chemical Corporation, Japan) shown in Table 1 were adhered to the polarizing layer of the commercially available polarizing plate (model: RTT00015TH, BenQ Materials Corp.) after the existing light-incident side protective film was removed, using a transparent optical adhesive to form a backlight-side polarizing plate. The above-described display-side and backlight-side polarizing plates were assembled with the liquid crystal panel and backlight module of a commercially available BenQ 32” VA C32-310 liquid crystal display to form the liquid crystal display of Example 1.

[0068] The thickness and haze of the surface functional layer of the display-side polarizing plate in Example 1 were measured using the following instruments and methods, and the stress color spots and interference rainbow patterns of the liquid crystal display were evaluated. The measurement and evaluation results are listed in Table 2.

[0069] Measurement of surface functional layer thickness: The surface functional layer thickness was measured using an electronic comparator Extramess 2001 (Mahr Inc., Germany) according to the description in JIS K5600-1-7:2014.

[0070] Measurement of total haze: The total haze of the surface functional layer was evaluated using NDH-2000 (Nippon Denshoku Corp.) according to the description in JIS K7136.

[0071] Measurement of internal and surface haze: A triacetyl cellulose substrate (Fujifilm, T40UZ, 40 μm thickness) was attached to the surface of the surface functional layer using a transparent optical adhesive to flatten the uneven surface of the surface functional layer. In this state, the haze was evaluated using an NDH-2000 (Nippon Denshoku Corp.) according to the description of JIS K7136 to obtain the internal haze value. Then, the surface haze value was obtained by subtracting the internal haze value from the total haze value.

[0072] Evaluation of stress spots: The evaluation method for stress spots is to allow the assembled LCD to stand at room temperature for 14 days to fully release the stress in each film layer. Then, the LCD is switched to a full-screen black display (dark state). If no obvious stress spots are visible, it is rated as "excellent". [〇]), if stress spots are observable, the rating is "poor" ( [╳])

[0073] Evaluation of interference rainbow patterns: The evaluation method for interference rainbow patterns is to switch the LCD monitor to full-screen white display mode (bright state) and evaluate the degree of interference rainbow patterns when viewing the LCD monitor from both a 0-degree frontal viewing angle and a 60-degree side viewing angle. If there are no obvious interference rainbow patterns, the evaluation is "excellent" (…). [〇]), if interference rainbow fringes can be observed, the evaluation is "poor" ( [╳]).

[0074] Example 2

[0075] The surface treatment solution (II) of Preparation Example 5 was coated onto a 50 μm polyethylene terephthalate substrate (PET-7, model: EBQ-410, purchased from Mitsubishi Chemical Corporation, Japan) as shown in Table 1. After the surface treatment solution (II) was dried, it was photocured under a nitrogen atmosphere with a UV lamp at a radiation dose of 80 mJ / cm2 to form a first polyester protective film with an anti-glare surface and a thickness of 8.4 μm on the polyethylene terephthalate substrate.

[0076] A first polyester protective film with a surface functional layer is bonded to the light-emitting surface of the polarizing layer of a commercially available polarizing plate (model: RTT00015TH, BenQ Materials Corp.) after the existing surface protective film has been removed, using a transparent optical adhesive to form a display-side polarizing plate. Different polyethylene terephthalate (PET-2) films shown in Table 1 are bonded to the polarizing layer of the commercially available polarizing plate (model: RTT00015TH, BenQ Materials Corp.) after the existing incident light-side protective film has been removed, using a transparent optical adhesive to form a backlight-side polarizing plate. The above-described display-side and backlight-side polarizing plates, combined with the liquid crystal panel and backlight module of a commercially available BenQ 32” VA C32-310 liquid crystal display, form the liquid crystal display of Example 2.

[0077] The liquid crystal display of Example 2 and the surface functional layer of its display-side polarizing plate were measured and evaluated using the same methods as in Example 1. The results are listed in Table 2.

[0078] Example 3

[0079] The surface treatment solution (III) of Preparation Example 6 was coated onto a 50 μm polyethylene terephthalate substrate (PET-8, model: EBQ-409, purchased from Mitsubishi Chemical Corporation, Japan) as shown in Table 1. After the surface treatment solution (III) was dried, it was photocured under a nitrogen atmosphere with a UV lamp at a radiation dose of 80 mJ / cm2 to form a first polyester protective film with an anti-glare surface and a thickness of 4.7 μm on the polyethylene terephthalate substrate.

[0080] A first polyester protective film with a surface functional layer was adhered to the light-emitting surface of the polarizing layer of a commercially available polarizing plate (model: RTT00015TH, BenQ Materials Corp.) after the existing surface protective film was removed, using a transparent optical adhesive to form a display-side polarizing plate. Different polyethylene terephthalate films (PET-3, model: QBN-0013, purchased from Mitsubishi Chemical Corporation, Japan) shown in Table 1 were adhered to the polarizing layer of the commercially available polarizing plate (model: RTT00015TH, BenQ Materials Corp.) after the existing light-incident side protective film was removed, using a transparent optical adhesive to form a backlight-side polarizing plate. The above-described display-side and backlight-side polarizing plates, combined with the liquid crystal panel and backlight module of a commercially available BenQ 32” VA C32-310 liquid crystal display, form the liquid crystal display of Example 3.

[0081] The liquid crystal display of Example 3 and the surface functional layer of its display-side polarizing plate were measured and evaluated using the same methods as in Example 1. The results are listed in Table 2.

[0082] Example 4

[0083] The surface treatment solution (V) of Preparation Example 8 was coated onto a 66 μm polyethylene terephthalate substrate (PET-9, model: QBN-0017, purchased from Mitsubishi Chemical Corporation, Japan) as shown in Table 1. After the surface treatment solution (IV) was dried, it was photocured under a nitrogen atmosphere with a UV lamp at a radiation dose of 80 mJ / cm2 to form a first polyester protective film with an anti-glare surface and a thickness of 3.2 μm on the polyethylene terephthalate substrate.

[0084] A first polyester protective film with a surface functional layer was adhered to the light-emitting surface of the polarizing layer of a commercially available polarizing plate (model: RTT00015TH, BenQ Materials Corp.) after the existing surface protective film was removed, using a transparent optical adhesive to form a display-side polarizing plate. Different polyethylene terephthalate films (PET-4, model: TA084, purchased from Toyobo Co., Ltd., Japan) shown in Table 1 were adhered to the polarizing layer of the commercially available polarizing plate (model: RTT00015TH, BenQ Materials Corp.) after the existing light-incident side protective film was removed, using a transparent optical adhesive to form a backlight-side polarizing plate. The above-described display-side and backlight-side polarizing plates, combined with the liquid crystal panel and backlight module of a commercially available BenQ 32” VA C32-310 liquid crystal display, form the liquid crystal display of Example 4.

[0085] The liquid crystal display of Example 4 and the surface functional layer of its display-side polarizing plate were measured and evaluated using the same methods as in Example 1. The results are listed in Table 2.

[0086] Example 5

[0087] The surface treatment solution (VI) of Preparation Example 9 was coated onto a 66 μm polyethylene terephthalate (PET-9) substrate as shown in Table 1. After the surface treatment solution (VI) was dried, it was photocured under a nitrogen atmosphere with a UV lamp at a radiation dose of 80 mJ / cm2 to form a first polyester protective film with an anti-glare surface and a thickness of 4.5 μm on the polyethylene terephthalate substrate.

[0088] A first polyester protective film with a surface functional layer is bonded to the light-emitting surface of the polarizing layer of a commercially available polarizing plate (model: RTT00015TH, BenQ Materials Corp.) after the existing surface protective film has been removed, using a transparent optical adhesive to form a display-side polarizing plate. Different polyethylene terephthalate (PET-4) films shown in Table 1 are bonded to the polarizing layer of the commercially available polarizing plate (model: RTT00015TH, BenQ Materials Corp.) after the existing incident light-side protective film has been removed, using a transparent optical adhesive to form a backlight-side polarizing plate. The above-described display-side and backlight-side polarizing plates, combined with the liquid crystal panel and backlight module of a commercially available BenQ 32” VA C32-310 liquid crystal display, form the liquid crystal display of Example 5.

[0089] The liquid crystal display of Example 5 and the surface functional layer of its display-side polarizing plate were measured and evaluated using the same methods as in Example 1. The results are listed in Table 2.

[0090] Example 6

[0091] The surface treatment solution (IV) of Preparation Example 7 was coated onto a 75 μm polyethylene terephthalate substrate (PET-10, model: O700E, purchased from Mitsubishi Chemical Corporation, Japan) as shown in Table 1. After the surface treatment solution (IV) was dried, it was photocured under a nitrogen atmosphere with a UV lamp at a radiation dose of 80 mJ / cm2 to form a first polyester protective film with an anti-glare surface and a thickness of 3.4 μm on the polyethylene terephthalate substrate.

[0092] A first polyester protective film with a surface functional layer was adhered to the light-emitting surface of the polarizing layer of a commercially available polarizing plate (model: RTT00015TH, BenQ Materials Corp.) after the existing surface protective film was removed, using transparent optical adhesive to form a display-side polarizing plate. Different polyethylene terephthalate films (PET-5, model: C87H, purchased from Shinco Optoelectronics, Taiwan) shown in Table 1 were adhered to the polarizing layer of the commercially available polarizing plate (model: RTT00015TH, BenQ Materials Corp.) after the existing light-incident side protective film was removed, using transparent optical adhesive to form a second polyester protective film, thus forming a backlight-side polarizing plate. The above-described display-side and backlight-side polarizing plates, combined with the liquid crystal panel and backlight module of a commercially available BenQ 32” VA C32-310 liquid crystal display, form the liquid crystal display of Example 6.

[0093] The liquid crystal display of Example 6 and the surface functional layer of its display-side polarizing plate were measured and evaluated using the same methods as in Example 1. The results are listed in Table 2.

[0094] Example 7

[0095] The surface treatment solution (VII) of Preparation Example 10 was coated onto a 75 μm polyethylene terephthalate (PET-10) substrate as shown in Table 1. After the surface treatment solution (VII) was dried, it was photocured under a nitrogen atmosphere with a UV lamp at a radiation dose of 80 mJ / cm2 to form a first polyester protective film with an anti-glare surface and a thickness of 3.4 μm on the polyethylene terephthalate substrate.

[0096] A first polyester protective film with a surface functional layer is bonded to the light-emitting surface of the polarizing layer of a commercially available polarizing plate (model: RTT00015TH, BenQ Materials Corp.) after the existing surface protective film has been removed, using a transparent optical adhesive to form a display-side polarizing plate. Different polyethylene terephthalate (PET-5) films shown in Table 1 are bonded to the polarizing layer of the commercially available polarizing plate (model: RTT00015TH, BenQ Materials Corp.) after the existing incident light-side protective film has been removed, using a transparent optical adhesive to form a backlight-side polarizing plate. The above-described display-side and backlight-side polarizing plates, combined with the liquid crystal panel and backlight module of a commercially available BenQ 32” VA C32-310 liquid crystal display, form the liquid crystal display of Example 7.

[0097] The liquid crystal display of Example 7 and the surface functional layer of its display-side polarizing plate were measured and evaluated using the same methods as in Example 1. The results are listed in Table 2.

[0098] Example 8

[0099] The surface treatment solution (VIII) of Preparation Example 11 was applied to a first polyester protective film with anti-glare properties, identical to that of the liquid crystal display of Example 7. After the surface treatment solution (VIII) was dried, it was photocured under a UV lamp with a radiation dose of 350 mJ / cm2 in a nitrogen atmosphere, thereby obtaining an anti-reflective layer with a thickness of approximately 0.13 μm on the first polyester protective film with anti-glare properties, thus forming a first polyester protective film with both anti-glare and anti-reflective surface functional layers.

[0100] A first polyester protective film with a surface functional layer is bonded to the light-emitting surface of the polarizing layer of a commercially available polarizing plate (model: RTT00015TH, BenQ Materials Corp.) after the existing surface protective film has been removed, using a transparent optical adhesive to form a display-side polarizing plate. Different polyethylene terephthalate (PET-5) films shown in Table 1 are bonded to the polarizing layer of the commercially available polarizing plate (model: RTT00015TH, BenQ Materials Corp.) after the existing incident light-side protective film has been removed, using a transparent optical adhesive to form a backlight-side polarizing plate. The above-described display-side and backlight-side polarizing plates, combined with the liquid crystal panel and backlight module of a commercially available BenQ 32” VA C32-310 liquid crystal display, form the liquid crystal display of Example 8.

[0101] The liquid crystal display of Example 8 and the surface functional layer of its display-side polarizing plate were measured and evaluated using the same methods as in Example 1. The results are listed in Table 2.

[0102] Comparative example

[0103] Comparative Example 1

[0104] The surface treatment solution (I) of Preparation Example 4 was coated onto a 75 μm polyethylene terephthalate (PET-1) substrate as shown in Table 1. After the surface treatment solution (I) was dried, it was photocured under a nitrogen atmosphere with a UV lamp at a radiation dose of 80 mJ / cm2 to form a first polyester protective film with an anti-glare surface and a thickness of 6.4 μm on the polyethylene terephthalate substrate.

[0105] A first polyester protective film with a surface functional layer was adhered to the light-emitting surface of the polarizing layer of a commercially available polarizing plate (model: RTT00015TH, BenQ Materials Corp.) after the existing surface protective film was removed, using a transparent optical adhesive to form a display-side polarizing plate. Different polyethylene terephthalate (PET-6) film substrates shown in Table 1 were adhered to the polarizing layer of the commercially available polarizing plate (model: RTT00015TH, BenQ Materials Corp.) after the existing incident light-side protective film was removed, using a transparent optical adhesive to form a backlight-side polarizing plate. The above-mentioned display-side polarizing plate and backlight-side polarizing plate were assembled with the liquid crystal panel and backlight module of a commercially available BenQ 32” VA C32-310 liquid crystal display to form the liquid crystal display of Comparative Example 1.

[0106] The liquid crystal display of Comparative Example 1 and the surface functional layer of its display-side polarizing plate were measured and evaluated using the same methods as in Example 1. The results are listed in Table 2.

[0107] Comparative Example 2

[0108] The surface treatment solution (II) of Preparation Example 5 was coated onto a 75 μm polyethylene terephthalate (PET-2) substrate as shown in Table 1. After the surface treatment solution (II) was dried, it was photocured under a nitrogen atmosphere with a UV lamp at a radiation dose of 80 mJ / cm2 to form a first polyester protective film with an anti-glare surface and a thickness of 7.0 μm on the polyethylene terephthalate substrate.

[0109] A first polyester protective film with a surface functional layer was adhered to the light-emitting surface of the polarizing layer of a commercially available polarizing plate (model: RTT00015TH, BenQ Materials Corp.) after the existing surface protective film was removed, using a transparent optical adhesive to form a display-side polarizing plate. Different polyethylene terephthalate (PET-7) films shown in Table 1 were adhered to the polarizing layer of the commercially available polarizing plate (model: RTT00015TH, BenQ Materials Corp.) after the existing incident light-side protective film was removed, using a transparent optical adhesive to form a backlight-side polarizing plate. The above-described display-side and backlight-side polarizing plates, combined with the liquid crystal panel and backlight module of a commercially available BenQ 32” VA C32-310 liquid crystal display, formed the liquid crystal display of Comparative Example 2.

[0110] The liquid crystal display of Comparative Example 2 and the surface functional layer of its display-side polarizing plate were measured and evaluated using the same methods as in Example 1. The results are listed in Table 2.

[0111] Comparative Example 3

[0112] The surface treatment solution (III) of Preparation Example 6 was coated onto a 75 μm polyethylene terephthalate (PET-3) substrate as shown in Table 1. After the surface treatment solution (III) was dried, it was photocured under a nitrogen atmosphere with a UV lamp at a radiation dose of 80 mJ / cm2 to form a first polyester protective film with an anti-glare surface and a thickness of 5.0 μm on the polyethylene terephthalate substrate.

[0113] A first polyester protective film with a surface functional layer was adhered to the light-emitting surface of the polarizing layer of a commercially available polarizing plate (model: RTT00015TH, BenQ Materials Corp.) after the existing surface protective film was removed, using a transparent optical adhesive to form a display-side polarizing plate. Different polyethylene terephthalate (PET-8) films shown in Table 1 were adhered to the polarizing layer of the commercially available polarizing plate (model: RTT00015TH, BenQ Materials Corp.) after the existing light-incident side protective film was removed, using a transparent optical adhesive to form a backlight-side polarizing plate. The above-described display-side and backlight-side polarizing plates, combined with the liquid crystal panel and backlight module of a commercially available BenQ 32” VA C32-310 liquid crystal display, formed the liquid crystal display of Comparative Example 3.

[0114] The liquid crystal display of Comparative Example 3 and the surface functional layer of its display-side polarizing plate were measured and evaluated in the same manner as in Example 1. The results are listed in Table 2.

[0115] Comparative Example 4

[0116] The surface treatment solution (V) of Preparation Example 8 was coated onto a 75 μm polyethylene terephthalate (PET-4) substrate as shown in Table 1. After the surface treatment solution (V) dried, it was photocured under a nitrogen atmosphere with a UV lamp at a radiation dose of 80 mJ / cm2 to form a first polyester protective film with an anti-glare surface and a thickness of 3.1 μm on the polyethylene terephthalate substrate.

[0117] A first polyester protective film with a surface functional layer was adhered to the light-emitting surface of the polarizing layer of a commercially available polarizing plate (model: RTT00015TH, BenQ Materials Corp.) after the existing surface protective film was removed, using a transparent optical adhesive to form a display-side polarizing plate. Different polyethylene terephthalate (PET-9) films shown in Table 1 were adhered to the polarizing layer of the commercially available polarizing plate (model: RTT00015TH, BenQ Materials Corp.) after the existing incident light-side protective film was removed, using a transparent optical adhesive to form a backlight-side polarizing plate. The above-described display-side and backlight-side polarizing plates, combined with the liquid crystal panel and backlight module of a commercially available BenQ 32” VA C32-310 liquid crystal display, formed the liquid crystal display of Comparative Example 4.

[0118] The liquid crystal display of Comparative Example 4 and the surface functional layer of its display-side polarizing plate were measured and evaluated using the same methods as in Example 1. The results are listed in Table 2.

[0119] Comparative Example 5

[0120] The surface treatment solution (VI) of Preparation Example 9 was coated onto a 75 μm polyethylene terephthalate (PET-4) substrate as shown in Table 1. After the surface treatment solution (VI) was dried, it was photocured under a nitrogen atmosphere with a UV lamp at a radiation dose of 80 mJ / cm2 to form a first polyester protective film with an anti-glare surface and a thickness of 4.3 μm on the polyethylene terephthalate substrate.

[0121] A first polyester protective film with a surface functional layer was adhered to the light-emitting surface of the polarizing layer of a commercially available polarizing plate (model: RTT00015TH, BenQ Materials Corp.) after the existing surface protective film was removed, using a transparent optical adhesive to form a display-side polarizing plate. Different polyethylene terephthalate (PET-9) films shown in Table 1 were adhered to the polarizing layer of the commercially available polarizing plate (model: RTT00015TH, BenQ Materials Corp.) after the existing light-incident side protective film was removed, using a transparent optical adhesive to form a backlight-side polarizing plate. The above-described display-side and backlight-side polarizing plates, combined with the liquid crystal panel and backlight module of a commercially available BenQ 32” VA C32-310 liquid crystal display, formed the liquid crystal display of Comparative Example 5.

[0122] The liquid crystal display of Comparative Example 5 and the surface functional layer of its display-side polarizing plate were measured and evaluated using the same methods as in Example 1. The results are listed in Table 2.

[0123] Comparative Example 6

[0124] The surface treatment solution (VII) of Preparation Example 10 was coated onto a 100 μm polyethylene terephthalate (PET-5) substrate as shown in Table 1. After the surface treatment solution (VII) was dried, it was photocured under a nitrogen atmosphere with a UV lamp at a radiation dose of 80 mJ / cm2 to form a first polyester protective film with an anti-glare surface and a thickness of 4.6 μm on the polyethylene terephthalate substrate.

[0125] A first polyester protective film with a surface functional layer was adhered to the light-emitting surface of the polarizing layer of a commercially available polarizing plate (model: RTT00015TH, BenQ Materials Corp.) after the existing surface protective film was removed, using a transparent optical adhesive to form a display-side polarizing plate. Different polyethylene terephthalate films (PET-10) shown in Table 1 were adhered to the polarizing layer of the commercially available polarizing plate (model: RTT00015TH, BenQ Materials Corp.) after the existing incident light-side protective film was removed, using a transparent optical adhesive to form a backlight-side polarizing plate. The above-described display-side and backlight-side polarizing plates, combined with the liquid crystal panel and backlight module of a commercially available BenQ 32” VA C32-310 liquid crystal display, formed the liquid crystal display of Comparative Example 6.

[0126] The liquid crystal display of Comparative Example 6 and the surface functional layer of its display-side polarizing plate were measured and evaluated in the same manner as in Example 1. The results are listed in Table 2.

[0127] Comparative Example 7

[0128] The surface treatment solution (IV) of Preparation Example 7 was coated onto a 40 μm polymethyl methacrylate (PMMA) substrate as shown in Table 1. After the surface treatment solution (IV) was dried, it was photocured under a nitrogen atmosphere with a UV lamp at a radiation dose of 80 mJ / cm2 to form a 3.5 μm thick polymethyl methacrylate protective film with an anti-glare surface layer on the polymethyl methacrylate substrate.

[0129] A polymethyl methacrylate (PMMA) protective film with a surface functional layer was adhered to the light-emitting surface of the polarizing layer of a commercially available polarizing plate (model: RTT00015TH, BenQ Materials Corp.) after the existing surface protective film was removed, using a transparent optical adhesive to form a display-side polarizing plate. A polyethylene terephthalate (PET-5) film as shown in Table 1 was adhered to the polarizing layer of the commercially available polarizing plate (model: RTT00015TH, BenQ Materials Corp.) after the existing incident light-side protective film was removed, serving as a second polyester protective film to form a backlight-side polarizing plate. The aforementioned display-side polarizing plate and backlight-side polarizing plate, combined with the liquid crystal panel and backlight module of a commercially available BenQ 32” VA C32-310 liquid crystal display, formed the liquid crystal display of Comparative Example 7.

[0130] The liquid crystal display of Comparative Example 7 and the surface functional layer of its display-side polarizing plate were measured and evaluated using the same methods as in Example 1. The results are listed in Table 2.

[0131] Comparative Example 8

[0132] The surface treatment solution (III) of Preparation Example 6 was coated onto a 60 μm cellulose triacetate substrate (TAC) as shown in Table 1. After the surface treatment solution (III) was dried, it was photocured under a nitrogen atmosphere with a UV lamp at a radiation dose of 80 mJ / cm2 to form a cellulose triacetate protective film with an anti-glare surface layer and a thickness of 4.3 μm on the cellulose triacetate substrate.

[0133] A cellulose triacetate protective film with a surface functional layer was adhered to the light-emitting surface of the polarizing layer of a commercially available polarizing plate (model: RTT00015TH, BenQ Materials Corp.) after the existing surface protective film was removed, using a transparent optical adhesive to form a display-side polarizing plate. A polyethylene terephthalate film (PET-5) as shown in Table 1 was adhered to the polarizing layer of the commercially available polarizing plate (model: RTT00015TH, BenQ Materials Corp.) after the existing incident light-side protective film was removed, serving as a second polyester protective film to form a backlight-side polarizing plate. The above-described display-side and backlight-side polarizing plates, combined with the liquid crystal panel and backlight module of a commercially available BenQ 32” VA C32-310 liquid crystal display, formed the liquid crystal display of Comparative Example 8.

[0134] The liquid crystal display of Comparative Example 8 and the surface functional layer of its display-side polarizing plate were measured and evaluated in the same manner as in Example 1. The results are listed in Table 2.

[0135] Table 2 First polyester protective film Second polyester protective film Surface functional layer Total haze (%) Surface functional layer Surface haze (%) Surface functional layer Internal haze (%) Surface functional layer Thickness (μm) Stress stains Evaluation of interference rainbow patterns from a 60° perspective Evaluation of interference rainbow patterns at 0° positive angle Example 1 PET-6 PET-1 2.07 1.18 0.89 7.2 [○] [○] [○] Example 2 PET-7 PET-2 27.16 13.22 13.94 8.4 [○] [○] [○] Example 3 PET-8 PET-3 31.89 27.87 4.02 4.7 [○] [○] [○] Example 4 PET-9 PET-4 47.9 14.0 33.9 3.2 [○] [○] [○] Example 5 PET-9 PET-4 45.05 42.07 2.98 4.5 [○] [○] [○] Example 6 PET-10 PET-5 32.32 20.75 11.57 3.4 [○] [○] [○] Example 7 PET-10 PET-5 52.60 35.99 16.61 3.4 [○] [○] [○] Example 8 PET-10 PET-5 50.73 33.62 17.11 3.5 [○] [○] [○] Comparative Example 1 PET-1 PET-6 2.17 1.01 1.16 6.4 [○] [╳] [╳] Comparative Example 2 PET-2 PET-7 29.16 16.25 12.91 7.0 [○] [╳] [╳] Comparative Example 3 PET-3 PET-8 27.26 23.11 4.15 5.0 [○] [╳] [╳] Comparative Example 4 PET-4 PET-9 47.49 15.48 32.01 3.1 [○] [╳] [╳] Comparative Example 5 PET-4 PET-9 46.13 43.37 2.76 4.3 [○] [╳] [╳] Comparative Example 6 PET-5 PET-10 52.66 39.13 13.53 4.6 [○] [╳] [╳] Comparative Example 7 PMMA PET-5 33.84 23.81 10.03 3.5 [╳] [○] [○] Comparative Example 8 TAC PET-5 30.12 26.69 3.43 4.3 [╳] [○] [○]

[0136] As shown in Tables 1 and 2, when both the protective film on the light-emitting surface of the display-side polarizer and the protective film on the light-receiving surface of the backlight-side polarizer are polyethylene terephthalate (PET) films, the stress spots visible in the dark state of the liquid crystal display can be avoided, as in Comparative Examples 7 and 8, due to the different pressure and tensile tension of the polarizer formed by using different protective film substrates. This results in different shrinkage stresses of each film layer after being attached to the liquid crystal panel, which cannot be completely released. Furthermore, when the birefringence difference (Δn) of the first PET protective film in the embodiment is between 0.003 and 0.015, and the birefringence difference (Δn) of the second PET protective film is between 0.030 and 0.080, the problems of uneven rainbow and interference rainbow patterns caused by backlight and external oblique reflected light at the two sides of the first PET protective film interface, or the interference rainbow patterns that are clearly visible at the positive viewing angle caused by the image light with higher collimation, polarization, and coherence generated by the high-intensity backlight, can be improved simultaneously. The dual-sided polyester protective film architecture offers superior resistance to water vapor penetration compared to using only a single high in-plane phase difference polyester protective film to avoid the aforementioned problems. The anti-glare layer and / or anti-reflective layer on the surface of the first polyester protective film of the viewing-side polarizer of the display, without the need for high total haze (e.g., greater than 80%) or a specific combination of surface haze / internal haze, effectively suppresses interference rainbow patterns caused by reflected light or backlight from the display surface. This avoids the disruption of light interference through the interfaces of the first polyester protective film by high haze or high surface roughness surface functional layers, thus reducing image light transmittance or clarity. This increases the versatility of LCDs using dual polyester protective films in various application areas when combined with surface functional layers.

[0137] Although the present invention has been disclosed above by way of embodiments, it is not intended to limit the present invention. Anyone skilled in the art can make various modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

[0138] 100, 200: LCD monitor 110: LCD panel 110A: Display side 110B: Backlight side 120, 220: Display side polarizer 130, 230: Backlight-side polarizing plate 121: First polarizing layer 121A: First light-emitting side 121B: First incident light side 122, 222: First polyester protective film 123: Surface functional layer 1221: First refractive index matching layer 1222: Second refractive index matching layer 131: Second polarizing layer 131A: Second light-emitting side 131B: Second incident light side 132: Second polyester protective film 1321: Third refractive index matching layer 1322: Fourth refractive index matching layer 140: Backlight

Claims

1. A liquid crystal display, comprising: a liquid crystal panel having a display side and a backlight side opposite to each other; a backlight source disposed on the backlight side of the liquid crystal panel; and a display-side polarizing plate disposed on the display side of the liquid crystal panel, comprising a first polarizing layer, a first polyester protective film, and a surface functional layer, wherein, The first polarizing layer has a first light-emitting side and a first light-receiving side, and is disposed on the display side of the liquid crystal panel via the first light-receiving side. A first polyester protective film is disposed on the first light-emitting side of the first polarizing layer, and a surface functional layer is disposed on the first polyester protective film. The birefringence difference of the first polyester protective film is between 0.003 and 0.

015. A backlight-side polarizing plate is disposed on the backlight side of the liquid crystal panel and located between the liquid crystal panel and the backlight source. It includes a second polarizing layer and a second polyester protective film. The second polarizing layer has a second light-emitting side and a second light-receiving side, with the second light-receiving side facing the backlight source. The second polarizing layer is disposed on the backlight side of the liquid crystal panel via the second light-emitting side. The second polyester protective film is disposed on the second light-receiving side of the second polarizing layer, and the birefringence difference of the second polyester protective film is between 0.

030. Up to 0.

080.

2. The liquid crystal display of claim 1, wherein the in-plane phase difference of the first polyester protective film is ≤1500 nm and the in-plane phase difference of the second polyester protective film is ≥2200 nm.

3. The liquid crystal display of claim 1, wherein the first polyester protective film has a first refractive index matching layer and a second refractive index matching layer on opposite two sides, and the second polyester protective film has a third refractive index matching layer and a fourth refractive index matching layer on opposite two sides, wherein the first refractive index n1 of the first refractive index matching layer and the second refractive index n2 of the second refractive index matching layer are both less than the first average refractive index np1 of the first polyester protective film, and the third refractive index n3 of the third refractive index matching layer and the fourth refractive index n4 of the fourth refractive index matching layer are both less than the second average refractive index np2 of the second polyester protective film.

4. The liquid crystal display as claimed in claim 3, wherein the first average refractive index np1 and the second average refractive index np2 are both between 1.60 and 1.70, and the first refractive index n1, the second refractive index n2, the third refractive index n3 and the fourth refractive index n4 are all between 1.51 and 1.

65.

5. The liquid crystal display of claim 3, wherein the thickness of the first refractive index matching layer, the second refractive index matching layer, the third refractive index matching layer and the fourth refractive index matching layer are all between 0.1 μm and 0.3 μm.

6. The liquid crystal display of claim 1, wherein the thickness of the first polyester protective film is between 20 μm and 80 μm, and the thickness of the second polyester protective film is between 60 μm and 110 μm.

7. The liquid crystal display of claim 1, wherein the first polyester protective film and the second polyester protective film are a uniaxially extended polyester film or a biaxially extended polyester film.

8. The liquid crystal display of claim 1, wherein the first polarizing layer and the second polarizing layer are an iodine-based or dye-based extended polarizing layer or an iodine-based or dye-based coated polarizing layer.

9. As claimed in claim 1, wherein the surface functional layer is selected from one or a combination of the group consisting of a hard coating layer, an anti-glare layer, an anti-fouling layer, an antistatic layer, and an anti-reflective layer.

10. The liquid crystal display of claim 1, wherein the total haze of the surface functional layer is between 1% and 60%.

11. The liquid crystal display of claim 1, wherein the thickness of the surface functional layer is between 2 μm and 10 μm.

12. The liquid crystal display of claim 1, wherein the first polyester protective film and the second polyester protective film are selected from polyethylene terephthalate film, polyethylene terephthalate film or polyethylene terephthalate film.

13. The liquid crystal display of claim 1, wherein the backlight is a polarized backlight.

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