Dimming laminate and smart window including same

Abstract

The present invention provides a dimming laminate and a smart window including the same. The dimming laminate includes: a first polarizing plate; a first transparent conductive layer formed on one surface of the first polarizing plate; a second polarizing plate facing the first polarizing plate; a second transparent conductive layer formed on one surface of the second polarizing plate and facing the first transparent conductive layer; and a liquid crystal layer provided between the first transparent conductive layer and the second transparent conductive layer, in which at least one of the first polarizing plate and the second polarizing plate has an S, calculated by formula 1, of 0.5-4.0 N.mm, the light-dimming laminate is easy to handle, does not have a risk of breakage during transfer, and does not have defects when bonded to a smart window.

Description

Technical Field

[0001] The present invention relates to a dimming stack and a smart window comprising the same. Background Art

[0002] Generally speaking, glass windows of vehicles and other mobile tools are often coated with external light blocking coatings. However, the transmittance of glass windows of conventional mobile tools is fixed, and the transmittance of the external light blocking coatings is also fixed.

[0003] Therefore, the fixed overall transmittance of the windows of conventional mobile vehicles can cause accidents. For example, if the overall transmittance is set low, there is no problem during the day when the surrounding light is sufficient. However, in situations such as at night when the surrounding light is insufficient, it becomes difficult for the driver to accurately see the surroundings of the mobile vehicle. Furthermore, if the overall transmittance is set high, there is the problem of causing glare to the driver during the day when the surrounding light is sufficient. To address this issue, a dimming laminate has been developed that can change the transmittance of light when a voltage is applied.

[0004] The above-mentioned light-adjusting stack drives the liquid crystal by applying voltage, thereby driving the transmittance in a variable manner. The light-adjusting stack developed so far is produced by forming a conductive layer for liquid crystal driving on a separate substrate and then combining it with other elements such as a polarizing plate.

[0005] For example, Japanese Patent Publication No. 2018-010035 also discloses a dimming laminate including a transparent electrode layer formed on a polycarbonate (PC) substrate or the like having a predetermined thickness.

[0006] However, when a separate substrate is included to form the conductive layer, there are problems such as the production process becomes complicated and the production cost increases, the thickness of the laminate increases, and the transmittance changes due to the generation of phase difference.

[0007] On the other hand, when the polarizing plate that was once used in traditional LCD and other image display devices is applied to the smart window as the above-mentioned polarizing plate, it is easy to bend during transfer due to the lack of a supporting substrate, which may cause bending and breakage, and when it is bonded to the smart window, there are problems such as warping and squeezing due to the bonding pressure.

[0008] Therefore, it is necessary to develop a light-adjusting laminate that does not have to worry about being damaged during transportation and does not cause defects even when attached to a smart window.

[0009] Prior art literature

[0010] Patent Literature

[0011] Patent Document 1: Japanese Patent Publication No. 2018-010035 Summary of the Invention

[0012] Issues to be addressed

[0013] An object of the present invention is to provide a light-adjusting laminate that does not include a separate substrate for forming a conductive layer, thereby simplifying the production process.

[0014] Another object of the present invention is to provide a light-adjusting laminate that is easy to handle without risk of damage during transportation and prevents defects from occurring when attached to a smart window.

[0015] Another object of the present invention is to provide a smart window including the light-controlling laminate and a window for a car or a building to which the smart window is applied.

[0016] However, the problems to be solved by the present invention are not limited to the problems mentioned above, and those skilled in the art should be able to clearly understand other problems not mentioned based on the following description.

[0017] Solutions to Problems

[0018] The present invention relates to a dimming stack, comprising: a first polarizing plate; a first transparent conductive layer formed on one surface of the first polarizing plate; a second polarizing plate opposite the first polarizing plate; a second transparent conductive layer formed on one surface of the second polarizing plate and opposite the first transparent conductive layer; and a liquid crystal layer disposed between the first transparent conductive layer and the second transparent conductive layer. For at least one of the first and second polarizing plates, S calculated by the following formula 1 is 0.5 to 4.0 N·mm.

[0019] [Formula 1]

[0020]

[0021] (In the above formula 1, E is the elastic modulus (modulus; N / mm 2 ), t is the thickness (mm), and ν is the Poisson's ratio.

[0022] At least one of the first polarizing plate and the second polarizing plate may include one or more functional layers selected from the group consisting of a protective layer, a phase difference adjusting layer, and a refractive index adjusting layer.

[0023] At least one of the first polarizing plate and the second polarizing plate may have a thickness of 50 to 300 μm.

[0024] At least one of the first transparent conductive layer and the second transparent conductive layer may be formed to be in direct contact with the first polarizing plate or the second polarizing plate without including a separate substrate.

[0025] At least one of the first transparent conductive layer and the second transparent conductive layer may be formed so as to be in direct contact with the first polarizing plate or the second polarizing plate by including an easy-adhesion layer therebetween.

[0026] At least one of the first transparent conductive layer and the second transparent conductive layer may include one or more selected from the group consisting of transparent conductive oxides, metals, carbon-based materials, conductive polymers, conductive inks, and nanowires.

[0027] The liquid crystal behavior mode of the liquid crystal layer can be any one selected from the group consisting of twisted nematic (TN) mode, super twisted nematic (STN) mode, in-plane switching (IPS) mode, fringe-field switching (FFS) mode and vertical alignment (VA) mode.

[0028] The liquid crystal behavior of the liquid crystal layer may be a twisted nematic (TN) mode.

[0029] The liquid crystal layer may include a cured product of a liquid crystal layer-forming composition containing a polymerizable monomer and a liquid crystal compound.

[0030] The liquid crystal layer may include a polymer network and a liquid crystal compound.

[0031] The light-adhesive laminate may further include one or more selected from the group consisting of an adhesive / bonding layer, an ultraviolet absorbing layer, and a hard coat layer.

[0032] Furthermore, the present invention relates to a smart window including the above-mentioned light-adjusting laminate.

[0033] In addition, the present invention relates to a car in which the above-mentioned smart window is applied to at least one of a front window, a rear window, a side window, a sunroof, and an interior partition.

[0034] Furthermore, the present invention relates to a window for a building including the smart window.

[0035] Effects of the Invention

[0036] According to the light-adjusting laminate of the present invention, a conductive layer is directly formed on one surface of a polarizing plate without including a separate substrate for forming the conductive layer, and thus the thickness can be significantly reduced compared to conventional light-adjusting laminates.

[0037] Furthermore, the light-adjusting laminate of the present invention is easy to handle and does not have to be damaged during transportation, and defects can be prevented from occurring when attached to a smart window.

[0038] Furthermore, the present invention can provide a smart window including the light-adjusting laminate and a window for a car or a building to which the smart window is applied. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 1 is a diagram showing the stacked structure of a light-adjusting stack according to an embodiment of the present invention.

[0040] Figures 2a to 2e 1 is a diagram illustrating a stacked structure of polarizing plates according to one or more embodiments of the present invention. DETAILED DESCRIPTION

[0041] The present invention relates to a dimming stack, comprising: a first polarizing plate; a first transparent conductive layer formed on one surface of the first polarizing plate; a second polarizing plate opposite the first polarizing plate; a second transparent conductive layer formed on one surface of the second polarizing plate and opposite the first transparent conductive layer; and a liquid crystal layer disposed between the first transparent conductive layer and the second transparent conductive layer. For at least one of the first and second polarizing plates, S calculated by the following formula 1 is 0.5 to 4.0 N·mm.

[0042] [Formula 1]

[0043]

[0044] (In the above formula 1, E is the elastic modulus (modulus; N / mm 2 ), t is the thickness (mm), and ν is the Poisson's ratio.

[0045] The light-adjusting laminate of the present invention is particularly suitable for the technical field in which light transmittance can be changed by application of voltage, and can be used, for example, in smart windows.

[0046] A smart window is an optical structure that changes its light transmittance in response to an electrical signal, thereby controlling the amount of light or heat that passes through it. Specifically, a smart window can change state to transparent, opaque, or translucent depending on the voltage applied. It is also known as variable-transmittance glass, dimming glass, or smart glass.

[0047] Smart windows can be used as partitions for dividing the interior space of vehicles and buildings or for protecting privacy, or as skylights arranged in openings of buildings. They can also be used as highway signs, billboards, scoreboards, clocks or advertising screens, and can replace the glass of transportation vehicles such as windows or skylights of cars, buses, airplanes, ships or trains.

[0048] The dimming laminate of the present invention can also be used as a smart window in the above-mentioned technical fields. However, since the conductive layer is directly formed on the polarizing plate and does not include a separate substrate for forming the conductive layer, the thickness is thin, which is beneficial for bending properties and can be particularly suitable for use as a smart window for vehicles or buildings. In one or more embodiments, a smart window using the dimming laminate of the present invention can be used for the front window, rear window, side window, and sunroof of a car, or a window for a building. In addition to being used to block external light, it can also be used for internal space division or privacy protection in cars or buildings, such as internal partitions.

[0049] The following describes the embodiments of the present invention in more detail with reference to the accompanying drawings. However, the following drawings attached to this specification are merely illustrative of preferred embodiments of the present invention and serve to further understand the above-mentioned invention contents and the technical concept of the present invention. Therefore, the present invention should not be interpreted solely in accordance with the matters described in these drawings.

[0050] The terms used in this specification are intended to describe the embodiments and are not intended to limit the present invention. In this specification, unless otherwise specified, the singular also includes the plural. For example, the term "polarizing plate" used in this specification may refer to at least one of the first polarizing plate and the second polarizing plate, and the term "transparent conductive layer" may refer to at least one of the first transparent conductive layer and the second transparent conductive layer.

[0051] The terms "comprises" and "comprising" used in this specification are used to mean that they do not exclude the existence or addition of one or more other constituent elements, steps, operations, and / or elements other than the mentioned constituent elements, steps, operations, and / or elements. Throughout the specification, the same reference numerals refer to the same constituent elements.

[0052] As illustrated in the accompanying drawings, spatially relative terms such as "below", "bottom", "lower", "above", "upper surface", "upper", etc. can be used to easily describe the relationship between one element or constituent element and other elements or constituent elements. Spatially relative terms should be understood as terms that include different directions of the elements when in use or in operation in addition to the directions illustrated in the drawings. For example, when the elements illustrated in the drawings are turned over, the elements described as "below" or "lower" of other elements can be placed "above" other elements. Therefore, the exemplary term "below" can include both directions below and above. Elements can also be oriented in other directions, so spatially relative terms can be interpreted based on orientation.

[0053] The “top-view direction” used in this specification may be interpreted as a direction perpendicular to the polarizing plate and / or the transparent conductive layer, that is, a direction viewed from the visible side of a user.

[0054] <Light Adjusting Laminated Body>

[0055] Figure 1 1 is a diagram showing a stacked structure of a light-adjusting stack according to an embodiment of the present invention. Figures 2a to 2e 1 is a diagram illustrating a stacked structure of polarizing plates according to one or more embodiments of the present invention.

[0056] Reference Figure 1 The dimming stack according to an embodiment of the present invention may include a first polarizing plate 100 - 1 , a second polarizing plate 100 - 2 , a first transparent conductive layer 200 - 1 , a second transparent conductive layer 200 - 2 , and a liquid crystal layer 300 .

[0057] 2 , the polarizing plate 100 may include a polarizer 110 , and may further include functional layers such as a protective layer 120 , a phase difference adjustment layer 130 , and a refractive index adjustment layer 140 on one or both sides of the polarizer 110 .

[0058] For example, the polarizing plate 100 may include a polarizer 110 and a protective layer 120 (see FIG. 1 ) stacked on one or both sides of the polarizer 110. Figure 2a and Figure 2b), which may include a polarizer 110, a protective layer 120 laminated on one surface of the polarizer 110, and a phase difference adjustment layer 130 laminated on the other surface of the polarizer 110 opposite to the one surface (see Figure 2c ). In addition, the polarizer 110 may be included, a protective layer 120 stacked on one side of the polarizer, and a phase difference adjustment layer 130 and a refractive index adjustment layer 140 stacked in sequence on the other side of the polarizer 110 opposite to the one side (see Figure 2d ), which may include a polarizer 110, a protective layer 120 stacked on one side of the polarizer, and a protective layer 120 and a phase difference adjustment layer 130 stacked in sequence on the other side of the polarizer 110 opposite to the one side (see Figure 2e ).

[0059] In one or more embodiments of the present invention, the S calculated by the following formula 1 of the polarizing plate 100, that is, at least one of the first polarizing plate 100-1 and the second polarizing plate 100-2, may be 0.5-4.0 N·mm, preferably 0.5-3.0 N·mm.

[0060] [Formula 1]

[0061]

[0062] In the above formula 1, E is the elastic modulus (modulus; N / mm 2 ), t is the thickness (mm), and ν is the Poisson's ratio.

[0063] Since the polarizing plate 100 of the present invention satisfies the above-mentioned formula 1, its rigidity can be improved and it can be suitably applied to smart windows.

[0064] That is, when S represented by the above formula 1 is out of the above range, the polarizing plate 100 may be easily bent or too soft and may be easily bent. In addition, it may be warped or squeezed during transportation or lamination, resulting in bubbles or damage.

[0065] The polarizing plate 100 may have a thickness of 50 to 300 μm, preferably 70 to 200 μm, and more preferably 80 to 170 μm. In this case, the polarizing plate 100 can be applied to a smart window while maintaining optical properties and preventing warping when attached to glass, thereby preventing the smart window from becoming thicker.

[0066] On the other hand, the elastic modulus of the polarizing plate 100 can be 2000~8000N / mm 2 , preferably 3000~6000N / mm 2, so that S calculated by the above formula 1 can satisfy 0.5~4.0N·mm. In this case, it is beneficial to prevent the polarizing plate 100 from being damaged by warping, squeezing, etc. during transfer or bonding.

[0067] The polarizer and the functional layer constituting the polarizing plate 100 are not particularly limited as long as they are made of materials that can satisfy S calculated by the above formula 1 of 0.5 to 4.0 N·mm.

[0068] The polarizer 110 may be a polarizer developed in the past or in the future, and for example, a stretched polarizer or a coating polarizer may be used.

[0069] In one embodiment, the stretched polarizer may include a stretched polyvinyl alcohol (PVA) resin. The polyvinyl alcohol (PVA) resin may be a polyvinyl alcohol resin obtained by saponifying a polyvinyl acetate resin. As the polyvinyl acetate resin, in addition to polyvinyl acetate which is a homopolymer of vinyl acetate, copolymers of vinyl acetate and other monomers copolymerizable therewith may also be mentioned. As the other monomers mentioned above, unsaturated carboxylic acid series, unsaturated sulfonic acid series, olefin series, vinyl ether series, acrylamide series monomers having an ammonium group, etc. may be mentioned. In addition, the polyvinyl alcohol (PVA) resin includes modified substances, for example, polyvinyl formal or polyvinyl acetal modified by aldehydes.

[0070] In one embodiment, the coating-type polarizer may be formed using a liquid crystal coating composition. In this case, the liquid crystal coating composition may include a reactive liquid crystal compound and a dichroic dye.

[0071] The reactive liquid crystal compound may be, for example, a compound containing a mesogen skeleton and one or more polymerizable functional groups. Such reactive liquid crystal compounds are widely known as reactive mesogens (RMs). These reactive liquid crystal compounds can be polymerized by light or heat to form a cured film that forms a polymer network while maintaining liquid crystal alignment.

[0072] The reactive liquid crystal compound may be a monofunctional or polyfunctional reactive liquid crystal compound. The monofunctional reactive liquid crystal compound may be a compound having one polymerizable functional group, and the polyfunctional reactive liquid crystal compound may be a compound having two or more polymerizable functional groups.

[0073] The above-mentioned dichroic dye is a component added in a liquid crystal coating composition to impart polarization characteristics, and has a property that the absorbance in the major axis direction of the molecule is different from the absorbance in the minor axis direction. The above-mentioned dichroic dye can use a dichroic dye developed in the past or in the future, for example, it can include one or more of the group selected from azo dyes (azo dyes), anthraquinone dyes (anthraquinone dyes), perylene dyes (perylene dyes), merocyanine dyes (merocyanine dyes), azomethine dyes (azomethine dyes), phthaloperylene dyes (phthaloperylene dyes), indigo dyes (indigodyes), dioxadine dyes (dioxadine dyes), polythiophene dyes (polythiophene dyes) and phenoxazine dyes (phenoxazine dyes).

[0074] The liquid crystal coating composition may further include a solvent capable of dissolving the reactive liquid crystal compound and the dichroic dye, for example, propylene glycol monomethyl ether acetate (PGMEA), methyl ethyl ketone (MEK), xylene, and chloroform. Furthermore, the liquid crystal coating composition may further include a leveling agent, a polymerization initiator, and the like within a range that does not hinder the polarization properties of the coating film.

[0075] The protective layer 120 is intended to protect the polarization characteristics of the polarizer 110 from being affected by subsequent processes and the external environment, and can be implemented in the form of a protective film or the like.

[0076] like Figure 2a and Figure 2b As shown, the protective layer 120 may be formed directly on one or both sides of the polarizer 110, but is not limited thereto. For example, the protective layer may be used as a multilayer structure in which more than one protective layer is continuously stacked and may be formed in direct contact with other functional layers.

[0077] In one or more embodiments, the protective layer 120 may include one or more selected from the group consisting of polyethylene terephthalate (PET), polyethylene isophthalate (PEI), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), diacetyl cellulose, triacetyl cellulose (TAC), polycarbonate (PC), polyethylene (PE), polypropylene (PP), polymethyl acrylate (PMA), polymethyl methacrylate (PMMA), polyethyl acrylate (PEA), polyethyl methacrylate (PEMA), and cyclic olefin polymer (COP).

[0078] The phase difference adjustment layer 130 is intended to supplement the optical properties of the dimming stack and can be implemented in the form of a phase difference film, and phase difference films developed previously or in the future can be used. For example, a quarter wave plate (1 / 4 wave plate) or a half wave plate (1 / 2 wave plate) for delaying the phase of light can be used, and these can be used alone or in combination.

[0079] like Figure 2c and Figure 2d As shown in the figure, the phase difference adjustment layer 130 can be formed in direct contact with one surface of the polarizer 110, but is not limited thereto. Figure 2e As shown in the figure, the phase difference adjustment layer 130 may be formed on one surface of the protective layer 120 so that the polarizer 110 , the protective layer 120 and the phase difference adjustment layer 130 are stacked in sequence.

[0080] The phase difference adjustment layer 130 may be a stretched polymer film or a liquid crystal polymer film obtained by appropriately stretching a polymer film capable of imparting optical anisotropy.

[0081] In one embodiment, the above-mentioned polymer stretch film can use a polymer layer containing the following substances: polyolefins such as polyethylene (PE) or polypropylene (PP), cyclo olefin polymers (COP: cyclo olefin polymer) such as polynorbornene, polyvinyl chloride (PVC), polyacrylonitrile (PAN), polysulfone (PSU), acrylic resin (acryl resin), polycarbonate (PC), polyesters such as polyethylene terephthalate (PET), polyacrylate, polyvinyl alcohol (PVA) or triacetyl cellulose (TAC) or other cellulose ester polymers, or copolymers of two or more monomers among the monomers forming the above-mentioned polymers, etc.

[0082] The method for obtaining the above-mentioned polymer stretch film is not particularly limited. For example, it can be obtained by stretching the above-mentioned polymer material after being shaped into a film. The above-mentioned method for being shaped into a film is not particularly limited. It can be shaped into a film by known methods such as injection molding, sheet molding, blow molding, injection blow molding, inflation molding, extrusion molding, foam molding, tape casting, or by 2nd processing molding methods such as compression molding and vacuum forming. Wherein, extrusion molding and tape casting are preferably used. At this time, for example, an extruder equipped with a T-die, a circular die, etc. can be utilized to extrusion mold the unstretched film. In the case of obtaining a molded product by extrusion molding, it is possible to use a material in which various resin components, additives, etc. have been melt-mixed in advance, or it is possible to mold via melt-mixing during extrusion molding. In addition, it is also possible to use a solvent shared by various resin components, such as chloroform, methylene chloride, etc., after dissolving various resin components, to perform tape casting, drying, and solidification, thereby performing tape casting on the unstretched film.

[0083] For the above-mentioned polymer stretched film, the above-mentioned formed film can be uniaxially stretched along the machine flow direction (MD; Mechanical Direction, longitudinal or length direction) and uniaxially stretched along the direction perpendicular to the machine flow direction (TD; Transverse Direction, transverse or width direction). In addition, the biaxially stretched film can also be manufactured by stretching through a successive biaxial stretching method of roller stretching and tenter stretching, a simultaneous biaxial stretching method based on tenter stretching, a biaxial stretching method based on tubular stretching, etc.

[0084] The liquid crystal polymer film may include a polymerized reactive liquid crystal compound. The reactive liquid crystal compound is similar to the reactive liquid crystal compound of the coating-type polarizer.

[0085] In one or more embodiments, the thickness of the phase difference adjustment layer 130 may be 10 μm to 100 μm in the case of a polymer stretched film, and 0.1 μm to 5 μm in the case of a liquid crystal polymer film.

[0086] The refractive index adjustment layer 140 is provided to compensate for the refractive index difference of the light-adjusting stack caused by the transparent conductive layer 200, thereby improving visual characteristics by reducing the refractive index difference. Furthermore, the refractive index adjustment layer 140 can also be provided to correct the color caused by the transparent conductive layer 200. Furthermore, if the transparent conductive layer has a pattern, the refractive index adjustment layer 140 can compensate for the difference in transmittance between the patterned area and the unpatterned area.

[0087] Specifically, when the transparent conductive layer 200 is stacked adjacent to other components with different refractive indices (e.g., the polarizer 110), the difference in refractive index with the adjacent layers can induce a difference in light transmittance. This difference can lead to a visual difference between the patterned and non-patterned areas, particularly when the transparent conductive layer is patterned. Therefore, the inclusion of the refractive index adjustment layer 140 compensates for the refractive index and reduces the difference in light transmittance of the dimming stack. This prevents the visual difference between the patterned and non-patterned areas, particularly when the transparent conductive layer is patterned.

[0088] In one embodiment, the refractive index of the refractive index adjustment layer 140 can be appropriately selected based on the materials of other adjacent components, and can preferably be 1.4 to 2.6, and more preferably 1.4 to 2.4. In this case, light loss caused by a significant refractive index difference between other components such as the polarizer 110 and the transparent conductive layer 200 can be prevented.

[0089] The above-mentioned refractive index adjustment layer 140 is not particularly limited as long as it can prevent a significant refractive index difference between other components such as the polarizer 110 and the transparent conductive layer 200. Compounds previously or later developed for forming a refractive index adjustment layer can be used. For example, it can be formed by a refractive index adjustment layer forming composition containing a polymerizable isocyanurate compound.

[0090] In one embodiment, in addition to the above functional layers, the polarizing plate 100 may further include other functional layers to assist or enhance the characteristics of the polarizer. For example, in order to further improve the mechanical durability, an overcoat layer may also be included.

[0091] The thickness of each functional layer other than the phase difference adjustment layer 130 may be 1-30 μm, more preferably 2-20 μm. The thickness may refer to the thickness after drying. If each thickness falls within the above range, the function of each functional layer can be smoothly exerted while achieving thinness.

[0092] The transparent conductive layer 200 is provided for driving the liquid crystal layer 300 and may be formed in direct contact with the polarizing plate 100 .

[0093] For example, Figure 1 As shown, the first transparent conductive layer 200 - 1 may be formed in direct contact with the first polarizing plate 100 - 1 , and the second transparent conductive layer 200 - 2 may be formed in direct contact with the second polarizing plate 100 - 2 .

[0094] Conventional dimming laminates used in the manufacture of smart windows and the like are manufactured by forming a conductive layer for liquid crystal driving on one side of a substrate and laminating the other side of the substrate to a polarizing plate. However, the dimming laminate of the present invention is characterized by forming a conductive layer directly on one side of the polarizing plate without including a separate substrate for forming the conductive layer, thereby reducing the thickness of the laminate and improving the transmittance and bending properties in the light transmission mode.

[0095] In one embodiment, the first transparent conductive layer 200-1 and / or the second transparent conductive layer 200-2 formed in direct contact with at least one of the first polarizing plate 100-1 and the second polarizing plate 100-2 are formed on the polarizing plate by sharing a contact surface with the first polarizing plate 100-1 and / or the second polarizing plate 100-2, without comprising a separate substrate. For example, the first transparent conductive layer 200-1 and / or the second transparent conductive layer 200-2 can be formed by vapor deposition on the upper surface of the coating layer formed on the first polarizing plate 100-1 and / or the second polarizing plate 100-2. In this case, in order to improve the adhesion between the first transparent conductive layer 200-1 and / or the second transparent conductive layer 200-2 and at least one of the first polarizing plate 100-1 and the second polarizing plate 100-2, the first transparent conductive layer 200-1 and / or the second transparent conductive layer 200-2 can be pre-treated by corona treatment or plasma treatment on one side of the polarizing plate, and then formed in direct contact with the pre-treated surface of the polarizing plate. The above-mentioned pretreatment is not limited to corona treatment or plasma treatment, and any pretreatment process developed in the past or in the future may be used within the scope not impairing the purpose of the present invention.

[0096] In another embodiment of the present invention, the first transparent conductive layer 200-1 and / or the second transparent conductive layer 200-2 formed in direct contact with at least one of the first polarizing plate 100-1 and the second polarizing plate 100-2 can be formed by directly contacting the polarizing plate through an easy-adhesion layer (not disclosed in the accompanying drawings) provided on one side of the polarizing plate to improve the adhesion to the polarizing plate. The easy-adhesion layer can use an adhesive developed in the past or in the future. In one or more embodiments, an acrylic adhesive, a rubber adhesive, a silicone adhesive, a urethane adhesive, a polyvinyl alcohol adhesive, a polyvinyl pyrrolidone adhesive, a polyacrylamide adhesive, a cellulose adhesive, a vinyl alkyl ether adhesive, etc. can be used. There is no particular limitation on the adhesive as long as it has adhesion and viscoelasticity. However, considering the ease of acquisition, it is preferably an acrylic adhesive. For example, it can contain a (meth)acrylate copolymer, a crosslinking agent, and a solvent.

[0097] The transparent conductive layer 200 can be formed by evaporating and coating one side of the polarizing plate 100 using a method commonly used in the art, for example, a coating process such as spin coating, roll coating, rod coating, dip coating, gravure coating, curtain coating, die coating, spray coating, doctor blade coating, and kneader coating; a printing (coating) process such as screen printing, spray printing, inkjet printing, letterpress printing, gravure printing, and lithographic printing; and a deposition process such as chemical vapor deposition (CVD), physical vapor deposition (PVD), and plasma enhanced chemical vapor deposition (PECVD).

[0098] In the dimming stack of the present invention, the transmittance of at least one of the first transparent conductive layer 200-1 and the second transparent conductive layer 200-2 relative to visible light is preferably greater than 50%. For example, it may include one or more selected from the group consisting of transparent conductive oxides, metals, carbon-based substances, conductive polymers, conductive inks and nanowires, but is not limited to this, and materials for transparent conductive layers developed in the past or in the future can be used.

[0099] In one or more embodiments, the transparent conductive oxide may include one or more selected from the group consisting of indium tin oxide (ITO), indium zinc oxide (IZO), indium tin zinc oxide (IZTO), aluminum zinc oxide (AZO), gallium zinc oxide (GZO), fluorine tin oxide (FTO) and zinc oxide (ZnO).

[0100] In addition, the above-mentioned metal may include one or more selected from the group consisting of gold (Au), silver (Ag), copper (Cu), aluminum (Al), platinum (Pt), palladium (Pd), chromium (Cr), titanium (Ti), tungsten (W), niobium (Nb), tantalum (Ta), vanadium (V), iron (Fe), manganese (Mn), cobalt (Co), nickel (Ni), zinc (Zn) and alloys containing at least one of them, for example, it may include silver-palladium-copper (APC) alloy or copper-calcium (CuCa) alloy.

[0101] The carbon-based substance may include one or more selected from the group consisting of carbon nanotubes (CNTs) and graphene.

[0102] The conductive polymer may be a conductive polymer material developed in the past or in the future, for example, it may include a material selected from the group consisting of polythiophene, poly (3,4-ethylenedioxythiophene), polyaniline, polyacetylene, polydiacetylene, polyphenylene, polyphenylene vinylene, polyphenylene sulfide, polythienylene vinylene, polythiophene ... At least one member selected from the group consisting of polyvinylene, polyfluorene, polypyrrole, poly(3,4-ethylenedioxythiophene):polystyrenesulfonate, poly(3,4-ethylenedioxythiophene):camphorsulfonic acid, poly(3,4-ethylenedioxythiophene):toluenesulfonic acid, poly(3,4-ethylenedioxythiophene):dodecylbenzenesulfonic acid, polyaniline:polystyrenesulfonate, polyaniline:camphorsulfonic acid, polypyrrole:polystyrenesulfonate, polypyrrole:camphorsulfonic acid, polypyrrole:toluenesulfonic acid, polypyrrole:dodecylbenzenesulfonic acid, polythiophene:polystyrenesulfonate, polythiophene:camphorsulfonic acid, polythiophene:toluenesulfonic acid, and polythiophene:dodecylbenzenesulfonic acid, and preferably poly(3,4-ethylenedioxythiophene) may be used.

[0103] The conductive ink may be an ink obtained by mixing metal powder and a curable polymer binder, and the nanowires may be, for example, silver nanowires (AgNWs).

[0104] In addition, at least one of the first transparent conductive layer 200-1 and the second transparent conductive layer 200-2 may be formed of a structure of two or more layers by combining the above-mentioned materials. For example, in order to reduce the reflectivity of incident light and increase the transmittance, it may be formed of a two-layer structure including a metal layer and a transparent conductive oxide layer.

[0105] An alignment film may be provided between the transparent conductive layer 200 and the liquid crystal layer 300 of the present invention. The alignment film is intended to provide alignment to the liquid crystal compound 310, preferably by photo-alignment. The alignment film can be produced by applying an alignment film coating composition comprising an aligning polymer, a photopolymerization initiator, and a solvent and curing the composition. The aligning polymer is not particularly limited, and polyacrylate resins, polyamic acid resins, polyimide resins, and polymers containing cinnamate groups may be used. Any polymer that exhibits alignment, previously developed or later developed, may be used.

[0106] The liquid crystal layer 300 included in the light-adjusting stack of the present invention adjusts the transmittance of light incident from one or more directions according to the electric field generated by the transparent conductive layer 200 , thereby changing the driving mode of the optical stack to a light-transmitting mode or a light-blocking mode.

[0107] The liquid crystal layer 300 may include a liquid crystal compound 310 and may be located, for example, within a space provided by a sealant layer (not shown) and a spacer (not shown) disposed between the first transparent conductive layer 200-1 and the second transparent conductive layer 200-2 in the light control region.

[0108] The liquid crystal compound 310 is not particularly limited as long as it can be driven by an electric field and can control the transmittance of light. Liquid crystal compounds developed previously or in the future can be used. For example, the contents regarding the reactive liquid crystal compound of the above-mentioned coating-type polarizer can be similarly applied.

[0109] The frame sealant may include a curable resin as a base resin. The base resin may be a UV-curable resin or a thermosetting resin known in the art for use in frame sealants. The UV-curable resin may be a polymer of a UV-curable monomer. The thermosetting resin may be a polymer of a thermosetting monomer.

[0110] As the base resin of the above-mentioned frame-sealing glue, for example, an acrylate resin, an epoxy resin, a urethane resin, a phenol resin or a mixture of the above-mentioned resins can be used. In one embodiment, the above-mentioned base resin can be an acrylate resin, and the above-mentioned acrylate resin can be a polymer of an acrylic monomer. The above-mentioned acrylic monomer can be, for example, a multifunctional acrylate. In another embodiment, the above-mentioned frame-sealing glue can further include a monomer component in the base resin. The above-mentioned monomer component can be, for example, a monofunctional acrylate. In this specification, a monofunctional acrylate can refer to a compound having one acryloyl group, and a multifunctional acrylate can refer to a compound having two or more acryloyl groups. The above-mentioned curable resin can be cured by irradiation with ultraviolet rays and / or heating. Regarding the above-mentioned ultraviolet irradiation conditions or heating conditions, they can be appropriately implemented within the scope that does not impair the purpose of the present application. The above-mentioned frame-sealing glue can further include an initiator, such as a photoinitiator or a thermal initiator, as needed.

[0111] The frame sealant can be formed by a method commonly used in the art. For example, a dispensing machine equipped with a nozzle can be used to apply the frame sealant to the periphery of the liquid crystal layer (ie, the inactive area).

[0112] The spacers may include at least one of ball spacers and column spacers, with ball spacers being particularly preferred. There may be one or more ball spacers, each preferably having a diameter of 1 to 10 μm. Furthermore, when viewed from above, the area of the ball spacers in the liquid crystal layer 300 is preferably 0.01 to 10% relative to the area of the liquid crystal layer 300, in order to improve user visibility and transmittance in the light-transmitting mode.

[0113] The liquid crystal layer 300 included in the dimming stack of the present invention may include a polymer network as described later, and the polymer network may be formed by a cross-linking reaction of a polymerizable compound. When forming the polymer network, in order to maintain a uniform initial orientation of the liquid crystal compound 310 in the liquid crystal layer, an orientation film with strong surface anchoring energy is preferably used. As a method for forming such an orientation film, a friction method using a rubbing process and a photo-orientation method using ultraviolet light can be cited. Generally speaking, the photo-orientation method has a weaker surface anchoring energy than the friction method. More specifically, the orientation film formed by the friction method has a surface anchoring energy of about 1X10 -3 J / m 2 The surface anchoring energy of the alignment film formed by the photo-alignment method is about 1X10 -6 J / m 2Therefore, in order to maintain a uniform initial orientation of the liquid crystal compound 310 when forming a polymer network in the liquid crystal layer 300, the surface of the second transparent conductive layer 200-2 in contact with the liquid crystal layer 300 can be rubbed and aligned by a rubbing method.

[0114] In one embodiment, the transparent conductive layer 200 may have a thickness of 1 μm or less, preferably 10 nm to 500 nm, and more preferably 30 nm to 200 nm. In this case, the transparent conductive layer 200 can maintain a predetermined transmittance and exhibit minimal property changes due to external stress, while also enabling the manufacture of a thin dimming stack.

[0115] The liquid crystal layer 300 may include a polymer network and a liquid crystal compound 310 , and may be located, for example, in a space provided by the polymer network between the first transparent conductive layer 200 - 1 and the second transparent conductive layer 200 - 2 in the light control region.

[0116] As mentioned above, the liquid crystal layer must include a sealant and a spacer to maintain a certain space for setting the liquid crystal compound, that is, the cell gap. However, if a columnar spacer is included in the liquid crystal layer in order to maintain the cell gap, the production process becomes complicated and the manufacturing cost increases, and the alignment film is damaged during the process of irradiating the photoresist with ultraviolet light to form the spacer, resulting in a change in transmittance. In addition, if a spherical spacer is used to maintain the cell gap of the liquid crystal layer, there is a problem that the cell gap cannot be maintained firmly and it is difficult to maintain a constant optical color in the plane, and the current short circuit of the dimming stack is induced. In addition, if a sealant is used to maintain the cell gap of the liquid crystal layer, the appearance quality may be reduced due to the visibility of the sealant, and the sealant may be broken when handling the dimming stack or the thickness difference with the spacer included may cause a defect.

[0117] Because the liquid crystal layer 300 includes both the liquid crystal compound 310 and the polymer network, it is able to appropriately maintain the cell gap of the liquid crystal layer without the need for separate sealants and / or spacers. Furthermore, because the cell gap is maintained solely by the polymer network, rather than a combination of sealants and spacers, defects caused by differences in the thickness of the sealants and spacers can be fundamentally eliminated.

[0118] The liquid crystal compound 310 is not particularly limited as long as it can be driven by an electric field and can control the transmittance of light. Liquid crystal compounds developed previously or in the future can be used. For example, the contents regarding the reactive liquid crystal compound of the above-mentioned coating-type polarizer can be similarly applied.

[0119] The liquid crystal compound may include a chiral nematic (cholesteric) liquid crystal compound, and the chiral nematic liquid crystal compound may include a nematic liquid crystal compound and a chiral compound.

[0120] In these nematic liquid crystal compounds, long, rod-shaped molecules are arranged parallel to each other. While the molecular centers are irregular, the molecular axes are orderly. The molecules of these nematic liquid crystal compounds can move freely along their long axes, resulting in low viscosity and excellent fluidity. Furthermore, because the vertical orientations of the molecules are nearly identical, polarization cancels out, generally preventing strong dielectric properties. The type of nematic liquid crystal compound is not particularly limited; any compound containing a mesogenic group is acceptable.

[0121] The stereoscopic structures of these chiral compounds are symmetrical, like the relationship between right and left hands. While they share the same chemical structure and physical properties, they are mirror images of each other, resulting in different stereoscopic structures. Inclusion of a certain amount of chiral compound in the nematic liquid crystal compound induces a helical cycle. The type of chiral compound can be used without particular limitation, as long as it can induce the desired helical cycle without impairing the liquid crystal properties of the liquid crystal compound, such as the nematic regularity.

[0122] The chiral compound for inducing a helical cycle in the liquid crystal compound 310 needs to contain at least chirality in its molecular structure. Examples of such chiral compounds include compounds having one or more asymmetric carbon atoms, compounds having an asymmetric point at a heteroatom such as chiral amines or chiral sulfoxides, and compounds having non-axially asymmetric, optically active sites such as cumulene and binaphthol.

[0123] The chiral compound may be, for example, a low molecular weight compound having a molecular weight of 1,500 or less. For example, commercially available chiral nematic liquid crystals, such as the chiral doped liquid crystal S-811 sold by Merck or Paliocolor LC 756 (manufactured by BASF), may be used as the chiral compound, but the invention is not limited thereto.

[0124] The chiral nematic liquid crystal compound may comprise 75-99% by weight of the nematic liquid crystal compound and 1-25% by weight of the chiral compound relative to the total weight of the chiral nematic liquid crystal compound, but is not limited thereto. By appropriately adjusting the content of the nematic liquid crystal compound and the chiral compound within the above range, the helical cycle, i.e., the pitch, of the chiral nematic liquid crystal compound can be adjusted. The pitch of the chiral nematic liquid crystal compound is not particularly limited and may be 5-20 μm.

[0125] There is no particular limitation on the liquid crystal behavior of the liquid crystal layer 300. For example, a twisted nematic (TN) mode, a super twisted nematic (STN) mode, an in-plane switching (IPS) mode, a fringe-field switching (FFS) mode, an electrically controlled birefringence (ECB) mode, and a vertical alignment (VA) mode can be used. From the perspective of controlling light transmittance, the twisted nematic (TN) mode is preferably used.

[0126] The liquid crystal layer 300 of the present invention can include a polymer network and a liquid crystal compound 310, which has a uniform initial alignment. The liquid crystal layer 300 of the present invention not only includes the polymer network 310 but also contains the liquid crystal compound 310, not in a phase-separated droplet or capsule form, but rather in a mixed form with the polymer network. Furthermore, the liquid crystal layer 300 has a uniform initial alignment within the liquid crystal layer, which differs from conventional polymer-dispersed liquid crystals (PDLCs). Thus, the liquid crystal layer 300 of the present invention, including the polymer network and the liquid crystal compound 310 with a uniform initial alignment, can achieve both a light-transmitting mode and a light-blocking mode by adjusting the transmittance of light incident from one or more directions based on the electric field generated by the transparent conductive layer 200. Consequently, compared to conventional polymer-dispersed liquid crystals that achieve a light-blocking mode by scattering incident light, it can exhibit a superior light-blocking efficiency. In addition, the dimming stack of the present invention can realize a light-transmitting mode without applying voltage by appropriately adjusting the transmission axis of the polarizing plate 100 and the optical axis of the liquid crystal layer 300. Moreover, compared with the previous polymer-dispersed liquid crystals in which the liquid crystals are arranged disorderly, the applied voltage required for driving is low, which has the advantage of reducing power consumption compared with the previous polymer-dispersed liquid crystals.

[0127] The liquid crystal layer 300 may include a cured product of a liquid crystal layer-forming composition containing a polymerizable monomer and a liquid crystal compound.

[0128] The above-mentioned polymerizable monomer refers to a compound that forms a polymer network through photopolymerization reaction or thermal polymerization reaction, and is not particularly limited. For example, it can include an acrylate monomer, and can include one or more selected from the group consisting of isobornyl acrylate, caprolactone acrylate, triethylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate and dipentaerythritol pentaacrylate.

[0129] The polymerizable monomer may include one or more monomers selected from monofunctional monomers to tetrafunctional monomers, and preferably includes a trifunctional monomer. Multifunctional monomers have the advantages of not impacting liquid crystals, having excellent compatibility with liquid crystals, and being able to exhibit appropriate phase separation with liquid crystals.

[0130] The content of the polymerizable monomer in the liquid crystal layer-forming composition may be 10 to 30% by weight, preferably 10 to 20% by weight, relative to the total weight of the composition. The liquid crystal layer-forming composition containing the polymerizable monomer in this content range is preferred because the resulting polymer network has a sufficient degree of curing to stably maintain the cell gap of the liquid crystal layer, and excellent light transmittance and adhesion can be achieved.

[0131] The method for forming the liquid crystal layer 300 using the liquid crystal layer forming composition is not particularly limited. For example, the liquid crystal layer 300 can be formed by applying the liquid crystal layer forming composition on the second transparent conductive layer 200-2 whose surface is rubbed and oriented and then photocuring or thermally curing the composition.

[0132] When the dimming stack of the present invention includes a polymer network in the liquid crystal layer 300, it can maintain a stable cell gap even without including a sealant and a spacer. However, if necessary, one or more of the above-mentioned sealants and spacers may be further added within the scope of not impairing the purpose of the present invention.

[0133] The light-adjusting laminate of the present invention may further include other members within a range not impairing the purpose of the present invention, for example, an adhesive / bonding layer, an ultraviolet absorbing layer, a hard coat layer, and the like.

[0134] The above-mentioned adhesive / bonding layer can be formed using an adhesive or pressure-sensitive adhesive, and preferably has appropriate adhesive / bonding strength to prevent peeling, bubbles, etc. during handling of the optical laminate, while also having transparency and thermal stability.

[0135] The adhesive may be any adhesive that has been developed in the past or will be developed later. For example, a photocurable adhesive may be used.

[0136] The photocurable adhesive exhibits strong adhesive strength by being crosslinked and cured upon exposure to active energy rays such as ultraviolet (UV) and electron beam (EB), and may be composed of reactive oligomers, reactive monomers, photopolymerization initiators, and the like.

[0137] The reactive oligomer is a key component that determines the properties of the adhesive. It forms a cured film by forming high-molecular bonds through photopolymerization. Examples of usable reactive oligomers include polyester resins, polyether resins, polyurethane resins, epoxy resins, polyacrylic resins, and silicone resins.

[0138] The reactive monomer acts as a crosslinking agent or diluent for the reactive oligomer, affecting the adhesive properties. Examples of the reactive monomer include monofunctional monomers, polyfunctional monomers, epoxy monomers, vinyl ethers, and cyclic ethers.

[0139] The photopolymerization initiator absorbs light energy to generate free radicals or cations, thereby initiating photopolymerization. A suitable photopolymerization initiator can be selected and used according to the photopolymerizable resin.

[0140] The adhesive may be any adhesive developed in the past or in the future. In one or more embodiments, an acrylic adhesive, a rubber adhesive, a silicone adhesive, a urethane adhesive, a polyvinyl alcohol adhesive, a polyvinyl pyrrolidone adhesive, a polyacrylamide adhesive, a cellulose adhesive, a vinyl alkyl ether adhesive, etc. may be used. The adhesive is not particularly limited as long as it has adhesive strength and viscoelasticity. However, from the perspective of ease of availability, an acrylic adhesive is preferably used. For example, the adhesive may contain a (meth)acrylate copolymer, a crosslinking agent, a solvent, etc.

[0141] The crosslinking agent may be a conventional or later developed crosslinking agent, and may include, for example, polyisocyanate compounds, epoxy resins, melamine resins, urea resins, dialdehydes, methylol polymers, and preferably polyisocyanate compounds.

[0142] The solvent may include common solvents used in the field of resin compositions, for example, alcohol compounds such as methanol, ethanol, isopropyl alcohol, butanol, and propylene glycol methoxy alcohol; ketone compounds such as methyl ethyl ketone, methyl butyl ketone, methyl isobutyl ketone, diethyl ketone, and dipropyl ketone; acetate compounds such as methyl acetate, ethyl acetate, butyl acetate, and propylene glycol methoxy acetate; cellosolve compounds such as methyl cellosolve, ethyl cellosolve, and propyl cellosolve; and hydrocarbon compounds such as hexane, heptane, benzene, toluene, and xylene. These solvents may be used alone or in combination of two or more.

[0143] The thickness of the adhesive / bonding layer can be appropriately determined depending on the type of resin serving as the adhesive / bonding agent, the adhesive / bonding strength, the environment in which the adhesive / bonding agent is used, etc. In one embodiment, to ensure sufficient adhesive / bonding strength and minimize the thickness of the optical laminate, the thickness of the adhesive / bonding layer can be 0.01 to 50 μm, preferably 0.05 to 20 μm, and more preferably 0.1 to 10 μm.

[0144] The ultraviolet absorbing layer is not particularly limited as long as it is used to prevent degradation of the dimming laminate due to ultraviolet rays. For example, salicylic acid ultraviolet absorbers (phenyl salicylate, p-tert-butyl salicylate, etc.), benzophenone ultraviolet absorbers (2,4-dihydroxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, etc.), benzotriazole ultraviolet absorbers (2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)benzotriazole, 2-(2'-hydroxy- 3'-tert-butyl-5'-methylphenyl)benzotriazole, 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-3'-(3",4",5",6"-tetrahydrophthalimidomethyl)-5'-methylphenyl)benzotriazole, 2,2-methylenebis(4-(1,1,3,3-tetramethylbutyl)-6-(2H-benzotriazol-2-yl)phenol), 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy- 3'-tert-butyl-5'-(2-octyloxycarbonylethyl)-phenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-3'-(1-methyl-1-phenylethyl)-5'-(1,1,3,3-tetramethylbutyl)-phenyl)benzotriazole, 2-(2H-benzotriazol-2-yl)-6-(straight chain and side chain dodecyl)-4-methylphenol, octyl-3-[3-tert-butyl-4-hydroxy-5-(chloro-2H-benzotriazol-2-yl)phenyl]propionate and 2-ethylhexyl-3-[3-tert-butyl-4-hydroxy-5-(

[0014] The present invention also includes a mixture of cyanoacrylate-based UV absorbers (such as 2'-ethylhexyl-2-cyano-3,3-diphenylacrylate and ethyl-2-cyano-3-(3',4'-methylenedioxyphenyl)-acrylate), and triazine-based UV absorbers. Benzotriazole-based UV absorbers or triazine-based UV absorbers are preferred, as they have high transparency and are excellent in preventing degradation of the polarizing plate or the transmittance variable layer. Benzotriazole-based UV absorbers with more suitable spectral absorption spectra are particularly preferred. The above-mentioned benzotriazole-based ultraviolet absorber can also be a bis (Bis) substance, for example, it can be 6,6'-methylenebis(2-(2H-benzo[d][1,2,3]triazol-2-yl)-4-(2,4,4-trimethylpentane-2-yl)phenol), 6,6'-methylenebis(2-(2H-benzo[d][1,2,3]triazol-2-yl)-4-(2-hydroxyethyl)phenol), etc.

[0145] The hard coat layer is not particularly limited as long as it is used to protect components such as polarizing plates and transmittance variable layers from external physical and chemical impacts, and any hard coat layer previously developed or developed in the future may be used.

[0146] In one embodiment, the hard coat layer can be formed by applying a hard coat layer-forming composition to another member and then curing the composition using light or heat. The hard coat layer-forming composition is not particularly limited and may include, for example, a photocurable compound and a photoinitiator.

[0147] The above-mentioned photocurable compound and photoinitiator can use substances generally used in the field without limitation. For example, the above-mentioned photocurable compound can be a photopolymerizable monomer, a photopolymerizable oligomer, etc., for example, monofunctional and / or multifunctional (meth)acrylates can be mentioned, and the photoinitiator can be hydroxycyclohexyl phenyl ketone, trimethylbenzoyldiphenylphosphine oxide, acetophenone series, oxime ester series, etc., and commercially available products include Irgacure-184, TPO, Irgacure-907, etc.

[0148] <Smart Windows, Windows for Cars and Buildings>

[0149] In addition to the above-mentioned dimming laminate, the present invention also includes a smart window including the above-mentioned dimming laminate. By applying the dimming laminate of the present invention to the above-mentioned smart window, it can be easily handled during the process and prevented from being damaged or defective.

[0150] In addition, the present invention includes an automobile in which the above-mentioned smart window is applied to at least one of a front window, a rear window, a side window, a skylight, and an interior partition, and a window for a building including the above-mentioned smart window.

[0151] The following describes specific embodiments of the present invention. However, the present invention is not limited to the embodiments disclosed below, but can be implemented in a variety of different ways. These embodiments are provided only to complete the disclosure of the present invention and to fully inform those skilled in the art of the present invention of the scope of the invention. The present invention is defined solely by the scope of the claims.

[0152] Manufacturing Example 1: Polarizing Plate Preparation

[0153] (1) Swelling treatment process

[0154] A 60 μm-thick polyvinyl alcohol film (stock film) (manufactured by Kuraray Co., Ltd., trade name "Kuraray polyval film VF-PE #6000," average degree of polymerization 2400, degree of saponification 99.9 mol%) was continuously unwound from a stock roll and transported. The film was then immersed in a swelling bath filled with 20°C pure water for 30 seconds. During this swelling treatment, inter-roll stretching (uniaxial longitudinal stretching) was performed by creating a difference in peripheral speed between the nip rolls. The stretch ratio was set to 2.5 times based on the stock film.

[0155] (2) Dyeing process

[0156] Next, the film, having passed through the nip rolls, was immersed for 120 seconds in a 30°C dye bath containing pure water / potassium iodide / iodine / boric acid (mass ratio: 100 / 2 / 0.01 / 0.3). During this dyeing process, inter-roll stretching (uniaxial longitudinal stretching) was performed by creating a difference in peripheral speed between the nip rolls. The stretch ratio was set to 1.1x based on the film after the swelling step.

[0157] (3) Cross-linking treatment process

[0158] Next, the film, having passed through the nip rolls, was immersed for 70 seconds in a first crosslinking bath at 56°C containing pure water, potassium iodide, and boric acid (mass ratio: 100 / 12 / 4). Inter-roll stretching (uniaxial longitudinal stretching) was performed by creating a peripheral speed difference between the nip rolls and the nip rolls positioned between the first and second crosslinking baths. The stretch ratio was set to 1.9x based on the film after the dyeing step.

[0159] (4) Color correction process

[0160] Next, the cross-linked film was immersed in a second cross-linking bath of potassium iodide / boric acid / pure water (mass ratio) of 9 / 2.9 / 100 at 40° C. for 10 seconds.

[0161] (5) Cleaning process

[0162] Next, the membrane after the second crosslinking treatment was immersed in a cleaning bath filled with pure water at 14°C for 5 seconds and rinsed with 5 ml 3 / h and elution temperature 14 ℃ for cleaning.

[0163] (6) Drying process

[0164] Next, the film after the washing step was passed through a drying oven and heated and dried at 80° C. for 190 seconds to produce a polarizer film. The moisture content after drying was 13.6%, and the thickness of the obtained polarizer film was about 18 μm.

[0165] (7) Lamination process

[0166] Next, a water-based adhesive containing 5 parts by mass of polyvinyl alcohol per 100 parts by mass of water was prepared as an adhesive. Protective films (PET) were then laminated on both sides of the polarizer film using the prepared UV adhesive. The resulting laminate was exposed to UV light to cure the adhesive, thereby producing a first polarizing plate and a second polarizing plate, respectively. The thickness of each polarizing plate is shown in Table 1.

[0167] Manufacturing Example 2: Preparation of Transparent Conductive Layer

[0168] A PEDOT functional conductive layer-forming composition was applied onto the protective layers of the first and second polarizing plates and dried at 90° C. for about 5 to 10 minutes to form a functional conductive layer. The first and second transparent conductive layers were then laminated.

[0169] At this time, the composition for forming the PEDOT functional conductive layer used was a mixture of 0.6 wt % of PEDOT:PSS, 32.4 wt % of ethanol, 40 wt % of deionized water, and 27 wt % of 2-methoxyethanol.

[0170] Manufacturing Example 3: Oriented Film Preparation

[0171] An alignment liquid was applied to each of the first transparent conductive layer and the second transparent conductive layer produced in Production Example 2 and dried (80° C. / 2 minutes).

[0172] Then, the dried alignment liquid is irradiated with UV light to form a first alignment film and a second alignment film.

[0173] Manufacturing Example 4: Manufacturing of a Polymer Dispersed Liquid Crystal Molecular Layer

[0174] A prepolymer of ethylene glycol dimethacrylate, 1,6-hexanediol diacrylate, and 3,5,5-trimethylhexyl acrylate was mixed and used. A single liquid crystal with bicyclohexylbenzene as its core skeleton and cyano as its functional group was used as the liquid crystal molecule. The prepolymer, liquid crystal molecule, and crosslinking agent concentrations were set at 25 weight percent, 70 weight percent, and 5 weight percent, respectively, to produce a polymer-dispersed liquid crystal layer.

[0175] Examples 1-1 to 1-7 and Comparative Examples 1-1 to 1-3: Preparation of light-adjusting laminates

[0176] A sealing glue (WORLDROCK No. 7632, Xie Li Co., Ltd.) was applied to the outer portion of the first polarizing plate, the first transparent conductive layer and the first orientation film manufactured by the above-mentioned manufacturing examples 1 to 3, and in order to form the polymer dispersed liquid crystal molecular layer manufactured in manufacturing example 4 on the portion where the sealing glue was not formed on the above-mentioned first orientation film, the above-mentioned second polarizing plate, the second transparent conductive layer and the second orientation film were attached to the above-mentioned first polarizing plate, the first transparent conductive layer and the first orientation film in a manner opposite to each other via the above-mentioned sealing glue and the liquid crystal molecular layer, and then the polymer dispersed liquid crystal molecular layer manufactured in manufacturing example 4 was injected, thereby producing the dimming stacks of Examples 1-1 to 1-7 and Comparative Examples 1-1 to 1-3, respectively.

[0177] Examples 2-1 to 2-7 and Comparative Examples 2-1 to 2-3: Smart Window Fabrication

[0178] After adding 6.5 g of HCl to 100 g of a PVA (Toyo Chemical) aqueous solution, 1.5 g of butyraldehyde (ACROS Chemical) was added with stirring. After the addition, the mixture was stirred at 40°C for 4 hours, and the resulting PVB was filtered using distilled water as a solvent to prepare an adhesive solution.

[0179] The adhesive solution prepared as above was applied on both sides of the dimming laminates of the above-mentioned Examples 1-1 to 1-7 and Comparative Examples 1-1 and 1-3 to form an adhesive layer with a thickness of 0.5 mm, and then a glass substrate with a thickness of 2 mm (Normal Sodalime Glass, JMC Glass Co., Ltd.) was attached respectively to produce the smart windows of Examples 2-1 to 2-7 and Comparative Examples 2-1 to 2-3, respectively.

[0180] Experimental example: physical property evaluation

[0181] (1) Elastic modulus of polarizing plate

[0182] The first and second polarizing plates prepared in Manufacturing Example 1 were cut into 100 mm × 10 mm pieces, and their tensile moduli were measured using a Shimadzu Autograph AG-X at a speed of 4 mm / min. The results are shown in Table 1 below.

[0183] (2)Thickness of polarizing plate

[0184] The first polarizing plate and the second polarizing plate manufactured in Manufacturing Example 1 were cut into pieces of 100 mm×10 mm, and their thicknesses were measured using a Sony LY51 film thickness meter. The results are shown in Table 1 below.

[0185] (3) Poisson's ratio of polarizer (ν)

[0186] The first and second polarizing plates prepared in Example 1 were cut into 85 mm x 7 mm pieces, and their Poisson's ratios were measured using a Linkam TST350E partial tensile tester at a speed of 3 mm / min. The results are shown in Table 1 below.

[0187] The elastic modulus, thickness, and Poisson's ratio of the first polarizing plate and the second polarizing plate measured in (1) to (3) above were substituted into Formula 1 and calculated. The results are shown in Table 1 below.

[0188] [Formula 1]

[0189]

[0190] In the above formula 1, E is the elastic modulus (modulus; N / mm 2 ), t is the thickness (mm), and ν is the Poisson's ratio.

[0191] (4) Evaluation of smart windows

[0192] The smart windows of Examples 2-1 to 2-7 and Comparative Examples 2-1 to 2-3 were visually inspected for defects such as wrinkles, bubbles, and black spots. The number of defects was visually confirmed, and the size of each defect was measured using an Olympus MX61 optical microscope. The size of the largest defect was recorded. These defects were evaluated according to the following defect evaluation criteria. The results are shown in Table 1.

[0193] <Bad Evaluation Criteria>

[0194] :Number of defects is less than 2 / Defect size is less than 0.1mm

[0195] ○: Number of defects is greater than 2 and less than 5 / Defect size is greater than 0.1mm and less than 0.3mm

[0196] △: Number of defects is greater than 5 and less than 10 / Defect size is greater than 0.3mm and less than 0.7mm

[0197] ×: The number of defective items is greater than 10 / the size of the defective items is greater than 0.7mm

[0198] [Table 1]

[0199]

[0200] The experimental results above confirm that in the embodiment where the S calculated by equation 1 for at least one of the first and second polarizers is between 0.5 and 4.0 N·mm, defects such as wrinkles, bubbles, and black spots can be minimized when used in smart windows. In contrast, in the comparative example where the S calculated by equation 1 for at least one of the first and second polarizers is outside the 0.5 to 4.0 N·mm range, the number and size of defects significantly increase when used in smart windows.

Claims

1. A dimming stack comprising: a first polarizing plate; a first transparent conductive layer formed on one surface of the first polarizing plate; a second polarizing plate, opposite to the first polarizing plate; a second transparent conductive layer formed on one side of the second polarizing plate and opposite to the first transparent conductive layer; as well as a liquid crystal layer disposed between the first transparent conductive layer and the second transparent conductive layer, At least one of the first polarizing plate and the second polarizing plate has an S calculated by the following formula 1 of 0.5 to 4.0 N·mm, Formula 1 In the formula 1, E is the elastic modulus, and the unit of the elastic modulus is N / mm 2 , t is the thickness in mm, and ν is the Poisson's ratio. 2 . The light-adjusting laminate according to claim 1 , wherein at least one of the first polarizing plate and the second polarizing plate comprises one or more functional layers selected from the group consisting of a protective layer, a phase difference adjusting layer, and a refractive index adjusting layer. 3 . The light-adjusting laminate according to claim 1 , wherein at least one of the first polarizing plate and the second polarizing plate has a thickness of 50 to 300 μm. 4 . The light-adjusting laminate according to claim 1 , wherein at least one of the first and second transparent conductive layers is formed to be in direct contact with one of the first and second polarizing plates without a separate substrate therebetween. The light-adjusting laminate according to claim 1 , wherein at least one of the first and second transparent conductive layers is formed to be in direct contact with one of the first and second polarizing plates by including an easy-adhesion layer therebetween. 6 . The dimming stack according to claim 1 , wherein at least one of the first transparent conductive layer and the second transparent conductive layer comprises one or more selected from the group consisting of transparent conductive oxides, metals, carbon-based materials, conductive polymers, conductive inks, and nanowires. 7 . The dimming stack according to claim 1 , wherein the liquid crystal behavior mode of the liquid crystal layer is any one selected from the group consisting of twisted nematic (TN) mode, super twisted nematic (STN) mode, in-plane switching (IPS) mode, fringe field switching (FFS) mode, and vertical alignment (VA) mode. A smart window comprising the light-adjusting laminate according to any one of claims 1 to 7.

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