Optical laminate, method for producing the same, and smart window including the same

Abstract

The present invention relates to a variable transmittance optical laminate including a first transparent member, a first laminate formed on the first transparent member and laminated in the order of a first polarizing plate, a first transparent conductive layer, and a first alignment film, a second transparent member facing the first transparent member, a second laminate formed on the second transparent member and laminated in the order of a second polarizing plate, a second transparent conductive layer, and a second alignment film, and a liquid crystal layer disposed between the first laminate and the second laminate. At least one of the first transparent conductive layer and the second transparent conductive layer is formed in direct contact with one of the first polarizing plate and the second polarizing plate. The first transparent member and the first polarizing plate are joined by a first joining layer, and the second transparent member and the second polarizing plate are joined by a second joining layer. At least one of the first joining layer and the second joining layer is formed of an adhesive. The present invention relates to a variable transmittance optical laminate and a method for manufacturing the same, and a smart window including the same.

Description

Technical Field

[0001] The present invention relates to a variable transmittance optical laminate, a method for manufacturing the same, and a smart window including the same.

Background Art

[0002] A variable transmittance optical laminate is driven by driving liquid crystal by applying a voltage to change the transmittance. The variable transmittance optical laminate can be joined to a transparent member such as glass and embodied in the form of a smart window or the like.

[0003] On the other hand, in a polarizer of a polarizing plate which is a member of a variable transmittance optical laminate, an extended polarizer is mainly used because of the advantages of relatively low manufacturing cost and simple manufacturing process. In the case of an extended polarizer, since a polarizing film is manufactured through a process of dyeing, crosslinking, stretching, and drying, stress generated in the stretching process remains in the polarizer. Therefore, when an external stimulus continues to be applied to the stretched polarizer, the polarizer cannot withstand the residual stress and undergoes shrinkage, deformation, etc., which directly induces a change in the size of the optical laminate itself, leading to a decrease in adhesion of a sealant or a polarizer, etc., and damage to the sealant, which induces liquid crystal outflow through the sealant adhesion interface.

[0004] Korean Patent Publication No. 10-2019-0124560 discloses a variable transmittance device capable of suppressing the inflow of air bubbles in liquid crystal by eliminating negative pressure due to deformation of a substrate in an environment where the external temperature changes by forming at least one of a first substrate layer and a second substrate layer with a heat-shrinkable substrate layer such as a polyethylene terephthalate (PET) or triacetyl cellulose (TAC) film. However, the disclosed patent still has a limitation in that it has not been able to present a configuration capable of preventing damage to the sealant and suppressing the inflow of air bubbles in the liquid crystal by improving the shrinkage force of a polyvinyl alcohol (PVA) film having the highest shrinkage force in a polarizing plate structure.

[0005] Therefore, there is a need to develop a transmissivity variable optical laminate that can suppress damage to the sealant and the inflow of air bubbles into the liquid crystal even when a stretched polarizer is included, and can suppress the size change of the optical laminate, by improving the contraction force of the stretched polarizer.

Summary of the Invention

Problems to be Solved by the Invention

[0006] An object of the present invention is to provide a transmissivity variable optical laminate in which the adhesion force of a sealant or a polarizing plate is maintained by controlling the contraction force of a stretched polarizer.

[0007] Another object of the present invention is to provide a transmissivity variable optical laminate in which the size change is minimized by controlling the contraction force of a stretched polarizer.

[0008] Another object of the present invention is to provide a transmissivity variable optical laminate in which damage to the sealant and the inflow of air bubbles into the liquid crystal are minimized even in a temperature-changing environment by controlling the contraction force of a stretched polarizer.

Means for Solving the Problems

[0009] To solve such technical problems, the present invention provides a transmissivity variable optical laminate including a first transparent member, a first laminate formed on the first transparent member and laminated in the order of a first polarizing plate, a first transparent conductive layer, and a first alignment film, a second transparent member facing the first transparent member, a second laminate formed on the second transparent member and laminated in the order of a second polarizing plate, a second transparent conductive layer, and a second alignment film, and a liquid crystal layer disposed between the first laminate and the second laminate, At least one of the first transparent conductive layer and the second transparent conductive layer is formed in direct contact with one of the first polarizing plate and the second polarizing plate. The first transparent member and the first polarizing plate are joined by a first joining layer, and the second transparent member and the second polarizing plate are joined by a second joining layer. At least one of the first joining layer and the second joining layer is formed of an adhesive. Provided are a variable transmittance optical laminate, a method for manufacturing the same, and a smart window including the same.

Advantages of the Invention

[0010] According to the variable transmittance optical laminate of the present invention, the contraction force of the stretched polarizer can be controlled, and the adhesion force of a sealant or a polarizing plate can be maintained.

[0011] Furthermore, according to the variable transmittance optical laminate of the present invention, the contraction force of the stretched polarizer can be controlled, and the size change of the variable transmittance optical laminate can be minimized.

[0012] Furthermore, according to the variable transmittance optical laminate of the present invention, the contraction force of the stretched polarizer can be controlled, and damage to the sealant of the variable transmittance optical laminate and the inflow of air bubbles into the liquid crystal can be minimized even in a variable temperature environment.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2a

Figure 2b

Figure 2c

Figure 2d

Figure 2e

Figure 3

BEST MODE FOR CARRYING OUT THE INVENTION

[0014] The present invention relates to a variable transmittance optical laminate, a method for manufacturing the same, and a smart window including the same, in which at least one of the first bonding layer for bonding the first transparent member and the first polarizing plate and the second bonding layer for bonding the second transparent member and the second polarizing plate is formed of an adhesive, whereby the shrinkage rate of the stretched polarizer can be controlled. Accordingly, it is possible to maintain the adhesion of a sealant or a polarizing plate, etc., minimize the size change of the optical laminate, and minimize the damage of the sealant and the inflow of air bubbles in a variable temperature environment.

[0015] More specifically, the present invention relates to a variable transmittance optical laminate including a first transparent member, a first laminate formed on the first transparent member and laminated in the order of a first polarizing plate, a first transparent conductive layer, and a first alignment film, a second transparent member facing the first transparent member, a second laminate formed on the second transparent member and laminated in the order of a second polarizing plate, a second transparent conductive layer, and a second alignment film, and a liquid crystal layer disposed between the first laminate and the second laminate, wherein at least one of the first transparent conductive layer and the second transparent conductive layer is formed in direct contact with one of the first polarizing plate and the second polarizing plate, the first transparent member and the first polarizing plate are bonded by a first bonding layer, the second transparent member and the second polarizing plate are bonded by a second bonding layer, and at least one of the first bonding layer and the second bonding layer is formed of an adhesive.

[0016] The present invention also relates to a method for manufacturing a variable transmittance optical laminate, which includes steps of: forming a first transparent conductive layer and a second transparent conductive layer on one surface of a first polarizing plate and a second polarizing plate respectively (P10); bonding a first transparent member and a second transparent member to the other surfaces of the first polarizing plate and the second polarizing plate respectively (P20); forming a first alignment film on one surface of the first transparent conductive layer to fabricate an upper laminate (P31); forming a second alignment film on one surface of the second transparent conductive layer to fabricate a lower laminate (P32-1), forming a liquid crystal layer on the second alignment film (P32-2); and bonding the upper laminate and the lower laminate (P40), wherein at least one of the first transparent member and the second transparent member is bonded to the polarizing plate by an adhesive.

[0017] The variable transmittance optical laminate of the present invention is particularly suitable for the technical field where the light transmissivity can be changed by applying a voltage, and can be used, for example, in a smart window.

[0018] A smart window means an optical structure that controls the amount of light or heat passing through by changing the light transmissivity by applying an electrical signal. That is, a smart window is provided to be able to change to a transparent, opaque or semi-transparent state by a voltage, and is also called a variable transmittance glass, a dimming glass or a smart glass.

[0019] A smart window may be used for partitioning the interior space of a vehicle or a building or for a privacy protection partition, or may be used as a daylighting window arranged at an opening of a building. It may also be used for a highway display board, a bulletin board, a scoreboard, a clock or an advertising screen, and can be used to replace the glass of a means of transportation such as a window or a sunroof of an automobile, a bus, an airplane, a ship or a train.

[0020] The variable transmittance optical laminate of the present invention can also be used for smart windows in various technical fields as described above. However, since the conductive layer is directly formed on the polarizing plate, it does not include a separate base material for forming the conductive layer, so it has a thin thickness and is advantageous in bending characteristics, and can be particularly preferably used for smart windows for vehicles or buildings. In one or more embodiments, a smart window to which the variable transmittance optical laminate of the present invention is applied can be used for transportation means, for example, the front window, rear window, side window, and sunroof window of an automobile, or building fixtures for buildings. In addition to the use of blocking external light, it can also be used for partitioning the internal space of an automobile or a building or protecting privacy, such as internal partitions, and can also be used for wearable devices such as helmets, glasses, or watches.

[0021] Hereinafter, embodiments of the present invention will be described more specifically with reference to the drawings. However, the following drawings attached to this specification illustrate preferred embodiments of the present invention, and together with the content of the above-described invention, serve to better understand the technical idea of the present invention. Therefore, the present invention should not be construed as being limited only to the matters described in these drawings.

[0022] The terms used in this specification are for explaining the examples and are not intended to limit the present invention. In this specification, the singular form also includes the plural form unless otherwise specifically mentioned in the text. For example, the "polarizing plate" used in this specification may mean at least one of the first polarizing plate and the second polarizing plate, and the "transparent conductive layer" may mean at least one of the first transparent conductive layer and the second transparent conductive layer.

[0023] As used herein, the terms "comprises" and / or "comprising" are used in a sense that does not exclude the presence or addition of one or more other components, steps, operations, and / or elements other than the recited components, steps, operations, and / or elements. The same reference numerals throughout the specification refer to the same components.

[0024] As used herein, the terms "substitutes" and / or "substituting" are used to mean that other components, steps, operations, and / or elements replace the position and function of the recited components, steps, operations, and / or elements.

[0025] Spatially relative terms such as "lower", "bottom surface", "lower part", "upper", "upper surface", "upper part", etc. can be used to easily describe the correlation between one element or component and another element or component as shown in the drawings. Spatially relative terms should be understood as terms that include different directions of elements relative to each other during use or operation in addition to the directions shown in the drawings. For example, when covering an element shown in the drawings, an element described as "lower" or "lower part" of another element may be placed "above" the other element. Thus, the exemplary term "lower" may include both the lower and upper directions. The element can also be oriented in other directions, and thus the spatially relative terms can be interpreted according to the orientation.

[0026] As used within this specification, the "plane direction" can be interpreted as the direction orthogonal to the polarizing plate and / or the transparent conductive layer, that is, the direction as seen from the user's viewing side.

[0027] As used within this specification, "substantially" can be interpreted to include not only being physically completely identical or coincident, but also being within the error range in the measurement or manufacturing process. For example, it can be interpreted as being within an error range of 0.1% or less.

[0028] FIG. 1 is a diagram showing the laminated structure of a variable transmittance optical laminate according to an embodiment of the present invention, FIG. 2 is a diagram showing the laminated structure of a polarizing plate according to one or more embodiments of the present invention, and FIG. 3 is a diagram showing a method for manufacturing a variable transmittance optical laminate according to an embodiment of the present invention.

[0029] Referring to FIG. 1, the variable transmittance optical laminate according to an embodiment of the present invention may include a transparent member 100, a polarizing plate 200, a transparent conductive layer 300, an alignment film 400, a liquid crystal layer 600, and a bonding layer 700.

[0030] The transparent member 100 is provided to prevent the optical characteristics of the optical laminate from being visually recognized and the internal laminated structure from being deformed due to changes in the external physicochemical environment, and may be provided in the form of a first transparent member 100-1 and a second transparent member 100-2 on the visual side surface and the back side surface of the optical laminate, respectively.

[0031] The transparent member 100 is not particularly limited as long as it can serve as a structural base of the laminated structure in the manufacturing method of the optical laminate described later without inhibiting the optical characteristics of the optical laminate. Preferably, a glass member can be used, and for example, it may include oxide glasses such as silicate glass, borate glass, and phosphate glass. In this case, there is an advantage in that no heat shrinkage phenomenon occurs during subsequent process steps and a predetermined hardness can be imparted to the optical laminate.

[0032] In one or more embodiments, the transparent member 100 may have a thickness of 1 mm to 20 mm. When the thickness of the transparent member 100 satisfies the above range, it is possible to achieve thinning while having excellent hardness and prevent internal panel deformation or crack generation. Specifically, when it is less than 1 mm, it may be difficult to protect the internal laminated structure from external air blocking or external impact, and when it exceeds 20 mm, it may be disadvantageous from the perspective of thinning or weight reduction.

[0033] In one or more embodiments, the transparent member 100 may have a single-layer or multi-layer structure. For example, the first transparent member 100-1 and the second transparent member 100-2 may have a single-layer structure formed of a single member as illustrated in FIG. 1, but are not necessarily limited thereto and may have a multi-layer structure in which several members are laminated.

[0034] Referring to FIG. 2, the polarizing plate 200 may include a stretched polarizer 210, and may further include functional layers such as a protective layer 220, a retardation adjustment layer 230, and / or a refractive index adjustment layer 240 on one or both surfaces of the stretched polarizer 210. For example, the polarizing plate 200 may include a stretched polarizer 210 and a protective layer 220 laminated on one or both surfaces of the stretched polarizer 210 (see FIGS. 2a and 2b). Further, the polarizing plate 200 of the present invention may include a stretched polarizer 210, a protective layer 220 laminated on one surface of the stretched polarizer 210, and a retardation adjustment layer 230 laminated on the other surface facing the one surface of the stretched polarizer 210 (see FIG. 2c). Further, the polarizing plate 200 of the present invention may include a stretched polarizer 210, a protective layer 220 laminated on one surface of the stretched polarizer, a retardation adjustment layer 230, and a refractive index adjustment layer 240 laminated in this order on the other surface facing the one surface of the stretched polarizer 210 (see FIG. 2d). Further, the polarizing plate 200 of the present invention may include a stretched polarizer 210, a protective layer 220 laminated on one surface of the stretched polarizer, and a protective layer 220 and a retardation adjustment layer 230 laminated in this order on the other surface facing the one surface of the stretched polarizer 210 (see FIG. 2e).

[0035] In one embodiment, the stretched polarizer 210 may include a stretched polyvinyl alcohol (PVA)-based resin. The polyvinyl alcohol (PVA)-based resin may be a polyvinyl alcohol-based resin obtained by saponifying a polyvinyl acetate-based resin. Examples of the polyvinyl acetate-based resin include polyvinyl acetate which is a homopolymer of vinyl acetate, and copolymers of vinyl acetate and other monomers copolymerizable therewith. Examples of the other monomers may include unsaturated carboxylic acid-based, unsaturated sulfonic acid-based, olefin-based, vinyl ether-based, and acrylamide-based monomers having an ammonium group. The polyvinyl alcohol (PVA)-based resin also includes modified ones, for example, polyvinyl formal or polyvinyl acetal modified with aldehydes.

[0036] The protective layer 220 is for preserving the polarization characteristics of the stretched polarizer 210 from subsequent processes and the external environment, and can be embodied in the form of a protective film or the like.

[0037] The protective layer 220 may be formed in direct contact with one or both surfaces of the stretched polarizer 210, but is not limited thereto. For example, the protective layer may be used as a multilayer structure in which one or more protective layers are continuously laminated, or may be formed in direct contact with other functional layers.

[0038] In one or more embodiments, the protective layer 220 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).

[0039] The retardation adjustment layer 230 is for complementing the optical characteristics of the optical laminate, and may be embodied in the form of a retardation film or the like, and a conventional or later-developed retardation film or the like may 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 may be used, and these may be used alone or in combination.

[0040] The retardation adjustment layer 230 may be formed in direct contact with one surface of the polarizer 110 as shown in FIGS. 2c and 2d, but is not limited thereto. For example, as shown in FIG. 2e, the retardation adjustment layer 230 may be formed on one surface of the protective layer 220, and the stretched polarizer 210, the protective layer 220, and the retardation adjustment layer 230 may be sequentially laminated.

[0041] The retardation adjustment layer 230 may be a polymer stretched film or a liquid crystal polymerization film obtained by stretching a polymer film capable of imparting optical anisotropy by stretching in an appropriate manner.

[0042] In one embodiment, the polymer stretched film may be a polyolefin such as polyethylene (PE) or polypropylene (PP), a cyclic olefin polymer (COP) such as polynorbornene, polyvinyl chloride (PVC), polyacrylonitrile (PAN), polysulfone (PSU), an acrylic resin, a polyester such as polycarbonate (PC) or polyethylene terephthalate (PET), a polyacrylate, a cellulose ester polymer such as polyvinyl alcohol (PVA) or triacetyl cellulose (TAC), or a copolymer of two or more monomers in the monomers forming the polymer. A polymer layer containing the like may also be used.

[0043] The method for obtaining the polymer stretched film is not particularly limited. For example, it can be obtained by stretching the polymer material after forming it into a film shape. The method for forming it into a film shape is not particularly limited, and it can be formed into a film by known methods such as injection molding, sheet molding, blow molding, injection blow molding, inflation molding, extrusion molding, foam molding, and cast molding, and secondary processing molding methods such as pressure air molding and vacuum molding may also be used. Among them, extrusion molding and cast molding are preferably used. At this time, for example, an unstretched film can be extrusion molded using an extruder equipped with a T-die, a circular die, etc. When obtaining a molded product by extrusion molding, a material obtained by previously melt-kneading various resin components, additives, etc. can be used, or it can also be molded through melt-kneading during extrusion molding. Further, after dissolving various resin components using a solvent common to various resin components, such as a solvent such as chloroform or methylene dichloride, an unstretched film may be cast-molded by cast drying and solidifying.

[0044] The polymer stretched film may be uniaxially stretched in the machine flow direction (MD; Mechanical Direction, longitudinal direction or length direction) of the formed film, or uniaxially stretched in the direction transverse to the machine flow direction (TD; Transverse Direction, transverse direction or width direction). Also, a biaxially stretched film may be manufactured by stretching by a sequential biaxial stretching method of roll stretching and tenter stretching, a simultaneous biaxial stretching method by tenter stretching, a biaxial stretching method by tubular stretching, etc.

[0045] The liquid crystal polymer film can contain the reactive liquid crystal compound in a polymerized state. The content regarding the reactive liquid crystal compound of the coating type polarizer described above can be similarly applied to the reactive liquid crystal compound.

[0046] In one or more embodiments, the thickness of the retardation adjustment layer 230 may be 10 to 100 μm in the case of a polymer stretched film, and may be 0.1 to 5 μm in the case of a liquid crystal polymer film.

[0047] The refractive index adjustment layer 240 is provided to compensate for the refractive index difference of the optical laminate due to the transparent conductive layer 300, and may serve to improve visual recognition characteristics, etc. by reducing the refractive index difference. Further, the refractive index adjustment layer 240 may be provided to correct the hue caused by the transparent conductive layer 300. On the other hand, when the transparent conductive layer has a pattern, the transmittance difference between the pattern region where the pattern is formed and the non-pattern region where the pattern is not formed can be compensated through the refractive index adjustment layer 240.

[0048] Specifically, the transparent conductive layer 300 is laminated adjacent to another member (for example, a polarizer, etc.) having a different refractive index from it, and a difference in light transmittance may be induced by the refractive index difference with the adjacent other layer. Particularly when a pattern is formed on the transparent conductive layer, a problem may occur in that it can be visually recognized so as to distinguish between the pattern region and the non-pattern region. Therefore, by including the refractive index adjustment layer 240, the refractive index is compensated so that the difference in light transmittance of the optical laminate can be reduced, and particularly when a pattern is formed on the transparent conductive layer, the pattern region and the non-pattern region are not distinguished and visually recognized.

[0049] In one embodiment, the refractive index of the refractive index adjustment layer 240 may be appropriately selected depending on the material of another adjacent member, but is preferably from 1.4 to 2.6, and more preferably may be from 1.4 to 2.4. In this case, light loss due to a sharp refractive index difference between the transparent conductive layer 300 and another member such as the stretched polarizer 210 can be prevented.

[0050] The refractive index adjustment layer 240 is not particularly limited as long as it can prevent a sharp refractive index difference between the transparent conductive layer 300 and another member such as the stretched polarizer 210, and a compound used for forming a conventional or later-developed refractive index adjustment layer may be used, for example, it may be formed from a refractive index adjustment layer forming composition containing a polymerizable isocyanurate compound.

[0051] In one embodiment, the polarizing plate 200 may further include other configurations for assisting or enhancing the characteristics of the polarizer in addition to the above-described components. For example, in order to further improve mechanical durability, it may further include an overcoat layer or the like.

[0052] In one or more embodiments, the polarizing plate 200 may have a thickness of 30 to 200 μm, preferably 30 to 170 μm, and more preferably 50 to 150 μm. In this case, the polarizing plate 200 enables the production of an optical laminate with a thin thickness while maintaining optical characteristics.

[0053] On the other hand, since the configuration of the optical laminate according to the present invention is not necessarily applicable only to stretched polarizers, in other embodiments of the present invention, it may also include a coating type polarizer.

[0054] The transparent conductive layer 300 is provided for driving the liquid crystal layer 600 and may be formed in direct contact with the polarizing plate 200. For example, as shown in FIG. 1, the first transparent conductive layer 300-1 and the second transparent conductive layer 300-2 may be formed in direct contact with the first polarizing plate 200-1 and the second polarizing plate 200-2, respectively.

[0055] An optical laminate used in the production of conventional smart windows or the like is manufactured by forming a conductive layer for liquid crystal driving on one surface of a substrate and bonding the other surface of the substrate to a polarizing plate. However, the transmissivity variable optical laminate according to the present invention is characterized by directly forming a conductive layer on one surface of a polarizing plate without including a separate substrate for forming the conductive layer, thereby reducing the thickness of the laminate and improving the transmissivity and bending characteristics in the light transmissive mode.

[0056] In one embodiment, the transparent conductive layer 300 may be formed by directly depositing it on one surface of the polarizing plate 200. At this time, in order to improve the adhesion between the transparent conductive layer 300 and the polarizing plate 200, after performing a pretreatment such as corona treatment or plasma treatment on one surface of the polarizing plate 200, it may be formed in direct contact with the pretreated surface of the polarizing plate 200. The pretreatment is not limited to corona treatment or plasma treatment, and pretreatment processes that are conventional or developed in the future may be used as long as the object of the present invention is not impaired.

[0057] In another embodiment, in order to improve the adhesion between the transparent conductive layer 300 and the polarizing plate 200, the transparent conductive layer 300 may be formed in direct contact with the polarizing plate 200 with an easy-adhesion layer (not shown) provided on one surface of the polarizing plate 200 interposed therebetween.

[0058] The transparent conductive layer 300 preferably has a transmittance of 50% or more with respect to visible light. 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 thereto, and materials for transparent conductive layers that are conventional or developed in the future may be used.

[0059] 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 zinc tin oxide (IZTO), aluminum zinc oxide (AZO), gallium zinc oxide (GZO), fluorine tin oxide (FTO), and zinc oxide (ZnO). Further, the 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 these, for example, it may include a silver-palladium-copper (APC) alloy or a copper-calcium (CuCa) alloy. The carbon-based material may include one or more selected from the group consisting of carbon nanotubes (CNT) and graphene, and the conductive polymer may include one or more selected from the group consisting of polypyrrole, polythiophene, polyacetylene, PEDOT, and polyaniline. The conductive ink may be an ink in which a metal powder and a curable polymer binder are mixed, and the nanowire may be, for example, a silver nanowire (AgNW).

[0060] Further, the transparent conductive layer 300 may be formed in a two-layer or more structure by combining the substances. For example, it may be formed in a two-layer structure including a metal layer and a transparent conductive oxide layer so as to reduce the reflectance of incident light and increase the transmittance.

[0061] The alignment film 400 is not particularly limited as long as it can add alignment properties to the liquid crystal compound. In one embodiment, it may be manufactured by a rubbing process. In this case, after manufacturing various material layers applicable to an alignment film such as polyimide, a fine linear uneven shape is manufactured and formed on the surface of this material layer by a rubbing process using a rubbing roll.

[0062] In other embodiments, the alignment film can be manufactured including a photo-alignment or photocurable polymer, etc. For example, it can be fabricated by applying and curing an alignment film coating composition containing a photo-alignment or photocurable polymer, a photoinitiator, and a solvent.

[0063] The photo-alignment or photocurable polymer is not particularly limited, and a cinnamate-based polymer, a polyimide-based polymer, etc. may be used. For example, poly(vinyl cinnamate) (PVCi), poly(siloxane cinnamate) (PSCN), poly(ω(4-chalconyloxy)alkoxyphenylmaleimide, 6-FDA-HAB-Cl, etc. may be used, or a polymer capable of exhibiting alignment properties developed conventionally or in the future may be used.

[0064] In still other embodiments, the alignment film may be manufactured by shaping a fine linear uneven shape manufactured by a rubbing process instead of the alignment film by the rubbing process described above or the photo-alignment film.

[0065] The liquid crystal layer 600 can change the driving mode of the optical laminate by adjusting the transmittance of light incident from one or more directions by an electric field.

[0066] The liquid crystal layer 600 may include a liquid crystal compound and a spacer. In one embodiment, the liquid crystal layer 600 may be a region defined by a first alignment film 400-1, a second alignment film 400-2, and a sealant (not shown). In other embodiments, the liquid crystal layer 600 may be a region defined by the first alignment film 400-1, the second alignment film 400-2, and an adhesive 500, where the sealant is integrally formed with an adhesive for joining the first transparent member 100-1 and the second transparent member 100-2. The method for manufacturing the liquid crystal layer according to the one or more embodiments will be described in detail later in the method for manufacturing an optical laminate.

[0067] The liquid crystal compound is driven by an electric field and is not particularly limited as long as it can control the light transmittance, and a conventional or later-developed liquid crystal compound can be used.

[0068] The liquid crystal behavior mode of the liquid crystal compound is not particularly limited. For example, it may be driven in a TN (Twisted nematic) mode, but is not limited thereto, and may also be driven by an STN (Super twisted nematic) mode, a VA (Vertical alignment) mode, an ECB (Electrically controlled birefringence) mode, etc.

[0069] The spacer may include at least one or more spacers among ball spacers and column spacers, and is particularly preferably a ball spacer. The spacer may be one or more, and preferably has a height of 1 μm to 10 μm.

[0070] Also, at this time in the planar direction, the area occupied by the spacer in the liquid crystal layer 600 is preferably 0.01 to 10% of the area of the liquid crystal layer 600 from the viewpoints of user visibility and improvement of transmittance in the transmissive mode.

[0071] The sealant may be located between the first laminate 800-1 and the second laminate 800-2 and be for attaching the first laminate 800-1 and the second laminate 800-2 to each other.

[0072] The sealant may contain a curable resin as a base resin. As the base resin, an ultraviolet curable resin or a thermosetting resin known to be used in sealants in the art may be used. The ultraviolet curable resin may be a polymer of an ultraviolet curable monomer. The thermosetting resin may be a polymer of a thermosetting monomer.

[0073] As the base resin of the sealant, for example, an acrylate resin, an epoxy resin, a urethane resin, a phenol resin, or a mixture of these resins may be used. In one embodiment, the base resin may be an acrylate resin, and the acrylate resin may be a polymer of an acrylic monomer. The acrylic monomer may be, for example, a polyfunctional acrylate. In other embodiments, the sealant may further contain a monomer component in the base resin. The monomer component may be, for example, a monofunctional acrylate. In this specification, the monofunctional acrylate can mean a compound having one acrylic group, and the polyfunctional acrylate can mean a compound having two or more acrylic groups. The curable resin can be cured by irradiation with ultraviolet rays and / or heating. The ultraviolet irradiation conditions or heating conditions may be appropriately carried out within a range not impairing the object of the present application. The sealant may further contain an initiator, for example, a photoinitiator or a thermal initiator, if necessary.

[0074] The sealant may be formed by a method commonly used in the art. For example, the sealant may be formed by drawing it on the outer contour (i.e., the non-active region) of the liquid crystal layer using a dispenser equipped with a nozzle.

[0075] The bonding material 500 may be located between the first transparent member 100-1 and the second transparent member 100-2 to bond and seal the first transparent member 100-1 and the second transparent member 100-2 to each other.

[0076] In one embodiment, the bonding material 500 is preferably formed along the outer peripheral surfaces of the first transparent member 100-1 and the second transparent member 100-2, and more preferably, may be arranged to surround the outer surfaces of the first laminate 800-1 and the second laminate 800-2. In this case, the laminated structures of the optical laminate can be more firmly bonded to each other.

[0077] On the other hand, as described above, the bonding material may be formed separately from the sealant or may be formed integrally with the sealant.

[0078] When the bonding material is formed integrally with the sealant, the bonding material 500 can serve as a partition for containing the liquid crystal medium when the liquid crystal medium is injected. Thus, the liquid crystal layer 600 of the optical laminate manufactured thereby can be defined in a region surrounded by the bonding material 500 that surrounds the first alignment film 400-1, the second alignment film 400-2, and the liquid crystal layer 600, as described above. In this case, the bonding material 500 can simultaneously serve as the sealant without the need to separately include a configuration corresponding to the sealant, which is advantageous in terms of reducing the occurrence rate of defects due to sealant deformation in the process of manufacturing the optical laminate into a smart window.

[0079] In one or more embodiments, the bonding material may be made of substantially the same composition as the sealant, but is not necessarily limited thereto.

[0080] The bonding layer 700 may be provided for bonding the first polarizing plate 200-1 and the first transparent member 100-1 provided in the first laminate 800-1, or for bonding the second polarizing plate 200-2 and the second transparent member 100-2 provided in the second laminate 800-2.

[0081] The bonding layer 700 may be formed using a bonding agent such as an adhesive or a cement, but it is preferable to use an adhesive in order to control the shrinkage force of the stretched polarizer. An adhesive that is cured into a solid by ultraviolet rays, heat, etc. and strongly fixes the polarizing plate and the transparent member transmits the shrinkage force of the stretched polarizer to other members as it is because the cohesive force due to elasticity is large. On the other hand, an adhesive that does not go through a curing step has a small cohesive force due to elasticity and a relatively large joining force due to viscosity, so it can relax the residual stress of the stretched polarizer, and thereby prevent the shrinkage force of the stretched polarizer from being transmitted to other members and inducing damage to the sealant, inflow of air bubbles into the liquid crystal, size change of the optical laminate, etc.

[0082] As the adhesive, a conventional or later-developed adhesive can be used, but it preferably has an appropriate adhesive strength so that peeling, air bubbles, etc. do not occur during handling of the optical laminate, and also has transparency and thermal stability. In one or more embodiments, the adhesive may be 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. The adhesive is not particularly limited as long as it has adhesive strength and viscoelasticity, but from the viewpoint of stress relaxation and shrinkage force suppression of the stretched polarizer, it may preferably be an acrylic adhesive, for example, one containing a (meth)acrylate copolymer, a crosslinking agent, a solvent, etc.

[0083] The crosslinking agent may be a conventional crosslinking agent or a crosslinking agent developed in the future. For example, it may include a polyisocyanate compound, an epoxy resin, a melamine resin, a urea resin, dialdehydes, a methylol polymer, etc., and preferably may include a polyisocyanate compound.

[0084] The solvent may include ordinary solvents used in the resin composition field. For example, alcohol-based compounds such as methanol, ethanol, isopropanol, butanol, propylene glycol monomethyl ether; ketone-based compounds such as methyl ethyl ketone, methyl butyl ketone, methyl isobutyl ketone, diethyl ketone, dipropyl ketone; acetate-based compounds such as methyl acetate, ethyl acetate, butyl acetate, propylene glycol monomethyl acetate; cellosolve-based compounds such as methyl cellosolve, ethyl cellosolve, propyl cellosolve; hydrocarbon-based compounds such as hexane, heptane, benzene, toluene, xylene, etc. may be used. These may be used alone or in combination of two or more.

[0085] The thickness of the bonding layer 700 can be appropriately determined according to the type of resin that plays the role of the bonded body, the bonding strength, the environment in which the adhesive is used, etc. In one embodiment, in order to ensure sufficient bonding force and minimize the thickness of the optical laminate, when the bonding layer is formed of an adhesive, it may have a thickness of 2 μm to 38 μm, preferably 5 μm to 35 μm, more preferably 10 μm to 30 μm, and when formed of an adhesive, it may have a thickness of 100 μm to 500 μm, preferably 200 μm to 400 μm.

[0086] In one embodiment, the bonding layer 700 may be formed on one or both surfaces of the polarizing plate by a laminating method.

[0087] The variable transmittance optical laminate of the present invention may further include other members as long as the object of the present invention is not impaired, and for example, it may further include an ultraviolet absorption layer, a hard coating layer, or the like.

[0088] The ultraviolet absorption layer is not particularly limited as long as it can prevent the deterioration of the optical laminate due to ultraviolet rays. For example, salicylic acid-based ultraviolet absorbers (such as phenyl salicylate, p-tert-butyl salicylate, etc.), benzophenone-based ultraviolet absorbers (such as 2,4-dihydroxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, etc.), benzotriazole-based ultraviolet absorbers (such as 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-(linear and branched dodecyl)-4-methylphenol, a mixture of 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-(5-chloro-2H-benzotriazol-2-yl)phenyl]propionate, etc.), cyanoacrylate-based ultraviolet absorbers (such as 2'-ethylhexyl-2-cyano-3,3-diphenylacrylate, ethyl-2-cyano-3-(3',(such as 4’-methylenedioxyphenyl)-acrylate), triazine-based ultraviolet absorbers, etc. may be used. Benzotriazole-based ultraviolet absorbers and triazine-based ultraviolet absorbers with high transparency and excellent effects in preventing deterioration of polarizing plates and variable transmittance layers are preferred, and benzotriazole-based ultraviolet absorbers with more appropriate spectral absorption spectra are particularly preferred. The benzotriazole-based ultraviolet absorber may be bis-ified, for example, 6,6’-methylenebis(2-(2H-benzo[d][1,2,3]triazol-2-yl)-4-(2,4,4-trimethylpentan-2-yl)phenol), 6,6’-methylenebis(2-(2H-benzo[d][1,2,3]triazol-2-yl)-4-(2-hydroxyethyl)phenol), etc. may also be used.,

[0089] The hard coating layer is not particularly limited as long as it is for protecting members such as polarizing plates and variable transmittance layers from external physical and chemical impacts, and conventional or later-developed hard coating layers can be used.

[0090] In one embodiment, the hard coating layer may be formed by applying a composition for forming a hard coating layer on another member and then curing it by light or heat. The composition for forming a hard coating layer is not particularly limited, and may include, for example, a photocurable compound and a photoinitiator.

[0091] The photocurable compound and the photoinitiator can be used without limitation those commonly used in the art. For example, the photocurable compound may be a photopolymerizable monomer, a photopolymerizable oligomer, etc., and examples include monofunctional and / or polyfunctional (meth)acrylates. The photoinitiator includes oxime ester-based ones, etc.

[0092] In addition to the variable transmittance optical laminate, the present invention includes a method for manufacturing the same.

[0093] Referring to FIGS. 1 and 3, a method for manufacturing a variable transmittance optical laminate according to an embodiment of the present invention includes a step (P10) of forming a transparent conductive layer 300 on one surface of a polarizing plate 200, a step (P20) of bonding a transparent member 100 to the other surface of the polarizing plate 200, a step (P31) of forming a first alignment film 400-1 on one surface of the first transparent conductive layer 300-1 to fabricate an upper laminate, a step (P32-1) of forming a second alignment film 400-2 on one surface of the second transparent conductive layer 300-2 to fabricate a lower laminate, a step (P32-2) of forming a liquid crystal layer 600 on the second alignment film 400-2, and a step (P40) of bonding the upper laminate and the lower laminate. At least one of the first transparent member 100-1 and the second transparent member 100-2 may be bonded to the polarizing plate 200 by an adhesive.

[0094] In one or more embodiments, the step (P20) of forming the transparent member 100 on the other surface of the polarizing plate 200 may be performed by bonding the first transparent member and the second transparent member to the other surfaces of the first polarizing plate and the second polarizing plate, respectively, using the bonding layer 700 described above. Further, the step (P31) of forming the first alignment film 400-1 on one surface of the first transparent conductive layer 300-1 to fabricate the upper laminate and the step (P32-1) of forming the second alignment film 400-2 on one surface of the second transparent conductive layer 300-2 to fabricate the lower laminate may be performed by forming the first alignment film and the second alignment film on one surfaces of the first transparent conductive layer and the second transparent conductive layer, respectively, using a rubbing treatment or an optically anisotropic compound.

[0095] In one embodiment of the present invention, when a sealant for bonding the first laminate 800-1 and the second laminate 800-2 and an adhesive for bonding the first transparent member 100-1 and the second transparent member 100-2 are independently formed, the step (P32-2) of forming the liquid crystal layer may be to spray spacers on the second alignment film, and then form a sealant along the outer peripheral surface of the second alignment film or the second transparent conductive layer, and inject a liquid crystal medium into the space formed by the sealant to form a liquid crystal layer. In this case, the step (P40) of bonding the upper laminate and the lower laminate may be to form an adhesive along the outer peripheral surface of the second transparent member after forming the liquid crystal layer as described above, and bond and seal the first transparent member and the second transparent member to each other by the adhesive.

[0096] In another embodiment of the present invention, when a sealant for bonding the first laminate 800-1 and the second laminate 800-2 and an adhesive for bonding the first transparent member 100-1 and the second transparent member 100-2 are integrally formed, the step (P32-2) of forming the liquid crystal layer may be to spray spacers on the second alignment film, and then form an adhesive along the outer peripheral surface of the second transparent member, and inject a liquid crystal medium into the space formed by the adhesive to form a liquid crystal layer. In this case, the step (P40) of bonding the upper laminate and the lower laminate may be to bond and seal the first transparent member and the second transparent member to each other by the adhesive for forming the liquid crystal layer.

[0097] According to the method for manufacturing the transmissivity variable optical laminate of the present invention, when manufacturing a conventional optical laminate into a smart window, not only is the risk of laminate deformation and the like generated during the process of bonding with a transparent member such as glass small, but also the manufacturing process of the optical laminate and the manufacturing process of the smart window can be continuously performed, thereby improving the process economy.

[0098] The transmissivity variable optical laminate produced by the method for producing the transmissivity variable optical laminate satisfies all of the above-described characteristics and may exhibit substantially the same characteristics.

[0099] In addition to the transmissivity variable optical laminate, the present invention includes a smart window including the same. Further, the present invention includes a transportation means including the smart window, for example, an automobile in which the smart window is applied to at least one of a front window, a rear window, a side window, a sunroof window, and an interior partition, a wearable device including the smart window, and architectural fixtures.

[0100] In one embodiment, since the optical laminate of the present invention is produced including a transparent member such as glass, it may be used as a smart window by itself without separately providing a glass member if necessary.

Example

[0101] Hereinafter, embodiments of the present invention will be specifically described. However, the present invention is not limited to the embodiments disclosed below and can be embodied in various different forms. However, these embodiments are provided to complete the disclosure of the present invention and to fully inform those with ordinary knowledge in the technical field to which the present invention pertains of the scope of the invention. The present invention is only defined by the scope of the claims.

[0102] Production Example 1: Production of a polarizing plate (1) Swelling treatment step A polyvinyl alcohol film (original film) with a thickness of 60 μm (manufactured by Kuraray Co., Ltd., trade name “Kuraray Poval Film VF-PE#6000”, average degree of polymerization 2400, saponification degree 99.9 mol%) was continuously drawn out from an original roll and conveyed, and immersed in a swelling bath filled with pure water at 20°C for 30 seconds. In this swelling treatment step, stretching (uniaxial stretching in the longitudinal direction) was performed between the nip rolls with a difference in peripheral speed. The stretching ratio based on the original film was set to 2.5 times.

[0103] (2) Dyeing treatment process Next, the film that passed through the nip roll was immersed in a 30 °C dyeing bath with a mass ratio of pure water / potassium iodide / iodine / boric acid of 100 / 2 / 0.01 / 0.3 for 120 seconds. Also in this dyeing treatment, stretching between rolls (uniaxial stretching in the longitudinal direction) was performed by creating a difference in peripheral speed between the nip rolls. The stretching ratio based on the film after the swelling treatment process was set to 1.1 times.

[0104] (3) Crosslinking treatment process Next, the film that passed through the nip roll was immersed in a first crosslinking bath at 56 °C with a mass ratio of pure water / potassium iodide / boric acid of 100 / 12 / 4 for 70 seconds. Stretching between rolls (uniaxial stretching in the longitudinal direction) was performed by creating a difference in peripheral speed between the nip roll and the nip roll provided between the first crosslinking bath and the second crosslinking bath. The stretching ratio based on the film after the dyeing treatment process was set to 1.9 times.

[0105] (4) Complementary color treatment process Next, the film after the crosslinking treatment was immersed in a second crosslinking bath at 40 °C with a mass ratio of potassium iodide / boric acid / pure water of 9 / 2.9 / 100 for 10 seconds.

[0106] (5) Cleaning treatment process Next, the film after the second crosslinking treatment was immersed in a cleaning bath filled with pure water at 14 °C for 5 seconds, and cleaned at a shower rate of 5 m 3 / h and a shower temperature of 14 °C.

[0107] (6) Drying treatment process Next, the film after the cleaning treatment process was passed through a drying furnace 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 approximately 21 μm.

[0108] (7) Bonding treatment process Next, as an adhesive, an aqueous adhesive containing 5 parts by mass of polyvinyl alcohol (PVA) with respect to 100 parts by mass of water was prepared. Then, a first protective film (TAC, 60 μm) and a second protective film (TAC, 40 μm) were laminated on both sides of the polarizer film using the prepared UV adhesive. The obtained laminate was subjected to UV exposure to cure the adhesive and produce a polarizing film. Also, the thickness of the adhesive layer in the obtained polarizing film was about 2 μm.

[0109] Production Example 2: Production of a Hard Coating Composition 16.2 g of a dendrimer compound (manufactured by Miwa Specialty Chemicals Co., Ltd., SP-1106), 14.4 g of inorganic nanoparticles (10 to 20 nm, silica particles: 50% by weight, solvent: methyl ethyl ketone (MEK)), 1.8 g of a polyfunctional (meth)acrylate compound containing an ethylene glycol group (manufactured by Nippon Kayaku Co., Ltd., DPEA126), 0.7 g of a photoinitiator (1-hydroxycyclohexyl phenyl ketone), and 2.9 g of methyl ethyl ketone were mixed to produce a hard coating composition.

[0110] Production Example 3: Production of a Hard Coating Layer The hard coating composition produced in Production Example 2 was dried on the second protective film (TAC, 40 μm) of the polarizing film, and then the thickness was adjusted with a Mayer Bar type and bar-coated. After drying at 80°C for 5 minutes, it was cured with a high-pressure mercury lamp at a light quantity of 500 mJ / cm 2 to produce a hard coating layer.

[0111] Production Example 4: Production of a Transparent Conductive Layer The polarizing plate fabricated in Production Example 3 was inserted, and after applying 450 W of DC power to operate the sputtering gun, plasma was induced on an ITO (10 wt% Sn doped In2O3) target to form a transparent conductive film (90 nm) on the hard coating layer. The formed transparent conductive film was ion-treated by operating an ion gun with 50 W of DC power. At this time, the pressure was maintained at 3 mTorr at room temperature, and it was manufactured while supplying argon gas and oxygen gas at 30 sccm and 1 sccm, respectively. At this time, the ITO thickness was measured by FT-SEM, and the ITO sheet resistance (Ω / square) was measured using a four-point probe.

[0112] Production Example 5: Fabrication of the First Bonding Layer and Bonding of Glass An adhesive (#3, 15 μm, manufactured by Lintec Special Rotifilm Co., Ltd.) was formed on the opposite surface of the first transparent conductive layer of the first polarizing plate of Production Example 4 by a roll lamination method. Then, the formed adhesive surface was bonded to soda-lime glass (manufactured by JMC Co., Ltd., 1.1T) by a roll lamination method to fabricate a polarizing plate bonded to glass.

[0113] Production Example 6: Fabrication of the Second Bonding Layer and Bonding of Glass An adhesive (#3, 15 μm, manufactured by Lintec Special Rotifilm Co., Ltd.) was formed on the opposite surface of the second transparent conductive layer of the second polarizing plate of Production Example 4 by a roll lamination method. Then, the formed adhesive surface was bonded to soda-lime glass (manufactured by JMC Co., Ltd., 1.1T) by a roll lamination method to fabricate a polarizing plate bonded to glass.

[0114] Production Example 7: Fabrication of the Alignment Film An alignment liquid was coated and dried (80 °C / 2 minutes) on the transparent conductive films of the first polarizing film of Production Example 5 and the second polarizing film of Production Example 6. Then, UV was irradiated on the dried alignment liquid to fabricate an alignment film.

[0115] Production Example 8: Fabrication of Ball Spacer Spraying The mixed solvent was prepared by mixing 0.03 g of the following ball spacers (manufactured by SEKISUI, SP series) based on 100 ml of IPA. The laminate of Production Example 7 was placed in a spacer spraying machine (SDSS-KHU02, SHINDO ENG LAB), and the prepared mixed solvent was sprayed under the condition of 110 °C, and then dried for 20 minutes to form ball spacers on the alignment film of the second laminate of Production Example 7. Then, the number of ball spacers present within an area of 1 mm 2 was confirmed using an optical microscope.

[0116] Production Example 9: Production of an optical laminate A sealant (UVF-006, 70,000 mPa·s, manufactured by SEKISUI) was applied onto the transparent conductive film surface of the second polarizing film of Production Example 8 using a sealant dispenser (SHOTmini 200Ωx, manufactured by MUSASHI) with a sharp needle (SPN-0.25-12.7L) at a discharge pressure of 200 mPa according to the drawing of the product size. Liquid crystal was injected onto the alignment film by the ODF (one drop filling) process method. Then, with the polarizing axes of the first polarizing film and the second polarizing film arranged parallel to each other at 0° or 90°, a smart window optical laminate was produced through a vacuum bonding method at a pressure of 3 Kg / cm 2 .

[0117] Examples and Comparative Examples Example 1 The transmissivity variable optical laminate of Example 1 was produced according to Production Examples 1 to 9 above.

[0118] Example 2 The transmissivity variable optical laminate of Example 2 was produced in the same manner as Example 1, except that a second protective film (COP, 50 μm) was used instead of the second protective film (TAC, 40 μm) in Production Example 1.

[0119] Example 3 In Production Example 5, except that a PVB film (manufactured by Sekisui, 380 μm) and soda-lime glass (manufactured by JMC, 1.1T) were placed on the opposite surface of the first transparent conductive layer of the first polarizing plate of Production Example 4 as adhesives, and then heated using a press machine at a temperature of 90 °C and in a vacuum state of about 1 bar for 10 to 20 minutes to produce the first bonding layer, a transmissivity variable optical laminate of Example 3 was produced in the same manner as in Example 1.

[0120] Example 4 In Production Example 6, except that a PVB film (manufactured by Sekisu, 380 μm) and soda-lime glass (manufactured by JMC, 1.1T) were placed on the opposite surface of the second transparent conductive layer of the second polarizing plate of Production Example 4 as adhesives, and then heated using a press machine at a temperature of 90 °C and in a vacuum state of about 1 bar for 10 to 20 minutes to produce the second bonding layer, a transmissivity variable optical laminate of Example 4 was produced in the same manner as in Example 1.

[0121] Example 5 In Production Example 6, except that an EVA film (manufactured by Panac Korea, 400 μm) and soda-lime glass (manufactured by JMC, 1.1T) were placed on the opposite surface of the second transparent conductive layer of the second polarizing plate of Production Example 4 as adhesives, and then heated using a press machine at a temperature of 90 °C and in a vacuum state of about 1 bar for 10 to 20 minutes to produce the second bonding layer, a transmissivity variable optical laminate of Example 5 was produced in the same manner as in Example 1.

[0122] Example 6 In Production Example 6, except that OCR (manufactured by Hansol Chemical, 200 μm) was applied as an adhesive on the opposite surface of the second transparent conductive layer of the second polarizing plate of Production Example 4, and then soda-lime glass (manufactured by JMC, 1.1T) was placed thereon and UV-cured to produce the second bonding layer, a transmissivity variable optical laminate of Example 6 was produced in the same manner as in Example 1.

[0123] Comparative Example 1 In the above Production Example 5, on the opposite surface of the first transparent conductive layer of the first polarizing plate of Production Example 4, and in the above Production Example 6, on the opposite surface of the second transparent conductive layer of the second polarizing plate of Production Example 4, a PVB film (manufactured by SEKISU, 380 μm) and a soda-lime glass (manufactured by JMC, 1.1T) were placed as adhesives, respectively. After that, except that heating was performed for 10 to 20 minutes at a temperature of 90 °C and in a vacuum state of about 1 bar using a press machine to produce the first bonding layer and the second bonding layer, a transmissivity variable optical laminate of Comparative Example 1 was produced in the same manner as in Example 1.

[0124] Comparative Example 2 In the above Production Example 5, on the opposite surface of the first transparent conductive layer of the first polarizing plate of Production Example 4, and in the above Production Example 6, on the opposite surface of the second transparent conductive layer of the second polarizing plate of Production Example 4, an EVA film (manufactured by PANAC Korea, 400 μm) and a soda-lime glass (manufactured by JMC, 1.1T) were placed as adhesives, respectively. After that, except that heating was performed for 10 to 20 minutes at a temperature of 90 °C and in a vacuum state of about 1 bar using a press machine to produce the first bonding layer and the second bonding layer, a transmissivity variable optical laminate of Comparative Example 2 was produced in the same manner as in Example 1.

[0125] Comparative Example 3 In the above Production Example 5, on the opposite surface of the first transparent conductive layer of the first polarizing plate of Production Example 4, and in the above Production Example 6, on the opposite surface of the second transparent conductive layer of the second polarizing plate of Production Example 4, an OCR (manufactured by Hansol Chemical, 200 μm) and a soda-lime glass (manufactured by JMC, 1.1T) were placed as adhesives, respectively. After that, except that UV curing was performed to produce the first bonding layer and the second bonding layer, a transmissivity variable optical laminate of Comparative Example 3 was produced in the same manner as in Example 1.

[0126] Experimental Example (1) Measurement of the change rate of the upper and lower laminate sizes (area) The first polarizing plate and the second polarizing plate sides of the optical laminates of Examples 1 to 6 and Comparative Examples 1 to 3 were exposed to a temperature of 85 °C and a temperature of 85% R.H. for 120 hours. Using a two-dimensional measuring instrument (PREMIUM-600C, manufactured by Intec IMS), the areas in the longitudinal and transverse directions of the first and second polarizing plates before and after the exposure were measured, respectively. Then, the area change rate was calculated and shown in Tables 1 and 2 below.

[0127] (2) Apparent evaluation The upper laminate sides of the optical laminates of Examples 1 to 6 and Comparative Examples 1 to 3 were exposed to a temperature of 85°C and a temperature of 85% R.H. for 120 hours, and the presence or absence of sealant breakage and generation of bubbles within the liquid crystal area was evaluated and shown in Tables 1 and 2 below. <Evaluation criteria> ○: No sealant breakage and no generation of bubbles within the liquid crystal area X: There is sealant breakage and / or generation of bubbles within the liquid crystal area

[0128]

Table 1

[0129]

Table 2

[0130] Referring to Tables 1 and 2 above, in the case of Examples 1 to 6 where at least one of the first bonding layer and the second bonding layer is formed of an adhesive, in the laminate including the bonding layer formed of an adhesive, there is almost no size change in the MD (longitudinal direction) and TD (transverse direction), and as a result of the apparent evaluation, it can be seen that there is no sealant breakage and no generation of bubbles in the liquid crystal. On the other hand, in the case of Comparative Examples 1 to 3 where both the first bonding layer and the second bonding layer are formed of an adhesive, it can be seen that the MD and TD size changes are larger compared to the examples, and the result of the apparent evaluation is poor.

[0131] Therefore, when at least one of the first bonding layer for bonding the first transparent member and the first polarizing plate and the second bonding layer for bonding the second transparent member and the second polarizing plate is formed of an adhesive, the shrinkage force of the stretched polarizer can be controlled, the size change can be minimized, the adhesion of the sealant or the polarizing plate can be maintained, and it can be understood that an optical laminate without sealant damage and inflow of bubbles into the liquid crystal can be provided.

Industrial applicability

[0132] According to the variable transmittance optical laminate of the present invention, the contraction force of the stretched polarizer can be controlled, and the adhesion force to a sealant or a polarizing plate can be maintained.

Explanation of Signs

[0133] 100: Transparent member 200: Polarizing plate 210: Stretched polarizer 220: Protective layer 230: Phase difference adjusting layer 240: Refractive index adjusting layer 300: Transparent conductive layer 400: Alignment film 500: Adhesive 600: Liquid crystal layer 700: Bonding layer

Claims

1. A first transparent member, A first laminate formed on the first transparent member and laminated in the order of a first polarizing plate, a first transparent conductive layer, and a first alignment film, A second transparent member facing the first transparent member, A second laminate formed on the second transparent member and laminated in the order of a second polarizing plate, a second transparent conductive layer, and a second alignment film, A liquid crystal layer disposed between the first laminate and the second laminate, A variable transmittance optical laminate comprising: At least one of the first transparent conductive layer and the second transparent conductive layer is formed in direct contact with one of the first polarizing plate and the second polarizing plate, The first transparent member and the first polarizing plate are joined by a first joining layer, The second transparent member and the second polarizing plate are joined by a second joining layer, A variable transmittance optical laminate, wherein at least one of the first joining layer and the second joining layer is formed of an adhesive.

2. The variable transmittance optical laminate according to claim 1, wherein the adhesive contains one or more selected from the group consisting of 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, and a vinyl alkyl ether adhesive.

3. The variable transmittance optical laminate according to claim 1, wherein the joining layer formed of the adhesive has a thickness of 2 μm to 38 μm.

4. The variable transmittance optical laminate according to claim 1, wherein at least one of the first polarizing plate and the second polarizing plate includes one or more functional layers selected from the group consisting of a protective layer, a retardation adjusting layer, and a refractive index adjusting layer.

5. The variable transmittance optical laminate according to claim 1, wherein at least one of the first polarizing plate and the second polarizing plate has a thickness of 30 μm to 200 μm.

6. The variable transmittance optical laminate according to claim 1, wherein at least one of the first transparent conductive layer and the second transparent conductive layer includes one or more selected from the group consisting of a transparent conductive oxide, a metal, a carbon-based material, a conductive polymer, a conductive ink, and a nanowire.

7. The variable transmittance optical laminate according to claim 1, wherein the liquid crystal layer includes one or more spacers selected from the group consisting of a ball spacer and a column spacer.

8. The spacer in the variable transmittance optical laminate according to claim 7, wherein the spacer has a height of 1 μm to 10 μm.

9. The variable transmittance optical laminate according to claim 7, wherein the occupied area of the spacer in the liquid crystal layer is 0.01% to 10% of the liquid crystal layer area.

10. The variable transmittance optical laminate according to claim 1, further comprising at least one selected from the group consisting of an overcoat layer, an ultraviolet absorption layer, and a hard coating layer.

11. A step (P10) of forming a first transparent conductive layer and a second transparent conductive layer on one surface of the first polarizing plate and the second polarizing plate, respectively; A step (P20) of bonding a first transparent member and a second transparent member to the other surfaces of the first polarizing plate and the second polarizing plate, respectively; A step (P31) of forming a first alignment film on one surface of the first transparent conductive layer and manufacturing an upper laminate; A step (P32-1) of forming a second alignment film on one surface of the second transparent conductive layer and manufacturing a lower laminate, and a step (P32-2) of forming a liquid crystal layer on the second alignment film; Including a step (P40) of bonding the upper laminate and the lower laminate, A method for manufacturing a variable transmittance optical laminate, wherein at least one of the first transparent member and the second transparent member is bonded to the polarizing plate by an adhesive.

12. The step of bonding the upper laminate and the lower laminate is to arrange the first transparent member and the second transparent member so that they are located on the outside, and then to bond and seal the first transparent member and the second transparent member to each other with a bonding material. The method for manufacturing a variable transmittance optical laminate according to claim 11.

13. A smart window including the variable transmittance optical laminate according to any one of claims 1 to 10.

14. A means of transportation including the smart window according to claim 13.

15. An automobile in which the smart window according to claim 13 is applied to at least one of a front window, a rear window, a side window, a sunroof window, and an interior partition.

16. A wearable device including the smart window according to claim 13.

17. An architectural fixture including the smart window according to claim 13.

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