Optical laminate, method for manufacturing the same, smart window comprising the same, and window for automobile

Abstract

The present invention provides a variable transmittance optical laminate, a method for manufacturing the same, a smart window including the same, and a window for an automobile or a building using the same. The variable transmittance optical laminate includes: a first polarizing plate; a transparent substrate laminated on one surface of the first polarizing plate; a first transparent conductive layer formed on the transparent substrate; an alignment film formed on the first transparent conductive layer; 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 alignment film and the second transparent conductive layer, in which the second transparent conductive layer contains a conductive polymer, the liquid crystal layer contains a polymer network and a liquid crystal compound, and the liquid crystal compound is arranged in a uniform initial alignment.

Description

Technical Field

[0001] The present invention relates to a variable transmittance optical laminate, a method for manufacturing the same, a smart window including the same, and a window for an automobile or a building to which the same is applied. Background Art

[0002] Generally, an external light blocking coating is often applied to the glass window of a moving vehicle or the like. However, the transmittance of the glass window of a conventional moving vehicle is fixed, and the transmittance of the external light blocking coating is also fixed. Therefore, since the overall transmittance of the window of such a conventional moving vehicle is fixed, accidents may occur. 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, there is a problem that it is difficult for a driver or the like to correctly view the surroundings of the moving vehicle. In addition, if the overall transmittance is set high, there is a problem that glare may occur to a driver or the like during the day when the surrounding light is sufficient. For this reason, a variable transmittance optical laminate that can change the light transmittance when a voltage is applied has been developed.

[0003] The above variable transmittance optical laminate is driven by applying a voltage to drive the liquid crystal to change the transmittance. The variable transmittance optical laminate developed so far is manufactured by providing spacers in the liquid crystal layer in order to maintain the cell gap of the liquid crystal layer.

[0004] For example, Japanese Patent Laid-Open No. 2018-010035 also discloses a variable transmittance optical laminate that uses a liquid crystal layer including columnar spacers or spherical spacers to maintain a predetermined cell gap.

[0005] However, when columnar spacers are included in the liquid crystal layer in this way, the manufacturing process becomes cumbersome, resulting in an increase in manufacturing cost, and there is a problem that the alignment film is damaged and the transmittance changes during the process of irradiating ultraviolet rays to the photoresist to form the spacers. In addition, when spherical spacers are used to maintain the cell gap of the liquid crystal layer, there are problems such as an inability to maintain a firm cell gap and difficulty in maintaining a constant optical color in the plane, causing a current short circuit in the optical laminate.

[0006] In addition, in the above variable transmittance optical laminate, in order to protect the lamination surface, provide a lamination surface with other members, a polarization function, etc., various optical members can be laminated in several layers. In addition, it can be manufactured by various manufacturing methods, but from the aspect of process economy, continuous production is preferably performed by a roll-to-roll (R2R) process including a lamination process.

[0007] However, a variable transmittance optical laminate is driven by applying a voltage to drive liquid crystals to vary the transmittance, and in order to vary the transmittance, a liquid crystal layer whose phase changes with the applied electric field is provided to achieve the target transmittance. For this purpose, in order to laminate the absorption axes of the two polarizing plates orthogonally, one of the polarizing plates must be rotated by 90° after cutting the polarizing plate and then laminated, so that it is difficult to apply the roll-to-roll process.

[0008] Thus, when manufacturing a variable transmittance optical laminate with the absorption axes of the two polarizing plates orthogonal, each laminate is formed into a separate sheet. After cutting each sheet, a liquid crystal layer is formed on any one of the sheets, and in order to be able to change the transmittance when a voltage is applied, the transmission axes of each sheet are orthogonally laminated for manufacturing. Therefore, there are problems that the manufacturing process becomes complicated and it is difficult to reduce the cost.

[0009] Therefore, in reality, it is necessary to develop a variable transmittance optical laminate and a manufacturing method that can maintain a firm cell gap even without using spacers in the liquid crystal layer and can apply the roll-to-roll process when forming the liquid crystal layer, thereby simplifying the manufacturing process.

[0010] Prior art documents

[0011] Patent documents

[0012] Patent Document 1: Japanese Laid-Open Patent No. 2018-010035 Summary of the invention

[0013] Problems to be solved

[0014] An object of the present invention is to provide a variable transmittance optical laminate including a liquid crystal layer containing a polymer network, thereby being able to prevent problems such as damage to the alignment film caused by using spacers or difficulty in maintaining a constant in-plane optical color.

[0015] In addition, an object of the present invention is to provide a variable transmittance optical laminate including a liquid crystal layer containing a polymer network and a liquid crystal compound arranged in a uniform initial alignment, thereby being able to adjust the transmittance of the incident light.

[0016] In addition, an object of the present invention is to provide a variable transmittance optical laminate with a simplified manufacturing process.

[0017] In addition, an object of the present invention is to provide a variable transmittance optical laminate with a significantly reduced thickness.

[0018] In addition, an object of the present invention is to provide a method for manufacturing a variable transmittance optical laminate, which can apply a roll-to-roll continuous process in the formation of a liquid crystal layer when manufacturing the variable transmittance optical laminate, thereby having excellent productivity and economy.

[0019] In addition, an object of the present invention is to provide an intelligent window including the above variable transmittance optical laminate and a window for an automobile or a building using the above intelligent window.

[0020] However, the problems to be solved by the present invention are not limited to the above-mentioned problems, and those of ordinary skill in the art should be able to understand other problems not mentioned based on the following description.

[0021] Method for Solving the Problems

[0022] The present invention relates to a variable transmittance optical laminate, which includes: a first polarizing plate; a transparent substrate laminated on one surface of the first polarizing plate; a first transparent conductive layer formed on the transparent substrate; an alignment film formed on the first transparent conductive layer; a second polarizing plate opposite to the first polarizing plate; a second transparent conductive layer formed on one surface of the second polarizing plate and opposite to the first transparent conductive layer; and a liquid crystal layer disposed between the alignment film and the second transparent conductive layer, wherein the second transparent conductive layer contains a conductive polymer, the liquid crystal layer contains a polymer network and a liquid crystal compound, and the liquid crystal compound is arranged in a uniform initial alignment.

[0023] In a first aspect of the present invention, the liquid crystal behavior mode of the liquid crystal layer may be any one selected from the group consisting of a twisted nematic (TN) mode, a super twisted nematic (STN) mode, an in-plane switching (IPS) mode, a fringe-field switching (FFS) mode, and a vertical alignment (VA) mode.

[0024] In a second aspect of the present invention, the liquid crystal behavior mode of the liquid crystal layer may be a twisted nematic (TN) mode.

[0025] In a third aspect of the present invention, 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.

[0026] In a fourth aspect of the present invention, the liquid crystal layer-forming composition may contain 10 to 30% by weight of a polymerizable monomer based on the total weight of the composition.

[0027] In the fifth aspect of the present invention, the surface of the second transparent conductive layer that contacts the liquid crystal layer can be rubbed for alignment.

[0028] In the sixth aspect of the present invention, the conductive polymer may include one or more selected from the group consisting of polythiophene, poly(3,4-ethylenedioxythiophene), polyaniline, polyacetylene, polydiacetylene, polyphenylene, polyphenylene vinylene, polyphenylene sulfide, polythienylene vinylene, polythiophene vinylene, polyfluorene, polypyrrole, poly(3,4-ethylenedioxythiophene):polystyrenesulfonate, poly(3,4-ethylenedioxythiophene):camphorsulfonic acid, poly(3,4-ethylenedioxythiophene):toluene sulfonic acid, poly(3,4-ethylenedioxythiophene):dodecylbenzenesulfonic acid, polyaniline:polystyrenesulfonate, polyaniline:camphorsulfonic acid, polypyrrole:polystyrenesulfonate, polypyrrole:camphorsulfonic acid, polypyrrole:toluene sulfonic acid, polypyrrole:dodecylbenzenesulfonic acid, polythiophene:polystyrenesulfonate, polythiophene:camphorsulfonic acid, polythiophene:toluene sulfonic acid, and polythiophene:dodecylbenzenesulfonic acid.

[0029] In the seventh aspect of the present invention, the second transparent conductive layer can be formed to be in direct contact with the second polarizing plate without including a separate substrate therebetween.

[0030] In the eighth aspect of the present invention, the second transparent conductive layer can be formed to be in direct contact with the second polarizing plate through an inclusion of an easy-bonding layer therebetween.

[0031] In the ninth aspect of the present invention, 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 retardation adjusting layer, and a refractive index adjusting layer.

[0032] In the tenth aspect of the present invention, the first polarizing plate and the second polarizing plate may have a thickness of 30 μm to 200 μm.

[0033] In the eleventh aspect of the present invention, the variable transmittance optical laminate may further include one or more selected from the group consisting of an adhesive / bonding layer, an ultraviolet absorption layer, and a hard coat layer.

[0034] In addition, the present invention relates to a method for manufacturing a variable transmittance optical laminate, which includes: (a) a step of preparing a first polarizing plate; (b) a step of forming a first transparent conductive layer on a transparent substrate; (c) a step of forming an alignment film on the first transparent conductive layer; (d) a step of forming a second transparent conductive layer on the second polarizing plate; (e) a step of forming a liquid crystal layer by coating a liquid crystal layer-forming composition on the second transparent conductive layer; (f) a step of laminating in such a manner that the alignment film of the laminate formed in step (c) is in contact with the liquid crystal layer of the laminate formed in step (e); and (g) a step of laminating the first polarizing plate prepared in step (a) on the transparent substrate of the laminate formed in step (f), wherein in step (g), the first polarizing plate and the second polarizing plate are laminated in such a manner that their absorption axes are orthogonal to each other in a plan view, and steps (b) to (f) are carried out by a roll-to-roll process.

[0035] In a twelfth aspect of the present invention, the second transparent conductive layer may contain a conductive polymer.

[0036] In a thirteenth aspect of the present invention, between steps (d) and (e), a step of forming a rubbing alignment on the surface of the second transparent conductive layer that contacts the liquid crystal layer may further be included.

[0037] In a fourteenth aspect of the present invention, in step (d), the second transparent conductive layer may be formed to be in direct contact with the second polarizing plate without including a separate substrate therebetween.

[0038] In a fifteenth aspect of the present invention, in step (d), the second transparent conductive layer may be formed to be in direct contact with the second polarizing plate by including an easy-bonding layer therebetween.

[0039] In a sixteenth aspect of the present invention, the liquid crystal behavior mode of the liquid crystal layer may be any one selected from the group consisting of a Twisted nematic (TN) mode, a Super twisted nematic (STN) mode, an In-plane switching (IPS) mode, a Fringe-field switching (FFS) mode, and a Vertical alignment (VA) mode.

[0040] In a seventeenth aspect of the present invention, the liquid crystal behavior mode of the liquid crystal layer may be a Twisted nematic (TN) mode.

[0041] In the eighteenth aspect of the present invention, 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.

[0042] In the nineteenth aspect of the present invention, the liquid crystal layer may include a polymer network and a liquid crystal compound.

[0043] In addition, the present invention relates to a smart window including the above-described variable transmittance optical laminate.

[0044] In addition, the present invention relates to an automobile in which the above smart window is applied to at least one of a front window, a rear window, a side window, a sunroof, and an interior partition.

[0045] In addition, the present invention relates to a building window including the above smart window.

[0046] Advantages of the Invention

[0047] According to the variable transmittance optical laminate of the present invention, by including a liquid crystal layer containing a polymer network, problems such as damage to the alignment film caused by using spacers in the past or difficulty in maintaining a constant in-plane optical color can be prevented, and thus, compared with conventional optical laminates, the driving stability can be improved.

[0048] In addition, according to the variable transmittance optical laminate of the present invention, although a polymer network is formed in the liquid crystal layer, the liquid crystal compound can be arranged in a state of maintaining a uniform initial alignment, and thus the transmittance of light incident on the optical laminate can be adjusted.

[0049] In addition, according to the variable transmittance optical laminate of the present invention, the conductive layer containing a conductive polymer substance can simultaneously function as an electrode for driving the liquid crystal layer and an alignment film, and thus, compared with conventional optical laminates, the manufacturing process can be simplified.

[0050] In addition, according to the variable transmittance optical laminate of the present invention, the conductive layer containing a conductive polymer substance can simultaneously function as an electrode for driving the liquid crystal layer and an alignment film, and thus, compared with conventional optical laminates, the thickness can be significantly reduced.

[0051] According to the manufacturing method of the variable transmittance optical laminate of the present invention, a roll-to-roll continuous process can be applied in the formation of the liquid crystal layer, and thus, when manufacturing the variable transmittance optical laminate, there are excellent effects in terms of productivity and economy. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 FIG. is a diagram showing the laminated structure of a variable transmittance optical laminate according to an embodiment of the present invention.

[0053] Figures 2a to 2eIt is a diagram showing the laminated structure of a polarizing plate according to one or more embodiments of the present invention.

[0054] Figure 3 It is a diagram showing the laminated structure of a transmissivity variable optical laminate according to another embodiment of the present invention.

[0055] Figure 4 It is a diagram schematically showing a method for manufacturing a transmissivity variable optical laminate according to one embodiment of the present invention. Detailed Description

[0056] The present invention relates to a transmissivity variable optical laminate including a liquid crystal layer containing a polymer network and a liquid crystal compound arranged in a uniform initial orientation. Specifically, the present invention relates to a transmissivity variable optical laminate capable of maintaining the cell gap of the liquid crystal layer through the polymer network in the liquid crystal layer, thereby preventing problems caused by the conventional use of a sealant and spacers, and capable of adjusting the transmissivity of light incident on the optical laminate because the liquid crystal compound is arranged in a uniform initial orientation.

[0057] More specifically, the present invention relates to a transmissivity variable optical laminate including: a first polarizing plate; a transparent substrate laminated on one surface of the first polarizing plate; a first transparent conductive layer formed on the transparent substrate; an alignment film formed on the first transparent conductive layer; a second polarizing plate opposed to the first polarizing plate; a second transparent conductive layer formed on one surface of the second polarizing plate and opposed to the first transparent conductive layer; and a liquid crystal layer disposed between the alignment film and the second transparent conductive layer, wherein the second transparent conductive layer contains a conductive polymer, the liquid crystal layer contains a polymer network and a liquid crystal compound, and the liquid crystal compound is arranged in a uniform initial orientation.

[0058] In addition, the present invention relates to a method for manufacturing a transmissivity variable optical laminate, which is excellent in productivity and economy because the transmissivity variable optical laminate is manufactured by a roll-to-roll continuous process.

[0059] More specifically, the present invention relates to a method for manufacturing a variable transmittance optical laminate, which comprises: (a) a step of preparing a first polarizing plate; (b) a step of forming a first transparent conductive layer on a transparent substrate; (c) a step of forming an alignment film on the first transparent conductive layer; (d) a step of forming a second transparent conductive layer on the second polarizing plate; (e) a step of forming a liquid crystal layer by coating a liquid crystal layer-forming composition on the second transparent conductive layer; (f) a step of laminating in such a manner that the alignment film of the laminate formed in the step (c) is in contact with the liquid crystal layer of the laminate formed in the step (e); and (g) a step of laminating the first polarizing plate prepared in the step (a) on the transparent substrate of the laminate formed in the step (f), wherein in the step (g), the first polarizing plate and the second polarizing plate are laminated in such a manner that their absorption axes are orthogonal to each other in a plan view, and the steps (b) to (f) are carried out by a roll-to-roll process.

[0060] The variable transmittance optical laminate of the present invention is particularly suitable for the technical field capable of changing the light transmittance according to the application of voltage. For example, it can be used for smart windows and the like.

[0061] A smart window refers to an optical structure that changes the light transmittance according to the application of an electrical signal to control the amount of light or heat passing therethrough. That is, a smart window can be changed into a transparent, opaque or semi-transparent state according to voltage, and is also called a variable transmittance glass, a dimming glass or a smart glass.

[0062] Smart windows can be used as partitions for dividing the interior space of vehicles and buildings or for privacy protection, or as daylighting windows arranged at the openings of buildings. They can also be used as highway road signs, billboards, scoreboards, clocks or advertising screens, and can replace the glass of transportation means such as the windows or skylights of cars, buses, airplanes, ships or trains.

[0063] The variable transmittance optical laminate of the present invention can also be used as a smart window in each of the above 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, it has a thin thickness, is advantageous for bending characteristics, and can be particularly suitable for use in smart windows for vehicles or buildings. In one or more embodiments, the smart window using the variable transmittance optical laminate of the present invention can be used for the front window, rear window, side window, and skylight of an automobile, or a building window, etc. In addition to the use of blocking external light, it can also be used for internal space partitioning or privacy protection purposes in an automobile or a building, such as an internal partition.

[0064] Hereinafter, embodiments of the present invention will be described more specifically with reference to the accompanying drawings. However, the following drawings attached to this specification only illustrate preferred embodiments of the present invention and serve to further understand the above-described invention content together with the technical idea of the present invention. Therefore, the present invention should not be interpreted only based on the matters described in these drawings.

[0065] 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 specifically mentioned in the context, the singular form also includes the plural form. For example, the "polarizing plate" used in this specification may refer to at least one of the first polarizing plate and the second polarizing plate, and the "transparent conductive layer" may refer to at least one of the first transparent conductive layer and the second transparent conductive layer.

[0066] The terms "comprises" and / or "comprising" used in this specification are used in the sense of not excluding the existence or addition of one or more other components, steps, actions, and / or elements other than the mentioned components, steps, actions, and / or elements. Throughout the specification, the same reference numerals refer to the same components.

[0067] As illustrated in the drawings, spatially relative terms such as "below", "bottom surface", "lower part", "above", "upper surface", "upper part", etc. may be used to easily describe the relative relationship between one element or component and other elements or components. The spatially relative terms should be understood as terms including directions different from each other when the elements are in use or operation, in addition to the directions illustrated in the drawings. For example, when the element illustrated in the drawing is flipped, the element described as "below" or "lower part" of other elements may be placed "above" other elements. Therefore, the exemplary term "below" may include both the below and above directions. The element may also be oriented in other directions, so the spatially relative terms may be interpreted according to the orientation.

[0068] As used in this specification, the "top view direction" can be interpreted as the direction orthogonal to the polarizing plate and / or the transparent conductive layer, that is, the direction observed from the visible side of the user.

[0069] <Variable transmittance optical laminate>

[0070] Figure 1 FIG. is a diagram showing the laminated structure of a variable transmittance optical laminate according to an embodiment of the present invention. Figures 2a to 2e FIG. is a diagram showing the laminated structure of a polarizing plate according to one or more embodiments of the present invention. Figure 3 FIG. is a diagram showing the laminated structure of a variable transmittance optical laminate according to another embodiment of the present invention.

[0071] Referring to Figure 1 , a variable transmittance optical laminate 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, a transparent substrate 150, an alignment film 210, and a liquid crystal layer 300.

[0072] Referring to FIG. 2, the polarizing plate 100 may include a polarizer 110, and may further include functional layers such as a protective layer 120, a retardation adjusting layer 130, and a refractive index adjusting layer 140 on one or both surfaces of the polarizer 110. For example, the polarizing plate 100 may include a polarizer 110 and a protective layer 120 laminated on one or both surfaces of the polarizer 110 (refer to Figure 2a and Figure 2b ), may include a polarizer 110, a protective layer 120 laminated on one surface of the polarizer 110, and a retardation adjusting layer 130 laminated on the other surface of the polarizer 110 opposite to the one surface (refer to Figure 2c ), may include a polarizer 110, a protective layer 120 laminated on one surface of the polarizer, and a retardation adjusting layer 130 and a refractive index adjusting layer 140 laminated in sequence on the other surface of the polarizer 110 opposite to the one surface (refer to Figure 2d ), may include a polarizer 110, a protective layer 120 laminated on one surface of the polarizer, and a protective layer 120 and a retardation adjusting layer 130 laminated in sequence on the other surface of the polarizer 110 opposite to the one surface (refer to Figure 2e ).

[0073] The polarizer 110 may use a polarizer developed in the past or in the future. For example, a stretched polarizer or a coated polarizer may be used.

[0074] In one embodiment, the above-mentioned stretched polarizer may include a stretched polyvinyl alcohol (PVA)-based resin. The above-mentioned polyvinyl alcohol (PVA)-based resin may be a polyvinyl alcohol-based resin obtained by saponifying a polyvinyl acetate-based resin. As the polyvinyl acetate-based resin, in addition to polyvinyl acetate which is a homopolymer of vinyl acetate, copolymers of vinyl acetate and other monomers capable of copolymerizing therewith may also be mentioned. As the above-mentioned other monomers, they may be unsaturated carboxylic acid-based, unsaturated sulfonic acid-based, olefin-based, vinyl ether-based, acrylamide-based monomers having an ammonium group, etc. In addition, the polyvinyl alcohol (PVA)-based resin includes modified substances. For example, it may also be polyvinyl formal or polyvinyl acetal modified by aldehydes.

[0075] In one embodiment, the above-mentioned coating-type polarizer may be formed using a liquid crystal coating composition. At this time, the above-mentioned liquid crystal coating composition may include a reactive liquid crystal compound, a dichroic dye, etc.

[0076] The above-mentioned reactive liquid crystal compound may refer to a compound that includes a mesogen skeleton, etc. and includes one or more polymerizable functional groups. Such a reactive liquid crystal compound has been widely known by the name of so-called reactive mesogen (RM). The above-mentioned reactive liquid crystal compound can be polymerized by means of light or heat to form a cured film in which a polymer network is formed while maintaining the liquid crystal alignment.

[0077] The above-mentioned reactive liquid crystal compound may be a monofunctional or polyfunctional reactive liquid crystal compound. The above-mentioned monofunctional reactive liquid crystal compound may refer to a compound having 1 polymerizable functional group, and the polyfunctional reactive liquid crystal compound may refer to a compound containing 2 or more polymerizable functional groups.

[0078] The above dichroic dye is a component added to the liquid crystal coating composition to impart polarization characteristics, and has the property that the absorbance in the long axis direction of the molecule is different from the absorbance in the short axis direction. The above dichroic dye can use dichroic dyes developed in the past or in the future. For example, it can include one or more selected from the group consisting of azo dyes, anthraquinone dyes, perylene dyes, merocyanine dyes, azomethine dyes, phthaloperylene dyes, indigo dyes, dioxadine dyes, polythiophene dyes, and phenoxazine dyes.

[0079] The above liquid crystal coating composition may further contain a solvent capable of dissolving the above reactive liquid crystal compound and the above dichroic dye. For example, propylene glycol monomethyl ether acetate (PGMEA), methyl ethyl ketone (MEK), xylene, chloroform, etc. can be used. In addition, the above liquid crystal coating composition may also contain a leveling agent, a polymerization initiator, etc. within the range that does not hinder the polarization characteristics of the coating film.

[0080] The above protective layer 120 is intended to protect the polarization characteristics of the polarizer 110 from the influence of subsequent processes and the external environment, and can be realized in the form of a protective film or the like.

[0081] As Figure 2a and Figure 2b As shown in the figure, the above protective layer 120 can be formed by directly contacting one or both sides of the polarizer 110, but it is not limited thereto. For example, the above protective layer can also be used in a multilayer structure formed by continuously laminating one or more protective layers, and can be formed by directly contacting other functional layers.

[0082] In one or more embodiments, the above-mentioned 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).

[0083] The above-mentioned retardation adjustment layer 130 is intended to supplement the optical properties of the optical laminate, and can be implemented in the form of a retardation film or the like. A retardation film or the like developed in the past 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 they can be used alone or in combination.

[0084] As Figure 2c and Figure 2d As illustrated, the above-mentioned retardation adjustment layer 130 may be formed in direct contact with one surface of the polarizer 110, but is not limited thereto. For example, as Figure 2e As illustrated, the above-mentioned retardation 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 retardation adjustment layer 130 are laminated in sequence.

[0085] The above-mentioned retardation adjustment layer 130 may use a polymer stretching film or a liquid crystal polymer film obtained by stretching a polymer film capable of imparting optical anisotropy in an appropriate manner by stretching.

[0086] In one embodiment, the above-mentioned polymer stretched film may use a polymer layer containing the following substances: polyolefins such as polyethylene (PE) or polypropylene (PP), cyclic olefin polymers (COP) such as polynorbornene, polyvinyl chloride (PVC), polyacrylonitrile (PAN), polysulfone (PSU), acrylic resin, polycarbonate (PC), polyesters such as polyethylene terephthalate (PET), polyacrylate, cellulose ester polymers such as polyvinyl alcohol (PVA) or triacetyl cellulose (TAC), or copolymers of two or more monomers among the monomers forming the above polymers, etc.

[0087] The method for obtaining the above-mentioned polymer stretched film is not particularly limited. For example, it can be obtained by stretching the above-mentioned 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, casting molding, etc., or by secondary processing molding methods such as compression molding and vacuum molding. Among them, extrusion molding and casting molding are preferably used. At this time, for example, an extruder equipped with a T-die, a circular die, etc. can be used to extrude and mold the unstretched film. In the case of obtaining a molded product by extrusion molding, a material in which various resin components, additives, etc. have been melt-kneaded in advance can be used, or it can be molded via melt-kneading during extrusion molding. In addition, a solvent common to various resin components, such as chloroform, dichloromethane, etc., can also be used to dissolve various resin components, and then casting drying and curing are carried out to form the unstretched film by casting molding.

[0088] For the above-mentioned polymer stretched film, the molded film can be uniaxially stretched along the mechanical flow direction (MD; Mechanical Direction, longitudinal or length direction), uniaxially stretched along the direction perpendicular to the mechanical flow direction (TD; Transverse Direction, transverse or width direction), or a biaxially stretched film can be manufactured by stretching through a sequential biaxial stretching method of roll stretching and tenter stretching, a simultaneous biaxial stretching method based on tenter stretching, a biaxial stretching method based on tubular stretching, etc.

[0089] The liquid crystal polymer film described above may contain a reactive liquid crystal compound in a polymerized state. The content of the reactive liquid crystal compound described above may be similarly applied to the reactive liquid crystal compound of the above-mentioned coating type polarizer.

[0090] In one or more embodiments, for the thickness of the above-mentioned retardation adjustment layer 130, in the case of a polymer stretching film, it may be 10 μm to 100 μm, and in the case of a liquid crystal polymer film, it may be 0.1 μm to 5 μm.

[0091] The above-mentioned refractive index adjustment layer 140 is provided to compensate for the refractive index difference of the optical laminate caused by the above-mentioned transparent conductive layer 200, and can play a role in improving visible characteristics, etc. by reducing the refractive index difference. In addition, the above-mentioned refractive index adjustment layer 140 may also be provided to correct the color caused by the above-mentioned transparent conductive layer 200. On the other hand, in the case where the above-mentioned transparent conductive layer has a pattern, through the above-mentioned refractive index adjustment layer 140, it is possible to compensate for the transmittance difference between the patterned pattern region and the non-patterned region where no pattern is formed.

[0092] Specifically, the above-mentioned transparent conductive layer 200 is adjacent and laminated to other members (such as the polarizer 110, etc.) having a different refractive index from it. Due to the refractive index difference with the adjacent other layers, a difference in light transmittance will be induced. Especially in the case where the transparent conductive layer has a pattern, there may be a problem that the pattern region and the non-pattern region look different. Therefore, by including the above-mentioned refractive index adjustment layer 140, it is possible to compensate for the refractive index and reduce the difference in light transmittance of the optical laminate. Especially in the case where the transparent conductive layer has a pattern, the pattern region and the non-pattern region will not look different.

[0093] In one embodiment, the refractive index of the above-mentioned refractive index adjustment layer 140 may be appropriately selected according to the material of the adjacent other members, preferably it may be 1.4 to 2.6, and more preferably it may be 1.4 to 2.4. In this case, it is possible to prevent light loss caused by a significant refractive index difference between the above-mentioned polarizer 110 and other members and the transparent conductive layer 200.

[0094] The above-mentioned refractive index adjustment layer 140 has no particular limitation as long as it can prevent a significant refractive index difference between the polarizer 110 and other members and the transparent conductive layer 200. Compounds used to form a refractive index adjustment layer in the past or developed in the future can be used. For example, it may be formed from a refractive index adjustment layer forming composition containing a polymerizable isocyanurate compound.

[0095] 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 mechanical durability, an overcoat layer or the like may be included.

[0096] In one or more embodiments, the polarizing plate 100 may have a thickness of 30 to 200 μm, preferably 30 to 170 μm, and more preferably 50 to 150 μm. In this case, an optical laminate with a thin thickness can be manufactured while maintaining the optical characteristics of the polarizing plate 100.

[0097] The transparent conductive layer 200 is provided for driving the liquid crystal layer 300 and can be formed by directly contacting the polarizing plate 100 or by coating it on a separate transparent substrate 150.

[0098] For example, as Figure 1 shown in the figure, the first transparent conductive layer 200-1 can be coated on the transparent substrate 150, the first polarizing plate 100-1 can be formed on the transparent substrate 150, and the second transparent conductive layer 200-2 can be formed by directly contacting the second polarizing plate 100-2.

[0099] Conventionally, an optical laminate used for manufacturing a smart window or the like is manufactured by forming a conductive layer for liquid crystal driving on one surface of a substrate and laminating a polarizing plate on the other surface of the substrate. However, the transmissivity-variable optical laminate of the present invention is characterized in that a conductive layer is directly formed on one surface of the polarizing plate, and a separate substrate for forming the conductive layer is intentionally not included, thereby reducing the thickness of the laminate and improving the transmissivity and bending characteristics in the light-transmitting mode.

[0100] In one embodiment, the transparent conductive layer 200 can be directly formed by evaporation coating on one surface of the transparent substrate 150 or the second polarizing plate 100-2. At this time, for the transparent conductive layer 200, in order to improve the adhesion to the transparent substrate 150 or the second polarizing plate 100-2, a pretreatment such as corona treatment or plasma treatment can be performed on one surface of the transparent substrate 150 or the second polarizing plate 100-2, and then it can be formed by directly contacting the pretreated surface of the transparent substrate 150 or the second polarizing plate 100-2. The above pretreatment is not limited to corona treatment or plasma treatment, and pretreatment processes developed in the past or in the future can be used within the scope that does not damage the purpose of the present invention.

[0101] In another embodiment, in order to improve the adhesion between the above-mentioned transparent conductive layer 200 and the transparent substrate 150 or the second polarizing plate 100-2, an easy-bonding layer (not shown) provided on one surface of the transparent substrate 150 or the second polarizing plate 100-2 can be disposed therebetween to directly contact the transparent substrate 150 or the second polarizing plate 100-2 for formation. The above-mentioned easy-bonding layer can use the materials described in the adhesion / adhesive layer in other components described later, but is not limited thereto.

[0102] The above-mentioned transparent substrate 150 is a structural basis for forming the above-mentioned first transparent conductive layer 200-1, and there is no particular limitation as long as it is a transparent material that does not reduce the transmittance. Preferably, it can 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), polyimide (PI), polyamideimide (PAI). Preferably, it can include one or more selected from polyimide (PI) and polyamideimide (PAI).

[0103] As a method of vapor-depositing and coating the above transparent conductive layer 200 on one surface of the above transparent substrate 150 or the second polarizing plate 100-2, it can be formed by a method commonly used in the art. For example, in coating processes such as spin coating, roll coating, bar coating, dip coating, gravure coating, curtain coating, die coating, spray coating, knife coating, kneader coating, etc.; printing (coating) processes such as screen printing, spray printing, inkjet printing, letterpress printing, gravure printing, lithographic printing, etc.; and vapor deposition processes such as chemical vapor deposition (CVD), physical vapor deposition (PVD), plasma enhanced chemical vapor deposition (PECVD), etc., an appropriate process can be selected to form it.

[0104] In the variable transmittance optical laminate of the present invention, the transmittance of the above first transparent conductive layer 200-1 with respect to visible light is preferably 50% or more. For example, it may contain one or more selected from the group consisting of transparent conductive oxides, metals, carbon-based materials, conductive polymers, conductive inks, and nanowires, but is not limited thereto, and materials of transparent conductive layers developed in the past or in the future can be used.

[0105] In one or more embodiments, the above-mentioned 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), zinc oxide (ZnO), and the like. 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 a silver-palladium-copper (APC) alloy or a copper-calcium (CuCa) alloy. The above-mentioned carbon-based material may include one or more selected from the group consisting of carbon nanotubes (CNT) and graphene. The above-mentioned conductive polymer may use conductive polymer materials developed in the past or in the future. For example, it may include one or more selected from the group consisting of polythiophene, poly(3,4-ethylenedioxythiophene), polyaniline, polyacetylene, polydiacetylene, polyphenylene, polyphenylene vinylene, polyphenylene sulfide, polythiophene acetylene, polythiophene vinylene, polyfluorene, polypyrrole, poly(3,4-ethylenedioxythiophene):polystyrene sulfonate, poly(3,4-ethylenedioxythiophene):camphorsulfonic acid, poly(3,4-ethylenedioxythiophene):toluene sulfonic acid, poly(3,4-ethylenedioxythiophene):dodecylbenzenesulfonic acid, polyaniline:polystyrene sulfonate, polyaniline:camphorsulfonic acid, polypyrrole:polystyrene sulfonate, polypyrrole:camphorsulfonic acid, polypyrrole:toluene sulfonic acid, polypyrrole:dodecylbenzenesulfonic acid, polythiophene:polystyrene sulfonate, polythiophene:camphorsulfonic acid, polythiophene:toluene sulfonic acid, and polythiophene:dodecylbenzenesulfonic acid, and is preferably poly(3,4-ethylenedioxythiophene). The above-mentioned conductive ink may be an ink obtained by mixing metal powder and a curable polymer binder. The nanowire may be, for example, a silver nanowire (AgNW). In addition, the above-mentioned first transparent conductive layer 200-1 may be formed of a structure with two or more layers by combining the above-mentioned substances. 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.

[0106] In the variable transmittance optical laminate of the present invention, the above-mentioned second transparent conductive layer 200-2 may include the above-mentioned conductive polymer, and preferably has a transmittance of 50% or more with respect to visible light. In this case, even if the transparent conductive layer is deformed due to external stress, it is possible to prevent cracks from occurring in the transparent conductive layer, and further prevent the sheet resistance from increasing excessively.

[0107] An alignment film 210 may be provided between the first transparent conductive layer 200-1 of the present invention and the liquid crystal layer 300. The alignment film 210 is intended to impart an alignment property to the liquid crystal compound and is preferably photo-aligned. The alignment film 210 can be produced by coating an alignment film coating composition containing an alignment polymer, a photoinitiator, and a solvent and curing it. The alignment polymer is not particularly limited, and polyacrylate resins, polyamic acid resins, polyimide resins, polymers containing cinnamate groups, etc. can be used. Polymers that can exhibit alignment properties developed in the past or in the future can be used.

[0108] As described in the <Method for Manufacturing a Variable Transmittance Optical Laminate> to be described later, the variable transmittance optical laminate of the present invention forms a second transparent conductive layer 200-2 on the second polarizing plate 100-2 by a roll-to-roll process, and a physical alignment is formed on the surface of the second transparent conductive layer 200-2 by rubbing, and an alignment angle in the forward direction (MD direction) is formed in the roll-to-roll process. That is, the physical alignment in the roll-to-roll process can only achieve alignment in the forward direction (MD direction). The alignment film 210 facing the second transparent conductive layer 200-2 across the liquid crystal layer 300 preferably achieves alignment in the direction perpendicular to the forward direction (TD direction) by photo-alignment rather than physical alignment in order to control the light transmittance. For example, the alignment angle formed in the second transparent conductive layer 200-2 may be 0°, and the alignment angle of the alignment film 210 may be 90°.

[0109] In one embodiment, the surface of the second transparent conductive layer 200-2 in contact with the liquid crystal layer 300 may be rubbed and aligned. Different from the transparent conductive layer containing a metal component, the conductive polymer contained in the second transparent conductive layer 200-2 of the present invention can form regular grooves on the surface, whereby the liquid crystal compounds in the liquid crystal layer can be arranged at desired positions and in desired directions. In this case, the second transparent conductive layer 200-2 can function as an electrode for driving the liquid crystal layer and also as an alignment film. Since no separate alignment film is included, an optical laminate with a thinner thickness can be manufactured, and the manufacturing process can also be simplified.

[0110] The liquid crystal layer 300 included in the variable transmittance optical laminate of the present invention may include a polymer network 310 as described later, and the polymer network may be formed by a crosslinking reaction of a polymerizable compound. When forming the polymer network 310, an alignment film with strong surface anchoring ability is required to keep the liquid crystal compound 320 in the liquid crystal layer uniformly oriented initially. In the present invention, for one surface of the second transparent conductive layer, instead of a separate alignment film, the surface of the second transparent conductive layer in contact with the liquid crystal layer may be treated by a rubbing method and / or a photo-alignment method, etc., in a manner of directly forming an alignment angle. As a method for forming an alignment film, a rubbing method using a rubbing process and a photo-alignment method using ultraviolet rays can be cited. Generally, the photo-alignment method has a weaker surface anchoring ability than the rubbing method. More specifically, the alignment film formed by the rubbing method has a surface anchoring energy of about 1×10 -3 J / m 2 , while the alignment film formed by the photo-alignment method has a surface anchoring energy of about 1×10 -6 J / m 2 . Therefore, when forming the polymer network 310 in the liquid crystal layer 300, considering keeping the liquid crystal compound 320 uniformly oriented initially, it is preferable to rub and align the surface of the second transparent conductive layer 200-2 of the present invention in contact with the liquid crystal layer 300 by the rubbing method.

[0111] In one embodiment, the above-mentioned 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 above-mentioned transparent conductive layer 200 can ensure a predetermined transmittance and the characteristic change caused by external stress is small, and an optical laminate with a thin thickness can be manufactured.

[0112] The above-mentioned liquid crystal layer 300 can adjust the transmittance of light incident from one or more directions according to the electric field generated by the above-mentioned transparent conductive layer 200, thereby changing the driving mode of the above-mentioned optical laminate to a light-transmitting mode or a light-blocking mode.

[0113] The above-mentioned liquid crystal layer 300 may include a polymer network 310 and a liquid crystal compound 320. For example, it may be disposed between the above-mentioned first transparent conductive layer 200-1 and the second transparent conductive layer 200-2 in the light control region, and may be located within the space provided by the polymer network 310.

[0114] In the past, an optical laminate had to include a sealing adhesive and spacers to maintain a certain space, i.e., a cell gap, required for liquid crystal compounds in a liquid crystal layer. However, in the case where columnar spacers are included in the liquid crystal layer to maintain the cell gap, there are problems that the manufacturing process becomes complicated and the manufacturing cost increases, and the alignment film is damaged during the process of irradiating ultraviolet rays to a photoresist to form spacers, resulting in a change in transmittance. In addition, in the case where spherical spacers are used to maintain the cell gap of the liquid crystal layer, there are problems that a firm cell gap cannot be maintained and it is difficult to maintain a constant in-plane optical color, and current short circuit of the optical laminate is induced. Further, in the case where a sealing adhesive is used to maintain the cell gap of the liquid crystal layer, there are problems that the appearance quality may be reduced due to the visibility of the sealing adhesive, and the sealing adhesive may be broken during the handling of the optical laminate or defects may occur due to the thickness difference from the spacers included at the same time.

[0115] The liquid crystal layer 300 included in the variable transmittance optical laminate of the present invention includes both a liquid crystal compound 320 and a polymer network 310, whereby the cell gap of the liquid crystal layer can be appropriately maintained even without including a separate sealing adhesive and / or spacers. In addition, since the cell gap is maintained by a polymer network alone instead of a combination of a sealing adhesive and spacers, there is an advantage that defects caused by the thickness difference between the sealing adhesive and spacers can be fundamentally blocked.

[0116] The above liquid crystal compound is not particularly limited as long as it can be driven by an electric field to control the light transmittance, and liquid crystal compounds developed in the past or in the future can be used. For example, the content of the reactive liquid crystal compound regarding the above coating type polarizer can be similarly applied.

[0117] The above 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.

[0118] In the above nematic liquid crystal compound, long rod-shaped molecules are arranged parallel to each other. Although the central positions of the molecules are not regular, the molecular axis directions are ordered. Each molecule of the nematic liquid crystal compound can move freely in the long axis direction, so it has low viscosity and good fluidity. And since the up-and-down directions of each molecule are almost the same, the polarizations cancel each other out and generally do not exhibit strong dielectric properties. The type of the above nematic liquid crystal compound is not particularly limited as long as it includes a mesogenic group.

[0119] The steric structures of the above chiral compounds have structures that are symmetric to each other like a right hand and a left hand. Although their chemical structures and physical properties are the same, due to their mirror-image relationship, they are compounds with different steric structures. If a certain content of chiral compounds is included in the above nematic liquid crystal compound, a helical cycle will be induced. Regarding the types of the above chiral compounds, as long as the liquid crystallinity of the above liquid crystal compound, such as nematic regularity, is not damaged and a target helical cycle can be induced, they can be used without particular limitation.

[0120] The chiral compound used to induce a helical cycle in a liquid crystal compound needs to contain at least chirality in its molecular structure. As the above chiral compound, for example, compounds having one or two or more asymmetric carbons, compounds having an asymmetric point on a heteroatom such as chiral amines or chiral sulfoxides, or compounds having an axially asymmetric, optically active site such as cumulene or binaphthol can be exemplified.

[0121] The above chiral compound can be, for example, a low-molecular compound having a molecular weight of 1,500 or less. For example, as the chiral compound, commercially available chiral nematic liquid crystals can be used. For example, chiral doped liquid crystal S-811 or Paliocolor LC 756 (manufactured by BASF) sold by Merck & Co., Inc. etc., but not limited thereto.

[0122] In the above chiral nematic liquid crystal compound, 75 to 99% by weight of a nematic liquid crystal compound and 1 to 25% by weight of a chiral compound can be included relative to the total weight of the chiral nematic liquid crystal compound, but not limited thereto. By appropriately adjusting the contents of the above nematic liquid crystal compound and chiral compound within the above range, the helical cycle of the chiral nematic liquid crystal compound, that is, the pitch, can be adjusted. The pitch of the above chiral nematic liquid crystal compound is not particularly limited and can be 5 to 20 μm.

[0123] The liquid crystal behavior mode of the above liquid crystal layer 300 is not particularly limited. 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, a vertical alignment (VA) mode, etc. can be used. Considering the control of light transmittance, a twisted nematic (TN) mode is preferably used.

[0124] As an example of a polymer contained in a liquid crystal layer in the past, polymer dispersed liquid crystal (PDLC) is known. In the above polymer dispersed liquid crystal, liquid crystal compounds are phase-separated and exist in the polymer in the form of droplets or capsules. The liquid crystal compounds in the form of the phase-separated droplets or capsules are arranged in irregular directions, so they cannot have a constant initial orientation. That is, in the state where no voltage is applied, the liquid crystal compounds in the polymer dispersed liquid crystal (PDLC) are irregularly arranged to scatter the incident light, thus maintaining an opaque state (light-shielding mode). In the state where a voltage is applied, the liquid crystal compounds are arranged in one direction to allow the incident light to pass through, thus forming a transparent state (light-transmitting mode). However, the light-shielding mode of the polymer dispersed liquid crystal (PDLC) utilizes the property that the incident light is scattered due to the irregular arrangement of the liquid crystal compounds. Therefore, there is a technical limitation that the light scattered in an arbitrary direction cannot be controlled and the light-shielding rate is somewhat unsatisfactory. In addition, in order to achieve the light-transmitting mode, the state of applying a voltage needs to be maintained, so the disadvantage of high power consumption has been criticized.

[0125] The liquid crystal layer 300 of the present invention includes a polymer network 310 and a liquid crystal compound 320, and the above liquid crystal compound 320 is arranged in a uniform initial orientation. The liquid crystal layer 300 of the present invention not only includes a polymer network 310, but also the liquid crystal compound 320 included therein does not phase-separate in the form of droplets or capsules, but exists in a form mixed with the polymer network 310 and is arranged in a uniform initial orientation within the liquid crystal layer, which is different from the conventional polymer dispersed liquid crystal (PDLC). Thus, the liquid crystal layer 300 of the present invention including the polymer network 310 and the liquid crystal compound 320 arranged in a uniform initial orientation can adjust the transmittance of light incident from one or more directions according to the electric field generated by the transparent conductive layer 200, thereby realizing a light-transmitting mode and a light-shielding mode. Therefore, compared with the conventional polymer dispersed liquid crystal that realizes the light-shielding mode by scattering the incident light, a more excellent light-shielding rate can be exhibited. In addition, the variable transmittance optical laminate of the present invention can realize the light-transmitting mode in a state where no voltage is applied by appropriately adjusting the transmission axis of the polarizing plate 100 and the optical axis of the liquid crystal layer 300, and has a lower applied voltage required during driving compared with the conventional polymer dispersed liquid crystal in which the liquid crystal is disorderly arranged, and has the advantage of being able to reduce power consumption compared with the conventional polymer dispersed liquid crystal.

[0126] The above 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.

[0127] The above polymerizable monomer refers to a compound that forms a polymer network through a photopolymerization reaction or a thermal polymerization reaction, and is not particularly limited. For example, it may include acrylate monomers, and may include one or more selected from the group consisting of isobornyl acrylate, caprolactone acrylate, triethylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, and dipentaerythritol pentaacrylate.

[0128] The above polymerizable monomer may include one or more monomers selected from monofunctional monomers to tetrafunctional monomers, and preferably may include trifunctional monomers. Multifunctional monomers have the advantages of not causing an impact on the liquid crystal, having excellent compatibility with the liquid crystal, and being able to exhibit appropriate phase separation from the liquid crystal.

[0129] The above liquid crystal layer-forming composition may include 10 to 30% by weight of the polymerizable monomer based on the total weight of the composition, and preferably may include 10 to 20% by weight. When the liquid crystal layer-forming composition includes the above polymerizable monomer in the above content range, it has the advantages that the curing degree of the polymer network formed thereby is sufficient to stably maintain the cell gap of the liquid crystal layer, and excellent light transmittance and adhesion can be obtained, and thus it is preferred.

[0130] The method for forming the liquid crystal layer 300 using the above-described liquid crystal layer-forming composition is not particularly limited. For example, it can be formed by coating the above-described liquid crystal layer-forming composition on the second transparent conductive layer 200-2 having a surface subjected to rubbing alignment and subjecting it to photocuring or thermocuring.

[0131] In the variable transmittance optical laminate of the present invention, since the polymer network 310 is included in the liquid crystal layer 300, a stable cell gap can be maintained even without including a sealant and spacers. However, one or more of a sealant and spacers can be further additionally included as needed within the scope not impairing the object of the present invention.

[0132] The above-described sealant can contain a curable resin as a base resin. As the above-described base resin, an ultraviolet curable resin or a thermosetting resin known in the art and usable for a sealant can be used. The above-described ultraviolet curable resin can be a polymer of an ultraviolet curable monomer. The above-described thermosetting resin can be a polymer of a thermosetting monomer.

[0133] As the base resin of the above-described sealant, for example, an acrylate resin, an epoxy resin, a urethane resin, a phenol resin, or a mixture of the above resins can be used. In one embodiment, the above-described base resin can be an acrylate resin, and the above-described acrylate resin can be a polymer of an acrylic monomer. The above-described acrylic monomer can be, for example, a polyfunctional acrylate. In another embodiment, the above-described sealant can further contain a monomer component in the base resin. The above-described monomer component can be, for example, a monofunctional acrylate. In the present specification, the monofunctional acrylate can refer to a compound having 1 acryloyl group, and the polyfunctional acrylate can refer to a compound having 2 or more acryloyl groups. The above-described curable resin can be cured by irradiating ultraviolet rays and / or heating. Regarding the above-described ultraviolet irradiation conditions or heating conditions, they can be appropriately implemented within the scope not impairing the object of the present application. The above-described sealant can also contain an initiator as needed, for example, a photoinitiator or a thermal initiator.

[0134] The above-described sealant can be formed by a method generally used in the art. For example, it can be formed by applying the sealant to the periphery (i.e., non-active region) of the above-described liquid crystal layer using an applicator equipped with a nozzle.

[0135] The above-mentioned spacer may include at least one of a ball spacer and a column spacer, and particularly preferably a ball spacer. The above-mentioned ball spacer may be one or more, preferably having a diameter of 1 to 10 μm. In addition, when viewed from the top-down direction, considering the visibility of the user and the transmittance in the enhanced light transmission mode, the area occupied by the above-mentioned ball spacer in the liquid crystal layer 300 is preferably 0.01 to 10% of the area of the liquid crystal layer 300.

[0136] The light transmittance variable optical laminate of the present invention may further include other components within the scope that does not damage the object of the present invention. For example, it may further include an adhesive / bonding layer 400 (refer to Figure 3 ), and may also further include an ultraviolet absorption layer, a hard coat, etc.

[0137] The above-mentioned adhesive / bonding layer 400 may be formed using an adhesive or an adhesive agent, and preferably has appropriate adhesive / adhesive force to prevent peeling, bubbles, etc. from occurring during the handling of the optical laminate, and also has transparency and thermal stability.

[0138] The above-mentioned adhesive may use adhesives developed in the past or in the future. For example, a photocurable adhesive may be used.

[0139] The above-mentioned photocurable adhesive exhibits strong adhesive force by undergoing crosslinking and curing upon receiving active energy rays such as ultraviolet rays (UV) and electron beams (EB), and may be composed of a reactive oligomer, a reactive monomer, a photoinitiator, etc.

[0140] The above-mentioned reactive oligomer is an important component that determines the characteristics of the adhesive, and forms a cured film by forming polymer bonds through a photopolymerization reaction. Examples of the reactive oligomer that can be used include polyester-based resins, polyether-based resins, polyurethane-based resins, epoxy-based resins, polyacrylic-based resins, silicone-based resins, etc.

[0141] The above-mentioned reactive monomer functions as a crosslinking agent and a diluent for the above-mentioned reactive oligomer, and also affects the adhesive characteristics. Examples of the reactive monomer that can be used include monofunctional monomers, polyfunctional monomers, epoxy-based monomers, vinyl ethers, cyclic ethers, etc.

[0142] The above-mentioned photoinitiator functions to absorb light energy to generate free radicals or cations to initiate photopolymerization, and a suitable photoinitiator can be selected according to the photopolymerization resin.

[0143] The above-mentioned adhesive can be 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 polyvinylpyrrolidone adhesive, a polyacrylamide adhesive, a cellulose adhesive, a vinyl alkyl ether adhesive, etc. can be used. The above-mentioned adhesive is not particularly limited as long as it has adhesiveness and viscoelasticity. However, considering aspects such as ease of acquisition, an acrylic adhesive is preferably used. For example, it can contain a (meth)acrylate copolymer, a crosslinking agent, a solvent, etc.

[0144] The above-mentioned crosslinking agent can be a crosslinking agent developed in the past or in the future. For example, it can contain a polyisocyanate compound, an epoxy resin, a melamine resin, a urea resin, a dialdehyde, a hydroxymethyl polymer, etc. Preferably, it can contain a polyisocyanate compound.

[0145] The above-mentioned solvent can contain common solvents used in the field of resin compositions. For example, alcohol-based compounds such as methanol, ethanol, isopropanol, butanol, and propylene glycol monomethyl ether can be used; ketone-based compounds such as methyl ethyl ketone, methyl butyl ketone, methyl isobutyl ketone, diethyl ketone, and dipropyl ketone; acetate-based compounds such as methyl acetate, ethyl acetate, butyl acetate, and propylene glycol monomethyl acetate; cellosolve-based compounds such as methyl cellosolve, ethyl cellosolve, and propyl cellosolve; hydrocarbon-based compounds such as hexane, heptane, benzene, toluene, and xylene, etc. These solvents can be used alone or in combination of two or more.

[0146] The thickness of the above-mentioned adhesion / bonding layer 400 can be appropriately determined according to the type of resin that functions as the adhesion / bonding body, the adhesion / bonding strength, the environment in which the adhesive is used, etc. In one embodiment, in order to ensure sufficient adhesion / cohesive force and minimize the thickness of the optical laminate, the thickness of the above-mentioned adhesion / bonding layer can be 0.01 to 50 μm, preferably it can have a thickness of 0.05 to 20 μm, and more preferably it can have a thickness of 0.1 to 10 μm.

[0147] The above-mentioned ultraviolet absorption layer is not particularly limited as long as it is used to prevent the deterioration of the optical laminate caused by 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, octyl 3-[3-tert-butyl-4-hydroxy-5-(chloro-2H-benzotriazol-2-yl)phenyl]propionate, and a mixture of 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',4'-methylenedioxyphenyl)acrylate, etc.), triazine-based ultraviolet absorbers, etc. Benzotriazole-based ultraviolet absorbers or triazine-based ultraviolet absorbers with high transparency and excellent effects in preventing the deterioration of polarizing plates or transmittance variable layers are preferred, and benzotriazole-based ultraviolet absorbers with more suitable spectral absorption spectra are particularly preferred. The above-mentioned benzotriazole-based ultraviolet absorbers can also be bis-ified substances. For example, they can be 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.

[0148] The above-mentioned hard coat 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 hard coats developed in the past or in the future can be used.

[0149] In one embodiment, the above hard coat can be formed by applying a composition for forming a hard coat on other members and then curing it using light or heat. The composition for forming the hard coat is not particularly limited. For example, it may contain a photocurable compound and a photoinitiator.

[0150] For the above photocurable compound and photoinitiator, substances generally used in the art can be used without limitation. For example, the photocurable compound can be a photopolymerizable monomer, a photopolymerizable oligomer, etc. For example, monofunctional and / or polyfunctional (meth)acrylates can be cited. As for the photoinitiator, hydroxycyclohexyl phenyl ketone, trimethylbenzoyl diphenyl phosphine oxide, acetophenone-based, oxime ester-based, etc. can be cited. As commercially available products, Irgacure-184, TPO, Irgacure-907, etc. can be cited.

[0151] <Method for manufacturing a variable transmittance optical laminate>

[0152] The variable transmittance optical laminate of the present invention described above can be formed by a roll-to-roll process, including the steps of forming a first transparent conductive layer 200-1 on a transparent substrate 150, forming an alignment film 210 on the first transparent conductive layer 200-1, forming a second transparent conductive layer 200-2 and a liquid crystal layer 300 on a second polarizing plate, and laminating the liquid crystal layer 300 and the alignment film 210.

[0153] That is, the method for manufacturing the variable transmittance optical laminate of the present invention may include: (a) a step of preparing a first polarizing plate; (b) a step of forming a first transparent conductive layer on a transparent substrate; (c) a step of forming an alignment film on the first transparent conductive layer; (d) a step of forming a second transparent conductive layer on a second polarizing plate; (e) a step of applying a composition for forming a liquid crystal layer on the second transparent conductive layer to form a liquid crystal layer; (f) a step of laminating in such a manner that the alignment film of the laminate formed in the above step (c) is in contact with the liquid crystal layer of the laminate formed in the above step (e); and (g) a step of laminating the first polarizing plate prepared in the above step (a) on the transparent substrate of the laminate formed in the above step (f), wherein in the above step (g), the absorption axes of the first polarizing plate and the second polarizing plate are laminated in a manner orthogonal to each other in the top view direction, and the above steps (b) to (f) are carried out by a roll-to-roll process.

[0154] The method for manufacturing the variable transmittance optical laminate of the present invention is a method for manufacturing the above variable transmittance optical laminate, and the content of the above <variable transmittance optical laminate> can be applied without limitation.

[0155] Figure 4It is a diagram schematically showing a method for manufacturing a variable transmittance optical laminate according to an embodiment of the present invention.

[0156] Referring Figure 4 , the second polarizing plate 100-2 having the second transparent conductive layer 200-2 formed thereon and the transparent substrate 150 having the first transparent conductive layer 200-1 and the alignment film 210 formed thereon in sequence can be continuously advanced through a roll-to-roll process in different production lines, and can be continuously advanced in a direction in which the two production lines can meet and be laminated to each other.

[0157] Hereinafter, the method for manufacturing the variable transmittance optical laminate of the present invention will be described step by step.

[0158] (a) Step of preparing the first polarizing plate

[0159] First, prepare the first polarizing plate 100-1 in a manner that can be used in step (g).

[0160] It can be attached to the transparent substrate 150 by forming an adhesive / bonding layer on the first polarizing plate 100-1. In this case, the adhesive / bonding layer can be manufactured on the first polarizing plate 100-1 through a roll-to-roll process.

[0161] The above-mentioned first polarizing plate 100-1 and the adhesive / bonding layer can be similarly applied to the content of the polarizing plate 100 and the adhesive / bonding layer 400 described in the above <variable transmittance optical laminate>.

[0162] After that, it is prepared by cutting in a manner that can be laminated orthogonally to the absorption axis of the second polarizing plate 100-2 in the top view direction.

[0163] (b) Step of forming the first transparent conductive layer on the transparent substrate

[0164] The first transparent conductive layer 200-1 is formed on the transparent substrate 150, which can be manufactured through a roll-to-roll process.

[0165] The above-mentioned first transparent conductive layer 200-1 can be formed by evaporation or coating on one surface of the transparent substrate 150. At this time, in order to improve the adhesion, a pretreatment such as corona treatment or plasma treatment can be performed on one surface of the transparent substrate 150 before forming the first transparent conductive layer 200-1.

[0166] In addition, an easy-bonding layer (not shown) can also be provided on one surface of the transparent substrate 150 to attach and form the first transparent conductive layer 200-1.

[0167] The above-mentioned first transparent conductive layer 200-1, transparent substrate 150, and easy-bonding layer can similarly apply the content of the transparent conductive layer 200, transparent substrate 150, and adhesive / adhesive layer 400 described in the above <transmittance variable optical laminate>.

[0168] (c) Step of forming the alignment film on the above-mentioned first transparent conductive layer

[0169] An alignment film 210 can be formed on one surface of the first transparent conductive layer 200-1 formed on the transparent substrate 150 through the above step (b).

[0170] The above alignment film 210 can be formed in a direction perpendicular to the alignment angle of the second transparent conductive layer 200-2 described later. The transmittance variable optical laminate of the present invention can be physically aligned by rubbing in the forward direction (MD direction) on the surface of the second transparent conductive layer 200-2 through a roll-to-roll process. However, the physical alignment in the roll-to-roll process can only achieve the alignment in the forward direction (MD direction). Therefore, the above alignment film 210 is preferably formed by photo-alignment rather than physical alignment to be able to be aligned in the direction perpendicular to the forward direction (TD direction).

[0171] The above alignment film 210 can be produced by coating an alignment film coating composition containing an alignment polymer, a photoinitiator, and a solvent and curing it. The above alignment polymer is not particularly limited, and polyacrylate resins, polyamic acid resins, polyimide resins, polymers containing cinnamate groups, etc. can be used, and polymers that can exhibit alignment properties developed in the past or in the future can be used.

[0172] For example, the alignment angle formed in the above alignment film 210 can be 90°, and the alignment angle formed in the second transparent conductive layer 200-2 can be 0°.

[0173] (d) Step of forming the second transparent conductive layer on the second polarizing plate

[0174] Prepare a second polarizing plate 100-2, and form the second transparent conductive layer 200-2 through a roll-to-roll process.

[0175] The above second transparent conductive layer 200-2 can be formed by directly coating on one surface of the above second polarizing plate 100-2. At this time, in order to improve the adhesion, pretreatment such as corona treatment or plasma treatment can be performed on one surface of the above second polarizing plate 100-2 and then directly contacted with the transparent conductive layer 200-2 to form it.

[0176] In addition, an easy-bonding layer (not shown) can also be provided on one surface of the above second polarizing plate 100-2 to attach and form the transparent conductive layer 200-2.

[0177] The above-mentioned second polarizing plate 100-2, second transparent conductive layer 200-2, and easy-bonding layer can similarly apply the content of the polarizing plate 100, transparent conductive layer 200, and adhesive / bonding layer 400 described in the above <transmittance-variable optical laminate>.

[0178] After the above step (d), through a roll-to-roll process, while passing through the alignment forming section 250, regular grooves can be formed on the surface of the second transparent conductive layer 200-2, thereby performing rubbing alignment.

[0179] The above-mentioned second transparent conductive layer 200-2 contains a conductive polymer. Different from the transparent conductive layer containing a metal component, the above-mentioned conductive polymer can form regular grooves on the surface, so that the liquid crystal compounds in the liquid crystal layer can be arranged at desired positions and in desired directions.

[0180] Since rubbing is obtained in the forward direction (MD direction) through the above roll-to-roll continuous process, alignment will occur at a certain angle, and the alignment angle of the second transparent conductive layer 200-2 can be formed in a manner consistent with the absorption axis of the above-mentioned second polarizing plate 100-2. For example, the absorption axis of the above-mentioned second polarizing plate 100-2 can be 0°, and the alignment angle formed in the second transparent conductive layer 200-2 can be 0°.

[0181] (e) Step of forming the liquid crystal layer by coating the composition for forming the liquid crystal layer on the second transparent conductive layer

[0182] As described above, the liquid crystal layer 300 included in the transmittance-variable optical laminate of the present invention contains both liquid crystal compounds 320 and a polymer network 310. Therefore, even without a separate sealant and / or spacer, the cell gap of the liquid crystal layer can be appropriately maintained, and the content regarding the liquid crystal layer 300 described in the above <transmittance-variable optical laminate> can be applied without limitation.

[0183] The above-mentioned liquid crystal layer 300 can be formed by using a liquid crystal layer-forming composition containing a polymerizable monomer and a liquid crystal compound. After the above step (d), while continuously passing through the liquid crystal layer forming section 350 through a roll-to-roll process, the liquid crystal layer-forming composition is coated on the second transparent conductive layer 200-2 after the above rubbing alignment and cured (not shown), thereby forming the liquid crystal layer 300.

[0184] (f) Step of laminating in such a manner that the alignment film of the laminate formed in the above step (c) is in contact with the liquid crystal layer of the laminate formed in the above step (e) (g) Step of laminating the first polarizing plate prepared in the above step (a) on the transparent substrate of the laminate formed in the above step (f)

[0185] Lamination is performed in such a way that the alignment film 210 in the laminate formed in the above step (c) is in contact with the liquid crystal layer 300 formed in the above step (e).

[0186] At this time, the laminate formed in the above step (c) and the laminate having the liquid crystal layer 300 formed in the above step (e) can be conveyed through different tracks, and the alignment film 210 and the liquid crystal layer 300 can be laminated to each other by a roll-to-roll process.

[0187] ​ ​

[0188] After the above step (f), the first polarizing plate 100-1 prepared in the above step (a) and the second polarizing plate 100-2 are laminated in such a manner that their absorption axes are orthogonal to each other.

[0189] That is, after sequentially laminating the second polarizing plate 100-2, the second transparent conductive layer 200-2, the liquid crystal layer 300, the alignment film 210, the first transparent conductive layer 200-1, and the transparent substrate 150 by a roll-to-roll process, the first polarizing plate 100-1 is laminated so that its absorption axis is perpendicular to that of the second polarizing plate 100-2 in the top view direction, whereby the variable transmittance optical laminate of the present invention can be manufactured.

[0190] For example, the absorption axis of the second polarizing plate 100-2 can be 0°, and the absorption axis of the first polarizing plate 100-1 can be 90°.

[0191] At this time, by arranging the absorption axes of the first polarizing plate 100-1 and the second polarizing plate 100-2 perpendicular to each other in the top view direction, it is possible to improve the variable transmittance range between the light transmission mode (ON) and the light shielding mode (OFF) of the optical laminate based on liquid crystal driving.

[0192] In this way, since the variable transmittance optical laminate is manufactured by forming the liquid crystal layer through a roll-to-roll continuous process, the process is continuous and can be economically manufactured.

[0193] <Smart windows, automotive and building windows>

[0194] In addition to the above variable transmittance optical laminate, the present invention also includes a smart window including the above variable transmittance optical laminate. Further, the present invention includes 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, and an interior partition, and a building window including the above smart window.

Claims

1. A variable transmittance optical stack, comprising: a first polarizing plate; a transparent substrate laminated on one side of the first polarizing plate; A first transparent conductive layer formed on the transparent substrate; an alignment film formed on the first transparent conductive layer; a second polarizing plate, which is 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 alignment film and the second transparent conductive layer, The second transparent conductive layer comprises a conductive polymer. The liquid crystal layer comprises a polymer network and a liquid crystal compound, The liquid crystal compound is arranged in a uniform initial orientation.

2. The variable transmittance optical 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 a twisted nematic TN mode, a super twisted nematic STN mode, an in-plane switching IPS mode, a fringe field switching FFS mode and a vertical alignment VA mode.

3. The variable transmittance optical stack according to claim 2, wherein: The liquid crystal behavior mode of the liquid crystal layer is a twisted nematic TN mode.

4. The variable transmittance optical stack according to claim 1, wherein: The liquid crystal layer includes a cured product of a liquid crystal layer-forming composition containing a polymerizable monomer and a liquid crystal compound.

5. The variable transmittance optical stack according to claim 4, wherein: The composition for forming a liquid crystal layer includes 10 to 30 wt % of a polymerizable monomer based on the total weight of the composition.

6. The variable transmittance optical stack according to claim 1, wherein: The surface of the second transparent conductive layer in contact with the liquid crystal layer is rubbed and aligned.

7. The variable transmittance optical stack according to claim 1, wherein: The conductive polymer comprises one or more selected from the group consisting of polythiophene, poly(3,4-ethylenedioxythiophene), polyaniline, polyacetylene, polydiacetylene, polyphenylene, polyphenylene vinylene, polyphenylene sulfide, polythiophene acetylene, polythiophene vinylene, polyfluorene, polypyrrole, poly(3,4-ethylenedioxythiophene):polystyrene sulfonate, poly(3,4-ethylenedioxythiophene):camphorsulfonic acid, poly(3,4-ethylenedioxythiophene):toluenesulfonic acid, poly(3,4-ethylenedioxythiophene):dodecylbenzenesulfonic acid, polyaniline:polystyrene sulfonate, polyaniline:camphorsulfonic acid, polypyrrole:polystyrene sulfonate, polypyrrole:camphorsulfonic acid, polypyrrole:toluenesulfonic acid, polypyrrole:dodecylbenzenesulfonic acid, polythiophene:polystyrene sulfonate, polythiophene:camphorsulfonic acid, polythiophene:toluenesulfonic acid and polythiophene:dodecylbenzenesulfonic acid.

8. The variable transmittance optical stack according to claim 1, wherein: The second transparent conductive layer is formed to be in direct contact with the second polarizing plate without including a separate substrate.

9. The variable transmittance optical stack according to claim 1, wherein: The second transparent conductive layer is formed so as to be in direct contact with the second polarizing plate by including an easy-adhesion layer therebetween.

10. The variable transmittance optical stack 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 phase difference adjusting layer, and a refractive index adjusting layer.

11. The variable transmittance optical stack according to claim 1, wherein: The first polarizing plate and the second polarizing plate have a thickness of 30 μm to 200 μm.

12. The variable transmittance optical stack according to claim 1, wherein: The variable transmittance optical layered body further includes at least one selected from the group consisting of an adhesive / bonding layer, an ultraviolet absorbing layer, and a hard coating layer.

13. A method for manufacturing a variable transmittance optical stack, comprising: (a) preparing a first polarizing plate; (b) forming a first transparent conductive layer on a transparent substrate; (c) forming an alignment film on the first transparent conductive layer; (d) forming a second transparent conductive layer on the second polarizing plate; (e) a step of coating a liquid crystal layer-forming composition on the second transparent conductive layer to form a liquid crystal layer; (f) laminating the stacked body formed in the step (c) so that the alignment film of the stacked body is in contact with the liquid crystal layer of the stacked body formed in the step (e); and (g) laminating the first polarizing plate prepared in step (a) on the transparent substrate of the laminate formed in step (f), In the step (g), the first polarizing plate and the second polarizing plate are laminated in such a manner that the absorption axis of the first polarizing plate and the absorption axis of the second polarizing plate are orthogonal to each other in the plan view direction. The steps (b) to (f) are performed by a roll-to-roll process.

14. The method for producing a variable transmittance optical layered body according to claim 13, wherein: The second transparent conductive layer includes a conductive polymer.

15. The method for producing a variable transmittance optical layered body according to claim 13, wherein: Between the steps (d) and (e), the method further includes a step of causing the surface of the second transparent conductive layer in contact with the liquid crystal layer to form a rubbing alignment.

16. The method for producing a variable transmittance optical layered body according to claim 13, wherein: In the step (d), the second transparent conductive layer is formed to be in direct contact with the second polarizing plate without including a separate substrate.

17. The method for producing a variable transmittance optical layered body according to claim 13, wherein: In the step (d), the second transparent conductive layer is formed so as to be in direct contact with the second polarizing plate by including an easy-adhesion layer therebetween.

18. The method for producing a variable transmittance optical layered body according to claim 13, wherein: The liquid crystal behavior mode of the liquid crystal layer is any one selected from the group consisting of a twisted nematic TN mode, a super twisted nematic STN mode, an in-plane switching IPS mode, a fringe field switching FFS mode and a vertical alignment VA mode.

19. The method for producing a variable transmittance optical layered body according to claim 18, wherein: The liquid crystal behavior mode of the liquid crystal layer is a twisted nematic TN mode.

20. The method for producing a variable transmittance optical layered body according to claim 13, wherein: The liquid crystal layer includes a cured product of a liquid crystal layer-forming composition containing a polymerizable monomer and a liquid crystal compound.

21. The method for producing a variable transmittance optical layered body according to claim 13, wherein: The liquid crystal layer includes a polymer network and a liquid crystal compound.

22. A smart window comprising the variable transmittance optical laminate according to any one of claims 1 to 12.

23. An automobile, wherein the smart window according to claim 22 is applied to at least one of a front window, a rear window, a side window, a skylight, and an interior partition.

24. A window for a building, comprising the smart window according to claim 22.

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