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

Abstract

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 using the same, the variable transmittance optical laminate comprising: a first polarizing plate; a first transparent conductive layer formed on one surface of the first polarizing plate; a second polarizing plate facing the first polarizing plate; a second transparent conductive layer formed on one surface of the second polarizing plate and facing the first transparent conductive layer; and a liquid crystal layer provided between the first transparent conductive layer and the second transparent conductive layer and including a spherical spacer, at least one of the first polarizing plate and the second polarizing plate including a functional layer, the functional layer including a plurality of pattern portions satisfying mathematical expression 1, and the spherical spacer being recessed in the pattern portions. The variable transmittance optical laminate of the present invention can minimize the flow of spherical spacers.

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 so as 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 containing spherical spacers to maintain a predetermined cell gap. However, in the case of using spherical spacers to maintain the cell gap of the liquid crystal layer, there are problems such as the phenomenon of the shift of the spherical spacers due to gravity, so that the cell gap cannot be firmly maintained, it is difficult to maintain a constant in-plane optical color, and current short circuits of the optical laminate are induced.

[0005] Therefore, in fact, it is necessary to develop a variable transmittance optical laminate that can uniformly maintain the cell gap of the liquid crystal, minimize the short circuit of the laminate circuit, thereby maintaining a constant in-plane optical color, and minimizing liquid crystal defects.

[0006] Prior Art Documents

[0007] Patent Documents

[0008] Patent Document 1: Japanese Patent Laid-Open No. 2018-010035 Summary of the Invention

[0009] Problems to be Solved

[0010] In order to solve the above problems, an object of the present invention is to provide a variable transmittance optical laminate which can minimize the flow of spherical spacers by introducing a functional layer having a plurality of pattern portions on a polarizing plate and causing the spherical spacers to be recessed into the pattern portions.

[0011] In addition, an object of the present invention is to provide a variable transmittance optical laminate which can maintain a constant in-plane optical color and minimize liquid crystal defects by uniformly maintaining the cell gap of the liquid crystal.

[0012] In addition, an object of the present invention is to provide a variable transmittance optical laminate which does not include a separate substrate for forming a transparent conductive layer, thereby simplifying the manufacturing process.

[0013] In addition, an object of the present invention is to provide a smart window including the above variable transmittance optical laminate and a window for an automobile or a building using the above smart window.

[0014] However, the problems to be solved by the present invention are not limited to the above-mentioned problems, and those skilled in the art should be able to understand other problems not mentioned based on the following description.

[0015] Means for Solving the Problems

[0016] The present invention relates to a variable transmittance optical laminate including: a first polarizing plate; a first transparent conductive layer formed on one surface of the first polarizing plate; 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 first transparent conductive layer and the second transparent conductive layer and including spherical spacers, wherein at least one of the first polarizing plate and the second polarizing plate includes a functional layer having a plurality of pattern portions satisfying the following Mathematical Formula 1, and the spherical spacers are recessed into the pattern portions.

[0017] [Mathematical Formula 1]

[0018] 2μm ≤ a ≤ 2r

[0019] (In the above Mathematical Formula 1, a is the distance between the closest ridges in each pattern portion, and r is the radius of the spherical spacer.)

[0020] In a first aspect of the present invention, the pattern portions may satisfy the following Mathematical Formula 2.

[0021] [Mathematical Formula 2]

[0022] 1μm ≤ h ≤ r

[0023] (In the above mathematical formula 2, h is the height of the pattern portion, and r is the radius of the spherical spacer.)

[0024] In the second aspect of the present invention, the above-mentioned pattern portion may satisfy the following mathematical formula 3.

[0025] [Mathematical formula 3]

[0026] 2r ≤ L

[0027] (In the above mathematical formula 3, r is the radius of the spherical spacer, and L is the distance between the respective pattern portions.)

[0028] In the third aspect of the present invention, the above-mentioned pattern portion may include a first concavo-convex portion and a second concavo-convex portion.

[0029] In the fourth aspect of the present invention, the above-mentioned functional layer may include a cured product of a composition for forming a functional layer.

[0030] In the fifth aspect of the present invention, the above-mentioned composition for forming a functional layer may include a photocurable composition and a photoinitiator.

[0031] In the sixth aspect of the present invention, the liquid crystal behavior mode of the above-mentioned 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, an electrically controlled birefringence (ECB) mode, and a vertical alignment (VA) mode.

[0032] In the seventh aspect of the present invention, at least one of the above-mentioned first transparent conductive layer and second transparent conductive layer may include a conductive polymer.

[0033] In an eighth aspect of the present invention, the above-mentioned 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):toluenesulfonic acid, poly(3,4-ethylenedioxythiophene):dodecylbenzenesulfonic acid, polyaniline:polystyrenesulfonate, polyaniline:camphorsulfonic acid, polypyrrole:polystyrenesulfonate, polypyrrole:camphorsulfonic acid, polypyrrole:toluenesulfonic acid, polypyrrole:dodecylbenzenesulfonic acid, polythiophene:polystyrenesulfonate, polythiophene:camphorsulfonic acid, polythiophene:toluenesulfonic acid, and polythiophene:dodecylbenzenesulfonic acid.

[0034] In a ninth aspect of the present invention, at least one of the first transparent conductive layer and the second transparent conductive layer may be formed to be in direct contact with one of the first polarizing plate and the second polarizing plate without including a separate substrate therebetween.

[0035] In a tenth aspect of the present invention, at least one of the first polarizing plate and the second polarizing plate may further include one or more selected from the group consisting of a protective layer, a retardation adjusting layer, and a refractive index adjusting layer.

[0036] In an eleventh aspect of the present invention, the above-mentioned 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.

[0037] In addition, the present invention relates to a smart window including the above-mentioned variable transmittance optical laminate.

[0038] In addition, the present invention relates to an automobile in which the above-mentioned smart window is applied to at least one of a front window, a rear window, a side window, a sunroof, and an interior partition.

[0039] In addition, the present invention relates to a building window including the above-mentioned smart window.

[0040] Advantages of the Invention

[0041] The variable transmittance optical laminate according to the present invention can minimize the flow of spherical spacers by introducing a functional layer having a plurality of pattern portions on a polarizing plate and causing the spherical spacers to be recessed in the pattern portions.

[0042] In addition, the variable transmittance optical laminate according to the present invention can maintain a constant in-plane optical color and minimize liquid crystal defects by uniformly maintaining the cell gap of the liquid crystal.

[0043] In addition, the variable transmittance optical laminate according to the present invention does not include a separate substrate for forming a transparent conductive layer, thus simplifying the manufacturing process. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is a diagram showing the laminated structure of the variable transmittance optical laminate according to an embodiment of the present invention.

[0045] Figure 2a ~ Figure 2e It is a diagram showing the laminated structure of the polarizing plate according to one or more embodiments of the present invention.

[0046] Figure 3 It is a top view showing the structure of the functional layer according to an embodiment of the present invention.

[0047] Figure 4 It is a cross-sectional view showing the structure of the pattern portion according to an embodiment of the present invention.

[0048] Figure 5 It is a diagram showing the laminated structure of the variable transmittance optical laminate according to another embodiment of the present invention. DETAILED DESCRIPTION

[0049] The present invention relates to a variable transmittance optical laminate in which at least one of a first polarizing plate and a second polarizing plate includes a functional layer having a plurality of pattern portions. Specifically, by satisfying the following mathematical formula 1 with the plurality of pattern portions included in the functional layer and causing spherical spacers to be recessed on the pattern portions, the flow of the spherical spacers can be minimized, the cell gap of the liquid crystal can be maintained uniformly, and a constant in-plane optical color can be maintained. Thus, the cell gap of the liquid crystal layer can be maintained by means of the polymer network in the liquid crystal layer.

[0050] More specifically, the present invention relates to a variable transmittance optical laminate comprising: a first polarizing plate; a first transparent conductive layer formed on one surface of the first polarizing plate; 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 first transparent conductive layer and the second transparent conductive layer and containing spherical spacers, wherein at least one of the first polarizing plate and the second polarizing plate includes a functional layer, the functional layer has a plurality of pattern portions satisfying the following Mathematical Formula 1, and the spherical spacers are recessed on the pattern portions.

[0051] [Mathematical Formula 1]

[0052] 2μm ≤ a ≤ 2r

[0053] (In the above Mathematical Formula 1, a is the distance closest to the distance between ridges within each pattern portion, and r is the radius of the spherical spacer.)

[0054] 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.

[0055] A smart window refers to an optical structure that changes the light transmittance according to the application of an electric signal to control the amount of light or heat passing through. That is, a smart window can change into a transparent, opaque, or translucent state according to voltage, and is also referred to as a variable transmittance glass, a dimming glass, or a smart glass.

[0056] A smart window can be used as a partition for dividing the interior space of a vehicle or a building or a partition for privacy protection, or as a daylighting window disposed at an opening of a building. It can also be used as a highway road sign, a billboard, a scoreboard, a clock, or an advertisement screen, and can be used instead of the glass of a transportation tool such as a window or a skylight of a car, a bus, an airplane, a ship, or a train.

[0057] The variable transmittance optical laminate of the present invention can also be used as a smart window in 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 and is advantageous for bending characteristics, and can be particularly suitable for smart windows for vehicles or buildings. In one or more embodiments, the smart window applying 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 building windows, 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 building, such as internal partitions.

[0058] 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 construed as being limited only to the matters described in these drawings.

[0059] 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 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.

[0060] The terms "comprises" and / or "comprising" used in this specification are used in the sense of not excluding the presence or addition of one or more other components, steps, operations, and / or elements other than the mentioned components, steps, operations, and / or elements. Throughout the specification, the same reference numerals refer to the same components.

[0061] 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 drawings 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.

[0062] 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.

[0063] <Variable transmittance optical laminate>

[0064] Figure 1 FIG. 1 is a diagram showing the laminate structure of a variable transmittance optical laminate according to an embodiment of the present invention, and FIG. 2 is a diagram showing the laminate structure of a polarizing plate according to one or more embodiments of the present invention.

[0065] 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, and a liquid crystal layer 300.

[0066] Referring to FIG. 2, the polarizing plate 100 may include a polarizer 110, and may further include one or more selected from the group consisting of 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 110, 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 110, 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 ).

[0067] The polarizer 110 may use a conventional or later-developed polarizer. For example, a stretched polarizer or a coated polarizer may be used.

[0068] In one embodiment, the above-mentioned stretching type polarizer may comprise 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 etc. may be cited. 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.

[0069] 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 contain a reactive liquid crystal compound, a dichroic dye, etc.

[0070] The above-mentioned reactive liquid crystal compound may refer to, for example, a compound containing a mesogen skeleton etc. and containing one or more polymerizable functional groups. Such a reactive liquid crystal compound has been widely known under 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.

[0071] 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.

[0072] 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.

[0073] In addition, the above liquid crystal coating composition can also contain a leveling agent, a polymerization initiator, etc. within a range that does not hinder the polarization characteristics of the coating film.

[0074] The above protective layer 120 is intended to protect the polarization characteristics of the polarizer 110 from the influence of post - processes and the external environment, and can be realized in the form of a protective film or the like.

[0075] As Figure 2a and Figure 2b As shown in the figure, the above protective layer 120 can be formed in direct contact on one or both sides of the polarizer 110, but 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 in direct contact with other functional layers.

[0076] In one or more embodiments, the above-described 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).

[0077] The above-described 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.

[0078] As Figure 2c and Figure 2d As illustrated, the above-described retardation adjustment layer 130 may be formed in direct contact on one surface of the polarizer 110, but is not limited thereto. For example, as Figure 2e As illustrated, the above-described retardation adjustment layer 130 may be formed on one surface of the protective layer 120 so as to laminate the polarizer 110, the protective layer 120, and the retardation adjustment layer 130 in this order.

[0079] The above-described retardation adjustment layer 130 may use a polymer stretched film or a liquid crystal polymer film obtained by stretching a polymer film capable of imparting optical anisotropy in an appropriate manner by stretching.

[0080] 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.

[0081] The method for obtaining the above-mentioned polymer stretched film is not particularly limited. For example, it can be obtained by stretching after forming the above-mentioned polymer material into a film shape. The method for forming 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, or can be formed 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 also 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 cast, dried, and cured to form the unstretched film by casting molding.

[0082] For the above-mentioned polymer stretched film, the molded film can be uniaxially stretched along the machine direction (MD; Mechanical Direction, longitudinal or length direction), uniaxially stretched along the direction perpendicular to the machine 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.

[0083] The liquid crystal polymer film described above may contain a reactive liquid crystal compound in a polymerized state. The above-mentioned reactive liquid crystal compound can equally apply the content of the reactive liquid crystal compound regarding the above-mentioned coating type polarizer.

[0084] In one or more embodiments, for the thickness of the above-mentioned retardation adjustment layer 130, in the case of a polymer stretched 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.

[0085] The above-mentioned refractive index adjustment layer 140 is provided to compensate for the refractive index difference of the optical laminate caused by the transparent conductive layer 200 described later, 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.

[0086] 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 from 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 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.

[0087] In one embodiment, the refractive index of the above-mentioned refractive index adjustment layer 140 can be appropriately selected according to the material of the adjacent other members, preferably it can be 1.4 to 2.6, and more preferably it can 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.

[0088] The above-mentioned refractive index adjustment layer 140 has no particular limitation as long as it can prevent a significant refractive index difference between other members such as the polarizer 110 and the transparent conductive layer 200. Compounds used for forming a refractive index adjustment layer in the past or developed in the future can be used. For example, it can be formed from a refractive index adjustment layer forming composition containing a polymerizable isocyanurate compound.

[0089] In one embodiment, in addition to the above functional layers, the polarizing plate 100 may further include other functional layers to assist or enhance the characteristics of the polarizer. For example, in order to further improve the mechanical durability, an overcoat layer or the like may be included.

[0090] 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 optically thin laminate can be manufactured while maintaining the optical characteristics of the polarizing plate 100.

[0091] Figure 3 is a top view showing the structure of a functional layer according to an embodiment of the present invention, Figure 4 is a cross-sectional view showing the structure of a pattern portion according to an embodiment of the present invention. For example, Figure 4 is along Figure 3 The cross-sectional view taken along the line A-A' shown in the thickness direction.

[0092] Referring to Figure 3 a functional layer 500 according to an embodiment of the present invention includes a plurality of pattern portions 510.

[0093] The functional layer 500 is a layer formed on the polarizing plate 100 to improve the physical or optical characteristics of the laminate. For example, it may be a hard coat layer with high hardness, an anti-fingerprint layer with fingerprint resistance, a low-reflection layer, or an anti-glare layer, but is not limited thereto.

[0094] In one embodiment, the functional layer 500 may be formed by coating a composition for forming a functional layer on the polarizing plate 100 and then curing it using light or heat. For example, a composition for forming a functional layer may be coated on the polarizing plate 100, and after forming the shape of the pattern portion on the functional layer 500 using a pattern roll having a predetermined pattern shape, it may be photocured by an ultraviolet irradiator, thereby forming a functional layer 500 having a pattern portion 510.

[0095] The composition for forming a functional layer is not particularly limited. For example, it may include a photocurable compound and a photoinitiator.

[0096] The photocurable compound and the photoinitiator may be used without limitation substances generally used in the art. For example, the photocurable compound may be a photopolymerizable monomer, a photopolymerizable oligomer, etc. For example, monofunctional and / or polyfunctional (meth)acrylates may be cited, and as the photoinitiator, hydroxycyclohexyl phenyl ketone, trimethylbenzoyl diphenyl phosphine oxide, acetophenone-based, oxime ester-based, etc. may be cited. As commercially available products, Irgacure-184, TPO, Irgacure-907, etc. may be cited.

[0097] The coating of the above-described composition for forming a functional layer can be carried out by unrestrictedly applying the methods commonly used in the art. For example, it can be carried out by gravure coating, roll coating, knife coating, etc. The coating thickness of the above-described photocurable resin composition is 1 to 50 μm, preferably 2 to 30 μm, and more preferably 2 to 10 μm.

[0098] In one embodiment, after coating the composition for forming a functional layer, UV light can be irradiated to cure the composition for forming a functional layer. At this time, the irradiation amount of UV light is about 0.1 to 2 J / cm 2 , preferably 0.2 to 0.5 J / cm 2 , and a high-pressure mercury lamp and a metal halide lamp having a main wavelength of 365 nm are preferably used.

[0099] Referring to Figure 4 , the pattern portion 510 included in the functional layer 500 of one embodiment of the present invention may include a first concavo-convex portion 511 and a second concavo-convex portion 512.

[0100] In this embodiment, the above-described pattern portion 510 formed by repeating two concavo-convex portions 511 and 512 having a triangular cross-sectional shape at a certain interval will be described as an example. That is, in Figure 3 , the dotted line shown in the center of the pattern portion 510 represents the valley between the above-described first concavo-convex portion 511 and the second concavo-convex portion 512, and the solid lines on both sides adjacent to the dotted line respectively represent the ridges of the first concavo-convex portion 511 and the second concavo-convex portion 512. In the present invention, the "ridge of the pattern portion" or the "ridge of the concavo-convex portion" may have the same meaning, and may be the outermost point protruding in the cross-sectional shape of the pattern portion or the concavo-convex portion. For example, as Figure 4 the end points of the triangles of the concavo-convex portions 511 and 512 having a triangular cross-sectional shape in, it may be the end points of the height h of the pattern portion.

[0101] However, it is not limited thereto, and the above-described pattern portion 510 can be applied in various shapes and intervals. For example, the surfaces of the above-described first concavo-convex portion 511 and the second concavo-convex portion 512 that come into contact with the spherical spacer 320 may also be formed to have a curved shape along the outer peripheral surface of the spherical spacer 320.

[0102] In one embodiment, the above-described pattern portion 510 can be provided repeatedly over the entire surface on one side of the functional layer 500, or can be provided at a predetermined interval. In addition, the above-described pattern portion 510 can be formed along the machine direction of flow (MD) and / or the direction perpendicular to the machine direction of flow (TD). From the aspect of the processability of forming the pattern portion, it is preferably formed along the machine direction of flow (MD).

[0103] In the past, attempts have been made to prevent the flow of spherical spacers by forming an alignment film after dispersing spherical spacers or by dispersing spherical spacers in a composition for forming an alignment film and then forming an alignment film, and forming micro-bends at the lower part of the dispersed spherical spacers. However, in the above-mentioned conventional method, since the spherical spacers are dispersed before forming micro-bends on the alignment film, there are limitations in spacing the spherical spacers at a certain interval.

[0104] However, the variable transmittance optical laminate of the present invention has a structure in which a functional layer 500 having a plurality of pattern portions 510 is provided on a polarizing plate 100. The pattern portion 510 of the recessed spherical spacers is formed first, and then the spherical spacers 320 are dispersed. Therefore, by dispersing the spherical spacers 320 intensively in the portion where the pattern portion 510 is formed, the spherical spacers 320 can be uniformly dispersed at a certain interval without aggregating together. Thus, the cell gap of the liquid crystal can be kept uniform and the in-plane constant optical color can be maintained, minimizing liquid crystal defects.

[0105] The above-mentioned pattern portion 510 may satisfy the following mathematical formula 1.

[0106] [Mathematical formula 1]

[0107] 2μm ≤ a ≤ 2r

[0108] In the above mathematical formula 1, a is the distance between the closest ridges in each pattern portion, and r is the radius of the spherical spacer.

[0109] As Figure 4 shown, a in the above mathematical formula 1 represents the distance between the highest parts of the first concavo-convex portion 511 and the second concavo-convex portion 512, that is, the distance between the ridges. The above a is preferably 2μm or more so that the spherical spacers 320 for maintaining the cell gap of the liquid crystal layer 300 can be recessed between the first concavo-convex portion 511 and the second concavo-convex portion 512 of the above pattern portion. In addition, if the above a is greater than the diameter of the spherical spacer 320 (i.e., 2r), the spherical spacer 320 may not be in close contact with either the first concavo-convex portion 511 or the second concavo-convex portion 512 of the pattern portion 510 and it is difficult to prevent the flow of the spherical spacer. Therefore, the above a is preferably 2r or less.

[0110] In one embodiment, the above-mentioned pattern portion 510 may satisfy the following mathematical formula 2.

[0111] [Mathematical formula 2]

[0112] 1μm ≤ h ≤ r

[0113] In the above mathematical formula 2, h is the height of the pattern portion, and r is the radius of the spherical spacer.

[0114] As Figure 4As shown, in the above Mathematical Formula 1, h represents the distance from the surface of the functional layer 500 to the highest part of the first uneven portion 511 and the second uneven portion 512, that is, the ridge. The above h is preferably 1 μm or more so that the spherical spacer 320 can be indented between the first uneven portion 511 and the second uneven portion 512 of the above pattern portion to minimize the flow. In addition, if the above h is greater than the radius of the spherical spacer 320 (i.e., r), the ratio of the pattern portion 510 in the liquid crystal layer 300 may be high, which may affect the helical orientation of the liquid crystal compound, and thus it may be difficult to exhibit a constant in-plane optical color. Therefore, the above h is preferably r or less.

[0115] In one embodiment, the above pattern portion 510 may be provided at a predetermined interval on one side of the functional layer 500, and preferably, the following Mathematical Formula 3 may be satisfied.

[0116] [Mathematical Formula 3]

[0117] 2r ≤ L

[0118] In the above Mathematical Formula 3, r is the radius of the spherical spacer, and L is the distance between the respective pattern portions.

[0119] As Figure 3 and Figure 4 shown, L in the above Mathematical Formula 3 represents the separation distance between the respective pattern portions 510. If the interval L between the respective pattern portions 510 is formed to be the diameter of the spherical spacer 320 (i.e., 2r) or more, it is possible to prevent the situation where the respective spherical spacers 320 come into contact with each other and disperse, which is more favorable for maintaining the cell gap and maintaining a constant optical color, and the alignment property of the liquid crystal compound can be improved due to the flat surface where the pattern portion 510 is not formed. Therefore, it is preferable. In addition, considering from the aspect of maintaining the minimum interval between the spherical spacers 320, the above L is preferably formed to be 5 mm or less.

[0120] The above transparent conductive layer 200 is provided for driving the liquid crystal layer 300 and can be formed in direct contact with the above polarizing plate 100. For example, as Figure 1 illustrated, the first transparent conductive layer 200-1 and the second transparent conductive layer 200-2 can be formed in direct contact with the first polarizing plate 100-1 and the second polarizing plate 100-2, respectively.

[0121] Conventionally, an optical laminate 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 the other surface of the substrate with a polarizing plate. However, the variable transmittance optical laminate of the present invention is characterized in that a conductive layer is directly formed on one surface of the polarizing plate without including a separate substrate for forming the conductive layer, thereby reducing the thickness of the laminate and improving the transmittance and bending characteristics in the light transmission mode.

[0122] In one embodiment, the transparent conductive layer 200 may be formed by direct evaporation on one side of the polarizing plate 100. In this case, in order to improve the adhesion between the transparent conductive layer 200 and the polarizing plate 100, the transparent conductive layer 200 may be formed by direct contact with the pre-treated side of the polarizing plate 100 after pre-treatment such as corona treatment or plasma treatment is performed on one side of the polarizing plate 100. The pre-treatment is not limited to corona treatment or plasma treatment, and a pre-treatment process previously or developed in the future may be used within the scope that does not impair the purpose of the present invention.

[0123] In another embodiment, in order to improve the adhesion between the transparent conductive layer 200 and the polarizing plate 100, the transparent conductive layer 200 can be directly in contact with the polarizing plate 100 via an easy-adhesion layer (not shown) disposed on one side of the polarizing plate 100. The easy-adhesion layer can use the material described in the adhesive / adhesive layer in the other components described later, but is not limited thereto.

[0124] As a method for evaporating and coating the above-mentioned transparent conductive layer 200 on one side of the above-mentioned polarizing plate 100, it can be formed by a method commonly used in the art, for example, it can be formed by selecting an appropriate process from among a coating process such as spin coating, roll coating, rod coating, dip coating, gravure coating, curtain coating, die coating, spray coating, blade coating, kneader coating, etc.; a printing (coating) process such as screen printing, spray printing, inkjet printing, letterpress printing, gravure printing, lithography, etc.; and a evaporation process such as chemical vapor deposition (CVD), physical vapor deposition (PVD), plasma enhanced chemical vapor deposition (PECVD), etc.

[0125] In the variable transmittance optical stack of the present invention, the transmittance of the transparent conductive layer 200 with respect to visible light is preferably greater than 50%. For example, it may include one or more selected from the group consisting of transparent conductive oxides, metals, carbon-based substances, conductive polymers, conductive inks and nanowires, but is not limited to this, and materials for transparent conductive layers developed in the past or in the future can be used.

[0126] 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), etc. 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 preferably may be 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 having 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.

[0127] In the variable transmittance optical laminate of the present invention, at least one of the above-mentioned first transparent conductive layer 200-1 and the second transparent conductive layer 200-2, i.e., the transparent conductive layer 200, 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 thus it is possible to prevent an excessive increase in the surface resistance.

[0128] In one embodiment, when the above-mentioned transparent conductive layer 200 contains a conductive polymer, the surface in contact with the liquid crystal layer 300 can be rubbed for alignment. Different from the transparent conductive layer containing a metal component, the conductive polymer contained in the transparent conductive layer 200 of the present invention can form regular grooves on the surface, thereby enabling the liquid crystal compounds in the liquid crystal layer to be arranged in a desired position and direction. In this case, the above-mentioned transparent conductive layer 200 can function as an electrode for driving the liquid crystal layer and can also function 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.

[0129] The above-mentioned liquid crystal layer 300 can adjust the transmittance of light incident from one or more directions according to an electric field, thereby changing the driving mode of the above-mentioned optical laminate.

[0130] The above-mentioned liquid crystal layer 300 may contain a liquid crystal compound 310. For example, it may be located in the space provided by a sealant layer (not shown) and spherical spacers 320 disposed between the first polarizing plate 100-1 and the second polarizing plate 100-2 in the light control region.

[0131] The above-mentioned liquid crystal compound 310 is not particularly limited as long as it can be driven by an electric field and can control the light transmittance. 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-mentioned coating type polarizer can be similarly applied.

[0132] The above-mentioned liquid crystal compound may contain a chiral nematic (cholesteric) liquid crystal compound, and the above-mentioned chiral nematic liquid crystal compound may contain a nematic liquid crystal compound and a chiral compound.

[0133] In the above-mentioned 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, strong dielectric properties are not exhibited. The type of the above-mentioned nematic liquid crystal compound is not particularly limited as long as it contains a mesogenic group.

[0134] The three-dimensional structures of the above-mentioned chiral compounds have structures that are symmetric to each other like the relationship between the right hand and the left hand. Although their chemical structures and physical properties are the same, they are compounds with different three-dimensional structures due to their mirror image relationship. If a certain content of chiral compound is included in the above-mentioned nematic liquid crystal compound, a helical cycle will be induced. Regarding the type of the above-mentioned chiral compound, as long as it can induce the target helical cycle without damaging the liquid crystallinity of the above-mentioned liquid crystal compound, such as the nematic regularity, it can be used without particular limitation.

[0135] Chiral compounds used to induce a helical cycle in liquid crystal compounds need to contain at least chirality in their molecular structure. As the above-mentioned chiral compounds, 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.

[0136] The above-mentioned chiral compounds can be, for example, low molecular weight compounds with a molecular weight of 1,500 or less. For example, as chiral compounds, 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.

[0137] In the above-mentioned chiral nematic liquid crystal compound, relative to the total weight of the 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, but not limited thereto. By appropriately adjusting the contents of the above-mentioned 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-mentioned chiral nematic liquid crystal compound is not particularly limited and can be 5 to 20 μm.

[0138] The liquid crystal behavior mode of the above-mentioned 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, an Electrically Controlled Birefringence (ECB) mode, and a Vertical alignment (VA) mode etc. can be used. From the aspect of controlling light transmittance, it is preferably possible to use a Twisted nematic (TN) mode.

[0139] The above-mentioned sealant can contain a curable resin as the base resin. As the above-mentioned base resin, an ultraviolet curable resin or a thermosetting resin known in the art and can be used for sealants can be used. The above-mentioned ultraviolet curable resin can be a polymer of an ultraviolet curable monomer. The above-mentioned thermosetting resin can be a polymer of a thermosetting monomer.

[0140] As the base resin of the above-mentioned 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-mentioned base resin can be an acrylate resin, and the above-mentioned acrylate resin can be a polymer of an acrylic monomer. The above-mentioned acrylic monomer can be, for example, a polyfunctional acrylate. In another embodiment, the above-mentioned sealant can further contain a monomer component in the base resin. The above-mentioned monomer component can be, for example, a monofunctional acrylate. In this specification, a monofunctional acrylate can refer to a compound having 1 acryloyl group, and a polyfunctional acrylate can refer to a compound having 2 or more acryloyl groups. The above-mentioned curable resin can be cured by irradiating ultraviolet rays and / or heating. Regarding the above-mentioned ultraviolet irradiation conditions or heating conditions, they can be appropriately implemented within the range that does not damage the purpose of this application. The above-mentioned sealant can also contain an initiator as needed, such as a photoinitiator or a thermal initiator.

[0141] The above-mentioned sealant can be formed by a method commonly used in the art. For example, the sealant can be applied to the periphery (i.e., the non-active region) of the above-mentioned liquid crystal layer by using a dispenser equipped with a nozzle to form.

[0142] The diameter of the above-mentioned spherical spacer 320 can be 1 to 10 μm, preferably 3 to 7 μm. In addition, when observed from the top view direction, considering improving the visibility of the user and the transmittance in the light transmission mode, the area occupied by the above-mentioned spherical spacer (Ballspacer) in the liquid crystal layer 300 relative to the area of the liquid crystal layer 300 is preferably 0.01 to 10%.

[0143] In one embodiment, the above-mentioned liquid crystal layer 300 can further contain an alignment film as needed. For example, it can be formed on both surfaces of the liquid crystal layer 300 containing a liquid crystal compound.

[0144] The above-mentioned alignment film is not particularly limited as long as it is used to impart orientation to the liquid crystal compound. For example, the above-mentioned alignment film can be produced by coating an alignment film coating composition containing an alignment polymer, a photoinitiator, and a solvent and curing it. The above-mentioned alignment polymer is not particularly limited, and a polyacrylate resin, a polyamic acid resin, a polyimide resin, a polymer containing a cinnamate group, etc. can be used, and a polymer that can exhibit orientation developed in the past or in the future can be used.

[0145] Figure 5 This is a diagram showing the laminated structure of a variable transmittance optical laminate according to another embodiment of the present invention.

[0146] The variable transmittance optical laminate of the present invention may further include other components within the scope that does not impair the object of the present invention. For example, it may further include an adhesive / bonding layer 400 and may also include an ultraviolet absorption layer or the like.

[0147] The above-mentioned adhesive / bonding layer 400 can be formed using an adhesive or an adhesive, and preferably has appropriate adhesive / bonding force to prevent peeling, bubbles, etc. from occurring during the processing of the optical laminate, and at the same time has transparency and thermal stability.

[0148] The above-mentioned adhesive can use adhesives developed in the past or in the future. For example, a photocurable adhesive can be used.

[0149] The above-mentioned photocurable adhesive exhibits strong adhesive force by receiving irradiation of active energy rays such as ultraviolet rays (UV) and electron beams (EB) and undergoing crosslinking and curing, and can be composed of a reactive oligomer, a reactive monomer, a photoinitiator, etc.

[0150] The above-mentioned reactive oligomer is an important component that determines the characteristics of the adhesive, and forms a cured film by forming a polymer bond through a photopolymerization reaction. Examples of the reactive oligomer that can be used include polyester resins, polyether resins, polyurethane resins, epoxy resins, polyacrylic resins, silicone resins, etc.

[0151] The above-mentioned reactive monomer functions as a crosslinking agent and a diluent for the above-mentioned reactive oligomer, and affects the adhesive characteristics. Examples of the reactive monomer that can be used include monofunctional monomers, polyfunctional monomers, epoxy monomers, vinyl ethers, cyclic ethers, etc.

[0152] 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 photopolymer resin.

[0153] The above-mentioned adhesive can use adhesives 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, but from the aspect of easy availability, etc., an acrylic adhesive is preferably used. For example, it may include a (meth) acrylate copolymer, a crosslinking agent, and a solvent, etc.

[0154] The above crosslinking agent may be a crosslinking agent developed in the past or in the future. For example, it may include polyisocyanate compounds, epoxy resins, melamine resins, urea resins, dialdehydes, hydroxymethyl polymers, etc., and preferably may include polyisocyanate compounds.

[0155] The above solvent may include 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.

[0156] The thickness of the above adhesive / bonding layer 400 can be appropriately determined according to the type of resin serving as the adhesive / bonding body, the adhesive / bonding strength, the environment in which the adhesive / bonding agent is used, etc. In one embodiment, in order to ensure sufficient adhesive / bonding force and minimize the thickness of the optical laminate, the thickness of the above adhesive / bonding layer may be 0.01 to 50 μm, preferably may have a thickness of 0.05 to 20 μm, and more preferably may have a thickness of 0.1 to 10 μm.

[0157] 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.

[0158] The present invention includes the method for manufacturing the variable transmittance optical laminate described above. The method for manufacturing the variable transmittance optical laminate is not particularly limited, and any bonding technique or the above lithography technique etc. can be used to manufacture the variable transmittance optical laminate.

[0159] <Smart windows, windows for automobiles and buildings>

[0160] 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 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, and a building window including the above smart window.

Claims

1. A variable transmittance optical laminate comprising: A first polarizing plate; A first transparent conductive layer formed on one surface of the first polarizing plate; A second polarizing plate opposite to the first polarizing plate; A second transparent conductive layer formed on one surface of the second polarizing plate and opposite to the first transparent conductive layer; And A liquid crystal layer disposed between the first transparent conductive layer and the second transparent conductive layer and containing spherical spacers, At least one of the first polarizing plate and the second polarizing plate includes a functional layer having a plurality of pattern portions satisfying the following Mathematical Formula 1, The spherical spacers are recessed on the pattern portions, Mathematical Formula 1 2μm ≤ a ≤ 2r In the Mathematical Formula 1, a is the distance between the closest ridges in each pattern portion, and r is the radius of the spherical spacer.

2. The variable transmittance optical laminate according to claim 1, wherein the pattern portion satisfies the following Mathematical Formula 2, Mathematical Formula 2 1μm ≤ h ≤ r In the Mathematical Formula 2, h is the height of the pattern portion, and r is the radius of the spherical spacer.

3. The variable transmittance optical laminate according to claim 1, wherein the pattern portion satisfies the following Mathematical Formula 3, Mathematical Formula 3 2r ≤ L In the Mathematical Formula 3, r is the radius of the spherical spacer, and L is the distance between each pattern portion.

4. The variable transmittance optical laminate according to claim 1, wherein the pattern portion includes a first concavo-convex portion and a second concavo-convex portion.

5. The variable transmittance optical laminate according to claim 1, wherein the functional layer includes a cured product of a composition for forming the functional layer.

6. The variable transmittance optical laminate according to claim 5, wherein the composition for forming the functional layer includes a photocurable composition and a photoinitiator.

7. The variable transmittance optical laminate 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, an fringe field switching (FFS) mode, an electrically controlled birefringence (ECB) mode, and a vertical alignment (VA) mode.

8. The variable transmittance optical laminate according to claim 1, wherein at least one of the first transparent conductive layer and the second transparent conductive layer includes a conductive polymer.

9. The variable transmittance optical laminate according to claim 8, 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):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.

10. The variable transmittance optical laminate according to claim 1, wherein at least one of the first transparent conductive layer and the second transparent conductive layer is formed to be in direct contact with one of the first polarizing plate and the second polarizing plate without including a separate substrate therebetween.

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

12. The variable transmittance optical laminate according to claim 1, wherein the variable transmittance optical laminate further comprises one or more selected from the group consisting of an adhesive / bonding layer, an ultraviolet absorption layer, and a hard coat layer.

13. An intelligent window comprising the variable transmittance optical laminate according to any one of claims 1 to 12.

14. An automobile applying the intelligent window according to claim 13 to at least one of a front window, a rear window, a side window, a sunroof, and an interior partition.

15. A building window comprising the intelligent window according to claim 13.

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