Film laminate, smart window comprising same, and method for manufacturing same

Abstract

To provide a film laminate excellent in quality and appearance by minimizing the pressure applied to a liquid crystal layer inside a dimming laminate at the time of joining glass which may occur in a display and suppressing the occurrence of liquid crystal unevenness even after joining the glass.SOLUTION: Provided is a film laminate including a dimming laminate and a surface-protecting layer laminated on at least one of an upper surface and a lower surface of the dimming laminate, wherein the surface-protecting layer is a low-temperature curable polyvinyl butyral (PVB) film cured at a temperature of 90 °C or less, has a thickness of 0. 01mm to 0. 35mm, and has a total area larger than an area of the dimming laminate in contact with the surface-protecting layer.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a film laminate, a smart window including the same, and a method for manufacturing the same. [Background technology]

[0002] Generally, glass windows of vehicles and other transportation devices are often coated with an external light blocking coating. However, conventional glass windows of transportation devices have a fixed transmittance, and the external light blocking coating also has a fixed transmittance. Therefore, such conventional transportation windows have a fixed overall transmittance, which can lead to accidents. For example, if the overall transmittance is set low, there is no problem during the daytime when there is sufficient surrounding light. However, there is a problem that drivers and others have difficulty properly checking the surroundings of the transportation device during times when there is insufficient surrounding light, such as at night. Alternatively, if the overall transmittance is set high, there is a problem that drivers and others may experience glare during times when there is sufficient surrounding light. For this reason, a light-control laminate capable of changing light transmittance when a voltage is applied has been developed.

[0003] The variable transmittance optical stack is driven by applying a voltage to drive the liquid crystal to change the transmittance. The variable transmittance optical stacks developed to date are manufactured by forming a conductive layer for driving the liquid crystal on a separate substrate and combining it with other elements such as a polarizer.

[0004] For example, Japanese Patent Application Publication No. 2018-010035 discloses a variable transmittance optical laminate including a transparent conductive layer formed on a polycarbonate PC substrate of a predetermined thickness. Such variable transmittance smart windows must include a liquid crystal layer to implement the variable transmittance function, and are ultimately bonded to glass. However, when using conventional technologies, the liquid crystal layer contained in the laminate is pressed during the bonding process of glass to the laminate, resulting in uneven liquid crystal flow, which was not visible before glass bonding. Furthermore, thinner light-control laminates, especially those with a structure in which the polarizer and conductive layer are in direct contact without a substrate, are more likely to develop liquid crystal unevenness due to glass bonding pressure. Therefore, there is a need to develop a variable transmittance optical laminate that has a structure that can minimize the pressure applied to the liquid crystal layer and a bonding method that can eliminate uneven pressure, thereby preventing liquid crystal unevenness even after glass bonding. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2018-010035 Summary of the Invention [Problem to be solved by the invention]

[0006] In order to solve the above-described problems, an object of the present invention is to provide a film laminate including a surface protection layer having an optimally thin thickness on at least one outer surface of a light control laminate.

[0007] Another object of the present invention is to provide a film laminate including a gap layer having optimal physical properties and structure suitable for the edge portion.

[0008] Another object of the present invention is to provide a film laminate with excellent quality and appearance by providing optimal physical properties and structure, thereby minimizing the pressure that may be applied to the liquid crystal layer inside the light control laminate when bonding glass to a display, and thereby suppressing the occurrence of liquid crystal unevenness even after bonding glass.

[0009] Another object of the present invention is to provide a method for manufacturing a smart window that does not stabilize uneven pressure applied to the liquid crystal layer inside the light-control laminate when the glass is bonded, by including two or more steps in the bonding process of bonding the glass to the film laminate in order to minimize the pressure applied to the liquid crystal layer.

[0010] Another object of the present invention is to provide a smart window that includes a light control laminate manufactured without a separate substrate for forming a conductive layer, and that has a significantly reduced thickness compared to conventional light control laminates.

[0011] Another object of the present invention is to provide a smart window including the film laminate, and a means of transportation, a wearable device, or a building fixture to which the smart window is applied.

[0012] However, the problems to be solved by the present invention are not limited to those mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description. [Means for solving the problem]

[0013] The present invention relates to a film laminate comprising: a photochromic laminate; and a surface protective layer laminated on at least one of the upper and lower surfaces of the photochromic laminate; wherein the surface protective layer is a low-temperature curable polyvinyl butyral (PVB) film that cures at a temperature of 90°C or less, has a thickness of 0.01 mm to 0.35 mm, and has an overall area greater than the area of ​​the photochromic laminate in contact with the surface protective layer.

[0014] The present invention may be characterized in that the surface protective layer does not flow at 100°C or less under a load of 21.6 kg, and has a melt flow rate (MFR) of 0.02 g / 10 min or less at 140°C and a load of 2.16 kg as measured in accordance with ASTM D1238.

[0015] The present invention is directed to a method for manufacturing a protective film having a tensile modulus E' of 10 at 60°C. 8 or 10 10 Pa, 10 at 90°C 6 or 10 7 It may also include a film that is Pa.

[0016] In the present invention, the light-controlling laminate may further include a first polarizing plate; a first transparent conductive layer formed on the inner surface of the first polarizing plate; a second polarizing plate facing the first polarizing plate; a second transparent conductive layer formed on the inner surface of the second polarizing plate and facing the first transparent conductive layer; a liquid crystal layer provided between the first transparent conductive layer and the second transparent conductive layer; and an alignment film formed between the transparent conductive layer and the liquid crystal layer.

[0017] In the present invention, at least one of the first transparent conductive layer and the second transparent conductive layer may be formed in direct contact with the first polarizing plate or the second polarizing plate.

[0018] In the present invention, at least one of the first transparent conductive layer and the second transparent conductive layer is made of polythiophene, poly(3,4-ethylenedioxythiophene), polyaniline, polyacetylene, polydiacetylene, polyphenylene, polyphenylene vinylene, polyphenylene sulfide, polythienylene vinylene, 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: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.

[0019] In the present invention, at least one of the first polarizing plate and the second polarizing plate may further include one or more layers selected from the group consisting of a protective layer, a retardation adjusting layer, and a refractive index adjusting layer.

[0020] In the present invention, the film laminate may include a gap layer containing a polyvinyl butyral (PVB) film at an end of the light control laminate.

[0021] The present invention relates to a gap layer having a storage modulus G' of 10 3 or 10 6 kPa, and the storage modulus G' at 100°C is 5 x 10 2 or 5 x 10 3 It may be of kPa.

[0022] In the present invention, the gap layer may include two or more layers of polyvinyl butyral (PVB) film.

[0023] In the present invention, the gap layer has a tensile modulus E' of 10 8 or 10 10 Pa, 10 at 90°C 6 or 10 7 It may also include a film that is Pa.

[0024] The present invention also relates to a smart window comprising the film laminate; an adhesive layer; and a substrate bonded to at least one of the upper and lower surfaces of the film laminate by the adhesive layer.

[0025] The present invention also relates to a method for manufacturing the smart window, which includes a step of bonding a substrate bonded with an adhesive layer to at least one of the upper and lower surfaces of a film laminate, and the bonding step includes a preliminary bonding step and a main bonding step, which includes: a) maintaining the film laminate in a chamber at 3.5 to 10 bar for 15 to 60 minutes; and b) following step a), reducing the pressure to a range of 1 bar to 3 bar and maintaining the pressure for 70 to 100 minutes. [Effects of the Invention]

[0026] According to the film laminate of the present invention, by laminating a surface protection layer having an optimal thickness, physical properties, and / or structure for protecting the liquid crystal layer on at least one of the upper and lower surfaces of the light control laminate, the pressure applied to the liquid crystal layer when bonding the glass is minimized, and the liquid crystal does not become biased, preventing the occurrence of liquid crystal unevenness, and a film laminate with excellent appearance can be manufactured.

[0027] Furthermore, according to the film laminate of the present invention, by including a gap layer at the end of the photochromic laminate that is thicker than the thickness of the photochromic laminate, it is possible to manufacture a film laminate that can suppress liquid crystal unevenness that may occur in the display.

[0028] Furthermore, the light-controlling laminate according to the present invention can be manufactured by a smart window manufacturing method including two or more steps using different pressures in the main bonding of glass to the film laminate, thereby significantly reducing the occurrence of liquid crystal unevenness compared to conventional film laminates.

[0029] In addition, the film laminate according to the present invention includes a light control laminate manufactured without including a separate substrate for forming a conductive layer, and therefore the thickness can be significantly reduced compared to conventional laminates.

[0030] In addition, by applying the light-control laminate according to the present invention and a film laminate including the same, it is possible to provide a smart window in which liquid crystal unevenness does not occur, and a means of transportation, a wearable device, or a building fixture to which the same is applied. [Brief explanation of the drawings]

[0031] [Figure 1] FIG. 1 is a simplified diagram showing the structure of a light-control stack according to one embodiment of the present invention. [Figure 2] FIG. 2 is a simplified diagram showing the structure of a film laminate according to one embodiment of the present invention. [Figure 3] FIG. 3 is a simplified diagram illustrating the structure of a smart window according to one embodiment of the present invention. [Figure 4] FIG. 4 is a process diagram showing a method for manufacturing a smart window according to an embodiment of the present invention. [Figure 5] FIG. 5 is a simplified diagram illustrating the structure of a smart window according to one embodiment of the present invention. [Figure 6a] FIG. 6a shows photographs of the appearance evaluation results of the bonded articles of Examples 1 to 6 of the present invention, taken by observing them on a backlight plate (light source) using a digital camera. [Figure 6b] FIG. 6b shows photographs of the appearance evaluation results of the bonded articles of Examples 1 to 6 of the present invention, taken by observing them on a backlight plate (light source) using a digital camera. [Figure 6c] FIG. 6c shows photographs of the appearance evaluation results of the bonded articles of Examples 1 to 6 of the present invention, taken by a digital camera on a backlight plate (light source). [Figure 6d] FIG. 6d shows photographs of the appearance evaluation results of the bonded articles of Examples 1 to 6 of the present invention, taken by a digital camera on a backlight plate (light source). [Figure 6e] FIG. 6e shows photographs of the appearance evaluation results of the bonded articles of Examples 1 to 6 of the present invention, taken by a digital camera on a backlight plate (light source). [Figure 6f] FIG. 6f shows photographs of the appearance evaluation results of the bonded articles of Examples 1 to 6 of the present invention, taken by observing them on a backlight plate (light source) using a digital camera. [Figure 7a] FIG. 7a shows photographs of the appearance evaluation results of the bonded articles of Comparative Examples 1 and 2 of the present invention, observed with a digital camera on a backlight plate (light source). [Figure 7b] FIG. 7b shows photographs of the appearance evaluation results of the bonded articles of Comparative Examples 1 and 2 of the present invention, taken by observing them on a backlight plate (light source) using a digital camera. [Figure 8a] FIG. 8a shows photographs of the appearance evaluation results of the bonded articles of Reference Examples 1 to 4 of the present invention, taken by observing them with a digital camera on a backlight plate (light source). [Figure 8b] FIG. 8b shows photographs of the appearance evaluation results of the bonded articles of Reference Examples 1 to 4 of the present invention, taken by observing them with a digital camera on a backlight plate (light source). [Figure 8c] FIG. 8c shows photographs of the appearance evaluation results of the bonded articles of Reference Examples 1 to 4 of the present invention, taken by observing them with a digital camera on a backlight plate (light source). [Figure 8d]FIG. 8d shows photographs of the appearance evaluation results of the bonded articles of Reference Examples 1 to 4 of the present invention, taken by observing them with a digital camera on a backlight plate (light source). DETAILED DESCRIPTION OF THE INVENTION

[0032] The present invention relates to a film laminate including a light control laminate and a surface protection layer on at least one of the upper and lower surfaces of the light control laminate, a smart window including the same, and a method for manufacturing the same. The surface protection layer is a low-temperature curable polyvinyl butyral (PVB) film that cures at temperatures below 90°C, has a thickness of 0.01 mm to 0.35 mm, and its overall area is larger than the area of ​​the light control laminate in contact with the surface protection layer. This minimizes (disperses) the pressure applied to the liquid crystal layer during glass bonding, preventing liquid crystal polarization and liquid crystal unevenness, providing a film laminate with excellent appearance. Furthermore, curing is performed at low temperatures below 90°C, preferably between 60°C and 90°C, thereby preventing heat damage to other components such as polarizers.

[0033] The light-controlling laminate of the present invention may be a variable transmittance optical laminate, and is particularly suitable for technical fields in which light transmittance can be changed by applying a voltage, and can be used, for example, in smart windows.

[0034] A smart window is an optical structure that controls the amount of light or heat passing through by changing its light transmittance in response to the application of an electrical signal. That is, a smart window can be changed between transparent, opaque, or translucent depending on the voltage applied, and is also called variable transmittance glass, light-control glass, or smart glass.

[0035] Smart windows can be used as partitions for dividing the interior space of vehicles and buildings or for privacy protection, or as light windows placed in openings in buildings. They can also be used for highway signs, bulletin boards, odometers, clocks, or advertising screens, and can be used to replace glass in vehicles such as windows or sunroofs in vehicles such as automobiles, buses, airplanes, ships, and trains.

[0036] The light-control laminate of the present invention can also be used in smart windows in the various technical fields mentioned above. However, since the transparent conductive layer is formed directly on the polarizer, no separate substrate is required for forming the conductive layer, resulting in a thin thickness and advantageous flexibility, making it particularly suitable for use in smart windows for vehicles or buildings. In one or more embodiments, smart windows using the light-control laminate of the present invention can be used in transportation, such as front windows, rear windows, side windows, and sunroofs of automobiles, or building fixtures. In addition to applications in blocking external light, they can also be used to divide the interior space of automobiles or buildings, such as interior partitions, or for privacy protection. They can also be used in wearable devices such as helmets, glasses, and watches.

[0037] Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings. However, the following drawings attached to this specification are intended to illustrate preferred embodiments of the present invention and, together with the above-described invention content, serve to further understand the technical concept of the present invention, and therefore the present invention should not be interpreted as being limited only to the matters depicted in these drawings.

[0038] The terms used herein are for the purpose of describing the embodiments and are not intended to limit the present invention. In this specification, the singular includes the plural unless otherwise specified in the context of the phrase. For example, the term "polarizer" used herein may refer to at least one polarizer selected from a first polarizer and a second polarizer, the term "transparent conductive layer" may refer to at least one transparent conductive layer selected from a first transparent conductive layer and a second transparent conductive layer, and the term "hard coating layer" may refer to at least one hard coating layer selected from a first hard coating layer and a second hard coating layer.

[0039] As used herein, the terms "comprises" and / or "comprising" do not exclude the presence or addition of one or more other components, steps, operations and / or elements other than the stated components, steps, operations and / or elements. Like reference numerals refer to like elements throughout the specification.

[0040] Spatially relative terms such as "below," "bottom," "lower," "upper," "top," "top," and the like may be used to easily describe the relationship of one element or component to another, as illustrated in the figures. Spatially relative terms should be understood to encompass different orientations of elements in use or operation in addition to the orientation depicted in the figures. For example, if an element depicted in the figures is inverted, an element described as "below" or "below" another element may also be positioned "above" the other element. Thus, the exemplary term "below" may encompass both an orientation of below and above. Elements may be oriented in other directions, and thus the spatially relative terms may be interpreted accordingly.

[0041] As used herein, the "planar direction" can be interpreted as the direction perpendicular to the polarizer and / or transparent conductive layer, ie, the direction viewed from the user's viewing side.

[0042] As used herein, "substantially" can be interpreted to include not only being completely physically identical or identical, but also being within the range of error in measurement or manufacturing processes, for example, being within an error range of 0.1% or less.

[0043] <<Light-control laminate 10>> FIG. 1 illustrates the structure of a light-controlling stack 10 according to one embodiment of the present invention. Referring to FIG. 1, in one embodiment of the present invention, the light-controlling stack 10 may include a first polarizer 110-1; a first transparent conductive layer 120-1 formed on the inner surface of the first polarizer 110-1; a second polarizer 110-2 facing the first polarizer 110-1; a second transparent conductive layer 120-2 formed on the inner surface of the second polarizer 110-2 and facing the first transparent conductive layer 120-1; a liquid crystal layer 130 disposed between the first transparent conductive layer 120-1 and the second transparent conductive layer 120-2; and an alignment film 140 formed between the transparent conductive layer 120 and the liquid crystal layer 130. The light-controlling stack may further include one or more layers selected from the group consisting of an adhesive layer, a bonding layer, a UV absorbing layer, and / or a hard coating layer (not shown). Also, a sealant 50 may be further included at the edge of the liquid crystal layer to ensure a space for the liquid crystal layer.

[0044] The switchable stack 10 according to one embodiment of the present invention includes a polarizer 110, a transparent conductive layer 120, and a liquid crystal layer 130. The switchable stack 10 according to the embodiment of the present invention may be a variable transmittance optical stack, and the transmittance of the switchable stack 10 may be changed in response to the application of a voltage. For example, the switchable stack 10 may have a transmittance of 0.1 to 45% in response to the application of a voltage.

[0045] Preferably, the photochromic stack of the present invention may have a thickness of 0.32 to 0.40 mm. When the thickness of the photochromic stack satisfies the above range, it is possible to form a gap layer thicker than the thickness of the photochromic stack.

[0046] The polarizer 110 may include a polarizer and a protective layer formed on at least one side of the polarizer. Two different polarizers 110 may be positioned on both sides of the liquid crystal layer 130. When the polarizers 110 are positioned on both sides of the liquid crystal layer 130, the mutual angle between the absorption axes of the two different polarizers 110 may be perpendicular or horizontal, preferably between 5 and 85° to ensure minimum transmittance. The polarizer 110 transmits sporadic light in one direction and adjusts the amount of light passing through using the polarization properties of the polarizer 110 to adjust the transmittance of the optical stack. The protective layer may be a member that preserves the polarization properties of the polarizer from post-processing and external environments. In one embodiment, the protective layer may serve to provide a structural base on which the transparent conductive layer 120 (described later) can be formed. In this case, the protective layer preferably has properties that facilitate the formation of the transparent conductive layer 120.

[0047] The protective layer may be provided on only one side of the polarizer or on both sides of the polarizer. When the polarizer 110 includes multiple protective layers, the two different protective layers may contain substantially the same or similar materials. In one or more embodiments, the protective layer may include polyester-based resins such as polyethylene terephthalate, polyethylene isophthalate, polyethylene naphthalate, and polybutylene terephthalate; cellulose-based resins such as diacetyl cellulose and triacetyl cellulose; polycarbonate-based resins; polyethylene resins; polypropylene resins; acrylic resins such as polymethyl (meth)acrylate and polyethyl (meth)acrylate; and cyclic olefin polymers (COPs).

[0048] The polarizer of the polarizing plate 110 may include a stretched polarizer or may be provided as a stretched polarizer. In one embodiment, the stretched polarizer may include a stretched polyvinyl alcohol (PVA)-based resin. The polyvinyl alcohol-based resin may preferably be a polyvinyl alcohol-based resin obtained by saponifying a polyvinyl acetate-based resin. Examples of polyvinyl acetate-based resins include polyvinyl acetate, which is a homopolymer of vinyl acetate, as well as copolymers of vinyl acetate with other monomers copolymerizable therewith. Examples of such other monomers include unsaturated carboxylic acid-based, unsaturated sulfonic acid-based, olefin-based, vinyl ether-based, and acrylamide-based monomers having an ammonium group. The polyvinyl alcohol-based resin may also be modified, such as polyvinyl formal or polyvinyl acetal modified with aldehydes.

[0049] The polarizing plate 110 may also include a coating type polarizer. In one embodiment, the coating type polarizer may be formed using a liquid crystal coating composition, for example, by coating the liquid crystal coating composition on the upper surface of the protective layer. In this case, the liquid crystal coating composition may include a reactive liquid crystal compound and a dichroic dye.

[0050] The reactive liquid crystal compound may include a reactive mesogen (RM) capable of exhibiting liquid crystallinity and / or a monomer molecule having a polymerizable terminal functional group and exhibiting a liquid crystal phase after a thermal or photocrosslinking reaction. When the reactive liquid crystal compound is polymerized by light or heat, it can form a polymer network while maintaining the liquid crystal alignment. By using the reactive liquid crystal compound, it is possible to form a thin-film polarizer with improved mechanical and thermal stability while maintaining the optical anisotropy and dielectric constant characteristics of the liquid crystal.

[0051] The dichroic dye is a component contained in the liquid crystal coating composition that imparts polarization properties and has a property that the absorbance in the long axis direction of the molecule differs from the absorbance in the short axis direction. The dichroic dye may be a conventional or later developed dichroic dye, such as an acridine dye, an oxazine dye, a cyanine dye, a naphthalene dye, an azo dye, or an anthraquinone dye. These may be used alone or in combination.

[0052] The liquid crystal coating composition may further include a solvent capable of dissolving the reactive liquid crystal compound and the dichroic dye, such as propylene glycol monomethyl ether acetate (PGMEA), methyl ethyl ketone (MEK), xylene, chloroform, etc. The liquid crystal coating composition may further include a labeling agent, a polymerization initiator, etc., within a range that does not impair the polarization properties of the coating film.

[0053] The polarizer 110 may also be formed by including an alignment member, for example, by applying and curing an alignment film coating composition containing an alignment polymer, a photopolymerization initiator, and a solvent on a protective layer to form the alignment member, and then applying and curing the liquid crystal coating composition on the alignment member. The alignment polymer is not particularly limited, but may be a polyacrylate resin, a polyamic acid resin, a polyimide resin, a polymer containing a cinnamate group, or the like. Conventional or later-developed polymers capable of exhibiting alignment may also be used.

[0054] The polarizing plate 110 included in the light-controlling laminate may further include a functional coating layer such as an overcoat layer and / or an optical functional layer to improve the surface hardness of the polarizer and the polarizing plate, and in one or more embodiments, may further include one or more layers selected from the group consisting of a protective layer, a phase difference adjusting layer, and / or a refractive index adjusting layer (not shown).

[0055] In one specific embodiment, the polarizer may further include an overcoat layer as a type of functional coating layer. For example, the overcoat layer may be located on the upper surface of the layer formed from the liquid crystal coating composition and may be provided facing the member having alignment properties. In one embodiment, a protective film may be further provided on the upper surface of the overcoat layer. In this case, the polarizer may have a laminated structure of the member having alignment properties - the layer formed from the liquid crystal coating composition - the overcoat layer - the protective film, thereby further improving mechanical durability while maintaining a certain level of transmittance.

[0056] The polarizer 110 may include an optical functional layer to improve the optical properties of the optical laminate. The optical functional layer may be provided on at least one surface of the protective layer, for example, on the upper surface of the protective layer. The optical functional layer is not particularly limited as long as it reinforces or complements the optical function of the polarizer 110. For example, a quarter-wave plate (¼ wave plate) or a half-wave plate (½ wave plate) for retarding the phase of light may be used, and these may be used alone or in combination. The retardation film may be manufactured including an obliquely stretched resin film, a liquid crystal coating layer, etc., and conventional or later-developed retardation films may be used.

[0057] In one embodiment, the polarizer 110 may have a thickness of 30 to 200 μm, preferably 30 to 170 μm, and more preferably 50 to 150 μm, which allows the polarizer 110 to maintain its optical properties while manufacturing a thin light-control stack.

[0058] The polarizer 110 may have a curved shape to manufacture an optical laminate having a curved surface. For example, the polarizer 110 may be formed in a curved shape toward one of two different polarizers 110 stacked on both sides of the liquid crystal layer 130.

[0059] The refractive index adjustment layer (not shown) is provided to compensate for a difference in transmittance of the light-control stack due to the transparent conductive layer 120 described below, and may serve to improve visibility by reducing the difference in refractive index. The refractive index adjustment layer may also be provided to correct a color due to the transparent conductive layer 120 described below. Meanwhile, when the transparent conductive layer 120 described below has a pattern, the refractive index adjustment layer can compensate for a difference in transmittance between a patterned region where the pattern is formed and a non-patterned region where the pattern is not formed.

[0060] Specifically, the transparent conductive layer 120 is stacked adjacent to another member (e.g., polarizer 110) having a different refractive index from the transparent conductive layer 120. This difference in refractive index between the adjacent layer and the transparent conductive layer 120 may cause a difference in light transmittance. In particular, if a pattern is formed on the transparent conductive layer 120, the patterned and non-patterned regions may be visually distinguishable. Therefore, the refractive index adjustment layer is positioned between the polarizer 110 and the transparent conductive layer 120 to compensate for the refractive index, thereby reducing the difference in light transmittance of the optical stack. In particular, if a pattern is formed on the transparent conductive layer 120, the patterned and non-patterned regions may be visually distinguishable. The refractive index of the refractive index adjustment layer may be preset to be greater than the refractive index of the protective layer of the polarizer 110 and less than the refractive index of the transparent conductive layer 120. The refractive index may be appropriately selected depending on the materials of the polarizer 110 and the transparent conductive layer 120, and may be preferably 1.4 to 2.6, and more preferably 1.4 to 2.4. By setting the refractive index of the refractive index adjustment layer to a predetermined value in this manner, it is possible to prevent light loss due to a sharp difference in refractive index between the polarizing plate 110 and the transparent conductive layer 120. The refractive index adjustment layer is not particularly limited as long as it can prevent a sharp difference in refractive index between the polarizing plate 110 and the transparent conductive layer 120, and may be formed from a refractive index adjustment layer-forming composition containing a polymerizable isocyanurate compound, for example.

[0061] The transparent conductive layer 120 may be formed on one surface of the polarizer 110 , and preferably, may be formed in direct contact with the polarizer 110 .

[0062] The transparent conductive layer 120 is provided for driving the liquid crystal layer 130. In one embodiment, at least one of the first transparent conductive layer 120-1 and the second transparent conductive layer 120-2 may be formed in direct contact with the first polarizer 110-1 or the second polarizer 110-2. For example, as shown in FIG. 1, the first transparent conductive layer 120-1 and the second transparent conductive layer 120-2 may be formed in direct contact with the first polarizer 110-1 and the second polarizer 110-2, respectively.

[0063] Conventional light-control laminates used in the manufacture of smart windows, etc., are manufactured by forming a conductive layer for driving liquid crystals on one side of the substrate and bonding the other side of the substrate to a polarizer. However, the light-control laminate of the present invention does not require a separate substrate for forming the conductive layer, and instead forms the conductive layer directly on one side of the polarizer, thereby reducing the thickness of the laminate and improving the transmittance and bending characteristics in the transmission mode.

[0064] Being in direct contact with the polarizer 110 means that the transparent conductive layer 120 shares a contact surface with the polarizer 110 and is provided on the polarizer 110 without a separate substrate. For example, the transparent conductive layer 120 may be formed by deposition on the upper surface of a protective layer formed on the polarizer 110.

[0065] In one embodiment, the transparent conductive layer 120 may be formed by direct deposition on one surface of the polarizer 110. In this case, in order to improve adhesion to the polarizer 110, the transparent conductive layer 120 may be formed by directly contacting the pre-treated surface of the polarizer after pre-treating the surface with a corona treatment or plasma treatment. The pre-treatment is not limited to a corona treatment or plasma treatment, and any conventional or later-developed pre-treatment process may be used within the scope of the present invention.

[0066] In another embodiment of the present invention, the transparent conductive layer 120 may be formed in direct contact with the polarizer 110, with an easy-adhesion layer provided on one side of the polarizer sandwiched therebetween, in order to improve adhesion to the polarizer 110.

[0067] The transparent conductive layer 120 preferably has a transmittance of 50% or more for visible light, and may include, for example, 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 any conventional or later-developed transparent conductive layer material may be used.

[0068] In one or more embodiments, the transparent conductive oxide may include one or more selected from the group consisting of indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), aluminum zinc oxide (AZO), gallium zinc oxide (GZO), fluorine tin oxide (FTO), zinc oxide (ZnO), etc. The metal may include one or more selected from the group consisting of gold (Au), silver (Ag), copper (Cu), aluminum (Al), platinum (Pt), palladium (Pd), chromium (Cr), titanium (Ti), tungsten (W), niobium (Nb), tantalum (Ta), vanadium (V), iron (Fe), manganese (Mn), cobalt (Co), nickel (Ni), zinc (Zn), and alloys containing at least one of these metals, such as a silver-palladium-copper (APC) alloy or a copper-calcium (CuCa) alloy. The carbon-based material may include at least one selected from the group consisting of carbon nanotubes (CNTs) and graphene.The conductive polymer may be a conventional or later developed conductive polymer material, for example, polythiophene, poly(3,4-ethylenedioxythiophene), polyaniline, polyacetylene, polydiacetylene, polyphenylene, polyphenylene vinylene, polyphenylene sulfide, polythienylene vinylene, 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): The conductive ink may include one or more selected from the group consisting of poly(3,4-ethylenedioxythiophene):dodecylbenzenesulfonic acid, polyaniline:polystyrenesulfonate, polyaniline:camphorsulfonic acid, polypyrrole:polystyrenesulfonate, polypyrrole:camphorsulfonic acid, polypyrrole:toluenesulfonic acid, polypyrrole:dodecylbenzenesulfonic acid, polythiophene:polystyrenesulfonate, polythiophene:camphorsulfonic acid, polythiophene:toluenesulfonic acid, and polythiophene:dodecylbenzenesulfonic acid, and is preferably poly(3,4-ethylenedioxythiophene). The conductive ink may be an ink containing a metal powder and a curable polymer binder, and the nanowires may be, for example, silver nanowires (AgNWs). In one embodiment of the present invention, the transparent conductive layer 120 preferably includes a conductive polymer such as polyethylenedioxythiophene (PEDOT).

[0069] The transparent conductive layer 120 may be formed by a deposition process such as chemical vapor deposition (CVD), physical vapor deposition (PVD), or plasma enhanced chemical vapor deposition (PECVD), a printing process such as screen printing, gravure printing, reverse offset, or inkjet, or a dry or wet plating process. The transparent conductive layer 120 may also be formed as a two-layer structure using a combination of the above materials. For example, the transparent conductive layer 120 may be formed as a two-layer structure including a metal layer and a transparent conductive oxide layer to reduce reflectance and increase transmittance of incident light.

[0070] In one embodiment, the first transparent conductive layer 120-1 and the second transparent conductive layer 120-2 may have a surface that contacts the liquid crystal layer 130 that is rubbed and aligned. Unlike transparent conductive layers containing metal components, the conductive polymer contained in the transparent conductive layer 120 of the present invention can form grooves on its surface, thereby aligning the liquid crystal molecules in the liquid crystal layer at the desired position and direction. In this case, the transparent conductive layer 120 can function as an electrode for driving the liquid crystal layer and as an alignment film. Since no separate alignment film is required, a thinner light-control stack can be manufactured, and the manufacturing process can be simplified.

[0071] To provide the rubbing-oriented transparent conductive layer 120, a rubbing method using a rubbing process and a photo-alignment method using ultraviolet light can be used. Generally, the photo-alignment method has weaker surface anchoring energy than the rubbing method, so it is preferable that the transparent conductive layer 120 of the present invention has a surface that contacts the liquid crystal layer 130 rubbing-oriented by a rubbing method.

[0072] The liquid crystal layer 130 is driven by an electric field. The liquid crystal layer 130 may be located between the first and second polarizers 110-1 and 110-2 located in the light control region of the light control stack 10. In one embodiment, the liquid crystal layer 130 may be located in the space provided by the sealant layer 150 and spacers (not shown) between the first and second polarizers 110-1 and 110-2 in the light control region. The liquid crystal layer 130 may also adjust the transmittance of light incident from an external light source by the electric field formed between the first and second transparent conductive layers 120-1 and 120-2.

[0073] In one or more embodiments, the liquid crystal layer 130 may be driven by any one of the following driving methods: twisted nematic (TN), super-twisted nematic (STN), in-plane switching (IPS), fringe field switching (FFS), plane line switching (PLS), advanced high-performance IPS (AH-IPS), polymer sustained alignment (PSA), and vertical alignment (VA). Any conventional or later-developed liquid crystal driving method may be applied.

[0074] According to another embodiment of the present invention, the liquid crystal layer 130 may include one or more spacers selected from the group consisting of ball spacers and column spacers, and ball spacers are particularly preferred. The number of ball spacers may be one or more, and the diameter of the ball spacers is preferably 1 to 10 μm. In addition, when viewed from the planar direction, the area of ​​the ball spacers in the liquid crystal layer 130 (i.e., the light control region) is preferably 0.01 to 10% of the area of ​​the liquid crystal layer 130 in terms of improving user visibility and transmittance in the light-transmitting mode.

[0075] The alignment film 140 may have substantially the same properties as those described above for the alignment material, and is not particularly limited as long as it is capable of imparting alignment to the liquid crystal compound. Preferably, the alignment film 140 may include a photoalignable or photocurable polymer. For example, the alignment film 140 may be fabricated by applying and curing an alignment film coating composition including a photoalignable or photocurable polymer, a photopolymerization initiator, and a solvent. For example, the alignment film 140 may be formed by applying an alignment material such as polyimide and then performing a rubbing process.

[0076] The sealant 150 is used to bond two different polarizers and may be positioned in an inactive region between the two different polarizers. In addition, the sealant 150, together with a spacer, may secure a space between the two different polarizers in which the liquid crystal layer is provided.

[0077] The sealant 150 may include a curable resin as a base resin. The base resin may be a UV-curable resin or a thermosetting resin, which are known in the art for use as sealants. The UV-curable resin may be a polymer of a UV-curable monomer. The thermosetting resin may be a polymer of a thermosetting monomer.

[0078] The base resin of the sealant may be, for example, an acrylate-based resin, an epoxy-based resin, a urethane-based resin, a phenol-based resin, or a mixture of these resins. In one embodiment, the base resin may be an acrylate-based resin, and the acrylate-based resin may be a polymer of an acrylic monomer. The acrylic monomer may be, for example, a multifunctional acrylate. In another embodiment, the sealant may further include a monomer component in the base resin. The monomer component may be, for example, a monofunctional acrylate. In this specification, a monofunctional acrylate may refer to a compound having one acrylic group, and a multifunctional acrylate may refer to a compound having two or more acrylic groups. The curable resin may be cured by ultraviolet irradiation and / or heating. The ultraviolet irradiation conditions or heating conditions may be appropriately adjusted within the scope of the present application. The sealant may further include an initiator, for example, a photoinitiator or a thermal initiator, if necessary.

[0079] The steps for manufacturing the light control laminate of the present invention are not limited to the above-described methods, as long as they are methods for realizing the light control laminate. For example, the transparent conductive layer 120 and the refractive index control layer (not shown) may be deposited by a deposition method commonly used in the art, such as a coating process such as spin coating, roller coating, bar coating, dip coating, gravure coating, curtain coating, die coating, spray coating, doctor coating, or kneader coating; a printing coating process such as screen printing, spray printing, inkjet printing, relief printing, intaglio printing, or lithographic printing; or a vacuum film formation method such as spot printing.

[0080] The light control laminate of the present invention may have a thickness of 0.300 mm to 0.450 mm. Generally, light control laminates having a thickness within this range are excessively thin, which tends to cause unevenness due to the significant effect of pressure when bonding glass. However, a smart window manufactured using the light control laminate of this thickness according to the manufacturing method of the present invention can significantly suppress liquid crystal unevenness. Preferably, the light control laminate of the present invention may have a thickness of 0.32 mm to 0.40 mm. When the thickness of the light control laminate is within this range, the gap layer containing a polyvinyl butyral (PVB) film, described below, can be formed thicker than the thickness of the light control laminate.

[0081] <<Film laminate 100>> Figure 2 is a simplified diagram illustrating a film laminate according to one embodiment of the present invention. Referring to Figure 2, the film laminate 100 of the present invention includes a photochromic stack 10 and a surface protective layer 40 on at least one of the upper and lower surfaces of the photochromic stack 10. According to Figure 2, including the surface protective layer 40 on both the upper and lower surfaces of the photochromic stack 10 is preferable in terms of minimizing the pressure applied to the liquid crystal layer. Furthermore, the film laminate according to one embodiment of the present invention may further include a gap layer 50 at an end of the photochromic stack 10.

[0082] The content relating to the light control laminate 10 is the same as that of the light control laminate 10 described above, and therefore will not be described here.

[0083] Surface protection layer 40 The surface protection layer 40, which is a relatively thin surface protection layer provided on one or both sides of the light-control laminate (pol cell), can improve defects caused by bonding pressure during the bonding process, prevent liquid crystal bias that can occur due to uneven pressure applied to the liquid crystal layer, and resolve the issue of liquid crystal unevenness. For example, when one or more ultra-thin polyvinyl butyral (PVB) films are further provided between the light-control laminate and a substrate such as glass, and / or an adhesive layer included to prevent the glass (substrate) from shattering, the light-control laminate and / or the liquid crystal in the light-control laminate are more effectively protected from damage caused by external physical pressure, such as compression. This is due to the characteristic of polyvinyl butyral (PVB) film, which hardens at a relatively low temperature, eliminating uneven bias in the liquid crystal (liquid phase) when bonding under pressure.

[0084] To this end, in the present invention, the surface protection layer 40 is characterized by a thickness of 0.01 mm to 0.35 mm and is made of a low-temperature curing polyvinyl butyral (PVB) film that cures at temperatures below 90°C. A 0.05 mm-thick thin PVB film is particularly preferred. The low-temperature curing PVB film cures at temperatures below 90°C, preferably between 60°C and 90°C. This ensures adhesion to the PVB film of the adhesive layer 20 used in bonding glass, while minimizing the pressure applied to the liquid crystal layer, especially when applied to displays and / or display devices with thin liquid crystals. Furthermore, because the PVB film has soft properties at the substrate (glass) bonding temperature of 60°C to 90°C, which will be described later, it is advantageous in that it can absorb the pressure applied to the liquid crystal layer in the light-control laminate during bonding. If the bonding temperature is below 60°C, the bonding will not be performed properly, and if it exceeds 90°C, the polarizer may be thermally damaged.

[0085] The surface protective layer has a tensile modulus E' of 10 8 or 10 10Pa, 10 at 90°C 6 or 10 7 Pa, preferably 10 at 60°C 9 Pa, 10 at 90°C 6 The film may include a low-temperature curable polyvinyl butyral (PVB) film having a tensile modulus E' of 100 Pa. A film having a tensile modulus E' within the range has the advantage of being able to more effectively reduce damage to the light-control laminate caused by high pressure.

[0086] The low-temperature curable polyvinyl butyral (PVB) film contained in the surface protective layer may be non-flowable at temperatures below 100°C under a load of 21.6 kg, and may have a melt mass-flow rate (MFR) of 0.02 g / 10 min or less at 140°C under a load of 2.16 kg as measured according to ASTM D1238. Melt flow rate is a standard physical property measured by the mass of a thermoplastic material passing through a die with specified dimensions and properties at a specified temperature and load within 10 minutes, and is used as a criterion for evaluating the processability of a resin. Specifically, the melt flow rate measures the ease of melt flow of a thermoplastic polymer and is also known as the melt flow velocity or melt flow index (MFI). It is measured by standard experimental methods in accordance with ASTM D1238 and / or ISO 1133 and is defined as the weight of a resin that flows out in a molten state through an orifice under specified temperature and load conditions for 10 minutes. Melt viscosity is significantly dependent on molecular weight, so the higher the molecular weight, the more entanglement occurs and the higher the melt viscosity. In this regard, it is preferable to select a material for the film contained in the surface protective layer that exhibits a melt flow rate (MFR) that is easy to form, is processable, and has sufficient mechanical strength considering that it will be contained in the final product.

[0087] The polyvinyl butyral (PVB) film contained in the surface protective layer of the present invention has low-temperature curing properties, providing crosslinking reactivity without the use of high heat, thereby maintaining the transparency of the coating layer. Furthermore, since high heat is not used during curing, it is possible to prevent the denaturation of other laminates, such as the resins to be bonded.

[0088] Table 1 below shows the melt flow rate (MFR) of a 0.05 mm thick polyvinyl butyral (PVB) film included in the surface protective layer according to one embodiment of the present invention, measured according to ASTM D1238.

[0089] [Table 1]

[0090] Referring to Table 1 above, in the case of a polyvinyl butyral (PVB) thin film, no flow was observed at 100°C under a load of 21.6 kg, but a melt flow rate of 0.02 g / 10 min or less was measured at 140°C under a load of 2.16 kg. In other words, the polyvinyl butyral (PVB) film included in one embodiment of the present invention is preferably comprised of one or more laminated thin films each having a thickness of about 0.05 mm, since it exhibits hardening properties at relatively low temperatures and is required to have excellent structural properties at high temperatures.

[0091] The surface protection layer is characterized in that its overall area is larger than the area of ​​the photochromic laminate in contact with the surface protection layer, and from the viewpoint of forming the sealant 150, it is preferable that the overall area is greater than 100% of the area of ​​the photochromic laminate, and more preferably, it is 101 to 150% of the area of ​​the photochromic laminate.

[0092] Gap layer 50 5, the film laminate 100 of the present invention may further include a gap layer 50 at the end of the photochromic laminate 10. The gap layer of the present invention may be laminated to a greater thickness than the photochromic laminate.

[0093] In the present invention, the gap layer can be laminated thicker than the light-controlling laminate. Specifically, after determining the total thickness of the light-controlling laminate, a polyvinyl butyral (PVB) film can be laminated thicker than that thickness and then fabricated through a pre-bonding and main bonding process. In the present invention, the gap layer is formed like a pillar at the edge of the light-controlling laminate to minimize the pressure directly applied to the liquid crystal layer in the light-controlling laminate. To achieve this purpose, the gap layer is thicker than the light-controlling laminate. For example, the thickness of the gap layer may be 101 to 120% of the thickness of the light-controlling laminate. If the thickness exceeds this range, the gap layer may interfere with the bonding between the light-controlling laminate, the surface protection layer, and the substrate, resulting in black spots and manufacturing defects.

[0094] In one embodiment of the present invention, the gap layer has a storage modulus G' at 60°C of 10 3 or 10 6 kPa, and the storage modulus G' at 100°C is 5 x 10 2 or 5 x 10 3The storage modulus may be, but is not limited to, 100 kPa. If the storage modulus satisfies this requirement, it can reduce unevenness in the liquid crystal layer by alleviating stress applied during subsequent bonding of substrates in the manufacture of smart windows. Furthermore, it has the advantage of being cured at low temperatures and acting as a pillar, minimizing the pressure applied to the light-switching laminate. More specifically, even if the gap layer is designed to be thicker than the light-switching laminate, if only a resin with hard properties is used, defects may occur in the subsequent bonding step of the substrates. On the other hand, even if the gap layer is designed to be thicker than the light-switching laminate, if only a resin with soft properties is used, the gap layer may not be able to sufficiently alleviate the pressure applied to the light-switching laminate in the subsequent bonding step of the substrates. Therefore, it is preferable that the gap layer satisfies the storage modulus range, and if the gap layer satisfies the storage modulus and has a thickness greater than the thickness of the light-controlling laminate, it can contain a low-temperature curing polyvinyl butyral (PVB) film, and although the type is not limited, it is preferable that the low-temperature curing polyvinyl butyral (PVB) film contained in the surface protection layer 40 described above can be applied as is.

[0095] The low-temperature curing polyvinyl butyral (PVB) film may be cured at a temperature of 90°C or less, but is not limited thereto. For example, two or more low-temperature curing polyvinyl butyral (PVB) films may be cured at a temperature of 90°C or less, but is not limited thereto. The low-temperature curing polyvinyl butyral (PVB) film has the advantage of being flexible at the substrate (glass) bonding temperature of 60 to 90°C, which will be described later, and thus capable of absorbing the pressure applied to the liquid crystal layer in the light-control laminate through bonding. Bonding temperatures below 60°C may not be performed properly, while temperatures above 90°C may cause thermal damage to the polarizer.

[0096] The film laminate of the present invention can have a gap layer formed by laminating two or more layers including the low-temperature curable polyvinyl butyral (PVB) film, and can have a storage modulus sufficient to absorb pressure by adjusting the type and thickness of the polyvinyl butyral (PVB) film contained and the number of layers to be laminated.

[0097] Preferably, in one embodiment of the present invention, the gap layer may be a multi-layer structure including two or more layers of film. In one example of the present invention, the gap layer may include multiple layers of polyvinyl butyral (PVB) film. Preferably, when the gap layer is formed of two or more layers, it is easy to form a thick gap layer and has the advantage of being able to absorb the pressure applied to the light-controlling stack, thereby reducing damage to the light-controlling stack. Specifically, since polyvinyl butyral (PVB) film is an elastic material, when it is included in a light-controlling stack for manufacturing a smart window, the temperature and pressure applied during the bonding process can damage the light-controlling stack including the liquid crystal layer, which can result in defects such as liquid crystal bias and unevenness. Therefore, in the film laminate according to the present invention, a gap layer thicker than the thickness of the photochromic laminate is formed, and in order to form a gap layer that exceeds the thickness of the photochromic laminate and can adequately relieve the pressure generated during bonding, a conventional single 0.38 mm polyvinyl butyral (PVB) film is not sufficient, so multiple layers of 0.05 mm polyvinyl butyral (PVB) film (thin film) can be laminated.

[0098] More preferably, the polyvinyl butyral (PVB) film contained in the gap layer has a tensile modulus E' of 10 at 60°C. 8 or 10 10 and 10 at 90°C. 6 or 10 7The light-controlling laminate may include a film characterized by the above, preferably a polyvinyl butyral (PVB) film satisfying the tensile modulus E' requirement. In this case, since a gap layer thicker than the light-controlling laminate can be formed by including a polyvinyl butyral (PVB) film with high hardness, there is an advantage in that damage to the light-controlling laminate due to high pressure can be reduced. In addition, impact resistance can be imparted to a smart window manufactured by subsequently laminating a substrate. According to one embodiment of the present invention, it is particularly preferable to use only 2 to 8 thin 0.05 mm PVB films as the surface protective layer 40, as described above, in view of excellent structural performance such as processability and strength, to form a gap layer thicker than the light-controlling laminate and having a desirable storage modulus.

[0099] For example, in the present invention, the gap layer may further include a 0.38 mm polyvinyl butyral (PVB) film with a thermal conductivity of 0.2 W / mK. When a polyvinyl butyral (PVB) film satisfying this thermal conductivity is included, a gap layer thicker than the light-controlling laminate can be formed by including a soft polyvinyl butyral (PVB) film, which may facilitate bonding. Specifically, with regard to the storage modulus of the gap layer, if the gap layer is too hard, it may not be pressed sufficiently when bonding the surface protection layer and / or substrate to the light-controlling laminate later, which may result in substantial bonding difficulties.

[0100] According to one embodiment of the present invention, when the thickness of the light-controlling laminate is 0.39 mm, a gap layer that is thicker than the light-controlling laminate and has a desirable storage modulus can be formed by laminating a 0.05 mm thick polyvinyl butyral (PVB) film that satisfies the tensile modulus and a 0.38 mm thick polyvinyl butyral (PVB) film that satisfies the thermal conductivity. The thermal conductivity is collected and measured using a thermal constants analyzer at 23°C and 50°C using a transient plane source (TPS) method.

[0101] Meanwhile, in the present invention, the gap layer may further include a 0.38 mm thick polyvinyl butyral (PVB) film having a specific heat of 1.9 to 2.3 kJ / (kg·K). The specific heat was measured using a differential scanning calorimeter (DSC).

[0102] Furthermore, a 0.38 mm thick polyvinyl butyral (PVB) film with a thermal conductivity of 0.2 w / mK and / or a 0.38 mm thick polyvinyl butyral (PVB) film with a specific heat of 1.9 to 2.3 kJ / (kg·K) can transmit 88.8% or more of visible light and preferably has a UV transmittance of 0.6% or less. When these conditions are satisfied, the PVB film contained in a smart window can block UV rays, improving the quality of the smart window.

[0103] The gap layer is formed by laminating the layers in the desired manner, and the laminating position and order are not specified.

[0104] <<Smart Window 1000>> The present invention includes a smart window manufactured using the light control laminate and / or film laminate. The present invention may also relate to a means of transportation including the smart window, for example, an automobile in which the smart window is applied to at least one of a front window, a rear window, a side window, a sunroof window, and an interior partition, and may also include a wearable device and a building fixture including the smart window.

[0105] 3 and 5 are diagrams illustrating a smart window manufactured by a method for manufacturing a smart window according to an embodiment of the present invention. Referring to FIG. 5, the smart window 1000 may be a laminate in the form of an adhesive layer 20 and a substrate 30 disposed on both sides of a film laminate 100 including a light control laminate 10, a gap layer 50, and a surface protection layer 40. The smart window of the present invention may include an adhesive layer having physical properties that can minimize the pressure applied to the liquid crystal layer included in the light control laminate during bonding to prevent the occurrence of liquid crystal unevenness that was not visible before glass bonding due to liquid crystal polarization that occurs during the process of bonding the glass to the film laminate.

[0106] 3 shows a smart window according to one embodiment of the present invention. Referring to FIG. 3, the smart window 1000 may include a substrate 30 bonded to at least one of the upper and lower surfaces of the film laminate (including 100, 10, 40, and 50) described above with an adhesive layer 20. The smart window 1000 may further include an adhesive layer (not shown), a transparent film (not shown), and / or an adhesive layer (not shown).

[0107] For example, a car including the smart window of the present invention may be manufactured by bonding a substrate (glass) to both sides of a light-control laminate including a polarizing plate, a transparent conductive layer, a liquid crystal layer, and a tacky adhesive layer, for example, by placing an adhesive layer and a substrate (glass) on both sides of the light-control laminate, and then heating the laminate at a temperature of 90°C and approximately 1 bar for 10 to 20 minutes using a press, and the adhesive film may include, but is not limited to, an EVA film, a PVB film, etc.

[0108] Adhesive layer 20-1, 20-2 The adhesive layers 20-1 and 20-2 may be manufactured using an adhesive or pressure-sensitive adhesive. They preferably have adequate adhesive strength to prevent peeling, bubbles, and the like during handling of the light-control laminate, as well as transparency and thermal stability. The adhesive layers can be made of conventional or later-developed adhesive films. From the perspective of safety (glass shattering, penetration), the adhesive layers preferably contain a low-temperature-curing polyvinyl butyral (PVB) film. A low-temperature-curing polyvinyl butyral (PVB) film has flexibility even at low temperatures, allowing it to absorb pressure applied to the film laminate and achieve the desired initial adhesive strength even when cured at low temperatures. For example, the adhesive layers 20-1 and 20-2 may be the same polyvinyl butyral (PVB) film contained in the surface protection layer and gap layer of the film laminate.

[0109] The adhesive may be a photo-curable adhesive, a thermosetting adhesive, or a pressure sensitive adhesive.

[0110] The photocurable adhesive exhibits strong adhesive strength by crosslinking and curing when exposed to active energy rays such as ultraviolet (UV) and electron beam (EB), and may be composed of reactive oligomers, reactive monomers, photopolymerization initiators, etc.

[0111] The reactive oligomer is an important component that determines the properties of the adhesive, and forms a polymer bond through a photopolymerization reaction to form a cured coating. Usable reactive oligomers include polyester resins, polyether resins, polyurethane resins, epoxy resins, polyacrylic resins, and silicone resins.

[0112] The reactive monomer functions as a crosslinking agent and a diluent for the reactive oligomer, and affects adhesive properties. Usable reactive monomers include monofunctional monomers, polyfunctional monomers, epoxy-based monomers, vinyl ethers, cyclic ethers, etc.

[0113] The photopolymerization initiator absorbs light energy to generate radicals or cations, thereby initiating photopolymerization, and may be selected to suit the photopolymerizable resin.

[0114] The pressure-sensitive adhesive may be a conventional or later-developed pressure-sensitive adhesive, and in one or more embodiments, may be an acrylic pressure-sensitive adhesive, a rubber pressure-sensitive adhesive, a silicone pressure-sensitive adhesive, a urethane pressure-sensitive adhesive, a polyvinyl alcohol pressure-sensitive adhesive, a polyvinylpyrrolidone pressure-sensitive adhesive, a polyacrylamide pressure-sensitive adhesive, a cellulose pressure-sensitive adhesive, a vinyl alkyl ether pressure-sensitive adhesive, etc. The pressure-sensitive adhesive is not particularly limited as long as it has adhesive strength and viscoelasticity, but from the viewpoint of availability, etc., it may preferably be an acrylic pressure-sensitive adhesive, which may contain, for example, a (meth)acrylate copolymer, a crosslinking agent, and a solvent.

[0115] The crosslinking agent may be a conventional or later developed crosslinking agent, and may include, for example, a polyisocyanate compound, an epoxy resin, a melamine resin, a urea resin, a dialdehyde, a methylol polymer, or the like, and preferably includes a polyisocyanate compound.

[0116] The solvent may include conventional solvents used in the field of resin compositions, such as alcohol-based compounds such as methanol, ethanol, isopropanol, butanol, and propylene glycol methoxyalcohol; 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 methoxyacetate; cellosolve-based compounds such as methyl cellosolve, ethyl cellosolve, and propyl cellosolve; and hydrocarbon-based compounds such as hexane, heptane, benzene, toluene, and xylene. These may be used alone or in combination of two or more.

[0117] The adhesive layers 20-1 and 20-2 may contain a hot melt adhesive such as an EVA (ethylene vinyl acetate) film or a PVB (polyvinyl butyral) film used in double-sided bonding glass for vehicles, and preferably contain a low-temperature curing PVB (polyvinyl butyral) film contained in the above-mentioned surface protection layer and / or gap (gpa) layer.

[0118] The thickness of the adhesive layers 20-1 and 20-2 can be appropriately determined depending on the type of resin acting as the adhesive, the adhesive strength, the environment in which the adhesive is used, etc. In one embodiment, the adhesive layers 20-1 and 20-2 may have a thickness of 0.01 to 1.5 mm, preferably 0.05 to 1.2 mm, and more preferably 0.1 to 1 mm, to ensure sufficient adhesive strength between the surface protection layer 40 and the substrate 30 or between the light control laminate 10 and the substrate 30 and minimize the thickness of the smart window. When a PVB (polyvinyl butyral) film is used, the thickness of the PVB film can vary depending on the application and the thickness of the transparent film and / or glass. From a commercial perspective, products with a thickness of 0.38 mm or 0.76 mm can be used.

[0119] In one embodiment, the adhesive layer 20 may be formed on one surface of the substrate (glass) by lamination.

[0120] Base material 30 The substrate 30 may be one or more selected from a glass plate and / or a polymer film that is generally transparent and does not impair optical properties, such as polyethylene terephthalate, cyclic olefin polymer, polyethylene naphthalate, polyethersulfone, polycarbonate, cellulose acetate, polymethyl methacrylate, colorless polyimide, glass, and ceramics, with glass being the most preferred.

[0121] Examples of the glass plate include inorganic glass and organic glass. Examples of the inorganic glass include float glass, heat-absorbing glass, heat-reflecting glass, polished glass, patterned glass, wired glass, striped glass, and green glass. The organic glass is synthetic resin glass that can be used in place of inorganic glass. Examples of the organic glass include polycarbonate plates and poly(meth)acrylic resin plates made from synthetic resins. Examples of the poly(meth)acrylic resin plates include polymethyl(meth)acrylate plates.

[0122] The substrate includes not only glass in which an interlayer film is sandwiched between two glass plates, but also glass in which an interlayer film is sandwiched between a glass plate and a PET film or the like, and may also be a glass-resin composite.

[0123] The thickness of the substrate is not particularly limited, but is preferably 1.6 mm or more and 2.1 mm or less.

[0124] The light-controlling laminate may be manufactured by placing an adhesive film and a vehicle glass on both sides of the light-controlling laminate and then using a press, or may be manufactured by coating a resin on one side of the vehicle glass, vacuum bonding the vehicle glass to both sides of the light-controlling laminate, and then UV-curing the resin. 3 or 10 5 The adhesive film may contain a hot-melt adhesive such as OCR or OCA resin. The adhesive film may contain a hot-melt adhesive such as an EVA (ethylene vinyl acetate) film or a PVB (polyvinyl butyral) film, and the materials for the adhesive layer 20 described above, i.e., a photo-curable adhesive, a thermo-curable adhesive, and a pressure-sensitive adhesive, can be used as is, so the description will be omitted. Preferably, a low-temperature curable adhesive may be used in some processes.

[0125] The film laminate may also have a building fixture bonded to one or both sides thereof, or may have a glass for fixture bonded to one side of the film laminate by lamination to produce a smart window product for fixtures, or may have glass for fixtures bonded to both sides of the film laminate after applying a UV adhesive and then UV curing the glass to produce a smart window product for fixtures.

[0126] <<Smart window manufacturing method>> FIG. 4 is a process diagram showing a method for manufacturing a smart window according to an embodiment of the present invention, and FIG. 5 is a simplified diagram showing the structure of a smart window according to an embodiment of the present invention.

[0127] The present invention relates to a method for manufacturing a smart window that prevents unevenness in the smart window. Specifically, the unevenness may be caused by a light-controlling laminate, and more specifically, the unevenness may be caused by a liquid crystal layer included in the light-controlling laminate being pressed during the process of bonding glass to the laminate during the smart window manufacturing process. Such unevenness is particularly likely to occur with thinner light-controlling laminates, which can be a fatal problem that reduces display quality. Accordingly, the present invention provides a manufacturing method that can effectively manufacture an excellent smart window even in cases where liquid crystal unevenness due to glass bonding pressure is more likely to occur, such as in light-controlling laminates manufactured by directly contacting a polarizer and a conductive layer without using a substrate between them.

[0128] 4 and 5, a method for manufacturing a smart window according to one embodiment of the present invention includes the steps of laminating a film laminate, an adhesive layer, and a substrate (glass) (S101); pre-bonding the laminate of the film laminate, the adhesive layer, and the substrate (S102); and finally bonding the pre-bonded laminate (S103). In one example of the present invention, the final bonding step (S103) includes at least two steps, including: a) maintaining the chamber at 3.5 to 10 bar for 15 to 60 minutes (S103-1); and b) reducing the pressure to 1 bar to 3 bar and maintaining the pressure therefor for 70 to 100 minutes (S103-2). Furthermore, the method for manufacturing a smart window according to the present invention may further include the step of manufacturing a film laminate including a light control laminate (S100) before the step of laminating the film laminate, the adhesive layer, and the substrate (S101).

[0129] <Step of Producing a Film Laminate Including a Light Control Laminate (S100)> The present invention can include a step of manufacturing a film laminate including a photochromic laminate. The film laminate 100 manufactured through step S100 can refer to the photochromic laminate 10 itself, or the photochromic laminate 10 further including a gap layer 50 and / or a surface protective layer 40. For example, as shown in FIG. 5, the film laminate 100 of the present invention can refer to the photochromic laminate 10, in which adhesive layers 20-1 and 20-2 and a substrate 30 are laminated, the gap layer 50, and the surface protective layer 40.

[0130] 5, one example of the present invention may include gap layers 50 as pillars on both side edges of the photochromic laminate 10, and may further include a surface protective layer 40 on at least one surface of the photochromic laminate 10. The surface protective layers 40 may be arranged facing each other at a certain distance via the gap layer 50 formed to surround the periphery of the photochromic laminate 10, and the photochromic laminate is sealed in the space formed by the surface protective layer 40 and the gap layer 50. The surface protective layer 40 and the photochromic laminate 10 may or may not be in contact depending on the thickness of the gap layer 50.

[0131] In the present invention, the step of manufacturing a film laminate may include a step of manufacturing a light-controlling laminate and / or a step of laminating a gap layer on an end of the light-controlling laminate.

[0132] <Lamination step (S101)> The method for manufacturing a smart window according to an embodiment of the present invention includes a step (S101) of preparing a film laminate 100 and laminating adhesive layers 20-1 and 20-2 and a substrate 30 on one or both sides of the film laminate 100.

[0133] In one embodiment, the adhesive layers 20-1 and 20-2 may be formed on one side of the surface protection layer 40 or one side of the light-control laminate 10 by lamination.

[0134] The lamination step may further include a fixing step before the pre-bonding step. To facilitate pre-bonding and final bonding, the film laminate, adhesive layer, and glass are fixed in place using taping or other methods. This may involve a conventional or later-developed method, such as sandwiching a ring that can surround the entire side and fixing it with adhesive tape. In this step, an ultrasonic fusion machine may be used to fix the laminates together, or a method may be used in which the laminates are tightly adhered together while being stacked without using an ultrasonic fusion machine, preventing gaps from widening.

[0135] The lamination step may further include a subsequent vacuum suction step. A vacuum suction process may be performed to ensure stable bonding between the film laminate and the glass. This creates a near-vacuum state between the film laminate and the glass, trapping air between them and preventing bubbles from forming after bonding or optical distortion after completion. This may be achieved using vacuum rubber bags or other conventional or later-developed methods.

[0136] <Preliminary bonding step (S102)> The pre-bonding step (S102) is a step in which each layer of the film laminate is melted and bonded by temperature and vacuum pressure, and is a step in which the glass and the polyvinyl butyral (PVB) film and / or the light control laminate are bonded to each other.

[0137] The pre-bonding step of the present invention may be performed at 0.1 to 3 bar and may include the steps of: S1) increasing the temperature to 40 to 90°C; S2) maintaining the temperature of S1); and S3) cooling to 0 to 30°C.

[0138] Specifically, more preferably, the method may include a step (S1) of raising the temperature to 50 to 70°C at a pressure of 0.1 to 1 bar, a step (S2) of maintaining the temperature at 50 to 70°C, and a step (S3) of cooling to 10 to 20°C.

[0139] <Main joining step (S103)> The main bonding step (S103) is a step of bonding the laminated bodies attached in the preliminary bonding step (S102) while further pressing down any air bubbles that may have formed between them. In the manufacturing method of a smart window, the glass bonding method is one of the important factors that determine the quality of the smart window. When bonding the glass to the film laminate, an appropriate bonding method is required that takes into account the elements contained therein. In particular, when using conventional methods on a laminated body including a thin light-control laminate, not only unevenness due to the misalignment of the liquid crystal layer but also haze due to optical distortion may occur. Simply reducing the bonding pressure to prevent this can result in poor bonding.

[0140] Therefore, the present invention provides a method for manufacturing a smart window, which includes at least two or more steps in the main bonding step.

[0141] In an embodiment of the present invention, the permanent bonding is performed in two or more stages, gradually applying different pressures to stabilize pressure unevenness that occurs during the bonding process. Specifically, preferably, the permanent bonding includes the following steps a) and b) to prevent bias in the liquid crystal layer included in the film laminate and produce a smart window with higher quality. In particular, the present invention is characterized by suppressing the bias phenomenon of the liquid crystal by performing a primary permanent bonding at 3.5 to 10 bar in step a) and then performing a secondary permanent bonding via step b), in which the pressure is reduced to 1 to 3 bar. Compared to conventional permanent bonding methods, which are performed in a single stage under high pressure and are prone to bias, the present invention can eliminate bias through the secondary bonding with reduced pressure in step b). However, since performing permanent bonding using only low pressure from the beginning can result in insufficient bonding and difficulty in removing air bubbles, a method of initially performing the bonding at a high pressure and then reducing the pressure to a low pressure at the end may be more preferable.

[0142] a) Step (S103-1) of maintaining a chamber at 3.5 to 10 bar for 15 to 60 minutes In step a), the temperature is controlled in an autoclave and pressure is applied using a compressor, completing the bonding through heating and pressure. Specifically, the temperature may be preferably 50 to 110°C, more preferably 80 to 100°C. Furthermore, step a) of this bonding process, which is divided into two or more stages, is preferably maintained within the above temperature range in a chamber at 3.5 to 6 bar for 20 to 40 minutes. Specifically, unlike conventional bonding glass, the temperature range is preferably maintained within this range because the light-controlling laminate cannot withstand temperatures up to 140°C, which can lead to discoloration of the light-controlling laminate. Furthermore, since the light-controlling laminate is manufactured using a liquid crystal-injected light-controlling laminate, it is highly sensitive to pressure. If high-pressure compressed air outside this range is used, uneven pressure during bonding can lead to liquid crystal misalignment.

[0143] b) Following step a), a step of reducing the pressure to a range of 1 bar to 3 bar and maintaining the pressure for 70 to 100 minutes (S103-2) Following step a), step b) gradually bonds the film by varying the pressure to prevent uneven pressure from being applied to the liquid crystal contained in the film laminate. Specifically, it is preferably performed at 50 to 110°C, more preferably 80 to 100°C. It is also preferable to maintain a reduced pressure of 1 to 2 bar for 80 to 100 minutes. After applying high pressure to remove air bubbles in step a), step b reduces the pressure to eliminate uneven pressure, which has the effect of stabilizing any liquid crystal polarization that may have occurred in step a), which is performed at a relatively high pressure, through step b.

[0144] In other words, the present invention's bonding method involves a) first bonding with high pressure, and then b) applying low pressure for a long time at the end to eliminate the liquid crystal bias, thereby distributing the liquid crystal contained in the light-control laminate evenly and stably bonding the substrates.In other words, unlike conventional bonding methods, the bonding method is performed in two stages, making it possible to manufacture smart windows with high reliability and significantly reduced liquid crystal unevenness defect rates. [Example]

[0145] In order to aid in understanding the present invention, experimental examples including specific examples and comparative examples are presented below, but these are merely illustrative of the present invention and do not limit the scope of the appended claims. It will be obvious to those skilled in the art that various changes and modifications to the examples are possible within the scope and technical spirit of the present invention, and it goes without saying that such changes and modifications also fall within the scope of the appended claims. Unless otherwise specified, "%" and "parts" in the examples are "% by mass" and "parts by mass", respectively.

[0146] Manufacturing Example 1: Steps for manufacturing a film laminate including a light control laminate A 60 μm-thick polyvinyl alcohol film (raw film) (manufactured by Kuraray Co., Ltd., product name "Kuraray Poval Film VF-PE#6000", average polymerization degree 2400, saponification degree 99.9 mol%) was continuously unwound from a raw roll and transported, then immersed in a swelling bath containing pure water at 20°C for 30 seconds. In this swelling process, roll-to-roll stretching (longitudinal uniaxial stretching) was performed by varying the peripheral speed between the nip rolls. The stretching ratio based on the raw film was 2.5 times. The film was then dyed, crosslinked, color-toned, washed, dried, and bonded using conventional techniques to produce a polarizing plate.

[0147] A hard coating layer-forming composition was prepared by mixing 16.2 g of a dendrimer compound (MIWON Specialty Chemicals, SP-1106), 14.4 g of inorganic nanoparticles (10 to 20 nm, silica particles: 50 wt%, solvent: methyl ethyl ketone (MEK)), 1.8 g of a multifunctional (meth)acrylate compound containing an ethylene glycol group, 0.7 g of a photoinitiator (1-hydroxycyclohexylphenyl ketone), and 2.9 g of methyl ethyl ketone on one side of each of the first and second polarizing plates prepared as above. The composition was cured by adjusting the type of Mayer bar and the solid content, and then bar-coated according to the calculated hard coating thickness. The composition was dried at 80°C for 5 minutes and then exposed to a high-pressure mercury lamp at 500 mJ / cm. 3 It hardened with a light intensity of .

[0148] A PEDOT composition was applied to the first and second polarizers and dried at 90°C for 5-10 minutes to form a 200 nm-thick transparent conductive layer. This produced a laminate comprising first and second transparent conductive layers made of a conductive polymer (PEDOT) on one side of each polarizer. The PEDOT composition was prepared by mixing coating solution 1 and coating solution 2 in a 1:1 ratio. Coating solution 1 was a mixture of 60-65 wt% ethenylbenzenesulfonic acid homopolymer compound with 2,3-dihydrothieno[3,4-b]-1,4-dioxin homopolymer (water-based), 15-20 wt% ethyl alcohol, and 20-25 wt% deionized water, based on the total weight of the coating solution. Coating solution 2 was a mixture of 0.5-1.0 wt% polyester resin (25% solids, water-based), 65-75 wt% ethyl alcohol, and 20-25 wt% deionized water, based on the total weight of the coating solution.

[0149] An alignment liquid was coated on the surfaces of the first and second transparent conductive layers of each polarizer and dried (80°C / 2 minutes), and then UV was irradiated onto the dried alignment liquid to form first and second alignment films.

[0150] Using a sealant dispenser (SHOTmini 200Ωχ, MUSASHI), sealant (UVF-006, 70,000 mPa·s, SEKISUI) was applied to the manufactured first transparent conductive layer using a sharp needle (SPN-0.25-12.7L) at a discharge pressure of 200 mPa according to the product size drawing, and liquid crystal was injected onto the first alignment film using the ODF process. Then, with the horizontal optical axes of the first and second polarizers aligned parallel to each other at 0° or 90°, the light-control laminate was applied with 3 kg / cm 2 After pressure bonding, UV curing (500 mJ / cm) was performed along the sealant line. 2 ) was performed to produce an optical laminate for smart windows. Then, conductive copper tape (TERAOKA, No. 8323) was adhered to the first transparent conductive layer and the second transparent conductive layer to connect them.

[0151] Manufacturing example 2: Production of surface protection layer The method for laminating and forming the surface protection layer is to cover the entire glass (substrate) with a low-temperature curing polyvinyl butyral (PVB) film (thin film, tensile modulus at 60°C: 1.9 x 10) of 0.05 mm thick. 9 Pa, 90°C tensile modulus 4×10 6 A surface protective layer is prepared by cutting out a film having a melt flow rate (MFR) of 0.02 g / 10 min or less at 140°C (Pa, measured according to ASTM D1238). The thickness and number of layers of the surface protective layer in each example, comparative example, and reference example are as shown in Table 2 below.

[0152] Manufacturing Example 3: Fabrication of Gap Layer The gap layer is laminated and formed using a 0.38 mm low-temperature curing polyvinyl butyral (PVB) film (0.38 mm, ISO 9050 standard visible light transmittance (Tv) 88.8% or more, ultraviolet transmittance (Tuv) 0.6% or less, thermal conductivity 0.2 W / mK at 23 to 50°C) and / or a 0.05 mm low-temperature curing polyvinyl butyral (PVB) film (60°C tensile modulus 1.9 x 10 9 Pa, 90°C tensile modulus 4×10 6 The thickness of the gap layer is formed to be greater than the thickness of the light-control laminate by laminating an additional layer of 0.02 g / 10 min or less at a melt flow rate (MFR) of 140°C measured according to ASTM D1238. The gap layer is cut out and placed so as to surround the entire glass (substrate) excluding the size of the light-control laminate. The thickness and number of layers of the gap layer for each example, comparative example, and reference example are as shown in Table 2 below.

[0153] Manufacturing Example 4: Lamination Step The laminates prepared according to Preparation Examples 1 to 3 were laminated by sequentially placing a second substrate (glass), a second adhesive layer, the laminate, a first adhesive layer, and a first substrate (glass). The first and second adhesive layers were made of 0.38 mm thick low-temperature curing polyvinyl butyral (PVB) film (ISO 9050 standard visible light transmittance (Tv) of 88.8% or more, ultraviolet transmittance (Tuv) of 0.6% or less, thermal conductivity of 0.2 W / mK at 23 to 50°C, specific heat capacity of 1.9 KJ / Kg·K at 20°C and 2.3 KJ / Kg·K at 100°C). The first and second substrates were made of 2.1 T soda-lime glass.

[0154] Manufacturing Example 5: Preliminary Bonding Step The laminated sample was placed in a Resuable Vacuum Rubber Bag (OBRJ-S) and pre-bonded. In Example 1, the pre-bonding step involved placing the laminated smart window in the Vacuum Rubber Bag, raising the temperature from 20°C to 65°C for 15 minutes at a pressure of 0.9 bar, maintaining the temperature at 65°C for 30 minutes, and then lowering the temperature from 65°C to 20°C for 15 minutes. The pressure, temperature, and time conditions for the pre-bonding step in each Example, Comparative Example, and Reference Example were as shown in Table 2 below.

[0155] Manufacturing Example 6: Main joining step After the preliminary bonding is completed, the final bonding (autoclave) is carried out. In the case of Example 1, the final bonding was carried out under the autoclave conditions of raising the temperature to 90°C under a pressure of 5 bar for 30 minutes, then reducing the pressure to 1.5 bar while maintaining the temperature at 90°C for 90 minutes, after which the final bonding was carried out. The pressure, temperature, and time conditions for the final bonding step in each Example, Comparative Example, and Reference Example are as shown in Table 2 below.

[0156] Examples and Comparative Examples Referring to Preparation Examples 1 to 6, smart windows according to the present invention were manufactured as shown in Table 2 below.

[0157] [Table 2]

[0158] The Smart Window manufactured according to Table 2 above was observed and evaluated for unevenness (LCD unevenness: a general term for a state in which the display characteristics of an LCD panel are not uniform and unevenness occurs) on a backlight plate (light source) using a conventional digital camera. The results are shown in Table 3 and Figures 6 to 8. Figures 6a to 6f are photographs of the appearance evaluation results of the bonded articles of Examples 1 to 6 of the present invention, respectively, observed on a backlight plate (light source) using a digital camera. Figures 7a and 7b are photographs of the appearance evaluation results of the bonded articles of Comparative Examples 1 and 2 of the present invention, respectively, observed on a backlight plate (light source). Figures 8a to 8d are photographs of the appearance evaluation results of the bonded articles of Reference Examples 1 to 4 of the present invention, respectively, observed on a backlight plate (light source) using a digital camera.

[0159] [Table 3]

[0160] Referring to Tables 2 and 3 above, when a smart window is manufactured using the manufacturing method of the present invention, no liquid crystal unevenness occurs even after bonding the glass (substrate), and no defective products that cannot be operated due to black spots are produced. [Explanation of symbols]

[0161] 10: Light-controlling laminate 20: Adhesive layer 30: Base material 40: Surface protective layer 50: Gap layer 100: Film laminate 110-1 and 110-2: first polarizing plate and second polarizing plate 120-1 and 120-2: First transparent conductive layer and second transparent conductive layer 130: Liquid crystal layer 140: Alignment film 150:Sealant 1000:Smart Window

Claims

1. a light-control stack; and a surface protection layer laminated on at least one of the upper and lower surfaces of the light-controlling laminate; The surface protective layer is a low-temperature curable polyvinyl butyral (PVB) film that cures at a temperature of 90°C or less, has a thickness of 0.01 mm to 0.35 mm, and has an overall area that is larger than the area of ​​the light-control laminate that is in contact with the surface protective layer.

2. 2. The film laminate according to claim 1, wherein the surface protective layer does not flow at 100°C or less under a load of 21.6 kg, and has a melt flow rate (MFR) of 0.02 g / 10 min or less at 140°C and a load of 2.16 kg as measured according to ASTM D1238.

3. The surface protective layer has a tensile modulus E' of 10 at 60°C. ８ or 10 １０ Pa and 10 at 90°C ６ or 10 ７ The film laminate of claim 1 , comprising a film having a viscosity of 1000 psig.

4. The light-controlling laminate is a first polarizer; a first transparent conductive layer formed on the inner surface of the first polarizer; a second polarizing plate facing the first polarizing plate; a second transparent conductive layer formed on the inner surface of the second polarizer and facing the first transparent conductive layer; a liquid crystal layer disposed between the first transparent conductive layer and the second transparent conductive layer; and A film laminate comprising the alignment film according to claim 1 formed between the transparent conductive layer and a liquid crystal layer.

5. The film laminate of claim 4 , wherein at least one of the first transparent conductive layer and the second transparent conductive layer is formed in direct contact with the first polarizing plate or the second polarizing plate.

6. At least one of the first and second transparent conductive layers may be made of polythiophene, poly(3,4-ethylenedioxythiophene), polyaniline, polyacetylene, polydiacetylene, polyphenylene, polyphenylene vinylene, polyphenylene sulfide, polythienylene vinylene, 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: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.

7. The film laminate of claim 4 , wherein at least one of the first polarizing plate and the second polarizing plate further comprises at least one layer selected from the group consisting of a protective layer, a retardation adjusting layer, and a refractive index adjusting layer.

8. The film stack of claim 1 , wherein the film stack includes a gap layer comprising a polyvinyl butyral (PVB) film at an edge of the light management stack.

9. The gap layer has a storage modulus G' of 10 ３ or 10 ６ kPa, and the storage modulus G' at 100°C is 5 x 10 ２ or 5 x 10 ３ The film laminate according to claim 8, characterized in that the modulus is 100 kPa.

10. 9. The film laminate of claim 8, wherein the gap layer comprises two or more layers of polyvinyl butyral (PVB) film.

11. The gap layer has a tensile modulus E' of 10 at 60°C. ８ or 10 １０ Pa and 10 at 90°C ６ or 10 ７ 9. The film laminate of claim 8, comprising a film having a viscosity of 1000 psig.

12. The film laminate of claim 1; an adhesive layer; and a substrate bonded to at least one of the upper and lower surfaces of the film laminate with the adhesive layer.

13. 13. A method for manufacturing a smart window according to claim 12, comprising the steps of: laminating a film laminate including a light-controlling laminate, an adhesive layer, and a substrate; a pre-bonding step; and This bonding step; The main bonding step includes: a) maintaining the chamber at 3.5 to 10 bar for 15 to 60 minutes; and b) after step a), reducing the pressure to 1 bar to 3 bar and maintaining the pressure for 70 to 100 minutes.

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