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

Abstract

The present invention relates to a film laminate, a smart window comprising the same, and a method for manufacturing the same, the film laminate being characterized by comprising a light-dimming laminate and a surface protective layer laminated on at least one of the upper surface and the lower surface of the light-dimming laminate, the surface protective layer is a low-temperature curable polyvinyl butyral (PVB) film that is cured at a temperature of 90 DEG C or less, has a thickness of 0.01-0.35 mm, and has a larger overall area than the area of the light-dimming laminate in contact with the surface protective layer. According to the present invention, it is possible to manufacture a film laminate which minimizes the pressure applied to a liquid crystal layer during glass bonding and does not cause liquid crystal displacement, thereby preventing the occurrence of liquid crystal speckles and having an excellent appearance.

Description

Technical Field

[0001] This invention relates to a membrane laminate and a smart window comprising the same, and a method for manufacturing the same. Background Technology

[0002] Generally, the windows of vehicles and other mobile vehicles are often coated with an external light-blocking coating. However, the transmittance of conventional mobile vehicle windows is fixed, as is the transmittance of the external light-blocking coating. Therefore, because the overall transmittance of such conventional mobile vehicle windows is fixed, it can potentially lead to accidents. For example, if the overall transmittance is set low, there is no problem during the day when the ambient light is sufficient, but in low-light conditions such as at night, it can be difficult for the driver or others to properly see the surroundings of the mobile vehicle. Conversely, if the overall transmittance is set high, it can cause glare for the driver or others even during the day when the ambient light is sufficient. To address this, a transmittance-variable optical laminate has been developed that can change the light transmittance when a voltage is applied.

[0003] The aforementioned transmittance variable optical laminate is driven by applying voltage to drive the liquid crystal, thereby making the transmittance variable. The transmittance variable optical laminates developed to date are made by forming a conductive layer for liquid crystal driving on a separate substrate and then combining it with other components such as a polarizing plate.

[0004] For example, Japanese Patent Publication No. 2018-010035 discloses a variable transmittance optical laminate comprising a transparent conductive layer formed on a polycarbonate (PC) substrate or the like having a predetermined thickness. For a smart window with variable transmittance, a liquid crystal layer must be included to achieve the variable function, and it must ultimately undergo a bonding process with glass. However, with conventional techniques, the following problems exist: during the smart window manufacturing process, due to displacement caused by pressure on the liquid crystal layer within the laminate during bonding of the glass to the laminate, liquid crystal patterns, invisible before glass bonding, appear in the final manufactured smart window. Furthermore, as the dimming laminate becomes thinner, especially in dimming laminates with a structure where a polarizing plate and a conductive layer are in direct contact without a substrate between them, liquid crystal patterns caused by glass bonding pressure are more likely to occur. Therefore, there is a practical need to develop a variable transmittance optical laminate with a structure that minimizes the pressure on the liquid crystal layer and a bonding method that eliminates pressure unevenness, preventing liquid crystal patterns from appearing after glass bonding.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Publication No. 2018-010035 Summary of the Invention

[0008] The problem to be solved

[0009] To address the aforementioned problems, the present invention aims to provide a film laminate having a surface protective layer of optimal thickness on at least one side of the outer side of the dimming laminate.

[0010] In addition, the present invention aims to provide a film laminate that includes a gap layer with suitable optimal physical properties and structure at its ends.

[0011] In addition, the present invention aims to provide a film laminate that, by providing optimal physical properties and structure, minimizes the pressure on the liquid crystal layer inside the dimming laminate that may occur during glass bonding in a display, thereby suppressing the appearance of liquid crystal speckles even after glass bonding, resulting in excellent quality and appearance.

[0012] In addition, the present invention aims to provide a method for manufacturing a smart window, which includes two or more steps in the formal bonding of glass to the above-mentioned film laminate to minimize the pressure on the liquid crystal layer, thereby stabilizing the uneven pressure on the liquid crystal layer inside the dimming laminate during glass bonding.

[0013] In addition, the present invention aims to provide a smart window comprising a dimming laminate manufactured without including a separate substrate for forming a conductive layer, thereby significantly reducing the thickness compared to conventional dimming laminates.

[0014] In addition, the present invention aims to provide a smart window comprising the above-described membrane laminate and a window for use in vehicles, wearable devices or buildings.

[0015] However, the problems to be solved by the present invention are not limited to those mentioned above, and those skilled in the art should be able to clearly understand other problems not mentioned based on the following description.

[0016] Methods for solving problems

[0017] This invention relates to a film laminate, characterized in that it comprises a dimming laminate and a surface protective layer laminated on at least one of the upper and lower surfaces of the dimming laminate, wherein the surface protective layer is a low-temperature curable polyvinyl butyral (PVB) film cured at a temperature below 90°C, with a thickness of 0.01 mm to 0.35 mm, and its overall area is larger than the area of ​​the dimming laminate in contact with the surface protective layer.

[0018] The invention is characterized in that the above-mentioned surface protective layer has no fluidity at 100°C and under a load of 21.6 kg, and the melt flow rate (MFR) measured according to ASTM D1238 at 140°C and under a load of 2.16 kg is less than 0.02 g / 10 min.

[0019] In this invention, the aforementioned surface protective layer may contain a tensile elastic modulus (E') of 10 at 60°C. 8 ~10 10 Pa and 10 at 90℃ 6 ~10 7 Pa membrane.

[0020] In this invention, the aforementioned dimming laminate may include: a first polarizing plate, a first transparent conductive layer formed on the inner side surface of the first polarizing plate, a second polarizing plate opposite to the first polarizing plate, a second transparent conductive layer formed on the inner side surface of the second polarizing plate and opposite to the first transparent conductive layer, a liquid crystal layer disposed 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.

[0021] In this invention, at least one of the first and second transparent conductive layers can be formed in direct contact with the first or second polarizing plate.

[0022] In this invention, at least one of the first and second transparent conductive layers may comprise a transparent conductive layer selected from polythiophene, poly(3,4-ethylenedioxythiophene), polyaniline, polyacetylene, polydiacetylene, polyphenylene, polyphenylene vinylene, polyphenylene sulfide, polythienylene vinylene, and polythiophene vinylene. A conductive polymer comprising one or more of the following polymers: vinylene, polyfluorene, polypyrrole, poly(3,4-ethylenedioxythiophene):polystyrenesulfonate, poly(3,4-ethylenedioxythiophene):camphorsulfonic acid, poly(3,4-ethylenedioxythiophene):toluenesulfonic acid, poly(3,4-ethylenedioxythiophene):dodecylbenzenesulfonic acid, polyaniline:polystyrenesulfonate, polyaniline:camphorsulfonic acid, polypyrrole:polystyrenesulfonate, polypyrrole:camphorsulfonic acid, polypyrrole:toluenesulfonic acid, polypyrrole:dodecylbenzenesulfonic acid, polythiophene:polystyrenesulfonate, polythiophene:camphorsulfonic acid, polythiophene:toluenesulfonic acid, and polythiophene:dodecylbenzenesulfonic acid polymers.

[0023] In this invention, at least one of the first polarizing plate and the second polarizing plate may further include one or more of the following: a protective layer, a phase difference adjustment layer, and a refractive index adjustment layer.

[0024] In this invention, the above-mentioned film laminate may include a gap layer containing a polyvinyl butyral (PVB) film at the end of the dimming laminate.

[0025] In this invention, the energy storage modulus (G') of the aforementioned interstitial layer at 60°C can be 10. 3 ~10 6 The storage modulus (G') at 100℃ can be 5 × 10 kPa. 2 ~5×10 3 kPa.

[0026] In this invention, the aforementioned interstitial layer may comprise two or more layers of polyvinyl butyral (PVB) film.

[0027] In this invention, the aforementioned gap layer may contain a tensile elastic modulus (E') of 10 at 60°C. 8 ~10 10 Pa and 10 at 90℃ 6 ~10 7 Pa membrane.

[0028] In addition, the present invention relates to a smart window comprising the above-described film laminate, an adhesive layer, and a substrate that is bonded to at least one of the upper and lower surfaces of the film laminate via the adhesive layer.

[0029] Furthermore, the present invention relates to a method for manufacturing the aforementioned smart window, which includes a step of bonding a substrate to at least one of the upper and lower surfaces of a film laminate using an adhesive layer. The bonding step includes a pre-bonding step and a formal bonding step. The formal bonding step includes: a) maintaining the film in a chamber at 3.5 to 10 bar for 15 to 60 minutes; and b) after step a), reducing the pressure to 1 to 3 bar and maintaining the pressure for 70 to 100 minutes.

[0030] Invention Effects

[0031] According to the film laminate of the present invention, by laminating a surface protective layer with 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 dimming laminate, it is possible to manufacture a film laminate with minimized pressure on the liquid crystal layer during glass bonding without liquid crystal displacement, thereby preventing liquid crystal speckles and resulting in an excellent appearance.

[0032] Furthermore, according to the film laminate of the present invention, by including a gap layer at the end of the dimming laminate that is thicker than the dimming laminate, a film laminate capable of suppressing liquid crystal patterns that may occur in a display can be manufactured.

[0033] Furthermore, the dimming laminate according to the present invention, since it is manufactured by a smart window manufacturing method that includes two or more steps of changing pressure in the formal bonding process of bonding the glass to the above-mentioned film laminate, may significantly reduce the occurrence of liquid crystal speckles compared to conventional film laminates.

[0034] Furthermore, the film laminate according to the present invention, since it comprises a dimming laminate manufactured without a separate substrate for forming a conductive layer, can significantly reduce its thickness compared to conventional laminates.

[0035] Furthermore, according to the dimming laminate of the present invention, by applying a film laminate containing the dimming laminate, a smart window without liquid crystal speckles and windows for vehicles, wearable devices or buildings using the smart window can be provided. Attached Figure Description

[0036] Figure 1 The diagram illustrates the structure of a dimming laminate according to an embodiment of the present invention.

[0037] Figure 2 The diagram illustrates the structure of a film laminate according to an embodiment of the present invention.

[0038] Figure 3 The structure of a smart window according to an embodiment of the present invention is illustrated in a simplified diagram.

[0039] Figure 4 This is a process diagram illustrating a method for manufacturing an intelligent window according to an embodiment of the present invention.

[0040] Figure 5 The structure of a smart window according to an embodiment of the present invention is illustrated in a simplified diagram.

[0041] Figures 6a to 6f These are photographs of the appearance evaluation results of the bonding articles of Embodiments 1 to 6 of the present invention, observed on a backlight panel (light source) using a digital camera.

[0042] Figures 7a-7b These are photographs of the appearance evaluation results of the bonding articles of Comparative Examples 1 to 2 of the present invention, observed on a backlight panel (light source) using a digital camera.

[0043] Figures 8a to 8d These are photographs of the appearance evaluation results of the bonding articles of Reference Examples 1 to 4 of the present invention, observed on a backlight panel (light source) using a digital camera.

[0044] Symbol Explanation

[0045] 10: Dimming layer,

[0046] 20, 20-1, 20-2: Adhesive layer,

[0047] 30: Substrate

[0048] 40: Surface protective layer

[0049] 50: Interstitial layer,

[0050] 100: Membrane laminate,

[0051] 110-1: First polarizing plate,

[0052] 110-2: Second polarizing plate,

[0053] 120-1: First transparent conductive layer

[0054] 120-2: Second transparent conductive layer

[0055] 130: Liquid crystal layer

[0056] 140: Orientation film,

[0057] 150: Sealant

[0058] 1000: Smart Window. Detailed Implementation

[0059] This invention relates to a film laminate comprising a dimming laminate and a surface protective layer laminated on at least one of the upper and lower surfaces of the dimming laminate, a smart window comprising the film laminate, and a method for manufacturing the same. The surface protective layer is characterized by being a low-temperature curable polyvinyl butyral (PVB) film cured at temperatures below 90°C, with a thickness of 0.01 mm to 0.35 mm, and an overall area larger than the area of ​​the dimming laminate in contact with the surface protective layer. This minimizes the pressure (dispersion) on the liquid crystal layer during glass bonding, preventing liquid crystal shift and liquid crystal speckling, resulting in a film laminate with excellent appearance. Furthermore, since curing is achieved at a low temperature below 90°C, preferably between 60°C and 90°C, heat damage to other components such as polarizers can be prevented.

[0060] The dimming laminate of the present invention can be a transmittance variable optical laminate, which is particularly suitable for the field of technology that can change the transmittance of light according to the application of voltage, for example, it can be used in smart windows.

[0061] A smart window is an optical structure that controls the amount of light or heat passing through by changing the light transmittance based on the application of an electrical signal. In other words, a smart window can change between transparent, opaque, or translucent states depending on the voltage; it is also known as variable transmittance glass, dimming glass, or smart glass.

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

[0063] The dimming laminate of the present invention can also be used as a smart window in the above-mentioned technical fields. However, since the conductive layer is formed directly on the polarizing plate without including a separate substrate for forming the conductive layer, it is thin and has good bending properties, making it particularly suitable for smart windows for vehicles or buildings. In one or more embodiments, smart windows using the dimming laminate of the present invention can be used in vehicles, such as the front window, rear window, side window, and sunroof of automobiles, or windows in buildings. In addition to blocking external light, they can also be used for interior space division or privacy protection purposes in automobiles or buildings, such as internal partitions. They can also be used in wearable devices such as helmets, glasses, or watches.

[0064] Hereinafter, embodiments of the present invention will be described in more detail with reference to the accompanying drawings. However, the following drawings accompanying this specification are merely illustrative of preferred embodiments of the present invention and serve to further illustrate the above-described invention and its technical concept. Therefore, the present invention should not be interpreted solely as described in these drawings.

[0065] The terminology used in this specification is intended to describe embodiments and is not intended to limit the invention. In this specification, the singular form includes the plural form unless specifically stated in the context. For example, as used herein, "polarizing plate" may refer to at least one of a first polarizing plate and a second polarizing plate, and "transparent conductive layer" may refer to at least one of a first transparent conductive layer and a second transparent conductive layer.

[0066] The terms "comprises" and / or "comprising" as used herein are used to mean that they do not exclude the presence or addition of more than one other component, step, operation, and / or element besides those mentioned. Throughout this specification, the same reference numerals refer to the same components.

[0067] As illustrated in the accompanying drawings, spatially relative terms such as "below," "bottom," "lower part," "above," "upper surface," and "upper part" are used to readily describe the relationship between one element or component and other elements or components. Spatially relative terms should be understood in accordance with terms that include the different orientations of the elements during use or operation, in addition to those illustrated in the drawings. For example, when the elements illustrated in the drawings are flipped, an element described as "below" or "lower part" of another element can be placed "above" the other element. Therefore, the illustrative term "below" can include both the lower and upper orientations. Elements can also face other directions, so spatially relative terms can be interpreted according to orientation.

[0068] The term "viewing direction" as used in this specification can be interpreted as a direction orthogonal to the polarizing plate and / or the transparent conductive layer, i.e., the direction of view from the user's visible side.

[0069] The term “substantially” as used in this specification can be interpreted not only as physically identical or identical, but also as including within the error range of the measurement or manufacturing process, for example, within the error range of less than 0.1%.

[0070] Dimming laminate (10)

[0071] Figure 1 The diagram illustrates the structure of a dimming laminate 10 according to an embodiment of the present invention. (Refer to...) Figure 1 In one embodiment of the present invention, the dimming laminate 10 may include: a first polarizing plate 110-1; a first transparent conductive layer 120-1 formed on the inner side surface of the first polarizing plate 110-1; a second polarizing plate 110-2 opposite to the first polarizing plate 110-1; a second transparent conductive layer 120-2 formed on the inner side surface of the second polarizing plate 110-2 and opposite to 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 layers (first transparent conductive layer 120-1 and second transparent conductive layer 120-2) and the liquid crystal layer 130. Furthermore, the dimming laminate may also include one or more layers selected from the group consisting of an adhesive layer, a bonding layer, an ultraviolet absorbing layer, and / or a hard coating layer (not shown). In addition, a sealant 50 may be further included at the end of the liquid crystal layer to ensure space for the liquid crystal layer.

[0072] The dimming laminate 10 of one embodiment of the present invention includes polarizing plates (first polarizing plate 110-1, second polarizing plate 110-2), transparent conductive layers (first transparent conductive layer 120-1, second transparent conductive layer 120-2), and a liquid crystal layer 130. The dimming laminate 10 of the embodiment of the present invention can be a variable transmittance optical laminate. The total light transmittance can be changed with the application of voltage. For example, the total light transmittance of the dimming laminate 10 can be from 0.1% to 45% depending on the applied voltage.

[0073] Preferably, the thickness of the dimming laminate of the present invention can be 0.32 to 0.40 mm. When the thickness of the dimming laminate meets the above range, a gap layer thicker than the thickness of the dimming laminate can be formed.

[0074] The aforementioned polarizing plates (first polarizing plate 110-1 and second polarizing plate 110-2) may include a polarizer and a protective layer formed on at least one side of the polarizer. The two polarizing plates (first polarizing plate 110-1 and second polarizing plate 110-2) that are different from each other may be located on both sides of the liquid crystal layer 130. When the polarizing plates (first polarizing plate 110-1 and second polarizing plate 110-2) are located on both sides of the liquid crystal layer 130, the angle formed between the absorption axes of the two polarizing plates (first polarizing plate 110-1 and second polarizing plate 110-2) that are different from each other may be formed to be vertical or horizontal. In addition, in order to ensure minimum transmittance, it is preferable to form an angle of 5 to 85°. The aforementioned polarizing plates (first polarizing plate 110-1 and second polarizing plate 110-2) can direct divergently irradiated light in one direction. The amount of transmitted light is adjusted by utilizing the polarizing properties of the polarizing plates (first polarizing plate 110-1 and second polarizing plate 110-2), thereby adjusting the transmittance of the optical laminate. The aforementioned protective layer can be a component designed to protect the polarizing characteristics of the polarizer from subsequent processes and external environmental influences. In one embodiment, the protective layer can serve to provide a structural basis for forming the transparent conductive layers (first transparent conductive layer 120-1 and second transparent conductive layer 120-2) described later. In this case, the protective layer preferably has the characteristic of easily forming the transparent conductive layers (first transparent conductive layer 120-1 and second transparent conductive layer 120-2).

[0075] The aforementioned protective layer may exist only on one side of the polarizer or may be disposed on both sides of the polarizer. When the polarizing plate (first polarizing plate 110-1, second polarizing plate 110-2) comprises multiple protective layers, two different protective layers may contain substantially the same or similar substances. In one or more embodiments, the protective layer may comprise polyester resins such as polyethylene terephthalate, polyethylene isophthalate, polyethylene naphthalate, and polybutylene terephthalate; cellulose resins such as diacetylcellulose and triacetylcellulose; polycarbonate resins; polyethylene resins; polypropylene resins; acrylic resins such as poly(methyl methacrylate) and poly(ethyl methacrylate); and cyclic olefin polymers (COP), etc.

[0076] The polarizers of the aforementioned polarizing plates (first polarizing plate 110-1, second polarizing plate 110-2) may include stretched polarizers or be provided as stretched polarizing plates. In one embodiment, the stretched polarizer may include stretched polyvinyl alcohol (PVA) resin. The aforementioned polyvinyl alcohol (PVA) resin may be a polyvinyl alcohol resin obtained by saponifying a polyvinyl acetate resin. As a polyvinyl acetate resin, in addition to polyvinyl acetate homopolymers, copolymers of vinyl acetate with other monomers that can copolymerize therewith may also be examples. As the aforementioned other monomers, unsaturated carboxylic acid monomers, unsaturated sulfonic acid monomers, olefin monomers, vinyl ether monomers, acrylamide monomers having ammonium groups, etc. In addition, as a modified material, the polyvinyl alcohol (PVA) resin may also be polyvinyl formal or polyvinyl acetal modified with aldehydes.

[0077] Furthermore, the aforementioned polarizing plates (first polarizing plate 110-1, second polarizing plate 110-2) may include a coated polarizer. In one embodiment, the coated polarizer may be formed using a liquid crystal coating composition, for example, by coating the liquid crystal coating composition onto the upper surface of a protective layer. In this case, the liquid crystal coating composition may include a reactive liquid crystal compound and a dichroic dye.

[0078] The aforementioned reactive liquid crystal compounds may contain reactive mesogens (RM) capable of exhibiting liquid crystal properties and / or monomer molecules containing polymerizable terminal functional groups that, after crosslinking via thermal or photochemical reactions, possess a liquid crystal phase. When these reactive liquid crystal compounds are polymerized using light or heat, a polymer network can be formed while maintaining the liquid crystal alignment. By utilizing these reactive liquid crystal compounds, polarizers in thin film form that maintain the optical anisotropy or dielectric constant properties of liquid crystals and improve mechanical and thermal stability can be formed.

[0079] The aforementioned dichroic dyes are components added to liquid crystal coating compositions to impart polarizing properties, exhibiting different absorbance along the long axis and short axis of the molecule. These dichroic dyes can be conventionally or subsequently developed dichroic dyes, such as acridine dyes, oxazine dyes, cyanine dyes, naphthalene dyes, azo dyes, anthraquinone dyes, etc., and can be used alone or in combination.

[0080] The liquid crystal coating composition described above 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, and chloroform. Furthermore, the liquid crystal coating composition may also include a leveling agent, a polymerization initiator, etc., within a range that does not impede the polarization properties of the coated film.

[0081] Furthermore, the aforementioned polarizing plates (first polarizing plate 110-1, second polarizing plate 110-2) can be formed by including oriented components. For example, the oriented components can be formed by coating an oriented film coating composition containing an oriented polymer, a photopolymerization initiator, and a solvent onto a protective layer and then curing it. The liquid crystal coating composition is then coated onto the components and cured. The oriented polymer is not particularly limited; polyacrylate resins, polyamic acid resins, polyimide resins, polymers containing cinnamate groups, etc., can be used. Conventionally or subsequently developed polymers capable of exhibiting orientation can be used.

[0082] The polarizing plates (first polarizing plate 110-1, second polarizing plate 110-2) included in the above-mentioned dimming laminate may also include functional coatings such as an outer coating layer and / or an optical functional layer to improve the surface hardness of the polarizer and the polarizing plate. In one or more embodiments, it may further include one or more of the group consisting of a protective layer, a phase difference adjustment layer and / or a refractive index adjustment layer (not shown).

[0083] Specifically, in one embodiment, the polarizing plate may further include an outer coating layer as one of the functional coatings, for example, which may be located on the upper surface of the layer formed using the liquid crystal coating composition and thus disposed opposite to the oriented member. In some embodiments, a protective film may be further provided on the upper surface of the outer coating layer. In this case, the polarizing plate may include a laminated structure of an oriented member - a layer formed using the liquid crystal coating composition - an outer coating layer - a protective film, thereby further improving mechanical durability while maintaining a certain level of transmittance.

[0084] The aforementioned polarizing plates (first polarizing plate 110-1 and second polarizing plate 110-2) may include optical functional layers to improve the optical properties of the optical laminate. These optical functional layers may be disposed on at least one side of the protective layer, for example, on the upper surface of the protective layer. There are no particular limitations on the optical functional layers as long as they are used to enhance or supplement the optical function of the polarizing plates (first polarizing plate 110-1 and second polarizing plate 110-2). For example, they may be retardation films such as quarter-wave plates or half-wave plates to delay the phase of light passing through the liquid crystal layer; they may be used individually or in combination. These retardation films may be fabricated by including tilted stretching resin films, liquid crystal coatings, etc., and conventionally or future-developed retardation films may be used.

[0085] In one embodiment, the polarizing plates (first polarizing plate 110-1 and second polarizing plate 110-2) may have a thickness of 30 to 200 μm, preferably 30 to 170 μm, and more preferably 50 to 150 μm. In this case, it is possible to manufacture a thin dimming laminate that maintains the optical properties of the polarizing plates (first polarizing plate 110-1 and second polarizing plate 110-2).

[0086] The aforementioned polarizing plates (first polarizing plate 110-1, second polarizing plate 110-2) may include a curved shape to manufacture an optical laminate with a curved surface. For example, the curved shape may be formed toward either of the two polarizing plates (first polarizing plate 110-1, second polarizing plate 110-2) that are different from each other and are stacked on both sides of the liquid crystal layer 130.

[0087] The aforementioned refractive index adjustment layer (not shown) is provided to compensate for the transmittance difference in the dimming laminate caused by the transparent conductive layers (first transparent conductive layer 120-1 and second transparent conductive layer 120-2), and can improve visibility characteristics by reducing the refractive index difference. Furthermore, the aforementioned refractive index adjustment layer can be provided to correct the color caused by the transparent conductive layers (first transparent conductive layer 120-1 and second transparent conductive layer 120-2). On the other hand, when the transparent conductive layers (first transparent conductive layer 120-1 and second transparent conductive layer 120-2) have a pattern, the aforementioned refractive index adjustment layer can compensate for the transmittance difference between the patterned areas and the unpatterned areas.

[0088] Specifically, the aforementioned transparent conductive layers (first transparent conductive layer 120-1, second transparent conductive layer 120-2) are stacked adjacent to other components with different refractive indices (e.g., polarizing plates (first polarizing plate 110-1, second polarizing plate 110-2) etc.). Due to the difference in refractive index with the adjacent other layers, differences in light transmittance may be induced. Especially when the transparent conductive layers (first transparent conductive layer 120-1, second transparent conductive layer 120-2) are patterned, there may be a problem that the patterned areas and the non-patterned areas look different. Therefore, by positioning the refractive index adjustment layer between the polarizing plates (first polarizing plate 110-1, second polarizing plate 110-2) and the transparent conductive layers (first transparent conductive layer 120-1, second transparent conductive layer 120-2), the refractive index can be compensated, thereby reducing the difference in light transmittance of the optical laminate. Especially when the transparent conductive layers (first transparent conductive layer 120-1, second transparent conductive layer 120-2) are patterned, the patterned and unpatterned areas will not appear indistinguishable. The refractive index of the refractive index adjustment layer can be preset to be greater than the refractive index of the protective layer of the polarizing plates (first polarizing plate 110-1, second polarizing plate 110-2) and less than the refractive index of the transparent conductive layers (first transparent conductive layer 120-1, second transparent conductive layer 120-2). The aforementioned refractive index can be appropriately selected based on the materials of the polarizing plates (first polarizing plate 110-1, second polarizing plate 110-2) and the transparent conductive layers (first transparent conductive layer 120-1, second transparent conductive layer 120-2), preferably 1.4 to 2.6, and more preferably 1.4 to 2.4. Thus, by setting the refractive index adjustment layer to a predetermined refractive index, light loss caused by the significant refractive index difference between the polarizing plates (first polarizing plate 110-1, second polarizing plate 110-2) and the transparent conductive layers (first transparent conductive layer 120-1, second transparent conductive layer 120-2) can be prevented. The aforementioned refractive index adjusting layer is not particularly limited as long as it can prevent a significant difference in refractive index between the polarizing plate (first polarizing plate 110-1, second polarizing plate 110-2) and the transparent conductive layer (first transparent conductive layer 120-1, second transparent conductive layer 120-2). For example, it can be formed by a composition containing a polymeric isocyanurate compound.

[0089] The aforementioned transparent conductive layers (first transparent conductive layer 120-1, second transparent conductive layer 120-2) can be formed on one side of the aforementioned polarizing plate (first polarizing plate 110-1, second polarizing plate 110-2), preferably, they can be formed in direct contact with the aforementioned polarizing plate (first polarizing plate 110-1, second polarizing plate 110-2).

[0090] The aforementioned transparent conductive layers (first transparent conductive layer 120-1, second transparent conductive layer 120-2) are 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 can be formed in direct contact with the first polarizing plate 110-1 or the second polarizing plate 110-2. For example, as... Figure 1 As shown, the first transparent conductive layer 120-1 and the second transparent conductive layer 120-2 can each be formed by direct contact with the first polarizing plate 110-1 and the second polarizing plate 110-2.

[0091] Conventional dimming laminates used in manufacturing smart windows and the like are manufactured by forming a conductive layer for driving liquid crystals on one side of a substrate and then bonding the other side of the substrate to a polarizing plate. However, the dimming laminate of the present invention is characterized by forming a conductive layer directly on one side of the polarizing plate without including a separate substrate for forming the conductive layer, thereby reducing the thickness of the laminate and improving transmittance and bending characteristics in the light transmission mode.

[0092] "Formed in direct contact with the aforementioned polarizing plates (first polarizing plate 110-1, second polarizing plate 110-2)" means that the transparent conductive layer (first transparent conductive layer 120-1, second transparent conductive layer 120-2) shares a contact surface with the polarizing plates (first polarizing plate 110-1, second polarizing plate 110-2) and is disposed on the polarizing plates (first polarizing plate 110-1, second polarizing plate 110-2) without a separate substrate. For example, the transparent conductive layer (first transparent conductive layer 120-1, second transparent conductive layer 120-2) can be deposited on the upper surface of the protective layer formed on the aforementioned polarizing plates (first polarizing plate 110-1, second polarizing plate 110-2).

[0093] In one embodiment, the aforementioned transparent conductive layers (first transparent conductive layer 120-1, second transparent conductive layer 120-2) can be directly vapor-deposited onto one side of the aforementioned polarizing plates (first polarizing plate 110-1, second polarizing plate 110-2). In this case, to improve adhesion to the polarizing plates (first polarizing plate 110-1, second polarizing plate 110-2), pretreatment such as corona treatment or plasma treatment can be performed on one side of the polarizing plates before direct contact with the pretreated surface of the polarizing plates. The aforementioned pretreatment is not limited to corona treatment or plasma treatment; conventional or future pretreatment processes can be used without impairing the purpose of the present invention.

[0094] In another embodiment of the present invention, in order to improve the adhesion between the above-mentioned transparent conductive layer (first transparent conductive layer 120-1, second transparent conductive layer 120-2) and the polarizing plate (first polarizing plate 110-1, second polarizing plate 110-2), it can be formed by directly contacting the polarizing plate through an easy-to-adhere layer disposed on one side of the polarizing plate.

[0095] The transmittance of the aforementioned transparent conductive layer (first transparent conductive layer 120-1, second transparent conductive layer 120-2) relative to visible light is preferably 50% or more. For example, it may contain one or more materials selected from the group consisting of transparent conductive oxides, metals, carbon-based materials, conductive polymers, conductive inks, and nanowires, but is not limited thereto. Materials for transparent conductive layers developed in the past or in the future may be used.

[0096] In one or more embodiments, the aforementioned transparent conductive oxide may comprise one or more elements selected from the group consisting of indium tin oxide (ITO), indium zinc oxide (IZO), indium tin zinc oxide (IZTO), zinc aluminum oxide (AZO), zinc gallium oxide (GZO), fluorine tin oxide (FTO), and zinc oxide (ZnO). Furthermore, the aforementioned metal may comprise one or more elements 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 elements; for example, it may comprise a silver-palladium-copper (APC) alloy or a copper-calcium (CuCa) alloy. The aforementioned carbon-based material may comprise one or more elements selected from the group consisting of carbon nanotubes (CNTs) and graphene. The aforementioned conductive polymer may comprise one or more polymers selected from the group consisting of polythiophene, poly(3,4-ethylenedioxythiophene), polyaniline, polyacetylene, polydiacetylene, polyphenylene, polyphenylene ethylene, polyphenylene sulfide, polythiophene acetylene, polythiophene ethylene, polyfluorene, polypyrrole, poly(3,4-ethylenedioxythiophene):polystyrene sulfonate, poly(3,4-ethylenedioxythiophene):camphor sulfonic acid, poly(3,4-ethylenedioxythiophene):toluene sulfonic acid, poly(3,4-ethylenedioxythiophene):dodecylbenzene sulfonic acid, polyaniline:polystyrene sulfonate, polyaniline:camphor sulfonic acid, polypyrrole:polystyrene sulfonate, polypyrrole:camphor sulfonic acid, polypyrrole:toluene sulfonic acid, polypyrrole:dodecylbenzene sulfonic acid, polythiophene:polystyrene sulfonate, polythiophene:camphor sulfonic acid, polythiophene:toluene sulfonic acid, and polythiophene:dodecylbenzene sulfonic acid polymers. The aforementioned conductive ink can be an ink made by mixing metal powder and a curable polymer binder, and the nanowires can be, for example, silver nanowires (AgNW). In one embodiment of the present invention, the aforementioned transparent conductive layers (first transparent conductive layer 120-1, second transparent conductive layer 120-2) preferably contain conductive polymers such as polyethylene glycol thiophene (PEDOT).

[0097] The aforementioned transparent conductive layers (first transparent conductive layer 120-1 and second transparent conductive layer 120-2) can be formed, for example, by vapor deposition processes such as chemical vapor deposition (CVD), physical vapor deposition (PVD), and plasma-enhanced chemical vapor deposition (PECVD); printing processes such as screen printing, gravure printing, reverse offset printing, and inkjet printing; and dry or wet plating processes. Furthermore, the aforementioned transparent conductive layers (first transparent conductive layer 120-1 and second transparent conductive layer 120-2) can be formed from two or more layers by combining the aforementioned materials. For example, to reduce the reflectivity of incident light and increase the transmittance, a two-layer structure comprising a metal layer and a transparent conductive oxide layer can be formed.

[0098] In one embodiment, the surfaces of the first transparent conductive layer 120-1 and the second transparent conductive layer 120-2 that contact the liquid crystal layer 130 can be rubbing-oriented. The conductive polymer contained in the transparent conductive layers (first transparent conductive layer 120-1, second transparent conductive layer 120-2) of the present invention differs from that contained in transparent conductive layers containing metal components; it can form regular trenches on its surface, thereby aligning the liquid crystal compound within the liquid crystal layer to the desired position and orientation. In this case, the transparent conductive layers (first transparent conductive layer 120-1, second transparent conductive layer 120-2) can function as both electrodes for driving the liquid crystal layer and alignment films. Since they do not contain a separate alignment film, thinner dimming laminates can be manufactured, and the manufacturing process can be simplified.

[0099] In order to provide the above-mentioned rubbing-oriented transparent conductive layers (first transparent conductive layer 120-1, second transparent conductive layer 120-2), examples include the rubbing method using a rubbing process and the photoalignment method using ultraviolet light. Generally speaking, the photoalignment method has a weaker surface anchoring energy than the rubbing method. Therefore, the surfaces of the transparent conductive layers (first transparent conductive layer 120-1, second transparent conductive layer 120-2) of the present invention that are in contact with the liquid crystal layer 130 are preferably rubbing-oriented by the rubbing method.

[0100] The liquid crystal layer 130 is characterized by being driven by an electric field. The liquid crystal layer 130 can be located between the first polarizing plate 110-1 and the second polarizing plate 110-2 in the light control region of the dimming laminate 10. In one embodiment, the liquid crystal layer 130 can be located within the space provided in the light control region by the sealant 150 and spacers (not shown) between the first polarizing plate 110-1 and the second polarizing plate 110-2. Furthermore, the liquid crystal layer 130 can adjust the transmittance of light incident from an external light source based on the electric field formed between the first transparent conductive layer 120-1 and the second transparent conductive layer 120-2.

[0101] In one or more embodiments, the liquid crystal layer 130 can 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 lines switching (PLS), advanced high-performance IPS (AH-IPS), polymer sustained alignment (PSA), and vertical alignment (VA). The driving method of liquid crystals developed in the past or in the future can be applied.

[0102] In another embodiment of the present invention, the liquid crystal layer 130 may include one or more spacers selected from the group consisting of ballspacers and column spacers, with ballspacers being particularly preferred. There may be one or more ballspacers, preferably with a diameter of 1 to 10 μm. Furthermore, when viewed from a top-down direction, considering the improvement of user visibility and transmittance in the light transmission mode, the area occupied by the ballspacers in the liquid crystal layer 130 (i.e., the light-adjusting region) is preferably 0.01 to 10% of the area of ​​the liquid crystal layer 130.

[0103] The alignment film 140 described above has substantially the same properties as the components described in the above-described orientation-oriented components. There are no particular limitations as long as it is used to impart orientation to a liquid crystal compound; it is preferable that it may contain photo-oriented or photocurable polymers. For example, the alignment film 140 can be manufactured by coating an alignment film coating composition containing a photo-oriented or photocurable polymer, a photopolymerization initiator, and a solvent, and then curing it. For example, it can be formed by a rubbing process after coating with an alignment material such as polyimide.

[0104] The sealant 150 is designed to bond two different polarizing plates together, and can be located in a non-active region between the two different polarizing plates. Furthermore, the sealant 150, together with spacers, can ensure the space for the liquid crystal layer to be disposed between the two different polarizing plates.

[0105] The sealant 150 described above may contain a curable resin as a base resin. As the base resin, a UV-curable resin or a thermosetting resin known in the art for use in sealants may be used. The UV-curable resin may be a polymer of a UV-curable monomer. The thermosetting resin may be a polymer of a thermosetting monomer.

[0106] As the base resin for the above-mentioned sealant, for example, acrylate resins, epoxy resins, urethane resins, phenolic resins, or mixtures of the above resins can be used. In one embodiment, the base resin can be an acrylate resin, which can be a polymer of acrylic monomers. The acrylic monomers can be, for example, polyfunctional acrylates. In another embodiment, the sealant may also contain monomer components in the base resin. The monomer components can be, for example, monofunctional acrylates. In this specification, monofunctional acrylates can refer to compounds having one acryloyl group, and polyfunctional acrylates can refer to compounds having two or more acryloyl groups. The above-mentioned curable resin can be cured by irradiation with ultraviolet light and / or heating. The ultraviolet irradiation conditions or heating conditions can be appropriately implemented without prejudice to the purpose of this application. The sealant may also contain an initiator, such as a photoinitiator or a thermal initiator, as needed.

[0107] Regarding the steps for manufacturing the dimming laminate of the present invention, there is no particular limitation as long as the method used to realize the dimming laminate is applicable. For example, the transparent conductive layer (first transparent conductive layer 120-1, second transparent conductive layer 120-2) and the refractive index adjusting layer (not shown) can be deposited by vapor deposition methods commonly used in the art. For example, they can be coated using methods such as spin coating, roll coating, bar coating, dip coating, gravure coating, curtain coating, mold coating, spray coating, blade coating, kneading coating, etc., or printed using methods such as screen printing, spray printing, inkjet printing, letterpress printing, gravure printing, lithography, etc.; or formed using vacuum film formation methods such as sputtering.

[0108] The thickness of the dimming laminate of the present invention can be 0.300 mm to 0.450 mm. Generally, when the thickness of the dimming laminate meets the above range, the effect of pressure during glass bonding is more pronounced due to its thinness, often resulting in stains. However, the smart window manufactured by the manufacturing method of this application and using a dimming laminate containing the above thickness can significantly suppress liquid crystal stains. Preferably, the thickness of the dimming laminate of the present invention can be 0.32 to 0.40 mm. When the thickness of the dimming laminate meets the above range, the gap layer containing the polyvinyl butyral (PVB) film, described later, can be formed to be thicker than the thickness of the dimming laminate.

[0109] 100 membrane laminates

[0110] Figure 2 A simplified illustration shows a film laminate according to an embodiment of the present invention. (Refer to...) Figure 2 The film laminate 100 of the present invention includes a dimming laminate 10 and a surface protective layer 40 disposed on at least one of the upper and lower surfaces of the dimming laminate 10. Figure 2 From the perspective of minimizing the pressure on the liquid crystal layer, it is preferable to include a surface protective layer 40 on both the upper and lower surfaces of the dimming layer stack 10. Additionally, in one embodiment of the present invention, the film stack may also include a gap layer 50 at the ends of the dimming layer stack 10.

[0111] The content regarding the dimming laminate 10 described above can be directly applied to the previously described dimming laminate 10, therefore the description is omitted.

[0112] Surface protective layer 40

[0113] The aforementioned surface protective layer 40 improves defects caused by bonding pressure during the bonding process by providing a relatively thin surface protective layer on one or both sides of the POLCELL, and prevents liquid crystal shifting that may occur due to uneven pressure on the liquid crystal layer, thereby solving the problem of liquid crystal speckles. As an example, when one or more ultra-thin polyvinyl butyral (PVB) films are further included between the adhesive layer (contained in conventional methods for bonding the POLCELL to a substrate such as glass and / or preventing glass (substrate) scattering) and the POLCELL, damage to the POLCELL and / or the liquid crystal of the POLCELL caused by external physical pressure such as pressing can be more effectively prevented. This is a characteristic obtained by utilizing the characteristic that the polyvinyl butyral (PVB) film hardens by curing at a lower temperature, eliminating uneven shifting of the liquid crystal (liquid phase) to one side during bonding under pressure.

[0114] Therefore, in this invention, the surface protective layer 40 is a low-temperature curable polyvinyl butyral (PVB) film characterized by a thickness of 0.01 mm to 0.35 mm, which cures at a temperature below 90°C. Particularly preferably, it may comprise a 0.05 mm thick PVB film. The low-temperature curable PVB film cures at a low temperature below 90°C, preferably between 60°C and 90°C, thus offering the advantage of ensuring strong adhesion to the adhesive layer 20 used for bonding with the glass, especially minimizing pressure on the liquid crystal layer when applied to displays and / or display devices with thinner liquid crystals. Furthermore, due to its flexible properties at the substrate (glass) bonding temperature (60–90°C), it has the advantage of absorbing the pressure on the liquid crystal layer within the dimming laminate caused by bonding. If the bonding temperature is below 60℃, bonding may not be able to proceed smoothly; if it is above 90℃, the polarizing plate may suffer thermal damage.

[0115] The aforementioned surface protective layer may contain a tensile elastic modulus (E') of 10. 8 ~10 10 Pa and at 90℃ it can be 10 6 ~10 7 Pa, preferably 10 at 60°C. 9 Pa and 10 at 90℃ 6 Low-temperature curable polyvinyl butyral (PVB) films (Pa). Films meeting the above-mentioned tensile modulus (E') range have the advantage of more effectively reducing damage to the dimming laminate under high pressure.

[0116] The low-temperature curable polyvinyl butyral (PVB) film contained in the aforementioned surface protective layer exhibits no flowability below 100°C and under a 21.6 kg load, and its melt mass-flow rate (MFR) as determined according to ASTM D1238 at 140°C and a 2.16 kg load is below 0.02 g / 10 min. Melt flow rate is a standard physical property value determined by the mass of a thermoplastic material passing through a mold of specified size and characteristics at a specified temperature and under a predetermined load within 10 minutes, forming a benchmark for evaluating resin processability. Specifically, the melt flow rate measures the ease of melt flow of the thermoplastic polymer, also known as melt flow velocity or melt flow index (MFI). It is determined by standard experimental methods based on ASTM D1238 and / or ISO 1133, defined by the weight of resin flowing out in a molten state through an orifice within 10 minutes under standard-defined temperature and load conditions. Melt viscosity largely depends on molecular weight; therefore, higher molecular weight results in more entanglement and higher melt viscosity. At this point, the film contained in the surface protective layer is preferably made of a material that exhibits a melt flow rate (MFR) sufficient to facilitate film formation and is processable, while also possessing sufficient mechanical strength to be included in the final product.

[0117] The polyvinyl butyral (PVB) film included in the surface protective layer of the present invention has low-temperature curing properties, providing cross-linking reactivity even without high temperatures, and maintaining the transparency of the coating. Furthermore, since high temperatures are not used during curing, deformation of other laminated resins and other components can be prevented.

[0118] Table 1 below shows the melt flow rate (MFR) of a 0.05 mm thick polyvinyl butyral (PVB) film included in a surface protective layer of an embodiment of the present invention, as determined by ASTM D1238.

[0119] [Table 1]

[0120]

[0121] Referring to Table 1 above, in the case of polyvinyl butyral (PVB) film, flowability could not be confirmed under 100°C and a 21.6 kg load, but a melt flow rate of less than 0.02 g / 10 min was measured under 140°C and a 2.16 kg load. That is, the polyvinyl butyral (PVB) film included in one embodiment of the present invention exhibits curability at relatively low temperatures, and considering the requirement for excellent structural performance at high temperatures, it is preferable to laminate and include one or more films with a thickness of approximately 0.05 mm.

[0122] The aforementioned surface protective layer is characterized in that its overall area is larger than the area of ​​the dimming laminate that is in contact with the surface protective layer. From the perspective of forming the sealant 150, it is preferably larger than 100% of the area of ​​the dimming laminate, and more preferably 101 to 150% of the area of ​​the dimming laminate.

[0123] Interstitial layer 50

[0124] Reference Figure 5 The film laminate 100 of the present invention may further include a gap layer 50 at the end of the dimming laminate 10. The gap layer of the present invention may be laminated to be thicker than the dimming laminate described above.

[0125] In this invention, to ensure that the aforementioned gap layer is thicker than the dimming laminate, specifically, after confirming the overall thickness of the dimming laminate, a polyvinyl butyral (PVB) film (in a stacked form) thicker than that thickness can be stacked, thereby manufacturing via a pre-lamination-formal lamination step. In this invention, to minimize the pressure directly exerted on the liquid crystal layer within the dimming laminate, the gap layer is formed at the ends of the dimming laminate like a pillar, and to achieve this objective, it is characterized by being thicker than the dimming laminate. As an example, preferably, the thickness of the gap layer can be in the range of 101% to 120% of the dimming laminate thickness. When it exceeds this range, the gap layer may hinder the bonding between the dimming laminate, the surface protective layer, and the substrate, potentially resulting in black spots and manufacturing defects.

[0126] In one embodiment of the present invention, the energy storage modulus (G') of the aforementioned interstitial layer at 60°C can be 10. 3 ~10 6 The storage modulus (G') at 100℃ can be 5 × 10 kPa. 2 ~5×10 3kPa, but not limited to this. If the above-mentioned energy storage modulus is met, stress on the liquid crystal layer can be reduced during subsequent substrate bonding in the manufacture of smart windows, thereby reducing staining. Furthermore, since it also cures at low temperatures and acts as a support, it has advantages in minimizing the pressure on the dimming laminate. More specifically, even if the gap layer is designed to be thicker than the dimming laminate, if only a resin with rigid properties is used, defects may occur in the subsequent substrate bonding step. On the other hand, even if the gap layer is designed to be thicker than the dimming laminate, if only a resin with flexible properties is used, the gap layer may not be able to adequately relieve the pressure on the dimming laminate during the subsequent substrate bonding step. Therefore, the gap layer preferably meets the above-mentioned energy storage modulus range. If the thickness of the gap layer is also thicker than the thickness of the dimming laminate while meeting the above-mentioned energy storage modulus, it may include a low-temperature curing polyvinyl butyral (PVB) film. There is no limitation on the type of PVB film. Preferably, the low-temperature curing polyvinyl butyral (PVB) film included in the above-mentioned surface protective layer 40 can be directly applied.

[0127] The aforementioned low-temperature curable polyvinyl butyral (PVB) film can be cured at temperatures below 90°C, but is not limited to this. As an example, it may contain two or more low-temperature curable PVB films, and these films can be cured at temperatures below 90°C, but are not limited to this. If a low-temperature curable PVB film is included, it will have a flexible characteristic at the substrate (glass) bonding temperature (60–90°C), as described later, thus having the advantage of absorbing the pressure on the liquid crystal layer within the dimming laminate due to bonding. Bonding will not proceed smoothly at bonding temperatures below 60°C, and thermal damage to the polarizing plate may occur if the temperature is above 90°C.

[0128] The membrane laminate of the present invention can be constructed by comprising two or more layers of the above-mentioned low-temperature curing polyvinyl butyral (PVB) membrane to form an interstitial layer. The energy storage modulus that can absorb pressure can be satisfied by adjusting the type and thickness of the above-mentioned polyvinyl butyral (PVB) membrane and adjusting the number of layers to be laminated.

[0129] Preferably, in one embodiment of the present invention, the gap layer may be a multilayer comprising two or more films. In one example of the present invention, the gap layer may comprise a multilayer polyvinyl butyral (PVB) film. Preferably, if the gap layer is formed as a multilayer comprising two or more films, it has the advantage of easily forming a thick gap layer, thereby reducing damage to the dimming laminate by replacing the pressure subjected to the dimming laminate. Specifically, polyvinyl butyral (PVB) film is an elastic material, and when applied to a dimming laminate used to manufacture a smart window, the dimming laminate containing the liquid crystal layer may be damaged due to the temperature and pressure applied during the bonding process, which may result in defects such as liquid crystal shift and speckles. Therefore, in the film laminate of the present invention, a gap layer thicker than that of the dimming laminate is formed. In order to form a gap layer thicker than that of the dimming laminate and to appropriately alleviate the pressure generated during bonding, it is not enough to use only the 0.38 mm polyvinyl butyral (PVB) film that is usually used alone in the past. Therefore, 0.05 mm polyvinyl butyral (PVB) films (thin films) can be laminated into multiple layers.

[0130] More preferably, the polyvinyl butyral (PVB) film included in the aforementioned interstitial layer may contain a tensile modulus (E') of 10 at 60°C. 8 ~10 10 Pa and 10 at 90℃ 6 ~10 7 The membrane characterized by Pa, preferably, may contain a polyvinyl butyral (PVB) membrane that satisfies the above-mentioned tensile modulus of elasticity (E'). In this case, a gap layer thicker than the dimming laminate can be formed by containing a polyvinyl butyral (PVB) membrane with high hardness, thus having the advantage of reducing damage to the dimming laminate caused by high pressure. In addition, it can impart impact resistance to the smart window subsequently manufactured by laminating substrates. According to an embodiment of the invention, particularly preferably, considering the excellent processability and strength of the polyvinyl butyral (PVB) membrane with surface protective layer 40, as described above, only 2 to 8 0.05 mm polyvinyl butyral (PVB) membranes (thin films) can be laminated to form a gap layer thicker than the dimming laminate and having an ideal energy storage modulus.

[0131] For example, in this invention, the aforementioned gap layer may further comprise a 0.38 mm thick polyvinyl butyral (PVB) film with a thermal conductivity of 0.2 W / mK. When a PVB film satisfying the aforementioned thermal conductivity is included, bonding can be smoother because a gap layer comprising a flexible PVB film and thicker than the dimming laminate can be formed. Specifically, regarding the storage modulus of the aforementioned gap layer, if the gap layer is too rigid, it will not be sufficiently pressed during subsequent bonding of the dimming laminate to the surface protective layer and / or substrate, potentially leading to problems with substantial bonding difficulties. According to one embodiment of the invention, when the thickness of the dimming laminate is 0.39 mm, by simultaneously laminating a 0.38 mm thick PVB film satisfying the aforementioned thermal conductivity onto a 0.05 mm thick PVB film satisfying the aforementioned tensile modulus, a gap layer thicker than the dimming laminate and possessing an excellent storage modulus can be formed. The thermal conductivity values ​​mentioned above were collected and measured using a thermal constants analyzer at 23°C and 50°C via the transient planar source (TPS) method.

[0132] On the other hand, in this invention, the aforementioned interstitial layer may further comprise a 0.38 mm thick polyvinyl butyral (PVB) film with a specific heat of 1.9–2.3 kJ / (kg·K). The specific heat was measured using a differential scanning calorimeter (DSC).

[0133] Furthermore, the aforementioned 0.38 mm thick polyvinyl butyral (PVB) film with a thermal conductivity of 0.2 W / mK and / or a specific heat of 1.9–2.3 kJ / (kg·K) allows for the transmission of visible light of 88.8% or more, and more preferably, ultraviolet transmittance of 0.6% or less. When these conditions are met, the polyvinyl butyral (PVB) film incorporated in the smart window can block ultraviolet rays, thereby improving the quality of the smart window.

[0134] The gap layer is formed by stacking layers in a stacked manner, without distinguishing individual stacking positions or order.

[0135] Smart Window 1000

[0136] This invention includes a smart window manufactured comprising the aforementioned dimming laminate and / or film laminate. Furthermore, this invention can relate to vehicles incorporating the aforementioned smart window, for example, automobiles in which the aforementioned smart window is applied to at least one of the following: front window, rear window, side window, sunroof, and interior partition; and can include wearable devices and architectural windows incorporating the aforementioned smart window.

[0137] Figure 3 and Figure 5 This is a diagram illustrating a smart window manufactured using a method for manufacturing a smart window according to an embodiment of the present invention. (Refer to...) Figure 5 The smart window 1000 can be a laminate in which an adhesive layer 20 and a substrate 30 are disposed on both sides of a film laminate 100 including a dimming laminate 10, a gap layer 50, and a surface protective layer 40. The smart window of this application may include an adhesive layer having properties that minimize the pressure on the liquid crystal layer contained in the dimming laminate during bonding, thereby suppressing the phenomenon of liquid crystal speckles that are not visible before glass bonding due to liquid crystal shift occurring during the bonding process of the glass and the film laminate.

[0138] Figure 3 The illustration shows a smart window according to an embodiment of the present invention. (Refer to...) Figure 3 The smart window 1000 may include a substrate 30 on at least one of the upper and lower surfaces of the film laminate 100 (including 10, 40 and 50) by an adhesive layer 20. Additionally, it may further include an adhesive layer (not shown), a transparent film (not shown), and / or an adhesive layer (not shown), etc.

[0139] For example, a car incorporating the smart window of the present invention can be made by bonding a substrate (glass) to both sides of a dimming laminate comprising a polarizing plate, a transparent conductive layer, a liquid crystal layer and an adhesive / bonding layer. For example, the adhesive layer and the substrate (glass) can be placed on both sides of the dimming laminate and then heated for 10 to 20 minutes using a press machine. The adhesive film may include EVA film, PVB film, etc., but is not limited thereto.

[0140] Adhesive layers 20-1, 20-2

[0141] The adhesive layers 20-1 and 20-2 described above can be manufactured using adhesives or bonding agents, preferably possessing appropriate adhesive / bonding strength to prevent peeling, bubbles, etc., during the processing of the dimming laminate, while also exhibiting transparency and thermal stability. The adhesive layers can utilize conventionally or subsequently developed adhesive films. Considering stability (glass scattering, penetration), the adhesive layers preferably contain a low-temperature curing polyvinyl butyral (PVB) film. When a low-temperature curing PVB film is included, it retains its flexibility even at low temperatures, thus absorbing pressure on the film laminate, and achieving the target initial adhesive strength even after curing at low temperatures. As an example, the adhesive layers 20-1 and 20-2 can use the same PVB film as those contained in the surface protective layer and interlayer in the film laminate.

[0142] In addition, the above-mentioned adhesives can be selected from light-curing adhesives or thermosetting adhesives and binders.

[0143] The aforementioned photocurable adhesives exhibit strong adhesive strength by being irradiated by active energy rays such as ultraviolet (UV) and electron beam (EB) and undergoing cross-linking and curing. They can be composed of reactive oligomers, reactive monomers, photopolymerization initiators, etc.

[0144] The aforementioned reactive oligomers are important components that determine the properties of adhesives. They form a cured film by forming polymer bonds through photopolymerization. Examples of usable reactive oligomers include polyester resins, polyether resins, polyurethane resins, epoxy resins, polyacrylic resins, and silicone resins.

[0145] The aforementioned reactive monomers act as crosslinking agents and diluents for the aforementioned reactive oligomers, affecting their adhesive properties. Examples of usable reactive monomers include monofunctional monomers, polyfunctional monomers, epoxy monomers, vinyl ethers, and cyclic ethers.

[0146] The aforementioned photopolymerization initiators absorb light energy to generate free radicals or cations, thereby initiating photopolymerization. A suitable photopolymerization initiator can be selected based on the photopolymerization resin.

[0147] The adhesives described above can be conventionally or subsequently developed adhesives. In one or more embodiments, acrylic adhesives, rubber adhesives, silicone adhesives, urethane adhesives, polyvinyl alcohol adhesives, polyvinylpyrrolidone adhesives, polyacrylamide adhesives, cellulose adhesives, vinyl alkyl ether adhesives, etc., can be used. There are no particular limitations on the adhesives as long as they possess adhesive strength and viscoelasticity; however, considering ease of acquisition, acrylic adhesives are preferred. For example, they may contain (meth)acrylate copolymers, crosslinking agents, and solvents.

[0148] The crosslinking agent mentioned above can be any crosslinking agent that has been developed in the past or in the future, for example, it can include polyisocyanate compounds, epoxy resins, melamine resins, urea resins, dialdehydes, hydroxymethyl polymers, etc., and preferably it can include polyisocyanate compounds.

[0149] The solvents mentioned above may include common solvents used in the field of resin compositions, such as alcohol compounds such as methanol, ethanol, isopropanol, butanol, and propylene glycol methoxyl; ketone compounds such as methyl ethyl ketone, methyl butyl ketone, methyl isobutyl ketone, diethyl ketone, and dipropyl ketone; acetate compounds such as methyl acetate, ethyl acetate, butyl acetate, and propylene glycol methoxyacetate; cellosolve compounds such as methyl cellosolve, ethyl cellosolve, and propyl cellosolve; and hydrocarbon compounds such as hexane, heptane, benzene, toluene, and xylene. These solvents may be used alone or in combination of two or more.

[0150] The adhesive layers 20-1 and 20-2 may include hot-melt adhesives such as EVA (ethylene vinyl acetate) film and PVB (polyvinyl butyral) film used for double-sided bonding of vehicle glass, and preferably include low-temperature curing PVB (polyvinyl butyral) film contained in the above-mentioned surface protective layer and / or gap layer.

[0151] The thickness of the adhesive layers 20-1 and 20-2 can be appropriately determined based on the type of resin acting as the adhesive, the adhesive strength, and the environment in which the adhesive is used. In one embodiment, to ensure sufficient adhesion between the surface protective layer 40 and the substrate 30 or between the dimming laminate 10 and the substrate 30 and to minimize the thickness of the smart window, the thickness of the adhesive layers 20-1 and 20-2 can be 0.01 to 1.5 mm, preferably 0.05 to 1.2 mm, and more preferably 0.1 to 1 mm. When using a PVB (polyvinyl butyral) film, the thickness of the PVB film can be varied 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.

[0152] In one embodiment, the adhesive layer 20 can be formed on one side of the substrate (glass) by lamination.

[0153] Substrate 30

[0154] The aforementioned substrate 30 can generally be one or more selected from transparent glass plates and / or polymer films that do not obstruct optical properties. Examples include polyethylene terephthalate, cyclic olefin polymers, polyethylene naphthalate, polyethersulfone, polycarbonate, cellulose acetate, polymethyl methacrylate, colorless polyimide, glass, ceramics, etc., with glass being the most preferred.

[0155] Examples of the aforementioned glass sheets include inorganic glass and plexiglass. Examples of inorganic glass include float glass, heat-absorbing glass, heat-reflective glass, polished glass, patterned glass, mesh glass, wire-embedded glass, and ordinary glass. Plexiglass is a synthetic resin glass used in place of inorganic glass. Examples of plexiglass include polycarbonate sheets and poly(meth)acrylic resin sheets made from synthetic resins. Examples of poly(meth)acrylic resin sheets include polymethyl methacrylate sheets.

[0156] The aforementioned substrate includes not only glass with an intermediate film sandwiched between two glass plates, but also glass with an intermediate film sandwiched between a glass plate and a PET film, etc., and can be a glass-resin composite.

[0157] The thickness of the substrate is not particularly limited, but is preferably 1.6 mm or more and 2.1 mm or less.

[0158] The light-switching laminate can be manufactured by placing an adhesive film and automotive glass on both sides of the laminate using a press machine, or by coating resin on one side of the automotive glass, vacuum-bonding the automotive glass to both sides of the laminate, and then UV curing. The resin may contain a storage modulus (G') of 10. 3 ~10 5Pa's OCR, OCA resin, etc. The aforementioned adhesive film may include hot-melt adhesives such as EVA (ethylene vinyl acetate) film and PVB (polyvinyl butyral) film. The material of the adhesive layer 20 can be directly applied, i.e., materials selected from photocurable adhesives, thermosetting adhesives, and adhesives; therefore, description is omitted. Preferably, from a process perspective, a low-temperature curing adhesive can be used.

[0159] In addition, building windows can be bonded to one or both sides of the above-mentioned film laminate, or window glass can be bonded to one side of the film laminate by lamination to manufacture smart window products. Alternatively, window glass can be bonded to both sides of the film laminate after applying UV adhesive, and then UV cured to manufacture smart window products.

[0160] Manufacturing method of smart windows

[0161] Figure 4 This is a process diagram illustrating a method for manufacturing a smart window according to an embodiment of the present invention. Figure 5 The structure of a smart window according to an embodiment of the present invention is illustrated in a simplified diagram.

[0162] This invention relates to a method for manufacturing a smart window designed to prevent streaks from appearing. Specifically, these streaks are caused by the dimming laminate, and more specifically, they can be caused by the pressing of the liquid crystal layer contained in the dimming laminate during the bonding process of the glass and the laminate in the manufacturing process of the smart window. Such streaks are more likely to appear, especially when the dimming laminate is thinner, which can lead to a fatal problem that degrades the quality of the display. To this end, the present invention provides a manufacturing method that can effectively manufacture a superior smart window even in cases where, for example, a dimming laminate is manufactured where liquid crystal streaks are more likely to appear due to glass bonding pressure, such as when a substrate is not included between the polarizer and the conductive layer and they are directly in contact.

[0163] Reference Figure 4 and Figure 5An embodiment of the present invention provides a method for manufacturing a smart window, comprising: a step of laminating a film laminate, an adhesive layer, and a substrate (glass) (S101); a step of pre-bonding the film laminate, adhesive layer, and substrate (S102); and a step of formally bonding the pre-bonded laminate (S103). In one example of the present invention, the formal bonding step (S103) includes at least two steps, including: a) maintaining the laminate in a chamber at 3.5 to 10 bar for 15 to 60 minutes (S103-1); and b) after step a), reducing the pressure to 1 to 3 bar and maintaining the laminate for 70 to 100 minutes (S103-2). Alternatively, the method for manufacturing a smart window of the present invention may also include a step of manufacturing a film laminate containing a dimming laminate (S100) before the step of laminating the film laminate, adhesive layer, and substrate (S101).

[0164] <Step of manufacturing a film laminate containing a dimming laminate (S100)>

[0165] This invention may include the step of manufacturing a film laminate comprising a dimming laminate. The film laminate 100 manufactured by the above-described S100 step may refer to the dimming laminate 10 itself, or it may refer to a dimming laminate 10 further comprising a spacer layer 50 and / or a surface protective layer 40. For example, as... Figure 5 As shown, the film laminate 100 of the present invention can refer to a laminate containing a dimming laminate 10, a gap layer 50 and a surface protective layer 40, which laminates adhesive layers 20-1, 20-2 and a substrate 30.

[0166] As an example of the present invention, refer to Figure 5 This can be a form in which gap layers 50 are included at both ends of the dimming laminate 10 as supports, and a surface protective layer 40 is also included on one side of the dimming laminate 10. This is a film laminate in which the surface protective layers 40 are arranged opposite each other at a certain interval by gap layers 50 formed around the outer periphery of the dimming laminate 10, and the dimming laminate is sealed within the space formed by the surface protective layers 40 and the gap layers 50. The surface protective layers 40 and the dimming laminate 10 may or may not be in contact depending on the thickness of the gap layers 50.

[0167] In this invention, the step of manufacturing the film laminate may include the step of manufacturing the dimming laminate and / or the step of laminating a gap layer at the end of the dimming laminate.

[0168] <Layering Steps (S101)>

[0169] A method for manufacturing a smart window according to an embodiment of the present invention includes the step of preparing a film laminate 100 and laminating adhesive layers 20-1, 20-2 and a substrate 30 on one or both sides thereof (S101).

[0170] In one embodiment, the adhesive layers 20-1 and 20-2 can be formed on one side of the surface protective layer 40 or on one side of the dimming laminate 10 by lamination.

[0171] In the lamination process, a fixing step may be included before the pre-lamination step. To facilitate pre-lamination and final lamination while the film laminate, adhesive layer, and glass are stacked, the edges are fixed using tape or similar materials. This can be achieved using conventional or future methods, such as inserting a loop that can wrap around the entire side and fixing it with adhesive tape. In this step, a method of fixing the laminates using an ultrasonic welding machine may be used, or alternatively, a method may be employed to ensure a tight, crack-free lamination between the laminates during the lamination process.

[0172] Furthermore, the lamination process can include a subsequent vacuum suction step. A vacuum suction process can be implemented to ensure stable bonding between the film laminate and the glass. This process creates a near-vacuum state between the film laminate and the glass, preventing air from entering between them and causing air bubbles after bonding, or optical distortion after completion. This can be achieved using vacuum rubber bags, or other methods that have been previously used or will be developed in the future.

[0173] <Pre-bonding step (S102)>

[0174] The pre-lamination step (S102) is a step in which the edges of each layer of the film laminate are melted and bonded by temperature and vacuum pressure. It is a step in which glass and polyvinyl butyral (PVB) film and / or dimming laminate are bonded to each other.

[0175] The pre-bonding step of the present invention is performed at 0.1 to 1 bar and may include: S1) heating to 40 to 90°C; S2) maintaining the temperature of S1); and S3) cooling to 0 to 30°C.

[0176] Specifically, more preferably, it may include: a step of heating to 50-70°C under a pressure of 0.1-1 bar (S1); a step of maintaining the temperature at 50-70°C (S2); and a step of cooling to 10-20°C (S3).

[0177] <Formal bonding steps (S103)>

[0178] The formal bonding step (S103) is a step of further pressing down any air bubbles generated between the laminates bonded in the pre-bonding step (S102) and bonding them together. In the manufacturing method of smart windows, the method of glass bonding is one of the important factors determining the quality of the smart window. When bonding the glass to the aforementioned film laminate, a suitable bonding method for the internal components needs to be considered. In particular, when using conventional methods for laminates containing thin dimming laminates, not only may streaks appear due to liquid crystal layer misalignment, but also fogging may occur due to optical distortion. If the bonding pressure is simply reduced to prevent this, poor bonding will occur.

[0179] Therefore, the present invention provides a method for manufacturing a smart window that includes at least two or more steps in the formal bonding process.

[0180] In embodiments of the present invention, since the formal bonding is performed in two or more steps, the bonding can be gradually implemented by changing the pressure, thereby stabilizing the pressure unevenness generated during the bonding process. Specifically, preferably, when the formal bonding includes the following steps a) and b), the displacement of the liquid crystal layer contained in the film stack can be prevented, resulting in a smart window with superior manufacturing quality. In particular, the present application is characterized in that after performing a formal bonding at 3.5 to 10 bar in step a), a second formal bonding is performed by reducing the pressure to 1 to 3 bar in step b), thereby suppressing liquid crystal displacement. Compared with conventional formal bonding methods that are prone to liquid crystal displacement due to a single step performed with high pressure, the present application can reduce liquid crystal displacement through a second bonding with reduced pressure in step b). On the other hand, if only low pressure is used for formal bonding from the beginning, it may not be possible to form a sufficient bond, and it may be difficult to remove air bubbles. Therefore, it may be more appropriate to perform bonding with high pressure at the beginning and then reduce it to low pressure at the end.

[0181] a) Maintain in a chamber of 3.5–10 bar for 15–60 minutes (S103-1)

[0182] In step a), the temperature is adjusted in an autoclave, and pressure is applied using a compressor, thereby completing the bonding process through heating and pressurization. Specifically, it is preferable to perform the bonding at 50–110°C, and more preferably at 80–100°C. Furthermore, for formal bonding steps a) that consist of two or more steps, it is preferable to maintain the bonding process within the above temperature range for 20–40 minutes in a chamber at 3.5–6 bar. Specifically, if the temperature is raised to the conventional bonding temperature of 140°C, the dimming laminate may not be able to withstand the pressure, and discoloration of the dimming laminate may occur. Therefore, unlike general glass bonding, it is preferable to perform the bonding process within the above temperature range. Additionally, since the dimming laminate is manufactured by including liquid crystal injected into it, it is highly sensitive to pressure. If compressed air with a pressure outside the above range is used, liquid crystal shift may occur due to uneven pressure during bonding.

[0183] b) Step a) after which the pressure is reduced to 1-3 bar and maintained for 70-100 minutes (S103-2)

[0184] Following step a) above, in step b), bonding is gradually performed by changing the pressure, thereby ensuring that the liquid crystal contained in the film laminate is not subjected to uneven pressure. Specifically, it is preferable to perform the bonding at 50–110°C, and more preferably at 80–100°C. Furthermore, it is even more preferable to reduce the pressure to the range of 1–2 bar and maintain this pressure for 80–100 minutes. If high pressure was applied in step a) to remove air bubbles, then step b) is a step of reducing the pressure to a low level to correct pressure unevenness, thus having the effect of stabilizing the liquid crystal shift that occurred in step a) under relatively high pressure during step b).

[0185] That is, the formal bonding in this application involves a) initially applying high pressure followed by b) applying low pressure for an extended period to reduce liquid crystal shift, thereby ensuring uniform distribution of the liquid crystal contained in the dimming laminate and inducing stable bonding of the substrate. In other words, unlike the formal bonding of conventional technologies, this two-step formal bonding process enables the manufacture of smart windows with high reliability and a significantly reduced liquid crystal spot defect rate.

[0186] The following experimental examples, including specific embodiments and comparative examples, are provided to aid in understanding the present invention. However, these are merely illustrative and do not limit the scope of the appended claims. It will be apparent to those skilled in the art that various changes and modifications can be made to the embodiments within the scope and technical concept of the present invention, and such changes and modifications also fall within the scope of the appended claims. Unless otherwise specified, "%" and "parts" in the examples refer to "% by mass" and "parts by mass," respectively.

[0187] Manufacturing Example 1: Steps for manufacturing a film laminate containing a dimming laminate

[0188] A 60μm thick polyvinyl alcohol film (raw material film) (manufactured by Kuraray Co., Ltd., trade name "Kuraraypoval film VF-PE#6000", average degree of polymerization 2400, degree of saponification 99.9 mol%) is continuously unwound from the raw material roll and immersed in a swelling bath containing pure water at 20°C for 30 seconds. In this swelling process, inter-roll stretching (longitudinal uniaxial stretching) is performed by creating a circumferential speed difference between the pinch rolls. The stretching ratio based on the raw material film is 2.5 times. Then, a polarizing plate is manufactured according to conventional technology, undergoing dyeing, crosslinking, color correction, cleaning, drying, and lamination processes.

[0189] On one side of each of the first and second polarizing plates manufactured above, by adjusting the type and solid content of the Mayer bar and calculating the thickness of the hard coating after curing, a hard coating forming composition was prepared by mixing 16.2g of dendritic macromolecular compound (Miyuan Special Chemicals, SP-1106), 14.4g of inorganic nanoparticles (10-20nm, silica particles: 50% by weight, solvent: methyl ethyl ketone (MEK)), 1.8g of a polyfunctional (meth)acrylate compound containing ethylene glycol groups, 0.7g of photoinitiator (1-hydroxycyclohexylphenyl ketone), and 2.9g of methyl ethyl ketone. After drying at 80°C for 5 minutes, the mixture was subjected to high pressure mercury lamp treatment at 500mJ / cm². 2 Light curing.

[0190] A PEDOT composition is coated onto the first and second polarizing plates manufactured above, and dried at 90°C for about 5 to 10 minutes to form a transparent conductive layer with a thickness of 200 nm. This creates a laminate containing a first and second transparent conductive layer formed of a conductive polymer (PEDOT) on one side of each polarizing plate. The PEDOT composition is manufactured by mixing coating solution 1 and coating solution 2 in a 1:1 ratio. Coating solution 1 uses a mixture of 60 to 65% by weight of a composite of 2,3-dihydrothiophene[3,4-b]-1,4-dioxin homopolymer and vinylbenzenesulfonic acid homopolymer (aqueous), 15 to 20% by weight of ethanol, and 20 to 25% by weight of deionized water relative to the total weight of the coating solution. Coating solution 2 uses a mixture of 0.5 to 1.0% by weight of polyester resin (25% solids, aqueous), 65 to 75% by weight of ethanol, and 20 to 25% by weight of deionized water relative to the total weight of the coating solution.

[0191] An alignment liquid is applied to the surface of the first and second transparent conductive layers of each polarizing plate and dried (80°C / 2 minutes). Then, UV light is irradiated onto the dried alignment liquid to produce the first and second alignment films.

[0192] On the first transparent conductive layer, a sealant applicator (SHOTmini 200Ωχ, Musashi Corporation) was used to apply sealant (UVF-006, 70,000 mPa·s, Sekisui Corporation) according to the product dimension drawing and using a pointed needle (SPN-0.25-12.7L) at a discharge pressure of 200 mPa. Liquid crystal was then injected onto the first alignment film using an ODF process. Then, with the polarization axes of the first and second polarizing plates arranged parallel to each other at 0° or 90°, a sealant was applied at a pressure of 3 kg / cm². 2 Pressure is applied to bond the dimming laminate together, followed by UV curing along the sealant line (500 mJ / cm). 2 This process is used to manufacture an optical laminate for smart windows. Then, a conductive copper strip (TERAOKA, No. 8323) is bonded to the first and second transparent conductive layers to connect them.

[0193] Manufacturing Example 2: Fabrication of Surface Protective Layer

[0194] The method for laminating and forming the surface protective layer involves cutting a 0.05 mm thick low-temperature curable polyvinyl butyral (PVB) film (thin film, with a tensile modulus of elasticity of 1.9 × 10⁻⁶ at 60°C) in a manner that can surround the entire glass (substrate). 9 Pa, tensile modulus at 90℃ is 4×10 Pa. 6 The surface protective layer was prepared according to the melt flow rate (MFR) measured by ASTM D1238 being less than 0.02 g / 10 min at 140 °C. The thickness and number of layers of the surface protective layer for each example, comparative example, and reference example are shown in Table 2 below.

[0195] Manufacturing Example 3: Fabrication of the Gap Layer

[0196] Regarding the method of laminating and forming the gap layer, a 0.38 mm low-temperature curing polyvinyl butyral (PVB) film (0.38 mm, with a visible light transmittance (Tv) of ≥88.8% and an ultraviolet light transmittance (Tuv) of ≤0.6% based on ISO 9050, and a thermal conductivity of 0.2 W / mK at 23–50 °C) and / or a 0.05 mm low-temperature curing polyvinyl butyral (PVB) film (with a tensile modulus of elasticity of 1.9 × 10⁻⁶ at 60 °C) is further laminated. 9 Pa, tensile modulus at 90℃ is 4×10 Pa. 6The interstitial layer is formed to a thickness greater than that of the dimming laminate, wherein the melt flow rate (MFR) measured according to ASTM D1238 is less than 0.02 g / 10 min at 140°C. The interstitial layer is cut and stacked in a manner that allows it to surround the entire glass (substrate) except for the dimensions of the dimming laminate. The thickness and number of interstitial layers in each embodiment, comparative example, and reference example are shown in Table 2 below.

[0197] Manufacturing Example 4: Lamination Steps

[0198] The first substrate (glass), the second adhesive layer, the laminate, the first adhesive layer, and the first substrate (glass) are sequentially stacked together by comprising the laminate manufactured according to Manufacturing Examples 1 to 3 described above. The first adhesive layer and the second adhesive layer are made of a 0.38 mm thick low-temperature curing polyvinyl butyral (PVB) film (with a visible light transmittance (Tv) of 88.8% or more, an ultraviolet light transmittance (Tuv) of 0.6% or less according to ISO 9050, a thermal conductivity of 0.2 W / mK at 23 to 50°C, and a specific heat capacity of 1.9 KJ / Kg·K at 20°C and 2.3 KJ / Kg·K at 100°C). The first substrate and the second substrate are made of 2.1 T soda-lime glass.

[0199] Manufacturing Example 5: Pre-lamination Step

[0200] The laminated samples were placed in a reusable vacuum rubber bag (OBRJ-S) for pre-bonding. In Example 1, the pre-bonding step involved placing the laminated smart window into the vacuum rubber bag, then heating it from 20°C to 65°C over 15 minutes at a pressure of 0.9 bar, maintaining the temperature at 65°C for 30 minutes, and finally cooling it from 65°C to 20°C over 15 minutes. Furthermore, the pressure, temperature, and time conditions for the pre-bonding steps in each example, comparative example, and reference example are shown in Table 2 below.

[0201] Manufacturing Example 6: Formal Bonding Steps

[0202] After pre-bonding, formal bonding (autoclave) is performed. In Example 1, the pressure is raised to 90°C at 5 bar and treated for 30 minutes using an autoclave, then the pressure is reduced to 1.5 bar while maintaining the temperature and treated for 90 minutes before formal bonding is performed. The pressure, temperature, and time conditions for the formal bonding steps of each example, comparative example, and reference example are shown in Table 2 below.

[0203] Examples and Comparative Examples

[0204] Referring to manufacturing examples 1 to 6 above, the smart window of the present invention is manufactured according to the following Table 2.

[0205] [Table 2]

[0206]

[0207]

[0208] The patterns (liquid crystal unevenness: a general term for the state of uneven image characteristics and patterns on a liquid crystal panel) of the smart window manufactured according to Table 2 above were observed on the backlight (light source) using a general digital camera, and the evaluation results are shown in Table 3 and Figures 6 to 8 below. Figures 6a to 6f These are photographs of the appearance evaluation results of the bonding articles of Embodiments 1 to 6 of the present invention, observed on a backlight (light source) using a digital camera. Figures 7a-7b These are photographs of the appearance evaluation results of the bonding articles of Comparative Examples 1 to 2 of the present invention, observed on a backlight panel (light source) using a digital camera. Figures 8a to 8d These are photographs of the appearance evaluation results of the bonding articles of Reference Examples 1 to 4 of the present invention, observed on a backlight panel (light source) using a digital camera.

[0209] [Table 3]

[0210]

[0211] Referring to Tables 2 and 3 above, it can be seen that when manufacturing a smart window using the manufacturing method of the present invention, liquid crystal patterns (unevenness) do not appear even after the glass (substrate) is bonded, and no defective products that cannot be started due to black spots are produced.

Claims

1. A membrane laminate, characterized in that, Include: dimming laminate; as well as A surface protective layer laminated on at least one of the upper and lower surfaces of the dimming laminate. The surface protective layer is a low-temperature curable polyvinyl butyral (PVB) film that is cured at a temperature below 90°C, with a thickness of 0.01 mm to 0.35 mm, and its overall area is larger than the area of ​​the dimming laminate that is in contact with the surface protective layer.

2. The film laminate according to claim 1, characterized in that, The surface protective layer has no fluidity below 100°C and under a load of 21.6 kg, and its melt flow rate (MFR) is below 0.02 g / 10 min as determined by ASTM D1238 at 140°C and a load of 2.16 kg.

3. The film laminate according to claim 1, wherein the surface protective layer comprises a tensile elastic modulus E' of 10 at 60°C. 8 ~10 10 Pa and 10 at 90℃ 6 ~10 7 Pa membrane.

4. The film laminate according to any one of claims 1 to 3, wherein the dimming laminate comprises: First polarizing plate; A first transparent conductive layer is formed on the inner surface of the first polarizing plate; The second polarizing plate is opposite to the first polarizing plate; A second transparent conductive layer is formed on the inner side of the second polarizing plate and is opposite to the first transparent conductive layer; A liquid crystal layer is disposed between the first transparent conductive layer and the second transparent conductive layer; and An alignment film is formed between the transparent conductive layer and the liquid crystal layer.

5. The film stack according to 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. The film laminate according to claim 4, wherein at least one of the first and second transparent conductive layers comprises a transparent conductive layer selected from polythiophene, poly(3,4-ethylenedioxythiophene), polyaniline, polyacetylene, polydiacetylene, polyphenylene, polyphenylene ethylene, polyphenylene sulfide, polythiophene acetylene, polythiophene ethylene, polyfluorene, polypyrrole, poly(3,4-ethylenedioxythiophene):polystyrene sulfonate, poly(3,4-ethylenedioxythiophene):camphor sulfonic acid ... The conductive polymer is one or more of the following groups: 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 polymers.

7. The film stack according to claim 4, wherein at least one of the first polarizing plate and the second polarizing plate further comprises one or more of the group consisting of a protective layer, a phase difference adjustment layer and a refractive index adjustment layer.

8. The film laminate according to any one of claims 1 to 3, wherein the film laminate includes a gap layer containing a polyvinyl butyral (PVB) film at the end of the dimming laminate.

9. The film laminate according to claim 8, characterized in that, The energy storage modulus G' of the interstitial layer at 60°C is 10. 3 ~10 6 The storage modulus G' at 100℃ is 5×10 kPa. 2 ~5×10 3 kPa.

10. The membrane stack according to claim 8, wherein the interstitial layer comprises two or more layers of polyvinyl butyral (PVB) membrane.

11. The membrane stack according to claim 8, wherein the interstitial layer comprises a tensile elastic modulus E' of 10 at 60°C. 8 ~10 10 Pa and 10 at 90℃ 6 ~10 7 Pa membrane.

12. A smart window, comprising: The film laminate according to any one of claims 1 to 11; Adhesive layer; and The substrate is bonded to at least one of the upper and lower surfaces of the film laminate via the adhesive layer.

13. A method for manufacturing a smart window, which is the method for manufacturing a smart window according to claim 12, comprising: The step of laminating a film laminate containing a dimming laminate, an adhesive layer and a substrate; Pre-lamination steps; as well as Formal fitting steps, The formal bonding step includes: a) The procedure of maintaining the chamber in 3.5–10 bar for 15–60 minutes; as well as b) Following step a), reduce the pressure to the range of 1 to 3 bar and maintain it for 70 to 100 minutes.

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