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

Abstract

The present invention provides a film laminate, a smart window including the same, and a method for manufacturing the same, the film laminate comprising a light-dimming laminate and a gap layer comprising a polyvinyl butyral (PVB) film at an end portion of the light-dimming laminate, the thickness of the gap layer being thicker than the thickness of the light-dimming laminate, and the thickness of the gap layer being smaller than the thickness of the light-dimming laminate. A structure for minimizing the pressure applied to a liquid crystal layer when glass is bonded is provided by including a gap layer as a pillar thicker than the light-dimming laminate at an end portion of the light-dimming laminate, thereby preventing liquid crystal speckles without causing displacement due to liquid crystal fluidity.

Description

TECHNICAL FIELD

[0001] The present application relates to a film laminate and a smart window comprising the same, a manufacturing method thereof. BACKGROUND

[0002] Generally, a glass window of a mobile tool such as a vehicle is often applied with an external light blocking coating. However, the transmittance of a conventional glass window of a mobile tool is fixed, and the transmittance of the external light blocking coating is also fixed. Therefore, since the overall transmittance of such a conventional window of a mobile tool is fixed, it can cause an accident. For example, if the overall transmittance is set to be low, there is no problem in a day when ambient light is sufficient, but in a situation such as night when ambient light is insufficient, there is a problem that a driver or the like can not properly view the surrounding situation of the mobile tool. In addition, if the overall transmittance is set to be high, there is a problem that a driver or the like can be dazzled in a day when ambient light is sufficient. For this reason, a transmittance-variable optical laminate that can change the transmittance of light when a voltage is applied has been developed.

[0003] The above-described transmittance-variable optical laminate is driven in a manner that the transmittance is variable by driving liquid crystals by applying a voltage, and the transmittance-variable optical laminate developed so far is manufactured by forming a conductive layer for liquid crystal driving on a separate substrate and combining it with other elements such as a polarizing plate.

[0004] For example, Japanese Laid-Open Patent No. 2018-010035 discloses a transmittance-variable optical laminate comprising a transparent conductive layer formed on a polycarbonate (PC) substrate or the like having a predetermined thickness. For such a transmittance-variable smart window, it is necessary to include a liquid crystal layer to achieve the variable function, and finally to go through a process of being attached to glass. However, in the case of applying the conventional technology, it is presumed that in the process of attaching glass in the manufacturing process, the liquid crystal layer included in the light control laminate is pressed and the liquid crystal has fluidity, and thus is shifted, and thus there is a problem that a liquid crystal mottle that is not visible before glass attachment appears in the finally manufactured smart window. As the light control laminate becomes thinner, it is more likely that a liquid crystal mottle appears due to glass attachment pressure, particularly in the case of a light control laminate including a structure in which a polarizing plate and a conductive layer are in direct contact without including a substrate therebetween. Therefore, as a matter of fact, it is necessary to develop a transmittance-variable optical laminate having a structure that can minimize the pressure received by the liquid crystal layer and that does not appear a liquid crystal mottle after glass attachment by an attachment method that can eliminate uneven pressure.

[0005] PRIOR ART DOCUMENTS

[0006] PATENT DOCUMENTS

[0007] Patent Document 1: Japanese Laid-Open Patent No. 2018-010035 SUMMARY

[0008] PROBLEMS TO BE SOLVED BY THE INVENTION

[0009] To solve the above problems, the present invention aims to provide a film laminate which minimizes the pressure received by the liquid crystal layer inside the light control laminate by including a gap layer at the end of the light control laminate, thereby not causing liquid crystal mura even after glass bonding and being excellent in quality and appearance.

[0010] In addition, the present invention aims to provide a film laminate which can suppress the liquid crystal mura that can occur in a display by providing the optimal properties and structure suitable for the gap layer, and particularly, the liquid crystal mura that is more likely to occur in a light control laminate manufactured without including a substrate between a polarizing plate and a conductive layer in which they are directly in contact.

[0011] In addition, the present invention aims to provide a film laminate which further includes a surface protection layer having optimal properties and structure to protect the liquid crystal layer.

[0012] In addition, the present invention aims to provide a film laminate which includes a light control laminate manufactured without including a separate substrate for forming a conductive layer, thereby significantly reducing the thickness compared to the conventional light control laminate.

[0013] In addition, the present invention aims to provide a manufacturing method of a smart window in which the formal bonding of bonding glass with the above film laminate includes two or more steps to minimize the pressure received by the liquid crystal layer.

[0014] In addition, the present invention aims to provide a smart window including the above film laminate and a vehicle, a wearable device, or a building window to which the smart window is applied.

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

[0016] METHOD FOR SOLVING THE PROBLEMS

[0017] The present invention relates to a film laminate characterized by including a light control laminate and a gap layer including a polyvinyl butyral (PVB) film at the end of the above light control laminate, the thickness of the above gap layer being thicker than that of the light control laminate.

[0018] In the present invention, the above gap layer is characterized in that the storage modulus (G') at 60°C can be 10 3 ~ 10 6 kPa, and the storage modulus (G') at 100°C can be 5 x 10 2~ 5 x 10 3 kPa.

[0019] In the present invention, the light control laminate can have a thickness of 0.32 to 0.40 mm, and the gap layer can have a thickness of 101 to 120% of the thickness of the light control laminate.

[0020] In the present invention, the light control laminate can include a first polarizing plate, a first transparent conductive layer formed on an inner side of the first polarizing plate, a second polarizing plate opposite the first polarizing plate, a second transparent conductive layer formed on an inner side of the second polarizing plate and opposite the first transparent conductive layer, a liquid crystal layer disposed between the first and second transparent conductive layers, and an alignment film formed between the transparent conductive layer and the liquid crystal layer.

[0021] In the present invention, the gap layer can include two or more polyvinyl butyral (PVB) films.

[0022] In the present invention, the gap layer can include a film having a tensile elastic modulus (E') of 10 8 ~ 10 10 Pa at 60°C and 10 6 ~ 10 7 Pa at 90°C.

[0023] In the present invention, a surface protection layer can be included on at least one of the upper and lower surfaces of the light control laminate, and the surface protection layer can be a low-temperature curable polyvinyl butyral (PVB) film cured at a temperature of 90°C or less, having a tensile elastic modulus (E') of 10 8 ~ 10 10 Pa at 60°C and 10 6 ~ 10 7 Pa at 90°C.

[0024] In the present invention, the surface protection layer can be characterized in that it has no flowability at 100°C or less under a load of 21.6 kg, and a melt flow rate (MFR) measured according to ASTM D1238 at 140°C under a load of 2.16 kg can be 0.02 g / 10 min or less.

[0025] In addition, the present invention relates to a smart window including the film laminate, an adhesive layer, and a substrate attached to at least one of the upper and lower surfaces of the film laminate via the adhesive layer.

[0026] In addition, the present invention relates to a method of manufacturing a smart window, which includes a preliminary attachment step and a formal attachment step as a method of manufacturing the smart window, and the formal attachment step includes two or more processes.

[0027] In the present invention, the above formal lamination step can include: a) a step of maintaining at 3.5 to 10 bars for 15 to 60 minutes; and b) a step of reducing the pressure to 1 to 3 bars and maintaining for 70 to 100 minutes after the above a) step.

[0028] Inventive Effects

[0029] According to the film laminate of the present invention, since the gap layer thicker than the thickness of the light control laminate and comprising a polyvinyl butyral (PVB) film is included at the end of the light control laminate, the pressure applied to the liquid crystal layer is minimized without causing the shift of the liquid crystal at the time of glass lamination, and thus a film laminate preventing the liquid crystal mura and having excellent appearance can be manufactured.

[0030] In addition, according to the film laminate of the present invention, since the surface protective layer having optimal physical properties and structure is further included to protect the liquid crystal layer, a film laminate significantly suppressing the liquid crystal mura that can occur at the time of glass lamination can be manufactured.

[0031] In addition, according to the film laminate of the present invention, since the film laminate is manufactured by the manufacturing method of the smart window including two or more steps of formal lamination for stabilizing the unevenness of the pressure applied to the liquid crystal layer by laminating the glass with the above film laminate, the occurrence of the liquid crystal mura can be significantly reduced compared to the conventional film laminate.

[0032] In addition, according to the film laminate of the present invention, since the light control laminate manufactured without including a separate substrate for forming the conductive layer is included, the thickness can be significantly reduced compared to the conventional film laminate.

[0033] By applying the film laminate of the present invention, a smart window in which the liquid crystal mura does not occur, and a vehicle, a wearable device, or a building window to which the smart window is applied can be provided. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 The structure of the film laminate of one embodiment of the present invention is simply illustrated.

[0035] Figure 2 The structure of the smart window of one embodiment of the present invention is simply illustrated.

[0036] Figure 3 The structure of the light control laminate of one embodiment of the present invention is simply illustrated.

[0037] Figures 4a to 4f It is a photograph of the appearance evaluation results after observing the laminated articles of Embodiments 1 to 6 of the present invention on a backlight (light source) by a general digital camera, respectively.

[0038] Figures 5a to 5care photographs of the appearance evaluation results after observing the adhered articles of Comparative Examples 1 to 3 of the present application on a backlight (light source) respectively by a general digital camera.

[0039] Figures 6a to 6c are photographs of the appearance evaluation results after observing the adhered articles of Reference Examples 1 to 3 of the present application on a backlight (light source) respectively by a general digital camera.

[0040] Explanation of symbols

[0041] 1000: smart window,

[0042] 100: film laminate,

[0043] 10: light control laminate,

[0044] 11: first polarizing plate,

[0045] 12: second polarizing plate,

[0046] 21: first transparent conductive layer,

[0047] 22: second transparent conductive layer,

[0048] 31: first orientation film,

[0049] 32: second orientation film,

[0050] 40: liquid crystal layer,

[0051] 50: sealant,

[0052] 120-1: first adhesive layer

[0053] 120-2: second adhesive layer,

[0054] 130-1, 130-2: substrate,

[0055] 140-1: first surface protection layer,

[0056] 140-2: second surface protection layer,

[0057] 150: gap layer. DETAILED DESCRIPTION

[0058] The present invention relates to a film laminate and a smart window comprising the same, a method for manufacturing the same, the film laminate being characterized by comprising a light adjusting laminate and a gap layer comprising a polyvinyl butyral (PVB) film at the end of the light adjusting laminate, the thickness of the gap layer being thicker than that of the light adjusting laminate, and a structure minimizing the pressure received by the liquid crystal layer when the glass is attached is formed due to the gap layer thicker than the light adjusting laminate like a pillar at the end of the light adjusting laminate, so that the shift caused by the fluidity of the liquid crystal does not occur, and the liquid crystal mottle can be prevented even in the case of manufacturing the smart window by attaching the film laminate to the glass. At this time, the storage modulus (G') of the gap layer at 60°C can be 10 3 ~ 10 6 kPa, and the storage modulus (G') at 100°C can be 5 x 10 2 ~ 5 x 10 3 kPa, and in the case of satisfying the above storage modulus range, it is sufficiently hard to withstand the pressure generated when attached to the glass, and thus is preferred. However, if it is too hard, the surface attachment of the light adjusting laminate is not easy due to no elasticity, and if it is too soft, the liquid crystal shift can occur due to the pressure, and thus it is more preferred to satisfy the above optimal range.

[0059] The light adjusting laminate 10 of the present invention is particularly suitable for the technical field capable of changing the light transmittance according to the application of voltage, for example, can be used for a smart window.

[0060] The so-called smart window refers to a window changing the light transmittance according to the application of electric signal to thereby control the amount of light or heat passing therethrough. That is, the smart window can be changed into a transparent, opaque or translucent state according to the voltage, and is also called a variable transmittance glass, a light adjusting glass or a smart glass, etc.

[0061] The smart window can be used as a partition for dividing the interior space of a vehicle or a building or a partition for privacy protection, or as a lighting window disposed at the opening portion of a building, and can be used as a highway sign, a billboard, a score board, a clock or an advertisement screen, and can be used instead of the glass of a transportation means such as a window or a sunroof of a car, a bus, an airplane, a ship or a train.

[0062] The light control laminate of the present application can also be used as a smart window in each of the technical fields described above, but since the transparent conductive layers (first transparent conductive layer 21, second transparent conductive layer 22) are formed directly on the polarizing plates (first polarizing plate 11, second polarizing plate 12) without including a separate substrate for forming the transparent conductive layers, the thickness is thin and the bending properties are favorable, and thus the light control laminate of the present application can be particularly suitable for use in a smart window for a vehicle or a building. In one or more embodiments, the smart window using the transmittance variable optical laminate of the present application can be used for a front window, a rear window, a side window, and a sunroof of an automobile, or a window for a building, and can be used for internal space division or privacy protection in addition to an external light blocking purpose, such as an internal partition in an automobile or a building, and can also be used for wearable devices such as a helmet, glasses, or a watch.

[0063] Hereinafter, embodiments of the present application will be described more specifically with reference to the accompanying drawings. However, the following drawings accompanying the present specification are merely illustrative of preferred embodiments of the present application, and serve to further understand the above summary of the application together with the technical idea of the present application, and thus the present application should not be construed as being limited only to the matters described in these drawings.

[0064] The terms used in the present specification are intended to describe the embodiments, and are not intended to limit the present application. In the present specification, the singular form also includes the plural form unless the context clearly dictates otherwise. For example, the "polarizing plate" used in the present specification can refer to at least one of the first polarizing plate and the second polarizing plate, and the "transparent conductive layer" can refer to at least one of the first transparent conductive layer and the second transparent conductive layer.

[0065] The terms "comprises" and / or "comprising", as used in the present specification, are used in the sense of "including, but not limited to", and thus are not intended to exclude other constituents, steps, operations, and / or elements not recited. Throughout the specification, the same reference numerals refer to the same constituent elements.

[0066] As illustrated in the drawings, spatially relative terms "below", "bottom", "lower", "above", "upper", "top", and the like can be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the drawings. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientations depicted in the drawings. For example, in the case of the device being turned over, the element or feature described as being "below" or "lower" another element or feature would be oriented "above" or "upper" the other element or feature. Thus, the exemplary term "below" can encompass both an orientation of below and above. The device can be otherwise oriented (e.g., rotated 90 degrees or at other orientations) and the spatially relative terms used herein interpreted accordingly.

[0067] The "upward direction" used in the present specification can be interpreted as a direction orthogonal to the polarizing plate and / or the transparent conductive layer, i.e., a direction viewed from the visible side of the user.

[0068] The "substantially" used in the present specification can be interpreted not only as physically exactly the same or identical, but also as including within an error range in a measurement or manufacturing process, for example, can be interpreted as within an error range of 0.1% or less.

[0069] Light control laminate 10

[0070] Figure 3 The structure of the light control laminate 10 of one embodiment of the present application is illustrated. Referring to Figure 3 In one embodiment of the present application, the light control laminate 10 can include a first polarizing plate 11, a first transparent conductive layer 21 formed on the inner side of the first polarizing plate, a second polarizing plate 12 opposite to the first polarizing plate 11, a second transparent conductive layer 22 formed on the inner side of the second polarizing plate 12 and opposite to the first transparent conductive layer 21, a liquid crystal layer 40 disposed between the first transparent conductive layer 21 and the second transparent conductive layer 22, and an alignment film (a first alignment film 31, a second alignment film 32) formed between the transparent conductive layers (the first transparent conductive layer 21, the second transparent conductive layer 22) and the liquid crystal layer 40. In addition, the light control laminate can further include one or more selected from the group consisting of an adhesive layer, a bonding layer, an ultraviolet absorbing layer, and / or a hard coat layer (not illustrated). In addition, a sealant 50 can be further included at the end of the liquid crystal layer to secure a space in which the liquid crystal layer is disposed.

[0071] The light control laminate 10 of one embodiment of the present application includes a polarizing plate (first polarizing plate 11, second polarizing plate 12), a transparent conductive layer (first transparent conductive layer 21, second transparent conductive layer 22), and a liquid crystal layer 40. The light control laminate 10 of one embodiment of the present application can be a transmittance variable optical laminate, and the total light transmittance thereof can be changed with voltage application. For example, the total light transmittance of the light control laminate 10 can be 0.1 to 45 % with voltage application.

[0072] Preferably, the thickness of the light control laminate of the present application can be 0.32 to 0.40 mm. In the case where the thickness of the light control laminate satisfies the above range, a gap layer thicker than the thickness of the light control laminate can be formed.

[0073] The polarizing plate (first polarizing plate 11, second polarizing plate 12) can include a polarizer and a protective layer formed on at least one side of the polarizer, and two polarizing plates (first polarizing plate 11, second polarizing plate 12) different from each other can be provided on both sides of the liquid crystal layer 40. In the case where the polarizing plate (first polarizing plate 11, second polarizing plate 12) is provided on both sides of the liquid crystal layer 40, the angle formed by the absorption axes of the two polarizing plates different from each other can be perpendicular or horizontal, and alternatively, in order to ensure the minimum transmittance, the angle can be preferably 5 to 85°. The polarizing plate can transmit light radiated in all directions in one direction, and the amount of light transmitted can be adjusted using the polarizing property of the polarizing plate, so that the transmittance of the optical laminate can be adjusted. The protective layer can be a member for protecting the polarizing property of the polarizer from the influence of subsequent processes and external environments. In one embodiment, the protective layer can be designed to function as a structure base on which the transparent conductive layer (first transparent conductive layer 21, second transparent conductive layer 22) described later can be formed, and in this case, the protective layer preferably has a property that the transparent conductive layer can be easily formed.

[0074] The protective layer can be provided on only one side of the polarizer or on both sides of the polarizer. In the case where the polarizing plate (first polarizing plate 11, second polarizing plate 12) includes a plurality of protective layers, the two protective layers different from each other can include substantially the same or similar substances. In one or more embodiments, the protective layer can include a polyester-based resin such as polyethylene terephthalate, polyethylene isophthalate, polyethylene naphthalate, polybutylene terephthalate, a cellulose-based resin such as diacetyl cellulose and triacetyl cellulose, a polycarbonate-based resin, a polyethylene resin, a polypropylene resin, an acrylic-based resin such as polymethyl (meth) acrylate and polyethyl (meth) acrylate, and a cyclic olefin-based polymer (COP).

[0075] The polarizer of the above-described polarizing plate (first polarizing plate 11, second polarizing plate 12) can include a stretched polarizer or be provided as a stretched polarizing plate. In one embodiment, the above-described stretched polarizer can include a stretched polyvinyl alcohol (PVA)-based resin. The above-described polyvinyl alcohol (PVA)-based resin can be a polyvinyl alcohol-based resin obtained by saponification of a polyvinyl acetate-based resin. As the polyvinyl acetate-based resin, in addition to a homopolymer polyvinyl acetate of vinyl acetate, a copolymer of vinyl acetate and another monomer copolymerizable therewith, or the like can be cited. As the above-described other monomer, an unsaturated carboxylic acid-based monomer, an unsaturated sulfonic acid-based monomer, an olefin-based monomer, a vinyl ether-based monomer, an acrylamide-based monomer having an ammonium group, or the like can be cited. In addition, the polyvinyl alcohol (PVA)-based resin, as a modified substance, can also be a polyvinyl formal or a polyvinyl acetal modified by an aldehyde.

[0076] In addition, the above-described polarizing plate (first polarizing plate 11, second polarizing plate 12) can include a coated polarizer. In one embodiment, the above-described coated polarizer can be formed using a liquid crystal coating composition, for example, can be formed by coating the liquid crystal coating composition on the upper surface of the protective layer. At this time, the above-described liquid crystal coating composition can include a reactive liquid crystal compound and a dichroic dye.

[0077] The above-described reactive liquid crystal compound can include a reactive mesogen (RM) capable of exhibiting liquid crystal properties and / or a monomer molecule including a polymerizable terminal functional group and having a liquid crystal phase after a cross-linking reaction by heat or light. When the above-described reactive liquid crystal compound is polymerized by means of light or heat, a polymer network can be formed while maintaining the liquid crystal arrangement. By using the above-described reactive liquid crystal compound, a thin film-shaped polarizer maintaining the optical anisotropy or dielectric constant properties of liquid crystals and having improved mechanical and thermal stability can be formed.

[0078] The above-described dichroic dye is a component added to the liquid crystal coating composition to impart polarizing properties, and has a property in which the absorbance in the long axis direction of the molecule is different from the absorbance in the short axis direction. The above-described dichroic dye can use a dichroic dye developed in the past or in the future, for example, can include an acridine dye, an oxazine dye, a cyanine dye, a naphthalene dye, an azo dye, an anthraquinone dye, or the like, and can be used alone or in combination.

[0079] The above-described liquid crystal coating composition can further include a solvent capable of dissolving the above-described reactive liquid crystal compound and the above-described dichroic dye, for example, propylene glycol monomethyl ether acetate (PGMEA), methyl ethyl ketone (MEK), xylene, chloroform, or the like can be used. In addition, the above-described liquid crystal coating composition can further include a leveling agent, a polymerization initiator, or the like within a range that does not hinder the polarizing properties of the coated film.

[0080] In addition, the polarizing plates (first polarizing plate 11, second polarizing plate 12) described above can be formed to include a member having orientation properties, for example, by coating an orientation film coating composition including an orientation polymer, a photopolymerization initiator, and a solvent on a protective layer and curing, and then coating the liquid crystal coating composition on the member and curing to produce. The orientation polymer is not particularly limited, and a polyacrylate resin, a polyamide acid resin, a polyimide resin, a polymer containing a cinnamate group, or the like can be used, and a polymer capable of exhibiting orientation properties developed in the past or in the future can be used.

[0081] The polarizing plates (first polarizing plate 11, second polarizing plate 12) included in the light control laminate can further include a functional coating layer such as an overcoat layer and / or an optical functional layer to improve the surface hardness of the polarizer and the polarizing plate, and in one or more embodiments, can further include one or more selected from the group consisting of a protective layer, a phase difference adjusting layer, and / or a refractive index adjusting layer (not shown).

[0082] Specifically, in one embodiment, the polarizing plate described above can further include an overcoat layer as one of the functional coating layers, for example, can be disposed on the upper surface of the layer formed using the liquid crystal coating composition so as to be disposed opposite the member having orientation properties. In some embodiments, a protective film can be further disposed on the upper surface of the overcoat layer. In this case, the polarizing plate can include a laminated structure of the member having orientation properties - the layer formed of the liquid crystal coating composition - the overcoat layer - the protective film, and thus, it is possible to further improve the mechanical durability while maintaining the transmittance at a certain level.

[0083] The polarizing plates (first polarizing plate 11, second polarizing plate 12) described above can include an optical functional layer to improve the optical properties of the optical laminate. The optical functional layer described above can be disposed on at least one side of the protective layer, for example, can be disposed on the upper surface of the protective layer. The optical functional layer described above is not particularly limited as long as it is used to enhance or supplement the optical function of the polarizing plate (first polarizing plate 11, second polarizing plate 12), for example, can be a phase difference film such as a quarter wave plate (1 / 4 wave plate), a half wave plate (1 / 2 wave plate), or the like to delay the phase of light passing through the liquid crystal layer, and they can be used alone or in combination. The phase difference film described above can be produced by including a tilted stretched resin film, a liquid crystal coating layer, or the like, and a phase difference film developed in the past or in the future can be used.

[0084] In one embodiment, the above-described polarizing plates (first polarizing plate 11, second polarizing plate 12) can have a thickness of 30 to 200 μm, preferably 30 to 170 μm, and more preferably 50 to 150 μm. In this case, a light control laminate having a thin thickness while maintaining the optical characteristics of the above-described polarizing plates (first polarizing plate 11, second polarizing plate 12) can be manufactured.

[0085] The above-described polarizing plates (first polarizing plate 11, second polarizing plate 12) can include a curved shape to manufacture an optical laminate having a curved surface, for example, a curved shape can be formed toward either of the two polarizing plates (first polarizing plate 11, second polarizing plate 12) that are laminated on both sides of the liquid crystal layer 40 and are different from each other.

[0086] The above-described refractive index adjusting layer (not shown) is provided to compensate for the transmittance difference of the light control laminate caused by the transparent conductive layers (first transparent conductive layer 21, second transparent conductive layer 22) described below, and can function to improve the visible characteristics and the like by reducing the refractive index difference. In addition, the above-described refractive index adjusting layer can be provided to correct the color caused by the transparent conductive layers (first transparent conductive layer 21, second transparent conductive layer 22) described below. On the other hand, in the case where the transparent conductive layers (first transparent conductive layer 21, second transparent conductive layer 22) described below have a pattern, the transmittance difference between the patterned pattern region and the non-patterned non-pattern region can be compensated for by the above-described refractive index adjusting layer.

[0087] In particular, the transparent conductive layers (first transparent conductive layer 21, second transparent conductive layer 22) are laminated adjacent to other members (such as a polarizer or the like) having different refractive indexes, and due to the difference in refractive index with the adjacent other layer, a difference in light transmittance can be induced, and in particular, in the case where the transparent conductive layer is formed with a pattern, a problem can occur in which the pattern region and the non-pattern region appear to be different. Therefore, by including the above-mentioned refractive index adjusting layer, the refractive index can be compensated to reduce the difference in light transmittance of the light control laminate, and in particular, in the case where the transparent conductive layer is formed with a pattern, the pattern region and the non-pattern region do not appear to be different. The refractive index of the above-mentioned refractive index adjusting layer can be set in advance to be greater than the refractive index of the protective layer of the polarizing plate (first polarizing plate 11, second polarizing plate 12) and be equal to or less than the refractive index of the transparent conductive layer (first transparent conductive layer 21, second transparent conductive layer 22). The above-mentioned refractive index can be appropriately selected depending on the materials of the polarizing plate (first polarizing plate 11, second polarizing plate 12) and the transparent conductive layer (first transparent conductive layer 21, second transparent conductive layer 22), and can be preferably 1.4 to 2.6, and more preferably 1.4 to 2.4. In this way, by setting the above-mentioned refractive index adjusting layer to a predetermined refractive index, light loss due to a significant difference in refractive index between the above-mentioned polarizing plate (first polarizing plate 11, second polarizing plate 12) and the above-mentioned transparent conductive layer (first transparent conductive layer 21, second transparent conductive layer 22) can be prevented. The above-mentioned refractive index adjusting layer is not particularly limited as long as it can prevent a significant difference in refractive index between the polarizing plate and the transparent conductive layer.

[0088] The above-mentioned transparent conductive layer (first transparent conductive layer 21, second transparent conductive layer 22) can be formed on one side of the above-mentioned polarizing plate (first polarizing plate 11, second polarizing plate 12), and preferably can be formed in direct contact with the above-mentioned polarizing plate (first polarizing plate 11, second polarizing plate 12).

[0089] The above-mentioned transparent conductive layer (first transparent conductive layer 21, second transparent conductive layer 22) is provided for the driving of the liquid crystal layer 40, and in one embodiment, at least one of the first transparent conductive layer 21 and the second transparent conductive layer 22 can be formed in direct contact with the first polarizing plate 11 or the second polarizing plate 12. For example, as shown in FIG. 1, the first transparent conductive layer 21 and the second transparent conductive layer 22 can each be formed in direct contact with the first polarizing plate 11 and the second polarizing plate 12. Figure 1

[0090] ​A light control laminate for manufacturing a smart window or the like in the past is manufactured by forming a conductive layer for liquid crystal driving on one surface of a substrate and adhering the other surface of the substrate to a polarizing plate. However, the light control laminate of the present application is characterized in that a conductive layer is formed directly on one surface of a polarizing plate without including a separate substrate for forming the conductive layer, thereby reducing the thickness of the laminate and improving the transmittance in a light transmission mode and the bending property.

[0091] Direct contact formation with the above-described polarizing plate (first polarizing plate 11, second polarizing plate 12) means that the transparent conductive layer (first transparent conductive layer 21, second transparent conductive layer 22) is provided on the polarizing plate with a common contact surface without a separate substrate. For example, the transparent conductive layer (first transparent conductive layer 21, second transparent conductive layer 22) can be formed by evaporation on the upper surface of a protective layer formed on the above-described polarizing plate (first polarizing plate 11, second polarizing plate 12).

[0092] In one embodiment, the above-described transparent conductive layer (first transparent conductive layer 21, second transparent conductive layer 22) is formed by direct evaporation on one surface of the above-described polarizing plate (first polarizing plate 11, second polarizing plate 12). At this time, in order to improve the adhesion of the above-described transparent conductive layer (first transparent conductive layer 21, second transparent conductive layer 22) to the polarizing plate (first polarizing plate 11, second polarizing plate 12), a pretreatment such as corona treatment or plasma treatment can be performed on one surface of the polarizing plate (first polarizing plate 11, second polarizing plate 12) and then formed in direct contact with the surface of the above-described polarizing plate (first polarizing plate 11, second polarizing plate 12) on which the pretreatment is performed. The above-described pretreatment is not limited to corona treatment or plasma treatment, and a pretreatment process developed in the past or hereafter can be used without impairing the object of the present application.

[0093] In another embodiment of the present application, in order to improve the adhesion of the above-described transparent conductive layer to the polarizing plate, direct contact formation with the polarizing plate can be performed through an easy-adhesion layer provided on one surface of the polarizing plate.

[0094] The transmittance of the above-described transparent conductive layer (first transparent conductive layer 21, second transparent conductive layer 22) with respect to visible light is preferably 50% or more, and for example, can include one or more selected from the group consisting of transparent conductive oxides, metals, carbon-based substances, conductive polymers, conductive inks, and nanowires, but is not limited thereto, and a material for a transparent conductive layer developed in the past or hereafter can be used.

[0095] In one or more embodiments, the transparent conductive oxide can include one or more selected from the group consisting of indium tin oxide (ITO), indium zinc oxide (IZO), indium tin zinc oxide (IZTO), aluminum zinc oxide (AZO), gallium zinc oxide (GZO), fluorine tin oxide (FTO), and zinc oxide (ZnO). In addition, the metal can include one or more selected from the group consisting of gold (Au), silver (Ag), copper (Cu), aluminum (Al), platinum (Pt), palladium (Pd), chromium (Cr), titanium (Ti), tungsten (W), niobium (Nb), tantalum (Ta), vanadium (V), iron (Fe), manganese (Mn), cobalt (Co), nickel (Ni), zinc (Zn), and an alloy containing at least one of them, for example, can include a silver-palladium-copper (APC) alloy or a copper-calcium (CuCa) alloy. The carbon-based substance can include one or more selected from the group consisting of carbon nanotubes (CNTs) and graphene, and the conductive polymer can include one or more selected from the group consisting of polythiophene, poly(3,4-ethylenedioxythiophene), polyaniline, polyacetylene, polydiacetylene, polyphenylene, polyphenylene vinylene, polyphenylene sulfide, polythienylene vinylene, polythiophene vinylene, polyfluorene, polypyrrole, poly(3,4-ethylenedioxythiophene):polystyrene sulfonate, poly(3,4-ethylenedioxythiophene):camphor sulfonic acid, poly(3,4-ethylenedioxythiophene):toluene sulfonic acid, poly(3,4-ethylenedioxythiophene):dodecylbenzenesulfonic acid, polyaniline:polystyrene sulfonate, polyaniline:camphor sulfonic acid, polypyrrole:polystyrene sulfonate, polypyrrole:camphor sulfonic acid, polypyrrole:toluene sulfonic acid, polypyrrole:dodecylbenzenesulfonic acid, polythiophene:polystyrene sulfonate, polythiophene:camphor sulfonic acid, polythiophene:toluene sulfonic acid, and polythiophene:dodecylbenzenesulfonic acid. The conductive ink can be an ink in which metal powder and a curable polymer binder are mixed, and the nanowire can be, for example, a silver nanowire (AgNW). In one embodiment of the present application, the transparent conductive layer preferably includes a conductive polymer such as polyethylenedioxythiophene (PEDOT).

[0096] The transparent conductive layer described above can be formed by, for example, an evaporation process such as chemical vapor deposition (CVD), physical vapor deposition (PVD), plasma enhanced chemical vapor deposition (PECVD), or the like; a printing process such as screen printing, gravure printing, reverse offset, ink jet, or the like; a dry or wet plating process, or the like. In addition, the transparent conductive layer (first transparent conductive layer 21, second transparent conductive layer 22) described above can be formed in a structure of two or more layers in combination with the above-described substances. For example, in order to reduce the reflectance of incident light and improve the transmittance, the transparent conductive layer can be formed in a two-layer structure including a metal layer and a transparent conductive oxide layer.

[0097] In one embodiment, the surface of the first transparent conductive layer 21 and the second transparent conductive layer 22 that contacts the liquid crystal layer 40 can be rubbing oriented. The conductive polymer included in the transparent conductive layer (first transparent conductive layer 21, second transparent conductive layer 22) of the present application is different from a transparent conductive layer including a metal component in that it can form regular grooves on the surface, and thus the liquid crystal compound in the liquid crystal layer can be aligned to the desired position and direction. In this case, the transparent conductive layer (first transparent conductive layer 21, second transparent conductive layer 22) described above can function as an alignment film while functioning as an electrode for driving the liquid crystal layer, and since it does not include a separate alignment film, it is possible to manufacture a thinner light control laminate, and it is also possible to simplify the manufacturing process.

[0098] In order to provide the transparent conductive layer (first transparent conductive layer 21, second transparent conductive layer 22) described above that is rubbing oriented, rubbing methods using a rubbing process and photoalignment methods using ultraviolet light can be cited, and in general, the photoalignment method has a weaker surface anchoring energy than the rubbing method, and thus the surface of the transparent conductive layer (first transparent conductive layer 21, second transparent conductive layer 22) of the present application that contacts the liquid crystal layer 40 is preferably rubbing oriented by the rubbing method.

[0099] The liquid crystal layer 40 described above is characterized by being driven in accordance with an electric field. The liquid crystal layer 40 can be positioned between the first polarizing plate 11 and the second polarizing plate 12 of the light control region of the light control stack 10. In one embodiment, the liquid crystal layer 40 can be positioned in a space provided by the sealant 50 and a spacer (not shown) between the first polarizing plate 11 and the second polarizing plate 12 in the light control region, or in a space provided by the sealant 50 and a spacer (not shown) between the first alignment film 31 and the second alignment film 32. In addition, the liquid crystal layer 40 can adjust the degree of transmission of light incident from an external light source in accordance with an electric field formed between the first conductive layer 21 and the second conductive layer 22.

[0100] In one or more embodiments, the liquid crystal layer 40 described above can be driven by any one of the driving methods selected from the group consisting of a twisted nematic (TN), a super-twisted nematic (STN), an in-plane switching (IPS), a fringe field switching (FFS), a plane line switching (PLS), an advanced high-performance IPS (AH-IPS), a polymer sustained alignment (PSA), and a vertical alignment (VA), and a driving method of liquid crystal developed in the past or in the future can be applied.

[0101] The liquid crystal layer 40 described above in another embodiment of the present application can include one or more spacers selected from the group consisting of a ball spacer and a column spacer, and a ball spacer is particularly preferable. The ball spacer can be one or more, and preferably has a diameter of 1 to 10 μm. In addition, from the viewpoint of improving the visibility of a user and the transmittance in a transmissive mode, the area of the ball spacer in the liquid crystal layer 40 (i.e., the light control region) with respect to the area of the liquid crystal layer 40 is preferably 0.01 to 10% when viewed from the top.

[0102] The above-mentioned alignment film (first alignment film 31, second alignment film 32) has substantially the same properties as the above-mentioned member having alignment properties, and is not particularly limited as long as it is used to impart alignment properties to a liquid crystal compound, and preferably can include a photoalignment or a photocurable polymer, or the like. For example, the above-mentioned alignment film (first alignment film 31, second alignment film 32) can be produced by coating an alignment film coating composition including a photoalignment or a photocurable polymer, a photopolymerization initiator, and a solvent, and performing curing. For example, it can be formed by a rubbing process after coating an alignment substance such as a polyimide.

[0103] The above-mentioned sealant 50 is intended to combine two polarizing plates different from each other, and can be positioned between the two polarizing plates different from each other in the non-active area. In addition, the above-mentioned sealant 50 can ensure a space for disposing the above-mentioned liquid crystal layer between the two polarizing plates different from each other together with the spacer. In addition, since the sealant exists at the end portion of the above-mentioned liquid crystal layer, it is possible to further reduce the pressure applied to the liquid crystal layer in the glass bonding process described later. At this time, the thickness of the above-mentioned sealant is not limited.

[0104] The above-mentioned sealant 50 can include a curable resin as a base resin. As the above-mentioned base resin, an ultraviolet curable resin or a thermosetting resin known in the art that can be used for a sealant can be used. The above-mentioned ultraviolet curable resin can be a polymer of an ultraviolet curable monomer. The above-mentioned thermosetting resin can be a polymer of a thermosetting monomer.

[0105] As the base resin of the above-mentioned sealant 50, for example, an acrylate-based resin, an epoxy-based resin, a urethane-based resin, a phenol-based resin, or a mixture of the above-mentioned resins can be used. In one embodiment, the above-mentioned base resin can be an acrylate-based resin, and the above-mentioned acrylate-based resin can be a polymer of an acrylic monomer. The above-mentioned acrylic monomer can be, for example, a multifunctional acrylate. In another embodiment, the above-mentioned sealant can further include a monomer component in the base resin. The above-mentioned monomer component can be, for example, a monofunctional acrylate. In this specification, a monofunctional acrylate can refer to a compound having one acryl group, and a multifunctional acrylate can refer to a compound having two or more acryl groups. The above-mentioned curable resin can be cured by irradiation of ultraviolet rays and / or heating. As for the above-mentioned ultraviolet irradiation conditions or heating conditions, appropriate implementation can be made within a range not impairing the purpose of the present application. The above-mentioned sealant can further include an initiator, such as a photoinitiator or a thermal initiator, as needed.

[0106] The manufacturing method of the light control laminate of the present application is not particularly limited as long as it is a method for realizing the above-described light control laminate. For example, the above-described transparent conductive layer (first transparent conductive layer 21, second transparent conductive layer 22) and the refractive index adjusting layer (not shown) can be vapor-deposited by a vapor deposition method commonly used in the art, for example, a coating process such as spin coating, roll coating, bar coating, dip coating, gravure coating, curtain coating, die coating, spray coating, blade coating, kneader coating, and the like; a printing process such as screen printing, spray printing, inkjet printing, relief printing, intaglio printing, lithographic printing, and the like; and a vacuum film formation-based method such as chemical vapor deposition (CVD), physical vapor deposition (PVD), plasma enhanced chemical vapor deposition (PECVD), sputtering, and the like, and an appropriate process is selected.

[0107] The thickness of the light control laminate of the present application can be 0.300 mm to 0.450 mm. In general, in the case of a light control laminate having a thickness that satisfies the above-described range, since the thickness is too thin, the influence of pressure is more apparent at the time of glass bonding, and mura is often easily generated, but the smart window manufactured by the manufacturing method of the present application and by the light control laminate including the above-described thickness can significantly suppress liquid crystal mura.

[0108] Preferably, the thickness of the above-described light control laminate of the present application can be 0.32 to 0.40 mm. In the case of a light control laminate having a thickness that satisfies the above-described range, the gap layer including a polyvinyl butyral (PVB) film, which will be described later, can be formed thicker than the thickness of the light control laminate.

[0109] Film laminate 100

[0110] This invention relates to a film laminate 100 comprising a dimming laminate 10 and a gap layer 150 disposed at the ends of the dimming laminate. Specifically, the gap layer is designed to suppress streaks caused by the dimming laminate, and more specifically, these streaks can be caused by pressure on the liquid crystal layer contained in the dimming laminate during the bonding process of the glass to the laminate in the manufacturing process of a smart window. Such streaks are more likely to occur, especially when the dimming laminate is thin, which can lead to fatal problems that degrade the quality of the display. To this end, the present invention provides a dimming laminate that can effectively manufacture a superior smart window even in cases where, for example, a dimming laminate manufactured in which liquid crystal streaks are more likely to occur due to glass bonding pressure, such as in a dimming laminate manufactured in which a substrate is not included between the polarizer and the conductive layer but they are in direct contact. More preferably, from the viewpoint of minimizing the pressure on the liquid crystal layer, a gap layer 150 is preferably included at the ends of the dimming laminate 10.

[0111] Figure 1 The diagram illustrates the structure of a film laminate according to an embodiment of the present invention.

[0112] For example, such as Figure 1 As shown, in the film laminate 100 of the present invention, gap layers 150 can be provided at both ends of the dimming laminate 10 as supports, such as... Figure 2 As shown, a surface protective layer (first surface protective layer 140-1, second surface protective layer 140-2) may also be included on one side or above of the aforementioned dimming layer stack 10. The surface protective layers (first surface protective layer 140-1, second surface protective layer 140-2) may be arranged opposite each other at a certain interval through a gap layer 150 formed around the outer periphery of the dimming layer stack 10, and the dimming layer stack is encapsulated within the space formed by the surface protective layers (first surface protective layer 140-1, second surface protective layer 140-2) and the gap layer 150.

[0113] Surface protective layer (first surface protective layer 140-1, second surface protective layer 140-2)

[0114] The surface protective layer described above is a surface protective layer having a relatively small thickness, which is provided on one or both sides of the light control laminate (POL CELL; light control laminate), thereby improving the defects caused by the pressure during the lamination process, and preventing the liquid crystal shift phenomenon that can occur due to the non-uniform pressure applied to the liquid crystal layer, thereby solving the liquid crystal mura problem. As an example, when one or more ultra-thin polyvinyl butyral (PVB) films are further included between the adhesive layer included in the conventional adhesive for lamination of the light control laminate and a substrate such as glass and / or for preventing the scattering of the glass (substrate) and the light control laminate, the damage to the light control laminate and / or the liquid crystal of the light control laminate caused by the physical pressure from the outside such as pressing can be more effectively prevented. This is a characteristic that can be obtained by using the polyvinyl butyral (PVB) film, which is hardened at a low temperature, eliminating the non-uniformity of the liquid crystal (liquid phase) shifted to one side when laminated under pressure.

[0115] To this end, in the present application, as the surface protective layer (first surface protective layer 140-1, second surface protective layer 140-2), a low-temperature-curable polyvinyl butyral (PVB) film characterized by a thickness of 0.01 mm to 0.35 mm and cured at a temperature of 90°C or less can be used. Particularly preferably, a polyvinyl butyral (PVB) thin film having a thickness of 0.05 mm can be included. The low-temperature-curable polyvinyl butyral (PVB) film described above is cured at a low temperature of 90°C or less, preferably 60°C to 90°C, and thus has the advantages of ensuring the adhesion force of the general polyvinyl butyral film used for lamination of glass and minimizing the pressure applied to the liquid crystal layer, especially when applied to a display and / or a display device having a relatively thin liquid crystal. In addition, since it has a soft characteristic at the substrate (glass) lamination temperature described later, i.e., 60 to 90°C, it has the advantage of being able to absorb the pressure applied to the liquid crystal layer within the light control laminate due to lamination. When the lamination temperature is less than 60°C, lamination can not proceed smoothly, and if it is higher than 90°C, the polarizing plate can be thermally damaged.

[0116] The tensile elastic modulus (E') of the low-temperature-curable polyvinyl butyral (PVB) film included in the surface protective layer can be 10 8 ~ 10 10 Pa at 90°C, preferably a low-temperature-curable polyvinyl butyral (PVB) film having a tensile elastic modulus (E') of 10 6 ~ 10 7 Pa at 60°C and 10 9 Pa at 90°C. The polyvinyl butyral (PVB) film satisfying the range of the tensile elastic modulus (E') described above has the advantage of being able to more effectively reduce the damage within the light control laminate caused by high pressure. 6 Pa at 90°C. The polyvinyl butyral (PVB) film satisfying the range of the tensile elastic modulus (E') described above has the advantage of being able to more effectively reduce the damage within the light control laminate caused by high pressure.

[0117] In addition, the low-temperature-curable polyvinyl butyral (PVB) film contained in the surface protective layer described above has no flowability at 100°C or lower under a load of 21.6 kg, and a melt mass-flow rate (MFR) measured according to ASTM D1238 at 140°C under a load of 2.16 kg can be 0.02 g / 10 min or less. The melt mass-flow rate is a standard physical property value measured for the mass of a thermoplastic material passing through a die having a specified temperature, a predetermined load, and a specified size and properties within 10 minutes, and constitutes a basis for evaluating the processability of a resin. Specifically, the melt mass-flow rate measures the melt flow easiness of a thermoplastic polymer, also referred to as the melt flow speed or the melt flow index. It is measured by a standard test method based on ASTM D1238 and ISO 1133, defined by the weight of a resin flowing in a molten state through an orifice within 10 minutes under a temperature and load condition defined by a standard, and the melt viscosity depends largely on the molecular weight, so the higher the molecular weight, the more entanglement, and the higher the melt viscosity. At this time, the film contained in the surface protective layer is preferably selected from a material that exhibits a melt flow speed (MFR) of a degree sufficient to easily form a film to have processability, while having a melt flow speed low enough to have sufficient mechanical strength in consideration of being contained in a final product.

[0118] The polyvinyl butyral (PVB) film contained in the surface protective layer of the present application has low-temperature-curing properties, that is, cross-linking reactivity is provided even without using high temperature, and can maintain the transparency of the coating layer. In addition, since high temperature is not used at the time of curing, denaturation of other laminates such as a resin layer to be attached can be prevented.

[0119] Table 1 below is a table of the melt flow rate (MFR) measured according to ASTM D1238 for a polyvinyl butyral (PVB) film having a thickness of 0.05 mm contained in the surface protective layer of one embodiment of the present application.

[0120] [Table 1]

[0121]

[0122] Referring to Table 1 above, in the case of a polyvinyl butyral (PVB) film, flowability could not be confirmed at 100°C under a load of 21.6 kg, but a melt flow rate of 0.02 g / 10 min or less was measured at 140°C under a load of 2.16 kg. That is, the polyvinyl butyral (PVB) film included in one embodiment of the present application exhibits solidification at a relatively low temperature, and in view of the excellent structural properties required in a high temperature range, it is preferable to laminate and include one or more films having a thickness of about 0.05 mm. In view of forming the sealant 50, the surface protective layer preferably has a total area that is greater than 100% of the area of the light control laminate in contact with the surface protective layer, and more preferably can be 101 to 150% of the area of the light control laminate.

[0123] Gap layer 150

[0124] Referring to FIG. 5, the film laminate 100 of the present application can further include a gap layer 150 at the end of the light control laminate 10. The gap layer of the present application can be laminated to be thicker than the light control laminate described above.

[0125] In the present application, in order to laminate the gap layer to be thicker than the light control laminate, specifically, a polyvinyl butyral (PVB) film (stacked form) thicker than the total thickness of the light control laminate can be laminated after confirming the total thickness of the light control laminate, thereby being manufactured through a pre-bonding - formal bonding process.

[0126] In the present application, in order to minimize the pressure directly received by the liquid crystal layer within the light control laminate, the gap layer is formed at the end of the light control laminate like a pillar, and in order to achieve the above-mentioned purpose, is characterized by being thicker than the thickness of the light control laminate. As an example, the thickness of the gap layer can be preferably in the range of 101 to 120% of the thickness of the light control laminate. When greater than the above-mentioned range, the gap layer can interfere with the bonding between the light control laminate, the surface protective layer, and the substrate, and thus black spots can occur, resulting in manufacturing defects.

[0127] In one embodiment of the present application, the storage modulus (G') of the gap layer at 60°C can be 10 3 ~ 10 6 kPa, and the storage modulus (G') at 100°C can be 5 x 10 2 ~ 5 x 10 3kPa, but is not limited thereto. If the above storage modulus is satisfied, in the manufacture of the smart window, stress received at the subsequent substrate lamination step can be alleviated, and the mura of the liquid crystal layer can be effectively reduced. More specifically, even if the above gap layer is designed to be thicker than the light control laminate, if only a resin having a hard characteristic is used, defects can occur at the subsequent substrate lamination step. On the other hand, even if the above gap layer is designed to be thicker than the light control laminate, if only a resin having a soft characteristic is used, the gap layer can not sufficiently alleviate the pressure received by the light control laminate at the subsequent substrate lamination step. Therefore, the gap layer preferably satisfies the above storage modulus range, and if the thickness of the gap layer is thicker than that of the light control laminate while satisfying the above storage modulus, a low-temperature curable polyvinyl butyral (PVB) film can be included without limitation, and preferably, the low-temperature curable polyvinyl butyral (PVB) film included in the above surface protective layer can be directly applied.

[0128] The above low-temperature curable polyvinyl butyral (PVB) film can be cured at a temperature of 90°C or less, but is not limited thereto. As an example, two or more low-temperature curable polyvinyl butyral (PVB) films can be included, and the above low-temperature curable polyvinyl butyral film can be cured at a temperature of 90°C or less, but is not limited thereto. If the low-temperature curable polyvinyl butyral (PVB) film is included, it has a soft characteristic at the substrate (glass) lamination temperature of 60 to 90°C described later, and thus has the advantage of being able to absorb the pressure received by the liquid crystal layer in the light control laminate due to lamination. If the lamination temperature is less than 60°C, lamination does not proceed smoothly, and if it is higher than 90°C, the polarizing plate can be thermally damaged.

[0129] The film laminate of the present application can satisfy a sufficient storage modulus capable of absorbing pressure by including the above low-temperature curable polyvinyl butyral (PVB) film and / or adjusting the kind and thickness of the above included polyvinyl butyral (PVB) film and adjusting the number of laminations.

[0130] Preferably, the above-mentioned gap layer of the present application can be a multilayer comprising two or more layers of film. In one example of the present application, the above-mentioned gap layer can comprise a multilayer of polyvinyl butyral (PVB) film. Specifically, PVB is an elastic material, and when disposed in a light control layer stack for making a smart window, the light control layer stack including a liquid crystal layer can be damaged due to temperature and pressure applied during lamination, and thus, liquid crystal shift and mura and the like can occur. Therefore, in the film stack of the present application, a gap layer thicker than the thickness of the light control layer stack is formed, and in order to form a gap layer thicker than the thickness of the light control layer stack and capable of appropriately relieving pressure generated during lamination, it is not sufficient to use only 0.38 mm polyvinyl butyral (PVB) film, which has been conventionally used alone, and thus, the PVB film can be stacked in multiple layers.

[0131] More preferably, the above-mentioned gap layer can comprise a film characterized in that the tensile elastic modulus (E') at 60°C is 10 8 ~ 10 10 Pa and at 90°C is 10 6 ~ 10 7 Pa, preferably, can comprise a polyvinyl butyral (PVB) film satisfying the above-mentioned tensile elastic modulus, and in particular, a 0.05 mm PVB film. In the case of comprising a polyvinyl butyral (PVB) film satisfying the above-mentioned tensile elastic modulus (E'), a gap layer thicker than the light control layer stack can be formed by comprising a PVB film having high hardness, and thus, has the advantage that damage in the light control layer stack due to high pressure can be more effectively reduced. In addition, impact resistance can be imparted to a smart window manufactured by subsequently laminating a substrate. According to one embodiment of the present application, it is particularly preferable that, as described above, from the viewpoint of structural properties having excellent processability and strength in a polyvinyl butyral (PVB) film of a surface protection layer, only 2 to 8 sheets of 0.05 mm polyvinyl butyral (PVB) film (thin film) can be stacked to form a gap layer thicker than the light control layer stack and having excellent storage modulus.

[0132] On the other hand, in the present application, the gap layer can further include a 0.38 mm polyvinyl butyral (PVB) film having a thermal conductivity of 0.2 W / mK. In the case of including the polyvinyl butyral (PVB) film satisfying the thermal conductivity, since a gap layer including a soft polyvinyl butyral (PVB) film and thicker than the light control laminate can be formed, the lamination can be more smoothly performed. Specifically, regarding the storage modulus of the gap layer, if the gap layer is too hard, it can not be sufficiently pressed when the light control laminate is subsequently laminated with the surface protective layer and / or the substrate, and thus a problem that the lamination is substantially difficult to perform can occur. According to one embodiment of the present application, in the case where the thickness of the light control laminate is 0.39 mm, by simultaneously laminating a 0.38 mm-thick polyvinyl butyral (PVB) film satisfying the thermal conductivity on a 0.05 mm-thick polyvinyl butyral (PVB) film satisfying the tensile elastic modulus, a gap layer thicker than the light control laminate and having an excellent storage modulus can be formed. The thermal conductivity is collected and measured at 23°C and 50°C by a Transient Plane Source (TPS) method using a thermal constants analyzer.

[0133] On the other hand, in the present application, the gap layer can further include a 0.38 mm polyvinyl butyral (PVB) film having a specific heat of 1.9 to 2.3 kJ / (kg·K). The specific heat is measured using a differential scanning calorimeter (DSC).

[0134] In addition, the 0.38 mm PVB film satisfying the thermal conductivity of 0.2 W / mK and / or the 0.38 mm PVB film satisfying the specific heat of 1.9 to 2.3 kJ / (kg·K) can transmit visible light of 88.8% or more, and more preferably, ultraviolet light at a transmittance of 0.6% or less. When the above conditions are satisfied, the polyvinyl butyral (PVB) film can block ultraviolet light as included in a smart window, thereby improving the quality of the smart window.

[0135] In the present application, the polyvinyl butyral (PVB) film included in the gap layer can also use the same film as the surface protective layer and the adhesive layer described later.

[0136] The method of forming the gap layer is to be laminated in a stacked form without distinguishing separate lamination positions or orders.

[0137] Smart window 1000

[0138] The present application includes a smart window manufactured by including the light adjusting laminate and / or film laminate described above. In addition, the present application can relate to a vehicle including the smart window described above, for example, a car in which the smart window described above is applied to at least one or more of a front window, a rear window, a side window, a sunroof, and an interior partition, can include a wearable device including the smart window described above, and a building window.

[0139] Figure 2 A smart window 1000 of one embodiment of the present application is illustrated. Referring to Figure 2 The smart window can be made by bonding an adhesive layer (first adhesive layer 120-1, second adhesive layer 120-2) and a substrate 130-1, 130-2 on both sides of a film laminate including a light adjusting laminate 10, a gap layer 150, and a surface protective layer (first surface protective layer 140-1, second surface protective layer 140-2). The smart window of the present application can include an adhesive layer having properties that can minimize pressure applied to a liquid crystal layer included in the light adjusting laminate at the time of bonding, to inhibit the phenomenon of a liquid crystal mottle that is not visible before glass bonding occurring due to liquid crystal shift occurring in the process of bonding the glass.

[0140] For example, a car including the smart window of the present application can be made by bonding a substrate (glass) on both sides of a light adjusting laminate including a polarizing plate, a transparent conductive layer, a liquid crystal layer, and an adhesive / bonding layer, for example, after placing an adhesive layer and a substrate (glass) on both sides of the light adjusting laminate, the car can be manufactured by heating at a temperature of 90°C and about 1 bar for 10 to 20 minutes using a press machine, and the adhesive film described above can include an EVA film, a PVB film, or the like, but is not limited thereto.

[0141] Adhesive layer (first adhesive layer 120-1, second adhesive layer 120-2)

[0142] The adhesive layer (first adhesive layer 120-1, second adhesive layer 120-2) described above can be manufactured using an adhesive or an adhesive agent, and preferably has appropriate adhesive / bonding force to prevent peeling, bubbles, or the like from occurring when the light adjusting laminate is handled, and also has transparency and heat stability. The adhesive layer described above can use an adhesive film developed in the past or in the future, and from the aspect of stability (glass scattering, penetration), the adhesive layer described above preferably includes a low-temperature curing polyvinyl butyral (PVB) film. In the case of including a low-temperature curing polyvinyl butyral (PVB) film, it has a soft characteristic even at low temperature, and thus can absorb pressure applied to the film laminate, and can obtain a target initial bonding force even at low temperature. As an example, the adhesive layer (first adhesive layer 120-1, second adhesive layer 120-2) described above can use the same material as the polyvinyl butyral (PVB) film included in the surface protective layer and the gap layer in the film laminate, but is not limited thereto.

[0143] In addition, the above-mentioned adhesive can use an adhesive developed in the past or in the future, and for example, can be selected from among photocurable adhesives or thermosetting adhesives and tackifiers.

[0144] The above-mentioned photocurable adhesive exhibits strong adhesive force by being irradiated with active energy rays such as ultraviolet rays (UV) or electron beams (EB) and undergoing cross-linking and curing, and can be composed of a reactive oligomer, a reactive monomer, a photopolymerization initiator, and the like.

[0145] The above-mentioned reactive oligomer is an important component that determines the characteristics of the adhesive and forms a cured film by forming a high molecular bond through photopolymerization. The reactive oligomer that can be used can include a polyester-based resin, a polyether-based resin, a polyurethane-based resin, an epoxy-based resin, a polyacrylic acid-based resin, a silicone-based resin, and the like.

[0146] The above-mentioned reactive monomer functions as a cross-linking agent or a diluent for the above-mentioned reactive oligomer and affects the adhesive characteristics. The reactive monomer that can be used can include a monofunctional monomer, a polyfunctional monomer, an epoxy-based monomer, a vinyl ether, a cyclic ether, and the like.

[0147] The above-mentioned photopolymerization initiator functions to absorb light energy to generate radicals or cations to initiate photopolymerization, and a suitable photopolymerization initiator can be selected and used according to the photopolymerization resin.

[0148] The above-mentioned tackifier can use a tackifier developed in the past or in the future, and in one or more embodiments, can use an acrylic-based tackifier, a rubber-based tackifier, a silicone-based tackifier, a urethane-based tackifier, a polyvinyl alcohol-based tackifier, a polyvinylpyrrolidone-based tackifier, a polyacrylamide-based tackifier, a cellulose-based tackifier, a vinyl alkyl ether-based tackifier, and the like. The above-mentioned tackifier is not particularly limited as long as it has tackiness and viscoelasticity, but from the viewpoint of ease of acquisition and the like, it is preferable that the tackifier can be an acrylic-based tackifier, and for example, can include a (meth)acrylate copolymer, a cross-linking agent, a solvent, and the like.

[0149] The above-mentioned cross-linking agent can use a cross-linking agent developed in the past or in the future, and for example, can include a polyisocyanate compound, an epoxy resin, a melamine resin, a urea resin, a dialdehyde, a methylol polymer, and the like, and it is preferable that the cross-linking agent can include a polyisocyanate compound.

[0150] The above solvent can include a general solvent used in the field of resin compositions, for example, alcohols such as methanol, ethanol, isopropanol, butanol, propylene glycol methoxy alcohol, and the like; ketones such as methyl ethyl ketone, methyl butyl ketone, methyl isobutyl ketone, diethyl ketone, dipropyl ketone, and the like; acetates such as methyl acetate, ethyl acetate, butyl acetate, propylene glycol methoxy acetate, and the like; cellosolves such as methyl cellosolve, ethyl cellosolve, propyl cellosolve, and the like; and hydrocarbons such as hexane, heptane, benzene, toluene, xylene, and the like. They can be used alone or in combination of two or more.

[0151] The above adhesive layer (first adhesive layer 120-1, second adhesive layer 120-2) can include a hot-melt type adhesive such as an EVA (ethylene vinyl acetate) film, a PVB (polyvinyl butyral) film, and the like for a two-sided glass for vehicles, and preferably includes a low-temperature curing PVB (polyvinyl butyral) film included in the above surface protection layer and / or gap (gpa) layer.

[0152] The thickness of the above adhesive layer (first adhesive layer 120-1, second adhesive layer 120-2) can be appropriately determined depending on the type of resin that functions as an adhesive, the adhesive strength, the environment in which the adhesive is used, and the like. In one embodiment, in order to secure sufficient adhesive force between the surface protection layer (first surface protection layer 140-1, second surface protection layer 140-2) and the substrate 130-1, 130-2, or between the light modulation stack 10 and the substrate 130-1, 130-2, and to minimize the thickness of the smart window, the thickness of the above adhesive layer (first adhesive layer 120-1, second adhesive layer 120-2) can be 0.01 to 1.5 mm, preferably 0.05 to 1.2 mm, and more preferably 0.1 to 1 mm. In the case of using a PVB (polyvinyl butyral) film as an adhesive layer, the thickness of the above PVB film can vary depending on the purpose and the thickness of the transparent film and / or glass, and a product having a thickness of 0.38 mm or 0.76 mm can be used in consideration of commercialization.

[0153] In one embodiment, the above adhesive layer 120 can be formed on one side of the substrate (glass) by a lamination method.

[0154] Substrate 130-1, 130-2

[0155] The above-mentioned substrates 130-1, 130-2 can be generally one or more selected from the group consisting of a glass plate and / or a polymer film that is transparent and does not obstruct optical properties. For example, there are polyethylene terephthalate, cyclic olefin polymer, polyethylene naphthalate, polyether sulfone, polycarbonate, cellulose acetate, polymethyl methacrylate, colorless polyimide, glass, ceramic, and the like, among which, glass is most preferably used.

[0156] As the above-mentioned glass plate, inorganic glass and organic glass can be mentioned. As the above-mentioned inorganic glass, there are float plate glass, heat absorbing plate glass, heat reflecting plate glass, polished plate glass, embossed plate glass, embedded net plate glass, embedded wire plate glass, and general plate glass, and the like. The above-mentioned organic glass is a synthetic resin glass used instead of inorganic glass. As the above-mentioned organic glass, there are polycarbonate plate and poly(meth)acrylic resin plate, and the like, made of synthetic resin. As the above-mentioned poly(meth)acrylic resin plate, there are poly(meth)acrylate plate, and the like.

[0157] The above-mentioned substrates include not only glass having an intermediate film interposed between two glass plates, but also glass having an intermediate film interposed between a glass plate and a PET film, and the like, and can be glass-resin composite.

[0158] The thickness of the above-mentioned substrates is not particularly limited, and is preferably 1.6 mm or more and 2.1 mm or less.

[0159] The pressure machine can be used after the adhesive film and the vehicle glass are placed on both sides of the light-adjusting laminate, or the vehicle glass can be coated with resin on one side, and the vehicle glass can be vacuum-bonded to both sides of the light-adjusting laminate and UV-cured to manufacture. The above-mentioned resin can include OCR, OCA resin, and the like, having a storage modulus (G') of 10 3 ~10 5 Pa. The above-mentioned adhesive film can include EVA (ethylene vinyl acetate) film, PVB (polyvinyl butyral) film, and the like, hot-melt type adhesives, and can directly use materials selected from the above-mentioned adhesive layer, i.e., photocurable adhesive, thermosetting adhesive, and adhesive, and thus the description is omitted. Preferably, a low-temperature curing adhesive can be preferably used in consideration of the process aspect.

[0160] In addition, the film laminate can be attached to one or both sides of a window for a building, and a window for an intelligent window product can be manufactured by laminating a glass for a window to one side of the film laminate, or by coating a UV adhesive to both sides of the film laminate and then laminating a glass for a window and performing UV curing.

[0161] Method for manufacturing a smart window

[0162] The present application relates to a manufacturing method of an intelligent window aimed at preventing the occurrence of mura in the intelligent window. The attachment of glass is an important factor in determining the quality of the intelligent window, and in particular, in the case of using the conventional method, mura can occur due to the shift of the liquid crystal layer, and fogging can occur due to optical distortion during the process of attaching the glass to the laminate in the intelligent window manufacturing process, and if the attachment pressure is simply reduced in order to prevent this, a problem of poor attachment can occur, and thus, when attaching the glass to the film laminate, a suitable attachment method considering the elements contained therein is required. To this end, the present application provides a manufacturing method that can effectively manufacture an excellent intelligent window even in a case where liquid crystal mura is more likely to occur due to the glass attachment pressure, such as in a light control laminate manufactured by directly contacting a polarizing plate and a conductive layer without containing a substrate therebetween.

[0163] <Layering step (S101)>

[0164] The manufacturing method of an intelligent window of one embodiment of the present application includes a step of preparing a film laminate 100 and layering an adhesive layer (first adhesive layer 120-1, second adhesive layer 120-2) and a substrate 130-1, 130-2 on one or both sides thereof. In one embodiment, the adhesive layer (first adhesive layer 120-1, second adhesive layer 120-2) described above can be formed on one side of the surface protective layer (first surface protective layer 140-1, second surface protective layer 140-2) or one side of the light control laminate 10 by a lamination method.

[0165] In the layering step, a fixing step can be further included before the pre-attachment step. In order to easily perform the pre-attachment and the formal attachment and the like in the state of layering the film laminate, the adhesive layer, and the glass, the edges can be fixed by a tape or the like. This can be performed in a conventional or future developed manner by inserting a ring capable of surrounding the entire side surface and fixing it using an attachment tape or the like. In this step, a method of fixing the laminates using an ultrasonic welding machine can also be used, or this method can not be used, and a method of layering the laminates without cracking between the laminates while layering can be used.

[0166] In addition, the laminating step can further include a subsequent vacuum suction step. In order to stably adhere the film laminate and the glass, a vacuum suction process can be performed. Through this process, a state close to vacuum is formed between the film laminate and the glass, so that no air bubbles are generated after the adhesion or optical distortion occurs after completion due to air entering between the film laminate and the glass. This can be performed using a vacuum rubber bag or the like, and can be performed in a manner developed in the past or in the future.

[0167] <Pre-adhesion step (S102)>

[0168] The pre-adhesion step (S102) is a step of bonding the glass and the polyvinyl butyral (PVB) film and / or the light control laminate to each other by melting and adhering the layers of the film laminate at a temperature and a vacuum pressure.

[0169] The pre-adhesion step of the present application is performed at 0.1 to 3 bar, and can include: S1) a step of increasing the temperature to 40 to 90°C; S2) a step of maintaining the temperature of the above S1); and S3) a step of cooling to 0 to 30°C.

[0170] Specifically, more preferably, it can include: a step (S1) of increasing the temperature to 50 to 70°C at a pressure of 0.1 to 1 bar; a step (S2) of maintaining the above 50 to 70°C; and a step (S3) of cooling to 10 to 20°C.

[0171] <Final adhesion step (S103)>

[0172] The final adhesion step (S103) is a step of further pressing and adhering the bubbles generated between the layers of the laminate adhered in the above pre-adhesion step (S102). In the method of manufacturing the smart window, the adhesion method of the glass is one of the important factors that determine the quality of the smart window. When the glass is adhered to the above film laminate, a suitable adhesion method considering the elements contained therein is required. In particular, in the case of using a conventional method for the laminate including a thin light control laminate, not only mottling can occur due to the shift of the liquid crystal layer, but also fogging can occur due to optical distortion, and if the adhesion pressure is simply reduced in order to prevent this, a problem of poor adhesion can occur.

[0173] To this end, the present application provides a method of manufacturing a smart window including at least two or more processes in the final adhesion step.

[0174] In the embodiment of the present application, since the formal lamination is performed in two or more steps, the lamination can be performed step by step by changing the pressure, thereby stabilizing the pressure unevenness generated in the lamination process. Specifically, when the formal lamination includes the following a) and b) steps, the shift of the liquid crystal layer included in the film laminate can be prevented, and a smart window having more excellent manufacturing quality can be manufactured. In particular, the present application is characterized in that, after the first formal lamination at 3.5 to 10 bar in the a) step, the second formal lamination is performed through the b) step of reducing the pressure to 1 to 3 bar, thereby suppressing the liquid crystal shift phenomenon. Compared to the conventional formal lamination method in which the liquid crystal shift is easily generated due to the single step performed by a strong pressure, the present application can alleviate the liquid crystal shift by the second lamination with the reduced pressure in the b) step. On the other hand, if the formal lamination is performed using only a low pressure from the beginning, the lamination can not be sufficiently formed, and it is difficult to remove bubbles, and thus it can be more appropriate to perform the lamination at a high pressure at the beginning and to reduce the pressure to a low pressure at the end.

[0175] a) Step of maintaining at 3.5 to 10 bar for 15 to 60 minutes (S103-1)

[0176] In the a) step, the temperature is adjusted in an autoclave, and the lamination is performed using a compressor, thereby completing the lamination by heating and pressurization. Specifically, it can be preferably performed at 50 to 110°C, and more preferably at 80 to 100°C. In addition, the a) step of the formal lamination divided into two or more steps is more preferably satisfied in the above temperature range and maintained in a chamber at 3.5 to 6 bar for 20 to 40 minutes. Specifically, if it is increased to the conventional lamination temperature of 140°C, the light control laminate can not be able to withstand, and a problem of discoloration of the polarizing film can occur, and thus it is preferably performed in the above temperature range, unlike general lamination glass. Specifically, since the light control laminate in which liquid crystal is injected is manufactured, it is most sensitive to the pressure, and if the compressed air using a high pressure deviating from the above range is used, a problem of the liquid crystal shift can occur due to the pressure unevenness at the time of lamination.

[0177] b) Step of reducing the pressure to a range of 1 to 3 bar after the step a) and maintaining for 70 to 100 minutes (S103-2)

[0178] After the above a) step, the lamination is performed step by step by changing the pressure in the b) step, thereby making the pressure received by the liquid crystal included in the film laminate not uneven. Specifically, it can be preferably performed at 50 to 110°C, and more preferably at 80 to 100°C. In addition, it is more preferable to reduce the pressure to the range of 1 to 2 bar and maintain it for 80 to 100 minutes. If the pressing is performed at a high pressure in the a) step in order to discharge bubbles, the b) step is a step of correcting the unevenness of the pressure by reducing the pressure to a low pressure, and thus has an effect of stabilizing the liquid crystal shift that can occur in the a) step performed at a relatively high pressure at the same time through the b) step.

[0179] That is, the present application is a method of performing a) initial lamination at a high pressure and b) final lamination for a long time at a low pressure to reduce liquid crystal shift, thereby uniformly distributing liquid crystal contained in the light control laminate and inducing stable lamination of the substrates. That is, unlike the conventional art, since the final lamination is performed in two steps, it is possible to manufacture a smart window having high reliability and a significantly reduced occurrence of liquid crystal mura.

[0180] Hereinafter, experimental examples including specific examples and comparative examples are provided to help understanding of the present application, but this is only to illustrate the present application and does not limit the scope of the appended claims, and it is obvious to those skilled in the art that various changes and modifications can be made to the examples within the scope and technical idea of the present application, and such changes and modifications also belong to the scope of the appended claims. The "%" and "parts" in the examples are "mass %" and "mass parts", respectively, unless otherwise specified.

[0181] Hereinafter, the embodiments of the present application are described in more detail. The terms used in the present specification are intended to describe the embodiments and are not intended to limit the present application.

[0182] Manufacturing Example 1: Manufacturing of light control laminate

[0183] A polyvinyl alcohol film (raw material film) having a thickness of 60 μm (manufactured by Kuraray Co., Ltd., trade name "Kuraray poval film VF-PE#6000", average polymerization degree 2400, saponification degree 99.9 mol%) was continuously unwound while being conveyed, and was immersed in a swelling bath containing pure water at 20°C for 30 seconds. In this swelling treatment step, inter-roller stretching (uniaxial stretching in the longitudinal direction) was performed by generating a difference in circumferential speed between the nip rollers. The stretching ratio with respect to the raw material film was 2.5 times. Then, a polarizing plate subjected to dyeing, crosslinking, color compensation, cleaning, drying, and lamination treatment was manufactured according to the conventional art.

[0184] On one side of each of the first and second polarizing plates manufactured above, a hard coat layer-forming composition prepared by mixing 16.2 g of a dendritic macromolecular compound (Mitsui Chemicals, Inc., SP-1106), 14.4 g of inorganic nanoparticles (10 to 20 nm, silica particles: 50% by weight, solvent: methyl ethyl ketone (MEK)), 1.8 g of a polyfunctional (meth)acrylate compound containing a glycol group, 0.7 g of a photoinitiator (1-hydroxycyclohexyl phenyl ketone), and 2.9 g of methyl ethyl ketone was bar coated so as to have a thickness of 1.5 μm, and was dried at 80°C for 5 minutes, and then was cured under a high-pressure mercury lamp at a light intensity of 500 mJ / cm2. 2 ​

[0185] The PEDOT composition was coated on the first and second polarizing plates, dried at 90°C for about 5 to 10 minutes, and a transparent conductive layer having a thickness of 200 nm was formed, thereby producing a laminate including the first and second transparent conductive layers formed of a conductive polymer (PEDOT) on one side of each polarizing plate. The PEDOT composition was produced by mixing coating solution 1 and coating solution 2 at a ratio of 1:1. The coating solution 1 was a mixture of 60 to 65 wt% of a complex of 2,3-dihydrothieno[3,4-b]-l,4-dioxine homopolymer and vinylbenzenesulfonic acid homopolymer (water-based) with respect to the total weight of the coating solution, 15 to 20 wt% of ethanol, and 20 to 25 wt% of deionized water. The coating solution 2 was a mixture of 0.5 to 1.0 wt% of a polyester resin (25% solid content, water-based) with respect to the total weight of the coating solution, 65 to 75 wt% of ethanol, and 20 to 25 wt% of deionized water.

[0186] An alignment liquid was coated on the first and second transparent conductive layers of each polarizing plate and dried (80°C / 2 minutes), and then UV was irradiated on the dried alignment liquid, thereby producing first and second alignment films.

[0187] On the first transparent conductive layer, a sealant (UVF-006, 70,000 mPa-s, SEKISUI) was coated using a sealant applicator (SHOT mini 200Ωχ, MUSASHI) at a discharge pressure of 200 mPa according to a product size drawing and using a sharp needle (SPN-0.25-12.7L), and liquid crystals were injected on the first alignment film in an ODF process. Then, the light control laminate was attached at a pressure of 3 Kg / cm 2 2 ), thereby producing an optical laminate for a smart window. Then, a conductive copper tape (TERAOKA, No. 8323) was attached to the first and second transparent conductive layers to connect them.

[0188] Manufacturing Example 2: Manufacturing of surface protective layer

[0189] Regarding the lamination method and the method of forming the surface protective layer, a low-temperature-curable polyvinyl butyral (PVB) film 0.05 mm (60°C tensile elastic modulus: 1.9 x 10 9 Pa, 90°C tensile elastic modulus: 4 x 10 6 ​The surface protective layer was prepared according to the melt flow rate (MFR) measured by ASTM D1238, which was less than 0.02 g / 10 min at 140 °C. The thicknesses of the surface protective layer and the spacer layer of each embodiment, comparative example, and reference example are shown in Table 2 below.

[0190] Manufacturing Example 3: Manufacturing of gap layer

[0191] Regarding the interlayer, a further layer of 0.38mm low-temperature curing polyvinyl butyral (PVB) film (0.38mm, 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℃) and / or a 0.05mm low-temperature curing polyvinyl butyral (PVB) film (with a tensile modulus of elasticity of 1.9 × 10⁻⁶ at 60℃) is laminated. 9 Pa, tensile modulus at 90℃ is 4×10 Pa. 6 The spacer layer is formed to a thickness greater than that of the dimming laminate (0.39 mm thick), based on the melt flow rate (MFR) measured according to ASTM D1238 being less than 0.02 g / 10 min at 140°C. The spacer 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 layers of the spacer layer in each embodiment, comparative example, and reference example are shown in Table 2 below.

[0192] Manufacturing Example 4: Laminating step (S101)

[0193] The second substrate (glass), the second adhesive layer, the film laminate, the first adhesive layer, and the first substrate (glass) are sequentially stacked using the film laminate manufactured according to Manufacturing Examples 1 to 3 described above. The first and second adhesive layers 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 23–50°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 and second substrates are made of 2.1 T soda-lime glass.

[0194] Manufacturing Example 5: Pre-laminating step (S102)

[0195] The laminated samples were pre-bonded by placing them in a reusable vacuum rubber bag (OBRJ-S). In Example 1, the pre-bonding step involved placing the laminated smart window in the vacuum rubber bag, heating it from 20°C to 65°C over 15 minutes at a pressure of 0.9 bar, maintaining it at 65°C for 30 minutes, and then 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.

[0196] Manufacturing Example 6: Official laminating step (S103)

[0197] 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 in 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.

[0198] Examples and comparative examples

[0199] Referring to the manufacturing examples 1 to 6 above, the smart window of the present invention is manufactured according to the following Table 2.

[0200] [Table 2]

[0201]

[0202]

[0203] Visually inspect the patterns (liquid crystal unevenness: a general term for uneven image characteristics and patterns in the manufactured liquid crystal panel) of the smart window manufactured according to Table 2 above, and the evaluation results are shown in Table 3 below. Figures 4a to 6c middle. Figures 4a to 4f 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 5a to 5c These are photographs of the appearance evaluation results of the bonding articles of Comparative Examples 1 to 3 of the present invention, observed on a backlight (light source) using a digital camera. Figures 6a to 6c Figures 4a to 6c These are photographs of the appearance evaluation results of the bonding articles of Reference Examples 1 to 3 of the present invention, observed on a backlight panel (light source) using a digital camera.

[0204] [Table 3]

[0205]

[0206] Referring to Tables 2 and 3 above, it can be seen that in the case of manufacturing a smart window using the film laminate manufactured according to the present application, no liquid crystal mura occurs even after lamination of the glass, and no defective product that cannot be activated due to black spots is generated.

[0207] On the other hand, in the case of Comparative Examples 1 and 2, which do not include the film laminate of the present application and in which the gap layer is thinner than the light control laminate, the pressure on the liquid crystal layer cannot be alleviated, and defects of liquid crystal shift occur. Specifically, in the case of Comparative Example 1, in which 7 sheets of a relatively hard 0.05 mm PVB film were used, and in the case of Comparative Example 2, in which 1 sheet of a relatively soft 0.38 mm PVB film was used, it can be confirmed that since the thickness of the gap layer is thinner than the light control laminate, liquid crystal mura occurs due to the pressure on the liquid crystal layer at the time of lamination. In addition, in the case of Comparative Example 3, in which 9 sheets of a relatively hard 0.05 mm PVB film were used to form a thicker gap layer, it can be confirmed that since it is too hard, the light control laminate itself is difficult to laminate, and in addition to liquid crystal mura, black spots also occur severely. This can be because in the case of laminating 9 sheets of 0.05 mm low-temperature-curable polyvinyl butyral (PVB) film, the gap layer exceeds the preferred storage modulus.

[0208] In the case of Reference Example 1, since the surface protective layer of the present application is not included, liquid crystal mura occurs despite the inclusion of a gap layer having suitable physical properties and thickness.

[0209] In the case of Reference Example 2, since the surface protective layer is too thick, liquid crystal mura occurs despite the inclusion of a gap layer having suitable physical properties and thickness.

[0210] In the case of Reference Example 3, since the formal lamination step is not performed in two steps, liquid crystal mura occurs.

Claims

1. A membrane laminate, characterized in that, Include: dimming laminate; and The gap layer, at the end of the dimming laminate, comprises a polyvinyl butyral (PVB) film. The thickness of the gap layer is greater than the thickness of the dimming laminate.

2. The film laminate according to claim 1, 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.

3. The film laminate according to claim 1 or 2, The thickness of the dimming laminate is 0.32–0.40 mm. The thickness of the gap layer is 101-120% of the thickness of the dimming laminate.

4. The film laminate according to claim 1 or 2, wherein the dimming laminate further 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 membrane stack according to claim 1 or 2, wherein the interstitial layer comprises two or more layers of polyvinyl butyral (PVB) membrane.

6. The film laminate according to claim 1 or 2, 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.

7. The film laminate according to claim 1 or 2, wherein at least one of the upper and lower surfaces of the dimming laminate comprises a surface protective layer. The surface protective layer is a low-temperature curable polyvinyl butyral (PVB) film that cures at temperatures below 90°C, with a tensile modulus E' of 10 at 60°C. 8 ~10 10 Pa and 10 at 90℃ 6 ~10 7 Pa.

8. The film laminate according to claim 7, 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.

9. A smart window, comprising: The film laminate according to any one of claims 1 to 8; 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.

10. A method for manufacturing a smart window, which is the method for manufacturing a smart window as described in claim 9. The manufacturing method of the smart window includes a pre-lamination step and a formal lamination step. The formal bonding process includes at least two steps.

11. The method for manufacturing a smart window according to claim 10, The formal bonding step includes: a) Maintain at 3.5–10 bar for 15–60 minutes; as well as b) Following step a), reduce the pressure to 1-3 bar and maintain it for 70-100 minutes.

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