Method for manufacturing an optical modulation device

Abstract

The present invention provides a method for manufacturing a light modulation device, the method including the step of attaching a first substrate having a glue layer or an adhesive layer formed on a first surface and a second substrate having a spacer and a liquid crystal alignment film formed on a first surface while being transported by a roller, wherein the first substrate and the second substrate are attached such that each first surface faces each other. Accordingly, the present invention can provide a so-called roll-to-roll process, whereby a light modulation device having excellent adhesion between two substrates can be rapidly manufactured while achieving a desired alignment state (e.g., a liquid crystal alignment state) of a light modulation layer.

Description

TECHNICAL FIELD

[0001] This application claims priority based on Korean Patent Application No. 10-2020-0119125, filed on September 16, 2020, the disclosure of which is incorporated herein in its entirety by reference.

[0002] The present application relates to a method for manufacturing an optical modulation device. BACKGROUND

[0003] An optical modulation device in which an optical modulation layer containing a liquid crystal compound or the like is positioned between two substrates is used in various applications.

[0004] In order for the optical modulation device to exhibit intended performance, it is important to precisely control the alignment state of the liquid crystal compound between the substrates.

[0005] In addition, in order to secure the performance of the optical modulation device, it is necessary to secure the adhesion force of the two substrates disposed to face each other.

[0006] Although various methods for manufacturing an optical device are known, a method capable of rapidly manufacturing an optical modulation device having excellent adhesion force between two substrates while achieving a desired alignment state in an optical modulation layer is not known. SUMMARY

[0007] TECHNICAL PROBLEM

[0008] The present application aims to provide a method for manufacturing an optical modulation device. The present application aims to provide a so-called roll-to-roll process capable of rapidly manufacturing an optical modulation device having excellent adhesion force between two substrates while achieving a desired alignment state (e.g., liquid crystal alignment state) of an optical modulation layer.

[0009] TECHNICAL SOLUTION

[0010] The present application can relate to a method for manufacturing an optical modulation device by a roll-to-roll process.

[0011] The manufacturing method can include the step of transporting, by a roll, a first substrate in which a pressure-sensitive adhesive layer or an adhesive layer is formed on a first surface and a second substrate in which a spacer and a liquid crystal alignment film are formed on a first surface, and simultaneously attaching the first substrate and the second substrate such that the respective first surfaces face each other.

[0012] In the manufacturing method, the liquid crystal alignment film can not be formed on the first substrate.

[0013] In the manufacturing method, the first substrate can further include a release film attached on the pressure-sensitive adhesive layer or the adhesive layer, and the manufacturing method can further include the step of peeling the release film before attaching the first substrate and the second substrate.

[0014] In the manufacturing method, the second substrate can further include a protective film attached on the first surface of the second substrate on which the spacers and the liquid crystal alignment film are formed, and the manufacturing method can further include a step of peeling off the protective film before attaching the first substrate and the second substrate.

[0015] The manufacturing method can further include a step of supplying a sealant to the edge of the first surface of the second substrate before attaching the first substrate and the second substrate.

[0016] In the manufacturing method, a step of supplying a liquid crystal compound; a liquid crystal compound and a dichroic dye; or a liquid crystal compound and a chiral dopant to the first surface of the second substrate can be further performed before attaching the first substrate and the second substrate.

[0017] In the manufacturing method, the distance (d) between the first substrate and the second substrate can be adjusted such that the ratio (d / p) of the distance (d) to the chiral pitch (p) formed by the chiral dopant is less than 1.

[0018] In the manufacturing method, the spacers of the second substrate can be partition wall spacers.

[0019] The manufacturing method can further include a step of heat-treating the first substrate before attaching the first substrate and the second substrate, and the heat-treatment can be performed at a temperature of 80°C or higher for 30 seconds or more.

[0020] In the manufacturing method, the attaching of the first substrate and the second substrate can be performed at a temperature range higher than 50°C and lower than 90°C.

[0021] The manufacturing method can further include a step of heat-treating the attached first substrate and the second substrate after attaching the first substrate and the second substrate, and the heat-treatment can be performed at a temperature of 80°C or higher for 30 seconds or more.

[0022] Advantageous effects

[0023] The present application can provide a so-called roll-to-roll process capable of rapidly manufacturing a light modulation device having excellent adhesion between two substrates while achieving a desired orientation state (e.g., liquid crystal orientation state) of a light modulation layer. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figures 1 to 3 is a schematic view of an exemplary light modulation device of the present application.

[0025] Figure 4 is a schematic view showing a manufacturing process of a light modulation device of the present application.

[0026] Figure 5 and Figure 6is a photograph showing the presence or absence of an alignment defect depending on whether or not heat treatment is performed on the first substrate.

[0027] Figure 7 is a graph showing the result when heat treatment is performed in the process of attaching the first substrate and the second substrate.

[0028] Figure 8 is a graph showing the result when heat treatment is performed after attaching the first substrate and the second substrate.

[0029] <Legend>

[0030] 100: first substrate

[0031] 200: second substrate

[0032] 1001: pressure-sensitive adhesive layer or adhesive layer

[0033] 2001: liquid crystal alignment film

[0034] 600: light modulation layer

[0035] 400: polarizing layer

[0036] 401: unwinding roll

[0037] 402: peeling roll

[0038] 403: attaching roll

[0039] 404: sealant supply member

[0040] 405: light modulation material supply member

[0041] 406: sealant curing member

[0042] 407: cutting member

[0043] 408: take-up roll DETAILED DESCRIPTION

[0044] In the present specification, the terms perpendicular, parallel, orthogonal, or horizontal and the like used when defining an angle, and the numerical value of the angle mean substantially perpendicular, parallel, orthogonal, or horizontal and the related numerical value within a range that does not impair the intended effect, and the range of perpendicular, parallel, orthogonal, or horizontal and the range of the numerical value include errors such as production errors or deviations (variations). For example, each of the foregoing cases can include an error within about ±5 degrees, an error within about ±4 degrees, an error within about ±3 degrees, an error within about ±2 degrees, or an error within about ±1 degree.

[0045] Among the physical properties mentioned herein, when the measured temperature affects the relevant physical property, the physical property is the physical property measured at room temperature, unless otherwise specified. The term room temperature is the temperature in a state without special heating or cooling, which can mean a temperature in the range of about 10°C to 30°C, for example, a temperature of about 15°C or higher, 18°C or higher, 20°C or higher, or about 23°C or higher and about 27°C or lower. Unless otherwise specified, the unit of temperature mentioned herein is °C.

[0046] Unless otherwise specified, the phase difference and the refractive index mentioned herein mean the refractive index for light having a wavelength of about 550 nm.

[0047] Unless otherwise specified, the angle formed by any two directions mentioned herein can be an acute angle to an obtuse angle formed by the two directions, or can be a small angle among the angles measured in the clockwise direction and the counterclockwise direction. Therefore, unless otherwise specified, the angle mentioned herein is positive. However, if necessary, in order to show the measurement direction between the angles measured in the clockwise direction or the counterclockwise direction, either of the angle measured in the clockwise direction and the angle measured in the counterclockwise direction can be expressed as a positive number, and the other angle can be expressed as a negative number.

[0048] The present application relates to a method for manufacturing an optical modulation device. The term optical modulation device can mean a device capable of switching between at least two or more different light states. Here, the different light states can mean states in which at least transmittance, reflectance, color, and / or haze are different.

[0049] Examples of the states that the optical modulation device can implement include a transparent mode state, a black mode state, a high reflection mode state, a low reflection mode state, and / or a color mode state indicating a specific color, etc., but are not limited thereto.

[0050] In one example, the optical modulation device can be a device capable of switching between at least a transparent mode state and a black mode state, or a device capable of switching between a high reflection mode state and a low reflection mode state.

[0051] The optical modulation device of the present application can be designed to switch between at least two or more states selected from any one of a transparent mode state, a black mode state, a high reflection mode state, a low reflection mode state, and a color mode state, and another state. If necessary, other third different states or more states in addition to the above states can also be implemented.

[0052] The switching of the light modulation device can be controlled depending on whether or not an external signal such as a voltage signal is applied. For example, in a state where no external signal such as a voltage is applied, the light modulation device can maintain any one of the above-described states, and then can switch to another state when a voltage is applied. By changing the intensity, frequency, and / or shape of the applied voltage, the mode state can be changed or a third different mode state can also be realized.

[0053] The light modulation device of the present application can include a light modulation film layer having two substrates disposed opposite to each other and a light modulation layer positioned between the substrates as a basic unit. Figure 1 is a drawing illustrating one example of a light modulation film layer. The light modulation film layer includes a first substrate 100 and a second substrate 200 disposed opposite to each other. As illustrated, in the light modulation device of the present application, a pressure-sensitive adhesive layer or an adhesive layer can be formed on one surface (hereinafter, can be referred to as a first surface) of the first substrate 100, a liquid crystal alignment film 2001 can be formed on the surface (hereinafter, can be referred to as a first surface) of the other second substrate 200, and a light modulation layer 600 can be positioned between the first substrate 100 and the second substrate 200 disposed opposite to each other. When the light modulation layer is a liquid crystal layer, a liquid crystal alignment film is generally formed on both surfaces of the first substrate 100 and the second substrate 200, but a pressure-sensitive adhesive layer or an adhesive layer is formed instead of a liquid crystal alignment film on the first substrate 100, and only a liquid crystal alignment film is formed on the second substrate 200, whereby an orientation state of a liquid crystal compound which is very useful in a specific application (for example, a smart window or an eye wear) can be obtained. In addition, such a structure makes it possible to quickly manufacture a light modulation device in which excellent adhesion between the first substrate 100 and the second substrate 200 is ensured when applied to the manufacturing process of the present application which will be described below. Therefore, a liquid crystal alignment film can not be formed on the first substrate of the light modulation film layer of the present application. In addition, although not illustrated in the drawing, in either one of the first substrate and the second substrate of the light modulation film layer, a spacer for maintaining the interval (cell gap) between the first substrate and the second substrate is present. When the pressure-sensitive adhesive layer or the adhesive layer 1001 is formed on the substrate 100, the pressure-sensitive adhesive layer or the adhesive layer 1001 is attached to the spacer, thereby being able to greatly improve the adhesion between the first substrate and the second substrate.

[0054] In the present specification, the first surface of a substrate means either one of the main surface and the opposite surface of the substrate, and the second surface means the other one of the main surface and the opposite surface of the substrate.

[0055] As the substrate, a known substrate material can be used without particular limitation. For example, an inorganic substrate such as a glass substrate, a crystalline or amorphous silicon substrate, or a quartz substrate, or a plastic substrate can be used as the substrate. However, in order to be effectively applied to the manufacturing process of the present application, a plastic substrate can be used as the substrate.

[0056] As the plastic substrate, a TAC (triacetyl cellulose) substrate; a COP (cyclo olefin copolymer) substrate such as a norbornene derivative substrate; a PMMA (poly(methyl methacrylate)) substrate; a PC (polycarbonate) substrate; a PE (polyethylene) substrate; a PP (polypropylene) substrate; a PVA (polyvinyl alcohol) substrate; a DAC (diacetyl cellulose) substrate; a Pac (polyacrylate) substrate; a PES (polyether sulfone) substrate; a PEEK (polyether ether ketone) substrate; a PPS (polyphenyl sulfone), a PEI (polyether imide) substrate; a PEN (polyethylene naphthalate) substrate; a polyester substrate such as a PET (polyethylene terephthalate) substrate; a PI (polyimide) substrate; a PSF (polysulfone) substrate; a PAR (polyarylate) substrate, or a fluororesin substrate, or the like can be used, but is not limited thereto. The thickness of such a substrate is not particularly limited and can be selected within an appropriate range.

[0057] The light modulation layer present between the substrates is a functional layer capable of changing the light transmittance, reflectance, haze, and / or color, etc. alone or in combination with other components depending on whether or not an external signal is applied. In this context, such a light modulation layer can be referred to as an active light modulation layer.

[0058] In the present specification, an external signal can mean an external factor such as an external voltage, etc. that can affect the behavior of a material (e.g., a light modulation material) contained in the light modulation layer. Thus, a state without any external signal can mean a state in which no external voltage, etc. is applied.

[0059] In the present application, the type of the light modulation layer is not particularly limited as long as it has the above-described function, and a known light modulation layer can be applied. The light modulation layer can be, for example, a liquid crystal layer, an electrochromic material layer, a photochromic material layer, an electrophoretic material layer, or a dispersed particle orientation layer.

[0060] In one example, a liquid crystal layer can be applied as the light modulating layer. The liquid crystal layer is a layer containing a liquid crystal compound. In the present specification, the term liquid crystal layer includes all layers containing a liquid crystal compound, for example, a so-called guest-host layer containing a liquid crystal compound (liquid crystal host) and a dichroic dye, or a layer containing other additives such as a chiral dopant as well as a liquid crystal compound is also defined as a liquid crystal layer in the present specification. The liquid crystal layer can be an active liquid crystal layer, and thus a liquid crystal compound can be present in the liquid crystal layer such that the alignment direction changes depending on whether or not an external signal is applied. As the liquid crystal compound, any kind of liquid crystal compound can be used as long as the alignment direction can be changed by applying an external signal. For example, a smectic liquid crystal compound, a nematic liquid crystal compound, or a cholesteric liquid crystal compound can be used as the liquid crystal compound. Further, the liquid crystal compound can be, for example, a compound having no polymerizable group or crosslinkable group such that the alignment direction can be changed by applying an external signal.

[0061] The liquid crystal layer can contain a liquid crystal compound having a positive or negative dielectric anisotropy. The absolute value of the dielectric anisotropy of the liquid crystal can be appropriately selected in view of the object of the present application. The term "dielectric anisotropy (Δε)" can mean the difference between the horizontal dielectric constant (ε / / ) and the vertical dielectric constant (ε⊥) of the liquid crystal (ε / / -ε⊥). In the present specification, the term horizontal dielectric constant (ε / / ) means a dielectric constant value measured in the direction of an electric field in a state where a voltage is applied such that the direction of a director of the liquid crystal and the direction of an electric field generated by the applied voltage are substantially horizontal, and the term vertical dielectric constant (ε⊥) means a dielectric constant value measured in the direction of an electric field in a state where a voltage is applied such that the direction of a director of the liquid crystal and the direction of an electric field generated by the applied voltage are substantially vertical.

[0062] The driving mode of the liquid crystal layer can be exemplified as, for example, a DS (dynamic scattering) mode, an ECB (electrically controllable birefringence) mode, an IPS (in-plane switching) mode, an FFS (fringe field switching) mode, an OCB (optically compensated birefringence) mode, a VA (vertically aligned) mode, an MVA (multi-domain vertically aligned) mode, a PVA (patterned vertically aligned) mode, a HAN (hybrid aligned nematic) mode, a TN (twisted nematic) mode, a STN (super twisted nematic) mode, or an R-TN (reverse twisted nematic) mode, and the like.

[0063] In terms of controlling the transmittance variable property together with the liquid crystal compound, the light modulation layer as the liquid crystal layer can also include a dichroic dye. In the present specification, the term dye can mean a material capable of strongly absorbing light in at least part or all of the range within the visible light region (for example, the wavelength range of 400 nm to 700 nm) and / or deforming it, and the term dichroic dye can mean a material capable of anisotropic absorption of light in at least part or all of the range within the visible light region. Such a dye is, for example, referred to as an azo dye or an anthraquinone dye, or the like, but is not limited thereto.

[0064] In one example, the light modulation layer is a liquid crystal layer including a liquid crystal and a dichroic dye, which can be a so-called guest-host liquid crystal layer (guest host liquid crystal cell). The term guest-host liquid crystal layer is a liquid crystal layer that can also be referred to as a GHLC layer, which can mean a functional layer in which dichroic dyes are aligned together according to the alignment of the liquid crystal to exhibit anisotropic light absorption properties with respect to the alignment direction of the dichroic dye and the direction perpendicular to the alignment direction, respectively. For example, the dichroic dye is a substance in which the absorption rate of light varies with the polarization direction, in which it can be referred to as a p-type dye if the absorption rate of light polarized in the long axis direction is large, and it can be referred to as an n-type dye if the absorption rate of light polarized in the short axis direction is large. In one example, when a p-type dye is used, polarized light vibrating in the long axis direction of the dye can be absorbed, and polarized light vibrating in the short axis direction of the dye can be less absorbed and transmitted. Hereinafter, unless otherwise specified, the dichroic dye is considered to be a p-type dye.

[0065] A light modulation film layer including a guest-host liquid crystal layer as a light modulation layer can be used as an active polarizing layer (active polarizer). In the present specification, the term active polarizing layer (active polarizer) can mean a functional element capable of controlling anisotropic light absorption according to an external signal application. Such an active polarizing layer can be distinguished from a passive polarizing layer described below, which has a constant light absorption or light reflection property regardless of the external signal application. The guest-host liquid crystal layer can control the anisotropic light absorption of polarized light in a direction parallel to the alignment direction of the dichroic dye and polarized light in a perpendicular direction by controlling the alignment of the liquid crystal and the dichroic dye. Since the alignment of the liquid crystal and the dichroic dye can be controlled by applying an external signal such as a magnetic field or an electric field, the guest-host liquid crystal layer can control the anisotropic light absorption according to the external signal application.

[0066] The liquid crystal layer as the light modulation layer can also contain a so-called chiral dopant as well as the liquid crystal compound. Such a chiral dopant can induce orientation of a helical structure in the liquid crystal compound. The type of the chiral dopant that can be contained is not particularly limited, and an appropriate chiral dopant can be selected from known types as needed. Further, the ratio of the chiral dopant is not particularly limited, but the chiral dopant can be contained at a ratio at which the ratio (d / p) of the thickness (d, cell gap) of the light modulation layer to the pitch (p) of the helical structure of the liquid crystal compound produced by the addition of the chiral dopant can be less than 1. In another example, the ratio (d / p) can be 0.95 or less, 0.9 or less, 0.85 or less, 0.8 or less, 0.75 or less, 0.7 or less, 0.65 or less, 0.6 or less, 0.55 or less, 0.5 or less, or 0.45 or less, or can be 0.05 or more, 0.1 or more, 0.15 or more, 0.2 or more, 0.25 or more, 0.3 or more, or 0.35 or more. Such a ratio (d / p) is related to the orientation of the liquid crystal compound induced by the pressure-sensitive adhesive layer or the adhesive layer and the liquid crystal alignment film, so that an orientation state suitable for the application use can be obtained.

[0067] The thickness (cell gap) of the light modulation layer can be appropriately selected in consideration of the object of the present application. In one example, the thickness of the light modulation layer can be 0.01 pm or more, 0.1 pm or more, 1 pm or more, 2 pm or more, 3 pm or more, 4 pm or more, 5 pm or more, 6 pm or more, 7 pm or more, 8 pm or more, 9 pm or more, or 10 pm or more. A device having a large difference in transmittance, reflectance, haze, and / or color depending on the mode state can be realized at such a thickness. The thicker the thickness, the more the difference can be realized, so that the thickness is not particularly limited, but it can generally be about 30 pm or less, 25 pm or less, 20 pm or less, or 15 pm or less.

[0068] In the light modulation film layer, the type of the pressure-sensitive adhesive layer or the adhesive layer formed on the first surface of the first substrate is not particularly limited. Various types of pressure-sensitive adhesives or adhesives known in the industry as so-called OCA (optically clear adhesive) or OCR (optically clear resin) can induce a suitable orientation of the liquid crystal compound in combination with the liquid crystal alignment film. As the pressure-sensitive adhesive or the adhesive, for example, an acrylic, silicone-based, epoxy-based, or urethane-based pressure-sensitive adhesive or adhesive can be applied.

[0069] As a suitable pressure-sensitive adhesive or adhesive, a pressure-sensitive adhesive or adhesive based on silicone can be exemplified. The specific surface properties of the pressure-sensitive adhesive or adhesive based on silicone can cause an alignment state of a liquid crystal compound suitable for the purpose in combination with a liquid crystal alignment film, particularly a vertical alignment film.

[0070] As the pressure-sensitive adhesive or adhesive based on silicone, a cured product of a curable silicone adhesive or pressure-sensitive adhesive composition (hereinafter, can be simply referred to as a curable silicone composition) can be used. The type of the curable silicone composition is not particularly limited, and for example, a heat-curable silicone composition or an ultraviolet-curable silicone composition can be used.

[0071] In one example, the curable silicone composition is an addition-curable silicone composition, which can include (1) an organopolysiloxane containing two or more alkenyl groups in a molecule, and (2) an organopolysiloxane containing two or more silicon-bonded hydrogen atoms in a molecule. Such a silicone compound can form a cured product by an addition reaction, for example, in the presence of a catalyst such as a platinum catalyst.

[0072] (1) The organopolysiloxane constituting the main component of the silicone cured product includes at least two alkenyl groups in one molecule. At this time, specific examples of the alkenyl group include a vinyl group, an allyl group, a butenyl group, a pentenyl group, a hexenyl group, or a heptenyl group, and the like, and a vinyl group among the foregoing is generally applied, but is not limited thereto. The bonding position of the alkenyl group in the (1) organopolysiloxane is not particularly limited as described above. For example, the alkenyl group can be bonded to the terminal of the molecular chain and / or the side chain of the molecular chain. Furthermore, in the (1) organopolysiloxane, the type of the substituent group that can be included in addition to the above-described alkenyl group can include an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, or a heptyl group; an aryl group such as a phenyl group, a tolyl group, a xylyl group, or a naphthyl group; an aralkyl group such as a benzyl group or a phenethyl group; a halogen-substituted alkyl group such as a chloromethyl group, a 3-chloropropyl group, or a 3,3,3-trifluoropropyl group; and the like, and a methyl group or a phenyl group among the foregoing is generally applied, but is not limited thereto.

[0073] The molecular structure of the (1) organopolysiloxane is not particularly limited, and can also have any shape such as linear, branched, cyclic, network, or linear with partial branching. In such a molecular structure, a molecular structure having a linear molecular structure is generally applied, but is not limited thereto.

[0074] (1) More specific examples of organopolysiloxanes may include: dimethylsiloxane-methylvinylsiloxane copolymers with trimethylsiloxane-terminated ends of the molecular chain; methylvinylpolysiloxanes with trimethylsiloxane-terminated ends of the molecular chain; dimethylsiloxane-methylvinylsiloxane-methylphenylsiloxane copolymers with trimethylsiloxane-terminated ends of the molecular chain; dimethylpolysiloxanes with dimethylvinylsiloxane-terminated ends of the molecular chain; methylvinylpolysiloxanes with dimethylvinylsiloxane-terminated ends of the molecular chain; dimethylsiloxane-methylvinylsiloxane copolymers with dimethylvinylsiloxane-terminated ends of the molecular chain; dimethylsiloxane-methylvinylsiloxane-methylphenylsiloxane copolymers with dimethylvinylsiloxane-terminated ends of the molecular chain; dimethylsiloxane-methylvinylsiloxane-methylphenylsiloxane copolymers containing R 1 2SiO 2 / 2 The siloxane unit represented by R and the siloxane unit represented by R 1 2R 2 SiO 1 / 2 The siloxane unit represented and the siloxane unit composed of SiO 4 / 2 The organopolysiloxane copolymer representing the siloxane unit, comprising R 1 2R 2 SiO 1 / 2 The siloxane unit represented and the siloxane unit composed of SiO 4 / 2 The organopolysiloxane copolymer representing the siloxane unit, comprising R 1 R 2 SiO 2 / 2 The siloxane unit represented by R and the siloxane unit represented by R 1 SiO 3 / 2 The siloxane unit represented by R or made of 2 SiO 3 / 2 The term refers to organopolysiloxane copolymers containing siloxane units, and mixtures of two or more of the aforementioned, but is not limited thereto. Here, R... 1 This refers to a hydrocarbon group other than an alkenyl group, specifically an alkyl group, such as methyl, ethyl, propyl, butyl, pentyl, hexyl, or heptyl; an aryl group, such as phenyl, tolyl, xylyl, or naphthyl; an aralkyl group, such as benzyl or phenethyl; a halogen-substituted alkyl group, such as chloromethyl, 3-chloropropyl, or 3,3,3-trifluoropropyl; and so on. Furthermore, R... 2 It is an alkenyl group, specifically, it can be vinyl, allyl, butenyl, pentenyl, hexenyl or heptenyl, etc.

[0075] In the addition-curable silicone composition, the (2) organopolysiloxane can be used to crosslink the (1) organopolysiloxane. In the (2) organopolysiloxane, the bonding site of the hydrogen atom is not particularly limited, and it can be bonded to the terminal and / or side chain of the molecular chain, for example. Furthermore, in the (2) organopolysiloxane, the kind of substituent group that can be included in addition to the silicon-bonded hydrogen atom is not particularly limited, and it can include, for example, an alkyl group, an aryl group, an aralkyl group, or a halogen-substituted alkyl group, or the like as mentioned in the (1) organopolysiloxane, wherein a methyl group or a phenyl group is generally applied, but is not limited thereto.

[0076] The molecular structure of the (2) organopolysiloxane is not particularly limited, and can also have any shape, such as linear, branched, cyclic, network, or linear with partial branching. In such a molecular structure, a molecular structure having a linear molecular structure is generally applied, but is not limited thereto.

[0077] More specific examples of the (2) organopolysiloxane can include a methyl hydrogen polysiloxane terminated at both ends of the molecular chain with a trimethylsiloxy group, a dimethylsiloxane-methyl hydrogen copolymer terminated at both ends of the molecular chain with a trimethylsiloxy group, a dimethylsiloxane-methyl hydrogen siloxane-methyl phenyl siloxane copolymer terminated at both ends of the molecular chain with a trimethylsiloxy group, a dimethyl polysiloxane terminated at both ends of the molecular chain with a dimethyl hydrogen siloxane group, a dimethyl siloxane-methyl phenyl siloxane copolymer terminated at both ends of the molecular chain with a dimethyl hydrogen siloxane group, a methyl phenyl polysiloxane terminated at both ends of the molecular chain with a dimethyl hydrogen siloxane group, an organopolysiloxane copolymer containing siloxane units represented by R 1 3SiO 1 / 2 , siloxane units represented by R 1 2HSiO 1 / 2 , and siloxane units represented by SiO 4 / 2 , an organopolysiloxane copolymer containing siloxane units represented by R 1 2HSiO 1 / 2 , and siloxane units represented by SiO 4 / 2 , an organopolysiloxane copolymer containing siloxane units represented by R 1 HSiO 2 / 2 , and siloxane units represented by R 1 SiO 3 / 2 , or siloxane units represented by HSiO 3 / 2 , and a mixture of two or more of the foregoing, but is not limited thereto. Here, R 1For hydrocarbon groups other than alkenyl groups, specifically, it can be an alkyl group, such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, or a heptyl group; an aryl group, such as a phenyl group, a tolyl group, a xylyl group, or a naphthyl group; an aralkyl group, such as a benzyl group or a phenethyl group; a halogen-substituted alkyl group, such as a chloromethyl group, a 3-chloropropyl group, or a 3,3,3-trifluoropropyl group; and the like.

[0078] (2) The content of the organopolysiloxane is not particularly limited, as long as it is included to an extent that allows proper curing. For example, the (2) organopolysiloxane can be included in an amount of 0.5 to 10 silicon-bonded hydrogen atoms per 1 alkenyl group included in the (1) organopolysiloxane as described above. Within such a range, curing can be sufficiently performed and heat resistance can be ensured.

[0079] The addition-curable silicone composition can also include platinum or a platinum compound as a catalyst for curing. The specific type of the platinum or platinum compound is not particularly limited. The ratio of the catalyst can also be adjusted to a level that allows proper curing.

[0080] The addition-curable silicone composition can also include, at an appropriate ratio, appropriate additives that are required from the viewpoint of improving storage stability, handling properties, and processability.

[0081] In another example, the silicone composition that is a condensation-curable silicone composition can include, for example, (a) an alkoxyl group-containing siloxane polymer; and (b) a hydroxyl group-containing siloxane polymer.

[0082] The (a) siloxane polymer can be, for example, a compound represented by the following Formula 1.

[0083] [Formula 1]

[0084] R 1 a R 2 b SiO c (OR 3 ) d

[0085] In Formula 1, R 1 and R 2 each independently represent a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group, R 3 represents an alkyl group, where when a plurality of R 1 , R 2 , and R 3 are present, each can be the same as or different from one another, and a and b each independently represent a number of 0 or more and less than 1, a + b represents a number of greater than 0 and less than 2, c represents a number of greater than 0 and less than 2, d represents a number of greater than 0 and less than 4, and a + b + c x 2 + d is 4.

[0086] In the definition of Formula 1, the monovalent hydrocarbon group can be, for example, an alkyl group having 1 to 8 carbon atoms, a phenyl group, a benzyl group, or a tolyl group, etc., in which the alkyl group having 1 to 8 carbon atoms can be a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, or an octyl group, etc. Further, in the definition of Formula 1, the monovalent hydrocarbon group can be substituted with a known substituent such as a halogen, an amino group, a mercapto group, an isocyanate group, a glycidyl group, a glycidyloxy group, or a urea group.

[0087] In the definition of Formula 1, R 3 Examples of the alkyl group of R

[0088] In the polymer of Formula 1, a branched or tertiary crosslinked siloxane polymer can be used. Further, in the (a) siloxane polymer, a hydroxyl group can remain within a range that does not impair the purpose, specifically within a range that does not inhibit the dealcoholization reaction.

[0089] The (a) siloxane polymer can be produced, for example, by hydrolysis and condensation of a polyfunctional alkoxysilane or a polyfunctional chlorosilane, etc. A person of ordinary skill in the art can easily select an appropriate polyfunctional alkoxysilane or chlorosilane according to the desired (a) siloxane polymer, and can also easily control the conditions of the hydrolysis and condensation reaction using the same. Meanwhile, in the production of the (a) siloxane polymer, an appropriate monofunctional alkoxysilane can also be used in combination according to the purpose.

[0090] As the (a) siloxane polymer, for example, a commercially available organosiloxane polymer such as X40-9220 or X40-9225 of Shin-Etsu Silicone, or XR31-B1410, XR31-B0270, or XR31-B2733 of GE Toray Silicone can be used.

[0091] As the (b) hydroxyl group-containing siloxane polymer included in the condensation-curable silicone composition, for example, a compound represented by the following Formula 2 can be used.

[0092] [Formula 2]

[0093]

[0094] In Formula 2, R4and R5each independently represent a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group, in which when a plurality of R4and R5are present, they can be the same as or different from each other, and n represents an integer of 5 to 2,000.

[0095] In the limitation of Formula 2, specific types of the monovalent hydrocarbon group can include, for example, the same hydrocarbon groups as in the case of Formula 1 above.

[0096] The silicone polymer (b) can be produced, for example, by hydrolysis and condensation of a dialkoxysilane and / or dichlorosilane, etc. A person of ordinary skill in the art can easily select an appropriate dialkoxysilane or dichlorosilane according to the desired silicone polymer (b), and can also easily control the conditions of the hydrolysis and condensation reaction using the same. As the silicone polymer (b) as above, a commercially available difunctional organosiloxane polymer such as XC96-723, YF-3800, or YF-3804 of GE Toray Silicone, etc. can be used.

[0097] The addition-cured or condensation-cured silicone composition described above is an example of a material for forming a silicone pressure-sensitive adhesive or an adhesive applied in the present application. That is, substantially all silicone pressure-sensitive adhesives or adhesives referred to as OCA or OCR, etc. in the industry can be applied to the present application.

[0098] The type of the pressure-sensitive adhesive or adhesive or the curable composition forming the same is not particularly limited, and can be appropriately selected according to the intended use. For example, a solid, semi-solid, or liquid pressure-sensitive adhesive or adhesive or curable composition can be used. The solid or semi-solid pressure-sensitive adhesive or adhesive or curable composition can be cured before the adherend is bonded. The liquid pressure-sensitive adhesive or adhesive or curable composition is referred to as a so-called optically clear resin (OCR), which can be cured after the adherend is bonded. According to one example, as the pressure-sensitive adhesive or adhesive or curable composition, a so-called polydimethylsiloxane-based pressure-sensitive adhesive or adhesive or curable composition, or a polymethylvinylsiloxane-based pressure-sensitive adhesive or adhesive or curable composition, or an alkoxysilicone-based pressure-sensitive adhesive or adhesive or curable composition can be used, but is not limited thereto.

[0099] The thickness of the pressure-sensitive adhesive layer or adhesive layer is not particularly limited, and can be selected within an appropriate range to ensure the desired adhesion or cohesion. The thickness can be in the range of about 1 to 50 μm. In another example, the thickness can be 2 μm or more, 3 μm or more, 4 μm or more, 5 μm or more, 6 μm or more, 7 μm or more, 8 μm or more, 9 μm or more, or 10 μm or more, or can also be about 45 μm or less, 40 μm or less, 35 μm or less, 30 μm or less, 25 μm or less, 20 μm or less, 15 μm or less, or 10 μm or less.

[0100] Further, the kind of the alignment film formed on the first surface of the second substrate is not particularly limited. That is, a known vertical alignment film or a horizontal alignment film or other alignment film can be applied as the alignment film in view of the desired initial alignment. As for the type of the alignment film, a contact alignment film such as a rubbing alignment film or a non-contact alignment film such as a photo-alignment film can be applied. In one example, a vertical alignment film can be used as the alignment film. The combination of the vertical alignment film and the pressure-sensitive adhesive layer or the adhesive layer can induce an alignment state of the liquid crystal compound suitable for various uses.

[0101] The initial alignment of the liquid crystal compound in the liquid crystal layer of the light modulation layer formed by the pressure-sensitive adhesive layer or the adhesive layer and the liquid crystal alignment film can be a vertical alignment, a horizontal alignment, an oblique alignment, or a homeotropic alignment. Further, the liquid crystal compound can or can not be twisted in the vertical alignment, the horizontal alignment, the oblique alignment, or the homeotropic alignment state, thereby existing in a twisted alignment or a cholesteric alignment. Here, the initial alignment means an alignment in a state where no external signal such as a voltage is applied to the light modulation layer containing the liquid crystal compound.

[0102] The meaning of the horizontal alignment, the oblique alignment, the vertical alignment, or the homeotropic alignment is as known in the art. When the liquid crystal compound of the light modulation layer remains in the horizontal alignment, the oblique alignment, the vertical alignment, or the homeotropic alignment state in the initial state, it can become in other alignment states according to an external signal.

[0103] In one example, the initial alignment of the liquid crystal compound in the light modulation layer can be a vertical alignment or an alignment state similar to the vertical alignment. Such an alignment state is obtained by applying a vertical alignment film as the liquid crystal alignment film. Such an alignment is useful in an element that realizes a so-called R-TN (reverse-twisted nematic) alignment.

[0104] Further, when the liquid crystal alignment film is a horizontal alignment film, it is useful in an element that realizes a so-called ECB mode.

[0105] Accordingly, the planar phase difference (based on a wavelength of 550 nm) of the light modulation layer in the vertical alignment or the alignment state similar to the vertical alignment can be, for example, about 30 nm or less, 25 nm or less, 20 nm or less, 15 nm or less, 10 nm or less, or 5 nm or less, or can be 0 nm or more, or more than 0 nm.

[0106] The planar phase difference (or in-plane phase difference) can be obtained according to the following Equation 1.

[0107] [Equation 1]

[0108] Rin = d x (nx - ny)

[0109] In Equation 1, Rin is a planar phase difference or in-plane phase difference, nx is a slow axis direction refractive index of a liquid crystal compound in the optical modulation layer, ny is a fast axis direction refractive index of the liquid crystal compound in the optical modulation layer, and d is a thickness of the optical modulation layer.

[0110] The optical modulation film layer can further include a spacer for maintaining a spacing between the first substrate and the second substrate. As the spacer, a spherical spacer, a columnar spacer, or a partition spacer, which are commonly applied as spacers, can be applied. As the partition spacer, a honeycomb or quadrangular partition spacer, or a random spacer can be applied. Here, when the shape of the partition spacer formed on the substrate is observed from the normal direction of the substrate, as is well known, the honeycomb or quadrangular partition spacer means a case where the pattern formed by the partition spacer is of a honeycomb type or a quadrangular type. The honeycomb type is generally a combination of regular hexagons, and in the case of the quadrangular type, there can be a square, a rectangle, or a combination of a square and a rectangle, and the like. Further, here, the random spacer means a case where the relevant partitions are randomly arranged, where the relevant partitions do not form a pattern, or even if a pattern is formed, the pattern is randomly formed rather than a standard pattern.

[0111] The pitch of the spacer can also be appropriately selected in consideration of desired adhesiveness or cell gap maintaining efficiency, and the like. For example, when the partition spacer is applied, the pitch of the partition spacer can be in the range of 300 μm to 900 μm. In another example, the pitch can be 350 μm or more, 400 μm or more, 450 μm or more, 500 μm or more, or 550 μm or more, or can also be about 850 μm or less, 800 μm or less, 750 μm or less, 700 μm or less, 650 μm or less, or 600 μm or less. A method of obtaining the pitch in the partition spacer is known. For example, if the partition spacer is of the honeycomb type, the pitch is obtained by the interval of the opposite sides in the hexagon forming the honeycomb, and in the case of the quadrangular type, the pitch is obtained by the length of the sides of the quadrangle. In a case where the interval of the sides facing each other in the hexagon forming the honeycomb or the length of the sides of the quadrangle is not constant, their average value can be defined as the pitch.

[0112] Meanwhile, the line width of the partition spacer, for example, the width of each wall of the hexagon forming the honeycomb, or the quadrangle, can be in the range of, for example, about 5 μm to 50 μm. In another example, the line width can be about 10 μm or more, or 15 μm or more, or can also be about 45 μm or less, 40 μm or less, 35 μm or less, 30 μm or less, 25 μm or less, or 20 μm or less.

[0113] In the above range, the cell gap can be appropriately maintained, and the adhesiveness between the substrates can also be very well maintained.

[0114] Methods of forming the above spherical spacers, columnar spacers, or partition spacers between substrates are known.

[0115] As an assembly for applying an external signal to the light modulation layer, an electrode layer can be formed on each substrate of the light modulation film layer. For example, the electrode layer can exist between the first surface in the first substrate and the pressure-sensitive adhesive layer or the adhesive layer (between 100 and 1001 in Figure 1 ) and / or the first surface in the second substrate and the alignment film (between 200 and 2001 in Figure 1 ) (between the spacer and the alignment film if the spacer exists). In the case of the second substrate, the electrode layer is usually formed first on the first surface, and the spacer and the alignment film are sequentially formed on the electrode layer, so that the electrode layer can be located between the first surface of the second substrate and the spacer and the alignment film when the spacer exists.

[0116] As the electrode layer, known transparent electrode layers can be applied, and for example, a so-called conductive polymer layer, a conductive metal layer, a conductive nanowire layer, or a metal oxide layer such as ITO (indium tin oxide) can be used as the electrode layer. In addition, various materials capable of forming a transparent electrode layer and formation methods are known, which can be applied without limitation.

[0117] The light modulation device can include other additional configurations as needed while mainly including the light modulation film layer. That is, the implementation of the above transparent mode, black mode, high reflection mode, and / or low reflection mode and the switching therebetween are possible even in the case of a single light modulation film layer depending on the driving mode, but in order to facilitate the implementation or switching of these modes, additional assemblies can also be included.

[0118] For example, the device can further include a polarizing layer (passive polarizing layer) provided on one side or both sides of the light modulation film layer. As an example of the above structure, Figure 2 is a case where the polarizing layer 400 is provided on one side of the light modulation film layer in the structure of Figure 1 is a case where the polarizing layer 400 is provided on one side of the light modulation film layer in the structure of Figure 3 is a case where the polarizing layer 400 is provided on both sides of the light modulation film layer in the structure of Figure 1 is a case where the polarizing layer 400 is provided on both sides of the light modulation film layer in the structure of

[0119] The term polarization layer can mean an element that converts natural light or non-polarized light into polarized light. In one example, the polarization layer can be a linear polarization layer. The linear polarization layer means a case where selectively transmitted light is linearly polarized light vibrating in any direction and selectively absorbed or reflected light is linearly polarized light vibrating in a direction orthogonal to the vibration direction of the linearly polarized light. That is, the linear polarization layer can have a transmission axis and an absorption axis or a reflection axis orthogonal to each other in a planar direction.

[0120] The polarization layer can be an absorptive polarization layer or a reflective polarization layer. As the absorptive polarization layer, for example, a polarization layer in which iodine is dyed to a polymer stretched film such as a PVA stretched film, or a guest-host polarization layer in which a liquid crystal polymerized in an oriented state is used as a host and a dichroic dye arranged along the orientation of the liquid crystal is used as a guest can be used, but is not limited thereto.

[0121] As the reflective polarization layer, for example, a reflective polarization layer called a so-called DBEF (dual brightness enhancement film), or a reflective polarization layer formed by coating a liquid crystal compound such as an LLC (lyotropic liquid crystal) can be used, but is not limited thereto.

[0122] As shown in FIG. 1, the light modulation device can have a structure in which a polarization layer is disposed on one side of the light modulation film layer. In this case, the angle formed by the transmission axis of the polarization layer disposed on one side can be in the range of 85 degrees to 95 degrees, or approximately perpendicular. Figure 3

[0123] In addition to the above configuration, the light modulation device can further include other necessary configurations. For example, any other configuration required for driving or use of the light modulation device, such as a pressure-sensitive adhesive layer or an adhesive layer for attaching other components in addition to the pressure-sensitive adhesive layer or the adhesive layer formed on the first surface of the first substrate, a hard coat film, an anti-reflection film, and / or an NIR (near infrared) cut layer can be added.

[0124] The light modulation device of the present application can be applied to various applications. The application to which the light modulation device can be applied can be exemplified as an opening such as a window or a sunroof in an enclosed space including a building, a container, or a vehicle, or an eyewear or the like. Herein, in the range of eyewear, all eyewear formed so that an observer can observe the outside through a lens such as ordinary glasses, sunglasses, sports goggles, or a helmet, or a device for experiencing augmented reality can be included.

[0125] The present application relates to a method for manufacturing a light modulation device. In the present application, the light modulation device is manufactured by applying a roll-to-roll process. ​

[0126] In one example, the manufacturing method of the present application can include the step of attaching a first substrate in which a pressure-sensitive adhesive layer or an adhesive layer is formed on a first surface and a second substrate in which a spacer and a liquid crystal alignment film are formed on a first surface so that each first surface faces each other.

[0127] The contents of the first substrate and the second substrate and matters of the pressure-sensitive adhesive layer, the adhesive layer, the spacer, and the liquid crystal alignment film formed on each first surface thereof are the same as described above. In addition, as described above, an electrode layer can be present between the first surface of the first substrate and the pressure-sensitive adhesive layer or the adhesive layer and / or between the first surface of the second substrate and the liquid crystal alignment film and / or the spacer. For example, the second substrate can have a structure in which an electrode layer, a spacer, and a liquid crystal alignment film are formed on a first surface in this order.

[0128] The attachment of the first substrate and the second substrate can be performed while each substrate is transported by a roller.

[0129] In addition, the attachment can be performed so that the pressure-sensitive adhesive layer or the adhesive layer on the first surface of the first substrate and the spacer and / or the liquid crystal alignment film on the first surface of the second substrate are in physical contact.

[0130] Figure 4 is a diagram schematically showing a process in which a roll-to-roll process is performed.

[0131] As shown in the figure, the transportation of the first substrate 100 and the second substrate 200 by a roller can be performed while the first substrate 100 and the second substrate 200 wound on the unwinding roller 401 are unwound from the unwinding roller 401, respectively.

[0132] In one example, the first substrate can further include a release film attached to the pressure-sensitive adhesive layer or the adhesive layer to protect the pressure-sensitive adhesive layer or the adhesive layer formed on the first surface until the manufacturing process of the light modulation device. In this case, the first substrate to which the release film is attached can be wound on the unwinding roller. At this time, the type of the release film that can be applied is not particularly limited. In this case, a step of peeling the release film can be further performed before the attachment of the first substrate and the second substrate. The peeling method of the release film is not particularly limited. For example, as shown in Figure 4 the release roller 402 can be used to peel the release film before the attachment of the first substrate and the second substrate.

[0133] To protect the spacers and liquid crystal alignment film formed on the first surface of the second substrate, a protective film can be further formed and attached to the liquid crystal alignment film (first surface). Even in this case, the specific type of protective film is not particularly limited. Furthermore, even in this case, a step of peeling off the protective film can be performed before attaching the first and second substrates. A suitable peeling roller 402 can also be used to peel off the protective film.

[0134] like Figure 4 As shown, the first and second substrates can be attached simultaneously, for example, as the laminate of the first and second substrates passes between two attachment rollers 403. By attaching the first substrate, in which a pressure-sensitive adhesive layer or adhesive layer is formed on the first surface, and the second substrate, in which a spacer wall is formed on the first surface, in this way, the adhesion between the substrates can be maintained very well, and the manufacturing process of the optical modulation device can be completed quickly in a short time.

[0135] If necessary, a further step of supplying sealant to the edge of the first surface of the second substrate can be performed before attaching the first and second substrates. Figure 4 As shown, such a process can be performed, for example, by positioning the sealant supply component 404 at an appropriate position along the travel path of the second substrate 200 to be conveyed by the rollers. At this time, there are no particular limitations on the type and form of application of the sealant. For example, a curable sealant material used in the production of known liquid crystal devices can be used. When the sealant is supplied in this manner during the process and a curing process is performed on the sealant at an appropriate time after the substrates are attached, a light modulation device with better adhesion between the substrates can be formed. When the sealant is applied, as... Figure 4 As shown, after attaching the first substrate 100 and the second substrate 200, a further process can be performed to cure the sealant by passing the attached substrates 100, 200 through a curing member 406 that cures the sealant. The shape of the sealant curing member 406 can be selected based on the type of sealant applied; for example, a light irradiation device that irradiates the sealant with suitable light or a heat application device that applies heat to the sealant can be used.

[0136] In the manufacturing method of this application, a step of supplying an optical modulation material to the first surface of the second substrate can be performed before attaching the first substrate and the second substrate. When performing the step of supplying a sealant, the supply of the optical modulation material can be performed before or after the supply of the sealant, or it can be performed simultaneously with the supply of the sealant.

[0137] exist Figure 4 In this case, it is an example of using a light modulation material supply device 405 to supply light modulation material after the supply of sealant.

[0138] The specific kind of the light-modulating material is not particularly limited. For example, as described above, the light-modulating material can be a liquid crystal compound; a mixture of a liquid crystal compound and a dichroic dye; a mixture of a liquid crystal compound and a chiral dopant; or a mixture of a liquid crystal compound, a dichroic dye, and a chiral dopant.

[0139] Therefore, the manufacturing process can further proceed the step of supplying a liquid crystal compound; or a liquid crystal compound and a dichroic dye; or a liquid crystal compound and a chiral dopant to the first surface of the second substrate before attaching the first substrate and the second substrate.

[0140] Here, when the material containing the chiral dopant is supplied as the light-modulating material, the distance (d) between the first substrate and the second substrate during the attaching process can be adjusted so that the ratio (d / p) of the distance (d) to the chiral pitch (p) formed by the chiral dopant is within the above range.

[0141] As described above, the spacers formed on the first surface of the second substrate in the above process can be partition wall spacers. By using such partition wall spacers, a light-modulating device having excellent adhesion between the substrates can be manufactured.

[0142] The manufacturing method of the present application can proceed the step of applying appropriate heat to the pressure-sensitive adhesive layer or the adhesive layer formed on the first substrate at an appropriate time.

[0143] That is, when the pressure-sensitive adhesive layer or the adhesive layer is formed on the first surface of the first substrate and attached to the spacers or the liquid crystal alignment film on the first surface of the second substrate to constitute the light-modulating device, the above-described excellent adhesion can be achieved, but irregularities due to liquid crystal orientation abnormalities can occur due to the specific surface properties of the adhesive or the pressure-sensitive adhesive and surface damage caused by the shear force applied in the roll-to-roll manufacturing process, and the like. Therefore, the orientation irregularities can be prevented by performing heat treatment at an appropriate time in the process.

[0144] For example, the manufacturing process can further proceed the step of heat-treating the first substrate before attaching the first substrate and the second substrate.

[0145] The heat treatment can be performed at an appropriate temperature for a predetermined time. For example, the heat treatment can be performed at a temperature of about 80°C or higher. In another example, the heat treatment can be performed at a temperature of about 85°C or higher, about 90°C or higher, about 95°C or higher, or about 100°C or higher, or can also be performed at a temperature of about 200°C or lower, 190°C or lower, 180°C or lower, 170°C or lower, 160°C or lower, 150°C or lower, 140°C or lower, 130°C or lower, 120°C or lower, or 110°C or lower.

[0146] Further, the heat treatment can be performed for a time of about 30 seconds or longer, 60 seconds or longer, 90 seconds or longer, 120 seconds or longer, 150 seconds or longer, 180 seconds or longer, 210 seconds or longer, 240 seconds or longer, 270 seconds or longer, or 300 seconds or longer, or can be performed for a time of about 20 minutes or shorter, 18 minutes or shorter, 16 minutes or shorter, 14 minutes or shorter, 12 minutes or shorter, 10 minutes or shorter, 8 minutes or shorter, or 6 minutes or shorter.

[0147] In one example, the heat treatment can be performed before or after peeling the release film when the release film is attached to the pressure-sensitive adhesive layer or the adhesive layer.

[0148] In another example, the heat treatment can also be performed during the process of attaching the first substrate and the second substrate. In this case, the attachment of the first substrate and the second substrate can be performed at a temperature range higher than 50°C and lower than 90°C.

[0149] In another example, the attachment process can also be performed in a range of about 51°C or higher, 52°C or higher, 53°C or higher, 54°C or higher, 55°C or higher, about 56°C or higher, about 57°C or higher, about 58°C or higher, about 59°C or higher, or about 60°C or higher and / or in a range of lower than about 90°C, about 89°C or lower, 88°C or lower, 87°C or lower, 86°C or lower, 85°C or lower, 84°C or lower, 83°C or lower, 82°C or lower, 81°C or lower, or 80°C or lower.

[0150] In another example, the heat treatment can also be performed after attaching the first substrate and the second substrate. In this case, the manufacturing method of the present application can further include a step of performing a heat treatment on the attached first substrate and second substrate after attaching the first substrate and the second substrate.

[0151] The heat treatment can be performed at an appropriate temperature for a predetermined time. For example, the heat treatment can be performed at a temperature of about 60°C or more. In another example, the heat treatment can be performed at a temperature of about 65°C or more, about 70°C or more, 75°C or more, 80°C or more, about 85°C or more, about 90°C or more, about 95°C or more, or about 100°C or more, or can also be performed at a temperature of about 200°C or less, 190°C or less, 180°C or less, 170°C or less, 160°C or less, 150°C or less, 140°C or less, 130°C or less, 120°C or less, or 110°C or less. Further, the heat treatment can be performed for a time of about 30 seconds or more, 60 seconds or more, 90 seconds or more, 120 seconds or more, 150 seconds or more, 180 seconds or more, 210 seconds or more, 240 seconds or more, 270 seconds or more, or 300 seconds or more, or can be performed for a time of about 20 minutes or less, 18 minutes or less, 16 minutes or less, 14 minutes or less, 12 minutes or less, 10 minutes or less, 8 minutes or less, or 6 minutes or less.

[0152] By the heat treatment as described above, it is possible to address the problem in which irregularity appears due to liquid crystal alignment abnormality caused by surface damage due to specific surface properties of the adhesive or pressure-sensitive adhesive and shear force applied in a roll-to-roll manufacturing process, and the like.

[0153] Figure 5 is a result of observing the alignment irregularity when a heat treatment of keeping the first substrate to which the release release film is attached at about 100°C for about 5 minutes or so is performed before attaching the first substrate and the second substrate in the process of manufacturing the light modulation device by applying the method of the present application, Figure 6 is a graph showing a result of observing the alignment irregularity of the light modulation device manufactured in the same manner except that the heat treatment is not performed. By comparing Figure 5 and Figure 6 it is determined that the alignment irregularity can be greatly improved by the heat treatment.

[0154] Figure 7 is a result of observing the alignment irregularity when the attachment of the first substrate and the second substrate is performed at a temperature of about 80°C or so (in the case of Figure 6 , the attachment is performed at room temperature) assuming that the light modulation device is manufactured in the same manner as in the case of Figure 6 By comparing Figure 6 and Figure 7 it is determined that the alignment irregularity can be greatly improved by the temperature control during the attachment process.

[0155] Figure 8 is a result of observing the alignment irregularity when the attachment of the first substrate and the second substrate is performed at a temperature of about 80°C or so (in the case of Figure 6The light modulation device was manufactured in the same manner as in the case of Example 1, but the results of observing the orientation irregularity when the first substrate and the second substrate were held at a temperature of about 80°C for about 5 minutes in the attached state after the attachment of the first substrate and the second substrate. By comparison with Figure 6 and Figure 8 it was determined that the orientation irregularity can be greatly improved by the heat treatment after the attachment.

[0156] In addition to the above steps, the manufacturing process of the light modulation device of the present application can further proceed with appropriate necessary steps.

[0157] For example, as shown in Figure 4 , the process of curing the applied sealant via the sealant curing member 406 after the attachment or the step of cutting the prepared laminated structure (structure of the light modulation film layer) of the first substrate and the second substrate by passing through the appropriate cutting member 407 can also be performed.

[0158] Furthermore, if necessary, the process of attaching another element such as a polarizing layer or the like to one side or both sides of the laminated structure (light modulation film layer) can also be performed.

[0159] Finally, the manufactured light modulation device (or light modulation film layer) can be recovered by the winding roller 408.

[0160] By such a process, the light modulation device in which the desired adhesion and orientation state are achieved can be efficiently and quickly manufactured.

Claims

1. A method for manufacturing an optical modulation device by a roll-to-roll process, comprising the steps of: transporting, by a roll, a first substrate in which a pressure-sensitive adhesive layer or an adhesive layer is formed on a first surface and a second substrate in which a spacer and a liquid crystal alignment film are formed on a first surface, and simultaneously attaching the first substrate and the second substrate such that each first surface faces each other, wherein the pressure-sensitive adhesive layer or the adhesive layer is a pressure-sensitive adhesive or an adhesive based on silicone which is a cured product of a curable silicone adhesive or pressure-sensitive adhesive composition, wherein a step of heat-treating the first substrate is further performed before the first substrate and the second substrate are attached.

2. A method for manufacturing an optical modulation device by a roll-to-roll process, comprising the steps of: transporting, by a roll, a first substrate in which a pressure-sensitive adhesive layer or an adhesive layer is formed on a first surface and a second substrate in which a spacer and a liquid crystal alignment film are formed on a first surface, and simultaneously attaching the first substrate and the second substrate such that each first surface faces each other, wherein the pressure-sensitive adhesive layer or the adhesive layer is a pressure-sensitive adhesive or an adhesive based on silicone which is a cured product of a curable silicone adhesive or pressure-sensitive adhesive composition, wherein the attachment of the first substrate and the second substrate is performed in a temperature range higher than 50°C and lower than 90°C.

3. A method for manufacturing an optical modulation device by a roll-to-roll process, comprising the steps of: transporting, by a roll, a first substrate in which a pressure-sensitive adhesive layer or an adhesive layer is formed on a first surface and a second substrate in which a spacer and a liquid crystal alignment film are formed on a first surface, and simultaneously attaching the first substrate and the second substrate such that each first surface faces each other, wherein the pressure-sensitive adhesive layer or the adhesive layer is a pressure-sensitive adhesive or an adhesive based on silicone which is a cured product of a curable silicone adhesive or pressure-sensitive adhesive composition, wherein a step of heat-treating the attached first substrate and the second substrate is further performed after the first substrate and the second substrate are attached.

4. The method for manufacturing an optical modulation device according to any one of claims 1 to 3, wherein no liquid crystal alignment film is formed on the first substrate.

5. The method for manufacturing an optical modulation device according to any one of claims 1 to 3, wherein the first substrate further comprises a release film attached on the pressure-sensitive adhesive layer or the adhesive layer, and the method further comprises a step of peeling the release film before the first substrate and the second substrate are attached.

6. The method for manufacturing an optical modulation device according to any one of claims 1 to 3, wherein the second substrate further comprises a protective film attached on the first surface on which the spacer and the liquid crystal alignment film are formed, and the method further comprises a step of peeling the protective film before the first substrate and the second substrate are attached.

7. The method for manufacturing a light-modulating device according to any one of claims 1 to 3, further comprising a step of supplying a sealant to the edge of the first surface of the second substrate before attaching the first substrate and the second substrate.

8. The method for manufacturing a light-modulating device according to claim 7, further comprising a step of supplying a liquid crystal compound to the first surface of the second substrate before attaching the first substrate and the second substrate.

9. The method for manufacturing a light-modulating device according to claim 7, further comprising a step of supplying a liquid crystal compound and a dichroic dye to the first surface of the second substrate before attaching the first substrate and the second substrate.

10. The method for manufacturing a light-modulating device according to claim 7, further comprising a step of supplying a liquid crystal compound and a chiral dopant to the first surface of the second substrate before attaching the first substrate and the second substrate.

11. The method for manufacturing a light-modulating device according to claim 10, wherein the first substrate and the second substrate are attached so that the ratio d / p of the distance d between the first substrate and the second substrate to the chiral pitch p formed by the chiral dopant is less than 1.

12. The method for manufacturing a light-modulating device according to any one of claims 1 to 3, wherein the spacers of the second substrate are partition wall spacers.

13. The method for manufacturing a light-modulating device according to claim 1, wherein the heat treatment is performed at a temperature of 80°C or higher for 30 seconds or more.

14. The method for manufacturing a light-modulating device according to claim 3, wherein the heat treatment is performed at a temperature of 80°C or higher for 30 seconds or more.

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