Method for manufacturing an optical modulation device

Abstract

The present application can provide a so-called roll-to-roll process that can rapidly manufacture a light modulation device with excellent adhesion between two substrates while achieving a desired alignment state of the light modulation layer (e.g., a liquid crystal alignment state).

Description

[Technical Field]

[0001] This application claims priority based on Korean Patent Application No. 10-2020-0119125, filed on September 16, 2020, and the contents disclosed in the documents of that Korean patent application are incorporated herein by reference.

[0002] This application relates to a method for manufacturing an optical modulation device. [Background technology]

[0003] 2. Description of the Related Art Light modulation devices, which have a light modulation layer containing a liquid crystal compound between two substrates, are used for a variety of purposes.

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

[0005] Furthermore, in order to ensure the performance of the optical modulation device, it is necessary to ensure the adhesive strength between the two substrates arranged opposite to each other.

[0006] Although various methods for manufacturing optical devices are known, no method is known that can rapidly manufacture an optical modulation device that has excellent adhesion between two substrates while achieving a desired alignment state in the optical modulation layer. Summary of the Invention [Problem to be solved by the invention]

[0007] The present application aims to provide a method for manufacturing a light modulation device, a so-called roll-to-roll process that can rapidly manufacture a light modulation device that has excellent adhesion between two substrates while achieving a desired alignment state of the light modulation layer (e.g., a liquid crystal alignment state). [Means for solving the problem]

[0008] The present application may relate to a method for manufacturing a light modulation device in a roll-to-roll process.

[0009] The manufacturing method may include a step of attaching a first substrate having a pressure-sensitive adhesive layer or an adhesive layer formed on a first surface and a second substrate having a spacer and a liquid crystal alignment layer formed on a first surface, while transferring the first and second substrates by rolls, so that the first surfaces of the first and second substrates face each other.

[0010] In the manufacturing method, the first substrate may not have a liquid crystal alignment film formed thereon.

[0011] In the manufacturing method, the first substrate may further include a release film attached on the pressure-sensitive adhesive layer or the adhesive layer, and the manufacturing method may further include a step of peeling off the release film before attaching the first and second substrates.

[0012] In the manufacturing method, the second substrate may further include a protective film attached to a first surface on which the spacers and the liquid crystal alignment film are formed, and the manufacturing method may further include a step of peeling off the protective film before attaching the first and second substrates.

[0013] The manufacturing method may further include applying a sealant to an edge of the first surface of the second substrate before attaching the first and second substrates.

[0014] The method may further include the step of providing a liquid crystal compound; a liquid crystal compound and a dichroic dye; or a liquid crystal compound and a chiral dopant on the first surface of the second substrate before attaching the first and second substrates.

[0015] In the manufacturing method, the distance d between the first and second substrates can be adjusted so that the ratio (d / p) of the distance d to the chiral pitch p formed by the chiral dopant is less than 1.

[0016] In the manufacturing method, the spacers of the second substrate may be partition-type spacers.

[0017] The method may further include a step of heat treating the first substrate before attaching the first and second substrates, and the heat treatment may be performed at a temperature of 80° C. or more for 30 seconds or more.

[0018] In the manufacturing method, the attachment of the first and second substrates can be performed within a temperature range of greater than 50°C and less than 90°C.

[0019] The manufacturing method may further include a step of heat-treating the first and second substrates after the first and second substrates are attached, and the heat-treating may be performed at a temperature of 80° C. or more for 30 seconds or more. [Effects of the Invention]

[0020] The present application can provide a so-called roll-to-roll process that can rapidly manufacture a light modulation device with excellent adhesion between two substrates while achieving a desired alignment state of the light modulation layer (e.g., a liquid crystal alignment state). [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a schematic diagram of an exemplary light modulation device of the present application. [Figure 2] 1 is a schematic diagram of an exemplary light modulation device of the present application. [Figure 3] 1 is a schematic diagram of an exemplary light modulation device of the present application. [Figure 4] 1A to 1C are schematic diagrams showing the progress of the manufacturing process of the optical modulation device of the present application. [Figure 5] 10 is a photograph showing the presence or absence of alignment defects depending on whether or not a first substrate is subjected to a heat treatment. [Figure 6] 10 is a photograph showing the presence or absence of alignment defects depending on whether or not a first substrate is subjected to a heat treatment. [Figure 7]10 is a diagram showing the results of performing a heat treatment during the attachment of the first and second substrates. [Figure 8] 10 is a diagram showing the results when a heat treatment is performed after attachment of the first and second substrates. [Explanation of symbols]

[0022] 100: First board 200: Second board 1001: Pressure sensitive adhesive layer or adhesive layer 2001: Liquid crystal alignment film 600: Light modulation layer 400: Polarizing layer 401: Unwinding roll 402: Peeling roll 403: Adhesion roll 404: Sealant supply section 405: Light modulation material supply unit 406: Sealant hardening area 407: Cutting section 408: Winding roll DETAILED DESCRIPTION OF THE INVENTION

[0023] The terms "perpendicular," "parallel," "orthogonal," and "horizontal" used in this specification to define angles and their corresponding numerical values mean substantially perpendicular, parallel, orthogonal, or horizontal and the corresponding numerical values within a range that does not impair the intended effect, and the ranges of "perpendicular," "parallel," "orthogonal," and "horizontal" and the numerical values include errors such as manufacturing errors or variations. For example, in each of the above cases, there may be 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.

[0024] In the present specification, when the measurement temperature affects a physical property, the physical property is measured at room temperature unless otherwise specified. The term "room temperature" refers to a temperature in a state where the temperature is not particularly heated or cooled, and may refer to any temperature within the range of about 10°C to 30°C, for example, about 15°C or higher, 18°C or higher, 20°C or higher, or about 23°C or higher, but not higher than about 27°C. Furthermore, unless otherwise specified, the unit of temperature referred to in the present specification is °C.

[0025] The retardation and refractive index referred to in this specification refer to the refractive index for light with a wavelength of about 550 nm, unless otherwise specified.

[0026] Unless otherwise specified, the angle formed by any two directions referred to in this specification may be the acute angle between the acute and obtuse angles formed by the two directions, or the smaller angle between the angles measured in a clockwise and counterclockwise direction. Therefore, unless otherwise specified, angles referred to in this specification are positive numbers. However, in some cases, to indicate the measurement direction between angles measured in a clockwise or counterclockwise direction, one of the angle measured in the clockwise direction and the angle measured in the counterclockwise direction may be expressed as a positive number and the other angle may be expressed as a negative number.

[0027] This application relates to a method for manufacturing a light-modulating device. The term light-modulating device may refer to a device that can be switched between at least two or more different light states. In this context, the different light states may refer to states that differ in at least transmittance, reflectance, hue, and / or haze.

[0028] Examples of states that a light modulating device may embody include, but are not limited to, transmission, blocking, high reflection, low reflection, and / or a color mode state representing a particular color.

[0029] In one example, the light modulating device may be a device that can be switched between at least the transmission and blocking mode states, or a device that can be switched between the high reflection and low reflection mode states.

[0030] The light modulation device of the present application may be designed to be switchable between at least two or more states, including one state selected from the transmission mode, blocking mode, high reflection mode, low reflection mode, and color mode, and another state, and if necessary, a third or more different states may be realized in addition to the above states.

[0031] The switching of the optical modulation device can be controlled by the application of an external signal, e.g., a voltage signal. For example, in the absence of an external signal such as a voltage, the optical modulation device can maintain one of the aforementioned states, and can switch to another state when a voltage is applied. The mode state can be changed or the third other mode state can be realized by changing the strength, frequency, and / or form of the applied voltage.

[0032] The light modulation device of the present application may include, as a basic unit, a light modulation film layer having two substrates arranged opposite to each other and a light modulation layer positioned between the substrates. FIG. 1 is a diagram showing an example of the light modulation film layer. The light modulation film layer includes a first substrate 100 and a second substrate 200 arranged opposite to each other. As shown in the diagram, in the light modulation device of the present application, a pressure-sensitive adhesive layer or adhesive layer is formed on one surface (hereinafter referred to as the first surface) of the first substrate 100, a liquid crystal alignment film 2001 is formed on the other surface (hereinafter referred to as the first surface) of the second substrate 200, and a light modulation layer 600 may be positioned between the first substrate 100 and the second substrate 200 arranged opposite to each other. When the light modulating layer is a liquid crystal layer, a liquid crystal alignment film is typically formed on both surfaces of the first and second substrates 100 and 200. However, by forming a pressure sensitive adhesive layer or glue layer instead of a liquid crystal alignment film on the first substrate 100 and forming a liquid crystal alignment film only on the second substrate 200, an alignment state of the liquid crystal compound that is very useful for specific applications (e.g., smart windows and eyewear) can be obtained. Furthermore, when applied to the manufacturing process of the present application described below, this structure enables the rapid manufacture of a light modulating device that ensures excellent adhesion between the first and second substrates 100 and 200. Therefore, a liquid crystal alignment film may not be formed on the first substrate of the light modulating film layer of the present application. In addition, although not shown in the drawing, one of the first and second substrates of the light modulation film layer has a spacer that maintains the cell gap between the first and second substrates. When an adhesive layer or glue layer 1001 is formed on the first substrate 100 as shown in the drawing, the adhesive layer or glue layer 1001 is attached to the spacer, thereby greatly improving the adhesion between the first and second substrates.

[0033] In this specification, the first surface of a substrate refers to either the main surface or the opposite surface of the substrate, and the second surface refers to the other surface of the main surface or the opposite surface of the substrate.

[0034] The substrate may be made of any known substrate material without any particular limitation. For example, the substrate may be a glass substrate, an inorganic substrate such as a crystalline or amorphous silicon substrate or a quartz substrate, or a plastic substrate. However, for effective application to the manufacturing process of the present application, a plastic substrate may be used.

[0035] Examples of plastic substrates that can be used include, but are not limited to, triacetyl cellulose (TAC) substrates; cycloolefin copolymer (COP) substrates such as norbornene derivative substrates; poly(methyl methacrylate) (PMMA) substrates; polycarbonate (PC) substrates; polyethylene (PE) substrates; polypropylene (PP) substrates; polyvinyl alcohol (PVA) substrates; diacetyl cellulose (DAC) substrates; polyacrylate (PAC) substrates; polyether sulfone (PES) substrates; polyetheretherketon (PEEK) substrates; polyester substrates such as polyphenylsulfone (PPS) and polyetherimide (PEI) substrates; polyethylenenaphthlate (PEN) substrates; polyethyleneterephtalate (PET) substrates; polyimide (PI) substrates; polysulfone (PSF) substrates; polyarylate (PAR) substrates, and fluororesin substrates. The thickness of such substrates is not particularly limited and can be selected within an appropriate range.

[0036] The light modulation layer between the substrates is a functional layer that can change the transmittance, reflectance, haze, and / or color of light, either alone or in combination with other components, depending on whether an external signal is applied. Such a light modulation layer may be referred to as an active light modulation layer in this specification.

[0037] In this specification, an external signal may refer to an external factor that can affect the behavior of a substance contained in the light-modulating layer, for example, a light-modulating substance, such as an external voltage, etc. Therefore, a state without an external signal may refer to a state without application of an external voltage, etc.

[0038] In the present application, the type of the light modulation layer is not particularly limited as long as it has the above-mentioned functions, and any known light modulation layer may be used. The light modulation layer may be, for example, a liquid crystal layer, an electrochromic material layer, a photochromic material layer, an electrophoretic material layer, or a dispersed particle alignment layer.

[0039] In one example, the light modulation layer may be a liquid crystal layer. The liquid crystal layer is a layer containing a liquid crystal compound. In this specification, the term "liquid crystal layer" encompasses all layers containing a liquid crystal compound. For example, as described below, a so-called guest-host layer containing a liquid crystal compound (liquid crystal host) and a dichroic dye, or a layer containing a liquid crystal compound and other additives such as a chiral dopant, are also types of liquid crystal layers defined in this specification. The liquid crystal layer may be an active liquid crystal layer, and therefore the liquid crystal compound may exist within the liquid crystal layer so that its alignment direction changes depending on whether or not an external signal is applied. Any type of liquid crystal compound may be used as long as its alignment direction can be changed by the application of an external signal. For example, a smectic liquid crystal compound, a nematic liquid crystal compound, or a cholesteric liquid crystal compound may be used. In addition, the liquid crystal compound may not have a polymerizable group or a crosslinkable group, so that its alignment direction can be changed by the application of an external signal.

[0040] The liquid crystal layer may contain a liquid crystal compound having a positive or negative dielectric anisotropy. The absolute value of the dielectric anisotropy of the liquid crystal may be appropriately selected taking into account the objectives of the present application. The term "dielectric anisotropy (βε)" may refer to the difference (ε / / -ε⊥) between the horizontal dielectric constant (ε / / ) and the vertical dielectric constant (ε⊥) of the liquid crystal. As used herein, the term "horizontal dielectric constant (ε / / )" refers to the dielectric constant measured along the direction of an electric field when a voltage is applied such that the direction of the electric field is substantially horizontal to the director of the liquid crystal molecules, and the term "vertical dielectric constant (ε⊥)" refers to the dielectric constant measured along the direction of the electric field when a voltage is applied such that the direction of the electric field is substantially perpendicular to the director of the liquid crystal molecules.

[0041] Examples of driving modes for the liquid crystal layer include DS (Dynamic Scattering) mode, ECB (Electrically Controllable Birefringence) mode, IPS (In-Plane Switching) mode, FFS (Fringe-Field Switching) mode, OCB (Optially Compensated Bend) mode, VA (Vertical Alignment) mode, MVA (Multi-domain Vertical Alignment) mode, PVA (Patterned Vertical Alignment) mode, HAN (Hybrid Aligned Nematic) mode, TN (Twisted Nematic) mode, STN (Super Twisted Nematic) mode, and R-TN (Reversed Twisted Nematic) mode.

[0042] The light modulation layer, which is a liquid crystal layer, may further include a dichroic dye to adjust the light transmittance variable characteristics together with the liquid crystal compound. As used herein, the term "dye" refers to a material that can intensively absorb and / or transform light within at least a portion or all of the visible light range, e.g., a wavelength range of 400 nm to 700 nm, and the term "dichroic dye" refers to a material that can anisotropically absorb light within at least a portion or all of the visible light range. Examples of such dyes include, but are not limited to, known azo dyes and anthraquinone dyes.

[0043] In one example, the light modulation layer may be a so-called guest-host liquid crystal layer, which is a liquid crystal layer containing liquid crystal and a dichroic dye. The term guest-host liquid crystal layer, also known as a GHLC layer, refers to a functional layer in which the dichroic dye is aligned along the alignment direction of the liquid crystal and exhibits anisotropic light absorption characteristics in both the alignment direction of the dichroic dye and the direction perpendicular to the alignment direction. For example, a dichroic dye is a material whose light absorption rate varies depending on the polarization direction. If the dichroic dye has a high absorption rate for light polarized along its long axis, it is called a p-type dye, and if the dichroic dye has a high absorption rate for light polarized along its short axis, it is called an n-type dye. In one example, when a p-type dye is used, polarized light vibrating along the long axis of the dye is absorbed, while polarized light vibrating along the short axis of the dye is less absorbed and can be transmitted. Hereinafter, unless otherwise specified, the dichroic dye is assumed to be a p-type dye.

[0044] A light-modulating film layer including a guest-host liquid crystal layer as a light-modulating layer can function as an active polarizer. As used herein, the term "active polarizer" refers to a functional element that can adjust anisotropic light absorption by applying an external signal. Such an active polarizer can be distinguished from a passive polarizer, which has constant light absorption or light reflection properties regardless of the application of an external signal. The guest-host liquid crystal layer can adjust the anisotropic light absorption for light polarized parallel and perpendicular to the dichroic dye alignment direction by adjusting the alignment of the liquid crystal and dichroic dye. Because the alignment of the liquid crystal and dichroic dye can be adjusted by applying an external signal, such as a magnetic field or an electric field, the guest-host liquid crystal layer can adjust the anisotropic light absorption by applying an external signal.

[0045] The liquid crystal layer, which is the light modulation layer, may contain a so-called chiral dopant together with the liquid crystal compound. Such a chiral dopant can induce helical structural alignment in the liquid crystal compound. The type of chiral dopant that can be contained is not particularly limited, and an appropriate chiral dopant can be selected from known types as needed. The ratio of the chiral dopant is also not particularly limited, but the chiral dopant can be contained in a ratio that allows 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 generated by the addition of the chiral dopant to be less than 1. In other examples, the ratio (d / p) may 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 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) may be linked to the alignment of the liquid crystal compound induced by the pressure-sensitive adhesive layer or adhesive layer and the liquid crystal alignment film, thereby leading to an alignment state suitable for the application.

[0046] The thickness of the light modulation layer (cell gap) may be appropriately selected taking into account the objectives of the present application. In one example, the thickness of the light modulation layer may be 0.01 μm or more, 0.1 μm or more, 1 μm or more, 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. In this way, a device with a large difference in transmittance, reflectance, haze, and / or hue depending on the mode state can be realized depending on the thickness. The thickness is not particularly limited because the greater the difference, the more easily the difference can be realized. However, the thickness may typically be about 30 μm or less, 25 μm or less, 20 μm or less, or 15 μm or less.

[0047] The type of adhesive layer or glue layer formed on the first surface of the first substrate in the light modulation film layer is not particularly limited. Various types of adhesives or glues, known in the industry as OCA (Optically Clear Adhesive) or OCR (Optically Clear Resin), can be combined with the liquid crystal alignment film to induce the appropriate alignment of the liquid crystal compound. Examples of the adhesive or glue include acrylic, silicone, epoxy, and urethane adhesives.

[0048] An example of a suitable adhesive or pressure-sensitive adhesive is a silicone adhesive or pressure-sensitive adhesive. The unique surface properties of the silicone adhesive or pressure-sensitive adhesive can induce a suitable alignment state of the liquid crystal compound in combination with a liquid crystal alignment film (particularly, a vertical alignment film).

[0049] The silicone-based adhesive or pressure-sensitive adhesive may be a cured product of a curable silicone adhesive or pressure-sensitive adhesive composition (hereinafter simply referred to as a curable silicone composition). The type of curable silicone composition is not particularly limited, and for example, a heat-curable silicone composition or an ultraviolet-curable silicone composition may be used.

[0050] In one example, the curable silicone composition is an addition-curable silicone composition that includes (1) an organopolysiloxane containing two or more alkenyl groups per molecule and (2) an organopolysiloxane containing two or more silicon-bonded hydrogen atoms per molecule. Such silicon compounds can form a cured product by addition reaction in the presence of a catalyst such as a platinum catalyst.

[0051] The organopolysiloxane (1) is the main component constituting the cured silicone material and contains at least two alkenyl groups per molecule. Specific examples of the alkenyl groups include vinyl, allyl, butenyl, pentenyl, hexenyl, and heptenyl groups, among which vinyl groups are commonly used, but are not limited thereto. The bonding position of the alkenyl groups in the organopolysiloxane (1) is not particularly limited. For example, the alkenyl groups may be bonded to the ends of branched chains and / or to side chains of branched chains. In addition to the alkenyl, the types of substituents that may be contained in the organopolysiloxane (1) include alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, and heptyl; aryl groups such as phenyl, tolyl, xylyl, and naphthyl; aralkyl groups such as benzyl and phenethyl; and halogen-substituted alkyl groups such as chloromethyl, 3-chloropropyl, and 3,3,3-trifluoropropyl. Of these, methyl and phenyl groups are typically used, but the present invention is not limited thereto.

[0052] The molecular structure of the organopolysiloxane (1) is not particularly limited, and may have any shape, such as linear, branched, cyclic, network, or linear with some branching, etc. Of the molecular structures described above, those having a linear molecular structure are usually used, but are not limited thereto.

[0053] More specific examples of the organopolysiloxane (1) include a dimethylsiloxane-methylvinylsiloxane copolymer having both branched chain ends capped with trimethylsiloxane groups, a methylvinylpolysiloxane having both branched chain ends capped with trimethylsiloxane groups, a dimethylsiloxane-methylvinylsiloxane-methylphenylsiloxane copolymer having both branched chain ends capped with trimethylsiloxane groups, a dimethylpolysiloxane having both branched chain ends capped with dimethylvinylsiloxane groups, a methylvinylpolysiloxane having both branched chain ends capped with dimethylvinylsiloxane groups, a dimethylsiloxane-methylvinylsiloxane copolymer having both branched chain ends capped with dimethylvinylsiloxane groups, a dimethylsiloxane-methylvinylsiloxane-methylphenylsiloxane copolymer having both branched chain ends capped with dimethylvinylsiloxane groups, and 1 2SiO 2 / 2 The siloxane unit represented by R 1 Siloxane unit expressed as 2R2SiO1 / 2 and SiO 4 / 2 Organopolysiloxane copolymers containing siloxane units represented by R 1 2R2SiO 1 / 2 The siloxane unit represented by SiO 4 / 2 Organopolysiloxane copolymers containing siloxane units represented by R 1 R 2 SiO 2 / 2 The siloxane unit represented by R 1 SiO 3 / 2 Siloxane units denoted by R 2 SiO 3 / 2 Examples of suitable organopolysiloxane copolymers include, but are not limited to, organopolysiloxane copolymers containing siloxane units represented by the formula: 1 is a hydrocarbon group other than an alkenyl group, specifically 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; or a halogen-substituted alkyl group such as a chloromethyl group, a 3-chloropropyl group, or a 3,3,3-trifluoropropyl group. 2is an alkenyl group, and specifically may be a vinyl group, an allyl group, a butenyl group, a pentenyl group, a hexenyl group, a heptenyl group, or the like.

[0054] In the addition-curable silicone composition, the (2) organopolysiloxane can crosslink the (1) organopolysiloxane. The bonding position of the hydrogen atoms in the (2) organopolysiloxane is not particularly limited, and for example, they may be bonded to the end of a branched chain and / or a side chain. Furthermore, the types of substituents that may be included in the (2) organopolysiloxane in addition to the silicon-bonded hydrogen atoms are not particularly limited, and examples include alkyl groups, aryl groups, aralkyl groups, and halogen-substituted alkyl groups, as described for the (1) organopolysiloxane. Among these, methyl groups and phenyl groups are typically used, but are not limited thereto.

[0055] The molecular structure of the organopolysiloxane (2) is not particularly limited, and may have any shape, such as linear, branched, cyclic, network, or linear with some branching, etc. Among the molecular structures described above, those having a linear molecular structure are usually used, but are not limited thereto.

[0056] More specific examples of the (2) organopolysiloxane include methylhydrogenpolysiloxanes having both branched chain ends blocked with trimethylsiloxane groups, dimethylsiloxane-methylhydrogen copolymers having both branched chain ends blocked with trimethylsiloxane groups, dimethylsiloxane-methylhydrogensiloxane-methylphenylsiloxane copolymers having both branched chain ends blocked with trimethylsiloxane groups, dimethylpolysiloxanes having both branched chain ends blocked with dimethylhydrogensiloxane groups, dimethylsiloxane-methylphenylsiloxane copolymers having both branched chain ends blocked with dimethylhydrogensiloxane groups, methylphenylpolysiloxanes having both branched chain ends blocked with dimethylhydrogensiloxane groups, R 1 3SiO 1 / 2 The siloxane unit represented by R 1 2HSiO 1 / 2The siloxane unit represented by SiO 4 / 2 Organopolysiloxane copolymers containing siloxane units represented by R 1 2HSiO 1 / 2 The siloxane unit represented by SiO 4 / 2 Organopolysiloxane copolymers containing siloxane units represented by R 1 HSiO 2 / 2 The siloxane unit represented by R 1 SiO 3 / 2 Siloxane units denoted by HSiO 3 / 2 Examples of suitable organopolysiloxanes include, but are not limited to, organopolysiloxane copolymers containing siloxane units represented by the formula: 1 is a hydrocarbon group other than an alkenyl group, and specifically may 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; or a halogen-substituted alkyl group such as a chloromethyl group, a 3-chloropropyl group, or a 3,3,3-trifluoropropyl group.

[0057] The content of the (2) organopolysiloxane is not particularly limited as long as it is present in an amount that allows for appropriate curing. For example, the (2) organopolysiloxane may be present in an amount such that the number of silicon-bonded hydrogen atoms is 0.5 to 10 per alkenyl group contained in the (1) organopolysiloxane. Within this range, curing can proceed sufficiently and heat resistance can be ensured.

[0058] The addition-curable silicone composition may further include platinum or a platinum compound as a curing catalyst. The specific type of platinum or platinum compound is not particularly limited. The catalyst ratio may be adjusted to a level that allows for appropriate curing.

[0059] The addition-curable silicone composition may contain appropriate additives in appropriate proportions required to improve storage stability, handling, and workability.

[0060] In another example, the silicone composition is a condensation-curable silicone composition, and can include, for example, (a) an alkoxy-containing siloxane polymer; and (b) a hydroxyl-containing siloxane polymer.

[0061] The (a) siloxane polymer may be, for example, a compound represented by the following Chemical Formula 1:

[0062] [Chemical formula 1] R 1 a R 2 b SiO c (OR 3 ) d

[0063] R in Chemical Formula 1 1 and R 2 each independently represents a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group, and R 3 represents an alkyl group, and R 1 , R 2 and R 3 When there are multiple of each, they may be the same or different, a and b each independently represent a number greater than or equal to 0 and less than 1, a+b represents a number greater than 0 and less than 2, c represents a number greater than 0 and less than 2, d represents a number greater than 0 and less than 4, and a+b+cX2+d is 4.

[0064] In the definition of Chemical Formula 1, the monovalent hydrocarbon group may be, for example, an alkyl group having 1 to 8 carbon atoms, a phenyl group, a benzyl group, or a tolyl group, and in this case, the alkyl group having 1 to 8 carbon atoms may 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. In addition, in the definition of Chemical Formula 1, the monovalent hydrocarbon group may be substituted with a known substituent such as a halogen, an amino group, a mercapto group, an isocyanate group, a glycidyl group, a glycidoxy group, or a ureido group.

[0065] In the definition of chemical formula 1, R 3 Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, and a butyl group. Among the alkyl groups, a methyl group or an ethyl group is usually used, but is not limited thereto.

[0066] A branched or tertiary crosslinked siloxane polymer can be used among the polymers of Chemical Formula 1. In addition, this (a) siloxane polymer may have residual hydroxyl groups within a range that does not impair the intended purpose, specifically, within a range that does not inhibit the dealcoholization reaction.

[0067] The (a) siloxane polymer can be produced, for example, by hydrolysis and condensation of a polyfunctional alkoxysilane or a polyfunctional chlorosilane. A skilled artisan can easily select an appropriate polyfunctional alkoxysilane or chlorosilane for the desired (a) siloxane polymer, and can easily control the conditions for the hydrolysis and condensation reaction using the selected alkoxysilane. Meanwhile, when producing the (a) siloxane polymer, an appropriate monofunctional alkoxysilane may also be used in combination depending on the purpose.

[0068] As the (a) siloxane polymer, for example, commercially available organosiloxane polymers such as X40-9220 or X40-9225 from Shin-Etsu Silicones, and XR31-B1410, XR31-B0270 or XR31-B2733 from GE Toray Silicones can be used.

[0069] As the (b) hydroxyl group-containing siloxane polymer contained in the condensation-curable silicone composition, for example, a compound represented by the following chemical formula 2 can be used.

[0070] [Chemical formula 2] [ka]

[0071] In formula 2, R 4 and R 5 each independently represents a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group; R 4 and R 5 When there are a plurality of each of these, they may be the same or different, and n represents an integer of 5 to 2,000.

[0072] In the definition of Chemical Formula 2, specific types of monovalent hydrocarbon groups include, for example, the same hydrocarbon groups as in Chemical Formula 1 above.

[0073] The (b) siloxane polymer can be produced, for example, by hydrolysis and condensation of dialkoxysilane and / or dichlorosilane. A person skilled in the art can easily select an appropriate dialkoxysilane or dichlorosilane for the desired (b) siloxane polymer, and can easily control the conditions for the hydrolysis and condensation reaction using the dialkoxysilane or dichlorosilane. As the (b) siloxane polymer, commercially available bifunctional organosiloxane polymers such as XC96-723, YF-3800, and YF-3804 from GE Toray Silicone Co., Ltd. can be used.

[0074] The above-mentioned addition-curing or condensation-curing silicone composition is one example of a material for forming a silicone pressure-sensitive adhesive or adhesive that can be used in the present application. In other words, basically, any silicone pressure-sensitive adhesive or adhesive known in the industry, such as OCA or OCR, can be used in the present application.

[0075] The type of the adhesive or pressure-sensitive adhesive or the curable composition forming the adhesive is not particularly limited and can be appropriately selected depending on the intended application. For example, solid, semi-solid, or liquid phase adhesives, adhesives, or curable compositions can be used. Solid or semi-solid phase adhesives, adhesives, or curable compositions can be cured before the objects to be bonded are joined. Liquid phase adhesives, adhesives, or curable compositions, known as optically clear resins (OCR), can be cured after the objects to be bonded are joined. For example, the adhesive or adhesive or curable composition can be, but is not limited to, a polydimethyl siloxane-based adhesive, adhesive, or curable composition, a polymethylvinyl siloxane-based adhesive, adhesive, or curable composition, or an alkoxy silicone-based adhesive, adhesive, or curable composition.

[0076] 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 adhesive strength. The thickness can be approximately within the range of 1 μm to 50 μm. Other examples of the thickness include 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 approximately 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.

[0077] The type of alignment layer formed on the first surface of the second substrate is not particularly limited. That is, the alignment layer may be a known vertical or horizontal alignment layer or other alignment layer, taking into account the desired initial alignment. The alignment layer may be a contact-type alignment layer such as a rubbing alignment layer or a non-contact-type alignment layer such as a photo-alignment layer. In one example, a vertical alignment layer may be used as the alignment layer. The combination of the vertical alignment layer and the pressure-sensitive adhesive layer or adhesive layer can induce an alignment state of the liquid crystal compound suitable for various applications.

[0078] In the liquid crystal layer, which is a light modulation layer, the initial alignment of the liquid crystal compound formed by the pressure-sensitive adhesive layer or adhesive layer and the liquid crystal alignment film may be vertical alignment, horizontal alignment, tilt alignment, or splay alignment. In addition, in the vertical alignment, horizontal alignment, tilt alignment, or splay alignment state, the liquid crystal compound may be twisted to exist in a twist alignment or cholesteric alignment state, or may not. The initial alignment refers to the alignment in a state where no external signal such as voltage is applied to the light modulation layer containing the liquid crystal compound.

[0079] The meanings of the horizontal alignment, tilt alignment, vertical alignment, and splay alignment are as known in the art. The liquid crystal compound in the light modulation layer initially maintains the horizontal alignment, tilt alignment, vertical alignment, or splay alignment state, and can be changed to a different alignment state by an external signal.

[0080] In one example, the initial alignment of the liquid crystal compound in the light modulation layer may be a vertical alignment or an alignment state similar to a vertical alignment. Such an alignment state can be obtained by using a vertical alignment film as the liquid crystal alignment film. Such an alignment is useful in a device that realizes a so-called R-TN (Reversed Twisted Nematic) alignment.

[0081] In addition, when the liquid crystal alignment film is a horizontal alignment film, it is useful for a device that realizes the so-called ECB mode.

[0082] Therefore, the in-plane retardation (based on a wavelength of 550 nm) of the light modulation layer in the vertically aligned or vertically similar alignment state may 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 may be 0 nm or more or greater than 0 nm.

[0083] The on-plane retardation (or in-plane retardation) can be calculated by the following Equation 1.

[0084] [Formula 1] Rin=d×(nx-ny)

[0085] In Equation 1, Rin is the in-plane retardation or in-plane retardation, nx is the refractive index of the liquid crystal compound in the light modulation layer in the slow axis direction, ny is the refractive index of the liquid crystal compound in the light modulation layer in the fast axis direction, and d is the thickness of the light modulation layer.

[0086] The light modulation film layer may further include spacers that maintain the distance between the first and second substrates. Commonly used spacers include ball spacers, column spacers, and partition-type spacers. The partition-type spacers may be honeycomb-type, rectangular partition-type spacers, or random-type spacers. As is well known, the honeycomb-type or rectangular partition-type spacers refer to a honeycomb-type or rectangular shape formed by the partition-type spacers when observed from the normal direction of the substrate. The honeycomb-type or rectangular shape is typically a combination of regular hexagons. The rectangular shape may be a regular square, a rectangle, or a combination of a square and a rectangle. The random-type spacers refer to a randomly arranged partition, where the partitions do not form a shape or, if formed, form a random shape without a fixed shape.

[0087] The pitch of the spacers may also be appropriately selected taking into consideration the desired adhesive strength and cell gap maintenance efficiency. For example, when partition-type spacers are used, the pitch of the partition-type spacers may be in the range of 300 μm to 900 μm. Other examples of the pitch include 350 μm or more, 400 μm or more, 450 μm or more, 500 μm or more, or 550 μm or more, or 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. Methods for determining the pitch of partition-type spacers are well known. For example, if the partition-type spacer is honeycomb-shaped, the pitch is determined from the distance between opposing sides of the hexagons constituting the honeycomb. If the distance between opposing sides of the hexagons constituting the honeycomb or the length of the sides of the rectangles is not constant, the average value of these distances may be defined as the pitch.

[0088] Meanwhile, the spacing between the partition-type spacers, for example, the width of each wall of the hexagonal or rectangular honeycomb, may be, for example, in the range of about 5 μm to 50 μm. In other examples, the spacing may be about 10 μm or more, or 15 μm or more, or 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.

[0089] Within this range, the cell gap can be appropriately maintained and excellent adhesion between the substrates can be maintained.

[0090] The method of forming the ball spacers, column spacers, or barrier-type spacers between substrates is well known.

[0091] An electrode layer may be formed on each substrate of the light modulation film layer as a component for applying an external signal to the light modulation layer. For example, an electrode layer may be present between the first surface and the pressure-sensitive adhesive or adhesive layer of the first substrate (between 100 and 1001 in FIG. 1) and / or between the first surface and the alignment layer of the second substrate (between 200 and 2001 in FIG. 1) (or between the spacer and the alignment layer if a spacer is present). In the case of the second substrate, it is common to first form an electrode layer on the first surface, and then sequentially form a spacer and alignment layer thereon. Therefore, if a spacer is present, the electrode layer may be located between the first surface of the second substrate and the spacer and alignment layer.

[0092] The electrode layer may be a known transparent electrode layer, such as a conductive polymer layer, a conductive metal layer, a conductive nanowire layer, or a metal oxide layer such as ITO (Indium Tin Oxide).A variety of materials and methods for forming a transparent electrode layer are known, and these may be used without limitation.

[0093] The light modulation device basically includes the light modulation film layer, and may include additional components as necessary. That is, depending on the driving mode, the light modulation film layer alone can realize the transmission, blocking, high reflection, and / or low reflection modes and switch between them, but the light modulation device may include additional components to facilitate the realization or switching of such modes.

[0094] For example, the device may further include a polarizing layer (passive polarizing layer) disposed on one or both sides of the light modulating film layer. Figure 2 shows an example of the structure, in which a polarizing layer 400 is disposed on only one side of the light modulating film layer in the structure of Figure 1, and Figure 3 shows a case in which a polarizing layer 400 is disposed on both sides of the light modulating film layer in the structure of Figure 1. In addition, when the partition-type spacer is used as the spacer and has a quadrilateral shape (a regular square or a rectangle), it is appropriate that the sides of the quadrilateral and the absorption axis of the polarizing layer are disposed substantially perpendicular or horizontal to each other.

[0095] The term "polarizing layer" may refer to an element that converts natural light or unpolarized light into polarized light. In one example, the polarizing layer may be a linear polarizing layer. A linear polarizing layer refers to a layer in which selectively transmitted light is linearly polarized light that vibrates in one direction, and selectively absorbed or reflected light is linearly polarized light that vibrates in a direction perpendicular to the vibration direction of the linearly polarized light. That is, the linear polarizing layer may have a transmission axis and an absorption axis or a reflection axis that are perpendicular to each other in the plane direction.

[0096] The polarizing layer may be an absorptive polarizing layer or a reflective polarizing layer, and examples of the absorptive polarizing layer include, but are not limited to, a polarizing layer obtained by dyeing a stretched polymer film such as a PVA (poly(vinyl alcohol)) stretched film with iodine, or a guest-host polarizing layer having a liquid crystal polymerized in an oriented state as a host and a dichroic dye aligned by the orientation of the liquid crystal as a guest.

[0097] The reflective polarizing layer may be, for example, a reflective polarizing layer known as a DBEF (Dual Brightness Enhancement Film) or a reflective polarizing layer formed by coating a liquid crystal compound such as LLC (Lyotropic liquid crystal), but is not limited thereto.

[0098] The polarizing layers may be disposed on both sides of the light modulation film layer as shown in Fig. 3. In this case, the angle formed by the transmission axes of the polarizing layers disposed on both sides may be within a range of 85 degrees to 95 degrees or may be approximately perpendicular.

[0099] The light modulation device may further include other components necessary for driving or using the light modulation device, such as a pressure-sensitive adhesive layer or adhesive layer for attaching other components in addition to the pressure-sensitive adhesive layer or adhesive layer formed on the first surface of the first substrate, a hard coating film, an anti-reflection film, and / or a near-infrared (NIR) cut layer.

[0100] The light modulation device of the present application may be applied to a variety of applications. Examples of applications to which the light modulation device may be applied include openings in enclosed spaces such as windows or sunroofs in buildings, containers, vehicles, etc., and eyewear. The scope of eyewear may include all eyewear that allows a viewer to view the outside through lenses, such as general glasses, sunglasses, sports goggles, helmets, and augmented reality devices.

[0101] The present application relates to a method for manufacturing the optical modulation device. In the present application, the optical modulation device is manufactured by applying a roll-to-roll process.

[0102] In one example, the manufacturing method of the present application may include a step of attaching a first substrate having a pressure-sensitive adhesive layer or adhesive layer formed on the first surface and a second substrate having a spacer and a liquid crystal alignment film formed on the first surface such that their first surfaces face each other.

[0103] The details of the first and second substrates and the adhesive layer, adhesive layer, spacer, and liquid crystal alignment layer formed on their respective first surfaces are as described above. Also, as described above, an electrode layer may be present between the first surface of the first substrate and the adhesive layer or adhesive layer and / or between the first surface of the second substrate and the liquid crystal alignment layer and / or spacer. For example, the second substrate may have a structure in which the electrode layer, the spacer, and the liquid crystal alignment layer are formed in this order on the first surface.

[0104] The attachment of the first and second substrates can be performed by transferring each substrate by a roll.

[0105] Also, the attachment may be performed so that the pressure sensitive adhesive layer or adhesive layer on the first surface of the first substrate is in physical contact with the spacer and / or liquid crystal alignment layer on the first surface of the second substrate.

[0106] FIG. 4 is a diagram illustrating a process of performing the roll-to-roll process.

[0107] As shown in the drawing, the first and second substrates 100 and 200 may be transported by the rolls while the first and second substrates 100 and 200 wound around the unwinding rolls 401 are unwound from the unwinding rolls 401 .

[0108] In one example, the first substrate may further include a release film attached to the pressure-sensitive adhesive layer or adhesive layer formed on the first surface to protect the pressure-sensitive adhesive layer or adhesive layer prior to the manufacturing process of the optical modulation device. In this case, the first substrate to which the release film is attached may be wound around a winding roll. In this case, the type of release film that can be applied is not particularly limited. In this case, a step of peeling the release film may be further performed before the first and second substrates are attached. The method of peeling the release film is not particularly limited. For example, as shown in FIG. 4, the release film may be peeled using a peeling roll 402 before the first and second substrates are attached.

[0109] The second substrate may also have a protective film attached to the liquid crystal alignment layer (first surface) to protect the spacers and the liquid crystal alignment layer formed on the first surface thereof. In this case, the specific type of the protective film is not particularly limited. Also, in this case, a step of peeling off the protective film may be further performed before the first and second substrates are attached. The peeling off of the protective film may also be performed using an appropriate peeling roll 402.

[0110] The attachment of the first and second substrates can be performed by passing the laminate of the first and second substrates between two attachment rolls 403, as shown in Fig. 4. By attaching the first substrate having a pressure-sensitive adhesive layer or adhesive layer formed on its first surface to the second substrate having a partition-type spacer formed on its first surface in this manner, excellent adhesion between the substrates can be maintained, and the manufacturing process of the optical modulation device can be completed quickly within a short period of time.

[0111] If necessary, a sealant may be applied to the edge of the first surface of the second substrate before the first and second substrates are attached. This process may be performed, for example, by positioning a sealant dispenser 404 at an appropriate position along the path of the second substrate 200, which is transported by a roll, as shown in FIG. 4. The type and application form of the sealant are not particularly limited. For example, a known curable sealant material used in the manufacture of liquid crystal devices may be used. By applying the sealant and curing the sealant at an appropriate time after the substrates are attached, a light modulation device with excellent adhesion between the substrates can be formed. If a sealant is applied, a process of curing the sealant may be performed after the attachment of the first and second substrates 100, 200 by passing the attached substrates 100, 200 through a curing unit 406, which cures the sealant, as shown in FIG. 4. The shape of the sealant curing portion 406 can be selected taking into consideration the type of sealant applied. For example, a light irradiation device that irradiates the sealant with appropriate light or a heat application device that applies heat to the sealant can be applied.

[0112] The manufacturing method of the present application may further include a step of applying a light modulating material to the first surface of the second substrate before attaching the first and second substrates. If a sealant is applied, the application of the light modulating material may be performed before or after the application of the sealant, or may be performed simultaneously with the application of the sealant.

[0113] FIG. 4 shows an example in which the light modulating material is supplied using the light modulating material supply unit 405 after the sealant is supplied.

[0114] The specific type of the light-modulating material is not particularly limited. For example, the light-modulating material may be the above-mentioned 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.

[0115] Therefore, the manufacturing process may further include the step of providing a liquid crystal compound; or a liquid crystal compound and a dichroic dye; or a liquid crystal compound and a chiral dopant on the first surface of the second substrate before attaching the first and second substrates.

[0116] When a material containing a chiral dopant is supplied as the light modulating material, the distance d between the first and second substrates during the deposition process can be adjusted so that the ratio (d / p) of the distance d to the chiral pitch p formed by the chiral dopant falls within the above-mentioned range.

[0117] As described above, the spacers formed on the first surface of the second substrate in the above process may be partition-type spacers. By using such partition-type spacers, a light modulation device with excellent adhesion between the substrates can be manufactured.

[0118] In the manufacturing method of the present application, a step of applying appropriate heat to the adhesive layer or the adhesive layer formed on the first substrate at an appropriate time may be performed.

[0119] That is, when a light modulation device is constructed by forming a pressure-sensitive adhesive layer or adhesive layer on the first surface of the first substrate and attaching this to a spacer or liquid crystal alignment film on the first surface of the second substrate, the aforementioned excellent adhesion can be achieved, but unevenness due to abnormal liquid crystal alignment can occur due to the surface characteristics unique to the adhesive or adhesive and surface damage caused by shear force applied during the roll-to-roll manufacturing process. Therefore, the uneven alignment can be prevented by performing heat treatment at an appropriate time during the process.

[0120] For example, the manufacturing process may further include a step of heat treating the first substrate before attaching the first and second substrates.

[0121] 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 other examples, the heat treatment can be performed at about 85° C. or higher, about 90° C. or higher, about 95° C. or higher, or about 100° C. or higher, or at 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.

[0122] The heat treatment may be carried out for 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 for 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.

[0123] In one example, when a release film is attached to the pressure-sensitive adhesive layer or adhesive layer, the heat treatment may be performed before or after peeling off the release film.

[0124] In another example, the heat treatment may be performed during the attachment of the first and second substrates. In this case, the attachment of the first and second substrates may be performed at a temperature in the range of more than 50°C and less than 90°C.

[0125] In other examples, the deposition step may be carried out at a temperature within the 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 less 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.

[0126] In another example, the heat treatment may be performed after the first and second substrates are attached. In this case, the manufacturing method of the present application may further include a step of heat treating the attached first and second substrates after the attachment of the first and second substrates.

[0127] 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 higher. In other examples, the heat treatment can be performed at about 65° C. or higher, about 70° C. or higher, 75° C. or higher, 80° C. or higher, about 85° C. or higher, about 90° C. or higher, about 95° C. or higher, or about 100° C. or higher. Alternatively, the heat treatment can be performed at 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. The heat treatment may be carried out for 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 for 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.

[0128] Through the heat treatment, it is possible to solve the problem of unevenness caused by abnormal liquid crystal alignment due to surface damage caused by the surface characteristics of the adhesive or pressure sensitive adhesive and shear force applied during the roll-to-roll manufacturing process.

[0129] Figure 5 shows the results of observing alignment irregularities when a heat treatment is performed on the first substrate, from which the release film has been removed, at about 100°C for about 5 minutes before attaching the first and second substrates in the process of manufacturing an optical modulation device using the method of the present application, and Figure 6 shows the results of observing alignment irregularities in an optical modulation device manufactured using the same method except without the heat treatment. Comparing Figures 5 and 6, it can be seen that alignment irregularities can be significantly improved by heat treatment.

[0130] Figure 7 shows the results of observing alignment irregularities when an optical modulation device is fabricated in the same manner as in Figure 6, but the attachment of the first and second substrates is performed at a temperature of about 80°C (in Figure 6, the process is carried out at room temperature). Comparing Figures 6 and 7, it can be seen that alignment irregularities can be significantly improved by controlling the temperature during the attachment process.

[0131] Figure 8 shows the results of observing alignment irregularities when an optical modulation device is fabricated in the same manner as in Figure 6, but after the first and second substrates are attached, they are maintained at a temperature of about 80°C for about 5 minutes in this attached state. Comparing Figures 6 and 8, it can be seen that alignment irregularities can be significantly improved by heat treatment after attachment.

[0132] The manufacturing process of the optical modulation device of the present application may include any other steps as necessary in addition to the steps described above.

[0133] For example, as shown in FIG. 4, a process of curing the applied sealant after the adhesion through a sealant curing section 406, or a step of cutting the laminated structure of the first and second substrates (structure of the light modulation film layer) manufactured through an appropriate cutting section 407 may be performed.

[0134] If necessary, a process of attaching other elements, such as a polarizing layer, to one or both sides of the laminated structure (light modulation film layer) may be carried out.

[0135] Ultimately, the fabricated light modulating device (or light modulating film layer) can be collected by take-up roll 408 .

[0136] Through this process, a light modulation device having the desired adhesion and alignment can be manufactured efficiently and quickly.

Claims

1. 1. A method for manufacturing an optical modulation device in a roll-to-roll process, comprising: the first substrate having a pressure-sensitive adhesive layer or an adhesive layer formed on a first surface thereof and the second substrate having a spacer and a liquid crystal alignment film formed on a first surface thereof are attached to each other while being transported by rolls, and the first and second substrates are attached to each other so that their first surfaces face each other, and the pressure-sensitive adhesive or the adhesive is a curable pressure-sensitive adhesive composition or a cured product of a curable adhesive composition; The method for manufacturing an optical modulation device further comprises the step of heat-treating the first substrate and the cured material before attaching the first and second substrates.

2. 1. A method for manufacturing an optical modulation device in a roll-to-roll process, comprising: a first substrate having a pressure-sensitive adhesive layer or an adhesive layer formed on a first surface thereof and a second substrate having a spacer and a liquid crystal alignment layer formed on a first surface thereof, the first and second substrates being attached to each other such that the first surfaces thereof face each other while being transported by a roll; The method for manufacturing a light modulation device, wherein the attachment of the first and second substrates is performed within a temperature range of more than 50°C and less than 90°C.

3. 1. A method for manufacturing an optical modulation device in a roll-to-roll process, comprising: The method includes a step of attaching a first substrate having a pressure-sensitive adhesive layer or an adhesive layer formed on a first surface thereof and a second substrate having a spacer and a liquid crystal alignment film formed on a first surface thereof by a roll, so that the first surfaces of the first and second substrates face each other, and further includes a step of supplying a liquid crystal compound as a light modulation material to the first surface of the second substrate before attaching the first and second substrates; the pressure-sensitive adhesive layer or the adhesive layer induces alignment of the liquid crystal compound, The method further includes the step of thermally treating the attached first and second substrates after the attachment of the first and second substrates; The method for manufacturing an optical modulation device, wherein the heat treatment is carried out at a temperature of 60° C. or more and 200° C. or less for 30 seconds or more and 20 minutes or less.

4. The method for manufacturing an optical modulation device according to claim 1 , wherein a liquid crystal alignment film is not formed on the first substrate.

5. 5. The method for manufacturing an optical modulation device according to claim 1, wherein the first substrate further comprises a release film attached to the pressure-sensitive adhesive layer or adhesive layer, and further comprises a step of peeling off the release film before attaching the first and second substrates.

6. 6. The method for manufacturing an optical modulation device according to claim 1, wherein the second substrate further comprises a protective film attached to the first surface on which the spacers and the liquid crystal alignment film are formed, and further comprises a step of peeling off the protective film before attaching the first and second substrates.

7. The method for manufacturing an optical modulation device according to claim 1 , further comprising the step of applying a sealant to an edge of the first surface of the second substrate before attaching the first and second substrates.

8. 3. The method for manufacturing a light modulation device according to claim 1, further comprising the step of supplying a liquid crystal compound to the first surface of the second substrate before attaching the first and second substrates.

9. 3. The method for manufacturing a light modulation device according to claim 1, further comprising the step of providing a liquid crystal compound and a dichroic dye on the first surface of the second substrate before attaching the first and second substrates.

10. 3. The method for manufacturing a light modulation device according to claim 1, further comprising the step of providing a liquid crystal compound and a chiral dopant on the first surface of the second substrate before attaching the first and second substrates.

11. 11. The method for manufacturing an optical modulation device according to claim 10, wherein the first and second substrates are attached so that the ratio (d / p) of the distance (d) between the first and second substrates and the chiral pitch (p) formed by the chiral dopant is less than 1.

12. The method for manufacturing an optical modulation device according to claim 1 , wherein the spacers of the second substrate are partition-type spacers.

13. 2. The method for manufacturing an optical modulation device according to claim 1, wherein the heat treatment is performed at a temperature of 80[deg.] C. or higher for 30 seconds or longer.

Images