Liquid crystal cells and optical devices

Abstract

The present application relates to a liquid crystal cell and an optical device, which can properly maintain the cell gap of a liquid crystal element, have excellent adhesion between an upper substrate and a lower substrate, and can solve the problems of pressing and liquid crystal overflow that may occur during the bonding process of an outer substrate due to delamination that may occur during a post-electrode process.

Description

[Technical field]

[0001] The present application relates to liquid crystal cells and optical devices.

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0039632 dated March 30, 2022, and all contents disclosed in the documents of the Korean patent application are incorporated herein by reference. [Background technology]

[0003] For the long-term stability and large-area scalability of a liquid crystal film cell using a flexible substrate, it is important to maintain a cell gap between the upper and lower substrates and to provide adhesive strength between the upper and lower substrates.

[0004] Non-Patent Document 1 ("Tight Bonding of Two Plastic Substrates for Flexible LCDs" SID Symposium Digest, 38, pp.653-656 (2007)) discloses a technique of forming a pillar or wall-shaped organic film pattern of the cell gap height on one substrate and fixing it to the opposite substrate using an adhesive. However, this technique requires that the adhesive be located only on the pillar or wall surfaces, and the technique of micro-stamping the adhesive on the pillar or wall surfaces is highly difficult to process, difficult to control the thickness and area of ​​the adhesive, and high possibility of the adhesive squeezing out when the upper and lower substrates are bonded, which may contaminate the alignment film or liquid crystal. Summary of the Invention [Problem to be solved by the invention]

[0005] In order to maintain the cell gap of the liquid crystal cell and ensure the adhesion between the upper and lower substrates, it is possible to consider forming a spacer and an alignment film on the lower substrate, and then forming an adhesive layer that has both liquid crystal alignment and adhesion on the upper substrate, and then bonding them together. However, in the liquid crystal cell, liquid crystal is filled between the adhesive layer and the spacer, but due to liquid crystal contamination at the interface between the adhesive layer and the spacer, there is a significant difference in adhesion between the area with liquid crystal and the area without liquid crystal, and problems such as delamination may occur due to low adhesion during the post-electrode process. In addition, during the process of bonding outer substrates to both sides of the liquid crystal cell, pushing due to the delamination phenomenon and overflow due to residual liquid crystal at the interface may occur.

[0006] An object of the present application is to provide a liquid crystal cell and an optical device in which the cell gap of the liquid crystal cell is properly maintained, which has excellent adhesion between the upper and lower substrates, and which can solve the problems of pressing and liquid crystal overflow that may occur during the bonding process of the outer substrates due to delamination that may occur during the post-electrode process. [Means for solving the problem]

[0007] In the present specification, when the measurement temperature affects the results of a physical property, the relevant physical property is a physical property measured at room temperature, unless otherwise specified. The term room temperature refers to a natural temperature without heating or cooling, and is usually a temperature within a range of about 10°C to 30°C, or about 23°C or about 25°C. Furthermore, unless otherwise specified in the present specification, the unit of temperature is °C. In the present specification, when the measurement pressure affects the results of a physical property, the relevant physical property is a physical property measured at normal pressure, unless otherwise specified. The term normal pressure refers to a natural pressure without heating or cooling, and usually refers to about 1 atmosphere.

[0008] The present application relates to a liquid crystal cell. Figure 1 shows an example of the liquid crystal cell of the present application. The liquid crystal cell includes an upper substrate including a first base layer 10a and an adhesive layer 10c, and a lower substrate including a second base layer 20a and a spacer 20c. The region between the upper substrate and the lower substrate can be divided into a liquid crystal region 100 including a liquid crystal compound 30 and non-liquid crystal regions 200a and 200b not including the liquid crystal compound 30.

[0009] The non-liquid crystal region may be filled with air. The non-liquid crystal region may be used as a bezel of the liquid crystal cell. The liquid crystal cell of the present application can ensure the processability of the liquid crystal cell and can control defects during the bonding process of the outer substrate by controlling the width of the non-liquid crystal region. The width (W1 or W2) of the non-liquid crystal region may be 4 mm or more. In the region where liquid crystal exists between the upper substrate and the lower substrate, the adhesion between the upper substrate and the lower substrate is poor, so that the above-mentioned defects may easily occur. According to the present invention, the width of the non-liquid crystal region is ensured to be greater than or equal to a predetermined range, thereby ensuring appropriate adhesion between the upper substrate and the lower substrate of the liquid crystal cell, thereby solving the problems of the present invention. The width (W1 or W2) of the non-liquid crystal region may be specifically 5 mm or more, 6 mm or more, 7 mm or more, 8 mm or more, 9 mm or more, or 10 mm or more. When the width (W1, W2) of the non-liquid crystal region is within the above range, it is possible to solve the liquid crystal squeezing and overflow defects that may occur during the bonding process of the outer substrate due to delamination that may occur during the post-electrode process. The width of the non-liquid crystal region (W1 or W2) can be, for example, 200 mm or less, 180 mm or less, 160 mm or less, 140 mm or less, 120 mm or less, 100 mm or less, 80 mm or less, 60 mm or less, 40 mm or less, 20 mm or less, or 15 mm or less.

[0010] The length of the non-liquid crystal region and the length of the liquid crystal region may be substantially the same as the length of the second substrate layer in the longitudinal direction. In one example, the difference (L1-L2) between the length (L1) of the non-liquid crystal region and the length (L2) of the liquid crystal region may be, for example, 10 mm or less, 5 mm or less, 3 mm or less, or 1 mm or less.

[0011] The non-liquid crystal region may have a line shape extending in a first direction. The first direction may be the length (horizontal) direction of the first substrate layer and / or the second substrate layer. In this specification, the longitudinal direction of the first substrate layer and / or the second substrate layer may mean a direction parallel to the longest side of the polygon when the plane of the first substrate layer and / or the second substrate layer has a polygonal shape. When all sides of the polygon have the same length, the longitudinal direction may mean a direction parallel to any side of the polygon. In one example, the plane of the first substrate layer and / or the second substrate layer may have a quadrilateral shape, more specifically, a rectangular shape. In one example, when the plane of the first substrate layer and / or the second substrate layer is rectangular, the first direction may mean a horizontal direction of the rectangle.

[0012] The non-liquid crystal regions may be located on the sides of the liquid crystal region. The non-liquid crystal regions may be located on both sides of the liquid crystal region or on one side of the liquid crystal region. Figures 2 and 3 each exemplarily show a structure of a liquid crystal cell observed from above. That is, Figures 2 and 3 each exemplarily show a structure of a liquid crystal cell observed from the side of the upper substrate with the lower substrate in contact with the bottom.

[0013] FIG. 2 exemplarily illustrates a liquid crystal cell in which non-liquid crystal regions 200a and 200b are located on both sides of the liquid crystal region 100. As illustrated in FIG. 2, the non-liquid crystal regions may be located on the first and second sides of the liquid crystal region. When the liquid crystal cell is observed from above, the first non-liquid crystal region 200a, the liquid crystal region 100, and the second non-liquid crystal region 200b may be present in this order. At this time, the non-liquid crystal region 200a located on the first side of the liquid crystal region 100 and the non-liquid crystal region 200b located on the second side of the liquid crystal region 100 may not be in contact with each other. At this time, the non-liquid crystal region 200a located on the first side of the liquid crystal region 100 and the non-liquid crystal region 200b located on the second side of the liquid crystal region 100 may be parallel to each other. The widths of the non-liquid crystal region 200a and the non-liquid crystal region 200b may be within the above range. In one example, the widths of the non-liquid crystal region 200a and the non-liquid crystal region 200b may be the same as each other.

[0014] 3 illustrates an example of a liquid crystal cell in which a non-liquid crystal region 200 is located on one side of a liquid crystal region 100. As illustrated in FIG. 3, the non-liquid crystal region may be located on only one side of the liquid crystal region. When the liquid crystal cell is observed from above, the liquid crystal region 100 and the non-liquid crystal region 200 may be present in this order.

[0015] The method for forming the liquid crystal region and the non-liquid crystal region between the upper substrate and the lower substrate is not particularly limited. For example, a liquid crystal layer may be formed in the region on the lower substrate corresponding to the liquid crystal region, and the upper substrate may be bonded without forming a liquid crystal layer in the region corresponding to the non-liquid crystal region.

[0016] The liquid crystal cell may be laminated with the upper and lower substrates alternately arranged. For example, as shown in FIG. 1, there may be a region where only one of the upper and lower substrates is present on the side of the non-liquid crystal region. A conductive tape 400a, 400b extending in a first direction may be formed on one of the substrates. FIG. 2 exemplarily shows a region 300a where only one of the upper and lower substrates is present and a region 300b where only the other of the upper and lower substrates is present at both ends of the liquid crystal cell. In this case, the region where only the upper substrate is present at the end of the liquid crystal cell may be referred to as a region where the upper substrate is exposed, and the region where only the lower substrate is present at the end of the liquid crystal cell may be referred to as a region where the lower substrate is exposed.

[0017] Fig. 2 exemplarily shows a structure including both the regions 300a and 300b. Meanwhile, Fig. 3 exemplarily shows a region 300 in which only one of the upper and lower substrates is present at one end of the liquid crystal cell. In this case, a conductive tape 400 may be formed on the region 300. The conductive tape may serve to pass electricity so that the liquid crystal cell can be driven uniformly. The width of the conductive tape may be within a range of, for example, 1 mm to 200 mm.

[0018] 4 illustrates the configuration of the liquid crystal cell in more detail by illustrating the liquid crystal region of the liquid crystal cell. In relation to the non-liquid crystal region of the liquid crystal cell, the region where the upper substrate is exposed, and / or the region where the lower substrate is exposed, the following matters regarding the first base layer, the first electrode layer, the adhesive layer, the second base layer, the second electrode layer, the spacer, and the alignment film may be equally applied.

[0019] As mentioned above, the upper substrate of the liquid crystal cell may include a first substrate layer 10a, and the lower substrate may include a second substrate layer 20a.

[0020] The first and second substrate layers may be, for example, inorganic films such as glass films, crystalline or non-crystalline silicone films, quartz or ITO (Indium Tin Oxide) films, or polymer films, and a polymer film may be used in terms of implementing a flexible element.

[0021] In one example, the first substrate layer and the second substrate layer may each be a polymer film. Examples of the polymer film include triacetyl cellulose (TAC); cycloolefin copolymer (COP) such as norbornene derivatives; poly(methyl methacrylate) (PMMA); polycarbonate (PC); polyethylene (PE); polypropylene (PP); polyvinyl alcohol (PVA); diacetyl cellulose (DAC); polyacrylate (PAC); polyether sulfone (PES); polyetheretherketon (PEEK); polyphenylsulfone (PPS), polyetherimide (PEI); polyethylenemaphthatlate (PEN); polyethyleneterephtalate (PET); polyimide (PI); polysulfone (PSF); polyarylate (PAR) or amorphous fluororesin, but are not limited thereto. The first substrate layer and the second substrate layer may have a coating layer of gold, silver, silicon dioxide, silicon monoxide or other silicon compound, or an anti-reflection layer, if necessary.

[0022] The thickness of the first substrate layer and the second substrate layer may be about 10 μm to about 1,000 μm. As another example, the thickness of the first substrate layer and the second substrate layer may be about 20 μm or more, 40 μm or more, 60 μm or more, 80 μm or more, 100 μm or more, 120 μm or more, 140 μm or more, 160 μm or more, or about 180 μm or more, and about 900 μm or less, 800 μm or less, 700 μm or less, 600 μm or less, 500 μm or less, or about 400 μm or less. When the thickness of the first substrate layer and the second substrate layer satisfies the above range, it may be advantageous to reduce appearance defects such as wrinkles when the liquid crystal cell is bonded to an outer substrate to manufacture an optical device.

[0023] In the upper substrate, the adhesive layer 10c may be present on the inner surface of the first base layer 10a. In this specification, the "inner surface" of the component included in the liquid crystal cell may refer to the surface facing the liquid crystal layer (the layer in which the liquid crystal compound is present).

[0024] In one example, the storage modulus of the pressure-sensitive adhesive layer at 25° C. and 1 Hz frequency may be within the range of 0.2 MPa to 10 MPa. The storage modulus of the pressure-sensitive adhesive layer may be specifically 0.3 MPa or more or 0.5 MPa or more, and 8 MPa or less, 6 MPa or less, 4 MPa or less, or 2 MPa or less. In one example, the loss modulus of the pressure-sensitive adhesive layer at 25° C. and 1 Hz frequency may be within the range of 0.5 MPa to 2 MPa. The loss modulus of the pressure-sensitive adhesive layer may be specifically 0.6 MPa or more, 0.7 MPa or more, or 0.8 MPa or more, and 1.8 MPa or less, 1.6 MPa or less, 1.4 MPa or less, or 1.2 MPa or less. If the modulus of the pressure-sensitive adhesive layer inside the liquid crystal cell is too low, it may be difficult to maintain the cell gap of the liquid crystal cell, and if the modulus of the pressure-sensitive adhesive layer inside the liquid crystal cell is too high, it may be difficult to impart an adhesive effect, so that the modulus may be advantageously within the above range. In one example, the storage modulus of the pressure-sensitive adhesive layer may have a lower value than the loss modulus.

[0025] The pressure-sensitive adhesive layer may be optically transparent, and may have an average transmittance of about 80% or more, 85% or more, 90% or more, or 95% or more in the visible light region, for example, wavelengths of 380 nm to 780 nm.

[0026] The adhesive layer may be a liquid crystal aligning adhesive layer. The adhesive layer may be, for example, a vertically aligning adhesive layer or a horizontally aligning adhesive layer. In this specification, the term "vertically aligning adhesive" may mean an adhesive that imparts a vertical alignment force to adjacent liquid crystal compounds and has an adhesive force capable of bonding an upper substrate and a lower substrate. In this specification, the term "horizontally aligning adhesive" may mean an adhesive that imparts a horizontal alignment force to adjacent liquid crystal compounds and has an adhesive force capable of bonding an upper substrate and a lower substrate. The pretilt angle of adjacent liquid crystal compounds relative to the vertically aligning adhesive may be within a range of 80 degrees to 90 degrees, 85 degrees to 90 degrees, or about 87 degrees to 90 degrees, and the pretilt angle of adjacent liquid crystal compounds relative to the horizontally aligning adhesive may be within a range of 0 degrees to 10 degrees, 0 degrees to 5 degrees, or 0 degrees to 3 degrees.

[0027] In this specification, the pretilt angle may refer to the angle that the director of the liquid crystal compound makes with respect to the liquid crystal alignment adhesive or alignment film and a plane horizontal thereto when no voltage is applied. In this specification, the director of the liquid crystal compound may refer to the optical axis or slow axis of the liquid crystal layer. Alternatively, the director of the liquid crystal compound may refer to the long axis direction when the liquid crystal compound is rod-shaped, or may refer to the axis parallel to the normal direction of the disc plane when the liquid crystal compound is discotic.

[0028] The thickness of the adhesive layer may be, for example, within a range of 3 μm to 15 μm. When the thickness of the adhesive layer is within this range, it may be advantageous to minimize defects such as pressure or gathering of the adhesive when used in manufacturing a liquid crystal cell while ensuring adhesion between the upper and lower substrates.

[0029] The adhesive layer may be made of various types of adhesives known in the industry as OCA (Optically Clear Adhesive). The adhesive may be different from OCR (Optically Clear Resin) type adhesives that are cured after the objects are bonded in that the adhesive is cured before the objects are bonded. The adhesive may be, for example, an acrylic, silicone, epoxy, or urethane adhesive.

[0030] The adhesive layer may include a cured product of an adhesive resin. In one embodiment, the adhesive layer may include a silicone-based adhesive. The silicone-based adhesive may include a cured product of a curable silicone compound as an adhesive resin.

[0031] The type of the curable silicone compound is not particularly limited, and for example, a heat-curable silicone compound or an ultraviolet-curable silicone compound can be used. The curable silicone compound can be called an adhesive resin.

[0032] In one example, the curable silicone compound can be an addition-curable silicone compound.

[0033] Specifically, the addition-curing silicone compound may be exemplified by, but is not limited to, (1) an organopolysiloxane containing two or more alkenyl groups in the molecule and (2) an organopolysiloxane containing two or more silicon-bonded hydrogen atoms in the molecule. The silicone compound can form a cured product by addition reaction, for example, in the presence of a catalyst described later.

[0034] More specific examples of the organopolysiloxane (1) that can be used in the present application include dimethylsiloxane-methylvinylsiloxane copolymers having both branched chain ends blocked by trimethylsiloxane groups, methylvinylpolysiloxanes having both branched chain ends blocked by trimethylsiloxane groups, dimethylsiloxane-methylvinylsiloxane-methylphenylsiloxane copolymers having both branched chain ends blocked by trimethylsiloxane groups, dimethylpolysiloxanes having both branched chain ends blocked by dimethylvinylsiloxane groups, methylvinylpolysiloxanes having both branched chain ends blocked by dimethylvinylsiloxane groups, dimethylsiloxane-methylvinylsiloxane copolymers having both branched chain ends blocked by dimethylvinylsiloxane groups, dimethylsiloxane-methylvinylsiloxane-methylphenylsiloxane copolymers having both branched chain ends blocked by dimethylvinylsiloxane groups, 1 2SiO 1 / 2 Siloxane units represented by and R 1 2R 2 SiO 1 / 2 The siloxane unit represented by and SiO 4 / 2 Organopolysiloxane copolymers containing siloxane units represented by R 1 2R 2 SiO 1 / 2 The siloxane unit represented by and SiO 4 / 2 Organopolysiloxane copolymers containing siloxane units represented by R 1 R 2 SiO 2 / 2 Siloxane units represented by and R 1 SiO 3 / 2 Siloxane units denoted by R 2 SiO 3 / 2 and mixtures of two or more of the above. 1is 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; a halogen-substituted alkyl group such as a chloromethyl group, a 3-chloropropyl group, or a 3,3,3-trifluoropropyl group; 2 is an alkenyl group, specifically, a vinyl group, an allyl group, a butenyl group, a pentenyl group, a hexenyl group, a heptenyl group, or the like.

[0035] More specific examples of the (2) organopolysiloxane that can be used in the present application include methylhydrogenpolysiloxanes blocked at both branched chain terminals with trimethylsiloxane groups, dimethylsiloxane-methylhydrogen copolymers blocked at both branched chain terminals with trimethylsiloxane groups, dimethylsiloxane-methylhydrogensiloxane-methylphenylsiloxane copolymers blocked at both branched chain terminals with trimethylsiloxane groups, dimethylpolysiloxanes blocked at both branched chain terminals with dimethylhydrogensiloxane groups, dimethylsiloxane-methylphenylsiloxane copolymers blocked at both branched chain terminals with dimethylhydrogensiloxane groups, methylphenylpolysiloxanes blocked at both branched chain terminals with dimethylhydrogensiloxane groups, R 1 3SiO 1 / 2 Siloxane units represented by and R 1 2HSiO 1 / 2 The siloxane unit represented by and SiO 4 / 2 Organopolysiloxane copolymers containing siloxane units represented by R 1 2HSiO 1 / 2 The siloxane unit represented by and SiO 4 / 2 Organopolysiloxane copolymers containing siloxane units represented by R 1 HSiO 2 / 2 Siloxane units represented by and R 1 SiO 3 / 2 Siloxane units represented by HSiO 3 / 2and mixtures of two or more of the above. 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; a halogen-substituted alkyl group such as a chloromethyl group, a 3-chloropropyl group, or a 3,3,3-trifluoropropyl group; 2 is an alkenyl group, specifically, a vinyl group, an allyl group, a butenyl group, a pentenyl group, a hexenyl group, a heptenyl group, or the like.

[0036] In one embodiment, when the adhesive layer is a vertically oriented adhesive layer, the surface energy of the adhesive layer may be 16 mN / m or less. The lower limit of the surface energy may be, for example, 5 mN / m or more. In one embodiment, when the adhesive layer is a horizontally oriented adhesive layer, the surface energy of the adhesive layer may be more than 16 mN / m. The upper limit of the surface energy may be, for example, 50 mN / m or less. The surface energy may be measured using a drop shape analyzer (DSA100 product of KRUSS). Specifically, the process of dropping deionized water, which has a known surface tension, onto the surface of the adhesive and measuring the contact angle is repeated five times, and the average value of the five contact angles obtained is calculated. Similarly, the process of dropping diiodomethane, which has a known surface tension, onto the surface of the adhesive and measuring the contact angle is repeated five times, and the average value of the five contact angles obtained is calculated. Then, the surface energy was calculated by substituting the value (Strom value) related to the surface tension of the solvent by the Owens-Wendt-Rabel-Kaelble method using the average contact angles for deionized water and diiodomethane. The surface energy (γsurface) of the sample can be calculated by taking into account the dispersion force between non-polar molecules and the interaction force between polar molecules (γsurface = γdispersion + γpolar), and the ratio of the polar term (γpolar) in the surface energy γsurface can be defined as the polarity of the surface.

[0037] The upper and lower substrates of the liquid crystal cell may be attached to each other by an adhesive layer. Specifically, the adhesive layer of the upper substrate may be attached to the spacer of the lower substrate. When an alignment film is formed on the spacer of the lower substrate, the area of ​​the alignment film corresponding to the spacer may be attached to the adhesive layer of the upper substrate.

[0038] The liquid crystal region may be referred to as an active area. The liquid crystal compound in the liquid crystal region may switch its alignment state by application of a voltage. The liquid crystal compound may be a liquid crystal compound whose alignment direction may be changed by application of an external action. In this specification, the term "external action" may refer to any external factor, such as an external voltage, that may affect the behavior of a substance contained in the liquid crystal layer. Therefore, a state without an external action may refer to a state without application of an external voltage or the like.

[0039] The type and properties of the liquid crystal compound may be appropriately selected in consideration of the purpose of the present application. In one example, the liquid crystal compound may be a nematic liquid crystal or a smectic liquid crystal. Nematic liquid crystal may refer to a liquid crystal in which rod-shaped liquid crystal molecules are arranged in parallel in the long axis direction of the liquid crystal molecules without any regularity in position, and smectic liquid crystal may refer to a liquid crystal in which rod-shaped liquid crystal molecules are regularly arranged to form a layered structure and are arranged in parallel with regularity in the long axis direction. According to one embodiment of the present application, the liquid crystal compound may be a nematic liquid crystal compound.

[0040] The nematic liquid crystal compound may be selected to have a clearing point of, for example, about 40° C. or more, 50° C. or more, 60° C. or more, 70° C. or more, 80° C. or more, 90° C. or more, 100° C. or more, or about 110° C. or more, or a phase transition point (i.e., a phase transition point from a nematic phase to an isotropic phase) within the above range. In one example, the clearing point or phase transition point may be about 160° C. or less, 150° C. or less, or about 140° C. or less.

[0041] The liquid crystal compound may be a non-reactive liquid crystal compound. The non-reactive liquid crystal compound may mean a liquid crystal compound that does not have a polymerizable group. The polymerizable group may be exemplified by, but is not limited to, an acryloyl group, an acryloyloxy group, a methacryloyl group, a methacryloyloxy group, a carboxy group, a hydroxy group, a vinyl group, or an epoxy group, and may include known functional groups known as polymerizable groups.

[0042] The liquid crystal compound may have a positive or negative dielectric anisotropy. The absolute value of the dielectric anisotropy of the liquid crystal compound may be appropriately selected in consideration of the object of the present application. The term "dielectric anisotropy (Δε)" may mean the difference (ε / / -ε⊥) between the horizontal dielectric constant (ε / / ) and the vertical dielectric constant (ε⊥) of the liquid crystal. In this specification, the term horizontal dielectric constant (ε / / ) means a dielectric constant value measured along the direction of an electric field in a state where a voltage is applied so that the direction of the electric field caused by the director of the liquid crystal compound and the applied voltage is substantially horizontal, and the term vertical dielectric constant (ε⊥) means a dielectric constant value measured along the direction of the electric field in a state where a voltage is applied so that the direction of the electric field caused by the director of the liquid crystal compound and the applied voltage is substantially perpendicular. The dielectric anisotropy of the liquid crystal compound may be in the range of 5 to 25.

[0043] The refractive index anisotropy (Δn) of a liquid crystal compound can be appropriately selected in consideration of the purpose of the present application. In this specification, the term "refractive index anisotropy" refers to the extraordinary refractive index (n e , extraordinary refractive index) and ordinary refractive index (n o , ordinary refractive index) difference (n e -n o The refractive index anisotropy of the liquid crystal compound may be, for example, 0.01 to 0.3. The refractive index anisotropy may be 0.01 or more, 0.05 or more, or 0.07 or more, and may be 0.3 or less, 0.2 or less, 0.15 or less, or 0.13 or less.

[0044] The liquid crystal layer (layer in which the liquid crystal compound exists) may further include a dichroic dye. When the liquid crystal layer includes a dichroic dye, even if the liquid crystal cell includes an adhesive layer, the liquid crystal cell is less affected by the variation in the cell gap during the bonding process of the outer substrates, and therefore, there is an advantage in that the thickness of the intermediate layer for ensuring the structural stability and quality uniformity of the liquid crystal cell can be relatively thin.

[0045] The dichroic dye can control the light transmittance variable property of the liquid crystal layer. In this specification, the term "dye" may refer to a material capable of intensively absorbing and / or transforming light in at least a part or the entire visible light range, for example, in the wavelength range of 400 nm to 700 nm, and the term "dichroic dye" may refer to a material capable of anisotropic absorption of light in at least a part or the entire visible light range.

[0046] The liquid crystal layer containing the liquid crystal compound and the dichroic dye may be a GHLC layer (Guest Host Liquid Crystal Layer). In this specification, the term "GHLC layer (Guest Host Liquid Crystal Layer)" may refer to a functional layer in which the dichroic dye is arranged together with the liquid crystal compound, and which exhibits anisotropic light absorption characteristics in the alignment direction of the dichroic dye and in the direction perpendicular to the alignment direction. For example, the dichroic dye is a material whose light absorption rate changes depending on the polarization direction, and if it has a high absorption rate for light polarized in the long axis direction, it may be called a p-type dye, and if it has a high absorption rate for light polarized in the short axis direction, it may be called an n-type dye. In one example, when a p-type dye is used, polarized light vibrating in the long axis direction of the dye is absorbed, and polarized light vibrating in the short axis direction of the dye is less absorbed and can be transmitted. Hereinafter, unless otherwise specified, it is assumed that the dichroic dye is a p-type dye.

[0047] As the dichroic dye, for example, a known dye that is known to have a property of being aligned according to the alignment state of the liquid crystal compound by the so-called guest-host effect can be selected and used. Examples of such dichroic dyes include azo dyes, anthraquinone dyes, methine dyes, azomethine dyes, merocyanine dyes, naphthoquinone dyes, tetrazine dyes, phenylene dyes, quaterrylene dyes, benzothiadiazole dyes, diketopyrrolopyrrole dyes, squaraine dyes, and pyrromethene dyes, but the dyes applicable in the present application are not limited to the above.

[0048] The dichroic ratio of the dichroic dye, i.e., the absorption of light polarized parallel to the long axis of the dichroic dye divided by the absorption of light polarized perpendicular to the long axis, may be 5 or more, 6 or more, or 7 or more. The dye may satisfy the dichroic ratio at at least a part or any one of the wavelengths within the wavelength range of the visible light region, for example, within the wavelength range of about 380 nm to 700 nm or about 400 nm to 700 nm. The upper limit of the dichroic ratio may be, for example, about 20 or less, 18 or less, 16 or less, or 14 or less.

[0049] The content of the dichroic dye in the liquid crystal layer may be appropriately selected in consideration of the object of the present application. For example, the content of the dichroic dye in the liquid crystal layer may be 0.2 wt% or more. The content of the dichroic dye may be specifically 0.5 wt% or more, 1 wt% or more, 2 wt% or more, or 3 wt% or more. The upper limit of the content of the dichroic dye may be, for example, 10 wt% or less, 9 wt% or less, 8 wt% or less, 6 wt% or less, or 5 wt% or less. If the content of the dichroic dye in the liquid crystal layer is too low, it may be difficult to achieve the desired transmittance variable characteristic, and it may be insufficient to reduce the thickness of the intermediate layer for reducing the variation in the cell gap that may occur during the bonding process of the outer substrate. On the other hand, if the content of the dichroic dye in the liquid crystal layer is too high, there is a risk of precipitation. Therefore, it may be advantageous for the content of the dichroic dye to be within the above range.

[0050] The thickness of the liquid crystal layer is not particularly limited, and for example, the thickness of the liquid crystal layer may be about 0.01 μm or more, 0.05 μm or more, 0.1 μm or more, 0.5 μm or more, 1 μm or more, 1.5 μm or more, 2 μm or more, 2.5 μm or more, 3 μm or more, 3.5 μm or more, 4 μm or more, 4.5 μm or more, 5 μm or more, 5.5 μm or more, or 6 μm or more. The upper limit of the thickness of the liquid crystal layer is not particularly limited, and generally may be about 30 μm or less, 25 μm or less, 20 μm or less, or 15 μm or less. The thickness of the liquid crystal layer may be determined by the height of the spacer.

[0051] The liquid crystal layer can be switched between a first alignment state and a second alignment state different from the first alignment state. The switching can be controlled by applying an external energy such as a voltage. For example, the liquid crystal layer can be maintained in one of the first and second alignment states in the absence of an applied voltage, and can be switched to the other alignment state by applying a voltage.

[0052] In one example, the first alignment state may be a twisted alignment state, i.e., the liquid crystal layer may be capable of switching between the twisted alignment and another alignment state through application of external energy.

[0053] In one example, the liquid crystal layer can be switched between a twisted and a homeotropic state, and in one example, the liquid crystal layer can be in a homeotropic state with no voltage applied and in a twisted state with a voltage applied.

[0054] In this specification, the "vertical alignment state" refers to a state in which the directors of the liquid crystal compound in the liquid crystal layer are aligned approximately perpendicular to the plane of the liquid crystal layer, and for example, the angle that the directors of the liquid crystal compound make with respect to the plane of the liquid crystal layer can be, for example, within a range of approximately 80 degrees to 100 degrees or 85 degrees to 95 degrees, or can be approximately 90 degrees.

[0055] In this specification, the term "twisted alignment state" may refer to a helical structure in which the directors of liquid crystal compounds are twisted along a virtual helical axis in a liquid crystal layer to form a layer. The twisted alignment state may be embodied as a vertical, horizontal, or tilted alignment state. That is, the vertical twist alignment mode is a state in which individual liquid crystal compounds are twisted along a helical axis in a vertically aligned state to form a layer, the horizontal twist alignment mode is a state in which individual liquid crystal compounds are twisted along a helical axis in a horizontally aligned state to form a layer, and the tilted twist alignment mode is a state in which individual liquid crystal compounds are twisted along a helical axis in a tilted state to form a layer. According to the present application, the twisted alignment state may be a twisted alignment state of a horizontal alignment state.

[0056] In the twisted alignment state, the ratio (d / p) of the thickness d to the pitch p of the liquid crystal layer may be 20 or less, with the lower limit being 0.5 or more. When the ratio (d / p) of the thickness d to the pitch p in the twisted alignment state is within the above range, the optical device can exhibit excellent light transmittance variable characteristics even without a polarizer. In general, when the ratio d / p is 0.7 or more and less than 2.5, it can be called STN (Super Twisted Nematic) mode, and when the ratio d / p is 2.5 or more, it can be called HTN (Highly Twisted Nematic) driving mode.

[0057] The pitch p of the liquid crystal layer can be measured by a measurement method using a wedge cell, specifically, by the method described in Simple method for accurate measurements of the cholesteric pitch using a "stripe-wedge Grandjean-Cano cell" by D. Podolskyy et al. (Liquid Crystals, Vol. 35, No. 7, July 2008, pp. 789-791). The ratio (d / p) can be achieved by introducing an appropriate amount of chiral dopant into the liquid crystal layer.

[0058] The liquid crystal layer may further include a chiral dopant. When the liquid crystal layer includes a chiral agent, a twisted alignment state may be realized. The chiral agent (or chiral dopant) that may be included in the liquid crystal layer may be any agent capable of inducing a desired twisting without damaging the liquid crystal property, for example, nematic regularity. The chiral agent for inducing rotation in the liquid crystal compound must at least include chirality in its molecular structure. Examples of the chiral agent include a compound having one or more asymmetric carbons, a compound having an asymmetric point on a heteroatom such as a chiral amine or chiral sulfoxide, or a compound having an axially asymmetric, optically active site such as cumulene or binaphthol. The chiral agent may be, for example, a low molecular weight compound having a molecular weight of 1,500 or less. As the chiral agent, commercially available chiral nematic liquid crystals, such as chiral dopant liquid crystal S-811 available from Merck or LC756 available from BASF, may be used.

[0059] The application ratio of the chiral dopant is selected so as to achieve the desired ratio (d / p). In general, the content (wt%) of the chiral dopant can be calculated by the formula: 100 / HTP (Helixcal Twisting power) x pitch p (nm). The HTP indicates the twisting strength of the chiral dopant, and the content of the chiral dopant can be determined by taking into account the desired pitch with reference to the formula.

[0060] The upper substrate of the liquid crystal cell may further include a first electrode layer 10b between the first base layer 10a and the adhesive layer 10c. The first electrode layer 10b may be in contact with the inner surface of the first base layer 10a. The adhesive layer 10c may be in contact with the inner surface of the first electrode layer 10b. The lower substrate of the liquid crystal cell may further include a second electrode layer 20b between the second base layer 20a and the spacer 20c. The second electrode layer 20b may be in contact with the inner surface of the second base layer 20a. The spacer 20c may be in contact with the inner surface of the second electrode layer 20b.

[0061] The first electrode layer and the second electrode layer may perform a role of applying an external action, for example, application of an electric field, so that a material contained in the liquid crystal layer transmits or blocks incident light. In one example, the first electrode layer and / or the second electrode layer may include, but is not limited to, a conductive polymer, a conductive metal, a conductive nanowire, or a metal oxide such as ITO (Indium Tin Oxide). The first electrode layer and / or the second electrode layer may be formed by depositing, for example, the conductive polymer, the conductive metal, the conductive nanowire, or a metal oxide such as ITO (Indium Tin Oxide).

[0062] The lower substrate of the liquid crystal cell may further include an alignment film 20d. The alignment film 20d may be present on the spacer 20c. That is, the upper surface and / or the side surface of the spacer 20c may be in contact with the alignment film. The lower surface of the spacer 20c may be in contact with the second electrode layer 20b. Since the adhesive layer included in the upper substrate may have liquid crystal alignment properties, the upper substrate may not include an alignment film. That is, the inner surface of the first electrode layer 10b may not include an alignment film.

[0063] In this specification, the combination of the first base layer, the first electrode layer, and the adhesive layer may be referred to as an upper substrate, and the combination of the second base layer, the second electrode layer, the spacer, and the alignment layer may be referred to as a lower substrate. In a liquid crystal cell, the upper substrate does not include a separate alignment layer other than the adhesive layer, and the lower substrate may include an alignment layer.

[0064] The alignment film and the liquid crystal layer may be in contact with each other. The alignment film may be a vertical alignment film or a horizontal alignment film. In this specification, the term "horizontal alignment film" may refer to a layer containing an alignment material that imparts a horizontal alignment force to the liquid crystal compound present in the adjacent liquid crystal layer. In this specification, the term "vertical alignment film" may refer to a layer containing an alignment material that imparts a vertical alignment force to the liquid crystal compound present in the adjacent liquid crystal layer. The pretilt angle of the adjacent liquid crystal compound with respect to the vertical alignment film may be within a range of 80 degrees to 90 degrees, 85 degrees to 90 degrees, or about 87 degrees to 90 degrees, and the pretilt angle of the adjacent liquid crystal compound with respect to the horizontal alignment film may be within a range of 0 degrees to 10 degrees, 0 degrees to 5 degrees, or 0 degrees to 3 degrees. Unlike the adhesive layer, the alignment film may not have an adhesive force that bonds the upper substrate and the lower substrate. In one example, the peel force of the alignment film with respect to the upper substrate may be close to 0 in the state of the liquid crystal cell of FIG. 4.

[0065] The alignment film may be a rubbing alignment film or a photo-alignment film. The alignment direction of the alignment film may be the rubbing direction in the case of a rubbing alignment film, and the direction of the irradiated polarized light in the case of a photo-alignment film. The alignment direction may be confirmed by a detection method using an absorbing linear polarizer. Specifically, the alignment direction may be confirmed by arranging an absorbing linear polarizer on one side of the liquid crystal layer in a state where the liquid crystal compound contained in the liquid crystal layer is horizontally aligned, and measuring the transmittance by rotating the polarizer 360 degrees. In the above state, when light is irradiated to the liquid crystal layer or the absorbing linear polarizer side and the brightness (transmittance) is measured on the other side, if the absorption axis or transmission axis coincides with the alignment direction of the liquid crystal alignment film, the transmittance tends to be low, but the alignment direction may be confirmed through a simulation that reflects the refractive index anisotropy of the applied liquid crystal compound. A method for confirming the alignment direction depending on the mode of the liquid crystal layer is well known, and the alignment direction of the alignment film may be confirmed by such a well-known method in the present application.

[0066] Examples of the alignment film include materials that are known to exhibit alignment ability through rubbing alignment, such as polyimide compounds, poly(vinyl alcohol) compounds, poly(amic acid) compounds, polystyrene compounds, polyamide compounds, and polyoxyethylene compounds, as well as polyimide compounds, polyamic acid compounds, polynorbornene compounds, phenylmaleimide copolymer compounds, polyvinylcinamate compounds, polyazobenzene compounds, polyethyleneimide compounds, polyvinylalcohol compounds, polyimide compounds, polyethylene compounds, polystyrene compounds, polyphenylenephthalamide compounds, polyester compounds, CMPI (chloromethylated The material may include, but is not limited to, one or more selected from the group consisting of materials known to be capable of exhibiting alignment ability upon light irradiation, such as a polyimide compound, a PVCI (polyvinylcinnamate) compound, and a polymethyl methacrylate compound.

[0067] The spacer 20c can maintain the distance between the upper and lower substrates. A liquid crystal layer can be present in the area where no spacer is present between the upper and lower substrates.

[0068] The spacer may be a patterned spacer. The spacer may have a column shape or a partition wall shape. The partition wall may divide the space between the lower substrate and the upper substrate into two or more spaces. In the area where the spacer is not present, other films or other layers present thereunder may be exposed. For example, the second electrode layer may be exposed in the area where the spacer is not present. The alignment film may cover the spacer and the second electrode layer exposed in the area where the spacer is not present. In a liquid crystal cell in which the upper substrate and the lower substrate are bonded together, the alignment film present on the spacer of the lower substrate and the adhesive layer of the upper substrate may be in contact with each other.

[0069] The spacer-free region between the upper and lower substrates may contain liquid crystal compounds and the above-mentioned additives, such as dichroic dyes, chiral agents, etc. The shape of the spacer is not particularly limited, and may be applied without limitation to have multiple sides, such as a circle, an ellipse, or other polygonal shapes.

[0070] The spacer may include a curable resin. The type of the curable resin is not particularly limited, and may be, for example, a thermosetting resin or a photocurable resin, such as an ultraviolet curable resin. The thermosetting resin may be, for example, a silicone resin, a silicon resin, a furan resin, a polyurethane resin, an epoxy resin, an amino resin, a phenol resin, a urea resin, a polyester resin, or a melamine resin, but is not limited thereto. The ultraviolet curable resin may be, for example, an acrylic polymer, such as a polyester acrylate polymer, a polystyrene acrylate polymer, an epoxy acrylate polymer, a polyurethane acrylate polymer, or a polybutadiene acrylate polymer, a silicone acrylate polymer, or an alkyl acrylate polymer, but is not limited thereto.

[0071] The spacer may be formed by a patterning process. For example, the spacer may be formed by a photolithography process. The photolithography process may include a process of applying a curable resin composition onto a substrate layer or an electrode layer, and then irradiating ultraviolet light through a pattern mask. The pattern mask may be patterned into an ultraviolet light transmitting region and an ultraviolet light blocking region. The photolithography process may further include a process of washing the curable resin composition irradiated with ultraviolet light. The region irradiated with ultraviolet light is cured, and the region not irradiated with ultraviolet light remains in a liquid state, so that it can be patterned into a partition wall by removing it through a washing process. In the photolithography process, in order to easily separate the resin composition and the pattern mask after ultraviolet light irradiation, the pattern mask may be subjected to a release treatment or a release paper may be placed between the layer of the resin composition and the pattern mask.

[0072] The width (line width), interval (pitch), height (thickness), and area of ​​the spacer may be appropriately selected within a range that does not impair the object of the present application. For example, the width (line width) of the spacer may be in the range of 10 μm to 500 μm or in the range of 10 μm to 50 μm. The interval (pitch) of the spacer may be in the range of 10 μm to 1000 μm or in the range of 100 μm to 1000 μm. The area of ​​the spacer may be about 5% or more and 50% or less with respect to 100% of the total area of ​​the second base layer. When the area of ​​the spacer is within the above range, it may be advantageous to ensure excellent electro-optical properties while adequately ensuring adhesion between the upper substrate and the lower substrate. The height (thickness) of the spacer may be, for example, in the range of 1 μm to 30 μm or 3 μm to 20 μm.

[0073] The present application relates to an optical device. The optical device of the present application may include a first outer substrate, the liquid crystal cell, and a second outer substrate in that order. In this case, an upper substrate of the liquid crystal cell may be disposed close to the first outer substrate, and a lower substrate of the liquid crystal cell may be disposed close to the second outer substrate.

[0074] The first outer substrate and the second outer substrate may be an inorganic substrate or a polymer substrate, independently. The inorganic substrate is not particularly limited, and a known inorganic substrate may be used. As an example, the inorganic substrate may be a glass substrate having excellent light transmittance. The glass substrate may be, but is not limited to, a soda lime glass substrate, a general reinforced glass substrate, a borosilicate glass substrate, or an alkali-free glass substrate. The polymer substrate may be a cellulose film such as TAC (triacetyl cellulose) or DAC (diacetyl cellulose); a COP (cycloolefin copolymer) film such as a norbornene derivative; an acrylic film such as PAR (Polyacrylate) or PMMA (poly(methyl methacrylate); a PC (polycarbonate) film; a polyolefin film such as PE (polyethylene) or PP (polypropylene); a PVA (polyvinyl Examples of the materials that can be used include, but are not limited to, sulfone-based films such as polysulfone (PSF) films, polyphenylsulfone (PPS) films, and polyethersulfone (PES) films; polyetheretherketon (PEEK) films; polyetherimide (PEI) films; polyester-based films such as polyethylenenaphthalate (PEN) films and polyethyleneterephtalate (PET) films; and fluororesin films. The first and second outer substrates may each have a functional layer such as a coating layer of gold, silver, or a silicon compound such as silicon dioxide or silicon monoxide, or an anti-reflection layer, as required.

[0075] In one embodiment, the first outer substrate and / or the second outer substrate may be a glass substrate, and the area of ​​the first outer substrate and / or the second outer substrate may be larger than the area of ​​the first base layer and / or the second base layer.

[0076] The thickness of each of the first and second outer substrates may be about 0.3 mm or more. In other examples, the thickness may be about 0.5 mm or more, 1 mm or more, 1.5 mm or more, or about 2 mm or more, and may be about 10 mm or less, 9 mm or less, 8 mm or less, 7 mm or less, 6 mm or less, 5 mm or less, 4 mm or less, or about 3 mm or less.

[0077] The first outer substrate and the second outer substrate may be flat or curved. For example, the first outer substrate and the second outer substrate may be flat or curved, or one of them may be flat and the other curved. If both of them are curved, their curvatures or radii of curvature may be the same or different. In this specification, the curvature or radii of curvature may be measured by a method known in the art, for example, using a non-contact device such as a 2D Profile Laser Sensor, a Chromatic Confocal Line Sensor, or a 3D Measuring Confocal Microscopy. Methods for measuring the curvature or radii of curvature using such devices are well known.

[0078] As one example, the first outer substrate and the second outer substrate may each be a substrate having a double curved surface. The autoclave process described below is performed under process conditions such as reduced pressure, increased pressure, or increased pressure. The double curved surface of the outer substrate may cause uneven stress, and in particular, under reduced pressure, delamination may occur if the adhesion between the upper and lower substrates is low. The delamination may cause the liquid crystal to flow and cause overflow defects. In particular, the adhesion is poor in the region where the liquid crystal is present between the upper and lower substrates, and therefore the above defects may easily occur. However, according to the present invention, the above defects can be solved by ensuring that the width of the non-liquid crystal region is greater than a predetermined range.

[0079] The optical device may further include at least one adhesive layer disposed between the first outer substrate and the liquid crystal cell, and between the second outer substrate and the liquid crystal cell.

[0080] In one example, the optical device may further include a first adhesive layer between the first outer substrate and the liquid crystal cell, and a second adhesive layer between the second outer substrate and the liquid crystal cell. One side of the first adhesive layer may be in direct contact with the first outer substrate, and the other side may be in direct contact with the liquid crystal cell. One side of the second adhesive layer may be in direct contact with the second outer substrate, and the other side may be in direct contact with the liquid crystal cell. In this specification, "A is in direct contact with B" may mean that A and B are in direct contact with each other without an intermediate between A and B.

[0081] In one embodiment, the optical device may further include at least one intermediate layer between the first outer substrate and the liquid crystal cell and between the second outer substrate and the liquid crystal cell. The intermediate layer may be, for example, a polarizer. In one embodiment, the optical device may include a first polarizer between the first outer substrate and the liquid crystal cell, and a second polarizer between the second outer substrate and the liquid crystal cell. When the optical device further includes a first polarizer and a second polarizer, the optical device may further include a first adhesive layer between the first outer substrate and the first polarizer, a second adhesive layer between the first polarizer and the liquid crystal cell, a third adhesive layer between the liquid crystal cell and the second polarizer, and a fourth adhesive layer between the second polarizer and the second outer substrate. In this case, one surface of the first adhesive layer may be in direct contact with the first outer substrate, and the other surface may be in direct contact with the first polarizer. One surface of the second adhesive layer may be in direct contact with the first polarizer, and the other surface may be in direct contact with the liquid crystal cell. One surface of the third adhesive layer may be in direct contact with the liquid crystal cell, and the other surface may be in direct contact with the second polarizer. One surface of the fourth adhesive layer may be in direct contact with the second polarizer, and the other surface may be in direct contact with the second outer substrate.

[0082] The term "polarizer" as used herein means a film, sheet, or element having a polarizing function. A polarizer is a functional element that can extract light vibrating in one direction from incident light vibrating in various directions.

[0083] The first polarizer and the second polarizer may be an absorptive polarizer or a reflective polarizer, respectively. In this specification, the absorptive polarizer refers to an element that exhibits selective transmission and absorption characteristics for incident light. For example, the absorptive polarizer can transmit light that vibrates in one direction from incident light that vibrates in various directions, and absorb light that vibrates in the remaining directions. In this specification, the reflective polarizer refers to an element that exhibits selective transmission and reflection characteristics for incident light. For example, the reflective polarizer can transmit light that vibrates in one direction from incident light that vibrates in various directions, and reflect light that vibrates in the remaining directions. According to one embodiment of the present application, the polarizer may be an absorptive polarizer.

[0084] The first polarizer and the second polarizer may each be a linear polarizer. In this specification, a linear polarizer means that 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. In the case of an absorptive linear polarizer, the light transmission axis and the light absorption axis may be perpendicular to each other. In the case of a reflective linear polarizer, the light transmission axis and the light reflection axis may be perpendicular to each other.

[0085] In one example, the first polarizer and the second polarizer may each be a polymer stretched film dyed with iodine or an anisotropic dye. An example of the polymer stretched film is a PVA (poly(vinyl alcohol)) stretched film. In another example, the first polarizer and the second polarizer may each be a guest-host type polarizer having a liquid crystal polymerized in an oriented state as a host and an anisotropic dye aligned by the orientation of the liquid crystal as a guest. In another example, the first polarizer and the second polarizer may each be a thermotropic liquid crystal film or a lyotropic liquid crystal film.

[0086] A protective film, an anti-reflection film, a retardation film, an adhesive layer, an adhesive layer, a surface treatment layer, etc. may be additionally formed on one or both sides of the first polarizer and the second polarizer. For example, a thermoplastic resin having excellent transparency, mechanical strength, thermal stability, moisture blocking property, or isotropy may be used as the material of the protective film. Examples of such resins include cellulose resins such as TAC (triacetyl cellulose), polyester resins, polyethersulfone resins, polysulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, (meth)acrylic resins, cyclic polyolefin resins such as norbornene resins, polyarylate resins, polystyrene resins, polyvinyl alcohol resins, and mixtures thereof. The retardation film may be, for example, a ¼ wave plate or a ½ wave plate. The ¼ wave plate may have an in-plane retardation value within a range of about 100 nm to 180 nm, 100 nm, or 150 nm for light with a wavelength of 550 nm. The half wave plate may have an in-plane retardation value within a range of about 200 nm to 300 nm or 250 nm to 300 nm for light with a wavelength of 550 nm. The retardation film may be, for example, a polymer stretched film or a liquid crystal polymerized film.

[0087] The transmittance of the first polarizer and the second polarizer for light with a wavelength of 550 nm may be within a range of 40% to 50%, respectively. The transmittance may refer to the single transmittance of the polarizer for light with a wavelength of 550 nm. The single transmittance of the polarizer may be measured, for example, using a spectrometer (V7100, manufactured by Jasco). For example, the air may be set as the baseline while the polarizer sample (without the upper and lower protective films) is placed in the instrument, and the axis of the polarizer sample may be aligned vertically and horizontally with the axis of the reference polarizer to measure the transmittance of each, and then the single transmittance may be calculated.

[0088] When the first intermediate layer and the second intermediate layer include a first polarizer and a second polarizer, respectively, the light transmission axis of the first polarizer and the light transmission axis of the second polarizer may be perpendicular to each other. Specifically, the angle between the light transmission axis of the first polarizer and the light transmission axis of the second polarizer may be within a range of 80 degrees to 100 degrees or 85 degrees to 95 degrees. In this case, the thickness of the second adhesive layer between the first intermediate layer and the liquid crystal cell and the third adhesive layer between the second intermediate layer and the liquid crystal cell may be 380 μm or less. When the light transmission axis of the first polarizer and the light transmission axis of the second polarizer are perpendicular to each other, light leakage may occur due to the distance between the first polarizer and the second polarizer. However, by setting the thickness of the second adhesive layer and the third adhesive layer within the above range, the distance between the first polarizer and the second polarizer can be minimized to reduce light leakage and ensure the structural safety of the liquid crystal cell. The lower limit of the thickness of the second adhesive layer and the third adhesive layer may be 10 μm or more.

[0089] In one example, the storage modulus of the first adhesive layer, the second adhesive layer, the third adhesive layer, and / or the fourth adhesive layer may be higher than the storage modulus of the adhesive layer included in the liquid crystal cell. Also, the loss modulus of the first adhesive layer, the second adhesive layer, the third adhesive layer, and / or the fourth adhesive layer may be higher than the loss modulus of the adhesive layer included in the liquid crystal cell. When the storage modulus or loss modulus of the first adhesive layer, the second adhesive layer, the third adhesive layer, and / or the fourth adhesive layer is higher than the storage modulus or loss modulus of the adhesive layer, appearance defects can be reduced even under durable conditions.

[0090] In one example, the storage modulus of the first adhesive layer, the second adhesive layer, the third adhesive layer and / or the fourth adhesive layer at a temperature of 25°C and a frequency of 1 Hz may be in the range of 1 MPa to 100 MPa. The storage modulus may be, specifically, 3 MPa or more, and 80 MPa or less, 60 MPa or less, 40 MPa or less, 20 MPa or less, or 10 MPa or less. In one example, the loss modulus of the first adhesive layer, the second adhesive layer, the third adhesive layer and / or the fourth adhesive layer at a temperature of 25°C and a frequency of 1 Hz may be, specifically, 1 MPa or more, and 80 MPa or less, 60 MPa or less, 40 MPa or less, 20 MPa or less, or 10 MPa or less. The storage modulus of the first adhesive layer, the second adhesive layer, the third adhesive layer and / or the fourth adhesive layer may each have a higher value than the loss modulus.

[0091] As an example, the first adhesive layer, the second adhesive layer, the third adhesive layer, and / or the fourth adhesive layer may have a Young's modulus (E) in the range of 0.1 MPa to 100 MPa. As another example, the Young's modulus (E) of the first adhesive layer, the second adhesive layer, the third adhesive layer, and / or the fourth adhesive layer may be 0.2 MPa or more, 0.4 MPa or more, 0.6 MPa or more, 0.8 MPa or more, 1 MPa or more, 5 MPa or more, or about 10 MPa or more, and may be about 95 MPa or less, 80 MPa or less, 75 MPa or less, 70 MPa or less, 65 MPa or less, 60 MPa or less, 55 MPa or less, or about 50 MPa or less. The Young's modulus (E) may be measured, for example, by a method specified in ASTM D882, and may be measured by cutting the film into a shape provided in the corresponding standard and using equipment capable of measuring a stress-strain curve (capable of simultaneously measuring force and length), for example, a universal testing machine (UTM). When the Young's modulus of the adhesive layer included in the optical device is within the above range, it may be more advantageous to ensure excellent durability of the optical device. When the adhesive layer is a laminate of at least two or more sub-adhesive layers, each of the sub-intermediate layers may satisfy the above Young's modulus range.

[0092] As one example, the first adhesive layer, the second adhesive layer, the third adhesive layer, and / or the fourth adhesive layer may each have a thermal expansion coefficient of 2,000 ppm / K or less. In other examples, the thermal expansion coefficient may be about 1,900 ppm / K or less, 1,700 ppm / K or less, 1,600 ppm / K or less, or about 1,500 ppm / K or less, or about 10 ppm / K or more, 20 ppm / K or more, 30 ppm / K or more, 40 ppm / K or more, 50 ppm / K or more, 60 ppm / K or more, 70 ppm / K or more, 80 ppm / K or more, 90 ppm / K or more, 100 ppm / K or more, 200 ppm / K or more, 300 ppm / K or more, 400 ppm / K or more, 500 ppm / K or more, 600 ppm / K or more, 700 ppm / K or more, or about 800 ppm / K or more. The thermal expansion coefficient of the adhesive layer can be measured, for example, according to the ASTM D696 standard, by cutting into a shape specified in the relevant standard and measuring the change in length per unit temperature to calculate the thermal expansion coefficient, or by a known method such as TMA (ThermoMechanic Analysis). If the thermal expansion coefficient of the adhesive layer included in the optical device is within the above range, it may be more advantageous to ensure excellent durability of the optical device. If the intermediate layer is a laminate of at least two or more sub-adhesive layers, each of the sub-adhesive layers may satisfy the above range of thermal expansion coefficient.

[0093] The first adhesive layer, the second adhesive layer, the third adhesive layer and / or the fourth adhesive layer may be a thermoplastic polyurethane (TPU) adhesive layer, a polyamide adhesive layer, a polyester adhesive layer, an EVA (Ethylene Vinyl Acetate) adhesive layer, an acrylic adhesive layer, a silicone adhesive layer or a polyolefin adhesive layer. According to one embodiment of the present application, the first adhesive layer, the second adhesive layer, the third adhesive layer and the fourth adhesive layer may be a thermoplastic polyurethane adhesive layer.

[0094] As an example, the sum of the total thicknesses of the adhesive layers included in the optical device may be 200 μm or more. The sum of the total thicknesses of the adhesive layers may mean the sum of the thicknesses of all the adhesive layers included in the optical device. In one example, when the optical device includes a first adhesive layer and a second adhesive layer, it may mean the sum of the thicknesses of the adhesive layers. In another example, when the optical device includes a first adhesive layer, a second adhesive layer, a third adhesive layer, and a fourth adhesive layer, it may mean the sum of the thicknesses of the adhesive layers. When the total thickness of the adhesive layers is within the above range, defects during the bonding process of the outer substrate can be minimized, thereby ensuring structural stability and uniform appearance characteristics of the optical device. The sum of the total thicknesses of the adhesive layers may be specifically 500 μm or more, 1,000 μm or more, 1,500 μm or more, or 2,000 μm or more. The sum of the total thicknesses of the adhesive layers may be, for example, about 6,000 μm or less, 5,000 μm or less, 4,000 μm or less, or 3,000 μm or less. If the total thickness of the adhesive layer is excessively thick, it may deteriorate the electro-optical properties, such as the transmittance properties, of the optical device, so it may be advantageous for the total thickness to be within the above range.

[0095] The first adhesive layer, the second adhesive layer, the third adhesive layer and / or the fourth adhesive layer may each have a single layer structure of one adhesive layer or may be a laminate of two or more sub-adhesive layers. The thickness and number of the sub-adhesive layers may be controlled in consideration of the desired thickness of the intermediate layer. In one example, the thickness of one adhesive layer or sub-intermediate layer having a single layer structure may be in the range of 100 μm to 500 μm or 300 μm to 400 μm.

[0096] The optical device may further include an outer layer surrounding a side of the liquid crystal cell. In the optical device, the area above the liquid crystal cell may be smaller than the area above the first outer substrate or the second outer substrate. Also, the area above the liquid crystal cell may be smaller than the area above the first to fourth adhesive layers included in the optical device. Also, the area above the liquid crystal cell may be smaller than the area above the first to second intermediate layers included in the optical device.

[0097] In one example, the liquid crystal cell may be encapsulated by the first adhesive layer to the fourth adhesive layer and the outer layer. In the present application, the term encapsulation may mean covering the entire surface of the liquid crystal cell with the adhesive layer and the outer layer. Depending on the desired structure, for example, the encapsulation structure may be realized by vacuum-pressing a laminate including a first outer substrate, a first adhesive layer, a first polarizer, a second adhesive layer, a liquid crystal cell, a third adhesive layer, a second polarizer, a fourth adhesive layer, and a second outer substrate in that order, and including an outer layer surrounding the side of the liquid crystal cell. Such an encapsulation structure significantly improves the durability and weather resistance of the optical device, and as a result, it can be stably applied to outdoor applications such as sunroofs.

[0098] The outer layer may include, for example, a thermoplastic polyurethane (TPU) adhesive, a polyamide adhesive, a polyester adhesive, an EVA (Ethylene Vinyl Acetate) adhesive, an acrylic adhesive, a silicone adhesive, or a polyolefin adhesive. In one example, the outer layer may be formed of the same material as the first to fourth adhesive layers. The physical properties of the outer layer may be the same as those described for the first and second adhesive layers.

[0099] The present application also relates to a method for manufacturing an optical device.

[0100] In one example, when the optical device does not include a polarizer as an intermediate layer, a method for manufacturing the optical device may include the steps of preparing a laminate including a first outer substrate, a first adhesive layer, a liquid crystal cell, a second adhesive layer, and a second outer substrate, in that order, and including an outer layer surrounding the sides of the liquid crystal cell, and autoclaving the laminate.

[0101] In another example, when the optical device includes a first polarizer and a second polarizer as an intermediate layer, the method may include preparing a laminate including an outer layer that includes, in order, a first outer substrate, a first adhesive layer, a first polarizer, a second adhesive layer, a liquid crystal cell, a third adhesive layer, a second polarizer, a fourth adhesive layer, and a second outer substrate and that surrounds the sides of the liquid crystal cell, and autoclaving the laminate.

[0102] Unless otherwise specified, the same description of the optical device may be applied to the method of manufacturing the optical device.

[0103] When the optical device further includes other elements other than the liquid crystal cell and the polarizer, the laminate can further include the other elements other than the liquid crystal cell and the polarizer at desired positions.

[0104] The autoclaving step may be performed by applying heat and / or pressure to the laminate formed after the lamination step.

[0105] The conditions of the autoclave process are not particularly limited, and may be performed under appropriate temperature and pressure depending on the type of intermediate layer applied. The temperature of the typical autoclave process is about 80°C or more, 90°C or more, or 100°C or more, and the pressure is 2 atm or more, but is not limited thereto. The upper limit of the process temperature may be about 200°C or less, 190°C or less, 180°C or less, or 170°C or less, and the upper limit of the process pressure may be about 10 atm or less, 9 atm or less, 8 atm or less, 7 atm or less, or 6 atm or less.

[0106] The optical device may be used in a variety of applications, such as eyewear, such as sunglasses, AR (Augmented Reality) or VR (Virtual Reality) eyewear, building exteriors, and vehicle sunroofs. In one example, the optical device may be a vehicle sunroof by itself. For example, the optical device may be mounted in at least one opening in a vehicle body having the vehicle body and used as a vehicle sunroof. Effect of the Invention

[0107] The liquid crystal cell and optical device of the present application properly maintain the cell gap of the liquid crystal cell, have excellent adhesion between the upper and lower substrates, and can solve the problems of pressing and liquid crystal overflow that may occur during the bonding process of the outer substrates due to delamination that may occur during the post-electrode process. [Brief description of the drawings]

[0108] [Figure 1] 1 illustrates an exemplary liquid crystal cell of the present application.

[0109] [Diagram 2] 1 illustrates an exemplary liquid crystal cell of the present application.

[0110] [Diagram 3] 1 illustrates an exemplary liquid crystal cell of the present application.

[0111] [Figure 4] 1 illustrates an exemplary liquid crystal cell of the present application.

[0112] [Diagram 5] 1 shows images of the pressing and overflow defects caused by delamination and after bonding in Example 1.

[0113] [Figure 6]13 is an image showing the observation of defects such as pressing and overflow caused by delamination in Comparative Example 3. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0114] Hereinafter, the present application will be described in detail with reference to examples, but the scope of the present application is not limited to the following examples.

[0115] Example 1.

[0116] A polycarbonate film (Keiwa) with a thickness of about 100 μm and a horizontal x vertical area of ​​900 mm x 600 mm was prepared as the first base layer. ITO (indium-tin-oxide) was deposited on the first base layer to a thickness of 50 nm to form a first electrode layer. An adhesive composition (KR-3700, Shin-Etsu) was bar-coated on the first electrode layer and then dried at about 150° C. for about 5 minutes to form an adhesive layer with a thickness of about 10 μm. The storage modulus of the adhesive layer at a temperature of 25° C. and a frequency of 1 Hz was about 754,500 Pa, and the loss modulus at a temperature of 25° C. and a frequency of 1 Hz was about 906,687 Pa. The combination of the first base layer, the first electrode layer, and the adhesive layer is referred to as the upper substrate.

[0117] A polycarbonate film (Keiwa) with a thickness of about 100 μm and a horizontal x vertical area of ​​900 mm x 600 mm was prepared as the second substrate layer. ITO (indium-tin-oxide) was deposited on the second substrate layer to a thickness of 50 nm to form a second electrode layer. An acrylic resin composition (KAD-03, Minutek) was coated on the second electrode layer, and a honeycomb-shaped spacer was formed by photolithography. The pitch of the regular hexagons (closed shapes) constituting the honeycomb was about 350 μm, the height was about 6 μm, and the line width was about 30 μm. A vertical alignment film (Nissan, 5661) was coated on the spacer to a thickness of about 300 nm, and then rubbed in one direction. The combination of the second substrate layer, the second electrode layer, the spacer, and the vertical alignment film is called the lower substrate.

[0118] A liquid crystal composition was coated on the vertical alignment film of the lower substrate to form a liquid crystal layer having a width (vertical length) of 560 mm. The widths of both ends of the lower substrate where the liquid crystal composition was not coated were 20 mm each. Next, a liquid crystal cell was manufactured by laminating the adhesive layer of the upper substrate so that it faced the liquid crystal layer. At this time, the upper substrate and the lower substrate were alternately laminated, so that the width of the liquid crystal region in the center between the upper substrate and the lower substrate was 560 mm, the widths of the non-liquid crystal regions on both sides of the liquid crystal region between the upper substrate and the lower substrate were 10 mm each, and the widths of the regions where only the upper substrate was exposed and the regions where only the lower substrate was exposed at both ends of the liquid crystal cell were 10 mm each. An electrode tape made of fabric carbon material having a width of about 4 mm to 6 mm was attached to the regions where the upper substrate was exposed and the regions where the lower substrate was exposed at both ends of the liquid crystal cell.

[0119] The non-liquid crystal regions extend in the longitudinal direction of the lower substrate (second base layer), and are located on both sides of the liquid crystal region, with the non-liquid crystal regions on both sides being parallel to each other. The liquid crystal composition contains a liquid crystal compound (JNC, SHN-5011XX) and a chiral dopant (HCCH, S811), and the pitch p of the liquid crystal layer is about 20 μm. The liquid crystal cell is an RTN (reverse twisted nematic) mode liquid crystal cell in an initial vertical alignment state.

[0120] Example 2.

[0121] The upper and lower substrates were manufactured in the same manner as in Example 1. Next, a liquid crystal composition was coated on the vertical alignment film of the lower substrate to form a liquid crystal layer with a width (vertical length) of 570 mm. The widths of both ends of the lower substrate where the liquid crystal composition was not coated were 15 mm each. Next, a liquid crystal cell was manufactured by laminating the adhesive layer of the upper substrate facing the liquid crystal layer. At this time, the upper substrate and the lower substrate were alternately laminated to make the width of the liquid crystal region in the center between the upper substrate and the lower substrate 570 mm, the widths of the non-liquid crystal regions on both sides of the liquid crystal region between the upper substrate and the lower substrate 5 mm each, and the widths of the regions where only the upper substrate was exposed and the regions where only the lower substrate was exposed at both ends of the liquid crystal cell were 10 mm each. Except for the above, the liquid crystal cell was manufactured in the same manner as in Example 1. The non-liquid crystal regions extended in the longitudinal direction of the lower substrate (second base layer), the non-liquid crystal regions were located on both sides of the liquid crystal region, and the non-liquid crystal regions on both sides were parallel to each other. The liquid crystal composition contained a liquid crystal compound (SHN-5011XX, JNC) and a chiral dopant (S811, HCCH), and the pitch p of the liquid crystal layer was about 20 μm. The liquid crystal cell was an RTN mode liquid crystal cell in an initial vertical alignment state.

[0122] Example 3.

[0123] The upper and lower substrates were manufactured in the same manner as in Example 1. Next, a liquid crystal composition was coated on the vertical alignment film of the lower substrate to form a liquid crystal layer having a width (vertical length) of 580 mm. The width of one side of the lower substrate where the liquid crystal composition was not coated was 20 mm. Next, a liquid crystal cell was manufactured by laminating the adhesive layer of the upper substrate facing the liquid crystal layer. At this time, the upper substrate and the lower substrate were alternately laminated, so that the width of the liquid crystal region between the upper substrate and the lower substrate was 580 mm, the width of the non-liquid crystal region on one side of the liquid crystal region between the upper substrate and the lower substrate was 10 mm, and the widths of the region where only the upper substrate was exposed and the region where only the lower substrate was exposed at both ends of the liquid crystal cell were each 10 mm. The non-liquid crystal region extended in the longitudinal direction of the lower substrate, and the non-liquid crystal region was located on one side of the liquid crystal region. The liquid crystal composition included a liquid crystal compound (JNC, SHN-5011XX) and a chiral dopant (HCCH, S811), and the pitch p of the liquid crystal layer was about 20 μm. The liquid crystal cell is an RTN mode liquid crystal cell in an initial vertical alignment state.

[0124] Example 4

[0125] The upper and lower substrates were manufactured in the same manner as in Example 1. A liquid crystal composition was coated on the vertical alignment film of the lower substrate to form a liquid crystal layer having a width (vertical length) of 180 mm. The widths of both ends of the lower substrate where the liquid crystal composition was not coated were 210 mm. Next, a liquid crystal cell was manufactured by laminating the adhesive layer of the upper substrate facing the liquid crystal layer. At this time, the upper substrate and the lower substrate were alternately laminated, so that the width of the liquid crystal region in the center between the upper substrate and the lower substrate was 180 mm, the widths of the non-liquid crystal regions on both sides of the liquid crystal region between the upper substrate and the lower substrate were 200 mm, and the widths of the regions where only the upper substrate was exposed and the regions where only the lower substrate was exposed at both ends of the liquid crystal cell were 10 mm, respectively. A liquid crystal cell was manufactured in the same manner as in Example 1 except for the above. The non-liquid crystal regions extended in the longitudinal direction of the lower substrate (second base layer), and the non-liquid crystal regions were located on both sides of the liquid crystal region, and the non-liquid crystal regions on both sides were parallel to each other. The liquid crystal composition contained a liquid crystal compound (SHN-5011XX, JNC) and a chiral dopant (S811, HCCH), and the pitch p of the liquid crystal layer was about 20 μm. The liquid crystal cell was an RTN mode liquid crystal cell in an initial vertical alignment state.

[0126] Comparative Example 1

[0127] The upper and lower substrates were manufactured in the same manner as in Example 1. Next, a liquid crystal composition was coated on the vertical alignment film of the lower substrate to form a liquid crystal layer having a width (vertical length) of 576 mm. The widths of both ends of the lower substrate where the liquid crystal composition was not coated were 12 mm each. Next, a liquid crystal cell was manufactured by laminating the adhesive layer of the upper substrate so that it faced the liquid crystal layer. At this time, the upper substrate and the lower substrate were alternately laminated to make the width of the liquid crystal region in the center between the upper substrate and the lower substrate 576 mm, the widths of the non-liquid crystal regions on both sides of the liquid crystal region between the upper substrate and the lower substrate 2 mm each, and the widths of the regions where only the upper substrate was exposed and the regions where only the lower substrate was exposed at both ends of the liquid crystal cell were 10 mm each. The non-liquid crystal regions extended in the longitudinal direction of the lower substrate, and the non-liquid crystal regions were located on both sides of the liquid crystal region, and the non-liquid crystal regions on both sides were parallel to each other. The liquid crystal composition contained a liquid crystal compound (SHN-5011XX, JNC) and a chiral dopant (S811, HCCH), and the pitch p of the liquid crystal layer was about 20 μm. The liquid crystal cell was an RTN mode liquid crystal cell in an initial vertical alignment state.

[0128] Comparative Example 2

[0129] The upper and lower substrates were manufactured in the same manner as in Example 1. Next, a liquid crystal composition was coated on the vertical alignment film of the lower substrate to form a liquid crystal layer having a width (vertical length) of 580 mm. The widths of both ends of the lower substrate where the liquid crystal composition was not coated were each 10 mm. Next, a liquid crystal cell was manufactured by laminating the adhesive layer of the upper substrate facing the liquid crystal layer. At this time, the upper substrate and the lower substrate were alternately laminated to form a liquid crystal region having a width of 580 mm in the center between the upper substrate and the lower substrate, and no non-liquid crystal region was formed between the upper substrate and the lower substrate, and the widths of the region where only the upper substrate was exposed and the region where only the lower substrate was exposed were each 10 mm. Apart from the above, the liquid crystal cell was manufactured in the same manner as in Example 1.

[0130] Example 5.

[0131] A laminate including a first outer substrate, a first adhesive layer, a first polarizer, a second adhesive layer, the liquid crystal cell of Example 1, a third adhesive layer, a second polarizer, a fourth adhesive layer, and a second outer substrate, in that order, and including an outer layer surrounding the side of the liquid crystal cell, was prepared. At this time, the first base layer of the liquid crystal cell was disposed close to the first outer substrate, and the second base layer of the liquid crystal cell was disposed close to the second outer substrate. The second outer substrate was disposed in the direction of gravity compared to the first outer substrate.

[0132] The first polarizer and the second polarizer were PVA polarizers, and the light transmission axis of the first polarizer and the light transmission axis of the second polarizer were arranged to be at about 90 degrees. The first and second outer substrates were each made of double-curved glass having a thickness of about 3 mm and an area of ​​1100 mm x 800 mm (horizontal x vertical). The first adhesive layer, the second adhesive layer, the third adhesive layer, and the fourth adhesive layer were each made of a TPU layer (Argotec) having a thickness of about 380 μm. The outer layer was made of a TPU layer (Argotec) having a thickness of 380 μm. The storage modulus of the TPU layer (Argotec) at 25° C. and 1 Hz was 3,357,730 Pa, and the loss modulus at 25° C. and 1 Hz was 1,485,510 Pa. The laminate was autoclaved at a temperature of about 110° C. and a pressure of about 2 atm to manufacture an optical device.

[0133] Example 6.

[0134] An optical device was fabricated in the same manner as in Example 5, except that the liquid crystal cell fabricated in Example 2 was used instead of the liquid crystal cell fabricated in Example 1.

[0135] Example 7.

[0136] An optical device was fabricated in the same manner as in Example 5, except that the liquid crystal cell fabricated in Example 3 was used instead of the liquid crystal cell fabricated in Example 1.

[0137] Example 8.

[0138] An optical device was fabricated in the same manner as in Example 5, except that the liquid crystal cell fabricated in Example 4 was used instead of the liquid crystal cell fabricated in Example 1.

[0139] Comparative Example 3.

[0140] An optical device was manufactured in the same manner as in Example 5, except that the liquid crystal cell manufactured in Comparative Example 1 was used instead of the liquid crystal cell manufactured in Example 1.

[0141] Comparative Example 4.

[0142] An optical device was manufactured in the same manner as in Example 5, except that the liquid crystal cell manufactured in Comparative Example 2 was used instead of the liquid crystal cell manufactured in Example 1.

[0143] Evaluation example 1. Evaluation of push and overflow defects due to delamination

[0144] The optical devices of Examples 5 to 8 and Comparative Examples 3 and 4 were evaluated for the pressing and overflow defects after bonding due to delamination. Specifically, before bonding the liquid crystal cell to the outer substrate, a voltage was applied in a cross-polarization state, and then non-uniform transmittance was observed in the corresponding area. FIG. 5 is an image of the pressing and overflow defects observed in the optical device of Example 1, and FIG. 6 is an image of the pressing and overflow defects observed in the optical device of Comparative Example 3. In FIG. 6, a is the outer substrate and adhesive layer area, b is the area of ​​the first polarizer, the first base layer, the electrode tape, and the second polarizer, c is the non-liquid crystal area, and d is the area of ​​the first polarizer, the first base layer, the liquid crystal layer, the second base layer, and the second polarizer. As shown in FIG. 6, in Comparative Example 3, liquid crystal flow occurred due to delamination, and non-uniform transmittance was observed in dark areas where the cell gap could not be maintained due to a lack of liquid crystal in certain areas, and in bright areas where the cell gap became large. Comparative Example 4 also showed similar results to Comparative Example 3. On the other hand, in Example 5, the above-mentioned defects were not observed as shown in FIG.

[0145] [Table 1] [Explanation of symbols]

[0146] 100:LCD area 200a, 200b, 200: Non-liquid crystal area 300a, 300b, 300: Regions in which only one of the upper and lower substrates is present 400a, 400b, 400: Conductive tape 10a: First base layer 10b: First electrode layer 10c:Adhesive layer 30: Liquid crystal compound 20a: Second base layer 20b: Second electrode layer 20c: Spacer 20d: Alignment film

Claims

1. An upper substrate including a first base layer and an adhesive layer, and a lower substrate including a second base layer and a spacer, A region between the upper substrate and the lower substrate is divided into a liquid crystal region including a liquid crystal compound and a non-liquid crystal region including no liquid crystal compound, A liquid crystal cell, wherein the width (W1) of the non-liquid crystal region is 4 mm or more.

2. 2. The liquid crystal cell according to claim 1, wherein the non-liquid crystal regions have a line shape extending in a first direction, the first direction being a longitudinal direction of the first base material layer or the second base material layer.

3. 2. The liquid crystal cell of claim 1, wherein the non-liquid crystal region is located on a first side and a second side of the liquid crystal region, and the non-liquid crystal region located on the first side of the liquid crystal region and the non-liquid crystal region located on the second side of the liquid crystal region are not in contact with each other.

4. 4. The liquid crystal cell of claim 3, wherein the non-liquid crystal region located on the first side of the liquid crystal region and the non-liquid crystal region located on the second side of the liquid crystal region are parallel to each other.

5. The liquid crystal cell according to claim 1 , wherein the non-liquid crystal region is located on only one of the sides of the liquid crystal region.

6. 2. The liquid crystal cell of claim 1, wherein there is an area on a side of the non-liquid crystal region where only one of the upper substrate and the lower substrate is present, and a conductive tape extending in a first direction is formed on one of the substrates.

7. 2. The liquid crystal cell according to claim 1, wherein the liquid crystal compound in the liquid crystal region switches its alignment state by application of a voltage.

8. The liquid crystal cell of claim 1 , wherein the upper substrate further comprises a first electrode layer between the first base layer and the adhesive layer, and the lower substrate further comprises a second electrode layer between the second base layer and the spacer.

9. The liquid crystal cell of claim 8 , wherein the upper substrate does not include an alignment film, and the lower substrate further includes an alignment film.

10. 10. An optical device comprising in sequence a first outer substrate, a liquid crystal cell according to claim 1 and a second outer substrate.

11. The optical device of claim 10 , wherein the first outer substrate and the second outer substrate are each a glass substrate.

12. The optical device of claim 10 , further comprising a first adhesive layer between the first outer substrate and the liquid crystal cell, and a second adhesive layer between the second outer substrate and the liquid crystal cell.

13. 13. The optical device of claim 12, wherein the first adhesive layer and the second adhesive layer are each a thermoplastic polyurethane (TPU) adhesive layer, a polyamide adhesive layer, a polyester adhesive layer, an EVA (Ethylene Vinyl Acetate) adhesive layer, an acrylic adhesive layer, a silicone adhesive layer, or a polyolefin adhesive layer.

14. 11. A motor vehicle comprising: a vehicle body having one or more openings formed therein; and an optical device according to claim 10 mounted in said openings.

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