KR20210038132A - Transmission Variable Device - Google Patents

Abstract

The present application relates to an optical modulation device. In the present application, it is possible to provide the optical modulation device having the excellent transmittance variable characteristics and not causing problems such as light leakage at an inclination angle so that the optical modulation device can be applied to various purposes. The optical modulation device comprises: a first polymer film substrate; and a second polymer film substrate.

Description

Optical Modulation Device {Transmission Variable Device}

The present application relates to an optical modulation device.

An optical modulation device means a device capable of switching between at least two or more different states. Such devices include, for example, wearable devices such as eyewear such as glasses or sunglasses, mobile devices, devices for virtual reality (VR), devices for augmented reality (AR), or Its use is gradually expanding, such as being used for the sunroof of a vehicle.

As shown in FIG. 1, the optical modulation device has a structure including two opposing polarizing layers 10 and 20 and an optical modulation layer 30 present between the polarizing layers. When an anisotropic film substrate other than an isotropic film substrate or a glass substrate is applied to such an optical modulation device, there is a problem in that light leaks to the side in a blocking mode.

To solve this problem, a method of applying a compensation film to a polarizing plate was considered, but in the case of a light modulation device including an anisotropic film substrate, the compensation effect of light passing through the compensation film is distorted by the optical properties of the anisotropic film substrate. There are such problems. For this, it is possible to consider applying the compensation film at an appropriate location, for example, between the anisotropic film substrate and the ITO film or on the ITO film, but in this case, another problem such as an increase in cell gap and an increase in unit cost. Occurs.

This application relates to an optical modulation device. The object of the present application is to provide an optical modulation device that can be applied to various purposes by having an excellent viewing angle compensation effect without applying a compensation film.

The angle defined in the present specification should be understood in consideration of errors such as manufacturing errors or variations. For example, in the present specification, the term vertical, parallel, orthogonal or horizontal means substantially vertical, parallel, orthogonal or horizontal within a range that does not impair the target effect, and, for example, in each of the above cases, about ± It may include an error within 10 degrees, an error within about ±5 degrees, an error within about ±3 degrees, an error within about ±2 degrees, an error within about ±1 degrees, or an error within about ±0.5 degrees. .

Among the physical properties mentioned in the present specification, the above properties are properties measured at room temperature unless otherwise specified in the case where the measurement temperature affects the property.

In the present specification, the term room temperature is a temperature in a state that is not particularly warmed or reduced in temperature, and any one temperature within the range of about 10° C. to 30° C., for example, about 15° C. or more, 18° C. or more, 20° C. or more, or about 23 It may mean a temperature of about 27°C or less while being equal to or higher than °C. In addition, unless otherwise specified, the unit of temperature referred to in this specification is °C.

The term inclination angle referred to in the present specification is defined as follows unless otherwise specified. In FIG. 5, when the plane formed by the x-axis and y-axis is referred to as a reference plane (for example, the reference plane may be a surface of a polarizing layer, a light modulation layer, or a polymer film substrate of an optical modulation device), the normal line of the reference plane The angle formed as in FIG. 5 with respect to the z-axis is defined as the inclination angle (the inclination angle at point P in FIG. 5 is Θ). When the plane formed by the x-axis and y-axis in FIG. 5 is referred to as a reference plane (for example, the reference plane may be a surface of a polarizing layer, a light modulation layer, or a polymer film substrate of an optical modulation device), the x-axis of the reference plane When set to 0 degrees, the angle formed as shown in Fig. 5 with respect to the x-axis is defined as the moving angle (in Fig. 5, the moving angle at point P is Φ). In the above, the x-axis of the reference plane may be any x-axis.

The phase difference, refractive index, refractive index anisotropy, and the like referred to in the present specification are physical quantities for light having a wavelength of about 550 nm unless otherwise specified.

Unless otherwise specified, the angle formed by any two directions referred to in the present specification may be an acute angle among an acute or obtuse angle formed by the two directions, or a smaller angle among angles measured in a clockwise direction and a counterclockwise direction. . Accordingly, unless otherwise specified, angles referred to in this specification are positive numbers. However, in some cases, in order to indicate the measurement direction between the angles measured in the clockwise or counterclockwise direction, the angle measured in the clockwise direction may be expressed as a positive number, and the angle measured in the counterclockwise direction may be expressed as a negative number.

The present application relates to a first polymer film substrate 102 on which an adhesive layer or pressure-sensitive adhesive layer 103 is formed on a first surface and a first polarizing layer 101 is attached to the second surface, as shown in FIG. A liquid crystal alignment layer 203 is formed on the first surface, and a second polymer film substrate 202 to which a second polarizing layer 201 is attached to the second surface, and the first and second polymer film substrates are It is for a light modulation device in which the first side of each other is disposed so as to face each other, and the light modulation layer 300 including a liquid crystal compound and a dichroic dye is present between the first and second polymer film substrates disposed opposite to each other. I can.

In the present application, the term optical modulation device may mean a device capable of switching between at least two or more different light states. In the above, different states of light may mean states in which at least one of transmittance, haze, and color is different from each other.

The optical modulation device of the present application may include at least an optical modulation layer for switching as described above. The light modulation layer may be a layer that generates a polarization component in an example.

The optical modulation layer of the present application is a layer including at least a liquid crystal compound, and may mean a liquid crystal layer capable of controlling an alignment state of the liquid crystal compound through application of an external signal or the like. As the liquid crystal compound, any kind of liquid crystal compound may be used as long as the orientation direction thereof can be changed by application of an external signal. As a liquid crystal compound, a nematic liquid crystal compound, a smectic liquid crystal compound, a cholesteric liquid crystal compound, etc. can be used, for example. In addition, the liquid crystal compound may be, for example, a compound that does not have a polymerizable group or a crosslinkable group so that the orientation direction thereof can be changed by the application of an external signal.

The light modulation layer of the present application may further include a dichroic dye together with the liquid crystal compound. In the present specification, the term ``dye'' may mean a material capable of intensively absorbing and/or modifying light in at least a part or the entire range in a visible light region, for example, 400 nm to 700 nm wavelength range, and the term `` The dichroic dye” may mean a material capable of anisotropic absorption of light in at least a part or the entire range of the visible light region. As such a dye, for example, an azo dye or an anthraquinone dye is known, but is not limited thereto.

In one example, the light modulation layer is a liquid crystal layer including a liquid crystal compound and a dichroic dye, and may be a so-called guest host liquid crystal cell. The term ``GHLC layer'' may refer to a functional layer in which dichroic dyes are arranged together according to the arrangement of liquid crystals and exhibits anisotropic light absorption characteristics with respect to the alignment direction of the dichroic dye and the direction perpendicular to the alignment direction. . For example, a dichroic dye is a material whose absorption rate of light varies depending on the polarization direction.If the absorption rate of light polarized in the long axis direction is large, it is called a p-type dye, and if the absorption rate of light polarized in the minor axis direction is large, it is called an n-type dye. It can be called. 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 thus can be transmitted. Unless otherwise specified, the dichroic dye is assumed to be a p-type dye.

The present inventors have confirmed that by including a dichroic dye together with a liquid crystal compound in the light modulation layer as described above, light leakage during side observation that may occur in the light modulation device can be prevented. The orientation of the dichroic dye in the guest host liquid crystal layer follows the orientation of the liquid crystal compound. Therefore, for example, in the case where the optical modulation device is a device designed to realize low transmittance when the liquid crystal compound is vertically aligned, the dichroic dye is also in a vertical alignment state or a state corresponding thereto in the vertical alignment state of the liquid crystal compound. Becomes. As such, the dichroic dye oriented in a vertical orientation or in a state equivalent thereto can absorb light to be leaked when viewed from the side. In particular, by introducing this method, it is possible to prevent side light leakage without introducing a separate compensation structure, and even when the polymer film substrate is not an isotropic substrate, side light leakage can be prevented without a complicated design.

The effect of preventing side light leakage by such a dichroic dye can be further improved according to the content of the optical device of the present application to be described later. That is, the alignment of the dichroic dye in the light modulation layer including the liquid crystal compound and the dichroic dye follows the alignment of the liquid crystal compound, and the alignment of the liquid crystal compound is determined according to the type of the liquid crystal alignment layer. The present inventors have confirmed that the alignment of the liquid crystal compound formed by the vertical alignment layer and the adhesive (adhesive agent) as described below is an alignment in which a dichroic dye following the alignment can effectively block light leaking to the side. . Therefore, the effect of preventing side light leakage by the dichroic dye may be more maximized according to the content of the present application to be described later.

The dichroic dye included in the light modulation layer may exhibit absorption in at least a visible light region, for example, a wavelength within a range of about 400 to 700 nm. If such absorption properties are ensured, one type of dichroic dye may be used, or a mixture of two or more types may be used.

The ratio of the dichroic dye included in the light modulation layer may be, for example, 5% by weight or less. The ratio of the dichroic dye is the ratio of the dichroic dye to the weight of all components included in the light modulation layer. For example, if the light modulation layer includes a liquid crystal compound, a dichroic dye, and a chiral dopant, the percentage of the dichroic dye relative to the total weight of the three components may be the ratio of the dichroic dye. If the ratio of the dichroic dye is too high, when the dichroic dye follows the horizontal orientation of the liquid crystal compound, too much light may be absorbed from the front, which is not an effect intended in the present application. That is, the ratio of the dichroic dye is controlled so as to effectively prevent side light leakage when the dye follows the vertical alignment of the liquid crystal compound, while absorbing the front light to a minimum when the dye follows the horizontal alignment of the liquid crystal compound. It is appropriate. In another example, the proportion of the dichroic dye is 4% by weight or less, 3% by weight or less, 2% by weight or less, or 1% by weight or less, or 0.1% by weight or more, 0.2% by weight or more, 0.3% by weight or more, or 0.4% by weight It may be above, but is not limited thereto.

In the present application, by including the dichroic dye in the above range in the optical modulation layer, light leakage from the side is controlled while exhibiting a transmittance in the range to be described later in the transmission mode of the optical modulation device, thereby providing excellent viewing angle compensation. It is possible to provide a modulation device.

The present application, for example, by adjusting the arrangement of the liquid crystal compound in the light modulation layer, the initial alignment is vertical alignment, the vertical alignment state is designed to be changed to a horizontal alignment state by the application of an external signal. It could be for a device. In the above, the initial orientation is an orientation state when no external signal is applied to the optical modulation layer.

In the present specification, the term vertical alignment is a state in which a director of the optical modulation layer or a director of a liquid crystal compound in the optical modulation layer is arranged substantially perpendicular to the plane of the optical modulation layer, for example, the optical modulation layer An angle formed by the z-axis, which is a normal of the reference plane of, and the director may be in a range of about 80 degrees to 100 degrees, 85 degrees to 95 degrees, or about 90 degrees. In addition, the term horizontal alignment may mean a state in which a director of the light modulation layer or a director of a liquid crystal compound in the light modulation layer is arranged substantially parallel to the reference plane of the light modulation layer, for example, the direction The angle between the ruler and the reference plane of the light modulation layer may be in the range of about 0° to 10° or about 0° to 5°, or about 0°.

In the present specification, the term director of the optical modulation layer or the director of the liquid crystal compound may mean an optical axis or a slow axis of the optical modulation layer. For example, the optical axis or the slow axis may mean a long axis direction when the liquid crystal molecules are in the shape of a rod, and when the liquid crystal molecules have a disc shape, it may mean an axis in the normal direction of the disk plane, When a plurality of liquid crystal compounds having different directors are included in the light modulation layer, it may mean a vector sum of directors of the liquid crystal compound.

In one example, the optical modulation layer may be designed to implement a twist orientation mode. In the present specification, the term twist alignment mode may mean a spiral structure in which the directors of the liquid crystal compounds are twisted along an imaginary spiral axis to form a layer and are aligned. The twist orientation mode may be implemented in the above-described vertical or horizontal orientation mode. For example, in the vertical twist alignment mode, individual liquid crystal compounds are vertically aligned and twisted along a spiral axis to form a layer, and in the horizontal twist alignment mode, individual liquid crystal compounds are horizontally aligned and twisted along the spiral axis. It can mean a layered state.

In the twist orientation mode, a ratio (d/p) of the thickness (d) and the pitch (p) of the optical modulation layer may be, for example, 1 or less. If the ratio (d/p) exceeds 1, a problem such as a finger domain may occur, and thus the range may be adjusted as much as possible. The ratio (d/p) is in another example about 0.95 or less, about 0.9 or less, about 0.85 or less, about 0.8 or less, about 0.75 or less, about 0.7 or less, about 0.65 or less, about 0.6 or less, about 0.55 or less, about 0.5 or less Alternatively, it may be about 0.45 or less, about 0.1 or more, about 1.15 or more, about 0.2 or more, about 0.25 or more, about 0.3 or more, or about 0.35 or more. In the above, the thickness d of the optical modulation layer may have the same meaning as a cell gap in the optical modulation device.

The pitch (p) of the optical modulation layer in the twist orientation mode can be measured by a measurement method using a wedge cell, and specifically, a simple method for accurate measurements of the cholesteric pitch using a stripe-wedge Grandjean- such as D. Podolskyy. Cano cells (Liquid Crystals, Vol. 35, No. 7, July 8\2008, 789-791) can be measured by the method described.

The alignment of the liquid crystal compound formed by the ratio of the thickness (d) and the pitch (p) as described above, the alignment of the dichroic dye following it effectively absorbs the light that will leak from the side during vertical alignment, and when horizontal alignment The absorption of frontal light can be minimized.

The optical modulation layer may further include a so-called chiral dopant so that the optical modulation layer can implement a twist mode. That is, the light modulation layer may further include a chiral dopant together with a liquid crystal compound and a dichroic dye.

The chiral dopant that may be included in the light modulation layer may be used without particular limitation as long as it can induce a desired twisting without impairing liquid crystal properties, for example, nematic regularity. . The chiral dopant for inducing rotation in the liquid crystal molecule needs to include at least chirality in the molecular structure. The chiral dopant is, for example, a compound having one or two or more asymmetric carbons, a compound having an asymmetric point on a heteroatom such as chiral amine or chiral sulfoxide, or cumulene. ) Or a compound having an axially asymmetric, optically active site having an axial subsidiary such as binaphthol. The chiral dopant may be, for example, a low molecular weight compound having a molecular weight of 1,500 or less. As the chiral dopant, a commercially available chiral nematic liquid crystal, for example, a chiral dopant liquid crystal S811 sold by Merck or LC756 of BASF may be applied.

The application rate of the chiral dopant is not particularly limited as long as it can achieve the desired ratio (d/p). In general, the content (% by weight) of the chiral dopant is calculated by the formula of 100/(Helixcal Twisting power (HTP) × pitch (nm)), and may be selected in an appropriate ratio in consideration of the desired pitch (p).

The light modulation layer may include a liquid crystal compound having a negative dielectric anisotropy, or the light modulation layer may exhibit the aforementioned dielectric anisotropy. The absolute value of dielectric anisotropy may be appropriately selected in consideration of the purpose of the present application. The term "dielectric anisotropy (Δε)" may mean the difference (ε// -ε⊥) between the horizontal permittivity (ε//) and the vertical permittivity (ε⊥). In the present specification, the term horizontal permittivity (ε//) refers to a dielectric constant value measured along the direction of the electric field while applying a voltage so that the direction of the liquid crystal molecules and the direction of the electric field by the applied voltage are substantially horizontal, The vertical permittivity (ε⊥) refers to a dielectric constant value measured along the direction of the electric field in a state in which a voltage is applied so that the direction of the liquid crystal molecules and the direction of the electric field by the applied voltage are substantially perpendicular.

The liquid crystal layer may include a liquid crystal compound having a refractive index anisotropy (n△) in the range of about 0.04 to 0.15, or the liquid crystal layer may exhibit the aforementioned refractive index anisotropy. The refractive index anisotropy (n△) referred to in the present application is the difference (ne-no) between the abnormal refractive index (ne, extraordinary refractive index) and the normal refractive index (no, ordinary refractive index), which can be confirmed using an Abbe refractometer. The specific manner follows the method disclosed in the following examples. In another example, the refractive index anisotropy (nΔ) may be about 0.14 or less, 0.13 or less, 0.12 or less, 0.11 or less, or 0.1 or less, or 0.05 or more, 0.06 or more, 0.07 or more, 0.08 or more, or 0.09 or more.

The thickness of the optical modulation layer of the present application may be appropriately selected in consideration of the purpose of the present application. In one example, the thickness of the light modulation layer may be about 15 μm or less. By controlling the thickness in this way, a device having a large difference in transmittance in the transmission mode and the blocking mode, that is, a device having excellent transmittance variable characteristics can be implemented. In another example, the thickness is about 14 μm or less, 13 μm or less, 12 μm or less, 11 μm or less, 10 μm or less, 9 μm or less, or 8 μm or less, or 1 μm or more, 2 μm or more, 3 μm or more, 4 μm It may be more than 5㎛, more than 6㎛, more than 7㎛, or more than 8㎛, but is not limited thereto.

In the light modulation device of the present application, for example, a first polymer film substrate and a second polymer film substrate may be disposed on both sides of the light modulation layer.

Each of the first and second polymer film substrates may have a plane retardation with respect to light having a wavelength of 550 nm, for example, 500 nm or more. In another example, it may be 1000 nm or more, 2000 nm or more, 3000 nm or more, 4000 nm or more, 5000 nm or more, 6000 nm or more, 7000 nm or more, 8000 nm or more, 9000 nm or more, or 10000 nm or more, or 50000 nm or less, 40000 nm or less, 30000 nm or less, 20000 nm or less, or 15000 nm or less. , But is not limited thereto.

In the present specification, the plane phase difference may mean a value calculated by Equation 1 below.

[Equation 1]

R _in = d × (n _x -n _y )

In Equation 1, R _in is the plane retardation, d is the thickness of the polymer film substrate, n _x is the refractive index in the slow axis direction of the polymer film substrate, and n _y is the refractive index in the fast axis direction, which is orthogonal to the slow axis direction. It is the refractive index in the plane direction.

Films having a high retardation as described above are known in the industry, and such films exhibit large optical anisotropy as well as mechanical properties due to high stretching during manufacturing. As a representative example of the retardation film known in the industry, there may be a polyester film such as a PET (ethylene terephthalate) (PET) film.

In the optical modulation device of the present application, the first and second polymer film substrates may be included in the device so that the slow axes of the first and second polymer film substrates have a specific positional relationship. In one example, the first and second polymer film substrates may be disposed so that their slow axes are horizontal.

By arranging the first and second polymer film substrates having the planar retardation as described above so that the slow axis of the polymer film substrate has the above range, while exhibiting excellent transmittance variable effect through combination with the above-described light modulation layer It is possible to provide an optical modulation device capable of compensating a viewing angle by controlling a light leakage phenomenon at an angle of inclination.

The first and second polymer film substrates of the present application may include, for example, first and second polarizing layers on one surface of the polymer film substrate, respectively. In the present specification, the polarizing layer may mean a device that converts natural or non-polarized light into polarized light. In one example, the polarizing layer may be a linear polarizing layer. In the present specification, the linear polarization layer refers to a case in which the selectively transmitted light is linearly polarized light vibrating in any one direction, and the selectively absorbed or reflected light is linearly polarized light that vibrates in a direction orthogonal to the vibration direction of the linearly polarized light. That is, the linear polarizer may have a transmission axis and an absorption axis or a reflection axis orthogonal to the plane direction.

The polarizing layer may be an absorption type polarizing layer or a reflective polarizing layer. As the absorption-type polarizing layer, for example, a polarizing layer in which iodine is dyed on a polymeric stretched film such as a PVA (PVA means polyvinyl alcohol in the present specification) stretched film, or a liquid crystal polymerized in an aligned state as a host And, a guest-host type polarizing layer using an anisotropic dye arranged according to the alignment of the liquid crystal as a guest may be used, but the present invention is not limited thereto. As the reflective polarizing layer, for example, a reflective polarizing layer known as DBEF (Dual Brightness Enhancement Film) or a reflective polarizing layer formed by coating a liquid crystal compound such as LLC (Lyotropic liquid crystal) may be used. However, it is not limited thereto.

In one example, absorption axes of the first polarizing layer and the second polarizing layer may be disposed so as to be perpendicular to each other. The optical modulation device of the present application may be advantageous in providing an optical modulation device with reduced light leakage, particularly at an inclination angle, through such an arrangement.

In the present application, for example, a liquid crystal alignment layer may be formed on the first surface of the second polymer film substrate. The liquid crystal alignment layer may be used to determine the initial alignment of the liquid crystal in the light modulation layer. The type of the liquid crystal alignment layer applied at this time is not particularly limited, and may be, for example, a known rubbing alignment layer or a photo alignment layer.

The orientation direction may be a rubbing direction in the case of a rubbing alignment layer and a direction of irradiated polarization in the case of a photo-alignment layer. Such an alignment direction can be confirmed by a detection method using a linear polarization layer. For example, when the optical modulation layer of the present application is in a twisted alignment mode such as a TN (Twisted Nematic) mode, a linear polarization layer is disposed on one surface and the transmittance is measured while changing the absorption axis of the polarization layer. Alternatively, when the transmission axis and the alignment direction of the liquid crystal alignment layer coincide, the transmittance tends to be low, and the alignment direction can be confirmed through a simulation reflecting the refractive index anisotropy of the applied liquid crystal compound. A method of confirming the orientation direction according to the mode of the light modulation layer of the present application is known.

The optical modulation device of the present application may further include a conductive layer on one surface of the first and second polymer film substrates, as long as the effect of the present application is not obstructed. In one example, as shown in FIG. 3, conductive layers 400a, respectively, between the adhesive layer or the pressure-sensitive adhesive layer 103 and the first polymer film substrate 102 and between the liquid crystal alignment layer 203 and the second polymer film substrate 202, 400b) may be formed.

The conductive layer may transfer an appropriate electric field to the light modulation layer so as to switch the alignment state of the light modulation layer. The direction of the electric field may be a vertical or horizontal direction, for example, a thickness direction or a surface direction of the light modulation layer.

The conductive layer may be, for example, a transparent conductive layer, and the transparent conductive layer may be formed by depositing, for example, a conductive polymer, a conductive metal, a conductive nanowire, or a metal oxide such as ITO (Indium Tin Oxide). have. In addition, various materials and methods for forming a transparent conductive layer are known, and can be applied without limitation.

The light modulation device of the present application may further include, for example, an adhesive layer or a pressure-sensitive adhesive layer applied to another layer or for attaching the polymer film substrate to another layer.

In one example, the adhesive layer or pressure-sensitive adhesive layer may include an adhesive or pressure-sensitive adhesive having a vertical orientation force. In the present specification, the term adhesive or pressure-sensitive adhesive having a vertical alignment force may mean a material having a vertical alignment force and an adhesive force or adhesive force to liquid crystal molecules at the same time.

In one example, the adhesive or pressure-sensitive adhesive having a vertical alignment force may be formed on at least one of the surface of the first polymer film substrate and the surface of the second polymer film substrate. According to the exemplary embodiment of the present application, an adhesive having a vertical alignment force may be present on one surface of the first polymer film substrate, and a liquid crystal alignment layer may be formed on one surface of the second polymer film substrate.

In the present application, as the adhesive or pressure-sensitive adhesive having a vertical orientation force, for example, a silicone adhesive or pressure-sensitive adhesive may be used. As the silicone adhesive or pressure-sensitive adhesive, a cured product of a composition including a curable silicone compound may be used. 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 may be used.

In one example of the present application, the curable silicone compound is an addition-curable silicone compound, including (1) an organopolysiloxane containing two or more alkenyl groups in the molecule, and (2) two or more silicon-bonded hydrogen atoms in the molecule. Organopolysiloxanes. The silicone compound as described above can form a cured product by an addition reaction, for example, in the presence of a catalyst to be described later.

In the above (1) organopolysiloxane, as a main component constituting the cured silicone product, it may contain at least two alkenyl groups in one molecule. In this case, specific examples of the alkenyl group may include a vinyl group, an allyl group, a butenyl group, a pentenyl group, a hexenyl group, or a heptenyl group, among which a vinyl group may be preferable, but is not limited thereto. In the above (1) organopolysiloxane, the bonding position of the alkenyl group described above is not particularly limited. For example, the alkenyl group may be bonded to the end of the molecular chain and/or to the side chain of the molecular chain. Further, in the above (1) ornagopolysiloxane, examples of the substituents that may be included in addition to the above alkenyl include alkyl groups such as methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group or heptyl group; Aryl groups such as phenyl group, tolyl group, xylyl group or naphthyl group; Aralkyl groups such as a benzyl group or a phenentyl group; And halogen-substituted alkyl groups such as a chloromethyl group, a 3-chloropropyl group, or a 3,3,3-trifluoropropyl group, among which a methyl group or a phenyl group is preferable, but is not limited thereto.

The molecular structure of the (1) organopolysiloxane is not particularly limited, and may have any shape, such as straight chain, branched, cyclic, reticulated, or partially branched. In the present application, it is particularly preferable to have a linear molecular structure among the above-described molecular structures, but is not limited thereto. On the other hand, in the present invention, it is preferable to use an organopolysiloxane containing an aromatic group such as an aryl group or an aralkyl group in the molecular structure as the (1) organopolysiloxane in terms of the hardness and refractive index of the cured product, It is not necessarily limited thereto.

More specific examples of the (1) organopolysiloxane that can be used in the present application are dimethylsiloxane-methylvinylsiloxane copolymers with trimethylsiloxane group blocking at both ends of the molecular chain, methylvinylpolysiloxane, molecular chain blocking trimethylsiloxane groups at both ends of the molecular chain Blockade of both ends of trimethylsiloxane groups Dimethylsiloxane-methylvinylsiloxane-methylphenylsiloxane copolymer, dimethylvinylsiloxane group blocking at both ends of the molecular chain dimethylpolysiloxane, blocking of dimethylvinylsiloxane groups at both ends of the molecular chain methyl vinylpolysiloxane, dimethylvinylsiloxane at both ends of the molecular chain Acid-blocked dimethylsiloxane-methylvinylsiloxane copolymer, dimethylvinylsiloxane-blocked dimethylsiloxane-methylvinylsiloxane-methylphenylsiloxane copolymer at both ends of the molecular chain, a siloxane unit represented by R12SiO1/2 and a siloxane unit represented by R12R2SiO1/2, and Organopolysiloxane copolymer comprising a siloxane unit represented by SiO4/2, an organopolysiloxane comprising a siloxane unit represented by R12R2SiO1/2 and a siloxane unit represented by SiO4/2

Copolymers, organopolysiloxane copolymers including a siloxane unit represented by R1R2SiO2/2 and a siloxane unit represented by R1SiO3/2 or a siloxane unit represented by R2SiO3/2, and a mixture of two or more of the above, but are limited thereto. It does not become. In the above, R1 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; Aryl groups such as phenyl group, tolyl group, xylyl group or naphthyl group; Aralkyl groups such as a benzyl group or a phenentyl group; It may be a halogen-substituted alkyl group such as a chloromethyl group, a 3-chloropropyl group, or a 3,3,3-trifluoropropyl group. In addition, in the above, R 2 is an alkenyl group, and specifically, may be a vinyl group, an allyl group, a butenyl group, a pentenyl group, a hexenyl group or a heptenyl group.

In one aspect of the present invention, the (1) organopolysiloxane may have a viscosity at 25° C. of 50 to 500,000 CP (centipoise), and preferably 400 to 100,000 CP. If the viscosity is less than 50 CP, the mechanical strength of the cured product of the silicone compound may be lowered, and if it exceeds 500,000 CP, the handling property or workability may be lowered.

In the addition-curable silicone compound, (2) organopolysiloxane may serve to crosslink the (1) organopolysiloxane. In the above (2) organopolysiloxane, the bonding position of the hydrogen atom is not particularly limited, and may be, for example, bonded to the end and/or side chain of the molecular chain. In addition, in the (2) organopolysiloxane, the kind of substituents that may be included in addition to the silicon-bonded hydrogen atom is not particularly limited, and, for example, as mentioned in (1) organopolysiloxane, an alkyl group, an aryl group, An aralkyl group or a halogen-substituted alkyl group, among which a methyl group or a phenyl group is preferable, but is not limited thereto.

On the other hand, (2) the molecular structure of the organopolysiloxane is not particularly limited, and may have any shape, such as straight chain, branched, cyclic, reticulated, or partially branched. In the present invention, it is particularly preferable to have a linear molecular structure among the above-described molecular structures, but is not limited thereto.

More specific examples of the (2) organopolysiloxane that can be used in the present invention include methylhydrogenpolysiloxane blocking trimethylsiloxane groups at both ends of the molecular chain, dimethylsiloxane-methylhydrogen copolymer blocking trimethylsiloxane groups at both ends of the molecular chain, and molecules. Blockade of trimethylsiloxane groups at both ends of the chain dimethylsiloxane-methylhydrogensiloxane-methylphenylsiloxane copolymer, blockade of dimethylhydrogensiloxane groups at both ends of the molecular chain dimethylpolysiloxane, blockade of dimethylhydrogensiloxane groups at both ends of the molecular chain dimethylsiloxane-methylphenylsiloxane copolymer , Methylphenylpolysiloxane with blockade of dimethylhydrogensiloxane groups at both ends of the molecular chain, an organopolysiloxane copolymer comprising a siloxane unit represented by R13SiO1/2, a siloxane unit represented by R12HSiO1/2, and a siloxane unit represented by SiO4/2, R12HSiO1 Organopolysiloxane copolymer comprising a siloxane unit represented by /2 and a siloxane unit represented by SiO4/2, a siloxane unit represented by R1HSiO2/2 and a siloxane unit represented by R1SiO3/2, or a siloxane represented by HSiO3/2 An organopolysiloxane copolymer including a unit and a mixture of two or more of the above may be exemplified, but are not limited thereto. In the above, R1 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; Aryl groups such as phenyl group, tolyl group, xylyl group or naphthyl group; Aralkyl groups such as a benzyl group or a phenentyl group; It may be a halogen-substituted alkyl group such as a chloromethyl group, a 3-chloropropyl group, or a 3,3,3-trifluoropropyl group.

In the present application, for example, the (2) organopolysiloxane may have a viscosity of 1 to 500,000 CP (centipoise), preferably 5 to 100,000 CP at 25°C. If the viscosity is less than 1 CP, the mechanical strength of the cured product of the silicone compound may be lowered, and if it exceeds 500,000 CP, the handling property or workability may be lowered.

In the present application, the content of the organopolysiloxane (2) is not particularly limited as long as it is included to the extent that appropriate curing can be performed. For example, the (2) organopolysiloxane may be contained in an amount of 0.5 to 10 silicon-bonded hydrogen atoms per one alkenyl group contained in the (1) organopolysiloxane described above. If the number of silicon atom-bonded hydrogen atoms is less than 0.5, there is a concern that curing of the curable silicone compound may be insufficiently performed, and if it exceeds 10, the heat resistance of the cured product may decrease. On the other hand, in the present invention, from the viewpoint of hardness and refractive index of the cured product, (2) organopolysiloxane containing an aromatic group such as an aryl group or aralkyl group in the molecular structure is used as the (2) organopolysiloxane. It is desirable to do, but is not necessarily limited thereto.

In the present application, the addition-curable silicone compound may further include platinum or a platinum compound as a catalyst for curing. Specific examples of such platinum or platinum compounds include fine platinum powder, platinum black, platinum-supported silica fine powder, platinum-supported activated carbon, chlorinated platinum acid, platinum tetrachloride, an alcohol solution of chlorinated platinum acid, a complex of platinum and olefin, platinum and 1,1, Complexes of alkenylsiloxanes such as 3,3-tetramethyl-1,3-divinyldisiloxane, and fine thermoplastic resin powders (polystyrene resin, nylon resin, polystyrene resin, nylon resin, polystyrene resin, polystyrene resin, polystyrene resin, polystyrene resin, polystyrene resin, polystyrene resin, polystyrene resin, etc.) Carbonate resin, silicone resin, etc.), but is not limited thereto.

The content of the above-described catalyst in the addition-curable silicone compound of the present invention is not particularly limited, and may be included in an amount of, for example, 0.1 to 500 ppm, preferably 1 to 50 ppm, by weight of the total compound. When the content of the catalyst is less than 0.1 ppm, the curability of the composition may be deteriorated, and when the content of the catalyst exceeds 500 ppm, there is a concern that economical efficiency may decrease.

In the present application, the addition-curable silicone compound is 3-methyl-1-butyn-3-ol, 3,5-dimethyl-1-hexin-3-ol And alkyne alcohols such as phenylbutynol; Enyne compounds such as 3-methyl-3-pentene-1-yne and 3,5-dimethyl-3-hexene-1-yne; 1,2,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane,1,3,5,7-tetramethyl-1,3,5,7-trahexenylcyclotetrasiloxane , A curing inhibitor such as benzotriazole, etc.

I can. The content of the curing inhibitor may be appropriately selected within a range that does not impair the object of the invention, and for example, may be included in the range of 10 ppm to 50,000 ppm based on weight.

In the present application, the silicone compound is a condensation-curable silicone compound, for example, (a) an alkoxy group-containing siloxane polymer; And (b) a hydroxyl group-containing siloxane polymer.

The (a) siloxane polymer that can be used in the present invention may be, for example, a compound represented by the following formula (1).

[Formula 1]

R1 _a R2 _b SiO _c (OR3) _d

In the above formula, R1 and R2 each independently represent a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group, R3 represents an alkyl group, and when a plurality of R1, R2 and R3 are present, respectively, they may be the same or different from each other, and , a and b each independently represent a number greater than or equal to 0 and less than 1, a+b represents a number greater than 0 and less than 2, c represents a number greater than 0 and less than 2, and d is greater than 0, 4 Represents a number less than, and a+b+c×2+d is 4.

In the present invention, the siloxane polymer represented by Formula 1 may have a weight average molecular weight of 1,000 to 100,000, preferably 1,000 to 80,000, and more preferably 1,500 to 70,000 in terms of polystyrene, as measured by gel permeation chromatography. . (a) When the weight average molecular weight of the siloxane polymer is within the above range, a good cured product can be obtained without causing defects such as cracks during formation of the cured silicone product.

In the definition of Formula 1, the monovalent hydrocarbon may be, for example, an alkyl group having 1 to 8 carbon atoms, a phenyl group, a benzyl group, or a tolyl group, and in this case, the alkyl group having 1 to 8 carbon atoms includes a methyl group, an ethyl group, a propyl group. , Isopropyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, and the like. In addition, in the definition of Formula 1, the monovalent hydrocarbon group may be substituted with a known substituent such as a halogen, amino group, mercapto group, isocyanate group, glycidyl group, glycidoxy group or ureido group. In addition, in the definition of Formula 1, examples of the alkyl group of R 3 include a methyl group, an ethyl group, a propyl group, an isopropyl group, or a butyl group. Among these alkyl groups, a methyl group or an ethyl group is preferable, but is not limited thereto.

In the present invention, it is preferable to use a branched or tertiary crosslinked siloxane polymer among the polymers of Formula 1. Further, in this (a) siloxane polymer, a hydroxyl group may remain within a range that does not impair the object of the present invention, specifically within a range that does not inhibit the dealcoholization reaction.

The above-described (a) siloxane polymer can be produced, for example, by hydrolyzing and condensing a polyfunctional alkoxysilane or a polyfunctional chlorosilane. An average technician in this field can easily select an appropriate polyfunctional alkoxysilane or chlorosilane according to the desired (a) siloxane polymer, and can easily control the conditions of the hydrolysis and condensation reactions using the same. On the other hand, in the production of the (a) siloxane polymer, an appropriate monofunctional alkoxy silane may be used in combination depending on the purpose.

Examples of (a) siloxane polymers as described above include commercially available orrogenic polymers such as X40-9220 or X40-9225 from Shin-Etsu Silicon, XR31-B1410, XR31-B0270 or XR31-B2733 from GE Toray Silicon. A ganosiloxane polymer can be used. On the other hand, in the present invention, from the viewpoint of hardness and refractive index of the cured product, (a) organopolysiloxane containing an aromatic group such as an aryl group or aralkyl group in the molecular structure is used as the (a) organopolysiloxane. It is desirable to do, but is not necessarily limited thereto. Meanwhile, as the (b) hydroxyl group-containing siloxane polymer contained in the condensation-curable silicone compound, for example, a compound represented by the following formula (2) may be used.

[Formula 2]

In Formula 2, R4 and R5 each independently represent a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group, and when a plurality of R5 and R6 are present, the above may be the same or different from each other, and n Represents an integer of 5 to 2,000.

In the definition of Chemical Formula 2, specific types of the monovalent hydrocarbon group include, for example, the same hydrocarbon group as in Chemical Formula 1.

In the present invention, the siloxane polymer of Formula 2 may have a weight average molecular weight of 500 to 100,000, preferably 1,000 to 80,000, and more preferably 1,500 to 70,000 in terms of polystyrene measured by gel permeation chromatography. (b) When the weight average molecular weight of the siloxane polymer is within the above range, a good cured product can be obtained without causing defects such as cracks during formation of the cured silicone product.

The above-described (b) siloxane polymer can be produced, for example, by hydrolyzing and condensing dialkoxysilane and/or dichlorosilane. An average person skilled in the art can easily select an appropriate dialkoxy silane or dichloro silane according to the desired (b) siloxane polymer, and can easily control the conditions of the hydrolysis and condensation reactions using the same. As the above-described (b) siloxane polymer, for example, a commercially available bifunctional organosiloxane polymer such as XC96-723, YF-3800, YF-3804, etc. from GE Toray Silicone can be used. On the other hand, in the present invention, from the viewpoint of the hardness and refractive index of the cured product, (1) organopolysiloxane containing an aromatic group such as an aryl group or aralkyl group in the molecular structure is used as the (1) organopolysiloxane. It is desirable to do, but is not necessarily limited thereto.

The type of adhesive or pressure-sensitive adhesive having a vertical orientation is not particularly limited, and may be appropriately selected according to the intended use, for example, a solid adhesive or adhesive, a semi-solid adhesive or an adhesive, an elastic adhesive or an adhesive or a liquid adhesive or an adhesive Can be appropriately selected and used. Solid adhesives or pressure-sensitive adhesives, semi-solid adhesives or pressure-sensitive adhesives, elastic adhesives or pressure-sensitive adhesives may be referred to as so-called pressure-sensitive adhesives or pressure-sensitive adhesives (PSA), and may be cured before the adhesion or adhesion object is bonded. The liquid adhesive or pressure-sensitive adhesive may be referred to as a so-called optical clear resin (OCR), and may be cured after the adhesion or adhesion object is bonded. In the present application, for example, as a PSA-type adhesive or pressure-sensitive adhesive having a vertical orientation force, a polydimethylsiloxane adhesive or a polymethylvinyl siloxane adhesive or a polymethylvinyl siloxane adhesive may be used. As an OCR type adhesive having an orientation force, an alkoxy silicone adhesive or an adhesive (Alkoxy silicone adhesive) may be used, but the present invention is not limited thereto.

By including the adhesive layer or the pressure-sensitive adhesive layer having the above characteristics under the arrangement as described above, it is possible to provide a light modulation device capable of exhibiting excellent optical properties by controlling light leakage, especially in a blocking mode, while having excellent adhesion or adhesion. have.

In one example of the present application, when the adhesive layer or the pressure-sensitive adhesive layer having a vertical alignment force as described above is formed on one surface of the first polymer film substrate, the liquid crystal alignment layer may not be formed on the first polymer film substrate. have.

As such, the alignment of the liquid crystal compound formed by the known vertical alignment layer and the adhesive or pressure-sensitive adhesive having a vertical alignment ability, and the alignment of the dichroic dye following it effectively suppresses side light leakage during vertical alignment, and when horizontal alignment The absorption of front light can be minimized.

As other configurations, a known configuration such as a hard coating layer, an antireflection layer, and a layer including a dye having a near-infrared (NIR) cut function may be additionally included as long as the effect of the present application is not hindered.

The present application, while having a unique arrangement structure, such as arranging the first and second polymer film substrates having the above-described plane retardation so that the slow axis of the polymer film substrate has the above range, the optical modulation layer described above It is possible to provide an optical modulation device capable of compensating a viewing angle by controlling a light leakage phenomenon at an inclination angle while exhibiting an excellent effect of varying transmittance through a combination of and the like.

In one example, the optical modulation device of the present application may have a transmittance of 20% or more in a transmission mode, and in another example, 21% or more, 22% or more, 23% or more, 24% or more, 25% or more, 30% It may be about 35% or more, 40% or more, 45% or more, 50% or more, 55% or more, 60% or more, 65% or more, 70% or more, 75% or more, or 80% or more. In addition, the transmittance of the blocking mode is 60% or less, 55% or less, 50% or less, 45% or less, 40% or less, 35% or less, 30% or less, 25% or less, 20% or less, 15% or less, 10 % Or less, 5% or less, 4% or less, 3% or less, 2% or less, 1% or less, 0.9% or less, 0.8% or less, 0.7% or less, 0.6% or less, 0.5% or less, 0.4% or less, or 0.3% or less I can. In the transmission mode, the higher the transmittance is, the better the transmittance is, and in the blocking mode, the lower the transmittance is, the more advantageous, the upper limit of the transmittance in the transmission mode state and the lower limit of the transmittance in the blocking mode state are not particularly limited. The upper limit of the transmittance of is about 100%, and the lower limit of the transmittance in the blocking mode state may be about 0%. The cutoff mode may mean a state in which no voltage is applied to the optical modulation device, and the transmission mode refers to a state in which a voltage is applied to the optical modulation device, and in one example, a state in which a voltage is applied at about 30V. I can.

In an example, the optical modulation device of the present application has a difference in transmittance of 15% or more, 16% or more, 17% or more, 18% or more, 19% or more, 20% or more, and 25 in the transmission mode and the cut-off mode state. % Or more, 30% or more, 35% or more, or 40% or more, or 90% or less, 85% or less, 80% or less, 75% or less, 70% or less, 65% or less, 60% or less, 55% or less, 50 % Or less or 45% or less.

The transmittance may be, for example, a straight light transmittance. The straight light transmittance may be a percentage of a ratio of light transmitted in the same direction as the incident direction with respect to the light incident on the optical modulation device. For example, if the device is in the form of a film or sheet, the percentage of light that has transmitted through the device in a direction parallel to the normal direction among the light incident in a direction parallel to the normal direction of the film or sheet surface is defined as the transmittance. I can.

The transmittance is, respectively, a transmittance or reflectance for any wavelength within a visible region, for example, about 400 nm to 700 nm or about 380 nm to 780 nm, or a transmittance or reflectance for the entire visible region, or for the entire visible region. Among the transmittance or reflectance, it may be the maximum or minimum transmittance or reflectance, or the average value of transmittance or reflectance in the visible light region. In addition, in another example, the transmittance may be a transmittance of light having a wavelength of about 550 nm.

In an example, in the optical modulation device of the present application, the maximum value of the inclination angle transmittance may be 17% or less in the blocking mode. In the present specification, the inclination angle transmittance is of the axis at which the inclination angle from the z-axis direction, which is the normal direction of the reference plane to be measured (for example, the surface of the polarizing layer, the optical modulation layer, and/or the polymer film substrate) is Θ. It may be the transmittance of light that passes through the measurement object in parallel with the direction, and the maximum value of the inclination angle transmittance refers to the largest value among the transmittances measured while varying the transmittance of the light at the inclination angle Θ from 0 degrees to 360 degrees. can do. For example, the inclination angle Θ from the z-axis direction, which is the normal direction of the reference plane of the optical modulation device, is changed to -60 degrees, -45 degrees, -30 degrees, -15 degrees, 15 degrees, 30 degrees, 45 degrees, and 60 degrees. , For each inclination angle Θ, it may mean the largest value among 56 types of transmittances measured with an elongation angle Φ of 0 degrees, 30 degrees, 60 degrees, 90 degrees, 120 degrees, 150 degrees, and 180 degrees. The elongation angle Φ 0 degrees, in one example, may mean the rubbing orientation of the alignment layer. In the present application, the maximum value of the inclination angle transmittance is, in other examples, 16% or less, 15% or less, 14% or less, 13% or less, 12% or less, 11% or less, 10% or less, 9% or less, 8% or less, 7 % Or less, 6% or less, 5% or less, 4% or less, 3% or less, 2% or less, or 1% or less, or 0% or more, 1% or more, 2% or more, 3% or more, 4% or more, 5% It may be more than, 6% or more, 7% or more, 8% or more, 9% or more, 10% or more, 11% or more, 12% or more, or 13% or more, but is not limited thereto.

The present application provides a specific ratio of a dichroic dye in the light modulation layer so that the transmittance in the transmission mode is 20% or more and the maximum value of the transmittance measured at all moving angles of the inclination angle is 17% or less under the unique structure as described above. As described above, the ratio may mean that the ratio of the dichroic dye in the light modulation layer is included in about 5% by weight or less.

The present application introduces a light modulation layer having the above-described unique structure and/or arrangement and containing a dichroic dye in the same ratio as described above, thereby exhibiting excellent transmittance variable characteristics and improved light leakage at an inclination angle. It is possible to provide a modulation device.

In the optical modulation device of the present application, for example, the distance between the first and second polymer film substrates disposed opposite to each other may be maintained by a spacer in the form of a partition wall.

In one example, the light modulation device of the present application is sequentially formed with a first polarizing layer 101, a first polymer film substrate 102, a conductive layer 400a, an adhesive layer or an adhesive layer 103, as shown in FIG. 4 The upper substrate 100 is formed, the liquid crystal alignment layer 203, the conductive layer 400b, the second polymer film substrate 202, the lower substrate 200 and the upper portion in which the second polarizing layer 201 is sequentially formed. A spacer 500 in the form of a partition wall to maintain the gap G between the substrate and the lower substrate may be included. In addition, as shown in FIG. 4, the optical modulation layer 300 may exist in a region where the spacer 500 does not exist.

In the present application, the spacer may include a curable resin. The kind of curable resin is not particularly limited, and for example, a heat curable resin or a photocurable resin such as an ultraviolet curable resin can be used. As the heat curable resin, for example, silicone resin, silicon resin, fran resin, polyurethane resin, epoxy resin, amino resin, phenol resin, urea resin, polyester resin, or melamine resin may be used, but is not limited thereto. . UV-curable resins are typically acrylic polymers, such as polyester acrylate polymers, polystyrene acrylate polymers, epoxy acrylate polymers, polyurethane acrylate polymers or polybutadiene acrylate polymers, silicone acrylate polymers or alkyl acrylates. Polymers and the like may be used, but are not limited thereto. In one example, the spacer may be formed using an acrylic polymer, more specifically a polyester-based acrylate main body, but is not limited thereto. In another example, it may be formed using a silicone polymer, and when the spacer is formed using a silicone polymer, since the silicone polymer remaining in the concave region of the spacer may serve as a vertical alignment layer, the spacer may be formed as described below. An additional vertical alignment layer may not be used on the existing substrate. As the silicone polymer, a known polymer having a silicon-oxygen bond (Si-O-Si) as a main axis may be used. For example, polydimethylsiloxane (PDMS) may be used, but the present invention is not limited thereto.

The shape and arrangement of the spacers may be appropriately designed within a range capable of maintaining a constant gap between the lower substrate and the upper substrate, for example. In one example, the spacer may be present to form a partition in the shape of a partition wall, and in another example, one or two or more column shapes may be spaced apart, but the present invention is not limited thereto.

The pitch, line width, height, and area ratio of the spacer on the upper or lower substrate may be appropriately selected within a range not impairing the object of the present application.

The pitch of the spacer may be, for example, 50 µm to 500 µm, and in another example, 100 µm or more, 150 µm or more, 200 µm or more, 250 µm or more, 300 µm or more, 350 µm or more, 450 µm or less, 400 It may be less than or equal to µm or less than or equal to 350 µm.

The line width of the spacer may be, for example, 1 µm to 50 µm, and in other examples, 2 µm or more, 3 µm or more, 4 µm or more, 5 µm or more, 6 µm or more, 7 µm or more, 8 µm or more, 9 Μm or more, 10 µm or more, 11 µm or more, 12 µm or more, 13 µm or more, 14 µm or more, 15 µm or more, 16 µm or more, 45 µm or less, 40 µm or less, 35 µm or less, 30 µm or less, 25 µm or less , 20 μm or less, 19 μm or less, 18 μm or less, 17 μm or less, or 16 μm or less.

In the present application, the height of the spacer may be adjusted in consideration of the distance between the upper substrate and the lower substrate. For example, the height of the spacer may be 1 μm to 20 μm, and in another example, 2 μm or more, 3 μm or more, 4 μm or more, 5 μm or more, 6 μm or more, 7 μm or more, or 8 μm or more, or 19 It may be µm or less, 18 µm or less, 17 µm or less, 16 µm or less, 15 µm or less, 14 µm or less, 13 µm or less, 12 µm or less, 11 µm or less, 10 µm or less, 9 µm or less, or 8 µm or less.

In the present application, the area ratio of the spacer existing on the lower substrate or the upper substrate may be about 0.1% to 50% with respect to the area of the upper or lower substrate. In the present application, as the area ratio of the spacer increases, the adhesion between the upper substrate and the lower substrate may increase. In another example, 1% or more, 2% or more, 3% or more, 4% or more, 5% or more, 6% or more, 7% or more, 8% or more, 9% or more, 45% or less, 40% or less, 35% It may be less than, 30% or less, 25% or less, 20% or less, 15% or less, 10% or less, or 9% or less.

The optical modulation device as described above can be applied to various applications. Applications to which the light modulation device can be applied include openings in closed spaces including buildings, containers, or vehicles such as windows or sunroofs, eyewear, or windows, and light shielding plates of organic light emitting devices (OLEDs). And the like can be exemplified. In the above, the range of eyewear includes all eyewear formed so that an observer can observe the outside through a lens, such as general glasses, sunglasses, sports goggles or helmets, or wearable devices such as virtual reality or augmented reality experience devices. I can.

A typical application to which the optical modulation device of the present application can be applied may be a sunroof for a vehicle.

In one example, the optical modulation device may itself be a sunroof for a vehicle. For example, in a vehicle including a vehicle body in which at least one opening is formed, the optical modulation device or a vehicle sunroof mounted on the opening may be mounted and used.

The sunroof is a fixed or actuated (venting or sliding) opening in the ceiling of a vehicle, and may collectively refer to a device capable of functioning to allow light or fresh air to flow into the interior of the vehicle. have. In the present application, the operating method of the sunroof is not particularly limited, for example, it may be manually operated or driven by a motor, and the shape, size, or style of the sunroof may be appropriately selected according to the intended use. For example, depending on how it works, a sunroof is a pop-up type sunroof, a tile & slide type sunroof, an in-built type sunroof, a folding type sunroof, a top-mount type sunroof, and a panoramic roof. A system type sunroof, a removable roof panel (t-tops or targa roofts) type sunroof, or a solar type sunroof may be exemplified, but is not limited thereto.

The exemplary sunroof of the present application may include the optical modulation device of the present application, and in this case, the details of the optical modulation device may be the same as those described in the item of the optical modulation device.

In the present application, it is possible to provide an optical modulation device that has excellent transmittance variable characteristics and does not cause problems such as light leakage at an inclination angle, and thus can be applied to various purposes.

1 to 4 are schematic diagrams of exemplary optical modulation devices.
5 is a schematic diagram for explaining an inclination angle and a moving angle.
6 is a diagram showing a method for evaluating refractive index anisotropy.

Hereinafter, the present application will be specifically described through Examples and Comparative Examples, but the scope of the present application is not limited by the following Examples.

One. Planar retardation evaluation of polymer film substrates

The plane retardation (Rin) of the polymer film was measured using Agilent's UV/VIS spectroscope 8453 equipment (based on a wavelength of 550 nm). Two polarizers are installed in a UV/VIS spectroscope so that their transmission axes are orthogonal to each other, and a polymer film is placed between the two polarizers so that the slow axis forms 45 degrees with the transmission axes of the two polarizers. The transmittance was measured. In the transmittance graph according to the wavelength, the phase retardation order of each peak was calculated. Specifically, in the transmittance graph according to wavelength, the waveform satisfies Equation A below, and the maximum peak Tmax condition in the Sine waveform satisfies Equation B below. In the case of λmax in Equation A, since T in Equation A and T in Equation B are the same, the equation is developed. Equations are also developed for n+1, n+2, and n+3, and the following equations C are derived by arranging n and n+1 equations to eliminate R and arranging n into λn and λn+1 equations. Since n and λ can be known based on the same T in Equation A and T in Equation B, R is obtained for each of λn, λn+1, λn+2, and λn+3. For 4 points, calculate the linear trend line of the R value according to the wavelength, and calculate the R value for Equation 550 nm. The function of a straight line trend line is Y=ax+b, and a and b are constants. When 550 nm is substituted for x of the function, the Y value is the Rin value for light having a wavelength of 550 nm.

[Equation A]

T = sin2[(2πR/λ)]

[Equation B]

T = sin2[((2n+1)π/2)]

[Equation C]

n = (λn -3λn+1)/(2λn+1 +1-2λn)

In the above, R denotes a plane phase difference (Rin), λ denotes a wavelength, and n denotes the peak order of a sine wave.

2. Thickness of light modulation layer

The thickness of the light modulation layer approximately coincides with the height of the spacer. Accordingly, the height of the spacer was checked using a measuring device (Optical profiler, Nano System Co., Nano View-E1000), and the height of the spacer was taken as the thickness of the optical modulation layer (cell gap).

3. Measurement of maximum values of frontal transmittance and inclination angle transmittance

In FIG. 3, the transmittance according to the applied voltage while connecting and driving AC power to each of the conductive layers 400a and 400b of the upper and lower substrates was measured using a haze meter (NDH5000SP, Sekos) according to ASTM D1003 standard. It was measured.

Specifically, when light with a wavelength of 380nm to 780nm is incident on the measurement object in the integrating sphere, the incident light is diffused light (DT, the sum of all the diffused and emitted light) and straight light (PT, excluding diffused light) by the measurement object. It is separated by a front-facing light). The diffused light and the straight light can be measured by condensing the light-receiving element in the integrating sphere. That is, through the above process, the total transmitted light TT may be defined as the sum of the diffused light DT and the straight light PT (DT+PT). The total transmitted light means total transmittance.

The front transmittance and the inclination angle transmittance were measured, respectively, and are shown in Table 1 below. The front transmittance was measured in a state in which voltages of 0 V (blocking mode) and 30 V were applied (transmission mode), respectively. The front transmittance is the transmittance of light that passes through the measurement object parallel to the z-axis direction, which is the normal direction of the reference plane of the measurement object (e.g., the surface of the polarizing layer, the optical modulation layer and/or the polymer film substrate of the optical modulation device). . The inclination angle transmittance is parallel to the direction of the axis at which the inclination angle from the z-axis direction, which is the normal direction of the reference plane of the measurement object (for example, the surface of the polarizing layer, the optical modulation layer, and/or the polymer film substrate) is Θ. It is the transmittance of light that passes through the object to be measured, and the maximum value of the inclination angle transmittance is different from the transmittance of the light at the inclination angle Θ to 0 degrees, 30 degrees, 60 degrees, 90 degrees, 120 degrees, 150 degrees, 180 degrees. After measuring while doing, it was set as the largest value among them. At this time, Θ was measured at -60 degrees, -45 degrees, -30 degrees, -15 degrees, 15 degrees, 30 degrees, 45 degrees, and 60 degrees (refer to FIG. 5). That is, for inclination angles Θ -60 degrees, -45 degrees, -30 degrees, -15 degrees, 15 degrees, 30 degrees, 45 degrees, 60 degrees, the elongation angle Φ is set to 0 degrees, 30 degrees, 60 degrees, 90 degrees, and 120 degrees. Table 1 shows the largest value among 56 inclination angle transmittances measured at different degrees, 150 degrees, and 180 degrees.

4. Evaluation of refractive index anisotropy of light modulation layer (liquid crystal layer)

The refractive index anisotropy (Δn) of the light modulation layer is evaluated in the following manner using an Abbe refractometer. After coating the vertical alignment layer on the measuring prism and illumination prism of Abbe refractometer, applying the liquid crystal compound to be measured to the measuring prism and covering it with illumination prism, the liquid crystal compound is vertically aligned by the vertical alignment force of the two interfaces. . The liquid crystal compound applied in the above process is only a liquid crystal compound to be applied to the light modulation layer that is not mixed with other materials such as dichroic dyes.

Thereafter, as shown in FIG. 6, when a linear polarizing plate is applied to the eyepiece side (grounded part) and observed by irradiating light, θ _e and θ _o as shown in FIG. 6 can be obtained, and Measuring prism The ideal refractive index (n _e = n _p sinθ _e ) and the normal refractive index (n _o = n _p sinθ _o ) can be obtained through the refractive index of (n _p ) and the angles (θ _e and θ _o ), and the difference (n _e -n _o ) can be defined as refractive index anisotropy. The reference wavelength at the time of the measurement is approximately 550 nm.

Example 1.

As the first and second polymer film substrates, a device was fabricated using a stretched PET (polyethylene terephthalate) film substrate (thickness: 145 μm, manufacturer: SKC). The PET film substrate had a plane retardation with respect to light having a wavelength of 550 nm in the range of about 10,000 nm to 15,000 nm.

First, an ITO (Indium Tin Oxide) film (conductive layer) is deposited on one surface of the first PET film substrate, and a silicone adhesive (Shinetsu, KR3700) is bar-coated on the ITO film, and then cured at about 100°C for 100 minutes. Then, an adhesive layer having a thickness of about 10 μm was formed (upper substrate). First, an indium tin oxide (ITO) film (conductive layer) is deposited on one surface of the second PET film substrate, and a spacer in the form of a square partition wall for maintaining a cell gap on the ITO film (pitch: 350 μm, Height: 8 µm, line width: 10 µm, area ratio: 9%) was formed. Thereafter, a polyimide vertical alignment film (SE-5661LB3, Nissan) having a thickness of approximately 100 nm was formed to control the initial orientation of the light modulation layer (liquid crystal layer), and then rubbing treatment was performed with a rubbing cloth. At this time, the rubbing direction was set to be horizontal to the slow axis of the lower PET film substrate (lower substrate).

Subsequently, the adhesive layer of the upper substrate and the alignment layer of the lower substrate were disposed to face each other (Cell gap: 8 μm), and a liquid crystal material was injected into the device, and then a device was manufactured through a lamination process. As the liquid crystal material, after mixing X12 (BASF) as a dichroic dye to a liquid crystal compound (SHN-7002XX T12, JNC) having a negative dielectric anisotropy having a refractive index anisotropy (Δn) of approximately 0.094, a chiral dopant (S811, Merck Co.) was used to add a composition. At this time, the dichroic dye was formulated to be contained in an amount of about 0.4% by weight with respect to the liquid crystal material, and the chiral dopant was formulated to be contained in an amount of approximately 0.5% by weight with respect to the liquid crystal material, so that a chiral pitch was approximately It was made to be about 20㎛.

Then, a first polarizing layer is attached to the surface of the first PET film substrate on which the ITO film (conductive layer) is not formed, and the second polarizing layer is attached to the surface of the second PET film substrate on which the ITO conductive layer is not formed. A polarizing layer was attached. As the first and second polarizing layers, a general PVA polarizing layer prepared through high temperature/stretching by adsorbing iodine on a PVA film was used.

In the above arrangement, the slow axis directions of the first and second PET film substrates and the absorption axis of the first polarizing layer are parallel to each other, and the absorption axis of the second polarizing layer is perpendicular to the absorption axis of the first polarizing layer. Placed.

As a result, a light modulation device having a structure of a first polarizing layer/first PET film substrate/ITO film/adhesive layer/light modulation layer (liquid crystal layer)/alignment film/ITO film/second PET film substrate/second polarizing layer Was formed.

Example 2.

A dichroic dye was prepared in the same manner as in Example 1, except that a dichroic dye was blended in an amount of about 0.6% by weight based on the liquid crystal material.

Example 3.

It was prepared in the same manner as in Example 1, except that the dichroic dye was blended in an amount of approximately 1% by weight based on the liquid crystal material.

Comparative Example 1.

It was prepared in the same manner as in Example 1, except that the dichroic dye was not mixed.

[Table 1]

The transmittance was measured for the optical modulation devices of Examples and Comparative Examples, and is shown in Table 1.

The front transmittance (Θ=0, Φ=0) at 0V (blocking mode) for the light modulation device of Comparative Example 1 without applying a dichroic dye was 0.21%, and when a voltage of 30V was applied (transmission mode) The front transmittance of was 23.59%. In addition, the maximum value of the inclination angle transmittance at 0V (blocking mode) was found to be 17.27%. The maximum value was an inclination angle transmittance value measured at an inclination angle of Θ=-60 degrees and a moving angle of Φ=120 degrees.

The front transmittance (Θ=0, Φ=0) at 0V (blocking mode) for the optical modulation device of Example 1 containing 0.4% by weight of the dichroic dye relative to the liquid crystal material was 0.29%, and a voltage of 30V was applied. The front transmittance at the time (transmission mode) was 22.84%. In addition, the maximum value of the inclination angle transmittance at 0V (blocking mode) was 13.92%. The maximum value was an inclination angle transmittance value measured at an inclination angle of Θ=-45 degrees and a dynamic inclination angle of Φ=120 degrees.

The front transmittance (Θ=0, Φ=0) at 0V (blocking mode) for the optical modulation device of Example 1 containing 0.6% by weight of the dichroic dye relative to the liquid crystal material was 0.24%, and a voltage of 30V was applied. The front transmittance at the time (transmission mode) was 21.32%. In addition, the maximum value of the inclination angle transmittance at 0V (blocking mode) was 12.8%. The maximum value was an inclination angle transmittance value measured at an inclination angle of Θ=-45 degrees and an elongation angle of Φ=60 degrees.

The front transmittance (Θ = 0, Φ = 0) at 0V (blocking mode) for the light modulation device of Example 1 containing 1% by weight of the dichroic dye relative to the liquid crystal material was 0.24%, and a voltage of 30V was applied. The front transmittance at the time (transmission mode) was 18.39%. In addition, the maximum value of the inclination angle transmittance at 0V (blocking mode) was 11.92%. The maximum value was an inclination angle transmittance value measured at an inclination angle of Θ=-45 degrees and a dynamic inclination angle of Φ=60 degrees.

As a result of the measurement, it was confirmed that the inclination angle transmittance at 0V (blocking mode) of the light modulating device of the example to which the dichroic dye was applied in an appropriate weight ratio compared to the light modulating device of Comparative Example 1 to which the dichroic dye was not applied was low. That is, it was confirmed that by including a dichroic dye in a certain range in the light modulation layer, it was possible to provide an optical modulation device exhibiting excellent transmittance variable characteristics while controlling light leakage at an inclination angle.

10, 20: polarizing plate 30: light modulation layer
100, 200: upper substrate, lower substrate
101, 201: first and second polarizing layers
102, 202: first and second polymer film substrates
103: adhesive layer or pressure-sensitive adhesive layer
203: liquid crystal alignment film
300: light modulation layer
400a, 400b: conductive layer
500: spacer

Claims (14)

An adhesive layer or pressure-sensitive adhesive layer is formed on the first surface, a first polymer film substrate on which a first polarizing layer is attached to the second surface, a liquid crystal alignment layer is formed on the first surface, and a second polarization layer is formed on the second surface. Including a second polymer film substrate to which the layer is attached,
The first and second polymer film substrates are disposed so that first surfaces of each other face each other,
A light modulation device in which a light modulation layer including a liquid crystal compound and a dichroic dye is present between the oppositely disposed first and second polymer film substrates. The light modulating device according to claim 1, wherein the ratio of the dichroic dye in the light modulating layer is 5% by weight or less. The optical modulation device according to claim 1, wherein absorption axes of the first and second polarizing layers are perpendicular to each other. The optical modulation device according to claim 1, wherein slow axes of the first and second polymer film substrates are horizontal to each other. The optical modulation device according to claim 1, wherein the first and second polymer film substrates each have a phase retardation of 500 nm or more with respect to a wavelength of 550 nm. The light modulating device according to claim 1, wherein a conductive layer is formed between the adhesive layer or the pressure-sensitive adhesive layer and the first polymer film substrate and between the liquid crystal alignment layer and the second polymer film substrate. The optical modulation device according to claim 1, wherein a liquid crystal alignment film is not formed on the first polymer film substrate. The optical modulation device according to claim 1, wherein the liquid crystal compound in the light modulation layer has an initial alignment of vertical alignment, and the vertical alignment state can be changed to a horizontal alignment state by application of an external signal. The optical modulation device of claim 1, wherein the optical modulation layer further comprises a chiral dopant. The optical modulation device according to claim 1, wherein the transmittance in the transmission mode is 20% or more. The optical modulation device according to claim 1, wherein the maximum value of the inclination angle transmittance is 17% or less in the cut-off mode. The optical modulation device according to claim 1, wherein an interval between the first and second polymer film substrates is maintained by a spacer in the form of a partition wall. The optical modulation device according to claim 1, wherein the thickness of the optical modulation layer is 15 µm or less. A vehicle body in which one or more openings are formed; And the optical modulation device of claim 1 mounted on the opening.

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