Optical element

0001The present invention relates to optical elements and their uses.

0002A sunroof serves to allow light or fresh air to flow into the interior of a vehicle by referring to a fixed or operating (venting or sliding) opening that is usually present on the ceiling of the vehicle. Such sunroofs can be manually operated or driven by a motor, and there are various types of sunroof shapes, sizes or styles depending on the intended application. For example, depending on the operating method, sunroofs include pop-up type sunroofs, spoiler (tile & slide) type sunroofs, built-in type sunroofs, folding type sunroofs, top mount type sunroofs, panoramic roof system type sunroofs, and removable roof panels (t- It is classified as a tops or targa roofts) type sunroof or a solar type sunroof. Research on sunroof materials is also being actively pursued. For example, Patent Document 1 (International Application Publication No. 2010-098576) has excellent absorption of ultraviolet rays and solar heat rays by using a glass composition having a specific composition. Disclosure of technology for manufacturing various sunroofs.

<p num="0003"> The present invention provides an optical element whose transmittance changes depending on whether or not an external signal is applied. The present invention also provides an energy-saving optical element having a heat blocking effect by applying the external signal using a composite layer having low transmittance in the infrared region.</p>

<p num="0004"> An exemplary optical element of the present invention can include a polarizing layer, a liquid crystal layer and a composite layer. The liquid crystal layer is formed on the polarizing layer and can contain a liquid crystal compound and an anisotropic dye. The composite layer can exist adjacent to the liquid crystal layer, and can include a first oxide layer, a metal layer, and a second oxide layer in this order. The liquid crystal compound and / or the anisotropic dye can be present in an oriented state, and the liquid crystal compound can be reoriented by a signal applied by the composite layer. One composite layer may be present adjacent to one side surface of the liquid crystal layer, or two composite layers may be present adjacent to both side surfaces of the liquid crystal layer. FIG. 1 shows a case where two composite layers are present on both side surfaces of a liquid crystal layer, for example, a polarizing layer 101; a liquid crystal layer 102 formed on the polarizing layer and two arranged on both sides of the liquid crystal layer. An optical element including the composite layers 103A and 103B of the above is exemplified.</p><p num="0005"> In the exemplary optical element of the present invention, the light transmittance can be changed by a signal applied from the outside. The signal applied from the outside can be, for example, a voltage applied by the composite layer. As will be described later, the composite layer has low transmittance for light in the infrared region. Therefore, when a voltage is applied by the composite layer, heat can be cut off, which has the effect of saving energy. Hereinafter, the optical element will be described more specifically.</p><p num="0006"> As used herein, the term "polarizing layer" means a functional layer that exhibits selective transmission and blocking properties, such as reflection or absorption properties, with respect to incident light. The polarizing layer can have, for example, a function of transmitting light vibrating in any one direction from incident light vibrating in various directions and blocking light vibrating in the remaining direction. The type of the polarizing layer is not particularly limited, and for example, as a reflective polarizing layer, for example, a DBEF (Dual Brightness Enhancement Film), a lyotropic liquid crystal layer (LLC layer: Lyotropic Liquid Crystal), or a wire grid polarizing element is used. ) Etc. can be used, and as the absorption type polarizing layer, for example, a polarizing element obtained by dyeing iodine on a polymer stretched film such as a PVA stretched film or a liquid crystal polymerized in an oriented state is used as a host. A guest-host type polarizer having an anisotropic dye oriented by the orientation of the liquid crystal as a guest can be used, but the present invention is not limited thereto.</p><p num="0007"> In the present invention, the liquid crystal layer can contain a liquid crystal compound and an anisotropic dye. The liquid crystal layer can be a guest-host type liquid crystal layer. In the guest-host type liquid crystal layer, anisotropic dyes are arranged together by the arrangement of liquid crystal compounds, and light parallel to the alignment direction of the dyes is absorbed, and light perpendicular to the alignment direction is transmitted, thereby absorbing anisotropic light. The effect can be shown. The alignment direction of the liquid crystal compound and / or the anisotropic dye in the liquid crystal layer can be changed by a signal applied from the outside. In this case, the externally applied signal means all kinds of signals executed to change the alignment of the liquid crystal compound and / or the anisotropic dye, and as a typical example, the application of a voltage. There is.</p><p num="0008"> As the liquid crystal compound, all kinds of liquid crystal compounds can be used as long as the orientation direction can be changed by applying an external signal. For example, as the liquid crystal compound, a smectic liquid crystal compound, a nematic liquid crystal compound, a cholesteric liquid crystal compound, or the like can be used. Further, the liquid crystal compound can be, for example, a compound having no polymerizable group or crosslinkable group so that the orientation direction is changed by applying an external signal.</p><p num="0009"> In one example, a nematic liquid crystal compound can be used as the liquid crystal compound. As the compound, for example, a nematic liquid crystal compound satisfying the following formula 1 can be used.</p><p num="0010"><maths num="1"><img id="000003" he="6" wi="161" file="JP2017508169A_D0001.tif" img-format="tif" img-content="drawing" /></maths></p><p num="0011"> In formula 1, n_{o o}Is the ordinary refractive index of the liquid crystal compound, for example, the refractive index of the nematic liquid crystal compound in the minor axis direction._eIs the extraordinary refractive index of the liquid crystal compound, for example, the refractive index of the nematic liquid crystal compound in the long axis direction, and b is a number satisfying 0.1 b 1. By selecting a liquid crystal compound that satisfies Equation 1, it is possible to manufacture a liquid crystal cell in which excellent transparency is ensured even when no voltage is applied. In Equation 1, b can be 0.1-0.9, 0.1-0.7, 0.1-0.5 or 0.1-0.3 in other examples.</p><p num="0012"> In addition, the liquid crystal compound has an abnormal dielectric constant (ε)._e, Extraordinary dielectric anisotropy, permittivity in the long axis direction) and normal permittivity (ε)₀, Ordinary dielectric anisotropy, dielectric constant in the minor axis direction) can be 3 or more, 3.5 or more, 4 or more, 6 or more, 8 or more or 10 or more. By having such a dielectric constant, it is possible to provide an element having excellent drive voltage characteristics. The higher the value of the difference in permittivity, the more appropriate the element can exhibit the characteristics, and the upper limit thereof is not particularly limited. For example, in liquid crystal compounds, the anomalous permittivity (ε)_e, Extraordinary dielectric anisotropy, permittivity in the long axis direction) is about 6 to 50, and normal permittivity (ε)₀, Ordinary dielectric anisotropy, dielectric constant in the minor axis direction) can be used.</p><p num="0013"> As used herein, "dye" means a substance capable of intensively absorbing and / or deforming light in the visible light region, for example, in the wavelength range of 400 nm to 700 nm, in at least a part or the whole range. The term "anisometric dye" can mean a substance capable of anisotropically absorbing light in at least a part or the whole range of the visible light region. The light transmittance of the optical element can be adjusted through the use of the anisotropic dye as described above. The anisotropic dye is not particularly limited, and for example, a black dye or a color dye can be used. The anisotropic dye has a dichroic ratio. Ratio), that is, the value obtained by dividing the absorption of polarized light parallel to the long axis direction of the anisotropic dye by the absorption of polarized light parallel to the direction perpendicular to the long axis direction is 5 or more, 6 or more, or 7 or more. Can be used. The dye can satisfy the different color ratio 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, at least a part of the wavelengths or any one of the wavelengths. The upper limit of the different color ratio can be, for example, about 20, 18, 16 or 14. The types of anisotropic dyes are not particularly limited, and for example, all known types of dyes can be used as long as they have the above-mentioned properties and are oriented by the orientation of the liquid crystal compound. Can be used.</p><p num="0014"> The optical element of the present invention adjusts the orientation of the liquid crystal compound and / or the anisotropic dye existing in the liquid crystal layer to obtain polarized light in a direction parallel to the arrangement direction of the anisotropic dye and in a direction perpendicular to the arrangement direction. Anisotropic light absorption for polarized light can be adjusted. For example, the orientation of the liquid crystal compound and / or the anisotropic dye in the liquid crystal layer can be adjusted by applying an external signal, whereby the liquid crystal layer is subjected to isotropic light depending on the presence or absence of application of the external signal. Absorption can be regulated. A liquid crystal layer having such characteristics can be referred to as a so-called Active Polarizer, and as described later, the relationship between the polarizing layer and the transmission axis and / or absorption axis by applying an external signal is established. By adjusting, the overall transmittance of the optical element can be adjusted.</p><p num="0015"> In one example, the liquid crystal layer switches the orientation of the liquid crystal compound and / or anisotropic dye between a horizontal alignment state, a tilted alignment state, or a homeotropic alignment state. ), The polarization characteristics can be adjusted.</p><p num="0016"> In the present specification, the horizontal orientation has an inclination angle in which the optical axis of the liquid crystal layer is in the range of about 0 degrees to 15 degrees, about 0 degrees to 10 degrees, and about 0 degrees to 5 degrees with respect to the plane of the liquid crystal layer. Can mean the case. Further, in the present specification, the vertical orientation can mean a case where the optical axis of the liquid crystal layer has an inclination angle of about 90 degrees to 85 degrees with respect to the plane of the liquid crystal layer. Further, in the present specification, the tilt orientation can mean a case where the optical axis of the liquid crystal layer has an inclination angle other than horizontal orientation or vertical orientation with respect to the plane of the liquid crystal layer. For example, the optical axis of the liquid crystal layer. Can mean a case where has an inclination angle of more than about 15 degrees to less than 85 degrees with respect to the plane of the liquid crystal layer. As used herein, the term "optical axis" can mean the slow-phase axis when incident light passes through the region, and when the liquid crystal compound is rod-shaped, it refers to the long-axis direction of the rod. It can mean that if the liquid crystal compound has a discostic shape, it can be in the normal direction of the disk surface.</p><p num="0017"> Further, the horizontal orientation, tilt orientation or vertical orientation of the liquid crystal layer means a substantially horizontal orientation, tilt orientation or vertical orientation in which the light transmittance of the target optical element can be adjusted, and in this case, the liquid crystal layer. The horizontal phase difference and the thickness direction retardation are not particularly limited.</p><p num="0018"> In another example, the optical element includes not only the case where the polarizing layer is present on any one surface of the liquid crystal layer as described above, but also the structure in which the liquid crystal layer is present between the two opposing polarizing layers. be able to. In this case, the liquid crystal layer can have a thickness direction phase difference described later in a predetermined range as long as the light transmittance can be appropriately adjusted in the horizontal orientation state, and the plane direction phase difference can exist in a predetermined range even in the vertical orientation state. However, the horizontal phase difference and the thickness direction retardation are not limited to the following.</p><p num="0019"> With the liquid crystal compound and / or anisotropic dye in the liquid crystal layer horizontally oriented, the plane direction phase difference (Rin) of the liquid crystal cell is, for example, 10 nm or more, 20 nm or more, 30 nm or more, 40 nm or more, 50 nm. It can be 60 nm or more, 70 nm or more, 80 nm or more, 90 nm or more, 100 nm or more, 110 nm or more, 120 nm or more, 130 nm or more, or 140 nm or more. Further, in the state where no voltage is applied, the upper limit of the phase difference in the plane direction of the liquid crystal layer is 300 nm or less, 290 nm or less, 280 nm or less, 270 nm or less, 260 nm or less, 250 nm or less, 240 nm or less, 230 nm or less, 220 nm or less, 210 nm. Below, it can be 200 nm or less, 190 nm or less, 180 nm or less, 170 nm or less, or 160 nm or less. Further, in a state where the liquid crystal compound and / or the anisotropic dye is vertically oriented by applying a voltage, the thickness direction phase difference (Rth) of the liquid crystal layer is, for example, 10 nm or more, 20 nm or more, 30 nm or more, 40 nm or more. , 50 nm or more, 60 nm or more, 70 nm or more, 80 nm or more, 90 nm or more, 100 nm or more, 110 nm or more, 120 nm or more, 130 nm or more or 140 nm or more. When a voltage is applied, the upper limit of the phase difference in the thickness direction of the liquid crystal layer is 300 nm or less, 290 nm or less, 280 nm or less, 270 nm or less, 260 nm or less, 250 nm or less, 240 nm or less, 230 nm or less, 220 nm or less, 210 nm. Below, it can be about 200 nm or less, 190 nm or less, 180 nm or less, 170 nm or less, or 160 nm or less.</p><p num="0020"> In the present specification, the term "plane direction phase difference (Rin)" is a numerical value calculated by the following general formula 1, and the term "thickness direction phase difference (Rth)" is a numerical value calculated by the following general formula 2. Is.</p><p num="0021"> [General formula 1]<maths num="2"><img id="000004" he="9" wi="87" file="JP2017508169A_D0001.tif" img-format="tif" img-content="drawing" /></maths></p><p num="0022"> [General formula 2]<maths num="3"><img id="000005" he="9" wi="87" file="JP2017508169A_D0001.tif" img-format="tif" img-content="drawing" /></maths></p><p num="0023"> In general formula 1 and general formula 2, the symbols nx, ny, nz and d are the refractive index in the in-plane slow phase axial direction, the refractive index in the in-plane advancing phase axial direction, and the refractive index in the thickness direction, respectively. Means thickness. Each of the refractive indexes can be, for example, a refractive index measured for light having a wavelength of 550 nm. Through the above, it is possible to manufacture an optical element in which a transmission mode is realized in a voltage-free state and a cutoff mode is realized in a voltage-applied state. The orientation state and the phase difference due to each state when the voltage of the liquid crystal compound and / or the anisotropic dye in the liquid crystal layer is applied or not applied have an appropriate effect of adjusting the light transmittance depending on the application to which the optical element is applied. It can be freely adjusted to be exerted.</p><p num="0024"> In one example, the liquid crystal compound and / or anisotropic dye in the liquid crystal layer in the initial state is oriented so that the optical axis of the liquid crystal layer forms an inclination angle of 0 to 90 degrees with respect to the plane of the liquid crystal layer. Can exist in the state of being. As used herein, the "initial state" can mean a state in which no external signal is applied that can affect the orientation of the liquid crystal compound and / or the anisotropic dye. In one specific example, the liquid crystal compound and / or anisotropic dye in the initial state can be present in a horizontally or vertically oriented state.</p><p num="0025"> Further, in the initial state, the liquid crystal compound and / or the anisotropic dye can exist in a state in which the optical axis of the liquid crystal layer is oriented so as to form a range of 0 to 90 degrees with the absorption axis direction of the polarizing layer. .. In one example, even when the liquid crystal layer exists in a horizontally oriented state, the transmittance of the optical element can be adjusted by adjusting the angle formed by the optical axis of the liquid crystal layer and the absorption axis direction of the polarizing layer. In one example, when the angle formed by the optical axis of the liquid crystal layer with the absorption axis direction of the polarizing layer is perpendicular, the transmittance of the optical element can be reduced, and the angle formed by the optical axis of the liquid crystal layer with the absorption axis direction. When they are parallel, the transmittance of the optical element can be increased.</p><p num="0026"> The liquid crystal compound and / or the anisotropic dye exists in a state of being oriented so as to form an angle with the absorption axis of the polarizing plate, or, for example, the liquid crystal compound and / or the anisotropic dye is oriented so as to be parallel to the absorption axis of the polarizing plate. It can be present in a twisted state or in a twisted state. In the present specification, the "twist-oriented state" means that the major axis of the liquid crystal compound and / or the anisotropic dye is parallel to the plane of the liquid crystal layer, but the major axis of the adjacent liquid crystal compound and / or the anisotropic dye. The direction of can mean a state in which the angles change little by little and are twisted and arranged. Further, the drive mode of the liquid crystal layer is not particularly limited as long as the orientation characteristics of the liquid crystal compound and / or the anisotropic dye as described above can be exhibited. For example, the liquid crystal layer can be driven in ECB (Electrically Controlled Birefringence) mode, TN (Twisted Nematic) mode or STN (Super Twisted Nematic) mode, but is not limited thereto.</p><p num="0027"> As described above, the liquid crystal compound and / or anisotropic dye in the liquid crystal layer can switch the orientation in the initial state by applying an external signal. In one example, when the liquid crystal layer is in the horizontal alignment state in the initial state, the transmittance can be increased by switching to the vertical alignment state by applying an external signal, and in the case of the vertical alignment state in the initial state, the external signal. By switching to the horizontal orientation state by applying the above, the transmittance can be reduced. Further, when switching from the initial vertical orientation state to the horizontal orientation state, a pre-tilt in a certain direction may be required to determine the orientation direction of the liquid crystal compound and / or the anisotropic dye. The method of applying the pre-tilt is not particularly limited, and for example, it is possible by arranging an appropriate alignment film so as to apply the intended pre-tilt.</p><p num="0028"> When the liquid crystal compound and / or the anisotropic dye of the liquid crystal layer is vertically oriented, the alignment direction of the anisotropic dye is perpendicular to the plane of the polarizing layer existing at the bottom, so that the anisotropic dye is transmitted through the polarizing layer. The light can be transmitted without being absorbed by the anisotropic dye in the liquid crystal layer, and the transmittance of the optical element can be increased through this. On the other hand, when the liquid crystal compound and / or the anisotropic dye of the liquid crystal layer is horizontally oriented, the alignment direction of the anisotropic dye is parallel to the plane of the polarizing layer existing at the bottom. When the liquid crystal layer is arranged so that the optical axis orientation direction has a predetermined angle with respect to the absorption axis of the polarizing layer, a part of the light transmitted through the polarizing layer can be absorbed by the anisotropic dye, through which the anisotropic dye can be absorbed. The transmittance of the optical element can be reduced.</p><p num="0029"> In one example, the optical element can switch between the transmission mode and the cutoff mode depending on whether or not an external signal is applied to the liquid crystal layer. The optical element can switch between a transmission mode in which the transmittance in the visible light region is 20% or more and a blocking mode in which the transmittance in the visible light region is 3% or less by applying an external signal to the liquid crystal layer, for example. However, the light transmittance in the transmission mode and the blocking mode is not limited to the above, and a wider variety of light transmittances can be obtained by adjusting the orientation characteristics of the liquid crystal compound and / or the anisotropic dye as described above. It can also be adjusted in the range.</p><p num="0030"> In one example, when the liquid crystal layer is in a horizontal orientation state in the initial state, the cutoff mode is realized by forming the orientation direction of the optical axis of the liquid crystal layer so as to form a predetermined angle with the absorption axis of the polarizing layer. When the liquid crystal layer is changed to the vertically oriented state by applying an external signal, the transmittance of the optical element is increased and the transmission mode can be realized. In another example, when the liquid crystal layer is in the vertical alignment state in the initial state, the optical element can realize the transmission mode in the initial state, and the liquid crystal layer is in the horizontal alignment state by the above-mentioned pretilt by applying an external signal. In the case of conversion, the transmittance can be reduced by making the orientation direction of the optical axis of the liquid crystal layer form a predetermined angle with the absorption axis of the polarizing layer, and in this case, the optical element realizes a blocking mode. be able to.</p><p num="0031"> The optical element may further include an alignment film adjacent to the liquid crystal layer to adjust the initial alignment of the liquid crystal compound and / or the anisotropic dye. As the alignment film, a known vertical or horizontal alignment film can be used without any special limitation. Such an alignment film may be a contact-type alignment film such as a rubbing alignment film, or may contain a photo-alignment compound and exhibit alignment characteristics by a non-contact method such as irradiation with linear polarization. If possible, a known alignment film can be used.</p><p num="0032"> When the liquid crystal layer is driven in TN mode or STN mode, the liquid crystal layer can further contain a chiral agent. The chiral agent can induce the molecular arrangement of the liquid crystal compound and / or the anisotropic dye to have a spiral structure. The chiral agent can be used without particular limitation as long as it can induce a desired helical structure without impairing liquid crystallinity, for example, nematic regularity. A chiral agent for inducing a helical structure in a liquid crystal needs to contain at least chirality in its molecular structure. Chiral agents include, for example, compounds with one or more asymmetric carbons, compounds with asymmetric points on heteroatoms such as chiralamines or chiral sulfoxides, cumulene or binaphthol (cumulene) or binaphthol ( Binaphthol) and other axially asymmetrically active sites A compound having site) can be exemplified. The chiral agent can be, for example, a low molecular weight compound having a molecular weight of 1,500 or less. As the chiral agent, a commercially available chiral nematic liquid crystal, for example, a commercially available chiral dopant liquid crystal S-811 manufactured by Merck or LC756 manufactured by BASF may be used.</p><p num="0033"> In addition, the liquid crystal layer can further include a pillar pattern. More specifically, the liquid crystal layer can further include a column pattern formed to maintain spacing between two adjacent layers present above and below the liquid crystal layer. When the liquid crystal layer is between the polarizing plate and the composite layer, the lower and upper layers can be the polarizing plate and the composite layer, and when the liquid crystal layer is between the two composite layers, the said The lower and upper layers can be two composite layers. The liquid crystal compound and / or the anisotropic dye can be present in the region where the pillar pattern does not exist. The pillar pattern is formed on one of the upper and lower layers adjacent to the liquid crystal layer, and is attached to the other layer by an adhesive. Can be done. The adhesive capable of adhering the column pattern and the composite layer can be present on the column surface of the column pattern, and the type of the adhesive is not particularly limited, and a known adhesive for joining optical elements is used. can do.</p><p num="0034"> The pillar pattern can include a curable resin. The type of curable resin is not particularly limited, and for example, a thermosetting resin or a photocurable resin, for example, an ultraviolet curable resin can be used. As the heat-curable resin, for example, silicon resin, silicon resin, plan resin, polyurethane resin, epoxy resin, amino resin, phenol resin, urea resin, polyester resin, melamine resin and the like can be used, but the present invention is limited thereto. It's not something. UV curable resins typically include acrylic polymers such as polyester acrylate polymers, polystyrene acrylate polymers, epoxy acrylate polymers, polyurethane acrylate polymers or polybutadiene acrylate polymers, silicon acrylate polymers or alkyl acrylate polymers. Can be used, but is not limited to this.</p><p num="0035"> The shape and arrangement of the column patterns may be appropriately designed within a range that does not impair the object of the present invention, eg, within a range formed to maintain a constant spacing between the two composite layers. it can. The column pattern may be such that one or more column shapes are separated from each other or are partitioned by a partition shape. Column width, spacing, and thickness of column pattern The proportion of area within the liquid crystal layer can be appropriately selected within a range that does not impair the object of the present invention. For example, the width of the columns can be 1 μm to 500 μm, the spacing between the columns can be 10 μm to 5000 μm, and the proportion of the area of the column pattern in the liquid crystal layer is 100% of the area of the liquid crystal layer. On the other hand, it can be about 0.1% to 50%. Further, the height of the pillar can be appropriately selected within a range similar to the thickness of the liquid crystal layer in consideration of the thickness of the liquid crystal layer.</p><p num="0036"> Hereinafter, the composite layer will be specifically described. The composite layer can include a first oxide layer, a metal layer and a second oxide layer in this order. The composite layer can act as an electrode layer that applies an external signal, for example, a voltage to the liquid crystal layer. Since the composite layer has a high light transmittance in the visible light region, it has excellent transparency, and since it has a low light transmittance in the infrared region, it not only has an effect of blocking heat but also has a high electrical conductivity. And has a low surface resistance value. Therefore, such a composite layer can save energy and can be usefully used as an electrode layer of an optical element.</p><p num="0037"> The composite layer can have a transmittance of 80% or more, 85% or more, or 90% or more for light in the visible light region, for example, any one wavelength in the range of about 400 nm to 700 nm or a wavelength of 550 nm. A composite layer satisfying the above numerical range can be usefully used as an electrode layer of an optical element. However, the light transmittance in the visible light region of the composite layer is not limited to the above numerical range, and can usually have a light transmittance in the visible light region to the extent applicable to the transparent electrode.</p><p num="0038"> The composite layer can have a transmittance of 70% or less, 65% or less, or 60% or less for light in the infrared region, for example, any one wavelength in the range of about 700 nm to 1000 nm or light of 780 nm or more. Since the composite layer satisfying the above numerical range can block heat in the infrared region, for example, energy saving is possible. The lower limit of the light transmittance in the infrared region of the composite layer is not particularly limited, and for example, when the composite layer is used as an electrode layer of a smart window, the lower limit can be 0% to 5%. ..</p><p num="0039"> The surface resistance value of the composite layer can be 20 Ω / or less, 15 Ω / or less, or 10 Ω / or less, and the lower limit can be 0.1 Ω / or more without particular limitation. When a composite layer having a surface resistance value in the numerical range is applied to an optical element, power consumption can be minimized, so that there is an advantage that the efficiency of the optical element can be increased.</p><p num="0040"> Properties such as light transmittance and surface resistance in the visible light region and / or infrared region of the composite layer are, for example, the refractive index, thickness, electrical conductivity or electric conductivity of the first oxide layer, the metal layer and the second oxide layer. It can be adjusted depending on the material and the like. In the present specification, the "oxide layer" can mean a layer containing an oxide as a main component, and the "metal layer" can mean a layer containing a metal as a main component. The oxide layer can mean, for example, a layer containing about 80% by weight or more of oxide, and the metal layer can mean, for example, a layer containing about 80% by weight or more of metal.</p><p num="0041"> In one example, the refractive index of the first oxide layer can be higher than that of the second oxide layer, and the refractive index of the metal layer can be lower than that of the second oxide layer. ..</p><p num="0042"> In one example, the metal layer can have a refractive index in the range of 0.1 to 1.0 for a wavelength of 550 nm. More specifically, the refractive index of the metal layer with respect to light having a wavelength of 550 nm can be 0.1 or more, 0.15 or more, 0.2 or more, 0.25 or more, 0.3 or more, 0.35 or more, 0.4 or more, 0.45 or more or 0.5 or more. , 1.0 or less, 0.95 or less, 0.9 or less, 0.85 or less, 0.8 or less, 0.75 or less, 0.7 or less, 0.65 or less, 0.6 or less or 0.55 or less.</p><p num="0043"> Further, the refractive index of the first oxide layer with respect to light having a wavelength of 550 nm is in the range of 1.2 to 2.8 or 1.9 to 2.75, and more specifically, with respect to light having a wavelength of 550 nm of the first oxide layer. Refractive index is 1.2 or more, 1.25 or more, 1.3 or more, 1.35 or more, 1.4 or more, 1.45 or more, 1.5 or more, 1.55 or more, 1.6 or more, 1.65 or more, 1.7 or more, 1.75 or more, 1.8 or more, 1.85 or more, 1.9 or more, 1.95. Can be above or 2.0, 2.8 or less, 2.75 or less, 2.7 or less, 2.65 or less, 2.6 or less, 2.55 or less, 2.5 or less, 2.45 or less, 2.4 or less, 2.35 or less, 2.3 or less, 2.25 or less, 2.2 or less, 2.15 Below, it can be 2.1 or less or 2.05 or less.</p><p num="0044"> Further, the refractive index of the second oxide layer with respect to light having a wavelength of 550 nm can be in the range of 1.5 to 2.5. More specifically, the refractive index of the second oxide layer with respect to light having a wavelength of 550 nm is 1.5 or more, 1.55 or more, 1.6 or more, 1.65 or more, 1.7 or more, 1.75 or more, 1.8 or more, 1.85 or more, 1.9 or more, 1.95. It can be greater than or equal to or greater than 2.0, and can be less than or equal to 2.5, 2.45 or less, 2.4 or less, 2.35 or less, 2.3 or less, 2.25 or less, 2.2 or less, 2.15 or less, 2.1 or less, or 2.0 or less. The refractive index can be measured using, for example, an M-2000 apparatus [manufacturer: JA Woollam Co., Inc. (USA)].</p><p num="0045"> When the metal layer, the first oxide layer, and the second oxide layer each satisfy the refractive index range, the composite layer has a high light transmittance in the visible light region and a low light transmittance in the infrared region. It can be usefully used in a transparent electrode layer in an energy-saving optical element.</p><p num="0046"> The method of adjusting the refractive index of the first oxide layer, the metal layer and the second oxide layer in the above range is not particularly limited, and for example, the thickness of each layer is adjusted or the vapor deposition process conditions of each layer are adjusted. It can be adjusted by adjusting. Specifically, the degree of crystallinity can be adjusted by adjusting the vapor deposition conditions of each layer, so that the refractive indexes can be different even if the thickness and material are the same. The vapor deposition step can be carried out by a known vapor deposition method, for example, by a sputtering method. More specifically, the first oxide layer and the second oxide layer can be vapor-deposited by, for example, an RF sputtering method, and the metal layer can be deposited, for example, by a DC sputtering method.</p><p num="0047"> In one example, the thickness of the metal layer can be in the range of 5 nm to 20 nm. More specifically, the thickness of the metal layer can be 5 nm or more, 6 nm or more, 7 nm or more, 8 nm or more, 9 nm or more, 10 nm or more, 11 nm or more or 12 nm or more, 20 nm or less, 19 nm or less, 18 nm or less, It can be 17 nm or less, 16 nm or less, 15 nm or less, 14 nm or less, or 13 nm or less. When the thickness of the metal layer is within the above range, it is easy to adjust the refractive index of the metal layer within the above range. Further, when the thickness of the metal layer is within the above-mentioned thickness range, continuous film formation of the metal layer is easy, so that excellent electric conductivity and low resistance can be realized, and in the visible light region of the optical element. The light transmittance can be increased.</p><p num="0048"> Further, the metal layer may contain a conductive metal having a surface resistance value of 20 Ω / or less, preferably 10 Ω / or less. When the electrical conductivity of the conductive metal contained in the metal layer is within the above range, the surface resistance value of the composite layer can be lowered, so that there is an advantage that the efficiency of the optical element can be increased.</p><p num="0049"> The metal layer can include, for example, a metal such as silver (Ag), aluminum (Al), platinum (Pt), copper (Cu) or gold (Au). The metal layer can include, for example, silver. In this case, a part of silver oxide can be contained in the metal layer by contact with air and moisture in the process of manufacturing the composite layer or the process of using the composite layer in the optical element. When the metal layer contains silver and silver oxide, the silver oxide can be contained in an amount of 0.1% by weight or more and 50% by weight or less with respect to 100% by weight of the metal layer.</p><p num="0050"> In one example, the thickness of the first oxide layer can be in the range of 20 nm to 60 nm or 40 nm to 50 nm. More specifically, the thickness of the first oxide layer is 20 nm or more, 25 nm or more, 30 nm or more, 35 nm or more or 40 nm or more, and 60 nm or less, 55 nm or less, 50 nm or less or 45 nm or less. When the thickness of the first oxide layer is within the above range, it is easy to adjust the transmittance or refractive index of the first oxide layer with respect to light within the above range, and the first oxide layer is formed on the first oxide layer. It is possible to reduce the defective rate of vapor deposition of the metal layer.</p><p num="0051"> In one example, the thickness of the second oxide layer can be in the range of 10 nm to 100 nm, preferably 20 nm to 60 nm. More specifically, the thickness of the second oxide layer is 10 nm or more, 15 nm or more, 20 nm or more, 25 nm or more, 30 nm or more, 35 nm or more, 40 nm or more, 45 nm or more or 50 nm or more, 100 nm or less, 95 nm or less, It can be 90 nm or less, 85 nm or less, 80 nm or less, 75 nm or less, 70 nm or less, 65 nm or less, 60 nm or less, or 55 nm or less. When the thickness of the second oxide layer is within the above range, it is easy to adjust the transmittance or refractive index of the second oxide layer with respect to light within the above range, and the excellent electrical conductivity and low resistance value are obtained. Has the advantage of being able to have.</p><p num="0052"> The resistivity value of the second oxide layer is, for example, 1.0x10.^-5Ωcm ~ 1.0x10⁵Ωcm, preferably 1.0x10^-4Ωcm ~ 1.0x10⁴Can be in the range of Ωcm. When the specific resistance value of the second oxide layer is within the above range, the surface resistance value of the composite layer can be lowered, so that there is an advantage that the efficiency of the optical element can be increased.</p><p num="0053"> The first oxide layer and the second oxide layer are antimony (Sb), barium (Ba), gallium (Ga), germanium (Ge), hafnium (Hf), indium (In), lanthanum (La), and magnesium, respectively. Selected from the group consisting of (Mg), selenium (Se), silicon (Si), tantalum (Ta), titanium (Ti), vanadium (V), yttrium (Y), zinc (Zn) and zirconium (Zr). It can contain metal oxides, including metals containing one or more.</p><p num="0054"> The second oxide layer is a group consisting of gallium (Ga), aluminum (Al), zirconium (Zr), titanium (Ti), niobium (Nb), tantalum (Ta), indium (In) and vanadium (V). It can further comprise one or more secondary metals of greater choice.</p><p num="0055"> The metal contained in the second oxide layer can be, for example, a doping substance. When the second oxide layer further contains a second metal and is used as an electrode layer in an optical element, the electron transfer can be improved, and the second oxide layer has high refraction characteristics like the first oxide layer. Therefore, the light transmittance in the visible light region of the composite layer can be increased and the light transmittance in the infrared region can be lowered through the optical design. Further, since the second oxide layer has electrical conductivity, the composite layer has a low radiation function ((Low-E)) with various optical elements without impairing the electrical conductivity of the metal layer. It can serve as a transparent electrode.</p><p num="0056"> The content of the second metal in the second oxide layer can be 0.1% by weight or more and 10% by weight or less. The refractive index of the second oxide layer can be changed, for example, depending on the content of the second metal. Therefore, it is necessary to adjust the content of the second metal in the second oxide layer so as to maximize the light transmittance in the visible light region of the composite layer. In addition, the second metal contained in the second oxide layer affects the electrical conductivity of the second oxide layer. When the content of the second metal in the second oxide layer satisfies the above range, the second oxide layer can realize the optimum refractive index and electrical conductivity.</p><p num="0057"> The thickness of the composite layer can be appropriately selected within a range that does not impair the object of the present invention. The thickness of the composite layer is in the range of 50 nm to 300 nm or 70 nm to 200 nm, for example, to show high light transmittance in the visible light region, low light transmittance in the infrared region, excellent electrical conductivity and low resistance characteristics. Can be adjusted to.</p><p num="0058"> The composite layer can further include a base material layer, for example, the first oxide layer can be present so as to be adjacent to the base material layer. In the base material layer, known materials can be used without any special limitation. For example, a glass film, a crystalline or non-crystalline silicon film, an inorganic film such as quartz or an ITO (Indium Tin Oxide) film, a plastic film, or the like can be used. As the base material layer, an optically isotropic base material layer, an optically anisotropic base material layer such as a retardation layer, a polarizing plate, a color filter substrate, or the like can be used. For example, when the polarizing layer exists inside the base material layer, that is, between the liquid crystal layer and the base material layer, the performance is appropriate even when the anisotropic base material layer is used as the base material layer. The element can be embodied.</p><p num="0059"> In the plastic substrate layer, TAC (triacetyl cellulose); COP (cyclo olefin copolymer) such as norbornene derivative; PMMA (poly (methylcry); PC (polycarbonate); PE (polyethylene); PP (polypropylene); PVA (polyvinyl alcohol) ); DAC (diacetyl cellulose); Pac (Polyacrylate); PES (poly ether) sulfone); PEEK (polyetheretherketon); PPS (polyphenylsulfone), PEI (polyetherimide); PEN (polyethylenemaphthatlate); PET (polyethyleneterephtalate); PI (polyimide); PSF (polysulfone); PAR (polyarylate) or amorphous fluororesin, etc. Equipment layers can be used, but are not limited to this. If necessary, the base material layer may include a coating layer of a silicon compound such as gold, silver, silicon dioxide or silicon monoxide, or a coating layer such as an antireflection layer.</p><p num="0060"> In the present invention, the second oxide layer can exist adjacent to the liquid crystal layer as compared with the first oxide layer. Further, the composite layer can exist on both sides of the liquid crystal layer. That is, the liquid crystal layer can be arranged between two composite layers arranged so as to face each other. In this case, the composite layers existing on both sides have the same structure having the same refractive index, thickness, surface resistance, etc., or independent having different refractive indexes, thickness, surface resistance, etc. Can have a structure.</p><p num="0061"> The present invention also relates to the use of the optical element. The optical element of the present invention can change the transmittance depending on whether or not an external signal is applied, and also applies an external signal using a composite layer having low transmittance for light in the infrared region, and thus heat. Can be cut off to save energy. Such optical elements can be applied and used in various optical devices. The optical element of the present invention can be applied to, for example, a sunroof.</p><p num="0062"> As used herein, a "sunroof" is a device that functions as a fixed or operating (venting or sliding) opening in the ceiling of a vehicle that allows light or fresh air to flow into the interior of the vehicle. It is a common name. In the present invention, the method of operating the sunroof is not particularly limited, for example, it can be operated manually or driven by a motor, and the shape, size or style of the sunroof is appropriately selected according to the intended application. Can be done. For example, depending on the operating method, sunroofs include pop-up type sunroofs, spoiler (tile &amp; slide) type sunroofs, built-in type sunroofs, folding type sunroofs, top mount type sunroofs, panoramic roof system type sunroofs, and removable roof panels (t- Tops or targa roofts) type sunroofs or solar type sunroofs can be exemplified, but are not limited thereto.</p><p num="0063"> The exemplary sunroof of the present invention may include the optical element of the present invention, in which case the specific matters for the optical element may be the same as those described in the item of the optical element. it can.</p><p num="0064"> In addition, the sunroof may further include an ultraviolet blocking layer. As used herein, the term "ultraviolet blocking layer" can mean a known functional layer having an ultraviolet blocking function. The UV blocking layer can be formed on one side or both sides of the polarizing layer, the liquid crystal layer or the composite layer. As the ultraviolet blocking layer, for example, the ultraviolet blocking layers 210A and 201B can be present on the outermost outer side surface of the sunroof, for example, as shown in FIG. In such an ultraviolet blocking layer, for example, an ultraviolet blocking adhesive or an ultraviolet blocking film can be used. As the UV-blocking pressure-sensitive adhesive, a known pressure-sensitive adhesive component to which an additive having a known UV-blocking function is added can be used. As the ultraviolet blocking film, for example, a film in which a layer containing a known additive having an ultraviolet blocking function is formed on one surface of a known pressure-sensitive adhesive can be used. As the ultraviolet blocking adhesive, for example, EW1501-D1-UV, EW1502-D1-UV or EW1504-D1-UV manufactured by DAIO Paper can be used, but the present invention is not limited thereto.</p>

<p num="0065"> The optical element of the present invention can change the transmittance depending on whether or not an external signal is applied, and can apply an external signal by using a composite layer having low transmittance for light in the infrared region. Therefore, heat can be blocked and energy can be saved. Such optical elements can be usefully used in various optical devices such as sunroofs.</p>

0066<figref num="1">It is a figure which showed the optical element exemplarily.</figref><figref num="2">It is a figure which showed the structure of the sunroof exemplarily.</figref><figref num="3">It is a figure which illustrated the structure of the optical element of Example 1 exemplarily.</figref><figref num="4">It is a figure which showed the transmittance by the drive voltage of the optical element of Example 1.</figref><figref num="5">It is a figure which showed the transmittance and the reflectance of the optical element of Example 1.</figref><figref num="6">It is a figure which showed the transmittance and the reflectance of the optical element of the comparative example 1.</figref><figref num="7">It is a figure which showed the characteristic by the wavelength of the metal layer of Example 1 and Comparative Example 2.</figref><figref num="8">It is a figure which showed the light transmittance evaluation result by the refractive index of a 1st metal oxide layer and a 2nd metal oxide layer.</figref>

0067Hereinafter, the above-mentioned technical contents will be described in more detail through Examples and Comparative Examples, but the scope of the present invention is not limited to the examples presented below.

0068&lt;Example 1&gt; Manufacture of composite layers CeO on a glass substrate using the RF Sputter method₂Was deposited to a thickness of 35 nm to form a first metal oxide layer. 1.5 W / cm on the first metal oxide layer using the DC sputter method²A metal layer made of Ag was deposited to a thickness of 10 nm under the conditions of 3 mTorr and a zinc oxide layer (GZO) doped with Ga as a second metal oxide layer was deposited to a thickness of 45 nm on the metal layer. Then, the composite layer was manufactured.

0069In this case, the refractive index of each layer was measured using an M-2000 device [manufacturer: JA Woollam Co., Inc. (USA)]. As a result, the refractive index of the first oxide layer was 2.34 at a wavelength of 550 nm. The refractive index of the metal layer was 0.19 at the wavelength of 550 nm, and the refractive index of the zinc oxide layer was 1.94 at the wavelength of 550 nm.

0070Moreover, as a result of measuring the visible light transmittance of the composite layer using a UV-vis spectrometer, it showed a transmittance of 87.2% at a wavelength of 550 nm.

0071Furthermore, as a result of measuring the surface resistance of the composite layer with a surface resistance measuring instrument, it was shown to be less than 10Ω / .

0072Manufacture of optical elements for sunroofs An optical element for a sunroof having the structure shown in FIG. 3 was manufactured by the following method. The composite layer 103A is laminated on the known absorption type linear polarizing layer 101 so that the first oxide layer of the composite layer produced above is in contact with the OCA surface through the OCA layer 301 (EW1501-D1-UV manufactured by DAIO Paper). Then, on the second oxide layer of the composite layer, 1 to 3 of a liquid crystal compound (HPC21600, manufactured by HCCH) and an anisotropic dye (X12, manufactured by BASF) with respect to 100 parts by weight of the liquid crystal compound. After forming the liquid crystal layer 102 contained in the proportion of parts by weight, the composite layer 103B was laminated so that the second oxide layer of the other manufactured composite layer was in contact with the liquid crystal layer to manufacture an optical element. .. The optical axis of the liquid crystal layer is formed so as to form an inclination angle of about 0 to 15 degrees with respect to the plane of the liquid crystal layer, that is, the liquid crystal compound and / or the anisotropic dye is horizontally oriented, and the liquid crystal is formed. The optical axis of the layer was formed so as to form an angle of about 90 degrees with the absorption axis of the absorption type linear polarizing layer.

0073&lt;Example 2&gt; The sunroof of Example 2 was manufactured by performing the same method as in Example 1 except that the composite layer produced below was used as the composite layer.

0074Manufacture of composite layers CeO on a glass substrate using the RF Sputter method₂Was deposited to a thickness of 30 nm to form a first metal oxide layer. 1.5 W / cm on the first metal oxide layer using the DC sputter method²A metal layer made of Ag was deposited to a thickness of 10 nm under the conditions of and 3 mTorr, and a zinc oxide layer (AZO) doped with Al as a second metal oxide layer was deposited to a thickness of 50 nm on the metal layer. Then, the composite layer was manufactured.

0075In this case, the refractive index of the first metal oxide layer is 2.34 at the wavelength of 550 nm, the refractive index of the metal layer is 0.19 at the wavelength of 550 nm, and the refractive index of the second metal oxide layer is 1.89 at the wavelength of 550 nm. there were. Moreover, as a result of measuring the visible light transmittance of the composite layer using a UV-vis spectrometer, it showed a transmittance of 85.5% at a wavelength of 550 nm. Furthermore, as a result of measuring the surface resistance of the composite layer with a surface resistance measuring instrument, it was shown to be less than 10Ω / .

0076&lt;Comparison example 1&gt; The sunroof of Comparative Example 1 was manufactured by performing the same method as in Example 1 except that the ITO transparent electrode layer was used as the composite layer.

0077&lt;Comparative example 2&gt; The sunroof of Comparative Example 2 was manufactured by executing the same method as in Example 1 except that the composite layer produced below was used as the composite layer.

0078Manufacture of composite layers CeO on a glass substrate using the RF Sputter method₂Was deposited to a thickness of 35 nm to form a first metal oxide layer. 0.5 W / cm on the first metal oxide layer by DC sputter method²A zinc oxide layer (GZO) in which Ag was vapor-deposited to a thickness of 10 nm to form a metal layer under the conditions of and 15 mTorr, and then Ga was doped on the metal layer as a second metal oxide layer on the metal layer. ) Was vapor-deposited to a thickness of 45 nm to produce a composite layer.

0079In this case, the refractive index of the first oxide layer was 2.34 at a wavelength of 550 nm, the refractive index of the metal layer was 1.95 at a wavelength of 550 nm, and the refractive index of the zinc oxide layer was 1.94 at a wavelength of 550 nm.

0080Further, as a result of measuring the surface resistance of the metal layer with a surface resistance measuring instrument, a value exceeding 10 Ω / was shown, and as a result of measuring the visible light transmittance of the metal layer using a UV-vis spectrometer, the visible light transmittance was 550 nm. It showed a transmittance of 46.8% at wavelength, and the refractive index was measured at 1.95. Furthermore, as a result of measuring the visible light transmittance of the composite layer using a UV-vis spectrometer, it showed a transmittance of 79.1% at a wavelength of 550 nm. Moreover, as a result of measuring the surface resistance of the composite layer with a surface resistance measuring instrument, a value exceeding 10Ω / was shown.

0081&lt;Comparative example 3&gt; Comparative Example 3 was carried out in the same manner as in Example 2 except that the first metal oxide layer was formed at 10 nm and the thickness of the second metal oxide layer was formed at 80 nm during the production of the composite layer. Manufactured the sunroof.

0082As a result of measuring the visible light transmittance of the composite layer using a UV-vis spectrometer, it showed a transmittance of 72.6% at a wavelength of 550 nm.

0083Moreover, as a result of measuring the surface resistance of the composite layer with a surface resistance measuring instrument, a value exceeding 10Ω / was shown.

0084&lt;Evaluation example 1&gt; With respect to the optical element manufactured in Example 1, the thickness of the liquid crystal layer is formed to be 10 μm and 15 μm, respectively, and after connecting a power source capable of applying a vertical electric field to the composite layer, the optical element is subjected to a driving voltage. The transmittance for light at about 550 nm was measured using a haze meter NDH 5000SP [manufacturer: Nippon Denshoku (JAPAN)], and the results are shown in Fig. 4. As shown in FIG. 4, it can be confirmed that the transmittance is low when no voltage is applied, and the more the voltage is applied, the more the liquid crystal compound and the anisotropic dye are transmitted while being converted into the vertically aligned state. It can be confirmed that the degree increases.

0085&lt;Evaluation example 2: Evaluation of transmittance and reflectivity&gt; The transmittance and reflectance of the optical elements manufactured in Examples and Comparative Examples were measured in a state where no voltage was applied. Specifically, measurements were made using a Solid Spec-3700 [manufacturer: shimadzu (JAPAN)] device, and the results are shown in Fig. 5 (Example 1) and Fig. 6 (Comparative Example 1), respectively. As shown in FIGS. 5 and 6, the optical element of the example in which the composite layer of the present invention is used as the transparent electrode layer has a visible light region as compared with the optical element of Comparative Example 1 in which the ITO transparent electrode layer is used. Although the light transmittance is similar, it can be confirmed that the light transmittance is remarkably low in the infrared region.

0086&lt;Evaluation example 3: Evaluation of refractive index and absorption coefficient by wavelength of metal layer&gt; The refractive index and absorption coefficient based on the refractive index of the metal layers produced in Example 1 and Comparative Example 2 were evaluated, and the results are shown in FIG. In FIG. 7, n means the refractive index of the metal layer by the wavelength of light, λ means the wavelength of light, and k means the absorption coefficient of the metal layer by the wavelength of light. As shown in FIG. 7, it can be confirmed that the refractive index and the absorption coefficient are different depending on the formation conditions of the metal layer even if the metal layers are formed with the same thickness.

0087&lt;Evaluation example 4: Evaluation of the transmittance of the composite layer by the refractive index of the first and second metal oxide layers&gt; The optical modulator is manufactured in the same manner as in Example 1 and Example 2, but the refractive index of the composite layer is applied to light having a wavelength of 550 nm while changing the refractive index of the first metal oxide layer and the second metal oxide layer. The transmittance was evaluated and the results are shown in Fig. 8. As shown in FIG. 8, it can be confirmed that the light transmittance of the composite layer is affected by the refractive indexes of the first metal oxide layer and the second metal oxide layer. In particular, when the refractive index range of the first metal oxide layer and the second metal oxide layer belongs to the range of the present invention, it is shown that an excellent light transmittance of about 80% or more is exhibited with respect to light having a wavelength of 550 nm. You can check.

0088101: Polarizing layer 102: Liquid crystal layer 103A, 103B: Composite layer 201A, 201B: UV blocking layer 301: OCA layer