WO2012064141A2 - Optical element - Google Patents

Abstract

The present invention relates to an optical element. An optical element which is illustrative of the present invention may be a light−splitting element; for example an element that splits incident light into two or more types of light of which the polarization states are different. The optical element may, by way of example, be used in creating stereoscopic images.

Description

Optical element

The present invention relates to an optical element and a stereoscopic image display device.

The technique of dividing light into two or more kinds of light having different polarization states from each other can be usefully used in various fields.

The light splitting technique may be applied to, for example, producing a stereoscopic image. Stereoscopic images may be implemented using binocular parallax. For example, when two two-dimensional images are respectively input to the left and right eyes of the human, the input information is transmitted and fused to the brain so that the human feels three-dimensional perspective and realism. Can be.

The technology of generating stereoscopic images may be usefully used in 3D measurement, 3D TV, camera or computer graphics.

An object of the present invention is to provide an optical element and a stereoscopic image display device.

The present invention relates to an optical element. Exemplary optical elements may include a liquid crystal layer, a base layer, and a polarizer sequentially disposed.

FIG. 1: is sectional drawing of the exemplary optical element 1, and shows the structure in which the liquid crystal layer 11, the base material layer 12, and the polarizer 13 are formed one by one.

In one example, the optical element may be an element that divides incident light into two or more kinds of light having different polarization states. Such a device may be used, for example, to implement a stereoscopic image.

The liquid crystal layer may have a difference in refractive index in the in-plane slow axis direction and in-plane fast axis direction in a range of 0.05 to 0.2, 0.07 to 0.2, 0.09 to 0.2, or 0.1 to 0.2. The refractive index in the in-plane slow axis direction refers to the refractive index in the direction showing the highest refractive index in the plane of the liquid crystal layer, and the refractive index in the fast axis direction indicates the difference in the refractive index in the direction showing the lowest refractive index on the plane of the liquid crystal layer. Can mean. In general, in the liquid crystal layer of optically anisotropy, the fast axis and the slow axis are formed in a direction perpendicular to each other. Each of the refractive indices may be a refractive index measured for light having a wavelength of 550 nm or 589 nm.

The liquid crystal layer may also have a thickness of about 0.5 μm to 2.0 μm or about 0.5 μm to 1.5 μm.

The liquid crystal layer having the relationship and thickness of the refractive index may implement a phase delay characteristic suitable for the application to be applied. In one example, the liquid crystal layer having a relationship between the refractive index and the thickness may be suitable for an optical element for splitting light.

The liquid crystal layer may include a polyfunctional polymerizable liquid crystal compound and a monofunctional polymerizable liquid crystal compound, and the compound may be included in the liquid crystal layer in a polymerized form.

As used herein, the term "polyfunctional polymerizable liquid crystal compound" may include a mesogen skeleton and the like, and may refer to a compound including two or more polymerizable functional groups. In one example, the multifunctional polymerizable liquid crystal compound has 2 to 10, 2 to 8, 2 to 6, 2 to 5, 2 to 4, 2 to 3 polymerizable functional groups Dogs or two.

In addition, in this specification, the term "monofunctional polymerizable liquid crystal compound" shows a liquid crystal including mesogenic skeleton etc., and can mean the compound containing one polymerizable functional group.

In addition, in this specification, the "liquid crystal compound contained in the form polymerized in the liquid crystal layer" may mean a state in which the liquid crystal compound is polymerized to form a liquid crystal polymer in the liquid crystal layer.

When the liquid crystal layer contains a polyfunctional and monofunctional polymerizable compound, it is possible to impart better phase delay characteristics to the liquid crystal layer, and the implemented phase delay characteristics, for example, the optical axis and phase delay values of the liquid crystal layer are severe. It can be kept stable even under conditions.

In one example, the multifunctional or monofunctional polymerizable liquid crystal compound may be a compound represented by the following Chemical Formula 1.

[Formula 1]

In Formula 1, A is a single bond, -COO- or -OCO-, and R ₁ to R ₁₀ are each independently hydrogen, halogen, alkyl group, alkoxy group, alkoxycarbonyl group, cyano group, nitro group, -OQP or Substituent of Formula 2, wherein at least one of R ₁ to R ₁₀ is -OQP or a substituent of Formula 2, two adjacent substituents of R ₁ to R ₅ or two adjacent substituents of R ₆ to R ₁₀ Connected to each other to form a benzene substituted with -OQP, wherein Q is an alkylene group or an alkylidene group, and P is an alkenyl group, epoxy group, cyano group, carboxyl group, acryloyl group, methacryloyl group, acrylo It is a polymerizable functional group, such as a oxy group or a methacryloyl oxy group.

[Formula 2]

In Formula 2, B is a single bond, -COO- or -OCO-, and R ₁₁ to R ₁₅ are each independently hydrogen, halogen, alkyl group, alkoxy group, alkoxycarbonyl group, cyano group, nitro group or -OQP. , At least one of R ₁₁ to R ₁₅ is -OQP, or two adjacent substituents of R ₁₁ to R ₁₅ are connected to each other to form a benzene substituted with -OQP, wherein Q is an alkylene group or an alkylidene group , P is a polymerizable functional group such as alkenyl group, epoxy group, cyano group, carboxyl group, acryloyl group, methacryloyl group, acryloyloxy group or methacryloyloxy group.

In Formulas 1 and 2, adjacent two substituents may be linked to each other to form benzene substituted with -OQP, which may mean that two adjacent substituents are connected to each other to form a naphthalene skeleton substituted with -OQP as a whole. have.

"-" Of the left side of B in Formula 2 may mean that B is directly connected to the benzene of Formula 1.

In Formulas 1 and 2, the term “single bond” refers to a case where no separate atom is present in a portion represented by A or B. For example, when A is a single bond in Formula 1, benzene on both sides of A may be directly connected to form a biphenyl structure.

As the halogen in Chemical Formulas 1 and 2, chlorine, bromine or iodine may be exemplified.

As used herein, unless otherwise specified, the term alkyl group is a straight or branched chain alkyl group having 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms or 1 to 4 carbon atoms, or 3 to 20 carbon atoms, It may mean a cycloalkyl group having 3 to 16 carbon atoms or 4 to 12 carbon atoms. The alkyl group may be optionally substituted with one or more substituents.

As used herein, unless otherwise specified, the term alkoxy group may mean an alkoxy group having 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms. The alkoxy group may be linear, branched or cyclic. In addition, the alkoxy group may be optionally substituted with one or more substituents.

In addition, in the present specification, the term alkylene group or alkylidene group may mean an alkylene group or alkylidene group having 1 to 12 carbon atoms, 4 to 10 carbon atoms or 6 to 9 carbon atoms, unless otherwise specified. The alkylene group or alkylidene group may be linear, branched or cyclic. In addition, the alkylene group or alkylidene group may be optionally substituted with one or more substituents.

In addition, an alkenyl group in the present specification may mean an alkenyl group having 2 to 20 carbon atoms, 2 to 16 carbon atoms, 2 to 12 carbon atoms, 2 to 8 carbon atoms, or 2 to 4 carbon atoms, unless otherwise specified. The alkenyl group may be linear, branched or cyclic. In addition, the alkenyl group may be optionally substituted with one or more substituents.

In Formulas 1 and 2, P is preferably acryloyl group, methacryloyl group, acryloyloxy group or methacryloyloxy group, more preferably acryloyloxy group or methacryloyloxy group, More preferably, it may be an acryloyloxy group.

As a substituent which may be substituted by the specific functional group in this specification, an alkyl group, an alkoxy group, an alkenyl group, an epoxy group, an oxo group, an oxetanyl group, a thiol group, a cyano group, a carboxyl group, acryloyl group, a methacryloyl group, Acryloyloxy group, methacryloyloxy group or an aryl group may be exemplified, but is not limited thereto.

At least one of -OQP or a residue of Formula 2, which may be present in Formulas 1 and 2, may be, for example, present at a position of R ₃ , R _8, or R ₁₃ . In addition, it may be preferably R ₃ and R ₄ , or R ₁₂ and R ₁₃ to be connected to each other to form a benzene substituted with —OQP. Further, substituents other than -OQP or residues of the formula (2) or substituents other than those linked to each other to form benzene in the compound of the formula (1) or the formula (2), for example, are hydrogen, halogen, straight chain of 1 to 4 carbon atoms Or an alkoxycarbonyl group including a branched alkyl group, a straight or branched alkoxy group having 1 to 4 carbon atoms, a cycloalkyl group having 4 to 12 carbon atoms, a cyano group, an alkoxy group having 1 to 4 carbon atoms, a cyano group or a nitro group, Preferably an alkoxycarbonyl group comprising chlorine, a straight or branched chain alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 4 to 12 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a straight or branched chain alkoxy group having 1 to 4 carbon atoms, or It may be a cyano group.

The liquid crystal layer is a monofunctional polymerizable liquid crystal compound, more than 0 parts by weight to 100 parts by weight, 1 part by weight to 90 parts by weight, 1 part by weight to 80 parts by weight, 1 part by weight relative to 100 parts by weight of the polyfunctional polymerizable liquid crystal compound. To 70 parts by weight, 1 to 60 parts by weight, 1 to 50 parts by weight, 1 to 30 parts by weight or 1 to 20 parts by weight.

Within this range, the mixing effect of the multifunctional and monofunctional polymerizable liquid crystal compound may be maximized, and the liquid crystal layer may exhibit excellent adhesiveness with the adhesive layer. Unless otherwise specified herein, the unit weight part may mean a ratio of weight.

The polyfunctional and monofunctional polymerizable liquid crystal compound may be included in the liquid crystal layer in a horizontally aligned state. As used herein, the term "horizontal alignment" means that the optical axis of the liquid crystal layer containing the polymerized liquid crystal compound is about 0 degrees to about 25 degrees, about 0 degrees to about 15 degrees, and about 0 degrees to about 10 with respect to the plane of the liquid crystal layer. Also, it may mean a case having an inclination angle of about 0 degrees to about 5 degrees or about 0 degrees. As used herein, the term optical axis may mean a fast axis or a slow axis when incident light passes through a corresponding area.

The liquid crystal layer may be formed to split incident light, for example, light incident through the polarizer into two or more types of light having different polarization states. To this end, for example, the liquid crystal layer may include first and second regions having different phase delay characteristics from each other. In the present specification, the phase delay characteristics of the first region and the second region are different from each other, wherein the first and second regions are the same as or different from each other in a state in which both the first and second regions have a phase delay characteristic. It may include a case where the optical axis is formed in the direction and the phase delay values are also different from each other, and the case where the optical axes are formed in different directions while having the same phase delay value. In another example, the difference in phase delay characteristics of the first and second regions means that any one of the first and second regions is a region having phase delay characteristics, and the other region is optically isotropic without phase delay characteristics. The case may also be included. Examples of such a case include a form in which the liquid crystal layer includes both the region in which the liquid crystal layer is formed and the region in which the liquid crystal layer is not formed. The phase delay characteristics of the first or second region may be controlled by adjusting, for example, the alignment state of the liquid crystal compound, the refractive index relationship of the liquid crystal layer, or the thickness of the liquid crystal layer.

In one example, the first region A and the second region B are alternately disposed adjacent to each other while having a stripe shape extending in a common direction as shown in FIG. 2, or FIG. 3. As shown in Fig. 1 may be arranged alternately adjacent to each other in a grid pattern.

When the optical element is used to display a stereoscopic image, any one of the first and second regions may be a left eye image signal polarization adjusting region (hereinafter referred to as an "LC region"), The other region may be a right eye image signal polarization adjusting region (hereinafter, may be referred to as an “RC region”).

In one example, the two or more kinds of light having different polarization states, divided by the liquid crystal layer including the first and second regions, include two kinds of linearly polarized light having directions substantially perpendicular to each other. Or, may include left circularly polarized light and right circularly polarized light.

When defining angles in this specification, when using terms such as vertical, horizontal, orthogonal or parallel, each of the above means substantially vertical, horizontal, orthogonal or parallel, unless otherwise specified, for example , Error including manufacturing error or variation. Thus, for example, each of the above may include an error within about ± 15 degrees, preferably an error within about ± 10 degrees, more preferably an error within about ± 5 degrees.

In one example, any one of the first and second regions is a region which is transmitted as it is without rotating the polarization axis of the incident light, and the other region is orthogonal to the polarization axis of the light transmitted through the other region. It may be a region that can be transmitted by rotating in the direction. In this case, the region containing the polymerizable liquid crystal compound in the liquid crystal layer may be formed only in one of the first and second regions. The region in which the liquid crystal layer is not formed may be an empty space, or a resin layer or a resin film or sheet having glass or optical isotropy may be formed.

In another example, one of the first and second regions may be a region capable of converting incident light into left circularly polarized light and transmitting the light, and another region may be an region capable of converting incident light into right circularly polarized light and transmitting the light. Can be. In this case, the first and second regions are regions having optical axes formed in different directions while exhibiting the same phase retardation values, or one region is a region capable of delaying incident light by a quarter wavelength of the wavelength. The other area may be an area capable of retarding incident light by 3/4 wavelength of the wavelength.

In a suitable example, the first and second regions have a phase retardation value equal to each other, for example, a value capable of retarding incident light by a quarter wavelength of the wavelength, and formed in different directions from each other. It may be an area having an optical axis. The angle formed by the optical axes formed in different directions as described above may be vertical, for example.

When the first and second regions are regions having optical axes formed in different directions, a line bisecting an angle formed by the optical axes of the first and second regions is formed to be perpendicular or horizontal to the absorption axis of the polarizer. It is preferable that it is done.

FIG. 4 is an exemplary view for explaining the arrangement of the optical axes when the first and second regions A and B in the example of FIG. 2 or 3 are regions having optical axes formed in different directions from each other. Referring to FIG. 4, a line that bisects the angle formed by the optical axes of the first and second regions A and B may mean a line that bisects the angle of (Θ1 + Θ2). For example, when Θ1 and Θ2 are the same angle, the bisector may be formed in a direction parallel to the boundary line L of the first and second regions A and B. In addition, the angle formed by the optical axes of the first and second regions, that is, (Θ1 + Θ2), may be, for example, 90 degrees.

The optical element as described above may satisfy the condition of the following general formula (1).

[Formula 1]

X <8%

In Formula 1, X is a percentage of the absolute value of the change amount of the phase difference value of the liquid crystal layer after leaving the optical element at 80 ° C. for 100 hours or 250 hours at an initial phase difference value of the liquid crystal layer of the optical element.

X may be calculated as, for example, "100 x (| R ₀ -R ₁ |) / R ₀ ". In the above description, R ₀ is the initial phase difference value of the liquid crystal layer of the optical element, and R ₁ means the phase difference value of the liquid crystal layer after leaving the optical element at 80 ° C. for 100 hours or 250 hours.

X may preferably be 7% or less, 6% or less or 5% or less. The amount of change in the phase difference value can be measured by the method given in the following Examples.

The optical device includes a base layer on which the liquid crystal layer is formed. The base material layer may have a single layer or a multilayer structure.

As a base material layer, a glass base material layer or a plastic base material layer can be used, for example. Examples of the plastic base layer include cellulose resins such as triacetyl cellulose (TAC) or diacetyl cellulose (DAC); Cyclo olefin polymers (COPs) such as norbornene derivatives; Acrylic resins such as poly (methyl methacrylate); polyolefin (PC); polyolefins such as polyethylene (PE) or polypropylene (PP); polyvinyl alcohol (PVA); poly ether sulfone (PES); polyetheretherketon (PEEK); Polyetherimide (PEN), polyestermaphthatlate (PEN), polyester such as polyethylene terephtalate (PET), polyimide (PI), polysulfone (PSF), or a fluorine resin or the like may be exemplified.

The substrate layer, for example, the plastic substrate layer, may have a lower refractive index than the liquid crystal layer. The refractive index of the exemplary substrate layer is in the range of about 1.33 to about 1.53. When the base layer has a lower refractive index than the liquid crystal layer, for example, it is advantageous to improve luminance, prevent reflection, and improve contrast characteristics.

The plastic base layer may be optically isotropic or anisotropic. When the base layer is optically anisotropic in the above, it is preferable that the optical axis of the base layer is disposed so as to be perpendicular or horizontal to a line bisecting the angle formed by the optical axes of the first and second regions.

In one example, the substrate layer may include a sunscreen or a UV absorber. When the sunscreen or absorbent is included in the base layer, deterioration of the liquid crystal layer due to ultraviolet rays or the like can be prevented. As the sunscreen or absorbent, a salicylic acid ester compound, a benzophenone compound, an oxybenzophenone compound, a benzotriazol compound, a cyanoacrylate compound or a benzoate Organics such as (benzoate) compounds or the like or inorganic materials such as zinc oxide or nickel complex salts may be exemplified. The content of the sunscreen or absorbent in the substrate layer is not particularly limited and may be appropriately selected in consideration of the desired effect. For example, the sunscreen or absorbent may be included in the manufacturing process of the plastic base layer in an amount of about 0.1 wt% to 25 wt% based on the weight ratio of the main material of the base layer.

The thickness of the substrate layer is not particularly limited and may be appropriately adjusted according to the intended use. The base material layer may have a single layer or a multilayer structure.

An exemplary optical element may further include an alignment layer existing between the base layer and the liquid crystal layer. The alignment layer may be a layer that serves to orient the liquid crystal compound in the process of forming the optical element. As the alignment layer, a conventional alignment layer known in the art, for example, a photo alignment layer or a rubbing alignment layer may be used. The alignment layer is an arbitrary configuration, and in some cases, it is possible to impart orientation without the alignment layer by rubbing or stretching the substrate layer directly.

In the optical device, a polarizer formed under the base layer is a functional device capable of extracting light vibrating in one direction from incident light while vibrating in various directions. As the polarizer, for example, a conventional polarizer such as a poly (vinyl alcohol) polarizer can be used.

In one example, the polarizer may be a polyvinyl alcohol film or sheet on which dichroic dyes or iodine are adsorbed and oriented. The polyvinyl alcohol can be obtained, for example, by gelling polyvinylacetate. As polyvinyl acetate, Homopolymer of vinyl acetate; And copolymers of vinyl acetate and other monomers, and the like. As another monomer copolymerized with vinyl acetate, one or more kinds of unsaturated carboxylic acid compounds, olefin compounds, vinyl ether compounds, unsaturated sulfonic acid compounds and acrylamide compounds having an ammonium group may be exemplified. The degree of gelation of polyvinylacetate may generally be about 85 mol% to about 100 mol% or 98 mol% to 100 mol%. The degree of polymerization of the polyvinyl alcohol used in the polarizer may generally be about 1,000 to about 10,000 or about 1,500 to about 5,000.

In one example, the polarizer may be attached to the base layer by an aqueous adhesive. 5 shows an exemplary optical element 5 in which a polarizer 13 is attached to the base layer 12 by a water-based adhesive 51. As the water-based adhesive in the above, it can be used without particular limitation as long as it can implement appropriate adhesion. In one example, the water-based adhesive, a polyvinyl alcohol-based water-based adhesive commonly used for the attachment of a polarizer and a protective film of the polarizer, for example, polyvinyl alcohol-based polarizer and TAC (Triacetyl cellulose) film at the time of manufacturing the polarizing plate Can be used.

The optical device may further include a surface treatment layer formed on the liquid crystal layer. 6 shows an exemplary optical element 6 in which a surface treatment layer 61 is formed on top of the liquid crystal layer 11.

Examples of the surface treatment layer include an anti-glare layer such as a high hardness layer, an anti-glare layer or a semi-glare layer, or a low reflection layer such as an anti reflection layer or a low reflection layer. Can be.

The high hardness layer may be a layer having a pencil hardness of at least 1H or at least 2H under a load of 500 g. The pencil hardness can be measured according to the ASTM D 3363 standard, for example using a pencil lead defined in KS G2603.

The high hardness layer may be, for example, a high hardness resin layer. The resin layer may include, for example, a room temperature curing type, a moisture curing type, a thermosetting type, or an active energy ray curing type resin composition in a cured state, and in one example, a thermosetting type or active energy ray curing type resin composition, or The active energy ray curable resin composition may be included in a cured state. In the description of the high hardness layer, the "cured state" may mean a case where the components contained in the respective resin compositions are converted into a hard state through a crosslinking reaction or a polymerization reaction. Further, in the above-mentioned room temperature curing type, moisture curing type, thermosetting type or active energy ray-curable resin composition, the cured state may be induced at room temperature or may be induced by application of heat or irradiation of active energy ray in the presence of appropriate moisture. By composition may be meant.

In this field, various resin compositions are known which can satisfy the pencil hardness in the above-mentioned range in a cured state, and the average technician can easily select a suitable resin composition.

In one example, the resin composition may include an acrylic compound, an epoxy compound, a urethane-based compound, a phenol compound, a polyester compound, or the like as a main material. In the above, the "compound" may be a monomeric, oligomeric or polymeric compound.

In one example, as the resin composition, an acrylic resin composition which is excellent in optical properties such as transparency and excellent in resistance to yellowing and the like, preferably an active energy ray-curable acrylic resin composition can be used.

The active energy ray-curable acrylic composition may include, for example, an active energy ray polymerizable polymer component and a monomer for reactive dilution.

The polymer component in the above includes components known in the art as so-called active energy ray polymerizable oligomers such as urethane acrylate, epoxy acrylate, ether acrylate or ester acrylate, or monomers such as (meth) acrylic acid ester monomers and the like. Polymerized mixtures can be exemplified. As the (meth) acrylic acid ester monomer, alkyl (meth) acrylate, (meth) acrylate having an aromatic group, heterocyclic (meth) acrylate or alkoxy (meth) acrylate and the like can be exemplified. In this field, various polymer components for producing an active energy ray-curable composition are known, and such compounds may be selected as necessary.

As the monomer for reactive dilution, which may be included in the active energy ray-curable acrylic composition, a monomer having one or two or more active energy ray-curable functional groups, for example, acryloyl group or methacryloyl group, may be exemplified. For example, the (meth) acrylic acid ester monomer or polyfunctional acrylate may be used.

The selection of the above components or the blending ratio of the selected components for producing the active energy ray-curable acrylic composition is not particularly limited and may be adjusted in consideration of the hardness and other physical properties of the desired resin layer.

As the AG (Anti-glare) layer or the SG (Semi-glare) layer, for example, a resin layer containing a resin layer or particles having an uneven surface formed therein, the particles having a refractive index different from that of the resin layer. The resin layer which is a particle | grain can be used.

As said resin layer, the resin layer used for formation of the said high hardness layer can be used, for example. When forming an anti-glare layer, although it is not necessary to adjust the component of a resin composition so that a resin layer may show high hardness, when the said particle | grain is mix | blended with the resin layer which forms the said high hardness layer, a high hardness layer and an anti-glare layer It is advantageous in terms of being able to form a surface treatment layer having the function of at the same time.

The method of forming the uneven surface on the resin layer is not particularly limited. For example, the resin layer may be cured in a state in which the coating layer of the resin composition is in contact with a mold having a desired concave-convex structure, or a particle having an appropriate particle size may be blended, coated, and cured in the resin composition to implement the concave-convex structure. Can be.

The anti-glare layer may also be implemented using particles having a different refractive index than that of the resin layer.

In one example, the particles, for example, the difference in refractive index with the resin layer may be 0.03 or less or 0.02 to 0.2. If the difference in the refractive index is too small, it is difficult to cause haze, and if the difference is too large, scattering occurs in the resin layer to increase the haze, but a decrease in light transmittance or contrast characteristics may be induced. Consideration can be given to selecting appropriate particles.

The shape of the particles contained in the resin layer is not particularly limited and may have, for example, spherical, elliptical, polyhedral, amorphous or other shapes. The particles may have an average diameter of 50 nm to 5,000 nm. In one example, the particle | grains in which the unevenness | corrugation is formed in the surface can be used as said particle | grain. Such particles may, for example, have an average surface roughness Rz of 10 nm to 50 nm or 20 nm to 40 nm, and / or a maximum height of irregularities formed on the surface of about 100 nm to 500 nm or 200 nm to 400 nm, and the width of the unevenness may be 400 nm to 1,200 nm or 600 nm to 1,000 nm. Such particles are excellent in compatibility with the resin layer or dispersibility therein.

As the particles, various inorganic or organic particles can be exemplified. Examples of the inorganic particles include silica, amorphous titania, amorphous zirconia, indium oxide, alumina, amorphous zinc oxide, amorphous cerium oxide, barium oxide, calcium carbonate, amorphous barium titanate or barium sulfate, and the like. Examples of the organic particles may include particles including a crosslinked or non-crosslinked material of an organic material such as an acrylic resin, a styrene resin, a urethane resin, a melamine resin, a benzoguanamine resin, an epoxy resin, or a silicone resin, but are not limited thereto. It is not.

The content of the uneven structure or the particles formed in the resin layer is not particularly limited. The shape of the uneven structure or the content of the particles, for example, in the case of the AG layer, so that the haze (haze) of the resin layer is about 5% to 15%, 7% to 13% or about 10% In the case of the SG layer, the haze may be adjusted to be about 1% to 3%. The haze may be measured according to a manufacturer's manual using a hazemeter such as Sepung's HR-100 or HM-150.

The low reflection layer, such as an anti reflection (AR) layer or a low reflection (LR) layer, may be formed by coating a low refractive material. There are a variety of low refractive materials that can form a low reflection layer, all of which may be appropriately selected and used in the optical element. The low reflection layer may be formed such that the reflectance is about 1% or less through the coating of the low refractive material.

In the formation of the surface treatment layer, Korean Unexamined Patent Publication Nos. 2007-0101001, 2011-0095464, 2011-0095004, 2011-0095820, 2000-0019116, 2000-0009647, 2000-0018983, 2003-0068335, 2002-0066505, 2002-0008267, 2001-0111362, 2004-0083916, 2004-0085484, 2008-0005722, 2008- Materials known from 0063107, 2008-0101801, 2009-0049557 and the like can also be used.

The surface treatment layer may be formed alone or in combination of two or more thereof. As an example of the combination, the case where a high hardness layer is formed first on the surface of a base material layer and a low reflection layer is formed again on the surface can be illustrated.

The optical element may further include a protective layer disposed under the polarizer. FIG. 7 is a diagram exemplarily showing the optical element 7 further including a protective layer 71 attached to the lower part of the polarizer 13. The protective layer may include, for example, a cellulose resin film such as a triacetyl cellulose (TAC) film; Polyester films such as PET (poly (ethylene terephthalate)) film and the like; Polycarbonate film; Polyethersulfone films; It may be an acrylic film or a polyolefin-based film such as polyethylene, polypropylene, or a cyclic olefin resin film, or the like, or a resin layer that is hardened to form a hard layer, but is not limited thereto.

The optical device may further include a phase delay layer disposed under the polarizer. The phase delay layer may be a quarter wave phase delay layer or a half wave phase delay layer. As used herein, the term 1/2 wavelength or 1/4 wavelength phase retardation layer may refer to a phase retardation element capable of retarding incident light by 1/2 or 1/4 wavelength of the wavelength. For example, the optical device having such a structure may be applied to an OLED (Organic Light Emitting Diode) to be useful as a device for implementing a light splitting function and an anti-reflection function. As the quarter-wave phase retardation layer, for example, a liquid crystal layer formed by polymerizing a polymer film or a polymerizable liquid crystal compound imparting birefringence by a stretching step or the like can be used.

The optical element may further include a pressure-sensitive adhesive layer formed on one surface of the polarizer. The pressure-sensitive adhesive layer may be, for example, a pressure-sensitive adhesive layer for attaching the optical element to an optical device, for example, a liquid crystal panel of a liquid crystal display device or a video display element of a stereoscopic image display device. FIG. 8 is a diagram illustrating an optical element 8 in which an adhesive layer 81 is formed below the polarizer 13.

The pressure-sensitive adhesive layer may have a storage modulus of at least 0.02 MPa, at least 0.03 MPa, at least 0.04 MPa, at least 0.05 MPa, at least 0.06 MPa, at least 0.07 MPa, at least 0.08 MPa, at least 0.08 MPa, or at least 0.09 MPa at 25 ° C. The upper limit of the storage elastic modulus of the pressure-sensitive adhesive is not particularly limited. For example, the storage modulus may be 0.25 MPa or less, 0.2 MPa or less, 0.16 MPa or less, 0.1 MPa or less, or 0.08 MPa or less.

When the pressure-sensitive adhesive layer exhibits the storage elastic modulus, the optical element exhibits excellent durability, and thus, for example, the phase retardation characteristic of the phase retardation layer can be stably maintained for a long time and under severe conditions, thereby exhibiting stable light splitting characteristics. In addition, side effects such as light leakage may be prevented in the optical device to which the optical element is applied. In addition, the hardness characteristics of the optical element are improved, and excellent resistance to external pressure, scratches, and the like can be exhibited, and reworkability can be appropriately maintained.

The pressure-sensitive adhesive layer may have a thickness of 25 μm or less, 20 μm or less, or 18 μm or less. When the pressure-sensitive adhesive layer has the thickness, the durability, hardness characteristics and reworkability may be further improved. The smaller the thickness of the pressure-sensitive adhesive layer is, the more excellent the physical properties are, and the lower limit of the thickness is not particularly limited, but may be adjusted in the range of about 1 μm or more or about 5 μm or more, in consideration of processability and the like.

The pressure-sensitive adhesive layer may include an acrylic pressure sensitive adhesive, a silicone pressure sensitive adhesive, an epoxy pressure sensitive adhesive or a rubber pressure sensitive adhesive.

When an adhesive layer contains an acrylic adhesive, the said adhesive can be formed by hardening | curing the adhesive composition containing a thermosetting component, an active energy ray curable component, or a thermosetting component and an active energy ray curable component, for example.

The term "curing" in the above, may mean a change in the chemical or physical state of the pressure-sensitive adhesive composition to enable the adhesive properties to be expressed. In addition, the thermosetting component and the active energy ray curable component may refer to components in which such curing is induced by application of appropriate heat or irradiation of active energy rays, respectively.

The pressure-sensitive adhesive layer formed of the pressure-sensitive adhesive composition containing a thermosetting component may include an acrylic polymer crosslinked by a multifunctional crosslinking agent.

As the acrylic polymer crosslinked by the polyfunctional crosslinking agent, for example, an acrylic polymer having a weight average molecular weight of 500,000 or more can be used. In the present specification, the weight average molecular weight is a conversion value with respect to standard polystyrene measured by Gel Permeation Chromatograph (GPC). In addition, in this specification, unless otherwise specified, the term "molecular weight" means a "weight average molecular weight." The molecular weight of a polymer is made into 500,000 or more, and the adhesive layer which has the outstanding durability under severe conditions can be formed. The upper limit of the molecular weight is not particularly limited, and for example, in consideration of durability and coating property of the composition, it can be adjusted in the range of 2.5 million or less.

In one example, the acrylic polymer may be a polymer including a (meth) acrylic acid ester monomer and a crosslinkable monomer as a polymer unit.

As the (meth) acrylic acid ester monomer, for example, alkyl (meth) acrylate can be used, and alkyl (meth) having an alkyl group having 1 to 20 carbon atoms in consideration of the cohesion force, glass transition temperature, or tackiness of the pressure-sensitive adhesive. Acrylate can be used. Such monomers include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, t-butyl (meth) Acrylate, sec-butyl (meth) acrylate, pentyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 2-ethylbutyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (Meth) acrylate, isononyl (meth) acrylate, lauryl (meth) acrylate, tetradecyl (meth) acrylate, and the like can be exemplified, and one or more of the above can be used.

The polymer may also further comprise crosslinkable monomers as polymerized units. The polymer may include, for example, 80 parts by weight to 99.9 parts by weight of the (meth) acrylic acid ester monomer and 0.1 parts by weight to 20 parts by weight of the crosslinkable monomer as a polymerized unit. As used herein, "crosslinkable monomer" means a monomer that can be copolymerized with other monomers forming an acrylic polymer and can provide a crosslinkable functional group to the polymer after copolymerization. The said crosslinkable functional group can react with the polyfunctional crosslinking agent mentioned later, and can form a crosslinked structure.

As a crosslinkable functional group, nitrogen containing functional groups, such as a hydroxyl group, a carboxyl group, an epoxy group, an isocyanate group, or an amino group, etc. can be illustrated, for example. The copolymerizable monomer which can provide such a crosslinkable functional group at the time of manufacture of an adhesive resin is known variously. As a crosslinkable monomer, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth Hydroxy group-containing monomers such as) acrylate, 8-hydroxyoctyl (meth) acrylate, 2-hydroxyethylene glycol (meth) acrylate or 2-hydroxypropylene glycol (meth) acrylate; (Meth) acrylic acid, 2- (meth) acryloyloxy acetic acid, 3- (meth) acryloyloxy propyl acid, 4- (meth) acryloyloxy butyl acid, acrylic acid duplex, itaconic acid, maleic acid and Carboxyl group-containing monomers such as maleic anhydride or nitrogen-containing monomers such as (meth) acrylamide, N-vinyl pyrrolidone or N-vinyl caprolactam, and the like can be exemplified, and one or more of the above can be used. However, it is not limited thereto.

In the acrylic polymer, other various monomers may be included as polymerized units as necessary. As another monomer, For example, Nitrogen containing monomers, such as (meth) acrylonitrile, (meth) acrylamide, N-methyl (meth) acrylamide, or N-butoxy methyl (meth) acrylamide; Styrene-based monomers such as styrene or methyl styrene; Glycidyl (meth) acrylate; Or carboxylic acid vinyl esters such as vinyl acetate, and the like. Such additional monomers may be adjusted in the range of 20 parts by weight or less relative to the other monomers in total weight ratio.

Acrylic polymers are prepared by applying a mixture of monomers selected and blended as necessary to each component described above in a polymerization mode such as solution polymerization, photopolymerization, bulk polymerization, suspension polymerization or emulsion polymerization. can do.

As a multifunctional crosslinking agent which crosslinks such an acrylic polymer in an adhesive layer, general thermosetting crosslinking agents, such as an isocyanate crosslinking agent, an epoxy crosslinking agent, an aziridine crosslinking agent, and a metal chelate crosslinking agent, can be illustrated. In the above isocyanate crosslinking agent, polyfunctional isocyanate compounds such as tolylene diisocyanate, xylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, isoborone diisocyanate, tetramethylxylene diisocyanate or naphthalene diisocyanate, or the The compound etc. which reacted the polyfunctional isocyanate compound with the polyol compound, such as a trimethylol propane, etc. can be illustrated. Epoxy crosslinkers include ethylene glycol diglycidyl ether, triglycidyl ether, trimethylolpropane triglycidyl ether, N, N, N ', N'-tetraglycidyl ethylenediamine and glycerin diglycidyl ether One or more selected from the group can be exemplified, and as the aziridine crosslinking agent, N, N'-toluene-2,4-bis (1-aziridinecarboxamide), N, N'-diphenylmethane-4,4 At least one selected from the group consisting of '-bis (1-aziridinecarboxamide), triethylene melamine, bisisoprotaloyl-1- (2-methylaziridine) and tri-1-aziridinylphosphineoxide Examples of the metal chelate crosslinking agent include compounds in which a polyvalent metal such as aluminum, iron, zinc, tin, titanium, antimony, magnesium or vanadium coordinates with acetyl acetone or ethyl acetoacetate, and the like. It is not limited to this .

The multifunctional crosslinking agent is included in the pressure-sensitive adhesive composition including the thermosetting component or the pressure-sensitive adhesive layer formed of the composition, for example, in an amount of 0.01 to 10 parts by weight or 0.01 to 5 parts by weight based on 100 parts by weight of the acrylic polymer. There may be. By adjusting the ratio of the crosslinking agent to 0.01 parts by weight or more, effectively maintaining the cohesive force of the pressure-sensitive adhesive, and when adjusted to 10 parts by weight or less, it is possible to prevent the occurrence of delamination or lifting phenomenon at the adhesive interface and to maintain excellent durability. Can be. However, the ratio may be changed depending on the physical properties such as the desired elastic modulus, the inclusion of other crosslinked structures in the pressure-sensitive adhesive layer, and the like.

The pressure-sensitive adhesive layer formed of the pressure-sensitive adhesive composition containing the active energy ray curable component may include a crosslinked structure of the polymerized active energy ray polymerizable compound. The pressure-sensitive adhesive layer may be, for example, a functional group capable of participating in a polymerization reaction by irradiation of an active energy ray, for example, an alkenyl group, acryloyl group, methacryloyl group, acryloyloxy group, methacryloyloxy group, or the like. After preparing a pressure-sensitive adhesive composition by blending a compound containing at least one, it can be formed by irradiating active energy rays to the composition to crosslink and polymerize the above components. Examples of the compound having a functional group capable of participating in the polymerization reaction by irradiation of the active energy ray, a functional group such as acryloyl group, methacryloyl group, acryloyloxy group or methacryloyloxy group in the side chain of the acrylic polymer A polymer introduced with; Compounds known in the art as so-called active energy ray-curable oligomers such as urethane acrylates, epoxy acrylates, polyester acrylates or polyether acrylates, or polyfunctional acrylates described below can be exemplified.

The pressure-sensitive adhesive layer formed of the pressure-sensitive adhesive composition comprising a thermosetting component and an active energy ray curable component may simultaneously include a crosslinked structure comprising an acrylic polymer crosslinked with the multifunctional crosslinking agent and a crosslinked structure of the polymerized active energy ray polymerizable compound. Can be.

Such an adhesive layer is an adhesive containing what is called an interpenetrating polymer network (hereinafter, "IPN"). The term "IPN" may refer to a state in which at least two crosslinked structures are present in the pressure-sensitive adhesive layer, and in one example, the crosslinked structures may be entangled with each other, or linked or penetrating. May be present. When the pressure-sensitive adhesive layer contains an IPN, an optical element having excellent durability under severe conditions and excellent in workability or suppression of light leakage or crosstalk can be realized.

In the pressure-sensitive adhesive layer containing IPN, as the multifunctional crosslinking agent and the acrylic polymer of the crosslinked structure embodied by the acrylic polymer crosslinked by the multifunctional crosslinking agent, for example, the above-described thermosetting component may be described in the section of the pressure-sensitive adhesive composition comprising the thermosetting component. Ingredients can be used.

Further, as the active energy ray-polymerizable compound of the crosslinked structure of the polymerized active energy ray-polymerizable compound, the above-described compounds may also be used.

In one example, the active energy ray polymerizable compound may be a multifunctional acrylate. As the polyfunctional acrylate, any compound having two or more (meth) acryloyl groups can be used without limitation. For example, 1, 4- butanediol di (meth) acrylate, 1, 6- hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, polyethyleneglycol di (meth) acrylate, neopentyl Neopentylglycol adipate di (meth) acrylate, hydroxyl puivalic acid neopentylglycol di (meth) acrylate, dicyclopentanyl di (meth) acrylate, caprolactone modified dish Clopentenyl di (meth) acrylate, ethylene oxide modified di (meth) acrylate, di (meth) acryloxy ethyl isocyanurate, allylated cyclohexyl di (meth) acrylate, tricyclodecane Dimethanol (meth) acrylate, dimethylol dicyclopentane di (meth) acrylate, ethylene oxide modified hexahydrophthalic acid di (meth) acrylate, tricyclodecane dimethanol (meth) acrylate Neopentyl glycol modified trimethylpropane di (meth) acrylate, adamantane di (meth) acrylate or 9,9-bis [4- (2-acryloyloxyethoxy) phenyl] fluorene difunctional acrylates such as (fluorine) and the like; Trimethylolpropane tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, propionic acid modified dipentaerythritol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, propylene oxide Trifunctional acrylates such as modified trimethylolpropane tri (meth) acrylate, trifunctional urethane (meth) acrylate or tris (meth) acryloxyethyl isocyanurate; Tetrafunctional acrylates such as diglycerin tetra (meth) acrylate or pentaerythritol tetra (meth) acrylate; 5-functional acrylates, such as propionic acid modified dipentaerythritol penta (meth) acrylate; And dipentaerythritol hexa (meth) acrylate, caprolactone modified dipentaerythritol hexa (meth) acrylate or urethane (meth) acrylate (ex. Isocyanate monomers and trimethylolpropane tri (meth) acrylate Hexafunctional acrylates such as reactants and the like can be used.

As a polyfunctional acrylate, the thing containing a ring structure in a molecule | numerator can be used. Ring structures included in the polyfunctional acrylate include carbocyclic structures or heterocyclic structures; Or any of a monocyclic or polycyclic structure. Examples of the polyfunctional acrylate including a ring structure include monomers having isocyanurate structures such as tris (meth) acryloxy ethyl isocyanurate and isocyanate-modified urethane (meth) acrylates (ex. Isocyanate monomers and trimethylol). Hexafunctional acrylates such as propane tri (meth) acrylate reactants) and the like can be exemplified, but is not limited thereto.

The active energy ray-polymerizable compound forming the crosslinked structure in the pressure-sensitive adhesive layer containing IPN may be included in an amount of 5 parts by weight to 40 parts by weight based on 100 parts by weight of the acrylic polymer, for example. Therefore, it can be changed.

The pressure-sensitive adhesive layer may include various additives known in the art, in addition to the aforementioned components.

For example, in the case of a composition containing an active energy ray curable component, a photoinitiator or the like for further promoting the polymerization reaction of the component may be further included. In addition, the pressure-sensitive adhesive layer further includes at least one additive selected from the group consisting of a silane coupling agent, a tackifying resin, an epoxy resin, a curing agent, an ultraviolet stabilizer, an antioxidant, a colorant, a reinforcing agent, a filler, an antifoaming agent, a surfactant, and a plasticizer. can do.

The pressure-sensitive adhesive layer may be, for example, a method of applying and curing the pressure-sensitive adhesive composition prepared by blending the above-described components by means such as a bar coater or a comma coater. In addition, the method of curing the pressure-sensitive adhesive composition is not particularly limited, for example, to maintain the composition at an appropriate temperature so that the crosslinking reaction of the acrylic polymer and the polyfunctional crosslinking agent and the polymerization of the active energy ray-curable compound is possible. It can harden | cure through the process of irradiating an active energy ray. If the maintenance at the appropriate temperature and the irradiation of the active energy ray is required at the same time, the process can be carried out sequentially or simultaneously. The irradiation of the active energy ray may be performed using, for example, a high-pressure mercury lamp, an electrodeless lamp, a xenon lamp, or the like, and the conditions such as the wavelength and the amount of light of the active energy ray to be irradiated may be the active energy. The polymerization of the precurable compound may be selected in a range within which it can be appropriately performed.

In one example, the pressure-sensitive adhesive layer has a storage modulus at 25 ° C. of 0.02 MPa or more, 0.05 MPa or more, or more than 0.08 MPa, or more than 0.08 MPa, 0.25 MPa or less, 0.09 MPa to 0.2 MPa or 0.09 MPa to It may be a pressure-sensitive adhesive layer of 0.16 MPa. Such an adhesive layer may be, for example, an adhesive layer including the IPN.

In another example, the pressure-sensitive adhesive layer may be a pressure-sensitive adhesive layer having a storage modulus at 25 ° C. of 0.02 MPa to 0.08 MPa or 0.04 MPa to 0.08 MPa. Such an adhesive may be an adhesive layer including a crosslinked structure of the thermosetting component.

The present invention also relates to a method for producing an optical element. An exemplary optical device manufacturing method may include forming a liquid crystal layer on an upper portion of a substrate layer and attaching a polarizer to a lower portion of the substrate layer.

In the above-mentioned liquid crystal layer, for example, an alignment film is formed on a base material layer, the coating layer of the liquid crystal composition containing the said polymeric liquid crystal compound is formed on the said alignment film, and it polymerizes in the state which orientated the said liquid crystal composition, and liquid-crystal It can be prepared by forming a layer.

For example, the alignment film may be formed by forming a polymer film such as polyimide on the substrate layer and rubbing the coating, coating a photo-alignment compound, and performing alignment treatment through irradiation of linearly polarized light. In this field, various methods of forming an alignment film are known in consideration of a desired alignment pattern, for example, the patterns of the first and second regions.

The coating layer of the liquid crystal composition can be formed by coating the composition on the alignment film of the base layer in a known manner. The liquid crystal layer may be formed by aligning the polymer according to the alignment pattern of the alignment film existing under the coating layer and then polymerizing the same.

The method of attaching the polarizer to the base material layer is also not particularly limited. For example, the aqueous adhesive composition is coated on one surface of the base layer or the polarizer, and the liquid crystal layer and the polarizer are laminated through the coating layer to cure the adhesive composition, or a dropping method using the aqueous adhesive composition. By laminating the surface and the polarizer in which the primer layer of the liquid crystal layer is present, and a method of curing the adhesive composition can be used.

The manufacturing method may further include forming a surface treatment layer on top of the liquid crystal layer. The method for forming the surface treatment layer in the above is not particularly limited.

For example, when forming the said resin layer with a surface treatment layer, the coating liquid containing the various resin composition mentioned above, for example, active energy ray hardening-type acrylic resin composition, etc. is coated on a liquid crystal layer, and the method of hardening The resin layer can be formed.

In the above, the coating liquid may be coated by, for example, a conventional coating method such as spin coating or bar coating, or a selective coating method using an ink jet method. The method of curing the coated coating liquid is not particularly limited, and a method of applying appropriate heat or moisture or irradiating active energy rays may be used depending on the form of the composition used.

In one example, as described above, the curing may be carried out in a state in which the coating liquid is brought into contact with an appropriate mold to provide the desired irregularities to the resin layer.

The manufacturing method may further include a step of forming an additional layer such as the quarter-wave retardation layer or the pressure-sensitive adhesive layer in addition to the above process, and the specific manner of performing the above process is not particularly limited.

The present invention also relates to a stereoscopic image display device. An exemplary stereoscopic image display device may include the optical element described above.

In one example, the apparatus further includes a display element capable of generating a left eye image signal (hereinafter referred to as an L signal) and a right eye image signal (hereinafter referred to as an R signal), wherein the optical element is provided in the liquid crystal layer. In one of the first and second regions, the L signal may be transmitted, and the other region may be disposed to allow the R signal to be transmitted. In the optical device, the R and L signals may be arranged to be emitted from the display device to transmit the polarizer of the optical device first, and then to be incident on the respective areas of the liquid crystal layer.

As long as the stereoscopic image display device includes the optical element as a light splitting element, various methods known in the art may be applied and manufactured.

9 illustrates, as one exemplary apparatus, an apparatus by which an observer may wear a polarized glasses and observe a stereoscopic image.

As shown in FIG. 9, the apparatus 9 may include, for example, a light source 91, a polarizing plate 92, the display element 93, and the optical element 94 sequentially.

In the above, the light source 91 may be, for example, a direct type or edge type backlight generally used in an LCD (Liquid Crystal Display) or the like.

In one example, the display element 93 may be a transmissive liquid crystal display panel including a plurality of unit pixels arranged in a row and / or column direction. One or more pixels may be combined to form a right eye image signal generation region (hereinafter referred to as RG region) for generating an R signal and a left eye image signal generation region (hereinafter referred to as LG region) for generating an L signal. .

The RG and LG regions may be alternately disposed adjacent to each other while having a stripe shape extending in a common direction as shown in FIG. 10, or alternately disposed adjacent to each other while forming a lattice pattern as illustrated in FIG. 11. In the liquid crystal layer 942 of the optical device 94, the first and second regions are LC or RC regions, respectively, and the R signal transmitted from the RG region is considered to be a polarizer 941 in consideration of the arrangement of the RG and LG regions. The L signal may be disposed to be incident to the RC region through the polarizer, and the L signal may be incident to the LC region through the polarizer 941.

The display element 93 may be, for example, a first transparent substrate, a pixel electrode, a first alignment film, a liquid crystal layer, a second alignment film, a common electrode, a color filter, a second transparent substrate, and the like arranged sequentially from the light source 91 side. It may be a liquid crystal panel comprising a. The polarizing plate 92 may be attached to the light incident side of the panel, that is, the light source 91 side, and the optical element 94 may be attached to the opposite side of the panel. The polarizer included in the polarizing plate 92 and the polarizer 941 included in the optical element 94 may be disposed such that, for example, both absorption axes form a predetermined angle, for example, 90 degrees. As a result, the light emitted from the light source 91 can be transmitted or blocked through the display element 93.

In the driving state, unpolarized light from the light source 91 of the display device 9 may be emitted to the polarizing plate 92 side. Among the light incident on the polarizer 92, light having a polarization axis in a direction parallel to the light transmission axis of the polarizer of the polarizer 92 may pass through the polarizer 92 and be incident to the display element 93. Light incident on the display element 93 and transmitted through the RG region becomes an R signal, and light passing through the LG region becomes an L signal and is incident on the polarizer 941 of the optical element 94.

Among the light incident to the liquid crystal layer 942 through the polarizer 941, the light transmitted through the LC region and the light transmitted through the RC region are respectively emitted in different polarization states. As described above, the R and L signals having different polarization states may be incident on the right and left eyes of the observer wearing polarized glasses, and thus the observer may observe a stereoscopic image.

An exemplary optical element of the present invention may be a light splitting element, for example, an element for dividing incident light into two or more types of light having different polarization states. The optical element may be used to implement, for example, a stereoscopic image.

1 is a schematic diagram illustrating an exemplary optical element.

2 and 3 are schematic diagrams showing an exemplary arrangement of the first and second regions of the liquid crystal layer.

4 is a schematic diagram showing an exemplary optical axis arrangement of the first and second regions of the liquid crystal layer.

5-8 is a schematic diagram which shows an exemplary optical element.

9 is a schematic diagram illustrating an exemplary stereoscopic image display device.

10 and 11 are schematic diagrams showing an exemplary arrangement of the RG and LG regions.

Hereinafter, the optical device will be described in more detail with reference to Examples and Comparative Examples, but the scope of the optical device is not limited to the following examples.

In the Examples and Comparative Examples, the physical properties were evaluated as follows.

1. Evaluation of Adhesion

The optical polarizer was manufactured in Examples 1 and 2 and Comparative Examples 2 to 4, and the polarizer had a peel angle of 90 degrees and 300 m / for an optical element in which a surface treatment layer, a liquid crystal layer, an alignment layer, a substrate layer, an adhesive layer, and a polarizer were sequentially formed. It peeled at the peeling speed of min, evaluated the peeling force of the said polarizer with respect to the said base material layer, and evaluated the adhesive force (in the comparative example 1, the peeling force of the polarizer with respect to the liquid crystal layer was evaluated.). The peeling experiment was performed by cutting the manufactured optical element to have a width of 20 mm and a length of 100 mm.

2. Evaluation of Durability of Liquid Crystal Layer

The durability of the liquid crystal layer was evaluated by measuring the rate of change of the retardation value generated after the endurance test for the archeological elements manufactured in Examples and Comparative Examples. Specifically, the optical element is cut to have a length of 10 cm in length and width, and then attached to the glass substrate through an adhesive layer, and left at 100 ° C. for 100 hours or 250 hours at 80 ° C. The amount of reduction of the phase difference value after standing in comparison with the phase difference value of the liquid crystal layer before being left is shown in Table 2 below. In the above, the retardation value was measured at a wavelength of 550 nm according to the manufacturer's manual using Axomatrix Axoscan.

The criteria at the time of durability evaluation are as follows.

<Evaluation Criteria>

O: When the amount of change in the phase difference value after 100 hours and 250 hours of standing under heat-resistant conditions is less than 8%

X: When the amount of change in the phase difference value after 100 hours and 250 hours of standing under heat-resistant conditions is 8% or more in either case

3. Crosstalk Evaluation

The crosstalk rate at the time of observing the stereoscopic image may be defined as a ratio of luminance in a dark state and a bright stat. In Examples and Comparative Examples, assuming that the optical element is applied to a three-dimensional image display device of the polarizing glasses method, the crosstalk rate is measured in the following manner. An optical element is used to construct a stereoscopic image display device as shown in FIG. Thereafter, the polarizing glasses for stereoscopic image observation are placed at the normal observation point of the stereoscopic image display apparatus. In the above-described general observation point, when the observer observes a stereoscopic image, the observation point is a distance that is 3/2 times the length of the horizontal direction of the stereoscopic image display device from the center of the stereoscopic image display device. In the polarizing glasses are positioned, assuming that the observer observes the center of the display device. The horizontal length of the stereoscopic image display device may be a horizontal length based on the observer, for example, a horizontal length of the image display device when a viewer observes a stereoscopic image. . In the above arrangement, while the stereoscopic image display device outputs the L signal, a luminance meter (equipment name: SR-UL2 Spectrometer) is disposed on the back of the left and right eye lenses of the polarizing glasses, and the luminance in each case Measure The luminance measured at the back of the left eye lens is the brightness of the bright state, and the luminance measured at the back of the lens of the right eye is the brightness of the dark state. After measuring each luminance, the ratio of the luminance of the dark state to the luminance of the bright state ([luminance in the dark state] / [luminance in the bright state]) can be obtained as a percentage, and this can be defined as the crosstalk rate (Y). have. In addition, the crosstalk rate may also be measured in the same manner as described above, and may be measured by obtaining luminance in a light and dark state while the stereoscopic image display device is outputting an R signal. In this case, the brightness measured at the back of the left eye lens is the brightness of the dark state, and the brightness measured at the back of the right eye lens is the brightness of the bright state. have.

4. Evaluation of phase difference and refractive index

Evaluation of the phase difference and the refractive index of the optical element or the liquid crystal layer was measured according to the manufacturer's manual using Axoscan, Axomatrix.

5. Evaluation of Thickness and Width or Length of Optical Elements

The measurement of the horizontal or vertical length of the optical device was performed using the premium 600C and IView Pro programs of Intec IMS Inc., which are three-dimensional measuring instruments. In addition, the thickness measurement was measured by using a spectral reflectometer, which is a device that can evaluate the characteristics of the thin film using the interference phenomenon or the phase difference of the light between the reflected light on the surface of the thin film and the light reflected at the lower interface.

Preparation Example 1. Preparation of Liquid Crystal Layer (A)

On one surface of the TAC substrate (refractive index: 1.49, thickness: 80,000 nm), the composition for forming a photo-alignment film was coated so that the thickness after drying was about 1,000 mm 3, and dried in an oven at 80 ° C. for 2 minutes. As the composition for forming the photo-alignment layer, a mixture of polynorbornene (molecular weight (M _w ) = 150,000) and an acrylic monomer having a cinnamate group represented by Formula 14 is mixed with a photoinitiator (Igacure 907), and the mixture is further added to toluene The composition prepared by dissolving so that the solid content concentration of polynorbornene was 2 wt% in a solvent was used (polynorbornene: acrylic monomer: photoinitiator = 2: 1: 0.25 (weight ratio)).

[Formula 14]

Subsequently, the dried photo-alignment film-forming composition was subjected to alignment treatment according to the method disclosed in Korean Patent Application No. 2010-0009723 to form a photo-alignment film including first and second alignment regions oriented in different directions. Specifically, a pattern mask having a light transmitting portion and a light blocking portion having a width of about 450 μm and a light blocking portion alternately formed up and down and left and right are positioned on the dried composition, and different from each other on the pattern mask. The polarizing plate in which two regions which transmit polarization were formed was located. Thereafter, while moving the TAC base material 30 on which the optical alignment layer is formed at a speed of about 3 m / min, ultraviolet rays (300 mW / cm ² ) are applied to the composition for forming the optical alignment layer through the polarizing plate and the pattern mask. The alignment treatment was performed by irradiation for about 30 seconds. Subsequently, a liquid crystal layer was formed on the alignment layer subjected to the alignment treatment. Specifically, the liquid crystal composition comprising 70 parts by weight of the polyfunctional polymerizable liquid crystal compound represented by the following general formula (A) and 30 parts by weight of the monofunctional polymerizable liquid crystal compound represented by the following general formula (B), comprising an appropriate amount of photoinitiator: After coating to have a dry thickness of about 1 μm, the lower alignment layer is aligned in accordance with the alignment, and then irradiated with ultraviolet (300 mW / cm ² ) for about 10 seconds to cross-link and polymerize the liquid crystal, so that the alignment of the lower photo alignment layer Therefore, the liquid crystal layer in which the 1st and 2nd area | regions which have the optical axis orthogonal to each other is formed is formed. In the liquid crystal layer, the difference between the refractive index in the slow axis direction and the refractive index in the fast axis direction was about 0.125.

[Formula A]

[Formula B]

Preparation Examples 2 to 5. Preparation of liquid crystal layer (B) to liquid crystal layer (E)

A liquid crystal layer was manufactured in the same manner as in Production Example 2, except that the weight ratios of the polyfunctional polymerizable liquid crystal compound and the monofunctional polymerizable liquid crystal compound contained in the liquid crystal composition were adjusted as in Table 1 below.

Table 1

	Liquid crystal layer (B)	Liquid crystal layer (C)	Liquid crystal layer (D)	Liquid crystal layer (E)
Polyfunctional polymerizable liquid crystal compound (A) content	55	45	40	10
Monofunctional Polymeric Liquid Crystal Compound (B) Content	45	55	60	90
Refractive index difference	0.125	0.125	0.125	0.125
Thickness (㎛)	One	One	One	One
Content Unit: Weight Partial Refractive Index Difference: Difference between the refractive index in the in-plane slow axis direction of the liquid crystal layer and the refractive index in the fast axis direction

Example 1.

An optical device was manufactured in the following manner. First, the polarizer and the water system of the polarizing plate including a polyvinyl alcohol-based polarizer having a TAC protective film formed on one surface of the TAC substrate in a structure prepared in Preparation Example 2, that is, a TAC substrate, an alignment layer and a liquid crystal layer in sequence. It adhered using the polyvinyl alcohol-type adhesive composition. As an adhesive composition, the adhesive composition normally used for attachment of a PVA polarizer and a TAC protective film was used. The surface of the TAC substrate and the polarizer were laminated in a droplet manner, but the adhesive composition had a thickness of 1 μm after curing, and maintained at an appropriate temperature to form an adhesive layer to attach the surface of the TAC substrate and the polarizer. Then, the conventional acrylic adhesive layer was formed on one surface of the TAC protective film which is the protective film of the said polarizer, and the optical element was manufactured.

Example 2.

An optical device was manufactured in the same manner as in Example 1, except that a structure prepared in Preparation Example 3, that is, a structure in which a TAC substrate, an alignment layer, and a liquid crystal layer (B) were formed sequentially were used.

Comparative Example 1.

Except for attaching the liquid crystal layer to the polarizer of the polyvinyl alcohol polarizer in which the TAC protective film is formed on one surface in the structure prepared in Preparation Example 2, that is, the structure in which the TAC base material, the alignment layer, and the liquid crystal layer are sequentially formed. Manufactured an optical device in the same manner as in Example 1.

Comparative Example 2.

An optical device was manufactured in the same manner as in Example 1, except that a structure prepared in Preparation Example 4, that is, a structure in which the TAC substrate, the alignment layer, and the liquid crystal layer (C) were formed in this order was used.

Comparative Example 3.

An optical device was manufactured in the same manner as in Example 1, except that a structure prepared in Preparation Example 5, that is, a structure in which the TAC base material, the alignment layer, and the liquid crystal layer (D) were formed in this order was used.

Comparative Example 4.

An optical device was manufactured in the same manner as in Example 1, except that a structure prepared in Preparation Example 6, that is, a structure in which a TAC substrate, an alignment layer, and a liquid crystal layer (E) were formed in this order was used.

Table 2 shows the results of evaluation of physical properties measured for the optical devices of the Examples and Comparative Examples.

TABLE 2

	Adhesive force (N / cm)	Liquid Crystal Layer Durability	Phase difference change rate (after leaving for 100 hours)
			Initial phase difference (nm)	Phase difference after heat resistant condition (nm)	% Change
Example 1	3.5 or more	○	125.4	119.7	4.5
Example 2	3.5 or more	○	120.7	114.1	5.5
Comparative Example 1	0.3	○	125.4	119.7	4.5
Comparative Example 2	3.5 or more	×	94.1	85.5	9.1
Comparative Example 3	3.5 or more	×	77.2	69.4	10.1
Comparative Example 4	3.5 or more	-	-	-	-

Test Example 1. Evaluation of light splitting characteristics according to refractive index relation and thickness of liquid crystal layer

In order to evaluate the light splitting characteristics according to the refractive index relation and the thickness of the liquid crystal layer, the following samples were prepared, respectively. Specifically, the phase retardation layer is formed in the same manner as in Preparation Example 1, but after the liquid crystal layer is formed, the thickness of the liquid crystal mixture is adjusted by adjusting the composition of the liquid crystal mixture so that the difference in refractive index is 0.03 in the slow axis direction and the fast axis direction. A liquid crystal layer having 0.3 μm, 1 μm and 2.5 μm was formed, respectively, to prepare a phase delay layer. In addition, a phase retardation layer was manufactured in the same manner using the same liquid crystal compound as Preparation Example 1, but a phase retardation layer was formed by forming a liquid crystal layer having a thickness of about 0.3 μm and 2.5 μm, respectively. In addition, a phase retardation layer was formed in the same manner as in Preparation Example 1, but after the liquid crystal layer was formed, the composition of the liquid crystal mixture was adjusted so that the difference in refractive index was 0.22 in the slow axis direction and the fast axis direction, so that the thickness was about 0.3 μm, 1 A phase retardation layer was prepared by forming liquid crystal layers having a thickness of 2.5 μm and 2.5 μm, respectively. Thereafter, an optical device was fabricated in the same manner as in Example 1 using the prepared phase retardation layer, and the crosstalk rate when the stereoscopic image was observed using the optical device and the optical device of Example 1 was evaluated. It is shown in Table 3 below.

TABLE 3

Liquid crystal layer of phase delay layer		Cross talk rate (%)
Refractive index difference	Thickness (㎛)
0.03	0.3	79.5
0.03	One	45.3
0.03	2.5	10.3
0.125	0.3	36
0.125	One	0.5
0.125	2.5	177.4
0.22	0.3	14.6
0.22	One	30.7
0.22	2.5	121.6
Refractive index difference: The difference between the refractive index of the liquid crystal layer in the in-plane slow axis direction and that of the fast axis direction

       (Explanation of the sign)

1, 5, 6, 7, 84: optical element

11, 942: liquid crystal layer

12: base material layer

13, 941: polarizer

51: adhesive layer

61: surface treatment layer

71: protective layer

81: pressure-sensitive adhesive layer

A: 1st area | region of a liquid crystal layer

B: second region of the liquid crystal layer

L: boundary line between the first and second regions of the liquid crystal layer

T1, T2: angle of optical axis

9: stereoscopic video display

91: light source

Claims (17)

1. Base layer; It is formed on top of the base layer, the difference between the refractive index in the in-plane slow axis direction and the refractive index in the fast axis direction is 0.05 to 0.2, the thickness is 0.5 ㎛ to 2.0 ㎛, the polyfunctional polymerizable liquid crystal compound and monofunctional polymerization A monofunctional polymerizable liquid crystal compound, wherein the monofunctional polymerizable liquid crystal compound is contained in an amount of more than 0 parts by weight and 100 parts by weight or less with respect to 100 parts by weight of the multifunctional polymerizable liquid crystal compound, and is different from each other in phase retardation characteristics. A liquid crystal layer comprising first and second regions; And a polarizer attached to a lower portion of the base layer.
2. The optical device of claim 1, wherein the optical device satisfies the following general formula (1):

   [Formula 1]

   X <8%

   In Formula 1, X is a percentage of the change amount of the phase difference value of the liquid crystal layer after leaving the optical element at 80 ° C. for 100 hours compared to the initial phase difference value of the liquid crystal layer of the optical element.
3. The optical device of claim 1, wherein the liquid crystal compound is represented by Formula 1 below:

   [Formula 1]

   

   In Formula 1, A is a single bond, -COO- or -OCO-, and R ₁ to R ₁₀ are each independently hydrogen, halogen, alkyl group, alkoxy group, alkoxycarbonyl group, cyano group, nitro group, -OQP or Substituent of Formula 2, wherein at least one of R ₁ to R ₁₀ is -OQP or a substituent of Formula 2, two adjacent substituents of R ₁ to R ₅ or two adjacent substituents of R ₆ to R ₁₀ Connected to each other to form a benzene substituted with -OQP, wherein Q is an alkylene group or an alkylidene group, and P is an alkenyl group, epoxy group, cyano group, carboxyl group, acryloyl group, methacryloyl group, acrylo Monooxy or methacryloyloxy groups:

   [Formula 2]

   

   In Formula 2, B is a single bond, -COO- or -OCO-, and R ₁₁ to R ₁₅ are each independently hydrogen, halogen, alkyl group, alkoxy group, alkoxycarbonyl group, cyano group, nitro group or -OQP. , At least one of R ₁₁ to R ₁₅ is -OQP, or two adjacent substituents of R ₁₁ to R ₁₅ are connected to each other to form a benzene substituted with -OQP, wherein Q is an alkylene group or an alkylidene group , P is an alkenyl group, epoxy group, cyano group, carboxyl group, acryloyl group, methacryloyl group, acryloyloxy group or methacryloyloxy group.
4. The optical device according to claim 1, wherein the polymerizable liquid crystal compound is polymerized in a horizontally oriented state to be included in the liquid crystal layer.
5. The optical element of claim 1, wherein the first region and the second region have optical axes formed in different directions from each other.
6. 6. The optical element of claim 5, wherein a line bisecting the angle formed by the optical axis of the first region and the optical axis of the second region is perpendicular or horizontal to the absorption axis of the polarizer.
7. The optical element according to claim 1, wherein the polarizer is attached to the base layer by an aqueous adhesive.
8. The optical device according to claim 1, further comprising a surface treatment layer formed on the liquid crystal layer.
9. The optical element according to claim 8, wherein the surface treatment layer is a high hardness layer, an antiglare layer or a low reflection layer.
10. The optical element according to claim 9, wherein the high hardness layer is a resin layer having a pencil hardness of 1H or more under a load of 500 g.
11. The optical element according to claim 10, wherein the resin layer further comprises particles having a refractive index different from that of the resin layer.
12. The optical element according to claim 11, wherein the particles have a difference in refractive index from the resin layer of 0.03 or less.
13. The optical device according to claim 1, further comprising a phase retardation layer disposed under the polarizer.
14. The optical element according to claim 1, further comprising a pressure-sensitive adhesive layer formed on one surface of the polarizer and having a storage modulus at 25 ° C of 0.02 MPa to 0.08 MPa and comprising a crosslinked structure of an acrylic polymer crosslinked with a polyfunctional crosslinking agent. .
15. The crosslinked structure and polymerized active energy ray-polymerizable compound according to claim 1, comprising an acrylic polymer formed on one surface of the polarizer and having a storage modulus at 25 ° C. exceeding 0.08 MPa and crosslinked with a multifunctional crosslinking agent. The optical element which further contains the adhesive layer which has a crosslinked structure containing.
16. A stereoscopic image display device comprising the optical element of claim 1.
17. 17. The display device of claim 16, further comprising a display element capable of generating a left eye image signal and a right eye image signal, wherein an optical element includes at least one of the first and second regions of the liquid crystal layer. And the other area is arranged to allow the right eye image to pass therethrough.

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