Optical laminate, smart window including the same, and automobile or fixture for building applied with the same

Abstract

To provide a transmittance-variable optical laminate, a smart window including the same, and an automobile or a fixture for a building applied with the same.SOLUTION: The present invention relates to: a transmittance-variable optical laminate comprising: a first polarization plate; a surface processing layer formed on one surface of the first polarization plate; a first transparent conductive layer formed on the other surface of the first polarization plate; a second polarization plate facing the first polarization plate; a second transparent conductive layer formed on one surface of the second polarization plate and facing the first transparent conductive layer; a liquid crystal layer provided between the first transparent conductive layer and the second transparent conductive layer; and an adhesive layer provided on a surface of the second polarization plate on which the second transparent conductive layer is not formed, wherein the thickness of the first polarization plate is equal to or more than the thickness of the second polarization plate, and a surface hardness being H or more can prevent scratches on the surface and prevent damage; a smart window including the same; and an automobile or a fixture for a building applied with the same.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a variable transmittance optical laminate, a smart window including the same, and a vehicle or building fixture to which the same is applied.

Background Art

[0002] Generally, an external light-blocking coating is often applied to the glass window of a moving means such as a vehicle. However, the glass window of a conventional moving means has a fixed transmittance, and the external light-blocking coating also has a fixed transmittance. Therefore, the overall transmittance of such a conventional moving means window is fixed, which may induce an accident. For example, when the overall transmittance is set low, there is no problem during the daytime when the amount of light in the surroundings is sufficient. However, at night when the amount of light in the surroundings is not sufficient, there is a problem that it is only difficult for a driver or the like to properly check the surroundings of the moving means. Or when the overall transmittance is set high, there is a problem that it may cause glare to a driver or the like during the daytime when the amount of light in the surroundings is sufficient. Accordingly, a variable transmittance optical laminate capable of changing the light transmittance when a voltage is applied has been developed.

[0003] The variable transmittance optical laminate is driven by driving liquid crystal by applying a voltage to vary the transmittance. However, the variable transmittance optical laminates developed to date are manufactured by forming a conductive layer for liquid crystal driving on a separate base material and then combining this with other elements such as a polarizing plate.

[0004] However, when a separate base material is included to form the conductive layer in this way, the manufacturing process becomes complicated, resulting in an increase in manufacturing cost, the thickness of the laminate increases, and a phase difference occurs, resulting in a problem that the transmittance changes.

[0005] In addition, by providing such a thinner optical laminate, there is a problem that the optical laminate is damaged or scratches are generated on the surface when applied to a vehicle or a building fixture.

[0006] On one hand, it is manufactured with spacers provided in the liquid crystal layer to maintain the cell gap of the liquid crystal layer containing the liquid crystal.

[0007] For example, Japanese Patent Application Laid-Open No. 2018-010035 also discloses a transmissivity variable optical laminate in which a liquid crystal layer containing column spacers or ball spacers is applied to maintain a predetermined cell gap.

[0008] However, when column spacers are included in the liquid crystal layer in this way, the manufacturing process becomes complicated, resulting in an increase in manufacturing costs, and there is a problem that the transmissivity changes due to damage to the alignment film during the process of irradiating ultraviolet rays on the photoresist to form the spacers. Also, when ball spacers are used to maintain the cell gap of the liquid crystal layer, it is impossible to maintain a firm cell gap, difficult to maintain a constant optical hue in the plane, and there are problems such as inducing a current short circuit in the optical laminate.

[0009] Therefore, there is a need to develop a transmissivity variable optical laminate that can maintain a firm cell gap without using spacers in the liquid crystal layer, can prevent damage or scratches while reducing the thickness of the optical laminate.

Prior Art Documents

Patent Documents

[0010]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0011] An object of the present invention is to provide a transmissivity variable optical laminate that prevents scratches on the surface, is excellent in surface hardness and antifouling properties, can be utilized in a form in which one-side polarizing plate is exposed to the outside, and thereby enables thinning.

[0012] Another object of the present invention is to provide a variable transmittance optical laminate that includes an adhesive layer having excellent elastic modulus, is excellent in flex resistance and prevents breakage, and is detachable from an adherend.

[0013] Another object of the present invention is to provide a variable transmittance optical laminate that simplifies the manufacturing process and significantly reduces the thickness by not including a separate substrate for forming a conductive layer.

[0014] Another object of the present invention is to provide a variable transmittance optical laminate that can prevent problems such as damage to an alignment film caused by using a spacer and difficulty in maintaining a constant optical hue in the plane by including a liquid crystal layer containing a polymer network.

[0015] Another object of the present invention is to provide a variable transmittance optical laminate that can adjust the transmittance of incident light by including a liquid crystal layer containing a polymer network and a liquid crystal compound arranged with a uniform initial alignment.

[0016] Another object of the present invention is to provide a smart window including the variable transmittance optical laminate and a fitting for an automobile or a building to which the same is applied.

[0017] However, the problems to be solved by the present invention are not limited to the problems mentioned above, and other problems not mentioned should be clearly understood by those skilled in the art from the following description.

Means for Solving the Problems

[0018] The present invention relates to a variable transmittance optical laminate including a first polarizing plate; a surface treatment layer formed on one surface of the first polarizing plate; a first transparent conductive layer formed on the other surface of the first polarizing plate; a second polarizing plate facing the first polarizing plate; a second transparent conductive layer formed on one surface of the second polarizing plate and facing the first transparent conductive layer; a liquid crystal layer provided between the first transparent conductive layer and the second transparent conductive layer; and an adhesive layer provided on the surface of the second polarizing plate where the second transparent conductive layer is not formed, wherein the thickness of the first polarizing plate is equal to or greater than the thickness of the second polarizing plate, and the variable transmittance optical laminate has a surface hardness of H or higher.

[0019] In a first aspect of the present invention, the surface treatment layer may have a thickness of 5 to 30 μm.

[0020] In a second aspect of the present invention, the first polarizing plate and the second polarizing plate may each have a thickness of 30 to 200 μm.

[0021] In a third aspect of the present invention, the adhesive layer may have a storage elastic modulus of 10 MPa or more at 25°C.

[0022] In a fourth aspect of the present invention, the surface treatment layer may have a water contact angle of 100° or more.

[0023] In a fifth aspect of the present invention, the liquid crystal behavior mode of the liquid crystal layer may be any one selected from the group consisting of TN (Twisted nematic) mode, STN (Super twisted nematic) mode, IPS (In-plane switching) mode, FFS (Fringe-field switching) mode, ECB (Electrically Controlled Birefringence) mode, and VA (Vertical alignment) mode.

[0024] In its sixth aspect, the liquid crystal behavior mode of the liquid crystal layer may be of the TN (Twisted nematic) mode.

[0025] In its seventh aspect, the liquid crystal layer may include a polymer network and a liquid crystal compound, and the liquid crystal compound may be arranged with a uniform initial alignment.

[0026] In its eighth aspect, the liquid crystal layer may include a cured product of a composition for forming a liquid crystal layer containing a polymerizable monomer and a liquid crystal compound.

[0027] In its ninth aspect, the composition for forming a liquid crystal layer may contain 10 to 30% by weight of a polymerizable monomer based on the total weight of the composition.

[0028] In its tenth aspect, at least one of the first transparent conductive layer and the second transparent conductive layer may be formed by directly contacting without including a separate base material between the first polarizing plate or the second polarizing plate.

[0029] In its eleventh aspect, at least one of the first transparent conductive layer and the second transparent conductive layer may include an easy adhesion layer between the first polarizing plate or the second polarizing plate and be formed by direct contact.

[0030] In its twelfth aspect, at least one of the first polarizing plate and the second polarizing plate may include one or more functional layers selected from the group consisting of a protective layer, an adhesion-imparting layer, a retardation adjusting layer, and a refractive index adjusting layer.

[0031] In its thirteenth aspect, at least one of the first transparent conductive layer and the second transparent conductive layer may include one or more selected from the group consisting of a transparent conductive oxide, a metal, a carbon-based material, a conductive polymer, a conductive ink, and a nanowire.

[0032] In a fourteenth aspect of the present invention, the variable transmittance optical laminate may further include at least one selected from the group consisting of an ultraviolet absorption layer and a hard coating layer.

[0033] The present invention also relates to a smart window including the variable transmittance optical laminate.

[0034] The present invention also relates to an automobile in which the smart window is applied to at least one of a front window, a rear window, a side window, a sunroof window, and an interior partition.

[0035] The present invention also relates to a building fixture including the smart window.

Advantages of the Invention

[0036] According to the variable transmittance optical laminate of the present invention, scratches on the surface can be prevented, and it is excellent in antifouling property, surface hardness, and flex resistance, and can prevent damage.

[0037] Also, according to the variable transmittance optical laminate of the present invention, a conductive layer is formed directly on one surface of the polarizing plate, and not only does it not include a separate base material for forming the conductive layer, but also one-sided polarizing plate can be utilized in a form where it is exposed to the outside, and no additional base material is required in the outermost part, and the thickness relative to the conventional optical laminate can be significantly reduced.

[0038] Also, according to the variable transmittance optical laminate of the present invention, a conductive layer is formed directly on one surface of the polarizing plate, and by not including a separate base material for forming the conductive layer, the transmittance in the light transmission mode relative to the conventional optical laminate can be improved.

[0039] According to the variable transmittance optical laminate of the present invention, by including a liquid crystal layer containing a polymer network, problems such as damage to the alignment film caused by using a conventional spacer and difficulty in maintaining a certain optical hue in the plane can be prevented, and the driving safety relative to the conventional optical laminate can be improved.

[0040] Also, according to the variable transmittance optical laminate of the present invention, even though a polymer network is formed in the liquid crystal layer, the liquid crystal compound can be arranged while maintaining a uniform initial alignment, and it can be made possible to adjust the transmittance of light incident on the optical laminate.

[0041] The present invention provides a variable transmittance optical laminate that includes an adhesive layer having excellent elastic modulus, is excellent in bending resistance and prevents breakage, and can be detached from an adherend.

Brief Description of the Drawings

[0042]

Figure 1

Figure 2a

Figure 2b

Figure 2c

Figure 2d

Figure 2e

Figure 2f

Modes for Carrying Out the Invention

[0043] The present invention relates to a variable transmittance optical laminate that can prevent scratches on the surface by including a surface treatment layer on one surface of a polarizing plate, and can prevent breakage by including an adhesive layer having excellent elastic modulus.

[0044] More specifically, a variable transmittance optical laminate including: a first polarizing plate; a surface treatment layer formed on one surface of the first polarizing plate; a first transparent conductive layer formed on the other surface of the first polarizing plate; a second polarizing plate facing the first polarizing plate; a second transparent conductive layer formed on one surface of the second polarizing plate and facing the first transparent conductive layer; a liquid crystal layer provided between the first transparent conductive layer and the second transparent conductive layer; and an adhesive layer provided on a surface of the second polarizing plate where the second transparent conductive layer is not formed, wherein the thickness of the first polarizing plate is equal to or greater than the thickness of the second polarizing plate, and the variable transmittance optical laminate has a surface hardness of H or higher. The present invention relates to a variable transmittance optical laminate, a smart window including the same, and a vehicle or building fixture to which the same is applied.

[0045] By including a surface treatment layer on one surface of the first polarizing plate, the variable transmittance optical laminate of the present invention prevents scratches on the surface and is excellent in surface hardness and antifouling properties, and can be utilized in a form in which one side polarizing plate is exposed to the outside, thereby enabling thinning. Further, by including an adhesive layer on one surface of the second polarizing plate, the variable transmittance optical laminate of the present invention is excellent in bending resistance, prevents breakage, and has the advantage of being easily detachable from an adherend.

[0046] A smart window means an optical structure that controls the amount of light or heat transmitted by changing the light transmittance by applying an electric signal. That is, a smart window is provided so that it can be changed to a transparent, opaque, or translucent state by voltage, and is also called variable transmittance glass, dimming glass, or smart glass.

[0047] A smart window can be used for partitioning the interior spaces of vehicles and buildings or as a privacy-protecting partition, or it can be used as a daylighting window arranged at the openings of buildings. It can also be used for highway signs, bulletin boards, scoreboards, clocks, or advertising screens, and can replace the glass of means of transportation such as the windows or sunroofs of automobiles, buses, airplanes, ships, or trains.

[0048] The variable transmittance optical laminate of the present invention can also be used for smart windows in the various technical fields described above. However, since the conductive layer is directly formed on the polarizing plate, it does not include a separate substrate for forming the conductive layer, so it has a thin thickness and is advantageous in bending characteristics, and can be particularly preferably used for smart windows for vehicles or buildings. In one or more embodiments, the smart window to which the variable transmittance optical laminate of the present invention is applied can be used for the front window, rear window, side window, and sunroof window of an automobile, or for building fittings for buildings, etc. In addition to the use of blocking external light, it can also be used for partitioning the interior space of an automobile or a building or for protecting privacy, such as for internal partitions.

[0049] Hereinafter, embodiments of the present invention will be described more specifically with reference to the drawings. However, the following drawings attached to this specification illustrate preferred embodiments of the present invention and serve to better understand the technical idea of the present invention together with the content of the above-described invention. Therefore, the present invention should not be construed as being limited only to the matters described in these drawings.

[0050] The terms used in this specification are for the purpose of describing embodiments and are not intended to limit the present invention. In this specification, the singular form also includes the plural form unless specifically stated otherwise in the text. For example, the "polarizing plate" used in this specification may mean at least one of the first polarizing plate and the second polarizing plate, and the "transparent conductive layer" may mean at least one of the first transparent conductive layer and the second transparent conductive layer.

[0051] As used in this specification, "comprises" and / or "comprising" are used in a sense that does not exclude the presence or addition of one or more other components, steps, operations, and / or elements other than the recited components, steps, operations, and / or elements. The same reference numerals throughout the specification refer to the same components.

[0052] Spatially relative terms such as "under", "bottom surface", "lower part", "above", "upper surface", "upper part", etc. can be used to easily describe the correlation between one element or component and another element or component as shown in the drawings. Spatially relative terms should be understood as terms that include different directions of elements relative to each other during use or operation in addition to the directions shown in the drawings. For example, when covering an element shown in the drawing, an element described as "under" or "lower part" of another element may be placed "above" the other element. Therefore, the exemplary term "under" can include both the downward and upward directions. The element can also be oriented in other directions, and thus the spatially relative terms can be interpreted according to the orientation.

[0053] As used in this specification, the "plane direction" can be interpreted as the direction perpendicular to the polarizing plate and / or the transparent conductive layer, that is, the direction seen from the user's viewing side.

[0054] <Variable transmittance optical laminate> FIG. 1 is a diagram showing the laminated structure of a variable transmittance optical laminate according to an embodiment of the present invention, and FIG. 2 is a diagram showing the laminated structure of a polarizing plate according to one or more embodiments of the present invention.

[0055] Referring to FIG. 1, the variable transmittance optical laminate according to an embodiment of the present invention may include a first polarizing plate 100-1, a second polarizing plate 100-2, a first transparent conductive layer 200-1, a second transparent conductive layer 200-2, a liquid crystal layer 300, an adhesive layer 400, and a surface treatment layer 500.

[0056] In the variable transmittance optical laminate of the present invention, a surface treatment layer 500 may be formed on one surface of the first polarizing plate 100-1, and a first transparent conductive layer 200-1 may be formed on the other surface where the surface treatment layer 500 is not formed. The second polarizing plate 100-2 may have a second transparent conductive layer 200-2 formed on one surface, and an adhesive layer 400 may be provided on the other surface where the second transparent conductive layer 200-2 is not formed.

[0057] The surface treatment layer 500 can be made excellent in antifouling property and abrasion resistance by being formed from a surface treatment layer composition containing a hydroxy group-containing light-transmitting resin, a fluorine-based UV-curable functional group-containing compound, a photoinitiator, and a solvent. Specifically, the hydroxy group of the hydroxy group-containing light-transmitting resin repels the fluorine atom of the fluorine-based UV-curable functional group-containing compound so that the fluorine atom can be oriented on the surface of the surface treatment layer. In particular, the hydroxy group-containing light-transmitting resin can form a matrix of the surface treatment layer by photocuring to improve the abrasion resistance of the surface treatment layer.

[0058] In one embodiment of the present invention, the hydroxy group-containing light-transmitting resin is a photocurable resin, and the photocurable resin may include a hydroxy group-containing (meth)acrylate compound.

[0059] Examples of the hydroxy group-containing (meth)acrylate compound include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 2-hydroxy-3-phenyloxypropyl (meth)acrylate, 1,4-butanediol mono(meth)acrylate, 2-hydroxyalkyl (meth)acryloyl phosphate (wherein the alkyl is, for example, methyl, ethyl or propyl), 4-hydroxycyclohexyl (meth)acrylate, 1,6-hexanediol mono(meth)acrylate, neopentyl glycol mono(meth)acrylate, trimethylolpropane di(meth)acrylate, trimethylolethane di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, etc. These may be used alone or in combination of two or more thereof.

[0060] In one embodiment of the present invention, the hydroxy group-containing light-transmissive resin may be contained in an amount of 1 to 50% by weight, preferably 5 to 50% by weight, based on 100% by weight of the whole composition for the surface treatment layer. If the content of the hydroxy group-containing light-transmissive resin is less than 1% by weight, the abrasion resistance may decrease, and it may be difficult to improve the hardness sufficiently. If it exceeds 50% by weight, there is a problem that curling becomes severe.

[0061] In one embodiment of the present invention, the fluorine-based UV-curable functional group-containing compound is a component that imparts antifouling property, abrasion resistance and chemical resistance. The fluorine-based UV-curable functional group-containing compound contains fluorine and has a UV-curable functional group together therewith, and is not particularly limited as long as it can chemically bond to the hydroxy group-containing light-transmissive resin forming the matrix of the surface treatment layer.

[0062] The fluorine-based UV-curable functional group-containing compound may be one or more selected from the group consisting of (meth)acrylate containing a perfluoroalkyl group, (meth)acrylate containing a perfluoropolyether group, (meth)acrylate containing a perfluorocyclic aliphatic group, and (meth)acrylate containing a perfluoroaromatic group. In this case, it exhibits excellent antifouling performance and at the same time forms a chemical bond with the surface treatment layer, having the advantage of excellent durability in maintaining the antifouling performance for a long time even after repeated use, which is preferable.

[0063] The fluorine-based UV-curable functional group-containing compound preferably has 1 to 6 UV-curable functional groups.

[0064] The fluorine-based UV-curable functional group-containing compound may be contained in an amount of 1 to 40% by weight, preferably 2 to 40% by weight, based on 100% by weight of the entire surface treatment layer composition. When the fluorine-based UV-curable functional group-containing compound is contained within the above range, it is preferable because it can impart excellent abrasion resistance and antifouling effect.

[0065] When the content of the UV-curable functional group-containing compound is less than the above range, it may be difficult to sufficiently achieve abrasion resistance or antifouling property. When it exceeds the above range, the hardness and / or scratch resistance may decrease.

[0066] In one embodiment of the present invention, the photoinitiator is included for inducing photocuring of the surface treatment layer composition, and for example, may include a photo radical initiator capable of forming radicals by light irradiation.

[0067] Examples of the photoinitiator include Type 1 initiators that generate radicals by decomposition of molecules due to differences in chemical structure or molecular bond energy, and Type 2 initiators that induce hydrogen abstraction in coexistence with a tertiary amine. For example, the Type 1 initiator includes acetophenones such as 4-phenoxydichloroacetophenone, 4-t-butyldichloroacetophenone, 4-t-butyltrichloroacetophenone, diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one, 1-(4-dodecylphenyl)-2-hydroxy-2-methylpropan-1-one, 4-(2-hydroxyethoxy)-phenyl(2-hydroxy-2-propyl)ketone, 1-hydroxycyclohexylphenylketone; benzoins such as benzoyl, benzoin methyl ether, benzoin ethyl ether, benzyldimethyl ketal; phosphine oxides; titanocene compounds, etc.

[0068] For example, the Type 2 initiator includes benzophenones such as benzophenone, benzoylbenzoic acid, benzoylbenzoic acid methyl ether, 4-phenylbenzophenone, hydroxybenzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, 3,3'-methyl-4-methoxybenzophenone; thioxanthones such as thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, etc.

[0069] The above-mentioned photoinitiators may be used alone or in combination of two or more. Also, the Type 1 and Type 2 initiators may be used alone or in combination.

[0070] The photoinitiator may be contained in an amount of about 0.1 to 10% by weight, preferably about 0.1 to 5% by weight, based on 100% by weight of the entire composition for the surface treatment layer. When the content of the photoinitiator is less than 0.1% by weight, sufficient curing may not proceed, and the mechanical properties and adhesion of the surface treatment layer may not be ensured. When the content of the photoinitiator exceeds 10% by weight, it may cause adhesion failure, cracking, and curling due to curing shrinkage.

[0071] In one embodiment of the present invention, the solvent can be used without limitation as long as it is known in the art and can dissolve or disperse the mentioned composition. Further, the solvent simultaneously serves to provide a time for the fluorine-based UV curable functional group-containing compound to float on the outermost surface of the coating layer due to the difference in surface tension during the process of applying and drying the composition for the surface treatment layer on the substrate.

[0072] Solvents that can be used include alcohol-based (such as methanol, ethyl alcohol, isopropyl alcohol, butanol, methyl cellosolve, ethyl cellosolve, etc.), ketone-based (such as methyl ethyl ketone, methyl butyl ketone, methyl isobutyl ketone, diethyl ketone, dipropyl ketone, cyclohexanone, etc.), acetate-based (such as ethyl acetate, propyl acetate, n-butyl acetate, t-butyl acetate, methyl cellosolve acetate, ethyl cellosolve acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, methoxybutyl acetate, methoxypentyl acetate, etc.), hexane-based (such as hexane, heptane, octane, etc.), benzene-based (such as benzene, toluene, xylene, etc.), ether-based (such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, diethylene glycol dibutyl ether, propylene glycol monomethyl ether, etc.), etc., and may preferably be used. The exemplified solvents may be used alone or in combination of two or more thereof.

[0073] The solvent may be contained in an amount of 10 to 50% by weight, preferably 20 to 50% by weight, based on 100% by weight of the entire composition for the surface treatment layer. If the content of the solvent is less than the above content, not only the viscosity becomes high and the workability deteriorates, but also the swelling of the substrate cannot proceed sufficiently. Conversely, if it exceeds the above range, there is a problem that it takes a lot of time in the drying process and the economy deteriorates. Therefore, it is appropriately used within the above range.

[0074] In one embodiment of the present invention, the composition for the surface treatment layer may further contain another light-transmissive resin in addition to the hydroxy group-containing light-transmissive resin.

[0075] The other light-transmissive resin may include a photocurable (meth)acrylate oligomer and / or monomer.

[0076] As the photocurable (meth)acrylate oligomer, epoxy (meth)acrylate, urethane (meth)acrylate, etc. can usually be used, and urethane (meth)acrylate is preferred. Urethane (meth)acrylate can be produced by reacting a (meth)acrylate having a hydroxy group in the molecule with a compound having an isocyanate group in the presence of a catalyst. Specific examples of the (meth)acrylate having a hydroxy group in the molecule include 2-hydroxyethyl (meth)acrylate, 2-hydroxyisopropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, caprolactone ring-opening hydroxyacrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, etc. Specific examples of the compound having an isocyanate group include 1,4-diisocyanatobutane, 1,6-diisocyanatohexane, 1,8-diisocyanatooctane, 1,12-diisocyanatododecane, 1,5-diisocyanato-2-methylpentane, trimethyl-1,6-diisocyanatohexane, 1,3-bis(isocyanatomethyl)cyclohexane, trans-1,4-cyclohexene diisocyanate, 4,4'-methylenebis(cyclohexyl isocyanate), isophorone diisocyanate, toluene-2,4-diisocyanate, toluene-2,6-diisocyanate, xylene-1,4-diisocyanate, tetramethylxylene-1,3-diisocyanate, 1-chloromethyl-2,4-diisocyanate, 4,4'-methylenebis(2,6-dimethylphenyl isocyanate), 4,4'-oxybis(phenyl isocyanate), trifunctional isocyanate derived from hexamethylene diisocyanate, trimethylolpropane adduct toluene diisocyanate, etc.

[0077] The monomers can be used without limitation as those commonly used. As the photocurable functional groups, monomers having unsaturated groups such as (meth)acryloyl group, vinyl group, styryl group, and allyl group in the molecule are preferable, and among them, monomers having a (meth)acryloyl group are particularly preferable.

[0078] Specific examples of the monomer having a (meth)acryloyl group include neopentyl glycol acrylate, 1,6 - hexanediol di(meth)acrylate, propylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, 1,2,4 - cyclohexanetetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, isooctyl (meth)acrylate, isodecyl (meth)acrylate, stearyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, phenoxyethyl (meth)acrylate, and isobornyl (meth)acrylate, and one or more selected from the group consisting of them may be used.

[0079] The photocurable (meth)acrylate oligomers and monomers, which are the other light - transmissive resins exemplified above, may be used alone or in combination of two or more.

[0080] The other light - transmissive resins are not particularly limited, but may be contained in an amount of 1 to 50% by weight based on 100% by weight of the whole composition for the surface treatment layer.

[0081] In addition to the components described above, the composition for the surface treatment layer may further contain components generally used in the art, such as leveling agents, ultraviolet stabilizers, heat stabilizers, antioxidants, surfactants, lubricants, and antifouling agents.

[0082] The surface treatment layer can be formed by applying the composition for the surface treatment layer to one or both sides of the substrate, drying it, and then subjecting it to UV curing.

[0083] The composition for the surface treatment layer can be applied (Coating Process) to the substrate by appropriately using known methods such as a die coater, an air knife, a reverse roll, spraying, a blade, casting, gravure, microgravure, spin coating, etc.

[0084] After applying the composition for the surface treatment layer to the substrate, the volatile matter is evaporated and dried at a temperature of 30 to 150°C for 10 seconds to 1 hour, more specifically 30 seconds to 30 minutes, and then cured by irradiating with UV light. The irradiation amount of the UV light may specifically be about 0.01 to 10 J / cm 2 and more specifically may be 0.1 to 2 J / cm 2 as well.

[0085] At this time, the thickness of the formed surface treatment layer may specifically be 5 to 30 μm, more specifically 5 to 20 μm. When the thickness of the surface treatment layer is within the above range, excellent hardness and flexural resistance can be obtained.

[0086] By being provided on one side of the second polarizing plate, the adhesive layer 400 enables the variable transmittance optical laminate of the present application to be easily detached from the substrate (adherend, automotive glass, etc.) to which the variable transmittance optical laminate is to be attached, and also plays a role in controlling the surface hardness of the variable transmittance optical laminate.

[0087] It is preferable that the surface hardness of the variable transmittance optical laminate of the present invention is H or more so as to prevent breakage during detachment from the target substrate and ensure flexural resistance.

[0088] For this reason, it is preferable that the adhesive layer has a storage elastic modulus at 25°C of 10 MPa or more, and more preferably, it may be 50 MPa or more. When the storage elastic modulus of the adhesive layer at 25°C is less than 10 MPa, the surface hardness of the optical laminate of the present invention becomes less than H, and since the bending resistance cannot be ensured, problems such as damage or lifting of the adhesive layer may occur.

[0089] The adhesive layer may be formed from an adhesive composition containing an acrylic random copolymer and a tackifier.

[0090] The acrylic random copolymer may be polymerized by containing 5 to 30% by weight of a first monomer having a glass transition temperature of the homopolymer of -40°C or less, 60 to 90% by weight of a second monomer having a glass transition temperature of the homopolymer of 80°C or more, and 3 to 20% by weight of a third monomer having at least one of a hydroxyl group and a carboxylic acid group in the molecule.

[0091] The acrylic random copolymer preferably has a glass transition temperature of 0°C or more, and more preferably, it may be 0 to 25°C. In this case, there is an advantage that the elastic force of the adhesive layer formed from the adhesive composition is improved, and it is excellent in adhesiveness and coatability, and the effect of improving the elastic force and adhesiveness can be obtained.

[0092] On the other hand, the acrylic random copolymer may have an acid value of 0.1 or less. When the acid value of the acrylic random copolymer exceeds 0.1, rather than the tackifier described later improving the adhesiveness of the adhesive composition, it acts as a crosslinking agent for each monomer contained for the polymerization of the acrylic random copolymer and oligomers during the polymerization reaction, etc., to increase the crosslinking degree of the copolymer, which may cause a decrease in the adhesiveness of the adhesive layer.

[0093] The first monomer with a glass transition temperature of the homopolymer of -40°C or lower is not particularly limited, and examples thereof may include one or more selected from the group consisting of n-butyl acrylate, t-butyl acrylate, sec-butyl acrylate, pentyl acrylate, 2-ethylbutyl acrylate, 2-ethylhexyl acrylate, 2-ethylhexyl diglycol acrylate, n-octyl acrylate, isooctyl acrylate, isononyl acrylate, lauryl acrylate, and tetradecyl acrylate.

[0094] The first monomer may be contained in an amount of 5 to 30% by weight, preferably 10 to 30% by weight, more preferably 15 to 20% by weight, based on the total weight of the monomers used for the polymerization of the acrylic random copolymer. When the first monomer is contained in an amount of less than 5% by weight during the polymerization of the acrylic random copolymer, film formation progresses during the curing of the pressure-sensitive adhesive composition, and there is a problem that it is difficult to function as a pressure-sensitive adhesive layer. When the content exceeds 30% by weight, there is a problem that the glass transition temperature of the copolymer becomes excessively low and it is difficult to exhibit high elastic properties.

[0095] The second monomer with a glass transition temperature of the homopolymer of 80°C or higher is not particularly limited, and examples thereof may include one or more selected from the group consisting of (meth)acryloylmorpholine, N-vinylpyrrolidone, isobornyl (meth)acrylate, methacrylate, carbazole acrylate, dihydrodicyclopentadienyl acrylate, and potassium acrylate.

[0096] The second monomer may be contained in an amount of 65 to 90% by weight, more preferably 70 to 80% by weight, based on the total weight of the monomers used for the polymerization of the acrylic random copolymer. When the second monomer is contained in an amount of less than 65% by weight during the polymerization of the acrylic random copolymer, there is a problem that the glass transition temperature of the pressure-sensitive adhesive composition becomes excessively low and it is difficult to exhibit high elastic properties. When the content exceeds 90% by weight, film formation progresses during the curing of the pressure-sensitive adhesive composition, and there is a problem that it is difficult to function as a pressure-sensitive adhesive layer.

[0097] In addition, the third monomer having one or more of a hydroxyl group and a carboxylic acid group in the molecule may include one or more selected from the group consisting of (meth)acrylic monomers having a hydroxyl group in the molecule and (meth)acrylic monomers having a carboxylic acid group in the molecule.

[0098] The (meth)acrylic monomer having a hydroxyl group is not particularly limited, and examples thereof may include one or more selected from the group consisting of 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 2-hydroxyethylene glycol (meth)acrylate, and 2-hydroxypropylene glycol (meth)acrylate.

[0099] The (meth)acrylic monomer having a carboxylic acid group is not particularly limited, and examples thereof may include one or more selected from the group consisting of (meth)acrylic acid, 2-(meth)acryloyloxyacetic acid, 3-(meth)acryloyloxypropionic acid, 4-(meth)acryloyloxybutyric acid, acrylic acid dimer, itaconic acid, maleic acid, and maleic anhydride.

[0100] The third monomer may be contained in an amount of 3 to 15% by weight, preferably 5 to 10% by weight, based on the total weight of the monomers used for the polymerization of the acrylic random copolymer. When the third monomer is contained in an amount of less than 3% by weight during the polymerization of the acrylic random copolymer, there is a problem that the degree of crosslinking of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition is excessively low and the durability and adhesiveness are insufficient. When the content exceeds 15% by weight, there is a problem that the glass transition temperature of the copolymer becomes excessively low and it is difficult to exhibit high elastic properties.

[0101] The first monomer, the second monomer, and the third monomer are distinguishable from each other, and the first monomer and the second monomer may not have one or more of a hydroxyl group and a carboxylic acid group in the molecule.

[0102] In addition to the monomers, the acrylic random copolymer may further contain other monomers that are ordinarily used in the technical field to which the present invention pertains, as long as they do not reduce the elastic force and the adhesive force.

[0103] The acrylic random copolymer may have a weight average molecular weight (polystyrene conversion; Mw) measured by gel permeation chromatography (GPC) of from 300,000 to 2,000,000, and more preferably from 500,000 to 1,200,000. When the weight average molecular weight of the acrylic random copolymer is less than 300,000, after ultraviolet polymerization and curing, the chain structure in the structure of the pressure-sensitive adhesive sheet is simple and the length is short, which is disadvantageous from the viewpoint of reliability such as the generation of bubbles, and there may be a decrease in durability due to discoloration or the like. When it exceeds 2,000,000, the viscosity of the pressure-sensitive adhesive resin composition is excessively high during the production of the pressure-sensitive adhesive film, and a large amount of monomer dilution is required to adjust to an appropriate viscosity required for production. As a result, a monomer that requires high energy or does not react may remain during ultraviolet polymerization and curing.

[0104] The method for producing the acrylic random copolymer is not particularly limited. For example, methods such as bulk polymerization, solution polymerization, emulsion polymerization, suspension polymerization, and UV polymerization that are ordinarily used in the technical field to which the present invention pertains may be used, and preferably, solution polymerization or UV polymerization may be used.

[0105] The tackifier is contained together with the acrylic random copolymer and can play a role in improving the adhesiveness and tack of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition.

[0106] The tackifier may have a weight average molecular weight of 1,000 or less. When a tackifier having a weight average molecular weight of 1,000 or less is used, uniform wettability and adhesiveness can be ensured.

[0107] The tackifier is not particularly limited as long as it can improve the adhesiveness and / or tack of the adhesive layer formed from the adhesive composition. For example, it may contain one or more selected from the group consisting of isocyanate compounds, aziridine compounds, epoxy compounds, melamine compounds, peroxide compounds, metal chelate compounds, and oxazoline compounds.

[0108] The isocyanate compounds include diisocyanate compounds such as xylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and tetramethylxylene diisocyanate; addition polymers obtained by reacting 3 moles of a diisocyanate compound with 1 mole of a polyhydric alcohol compound such as trimethylolpropane; isocyanurate polymers obtained by self-condensing 3 moles of a diisocyanate compound; biuret bodies in which 1 mole of the remaining diisocyanate is condensed with the diisocyanate urea obtained from 2 moles out of 3 moles of the diisocyanate compound; and one or more selected from the group consisting of polyfunctional isocyanate compounds containing 3 functional groups such as triphenylmethane triisocyanate and methylene bis triisocyanate.

[0109] The aziridine compounds may include one or more selected from the group consisting of pentaerythritol-tris-(beta-(N-aziridinyl)propionate), trimethylolpropane-tris(beta-N-aziridinyl)propionate, trimethylolpropane tris(2-methyl-1-aziridinepropionate), N,N'-toluene-2,4-bis(1-aziridinecarboxamide), N,N'-diphenylmethane-4,4'-bis(1-aziridinecarboxamide), triethylenemelamine, bisisophthaloyl-1-(2-methylaziridine), and tri-1-aziridinylphosphine oxide.

[0110] The epoxy compound may contain one or more selected from the group consisting of ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl ether, 1,6 - hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, and pentaerythritol polyglycidyl ether.

[0111] The melamine compound may contain one or more selected from the group consisting of hexamethoxymethyl melamine, hexaethoxymethyl melamine, hexapropoxymethyl melamine, hexabutoxymethyl melamine, hexapentyloxymethyl melamine, and hexapentyloxymethyl melamine.

[0112] The peroxide compound may contain one or more selected from the group consisting of di(2 - ethylhexyl) peroxydicarbonate, di(4 - t - butylcyclohexyl) peroxydicarbonate, di - sec - butyl peroxydicarbonate, t - butyl peroxyneodecanoate, t - hexyl peroxypivalate, t - butyl peroxypivalate, dilauroyl peroxide, di - n - octanoyl peroxide, 1,1,3,3 - tetramethylbutyl peroxy - 2 - ethylhexanoate, di(4 - methylbenzoyl) peroxide, dibenzoyl peroxide, t - butyl peroxyisobutyrate, and 1,1 - di(t - hexylperoxy) cyclohexane.

[0113] Examples of the metal chelate compound include compounds in which at least one ligand of a compound in which a polyvalent metal is covalently or coordinately bonded to an organic compound is substituted with an alkoxy group. The polyvalent metal may be any one selected from the group consisting of titanium, zirconium, aluminum, zinc, iron, and tin, and is preferably any one selected from the group consisting of titanium, zirconium, and aluminum. Examples of the atoms in the organic compound that forms the covalent bond or coordination bond include oxygen atoms, and the organic compound may be any one selected from the group consisting of alkyl esters, alcohol compounds, carboxylic acid compounds, ether compounds, and ketone compounds.

[0114] The oxazoline compound may contain one or more selected from the group consisting of 2-isopropyl-2-oxazoline, 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline, 2-isopropenyl-4-methyl-2-oxazoline, and 2-isopropenyl-5-ethyl-2-oxazoline.

[0115] The tackifier may be contained in an amount of 2 parts by weight or more, preferably 2 to 20 parts by weight, based on 100 parts by weight of the acrylic random copolymer. When the tackifier satisfies the above content range, the adhesiveness and tack of the adhesive composition can be further improved.

[0116] When the tackifier is contained in an amount of less than 2 parts by weight based on 100 parts by weight of the acrylic random copolymer, the adhesion and adhesiveness to the substrate may decrease. When the content exceeds 20 parts by weight, the elastic force may decrease due to the remaining compound.

[0117] In addition to the foregoing components, the composition for the adhesive layer may further contain additives as necessary for an ordinary technician within a range not impairing the object of the present invention to enhance coating properties, adhesion, etc. For this purpose, components generally used in the art, such as surfactants, silane coupling agents, antioxidants, ultraviolet absorbers, and / or anti-aggregation agents, etc., may be further contained. These may be used alone or in combination of two or more in any combination and ratio.

[0118] The thickness of the adhesive layer 400 may be 5 to 80 μm. If the thickness of the adhesive layer is within the above range, it has excellent adhesive force and has advantages in terms of light transmittance, reliability, step absorption, etc.

[0119] Referring to FIG. 2, the polarizing plate 100 may include a polarizer 110, and may further include functional layers such as a protective layer 120, a retardation adjusting layer 130, a refractive index adjusting layer 140, an adhesion realization layer 150, etc. on one or both surfaces of the polarizer 110.

[0120] For example, the polarizing plate 100 may include a polarizer 110 and a protective layer 120 laminated on one or both surfaces of the polarizer 110 (see FIGS. 2a and 2b), a polarizer 110, a protective layer 120 laminated on one surface of the polarizer 110, and a retardation adjusting layer 130 laminated on the other surface facing the one surface of the polarizer 110 (see FIG. 2c), a polarizer 110, a protective layer 120 laminated on one surface of the polarizer, and a retardation adjusting layer 130 and a refractive index adjusting layer 140 sequentially laminated on the other surface facing the one surface of the polarizer 110 (see FIG. 2d), a polarizer 110, a protective layer 120 laminated on one surface of the polarizer, and a protective layer 120 and a retardation adjusting layer 130 sequentially laminated on the other surface facing the one surface of the polarizer 110 (see FIG. 2e), or a protective layer 120 laminated on one surface of the polarizer 110 and an adhesion realization layer 150 laminated on the other surface (see FIG. 2f).

[0121] The polarizer 110 can use a conventional or later-developed polarizer. For example, a stretched polarizer or a coating polarizer can be used.

[0122] In one embodiment, the stretched polarizer may include a stretched polyvinyl alcohol (PVA)-based resin. The polyvinyl alcohol (PVA)-based resin may be a polyvinyl alcohol-based resin obtained by saponifying a polyvinyl acetate-based resin. Examples of the polyvinyl acetate-based resin include polyvinyl acetate, which is a homopolymer of vinyl acetate, and copolymers of vinyl acetate and other monomers copolymerizable therewith. Examples of the other monomers may include unsaturated carboxylic acid-based, unsaturated sulfonic acid-based, olefin-based, vinyl ether-based, acrylamide-based monomers having an ammonium group, and the like. The polyvinyl alcohol (PVA)-based resin also includes modified ones, for example, polyvinyl formal or polyvinyl acetal modified with aldehydes.

[0123] In one embodiment, the coating polarizer may be formed of a liquid crystal coating composition. At this time, the liquid crystal coating composition may include a reactive liquid crystal compound, a dichroic dye, and the like.

[0124] The reactive liquid crystal compound can mean a compound containing, for example, a mesogen skeleton and further containing one or more polymerizable functional groups. Such reactive liquid crystal compounds are variously known under the name of so-called RM (Reactive Mesogen). The reactive liquid crystal compound can form a cured film in which a polymer network is formed while maintaining a liquid crystal alignment by being polymerized by light or heat.

[0125] The reactive liquid crystal compound may be a monofunctional or polyfunctional reactive liquid crystal compound. The monofunctional reactive liquid crystal compound is a compound having one polymerizable functional group, and the polyfunctional reactive liquid crystal compound can mean a compound containing two or more polymerizable functional groups.

[0126] The dichroic dye is a component contained in the composition for liquid crystal coating and imparts polarization characteristics, and has the property that the absorbance in the long axis direction of the molecule is different from the absorbance in the short axis direction. The dichroic dye may use a conventional or later-developed dichroic dye. For example, it may contain one or more selected from the group consisting of azo dyes, anthraquinone dyes, perylene dyes, merocyanine dyes, azomethine dyes, phthaloperylene dyes, indigo dyes, dioxazine dyes, polythiophene dyes, and phenoxazine dyes.

[0127] The composition for liquid crystal coating may further contain a solvent capable of dissolving the reactive liquid crystal compound and the dichroic dye. For example, propylene glycol monomethyl ether acetate (PGMEA), methyl ethyl ketone (MEK), xylene, chloroform, etc. may be used. Further, the composition for liquid crystal coating may further contain a leveling agent, a polymerization initiator, etc. within a range that does not impair the polarization characteristics of the coating film.

[0128] The protective layer 120 is for preserving the polarization characteristics of the polarizer 110 from subsequent processes and the external environment, and can be embodied in the form of a protective film or the like.

[0129] The protective layer 120 may be formed in direct contact with one or both surfaces of the polarizer 110 as shown in FIGS. 2A and 2B, but is not limited thereto. For example, the protective layer may be used as a multilayer structure in which one or more protective layers are continuously laminated, and may be formed in direct contact with other members such as a retardation adjustment layer.

[0130] In one or more embodiments, the protective layer 120 may include one or more selected from the group consisting of polyethylene terephthalate (PET), polyethylene isophthalate (PEI), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), diacetyl cellulose, triacetyl cellulose (TAC), polycarbonate (PC), polyethylene (PE), polypropylene (PP), polymethyl acrylate (PMA), polymethyl methacrylate (PMMA), polyethyl acrylate (PEA), polyethyl methacrylate (PEMA), and cyclic olefin polymer (COP).

[0131] The retardation adjustment layer 130 is for compensating for the optical characteristics of the optical laminate, and can be embodied in the form of a retardation film or the like, and a conventional or later-developed retardation film or the like can be used. For example, a quarter-wave plate (1 / 4 wave plate) or a half-wave plate (1 / 2 wave plate) for delaying the phase of light may be used, and these may be used alone or in combination.

[0132] The retardation adjustment layer 130 may be formed in direct contact with one surface of the polarizer 110 as shown in FIGS. 2c and 2d, but is not limited thereto. For example, as shown in FIG. 2e, the retardation adjustment layer 130 may be formed on one surface of the protective layer 120, and the polarizer 110, the protective layer 120, and the retardation adjustment layer 130 may be sequentially laminated.

[0133] As the retardation adjustment layer 130, a polymer stretched film or a liquid crystal polymer film obtained by stretching a polymer film capable of imparting optical anisotropy by stretching in an appropriate manner can be used.

[0134] In one embodiment, the polymer stretched film may be a polyolefin such as polyethylene (PE) or polypropylene (PP), a cyclic olefin polymer (COP) such as polynorbornene, polyvinyl chloride (PVC), polyacrylonitrile (PAN), polysulfone (PSU), an acrylic resin, a polyester such as polycarbonate (PC) or polyethylene terephthalate (PET), a polyacrylate, a cellulose ester polymer such as polyvinyl alcohol (PVA) or triacetyl cellulose (TAC), or a copolymer of two or more monomers in the monomers forming the polymer. A polymer layer including the like can be used.

[0135] The method for obtaining the polymer stretched film is not particularly limited. For example, it can be obtained by stretching the polymer material after forming it into a film shape. The method for forming it into a film shape is not particularly limited, and it can be formed into a film by known methods such as injection molding, sheet molding, blow molding, injection blow molding, inflation molding, extrusion molding, foam molding, and cast molding, and secondary processing molding methods such as pressure air molding and vacuum molding can be used. Among them, extrusion molding and cast molding are preferably used. At this time, for example, an unstretched film can be extrusion molded using an extruder equipped with a T-die, a circular die, etc. When obtaining a molded product by extrusion molding, a material obtained by previously melt-kneading various resin components, additives, etc. can be used, or it can also be molded through melt-kneading during extrusion molding. Further, after dissolving various resin components using a solvent common to various resin components, such as a solvent such as chloroform or methylene dichloride, an unstretched film may be cast-molded by cast drying and solidifying.

[0136] The polymer stretched film may be uniaxially stretched in the machine flow direction (MD; Mechanical Direction, longitudinal direction or length direction) of the formed film, uniaxially stretched in the direction transverse to the machine flow direction (TD; Transverse Direction, transverse direction or width direction), or a biaxially stretched film may be manufactured by stretching by a sequential biaxial stretching method of roll stretching and tenter stretching, a simultaneous biaxial stretching method by tenter stretching, a biaxial stretching method by tubular stretching, etc.

[0137] The liquid crystal polymer film can contain the reactive liquid crystal compound in a polymerized state. The content regarding the reactive liquid crystal compound of the coating type polarizer described above can be similarly applied to the reactive liquid crystal compound.

[0138] In one or more embodiments, the thickness of the retardation adjustment 130 layer may be 10 to 100 μm in the case of a polymer stretched film, and may be 0.1 to 5 μm in the case of a liquid crystal polymer film.

[0139] The refractive index adjustment layer 140 is provided to compensate for the refractive index difference of the optical laminate due to the transparent conductive layer 200, and may play a role in improving visual recognition characteristics, etc. by reducing the refractive index difference. Further, the refractive index adjustment layer 140 may be provided to correct the hue caused by the transparent conductive layer 200. On the other hand, when the transparent conductive layer has a pattern, the transmittance difference between the pattern region where the pattern is formed and the non-pattern region where the pattern is not formed can be compensated through the refractive index adjustment layer 140.

[0140] Specifically, the transparent conductive layer 200 is laminated adjacent to another member (for example, the polarizer 110, etc.) having a different refractive index from it, and a difference in light transmittance may be induced by the refractive index difference from the adjacent other layer. In particular, when a pattern is formed on the transparent conductive layer, a problem may occur in that it can be visually recognized so as to distinguish the pattern region and the non-pattern region. Therefore, by including the refractive index adjustment layer 140, the refractive index is compensated so that the difference in light transmittance of the optical laminate can be reduced. In particular, when a pattern is formed on the transparent conductive layer, the pattern region and the non-pattern region are not distinguished and not visually recognized.

[0141] In one embodiment, the refractive index of the refractive index adjustment layer 140 may be appropriately selected depending on the material of another adjacent member, but is preferably from 1.4 to 2.6, and more preferably may be from 1.4 to 2.4. In this case, light loss due to a sharp refractive index difference between the transparent conductive layer 200 and another member such as the polarizer 110 can be prevented.

[0142] The refractive index adjustment layer 140 is not particularly limited as long as it can prevent a sharp refractive index difference between the transparent conductive layer 200 and another member such as the polarizer 110, and a compound used for forming a conventional or later-developed refractive index adjustment layer may be used. For example, it may be formed from a refractive index adjustment layer forming composition containing a polymerizable isocyanurate compound.

[0143] The adhesion-imparting layer 150 is preferably formed on the liquid crystal layer 300 side of the polarizer 110, that is, on the inner side of the polarizer 110. For example, the adhesion-imparting layers may be provided on the inner sides of the first polarizer 110-1 and the second polarizer 110-2, respectively, and may be arranged to face each other.

[0144] In this case, the adhesion-imparting layer 150 may be formed in direct contact with the transparent conductive layer 200 and may serve as a primer so that the adhesion to the transparent conductive layer 200 described later does not decrease.

[0145] In addition, the adhesion-imparting layer 150 has an advantage that cracks or scratches generated in the manufacturing process of the optical laminate can be minimized by imparting a hardness level suitable for forming the transparent conductive layer 200 on the polarizing plate 100.

[0146] In one embodiment, the polarizing plate 100 may further include other functional layers for assisting or enhancing the characteristics of the polarizer in addition to the functional layers described above. For example, in order to further improve mechanical durability, it may further include an overcoat layer or the like.

[0147] The thicknesses of the functional layers other than the retardation layer 130 may each be 1 to 30 μm, and more preferably 2 to 20 μm. The thickness may mean the thickness after drying. When each thickness satisfies the above range, thinning is possible and the functions of each functional layer can be performed without problems.

[0148] In one or more embodiments, the polarizing plate 100 may have a thickness of 30 to 200 μm, preferably 30 to 170 μm, and more preferably 50 to 150 μm. In this case, the polarizing plate 100 can maintain optical characteristics and enable the production of an optical laminate with a thin thickness.

[0149] In particular, the polarizing plate 100 included in the optical laminate of the present invention is characterized in that within the above thickness range, the thickness of the first polarizing plate 100-1 is equal to or greater than the thickness of the second polarizing plate 100-2. That is, when the thickness of the first polarizing plate 100-1 corresponding to the outer portion of the optical laminate is the same as or thicker than the thickness of the second polarizing plate 100-2 corresponding to the inner portion of the optical laminate, there is an advantage that deformation due to changes in the external environment, that is, temperature and humidity, etc., can be suppressed. Thereby, the difference in shrinkage and expansion rates between the first polarizing plate and the second polarizing plate can be reduced, and problems such as driving failure and floating of the liquid crystal layer can be prevented.

[0150] The transparent conductive layer 200 is provided for driving the liquid crystal layer 300 and may be formed in direct contact with the polarizing plate 100.

[0151] For example, as shown in FIG. 1, the first transparent conductive layer 200-1 may be formed in direct contact with the first polarizing plate 100-1, and the second transparent conductive layer 200-2 may be formed in direct contact with the second polarizing plate 100-2.

[0152] An optical laminate used in the manufacture of a conventional smart window or the like is manufactured by forming a conductive layer for liquid crystal driving on one surface of a substrate and bonding the other surface of the substrate to a polarizing plate. However, the transmissivity variable optical laminate according to the present invention directly forms a conductive layer on one surface of a polarizing plate without including a separate substrate for forming the conductive layer, thereby reducing the thickness of the laminate and improving the transmissivity and bending characteristics in the light transmission mode.

[0153] In one embodiment, the first transparent conductive layer 200-1 and / or the second transparent conductive layer 200-2 formed in direct contact with at least one of the first polarizing plate 100-1 and the second polarizing plate 100-2 share a contact surface with the first polarizing plate 100-1 and / or the second polarizing plate 100-2, and are formed on the polarizing plate without including a separate substrate. For example, the first transparent conductive layer 200-1 and / or the second transparent conductive layer 200-2 may be formed by vapor deposition on the upper surface of a coating layer formed on the first polarizing plate 100-1 and / or the second polarizing plate 100-2. At this time, the first transparent conductive layer 200-1 and / or the second transparent conductive layer 200-2 may be formed in direct contact with the surface of the polarizing plate that has been pretreated, such as corona treatment or plasma treatment, on one surface of the polarizing plate in order to improve the adhesion to at least one of the first polarizing plate 100-1 and the second polarizing plate 100-2. The pretreatment is not limited to corona treatment or plasma treatment, and pretreatment steps that are conventional or developed in the future can be used as long as the object of the present invention is not impaired.

[0154] In another embodiment of the present invention, the first transparent conductive layer 200-1 and / or the second transparent conductive layer 200-2 formed in direct contact with at least one of the first polarizing plate 100-1 and the second polarizing plate 100-2 may be formed in direct contact with the polarizing plate with an easy adhesion layer (not shown) provided on one surface of the polarizing plate interposed therebetween in order to improve the adhesion to the polarizing plate. The easy adhesion layer may use a conventional or future-developed adhesive, and in one or more embodiments, an acrylic adhesive, a rubber adhesive, a silicone adhesive, a urethane adhesive, a polyvinyl alcohol adhesive, a polyvinyl pyrrolidone adhesive, a polyacrylamide adhesive, a cellulose adhesive, a vinyl alkyl ether adhesive, etc. can be used. The adhesive is not particularly limited as long as it has adhesive strength and viscoelasticity, but from the viewpoint of easy availability, etc., it may preferably be an acrylic adhesive, for example, one containing a (meth)acrylate copolymer, a crosslinking agent, a solvent, etc.

[0155] As a method of depositing and coating the transparent conductive layer 200 on one surface of the polarizing plate 100, it may be formed by a method commonly used in the art. For example, coating processes such as spin coating method, roller coating method, bar coating method, dip coating method, gravure coating method, curtain coating method, die coating method, spray coating method, doctor coating method, kneader coating method, etc.; printing processes such as screen printing method, spray printing method, inkjet printing method, letterpress printing method, intaglio printing method, lithographic printing method, etc.; deposition processes such as CVD (chemical vapor deposition), PVD (physical vapor deposition), PECVD (plasma enhanced chemical vapor deposition), etc. Among these methods, an appropriate process may be selected for formation.

[0156] In the variable transmittance optical laminate of the present invention, it is preferable that at least one of the first transparent conductive layer 200-1 and the second transparent conductive layer 200-2 has a transmittance of 50% or more with respect to visible light. For example, it may contain one or more selected from the group consisting of transparent conductive oxides, metals, carbon-based substances, conductive polymers, conductive inks, and nanowires, but is not limited thereto, and materials of conventional or newly developed transparent conductive layers may be used.

[0157] In one or more embodiments, the transparent conductive oxide may contain one or more selected from the group consisting of indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), aluminum zinc oxide (AZO), gallium zinc oxide (GZO), fluorine tin oxide (FTO), and zinc oxide (ZnO).

[0158] In addition, the metal may include one or more selected from the group consisting of gold (Au), silver (Ag), copper (Cu), aluminum (Al), platinum (Pt), palladium (Pd), chromium (Cr), titanium (Ti), tungsten (W), niobium (Nb), tantalum (Ta), vanadium (V), iron (Fe), manganese (Mn), cobalt (Co), nickel (Ni), zinc (Zn), and alloys containing at least one of these. For example, it may include a silver-palladium-copper (APC) alloy or a copper-calcium (CuCa) alloy.

[0159] The carbonaceous material may include one or more selected from the group consisting of carbon nanotubes (CNT) and graphene.

[0160] As the conductive polymer, conventional or newly developed conductive polymer materials may be used. For example, it may include one or more selected from the group consisting of polythiophene, poly(3,4-ethylenedioxythiophene), polyaniline, polyacenylene, polydiacetylene, polyphenylene, polyphenylene vinylene, polyphenylene sulfide, polythienylene vinylene, polythiophene vinylene, polyfluorene, polypyrrole, poly(3,4-ethylenedioxythiophene):polystyrene sulfonate, poly(3,4-ethylenedioxythiophene):camphor sulfonic acid, poly(3,4-ethylenedioxythiophene):toluene sulfonic acid, poly(3,4-ethylenedioxythiophene):dodecylbenzene sulfonic acid, polyaniline:polystyrene sulfonate, polyaniline:camphor sulfonic acid, polypyrrole:polystyrene sulfonate, polypyrrole:camphor sulfonic acid, polypyrrole:toluene sulfonic acid, polypyrrole:dodecylbenzene sulfonic acid, polythiophene:polystyrene sulfonate, polythiophene:camphor sulfonic acid, polythiophene:toluene sulfonic acid, and polythiophene:dodecylbenzene sulfonic acid. Preferably, it may be poly(3,4-ethylenedioxythiophene).

[0161] The conductive ink may be an ink in which metal powder and a curable polymer binder are mixed, and the nanowire may be, for example, a silver nanowire (AgNW).

[0162] Further, at least one of the first transparent conductive layer 200-1 and the second transparent conductive layer 200-2 may be formed in a structure of two or more layers by combining the substances. For example, it may be formed in a two-layer structure including a metal layer and a transparent conductive oxide layer so as to reduce the reflectance of incident light and increase the transmittance.

[0163] The transparent conductive layer 200 of the present invention can be provided with an alignment film between the liquid crystal layer 300, and the alignment film is for adding alignment properties to the liquid crystal compound, and is preferably photo-aligned. The alignment film may be produced by applying and curing an alignment film coating composition containing an alignment polymer, a photoinitiator, and a solvent. The alignment polymer is not particularly limited, and a polyacrylate resin, a polyamic acid resin, a polyimide resin, a polymer containing a cinnamate group, or the like may be used, and a polymer capable of exhibiting alignment properties developed conventionally or in the future may also be used.

[0164] The liquid crystal layer 300 included in the variable transmittance optical laminate of the present invention can include a polymer network 310 as described later, and the polymer network can be formed through a crosslinking reaction of a polymerizable compound. In order for the liquid crystal compound 320 in the liquid crystal layer to maintain a uniform initial alignment during the formation of the polymer network 310, it is preferable to use an alignment film having strong surface anchoring energy. Examples of methods for forming such an alignment film include a rubbing method using a rubbing process and a photo-alignment method using ultraviolet light. Generally, the photo-alignment method has weaker surface anchoring energy than the rubbing method. More specifically, the alignment film formed by the rubbing method has a surface anchoring energy of about 1×10 -3 J / m 2 whereas the alignment film formed by the photo-alignment method has a surface anchoring energy of about 1×10 -6J / m 2 It has a surface anchoring energy of 2 . Therefore, from the perspective of enabling the liquid crystal compound 320 to maintain a uniform initial alignment during the formation of the polymer network 310 within the liquid crystal layer 300, the second transparent conductive layer 200-2 of the present invention preferably has a surface in contact with the liquid crystal layer 300 that is rubbed and aligned by the rubbing method.

[0165] In one embodiment, the transparent conductive layer 200 may have a thickness of 1 μm or less, preferably 10 nm to 500 nm, and more preferably 30 nm to 200 nm. In this case, while ensuring a predetermined transmittance, the transparent conductive layer 200 does not have a large change in characteristics due to external stress, and it is possible to manufacture an optical laminate with a thin thickness.

[0166] The liquid crystal layer 300 can change the driving mode of the optical laminate to a light-transmitting mode or a light-blocking mode by adjusting the transmittance of light incident from one or more directions by the electric field generated by the transparent conductive layer 200.

[0167] The liquid crystal layer 300 may include a polymer network 310 and a liquid crystal compound 320. For example, it can be provided between the first transparent conductive layer 200-1 and the second transparent conductive layer 200-2 in the light control region and located within the space provided by the polymer network 310.

[0168] Conventional optical laminates necessarily included a sealant and spacers in order to maintain a certain space within the liquid crystal layer, i.e., a cell gap, in which a liquid crystal compound was provided. However, when column spacers are included in the liquid crystal layer to maintain the cell gap, the manufacturing process becomes complicated, resulting in an increase in manufacturing costs. There is also a problem that the transmittance changes due to damage to the alignment film during the process of forming spacers by irradiating the photoresist with ultraviolet light. Further, when ball spacers are used to maintain the cell gap of the liquid crystal layer, it is impossible to maintain a firm cell gap, difficult to maintain a certain in-plane optical hue, and there are problems such as inducing a current short circuit in the optical laminate. Also, when a sealant is used to maintain the cell gap of the liquid crystal layer, the apparent quality may be degraded by the visibility of the sealant, and there may be problems such as defects occurring when the sealant breaks during handling of the optical laminate, or defects occurring due to the thickness difference from the spacers included together.

[0169] The liquid crystal layer 300 included in the variable transmittance optical laminate of the present invention includes a polymer network 310 together with a liquid crystal compound 320, and thus can appropriately maintain the cell gap of the liquid crystal layer without including a separate sealant and / or spacers. Further, since the cell gap is maintained by a single configuration of the polymer network instead of a combination of a sealant and spacers, there is an advantage that defects due to the thickness difference between the sealant and the spacers can be fundamentally blocked.

[0170] The liquid crystal compound is driven by an electric field and is not particularly limited as long as it can control the light transmittance, and a conventional or later-developed liquid crystal compound can be used. For example, the content regarding the reactive liquid crystal compound of the coating type polarizer described above can be similarly applied.

[0171] The liquid crystal compound may include a chiral nematic (cholesteric) liquid crystal compound, and the chiral nematic liquid crystal compound may include a nematic liquid crystal compound and a chiral compound.

[0172] In the nematic liquid crystal compound, long rod-shaped molecules are arranged parallel to each other. Although there is no regularity in the central positions of the molecules, there is an order in the molecular axis direction. Since each molecule of the nematic liquid crystal compound can move freely in the long axis direction, it has low viscosity and good fluidity. Since the directions of each molecule are almost the same up and down, the polarization is canceled out and generally does not show strong ferroelectricity. The type of the nematic liquid crystal compound is not particularly limited, and any compound containing a mesogenic group is possible without limitation.

[0173] The chiral compound has a symmetrical structure in its three-dimensional structure like the relationship between the right hand and the left hand. Although the chemical structure and physical properties are the same, they are in a mirror image relationship with each other, so they are compounds with different three-dimensional structures. When a certain content of the chiral compound is contained in the nematic liquid crystal compound, a helical period is induced. The type of the chiral compound is not particularly limited as long as it can induce the desired helical period without damaging the liquid crystallinity of the liquid crystal compound, for example, the nematic regularity.

[0174] The chiral compound for inducing a helical period in the liquid crystal compound needs to contain at least chirality in its molecular structure. Examples of the chiral compound include a compound having one or more asymmetric carbons, a compound having an asymmetric point on a heteroatom such as a chiral amine or a chiral sulfoxide, or a compound having an axially asymmetric and optically active site having an axial member such as cumulene or binaphthol.

[0175] The chiral compound may be, for example, a low molecular weight compound having a molecular weight of 1,500 or less. For example, as the chiral compound, commercially available chiral nematic liquid crystals such as chiral dopant liquid crystal S-811 manufactured by Merck or Paliocolor LC756 (manufactured by BASF) can be used, but it is not limited thereto.

[0176] The chiral nematic liquid crystal compound may contain 75 to 99% by weight of a nematic liquid crystal compound and 1 to 25% by weight of a chiral compound based on the total weight of the chiral nematic liquid crystal compound, but it is not limited thereto. By appropriately adjusting the contents of the nematic liquid crystal compound and the chiral compound within the above range, the helical period of the chiral nematic liquid crystal compound, that is, the pitch can be adjusted. The pitch of the chiral nematic liquid crystal compound is not particularly limited, but may be 5 to 20 μm.

[0177] The liquid crystal behavior mode of the liquid crystal layer 300 is not particularly limited, and for example, TN (Twisted nematic) mode, STN (Super twisted nematic) mode, IPS (In-plane switching) mode, FFS (Fringe-field switching) mode, and VA (Vertical alignment) mode can be used. From the viewpoint of controlling the light transmittance, preferably, the TN (Twisted nematic) mode can be used.

[0178] As an example of a conventional liquid crystal layer containing a polymer, polymer dispersed liquid crystal (PDLC) is known. In the polymer dispersed liquid crystal, the liquid crystal compound is phase-separated and exists in the form of droplets or capsules within the polymer, and the phase-separated droplets or capsule-type liquid crystal compounds cannot be aligned in a regular direction and have a certain initial alignment. That is, in the polymer dispersed liquid crystal (PDLC), when no voltage is applied, the liquid crystal compound has an irregular arrangement and maintains an opaque state (light-shielding mode) by scattering the incident light. When a voltage is applied, the liquid crystal compound is aligned in one direction and becomes a transparent state (light-transmitting mode) by allowing the incident light to pass through. However, since the light-shielding mode of the polymer dispersed liquid crystal (PDLC) uses the property that the incident light is scattered by the irregular arrangement of the liquid crystal compound, the light scattered in an arbitrary direction cannot be controlled, and there are technical limitations where the light-shielding rate is somewhat unsatisfactory. In order to implement the light-transmitting mode, it is necessary to maintain the state with a voltage applied, so it has been pointed out that there is a disadvantage of high power consumption.

[0179] The liquid crystal layer 300 of the present invention includes a polymer network 310 and a liquid crystal compound 320, and the liquid crystal compound 320 is arranged with a uniform initial alignment. The liquid crystal layer 300 of the present invention includes a polymer network 310, but the liquid crystal compound 320 included therein is not phase-separated into a droplet or capsule type, and exists in a form mixed with the polymer network 310, and has a uniform initial alignment in the liquid crystal layer. It is different from the conventional polymer dispersed liquid crystal (PDLC) in that it is arranged. Thus, the liquid crystal layer 300 of the present invention including the polymer network 310 and the liquid crystal compound 320 arranged with a uniform initial alignment can implement a light transmission mode and a light shielding mode by adjusting the transmittance of light incident in one or more directions according to the electric field generated by the transparent conductive layer 200. Therefore, it can exhibit an excellent light shielding rate compared to the conventional polymer dispersed liquid crystal that scatters incident light to implement the light shielding mode. In addition, the variable transmittance optical laminate of the present invention can implement a light transmission mode without applying a voltage by appropriately adjusting the transmission axis of the polarizing plate 100 and the optical axis of the liquid crystal layer 300, and also, compared to the conventional polymer dispersed liquid crystal in which the liquid crystals are arranged disorderly, there is an advantage that the power consumption can be reduced compared to the conventional polymer dispersed liquid crystal because the applied voltage required for driving is low.

[0180] The liquid crystal layer 300 may include a cured product of a liquid crystal layer-forming composition containing a polymerizable monomer and a liquid crystal compound.

[0181] The polymerizable monomer means a compound that forms a polymer network by a photopolymerization reaction or a thermal polymerization reaction, and is not particularly limited. For example, it may include an acrylate-based monomer, and is selected from the group consisting of isobornyl acrylate, caprolactone acrylate, triethylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, and dipentaerythritol pentaacrylate. It may include one or more selected.

[0182] The polymerizable monomer may contain one or more monomers selected from monofunctional monomers to tetrafunctional monomers, and preferably may contain a trifunctional monomer. The polyfunctional monomer has the advantage that it does not impact the liquid crystal and has excellent compatibility with the liquid crystal, and appropriate phase separation with the liquid crystal can be exhibited.

[0183] The composition for forming a liquid crystal layer may contain the polymerizable monomer in an amount of 10 to 30% by weight, preferably 10 to 20% by weight, based on the total weight of the composition. When the composition for forming a liquid crystal layer contains the polymerizable monomer within the above content range, the degree of cure of the polymer network formed therefrom is sufficient and can stably maintain the cell gap of the liquid crystal layer, and there is an advantage that excellent light transmittance and adhesion can be obtained, so it is preferable.

[0184] The method for forming the liquid crystal layer 300 using the composition for forming a liquid crystal layer is not particularly limited. For example, it can be formed by applying the composition for forming a liquid crystal layer onto the second transparent conductive layer 200-2 whose surface is rubbed and aligned, and then photocuring or thermocuring this.

[0185] The variable transmittance optical laminate according to the present invention includes a polymer network 310 in the liquid crystal layer 300, and in addition to being able to maintain a stable cell gap without including a sealant and a spacer, optionally, within a range not impairing the object of the present invention, it may further include one or more of a sealant and a spacer.

[0186] The sealant may contain a curable resin as a base resin. As the base resin, an ultraviolet curable resin or a thermosetting resin known to be used for sealants in the art may be used. The ultraviolet curable resin may be a polymer of an ultraviolet curable monomer. The thermosetting resin may be a polymer of a thermosetting monomer.

[0187] As the base resin of the sealant, for example, an acrylate resin, an epoxy resin, a urethane resin, a phenolic resin, or a mixture of the resins may be used. In one embodiment, the base resin may be an acrylate resin, and the acrylate resin may be a polymer of an acrylic monomer. The acrylic monomer may be, for example, a polyfunctional acrylate. In other embodiments, the sealant may further contain a monomer component in the base resin. The monomer component may be, for example, a monofunctional acrylate. In this specification, the monofunctional acrylate can mean a compound having one acrylic group, and the polyfunctional acrylate can mean a compound having two or more acrylic groups. The curable resin can be cured by irradiation with ultraviolet rays and / or heating. The ultraviolet irradiation conditions or heating conditions may be appropriately carried out within a range that does not impair the object of the present application. The sealant may further contain an initiator, for example, a photoinitiator or a thermal initiator, if necessary.

[0188] The sealant can be formed by a method commonly used in the art. For example, the sealant can be formed by drawing the sealant onto the outer contour (i.e., the inactive region) of the liquid crystal layer using a dispenser equipped with a nozzle.

[0189] The spacer may include at least one or more spacers among a ball spacer and a column spacer, and particularly preferably a ball spacer. The number of spacers may be one or more, and those having a diameter of 1 to 10 μm are more preferable. When viewed from the planar direction, the area occupied by the spacer in the liquid crystal layer 300 is preferably 0.01 to 10% of the area of the liquid crystal layer 300 from the viewpoints of user visibility and improvement of the transmittance in the transmissive mode.

[0190] The variable transmittance optical laminate of the present invention may further include other members as long as the object of the present invention is not impaired, and may include, for example, an ultraviolet absorption layer, a hard coating layer, and the like.

[0191] The ultraviolet absorber is not particularly limited as long as it can prevent the deterioration of the optical laminate caused by ultraviolet rays. For example, salicylic acid-based ultraviolet absorbers (such as phenyl salicylate, p-tert-butyl salicylate, etc.), benzophenone-based ultraviolet absorbers (such as 2,4-dihydroxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, etc.), benzotriazole-based ultraviolet absorbers (such as 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)benzotriazole, 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)benzotriazole, 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-3'-(3'',4'',5'',6''-tetrahydrophthalimidomethyl)-5'-methylphenyl)benzotriazole, 2,2-methylenebis(4-(1,1,3,3-tetramethylbutyl)-6-(2H-benzotriazol-2-yl)phenol), 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-3'-tert-butyl-5'-(2-octyloxycarbonylethyl)-phenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-3'-(1-methyl-1-phenylethyl)-5'-(1,1,3,3-tetramethylbutyl)-phenyl)benzotriazole, 2-(2H-benzotriazol-2-yl)-6-(linear and branched dodecyl)-4-methylphenol, a mixture of octyl 3-[3-tert-butyl-4-hydroxy-5-(chloro-2H-benzotriazol-2-yl)phenyl]propionate and 2-ethylhexyl 3-[3-tert-butyl-4-hydroxy-5-(5-chloro-2H-benzotriazol-2-yl)phenyl]propionate, etc.), cyanoacrylate-based ultraviolet absorbers (such as 2'-ethylhexyl 2-cyano-3,3-diphenylacrylate, ethyl 2-cyano-3-(3',(such as 4’-methylenedioxyphenyl)-acrylate), triazine-based ultraviolet absorbers, etc. may be used. Benzotriazole-based ultraviolet absorbers and triazine-based ultraviolet absorbers with high transparency and excellent effects in preventing deterioration of polarizing plates and variable transmittance layers are preferred, and benzotriazole-based ultraviolet absorbers with more appropriate spectral absorption spectra are particularly preferred. The benzotriazole-based ultraviolet absorber may be bis-formed. For example, 6,6’-methylenebis(2-(2H-benzo[d][1,2,3]triazol-2-yl)-4-(2,4,4-trimethylpentan-2-yl)phenol), 6,6’-methylenebis(2-(2H-benzo[d][1,2,3]triazol-2-yl)-4-(2-hydroxyethyl)phenol), etc. may also be used.,

[0192] The hard coating layer is not particularly limited as long as it is for protecting members such as polarizing plates and variable transmittance layers from external physical and chemical impacts, and conventional or later-developed hard coating layers may be used.

[0193] In one embodiment, the hard coating layer may be formed by applying a composition for forming a hard coating layer on another member and then curing it by light or heat. The composition for forming a hard coating layer is not particularly limited. For example, it can contain a photocurable compound and a photoinitiator.

[0194] The photocurable compound and the photoinitiator can be used without limitation as those generally used in the art. For example, the photocurable compound may be a photopolymerizable monomer, a photopolymerizable oligomer, etc. For example, monofunctional and / or polyfunctional (meth)acrylates can be mentioned. Photoinitiators include hydroxycyclohexyl phenyl ketone, trimethylbenzoyl diphenylphosphine oxide, acetophenone-based, oxime ester-based, etc. Commercially available products include Irgacure-184, TPO, Irgacure-907, etc.

[0195] <Smart window, automotive and building fixtures> The present invention includes, in addition to the variable transmittance optical laminate, a smart window including the same. The present invention also includes an automobile in which the smart window is applied to at least one or more of a front window, a rear window, a side window, a sunroof window, and an interior partition, and building fixtures including the smart window.

[0196] The variable transmittance optical laminate of the present invention can be provided so as to be detachable on the indoor side of the automobile or building fixtures, etc., has a surface hardness of H or more, is excellent in scratch resistance, and can prevent damage. It has the advantage of excellent antifouling performance that no stain remains even with frequent fingerprint contact.

Examples

[0197] Hereinafter, embodiments of the present invention will be specifically described. However, the present invention is not limited to the embodiments disclosed below and can be embodied in various different forms. However, these embodiments are provided to complete the disclosure of the present invention and to fully inform those with ordinary knowledge in the technical field to which the present invention pertains of the scope of the invention. The present invention is only defined by the scope of the claims.

[0198] Production Example 1: Production of a polarizing plate (1) Swelling treatment step A polyvinyl alcohol film (raw film) with a thickness of 60 μm (manufactured by Kuraray Co., Ltd., trade name "Kuraray Poval Film VF-PE#6000", average degree of polymerization 2400, saponification degree 99.9 mol%) was continuously drawn out from the raw film roll and conveyed, and immersed in a swelling bath filled with pure water at 20°C for 30 seconds. In this swelling treatment step, roll stretching (uniaxial stretching in the longitudinal direction) was performed with a difference in peripheral speed between the nip rolls. The stretching ratio based on the raw film was 2.5 times.

[0199] (2) Dyeing treatment step Next, the film that passed through the nip roll was immersed in a dyeing bath at 30°C with a mass ratio of pure water / potassium iodide / iodine / boric acid of 100 / 2 / 0.01 / 0.3 for 120 seconds. Also in this dyeing process, stretching between rolls (uniaxial stretching in the longitudinal direction) was performed with a difference in peripheral speed between the nip rolls. The stretching ratio was set to 1.1 times based on the film after the swelling treatment step.

[0200] (3) Crosslinking treatment step Next, the film that passed through the nip roll was immersed in a first crosslinking bath at 56°C with a mass ratio of pure water / potassium iodide / boric acid of 100 / 12 / 4 for 70 seconds. Stretching between rolls (uniaxial stretching in the longitudinal direction) was performed with a difference in peripheral speed between the nip roll and the nip roll provided between the first crosslinking bath and the second crosslinking bath. The stretching ratio was set to 1.9 times based on the film after the dyeing treatment step.

[0201] (4) Complementary color treatment step Next, the film after the crosslinking treatment was immersed in a second crosslinking bath at 40°C with a mass ratio of potassium iodide / boric acid / pure water of 9 / 2.9 / 100 for 10 seconds.

[0202] (5) Washing treatment step Next, the film after the second crosslinking treatment was immersed in a washing bath filled with pure water at 14°C for 5 seconds and washed at a shower rate of 5 m 3 / h and a shower temperature of 14°C.

[0203] (6) Drying treatment step Next, the film after the washing treatment step was passed through a drying furnace and heated and dried at 80°C for 190 seconds to produce a polarizer film. The moisture content after drying was 13.6%, and the thickness of the obtained polarizer film was approximately 18 μm.

[0204] (7) Bonding treatment step Next, as an adhesive, an aqueous adhesive containing 5 parts by mass of polyvinyl alcohol with respect to 100 parts by mass of water was prepared. Then, a protective film was laminated on both sides of the polarizing film using the prepared UV adhesive. The obtained laminate was subjected to UV exposure to cure the adhesive, and a first polarizing plate and a second polarizing plate were each produced. The thicknesses of the first polarizing plate and the second polarizing plate are shown in Table 1 below.

[0205] Production Example 2: Production of an adhesion manifestation layer 16.2 g of a dendrimer compound (SP-1106, manufactured by Miwon Specialty Chemicals), 14.4 g of inorganic nanoparticles (10 to 20 nm, silica particles: 50 wt%, solvent: methyl ethyl ketone (MEK)), 1.8 g of a polyfunctional (meth)acrylate compound containing an ethylene glycol group, 0.7 g of a photoinitiator (1-hydroxycyclohexyl phenyl ketone), and 2.9 g of methyl ethyl ketone were mixed to produce a composition for forming an adhesion manifestation layer.

[0206] The obtained composition for forming an adhesion manifestation layer was applied to one surface of the first polarizing plate and the second polarizing plate produced in Production Example 1 by adjusting the Mayer bar type and the solid powder content. After curing, the hard coating thickness was calculated and bar-coated, dried at 80°C for 5 minutes, and then cured with a high-pressure mercury lamp at a light quantity of 500 mJ / cm 2 to produce a first polarizing plate and a second polarizing plate each having an adhesion manifestation layer with a thickness of 7 μm formed on one surface.

[0207] Production Example 3: Production of a surface treatment layer 22.25 wt% of a trifunctional acrylate (MIRAMER M340, manufactured by MIWON), 22.25 wt% of a pentafunctional acrylate (SR399LV NS, manufactured by Sartomer), 10 wt% of a fluorine-based UV-curable functional group-containing compound (KY-1203, diluted with 80 wt% MEK (methyl ethyl ketone), solid powder content 20 wt%, manufactured by Shin-Etsu Chemical Co., Ltd.), 3.5 wt% of 1-hydroxycyclohexyl phenyl ketone, and 42 wt% of methyl ethyl ketone were blended using a stirrer and filtered using a filter made of a PP material to produce a composition for a surface treatment layer.

[0208] After coating the composition for the surface treatment layer on the surface where the adhesion realization layer of the first polarizing plate is not formed and drying the solvent, under a nitrogen atmosphere, the surface treatment layer was fabricated by irradiating with a UV integrated light amount of 600 mJ / cm 2 . The thickness of the fabricated surface treatment layer is shown in Table 1 below.

[0209] Comparative Production Example 3: Fabrication of Surface Treatment Layer 13.25% by weight of trifunctional acrylate (MIRAMER M340, manufactured by MIWON Co., Ltd.), 13.25% by weight of hexafunctional urethane acrylate (UA-110H, manufactured by Shin-Nakamura Chemical Co., Ltd.), 20% by weight of a silicone-based UV curable functional group-containing compound (BYK UV3570, manufactured by BYK Co., Ltd.), 3.5% by weight of 1-hydroxycyclohexyl phenyl ketone, and 50% by weight of methyl ethyl ketone were blended using a stirrer and filtered using a filter made of PP material to produce a composition for the surface treatment layer.

[0210] A surface treatment layer was fabricated in the same manner as in Production Example 3 on the surface where the adhesion realization layer of the first polarizing plate was not formed, and it was shown as Comparative Example 1.

[0211] Production Example 4-1: Fabrication of Adhesive Layer A monomer mixture containing 20% by weight of 2-ethylhexyl acrylate (2-EHA; the first monomer, Tg of the homopolymer: -70°C; manufactured by Sigma-Aldrich), 60% by weight of isobornyl acrylate (IBOA; the second monomer, Tg of the homopolymer: 94°C; manufactured by Sigma-Aldrich), 10% by weight of dicyclopentadienyl acrylate (DCPA; the second monomer, Tg of the homopolymer: 110°C; BASF), and 10% by weight of 2-hydroxyethyl acrylate (2-HEA; the third monomer, Tg of the homopolymer: -15°C; manufactured by Sigma-Aldrich) was combined with 20% by weight of solid powder, and ethyl acetate (EA) was added as a solvent.

[0212] Nitrogen gas was purged for 1 hour to remove oxygen and maintained at 80°C. After uniformly mixing the monomer mixture, azobisisobutyronitrile (AIBN) was added as a polymerization initiator in an amount of 0.07 parts by weight per 100 parts by weight of the monomer mixture, and reacted for 8 hours to produce an acrylic random copolymer (weight average molecular weight: 650,000, PDI 4.5).

[0213] The glass transition temperature (DSC2500, TA Instruments Inc.) of the obtained acrylic random copolymer was 23.1°C, and the acid value was 0.015.

[0214] 100 parts by weight of the obtained acrylic random copolymer, 5 parts by weight of an isocyanate compound (D-110N, manufactured by Mitsui Chemicals, Inc.) as a tackifier, and 0.1 parts by weight of a silane coupling agent (KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd.) were mixed to produce a pressure-sensitive adhesive composition. Then, it was applied onto a 75-μm release film coated with a silicone release agent to a thickness of 5 μm and dried at 120°C for 5 minutes to produce a pressure-sensitive adhesive layer. In order to protect the pressure-sensitive adhesive layer until it was used in the subsequent process, a release film coated with a silicone release agent was laminated onto the pressure-sensitive adhesive layer to produce a pressure-sensitive adhesive sheet.

[0215] The release film of the produced pressure-sensitive adhesive sheet was removed and bonded to the surface of the second polarizing plate where the adhesion-imparting layer was not formed.

[0216] Production Example 4-2: Production of Adhesive Layer Into a 1-L reactor, a monomer mixture containing 20% by weight of n-butyl acrylate (BA; the first monomer, Tg of the homopolymer: -54°C; manufactured by Sigma-Aldrich), 70% by weight of isobornyl acrylate (IBOA; the second monomer, Tg of the homopolymer: 94°C; manufactured by Sigma-Aldrich), and 10% by weight of 4-hydroxybutyl acrylate (4-HEA; the third monomer, Tg of the homopolymer: -40°C; manufactured by Sigma-Aldrich) was adjusted to 20% by weight of solid powder, and ethyl acetate (EA) was added as a solvent.

[0217] Nitrogen gas was purged for 1 hour to remove oxygen and maintained at 80°C. After uniformly mixing the monomer mixture, azobisisobutyronitrile (AIBN) was added as a polymerization initiator in an amount of 0.07 parts by weight per 100 parts by weight of the monomer mixture, and reacted for 8 hours to produce an acrylic random copolymer (weight average molecular weight: 890,000).

[0218] The glass transition temperature (DSC2500, TA Instruments Inc.) of the obtained acrylic random copolymer was 23.7°C, and the acid value was 0.01.

[0219] 100 parts by weight of the obtained acrylic random copolymer, 15 parts by weight of trimethylolpropane tris(2-methyl-1-aziridinepropionate) (CL-467, manufactured by MENADIONA) as a tackifier, and 0.1 parts by weight of a silane coupling agent (KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd.) were mixed to produce an adhesive composition, and an adhesive sheet was produced in the same manner as in Production Example 4-1.

[0220] The release film of the produced adhesive sheet was removed and bonded to the surface of the second polarizing plate where the adhesion-imparting layer was not formed, and shown as Example 4.

[0221] Comparative Production Example 4: Production of Adhesive Layer In the above Production Example 4, 20% by weight of 2-ethylhexyl acrylate (2-EHA; the first monomer, Tg of homopolymer: -70°C; manufactured by Sigma-Aldrich), 50% by weight of isobornyl acrylate (IBOA; the second monomer, Tg of homopolymer: 94°C; manufactured by Sigma-Aldrich), 10% by weight of dihydrodicyclopentadienyl acrylate (DCPA; the second monomer, Tg of homopolymer: 110°C; BASF), 19.5% by weight of 2-hydroxyethyl acrylate (2-HEA; the third monomer, Tg of homopolymer: -15°C; manufactured by Sigma-Aldrich), and 0.5% by weight of acrylic acid (the third monomer, Tg of homopolymer: 105°C; manufactured by Sigma-Aldrich) were included, and an acrylic random copolymer was produced in the same manner.

[0222] The weight-average molecular weight of the obtained acrylic random copolymer was 1.01 million, the glass transition temperature (DSC2500, TA Instruments Inc.) was 3.3 °C, and the acid value was 2.1.

[0223] 100 parts by weight of the obtained acrylic random copolymer, 10 parts by weight of an isocyanate-based compound (D-110N, manufactured by Mitsui Chemicals, Inc.) as a tackifier, and 0.1 part by weight of a silane coupling agent (KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd.) were mixed to produce an adhesive composition, and an adhesive sheet was produced in the same manner as in Production Example 4-1.

[0224] The release film of the produced adhesive sheet was removed and bonded to the surface of the second polarizing plate where the adhesion-implementing layer was not formed to show it as Comparative Example 3.

[0225] Production Example 5: Fabrication of a transparent conductive layer A composition for forming a PEDOT functional conductive layer was applied onto the adhesion-implementing layers of the first polarizing plate and the second polarizing plate and dried at 90 °C for about 5 to 10 minutes to form a functional conductive layer, thereby fabricating a transparent heat-blocking functional layer having a laminated structure of a functional conductive layer (PEDOT) / a substrate layer (PET). The thickness of the functional conductive layer is shown in Table 1 below.

[0226] At this time, as the composition for forming the PEDOT functional conductive layer, a mixture obtained by mixing 0.6% by weight of PEDOT:PSS, 32.4% by weight of ethyl alcohol, 40% by weight of deionized water, and 27% by weight of 2-methoxyethanol was used.

[0227] Production Example 6: Fabrication of an alignment film An alignment agent was coated and dried (80 °C / 2 minutes) on the conductive layer fabricated in Production Example 5. Thereafter, UV was irradiated onto the dried alignment agent to fabricate an alignment film.

[0228] Production Example 7: Fabrication of a polymer-dispersed liquid crystal molecular layer As prepolymers, ethylene glycol dimethacrylate, 1,6 - hexanediol diacrylate, and 3,5,5 - trimethylhexyl acrylate are mixed and used. As liquid crystal molecules, a single liquid crystal containing a cyano group as a functional group with bicyclohexylbenzene as the central skeleton is used. A polymer - dispersed liquid crystal molecule layer is manufactured with the prepolymer, liquid crystal molecules, and cross - linker being 25 wt%, 70 wt%, and 5 wt% respectively.

[0229] Examples and Comparative Examples: Fabrication of Optical Laminate The alignment film on the first polarizing plate and the alignment film on the second polarizing plate manufactured through the above - mentioned Production Examples 1 to 6 face each other with the polymer - dispersed liquid crystal molecule layer manufactured in Production Example 7 interposed therebetween, and are bonded to an acrylic adhesive (DONGWOO FINE - CHEM, #NS NCF) with a thickness of 25 μm to fabricate an optical laminate. The composition and thickness of each layer in the examples and comparative examples are shown in Table 1 below.

[0230] Experimental Example: Evaluation of Physical Properties (1) Storage Elastic Modulus of Adhesive Layer For the adhesive layers of Production Examples 4 - 1, 4 - 2 and Comparative Production Example 4, the storage elastic modulus at 25°C was measured using a viscoelasticity measuring device (MCR - 301, manufactured by Anton Paar). More specifically, the size of the adhesive sheet was cut out to be 30 mm in length × 30 mm in width, and after removing the release film attached to one side of the cut - out adhesive sheet, it was bonded to a glass substrate. Then, in a state of being adhered to the measurement tip, it was measured under the conditions of a temperature range from - 20 to 100°C, a frequency of 1.0 Hz, a deformation of 2%, and a heating rate of 5°C / min, and at this time, the measured value at 25°C was read. The storage elastic modulus was evaluated according to the following evaluation criteria, and the results are shown in Table 1 below. <Evaluation Criteria> ◎: Storage elastic modulus at 25°C is 50 MPa or more ○: Storage elastic modulus at 25°C is 10 MPa or more and less than 50 MPa ×: Storage elastic modulus at 25°C is less than 10 MPa

[0231] (2) Surface hardness of the optical laminate Using a pencil hardness tester (Pencil Hardness Tester, manufactured by SUKBO Science Co., Ltd., Korea), a 500 g load was applied to the first polarizer side of the optical laminates of the examples and comparative examples to measure the pencil hardness of the hard coating layer surface (or the inner surface of the polarizer). Mitsubishi products were used for the pencils, and the measurement was carried out 5 times for each pencil hardness. After heat treatment at 100°C for 10 minutes, the pencil hardness was measured based on whether scratches occurred or not, and it was shown as the surface hardness in Table 1 below.

[0232] (3) Antifouling property The water contact angle was measured using a contact angle measuring instrument DSA100 manufactured by KRUSS. The droplet volume was 3 μl at room temperature. When the measured water contact angle was 100° or more, it was rated as OK, and when it was less than 100°, it was rated as NG, as shown in Table 1 below.

[0233]

Table 1

[0234] From the above experimental results, it can be confirmed that the optical laminates of Examples 1 to 4 of the present invention not only have excellent storage elastic modulus of the adhesive layer formed on one surface, but also ensure very excellent surface hardness and antifouling property by the surface treatment layer formed on the other surface. On the contrary, in the case of the optical laminates of Comparative Examples 1 to 3, they are inferior in surface hardness and / or antifouling property, it is difficult to utilize the optical laminates with one surface of the polarizer exposed to the outside, or the storage elastic modulus of the adhesive layer is not sufficiently ensured, so it can be confirmed that it is not easy to desorb the adherend.

Claims

1. A first polarizing plate; A surface treatment layer formed on one surface of the first polarizing plate; A first transparent conductive layer formed on the other surface of the first polarizing plate; A second polarizing plate facing the first polarizing plate; A second transparent conductive layer formed on one surface of the second polarizing plate and facing the first transparent conductive layer; A liquid crystal layer provided between the first transparent conductive layer and the second transparent conductive layer; and A transmittance variable optical laminate including an adhesive layer provided on a surface of the second polarizing plate where the second transparent conductive layer is not formed, wherein the thickness of the first polarizing plate is equal to or greater than the thickness of the second polarizing plate, and the transmittance variable optical laminate has a surface hardness of H or more.

2. The transmittance variable optical laminate according to claim 1, wherein the surface treatment layer has a thickness of 5 to 30 μm.

3. The transmittance variable optical laminate according to claim 1, wherein the first polarizing plate and the second polarizing plate each have a thickness of 30 to 200 μm.

4. The transmittance variable optical laminate according to claim 1, wherein the adhesive layer has a storage elastic modulus of 10 MPa or more at 25°C.

5. The transmittance variable optical laminate according to claim 1, wherein the surface treatment layer has a water contact angle of 100° or more.

6. The transmittance variable optical laminate according to claim 1, wherein the liquid crystal behavior mode of the liquid crystal layer is any one selected from the group consisting of a TN (Twisted nematic) mode, an STN (Super twisted nematic) mode, an IPS (In-plane switching) mode, an FFS (Fringe-field switching) mode, an ECB (Electrically Controlled Birefringence) mode, and a VA (Vertical alignment) mode.

7. The transmittance variable optical laminate according to claim 6, wherein the liquid crystal behavior mode of the liquid crystal layer is a TN (Twisted nematic) mode.

8. The liquid crystal layer includes a polymer network and a liquid crystal compound, and the liquid crystal compound is arranged with a uniform initial alignment.

9. The transmittance variable optical laminate according to claim 8, wherein the liquid crystal layer includes a cured product of a liquid crystal layer forming composition containing a polymerizable monomer and a liquid crystal compound.

10. The variable transmittance optical laminate according to claim 9, wherein the composition for forming the liquid crystal layer contains 10 to 30% by weight of a polymerizable monomer based on the total weight of the composition.

11. The variable transmittance optical laminate according to claim 1, wherein at least one of the first transparent conductive layer and the second transparent conductive layer is formed in direct contact without including a separate substrate between the first polarizing plate or the second polarizing plate.

12. The variable transmittance optical laminate according to claim 1, wherein at least one of the first transparent conductive layer and the second transparent conductive layer includes an easy adhesion layer between the first polarizing plate or the second polarizing plate and is formed in direct contact.

13. The variable transmittance optical laminate according to claim 1, wherein at least one of the first polarizing plate and the second polarizing plate includes one or more functional layers selected from the group consisting of a protective layer, an adhesion-imparting layer, a retardation adjusting layer, and a refractive index adjusting layer.

14. The variable transmittance optical laminate according to claim 1, wherein at least one of the first transparent conductive layer and the second transparent conductive layer includes one or more selected from the group consisting of a transparent conductive oxide, a metal, a carbon-based material, a conductive polymer, a conductive ink, and a nanowire.

15. The variable transmittance optical laminate according to claim 1, further including one or more selected from the group consisting of an adhesive layer, an ultraviolet absorption layer, and a hard coating layer.

16. A smart window including the variable transmittance optical laminate according to any one of claims 1 to 15.

17. An automobile in which the smart window according to claim 16 is applied to at least one of a front window, a rear window, a side window, a sunroof window, and an interior partition.

18. A building fitting including the smart window according to claim 16.

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