Optical member and display device including the same

Abstract

The invention provides an optical member and an optical display apparatus including the same. The optical member includes: an adhesive layer; a transmittance control layer formed on an upper surface of the adhesive layer; and a base film formed on an upper surface of the transmittance control layer. The transmittance control layer contains a (meth) acrylic copolymer and a dye mixture. The dye mixture includes a first dye having a maximum absorption wavelength of 400 nm to 440 nm, a second dye having a maximum absorption wavelength of 480 nm to 520 nm, a third dye having a maximum absorption wavelength of 570 nm to 610 nm, and a fourth dye having a maximum absorption wavelength of 650 to 700 nm. The (meth) acrylic copolymer includes an alicyclic group-containing (meth) acrylic copolymer having a glass transition temperature of 50-150 DEG C. The alicyclic group-containing (meth) acrylic copolymer contains 35 wt% to 70 wt% of an alicyclic group-containing (meth) acrylic monomer.

Description

[0001] Cross Reference to Related Applications

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2024-0057505, filed on April 30, 2024, in the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0003] The present disclosure relates to an optical member and a display apparatus including the same. BACKGROUND

[0004] Light emitting display apparatuses including organic light emitting display apparatuses and the like can have no polarizing plate. However, such light emitting display apparatuses can have poor screen quality due to total reflection of external light at the surface of the panel included therein. Accordingly, light emitting display apparatuses typically have a polarizing plate on the upper surface of the panel. The polarizing plate typically includes a polarizer and a phase difference film. In addition, the polarizing plate contains a UV absorber. The polarizing plate also serves to prevent external light from damaging the light emitting device.

[0005] With recent trends toward reducing the thickness of optical display apparatuses, optical display apparatuses without a polarizing plate (as known as "extreme" optical display apparatuses) have been developed. In addition, the light emitting device in such an extreme display apparatus is directly exposed to external light, and thus is easily damaged by external light.

[0006] Background art of the present disclosure is disclosed in Japanese Patent Application Publication No. 2015-010192. SUMMARY

[0007] Embodiments of the present disclosure provide an optical member that has a low change in light transmittance at wavelengths from 400 nanometers to 600 nanometers, even after long-term exposure to UV light, and even under repeated temperature changes between room temperature and high temperature.

[0008] Embodiments of the present disclosure provide an optical member that provides a reflectance of 6.5% to 9.5%, as measured on a panel for a display apparatus.

[0009] Embodiments of the present disclosure relate to an optical member.

[0010] In one embodiment, the optical member includes an adhesive layer, a transmittance control layer formed on an upper surface of the adhesive layer, and a base film formed on an upper surface of the transmittance control layer. The transmittance control layer includes a (meth)acrylic copolymer and a dye mixture. The dye mixture includes a first dye having a maximum absorption wavelength of 400 nm to 440 nm, a second dye having a maximum absorption wavelength of 480 nm to 520 nm, a third dye having a maximum absorption wavelength of 570 nm to 610 nm, and a fourth dye having a maximum absorption wavelength of 650 to 700 nm. The (meth)acrylic copolymer includes an alicyclic group-containing (meth)acrylic copolymer having a glass transition temperature of 50℃ to 150℃. The alicyclic group-containing (meth)acrylic copolymer includes 35% by weight to 70% by weight of an alicyclic group-containing (meth)acrylic monomer.

[0011] Embodiments of the present disclosure relate to an optical display apparatus.

[0012] In one embodiment, the optical display apparatus includes an optical member.

[0013] Embodiments of the present disclosure provide an optical member having a low change in light transmittance at wavelengths from 400 nm to 600 nm, even after long-term exposure to UV light, and even under repeated temperature fluctuations between room temperature and high temperature, thereby improving reliability of a display apparatus.

[0014] Embodiments of the present disclosure provide an optical member having a reflectance of 6.5% to 9.5% measured on a panel for a display apparatus, thereby improving screen quality. BRIEF DESCRIPTION OF DRAWINGS

[0015] The following drawings illustrate embodiments of the present disclosure and, together with the detailed description below, further describe aspects and features of the present disclosure. Accordingly, the present disclosure should not be construed as being limited to the drawings.

[0016] Figure 1 is a cross-sectional view of an optical member according to an embodiment of the present disclosure.

[0017] Figure 2 is a graph depicting light transmittance of an optical member of Example 1 according to an embodiment of the present disclosure as a function of wavelength.

[0018] Figure 3 is a graph depicting light transmittance of an optical member of Comparative Example 1 according to an embodiment of the present disclosure as a function of wavelength.

[0019] In Figure 2 and Figure 3 In Examples 1 and 2, the solid line indicates the initial light transmittance, and the dotted line indicates the light transmittance after the sunlight test.

[0020] Reference Signs List

[0021] 100: transmittance control layer

[0022] 200: base film

[0023] 300: adhesive layer DETAILED DESCRIPTION

[0024] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The terms or words used in the present specification and claims should not be interpreted as being limited to commonly or dictionaries meanings, but should be interpreted as having a concept matching the technical idea of the present disclosure based on the idea of an inventor who can appropriately define the terms in order to best explain his / her own invention. Accordingly, the present disclosure should be interpreted as including all equivalents or modifications of the embodiments described in the present specification and the attached drawings.

[0025] The embodiments described in the present specification and the configurations shown in the accompanying drawings are only some embodiments of the present disclosure, and do not represent all technical ideas, aspects, and features of the present disclosure. Therefore, it should be understood that at the time of filing the present application, there can be various equivalents and modifications that can replace or modify the embodiments described herein.

[0026] It should be understood that when an element or layer is referred to as being "on", "connected to", or "coupled to" another element or layer, it can be directly on, connected or coupled to the other element or layer, or one or more intervening elements or layers can also be present. When an element or layer is referred to as being "directly on", "directly connected to", or "directly coupled to" another element or layer, there are no intervening elements or layers present. For example, when a first element is described as being "coupled" or "connected" to a second element, the first element can be directly coupled or connected to the second element, or the first element can be indirectly coupled or connected to the second element through one or more intervening elements.

[0027] In the drawings, the size of various elements, layers, etc., can be exaggerated for clarity. Like reference numbers signify like elements. As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed items. In addition, use of “may” when describing embodiments of the present disclosure relates to “one or more embodiments of the present disclosure.” Expressions such as “at least one of,” and “any one of,” when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list. When such expressions are used, they are used to reduce the likelihood that the phrase will be interpreted to mean only one of the elements in the list. When a phrase such as “at least one of,” “any one of,” or “selected from the group consisting of” is used to specify elements A, B, and C, the phrase can refer to any and all combinations of A, B, and C, such as A, B, C, A and B, A and C, B and C, or A and B and C. And “used” can be considered synonymous with the term “utilized.” As used herein, the terms “substantially,” “approximately,” and similar terms are used as terms of approximation and not as terms of degree, and are intended to account for the inherent variations in a measurement or calculated value that would be recognized by those of ordinary skill in the art.

[0028] It should be understood that, although the terms first, second, third, etc. can be used herein to describe various elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms are used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of example embodiments.

[0029] To facilitate description, spatially relative terms, such as “beneath,” “below,” “lower,” “above,” “upper,” and the like, can be used herein for describing the relationship of one element or feature to another element or feature as shown in the drawings. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation, in addition to the orientations depicted in the drawings. For example, if a device in the drawings is inverted, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the term “below” can encompass both an orientation of above and below. The device can be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

[0030] The terminology used herein is for the purpose of describing embodiments of the present disclosure and is not intended to be limiting of the present disclosure. As used herein, the singular forms "a" and "an" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "includes," "including," "comprises," and / or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0031] Further, any numerical range recited herein is intended to include all sub-ranges of the same whole number precision subsumed within the recited range. For example, a range of "1.0 to 10.0" is intended to include all sub-ranges, half- sub-ranges, whole number sub-ranges, and / or decimal number sub-ranges, within the same precision, within the indicated range (e.g., 2.4 to 7.6, 3.14 to 5.1, 0 to 10, 10 to 10, 5.5 to 6.4, etc.). Any maximum numerical limitation recited herein is intended to include all lower numerical limitations subsumed therein and any minimum numerical limitation recited in this detailed description is intended to include all higher numerical limitations subsumed therein. Accordingly, Applicant reserves the right to amend this specification, including the claims, to expressly recite any sub-range subsumed within the ranges expressly recited in this detailed description. All such ranges are intended to be inherently described in this specification such that amending to expressly recite any such sub-ranges would conform to the requirements of 35 U.S.C. § 112, first paragraph, and 35 U.S.C. § 132(a). All such ranges are intended to be inherently described in this specification such that amending to expressly recite any such sub-ranges would conform to the requirements of 35 U.S.C. § 112, first paragraph, and 35 U.S.C. § 132(a).

[0032] Referring to two compared elements, features, etc. as "the same" can mean that they are "substantially the same." Thus, the phrase "substantially the same" can include having a deviation that is considered low in the art, such as 5% or less. Further, when a certain parameter is referred to as uniform in a given region, this can mean that it is uniform in terms of average.

[0033] Throughout this specification, unless otherwise indicated, each element can be singular or plural.

[0034] Arranging an arbitrary element "on (or under)" or "above (below)" another element can mean that the arbitrary element can be elementally arranged with the upper (or lower) surface element of the contact, and another element can also be interposed between the element and the arbitrary element arranged on (or under) the element.

[0035] Further, it should be understood that when a component is referred to as being "connected," "coupled," or "connected" to another component, the element can be directly "connected," "coupled," or "connected" to each other, or another component can be "interposed" between the components.

[0036] Throughout the specification, unless otherwise indicated, when stating "A and / or B", it is meant A, B, or A and B. That is, "and / or" includes any or all combinations of the items in the list. "C ~ D" means C or more and D or less, unless otherwise indicated.

[0037] As used herein, "homopolymer glass transition temperature" can refer to a glass transition temperature (Tg) measured using a differential scanning calorimeter (Discovery, TA Instruments Inc.) on a homopolymer of a target monomer. Specifically, a homopolymer of a target monomer is heated to 180 °C at a heating rate of 20 °C / min, gradually cooled to -100 °C, and heated to 100 °C at a heating rate of 10 °C / min to obtain data on an endothermic transition curve, and the glass transition temperature is found by an inflection point of the endothermic transition curve.

[0038] As used herein, "light transmittance" refers to total light transmittance.

[0039] As used herein, "light emitting device" includes organic or organic / inorganic hybrid light emitting devices, and can refer to a device including a light emitting diode (LED), an organic light emitting diode (OLED), a quantum dot light emitting diode (QLED), a light emitting material such as a phosphor, etc.

[0040] As used herein, "(meth)acrylic acid" refers to acrylic acid and / or methacrylic acid.

[0041] As used herein, "maximum absorption wavelength" refers to a wavelength at which a maximum absorbance occurs in an absorbance measurement of a dye solution in which a dye is dissolved at a concentration of 10 ppm in methyl ethyl ketone. The absorbance can be measured by typical methods known to those skilled in the art.

[0042] As used herein, to express a specific numerical range, the expression "X to Y" means "greater than or equal to X and less than or equal to Y (X ≤ and ≤ Y)".

[0043] Embodiments of the present disclosure provide an optical member. The optical member can be used in an optical display device in the absence of a polarizing plate, which can include a polarizer. In one embodiment, the optical display device can be a light emitting display device in the absence of a polarizing plate.

[0044] The optical member can have a low change in light transmittance even after long-term exposure to UV light, and even under repeated temperature fluctuations between room temperature and high temperature. In one embodiment, the optical member can be configured to prevent external light from damaging a light emitting device even after long-term exposure to UV light and even under repeated temperature fluctuations between room temperature and high temperature.

[0045] In one embodiment, the optical member can have a change in optical transmittance (AT( )) equal to or less than 3% calculated according to Equation 1. In this way, the optical member can be configured to reduce damage to the light emitting device, thereby improving the lifetime of the light emitting display device, even after long exposure to UV light.

[0046] [Equation 1]

[0047] AT( ) = |T2( ) - T1( )|,

[0048] where T1( ) is the optical transmittance of the optical member at a wavelength of (nm) in the range of 400 nm to 585 nm (unit: %), T2( ) is the optical transmittance of the optical member at a wavelength of (nm) in the range of 400 nm to 585 nm (unit: %), which is measured after a total of, for example, 21 light irradiation cycles, where one cycle is defined as irradiating the optical member with UV light of 340 nm at 0.35 W / m2for 4 hours at 25 °C, followed by 8 hours at 63 °C. 2 The optical member is irradiated while the optical member is placed at 25 °C for 4 hours, followed by 8 hours at 63 °C.

[0049] In one embodiment, AT( ) calculated according to Equation 1 can be a value measured at a wavelength of 400 nm.

[0050] In one embodiment, AT( ) calculated according to Equation 1 can be a value measured at a wavelength of 490 nm.

[0051] In one embodiment, AT( ) calculated according to Equation 1 can be a value measured at a wavelength of 585 nm.

[0052] In one embodiment, the optical member can have a change in optical transmittance (AT( )) equal to or less than 3%, for example, 1% to 2.9% or 2.15% to 2.84%, calculated according to Equation 1.

[0053] In an embodiment, T1 in Equation 1 can be equal to or less than 30%, for example, 10% to 27%.

[0054] In an embodiment, T2 in Equation 1 can be equal to or less than 30%, for example, 10% to 27%.

[0055] The optical member can include an adhesive layer, a transmittance control layer formed on an upper surface of the adhesive layer, and a base film formed on an upper surface of the transmittance control layer. The transmittance control layer includes a (meth)acrylic copolymer and a dye mixture. The dye mixture includes a first dye having a maximum absorption wavelength of 400 nm to 440 nm, a second dye having a maximum absorption wavelength of 480 nm to 520 nm, a third dye having a maximum absorption wavelength of 570 nm to 610 nm, and a fourth dye having a maximum absorption wavelength of 650 to 700 nm. The (meth)acrylic copolymer includes an alicyclic group-containing (meth)acrylic copolymer having a glass transition temperature of 50℃ to 150℃. The alicyclic group-containing (meth)acrylic copolymer includes 35 wt% to 70 wt% of an alicyclic group-containing (meth)acrylic monomer.

[0056] The optical member can further include a release film applied on a lower surface of the adhesive layer to protect the adhesive layer.

[0057] The adhesive layer

[0058] The adhesive layer can be configured to adhere the optical member to a panel for an optical display apparatus. The adhesive layer can include a cured product of a composition.

[0059] In one embodiment, the cured product can be a thermally cured product of the composition.

[0060] The composition can include a UV absorber and a (meth)acrylic copolymer.

[0061] The UV absorber can be configured to absorb light having a wavelength range of 360 nm to 410 nm. The UV absorber can be configured to substantially prevent external light from damaging a light emitting device by absorbing light having a wavelength range of 360 nm to 410 nm.

[0062] In one embodiment, the UV absorber can be an indole UV absorber.

[0063] The indole UV absorber can not only have a low light transmittance at a wavelength of 360 nm to 410 nm or 400 nm to 405 nm compared to other types of UV absorbers, and thus can be configured to sufficiently suppress damage to a light emitting device. In one embodiment, the optical member including the indole UV absorber can have a light transmittance equal to or less than 5% at a wavelength of 405 nm.

[0064] In one embodiment, the indole UV absorber can include a compound represented by Formula 1:

[0065] < Formula 1 >

[0066] wherein R 1It is hydrogen or substituted or unsubstituted C1 to C2. 10 alkyl,

[0067] R 2 It is hydrogen or substituted or unsubstituted C6 to C6. 20 Aryl,

[0068] R 3 It is hydrogen or substituted or unsubstituted C1 to C2. 10 alkyl,

[0069] R 4 It is hydrogen, cyano (-CN), or substituted or unsubstituted C1 to C2. 10 Alkyl, and

[0070] R 5 It is cyano or -(C=O)-OR 6 (R 6 It is substituted or unsubstituted C1 to C 10 Alkyl groups or substituted or unsubstituted C6 to C6 20 Aryl).

[0071] In one embodiment, R 1 It can be a C1 to C5 alkyl group, such as methyl, R 2 It can be C6 to C 10 Aryl, such as phenyl, R 3 It can be hydrogen or C1 to C5 alkyl, such as hydrogen, R 4 It can be cyano, R 5 It can be cyano or -(C=O)-OR 6 (R 6 (It is a substituted or unsubstituted C1 to C5 alkyl group). In one embodiment, the compound represented by Formula 1 may include the compound represented by Formula 1-1 or the compound represented by Formula 1-2:

[0072] <Formula 1-1>

[0073]

[0074] <Formula 1-2>

[0075]

[0076] The compounds represented by Formula 1 may have a melting point equal to or greater than 100 °C, for example, from 140 °C to 220 °C, and may exist in a solid phase at room temperature. The compounds represented by Formula 1 may be synthesized by methods known in the art or may be commercially available products.

[0077] The compound represented by Formula 1 can have an absorbance equal to or greater than 0.8 absorbance units (AU), for example, 0.8 AU to 1.0 AU at a wavelength of 390 nanometers under the following conditions: chloroform concentration: 10 mg / L; and path length: 1 cm, and can have a maximum absorption wavelength greater than 390 nanometers, for example, greater than 390 nanometers and equal to or less than 400 nanometers, or greater than 390 nanometers and less than 400 nanometers. Within these ranges, the compound represented by Formula 1 can reduce the light transmittance of the optical member by sufficiently absorbing light having a wavelength of less than or equal to 420 nanometers, for example, at a wavelength of 400 nanometers to 420 nanometers, thereby improving the stability of the light-emitting device with respect to external light. As used herein, the "maximum absorption wavelength" refers to the wavelength at which a maximum absorption peak occurs, i.e., the wavelength corresponding to the maximum absorbance in the absorbance curve as a function of wavelength. The absorbance can be measured by methods known in the art.

[0078] The UV absorber can be present in an amount of 0.1% to 3% by weight with respect to the adhesive layer. In this way, damage to the light-emitting device can be sufficiently suppressed without reducing the light transmittance of the optical member, for example, by having an excess of the UV absorber. In one embodiment, the UV absorber can be present in an amount of 0.3% to 1.5% by weight with respect to the adhesive layer.

[0079] The UV absorber can be present in an amount of 0.3 parts by weight to 3 parts by weight, for example, 0.3 parts by weight to 1.5 parts by weight with respect to 100 parts by weight of the (meth)acrylic copolymer. In this way, the UV absorber can be configured to ensure a reduced light transmittance of the optical member at a wavelength of 380 nanometers without excessively increasing the color value b*, for example, by having an excess of the UV absorber.

[0080] In one embodiment, the adhesive layer can be a pressure-sensitive adhesive layer.

[0081] The (meth)acrylic copolymer can be a non-carboxylic copolymer that does not contain a carboxylic acid group. Use of a (meth)acrylic copolymer containing a carboxylic acid group can result in poor durability of the optical member when the optical member is bonded to a panel for an optical display device.

[0082] The (meth)acrylic copolymer can be a copolymer of a monomer mixture containing an alkyl-containing (meth)acrylic monomer having a homopolymer glass transition temperature equal to or less than -40°C, a monomer having a homopolymer glass transition temperature equal to or greater than 15°C, and a hydroxyl-containing (meth)acrylic monomer.

[0083] In one embodiment, the alkyl group-containing (meth)acrylic monomer having a homopolymer glass transition temperature of equal to or lower than -40°C, the monomer having a homopolymer glass transition temperature of equal to or higher than 15°C, and the hydroxyl group-containing (meth)acrylic monomer can be present in the monomer mixture in a total amount of 99 mol% or more, for example, 100 mol% or more. In this way, the (meth)acrylic copolymer can be configured to achieve the desired effects of the optical member described above.

[0084] The alkyl group-containing (meth)acrylic monomer having a homopolymer glass transition temperature of equal to or lower than -40°C can be configured to contribute to the improvement of the peeling strength of the adhesive layer and the formation of the matrix of the adhesive layer. In one embodiment, the alkyl group-containing (meth)acrylic monomer can have a homopolymer glass transition temperature of -80°C to -40°C. In one embodiment, the alkyl group-containing (meth)acrylic monomer can have a homopolymer glass transition temperature of -80°C to -50°C, for example, -80°C to -60°C. In this way, the alkyl group-containing (meth)acrylic monomer in combination with the (meth)acrylic monomer having a higher homopolymer glass transition temperature can be configured to achieve the desired effects of the optical member described above.

[0085] The alkyl group-containing (meth)acrylic monomer can include a (meth)acrylate having a C1 to C8 alkyl group having a straight chain or a branched chain at an ester site thereof. Here, the number of carbons refers to the number of carbon atoms forming the main chain of the alkyl group. In one embodiment, the alkyl group has a carbon number of 6 to 8.

[0086] In one embodiment, the alkyl group-containing (meth)acrylic monomer can include one or more of n-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, and isooctyl (meth)acrylate, but is not limited thereto. These compounds can be used alone or in combination. In one embodiment, the alkyl group-containing (meth)acrylic monomer having a homopolymer glass transition temperature of equal to or lower than -40°C is 2-ethylhexyl (meth)acrylate.

[0087] The alkyl group-containing (meth)acrylic monomer can be present in an amount of 65 mol% to 90 mol%, for example, 70 mol% to 90 mol% or 70 mol% to 85 mol% with respect to the monomer mixture. In this way, the alkyl group-containing (meth)acrylic monomer can be configured to improve the peeling strength of the adhesive layer.

[0088] The monomer having a homopolymer glass transition temperature of equal to or higher than 15°C can be essential to produce the desired effects of the optical member.

[0089] Monomers having a homopolymer glass transition temperature below 15 °C can result in undesirable optical properties, for example, during a sunlight test. For example, such monomers can have a homopolymer glass transition temperature of -30 °C to -10 °C.

[0090] In one embodiment, monomers having a homopolymer glass transition temperature equal to or greater than 15 °C can have a homopolymer glass transition temperature of 15 °C to 260 °C, for example, 15 °C to 210 °C. In this way, the monomers can be configured to achieve the desired effects of the optical member in combination with (meth)acrylic monomers having a lower homopolymer glass transition temperature.

[0091] Monomers having a homopolymer glass transition temperature of 15 °C or greater can include at least one of a (meth)acrylate having an alkyl or alicyclic group at the ester site, or a maleimide having an alicyclic group or an aromatic group.

[0092] In one embodiment, the (meth)acrylate having an alkyl group at the ester site is t-butyl (meth)acrylate or vinyl acetate. In one embodiment, the (meth)acrylate having an alicyclic group at the ester site can include one or more of isobornyl (meth)acrylate, cyclohexyl (meth)acrylate, and dicyclopentadienyl (meth)acrylate. In one embodiment, the maleimide having an alicyclic group is N-cyclohexyl maleimide, or the like. In one embodiment, the maleimide having an aromatic group is phenyl maleimide, or the like.

[0093] Monomers having a homopolymer glass transition temperature equal to or greater than 15 °C can be present in an amount of 5 mol% to 40 mol%, for example, 10 mol% to 30 mol% or 15 mol% to 30 mol% relative to the monomer mixture. In this way, the monomers can be configured to ensure that the optical member meets the requirements of Equation 1 without negatively impacting the peel strength of the adhesive layer.

[0094] Hydroxyl-containing (meth)acrylic monomers can enhance the peel strength of the adhesive layer by reacting with the curing agent. The hydroxyl-containing (meth)acrylic monomers are hydroxyl-containing (meth)acrylates, which can include C1-C20 (meth)acrylates having at least one hydroxyl group at the ester site. 20 In one embodiment, the hydroxyl-containing (meth)acrylic monomers can be one or more of 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, and 1-chloro-2-hydroxypropyl (meth)acrylate. These compounds can be used individually or in a mixture.

[0095] The hydroxyl group-containing (meth)acrylic monomer can be present in an amount of 0.1 to 5 mole %, for example, 0.5 to 3 mole % or 0.5 to 1 mole % relative to the monomer mixture. As such, the hydroxyl group-containing (meth)acrylic monomer can be configured to ensure that the optical member satisfies the requirement of Equation 1 without reducing the mechanical strength of the adhesive layer.

[0096] The monomer mixture can be free of a long-chain alkyl group-containing (meth)acrylate. The use of a long-chain alkyl group-containing (meth)acrylate in the monomer mixture can result in insufficient cohesion and adhesion of the adhesive layer. As used herein, a “long-chain alkyl group-containing (meth)acrylate” can refer to a (meth)acrylate having a C 10 to a C 25 alkyl group. Here, the number of carbons refers to the number of carbon atoms forming the main chain of the long-chain alkyl group.

[0097] The glass transition temperature of the (meth)acrylic copolymer can be -60 to -10 °C, for example, -60 to -30 °C, -60 to -40 °C, or -60 to -50 °C. As such, the (meth)acrylic copolymer can be configured to achieve a desired effect of the optical member.

[0098] The weight average molecular weight of the (meth)acrylic copolymer can be 500,000 to 1,500,000 g / mol, for example, 500,000 to 1,000,000 g / mol or 600,000 to 1,000,000 g / mol. As such, the (meth)acrylic copolymer can be configured to achieve a desired effect of the optical member.

[0099] The (meth)acrylic copolymer can be prepared by polymerizing the monomer mixture using a polymerization method known in the art. In one embodiment, the (meth)acrylic copolymer can be prepared by adding an initiator to the monomer mixture, followed by a typical copolymer polymerization process / fabrication process, such as suspension polymerization, emulsion polymerization, solution polymerization, etc. In one embodiment, the polymerization of the monomer mixture can be performed at a temperature of 65 to 70 °C for 6 to 8 hours. The initiator can be an initiator known in the art, including but not limited to an azo polymerization initiator and a peroxide polymerization initiator, such as benzoyl peroxide or acetyl peroxide.

[0100] The composition can further include a curing agent.

[0101] The curing agent can provide a peeling strength by reacting with the (meth)acrylic copolymer.

[0102] The curing agent can include a thermal curing agent. The thermal curing agent can be configured to facilitate the formation of the adhesive layer from the adhesive layer composition including the UV absorber.

[0103] The curing agent can be present in an amount of 0.1 parts by weight to 5 parts by weight, for example, 0.05 parts by weight to 2.5 parts by weight, relative to 100 parts by weight of the (meth)acrylic copolymer. In this way, the curing agent can be configured to ensure adhesion of the adhesive layer by inducing crosslinking of the adhesive layer composition, without sacrificing transparency due to an excess of the curing agent.

[0104] The thermal curing agent can include one or more of isocyanate curing agents, metal chelate curing agents, epoxy curing agents, aziridine curing agents, amine curing agents, and thermal polymerization initiators. In one embodiment, the thermal curing agent can include at least one of isocyanate curing agents or metal chelate curing agents. These curing agents can be used individually or in combination.

[0105] The isocyanate curing agent can be multifunctional, for example, a di- to hexa-functional isocyanate curing agent, and can include one or more of xylene diisocyanate (XDI) such as m-xylene diisocyanate, methylene bis(phenyl isocyanate) (MDI) such as 4,4’-methylene bis(phenyl isocyanate), naphthalene diisocyanate, toluene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and adducts thereof.

[0106] The metal chelate curing agent can include a coordination compound of a polyvalent metal such as aluminum. In one embodiment, the metal chelate curing agent can include an aluminum chelate compound, for example, aluminum tris(ethylacetoacetate), aluminum diisopropylate ethylacetoacetate, aluminum tris(acetylacetone), and the like.

[0107] The adhesive layer composition can include a solvent. The solvent can be configured to improve coatability of the adhesive layer composition while preventing self-curing of the adhesive layer composition. The solvent can include typical solvents known in the art. In one embodiment, the solvent can include one or more of methyl ethyl ketone, ethyl acetate, and toluene.

[0108] The adhesive layer composition can further include one or more of a silane coupling agent, a rework agent, a curing catalyst, and an antistatic agent.

[0109] The silane coupling agent can be configured to provide better adhesion of the adhesive layer to a substrate such as glass. The silane coupling agent can include typical silane coupling agents known in the art. In one embodiment, the silane coupling agent can include one or more of silicone compounds having an epoxy structure such as 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropylmethyldimethoxysilane, and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane; vinyltrimethoxysilane, vinyltriethoxysilane, (meth)acryloxypropyltrimethoxysilane, and the like polymerizable organosilicon compounds containing an unsaturated group; 3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, and the like amino group-containing organosilicon compounds; and 3-chloropropyltrimethoxysilane, but not limited thereto. The silane coupling agent can be present in an amount of 0.001 parts by weight to 5 parts by weight, for example, 0.001 parts by weight to 3 parts by weight, with respect to 100 parts by weight of the (meth)acrylic copolymer. In this way, the silane coupling agent can be configured to ensure good durability of the adhesive layer while reducing changes in the composition and properties of the adhesive layer over time.

[0110] The reprocessing agent can be configured to improve the reprocessability of the adhesive layer, and can include a polysiloxane oligomer or a mixture including a polysiloxane oligomer. The reprocessing agent can be present in an amount of 0.001 parts by weight to 5 parts by weight, for example, 0.005 parts by weight to 1 part by weight, with respect to 100 parts by weight of the (meth)acrylic copolymer. In this way, the reprocessing agent can improve the reprocessability of the adhesive layer without negatively affecting the properties of the adhesive layer.

[0111] The antistatic agent can be configured to suppress the generation of static electricity during the reprocessing of the adhesive layer, and can include typical antistatic agents known in the art. The antistatic agent can be present in an amount of 0.001 parts by weight to 5 parts by weight, for example, 0.1 parts by weight to 5 parts by weight, with respect to 100 parts by weight of the (meth)acrylic copolymer. In this way, the antistatic agent can provide antistatic properties without affecting the performance of the adhesive layer.

[0112] The curing catalyst can include one or more of a boron compound such as a boron trifluoride complex, particularly an etherate of boron trifluoride, a tetrahydrofuran complex of boron trifluoride (BF3-THF), or an aniline complex of boron trifluoride (BF3-aniline), such as BF3·O(CH3)2(borondimethyl etherate) or BF3·O(C2H5)2·O(boron diethyl etherate); a phosphine compound such as triphenylphosphine, tributylphosphine, tri(p-methylphenyl)phosphine, tri(nonylphenyl)phosphine, triphenylphosphine / triphenylborate, tetraphenylborate, or the like; a secondary or tertiary amine compound such as an α-tertiary amine compound (e.g., KH-30, Kukdo Chemical Co., Ltd.) such as triethylamine, benzyldiethylamine, or benzyldimethylamine; an imidazole compound such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, or the like; or a sulfonic acid compound such as p-toluenesulfonic acid, dodecylbenzenesulfonic acid, naphthalenesulfonic acid, naphthalenedisulfonic acid, methanesulfonic acid, methanedisulfonic acid, phenolsulfonic acid, or the like. The curing catalyst can be present in an amount of 0.01 to 5 parts by weight, such as 0.05 to 2 parts by weight, with respect to 100 parts by weight of the (meth)acrylic copolymer. In this way, the curing catalyst can be configured to reduce the time required to complete curing.

[0113] The adhesive layer composition can further include additives known in the art. The additives can include antioxidants, adhesion-imparting resins, plasticizers, and the like. The additives can be present in an amount of 0.001 parts by weight to 5 parts by weight, such as 0.01 parts by weight to 1 parts by weight, with respect to 100 parts by weight of the (meth)acrylic copolymer. In this way, the additives can be configured to provide the intended effects without negatively affecting the properties of the adhesive layer.

[0114] The adhesive layer composition can have a viscosity of 1,000 centipoise (cP) to 4,000 cP at 25°C. In this way, the adhesive layer composition can be configured to allow easy adjustment of the thickness of the adhesive layer, ensure that the adhesive layer is free of stains, and ensure a uniform coating surface.

[0115] The thickness of the adhesive layer can be equal to or less than 100 µm, such as 5 µm to 50 µm. In this way, the adhesive layer can be used in optical display devices.

[0116] The adhesive layer can be formed by, but is not limited to, coating the adhesive layer composition to a predetermined thickness, drying the coated composition, and aging the dried composition in a constant temperature and humidity chamber at a temperature of 25°C to 35°C and a relative humidity of 30% to 60%.

[0117] Transmittance control layer

[0118] A transmittance control layer can be formed between the adhesive layer and the base film and configured to provide color conversion. In one embodiment, the transmittance control layer includes a dye mixture including a first dye having a maximum absorption wavelength of 400 nanometers to 440 nanometers, a second dye having a maximum absorption wavelength of 480 nanometers to 520 nanometers, a third dye having a maximum absorption wavelength of 570 nanometers to 610 nanometers, and a fourth dye having a maximum absorption wavelength of 650 nanometers to 700 nanometers.

[0119] The first dye has a maximum absorption wavelength from 400 nanometers to 440 nanometers and can be configured to reduce reflectance and improve screen quality. In one embodiment, the first dye can have a maximum absorption wavelength of 420 nanometers to 440 nanometers, such as 400, 405, 410, 415, 420, 425, 430, 435, 440 nanometers.

[0120] The first dye can be a dialkoxy-substituted porphyrin dye. In one embodiment, the first dye can be a dye represented by Formula 2:

[0121] < Formula 2 >

[0122]

[0123] The first dye can be present in an amount of 0.001 wt% to 5 wt%, such as 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5 wt%, 1 wt% to 5 wt%, or 0.1 wt% to 2% relative to the transmittance control layer. In this way, the first dye can be configured to increase transmittance and reduce reflectance in combination with other dyes in the transmittance control layer.

[0124] The second dye can have a maximum absorption wavelength from 480 nanometers to 520 nanometers and can be configured to reduce reflectance and improve screen quality. In one embodiment, the second dye can have a maximum absorption wavelength of 490 nanometers to 520 nanometers, such as 480, 485, 490, 495, 500, 505, 510, 515, 520 nanometers.

[0125] The second dye can be a BODIPY (4,4-difluoro-4-bora-3a,4a-diaza-s-indacene) dye or a mixture including a BODIPY dye. For example, the BODIPY dye can include a dye represented by Formula 3:

[0126] < Formula 3 >

[0127]

[0128] The second dye can be present in an amount of 0.001 to 5 weight percent, for example, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5 weight percent, 0.1 to 5 weight percent, or 0.1 to 2 weight percent relative to the transmittance control layer. In this way, the second dye can be configured to increase transmittance and decrease reflectance in combination with other dyes in the transmittance control layer.

[0129] The third dye can have a maximum absorption wavelength of from 570 to 610 nanometers, for example, 570, 575, 580, 585, 590, 595, 600, 605, 610 nanometers.

[0130] The third dye can be a tetraazaporphyrin dye or a mixture including a tetraazaporphyrin dye.

[0131] The third dye can be present in an amount of 0.001 to 5 weight percent, for example, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5 weight percent, 0.1 to 5 weight percent, or 0.1 to 2 weight percent relative to the transmittance control layer. In this way, the third dye can be configured to increase transmittance and decrease reflectance in combination with other dyes in the transmittance control layer.

[0132] The fourth dye can have a maximum absorption wavelength from 650 nanometers to 700 nanometers and can be configured to reduce reflectance and improve screen quality.

[0133] The fourth dye can be a sulfonamide-substituted copper complex dye or the like. In one embodiment, the sulfonamide-substituted copper complex dye can include a dye represented by Formula 4:

[0134] < Formula 4 >

[0135]

[0136] The fourth dye can be present in an amount of 0.001 wt% to 5 wt%, such as 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5 wt%, 0.1 wt% to 5 wt%, or 0.1 wt% to 2 wt% relative to the transmittance control layer. In this way, the fourth dye can be configured to increase transmittance and reduce reflectance in combination with other dyes in the transmittance control layer.

[0137] The mixture of the first dye, the second dye, the third dye, and the fourth dye mixture can be present in an amount of 3 wt% to 15 wt%, such as 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 wt%, 3 wt% to 10 wt% relative to the transmittance control layer. In this way, the dye mixture can be configured to reduce reflectance and improve screen quality.

[0138] The dye mixture can degrade when exposed to UV light for a long time under repeated temperature fluctuations between room temperature and high temperature.

[0139] The transmittance control layer can include a (meth)acrylic copolymer, where the (meth)acrylic copolymer can be a alicyclic group-containing (meth)acrylic copolymer having a glass transition temperature of 50°C to 150°C. Since the (meth)acrylic copolymer has a glass transition temperature equal to or greater than 50°C, the (meth)acrylic copolymer can be configured to prevent degradation of the dye mixture while minimizing changes in brightness and reflectance. Further, since the (meth)acrylic copolymer has a glass transition temperature equal to or less than 150°C, the (meth)acrylic copolymer can be configured to prevent degradation of the dye mixture while minimizing changes in brightness and reflectance.

[0140] In one embodiment, the (meth)acrylic copolymer can be a copolymer of a monomer mixture including a cycloaliphatic group-containing monomer, where the cycloaliphatic group-containing monomer can be present in an amount of 35 to 70 weight percent, for example, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70 weight percent, 40 to 70 weight percent, or 50 to 60 weight percent, with respect to the monomer mixture. As such, the cycloaliphatic group-containing monomer can be configured to further enhance the effectiveness of the (meth)acrylic copolymer in protecting the dye mixture and minimize changes in brightness and reflectance.

[0141] The cycloaliphatic group-containing (meth)acrylic monomer can include a C5 to C 20 The cycloaliphatic group-containing (meth)acrylic monomer can include a C5 to C

[0142] In one embodiment, the cycloaliphatic group-containing (meth)acrylic monomer can include one or more of cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentyl (meth)acrylate, methylcyclohexyl (meth)acrylate, and dicyclopentenyl (meth)acrylate.

[0143] In addition to the cycloaliphatic group-containing (meth)acrylic monomer, the monomer mixture can include a co-monomer (or second monomer). The co-monomer can have a homopolymer glass transition temperature equal to or greater than 50°C, for example, 50°C to 150°C. As such, the (meth)acrylic copolymer can be configured to meet the glass transition temperature requirement.

[0144] The co-monomer can include any co-monomer having a homopolymer glass transition temperature equal to or greater than 50°C, for example, 50°C to 150°C, but is not limited thereto.

[0145] In one embodiment, the co-monomer can include an alkyl group-containing (meth)acrylic monomer. In one embodiment, the alkyl group-containing (meth)acrylic monomer can include a (meth)acrylate having a C1 to C 10 The alkyl group-containing (meth)acrylic monomer can include a (meth)acrylate having a C1 to C

[0146] The comonomer can be present in an amount of 30 to 65 weight percent, for example 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60 weight percent, 30 to 60 weight percent, or 40 to 50 weight percent, relative to the monomer mixture. As such, the comonomer can be configured to form a matrix of the transmittance control layer.

[0147] In one embodiment, the alicyclic group-containing (meth)acrylic monomer and the comonomer having a homopolymer glass transition temperature equal to or greater than 50°C, for example 50 to 150°C, can be present in a total amount equal to or greater than 95 weight percent, for example 98 to 100 weight percent, or 100 weight percent, relative to the monomer mixture. As such, the transmittance control layer can be configured to achieve a desired effect of the optical member.

[0148] The transmittance control layer can have a thickness equal to or less than 100 pm, for example 1 to 50 pm. As such, the transmittance control layer can be used in an optical display device.

[0149] Substrate film

[0150] The substrate film can be formed on the transmittance control layer and can be configured to protect the adhesive layer and the transmittance control layer and to enhance the mechanical strength of the optical member. In one embodiment, the substrate film can be directly formed on the transmittance control layer. As used herein, the expression “directly formed” means that there is no other adhesive layer or bonding layer between the substrate film and the transmittance control layer.

[0151] In one embodiment, the substrate film can have a light transmittance equal to or greater than 80%, for example 90 to 99%. As such, the substrate film can be configured to improve the luminous efficiency by not negatively affecting the optical path of external light or internal light that transmits through the optical member.

[0152] In one embodiment, the substrate film can have a light transmittance equal to or less than 1%, for example 0.1 to 1%, at a wavelength of 380 nanometers.

[0153] The substrate film can include at least one of an optically transparent protective film or an optically transparent protective coating.

[0154] In one embodiment, the base film is a protective film type. The base film can include a protective film formed of an optically transparent resin. The protective film can be formed by melt-extrusion of the resin. As necessary, the resin can be further subjected to a stretching process / fabrication process. The resin can include one or more of a cellulose ester resin such as triacetyl cellulose, a cyclic polyolefin resin such as amorphous cyclic olefin polymer (COP), a polycarbonate resin, a polyester resin such as polyethylene terephthalate (PET), a polyethersulfone resin, a polysulfone resin, a polyamide resin, a polyimide resin, an acyclic polyolefin resin, a poly(meth)acrylate resin such as poly(methyl methacrylate), a polyvinyl alcohol resin, a polyvinyl chloride resin, and a polyvinylidene chloride resin.

[0155] In one embodiment, the base film is a protective coating type. The base film can have good properties in terms of adhesion to the adhesive layer, transparency, mechanical strength, thermal stability, moisture barrier ability, and durability. In one embodiment, the protective coating as the base film can be formed of an actinic radiation-curable resin composition including an actinic radiation-curable compound and a polymerization initiator.

[0156] The actinic radiation-curable compound can include one or more of a cationically polymerizable curable compound, a radically polymerizable curable compound, a urethane resin, and a silicone resin. The cationically polymerizable curable compound can be an epoxy compound having at least one epoxy group in a molecule or an oxetane compound having at least one oxetane ring in a molecule. The radically polymerizable curable compound can be a (meth)acrylic compound having at least one (meth)acryloyloxy group in a molecule.

[0157] The thickness of the base film can be 5 μm to 200 μm, for example, 30 μm to 120 μm or 50 μm to 100 μm (in the case of the protective film type), or 5 μm to 50 μm (in the case of the protective coating type). As such, the base film can be used for an optical display device.

[0158] The optical member can be free of a functional coating, such as an anti-reflection layer, on one or more surfaces of the base film.

[0159] Figure 1 is a cross-sectional view of an optical member according to an embodiment of the disclosure.

[0160] Referring to Figure 1 , the optical member includes an adhesive layer 300, and a transmittance control layer 100 and a base film 200 formed in that order on an upper surface of the adhesive layer 300. Although not shown in Figure 1 , the optical member can further include a release film formed on a lower surface of the adhesive layer 300.

[0161] Embodiments of the present disclosure provide an optical display apparatus.

[0162] The optical display apparatus can include an optical member.

[0163] In one embodiment, the optical display apparatus can include a panel for the optical display apparatus, and the optical member can be stacked on the panel.

[0164] In one embodiment, the optical display does not have a polarizing plate. By the optical member capable of replacing the function of the polarizing plate, it is possible to configure to prevent damage to the light emitting device even in the absence of the polarizing plate.

[0165] The optical display apparatus can include a liquid crystal display apparatus, a light emitting display apparatus such as an organic light emitting display apparatus, etc., but is not limited thereto.

[0166] Examples

[0167] The present disclosure includes a more detailed description with reference to certain examples. However, it should be noted that these examples are provided only for illustration and should not be construed in any way as limiting.

[0168] Preparation Example 1: Preparation of (Meth)acrylic Acid Copolymer

[0169] First, 50 g of toluene was put into a 500 mL reactor having a reflux condenser for temperature control and a nitrogen inlet. Then, 100 parts by weight of a monomer mixture containing the monomers listed in Table 1 in the amounts listed in Table 1 was added to the reactor. Thereafter, nitrogen was introduced into the reactor for 30 minutes to purge oxygen from the reactor, remove any residual oxygen from the monomer mixture, and then the internal temperature of the reactor was maintained at 70°C. After the monomer mixture was sufficiently stirred, 0.06 parts by weight of V601 (2,2'-azobis(2-methylpropanediol dimethylate)) was added to the reactor as an initiator and chain extender, the internal temperature of the reactor was raised to 75°C, and maintained for 4 hours. After maintaining the internal temperature at 75°C for an additional 2 hours, the reactor was cooled to room temperature, and toluene was added to the reactor, thereby preparing a solution containing 35% by weight of the (meth)acrylic acid copolymer. The weight average molecular weight and glass transition temperature of the prepared (meth)acrylic acid copolymer were analyzed by gel permeation chromatography (GPC) and differential scanning calorimetry (DSC).

[0170] Preparation Examples 2 to 6, 8: Preparation of (Meth)acrylic Acid Copolymer

[0171] (Meth)acrylic acid copolymers were prepared in the same manner as in Preparation Example 1, except that the types and contents of each monomer in the monomer mixture were changed, as shown in Table 1, and the content of the initiator or the reaction time were also changed. In Table 1, "-" indicates that the content of the corresponding component is 0 mol%.

[0172] Preparation Example 7: IF850NP was used as a (meth)acrylic acid copolymer.

[0173] Table 1

[0174] Preparation Example MMA MA CHA IBXA DCPA Mw Tg 1 50 - 50 - - 165,550 53.8 2 50 - - 50 - 177,276 112.4 3 50 - - - 50 190,092 95.9 4 40 - 60 - - 158,500 52.1 5 100 - - - - 166,561 105 6 46 54 - - - 199,436 45.6 7 100 - - - - 87,021 105 8 80 - 20 - - 187,551 84

[0175] *In Table 1,

[0176] MMA: Methyl methacrylate (homopolymer Tg: 105℃, Sigma-Aldrich Chemical Co., Inc.)

[0177] MA: Methyl acrylate (homopolymer Tg: 8℃, Sigma-Aldrich Chemical Co., Inc.)

[0178] CHA: Cyclohexyl acrylate (homopolymer Tg: 19℃, TCI Corporation)

[0179] IBXA: Isoborneol acrylate (homopolymer Tg: 94℃, Sigma-Aldrich Chemical Co., Inc.)

[0180] DCPA: Dicyclopentyl acrylate (homopolymer Tg: 120℃, TCI Corporation)

[0181] Details of the ingredients used in the examples and comparative examples are described below.

[0182] (A) (Meth)acrylic acid copolymer: (Meth)acrylic acid copolymers prepared in Examples 1 to 8 (see Table 1).

[0183] (B) Dyes

[0184] (B1)VP-40 (maximum absorption wavelength: 431 nm, diekoxy-substituted porphyrin (Cu) 2+ (Complex) dye, synthesis, represented by the following formula)

[0185]

[0186] (B2)FDB-022 (Maximum absorption wavelength: 493 nm, structure not disclosed, Yamada Chemical Co., Ltd.)

[0187] (B3) CD30 (maximum absorption wavelength: 506 nm, py-EWG-substituted BODIPY dye, synthesized, represented by the following formula)

[0188]

[0189] (B4) FDG-004 (maximum absorption wavelength: 576 nm, undisclosed structure, Yamada Chemical Co., Ltd.)

[0190] (B5) AMC 581 (maximum absorption wavelength: 581 nm, undisclosed structure, AMC Co.)

[0191] (B6) KIS-001 (maximum absorption wavelength: 593 nm, tetraazaporphyrin dye, Kyowha Synthetic Co., Ltd.)

[0192] (B7) FDR-001 (maximum absorption wavelength: 604 nm, undisclosed structure, Yamada Chemical Co., Ltd.)

[0193] (B8) RP-Cu-01 (maximum absorption wavelength: 676 nm, sulfonamide-substituted PC dye, synthesized, represented by the following formula)

[0194]

[0195] Example 1

[0196] The (meth)acrylic acid copolymer prepared in Preparation Example 1 was dissolved in toluene at a concentration of 35% by weight. Each of the dyes (B1) to (B8) was dissolved in methyl ethyl ketone or toluene at a concentration of 1% to 5% by weight. The resulting solutions were mixed in amounts corresponding to the solid contents listed in Table 3, thereby preparing transmittance control layer compositions.

[0197] The prepared transmittance control layer compositions were coated on the lower surface of a base film (triacetyl cellulose, thickness: 40 μm, PG402S, Showa Denko K.K.) at a prescribed thickness, and dried at 120°C for 2 minutes, thereby forming a transmittance control layer (thickness: 2.3 μm) on the lower surface of the base film.

[0198] An acrylic copolymer (containing no carboxylic acid group, CI-247, SOKEN Chemical Co., Ltd.) was mixed with a UV absorber (UA-3912, Orient Chemical Co., Ltd.), an isocyanate curing agent (TD-75, SOKEN Chemical Co., Ltd.), a crosslinking catalyst (Sn catalyst (DBTDL)), an adhesion promoter (CK-500), and a silane coupling agent (A-50), and then stirred with a mechanical stirrer for 20 minutes. Then, the resulting mixture was degassed for 40 minutes, thereby preparing an adhesive layer composition. The content of each component in the adhesive layer composition is shown in Table 2.

[0199] Table 2

[0200] Ingredient Content (g) CI-247 87.056 TD-75 0.091 tin catalyst 0.003 A-50 0.22 CK-500 12 UA-3912 0.63

[0201] The prepared adhesive layer composition was applied to one surface of a release film (thickness: 38 μm) at a prescribed thickness, dried at 100°C for 4 minutes, overlaid with a triacetyl cellulose film (thickness: 50 μm), and aged at 35°C, 45% RH for 2 days, thereby producing a stacked release film / adhesive layer (thickness: 15 μm) / triacetyl cellulose film.

[0202] Then, only the adhesive layer was attached to the lower surface of the transmittance control layer, thereby producing an optical member.

[0203] Examples 2 to 4

[0204] The kind of the (meth)acrylic acid copolymer in the transmittance control layer composition was changed as shown in Table 3, and otherwise, the optical member was produced in the same manner as in Example 1.

[0205] Comparative Examples 1 to 4

[0206] The kind of the (meth)acrylic acid copolymer in the transmittance control layer composition was changed as shown in Table 3, and otherwise, the optical member was produced in the same manner as in Example 1.

[0207] The properties listed in Tables 3 and 4 of the optical members produced in Examples 1 to 4 and Comparative Examples 1 to 4 were evaluated. The results are shown in Tables 3, 4, Figure 2 and Figure 3

[0208] (1) Color coordinates of the optical member

[0209] The luminance L, color value A*, and color value b* of each of the optical members produced in Examples 1 to 4 and Comparative Examples 1 to 4 under D65 light source extreme were calculated from the transmission spectrum of the optical member using a light transmittance measuring device (V-650 UV-Spectrometer, JASCO Corp.).​

[0210] (2) Reflectance of optical member

[0211] After each of the optical members manufactured in Examples 1 to 4 and Comparative Examples 1 to 4 was attached to a movable OLED panel using an adhesive layer of an optical member, the reflectance was measured using a spectrophotometer (CM-3600a, Konica Minolta, Inc.) in a reflection mode and an SCI mode.

[0212] (3) Estimated luminous efficiency

[0213] The film transmittance spectrum of each of the optical members manufactured in Examples 1 to 4 and Comparative Examples 1 to 4 was used to estimate the luminous efficiency of the panel. Assuming that the transmittance of a typical polarizing film is 50%, the luminance ratio of the optical member with respect to the polarizing film was calculated.

[0214] P(λ): OLED spectrum, y(λ): spectrum of each of the optical members manufactured in Examples 1 to 4 and Comparative Examples 1 to 4

[0215] Estimated luminous efficiency = (A / B)*100

[0216]

[0217] (4) Initial light transmittance of optical member

[0218] The optical members manufactured in Examples 1 to 4 and Comparative Examples 1 to 4 were each cut to a size of 25 mm x 200 mm (width x length), mounted on a glass plate, and samples were prepared. The light transmittance of the samples was measured using a light transmittance measuring device (V-650 UV-spectrometer, JASCO Corp.) in a wavelength range of 300 nm to 800 nm. The light transmittance at 400 nm, 490 nm, and 585 nm was calculated from the measurement results.

[0219] (5) Sunlight test

[0220] The optical members manufactured in Examples 1 to 4 and Comparative Examples 1 to 4 were each cut to a size of 25 mm x 200 mm (width x length), mounted on a glass plate, and samples were prepared. The prepared samples were placed in a UV chamber and irradiated with 340 nm UV light under the following conditions:

[0221] Sunlight test conditions: a total of 21 light irradiation cycles (a total of 252 hours), wherein one cycle is defined as irradiating the sample with 340 nm ultraviolet light at a fluence of 0.35 W / m 2 while the sample was left to stand at 25°C for 4 hours and at 63°C for 8 hours.

[0222] After the sample was removed from the UV chamber, the light transmittance at 400 nm, 490 nm, and 585 nm was measured at room temperature after 30 minutes, as in (4). The difference in light transmittance AT of the sample before and after the sunlight test was calculated.

[0223] Table 3

[0224]

[0225] Table 4

[0226]

[0227] As can be seen from Table 3, the optical members according to the present disclosure had reflectance of 6.5% to 9.5% measured on a panel and had minimal changes in light transmittance at wavelengths from 400 nm to 600 nm after long-term exposure to UV light under repeated temperature fluctuations between room temperature and high temperature.

[0228] In contrast, as shown in Table 4, the optical members of Comparative Examples 1 to 4 had reflectance of 6.5% to 9.5% measured on a panel compared to the optical members of Examples 1 to 4, but had relatively large changes in light transmittance at wavelengths from 400 nm to 600 nm after long-term exposure to UV light under repeated temperature fluctuations between room temperature and high temperature. In particular, the optical members of Comparative Examples 1 to 4 exhibited light transmittance changes of greater than 3% at wavelengths of 490 nm and 585 nm after long-term exposure to UV light under repeated temperature fluctuations between room temperature and high temperature.

[0229] It should be understood that various modifications, changes, alterations and equivalents can be made by those skilled in the art without departing from the spirit of the present disclosure.

Claims

1. An optical member comprising: an adhesive layer; a transmittance control layer formed on an upper surface of the adhesive layer, the transmittance control layer including a (meth)acrylic copolymer and a dye mixture, the dye mixture including a first dye having a maximum absorption wavelength of 400 to 440 nanometers, a second dye having a maximum absorption wavelength of 480 to 520 nanometers, a third dye having a maximum absorption wavelength of 570 to 610 nanometers, and a fourth dye having a maximum absorption wavelength of 650 to 700 nanometers; and a base film formed on an upper surface of the transmittance control layer, wherein the (meth)acrylic copolymer includes an alicyclic group-containing (meth)acrylic copolymer having a glass transition temperature of 50 to 150°C, and wherein the alicyclic group-containing (meth)acrylic copolymer includes 35 to 70% by weight of an alicyclic group-containing (meth)acrylic monomer.

2. The optical member of claim 1, wherein the alicyclic group-containing (meth)acrylic monomer comprises a mono- or bicyclic C5 to C 20 alicyclic group-containing (meth)acrylate.

3. The optical member according to claim 1, wherein the alicyclic group-containing (meth)acrylic monomer includes at least one of cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentyl (meth)acrylate, methylcyclohexyl (meth)acrylate, or dicyclopentenyl (meth)acrylate.

4. The optical member according to claim 1, wherein the alicyclic group-containing (meth)acrylic copolymer further includes a second monomer having a homopolymer glass transition temperature equal to or greater than 50°C.

5. The optical member according to claim 4, wherein the second monomer includes an alkyl-containing (meth)acrylic monomer.

6. The optical member according to claim 4, wherein the alicyclic group-containing (meth)acrylic copolymer includes the alicyclic group-containing (meth)acrylic monomer and the second monomer in a total amount equal to or greater than 95% by weight.

7. The optical member according to claim 1, wherein the first dye is a dialkoxy-substituted porphyrin dye.

8. The optical member according to claim 1, wherein the first dye includes a dye represented by Formula 2: <Formula 2> 9. The optical member according to claim 1, wherein the second dye includes a 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene dye.

10. The optical member according to claim 9, wherein the 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene dye includes a dye represented by Formula 3: <Formula 3> 11. The optical member according to claim 1, wherein the third dye includes a tetraazaporphyrin dye.

12. The optical member according to claim 1, wherein the fourth dye includes a sulfonamide-substituted copper complex dye.

13. The optical member according to claim 12, wherein the sulfonamide-substituted copper complex dye includes a dye represented by Formula 4: <Formula 4> 14. The optical member according to claim 1, wherein the dye mixture includes: 0.001 to 5% by weight of the first dye; 0.001 to 5% by weight of the second dye; 0.001 to 5% by weight of the third dye; and 0.001 to 5% by weight of the fourth dye. 0.001 to 5 wt. % of the third dye; and 0.001 to 5 wt. % of the fourth dye.

15. The optical member of claim 1, wherein the base film does not have an anti- reflective layer.

16. The optical member of claim 1, wherein the adhesive layer includes a UV absorber.

17. An optical display device comprising the optical member of any one of claims 1 to 16.

18. The optical display device of claim 17, wherein the optical display device is absent a polarizer.

Images