Optical member and optical display device

Abstract

Provided are an optical element and an optical display device including the same, which include a substrate layer having a light transmittance of 80% or more at wavelengths of 350 nm to 400 nm, and an adhesive film adhered to one or more surfaces of the substrate layer and having a light transmittance of 4% or less at wavelengths of 350 nm to 400 nm.

Description

[Technical Field]

[0001] The present invention relates to an optical member and an optical display device. More specifically, the present invention provides an optical member that prevents damage to a light emitting element caused by ultraviolet rays, provides excellent peel strength and folding properties due to the excellent cohesion of an adhesive film, and has UV blocking properties, reduces manufacturing costs, and simplifies processes. [Background technology]

[0002] Light emitting device displays have light emitting elements that emit light themselves, making them thinner than LCDs and providing high efficiency even with low power consumption. As a result, light emitting device displays are widely used in mobile displays such as TVs and mobile phones, replacing LCDs.

[0003] However, when exposed to ultraviolet rays, the light emitting element is damaged and unable to perform its original function, which may shorten the life of the light emitting element display device. Therefore, the optical display device needs to include an optical member that can absorb ultraviolet rays to prevent the ultraviolet rays from reaching the light emitting element. The position of the optical member in the optical display device is not particularly limited, but it is preferably stacked on the light emitting element.

[0004] As one such method, when the optical member includes an optical film and an adhesive film, a method of incorporating an ultraviolet absorber into the optical film can be considered. However, incorporating an ultraviolet absorber into the optical film can increase the cost of manufacturing the optical member and require an additional process when assembling the optical member into a display device.

[0005] Meanwhile, since light-emitting device display devices are also required to have foldable properties, the adhesive film must also have flexibility. However, when an ultraviolet absorber is to be contained in the adhesive film, if the adhesive film is formed from a photocurable adhesive composition, the curing degree of the composition is reduced and the cohesive strength is also reduced, which may limit the provision of excellent peel strength and excellent folding properties.

[0006] The background art of the present invention is disclosed in Patent Document 1 and the like. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-072951 Summary of the Invention [Problem to be solved by the invention]

[0008] The object of the present invention is to provide an optical member having an adhesive film that has low light transmittance at wavelengths of 350 nm to 400 nm and high cohesive strength, thereby providing excellent peel strength and folding properties, and that has the effect of reducing costs and simplifying the process when assembling into a display device. [Means for solving the problem]

[0009] One aspect of the present invention is an optical member.

[0010] 1. The optical component includes a substrate layer having a light transmittance of 80% or more at wavelengths of 350 nm to 400 nm, and an adhesive film adhered to one or more surfaces of the substrate layer and having a light transmittance of 4% or less at wavelengths of 350 nm to 400 nm.

[0011] In 2.1, the adhesive film may contain a triazine-based UV absorber.

[0012] In 3.1-2, the triazine-based UV absorber may be a hydroxyphenyltriazine-based UV absorber.

[0013] In 4.1-3, the triazine-based UV absorber may be contained in the adhesive film in an amount of 0.1% by weight to 4% by weight.

[0014] In 5.1-4, the adhesive film may have a peel strength of 600 gf / inch or more.

[0015] In 6.1-5, the pressure-sensitive adhesive film may have a storage modulus at -20°C of 0.2 MPa or less.

[0016] In 7.1-6, the adhesive film may be formed of a heat-curable adhesive composition or a photo-curable adhesive composition.

[0017] In 8.1-7, the adhesive film may be formed of a photocurable adhesive composition containing a UV absorber, a polymer of a monomer mixture, and a photoinitiator.

[0018] In 9.8, the monomer mixture can contain a (meth)acrylic monomer having an alkyl group, a (meth)acrylic monomer having a hydroxyl group, and a (meth)acrylic monomer having a heteroalicyclic group.

[0019] In 10.1-9, the (meth)acrylic monomer having a heteroalicyclic group may be contained in the monomer mixture in an amount of 1% by weight to 10% by weight.

[0020] In 11.1-10, the monomer mixture may further contain an alkylene glycol group-containing (meth)acrylic monomer.

[0021] In 12.1-11, the total content of the (meth)acrylic monomer having a heteroalicyclic group and the (meth)acrylic monomer containing an alkylene glycol group in the monomer mixture may be 5% by weight to 20% by weight.

[0022] In 13.1-12, the photoinitiator may be contained in an amount of 0.0001 to 5 parts by weight based on 100 parts by weight of the monomer mixture.

[0023] In 14.1-13, the photocurable pressure-sensitive adhesive composition may contain at least one of a crosslinking agent and a silicone-containing (meth)acrylate.

[0024] In 15.14, the silicone-containing (meth)acrylate can be represented by the following chemical formula 1:

[0025] (chemical formula 1) [ka]

[0026] In Chemical Formula 1, R1, R2, R3, R4, R5, R6, and R7 each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, or an aryl group having 6 to 10 carbon atoms; R8 represents an alkylene group having 1 to 10 carbon atoms, or an arylene group having 6 to 10 carbon atoms; R9 represents a hydrogen atom or a methyl group; and n represents an integer from 10 to 100.

[0027] In 16.1-15, the content of the triazine-based UV absorber having a maximum absorption wavelength of 370 nm to 430 nm in the base layer may be 0.05 wt % or less.

[0028] Another aspect of the present invention is an optical display device.

[0029] The optical member includes the optical member of the present invention. [Effects of the Invention]

[0030] The present invention provides an optical member having an adhesive film with low light transmittance at wavelengths of 350 nm to 400 nm and high cohesive strength, thereby providing excellent peel strength and folding properties, thereby reducing costs and simplifying the process of assembling the optical member into a display device. DETAILED DESCRIPTION OF THE INVENTION

[0031] Each embodiment of the present application will be described in more detail below. However, the technology disclosed in the present application is not limited to the embodiments described herein and may be embodied in other embodiments. However, the embodiments introduced herein are provided to thoroughly and completely disclose the contents and to fully convey the concept of the present application to those skilled in the art.

[0032] The terms used herein are merely for the purpose of describing exemplary embodiments and are not intended to limit the present invention. The singular expressions include the plural expressions unless the context clearly indicates otherwise.

[0033] As used herein, "(meth)acrylic" can mean acrylic and / or methacrylic.

[0034] In this specification, "light transmittance" means total light transmittance. In this specification, the light transmittance referred to in the wavelength range from wavelength X to Y means the average light transmittance in that wavelength range.

[0035] As used herein, the term "glass transition temperature of a homopolymer" refers to the glass transition temperature (Tg) of a homopolymer of a target monomer measured using a DSC Discovery manufactured by TA Instruments. Specifically, the homopolymer of a target monomer is heated to 180°C at a rate of 20°C / min, then gradually cooled to -100°C, and then heated to 100°C at a rate of 10°C / min to obtain data on an endothermic transition curve, and the glass transition temperature can be determined from the inflection point of the endothermic transition curve.

[0036] In this specification, the "average particle size of organic nanoparticles" refers to the particle size of organic nanoparticles measured in an aqueous or organic solvent using a Malvern Zetasizer nano-ZS device and expressed as a Z-average value, and the particle size confirmed during SEM / TEM observation.

[0037] In this specification, when a numerical range is described, "X to Y" means "X≦and≦Y".

[0038] It is known that various light-emitting elements, including organic light-emitting elements, are vulnerable to ultraviolet light. If the light-emitting element is damaged by ultraviolet light, the life of the light-emitting element may be shortened, which may ultimately shorten the life of the optical display device.

[0039] Generally, methods for reducing light transmittance in the ultraviolet region (350 nm to 400 nm) can be considered, such as using a monomer that has a light absorbing effect in that wavelength region or using a filler that has a light absorbing effect in that wavelength region. Among these methods, the simplest method is to incorporate a light absorber, i.e., a UV absorber. However, incorporating a UV absorber into the substrate layer (described below) can result in problems such as high manufacturing costs and the need for additional processes when assembling the optical element into a display device. Therefore, there is a need to develop an optical element that does not incorporate a UV absorber into the substrate layer and that can block ultraviolet light from reaching the light emitting element.

[0040] The present invention relates to an optical element included in an optical display device, the optical element comprising a base layer and an adhesive film, the adhesive film having low light transmittance at wavelengths of 350 nm to 400 nm and high cohesive strength.

[0041] Since the adhesive film has low light transmittance in the wavelength range of 350nm to 400nm, when the optical member is applied to an optical display device, particularly a light emitting device display device, it can block ultraviolet rays, including light with a wavelength of 350nm to 400nm, incident from the outside from reaching the light emitting device, thereby preventing damage to the light emitting device caused by ultraviolet rays.

[0042] The substrate layer of the present invention is characterized by having a high light transmittance at wavelengths of 350 nm to 400 nm, while the PSA film has a significantly low light transmittance at wavelengths of 350 nm to 400 nm. Therefore, the present invention does not require the substrate layer to contain a UV absorber, and therefore problems caused by including a UV absorber in the substrate layer can be eliminated.

[0043] In one embodiment, the substrate layer may have a light transmittance of 80% or more, for example, 85% to 100%, at a wavelength of 350 nm to 400 nm, preferably 380 nm.

[0044] In one embodiment, the adhesive film may have a light transmittance of 4% or less, for example, 0.1% to 3%, for example, 2% to 3%, at a wavelength of 350 nm to 400 nm, preferably 380 nm. Within this range, the adhesive film can sufficiently prevent damage to light emitting elements caused by ultraviolet rays when applied to an optical display device.

[0045] The pressure-sensitive adhesive film and the substrate layer of the present invention will be described in detail below.

[0046] <Adhesive film> The pressure-sensitive adhesive film may be formed from a heat-curable pressure-sensitive adhesive composition or a photo-curable pressure-sensitive adhesive composition.

[0047] In one embodiment, the adhesive film may include a thermoset product of a thermosetting adhesive composition. An adhesive film formed from a thermosetting adhesive composition can be produced by applying the adhesive composition to a substrate layer or a release film, followed by heat treatment. Therefore, when a UV absorber is included, the curing rate and other factors are not an issue. The thermosetting adhesive composition may be a conventional adhesive composition known to be capable of providing an adhesive film with excellent folding properties, as described below.

[0048] For example, a thermosetting pressure-sensitive adhesive composition may include a UV absorber, a (meth)acrylic copolymer, and a curing agent, and the composition and weight-average molecular weight of the monomer mixture for the (meth)acrylic copolymer may be adjusted to provide excellent folding properties. The UV absorber will be described in detail below.

[0049] In another embodiment, the adhesive film may include a photocured product of the photocurable adhesive composition. In the present invention, the adhesive film is formed from the photocurable adhesive composition, and the components and / or content of the adhesive composition are controlled to compensate for the low photocuring rate of the adhesive film composition due to the UV absorber and to provide high cohesive strength as described below.

[0050] The photocurable pressure-sensitive adhesive composition may contain a UV absorber, a polymer of a monomer mixture, and a photoinitiator.

[0051] The UV absorber may be selected from an appropriate type so that the adhesive film provides a light transmittance of 4% or less at wavelengths of 350 nm to 400 nm.

[0052] In one embodiment, the UV absorber may have a maximum absorption wavelength of 370 nm to 430 nm, preferably 390 nm to 430 nm. In this range, even when a small amount of UV absorber is contained in the PSA film, it can reduce the light transmittance at wavelengths of 350 nm to 400 nm. The "maximum absorption wavelength" refers to the wavelength at which the UV absorber exhibits the maximum absorption peak, i.e., the wavelength at which the UV absorber exhibits the maximum absorbance in the wavelength-dependent absorbance curve. The maximum absorption wavelength can be measured by a conventional method known to those skilled in the art.

[0053] In one embodiment, the UV absorber may include one or more of a benzotriazole-based UV absorber, a benzophenone-based UV absorber, and a triazine-based UV absorber, which may be contained in the PSA film alone or in combination of two or more.

[0054] However, in the present invention, taking into consideration ultraviolet light absorption properties, high compatibility with the monomer described below, and ease of ensuring the cohesive strength of the PSA film described below, a triazine-based UV absorber, preferably a hydroxyl group-containing triazine-based UV absorber, more preferably a hydroxyphenyltriazine-based UV absorber, may be used as the UV absorber.

[0055] Triazine-based UV absorbers include 4-diphenyl-6-(2-hydroxy-4-methoxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-ethoxyphenyl)-1,3,5-triazine, 2,4-diphenyl-(2-hydroxy-4-propoxyphenyl)-1,3,5-triazine, 2,4-diphenyl-(2-hydroxy-4-propoxyphenyl)-1,3,5-triazine, 2,4-diphenyl-(2-hydroxy-4-butoxyphenyl)-1,3,5-triazine, and 2,4-diphenyl-6-(2-hydroxy-4-methoxyphenyl)-1,3,5-triazine. 2,4-Diphenyl-6-(2-hydroxy-4-hexyloxyphenyl)-1,3,5-triazine, 2,4-Diphenyl-6-(2-hydroxy-4-octyloxyphenyl)-1,3,5-triazine, 2,4-Diphenyl-6-(2-hydroxy-4-dodecyloxyphenyl)-1,3,5-triazine, 2,4-Diphenyl-6-(2-hydroxy-4-benzyloxyphenyl)-1,3,5-triazine, 2,4-Diphenyl-6-(2-hydroxy-4-butoxyphenyl)-1,3,5-triazine 2,4,6-tris(2-hydroxy-4-methoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-4-ethoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-4-propoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-4-butoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-4-butoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-4-butoxyphenyl)-1,3,5-triazine, Tris(2-hydroxy-4-butoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-4-hexyloxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-4-octyloxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-4-dodecyloxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-4-benzyloxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-4-ethoxyethoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-4-butoxyethoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-4-propoxyethoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-4-methoxycarbonylpropyloxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-4-ethoxycarbonylethyloxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-4-(1-(2-ethoxyhexyloxy) -1-oxopropan-2-yloxy)phenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-methoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-ethoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-propoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-butoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-butoxyphenyl)-1,3,5-triazine, -methyl-4-butoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-hexyloxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-octyloxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-dodecyloxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-benzyloxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-benzyloxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-butoxyethoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-propoxyethoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-methoxycarbonylpropoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-ethoxycarbonylethoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-(1-(2-ethoxyhexyloxy)-1-oxopropan-2-yloxy)phenyl)-1,3,5-triazine,

[0056] The UV absorber is contained in the adhesive film in an amount of 0.1 to 4% by weight, for example, 0.1% by weight, 0.2% by weight, 0.3% by weight, 0.4% by weight, 0.5% by weight, 0.6% by weight, 0.7% by weight, 0.8% by weight, 0.9% by weight, 1.0% by weight, 1.1% by weight, 1.2% by weight, 1.3% by weight, 1.4% by weight, 1.5% by weight, 1.6% by weight, 1.7% by weight, 1.8% by weight, 1.9% by weight, 2.0% by weight, 2.1% by weight, %, 2.2 wt%, 2.3 wt%, 2.4 wt%, 2.5 wt%, 2.6 wt%, 2.7 wt%, 2.8 wt%, 2.9 wt%, 3.0 wt%, 3.1 wt%, 3.2 wt%, 3.3 wt%, 3.4 wt%, 3.5 wt%, 3.6 wt%, 3.7 wt%, 3.8 wt%, 3.9 wt%, 4 wt%, preferably 1 wt% to 2.5 wt%, more preferably 1 wt% to 2 wt%. Within this range, the light transmittance at wavelengths of 350 nm to 400 nm of the present invention can be ensured and an increase in haze and yellowness index (YI) in the PSA film due to the excessive addition of a UV absorber can be prevented.

[0057] The UV absorber is used in an amount of 0.1 to 4 parts by weight, for example, 0.1 parts by weight, 0.2 parts by weight, 0.3 parts by weight, 0.4 parts by weight, 0.5 parts by weight, 0.6 parts by weight, 0.7 parts by weight, 0.8 parts by weight, 0.9 parts by weight, 1.0 parts by weight, 1.1 parts by weight, 1.2 parts by weight, 1.3 parts by weight, 1.4 parts by weight, 1.5 parts by weight, 1.6 parts by weight, 1.7 parts by weight, 1.8 parts by weight, 1.9 parts by weight, 1.10 parts by weight, 1.11 parts by weight, 1.12 parts by weight, 1.13 parts by weight, 1.14 parts by weight, 1.15 parts by weight, 1.16 parts by weight, 1.17 parts by weight, 1.18 parts by weight, 1.19 parts by weight, 1.20 parts by weight, 1.21 parts by weight, 1.22 parts by weight, 1.23 parts by weight, 1.24 parts by weight, 1.25 parts by weight, 1.26 parts by weight, 1.27 parts by weight, 1.28 parts by weight, 1.29 parts by weight, 1.29 parts by weight, 1.30 parts by weight, 1.31 parts by weight, 1.32 parts by weight, 1.33 parts by weight, 1.34 parts by weight, 1.35 parts by weight, 1.36 parts by weight, 1.37 parts by weight, 1.38 parts by weight, 1.39 ... The UV absorber may be contained in an amount of 9 parts by weight, 2.0 parts by weight, 2.1 parts by weight, 2.2 parts by weight, 2.3 parts by weight, 2.4 parts by weight, 2.5 parts by weight, 2.6 parts by weight, 2.7 parts by weight, 2.8 parts by weight, 2.9 parts by weight, 3.0 parts by weight, 3.1 parts by weight, 3.2 parts by weight, 3.3 parts by weight, 3.4 parts by weight, 3.5 parts by weight, 3.6 parts by weight, 3.7 parts by weight, 3.8 parts by weight, 3.9 parts by weight, 4 parts by weight, preferably 1 part to 2 parts by weight. Within this range, the light transmittance at wavelengths of 350 nm to 400 nm of the present invention can be ensured and increases in haze and YI (yellow index) in the PSA film due to excessive addition of a UV absorber can be prevented.

[0058] The monomer mixture can contain a (meth)acrylic monomer having an alkyl group, a (meth)acrylic monomer having a hydroxyl group, and a (meth)acrylic monomer having a heteroalicyclic group.

[0059] The alkyl group-containing (meth)acrylic monomer can easily form the matrix of the PSA film. In one embodiment, the alkyl group-containing (meth)acrylic monomer may be a (meth)acrylate containing an alkyl group having 1 to 10 carbon atoms and unsubstituted at the ester moiety, which is linear or branched. For example, the alkyl group-containing (meth)acrylic monomer may include one or more of 2-ethylhexyl (meth)acrylate, n-butyl (meth)acrylate, isooctyl (meth)acrylate, propyl (meth)acrylate, t-butyl (meth)acrylate, iso-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, nonyl (meth)acrylate, and decyl (meth)acrylate, preferably one or more of 2-ethylhexyl (meth)acrylate, n-butyl (meth)acrylate, and isooctyl (meth)acrylate, more preferably 2-ethylhexyl (meth)acrylate.

[0060] The alkyl group-containing (meth)acrylic monomer may have a homopolymer glass transition temperature of −80° C. to −20° C., specifically −80° C. to −40° C. In this range, the PSA film may have good folding properties at low temperature and at high temperature and humidity.

[0061] The alkyl group-containing (meth)acrylic monomer is contained in the monomer mixture in an amount of 10% by weight to 85% by weight, for example, 10% by weight, 11% by weight, 12% by weight, 13% by weight, 14% by weight, 15% by weight, 16% by weight, 17% by weight, 18% by weight, 19% by weight, 20% by weight, 21% by weight, 22% by weight, 23% by weight, 24% by weight, 25% by weight, 26% by weight, 27% by weight, 28% by weight, 29% by weight, 30% by weight, 31% by weight, 32% by weight, 33% by weight, 34% by weight, 35% by weight, 36% by weight, 37% by weight, 38% by weight, 39% by weight, 40% by weight, 41% by weight, 42% by weight, 43% by weight, 44% by weight, 45% by weight, 46% by weight, 47% by weight, 48% by weight, 49% by weight, 50% by weight, 51% by weight, 52% by weight, 53% by weight, 54% by weight, 55% by weight, 56% by weight, 57% by weight, 58% by weight, 59% by weight, 60% by weight, 61% by weight, 62% by weight, 63% by weight, 64% by weight, 65% by weight, 66% by weight, 67% by weight, 68% by weight, 69% by weight, 70% by weight, 71% by weight, 72% by weight, 73% by weight, 74% by weight, 75% by weight, 76% by weight, 77% by The amount of the acrylic acid may be 48% by weight, 49% by weight, 50% by weight, 51% by weight, 52% by weight, 53% by weight, 54% by weight, 55% by weight, 56% by weight, 57% by weight, 58% by weight, 59% by weight, 60% by weight, 61% by weight, 62% by weight, 63% by weight, 64% by weight, 65% by weight, 66% by weight, 67% by weight, 68% by weight, 69% by weight, 70% by weight, 71% by weight, 72% by weight, 73% by weight, 74% by weight, 75% by weight, 76% by weight, 77% by weight, 78% by weight, 79% by weight, 80% by weight, 81% by weight, 82% by weight, 83% by weight, 84% by weight, or 85% by weight, preferably 60% to 85% by weight, or 70% to 85% by weight. Within this range, the folding properties of the PSA film at low temperature and high temperature and humidity may be good.

[0062] The hydroxyl group-containing (meth)acrylic monomer can easily provide peel strength to the PSA film. The hydroxyl group-containing (meth)acrylic monomer may be a C1 to C10 (meth)acrylate containing one or more hydroxyl groups in the ester moiety. For example, the hydroxyl group-containing (meth)acrylic monomer may include one or more of 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and 6-hydroxyhexyl (meth)acrylate, but is not limited thereto.

[0063] The hydroxyl group-containing (meth)acrylic monomer may have a homopolymer glass transition temperature of −70° C. to 0° C., preferably −60° C. to −10° C., and more preferably −50° C. to −10° C. Within this range, the peel strength and folding properties of the PSA film may be improved.

[0064] The hydroxyl group-containing (meth)acrylic monomer may be included in the monomer mixture in an amount of 5 to 40% by weight, for example, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, or 40% by weight, for example, 5 to 30% by weight or 5 to 20% by weight. This range may further improve the adhesive strength and durability reliability of the PSA film.

[0065] Even if the curing rate of the composition is reduced by the UV absorber, the heteroalicyclic group-containing (meth)acrylic monomer can increase the cohesive strength of the adhesive film through intermolecular interactions (e.g., hydrogen bonding) between the monomers. This can prevent a decrease in adhesive strength of the adhesive film and minimize an increase in low-temperature modulus, thereby providing excellent peel strength and folding properties.

[0066] The heteroalicyclic group-containing (meth)acrylic monomer is a (meth)acrylic monomer having a ring with 3 to 8 carbon atoms and containing oxygen and / or sulfur as a heteroatom, and may be, for example, (meth)acryloylmorpholine.

[0067] The heteroalicyclic group-containing (meth)acrylic monomer may be contained in the monomer mixture in an amount of 1 wt% to 10 wt%, for example, 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, or 10 wt%, preferably 1 wt% to 5 wt%, which may facilitate ensuring the cohesive strength and adhesive strength of the PSA film.

[0068] In one embodiment, the total amount of the alkyl group-containing (meth)acrylic monomer, the hydroxyl group-containing (meth)acrylic monomer, and the heteroalicyclic group-containing (meth)acrylic monomer may be 90% by weight or more, for example, 90% to 100% by weight, for example, 90% to 95% by weight, of the monomer mixture. Within this range, the effects of the present invention may be easily achieved.

[0069] The monomer mixture may further contain an alkylene glycol group-containing (meth)acrylic monomer.

[0070] The alkylene glycol group-containing (meth)acrylic monomer can compensate for the reduced flexibility of the PSA film due to the inclusion of the heteroalicyclic group-containing (meth)acrylic monomer when the curing rate of the composition is reduced by the UV absorber. Furthermore, the alkylene glycol group-containing (meth)acrylic monomer can easily provide the PSA film with excellent folding properties by containing an alkylene glycol group in the ester moiety. In this specification, "alkylene glycol group" means (C2 to C4 alkylene-O-).

[0071] The total amount of the (meth)acrylic monomer having a heteroalicyclic group and the (meth)acrylic monomer having an alkylene glycol group in the monomer mixture may be 5% by weight to 20% by weight, for example, 5% by weight, 6% by weight, 7% by weight, 8% by weight, 9% by weight, 10% by weight, 11% by weight, 12% by weight, 13% by weight, 14% by weight, 15% by weight, 16% by weight, 17% by weight, 18% by weight, 19% by weight, or 20% by weight, preferably 10% by weight to 15% by weight. Within this range, the effects of the present invention may be easily realized.

[0072] The alkylene glycol group-containing (meth)acrylic monomer may have a homopolymer glass transition temperature of -90°C to -55°C, preferably -90°C to -60°C, and more preferably -75°C to -60°C. Within this range, the modulus of the PSA film at low temperatures can be reduced, and the PSA film's folding properties at low temperatures can be improved. The alkylene glycol group-containing (meth)acrylate can contain an ethylene oxide group (-CH2CHO-) or a propylene oxide group (-CH2CH2CHO-), preferably a monofunctional acrylate having an ethylene oxide group.

[0073] The (meth)acrylic monomer having an alkylene glycol group may be, for example, an ether-based (meth)acrylate containing 1 mole or more, for example, 2 to 20 moles, of ethylene glycol. Specifically, the ethylene glycol group-containing (meth)acrylate may include one or more of poly(ethylene glycol) methyl ether (meth)acrylate containing 6 to 13 moles of ethylene glycol, poly(ethylene glycol) ethylhexyl ether (meth)acrylate containing 2 to 10 moles of ethylene glycol, and poly(ethylene glycol) octyl ether (meth)acrylate containing 2 to 20 moles of ethylene glycol.

[0074] Preferably, the alkylene glycol group-containing (meth)acrylate may include one or more of di(ethylene glycol) 2-ethylhexyl ether (meth)acrylate, triethylene glycol 2-ethylhexyl ether (meth)acrylate, and di(ethylene glycol) octyl ether (meth)acrylate.

[0075] The alkylene glycol group-containing (meth)acrylic monomer is contained in the monomer mixture in an amount of 0 to 40% by weight, for example, 0% by weight, 1% by weight, 2% by weight, 3% by weight, 4% by weight, 5% by weight, 6% by weight, 7% by weight, 8% by weight, 9% by weight, 10% by weight, 11% by weight, 12% by weight, 13% by weight, 14% by weight, 15% by weight, 16% by weight, 17% by weight, 18% by weight, 19% by weight, 20% by weight, It may be contained in an amount of 21 wt%, 22 wt%, 23 wt%, 24 wt%, 25 wt%, 26 wt%, 27 wt%, 28 wt%, 29 wt%, 30 wt%, 31 wt%, 32 wt%, 33 wt%, 34 wt%, 35 wt%, 36 wt%, 37 wt%, 38 wt%, 39 wt%, or 40 wt%, preferably 0.5 wt% to 40 wt%, and more preferably 5 wt% to 20 wt%. Within this range, the repeated folding properties of the PSA film at low temperatures can be improved.

[0076] In one embodiment, the total amount of the alkyl group-containing (meth)acrylic monomer, the hydroxyl group-containing (meth)acrylic monomer, the heteroalicyclic group-containing (meth)acrylic monomer, and the alkylene glycol group-containing (meth)acrylic monomer may be 98% by weight or more, for example, 98% by weight to 100% by weight, for example, 100% by weight, of the monomer mixture. Within this range, the effects of the present invention may be easily achieved.

[0077] The monomer mixture may further contain other comonomers in addition to the alkyl group-containing (meth)acrylic monomer, the hydroxyl group-containing (meth)acrylic monomer, the heteroalicyclic group-containing (meth)acrylic monomer, and the alkylene glycol group-containing (meth)acrylic monomer. The comonomers may be contained in the polymer to provide additional effects to the PSA film.

[0078] The comonomer is a monomer different from the above-mentioned monomers, and may include one or more of a monomer having an amine group, a monomer having an alkoxy group, a monomer having a phosphate group, a monomer having a sulfonic acid group, a monomer having a phenyl group, a monomer having a silane group, a monomer having a carboxylic acid group, and an amide group-containing monomer.

[0079] The monomer having an amine group may be an amine group-containing acrylic monomer such as monomethylaminoethyl acrylate, monoethylaminoethyl acrylate, monomethylaminopropyl acrylate, monoethylaminopropyl acrylate, dimethylaminoethyl acrylate, diethylaminoethyl acrylate, N-tert-butylaminoethyl acrylate, acryloxyethyltrimethylammonium chloride acrylate, but is not limited thereto.

[0080] The monomer having an alkoxy group may be, but is not limited to, 2-methoxyethyl acrylate, 2-methoxypropyl acrylate, 2-ethoxypropyl acrylate, 2-butoxypropyl acrylate, 2-methoxypentyl acrylate, 2-ethoxypentyl acrylate, 2-butoxyhexyl acrylate, 3-methoxypentyl acrylate, 3-ethoxypentyl acrylate, and 3-butoxyhexyl acrylate.

[0081] The monomer having a phosphate group may be an acrylic monomer having a phosphate group such as 2-methacryloyloxyethyl diphenyl phosphate acrylate, trimethacryloyloxyethyl phosphate acrylate, or triacryloyloxyethyl phosphate acrylate, but is not limited thereto.

[0082] The monomer having a sulfonic acid group may be an acrylic monomer having a sulfonic acid group, such as sodium sulfopropyl acrylate, sodium 2-sulfoethyl acrylate, or sodium 2-acrylamido-2-methylpropanesulfonate, but is not limited thereto.

[0083] The monomer having a phenyl group may be an acrylic vinyl monomer having a phenyl group, such as p-tert-butylphenyl acrylate, o-biphenyl acrylate, or phenoxyethyl acrylate, but is not limited thereto.

[0084] The monomer having a silane group may be a vinyl monomer having a silane group, such as, but not limited to, 2-acetoacetoxyethyl acrylate, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(2-methoxyethyl)silane, vinyltriacetoxysilane, and acryloyloxypropyltrimethoxysilane.

[0085] The monomer having a carboxylic acid group may be, but is not limited to, acrylic acid, 2-carboxyethyl acrylate, 3-carboxypropyl acrylate, 4-carboxybutyl acrylate, itaconic acid, crotonic acid, maleic acid, fumaric acid, and maleic anhydride.

[0086] The amide group-containing monomer may be, but is not limited to, acrylamide, N-methylacrylamide, N-methylolacrylamide, N-methoxymethylacrylamide, N,N-methylenebisacrylamide, N-hydroxyethylacrylamide, N,N-diethylacrylamide, etc.

[0087] The comonomer may be contained in the monomer mixture in an amount of 30% by weight or less, preferably 0% to 30% by weight, and can be used to adjust the adhesive strength with the adherend and to provide optical properties.

[0088] The photoinitiator may form an adhesive film by curing the composition or may polymerize residual monomers remaining in the adhesive film composition after polymerizing the monomer mixture. The photoinitiator may preferably include a photoradical initiator.

[0089] Any photoinitiator can be used as long as it can induce a polymerization reaction of the radical polymerizable compound described above during the curing process by irradiation with light or the like. For example, as the photoinitiator, a benzoin-based, hydroxyketone-based, aminoketone-based or phosphine oxide-based photoinitiator can be used. Specific examples thereof include acetophenone compounds such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin n-butyl ether, benzoin isobutyl ether, 2,2-dimethoxy-2-phenylacetophenone, 2,2'-diethoxyacetophenone, 2,2'-dibutoxyacetophenone, 2-hydroxy-2-methylpropiophenone, pt-butyltrichloroacetophenone, pt-butyldichloroacetophenone, 4-chloroacetophenone, and 2,2'-dichloro-4-phenoxyacetophenone, dimethylaminoacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, and 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)acetophenone. )-butan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propan-1-one, 4-(2-hydroxyethoxy)phenyl-2-(hydroxy-2-propyl) ketone, benzophenone, p-phenylbenzophenone, 4,4-diethylaminobenzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-t-butylanthraquinone, 2-aminoanthraquinone, Examples include 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzil dimethyl ketal, acetophenone dimethyl ketal, p-dimethylaminobenzoic acid ester, oligo[2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone], and 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide.

[0090] The photoinitiator may be included in an amount of 0.0001 to 5 parts by weight, specifically 0.5 to 3 parts by weight, and more specifically 0.5 to 1 part by weight, based on 100 parts by weight of the monomer mixture. Within this range, the curing reaction can be completed, the remaining initiator can be prevented from reducing the light transmittance of the PSA film, and the generation of bubbles can be reduced, resulting in excellent reactivity.

[0091] The pressure-sensitive adhesive composition may further include a crosslinking agent, which can increase the degree of crosslinking of the pressure-sensitive adhesive composition and increase the mechanical strength of the pressure-sensitive adhesive film.

[0092] The crosslinking agent may include a multifunctional (meth)acrylate that can be cured with active energy rays. Examples of the crosslinking agent include 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, neopentyl glycol adipate di(meth)acrylate, dicyclopentanyl di(meth)acrylate, caprolactone-modified dicyclopentenyl di(meth)acrylate, ethylene oxide-modified di(meth)acrylate, di(meth)acryloxyethyl isocyanurate, and aryl di(meth)acrylate. modified cyclohexyl di(meth)acrylate, tricyclodecane dimethanol (meth)acrylate, dimethylol dicyclopentane di(meth)acrylate, ethylene oxide-modified hexahydrophthalic acid di(meth)acrylate, tricyclodecane dimethanol (meth)acrylate, neopentyl glycol-modified trimethylpropane di(meth)acrylate, adamantane di(meth)acrylate, or 9,9-bis[4-(2-acryloyloxyethoxy)phenyl]fluorene, etc. difunctional acrylates; trifunctional acrylates such as trimethylolpropane tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, propionic acid-modified dipentaerythritol tri(meth)acrylate, pentaerythritol tri(meth)acrylate, propylene oxide-modified trimethylolpropane tri(meth)acrylate, trifunctional urethane (meth)acrylate or tris(meth)acryloxyethyl isocyanurate; diglycerin tetra(meth)acrylate or penta Examples of the acrylate include, but are not limited to, tetrafunctional acrylates such as erythritol tetra(meth)acrylate; pentafunctional acrylates such as dipentaerythritol penta(meth)acrylate; and hexafunctional acrylates such as dipentaerythritol hexa(meth)acrylate, caprolactone-modified dipentaerythritol hexa(meth)acrylate, or urethane(meth)acrylate (e.g., a reaction product of an isocyanate monomer and trimethylolpropane tri(meth)acrylate).Preferably, the crosslinking agent may be a polyfunctional (meth)acrylate of a triol, tetraol, pentaol or hexaol having 5 to 15 carbon atoms.

[0093] The crosslinking agent may be included in an amount of 0.001 to 5 parts by weight, specifically 0.1 to 3 parts by weight, specifically 0.1 to 1 part by weight, based on 100 parts by weight of the monomer mixture or the polymer of the monomer mixture, which has the effect of providing excellent peel strength and increasing reliability in the PSA film.

[0094] The pressure-sensitive adhesive composition may not contain organic nanoparticles. In one embodiment, the organic nanoparticles may be the organic nanoparticles described below.

[0095] The pressure-sensitive adhesive composition may further include organic nanoparticles.

[0096] The organic nanoparticles can increase the storage modulus of the adhesive film at high temperatures, prevent peeling and / or lifting and / or bubble formation in the adhesive film at high temperatures, and further increase reliability at high temperatures.The organic nanoparticles have a high glass transition temperature, so they can increase the modulus of the adhesive film at high temperatures.

[0097] The organic nanoparticles may have an average particle size of 10 to 400 nm, specifically 10 to 300 nm, more specifically 30 to 280 nm, and even more specifically 50 to 280 nm. Within this range, the total light transmittance in the visible light region is 90% or more without affecting the folding characteristics of the PSA film, and therefore the transparency of the PSA film may be good.

[0098] The difference in refractive index between the organic nanoparticles and the polymer of the monomer mixture containing the (meth)acrylic monomer may be 0.1 or less, specifically 0 to 0.05, specifically 0 to 0.02. In this range, the transparency of the PSA film may be excellent.

[0099] In one embodiment, the organic nanoparticles may have a refractive index of 1.35 to 1.70, specifically 1.40 to 1.60, in which case the transparency of the adhesive film may be excellent.

[0100] Organic nanoparticles may include, but are not limited to, simple nanoparticles such as core-shell nanoparticles and bead nanoparticles. In the case of core-shell nanoparticles, the core and shell may satisfy the following formula 1. That is, both the core and shell may be nanoparticles made of organic materials. When the particle has the above particle morphology, the folding characteristics of the adhesive film may be good and the balance of elasticity and flexibility may be effective.

[0101] (Formula 1) Tg(c) <Tg(s)

[0102] In the above formula 1, Tg(c) is the glass transition temperature (unit: ° C.) of the core, and Tg(s) is the glass transition temperature (unit: ° C.) of the shell.

[0103] As used herein, the term "shell" refers to the outermost layer of an organic nanoparticle. The core may be a single spherical particle. However, the core may also include an additional layer surrounding the spherical particle, as long as the core has the glass transition temperature.

[0104] Specifically, the glass transition temperature of the core may be -150°C to 10°C, more specifically -150°C to -5°C, and more specifically -150°C to -20°C. Within this range, the PSA film may have a viscoelastic effect at low and / or room temperatures. The core may contain one or more of polyalkyl acrylate, polysiloxane, and polybutadiene having the above glass transition temperature.

[0105] The polyalkyl acrylate may include, but is not necessarily limited to, one or more of polymethyl acrylate, polyethyl acrylate, polypropyl acrylate, polybutyl acrylate, polyisopropyl acrylate, polyhexyl acrylate, polyhexyl methacrylate, polyethylhexyl acrylate, polyethylhexyl methacrylate, and polysiloxane.

[0106] The polysiloxane may be, for example, an organosiloxane (co)polymer. As the organosiloxane (co)polymer, either a non-crosslinked one or a crosslinked (co)polymer can be used. For impact resistance and colorability, a crosslinked organosiloxane (co)polymer can be used. This is a crosslinked organosiloxane, specifically, crosslinked dimethylsiloxane, methylphenylsiloxane, diphenylsiloxane, or a mixture of two or more thereof can be used. By using a copolymer of two or more organosiloxanes, the refractive index can be adjusted to 1.41 to 1.50.

[0107] The crosslinking state of an organosiloxane (co)polymer can be determined based on the degree of solubility in various organic solvents. The more crosslinked the polymer, the less soluble it is in the solvent. Acetone, toluene, etc. can be used as a solvent for determining the crosslinking state. Specifically, the organosiloxane (co)polymer may have a portion that is insoluble in acetone or toluene. Furthermore, the organosiloxane copolymer may have a toluene-insoluble component of 30% or more.

[0108] Additionally, the organosiloxane (co)polymer may further include an alkyl acrylate crosslinked polymer, such as methyl acrylate, ethyl acrylate, n-butyl acrylate, or 2-ethylhexyl acrylate, which has a low glass transition temperature.

[0109] Specifically, the glass transition temperature of the shell may be 15°C to 150°C, more specifically 35°C to 150°C, and more specifically 50°C to 140°C. Within this range, the dispersibility of organic nanoparticles in the acrylic copolymer may be excellent. The shell may include a polyalkyl methacrylate having the above glass transition temperature, such as, but not limited to, one or more of polymethyl methacrylate (PMMA), polyethyl methacrylate, polypropyl methacrylate, polybutyl methacrylate, polyisopropyl methacrylate, polyisobutyl methacrylate, and polycyclohexyl methacrylate.

[0110] The core may be contained in the organic nanoparticles at 30% to 99% by weight, specifically 40% to 95% by weight, and more specifically 50% to 90% by weight. This range may result in good folding properties of the PSA film over a wide temperature range. The shell may be contained in the organic nanoparticles at 1% to 70% by weight, specifically 5% to 60% by weight, and more specifically 10% to 50% by weight. This range may result in good folding properties of the PSA film over a wide temperature range.

[0111] The organic nanoparticles may be contained in the adhesive film in an amount of 0 to 20 wt%, specifically 0.1 to 20 wt%, specifically 0.5 to 12 wt%, specifically 0.5 to 8 wt%. This range can increase the modulus of the adhesive film at high temperatures, improve the folding properties of the adhesive film at room and high temperatures, and provide excellent viscoelasticity of the adhesive film at low and / or room temperatures.

[0112] The organic nanoparticles may be included in an amount of 0 to 1 part by weight, for example, 0.01 to 1 part by weight, for example, 0.01 to 0.5 parts by weight, based on 100 parts by weight of the monomer mixture. This range may have the effect of improving the folding properties of the PSA film at high temperatures.

[0113] The organic nanoparticles may be produced by conventional emulsion polymerization, suspension polymerization, or solution polymerization methods.

[0114] The pressure-sensitive adhesive composition may further contain a silicone-containing (meth)acrylate, which, when contained in the pressure-sensitive adhesive film, can provide an effect of improving adhesion to glass.

[0115] The silicone-containing (meth)acrylate may be a photoreactive single-terminated silicone-containing (meth)acrylate. This means that the silicone-containing (meth)acrylate has one (meth)acrylate group at one end. The silicone-containing (meth)acrylate may be represented by the following chemical formula 1:

[0116] (chemical formula 1) [ka]

[0117] In Chemical Formula 1, R1, R2, R3, R4, R5, R6, and R7 each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, or an aryl group having 6 to 10 carbon atoms; R8 represents an alkylene group having 1 to 10 carbon atoms, or an arylene group having 6 to 10 carbon atoms; R9 represents a hydrogen atom or a methyl group; and n represents an integer from 10 to 100.

[0118] The silicone-containing (meth)acrylate may be included in an amount of 0 to 1 part by weight, for example, 0.1 parts by weight, 0.2 parts by weight, 0.3 parts by weight, 0.4 parts by weight, 0.5 parts by weight, 0.6 parts by weight, 0.7 parts by weight, 0.8 parts by weight, 0.9 parts by weight, or 1 part by weight, for example, 0.01 to 1 part by weight, for example, 0.01 to 0.5 parts by weight, relative to 100 parts by weight of the monomer mixture. This range may have the effect of further improving folding properties.

[0119] The pressure-sensitive adhesive composition may further contain conventional additives known to those skilled in the art, including, but not limited to, one or more of a silane coupling agent, a pigment, an ultraviolet absorber, a leveling agent, and an antistatic agent.

[0120] The PSA film may have a haze of 5% or less, and within this range, when applied to an optical display device, the image display may not be affected. Specifically, the PSA film may have a haze of 0% to 5%, more specifically 0.1% to 3%.

[0121] The PSA film may have a storage modulus of 0.2 MPa or less at -20°C. Within this range, the PSA film can provide excellent folding properties at low, normal, and high temperatures. Specifically, the PSA film may have a storage modulus of 0.001 MPa to 0.2 MPa, more specifically 0.1 MPa to 0.2 MPa, at -20°C.

[0122] The PSA film may have a peel strength of 600 gf / inch or more, for example, 600 gf / inch to 1500 gf / inch at 25°C. Within this range, the PSA film may easily provide excellent folding properties. In this specification, "peel strength" refers to T-peel strength. The T-peel strength may be measured by the method described in the following experimental examples, and the adherend may be a glass plate, for example, an alkali-free glass plate.

[0123] The adhesive film may have a thickness of 10 μm to 300 μm, specifically 20 μm to 100 μm, which may be used in optical display devices.

[0124] The PSA film composition may be prepared by partially polymerizing the monomer mixture with an initiator and adding a photoinitiator and a UV absorber. The PSA film composition may further contain the organic nanoparticles, crosslinking agents, additives, and the like. The partial polymerization may include solution polymerization, suspension polymerization, photopolymerization, bulk polymerization, or emulsion polymerization. Specifically, solution polymerization may be carried out at 50°C to 100°C after adding an initiator to the monomer mixture. Examples of initiators that can be used include acetophenone-based initiators, such as 2,2-dimethoxy-2-phenylacetophenone, and photopolymerization initiators, such as 1-hydroxycyclohexyl phenyl ketone. The partial polymerization may be carried out at 25°C and a viscosity of 300 cPs to 50,000 cPs, specifically 500 cPs to 9,000 cPs.

[0125] The pressure-sensitive adhesive film is a reduced-pressure pressure-sensitive adhesive film and may be produced by a conventional method, for example, by coating a pressure-sensitive adhesive film composition on a release film and then curing it. The curing is photo-curing using a low-pressure lamp in an oxygen-free environment with an irradiation dose of 400 mJ / cm at a wavelength of 300 nm to 400 nm. 2 ~3000mJ / cm 2 The irradiation may include

[0126] <Base material layer> The substrate layer is one that substantially completely transmits light with a wavelength of 350 nm to 400 nm, and may be substantially free of the above-mentioned UV absorbers, for example, UV absorbers having a maximum absorption wavelength of 370 nm to 430 nm, e.g., 390 nm to 430 nm, such as triazine-based UV absorbers and hydroxyphenyltriazine-based UV absorbers. Here, "substantially free of UV absorbers" means that the content of the above-mentioned UV absorbers in the substrate layer is 0.05 wt % or less, for example, 0 wt % to 0.001 wt %.

[0127] The substrate layer not only serves to support the adhesive film, but also performs certain optical functions in the optical display device.

[0128] In one embodiment, the substrate layer provides polarization, optical compensation, improvement of display quality, and / or conductivity. Examples of the substrate layer include ultra thin glass (UTG), window films, windows, polarizing plates, color filters, retardation films, elliptical polarizing films, reflective polarizing films, anti-reflection films, compensation films, brightness enhancement films, alignment films, light diffusing films, shatterproof glass films, surface protective films, barrier layers for OLED devices, plastic LCD substrates, transparent electrode films including indium tin oxide (ITO), fluorinated tin oxide (FTO), aluminum doped zinc oxide (AZO), carbon nanotubes (CNT), Ag nanowires, and graphene.

[0129] The substrate layer can be easily manufactured by a person having ordinary skill in the art to which the present invention pertains.

[0130] For example, a touch panel can be formed by attaching a touch pad to a window or a substrate layer using an adhesive film, or an adhesive film can be applied to a conventional polarizing film.

[0131] In another embodiment, the substrate layer is an optically transparent optical film, and the optical member including the substrate layer and the adhesive film can function as a support layer of a display element. For example, the display element can include a window film. The window film can include a substrate layer and a window coating layer (e.g., a silicone-based coating layer) formed on the substrate layer. Specifically, the substrate layer can have a total light transmittance of 90% or more in the visible light range and can be made of one or more resins selected from the group consisting of cellulose resins such as triacetyl cellulose, polyester resins such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, and polybutylene naphthalate, polycarbonate resins, polyimide resins, polystyrene resins, polyacrylate resins such as polymethyl methacrylate, cyclic olefin polymer resins, acrylic resins, and polyamide resins. The substrate layer can have a thickness of 10 μm to 100 μm, specifically 20 μm to 75 μm, and more specifically 30 μm to 50 μm. Within this range, the substrate layer can be used as a support layer of a display element.

[0132] The optical display device of the present invention includes the optical member of the present invention.

[0133] The optical display device may include a light emitting device display device having an organic light emitting device, an inorganic light emitting device, an organic / inorganic light emitting device, a liquid crystal display device, etc. The optical display device may include a flexible display device, but may also include a non-flexible display device.

[0134] According to an embodiment, the optical member may be used to adhere a plurality of optical elements in a flexible display device. [Example]

[0135] The present invention will be described in more detail with reference to the following examples, which are provided for the purpose of facilitating understanding of the present invention and are not intended to limit the scope of the present invention.

[0136] Example 1 As shown in Table 1 below, 100 parts by weight of a monomer mixture was prepared, and 0.005 parts by weight of a photoinitiator, Irgacure 651, was added and thoroughly mixed in a reactor. After replacing the dissolved oxygen in the reactor with nitrogen gas, the monomer mixture was partially polymerized by irradiating it with ultraviolet light using a low-pressure mercury lamp for several minutes, producing a composition containing a partially (meth)acrylic copolymer of the monomer mixture. In Table 1 below, "-" means that the corresponding component was not included.

[0137] To the composition, 0.5 parts by weight of TPO as a photoinitiator, 2 parts by weight of Tinuvin 477 (hydroxyphenyltriazine type) as a UV absorber, and 0.1 parts by weight of dipentaerythritol hexaacrylate (DPHA) as a crosslinker were added and mixed as shown in Table 1 below to prepare a photocurable pressure-sensitive adhesive composition.

[0138] The pressure-sensitive adhesive composition thus prepared was applied to a PET (polyethylene terephthalate) film (light transmittance of 90% at a wavelength of 380 nm) which is an optical film, and the resulting coating layer was covered with a PET film which is a release film, and ultraviolet light was applied at 2000 mJ / cm. 2 A laminate of the optical member (PET film-adhesive film) and the release film was produced.

[0139] (Examples 2 and 3) When preparing the pressure-sensitive adhesive composition in Example 1, a laminate of an optical member and a release film was prepared in the same manner as in Example 1, except that the content was changed as shown in Table 1 below.

[0140] Example 4 In Example 1, when preparing the pressure-sensitive adhesive composition, the monomer mixture was partially polymerized, and then 0.3 parts by weight of KF2012 (Shin-Etsu Chemical Co., Ltd.), a monofunctional (meth)acrylate-modified siloxane compound, was further added. A laminate of an optical member and a release film was prepared in the same manner as in Example 1, except that the monomer mixture was partially polymerized and then 0.3 parts by weight of KF2012 (Shin-Etsu Chemical Co., Ltd.), a monofunctional (meth)acrylate-modified siloxane compound, was further added.

[0141] (Comparative Examples 1 to 3) When preparing the pressure-sensitive adhesive composition in Example 1, a laminate of an optical member and a release film was prepared in the same manner as in Example 1, except that the content was changed as shown in Table 1 below.

[0142] The structures of the adhesive films of the Examples and Comparative Examples are shown in the following Table 1. The adhesive films of the Examples and Comparative Examples were evaluated for the physical properties shown in the following Table 1.

[0143] (1) Light transmittance (unit: %) and yellowness index of adhesive film at a wavelength of 380 nm: The optical film and the release film were all peeled off from the laminate of the optical member and the release film of each of the examples and comparative examples to obtain a pressure-sensitive adhesive film. The light transmittance and yellowness index of the pressure-sensitive adhesive film were measured at a wavelength of 380 nm in transmittance mode using a spectrophotometer (Konica Minolta, Inc., CM-3600A).

[0144] (2) Storage modulus (unit: MPa): Using a dynamic viscoelasticity measuring device, a rheometer (TA, ARES DHR-3), viscoelasticity was measured under autostrain conditions at a shear rate of 1 rad / sec and a strain of 1%. The optical film and release film were all peeled off from the laminates of optical members and release films of the Examples and Comparative Examples to obtain adhesive films. Multiple adhesive films were laminated to a thickness of 500 μm, and the laminate was punched using an 8 mm diameter punch to serve as a test specimen. Using an 8 mm diameter stainless steel jig, the storage modulus was measured at temperatures from -60°C to 90°C and at a temperature increase rate of 5°C / min while applying a load of 1.0 N to the test specimen, and the storage modulus at -20°C was determined.

[0145] (3) Peeling force against glass plate (unit: gf / inch): The laminates of the optical members and release films of the examples and comparative examples were cut into strips measuring 100 mm x 25 mm. A PET (polyethylene terephthalate) film measuring 150 mm x 25 mm x 75 μm was subjected to two corona treatments (total dose: 156 doses) at a dose of 78 using a corona treatment machine. One side of the PET film was released from the cut adhesive sheet, and a glass plate (150 mm x 25 mm x 75 μm) was attached to the exposed surface of the adhesive film. The PET release film on the other side of the adhesive sheet was released, and the corona-treated PET film (150 mm x 25 mm x 75 μm) was then bonded to the glass plate to prepare a test specimen for peel strength measurement.

[0146] The test specimen was autoclaved at a pressure of 3.5 bar and 50°C for 1000 seconds, and then attached to a TA.XT_Plus Texture Analyzer (Stable Micro System). A glass plate was attached to the TA.XT_Plus Texture Analyzer, and the T-peel force was measured at 25°C when the PET film was pulled at a speed of 50 mm / min.

[0147] (4) Folding characteristics: A module specimen was fabricated by laminating a window film, an adhesive film, a polarizer, an adhesive film, and an OLED panel in this order. The following window film, adhesive film, polarizer, adhesive film, and OLED panel were used to fabricate the module, and the adhesive film was laminated on the polyimide film of the OLED panel.

[0148] -Window Film: A PET film (thickness: 100 μm, Cosmoshine TA015, Toyobo Co., Ltd.) was used.

[0149] -Adhesive film: The adhesive films (thickness: 15 μm) produced in the examples and comparative examples were used.

[0150] -Polarizer: Iodine-dyed PVA resin was used. An 80 μm-thick polyvinyl alcohol film (saponification degree: 99.5, polymerization degree: 2000) was immersed in a 0.3% iodine aqueous solution to dye it, and then stretched in the MD direction to a stretch ratio of 5.0. The stretched polyvinyl alcohol film was then immersed in a 3% boric acid solution and a 2% potassium iodide aqueous solution to correct the color, and then dried at 50°C for 4 minutes to produce a polarizer (thickness: 25 μm).

[0151] -OLED panel: A polyimide film (thickness: 100 μm, Cosmoshine TA015, Toyobo Co., Ltd.) was used.

[0152] The fabricated module specimens were cut into lengths of 170 mm x 110 mm and folded 100,000 times at -20°C to evaluate whether bubbles, cracks, or delamination occurred in the module specimens. The module specimens were folded lengthwise and toward the OLED panel (with a 1.5 mm radius of curvature during folding, at a rate of 30 cycles per minute), where one cycle was defined as folding the specimen at the radius of curvature and then unfolding it 180°. A test specimen that did not exhibit bubbles, cracks, or delamination was rated as "good," while a test specimen that exhibited one or more of bubbles, cracks, and delamination was rated as "poor."

[0153] [Table 1]

[0154] * EHA: 2-ethylhexyl acrylate HBA: 4-hydroxybutyl acrylate EHDG: Di(ethylene glycol) 2-ethylhexyl ether acrylate ACMO: acryloylmorpholine DPHA: Dipentaerythritol hexaacrylate KF2012: Siloxane monofunctional acrylate Tinuvin 477: Hydroxyphenyltriazine UV absorber (2-hydroxyphenyl-s-triazine) Tinuvin 384-2: Hydroxyphenylbenzotriazole UV absorber

[0155] As shown in Table 1, the adhesive film included in the optical member of the present invention has low light transmittance at wavelengths of 350 nm to 400 nm and high cohesive strength, thereby providing excellent peel strength and folding properties. On the other hand, the adhesive film of the comparative example could not provide the effects of the present invention.

[0156] Simple modifications or variations of the present invention can be easily implemented by those skilled in the art, and all such modifications and variations are considered to be included within the scope of the present invention.

Claims

1. A substrate layer having a light transmittance of 80% or more at a wavelength of 350 nm to 400 nm; and An optical component comprising an adhesive film adhered to one surface or the other surface of the base layer, the adhesive film having a light transmittance of 4% or less at a wavelength of 350 nm to 400 nm.

2. The optical member according to claim 1 , wherein the adhesive film contains a triazine-based UV absorber.

3. The optical member according to claim 2 , wherein the triazine-based UV absorber is a hydroxyphenyltriazine-based UV absorber.

4. The optical member according to claim 2 , wherein the triazine-based UV absorber is contained in the adhesive film in an amount of 0.1 to 4% by weight.

5. The optical member according to claim 1 , wherein the adhesive film has a peel strength of 600 gf / inch or more.

6. 2. The optical member according to claim 1, wherein the pressure-sensitive adhesive film has a storage modulus at −20° C. of 0.2 MPa or less.

7. The optical member according to claim 1 , wherein the adhesive film is formed from a heat-curable adhesive composition or a photo-curable adhesive composition.

8. The optical member according to claim 1 , wherein the adhesive film is formed of a photo-curable adhesive composition containing a UV absorber, a polymer of a monomer mixture, and a photoinitiator.

9. 9. The optical member according to claim 8, wherein the monomer mixture contains a (meth)acrylic monomer having an alkyl group, a (meth)acrylic monomer having a hydroxyl group, and a (meth)acrylic monomer having a heteroalicyclic group.

10. 10. The optical member according to claim 9, wherein the (meth)acrylic monomer having a heteroalicyclic group is contained in the monomer mixture in an amount of 1% by weight to 10% by weight.

11. The optical member according to claim 9 , wherein the monomer mixture further contains an alkylene glycol group-containing (meth)acrylic monomer.

12. 12. The optical member according to claim 11, wherein the total content of the (meth)acrylic monomer having a heteroalicyclic group and the (meth)acrylic monomer having an alkylene glycol group in the monomer mixture is 5% by weight to 20% by weight.

13. The optical member according to claim 8 , wherein the photoinitiator is contained in an amount of 0.0001 to 5 parts by weight based on 100 parts by weight of the monomer mixture.

14. The optical member according to claim 8 , wherein the photocurable pressure-sensitive adhesive composition contains at least one of a crosslinking agent and a silicone-containing (meth)acrylate.

15. The optical member according to claim 14 , wherein the silicone-containing (meth)acrylate is represented by the following chemical formula 1: (Chemical formula 1) 【Chemistry 1】 (In the above-mentioned Chemical Formula 1, R １ , R ２ , R ３ , R ４ , R ５ , R ６ , R ７ are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, or an aryl group having 6 to 10 carbon atoms; R ８ is an alkylene group having 1 to 10 carbon atoms or an arylene group having 6 to 10 carbon atoms, R ９ is hydrogen or a methyl group, and n is an integer from 10 to 100.

16. 2. The optical member according to claim 1, wherein the content of the triazine-based UV absorber having a maximum absorption wavelength of 370 nm to 430 nm in the substrate layer is 0.05 wt % or less.

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

Images