Optical member and optical display device

Abstract

Provided are an optical member and an optical display device including the same, the optical member including: a base layer having a light transmittance of 80% or more at a wavelength of 350-400 nm; and an adhesive film adhered to one surface or the other surface of the base layer and having a light transmittance of 4% or less at a wavelength of 350-400 nm.

Description

Technical Field

[0001] The present invention relates to an optical member and an optical display device. More particularly, the present invention relates to an optical member that can prevent a light-emitting diode from being damaged by UV light, includes an adhesive film having good cohesion to provide good peel strength and foldability, and can ensure UV light blocking, reduce manufacturing costs, and simplify processes. Background Art

[0002] Using self-luminous light-emitting diodes, light-emitting diode displays have a thinner thickness than liquid crystal displays and can provide high efficiency even at low power. Therefore, light-emitting diode displays are replacing liquid crystal displays and are widely used in mobile displays such as TVs, mobile phones, etc.

[0003] However, when LEDs are exposed to UV light, they can be damaged and rendered ineffective, shortening the life of LED displays. Therefore, optical display devices require optical components that can absorb UV light to prevent it from reaching the LEDs. While the optical components can be positioned anywhere within the optical display device, it is desirable to stack the optical components above the LEDs.

[0004] In one method, for an optical member including an optical film and an adhesive film, the optical film may contain a UV absorber. However, the use of a UV absorber in the optical film may increase the manufacturing cost of the optical member and may require an additional process for assembling the optical member to a display device.

[0005] Since light-emitting diode displays require foldable properties, adhesive films are also required to have flexibility. However, when an adhesive film formed from a photocurable adhesive composition contains a UV absorber, the adhesive film may suffer from reduced cohesion due to reduced curing degree of the adhesive composition, thereby being limited in ensuring good peel strength and good foldability.

[0006] Background art of the present invention is disclosed in Japanese Unexamined Patent Publication No. 2013-072951 and the like. Summary of the Invention

[0007] Technical issues

[0008] One aspect of the present invention provides an optical member including an adhesive film having low light transmittance at a wavelength of 350 nm to 400 nm and having high cohesion to provide high peel strength and good foldability while ensuring reduced manufacturing costs and simplified processes in assembling the optical member into a display device.

[0009] Technical Solution

[0010] One aspect of the present invention relates to an optical component.

[0011] 1. An optical member comprising: a base layer having a light transmittance of 80% or more at a wavelength of 350 nm to 400 nm; and an adhesive film adhesively attached to one surface or the other of the base layer and having a light transmittance of 4% or less at a wavelength of 350 nm to 400 nm.

[0012] 2. In 1, the adhesive film may contain a triazine-based UV absorber.

[0013] 3. In 1-2, the triazine-based UV absorber may include a hydroxyphenyltriazine-based UV absorber.

[0014] 4. In 1-3, the triazine-based UV absorber may be present in the adhesive film in an amount of 0.1% by weight (wt%) to 4 wt%.

[0015] 5. In 1-4, the adhesive film may have a peel strength of 600 gf / inch or more.

[0016] 6. In 1-5, the adhesive film may have a storage modulus of 0.2 MPa or less at -20°C.

[0017] 7. In 1-6, the adhesive film may be formed of a thermosetting adhesive composition or a photocurable adhesive composition.

[0018] 8. In 1-7, the adhesive film may be formed of a photocurable adhesive composition comprising a UV absorber, a polymer of a monomer mixture, and a photoinitiator.

[0019] 9. In 8, the monomer mixture may contain an alkyl group-containing (meth)acrylic monomer, a hydroxyl group-containing (meth)acrylic monomer, and a heteroalicyclic group-containing (meth)acrylic monomer.

[0020] 10. In 1-9, the heteroalicyclic group-containing (meth)acrylic monomer may be present in the monomer mixture in an amount of 1 wt % to 10 wt %.

[0021] 11. In 1-10, the monomer mixture may further contain an alkylene glycol group-containing (meth) acrylic monomer.

[0022] 12. In 1-11, the heteroalicyclic group-containing (meth)acrylic monomer and the alkylene glycol group-containing (meth)acrylic monomer may be present in the monomer mixture in a total amount of 5 wt % to 20 wt %.

[0023] 13. In 1-12, the photoinitiator may be present in an amount of 0.0001 parts by weight to 5 parts by weight relative to 100 parts by weight of the monomer mixture.

[0024] 14. In 1-13, the photocurable adhesive composition may contain at least one selected from a crosslinking agent and a silicone-containing (meth)acrylate.

[0025] 15. In 14, the silicone-containing (meth)acrylate can be represented by the following Chemical Formula 1:

[0026] [Chemical Formula 1]

[0027]

[0028] (In Chemical Formula 1, R1, R2, R3, R4, R5, R6 and R7 are each independently hydrogen, C1 to C 10 Alkyl, C3 to C 10 Cycloalkyl or C6 to C 10 Aryl; R8 is C1 to C 10 Alkylene or C6 to C 10 arylene; R9 is hydrogen or methyl; and n is an integer from 10 to 100).

[0029] 16. In 1-15, the base layer may contain 0.05 wt% or less of a triazine-based UV absorber having a maximum absorption wavelength of 370 nm to 430 nm.

[0030] Another aspect of the present invention relates to an optical display device.

[0031] An optical display device includes the optical component according to the present invention.

[0032] Beneficial effects

[0033] The present invention provides an optical member including an adhesive film having low light transmittance at a wavelength of 350 nm to 400 nm and having high cohesion to provide high peel strength and good foldability while ensuring reduced manufacturing costs and simplified processes in assembling the optical member into a display device. DETAILED DESCRIPTION

[0034] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, it should be understood that the present invention can be embodied in various ways and is not limited to the following embodiments. The following embodiments are provided herein to make the disclosure herein comprehensive and complete and to fully convey the concept of the present invention to those skilled in the art.

[0035] The terminology used herein is for the purpose of describing exemplary embodiments and is not intended to limit the scope of the present invention.Herein, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include the plural forms as well.

[0036] As used herein, the term "(meth)acryloyl" refers to acryloyl and / or methacryloyl.

[0037] Herein, "light transmittance" refers to total transmittance. The light transmittance in the wavelength ranges X to Y refers to the average value of the light transmittance values in the corresponding wavelength ranges.

[0038] Herein, "homopolymer glass transition temperature" may refer to the glass transition temperature (Tg) measured on a homopolymer of a target monomer using a differential scanning calorimeter (DSC Discovery, TA Instruments Inc.). Specifically, the homopolymer of the target monomer is heated to 180° C. at a heating rate of 20° C. / min, slowly cooled to −100° C., and then heated to 100° C. at a heating rate of 10° C. / min to obtain data on an endothermic transition curve, and then the glass transition temperature is determined at the inflection point of the endothermic transition curve.

[0039] Herein, “average particle size of organic nanoparticles” refers to the particle size of organic nanoparticles, as measured using a Zetasizer nano-ZS (Malvern Co., Ltd.) in a water-based solvent or an organic solvent and as represented by a Z average value and observed by SEM / TEM.

[0040] As used herein, to express a specific numerical range, the expression “X to Y” means “≥X and ≤Y”.

[0041] It is known in the art that various light emitting diodes, including organic light emitting diodes, are susceptible to UV light. The damage to light emitting diodes by UV light can shorten the life of the light emitting diodes, which in turn can shorten the life of the optical display device.

[0042] Generally, as a method of reducing the light transmittance in the ultraviolet spectrum including wavelengths in the range of 350nm to 400nm, the use of monomers or fillers that have a light-absorbing effect in this wavelength range can be considered. Among these methods, the use of a light absorber, i.e., a UV absorber, is the simplest method. However, the incorporation of a UV absorber into the base layer described below can cause various problems, such as high manufacturing costs in the manufacture of optical components and the need for additional processes in the assembly of the optical components into the display device. Therefore, it is necessary to develop an optical component that can block UV light from reaching the light-emitting diode without including a UV absorber in the base layer.

[0043] The present invention relates to an optical member included in an optical display device, wherein the optical member includes a base layer and an adhesive film having low light transmittance at a wavelength of 350 nm to 400 nm and having high cohesion.

[0044] Since the adhesive film has low light transmittance at wavelengths of 350nm to 400nm, when the optical component is applied to an optical display device (especially a light-emitting diode display), the adhesive film can prevent damage to the light-emitting diode caused by UV light by blocking UV light (which includes external incident light with a wavelength of 350nm to 400nm) from reaching the light-emitting diode.

[0045] According to the present invention, the base layer has high light transmittance at a wavelength of 350 nm to 400 nm, whereas the adhesive film has significantly low light transmittance at a wavelength of 350 nm to 400 nm. Therefore, the present invention does not require the base layer to contain a UV absorber, thereby preventing problems caused by the presence of a UV absorber in the base layer.

[0046] In one embodiment, the base layer may have a light transmittance of 80% or more (eg, 85% to 100%) at a wavelength of 350 nm to 400 nm, preferably at a wavelength of 380 nm.

[0047] In one embodiment, the adhesive film may have a light transmittance of 4% or less (e.g., 0.1% to 3%, such as 2% to 3%) at a wavelength of 350 nm to 400 nm, preferably at a wavelength of 380 nm. Within this range, when the adhesive film is applied to an optical display device, the adhesive film can sufficiently prevent UV light from damaging light-emitting diodes.

[0048] Hereinafter, the adhesive film and the base layer of the present invention will be described in detail.

[0049] Adhesive film

[0050] The adhesive film may be formed of a thermosetting adhesive composition or a photocurable adhesive composition.

[0051] In one embodiment, the adhesive film may include a heat-cured product of a thermosetting adhesive composition. The adhesive film formed by the thermosetting adhesive composition can be prepared by applying the thermosetting adhesive composition to a base layer or a release film, followed by heat treatment to prevent problems with the cure rate in the presence of a UV absorber. The thermosetting adhesive composition can be selected from any type of adhesive composition that can provide an adhesive film with good foldability as described below.

[0052] For example, the thermosetting adhesive composition includes a UV absorber, a (meth)acrylic copolymer, and a curing agent, wherein the composition and weight average molecular weight of the monomer mixture for the (meth)acrylic copolymer can be adjusted to provide good foldability. The UV absorber will be described in more detail below.

[0053] In other embodiments, the adhesive film may include a photocurable adhesive composition. The adhesive film according to the present invention is formed from a photocurable adhesive composition while controlling the components and / or content of the adhesive composition to compensate for the decrease in the photocuring rate of the adhesive composition for the adhesive film due to the UV absorber and to ensure high cohesion as described below.

[0054] The photocurable adhesive composition may include a UV absorber, a polymer of the monomer mixture, and a photoinitiator.

[0055] The UV absorber may be selected from any type of UV absorbers to ensure that the adhesive film has a light transmittance of 4% or less at a wavelength of 350 nm to 400 nm.

[0056] In one embodiment, the UV absorber may have a maximum absorption wavelength of 370 nm to 430 nm, preferably 390 nm to 430 nm. Within this range, even when the UV absorber is included in a small amount, the UV absorber can ensure low light transmittance of the adhesive film at a wavelength of 350 nm to 400 nm. As used herein, "maximum absorption wavelength" refers to the wavelength at which the UV absorber exhibits a maximum absorption peak, i.e., the wavelength at which the UV absorber exhibits maximum absorbance on a wavelength-dependent absorbance curve. The maximum absorption wavelength can be measured by typical methods known to those skilled in the art.

[0057] In one embodiment, the UV absorber may include at least one selected from the group consisting of a benzotriazole-based UV absorber, a benzophenone-based UV absorber, a triazine-based UV absorber, and combinations thereof.

[0058] In the present invention, a triazine-based UV absorber, preferably a hydroxyl-containing triazine-based UV absorber, more preferably a hydroxyphenyltriazine-based UV absorber can be used as the UV absorber in consideration of UV absorbency, high compatibility with monomers described below, and easiness of ensuring cohesion of the adhesive film described below.

[0059] Triazine-based UV absorbers may 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, 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-butoxyethoxy)-1,3,5-triazine, 2,4-bis(2-hydroxy-4-butoxyphenyl)-6-(2,4-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 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-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-hexyloxyphenyl)-1,3,5-triazine 2,4,6-tris(2-hydroxy-4-(1-(2-ethoxyhexyloxy)-1-oxoprop-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-4-(1-(2-ethoxyhexyloxy)-1-oxoprop-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,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, 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-ethoxyethoxyphenyl)-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 and 2,4,6-tris(2-hydroxy-3-methyl-4-(1-(2-ethoxyhexyloxy)-1-oxoprop-2-yloxy)phenyl)-1,3,5-triazine.

[0060] In the adhesive film, the UV absorber may be present in an amount of 0.1 wt % to 4 wt % (e.g., 0.1 wt %, 0.2 wt %, 0.3 wt %, 0.4 wt %, 0.5 wt %, 0.6 wt %, 0.7 wt %, 0.8 wt %, 0.9 wt %, 1.0 wt %, 1.1 wt %, 1.2 wt %, 1.3 wt %, 1.4 wt %, 1.5 wt %, 1.6 wt %, 1.7 wt %, 1.8 wt %, 1.9 wt %, 2.0 wt %, 3.0 wt %, 4.0 wt %, 5.0 wt %, 6.0 wt %, 7.0 wt %, 8.0 wt %, 9.0 wt %, 10.0 wt %, 11.0 wt %, 12.0 wt %, 13.0 wt %, 14.0 wt %, 15.0 wt %, 16.0 wt %, 17.0 wt %, 18.0 wt %, 19.0 wt %, 20.0 wt %, 21.0 wt %, 22.0 wt %, 23.0 wt %, 24.0 wt %, 25.0 wt %, 26.0 wt %, 27.0 wt %, 28.0 wt %, 29.0 wt %, 30.0 The UV absorber is preferably present in an amount of 2.1 wt%, 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% or 4 wt%, preferably 1 wt% to 2.5 wt%, more preferably 1 wt% to 2 wt%. Within this range, the adhesive film can ensure light transmittance at a wavelength of 350 nm to 400 nm and can prevent increases in haze and yellowness index (YI) due to excessive addition of the UV absorber.

[0061] The UV absorber may be present in an amount of 0.1 to 4 parts by weight (e.g., 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9 or 4 parts by weight, preferably 1 to 2 parts by weight) relative to 100 parts by weight of the monomer mixture described below. Within this range, the adhesive film may secure light transmittance at a wavelength of 350 nm to 400 nm and may prevent increases in haze and yellowness index (YI) due to excessive addition of the UV absorber.

[0062] The monomer mixture may include an alkyl group-containing (meth)acrylic monomer, a hydroxyl group-containing (meth)acrylic monomer, and a heteroalicyclic group-containing (meth)acrylic monomer.

[0063] The alkyl-containing (meth) acrylic monomer is used to facilitate the formation of a matrix for the adhesive film. In one embodiment, the alkyl-containing (meth) acrylic monomer may include an unsubstituted linear or branched C1 to C2 alkyl group at its ester site. 10 Alkyl (meth)acrylate. For example, the alkyl-containing (meth)acrylic monomer may include at least one selected from the group consisting of 2-ethylhexyl (meth)acrylate, n-butyl (meth)acrylate, isooctyl (meth)acrylate, propyl (meth)acrylate, tert-butyl (meth)acrylate, isobutyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, nonyl (meth)acrylate, and decyl (meth)acrylate, preferably at least one selected from the group consisting of 2-ethylhexyl (meth)acrylate, n-butyl (meth)acrylate, and isooctyl (meth)acrylate, more preferably 2-ethylhexyl (meth)acrylate.

[0064] 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. Within this range, the adhesive film may have good foldability at low temperatures and under high temperature / high humidity conditions.

[0065] In the monomer mixture, the alkyl-containing (meth)acrylic monomer may be present in an amount of 10 wt % to 85 wt % (e.g., 10 wt %, 11 wt %, 12 wt %, 13 wt %, 14 wt %, 15 wt %, 16 wt %, 17 wt %, 18 wt %, 19 wt %, 20 wt %, 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 %, 40 wt %, 41 wt %, 42 wt %, 43 wt %, 44 wt %, 45 wt %, 46 wt %, 47 wt %, 48 wt %, 49 wt %, 50 wt %, 51 wt %, 52 wt %, 53 wt %, 54 wt %, 55 wt %, 56 wt %, 57 wt %, 58 wt %, 59 wt %, %, 7wt%, 78wt%, 79wt%, 80wt%, 81wt%, 82wt%, 83wt%, 84wt% or 85wt%, preferably 60wt% to 85wt% or 70wt% to 85wt%). Within this range, the adhesive film can have good foldability at low temperatures and under high temperature / high humidity conditions.

[0066] The hydroxyl-containing (meth) acrylic monomer is used to impart peel strength to the adhesive film. The hydroxyl-containing (meth) acrylic monomer may include C1 to C2 containing at least one hydroxyl group at its ester site. 10 (Meth)acrylate. For example, the hydroxyl group-containing (meth)acrylic monomer may include at least one selected from the group consisting 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.

[0067] The hydroxyl group-containing (meth)acrylic monomer may have a homopolymer glass transition temperature of -70 to 0° C., preferably -60 to -10° C., more preferably -50 to -20° C. Within this range, the adhesive film may achieve improved peel strength and foldability.

[0068] In the monomer mixture, the hydroxyl-containing (meth) acrylic monomer can be present in an amount of 5 wt % to 40 wt % (e.g., 5 wt %, 6 wt %, 7 wt %, 8 wt %, 9 wt %, 10 wt %, 11 wt %, 12 wt %, 13 wt %, 14 wt %, 15 wt %, 16 wt %, 17 wt %, 18 wt %, 19 wt %, 20 wt %, 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 %, e.g., 5 wt % to 30 wt %, e.g., 5 wt % to 20 wt %). Within this range, the adhesive film can achieve improvements in bonding strength and durability.

[0069] Even when the curing rate of the composition is reduced by the UV absorber, the heteroalicyclic group-containing (meth)acrylic monomer is used to improve the cohesion of the adhesive film through intermolecular interaction (hydrogen bonding) between the monomers. As a result, the adhesive film can prevent the deterioration of adhesive strength while minimizing the increase in low-temperature modulus, thereby ensuring high peel strength and good foldability.

[0070] The heteroalicyclic group-containing (meth)acrylic monomer is a (meth)acrylic monomer having a C3 to C8 ring with oxygen and / or sulfur as a heteroatom, for example, (meth)acryloylmorpholine.

[0071] In the monomer mixture, the heteroalicyclic group-containing (meth) acrylic monomer may be present in an amount of 1 wt % to 10 wt % (e.g., 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 %). Within this range, the adhesive film can easily ensure cohesion and adhesion.

[0072] In one embodiment, the total amount of the alkyl-containing (meth) acrylic monomer, the hydroxyl-containing (meth) acrylic monomer, and the heteroalicyclic group-containing (meth) acrylic monomer in the monomer mixture may be 90 wt% or more (e.g., 90 wt% to 100 wt%, e.g., 90 wt% to 95 wt%). Within this range, the adhesive film can easily achieve the effects of the present invention.

[0073] The monomer mixture may further contain an alkylene glycol group-containing (meth)acrylic monomer.

[0074] When the curing rate of the composition is reduced due to the UV absorber, the (meth) acrylic monomer containing an alkylene glycol group is used to compensate for the reduced flexibility of the adhesive film caused by the presence of the (meth) acrylic monomer containing a heteroalicyclic group. In addition, the (meth) acrylate containing an alkylene glycol group contains an alkylene glycol group, thereby easily imparting foldability to the adhesive film. In this article, "alkylene glycol group" refers to (C2 to C4 alkylene-O-).

[0075] The (meth) acrylic monomer containing a heteroalicyclic group and the (meth) acrylic monomer containing an alkylene glycol group may be present in the monomer mixture in an amount of 5 wt % to 20 wt % (e.g., 5 wt %, 6 wt %, 7 wt %, 8 wt %, 9 wt %, 10 wt %, 11 wt %, 12 wt %, 13 wt %, 14 wt %, 15 wt %, 16 wt %, 17 wt %, 18 wt %, 19 wt % or 20 wt %, preferably 10 wt % to 15 wt %). Within this range, the adhesive film can easily achieve the effects of the present invention.

[0076] The (meth) acrylic monomer containing an alkylene glycol group 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 adhesive film may have a low modulus at low temperatures while improving foldability at low temperatures. The (meth) acrylate containing an alkylene glycol group may include a monofunctional acrylate having an ethyleneoxy group (-CH2CH2O-) or a propyleneoxy group (-CH2CH2CH2O-), preferably an ethyleneoxy group.

[0077] The (meth) acrylic monomer containing an alkylene glycol group may include, for example, an ether-based (meth) acrylate containing 1 mol or more (e.g., 2 to 20 mol) of ethylene glycol. Specifically, the (meth) acrylate containing an ethylene glycol group may include at least one selected from the group consisting of poly(ethylene glycol) methyl ether (meth) acrylate containing 6 to 13 mol of ethylene glycol, poly(ethylene glycol) ethylhexyl ether (meth) acrylate containing 2 to 10 mol of ethylene glycol, and poly(ethylene glycol) octyl ether (meth) acrylate containing 2 to 20 mol of ethylene glycol.

[0078] Preferably, the alkylene glycol group-containing (meth)acrylate may include at least one selected from the group consisting of di(ethylene glycol) 2-ethylhexyl ether (meth)acrylate, triethylene glycol 2-ethylhexyl ether (meth)acrylate, and di(ethylene glycol) octyl ether (meth)acrylate.

[0079] In the monomer mixture, the (meth) acrylic monomer containing an alkylene glycol group may be optionally present in an amount of 40 wt % or less (e.g., 0 wt %, 1 wt %, 2 wt %, 3 wt %, 4 wt %, 5 wt %, 6 wt %, 7 wt %, 8 wt %, 9 wt %, 10 wt %, 11 wt %, 12 wt %, 13 wt %, 14 wt %, 15 wt %, 16 wt %, 17 wt %, 18 wt %, 19 wt %, 20 wt % or less). %, more preferably 5 wt% to 20 wt%). Within this range, the adhesive film can have improved folding resistance at low temperatures.

[0080] In one embodiment, the total amount of the alkyl-containing (meth) acrylic monomer, the hydroxyl-containing (meth) acrylic monomer, the heteroalicyclic group-containing (meth) acrylic monomer, and the alkylene glycol group-containing (meth) acrylic monomer in the monomer mixture may be 98 wt% or more (e.g., 98 wt% to 100 wt%, e.g., 100 wt%). Within this range, the adhesive film can easily achieve the effects of the present invention.

[0081] In addition to the alkyl-containing (meth) acrylic monomer, the hydroxyl-containing (meth) acrylic monomer, the heteroalicyclic group-containing (meth) acrylic monomer, and the alkylene glycol group-containing (meth) acrylic monomer, the monomer mixture may further include another comonomer. The comonomer may be included in the polymer to provide additional effects to the adhesive film.

[0082] The comonomer refers to a monomer other than the monomers described above and may include at least one selected from the group consisting of an amine group-containing monomer, an alkoxy group-containing monomer, a phosphoric acid group-containing monomer, a sulfonic acid group-containing monomer, a phenyl group-containing monomer, a silane group-containing monomer, a carboxylic acid group-containing monomer, and an amide group-containing monomer.

[0083] The amino group-containing monomer may be an amino 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, etc., but is not limited thereto.

[0084] The alkoxy-containing monomer may include 2-methoxyethyl (meth)acrylate, 2-methoxypropyl (meth)acrylate, 2-ethoxypropyl (meth)acrylate, 2-butoxypropyl (meth)acrylate, 2-methoxypentyl (meth)acrylate, 2-ethoxypentyl (meth)acrylate, 2-butoxyhexyl (meth)acrylate, 3-methoxypentyl (meth)acrylate, 3-ethoxypentyl (meth)acrylate, and 3-butoxyhexyl (meth)acrylate, but is not limited thereto.

[0085] The phosphoric acid group-containing monomer may be a phosphoric acid group-containing acrylic monomer such as 2-methacryloyloxyethyl diphenyl phosphate acrylate, trimethacryloyloxyethyl phosphate acrylate, and triacryloyloxyethyl phosphate acrylate, but is not limited thereto.

[0086] The sulfonic acid group-containing monomer may be a sulfonic acid group-containing acrylic monomer, such as sodium sulfopropyl acrylate, sodium 2-sulfoethyl acrylate, sodium 2-acrylamide-2-methylpropane sulfonate, etc., but is not limited thereto.

[0087] The phenyl group-containing monomer may be a phenyl group-containing acrylic vinyl monomer such as p-tert-butyl phenyl acrylate, o-biphenyl acrylate, phenoxy ethyl acrylate, and the like, but is not limited thereto.

[0088] The silyl group-containing monomer may be a silyl group-containing vinyl monomer such as 2-acetoacetoxyethyl acrylate, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri(2-methoxyethyl)silane, vinyltriacetoxysilane, and acryloxypropyltrimethoxysilane, but is not limited thereto.

[0089] The carboxylic acid group-containing monomer may include acrylic acid, 2-carboxyethyl acrylate, 3-carboxypropyl acrylate, 4-carboxybutyl acrylate, itaconic acid, crotonic acid, maleic acid, fumaric acid, maleic anhydride, and the like, but is not limited thereto.

[0090] The amide group-containing monomer may include acrylamide, N-methylacrylamide, N-methylolacrylamide, N-methoxymethylacrylamide, N,N-methylenebisacrylamide, N-hydroxyethylacrylamide, N,N-diethylacrylamide, etc., but is not limited thereto.

[0091] In the monomer mixture, the comonomer may be present in an amount of 30 wt% or less, preferably 0 wt% to 30 wt%.The comonomer is used to control adhesion to an adherend and to provide optical properties.

[0092] The photoinitiator is used to form an adhesive film by curing the adhesive composition, or to polymerize the remaining monomers after the monomer mixture in the composition for the adhesive film is polymerized. Preferably, the photoinitiator includes a photo radical initiator.

[0093] The photoinitiator may be selected from any photoinitiator capable of inducing polymerization of the radical polymerizable compound described above in a curing process by irradiation with light, etc. For example, the photoinitiator may include benzoin-based, hydroxyketone-based, aminoketone-based, or phosphine oxide-based photoinitiators. Specifically, the photoinitiator may include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin n-butyl ether, benzoin isobutyl ether, acetophenone compounds such as 2,2-dimethoxy-2-phenylacetophenone, 2,2'-diethoxyacetophenone, 2,2'-dibutoxyacetophenone, 2-hydroxy-2-methylpropiophenone, p-tert-butyltrichloroacetophenone, p-tert-butyldichloroacetophenone, 4-chloroacetophenone, 2,2'-dichloro-4-phenoxyacetophenone, etc., dimethylaminoacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butane-1-one, 1-hydroxycyclohexane The present invention also includes, but is not limited to, benzophenone, 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-tert-butylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyl dimethyl ketal, acetophenone dimethyl ketal, p-dimethylaminobenzoate, oligo[2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone] and 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide.

[0094] The photoinitiator may be present in an amount of 0.0001 to 5 parts by weight (specifically, 0.5 to 3 parts by weight, more specifically, 0.5 to 1 part by weight) relative to 100 parts by weight of the monomer mixture. Within this range, the photoinitiator allows the adhesive composition to be completely cured, can prevent degradation of the light transmittance of the adhesive film due to residual initiator, can reduce bubble generation, and can exhibit good reactivity.

[0095] The adhesive composition may further include a crosslinking agent, which may increase the degree of crosslinking of the adhesive composition to improve the mechanical strength of the adhesive film.

[0096] The crosslinking agent may include a multifunctional (meth)acrylate that can be cured by actinic radiation. For example, the crosslinking agent may include a difunctional acrylate such as 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, or a combination thereof. di(meth)acrylate), dicyclopentyl di(meth)acrylate, caprolactone-modified dicyclopentenyl di(meth)acrylate, ethylene oxide-modified di(meth)acrylate, di(meth)acryloyloxyethyl isocyanurate, allylated cyclohexyl di(meth)acrylate, tricyclodecane dimethanol (meth)acrylate, dimethylol dicyclopentane di(meth)acrylate, ethylene oxide-modified hexahydrophthalic acid di(meth)acrylate, tricyclodecane dimethanol (meth)acrylate, neopentyl glycol-modified trimethylpropane di(meth)acrylate, adamantane di(meth)acrylate, 9,9-bis[4-(2-acryloyloxyethoxy)phenyl]fluorene, and the like; trifunctional acrylates such as trimethylolpropane tri(meth)acrylate, dipentylethylenetriamine tri(meth)acrylate, Tetraol 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, tri(meth)acryloyloxyethyl isocyanurate, etc.; tetrafunctional acrylates such as diglycerol tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, etc.; pentafunctional acrylates such as dipentaerythritol penta(meth)acrylate, etc.; and hexafunctional acrylates such as dipentaerythritol hexa(meth)acrylate, caprolactone-modified dipentaerythritol hexa(meth)acrylate, and urethane (meth)acrylate (e.g., the reaction product of an isocyanate monomer and trimethylolpropane tri(meth)acrylate), etc., but are not limited thereto. Preferably, the crosslinking agent includes C5 to C6 of a triol, tetraol, pentaol, or hexaol. 15 Multifunctional (meth)acrylate.

[0097] The crosslinking agent may be present in an amount of 0.001 to 5 parts by weight (specifically, 0.1 to 3 parts by weight, more specifically, 0.1 to 1 part by weight) relative to 100 parts by weight of the monomer mixture or the polymer of the monomer mixture. Within this range, the adhesive film may exhibit good peel strength and improved reliability.

[0098] The adhesive composition may not include organic nanoparticles. In one embodiment, the organic nanoparticles may be the organic nanoparticles described below.

[0099] The adhesive composition may also contain organic nanoparticles.

[0100] Organic nanoparticles can further improve the reliability of adhesive films at high temperatures by increasing the storage modulus of the adhesive film at high temperatures to prevent delamination, slight warping, and / or bubble generation at high temperatures. Organic nanoparticles have a high glass transition temperature, thereby improving the modulus of the adhesive film at high temperatures.

[0101] The average particle size of the organic nanoparticles may be 10 nm to 400 nm, specifically 10 nm to 300 nm, more specifically 30 nm to 280 nm, and even more specifically 50 nm to 280 nm. Within this average particle size range, the organic nanoparticles do not affect the foldability of the adhesive film and can ensure good transparency of the adhesive film by ensuring a total light transmittance of about 90% or more in the visible spectrum.

[0102] The difference in refractive index between the organic nanoparticles and the polymer of the monomer mixture including the (meth)acrylic monomer may be 0.1 or less, specifically 0.0 to 0.05, more specifically 0.0 to 0.02. Within this range, the adhesive film may exhibit good transparency.

[0103] In one embodiment, the refractive index of the organic nanoparticles may be 1.35 to 1.70, specifically 1.40 to 1.60. Within this range, the adhesive film may exhibit good transparency.

[0104] The organic nanoparticles may have a core-shell structure or a simple structure, such as bead-type nanoparticles, but are not limited thereto. In one embodiment, the organic nanoparticles may have a core-shell structure, wherein the core and the shell satisfy the following equation 1. That is, the organic nanoparticles may include nanoparticles in which the core and the shell are formed of organic materials. Utilizing organic nanoparticles having a core-shell structure, the adhesive film may exhibit good foldability and a balance between elasticity and flexibility.

[0105] [Equation 1]

[0106] Tg(c) <Tg(s),

[0107] (In Relationship 1, Tg(c) is the glass transition temperature of the core (unit: °C), and Tg(s) is the glass transition temperature of the shell (unit: °C)).

[0108] Herein, the term "shell" refers to the outermost layer of an organic nanoparticle. The core may be a spherical particle. In some embodiments, the core may further include an additional layer surrounding the spherical particle, as long as the core has a glass transition temperature that satisfies the above relationship.

[0109] Specifically, the core may have a glass transition temperature of -150°C to 10°C (specifically, -150°C to -5°C, more specifically, -150°C to -20°C). Within this range, the adhesive film may have good viscoelasticity at low temperatures and / or at room temperature. The core may include at least one selected from the group consisting of poly(alkyl acrylate), polysiloxane, or polybutadiene having a glass transition temperature within this range.

[0110] The poly(alkyl acrylate) may include at least one selected from the group consisting of poly(methyl acrylate), poly(ethyl acrylate), poly(propyl acrylate), poly(butyl acrylate), poly(isopropyl acrylate), poly(hexyl acrylate), poly(hexyl methacrylate), poly(ethylhexyl acrylate), poly(ethylhexyl methacrylate), and polysiloxane, but is not limited thereto.

[0111] Polysiloxane can be for example organosiloxane (to) polymer.Organosiloxane (to) polymer can be non-crosslinked or crosslinked organosiloxane (to) polymer.Crosslinked organosiloxane (to) polymer can be used to ensure impact resistance and colorability.Particularly, crosslinked organosiloxane (to) polymer can comprise crosslinked dimethylsiloxane, methylphenylsiloxane, diphenylsiloxane or its mixture.Utilize the copolymer of two or more organosiloxanes, nanoparticle can have a refractive index of 1.41 to 1.50.

[0112] The crosslinking state of the organosiloxane (co)polymer can be determined based on its solubility in various organic solvents. As the degree of crosslinking of the organosiloxane (co)polymer increases, the solubility of the organosiloxane (co)polymer decreases. The solvent used to determine the crosslinking state can include acetone, toluene, etc. Specifically, the organosiloxane (co)polymer can have a portion that is insoluble in acetone or toluene. The organosiloxane copolymer can include 30% or more of insoluble matter in toluene.

[0113] The organosiloxane (co)polymer may also include an alkyl acrylate cross-linked polymer. The alkyl acrylate cross-linked polymer may include methyl acrylate, ethyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, etc. For example, the alkyl acrylate cross-linked polymer may be n-butyl acrylate or 2-ethylhexyl acrylate having a low glass transition temperature.

[0114] Specifically, the shell may have a glass transition temperature of 15° C. to 150° C. (specifically, 35° C. to 150° C., more specifically, 50° C. to 140° C.). Within this range, the organic nanoparticles can exhibit good dispersion in the acrylic copolymer. The shell may include a poly(alkyl methacrylate) having a glass transition temperature within this range. For example, the shell may include at least one selected from the group consisting of poly(methyl methacrylate) (PMMA), poly(ethyl methacrylate), poly(propyl methacrylate), poly(butyl methacrylate), poly(isopropyl methacrylate), poly(isobutyl methacrylate), and poly(cyclohexyl methacrylate), but is not limited thereto.

[0115] In the organic nanoparticles, the core may be present in an amount of 30 wt % to 99 wt % (specifically, 40 wt % to 95 wt %, more specifically, 50 wt % to 90 wt %). Within these ranges, the adhesive film may exhibit good foldability over a wide temperature range. In the organic nanoparticles, the shell may be present in an amount of 1 wt % to 70 wt % (specifically, 5 wt % to 60 wt %, more specifically, 10 wt % to 50 wt %). Within these ranges, the adhesive film may have good foldability over a wide temperature range.

[0116] The organic nanoparticles may optionally be present in the adhesive film in an amount of 20 wt% or less, specifically, 0.1 wt% to 20 wt%, specifically, 0.5 wt% to 12 wt%, specifically, 0.5 wt% to 8 wt%. Within these ranges, the organic nanoparticles can ensure good properties in terms of the modulus of the adhesive film at high temperature, the foldability of the adhesive film at room temperature and high temperature, and the viscoelasticity of the adhesive film at low temperature and / or room temperature.

[0117] The organic nanoparticles may optionally be present in an amount of 1 part by weight or less (e.g., 0.01 to 1 part by weight, e.g., 0.01 to 0.5 parts by weight) relative to 100 parts by weight of the monomer mixture. Within this range, the adhesive film may have improved foldability at high temperatures.

[0118] Organic nanoparticles can be prepared by typical emulsion polymerization, suspension polymerization or solution polymerization.

[0119] The adhesive composition may further comprise a silicone-containing (meth)acrylate. The silicone-containing (meth)acrylate may be included in the adhesive film to provide improved glass adhesion.

[0120] 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 Chemical Formula 1.

[0121] [Chemical Formula 1]

[0122]

[0123] (In Chemical Formula 1, R1, R2, R3, R4, R5, R6 and R7 are each independently hydrogen, C1 to C 10 Alkyl, C3 to C 10 Cycloalkyl or C6 to C 10 Aryl, R8 is C1 to C 10 Alkylene or C6 to C 10 arylene, R9 is hydrogen or methyl, and n is an integer from 10 to 100).

[0124] The silicone-containing (meth)acrylate may optionally be present in an amount of 1 part by weight or less (0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 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. Within this range, the adhesive film can ensure further improved foldability.

[0125] The adhesive composition may further include typical additives known to those skilled in the art. The additives may include at least one selected from the group consisting of a silane coupling agent, a pigment, a UV absorber, a leveling agent, and an antistatic agent, but are not limited thereto.

[0126] The adhesive film may have a haze of 5% or less. Within this range, when the adhesive film is applied to an optical display device, the adhesive film does not affect image display. Specifically, the adhesive film may have a haze of 0% to 5% (more specifically, 0.1% to 3%).

[0127] The adhesive film may have a storage modulus of 0.2 MPa or less at -20°C. Within this range, the adhesive film may provide good foldability at low temperatures, at room temperature, and at high temperatures. Specifically, the adhesive 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.

[0128] The adhesive film can have a peel strength of 600 gf / inch or greater (e.g., 600 gf / inch to 1,500 gf / inch) at 25°C. Within this range, the adhesive film can ensure good foldability. In this article, "peel strength" refers to T-peel strength. T-peel strength can be measured by the method as in the following experimental example, wherein the adherend can be a glass plate, for example, an alkali-free glass plate.

[0129] The adhesive film may have a thickness of 10 μm to 300 μm, specifically, 20 μm to 100 μm. Within this range, the adhesive film may be used in optical display devices.

[0130] The composition for the adhesive film can be prepared by partially polymerizing the monomer mixture with an initiator, followed by adding a photoinitiator and a UV absorber. The composition may also contain the organic nanoparticles, crosslinking agents, additives, etc. described above. Partial polymerization may include solution polymerization, suspension polymerization, photopolymerization, bulk polymerization, or emulsion polymerization. Specifically, solution polymerization can be carried out by adding an initiator to the monomer mixture and then heating the resulting mixture to 50°C to 100°C. The initiator may include an acetophenone initiator (which includes 2,2-dimethoxy-2-phenylacetophenone) and a photopolymerization initiator, such as 1-hydroxycyclohexylphenyl ketone, etc. Partial polymerization can achieve a viscosity of 300cP to 50,000cP (specifically, 500cP to 9,000cP) at 25°C.

[0131] The adhesive film is a pressure sensitive adhesive film and can be prepared by typical methods. For example, the adhesive film can be prepared by coating the composition for the adhesive film onto a release film and then curing the adhesive film. Curing can include in the absence of oxygen, at a wavelength of 300 nm to 400 nm and at 400 mJ / cm 2 Up to 3,000mJ / cm 2 Irradiation is carried out using light emitted by a low-pressure lamp at a dose of .

[0132] Base layer

[0133] The base layer allows light to be substantially completely transmitted at a wavelength of 350 nm to 400 nm, and may be substantially free of the UV absorber described above, for example, a UV absorber having a maximum absorption wavelength of 370 nm to 430 nm (e.g., 390 nm to 430 nm), for example, a triazine-based UV absorber, such as a hydroxyphenyltriazine-based UV absorber. Herein, "the base layer may be substantially free of a UV absorber" means that the content of the UV absorber described above in the base layer is 0.05 wt% or less, for example, 0 wt% to 0.001 wt%.

[0134] The base layer serves to support the adhesive film and may also perform a specific optical function in the optical display device.

[0135] In one embodiment, the base layer provides polarization, optical compensation, display quality improvement and / or conductivity, and may include ultra-thin glass (UTG), window film, window, polarizer, color filter, delay film, elliptically polarizing film, reflective polarizing film, anti-reflective film, compensation film, brightness enhancement film, orientation film, light diffuser film, glass anti-shatter film, surface protection film, OLED element barrier layer, plastic LCD substrate and transparent electrode film, including indium tin oxide (ITO), fluorinated tin oxide (FTO), aluminum-doped zinc oxide (AZO), carbon nanotubes (CNT), Ag nanowires, graphene, etc.

[0136] The base layer can be easily manufactured by a person of ordinary skill in the art.

[0137] For example, the touch pad may be attached to a window or a base layer via an adhesive film, thereby forming a touch panel. Alternatively, as in the related art, the adhesive film may be applied to a typical polarizing film.

[0138] In other embodiments, the base layer is an optically transparent film, and the optical component including the base layer and the adhesive film can serve as a supporting layer for the display element. For example, the display element may include a window film, etc. The window film may include a base layer and a window coating (e.g., a silicone coating) formed on the base layer. Specifically, the base layer may have a total light transmittance of 90% or more in the visible spectrum and may be formed from at least one resin selected from the following: cellulose resins, including triacetyl cellulose, etc.; polyester resins, including polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polybutylene naphthalate, etc.; polycarbonate resins; polyimide resins; polystyrene resins; polyacrylate resins, including poly(methyl methacrylate), etc.; cycloolefin polymer resins; acrylic resins and polyamide resins. The base layer may have a thickness of 10 μm to 100 μm (specifically, 20 μm to 75 μm, more specifically, 30 μm to 50 μm). Within this range, the base layer can serve as a support layer for the display element.

[0139] The optical display device according to the present invention includes the optical component according to the present invention.

[0140] The optical display device may include a light-emitting diode display (including an organic light-emitting diode, an inorganic light-emitting diode, or a combination of organic and inorganic light-emitting diodes), a liquid crystal display, etc. The optical display device may include a flexible display device. Alternatively, the optical display device may also include a non-flexible display device.

[0141] In one embodiment, the optical member may be used to adhere a plurality of optical elements in a flexible display device.

[0142] Invention Mode

[0143] Next, the present invention will be described in more detail with reference to some examples. However, it should be noted that these examples are provided for illustrative purposes only and should not be construed as limiting the present invention in any way.

[0144] Example 1

[0145] 100 parts by weight of the monomer mixture prepared as listed in Table 1 and 0.005 parts by weight of a photoinitiator (Irgacure 651) were thoroughly mixed in a reactor. After dissolving oxygen in the reactor with nitrogen, the monomer mixture was partially polymerized by irradiation with UV light for several minutes under a low-pressure mercury lamp, thereby preparing a composition comprising a partial (meth)acrylic copolymer of the monomer mixture. In Table 1 below, "-" indicates the absence of the corresponding component.

[0146] As shown in Table 1, 0.5 parts by weight of a photoinitiator (TPO), 2 parts by weight of a UV absorber (Tinuvin 477, hydroxyphenyl triazine), and 0.1 parts by weight of a crosslinker (dipentaerythritol hexaacrylate (DPHA)) were added to the prepared composition and mixed therewith, thereby preparing a photocurable adhesive composition.

[0147] The prepared adhesive composition was applied onto a polyethylene terephthalate (PET) film (light transmittance at a wavelength of 380 nm: 90%) as an optical film and covered with a PET film as a release film, followed by irradiation at 2,000 mJ / cm 2 The resultant was irradiated with UV light at a dose of 100 Å to 200 Å, thereby preparing a stacked body of the optical member (PET film-adhesive film) and the release film.

[0148] Examples 2 and 3

[0149] Each stack of an optical member and a release film was prepared in the same manner as in Example 1, except that the content of each component was changed as listed in Table 1 in the preparation of the adhesive composition.

[0150] Example 4

[0151] A stack of an optical member and a release film was prepared in the same manner as in Example 1, except that in the preparation of the adhesive composition, after partial polymerization of the monomer mixture, 0.3 wt % of a monofunctional (meth)acrylate-modified siloxane compound (KF2012, Shin-Etsu) was further added to the monomer mixture.

[0152] Comparative Examples 1 to 3

[0153] Each stack of an optical member and a release film was prepared in the same manner as in Example 1, except that the content of each component was changed as listed in Table 1 in the preparation of the adhesive composition.

[0154] Details of the adhesive films prepared in Examples and Comparative Examples are shown in Table 1. The properties listed in Table 1 were evaluated for the adhesive films of Examples and Comparative Examples.

[0155] (1) Light transmittance (unit: %) and yellowness of adhesive films at a wavelength of 380 nm: Adhesive films were obtained by removing both the optical film and the release film from the stack of the optical member and the release film prepared in each of Examples and Comparative Examples. The light transmittance and yellowness of the adhesive films at a wavelength of 380 nm were measured using a spectrophotometer (CM-3600A, Konica Minolta) in transmission mode.

[0156] (2) Storage modulus (unit: MPa): Viscoelasticity was measured under automatic strain conditions at a shear rate of 1 rad / s and a strain of 1% using a dynamic viscoelasticity rheometer (ARESDHR-3, TA Instrument Inc.). An adhesive film was obtained by removing both the optical film and the release film from the stack of the optical member and the release film prepared in each of the Examples and Comparative Examples. A plurality of adhesive films were stacked one on top of another to form a 500 μm thick laminate, which was then punched using an 8 mm diameter punch to prepare a specimen. The storage modulus of the specimen was measured by applying a load of 1.0 N to the specimen using a stainless steel fixture having a diameter of 8 mm while heating the specimen from -60°C to 90°C at a heating rate of 5°C / min, and then obtaining the storage modulus at -20°C.

[0157] (3) Peel strength from a glass plate (unit: gf / inch): A stack of the optical member and release film prepared in each of the Examples and Comparative Examples was cut into a size of 100 mm × 25 mm (length × width). One surface of a PET (polyethylene terephthalate) film having a size of 150 mm × 25 mm × 75 μm (length × width × thickness) was subjected to two corona treatments (total dose: 156) using a corona treatment apparatus at a dose of 78. After removing the PET release film from one surface of the adhesive sheet, a glass plate (150 mm × 25 mm × 75 μm, length × width × thickness) was attached to the exposed surface of the adhesive film and the remaining PET release film was removed from the other surface of the adhesive sheet. The corona-treated PET film was then attached to the other surface of the adhesive film to prepare a specimen for measuring peel strength.

[0158] The prepared specimen was autoclaved at 50°C and 3.5 bar for 1,000 seconds and attached to a peel strength meter (TA.XT-Plus Texture Analyzer, Stable Micro System Co., Ltd.). The T-peel strength was measured by attaching a glass plate to the peel strength meter and pulling the PET film from the glass plate at a rate of 50 mm / min at 25°C.

[0159] (4) Foldability: A module sample was prepared by sequentially stacking a window film, an adhesive film, a polarizer, an adhesive film, and an OLED panel. The module was prepared using the window film, adhesive film, polarizer, adhesive film, and OLED panel shown below. The adhesive film was stacked on the polyimide film of the OLED panel.

[0160] - Window film: A PET film (thickness: 100 μm, Cosmoshine TA015, Toyobo Co., Ltd.) was used.

[0161] - Adhesive film: The adhesive films (thickness: 15 μm) prepared in Examples and Comparative Examples were used.

[0162] Polarizer: PVA resin dyed with iodine. An 80 μm thick polyvinyl alcohol film (degree of saponification: 99.5, degree of polymerization: 2,000) was immersed in a 0.3% iodine aqueous solution for dyeing and stretched in the machine direction to an elongation of 5.0. The stretched polyvinyl alcohol film was then immersed in a 3% boric acid solution and a 2% potassium iodide aqueous solution for color correction, followed by drying at 50°C for 4 minutes to produce a polarizer (thickness: 25 μm).

[0163] -OLED panel: A PET film (thickness: 100 μm, Cosmoshine TA015, Toyobo Co., Ltd.) was used.

[0164] Each prepared module sample was cut into 170 mm x 110 mm (length x width) dimensions and then subjected to 100,000 folding cycles at -20°C to evaluate the occurrence of bubbles, cracks, and delamination. During folding, the sample was folded in both the longitudinal direction and the OLED panel direction at a folding rate of 30 cycles per minute, so that the curved portion of the sample had a curvature radius of 1.5 mm. One cycle refers to the operation of folding the adhesive film to have the specified curvature radius and then unfolding the adhesive film back to 180°. The absence of bubbles, cracks, and delamination was rated as good, while the occurrence of at least one of bubbles, cracks, and delamination was rated as poor.

[0165] [Table 1]

[0166]

[0167] *EHA: 2-Ethylhexyl acrylate

[0168] HBA: 4-Hydroxybutyl acrylate

[0169] EHDG: Di(ethylene glycol) 2-ethylhexyl ether acrylate

[0170] ACMO: Acryloylmorpholine

[0171] DPHA: Dipentaerythritol hexaacrylate

[0172] KF2012: Silicone monofunctional acrylate

[0173] Tinuvin 477: Hydroxyphenyltriazine UV absorber (2-hydroxyphenyl-s-triazine)

[0174] Tinuvin 384-2: Hydroxyphenylbenzotriazole UV absorber

[0175] As shown in Table 1, the adhesive film in the optical member according to the present invention has low light transmittance at a wavelength of 350 to 400 nm and has high cohesion, thereby providing good peel strength and good foldability. In contrast, the adhesive film of the comparative example cannot provide the effects of the present invention.

[0176] It should be understood that numerous modifications, changes, variations and equivalent embodiments may be made by those skilled in the art without departing from the spirit and scope of the present invention.

Claims

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

2. The optical component according to claim 1, wherein The adhesive film includes a triazine-based UV absorber.

3. The optical component according to claim 2, wherein The triazine-based UV absorber includes a hydroxyphenyltriazine-based UV absorber.

4. The optical component according to claim 2, wherein The triazine-based UV absorber is present in the adhesive film in an amount of 0.1 wt % to 4 wt %. The optical component according to claim 1 , wherein The adhesive film has a peel strength of 600 gf / inch or greater. The optical component according to claim 1 , wherein The adhesive film has a storage modulus of 0.2 MPa or less at -20°C.

7. The optical component according to claim 1, wherein The adhesive film is formed of a thermosetting adhesive composition or a photocurable adhesive composition.

8. The optical component according to claim 1, wherein The adhesive film is formed of a photocurable adhesive composition including a UV absorber, a polymer of a monomer mixture, and a photoinitiator.

9. The optical component according to claim 8, wherein The monomer mixture includes an alkyl group-containing (meth)acrylic monomer, a hydroxyl group-containing (meth)acrylic monomer, and a heteroalicyclic group-containing (meth)acrylic monomer.

10. The optical component according to claim 9, wherein The heteroalicyclic group-containing (meth)acrylic monomer is present in an amount of 1 wt % to 10 wt % in the monomer mixture. The optical component according to claim 9 , wherein The monomer mixture further includes an alkylene glycol group-containing (meth)acrylic monomer.

12. The optical component according to claim 11, wherein The heteroalicyclic group-containing (meth)acrylic monomer and the alkylene glycol group-containing (meth)acrylic monomer are present in the monomer mixture in a total amount of 5 wt % to 20 wt %.

13. The optical component according to claim 8, wherein The photoinitiator is present in an amount of 0.0001 parts by weight to 5 parts by weight relative to 100 parts by weight of the monomer mixture.

14. The optical component according to claim 8, wherein The photocurable adhesive composition includes at least one selected from a crosslinking agent and a silicone-containing (meth)acrylate.

15. The optical component according to claim 14, wherein The silicone-containing (meth)acrylate is represented by the following Chemical Formula 1: [Chemical Formula 1] (In Chemical Formula 1, R1, R2, R3, R4, R5, R6 and R7 are each independently hydrogen, C1 to C 10 Alkyl, C3 to C 10 Cycloalkyl or C6 to C 10 Aryl; R8 is C1 to C 10 Alkylene or C6 to C 10 arylene group; R9 is hydrogen or methyl; n is an integer from 10 to 100).

16. The optical component according to claim 1, wherein The base layer includes 0.05 wt % or less of a triazine-based UV absorber having a maximum absorption wavelength of 370 nm to 430 nm. 17 . An optical display device comprising the optical member according to claim 1 .

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