Barrier film

Abstract

In one embodiment of the present invention, a barrier film may have a laminate in which a polymer substrate layer, a planarization layer, an inorganic gas barrier layer, and an organic-inorganic hybrid coating layer are sequentially laminated, and the laminate may be disposed on both sides of a bonding layer. The barrier film according to one embodiment of the present invention has excellent reliability, optical properties, and moisture and oxygen barrier properties.

Description

Technology Field

[0001] The present invention relates to a barrier film.

[0002] More specifically, the present invention relates to a laminated barrier film having a structure in which a laminate comprising an inorganic gas barrier layer is disposed on both sides of a bonding layer. Background Technology

[0004] Materials such as displays, solar cells, and batteries are vulnerable to the penetration of moisture and oxygen, so their intrusion must be blocked.

[0005] Conventional display materials have utilized glass substrates to block the penetration of moisture and oxygen, possessing various advantages such as a low coefficient of linear expansion, excellent gas barrier properties, high light transmittance, excellent surface flatness, superior heat resistance, and excellent chemical resistance. However, glass has disadvantages, including being fragile and easily broken upon impact, as well as being heavy due to its high density. In particular, glass is unsuitable for use in flexible displays, which are attracting attention as key next-generation displays. Consequently, research on polymer films capable of replacing glass is actively underway.

[0006] Flexible displays are a key technology industry capable of achieving low power consumption, low cost, ultra-lightweight design, and large screen sizes. Their portability allows for easy access to information anytime and anywhere, making them a potential focus of the general consumer market. Furthermore, flexible displays utilizing polymer films as substrates allow for the application of roll-to-roll production methods. Consequently, this industry has the potential to emerge as a core component of the display market, driven by the commercialization of mass production technologies centered on small consumer devices such as mobile phones. In particular, flexible substrates are already being researched as an interesting topic by many companies and research institutes.

[0007] Thermoplastic polymers such as polycarbonate (PC), polyimide (PI), polyethersulfone (PES), polyarylate (PAR), poly(ethylene naphthalate), poly(ethylene terephthalate) (PET), and cycloolefin copolymer, as well as polymers obtained by curing curable resins such as acrylic resin, epoxy resin, and unsaturated polyester, are used in flexible substrates because they have excellent optical properties.

[0008] However, flexible substrates containing only transparent polymer films made of the above polymers have very poor barrier capabilities against moisture and oxygen penetration. Accordingly, experiments are actively being conducted to coat transparent polymer films with multiple layers of functional coating layers that have excellent barrier capabilities against moisture and oxygen penetration. Currently, inorganic gas barrier layers and organic-inorganic hybrid coating layers are mainly used as functional coating layers.

[0009] However, the optical properties of the functional coating layer are not superior to those of the polymer transparent film. Consequently, when applied to LCD or OLED displays capable of achieving high image quality, it is difficult to produce products that meet consumer demands. Furthermore, if a functional coating layer, such as an inorganic gas barrier layer that blocks moisture and oxygen penetration, is located on the outer side of the barrier film, the durability of the inorganic gas barrier layer may easily deteriorate after the barrier film is applied to the product, leading to a problem of reduced reliability of the barrier film.

[0010] Therefore, a barrier film with excellent reliability, optical properties, and moisture and oxygen barrier properties is required. Prior art literature

[0012] Republic of Korea Published Patent No. 10-2021-0156622 The problem to be solved

[0013] The problem that the present invention aims to solve is to provide a barrier film with excellent reliability, optical properties, and moisture and oxygen barrier properties. means of solving the problem

[0015] According to one embodiment of the present invention, a barrier film is provided in which a laminate comprising a polymer substrate layer, a planarization layer, an inorganic gas barrier layer, and an organic-inorganic hybrid coating layer sequentially laminated is disposed on both sides of a bonding layer.

[0016] In one embodiment, the bonding layer may have a thickness of 5 μm to 50 μm.

[0017] In one embodiment, the refractive index of the bonding layer may be smaller than the refractive index of the polymer substrate layer.

[0018] In one embodiment, the bonding layer may have an adhesive strength of 2000 gf / 25 mm or more as measured according to ASTM D1876-08.

[0019] In one embodiment, the bonding layer may include an acrylic resin, an epoxy resin, a silicone resin, a fluorine resin, a styrene resin, a polyolefin resin, a thermoplastic elastomer, a polyoxyalkylene resin, a polyester resin, a polyvinyl chloride resin, a polycarbonate resin, a polyphenylene sulfide resin, a mixture of hydrocarbons, a polyamide resin, or a mixture thereof.

[0020] In one embodiment, the laminates disposed on both sides of the bonding layer may be arranged such that the organic-inorganic hybrid coating layer is located on the bonding layer side.

[0021] In one embodiment, a laminate disposed on one side of the bonding layer may be disposed such that a polymer substrate layer is located on one side, and a laminate disposed on the other side of the bonding layer may be disposed such that an organic-inorganic hybrid coating layer is located on the bonding layer side.

[0022] In one embodiment, the laminates disposed on both sides of the bonding layer may be arranged such that the polymer substrate layer is located on the bonding layer side.

[0023] In one embodiment, the polymer substrate layer comprises a thermoplastic transparent base resin, and the thermoplastic transparent base resin may comprise one or more selected from the group consisting of polyethylene terephthalate, polyethersulfone, polycarbonate, polyimide, polyarylate, polyethylene naphthalate, polyethylene terephthalate glycol, polycyclohexylene dimethylene terephthalate glycol, and cycloolefin copolymer.

[0024] In one embodiment, the polymer substrate layer may have a coefficient of thermal expansion of 100 ppm / ℃ or less in the range of 100 ℃ or higher and 130 ℃ or lower.

[0025] In one embodiment, the polymer substrate layer may have a thermal shrinkage rate in the MD (Machine Direction) direction of 0.5% or less and a thermal shrinkage rate in the TD (Transverse Direction) direction of 0.3% or less, and the thermal shrinkage rate may be calculated by the following Equation 1.

[0026] [Mathematical Formula 1]

[0027] (Initial length of polymer substrate layer - Length of polymer substrate layer after heat shrinkage treatment at 150 ℃ for 30 minutes / Initial length of polymer substrate layer) × 100

[0029] In one embodiment, the planarization layer may have the same composition as the organic-inorganic hybrid coating layer.

[0030] In one embodiment, the planarization layer and the organic-inorganic hybrid coating layer may comprise a cured product of a curable sol solution mixed with a (meth)acrylate monomer, a (meth)acrylate oligomer having an epoxy group and a weight-average molecular weight of 500 to 10,000, an initiator, silica particles, and a dispersion medium, and a sol solution comprising a metal alkoxide, a curing accelerator, an inorganic acid, and a solvent.

[0031] In one embodiment, the inorganic gas barrier layer may include an oxide, nitride, carbide, oxynitride, oxycarbide, nitride carbide, or oxynitride carbide containing one or more metals selected from the group consisting of Si, Al, In, Sn, Zn, Ti, Cu, Ce, and Ta. Effects of the invention

[0033] A barrier film according to one embodiment of the present invention has excellent reliability, optical properties, and moisture and oxygen barrier properties. Brief explanation of the drawing

[0035] FIG. 1 is a diagram briefly illustrating the structure of a barrier film according to one embodiment of the present invention. FIG. 2 is a diagram briefly showing the structure of a barrier film according to one embodiment of the present invention. FIG. 3 is a diagram briefly showing the structure of a barrier film according to one embodiment of the present invention. Figure 4 is a simplified diagram showing the structure of a laminate in which a polymer substrate layer, a planarization layer, an inorganic gas barrier layer, and an organic-inorganic hybrid coating layer are sequentially stacked. Specific details for implementing the invention

[0036] The advantages and features of the present invention and the methods for achieving them will become clear by referring to the embodiments described below in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below but may be implemented in different forms. The embodiments are provided merely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the scope of the claims.

[0037] The size and thickness of each component shown in the drawings are depicted arbitrarily for the convenience of explanation, and thus the present invention is not necessarily limited to what is shown in the drawings; furthermore, the thickness has been enlarged to clearly represent various parts and regions.

[0038] The terms used in this invention have been selected based on currently widely used general terms, taking into account their functions within the invention; however, these terms may vary depending on the intent of those skilled in the art, case law, the emergence of new technologies, etc. Additionally, in specific cases, terms may be arbitrarily selected by the applicant, and in such cases, their meanings will be described in detail in the relevant description of the invention. Therefore, the terms used in this invention should be defined not merely by their names, but based on their meanings and the overall content of the invention.

[0040] We will explain the terms used in this specification and describe specific details for implementing the present invention.

[0041] In this specification, terms such as "comprising" or "having" are intended to specify the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof. Furthermore, when a part such as a layer, film, region, plate, or laminate is described as being placed "on" another part, this includes not only cases where it is placed "immediately above" the other part, but also cases where another part is placed in the middle. Conversely, when a part such as a layer, film, region, plate, or laminate is described as being placed "under" another part, this includes not only cases where it is placed "immediately below" the other part, but also cases where another part is placed in the middle. Additionally, in this specification, being described as being placed "on" may include cases where it is placed on the lower part as well as on the upper part.

[0043] Hereinafter, specific details regarding the components included in the present invention will be described.

[0045] barrier film

[0046] Referring to FIGS. 1 to 3, a barrier film according to one embodiment of the present invention has a structure in which a laminate in which a polymer substrate layer (1), a flattening layer (2), an inorganic gas barrier layer (3), and an organic-inorganic hybrid coating layer (4) are sequentially laminated is disposed on both sides of a bonding layer (5), thereby having excellent reliability, optical properties, and moisture and oxygen barrier properties.

[0047] Referring to FIG. 1, a barrier film according to one embodiment of the present invention may have a structure in which a laminate disposed on both sides of a bonding layer (5) has an organic-inorganic hybrid coating layer (4) located on the bonding layer (5) side. A barrier film according to one embodiment having such a structure may have a better reliability of the barrier film because an inorganic gas barrier layer (3) is located on the inner side of the barrier film.

[0048] Referring to FIG. 2, a barrier film according to one embodiment of the present invention may have a structure in which a laminate disposed on one side of a bonding layer (5) has a polymer substrate layer (1) located toward the bonding layer (5), and a laminate disposed on the other side of a bonding layer (5) has an organic-inorganic hybrid coating layer (4) located toward the bonding layer (5). FIG. 2 illustrates a barrier film having a structure in which a laminate disposed on the lower side of a bonding layer (5) has a polymer substrate layer (1) located toward the bonding layer (5), and a laminate disposed on the upper side of a bonding layer (5) has an organic-inorganic hybrid coating layer (4) located toward the bonding layer (5), but this is merely an example. That is, the laminates disposed on the upper and lower sides of a bonding layer (5) may be disposed in different positions. In a barrier film according to the same embodiment with such a structure, the inorganic gas barrier layer (3) of the laminated structure disposed on one side of the bonding layer (5) is located on the inner side of the barrier film, and the polymer substrate layer (1) of the laminated structure disposed on the other side is located on the bonding layer (5), so the reliability and optical properties of the barrier film can be excellent.

[0049] Referring to FIG. 3, a barrier film according to one embodiment of the present invention may have a structure in which a laminate disposed on both sides of a bonding layer (5) has a polymer substrate layer (1) located on the bonding layer (5). A barrier film according to one embodiment having such a structure may have superior optical properties because a polymer substrate layer (1) having a refractive index similar to that of the bonding layer (5) is located on the bonding layer (5).

[0050] A barrier film according to one embodiment of the present invention has a structure in which the same laminate is arranged on both sides of a bonding layer (5), so the manufacturing process is more economical and the manufacturing yield can be further improved.

[0051] A barrier film according to one embodiment of the present invention may have low water vapor permeability as it has a multilayer structure.

[0053] A barrier film according to one embodiment may have a light transmittance (550 nm) of 85% to 95%. The light transmittance can be measured in accordance with ASTM D1003 using a Minolta 3600D instrument.

[0054] A barrier film according to one embodiment may have a water vapor permeability of 0.004 or less. The water vapor permeability is 37.8 using a Mocon PERMATRAN-W3 / 31 instrument. and can be measured for 48 hours under RH 100%.

[0055] A barrier film according to one embodiment may have a haze of 1.00% or less. The haze can be measured in accordance with ASTM D1003 using an NDH-5000 instrument from Nippon Denshoku.

[0057] polymer substrate layer

[0058] In one embodiment, the polymer substrate layer may comprise a thermoplastic transparent base resin. Non-limiting examples of the thermoplastic transparent base resin include polyethylene terephthalate, polyethersulfone, polycarbonate, polyimide, polyarylate, polyethylene naphthalate, polyethylene terephthalate glycol, polycyclohexylene dimethylene terephthalate glycol, and cycloolefin copolymer.

[0059] In one embodiment, the thickness of the polymer substrate layer may be 0.01 μm to 1000 μm. If the thickness of the polymer substrate layer increases or decreases by a specific amount, the physical properties of the polymer substrate layer may also change.

[0060] In one embodiment, the polymer substrate layer may have a coefficient of thermal expansion of 100 ppm / ℃ or less in the range of 100 ℃ to 130 ℃, preferably 80 ppm / ℃ or less, and most preferably 50 ppm / ℃ or less. The range of 100 ℃ to 130 ℃ may refer to a temperature range of 100 ℃ to 130 ℃.

[0061] If the coefficient of thermal expansion of the polymer substrate layer is high, significant shrinkage occurs when returning to room temperature after high-temperature processing, which may result in a failure to ensure the dimensional stability of the barrier film. Additionally, differences in the coefficients of thermal expansion with other layers may cause cracking, delamination, or curling, which can reduce the durability and reliability of the barrier film.

[0062] The above coefficient of thermal expansion can be measured using a TMA (TMA Q400 V20.7 Build 21) instrument manufactured by TA, when a tensile force is set to 0.01 N or more and 0.5 N or less, or 0.1 N or more and 0.3 N or less for a polymer substrate layer sample with a thickness of 10 μm to 200 μm, a first heating process is carried out at a heating rate of 1 °C / min or more and 10 °C / min or 4 °C / min or more and 6 °C / min in a temperature range of 100 °C or more and 130 °C or less, and the thermal expansion change pattern is measured at a cooling rate of 1 °C / min or more and 10 °C / min or 4 °C / min or more and 6 °C / min or less in a temperature range of 130 °C or less and 10 °C / min or more and 4 °C / min or more and 6 °C / min or less.

[0063] In one embodiment, the polymer substrate layer may have a thermal shrinkage rate in the Machine Direction (MD) direction of 0.5% or less and a thermal shrinkage rate in the Transverse Direction (TD) direction of 0.3% or less. The thermal shrinkage rate can be calculated by the following Equation 1. The MD direction may be the longitudinal or transverse direction of the polymer substrate layer, and the TD direction may be the transverse or longitudinal direction of the polymer substrate layer. It is obvious that when calculating the thermal shrinkage rate in the MD direction, the "length in the MD direction" is substituted into "length" in Equation 1 below, and when calculating the thermal shrinkage rate in the TD direction, the "length in the TD direction" is substituted into "length" in Equation 1 below.

[0064] [Mathematical Formula 1]

[0065] (Initial length of polymer substrate layer - Length of polymer substrate layer after heat shrinkage treatment at 150 ℃ for 30 minutes / Initial length of polymer substrate layer) × 100

[0067] If the thermal shrinkage rate of the polymer substrate layer is too high, the dimensional stability of the barrier film may not be ensured. In addition, cracking, delamination, or curling may occur, which may reduce the durability and reliability of the barrier film.

[0068] In one embodiment, the refractive index of the polymer substrate layer may be 1.5 to 2.5, preferably 1.6 to 1.7, but is not limited thereto. In one embodiment, considering the optical properties of the barrier film, it is preferable that the refractive index of the polymer substrate layer be greater than the refractive index of the bonding layer described later. The refractive index may refer to the refractive index for light with wavelengths in the range of 500 nm to 600 nm. In other examples, the measurement wavelength of the refractive index may be 520 nm to 580 nm, 540 nm to 560 nm, or 545 nm to 555 nm.

[0069] In one embodiment, the polymer substrate layer may include a glass fiber fabric as needed, and the glass fiber fabric may be impregnated with a thermoplastic transparent polymer resin. Additionally, the polymer substrate layer may include an inorganic nanomaterial dispersed in the thermoplastic transparent polymer resin as needed. The glass fiber fabric and the inorganic nanomaterial may be included in the polymer substrate layer to improve the mechanical or optical properties of the barrier film. A detailed description of the glass fiber fabric and the inorganic nanomaterial is omitted. However, the glass fiber fabric and the inorganic nanomaterial that may be included for such purposes in the art may be included in the polymer substrate layer in one embodiment of the present invention.

[0070] In one embodiment, a plasma surface treatment layer may be disposed on the polymer substrate layer as needed. The plasma surface treatment layer may be disposed to improve the adhesion of the polymer substrate layer and to improve the moisture and oxygen barrier properties of the barrier film. A detailed description of the plasma surface treatment layer is omitted. However, in one embodiment of the present invention, a plasma surface treatment layer that can be disposed for such purposes may be disposed on the polymer substrate layer.

[0071] Among the polymer substrate layer, planarization layer, inorganic gas barrier layer, and organic-inorganic hybrid coating layer of the laminate described below, the layer with the smallest difference in refractive index with the bonding layer may be the polymer substrate layer. Therefore, when the laminate is placed on one side of the bonding layer, the polymer substrate layer of the laminate must be positioned so that it is located toward the bonding layer so that the optical properties of the barrier film can be improved.

[0073] flattening layer

[0074] In one embodiment, the planarization layer may have the same composition as the organic-inorganic hybrid coating layer described below. The description of the planarization layer may be the same as the description of the organic-inorganic hybrid coating layer described below.

[0075] Even if the planarization layer and the organic-inorganic hybrid coating layer have the same composition, their positions within the laminate may differ, so the function or role of each layer may differ.

[0076] The planarization layer can reduce stress at high temperatures caused by the difference in thermal expansion coefficients between the polymer substrate layer and the inorganic barrier layer, and can minimize defects that may occur during deposition by increasing the planarization degree of the polymer substrate layer.

[0078] Inorganic gas barrier layer

[0079] In one embodiment, the inorganic gas barrier layer may comprise an oxide, nitride, carbide, oxynitride, oxycarbide, nitride carbide, or oxynitride carbide containing one or more metals selected from the group consisting of Si, Al, In, Sn, Zn, Ti, Cu, Ce, and Ta, but is not limited thereto. More specifically, in one embodiment, the inorganic gas barrier layer may comprise silicon oxide, silicon nitride, aluminum oxide, or ITO (indium tin oxide), but is not limited thereto.

[0080] In one embodiment, the thickness of the inorganic gas barrier layer may be 10 nm to 200 nm, preferably 20 nm to 150 nm, and most preferably 30 nm to 100 nm.

[0081] When the thickness of the inorganic gas barrier layer satisfies this range, a uniform film can be formed, dispersion is facilitated to exhibit excellent gas barrier properties, the effect of reducing interlayer stress by the coating layer is sufficiently manifested, and problems such as cracking or delamination can be prevented.

[0082] In a barrier film, the layer that contributes most to blocking moisture and oxygen may be the inorganic gas barrier layer. Therefore, when a laminate in which a polymer substrate layer, a planarization layer, an inorganic gas barrier layer, and an organic-inorganic hybrid coating layer are sequentially stacked is placed on one side of a bonding layer described later, it may be advantageous for the reliability of the barrier film to position the organic-inorganic hybrid coating layer of the laminate toward the bonding layer. This is because, when positioned as described above, the inorganic gas barrier layer can be located further inward within the barrier film that is finally manufactured, thereby ensuring that the durability of the inorganic gas barrier layer is maintained excellently even after the barrier film is applied to a product.

[0084] Organic-inorganic hybrid coating layer

[0085] In one embodiment, the organic-inorganic hybrid coating layer may comprise a curable sol solution mixed with a (meth)acrylate monomer, a (meth)acrylate oligomer having an epoxy group and a weight-average molecular weight of 500 to 10,000, an initiator, silica particles, and a dispersion medium, and a sol solution comprising a metal alkoxide, a curing accelerator, an inorganic acid, and a solvent.

[0086] The above curable sol solution may include a curable coating solution in which silica particles are dispersed by dissolving a (meth)acrylate monomer, a (meth)acrylate oligomer having an epoxy group and a weight-average molecular weight of 500 to 10,000, and an initiator in a solvent.

[0087] The above (meth)acrylate monomer performs the function of controlling the viscosity and curing density of the curable coating solution and improving adhesion to the inorganic gas barrier layer. The (meth)acrylate monomer may be a monofunctional or polyfunctional monomer. In addition, it may exist in an ethoxylated or propoxylated form. (Meth)acrylate monomers include 2(2-ethoxyethoxy)ethyl acrylate, 2-phenoxyethyl acrylate, 2-phenoxyethyl methacrylate, caprolactone acrylate, dicyclopentadienyl methacrylate, tetrahydrofurfuryl acrylate, tetrahydrofurfuryl methacrylate, 1,3-butylene glycol diacrylate, 1,4-butanediol dimethacrylate, diethylene glycol diacrylate, ethoxylated bisphenol A diacrylate, ethoxylated bisphenol A dimethacrylate, ethylene glycol dimethacrylate, ethoxylated trimethylolpropane triacrylate, pentaerythritol triacrylate, propoxylated glyceryl triacrylate, propoxylated trimethylolpropane triacrylate, Trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, tris(2-hydroxyethyl)isocyanurate triacrylate, etc., can each be used individually or in a mixture of two or more of these.

[0088] The (meth)acrylate oligomer having the above-mentioned epoxy group and a weight-average molecular weight of 500 to 10,000 is an oligomer having (meth)acrylate groups and epoxy groups, and contributes to the good adhesion of an organic-inorganic hybrid coating layer to a polymer substrate layer or an inorganic gas barrier layer. In particular, it contributes to improving adhesion to the polymer substrate layer, and, for example, bisphenol-A epoxy acrylate oligomer, flame-retardant epoxy acrylate oligomer, novolak-type epoxy acrylate oligomer, bisphenol-F epoxy acrylate oligomer, glycidylamine-type epoxy acrylate oligomer, rubber-modified epoxy acrylate oligomer, etc., can be used individually or in a mixture of two or more of these.

[0089] The above initiator may be any chemical compound capable of initiating the polymerization reaction of (meth)acrylate functional groups by a chemical beam. Examples of suitable photoinitiators include 1-hydroxy-cyclohexyl-phenyl-ketone, benzophenone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, 2-hydroxy-1-[4-(2-hydroxyethoxy)phenyl]-2-methyl-1-propanone, 2-benzyl-2-(dimethylamino)-1-[4-(4-morpholinyl)phenyl]-1-butanone, diphenyl(2,4,6-trimethylbenzoyl)-phosphine oxide, and mixtures thereof. Photolatent base type photoinitiators, such as 2-methyl-1-[4-(methylthio)phenyl]-2-(4-morpholinyl)-1-propanone, may also be used as photoinitiators.

[0090] The dispersion medium used in the above-mentioned curable coating solution includes methanol, ethanol, propanol, isopropanol, butanol, isobutanol, secondary butanol, tertiary butanol, cyclohexanol, pentanol, octanol, decanol, di-n-butyl ether, ethylene glycol dimethyl ether, propylene glycol dimethyl ether, propylene glycol methyl ether, dipropylene glycol methyl ether, tripropylene glycol dimethyl ether, ethylene glycol butyl ether, diethylene glycol butyl ether, ethylene glycol dibutyl ether, ethylene glycol methyl ether, diethylene glycol ethyl ether, diethylene glycol dimethyl ether, ethylene glycol ethyl ether, ethylene glycol diethyl ether, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, butylene glycol, dibutylene glycol, tributylene glycol, tetrahydrofuran, It may include dioxane, acetone, diacetone alcohol, methyl ethyl ketone, cyclohexanone, methyl isobutyl ketone, ethyl acetate, n-propyl acetate, n-butyl acetate, t-butyl acetate, propylene glycol monomethyl ether acetate, dipropylene glycol methyl ether acetate, 1-methoxy-2-propanol, ethyl 3-ethoxypropionate, 2-propoxyethanol, ethylene glycol ethyl ether acetate, or mixtures thereof.

[0091] The silica particles dispersed in the curable coating solution preferably have an average particle size of about 100 nm or less, and more preferably about 50 nm or less. The silica particles may be added to the coating solution in the form of a dry powder, a colloidal dispersion in a suitable liquid, or other forms. The silica particles may be included as they are or chemically modified, such as by introducing suitable functional groups to the surface to increase the miscibility of the particles with the curable coating solution.

[0092] In addition, the curable coating solution may further include a silicon alkoxide having a (meth)acrylate group. In this specification, (meth)acrylate means acrylate or methacrylate.

[0093] Examples of silicon alkoxides having the above (meth)acrylate group include (3-acryloxypropyl)dimethylmethoxysilane, (3-acryloxypropyl)methyldimethoxysilane, (3-acryloxypropyl)trimethoxysilane, (methacryloxymethyl)dimethylethoxysilane, methacryloxymethyltriethoxysilane, methacryloxymethyltrimethoxysilane, methacryloxypropylmethyldiethoxysilane, methacryloxypropylmethyldimethoxysilane, (3-methacryloxypropyl)triethoxysilane, (3-methacryloxypropyl)trimethoxysilane, and (3-methacryloxypropyl)trimethoxysilane, each used individually or mixed in combination of two or more of these.

[0094] The relative amounts of each compositional component constituting the curable coating solution for forming the above organic-inorganic hybrid overcoating layer can be adjusted according to the physical properties of the desired film, and the weight ratio of the (meth)acrylate monomer, the (meth)acrylate oligomer having an epoxy group and a weight-average molecular weight of 500 to 10,000, and the silica particles included in the curable coating solution is preferably 1 to 40 : 1 to 40 : 1 to 25 or preferably 10 to 30 : 10 to 30 : 1 to 10 or more preferably 15 to 25 : 15 to 25 : 1 to 7.

[0095] Then, a sol solution in which a metal alkoxide, a curing accelerator, an inorganic acid, and water are dissolved in a solvent is mixed with the curable coating solution.

[0096] As the metal alkoxide included in the sol solution, it is preferable to use any one selected from metal alkoxides represented by the following chemical formulas 1 to 3, or a mixture of two or more of these.

[0097] <Chemical Formula 1>

[0098] R 1x M 1 (OR 2 ) 4-x

[0099] <Chemical Formula 2>

[0100] R 1y M 2 (OR 2 ) 3-y

[0101] <Chemical Formula 3>

[0102] R 1 z Nb(OR 2 ) 5-z

[0103] In the above chemical formulas 1 to 3, R1 is any one selected from the group consisting of an alkyl group having 1 to 4 carbon atoms, a vinyl group, an allyl group, a (meth)acryloxy group, an epoxide group, and an amino group; R2 is an alkyl group having 1 to 4 carbon atoms; M1 is a metal selected from the group consisting of Si, Ti, Zr, Ge, and Sn; M2 is a metal selected from the group consisting of Al, In, and Sb; x is 0, 1, 2, or 3; y is 0, 1, or 2; and z is 0, 1, 2, 3, or 4.

[0104] These metal alkoxides include aluminum acrylate, aluminum ethoxide, aluminum isopropoxide, aluminum methacrylate, antimony III n-butoxide, antimony III ethoxide, antimony III methoxide, germanium n-butoxide, germanium ethoxide, germanium isopropoxide, germanium methoxide, methacryloxytriethylgerman, indium methoxyethoxide, niobium V n-butoxide, niobium V ethoxide, tin II ethoxide, tin II methoxide, di-n-butyl diacrylate tin, di-n-butyl dimethacrylate tin, titanium n-butoxide, titanium ethoxide, titanium isobutoxide, titanium isopropoxide, titanium methacrylate triisopropoxide, titanium methacrylate triisopropoxide, titanium Examples include n-propoxide zirconium n-butoxide, zirconium t-butoxide, zirconium dimethacrylate dibutoxide, zirconium ethoxide, zirconium isopropoxide, zirconium methacrylate, zirconium methacrylate tri-n-butoxide, zirconyl dimethacrylate, methyltrimethoxysilane, methyltriethoxysilane, tetraethoxysilane (tetraethyl orthosilicate, TEOS), tetramethoxysilane, etc., and these may be used individually or in combination of two or more types.

[0105] Meanwhile, the curing accelerator included in the sol solution is preferably an organic acid, as it enables condensation reactions even at relatively low temperatures, thereby contributing to the application of the roll-to-roll method. Such curing accelerators may be anhydrides, carboxylic acids, or mixtures thereof. Suitable examples of anhydrides include acetic anhydride, acrylic anhydride, cyclic anhydride, hexahydrophthalic anhydride, methacrylic anhydride, propionic anhydride, and mixtures thereof. Possible carboxylic acid components include acetic acid, acrylic acid, formic acid, fumaric acid, itaconic acid, maleic acid, methacrylic acid, propionic acid, methylene succinic acid, and mixtures thereof. Each of these may be used individually or in a mixture of two or more.

[0106] The above inorganic acid may be any inorganic acid capable of catalyzing the sol-gel hydrolysis reaction. Suitable inorganic acids include hydrochloric acid, nitric acid, sulfuric acid, hydrofluoric acid, and mixtures thereof.

[0107] The above solvents include methanol, ethanol, propanol, isopropanol, butanol, isobutanol, secondary butanol, tertiary butanol, cyclohexanol, pentanol, octanol, decanol, di-n-butyl ether, ethylene glycol dimethyl ether, propylene glycol dimethyl ether, propylene glycol methyl ether, dipropylene glycol methyl ether, tripropylene glycol methyl ether, dipropylene glycol dimethyl ether, tripropylene glycol dimethyl ether, ethylene glycol butyl ether, diethylene glycol butyl ether, ethylene glycol dibutyl ether, ethylene glycol methyl ether, diethylene glycol ethyl ether, diethylene glycol dimethyl ether, ethylene glycol ethyl ether, ethylene glycol diethyl ether, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, butylene glycol, dibutylene glycol, tributylene glycol, tetrahydrofuran, dioxane, acetone, Examples include diacetone alcohol, methyl ethyl ketone, cyclohexanone, methyl isobutyl ketone, ethyl acetate, n-propyl acetate, n-butyl acetate, t-butyl acetate, propylene glycol monomethyl ether acetate, dipropylene glycol methyl ether acetate, 1-methoxy-2-propanol, ethyl 3-ethoxypropionate, 2-propoxyethanol, ethylene glycol ethyl ether acetate, etc., and each of these can be used alone or in a mixture of two or more.

[0108] The relative amounts of each compositional component constituting the sol solution for forming the aforementioned organic-inorganic hybrid coating layer can be appropriately adjusted according to the physical properties of the desired film, and the thickness of the hybrid coating layer is preferably 0.1 to 10 μm.

[0109] The organic-inorganic hybrid coating layer can protect the aforementioned inorganic gas barrier layer.

[0111] laminate

[0112] The structure of the laminate is explained with reference to Fig. 4.

[0113] In one embodiment, the laminate may have a structure in which a polymer substrate layer (1), a flattening layer (2), an inorganic gas barrier layer (3), and an organic-inorganic hybrid coating layer (4) are sequentially laminated.

[0114] Here, the structure in which a polymer substrate layer, a planarization layer, an inorganic gas barrier layer, and an organic-inorganic hybrid coating layer are sequentially stacked refers to a structure in which the planarization layer is stacked on the polymer substrate layer, the inorganic gas barrier layer is stacked on the planarization layer, and the organic-inorganic hybrid coating layer is stacked on the inorganic gas barrier layer.

[0116] The following describes a method for manufacturing a laminated material. However, the following description is merely an example, and it should be noted that the stacking order of each layer can be varied.

[0117] The planarization layer can be formed by applying the aforementioned curable sol solution onto a polymer substrate layer and UV curing or thermal curing. UV curing is not particularly limited as long as a radical reaction can be achieved by a UV light source, but mercury or metal halide lamps may be used alone or in combination. For example, UV curing can be performed at an energy of 160 mJ / cm². 2 Up to 1600 mJ / cm² 2 It can be performed for 1 second to several minutes, for example, 1 minute or less. Meanwhile, heat curing can be performed for, for example, at a temperature of 100°C to 200°C for 1 minute to several hours, for example, 1 hour or less, or 2 to 10 minutes.

[0118] The inorganic gas barrier layer can be formed by depositing and coating it on the planarization layer using physical or chemical methods.

[0119] The organic-inorganic hybrid coating layer can be formed through methods such as bar coating, spin coating, dip coating, and spray coating.

[0120] The organic-inorganic hybrid coating layer can be formed by applying the aforementioned curable sol solution onto an inorganic gas barrier layer and UV curing or thermal curing. UV curing is not particularly limited as long as a radical reaction can be achieved by a UV light source, but mercury or metal halide lamps may be used alone or in combination. For example, UV curing can be performed at an energy of 160 mJ / cm². 2 Up to 1600 mJ / cm² 2 It can be performed for 1 second to several minutes, for example, 1 minute or less. Meanwhile, heat curing can be performed for, for example, at a temperature of 100°C to 200°C for 1 minute to several hours, for example, 1 hour or less, or 2 to 10 minutes.

[0122] bonding layer

[0123] In one embodiment, the bonding layer may be a pressure-sensitive adhesive (PSA), an optical clear adhesive (OCA), or an optical clear resin (OCR).

[0124] In one embodiment, the bonding layer may include an adhesive component or an adhesive component. In this specification, "adhesive component" may refer to a component that possesses viscosity at room temperature, can be bonded by applying pressure without activation by heat, water, or solvents, exhibits strong holding power after bonding, and possesses cohesiveness and elasticity. In this specification, "adhesive component" may refer to a component that, unlike an adhesive component, can provide permanent bonding rather than temporary bonding, is typically applied to bonding in a liquid state, exhibits adhesive power upon solidification, cooling, or curing, and may cause physical destruction when the bonded objects are separated after bonding. That is, if the bonding layer includes an adhesive component, an adhesive layer can be realized, and if the resin layer includes an adhesive component, an adhesive layer can be realized.

[0125] In one embodiment, the bonding layer may include an acrylic resin, an epoxy resin, a silicone resin, a fluorine resin, a styrene resin, a polyolefin resin, a thermoplastic elastomer, a polyoxyalkylene resin, a polyester resin, a polyvinyl chloride resin, a polycarbonate resin, a polyphenylene sulfide resin, a mixture of hydrocarbons, a polyamide resin, or a mixture thereof. Additionally, the listed resins may include one or more functional groups or sites capable of curing by heat, such as glycidyl groups, isocyanate groups, hydroxyl groups, carboxyl groups, or amide groups, so that they can be cured to exhibit adhesiveness, for example, or may include one or more functional groups or sites capable of curing by irradiation with an active energy beam, such as epoxide groups, cyclic ether groups, sulfide groups, acetal groups, or lactone groups.

[0126] In one embodiment, the thickness of the bonding layer may be 5 μm to 50 μm. If the thickness of the bonding layer is too thick, it may have a negative effect on the optical properties of the barrier film, and if the thickness of the bonding layer is too thin, the adhesion between the laminates may be insufficient, which may reduce the reliability of the barrier film.

[0127] In one embodiment, the refractive index of the bonding layer may be smaller than the refractive index of the polymer substrate layer. If the refractive index of the bonding layer is larger than the refractive index of the polymer substrate layer, the optical properties of the barrier film may be degraded.

[0128] In one embodiment, the refractive index of the bonding layer may be 1.45 or higher, preferably 1.47 to 1.50. The refractive index may refer to the refractive index for light with wavelengths in the range of 500 nm to 600 nm. In other examples, the measurement wavelength of the refractive index may be 520 nm to 580 nm, 540 nm to 560 nm, or 545 nm to 555 nm.

[0129] In one embodiment, the adhesive strength of the bonding layer may be 2000 gf / 25 mm or more, preferably 2500 gf / 25 mm or more. The adhesive strength may be measured according to ASTM D1876-08 "Standard test method for peel resistance of adhesives (T-peel test)".

[0131] The details for implementing the present invention will be explained in more detail below through comparative examples and practical examples, but the examples are merely illustrative and the present invention is not limited thereto.

[0132] Comparative Example 1 (Laminate, Fig. 4)

[0133] A polyethylene terephthalate film (V5410) manufactured by SKC was prepared as a polymer substrate layer. The thickness of the film was 50 μm, the coefficient of thermal expansion in the range of 100 ℃ to 130 ℃ was 70.65 ppm / ℃, the thermal shrinkage rate in the MD direction calculated by the above-described Equation 1 was 0.4% and the thermal shrinkage rate in the TD direction was 0.2%, and the refractive index was 1.65.

[0135] A curable sol solution was prepared as follows to form a planarization layer and an organic-inorganic hybrid coating layer.

[0136] First, 238.1 g of ethanol, 120.7 g of tetraethyl orthosilicate (TEOS), 3.2 g of 36 wt% hydrochloric acid, and 41.1 g of water were stirred at 200 rpm for 1 hour at room temperature. Then, 562.5 g of ethanol was added to form a primary mixture. Next, 0.55 g of hexahydrophthalic anhydride (HHPA) (Lonza Chemicals), 1.4 g of water, and 32 g of ethyl alcohol were stirred at 250 rpm for 1 hour at room temperature, then added to the primary mixture and stirred at approximately 200 rpm for 4 hours at room temperature, followed by filtration through a 0.2 µm filter to prepare a sol solution.

[0137] 31 g of a 30 wt% colloidal silica solution based on isopropyl alcohol as a solvent (Nissan Chemicals, catalog no. IPA-ST) was prepared by sonicating it at room temperature for 60 minutes. Then, 52.7 g of ethoxylated trimethylolpropane triacrylate (Satomer, catalog number SR-454), 59.8 g of bisphenol-A epoxyacrylate oligomer with a molecular weight of about 4,700 (Satomer, catalog number CN120), 2.84 g of photoinitiator 1-hydroxy-cyclohexyl-phenyl-ketone (Ciba, catalog number Irgacure 184), and 1.17 g of photolatent heat base 2-methyl-1-[4-(methylthio)phenyl]-2-(4-morpholinyl)-1-propanone (Ciba, catalog number 907) were mixed and stirred at about 200 rpm for 5 minutes. Afterwards, 110 g of 1-methoxy-2-2-propanol and 305 g of 1-methoxy-2-2-propanol were added to the ethyl acetate prepared earlier and stirred at 250 rpm at room temperature for 30 minutes. The mixture thus formed was mixed again with the prepared silica solution and 438 g of isopropanol, stirred at 250 rpm at room temperature for 1 hour, and then a curable coating solution was prepared.

[0138] A sol solution was added to the above-mentioned curable coating solution while stirring at 200 rpm, stirred for 1 hour, and then filtered through a 1 μm filter to prepare a curable sol solution.

[0140] The above curable sol solution was bar-coated onto the polymer substrate layer, dried at 100°C for 30 seconds, and then UV-cured with an energy of 1,000 mJ / cm² to form a planarized layer on the polymer substrate layer. At this time, the thickness of the planarized layer was 2 μm.

[0142] To form an inorganic gas barrier layer on the above-mentioned planarization layer, a reactive sputtering method was used as follows.

[0143] A dual magnetron sputtering device using mid-frequency (MF) power was used, and power was applied to a silicon target with 99.999% purity, with the power density adjusted to 7.3 watt / cm². Simultaneously, sputtering was performed by forming a plasma under a pressure of 3 mtorr while injecting 200 sccm of argon (Ar) gas and 50 sccm of oxygen gas, and a silicon oxide thin film was deposited while transporting the substrate film at a speed of 1 M / min.

[0145] The curable sol solution was bar-coated onto the inorganic gas barrier layer, dried at 100°C for 30 seconds, and then UV-cured with an energy of 1,000 mJ / cm² to form an organic-inorganic hybrid coating layer. At this time, the thickness of the organic-inorganic hybrid coating layer was 2 μm.

[0147] In this way, a laminate was manufactured in which a polymer substrate layer, a planarization layer, an inorganic gas barrier layer, and an organic-inorganic hybrid coating layer were sequentially stacked. The structure of the laminate according to Comparative Example 1 is as shown in FIG. 4.

[0149] Example 1 (Barrier film, Fig. 1)

[0150] Two laminates according to Comparative Example 1 were prepared.

[0151] Acrylic OCA was prepared as a bonding layer. At this time, the thickness of the acrylic OCA was 25 μm and the refractive index was 1.49.

[0152] Two laminates according to Comparative Example 1 were bonded using acrylic OCA. At this time, the organic-inorganic hybrid coating layers of both laminates according to Comparative Example 1 were positioned on the acrylic OCA side. The structure of the barrier film according to Example 1 is as shown in FIG. 1.

[0154] Example 2 (Barrier film, Fig. 2)

[0155] Two laminates according to Comparative Example 1 were prepared.

[0156] Acrylic OCA was prepared as a bonding layer. At this time, the thickness of the acrylic OCA was 25 μm and the refractive index was 1.49.

[0157] Two laminates according to Comparative Example 1 were bonded using acrylic OCA. At this time, one of the two laminates according to Comparative Example 1 had its polymer substrate layer positioned toward the acrylic OCA side, and the other had its organic-inorganic hybrid coating layer positioned toward the acrylic OCA side. The structure of the barrier film according to Example 2 is as shown in FIG. 2.

[0159] Example 3 (Barrier film, Fig. 3)

[0160] Two laminates according to Comparative Example 1 were prepared.

[0161] Acrylic OCA was prepared as a bonding layer. At this time, the thickness of the acrylic OCA was 25 μm and the refractive index was 1.49.

[0162] Two laminates according to Comparative Example 1 were bonded using acrylic OCA. At this time, the polymer substrate layers of both laminates according to Comparative Example 1 were positioned on the acrylic OCA side. The structure of the barrier film according to Example 3 is as shown in FIG. 3.

[0164] Experimental Example 1

[0165] The adhesive strength of the bonding layer of the barrier film according to Examples 1 to 3 was measured by ASTM D1876-08 "Standard test method for peel resistance of adhesives (T-peel test)," and the results are as shown in Table 1.

[0167] Experimental Example 2

[0168] The light transmittance (550 nm), water vapor transmittance, and haze of Comparative Example 1 and Examples 1 to 3 were measured by the following method, and the results are as shown in Table 1.

[0169] 1) Light transmittance (550 nm): Measured according to ASTM D1003 using a Minolta CM-3600d instrument.

[0170] 2) Water vapor permeability: 37.8 using Mocon PERMATRAN-W3 / 31 equipment and measured for 48 hours under RH 100%.

[0171] 3) Haze: Measured according to ASTM D1003 using a Nippon Denshoku NDH-5000 instrument.

[0173] Comparative Example 1 Example 1 Example 2 Example 3 Light transmittance (%) 91.3 88.1 89.15 91.65 Water vapor permeability (g / m²) 2 / day) 0.005 0.001 0.001 0.001 Haze(%) 0.45 0.96 0.62 0.84 Bonding layer adhesion (gf / 25 mm) - 2500 2000 2200

[0174] The foregoing description is merely an illustrative explanation of the technical concept of the present invention, and those skilled in the art to which the present invention pertains will be able to make various modifications and variations within the scope of the essential characteristics of the present invention. The drawings disclosed in this specification are intended to explain, not limit, the technical concept of the present invention, and the scope of the technical concept of the present invention is not limited by these drawings. The scope of protection of the present invention shall be interpreted by the claims, and all technical concepts within an equivalent scope shall be interpreted as being included within the scope of rights of the present invention. Explanation of the symbols

[0176] 1: Polymer substrate layer 2: Leveling layer 3: Inorganic gas barrier layer 4: Organic-inorganic hybrid coating layer 5: Bonding layer

Claims

Claim 1 A laminate comprising a polymer substrate layer, a planarization layer, an inorganic gas barrier layer, and an organic-inorganic hybrid coating layer sequentially stacked is disposed on both sides of a bonding layer, wherein the laminate disposed on one side of the bonding layer is disposed such that the polymer substrate layer is positioned toward the bonding layer, and the laminate disposed on the other side of the bonding layer is disposed such that the organic-inorganic hybrid coating layer is positioned toward the bonding layer; wherein the planarization layer has the same composition as the organic-inorganic hybrid coating layer, and the planarization layer and the organic-inorganic hybrid coating layer comprise a barrier film comprising a curable sol solution that is a curable coating solution comprising a (meth)acrylate monomer, a (meth)acrylate oligomer having an epoxy group and a weight-average molecular weight of 500 to 10,000, an initiator, silica particles, and a dispersion medium, and a sol solution comprising a metal alkoxide, a curing accelerator, an inorganic acid, and a solvent. Claim 2 In claim 1, the bonding layer is a barrier film having a thickness of 5 μm to 50 μm. Claim 3 A barrier film according to claim 1, wherein the refractive index of the bonding layer is smaller than the refractive index of the polymer substrate layer. Claim 4 In claim 1, the bonding layer is a barrier film having an adhesion strength of 2000 gf / 25 mm or more as measured according to ASTM D1876-08. Claim 5 In claim 1, the bonding layer comprises an acrylic resin, an epoxy resin, a silicone resin, a fluorine resin, a styrene resin, a polyolefin resin, a thermoplastic elastomer, a polyoxyalkylene resin, a polyester resin, a polyvinyl chloride resin, a polycarbonate resin, a polyphenylene sulfide resin, a mixture of hydrocarbons, a polyamide resin, or a mixture thereof, forming a barrier film. Claim 6 delete Claim 7 delete Claim 8 delete Claim 9 A barrier film according to claim 1, wherein the polymer substrate layer comprises a thermoplastic transparent base resin, and the thermoplastic transparent base resin comprises one or more selected from the group consisting of polyethylene terephthalate, polyethersulfone, polycarbonate, polyimide, polyarylate, polyethylene naphthalate, polyethylene terephthalate glycol, polycyclohexylene dimethylene terephthalate glycol, and cycloolefin copolymer. Claim 10 In claim 9, the polymer substrate layer is a barrier film having a coefficient of thermal expansion of 100 ppm / ℃ or less in the range of 100 ℃ to 130 ℃. Claim 11 In claim 9, the polymer substrate layer is a barrier film having a thermal shrinkage rate in the MD (Machine Direction) direction of 0.5% or less and a thermal shrinkage rate in the TD (Transverse Direction) direction of 0.3% or less, wherein the thermal shrinkage rate is calculated by the following Equation 1. [Equation 1] (Initial length of polymer substrate layer - Length of polymer substrate layer after thermal shrinkage treatment at 150 ℃ for 30 minutes / Initial length of polymer substrate layer) × 100 Claim 12 delete Claim 13 delete Claim 14 In claim 1, the inorganic gas barrier layer comprises a barrier film including an oxide, nitride, carbide, oxynitride, oxycarbide, nitride carbide, or oxynitride carbide containing one or more metals selected from the group consisting of Si, Al, In, Sn, Zn, Ti, Cu, Ce, and Ta.

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