Laminate for covering window

Abstract

Provided is a laminate for covering a window, comprising: a hard coat layer comprising a cured product of a composition for forming the hard coat layer, the composition for forming the hard coat layer comprising a polysilsesquioxane; an aliphatic polyurethane (meth) acrylate oligomer; and an oxygen-containing heterocyclic compound; and an acrylic coating layer comprising a cured product of a composition for forming an acrylic coating layer, the composition for forming an acrylic coating layer comprising a silane coupling agent in the form of an oligomer, in the composition for forming a hard coating layer, the weight ratio of the aliphatic polyurethane (methyl) acrylate oligomer to the oxygen-containing heterocyclic compound is 1: (1.5-7).

Description

Technical Field

[0001] This invention relates to a laminate for covering windows. Background Technology

[0002] Tempered glass and plastic are common materials used as cover materials to protect the screen portion of display panels. In recent years, flexible display panels that can be bent or flexibly garnered significant interest in the industry. Following this trend, ultra-thin tempered glass (UTG) or colorless polyimide (CPI) films with flexible properties are being used as cover window materials. However, because these materials are weaker than existing glass, they are prone to breakage or physical deformation. To overcome these drawbacks, inventors are working to add other thin-film materials as protective layers to the top and bottom surfaces or use coating materials to maintain flexibility and improve strength. Summary of the Invention

[0003] The problem the invention aims to solve The purpose of this invention is to provide a laminate for covering windows, which has excellent hardness, surface physical properties, bending characteristics and viscoelastic properties.

[0004] The purpose of this invention is to provide a laminate for covering windows, comprising a hard coating and an acrylic coating, and having excellent hardness, surface physical properties, bending characteristics and viscoelastic properties.

[0005] The object of the present invention is to provide a composition for forming a hard coating for preparing the hard coating of the laminate for covering the window.

[0006] The object of the present invention is to provide a composition for forming an acrylic coating, which is used to prepare the acrylic coating of the laminate for covering the window.

[0007] The objectives of this invention are not limited to those described above. Other objectives and advantages of this invention not mentioned herein will be understood through the following description and will become clearer through embodiments of the invention. Furthermore, it will be apparent that the objectives and advantages of this invention can be achieved by the means and combinations thereof shown in the claims.

[0008] means for solving problems In one embodiment of the present invention, a laminate for covering a window is provided, comprising: A hard coating comprising a cured product of a composition for forming the hard coating, said composition comprising a polysilsesquioxane; an aliphatic polyurethane (meth)acrylate oligomer; and an oxygen-containing heterocyclic compound; and An acrylic coating comprising a cured product of a composition for forming an acrylic coating, wherein the composition for forming the acrylic coating comprises a silane coupling agent in the form of an oligomer. In the composition for forming a hard coating, the weight ratio of the aliphatic polyurethane (meth)acrylate oligomer to the oxygen-containing heterocyclic compound is 1:1.5 to 7.

[0009] The polysilsesquioxane may contain structural units represented by chemical formula 1-1 and structural units represented by chemical formula 1-2.

[0010] Chemical formula 1-1:

[0011] Chemical formula 1-2:

[0012] In the aforementioned chemical formulas 1-1 and 1-2, R1 is independently a halogen group, an alkyl group with 1 to 10 carbon atoms, an aryl group with 6 to 30 carbon atoms, an amino group, a (meth)acryloyl group, a vinyl group, an epoxy group, a thiol group, a glycidyl ether substituted alkyl group with 1 to 10 carbon atoms, or an alicyclic epoxy substituted alkyl group with 1 to 10 carbon atoms. R2 is independently a hydrogen or a straight-chain or branched alkyl group having 1 to 10 carbon atoms.

[0013] The polysilsesquioxane may contain 0.1 wt% to 10 wt% of an alkoxy group represented by -OR2 in the chemical formulas 1-2.

[0014] The polysilsesquioxane can be represented by chemical formula 1.

[0015] Chemical Formula 1:

[0016] In the chemical formula 1, R1 is independently a halogen group, an alkyl group with 1 to 10 carbon atoms, an aryl group with 6 to 30 carbon atoms, an amino group, a (meth)acryloyl group, a vinyl group, an epoxy group, a thiol group, a glycidyl ether substituted alkyl group with 1 to 10 carbon atoms, or an alicyclic epoxy substituted alkyl group with 1 to 10 carbon atoms. R2 is independently hydrogen or a straight-chain or branched alkyl group having 1 to 10 carbon atoms. n and m are each an independent integer between 1 and 100,000, but n and m only represent the quantity contained in a molecule of polysilsesquioxane represented by the chemical formula 1. The connection order of the structural units of the chemical formula 1-1 with n units and the structural units of the chemical formula 1-2 with m units is unrestricted and can be connected randomly.

[0017] The composition for forming a hard coating may comprise (a) 100 parts by weight of polysilsesquioxane; (b) 7 to 350 parts by weight of aliphatic polyurethane (meth)acrylate oligomer; (c) 25 to 750 parts by weight of an oxygen-containing heterocyclic compound; (d) 0.1 to 5 parts by weight of a cationic photopolymerization initiator and a free radical initiator; and (e) the balance of additives.

[0018] The composition used to form a hard coating can be solvent-free.

[0019] The aliphatic polyurethane (meth)acrylate oligomer can be represented by the following chemical formula 3.

[0020] Chemical formula 3:

[0021] In the chemical formula 3, A is a divalent aliphatic hydrocarbon group with 1 to 12 carbon atoms, a divalent aromatic hydrocarbon group with 5 to 60 carbon atoms, or a divalent siloxane group. B is either hydrogen or methyl. n and m are integers from 1 to 20.

[0022] In the chemical formula 3, A can be a group represented by at least one of the following chemical formulas 3-1, 3-2 and 3-3.

[0023] Chemical formula 3-1:

[0024] Chemical formula 3-2:

[0025] Chemical formula 3-3:

[0026] In the chemical formulas 3-1 to 3-3, R1 and R2 are each independently an alkyl group having 1 to 12 carbon atoms, n is an integer from 1 to 30, and * indicates a connecting site.

[0027] The compound represented by the chemical formula 3 can be a compound represented by the chemical formula 31 or the chemical formula 32 described below.

[0028] Chemical formula 31:

[0029] Chemical formula 32:

[0030] In the aforementioned chemical formulas 31 and 32, B is either hydrogen or methyl. PDMS is represented by the following structural formula.

[0031] n is an integer from 1 to 30, and * indicates a connection part.

[0032] The oxygen-containing heterocyclic compound can be a compound containing an oxocyclic butane ring with a hydroxyl group.

[0033] The composition for forming an acrylic coating may include: (a) 100 parts by weight of a monofunctional component comprising a monofunctional (meth)acrylate monomer or oligomer; (b) 50 to 250 parts by weight of a polyfunctional (meth)acrylate monomer or oligomer; (c) 10 to 50 parts by weight of a polyfunctional thiol compound; (d) 0.1 to 50 parts by weight of one or more photopolymerization initiators; and (e) 0.1 to 50 parts by weight of a silane coupling agent.

[0034] The silane coupling agent may be in the form of an oligomer containing 2 to 20 structural units represented by the following chemical formula 2.

[0035] Chemical formula 2:

[0036] In the chemical formula 2, R3 is an alkyl group with 1 to 20 carbon atoms, either substituted or unsubstituted. X is an alkyl, epoxy, mercapto, acrylate, or aryl group having 1 to 20 carbon atoms. L1 and L2 are each independently a single bond, an alkylene group having 1 to 30 carbon atoms, or a heteroalkylene group having 1 to 20 carbon atoms. b is an integer between 0 and 5.

[0037] The weight-average molecular weight of the silane coupling agent can be between 1000 and 2000.

[0038] In the chemical formula 2, -OR3 can be selected from the group consisting of hydroxyl, methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, sec-butoxy, pentoxy, hexoxy, and combinations thereof.

[0039] The silane coupling agent can be represented by the following chemical formula 21.

[0040] Chemical formula 21:

[0041] In the chemical formula 21, R3 is an alkyl group having 1 to 20 carbon atoms. L3 is an alkylene group having 1 to 10 carbon atoms. m2 and n2 are each an independent integer from 1 to 10, but n2 and m2 only represent the number contained in a molecule of the compound represented by the chemical formula 21. The connection order of the structural units with n2 units and the structural units with m2 units is unrestricted and can be randomly connected.

[0042] The modulus of the acrylic coating can be from 10 MPa to 5000 MPa.

[0043] The hardness of the hard coating can be 3H or higher.

[0044] The thickness of the acrylic coating can be from 10 μm to 600 μm, and the thickness of the hard coating can be from 10 μm to 200 μm.

[0045] The thickness ratio of the acrylic coating to the hard coating can be from 20:1 to 1:4.

[0046] In one embodiment of the present invention, A composition is provided for forming a hard coating for covering windows, comprising: Polysilsesquioxanes; aliphatic polyurethane (meth)acrylate oligomers; and oxygen-containing heterocyclic compounds, The weight ratio of the aliphatic polyurethane (meth)acrylate oligomer to the oxygen-containing heterocyclic compound is 1:1.5 to 7.

[0047] The polysilsesquioxane may contain structural units represented by chemical formula 1-1 and structural units represented by chemical formula 1-2.

[0048] Chemical formula 1-1:

[0049] Chemical formula 1-2:

[0050] In the aforementioned chemical formulas 1-1 and 1-2, R1 is independently a halogen group, an alkyl group with 1 to 10 carbon atoms, an aryl group with 6 to 30 carbon atoms, an amino group, a (meth)acryloyl group, a vinyl group, an epoxy group, a thiol group, a glycidyl ether substituted alkyl group with 1 to 10 carbon atoms, or an alicyclic epoxy substituted alkyl group with 1 to 10 carbon atoms. R2 is independently a hydrogen or a straight-chain or branched alkyl group having 1 to 10 carbon atoms.

[0051] In one embodiment of the present invention, a composition for forming an acrylic coating for covering windows is provided, comprising a silane coupling agent in oligomer form represented by the following chemical formula 2.

[0052] Chemical formula 2:

[0053] In the chemical formula 2, R3 is an alkyl group with 1 to 20 carbon atoms, either substituted or unsubstituted. X is an alkyl, epoxy, mercapto, acrylate, or aryl group having 1 to 20 carbon atoms. L1 and L2 are each independently a single bond, an alkylene group having 1 to 30 carbon atoms, or a heteroalkylene group having 1 to 20 carbon atoms. b is an integer between 0 and 5.

[0054] The effects of the invention The laminate for covering windows of the present invention has excellent hardness, surface physical properties, bending characteristics and viscoelastic properties.

[0055] In addition to the effects described above, the specific effects of the present invention will be described while explaining the specific embodiments of the invention below. Attached Figure Description

[0056] Figure 1 The diagram schematically illustrates a cross-section of a laminate for covering a window according to an embodiment of the present invention. Detailed Implementation

[0057] Examples of the present invention will now be described in detail. However, these examples are provided by way of illustration only, and the invention is not limited thereto, but is defined only by the scope of the claims described below.

[0058] In this specification, "substitution" means, unless otherwise defined, substitution by a substituent selected from the group consisting of hydrogen, deuterium, halogen atom, C1-C30 alkyl, C3-C50 cycloalkyl, C2-C30 alkenyl, C3-C50 cycloalkenyl, C2-C30 alkynyl, C5-C50 cycloalkynyl, cyano, silyl, C1-C20 alkoxy, C5-C60 aryl, C1-C60 heteroaryl and C6-C60 arylalkyl and combinations thereof.

[0059] In one embodiment of the present invention, A laminate for covering a window is provided, comprising: A hard coating comprising a cured product of a composition for forming the hard coating, said composition comprising a polysilsesquioxane; an aliphatic polyurethane (meth)acrylate oligomer; and an oxygen-containing heterocyclic compound; and An acrylic coating comprising a cured product of a composition for forming an acrylic coating, wherein the composition for forming the acrylic coating comprises a silane coupling agent in the form of an oligomer. In the composition for forming a hard coating, the weight ratio of the aliphatic polyurethane (meth)acrylate oligomer to the oxygen-containing heterocyclic compound is 1:1.5 to 7.

[0060] In one example, the polysilsesquioxane may comprise structural units represented by chemical formula 1-1 and structural units represented by chemical formula 1-2.

[0061] Chemical formula 1-1:

[0062] Chemical formula 1-2:

[0063] In the aforementioned chemical formulas 1-1 and 1-2, R1 is independently a halogen group, an alkyl group with 1 to 10 carbon atoms, an aryl group with 6 to 30 carbon atoms, an amino group, a (meth)acryloyl group, a vinyl group, an epoxy group, a thiol group, a glycidyl ether substituted alkyl group with 1 to 10 carbon atoms, or an alicyclic epoxy substituted alkyl group with 1 to 10 carbon atoms. R2 is independently a hydrogen or a straight-chain or branched alkyl group having 1 to 10 carbon atoms.

[0064] The laminate used to cover the window includes an acrylic coating and a hard coating. The acrylic coating provides bending control and viscoelastic properties of the coating film, while the hard coating provides hardness and surface physical properties.

[0065] The laminated body used for the cover window can be used as a covering material, such as a cover window to protect a display panel screen. In one example, the laminated body used for the cover window can be used as a cover window for a flexible display panel. The laminated body used for the cover window can replace existing glass, UTG, or CPI film.

[0066] Figure 1 A cross-section of a laminate for covering a window, according to an example of the present invention, is shown schematically. Figure 1 In this embodiment, the laminate 110 for covering the window can be laminated such that the acrylic coating 102 faces the substrate 103, and the hard coating 101 faces outward. In one example, the hard coating 101 can be the outermost layer. In another example, the laminate for covering the window can be applied to a display panel, etc.

[0067] The laminate used for covering the window can be coated not only on a substrate 103 or glass containing a touch optical film (PET film, PC film, PMMA film, PI film, polarizing film or other auxiliary films, etc.), but also directly coated on a display panel to achieve a covering window.

[0068] For example, the substrate 103 can be a thin film such as a polarizing film or an auxiliary film, or it can be in the form of a panel.

[0069] The laminate 110 for covering the window can be formed by sequentially laminating a composition for forming an acrylic coating and a composition for forming a hard coating on the substrate 103, or by sequentially laminating a composition for forming a hard coating and a composition for forming an acrylic coating on the substrate 103.

[0070] Specifically, the polysilsesquioxane may be connected in a random order and comprise structural units represented by Formula 1-1 and structural units represented by Formula 1-2. In one example, the polysilsesquioxane may comprise 1 to 100,000 of the structural units represented by Formula 1-1 and the structural units represented by Formula 1-2, respectively. The content of the -OR2 alkoxy group contained in the structural units represented by Formula 1-2 can be adjusted by the content of the structural units represented by Formula 1-2.

[0071] In one example, in the structural units represented by chemical formula 1-1 and chemical formula 1-2, R1 can be... or .

[0072] In one example, in the structural unit represented by chemical formulas 1-2, R2 is methyl or ethyl.

[0073] In one example, the polysilsesquioxane may contain 0.1 wt% to 10 wt% of an alkoxy group represented by -OR2 in the chemical formulas 1-2. The hard coating can improve compatibility with the aliphatic polyurethane (meth)acrylate oligomer by using a polysilsesquioxane containing alkoxy groups within the aforementioned range.

[0074] In one example, the polysilsesquioxane may be represented by chemical formula 1.

[0075] Chemical Formula 1:

[0076] In the chemical formula 1, R1 is independently a halogen group, an alkyl group with 1 to 10 carbon atoms, an aryl group with 6 to 30 carbon atoms, an amino group, a (meth)acryloyl group, a vinyl group, an epoxy group, a thiol group, a glycidyl ether substituted alkyl group with 1 to 10 carbon atoms, or an alicyclic epoxy substituted alkyl group with 1 to 10 carbon atoms. R2 is independently hydrogen or a straight-chain or branched alkyl group having 1 to 10 carbon atoms. n and m are each an independent integer between 1 and 100,000, but n and m only represent the quantity contained in a molecule of polysilsesquioxane represented by the chemical formula 1. The connection order of the structural units of the chemical formula 1-1 with n units and the structural units of the chemical formula 1-2 with m units is unrestricted and can be connected randomly.

[0077] In this invention, n and m can have different definitions depending on the chemical formula.

[0078] In one example, the polysilsesquioxane represented by the chemical formula 1 can be a random copolymer, block copolymer, or the like of the structural units of the chemical formula 1-1 and the structural units of the chemical formula 1-2, and is not limited thereto.

[0079] In one example, in the chemical formula 1, n / m can be from 1 to 50. The ratio of ladder-like silsesquioxane units to open-cage silsesquioxane units in the polysilsesquioxane can be adjusted according to the n / m ratio. By adjusting the n / m ratio to the range described, physical properties such as the strength of the coated film can be improved, while adhesion to the substrate 103 or the acrylic coating 102 and compatibility with aliphatic polyurethane (meth)acrylate oligomers can be enhanced.

[0080] In the chemical formula 1, as defined, the structural units of chemical formula 1-1 and the structural units of chemical formula 1-2 can be arranged randomly or regularly. According to one example, the polysilsesquioxane may contain ladder-like silsesquioxanes. According to another example, the polysilsesquioxane may contain ladder-like silsesquioxane structural units and open-cage silsesquioxane structural units, but may not contain random silsesquioxane structural units or cage silsesquioxane structural units. According to one example, in the polysilsesquioxane, the proportion of ladder-like silsesquioxanes can be 15 mol% or more of the total silsesquioxanes, for example, 19 mol% or more. The more ladder-like silsesquioxane structures there are, the higher the physical properties (e.g., film strength) of the coating film formed after coating; however, if there are too many ladder-like silsesquioxane structures, the coating film is prone to breakage or cracking. Furthermore, with the increase of open-cage silsesquioxane structures, adhesive strength may increase and compatibility with aliphatic polyurethane acrylate oligomers may increase, while strength may decrease.

[0081] In one example, in chemical formula 1, R1 can be... or .

[0082] In one example, in the chemical formula 1, R2 is methyl or ethyl.

[0083] In one example, the composition for forming a hard coating may comprise (a) 100 parts by weight of the polysilsesquioxane; (b) 7 to 350 parts by weight of the aliphatic polyurethane (meth)acrylate oligomer; (c) 25 to 750 parts by weight of the oxygen-containing heterocyclic compound; (d) 0.1 to 5 parts by weight of a cationic photopolymerization initiator and a free radical initiator; and (e) the balance of additives.

[0084] The composition used to form a hard coating can be solvent-free.

[0085] The composition for forming the hard coating comprises the aliphatic polyurethane (meth)acrylate oligomer, thereby enabling low bending of the hard coating and improved adhesion to the underlying acrylic coating.

[0086] The content of the aliphatic polyurethane (meth)acrylate oligomer in the composition for forming the hard coating can be from 7 parts by weight to 350 parts by weight, specifically from 9 parts by weight to 100 parts by weight, and more specifically from 9.5 parts by weight to 50 parts by weight. The composition for forming the hard coating, comprising the aliphatic polyurethane (meth)acrylate oligomer within the aforementioned range, can thus possess a glass-like texture and surface strength, while exhibiting no bending or cracking during high-temperature and high-humidity reliability testing.

[0087] In one example, the aliphatic polyurethane (meth)acrylate oligomer may include at least one selected from the group consisting of aliphatic difunctional polyurethane acrylate, aliphatic trifunctional polyurethane acrylate, aliphatic hexafunctional polyurethane acrylate, silicone urethane acrylate, silicone urethane methacrylate, and combinations thereof.

[0088] In one example, the aliphatic polyurethane (meth)acrylate oligomer can be represented by the following chemical formula 3.

[0089] Chemical formula 3:

[0090] In the chemical formula 3, A is a divalent aliphatic hydrocarbon group with 1 to 12 carbon atoms, a divalent aromatic hydrocarbon group with 5 to 60 carbon atoms, or a divalent siloxane group. B is either hydrogen or methyl. n and m are each an independent integer from 1 to 20.

[0091] Specifically, in the chemical formula 3, A can be a group represented by at least one of the following chemical formulas 3-1, 3-2 and 3-3.

[0092] Chemical formula 3-1:

[0093] Chemical formula 3-2:

[0094] Chemical formula 3-3:

[0095] In the chemical formulas 3-1 to 3-3, R1 and R2 are each independently an alkyl group having 1 to 12 carbon atoms, n is an integer from 1 to 30, and * indicates a connecting site.

[0096] In one instance, the compound represented by the chemical formula 3 may be a compound represented by the following chemical formula 31 or the following chemical formula 32.

[0097] Chemical formula 31:

[0098] Chemical formula 32:

[0099] In the aforementioned chemical formulas 31 and 32, B is either hydrogen or methyl. PDMS is represented by the following structural formula.

[0100] n is an integer from 1 to 30, and * indicates a connection part.

[0101] The oxygen-containing heterocyclic compound can be a compound containing an oxetane ring having a hydroxyl group. For example, the oxygen-containing heterocyclic compound can include at least one selected from the group consisting of 3-hydroxymethyloxetane, 3-methyl-3-hydroxymethyloxetane, 3-ethyl-3-hydroxymethyloxetane, and combinations thereof.

[0102] The composition for forming a hard coating contains the oxygen-containing heterocyclic compound, which can alleviate bending and increase curing density.

[0103] In one example, the content of the oxygen-containing heterocyclic compound in the composition for forming the hard coating can be from 25 parts by weight to 750 parts by weight, specifically from 25 parts by weight to 200 parts by weight, and more specifically from 30 parts by weight to 150 parts by weight. The composition for forming the hard coating contains the oxygen-containing heterocyclic compound within the aforementioned range, thereby maintaining an appropriate level of film strength, making it suitable for use as a cover window, while mitigating bending and appropriately adjusting viscosity.

[0104] In one example, when the weight ratio of the aliphatic polyurethane (meth)acrylate oligomer to the oxygen-containing heterocyclic compound in the composition for forming a hard coating is 1:1.5 to 7, the oxygen-containing heterocyclic compound and the aliphatic polyurethane (meth)acrylate oligomer exhibit excellent compatibility, thereby resulting in improved haze characteristics. At the same time, the crosslinking density can be appropriately adjusted to prevent a decline in the physical properties of the coating.

[0105] The composition for forming a hard coating may also include a cationic photopolymerization initiator, a free radical initiator, or both.

[0106] For example, examples of the cationic photopolymerization initiator may include sulfonium such as triphenylsulfonium and diphenyl-4-(phenylthio)phenylsulfonium, iodonium such as diphenyliodonium or bis(dodecylphenyl)iodonium, diazonium such as phenyl diazonium, ammonium such as 1-benzyl-2-cyanopyrroleonium or 1-(naphthylmethyl)-2-cyanopyridinium, (4-methylphenyl)[4-(2-methylpropyl)phenyl]-hexafluorophosphate iodonium, bis(4-tert-butylphenyl)hexafluorophosphate iodonium, diphenylhexafluorophosphate iodonium, diphenyltrifluoromethanesulfonate iodonium, triphenylsulfonium tetrafluoroborate, tri-p-toluenesulfonium hexafluorophosphate, tri-p-toluenesulfonyltrifluoromethanesulfonate, and Fe cations such as (2,4-cyclopentadien-1-yl)[(1-methylethyl)benzene]-Fe and BF 4- PF 6- 、SbF 6- Wait for [BQ4] - Onium salts (wherein Q is a phenyl group substituted with at least two fluorine or trifluoromethyl groups), etc., may be used, and are not limited thereto, and may be used compounds known as cationic photopolymerization initiators.

[0107] For example, examples of the free radical initiator may include hydroxy ketones such as 1-hydroxycyclrohexylphenyl ketone (Irgacure 184), 2-benzyl-2-(dimethylamino)-1-[4-(morpholinyl)phenyl]-1-butanone (Irgacure 369), α-aminoacetophenone (Irgacure 907), benzyl dimethyl ketals such as benzyl dimethyl ketal (Irgacure-651), and bis-acylphosphines such as phenyl bis(2,4,6-trimethylbenzoyl) (Irgacure 819). The following compounds may be used: mono-acyl phosphines such as phosphine (e.g., 2,4,6-trimethylbenzoyl diphenylphosphine oxide (TPO)); one or more of these compounds may be used, and the use of these compounds may be limited to them; well-known compounds known as free radical initiators may also be used.

[0108] The composition for forming a hard coating may also include at least one additive selected from the group consisting of antioxidants, leveling agents, coating agents, and combinations thereof.

[0109] In one example, the thickness of the hard coating can be from 10 μm to 200 μm, specifically from 30 μm to 200 μm, and more specifically from 50 μm to 100 μm.

[0110] In one example, the hard coating can have a hardness of 3H or higher and can prevent bending and surface defects within the thickness range.

[0111] In one example, the composition for forming an acrylic coating may comprise (a) 100 parts by weight of a monofunctional component comprising a monofunctional (meth)acrylate monomer or oligomer; (b) 50 to 250 parts by weight of a polyfunctional (meth)acrylate monomer or oligomer; (c) 10 to 50 parts by weight of a polyfunctional thiol compound; (d) 0.1 to 50 parts by weight of one or more photopolymerization initiators; and (e) 0.1 to 50 parts by weight of a silane coupling agent.

[0112] The composition for forming an acrylic coating may also contain (f) additives, including one or more of antioxidants, ultraviolet (UV) stabilizers, etc.

[0113] The composition used to form an acrylic coating can be solvent-free.

[0114] The composition used to form an acrylic coating can reduce shrinkage during photocuring, thereby preventing deformation caused by shrinkage and achieving excellent dimensional stability.

[0115] The monofunctional (meth)acrylate oligomer can be a monofunctional polyurethane (meth)acrylate oligomer, specifically, it can include at least one selected from the group consisting of polybutadiene polyurethane (meth)acrylate oligomer, epoxy polyurethane (meth)acrylate oligomer, polyester polyurethane (meth)acrylate oligomer, polyether polyurethane (meth)acrylate oligomer, and combinations thereof.

[0116] The monofunctional acrylate monomer may specifically include, selected from (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, and (meth)acrylate. Man At least one of the group consisting of esters, 2-ethylhexyl (meth)acrylate, dodecyl (meth)acrylate, octadecyl (meth)acrylate, methoxyethyl (meth)acrylate, ethoxyethyl (meth)acrylate, hydroxyethyl (meth)acrylate, and combinations thereof.

[0117] The content of the polyfunctional (meth)acrylate monomer or oligomer in the composition for forming an acrylic coating can be from 50 parts by weight to 250 parts by weight, specifically from 70 parts by weight to 200 parts by weight. The composition for forming an acrylic coating contains the polyfunctional (meth)acrylate monomer or oligomer within the range described above, thereby improving the hardness and durability of the coating.

[0118] The multifunctional (meth)acrylate oligomer can be a multifunctional polyurethane (meth)acrylate oligomer, specifically, it can include at least one selected from the group consisting of polybutadiene polyurethane (meth)acrylate oligomer, epoxy polyurethane (meth)acrylate oligomer, polyester polyurethane (meth)acrylate oligomer, polyether polyurethane (meth)acrylate oligomer, and combinations thereof.

[0119] The polyfunctional (meth)acrylate monomer can specifically be a trifunctional or higher (meth)acrylate, for example, it can include at least one selected from the group consisting of pentaerythritol tetra(3-mercaptobutyrate), trihydroxyethyl isocyanurate tri(meth)acrylate, trimethylpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and combinations thereof.

[0120] The composition for forming an acrylic coating contains the polyfunctional thiol compound, thereby preventing reduced surface curing due to crosslinking density and oxygen interference.

[0121] The content of the polyfunctional thiol compound in the composition for forming an acrylic coating can be from 10 parts by weight to 50 parts by weight, specifically from 15 parts by weight to 40 parts by weight. The composition for forming an acrylic coating contains the polyfunctional thiol compound within the aforementioned range, thereby improving adhesion.

[0122] Examples of the polyfunctional thiol compounds may include at least one selected from the group consisting of 1,4-bis(3-mercaptobutyryloxy)butane, 1,3,5-tris(3-mercaptobutyryloxyheterobutyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, pentaerythritol tetra(3-mercaptobutyrate), and combinations thereof.

[0123] The composition for forming an acrylic coating may contain one or more photoinitiators in an amount ranging from 0.1 parts by weight to 50 parts by weight, specifically from 1 part by weight to 20 parts by weight. The composition for forming an acrylic coating further comprises the photoinitiator within the range described above, thereby exhibiting excellent photoinitiation efficiency.

[0124] Examples of the photopolymerization initiators may include hydroxy ketones selected from 1-hydroxycyclrohexylphenyl ketone (Irgacure 184), 2-benzyl-2-(dimethylamino)-1-[4-(morpholinyl)phenyl]-1-butanone (Irgacure 369), α-aminoacetophenone (Irgacure 907), benzyl dimethyl ketals (Irgacure-651), and bis-acylphosphines selected from phenyl bis(2,4,6-trimethylbenzoyl) (Irgacure 819). It comprises at least one of the following groups: phosphine, mono-acyl phosphine such as 2,4,6-trimethylbenzoyl diphenylphosphine oxide (TPO), and combinations thereof.

[0125] The acrylic coating can have its interfacial adhesion to the hard coating improved by the silane coupling agent.

[0126] The content of the silane coupling agent in the composition for forming an acrylic coating can be from 0.1 parts by weight to 50 parts by weight, specifically from 0.5 parts by weight to 30 parts by weight. The composition for forming an acrylic coating contains the silane coupling agent within the range described above, thereby improving interfacial adhesion to the hard coating.

[0127] The silane coupling agent may be in the form of an oligomer containing 2 to 20 structural units represented by the following chemical formula 2.

[0128] Chemical formula 2:

[0129] In the chemical formula 2, R3 is an alkyl group with 1 to 20 carbon atoms, either substituted or unsubstituted. X is an alkyl, epoxy, mercapto, acrylate, or aryl group having 1 to 20 carbon atoms. L1 and L2 are each independently a single bond, an alkylene group having 1 to 30 carbon atoms, or a heteroalkylene group having 1 to 20 carbon atoms. b is an integer between 0 and 5.

[0130] The heteroalkylene group is a structure containing at least one heteroatom that substituted a carbon atom in the alkylene group, the heteroatom including at least one selected from the group consisting of -O-, -S- and combinations thereof.

[0131] In one example, X in chemical formula 2 can be methyl or phenyl.

[0132] The weight-average molecular weight of the silane coupling agent can be between 1000 and 2000. When the silane coupling agent has a weight-average molecular weight within the range of this value, it can improve the adhesion between the upper hard coating and the lower substrate due to its low volatility and numerous reaction sites with the resin.

[0133] In one example, in the chemical formula 2, -OR3 can be selected from the group consisting of hydroxyl, methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, sec-butoxy, pentoxy, hexoxy, and combinations thereof.

[0134] In one example, the silane coupling agent may be a compound represented by the following chemical formula 21.

[0135] Chemical formula 21:

[0136] In the chemical formula 21, R3 is an alkyl group having 1 to 20 carbon atoms. L3 is an alkylene group having 1 to 10 carbon atoms. m2 and n2 are each an independent integer from 1 to 10, but n2 and m2 only represent the number contained in a molecule of the compound represented by the chemical formula 21. The connection order of the structural units with n2 units and the structural units with m2 units is unrestricted and can be randomly connected.

[0137] Depending on the requirements or the physical properties required for the application, the composition for forming an acrylic coating may also contain silicone-based or acrylic-based additives. Examples of silicone additives include BYK-300, BYK-301, BYK-302, BYK-331, BYK-335, BYK-306, BYK-330, BYK-341, BYK-344, BYK-307, BYK-333, and BYK-310. Examples of acrylic additives include BYK-340, BYK-350, BYK-352, BYK-354, BYK-355, BYK-356, BYK-358N, BYK-359, BYK-361N, BYK-380N, BYK-381, BYK-388, BYK-390, BYK-392, and BYK-394. The composition for forming an acrylic coating further includes the silicone additives and / or acrylic additives, thereby further improving the smoothness of the coating surface.

[0138] In one example, the composition for forming the acrylic coating may contain methacrylate to control the mixing ratio of monofunctional and polyfunctional polyurethane (meth)acrylate oligomers to monofunctional and polyfunctional (meth)acrylates and to slow down the reaction rate.

[0139] In one example, the shrinkage rate of the acrylic coating formed by coating the composition for forming an acrylic coating and then photocuring it can be less than 3% before and after photocuring.

[0140] The Young's modulus of the laminate used to cover the window can be from 0.1 GPa to 15 GPa.

[0141] In one example, the modulus of the acrylic coating can be from 10 MPa to 5000 MPa, specifically from 20 MPa to 2000 MPa. This allows the acrylic coating to have a modulus within this range, enabling it to easily absorb external impacts while ensuring sufficient film strength in the final coating.

[0142] In one example, the thickness of the acrylic coating can be from 10 μm to 600 μm, specifically from 50 μm to 600 μm, and more specifically from 100 μm to 300 μm.

[0143] The laminate used to cover the window can be photocured to form a thick coating, thereby replacing existing glass, ultra-thin glass (UTG), or colorless polyimide (CPI) films.

[0144] The laminate for covering windows has the hard coating laminated on one side of the acrylic coating having a specified modulus, thereby absorbing external impacts and overcoming the thickness limitations of existing hard coatings. Furthermore, because the composition of each layer contains an oligomeric adhesive that improves adhesion, excellent adhesion can be achieved even using the composition of each layer without the need for additional processes or layers such as a primer coating, and freestanding specimens without bending or cracking can be prepared even under high temperature and high humidity environments.

[0145] When the hard coating is applied to the acrylate layer having a specified modulus, the physical properties of the hard coating, applicable to next-generation display devices, can be maintained while ensuring flexibility. The composition for forming the hard coating, based on polysilsesquioxane as defined above, has a glass-like texture and surface strength, thus making it suitable as the outermost coating. By using this hard coating in a laminated manner with the acrylate coating, resistance to external impacts can be enhanced. Furthermore, when simply preparing a single-layer hard coating of thickness suitable for use as a cover window and then photocuring it, there may be a problem that areas far from the light source are not easily cured. However, the laminate for the cover window, with the viscoelastic acrylate coating positioned beneath the hard coating, allows the acrylate coating to absorb externally applied stress, thereby preventing damage to the hard coating and maintaining its mechanical and physical properties without cracking even under severe deformations such as folding, making it highly suitable for cover window applications.

[0146] The composition for forming the hard coating can be rapidly cured using irradiated light energy via cationic polymerization or free radical polymerization. Lewis acids generated by the cationic photopolymerization initiator attack and open the oxygen atoms of the oxygen-containing heterocyclic compound and the ethylene oxide ring in the polysilsesquioxane. Through these continuous reactions, a cured product with a three-dimensional network structure can be formed. When the polysilsesquioxane contains an ethylene oxide ring, it can exhibit an effect of mitigating bending. The oxygen-containing heterocyclic compound, acting as a reaction diluent, not only facilitates coating by reducing the overall viscosity of the composition for forming the hard coating, but also forms a transparent coating film by improving the compatibility between the aliphatic polyurethane (meth)acrylate and the polysilsesquioxane. The aliphatic polyurethane (meth)acrylate forms a network structure through free radical reaction with the free radical initiator and inserts into the polysilsesquioxane inner layer, reducing the crosslinking density, thereby controlling the bending of the hard coating. For these reasons, during the curing process, the adhesion between the polymer substrate and the hard coating, which is difficult to achieve with existing polysilsesquioxane polymer adhesives, can be improved by mixing the aliphatic polyurethane (meth)acrylate oligomer and the oxygen-containing heterocyclic compound in an appropriate ratio. Therefore, adhesion to the underlying acrylic coating can be improved while maintaining the surface strength of the polysilsesquioxane, while simultaneously increasing flexibility. Furthermore, even after high-temperature and high-humidity reliability testing, a coating film without changes in optical properties or appearance such as bending or cracking can be prepared.

[0147] For example, the content of the oxygen-containing heterocyclic compound is from 25 parts by weight to 750 parts by weight relative to 100 parts by weight of the polysilsesquioxane. This allows for improved haze characteristics by optimizing compatibility with the aliphatic polyurethane (meth)acrylate oligomer, while simultaneously allowing for appropriate adjustment of the crosslinking density to prevent a decrease in the physical properties of the coating film. Furthermore, when the aliphatic polyurethane (meth)acrylate oligomer is not included in the composition for forming the hard coating, although high film strength can be achieved, surface defects such as easy breakage due to external impact may occur due to reduced impact resistance. Conversely, when the above-mentioned content range is exceeded and the aliphatic polyurethane (meth)acrylate oligomer is excessively included, haze impairment or reduced film strength of the coating film occurs due to decreased compatibility.

[0148] Meanwhile, the composition constituting the acrylic coating uses an organosilicon coupling agent capable of maintaining bonding with the composition containing the polysilsesquioxane for forming the hard coating, thereby improving adhesion to the hard coating. Compared to low-molecular-weight silane coupling agents, the oligomeric form of the silane coupling agent has more reaction sites, thus inducing the formation of more chemical bonds between the acrylic coating and the hard coating, and its large molecular weight allows for the preparation of coatings with high film strength. Therefore, even under high temperature and high humidity conditions, interlayer delamination does not occur, and physical property degradation such as bending, cracking, and reduced adhesion caused by interfacial delamination can be prevented.

[0149] The laminate for covering the window, through the lamination structure of the acrylic coating and the hard coating alone, without the addition of any additional layers, auxiliary layers or adhesive layers, can have excellent adhesion and can achieve excellent hardness, surface physical properties, bending characteristics and viscoelastic properties.

[0150] In one example, in the laminate for covering a window, the thickness ratio of the acrylic coating to the hard coating can be from 20:1 to 1:4. The laminate for covering a window, including the acrylic coating and the hard coating within this thickness ratio range, exhibits excellent hardness, surface physical properties, flexural characteristics, and viscoelastic properties.

[0151] In one embodiment of the present invention, A composition is provided for forming a hard coating for covering windows, comprising: Polysilsesquioxanes; aliphatic polyurethane (meth)acrylate oligomers; and oxygen-containing heterocyclic compounds, The weight ratio of the aliphatic polyurethane (meth)acrylate oligomer to the oxygen-containing heterocyclic compound is 1:1.5 to 7.

[0152] In one example, the polysilsesquioxane may comprise structural units represented by chemical formula 1-1 and structural units represented by chemical formula 1-2.

[0153] Chemical formula 1-1:

[0154] Chemical formula 1-2:

[0155] In the aforementioned chemical formulas 1-1 and 1-2, R1 is independently a halogen group, an alkyl group with 1 to 10 carbon atoms, an aryl group with 6 to 30 carbon atoms, an amino group, a (meth)acryloyl group, a vinyl group, an epoxy group, a thiol group, a glycidyl ether substituted alkyl group with 1 to 10 carbon atoms, or an alicyclic epoxy substituted alkyl group with 1 to 10 carbon atoms. R2 is independently a hydrogen or a straight-chain or branched alkyl group having 1 to 10 carbon atoms.

[0156] Detailed description of the composition for forming a hard coating is as described in the laminate for covering windows.

[0157] In one embodiment of the present invention, A composition for forming an acrylic coating for covering windows is provided, comprising a silane coupling agent in oligomer form represented by the following chemical formula 2.

[0158] Chemical formula 2:

[0159] In the chemical formula 2, R3 is an alkyl group with 1 to 20 carbon atoms, either substituted or unsubstituted. X is an alkyl, epoxy, mercapto, acrylate, or aryl group having 1 to 20 carbon atoms. L1 and L2 are each independently a single bond, an alkylene group having 1 to 30 carbon atoms, or a heteroalkylene group having 1 to 20 carbon atoms. b is an integer between 0 and 5.

[0160] Detailed description of the composition for forming the acrylic coating is as described in the laminate for covering windows.

[0161] The following will describe embodiments and comparative examples of the present invention. The following embodiments are merely one example of the present invention, and the present invention is not limited to the following embodiments.

[0162] (Material) Reactive oxobutane compounds: S-101 from SYNASIA Cationic photopolymerization initiator: SYNASIA's PI-CAT-6974 Free radical initiator: YUWON INTEC TPO Photoinitiator: Heraeus NIN Leveling agents: BYK Instruments BYK-333, BYK-UV3505 Multifunctional (meth)acrylates: DKS NEWFRONTIER MF-001 Multifunctional polyurethane acrylate oligomer: CHEMTON CHTF-5601A Monofunctional (meth)acrylate monomer: SARTOMER SR506 Monofunctional (meth)acrylates (-OH): ALDRICH HEA Free radical photoinitiator 1: BASF IRGACURE 184 Free radical photoinitiator 2: YUWON INTEC TPO Thiol compounds: Showa Denko Co., Ltd. Karenz MT PE1 (Example) Preparation Example 1: Synthesis of polysilsesquioxane In a flask equipped with a cooling tube and a stirrer, 32 g of distilled water and 100 g of methanol were added. While maintaining a temperature of -4°C, 261.61 g of 3-(trichlorosilyl)propylmethacrylate was slowly added dropwise over 10 minutes. The mixture was stirred for another 20 minutes, then 500 g of toluene was added dropwise. The temperature was raised to room temperature, and the mixture was stirred for another 10 minutes (simultaneously yielding Si-OH and Si-alkoxy (OR2)). Then, 24.64 g of 2-(3,4-epoxycyclohexyl)ethyl trimethoxysilane was added dropwise and stirred for 10 minutes. Finally, 10 g of a 20% by weight Na2CO3 aqueous solution was added dropwise to the reaction mixture, the temperature was raised to 100°C, and the condensation reaction was carried out for one day. The reaction solution was separated into an aqueous layer and a toluene layer for purification. After confirming that the pH was neutral, the toluene layer was subjected to vacuum decompression to remove all toluene, thereby obtaining polysilsesquioxane.

[0163] The obtained polysilsesquioxane has a linear structure, a weight-average molecular weight of 10,000, and contains no unreacted monomers. The weight-average molecular weight is the polystyrene conversion average molecular weight determined by gel permeation chromatography. Analysis of the polymerization of the obtained silsesquioxane using a thermogravimetric analyzer (TGA) with a decomposition temperature determination method revealed a residual alkoxy (methoxy) content of 3% by weight. ¹H-NMR analysis showed an n:m ratio of approximately 2:1. The residual alkoxy content was determined by TGA to confirm the amount of alkoxy groups decomposed by the condensation reaction within the temperature range of 150°C to 250°C. The n:m ratio was determined by calculating the area integral of Si-C derived from the functional groups of repeating units n and m, and the C portion integral of Si-OCH3 appearing only in repeating unit m.

[0164] Preparation Example 2: Synthesis of Aliphatic Polyurethane Acrylate Oligomers In a four-necked beaker reactor, 215 g of hydroxypropyl polydimethylsiloxane (HPPDMS), 258 g of diluent (isobornyl acrylate (IBOA), 0.05 g), 0.05 g of catalyst (dibutyltin dilaurate (DBTDL), 0.54 g), and 0.54 g of heat stabilizer (butylated hydroxytoluene (BHT), denoted by Formula 4) were added. The temperature was then raised to 60 °C and the mixture was homogeneously mixed for 1 hour. The internal temperature of the reactor was then raised to 85 °C, and isophorone diisocyanate (IPDI) was slowly added dropwise over 20 minutes at the temperature stabilization point to synthesize a silicone-modified polyurethane prepolymer (represented by Formula 41). The reactor temperature was then maintained at 85 °C, and 10.3 g of hydroxyethyl acrylate (HEA) was added to introduce the acrylate into the acrylate reactor at the end of the polyurethane prepolymer. During the reaction, the reaction was terminated after the -NCO characteristic peak was completely disappeared, as confirmed by Fourier transform infrared spectroscopy (FTIR, Agilent, Cary 660). The polydimethylsiloxane-modified urethane acrylate with acrylate groups, represented by the following chemical formula 42, was synthesized as an aliphatic polyurethane acrylate oligomer.

[0165] Chemical formula 4:

[0166] In the chemical formula 4, n is an integer from 1 to 10 (for hydroxypropyl polydimethylsiloxane, n=2).

[0167] Chemical formula 41:

[0168] In the chemical formula 41, PDMS is represented by the following structural formula.

[0169]

[0170] n is 15, and * indicates the connection part.

[0171] Chemical formula 42:

[0172] In the chemical formula 42, Y is hydrogen. PDMS is represented by the following structural formula.

[0173]

[0174] n is 15, and * indicates the connection part.

[0175] Examples 1-9 and Comparative Examples 1-9: Preparation of compositions for forming hard coatings Compositions for forming hard coatings were prepared by mixing the polysilsesquioxane prepared in Preparation Example 1, the polydimethylsiloxane-modified urethane acrylate prepared in Preparation Example 2 as an aliphatic polyurethane acrylate oligomer, the reactive oxetane compound as an oxygen-containing heterocyclic compound, the cationic photopolymerization initiator, and the free radical initiator in the amounts shown in Tables 1 to 2 and Tables 4 to 5 below.

[0176] Examples 10-13: Preparation of compositions for forming hard coatings Compositions for forming hard coatings were prepared by mixing polysilsesquioxane represented by the following structural formula, polydimethylsiloxane-modified urethane acrylate prepared in Example 2 as an aliphatic polyurethane acrylate oligomer, reactive oxetane compound as an oxygen-containing heterocyclic compound, cationic photopolymerization initiator and free radical initiator in the amounts shown in Table 3 below.

[0177] Polysilsesquioxane: MA 0735: Methacrylate POSS cage mixture (manufacturer: Hybridplastics)

[0178] Evaluation Example 1 Using 300mW / cm 2 Metal halide lamps at 2000 mJ / cm2 The amount of the composition prepared in Examples 1-13 and Comparative Examples 1-9 for forming a hard coating was photocured to form a hard coating film.

[0179] The physical properties are evaluated as follows and are shown in Tables 1 to 5.

[0180] (Determination of Young's modulus) 1) Sample preparation method: The coating film with a thickness of 100μm is cut into 1cm (length) x 10cm (width) size by laser cutting.

[0181] 2) The prepared sample is stretched at a speed of 50 mm / min in a Universal Testing Machine (UTM).

[0182] 3) Under these circumstances, the measured Young's modulus value is obtained.

[0183] (Measurement of transmittance) Measurements were performed using a colorimeter (Minolta CM-3700A) in transmission mode. Each sample was measured five times, and the average value was recorded.

[0184] (Measuring membrane strength) According to ASTM D3363 standard, membrane strength is determined under a 1 kg load by the following method.

[0185] 1. With the core material exposed in a cylindrical shape for about 3-4 mm, the core material is shaped to have a flat tip and a sharp angle.

[0186] 2. Place the pencil lead at an angle of approximately 45 degrees to the coating surface, and then move it 15 mm at a speed of 100 mm / min.

[0187] 3. After 5 times, erase the middle of the line with an eraser. If there are no abnormalities in more than 3 out of 5 scratches, mark it as the corresponding hardness.

[0188] ※The pencil is re-sharpened and used after being tested once.

[0189] ※Pencil hardness: 9B~3B→2B→1B→HB→F→H→2H→3H~9H. (Interfacial adhesion) Evaluate the interfacial adhesion to the acrylic coating.

[0190] According to ASTM-D3359 standard, use a cutting knife to make 25 slits in a grid pattern at 2mm intervals, then apply tape to the surface and apply it at a 90° angle. oTear off the tape in one direction and visually inspect the coating surface to see if it has peeled off and adhered to the tape. (0 indicates the lowest adhesion, 5B indicates the highest adhesion.) 5B: The cut surface is flat, and the quadrilaterals of the grid are not separated. 4B: Coating fragments separate at intersections (less than 5% of the mesh area). 3B: Small coating fragments separate along the edges at the intersection of the cut sections (5-15% of the mesh area). 2B: The edge of the coating cut surface and a portion of the quadrilateral are separated (15-35% of the mesh area). 1B: Severe peeling and quadrilateral separation along the edge of the coating cut surface. (35-65% of the mesh area) 0: More prone to detachment and separation than 1B (over 65% of the grid area) (Initial curvature) A sample measuring 73 mm in length, 150 mm in width, and 50 μm in thickness was prepared and placed on a flat surface (tabletop). Under these conditions, the maximum height from the flat surface to the point where the sample was raised was measured.

[0191] Table 1

[0192] Table 2

[0193] Table 3

[0194] Table 4

[0195] Table 5

[0196] As can be seen from the results in Tables 1 to 5, compared with the hard coatings of Comparative Examples 1-9, the hard coatings of Examples 1-13 have high surface strength and modulus, and even after high temperature and high humidity reliability tests, they do not show any appearance deformation and can maintain low curvature.

[0197] Examples 14-19 and Comparative Examples 10-14: Preparation of compositions for forming acrylic coatings Compositions for forming acrylic coatings were prepared according to the amounts of the following compounds shown in Tables 7 and 8.

[0198] Silane coupling agents: silane coupling agents using the substituents of the following chemical formula 2 as defined in Table 6 below.

[0199] Chemical formula 2:

[0200] Table 6

[0201] Using 300mW / cm 2 Metal halide lamps at 2000 mJ / cm 2 The amount of the composition prepared in Examples 14-19 and Comparative Examples 10-14 for forming an acrylic coating was photocured to form an acrylic coating film.

[0202] The physical properties are evaluated as follows and are shown in Tables 7 and 8.

[0203] Evaluation Example 2 The evaluation of Young's modulus, transmittance, film strength, initial curvature, and curvature after 85°C and 85% / 240hr is the same as that in Evaluation Example 1.

[0204] (Ultraviolet (UV) curing shrinkage rate) UV (ultraviolet) curing shrinkage was determined using a TA Instruments DHR-3 instrument by measuring the change in gap size before and after UV curing. Shrinkage was measured under the following conditions using a fast oscillation step method.

[0205] Geometry: 8mm parallel plate Strain: 1% Frequency: 1Hz Light curing energy: 2000 mJ / cm 2 @(365nm LED lamp 200mW / cm) 2 ) (Haze) Measurements were performed using a colorimeter (Minolta CM-3700A) in transmission mode. Each sample was measured five times, and the average value was recorded.

[0206] (Yellow Degree: YI) Measurements were performed using a colorimeter (Minolta CM-3700A) in transmission mode. Each sample was measured five times, and the average value was recorded.

[0207] Table 7

[0208] Table 8

[0209] As can be seen from the results in Tables 7 and 8, compared with the acrylic coatings of Comparative Examples 10-14, the acrylic coatings of Examples 14-19 have excellent interfacial adhesion to the upper hard coating and have high surface strength and modulus.

[0210] Example 20: A laminate for covering windows The composition for forming an acrylic coating of Example 15 and the composition for forming a hard coating of Example 2 were sequentially coated onto a substrate to prepare a material having the following properties: Figure 1 The structure shown is a laminate used to cover the window.

[0211] Comparative Example 15: A laminate used to cover a window The composition of Example 15 for forming an acrylic coating and the composition of Comparative Example 10 for forming a hard coating were sequentially coated onto a substrate to prepare a coating having the following properties: Figure 1 The structure shown is a laminate used to cover the window.

[0212] Comparative Example 16: A laminate used to cover a window The composition of Example 15 for forming an acrylic coating and the composition of Comparative Example 1 for forming a hard coating were sequentially coated onto a substrate to prepare a coating having the following properties: Figure 1 The structure shown is a laminate used to cover the window.

[0213] Comparative Example 17: A laminated structure used to cover a window The composition for forming an acrylic coating of Comparative Example 10 and the composition for forming a hard coating of Comparative Example 1 were sequentially coated onto a substrate to prepare a material having the following properties: Figure 1 The structure shown is a laminate used to cover the window.

[0214] Evaluation Example 3 The laminates for covering windows prepared in Examples 20 and Comparative Examples 15-17 are evaluated below, and the results are shown in Table 9. The methods for measuring the physical properties evaluated below are the same as those for Examples 1 and 2.

[0215] Table 9

[0216] The results in Table 9 confirm that, compared with Comparative Examples 15-17, Example 20 has excellent interfacial adhesion, and also exhibits excellent initial flexural properties and flexural properties after curing for 240 hours under high temperature and high humidity conditions.

[0217] As described above, the present invention has been illustrated with reference to embodiments, but the present invention is not limited to the embodiments disclosed in this specification, and it will be apparent to those skilled in the art that various modifications can be made within the scope of the technical concept of the present invention. Furthermore, even if the effects of the composition according to the present invention are not explicitly described in the description of embodiments, the predictable effects of the composition should be acknowledged. Claims (as amended under Article 19 of the Treaty) 1. A laminate for covering a window, characterized in that, include: A hard coating comprising a cured product of a composition for forming the hard coating, said composition comprising a polysilsesquioxane; an aliphatic polyurethane (meth)acrylate oligomer; and an oxygen-containing heterocyclic compound; and An acrylic coating comprising a cured product of a composition for forming an acrylic coating, wherein the composition for forming the acrylic coating comprises a silane coupling agent in the form of an oligomer. In the composition for forming a hard coating, the weight ratio of the aliphatic polyurethane acrylate oligomer to the oxygen-containing heterocyclic compound is 1:1.5 to 7. 2. The laminate for covering a window according to claim 1, characterized in that, The polysilsesquioxane comprises structural units represented by chemical formula 1-1 and structural units represented by chemical formula 1-2: Chemical formula 1-1: , Chemical formula 1-2: , In the aforementioned chemical formulas 1-1 and 1-2, R1 is independently a halogen group, an alkyl group with 1 to 10 carbon atoms, an aryl group with 6 to 30 carbon atoms, an amino group, a (meth)acryloyl group, a vinyl group, an epoxy group, a thiol group, a glycidyl ether substituted alkyl group with 1 to 10 carbon atoms, or an alicyclic epoxy substituted alkyl group with 1 to 10 carbon atoms. R2 is independently a hydrogen or a straight-chain or branched alkyl group having 1 to 10 carbon atoms. 3. The laminate for covering a window according to claim 2, characterized in that the polysilsesquioxane comprises 0.1 wt% to 10 wt% of an alkoxy group represented by -OR2 in the chemical formulas 1-2. 4. The laminate for covering a window according to claim 2, characterized in that, The polysilsesquioxane is represented by chemical formula 1: Chemical Formula 1: , In the chemical formula 1, R1 is independently a halogen group, an alkyl group with 1 to 10 carbon atoms, an aryl group with 6 to 30 carbon atoms, an amino group, a (meth)acryloyl group, a vinyl group, an epoxy group, a thiol group, a glycidyl ether substituted alkyl group with 1 to 10 carbon atoms, or an alicyclic epoxy substituted alkyl group with 1 to 10 carbon atoms. R2 is independently hydrogen or a straight-chain or branched alkyl group having 1 to 10 carbon atoms. n and m are each an independent integer between 1 and 100,000, but n and m only represent the quantity contained in a molecule of polysilsesquioxane represented by the chemical formula 1. The connection order of the structural units of the chemical formula 1-1 with n units and the structural units of the chemical formula 1-2 with m units is unrestricted and can be connected randomly. 5. The laminate for covering a window according to claim 1, characterized in that, The composition for forming a hard coating comprises: (a) 100 parts by weight of polysilsesquioxane; (b) 7 to 350 parts by weight of aliphatic polyurethane (meth)acrylate oligomer; (c) 25 to 750 parts by weight of oxygen-containing heterocyclic compound; (d) 0.1 to 5 parts by weight of cationic photopolymerization initiator and free radical initiator; and (e) the balance of additives. 6. The laminate for covering a window according to claim 1, wherein the composition for forming the hard coating is solvent-free. 7. The laminate for covering a window according to claim 1, characterized in that, The aliphatic polyurethane (meth)acrylate oligomer is represented by the following chemical formula 3: Chemical formula 3: , In the chemical formula 3, A is a divalent aliphatic hydrocarbon group with 1 to 12 carbon atoms, a divalent aromatic hydrocarbon group with 5 to 60 carbon atoms, or a divalent siloxane group. B is either hydrogen or methyl. n and m are integers from 1 to 20. 8. The laminate for covering a window according to claim 7, characterized in that, In the aforementioned chemical formula 3, A is a group represented by at least one of the following chemical formulas: 3-1, 3-2, and 3-3. Chemical formula 3-1: , Chemical formula 3-2: , Chemical formula 3-3: , In the chemical formulas 3-1 to 3-3, R1 and R2 are each independently an alkyl group having 1 to 12 carbon atoms, n is an integer from 1 to 30, and * indicates a connecting site. 9. The laminate for covering a window according to claim 7, characterized in that, The compound represented by chemical formula 3 is a compound represented by chemical formula 31 or chemical formula 32 as follows: Chemical formula 31: , Chemical formula 32: , In the aforementioned chemical formulas 31 and 32, B is either hydrogen or methyl. PDMS is represented by the following structural formula: , n is an integer from 1 to 30, and * indicates a connection part. 10. The laminate for covering a window according to claim 1, wherein the oxygen-containing heterocyclic compound is a compound containing an oxocyclic butane ring having a hydroxyl group. 11. The laminate for covering a window according to claim 1, characterized in that, The composition for forming an acrylic coating comprises: (a) 100 parts by weight of a monofunctional component comprising a monofunctional (meth)acrylate monomer or oligomer; (b) 50 to 250 parts by weight of a polyfunctional (meth)acrylate monomer or oligomer; (c) 10 to 50 parts by weight of a polyfunctional thiol compound; (d) 0.1 to 50 parts by weight of one or more photopolymerization initiators; and (e) 0.1 to 50 parts by weight of a silane coupling agent. 12. The laminate for covering a window according to claim 1, characterized in that, The silane coupling agent is in the form of an oligomer containing 2 to 20 structural units represented by the following chemical formula 2: Chemical formula 2: , In the chemical formula 2, R3 is hydrogen, or an alkyl group having 1 to 20 carbon atoms, substituted or unsubstituted. X is an alkyl, epoxy, mercapto, acrylate, or aryl group having 1 to 20 carbon atoms. L1 and L2 are each independently a single bond, an alkylene group having 1 to 30 carbon atoms, or a heteroalkylene group having 1 to 20 carbon atoms. b is an integer between 0 and 5. 13. The laminate for covering a window according to claim 1, wherein the weight-average molecular weight of the silane coupling agent is 1000 g / mol to 2000 g / mol. 14. The laminate for covering a window according to claim 12, characterized in that, in the chemical formula 2, -OR3 is selected from the group consisting of hydroxyl, methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, sec-butoxy, pentoxy, hexoxy, and combinations thereof. 15. The laminate for covering a window according to claim 1, characterized in that, The silane coupling agent is represented by the following chemical formula 21: Chemical formula 21: , In the chemical formula 21, R3 is an alkyl group having 1 to 20 carbon atoms. L3 is an alkylene group having 1 to 10 carbon atoms. m2 and n2 are each an independent integer from 1 to 10, but n2 and m2 only represent the number contained in a molecule of the compound represented by the chemical formula 21. The connection order of the structural units with n2 units and the structural units with m2 units is unrestricted and can be randomly connected. 16. The laminate for covering a window according to claim 1, wherein the modulus of the acrylic coating is from 10 MPa to 5000 MPa. 17. The laminate for covering a window according to claim 1, wherein the hard coating has a hardness of 3H or higher. 18. The laminate for covering a window according to claim 1, wherein the thickness of the acrylic coating is from 10 μm to 600 μm, and the thickness of the hard coating is from 10 μm to 200 μm. 19. The laminate for covering a window according to claim 1, wherein the thickness ratio of the acrylic coating to the hard coating is 20:1 to 1:4. 20. A composition for forming a hard coating for covering windows, characterized in that, Include: Polysilsesquioxanes; aliphatic polyurethane (meth)acrylate oligomers; and oxygen-containing heterocyclic compounds, The weight ratio of the aliphatic polyurethane (meth)acrylate oligomer to the oxygen-containing heterocyclic compound is 1:1.5 to 7. 21. The composition for forming a hard coating for covering windows according to claim 20, characterized in that, The polysilsesquioxane comprises structural units represented by chemical formula 1-1 and structural units represented by chemical formula 1-2: Chemical formula 1-1: , Chemical formula 1-2: , In the aforementioned chemical formulas 1-1 and 1-2, R1 is independently a halogen group, an alkyl group with 1 to 10 carbon atoms, an aryl group with 6 to 30 carbon atoms, an amino group, a (meth)acryloyl group, a vinyl group, an epoxy group, a thiol group, a glycidyl ether substituted alkyl group with 1 to 10 carbon atoms, or an alicyclic epoxy substituted alkyl group with 1 to 10 carbon atoms. R2 is independently a hydrogen or a straight-chain or branched alkyl group having 1 to 10 carbon atoms. 22. A composition for forming an acrylic coating for covering windows, characterized in that, Silane coupling agents comprising oligomers represented by the following chemical formula 2: Chemical formula 2: , In the chemical formula 2, R3 is hydrogen, or an alkyl group having 1 to 20 carbon atoms, substituted or unsubstituted. X is an alkyl, epoxy, mercapto, acrylate, or aryl group having 1 to 20 carbon atoms. L1 and L2 are each independently a single bond, an alkylene group having 1 to 30 carbon atoms, or a heteroalkylene group having 1 to 20 carbon atoms. b is an integer between 0 and 5.

Claims

1. A laminate for covering a window, characterized in that, include: A hard coating comprising a cured product of a composition for forming the hard coating, said composition comprising a polysilsesquioxane; an aliphatic polyurethane (meth)acrylate oligomer; and an oxygen-containing heterocyclic compound; and An acrylic coating comprising a cured product of a composition for forming an acrylic coating, wherein the composition for forming the acrylic coating comprises a silane coupling agent in the form of an oligomer. In the composition for forming a hard coating, the weight ratio of the aliphatic polyurethane acrylate oligomer to the oxygen-containing heterocyclic compound is 1:1.5 to 7.

2. The laminate for covering a window according to claim 1, characterized in that, The polysilsesquioxane comprises structural units represented by chemical formula 1-1 and structural units represented by chemical formula 1-2: Chemical formula 1-1: ， Chemical formulas 1-2: ， In the aforementioned chemical formulas 1-1 and 1-2, R1 is independently a halogen group, an alkyl group with 1 to 10 carbon atoms, an aryl group with 6 to 30 carbon atoms, an amino group, a (meth)acryloyl group, a vinyl group, an epoxy group, a thiol group, a glycidyl ether substituted alkyl group with 1 to 10 carbon atoms, or an alicyclic epoxy substituted alkyl group with 1 to 10 carbon atoms. R2 is independently a hydrogen or a straight-chain or branched alkyl group having 1 to 10 carbon atoms.

3. The laminate for covering a window according to claim 1, characterized in that, The polysilsesquioxane contains 0.1 wt% to 10 wt% of an alkoxy group represented by -OR2 in the chemical formulas 1-2.

4. The laminate for covering a window according to claim 1, characterized in that, The polysilsesquioxane is represented by chemical formula 1: Chemical Formula 1: ， In the chemical formula 1, R1 is independently a halogen group, an alkyl group with 1 to 10 carbon atoms, an aryl group with 6 to 30 carbon atoms, an amino group, a (meth)acryloyl group, a vinyl group, an epoxy group, a thiol group, a glycidyl ether substituted alkyl group with 1 to 10 carbon atoms, or an alicyclic epoxy substituted alkyl group with 1 to 10 carbon atoms. R2 is independently hydrogen or a straight-chain or branched alkyl group having 1 to 10 carbon atoms. n and m are each an independent integer between 1 and 100,000, but n and m only represent the quantity contained in a molecule of polysilsesquioxane represented by the chemical formula 1. The connection order of the structural units of the chemical formula 1-1 with n units and the structural units of the chemical formula 1-2 with m units is unrestricted and can be connected randomly.

5. The laminate for covering a window according to claim 1, characterized in that, The composition for forming a hard coating comprises: (a) 100 parts by weight of polysilsesquioxane; (b) 7 to 350 parts by weight of aliphatic polyurethane (meth)acrylate oligomer; (c) 25 to 750 parts by weight of oxygen-containing heterocyclic compound; (d) 0.1 to 5 parts by weight of cationic photopolymerization initiator and free radical initiator; and (e) the balance of additives.

6. The laminate for covering a window according to claim 1, characterized in that, The composition used to form a hard coating is solvent-free.

7. The laminate for covering a window according to claim 1, characterized in that, The aliphatic polyurethane (meth)acrylate oligomer is represented by the following chemical formula 3: Chemical formula 3: ， In the chemical formula 3, A is a divalent aliphatic hydrocarbon group with 1 to 12 carbon atoms, a divalent aromatic hydrocarbon group with 5 to 60 carbon atoms, or a divalent siloxane group. B is either hydrogen or methyl. n and m are integers from 1 to 20.

8. The laminate for covering a window according to claim 7, characterized in that, In the aforementioned chemical formula 3, A is a group represented by at least one of the following chemical formulas: 3-1, 3-2, and 3-3. Chemical formula 3-1: ， Chemical formula 3-2: ， Chemical formula 3-3: ， In the chemical formulas 3-1 to 3-3, R1 and R2 are each independently an alkyl group having 1 to 12 carbon atoms, n is an integer from 1 to 30, and * indicates a connecting site.

9. The laminate for covering a window according to claim 7, characterized in that, The compound represented by chemical formula 3 is a compound represented by chemical formula 31 or chemical formula 32 as follows: Chemical formula 31: ， Chemical formula 32: ， In the aforementioned chemical formulas 31 and 32, B is either hydrogen or methyl. PDMS is represented by the following structural formula: ， n is an integer from 1 to 30, and * indicates a connection part.

10. The laminate for covering a window according to claim 1, characterized in that, The oxygen-containing heterocyclic compound is a compound containing an oxocyclic butane ring with a hydroxyl group.

11. The laminate for covering a window according to claim 1, characterized in that, The composition for forming an acrylic coating comprises: (a) 100 parts by weight of a monofunctional component comprising a monofunctional (meth)acrylate monomer or oligomer; (b) 50 to 250 parts by weight of a polyfunctional (meth)acrylate monomer or oligomer; (c) 10 to 50 parts by weight of a polyfunctional thiol compound; (d) 0.1 to 50 parts by weight of one or more photopolymerization initiators; and (e) 0.1 to 50 parts by weight of a silane coupling agent.

12. The laminate for covering a window according to claim 1, characterized in that, The silane coupling agent is in the form of an oligomer containing 2 to 20 structural units represented by the following chemical formula 2: Chemical formula 2: ， In the chemical formula 2, R3 is an alkyl group with 1 to 20 carbon atoms, either substituted or unsubstituted. X is an alkyl, epoxy, mercapto, acrylate, or aryl group having 1 to 20 carbon atoms. L1 and L2 are each independently a single bond, an alkylene group having 1 to 30 carbon atoms, or a heteroalkylene group having 1 to 20 carbon atoms. b is an integer between 0 and 5.

13. The laminate for covering a window according to claim 1, characterized in that, The weight-average molecular weight of the silane coupling agent is 1000 to 2000.

14. The laminate for covering a window according to claim 12, characterized in that, In the chemical formula 2, -OR3 is selected from the group consisting of hydroxyl, methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, sec-butoxy, pentoxy, hexoxy, and combinations thereof.

15. The laminate for covering a window according to claim 1, characterized in that, The silane coupling agent is represented by the following chemical formula 21: Chemical formula 21: ， In the chemical formula 21, R3 is an alkyl group having 1 to 20 carbon atoms. L3 is an alkylene group having 1 to 10 carbon atoms. m2 and n2 are each an independent integer from 1 to 10, but n2 and m2 only represent the number contained in a molecule of the compound represented by the chemical formula 21. The connection order of the structural units with n2 units and the structural units with m2 units is unrestricted and can be randomly connected.

16. The laminate for covering a window according to claim 1, characterized in that, The modulus of the acrylic coating is from 10 MPa to 5000 MPa.

17. The laminate for covering a window according to claim 1, characterized in that, The hardness of the hard coating is 3H or higher.

18. The laminate for covering a window according to claim 1, characterized in that, The thickness of the acrylic coating is from 10 μm to 600 μm, and the thickness of the hard coating is from 10 μm to 200 μm.

19. The laminate for covering a window according to claim 1, characterized in that, The thickness ratio of the acrylic coating to the hard coating is 20:1 to 1:

4.

20. A composition for forming a hard coating for covering windows, characterized in that, Include: Polysilsesquioxanes; aliphatic polyurethane (meth)acrylate oligomers; and oxygen-containing heterocyclic compounds, The weight ratio of the aliphatic polyurethane (meth)acrylate oligomer to the oxygen-containing heterocyclic compound is 1:1.5 to 7.

21. The composition for forming a hard coating for covering windows according to claim 20, characterized in that, The polysilsesquioxane comprises structural units represented by chemical formula 1-1 and structural units represented by chemical formula 1-2: Chemical formula 1-1: ， Chemical formulas 1-2: ， In the aforementioned chemical formulas 1-1 and 1-2, R1 is independently a halogen group, an alkyl group with 1 to 10 carbon atoms, an aryl group with 6 to 30 carbon atoms, an amino group, a (meth)acryloyl group, a vinyl group, an epoxy group, a thiol group, a glycidyl ether substituted alkyl group with 1 to 10 carbon atoms, or an alicyclic epoxy substituted alkyl group with 1 to 10 carbon atoms. R2 is independently a hydrogen or a straight-chain or branched alkyl group having 1 to 10 carbon atoms.

22. A composition for forming an acrylic coating for covering windows, characterized in that, Silane coupling agents comprising oligomers represented by the following chemical formula 2: Chemical formula 2: ， In the chemical formula 2, R3 is an alkyl group with 1 to 20 carbon atoms, either substituted or unsubstituted. X is an alkyl, epoxy, mercapto, acrylate, or aryl group having 1 to 20 carbon atoms. L1 and L2 are each independently a single bond, an alkylene group having 1 to 30 carbon atoms, or a heteroalkylene group having 1 to 20 carbon atoms. b is an integer between 0 and 5.

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