Display protector

Abstract

The technical idea of the present invention provides a display protector comprising: a transparent substrate layer including a first surface and a second surface facing each other; a first stress relief adhesive layer disposed on the first surface of the transparent substrate layer and including a central area and an edge area surrounding the central area; a second stress relief adhesive layer disposed on the second surface of the transparent substrate layer; an ultra-thin glass layer covering the central area of the first stress relief adhesive layer; and a coating layer covering the edge area of the first stress relief adhesive layer, a side wall of the ultra-thin glass layer, and the top surface of the ultra-thin glass layer, wherein the coating layer has a first elongation, and the first stress relief adhesive layer has a second elongation smaller than the first elongation.

Description

display protector

[0001] The present invention relates to a display protector, and more particularly, to a display protector including a coating layer covering a side wall of an ultra-thin glass layer.

[0002] As foldable and rollable devices become increasingly practical, the demand for display protectors capable of protecting their displays is also increasing. In particular, display protectors used in foldable and rollable devices must withstand numerous folding and rolling cycles over extended periods. Therefore, display protectors with high reliability during such folding and rolling are in demand. In particular, display protectors are vulnerable to impacts from the sides, and microcracks on the sides can cause cracks, wrinkles, and other issues throughout the entire display protector.

[0003] The technical problem to be achieved by the present invention is to provide a display protector including a coating layer covering the side wall of an ultra-thin glass layer, thereby providing a display protector having excellent resilience and reducing the occurrence of creases even when the display protector is repeatedly folded, and having excellent impact resistance on the top and side surfaces of the display protector.

[0004] In order to solve the above-described problem, the technical idea of ​​the present invention provides a display protector including a transparent substrate layer including opposing first and second surfaces; a first stress-relieving adhesive layer disposed on the first surface of the transparent substrate layer and including a central region and an edge region surrounding the central region; a second stress-relieving adhesive layer disposed on the second surface of the transparent substrate layer; an ultra-thin glass layer covering the central region of the first stress-relieving adhesive layer; and a coating layer covering an edge region of the first stress-relieving adhesive layer, a side wall of the ultra-thin glass layer, and an upper surface of the ultra-thin glass layer, wherein the coating layer has a first elongation, and the first stress-relieving adhesive layer has a second elongation that is smaller than the first elongation.

[0005] In addition, the technical idea of ​​the present invention provides a display protector including a transparent substrate layer including opposing first and second surfaces; a first stress relieving adhesive layer disposed on the first surface of the transparent substrate layer and including a central region and an edge region surrounding the central region; a second stress relieving adhesive layer disposed on the second surface of the transparent substrate layer; an ultra-thin glass layer disposed on the central region of the first stress relieving adhesive layer; and a coating layer including a horizontal portion covering the central region of the first stress relieving adhesive layer and a vertical portion connected to the horizontal portion and covering the edge region of the first stress relieving adhesive layer and a side wall of the ultra-thin glass layer, wherein the coating layer has a first elongation, and the first stress relieving adhesive layer has a second elongation that is smaller than the first elongation.

[0006] The display protector of the present invention is not only compatible with foldable terminals or rollable terminals, but also has excellent resilience even when the display protector is repeatedly folded, thereby reducing the occurrence of wrinkles and lifting, and has excellent impact resistance on the top and sides of the display protector.

[0007] FIG. 1 is a schematic diagram conceptually illustrating a laminated structure of a display protector according to one embodiment of the present invention.

[0008] FIG. 2 is a top view of a display protector according to one embodiment of the present invention.

[0009] FIG. 3 is a cross-sectional view schematically showing a folded state of a display protector according to one embodiment of the present invention.

[0010] Figure 4 is an enlarged cross-sectional view of the EX1 portion of Figure 3.

[0011] FIG. 5 is a perspective view showing a display protector according to one embodiment of the present invention attached to a foldable display device.

[0012] FIG. 6 is a perspective view showing a display protector according to one embodiment of the present invention attached to a rollable display device.

[0013] FIG. 7 is a schematic diagram illustrating a folding test of a display protector according to one embodiment of the present invention.

[0014] FIG. 8 is a schematic diagram showing a test of the strength of a display protector according to one embodiment of the present invention.

[0015] FIG. 9 is a schematic diagram illustrating a test of the side strength of a display protector according to one embodiment of the present invention.

[0016] Figures 10 to 15 are schematic diagrams conceptually illustrating a laminated structure of a display protector according to one embodiment of the present invention.

[0017] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. However, the embodiments of the present invention may be modified in various different forms, and the scope of the present invention should not be construed as being limited by the embodiments described below. It is preferable to interpret that the embodiments of the present invention are provided to more completely explain the present invention to those of ordinary skill in the art. Like numbers refer to like elements throughout. Furthermore, various elements and areas in the drawings are schematically drawn. Therefore, the present invention is not limited by the relative sizes or spacings depicted in the attached drawings.

[0018] While terms like "first" and "second" may be used to describe various components, these components are not limited by these terms. These terms are used solely to distinguish one component from another. For example, a first component could be referred to as a "second component," and vice versa, without departing from the scope of the present invention.

[0019] The terminology used in this application is only used to describe specific embodiments and is not intended to limit the inventive concept. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, it should be understood that the expressions "comprises" or "has" indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but do not preclude the possibility of the presence or addition of one or more other features, numbers, operations, components, parts, or combinations thereof.

[0020] Unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention pertains. Furthermore, it is to be understood that commonly used terms, such as those defined in dictionaries, should be interpreted to have a meaning consistent with their meaning within the relevant technical context, and should not be interpreted in an overly formal sense unless explicitly defined herein.

[0021] FIG. 1 is a schematic diagram conceptually illustrating a laminated structure of a display protector (100) according to one embodiment of the present invention. FIG. 2 is a top view of a display protector (100) according to one embodiment of the present invention. FIG. 3 is a cross-sectional view schematically illustrating a folded state of a display protector (100) according to one embodiment of the present invention. FIG. 4 is an enlarged cross-sectional view of a portion EX1 of FIG. 3.

[0022] Referring to FIGS. 1 to 4, the display protector (100) of the present disclosure may include a transparent substrate layer (110), a first stress relieving adhesive layer (121), a second stress relieving adhesive layer (122), an ultra-thin glass (UTG) layer (130), and a coating layer (140). The transparent substrate layer (110) may have a first surface (110a) and a second surface (110b) that face each other and extend in parallel. The first stress relieving adhesive layer (121) and the second stress relieving adhesive layer (122) may be disposed on the first surface (110a) and the second surface (110b) of the transparent substrate layer (110), respectively. The UTG layer (130) may be disposed on the first stress relieving adhesive layer (121). The coating layer (140) may be provided to cover the UTG layer (130).

[0023] transparent substrate layer

[0024] In some embodiments, the transparent substrate layer (110) may have a first surface (110a) and a second surface (110b) that face each other and extend parallel to each other. The transparent substrate layer (110) may include, for example, a polyurethane resin, a polyester-based resin, and / or a (meth)acrylic resin.

[0025] In some embodiments, the polyurethane resin may have a weight average molecular weight of about 100,000 to about 1,000,000.

[0026] In some embodiments, the polyurethane resin may be a polymerization product of a polyfunctional isocyanate compound having two or more isocyanate groups (-N=C=O) and a polyol compound.

[0027] The above polyfunctional isocyanate compound may be an aliphatic, aromatic, alicyclic, or araliphatic isocyanate compound.

[0028] Among the above polyfunctional isocyanate compounds, the aliphatic isocyanate compounds include, for example, ethylene diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HMDI), octamethylene diisocyanate, nonamethylene diisocyanate, dodecamethylene diisocyanate, 2,2-dimethylpentane diisocyanate, 2,2,4-trimethyl hexamethylene diisocyanate, decamethylene diisocyanate, butene diisocyanate, 1,3-butadiene-1,4-diisocyanate, 2,4,4-trimethyl hexamethylene diisocyanate, 1,6,11-undecane triisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, 2,6-Diisocyanate methyl caproate, bis(2-isocyanate ethyl) fumarate, bis(2-isocyanate ethyl) carbonate, 2-isocyanate ethyl-2,6-diisocyanate hexanoate, 1,3,5-hexamethylene triisocyanate, 1,8-diisocyanato-4-isocyanate, bis(isocyanatoethyl) ether, 1,4-butylene glycol dipropyl ether-w, w'-diisocyanate, lysine diisocyanato methyl ester, lysine triisocyanate, 2-isocyanatoethyl-2,6-diisocyanato ethyl-2,6-diisocyanato hexanoate, 2-isocyanatopropyl-2,6-diisocyanato The present invention may be at least one selected from the group consisting of hexanoate, 2,6-di(isocyanatomethyl)furan, 1,3-bis(6-isocyanato hexyl)-uretidine-2,4-dione, and 1,3,5-tris(6-isocyanato hexyl)isocyanurate, but the present invention is not limited thereto.

[0029] Among the above multifunctional isocyanate compounds, the aromatic isocyanate compound may be, for example, phenylene 1,4-diisocyanate, tolylene 2,4- and / or 2,6-diisocyanate (TDI), naphthylene 1,5-diisocyanate, diphenylmethane 2,2'- and / or 2,4'-, and / or 4,4'-diisocyanate (MDI) and / or higher homologues (pMDI), but the present invention is not limited thereto.

[0030] Among the above polyfunctional isocyanate compounds, alicyclic isocyanate compounds include, for example, isophorone diisocyanate (IPDI), 4,4'-dicyclohexylmethane diisocyanate, cyclohexylene diisocyanate, methylcyclohexylene diisocyanate, bis(2-isocyanateethyl)-4-cyclohexene-1,2-dicarboxylate, 2,5-norbornane diisocyanate, 2,6-norbornane diisocyanate, 2,2-dimethyl dicyclohexylmethane diisocyanate, bis(4-isocyanato-n-butylidene)pentaerythritol, dimer acid diisocyanate, 2-isocyanatomethyl-3-(3-isocyanato 2-Isocyanatomethyl-3-(3-isocyanatopropyl)-6-isocyanatomethyl-bicyclo[2.2.1]-heptane, 2-Isocyanatomethyl-2-(3-isocyanatopropyl)-5-isocyanatomethyl-bicyclo[2.2.1]-heptane, 2-Isocyanatomethyl-2-(3-isocyanatopropyl)-6-isocyanatomethyl-bicyclo[2.2.1]-heptane, 2-Isocyanatomethyl-3-(3-isocyanatopropyl)-6-(2-isocyanatoethyl)-bicyclo[2.2.1]-heptane, 2-isocyanatomethyl-3-(3-isocyanatopropyl)-6-(2-isocyanatoethyl)-bicyclo[2.1.1]-heptane, 2-isocyanatomethyl-2-(3-isocyanatopropyl)-5-(2-isocyanatoethyl)-bicyclo[2.1.1]-heptane, 2-isocyanatomethyl-2-(3-isocyanatopropyl)-6-(2-isocyanatoethyl)-bicyclo[2.2.1]-heptane, and norbornane bis(isocyanatomethyl), but the present invention is not limited thereto.

[0031] Among the above multifunctional isocyanate compounds, the aromatic aliphatic isocyanate compounds include, for example, 1,3-bis(isocyanatomethyl)benzene (m-xylene diisocyanate, m-XDI), 1,4-bis(isocyanatomethyl)benzene (p-xylene diisocyanate, p-XDI), 1,3-bis(2-isocyanatopropan-2-yl)benzene (m-tetramethyl xylene diisocyanate, m-TMXDI), 1,3-bis(isocyanatomethyl)-4-methylbenzene, 1,3-bis(isocyanatomethyl)-4-ethylbenzene, 1,3-bis(isocyanatomethyl)-5-methylbenzene, 1,3-bis(isocyanatomethyl)-4,5-dimethylbenzene, 1,4-bis(isocyanatomethyl)-2,5-dimethylbenzene, 1,4-bis(isocyanatomethyl)-2,3,5,6-tetramethylbenzene, 1,3-bis(isocyanatomethyl)-5-tert-butylbenzene, 1,3-bis(isocyanatomethyl)-4-chlorobenzene, 1,3-bis(isocyanatomethyl)-4,5-dichlorobenzene, 1,3-bis(isocyanatomethyl)-2,4,5,6-tetrachlorobenzene, 1,4-bis(isocyanatomethyl)-2,3,5,6-tetrachlorobenzene, 1,4-bis(isocyanatomethyl)-2,3,5,6-tetrabromobenzene, 1,4-bis(2-isocyanatoethyl)benzene, 1,4-bis(isocyanatomethyl)naphthalene, xylylene diisocyanate, bis(isocyanatoethyl)benzene, bis(isocyanatopropyl)benzene, α,α, α',α'-tetramethyl xylylene diisocyanate, bis(isocyanatobutyl)benzene, bis(isocyanatopropyl)naphthalene, bis(isocyanatomethyl)diphenylether, and bis(isocyanatoethyl)phthalate, but the present invention is not limited thereto.

[0032] The above polyol compound may be, for example, ethylene glycol, diethylene glycol, 1,2-propylene glycol, 1,3-butylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,9-nonanediol, 1,10-decanediol, 2,2-dimethyl-1,3-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, 2-methyl-1,8-octanediol, dipropylene glycol, etc., and the present invention is not limited thereto.

[0033] In some embodiments, the polyester resin may have a weight average molecular weight of about several tens to about 1,000,000.

[0034] The above polyester resin is a polymer having ester bonds, and is mainly a polycondensation polymer of a polyhydric carboxylic acid and a polyhydric alcohol. The polyhydric carboxylic acid used is mainly a dihydric dicarboxylic acid, and examples thereof include isophthalic acid, terephthalic acid, dimethyl terephthalate, and methyl naphthalenedicarboxylate. In addition, the polyhydric alcohol used is mainly a dihydric diol, and as it has been explained in detail above, further explanation is omitted here.

[0035] Specific examples of the polyester resin include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polytrimethylene terephthalate, polytrimethylene naphthalate, polycyclohexane dimethyl terephthalate, polycyclohexane dimethyl naphthalate, etc. Blended resins or copolymers of these can also be preferably used.

[0036] In some embodiments, the (meth)acrylic resin may have a weight average molecular weight of about 100,000 to about 3,000,000.

[0037] The above (meth)acrylic resin may be a polymerization product of a (meth)acrylate monomer and / or a (meth)acrylate oligomer.

[0038] The above (meth)acrylate monomer may be, for example, a polyfunctional (meth)acrylate compound. The term 'polyfunctional (meth)acrylate compound' may mean a (meth)acrylate compound having two or more polymerizable functional groups.

[0039] Specifically, the above multifunctional (meth)acrylate is ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, butanediol (meth)acrylate, hexanediol di(meth)acrylate, nonanediol di(meth)acrylate, ethoxylated hexanediol di(meth)acrylate, propoxylated hexanediol di(meth)acrylate, diethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, acrylated neopentyl glycol di(meth)acrylate, epoxidized neopentyl glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, ethoxylated neopentyl glycol It may be a bifunctional acrylate compound such as di(meth)acrylate, tripropylene glycol di(meth)acrylate or hydroxypivalic acid neopentyl glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, ethoxylated trimethylolpropane tri(meth)acrylate, propoxylated trimethylolpropane tri(meth)acrylate, tris2-hydroxyethylisocyanurate tri(meth)acrylate or glycerin tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol tri(meth)acrylate or ditrimethylolpropane tri(meth)acrylate, or a trifunctional acrylate compound such as pentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, It may be a trifunctional or more polyfunctional acrylate compound such as dipentaerythritol penta(meth)acrylate, ditrimethylolpropane penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, or ditrimethylolpropane hexa(meth)acrylate, but the present invention is not limited thereto.

[0040] The above (meth)acrylate oligomer may be, for example, epoxy (meth)acrylate, urethane (meth)acrylate, polyester (meth)acrylate, polybutadiene (meth)acrylate, silicone (meth)acrylate, or alkyl (meth)acrylate, and the present invention is not limited thereto.

[0041] In some embodiments, the transparent substrate layer (110) may have a thickness of about 10 μm to about 40 μm, about 12 μm to about 35 μm, about 14 μm to about 30 μm, about 15 μm to about 25 μm, or any range therebetween.

[0042] If the thickness of the transparent substrate layer (110) is too thin and outside the above range, the mechanical strength may be insufficient and the effect of preventing glass from scattering when the UTG layer is damaged may be insufficient. Conversely, if the thickness of the transparent substrate layer (110) is too thick and outside the above range, when the display protector (100) is folded, shear stress may be excessively concentrated at the folded portion, and a lifting phenomenon may easily occur when folding and unfolding are repeated.

[0043] First stress-relieving adhesive layer and second stress-relieving adhesive layer

[0044] In some embodiments, the first stress relieving adhesive layer (121) and the second stress relieving adhesive layer (122) may each independently include an acrylic polymer or a polysiloxane compound.

[0045] The above acrylic polymer may be, for example, a polymerization product of a (meth)acrylic monomer.

[0046] Specifically, the (meth)acrylic monomers are n-butyl (meth)acrylate, 2-butyl (meth)acrylate, t-butyl (meth)acrylate, isobutyl (meth)acrylate, hexyl (meth)acrylate, cyclohexyl (meth)acrylate, N-vinylpyrrolidone, 2-ethylhexyl (meth)acrylate, ethyl (meth)acrylate, methyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, pentyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, 2-methylbutyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, isoamyl (meth)acrylate, Monofunctional monomers such as n-decyl (meth)acrylate, isodecyl (meth)acrylate, isobornyl (meth)acrylate, 4-methyl-2-pentyl (meth)acrylate, dodecyl (meth)acrylate, 2-dodecylthioethyl (meth)acrylate, lauryl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, allyl (meth)acrylate, stearyl (meth)acrylate, phenoxyethyl (meth)acrylate, tetrafurfuryl (meth)acrylate, tetrahydrofuryl (meth)acrylate, and acryloylmorpholine;1,3-Butanediol di(meth)acrylate, 1,4-Butanediol di(meth)acrylate, 1,6-Hexanediol di(meth)acrylate, 2-Butyl-2-ethyl-1,3-propanediol diacrylate, 1,9-Nonanediol diacrylate, Ethylene glycol di(meth)acrylate, Bisphenol A-ethylene glycol diacrylate, Diethylene glycol di(meth)acrylate, Triethylene glycol di(meth)acrylate, Tetraethylene glycol di(meth)acrylate, Propylene glycol di(meth)acrylate, Dipropylene glycol di(meth)acrylate, Tripropylene glycol di(meth)acrylate, Neopentyl glycol di(meth)acrylate, Dicyclopentanyl di(meth)acrylate, Caprolactone-modified dicyclopentenyl di(meth)acrylate, Bifunctional monomers such as ethylene oxide-modified phosphoric acid di(meth)acrylate, bis(2-hydroxyethyl)isocyanurate di(meth)acrylate, di(acryloxyethyl)isocyanurate, allylated cyclohexyl di(meth)acrylate, dimethyloldicyclopentane diacrylate, ethylene oxide-modified hexahydrophthalic acid diacrylate, tricyclodecane dimethanol acrylate, neopentyl glycol-modified trimethylolpropane diacrylate, and adamantane diacrylate; Trifunctional monomers such as trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, propionic acid-modified trimethylolpropane tri(meth)acrylate, propylene oxide-modified trimethylolpropane tri(meth)acrylate, tris(2-hydroxyethyl)isocyanurate tri(meth)acrylate, tris(acryloxyethyl)isocyanurate, and glycerol tri(meth)acrylate; tetrafunctional monomers such as diglycerin tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, and tetramethylolpropane tetra(meth)acrylate; Pentafunctional monomers such as dipentaerythritol penta(meth)acrylate, propionic acid-modified dipentaerythritol penta(meth)acrylate, etc.;Examples thereof include hexafunctional monomers such as dipentaerythritol hexa(meth)acrylate, caprolactone-modified dipentaerythritol hexa(meth)acrylate, etc., but the present invention is not limited thereto.

[0047] The above (meth)acrylic monomer can be polymerized with a comonomer. In some embodiments, the comonomer may include, but is not necessarily limited to, one or more of an alkyl (meth)acrylate monomer, a monomer having ethylene oxide, a monomer having propylene oxide, a monomer having an amine group, a monomer having an amide group, a monomer having an alkoxy group, a monomer having a phosphoric acid group, a monomer having a sulfonic acid group, a monomer having a phenyl group, and a monomer having a silane group.

[0048] In some embodiments, the alkyl (meth)acrylate monomer may include, for example, an unsubstituted C1-C20 linear or branched alkyl (meth)acrylic acid ester. For example, it may include one or more of methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, t-butyl (meth)acrylate, iso-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, ethylhexyl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, lauryl (meth)acrylate, and isobornyl (meth)acrylate. Specifically, by using an alkyl (meth)acrylic monomer having 4 to 8 carbon atoms as a comonomer, the initial adhesive strength may be further increased.

[0049] In some embodiments, the monomer having ethylene oxide may be, for example, one or more (meth)acrylate monomers containing an ethylene oxide group (-CH2CH2O-). For example, it can be a polyethylene oxide alkyl ether (meth)acrylate such as polyethylene oxide monomethyl ether (meth)acrylate, polyethylene oxide monoethyl ether (meth)acrylate, polyethylene oxide monopropyl ether (meth)acrylate, polyethylene oxide monobutyl ether (meth)acrylate, polyethylene oxide monopentyl ether (meth)acrylate, polyethylene oxide dimethyl ether (meth)acrylate, polyethylene oxide diethyl ether (meth)acrylate, polyethylene oxide monoisopropyl ether (meth)acrylate, polyethylene oxide monoisobutyl ether (meth)acrylate, polyethylene oxide monotert-butyl ether (meth)acrylate, but is not necessarily limited thereto.

[0050] In some embodiments, the monomer having propylene oxide may be, but is not limited to, a polypropylene oxide alkyl ether (meth)acrylate, such as, for example, polypropylene oxide monomethyl ether (meth)acrylate, polypropylene oxide monoethyl ether (meth)acrylate, polypropylene oxide monopropyl ether (meth)acrylate, polypropylene oxide monobutyl ether (meth)acrylate, polypropylene oxide monopentyl ether (meth)acrylate, polypropylene oxide dimethyl ether (meth)acrylate, polypropylene oxide diethyl ether (meth)acrylate, polypropylene oxide monoisopropyl ether (meth)acrylate, polypropylene oxide monoisobutyl ether (meth)acrylate, polypropylene oxide monotert-butyl ether (meth)acrylate.

[0051] In some embodiments, the amino group-containing monomer may be, but is not necessarily limited to, an amino group-containing (meth)acrylic monomer such as, for example, monomethylaminoethyl (meth)acrylate, monoethylaminoethyl (meth)acrylate, monomethylaminopropyl (meth)acrylate, monoethylaminopropyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, N-tert-butylaminoethyl (meth)acrylate, and methacryloxyethyltrimethylammonium chloride (meth)acrylate.

[0052] In some embodiments, the monomer having an amide group may be, but is not necessarily limited to, an amide group-containing (meth)acrylic monomer such as, for example, (meth)acrylamide, N-methylacrylamide, N-methylmethacrylamide, N-methylol(meth)acrylamide, N-methoxymethyl(meth)acrylamide, N,N-methylene bis(meth)acrylamide, 2-hydroxyethylacrylamide, etc.

[0053] In some embodiments, the monomer having the alkoxy group may be, but is not necessarily limited to, for example, 2-methoxyethyl (meth)acrylate, 2-methoxypropyl (meth)acrylate, 2-ethoxypropyl (meth)acrylate, 2-butoxypropyl (meth)acrylate, 2-methoxypentyl (meth)acrylate, 2-ethoxypentyl (meth)acrylate, 2-butoxyhexyl (meth)acrylate, 3-methoxypentyl (meth)acrylate, 3-ethoxypentyl (meth)acrylate, 3-butoxyhexyl (meth)acrylate.

[0054] In some embodiments, the monomer having the phosphoric acid group may be, but is not necessarily limited to, an acrylic monomer having a phosphoric acid group such as 2-methacryloyloxyethyldiphenylphosphate (meth)acrylate, trimethacryloyloxyethylphosphate (meth)acrylate, or triacryloyloxyethylphosphate (meth)acrylate.

[0055] In some embodiments, the monomer having a sulfonic acid group may be, but is not necessarily limited to, an acrylic monomer having a sulfonic acid group, such as sodium sulfopropyl (meth)acrylate, sodium 2-sulfoethyl (meth)acrylate, sodium 2-acrylamido-2-methylpropanesulfonate, etc.

[0056] In some embodiments, the monomer having a phenyl group may be, but is not necessarily limited to, an acrylic vinyl monomer having a phenyl group, such as p-tert-butylphenyl(meth)acrylate or o-biphenyl(meth)acrylate.

[0057] In some embodiments, the monomer having a silane group may be a vinyl monomer having a silane group, such as, but not limited to, 2-acetoacetoxyethyl(meth)acrylate, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(β-methoxyethyl)silane, vinyltriacetylsilane, methacryloyloxypropyltrimethoxysilane, and the like.

[0058] The above-mentioned comonomer may be included in the monomer mixture at 60 wt% to 95 wt%, for example, 70 wt% to 90 wt%. Within this range, the first stress-relieving adhesive layer (121) and the second stress-relieving adhesive layer (122) can obtain excellent adhesive strength and stress-dispersing effect.

[0059] The above acrylic polymer may have a weight average molecular weight of about 100,000 to about 3,000,000.

[0060] The above polysiloxane compound may be, for example, a polysiloxane compound of the following chemical formula 1.

[0061] <Chemical Formula 1>

[0062]

[0063] (Wherein, n is an integer from 100 to 10,000, and R1 to R8 are each independently hydrogen, halogen, a nitrile group, a nitro group, a hydroxy group, an amino group, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 10 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 10 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 10 carbon atoms, a substituted or unsubstituted alkylenyl group having 2 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 15 carbon atoms, a substituted or unsubstituted aryl group having 6 to 15 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 15 carbon atoms, a substituted or unsubstituted arylalkyl group having 7 to 15 carbon atoms, or a substituted or unsubstituted aryl group having 7 to 15 carbon atoms. (alkylaryl group)

[0064] Here, 'substituted' means that a hydrogen atom bonded to a carbon atom of a compound or functional group is replaced with a different substituent. The position of the substitution is not particularly limited as long as it is a position where the substituent can be substituted, and the position at which the hydrogen atom is replaced. In addition, when two or more are substituted, the two or more substituents may be the same or different.

[0065] Here, 'substituted or unsubstituted' means substituted with one or more substituents selected from the group consisting of deuterium; halogen; nitrile group (-CN); nitro group; hydroxy group; amino group; silyl group; boron group; alkoxy group; aryloxy group; alkyl group; cycloalkyl group; aryl group; and heterocyclic group, or substituted with a substituent in which two or more substituents among the above-mentioned substituents are connected, or having no substituents. For example, 'a substituent in which two or more substituents are connected' may be a biphenyl group. That is, the biphenyl group may be an aryl group, or may be interpreted as a substituent in which two phenyl groups are connected.

[0066] The first stress relieving adhesive layer (121) and the second stress relieving adhesive layer (122) can each independently have a thickness of about 10 μm to about 40 μm, about 11 μm to about 38 μm, about 12 μm to about 36 μm, about 13 μm to about 34 μm, about 14 μm to about 32 μm, about 15 μm to about 30 μm, or any range therebetween.

[0067] If the thickness of the first stress relieving adhesive layer (121) and the second stress relieving adhesive layer (122) is too thin and outside the above range, the effect of relieving stress during folding is insufficient, and peeling (lifting) may occur. Conversely, if the thickness of the first stress relieving adhesive layer (121) and the second stress relieving adhesive layer (122) is too thick and outside the above range, the stress during folding is withstood, but the stress generated on both sides of the stress relieving adhesive layer becomes excessively unbalanced, which may cause peeling (lifting) at the folding portion.

[0068] The first stress relieving adhesive layer (121) and the second stress relieving adhesive layer (122) can each independently have a storage modulus of about 0.03 MPa to about 0.2 MPa at -10°C. In some embodiments, the first stress relieving adhesive layer (121) and the second stress relieving adhesive layer (122) can each independently have a storage modulus of about 0.03 MPa to about 0.20 MPa, about 0.04 MPa to about 0.18 MPa, about 0.05 MPa to about 0.16 MPa, about 0.06 MPa to about 0.14 MPa, about 0.07 MPa to about 0.12 MPa, about 0.08 MPa to about 0.11 MPa, about 0.08 MPa to about 0.10 MPa, or any range therebetween at -10°C.

[0069] In some embodiments, the first stress relieving adhesive layer (121) and the second stress relieving adhesive layer (122) can each independently have a storage modulus of about 0.02 MPa to about 0.2 MPa at +40°C. In some embodiments, the first stress relieving adhesive layer (121) and the second stress relieving adhesive layer (122) can each independently have a storage modulus at +40° C. of about 0.02 MPa to about 0.20 MPa, about 0.03 MPa to about 0.18 MPa, about 0.04 MPa to about 0.16 MPa, about 0.05 MPa to about 0.14 MPa, about 0.06 MPa to about 0.13 MPa, about 0.07 MPa to about 0.12 MPa, about 0.08 MPa to about 0.11 MPa, about 0.09 MPa to about 0.10 MPa, or any range therebetween.

[0070] If the storage modulus of the first stress-relieving adhesive layer (121) and the second stress-relieving adhesive layer (122) is too small and falls outside the above range, the material properties become excessively soft, making manufacturing difficult, and peeling (lifting) may occur during folding due to reduced adhesive strength.

[0071] Conversely, if the storage modulus of the first stress-relieving adhesive layer (121) and the second stress-relieving adhesive layer (122) is too large and falls outside the above range, the effect of relieving the shear stress generated within the display protector (100) against deformation of the display protector (100) becomes insufficient.

[0072] In some embodiments, the storage modulus of the first stress relieving adhesive layer (121) may be substantially the same as the storage modulus of the second stress relieving adhesive layer (122). Here, “substantially the same” means that the difference between these two values ​​is within + / - 10% based on the larger of the two.

[0073] In some embodiments, the first stress relieving adhesive layer (121) and the second stress relieving adhesive layer (122) can each independently have an adhesive strength of about 600 gf / in to about 1500 gf / in at a temperature of 20°C to 25°C. In some embodiments, the first stress relieving adhesive layer (121) and the second stress relieving adhesive layer (122) can each independently have an adhesive strength of from about 600 gf / in to about 1500 gf / in, from about 650 gf / in to about 1450 gf / in, from about 700 gf / in to about 1400 gf / in, from about 750 gf / in to about 1350 gf / in, from about 800 gf / in to about 1300 gf / in, from about 850 gf / in to about 1250 gf / in, from about 900 gf / in to about 1200 gf / in, from about 950 gf / in to about 1150 gf / in, from about 1000 gf / in to about 1110 gf / in, or any range therebetween.

[0074] If the adhesive strength of the first stress-relieving adhesive layer (121) and the second stress-relieving adhesive layer (122) is too small and falls outside the above range, the adhesive strength is insufficient, making it difficult to maintain the attachment of the display protector.

[0075] Conversely, if the adhesive strength of the first stress-relieving adhesive layer (121) and the second stress-relieving adhesive layer (122) is too great and exceeds the above range, it is difficult to peel off the display protector (100) from the attached electronic device display when attempting to replace it, and there is a risk of damaging the electronic device display when peeling it off.

[0076] UTG floor

[0077] In some embodiments, the UTG layer (130) may be a layer made of a tempered glass material having a thickness of about 30 micrometers (μm) to about 70 μm. In some embodiments, the UTG layer (130) may have a thickness of about 30 μm to about 70 μm, about 32 μm to about 70 μm, about 34 μm to about 65 μm, about 36 μm to about 60 μm, about 38 μm to about 55 μm, about 40 μm to about 50 μm, or any range therebetween.

[0078] If the thickness of the UTG layer (130) is too thin and outside the above range, the impact resistance may be insufficient. If the thickness of the UTG layer (130) is too thick and outside the above range, the layer may be easily damaged by repeated folding or rolling, and the repulsive force becomes strong when folding.

[0079] The UTG layer (130) may be made of, but is not limited to, aluminosilicate, alkali-aluminosilicate, borosilicate, alkali-borosilicate, aluminoborosilicate, alkali-aluminoborosilicate, soda-lime, or other suitable glasses.

[0080] In some embodiments, the UTG layer (130) may be obtained from commercially available mother glass from NEG, Corning Inc., Schott, etc. The mother glass is formed into the UTG layer (130) by applying a slimming process, a cell-shaped cutting process, a glass strengthening process, an AF coating process, etc. Additionally, an anti-shatter coating process may be applied.

[0081] coating layer

[0082] In some embodiments, the coating layer (140) may be composed of an optical resin composition including a urethane acrylate oligomer having the following chemical formula 2 and a (meth)acrylate monomer. In addition, at least one photoinitiator may be added to the optical resin composition. At this time, the (meth)acrylate monomer may be, for example, a polyfunctional (meth)acrylate compound. The term 'polyfunctional (meth)acrylate compound' may mean a (meth)acrylate compound having two or more polymerizable functional groups.

[0083]

[0084] [Chemical Formula 2]

[0085]

[0086]

[0087] In some embodiments, from a manufacturing perspective, the coating layer (140) may be provided in the form of a film on the upper surface of a display device or the like to which the display protector (100) is attached by photocuring the optical resin composition. According to one embodiment, the display protector (100) including the coating layer (140) is attached to the upper surface of the display device or the like, thereby protecting the display device from external impact.

[0088] In some embodiments, the urethane acrylate oligomer may be provided as a compound synthesized by synthesizing isophorone diisocyanate centered on polyoxypropylene triol, synthesizing polytetramethylene ether glycol, and finally synthesizing 2-hydroxyethyl acrylate of Chemical Formula 5. That is, the urethane acrylate oligomer is a compound produced by synthesizing polyoxypropylene triol, isophorone diisocyanate, polytetramethylene ether glycol, and 2-hydroxyethyl acrylate, and the synthesized urethane acrylate oligomer may include a triol group and a glycol group in a single molecule.

[0089] In some embodiments, the urethane acrylate oligomer may be contained in an amount ranging from 30 wt% to 70 wt%, more preferably from 40 wt% to 60 wt%, based on 100 wt% of the optical resin compound providing the coating layer (140). In addition, the storage elastic modulus of the coating layer (140) at -20°C may be within a range of 100 MPa to 2 GPa.

[0090] In some embodiments, when the content of the urethane acrylate oligomer compound exceeds 70 wt%, it is difficult to manufacture a thin film due to high viscosity, and when formed into a film, the low-temperature (-20°C) storage elastic modulus (G') may increase to more than 2 GPa, which may cause problems with folding or rolling properties.

[0091] In some embodiments, when the content of the urethane acrylate oligomer compound is less than 30 wt%, the low-temperature (-20°C) storage elastic modulus (G') may be less than 100 MPa when formed into a film, resulting in reduced restorability and a problem in which the film does not return to its original state after folding or rolling.

[0092] In some embodiments, the coating layer (140) may be composed to have a Shore D hardness ranging from 21 to 85. The Shore D hardness may be calculated by the Shore test method (ASTM D2240). In the present invention, in order to distinguish the degree of Shore D hardness of the coating layer (140), it is indicated as low hardness from 20 to 40, medium hardness from 41 to 60, and high hardness from 61 to 85.

[0093] In some embodiments, the coating layer (140) may be formed using a composition having a tensile strength in the medium hardness range of 10 to 25 MPa, an elongation rate of 100 to 250%, and a Young's modulus of 10 to 30.

[0094] In some embodiments, the coating layer (140) may be formed using a composition having a tensile strength in the range of 20 to 40 MPa, an elongation rate in the range of 5 to 100%, and a Young's modulus in the range of 500 to 1,500 in the high hardness range.

[0095] Referring to FIGS. 1 and 2, the first stress relieving adhesive layer (121) may include a central region (121a) and an edge region (121b). The UTG layer (130) may be configured to cover a portion of the first stress relieving adhesive layer (121). For example, the UTG layer (130) may be configured to cover the central region (121a) of the first stress relieving adhesive layer (121). The coating layer (140) may be configured to cover the UTG layer (130). For example, the coating layer (140) may cover the side walls of the UTG layer (130) and the upper surface of the UTG layer (130). In addition, the coating layer (140) may cover the edge region (121b) of the first stress relieving adhesive layer (121).

[0096] In some embodiments, the coating layer (140) may include a vertical portion (141) and a horizontal portion (143). The vertical portion (141) and the horizontal portion (143) may be connected to each other while intersecting each other, but the present disclosure is not limited thereto. The vertical portion (141) may refer to a portion covering the side wall of the UTG layer (130) of the edge region (121b) of the first stress relieving adhesive layer (121). The horizontal portion (143) may refer to a portion connected to the vertical portion (141) and covering the upper surface of the UTG layer (130).

[0097] In some embodiments, the vertical portion (141) and the horizontal portion (143) are connected to cover the UTG layer (130), so that when the display protector (100) is folded, the stress applied to the horizontal portion (143) can be distributed to the vertical portion (141). Accordingly, the restoring force of the coating layer (140) is improved, so that wrinkles may not occur at a portion where the display protector (100) is folded, for example, at the center of the display protector (100). For example, the coating layer (140) may not be wrinkled even when repeatedly folded to have a radius of curvature of about 0.5 mm to 1.3 mm.

[0098] In some embodiments, the horizontal portion (143) may have a first thickness (T1) in the vertical direction (Z), and the vertical portion (141) may have a second thickness (T2) in the horizontal direction (X or Y). In this case, the second thickness (T2) may be greater than the first thickness (T1), but the present disclosure is not limited thereto. For example, the second thickness (T2) may be less than the first thickness (T1).

[0099] In some embodiments, the display protector (100) of the present disclosure includes a coating layer (140) including a urethane acrylate oligomer, thereby improving the recovery properties of the folded portion despite repeated folding of the display protector (100), thereby reducing the occurrence of wrinkles.

[0100] Referring to FIGS. 3 and 4, the elongation of the coating layer (140) and the first stress-relieving adhesive layer (121) may be different from each other. For example, the coating layer (140) may have a first elongation, and the first stress-relieving adhesive layer (121) may have a second elongation that is smaller than the first elongation. When the display protector (100) is folded (for example, a radius of curvature of 1.0 mm), the first elongation length (L1) of the coating layer (140) may be longer than the elongation length (L2) of the first stress-relieving adhesive layer (121). At this time, the first elongation length (L1) may refer to a length by which the coating layer (140) increases as the display protector (100) is folded, and the second elongation length (L2) may refer to a length by which the first stress-relieving adhesive layer (121) increases as the display protector (100) is folded. For example, when the first extension length (L1) in FIG. 4 is 10 um, the second extension length (L2) may be 5 um.

[0101] In some embodiments, the coating layer (140) may have a first recovery rate and the first stress relieving adhesive layer (121) may have a second recovery rate that is smaller than the first recovery rate. Since the elongation of the coating layer (140) is greater than the elongation of the first stress relieving adhesive layer (121), the recovery rate of the coating layer (140) may be greater than the recovery rate of the first stress relieving adhesive layer (121). For example, the first recovery rate of the coating layer (140) including the urethane acrylate oligomer may be 95% to 100%. The second recovery rate of the first stress relieving adhesive layer (121) may be 90% to 95%. In this case, the recovery rate may mean the extent to which the coating layer (140) and the first stress relieving adhesive layer (121) are restored after a reference folding (e.g., 1000 times).

[0102] For example, when the first stretching length (L1) is 10 um and the recovery rate of the coating layer (140) is 100%, the occurrence of wrinkles by the coating layer (140) may be 0 um. When the second stretching length (L2) is 5 um and the recovery rate of the first stress-relieving adhesive layer (121) is 90%, the occurrence of wrinkles by the first stress-relieving adhesive layer (121) may be 0.5 um. Since the coating layer (140) including the urethane acrylate oligomer and the coating layer (140) are provided on the first stress-relieving adhesive layer (121), the recovery characteristics of the folded portion of the coating layer (140) and the first stress-relieving adhesive layer (121) are improved, and as a result, the occurrence of wrinkles in the folded portion of the display protector (100) may be reduced.

[0103] FIG. 5 is a perspective view showing a display protector (100) attached to a foldable display device (1) according to one embodiment of the present invention.

[0104] Referring to FIG. 5, a foldable display device (1) may include a display panel (10) and a lower cover (90). The lower cover (90) may include a first portion (90_1) and a second portion (90_2) that support the display panel (10). The lower cover (90) may be folded around a folding axis (FAX) between the first portion (90_1) and the second portion (90_2). In one embodiment, a hinge portion (90H) may be included between the first portion (90_1) and the second portion (90_2). In addition, in one embodiment, the second portion (90_2) may include a light-transmitting material.

[0105] The above display protector (100) may be provided to cover at least a portion of the display panel (10).

[0106] When the foldable display device (1) is folded around the folding axis (FAX), the display protector (100) is also folded. At this time, the folded portion of the display protector (100) has a radius of curvature of approximately 0.5 mm to approximately 1.3 mm. Accordingly, the UTG layer (130) (see FIG. 1) of the display protector (100) may be reinforced glass that is not broken even at a radius of curvature of 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, and 1.3 mm.

[0107] In some embodiments, an anti-fingerprint coating (AF coating) may be further provided on the surface of the UTG layer (130) (see FIG. 1).

[0108] FIG. 6 is a perspective view showing a display protector (100) attached to a rollable display device (2) according to one embodiment of the present invention.

[0109] Referring to FIG. 6, the rollable display device (2) may include a display panel (10), a roller portion (20), a housing portion (30), a module portion (BP), and a gap adjustment portion (L).

[0110] The display panel (10) may be a flexible display panel that is flexible and can be easily bent, folded, or rolled. Specifically, the display panel (10) may be a rollable display panel that can be rolled or unfolded.

[0111] The display panel (10) can be rolled or unfolded by the roller unit (20). For example, when the display panel (10) is rolled around the roller unit (20), the display panel (10) can be exposed by the housing unit (30) by a first interval in a first direction (e.g., +x direction or -x direction). When the display panel (10) is unrolled around the roller unit (20), the display panel (10) can be exposed by the housing unit (30) by a second interval that is larger than the first interval in the first direction (e.g., x direction or -x direction). Accordingly, the size of the display panel (10) that is exposed by the housing unit (30) and recognized by the user can be changed.

[0112] The roller unit (20) can roll the display panel (10). Alternatively, the roller unit (20) can unroll the display panel (10). In some embodiments, the roller unit (20) can be connected to a driving unit. In this case, the driving unit can include a motor or the like and can rotate the roller unit (20). Alternatively, the roller unit (20) can manually roll or unroll the display panel (10).

[0113] In one embodiment, the roller unit (20) may include a first roller unit (20A) and a second roller unit (20B). The first roller unit (20A) and the second roller unit (20B) may be spaced apart from each other in a first direction (e.g., in the x direction or the -x direction). In some embodiments, one of the first roller unit (20A) and the second roller unit (20B) may be omitted.

[0114] The housing portion (30) can accommodate the roller portion (20). Accordingly, a portion of the display panel (10) can be accommodated in the housing portion (30). A portion of the display panel (10) can be brought into the housing portion (30) or taken out of the housing portion (30). The housing portion (30) can include a curved portion. Therefore, a user can easily hold the housing portion (30).

[0115] In one embodiment, the housing portion (30) may include a first housing portion (30A) and a second housing portion (30B). The first housing portion (30A) and the second housing portion (30B) may be spaced apart from each other in a first direction (e.g., in the x-direction or the -x-direction). In some embodiments, one of the first housing portion (30A) and the second housing portion (30B) may be omitted. The first housing portion (30A) may accommodate the first roller portion (20A). The second housing portion (30B) may accommodate the second roller portion (20B).

[0116] The display protector (100) may be provided to cover at least a portion of the display panel (10). In particular, the display protector (100) may be rolled up together with the display panel (10) when the display panel (10) is rolled up.

[0117] When the foldable display device (1) is folded around the folding axis (FAX), the display protector (100) is also folded. At this time, the folded portion of the display protector (100) has a radius of curvature of approximately 0.5 mm to approximately 1.3 mm. Accordingly, the UTG layer (130) (see FIG. 1) of the display protector (100) may be reinforced glass that is not broken even at a radius of curvature of 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, and 1.3 mm.

[0118] In some embodiments, an AF coating may be further provided on the surface of the display protector (100), specifically on the surface of the UTG layer (130) (see FIG. 1).

[0119] Hereinafter, the configuration and effects of the present invention will be described in more detail with specific examples and comparative examples, but these examples are only intended to make the present invention more clearly understood and are not intended to limit the scope of the present invention.

[0120] FIG. 7 is a schematic drawing showing a folding test of a display protector (100) according to one embodiment of the present invention.

[0121] Referring to Fig. 7, when the display protector (100) is folded using a folding device (F), damage to the display protector (100) can be confirmed according to the change in the thickness of the coating layer (140). Tables 1 and 2 below are tables showing the condition after folding the display protector (100) to a curvature radius of 1.0 mm for 12 hours using a folding device (F) and then folding it.

[0122] In some embodiments, referring to Table 1 below, the second thickness (T2, referring to FIG. 1) of the vertical portion (141, referring to FIG. 1) of the coating layer (140) may be maintained constant, and the first thickness (T1) of the horizontal portion (143, referring to FIG. 1) may be varied. At this time, the second thickness (T2) of the vertical portion (141) may be 150 um. Referring to Table 2 below, the first thickness (T1) of the horizontal portion (143) of the coating layer (140) may be maintained constant, and the second thickness (T2) of the vertical portion (141) may be varied. At this time, the first thickness (T1) of the horizontal portion (143) may be 50 um.

[0123] Thickness (um) comparison example 10253550751 st 0 / 200 / 200 / 200 / 201 / 204 / 202 nd 0 / 200 / 200 / 200 / 200 / 204 / 203 rd0 / 200 / 200 / 200 / 200 / 203 / 20

[0124] (Number of damages / Number of experiments)

[0125] Thickness (um) Comparison Example 50 100 150 200 250 300 500 750 1st0 / 200 / 200 / 200 / 201 / 201 / 200 / 200 / 200 / 202nd0 / 200 / 200 / 200 / 201 / 200 / 200 / 200 / 200 / 203rd0 / 200 / 200 / 201 / 200 / 200 / 201 / 201 / 201 / 201 / 201 / 201 / 201 / 201

[0126] (Number of damages / Number of experiments)

[0127] The comparative example may refer to a display protector in which the coating layer (140) is omitted. Referring to Table 1 above, it can be confirmed that when the first thickness (T1) of the horizontal portion (143) is 75 um or more, the possibility of damage to the display protector (100) increases as the thickness of the coating layer (140) increases. In addition, referring to Table 2 above, it can be confirmed that the second thickness (T2) of the vertical portion (141) does not affect the folding test of the display protector (100).

[0128] FIG. 8 is a schematic drawing showing a test of the strength of a display protector (100) according to one embodiment of the present invention.

[0129] Referring to Fig. 8, after attaching the display protector (100) on a flat stone plate (S), the strength of the display protector (100) can be confirmed by applying pressure to the center of the display protector (100). At this time, the center may be a position that overlaps the center region (121a) of the first stress-relieving adhesive layer (121) in the vertical direction (Z). Tables 3 and 4 below represent the heights at which pens weighing 4.5 g and 12 g are dropped, respectively, on the center of the display protector (100), and are tables showing the heights at which the display protector (100) begins to break.

[0130] In some embodiments, referring to Tables 3 and 4 below, the second thickness (T2, see FIG. 1) of the vertical portion (141, see FIG. 1) of the coating layer (140) may be kept constant, while the first thickness (T1) of the horizontal portion (143, see FIG. 1) may be changed. In this case, the second thickness (T2) of the vertical portion (141) may be 150 um.

[0131] Thickness (um) Comparison Example 10253550751st1501502102602602702nd1401402102302502603rd120160200240260250

[0132] (Unit: mm)

[0133] Thickness (um) comparison example 10253550751st1015253550652nd1010303560653rd101030406065

[0134] (Unit: mm)

[0135] The comparative example may refer to a display protector in which the coating layer (140) is omitted. Referring to Tables 3 and 4 above, it can be confirmed that as the first thickness (T1) of the horizontal portion (143) increases, the height from which the display protector (100) begins to break increases. That is, it can be confirmed that the display protector (100) including the coating layer (140) of the present disclosure has improved impact resistance compared to the comparative example in which the coating layer is omitted. In addition, it can be confirmed that as the first thickness (T1) of the horizontal portion (143) increases, the impact resistance of the display protector (100) improves. In particular, when the first thickness (T1) of the horizontal portion (143) is 25 mm or more, it can be confirmed that the strength of the display protector (100) is significantly increased compared to the comparative example in which the coating layer is omitted.

[0136] FIG. 9 is a schematic diagram showing a test of the side strength of a display protector (100) according to one embodiment of the present invention.

[0137] Referring to Fig. 9, after attaching the display protector (100) on a flat stone plate (S), pressure is applied to the edge of the display protector (100) to check the lateral strength of the display protector (100). At this time, the edge may be at a position where it overlaps with the edge region (121b) of the first stress-relieving adhesive layer (121) in the vertical direction (Z). Tables 5 and 6 below show the force applied to the edge of the display protector (100), and are tables showing the force when the display protector (100) begins to break.

[0138] In some embodiments, referring to Table 5 below, the second thickness (T2, referring to FIG. 1) of the vertical portion (141, referring to FIG. 1) of the coating layer (140) may be maintained constant, and the first thickness (T1) of the horizontal portion (143, referring to FIG. 1) may be varied. At this time, the second thickness (T2) of the vertical portion (141) may be 150 um. Referring to Table 6 below, the first thickness (T1) of the horizontal portion (143) of the coating layer (140) may be maintained constant, and the second thickness (T2) of the vertical portion (141) may be varied. At this time, the first thickness (T1) of the horizontal portion (143) may be 50 um.

[0139] Thickness (um) Comparison Example 10 2 5 3 5 5 0 7 5 Lateral Strength 1.38 1.44 2.16 4.26 4.93 No Breakage

[0140] (Unit: kgf)

[0141] Thickness (um) Comparison Example 50 100 150 200 250 300 500 750 Lateral Strength 1.56 2.51 3.98 4.98 4.84 4.91 4.79 4.88 4.91

[0142] (Unit: kgf)

[0143] The comparative example may refer to a display protector in which the coating layer (140) is omitted. Referring to Table 5 above, it can be confirmed that as the first thickness (T1) of the horizontal portion (143) increases, the force at which the edge of the display protector (100) begins to break increases. Referring to Table 6 above, it can be confirmed that as the second thickness (T2) of the vertical portion (141) increases, the force at which the edge of the display protector (100) begins to break increases. That is, it can be confirmed that the display protector (100) including the coating layer (140) of the present disclosure has improved impact resistance at the edge compared to the comparative example in which the coating layer is omitted. In addition, it can be confirmed that as the first thickness (T1) of the horizontal portion (143) and the second thickness (T2) of the vertical portion (141) increase, the impact resistance at the edge of the display protector (100) improves. In particular, when the first thickness (T1) of the horizontal portion (143) is 25 mm or more, it can be confirmed that the lateral strength of the display protector (100) is significantly increased compared to the comparative example in which the coating layer is omitted. In addition, when the second thickness (T2) of the vertical portion (141) is 50 mm or more, it can be confirmed that the lateral strength of the display protector (100) is significantly increased compared to the comparative example in which the coating layer is omitted.

[0144] In some embodiments, Table 7 below is a table showing the wrinkle improvement effect of the display protector (100) of the present disclosure. For example, the table shows the wrinkle height over time when the display protector (100) is folded with a radius of curvature of 1.5 mm for 30 minutes and then moved onto a flat plate. After folding the display protector (100), it is moved onto the flat plate in the opposite direction to the folding direction, and the wrinkle height over time can be measured. At this time, the wrinkle height is the center of the display protector (100), for example, the part where the display protector (100) is folded.

[0145] Classification 0 min 5 min 10 min 20 min 30 min Comparison Example (mm) 158655 Main Disclosure (mm) 134310.5

[0146] Referring to Table 7 above, it can be confirmed that the display protector (100) of the present disclosure has a lower wrinkle height compared to the comparative example. Furthermore, it can be confirmed that the wrinkle height decreases over time. By including a coating layer (140) containing a urethane acrylate oligomer, the restoration properties of the folded portion are improved, and it can be confirmed that the restoration properties of the folded portion are higher compared to the comparative example in which the coating layer is omitted.

[0147] In some embodiments, referring to Table 8 below, the first thickness (T1) of the horizontal portion (143) of the coating layer (140) may be maintained constant, and the second thickness (T2) of the vertical portion (141) may be changed. In this case, the first thickness (T1) of the horizontal portion (143) may be 50 um.

[0148] Thickness (um) 50 100 150 200 250 300 500 Moire phenomenon occurrence XXXXXXO

[0149] Referring to Table 8 above, it can be confirmed that a moire phenomenon occurs when the second thickness (T2) of the vertical portion (141) of the coating layer (140) exceeds 300 μm. When the second thickness (T2) of the vertical portion (141) becomes thicker, a moire phenomenon may occur at the edge of the display protector (100) and the display device to which the display protector (100) is attached. In this case, the moire phenomenon may be a problem caused by interference between the display device and the pattern of the display protector (100).

[0150] As a result, referring to Tables 1 to 8 above, the display protector (100) of the present disclosure can improve the impact resistance of the display protector (100) by including a coating layer (140) covering the side walls of the UTG layer (130) and the upper surface of the UTG layer (130). In particular, the impact resistance of the edge as well as the center of the display protector (100) can be improved.

[0151] In some embodiments, the vertical portion (141) and the horizontal portion (143) are connected to cover the UTG layer (130), so that when the display protector (100) is folded, the stress applied to the horizontal portion (143) can be distributed to the vertical portion (141). Accordingly, the restoring force of the coating layer (140) is improved, so that wrinkles may not occur at the folded portion of the display protector (100), for example, at the center of the display protector (100).

[0152] In some embodiments, the second thickness (T2) of the vertical portion (141) of the coating layer (140) and the first thickness (T1) of the horizontal portion (143) can be adjusted with reference to the results of Tables 1 to 8. For example, the second thickness (T2) of the vertical portion (141) of the coating layer (140) can be adjusted from 50 um to 300 um, and the first thickness (T1) of the horizontal portion (143) can be adjusted from 10 um to 75 um, but the present disclosure is not limited thereto. For example, the first thickness (T1) of the horizontal portion (143) can be adjusted from 25 um to 75 um.

[0153] In addition, by including a coating layer (140) containing a urethane acrylate oligomer, the restoration characteristics of the folded portion are improved, and as a result, the occurrence of wrinkles in the folded portion of the display protector (100) can be reduced.

[0154] FIGS. 10 to 15 are schematic diagrams conceptually illustrating a laminated structure of a display protector according to one embodiment of the present invention. In the following description with reference to FIGS. 10 to 15, descriptions of common elements with the display protector (100) described with reference to FIGS. 1 to 9 will be omitted, and descriptions will be focused on differences.

[0155] Referring to FIG. 10, the UTG layer (130) of the display protector (100a) according to one embodiment of the present invention may include a groove (130a). The groove (130a) may have a concave shape that is sunken from the upper surface of the UTG layer (130) into the first stress-relieving adhesive layer (121). In this case, the groove (130a) may have a rectangular cross-section.

[0156] In some embodiments, the groove (130a) may be formed at the center of the horizontal direction (X) of the UTG layer (130). The groove (130a) may be formed at a position overlapping the center region (121a) of the first stress relieving adhesive layer (121) in the vertical direction (Z). For example, the groove (130a) may be formed at a position corresponding to a folded portion when the display protector (100a) is folded.

[0157] In some embodiments, the coating layer (140) may be formed to fill the groove (130a). The coating layer (140) may cover the upper surface of the UTG layer (130) and the upper surface of the groove (130a). The coating layer (140) may further include a protrusion (140a) formed to fill the groove (130a). The protrusion (140a) protrudes from the lower surface of the horizontal portion (143) toward the UTG layer (130) and may have a shape corresponding to the groove (130a). Since the coating layer (140) with high resilience is formed to fill the groove (130a), the display protector (100a) has excellent resilience even after repeated folding, thereby alleviating the occurrence of wrinkles, and improving the impact resistance of the display protector (100a).

[0158] Referring to Fig. 11, the UTG layer (130) of the display protector (100b) according to one embodiment of the present invention may include a groove (130b). The groove (130a) may have a concave shape that is sunken from the upper surface of the UTG layer (130) into the first stress-relieving adhesive layer (121). In this case, the groove (130b) may have a triangular cross-section.

[0159] In some embodiments, the groove (130b) may be formed at the horizontal direction (X) center of the UTG layer (130). The groove (130b) may be formed deeper as it gets closer to the horizontal direction (X) center of the UTG layer (130). The groove (130b) may be formed at a position that overlaps the central region (121a) of the first stress relieving adhesive layer (121) in the vertical direction (Z). For example, the groove (130b) may be formed at a position corresponding to a folded portion when the display protector (100b) is folded.

[0160] In some embodiments, the coating layer (140) may be formed to fill the groove (130b). The coating layer (140) may cover the upper surface of the UTG layer (130) and the upper surface of the groove (130b). The coating layer (140) may further include a protrusion (140b) formed to fill the groove (130b). The protrusion (140b) protrudes from the lower surface of the horizontal portion (143) toward the UTG layer (130) and may have a shape corresponding to the groove (130b). Since the highly resilient coating layer (140) is formed to fill the groove (130b), the display protector (100b) has excellent resilience even after repeated folding, thereby alleviating the occurrence of wrinkles, and improving the impact resistance of the display protector (100b).

[0161] Referring to FIG. 12, the UTG layer (130) of the display protector (100c) according to one embodiment of the present invention may include a groove (130c). The groove (130c) may have a concave shape that is sunken from the upper surface of the UTG layer (130) into the first stress-relieving adhesive layer (121). In this case, the groove (130c) may have a trapezoidal cross-section.

[0162] In some embodiments, the groove (130c) may be formed at the center of the horizontal direction (X) of the UTG layer (130). The groove (130c) may be formed at a position overlapping the center region (121a) of the first stress-relieving adhesive layer (121) in the vertical direction (Z). For example, the groove (130a) may be formed at a position corresponding to a folded portion when the display protector (100c) is folded.

[0163] In some embodiments, the coating layer (140) may be formed to fill the groove (130c). The coating layer (140) may cover the upper surface of the UTG layer (130) and the upper surface of the groove (130c). The coating layer (140) may further include a protrusion (140c) formed to fill the groove (130c). The protrusion (140c) protrudes from the lower surface of the horizontal portion (143) toward the UTG layer (130) and may have a shape corresponding to the groove (130c). Since the highly resilient coating layer (140) is formed to fill the groove (130c), the display protector (100c) has excellent resilience even after repeated folding, thereby alleviating the occurrence of wrinkles, and improving the impact resistance of the display protector (100c).

[0164] Referring to FIG. 13, the UTG layer (130) of the display protector (100d) according to one embodiment of the present invention may include a groove (130d). The groove (130d) may have a concave shape that is sunken from the upper surface of the UTG layer (130) into the first stress-relieving adhesive layer (121). In this case, the groove (130d) may have a semicircular cross-section.

[0165] In some embodiments, the groove (130d) may be formed at the horizontal direction (X) center of the UTG layer (130). The groove (130d) may be formed deeper as it gets closer to the horizontal direction (X) center of the UTG layer (130). The groove (130d) may be formed at a position that overlaps the central region (121a) of the first stress relieving adhesive layer (121) in the vertical direction (Z). For example, the groove (130d) may be formed at a position corresponding to a folded portion when the display protector (100) is folded.

[0166] In some embodiments, the coating layer (140) may be formed to fill the groove (130d). The coating layer (140) may cover the upper surface of the UTG layer (130) and the upper surface of the groove (130d). The coating layer (140) may further include a protrusion (140d) formed to fill the groove (130d). The protrusion (140d) protrudes from the lower surface of the horizontal portion (143) toward the UTG layer (130) and may have a shape corresponding to the groove (130d). Since the coating layer (140) with high resilience is formed to fill the groove (130d), the occurrence of wrinkles in the display protector (100d) can be alleviated due to excellent resilience even after repeated folding, and the impact resistance of the display protector (100d) can be improved.

[0167] Referring to FIG. 14, the UTG layer (130) of the display protector (100e) according to one embodiment of the present invention may include an upper groove portion (130ue) and a lower groove portion (130le). The upper groove portion (130ue) may have a concave shape recessed from the upper surface of the UTG layer (130) into the first stress-relieving adhesive layer (121). The lower groove portion (130le) may have a concave shape recessed from the lower surface of the UTG layer (130) toward the horizontal portion (143) of the coating layer (140). At this time, the upper groove portion (130ue) and the lower groove portion (130le) may have a rectangular cross-section, but the present disclosure is not limited thereto.

[0168] In some embodiments, the upper groove portion (130ue) and the lower groove portion (130le) may be formed at the center of the horizontal direction (X) of the UTG layer (130). The upper groove portion (130ue) and the lower groove portion (130le) may be formed at a position overlapping the center region (121a) of the first stress relieving adhesive layer (121) in the vertical direction (Z). For example, the upper groove portion (130ue) and the lower groove portion (130le) may be formed at a position corresponding to a folded portion when the display protector (100e) is folded.

[0169] In some embodiments, the coating layer (140) may be formed to fill the upper groove portion (130ue) and the lower groove portion (130le). The coating layer (140) may cover the upper surface of the UTG layer (130) and the upper surfaces of the upper groove portion (130ue) and the lower groove portion (130le). The coating layer (140) may further include an upper protrusion portion (140ue) and a lower protrusion portion (140le) formed to fill the upper groove portion (130ue) and the lower groove portion (130le), respectively. The upper protrusion portion (140ue) and the lower protrusion portion (140le) may have a shape corresponding to the upper groove portion (130ue) and the lower groove portion (130le), respectively. Since a highly resilient coating layer (140) is formed to fill the upper groove (130ue) and the lower groove (130le), the display protector (100e) can be prevented from forming wrinkles due to its excellent resilience even after repeated folding, and the impact resistance of the display protector (100e) can be improved.

[0170] Referring to FIG. 15, a display protector (200) according to one embodiment of the present invention may have a coating layer (240) interposed between a first stress relieving adhesive layer (121) and a UTG layer (230). The coating layer (240) may cover an upper surface of the first stress relieving adhesive layer (121). For example, a horizontal portion (243) of the coating layer (240) may be configured to cover a central region (121a) of the first stress relieving adhesive layer (121). A vertical portion (241) of the coating layer (240) may cover an edge region (121b) of the first stress relieving adhesive layer (121) and a side wall of the UTG layer (230).

[0171] In some embodiments, the vertical portion (241) and the horizontal portion (243) are connected to cover the UTG layer (130), so that when the display protector (200) is folded, the stress applied to the horizontal portion (243) can be distributed to the vertical portion (241). Accordingly, the restoring force of the coating layer (240) is improved, so that wrinkles may not occur at the folded portion of the display protector (200), for example, at the center of the display protector (200).

[0172] In some embodiments, the horizontal portion (243) may have a first thickness (T1) in the vertical direction (Z), and the vertical portion (241) may have a second thickness (T2) in the horizontal direction (X or Y). In this case, the second thickness (T2) may be greater than the first thickness (T1), but the present disclosure is not limited thereto. For example, the second thickness (T2) may be less than the first thickness (T1).

[0173] In some embodiments, the display protectors (100a, 100b, 100c, 100d, 100e, and 200) of the present disclosure can improve the impact resistance of the display protectors (100a, 100b, 100c, 100d, 100e, and 200) by including a coating layer (140 and 240). In particular, the impact resistance of the edges as well as the center of the display protectors (100a, 100b, 100c, 100d, 100e, and 200) can be improved.

[0174] In addition, by including a coating layer (140 and 240) containing a urethane acrylate oligomer, the restoration properties of the folded portion are improved, and as a result, the occurrence of wrinkles in the folded portion of the display protector (100a, 100b, 100c, 100d, 100e, and 200) can be reduced.

[0175] As described above, exemplary embodiments have been disclosed in the drawings and specifications. While specific terminology has been used to describe embodiments herein, it is intended solely to illustrate the technical concept of the present disclosure and is not intended to limit the scope of the present disclosure as defined in the claims. Therefore, those skilled in the art will appreciate that various modifications and equivalent embodiments are possible. Therefore, the true technical protection scope of the present disclosure should be determined by the technical concept of the appended claims.

Claims

1. A transparent substrate layer including opposing first and second surfaces; A first stress-relieving adhesive layer disposed on the first surface of the transparent substrate layer and including a central region and an edge region surrounding the central region; A second stress-relieving adhesive layer disposed on the second surface of the transparent substrate layer; an ultra-thin glass layer covering the central region of the first stress-relieving adhesive layer; and It includes a coating layer covering the edge region of the first stress-relieving adhesive layer, the side wall of the ultra-thin glass layer, and the upper surface of the ultra-thin glass layer, The above coating layer has a first elongation, A display protector, characterized in that the first stress relieving adhesive layer has a second elongation that is smaller than the first elongation.

2. In paragraph 1, The above coating layer is, A horizontal portion covering the upper surface of the above ultra-thin glass layer; and A display protector characterized by comprising a vertical portion covering the edge region of the first stress relieving adhesive layer and the side wall of the ultra-thin glass layer, and configured to distribute stress applied to the horizontal portion when the display protector is folded by being connected to the horizontal portion.

3. In paragraph 2, The above coating layer is, A display protector characterized in that it does not wrinkle even when repeatedly folded to have a curvature radius of 0.5 mm to 1.3 mm.

4. In paragraph 3, The above horizontal portion has a first thickness in the vertical direction, The above vertical portion has a second thickness in the horizontal direction, A display protector characterized in that the first thickness is smaller than the second thickness.

5. In paragraph 4, The above first thickness is, A display protector characterized by a thickness ranging from 10 um to 75 um.

6. In paragraph 4, The above second thickness is, A display protector characterized by a thickness ranging from 50 um to 300 um.

7. In paragraph 1, The above coating layer is, A display protector characterized by comprising a urethane acrylate oligomer of the following chemical formula 1. [Chemical Formula 1] 8. In paragraph 1, The above ultra-thin glass layer is, A display protector further characterized by including a groove portion that is concavely sunken in the direction of the first stress relief adhesive layer from the upper surface.

9. In paragraph 8, The above home part, A display protector characterized in that it is formed at a position that vertically overlaps the central region of the first stress relieving adhesive layer.

10. In paragraph 9, The above home part, A display protector characterized by having a shape that becomes deeper as it approaches the horizontal center of the ultra-thin glass layer.

11. In paragraph 8, The above coating layer is, A display protector characterized in that it further includes a protrusion protruding toward the ultra-thin glass layer to fill the groove.

12. A transparent substrate layer including opposing first and second surfaces; A first stress-relieving adhesive layer disposed on the first surface of the transparent substrate layer and including a central region and an edge region surrounding the central region; A second stress-relieving adhesive layer disposed on the second surface of the transparent substrate layer; an ultra-thin glass layer disposed on the central region of the first stress-relieving adhesive layer; and A coating layer comprising a horizontal portion covering the central region of the first stress relieving adhesive layer and a vertical portion connected to the horizontal portion and covering the edge region of the first stress relieving adhesive layer and the side wall of the ultra-thin glass layer, The above coating layer has a first elongation, A display protector, characterized in that the first stress relieving adhesive layer has a second elongation that is smaller than the first elongation.

13. In paragraph 12, The above vertical part, A display protector characterized in that it is configured to disperse stress applied to the horizontal portion when the coating layer is folded so that wrinkles do not occur in the coating layer.

14. In paragraph 12, The above coating layer is, A display protector characterized by comprising a urethane acrylate oligomer of the following chemical formula 1. [Chemical Formula 1]

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