Resin composition, and display device including adhesive member formed from resin composition

Abstract

To provide a resin composition excellent in discharge stability and adhesive strength, an adhesive member formed from the resin composition and excellent in adhesive strength, and a display device having excellent reliability under various operating conditions.SOLUTION: A display device includes a display panel, a window arranged on the display panel, and an adhesive member arranged between the display panel and the window, wherein the adhesive member is derived from a resin composition, the resin composition includes a (meth)acrylate oligomer (A) containing a siloxane skeleton, a photo initiator (B), a (meth)acrylate monomer (C) that has a surface tension of about 20 mN / m to about 30 mN / m and is represented by a specific chemical formula, and a urethane (meth)acrylate oligomer (D), and a shear viscosity of the resin composition at 25°C is about 8 mPa s to 50 mPa s.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a resin composition and a display device including an adhesive member made of the resin composition. [Background technology]

[0002] Display devices are used in various multimedia devices such as televisions, mobile phones, tablet PCs, game consoles, etc. to provide users with video information. Recently, various types of flexible display devices that can be folded, bent, or rolled up have been developed. Flexible display devices must ensure reliability during folding, bending, or roll-up operations.

[0003] The display device is composed of a plurality of components, and includes an adhesive layer for adhering the components. The adhesive layer applied to display devices of various shapes can be formed by applying an adhesive resin composition by an inkjet method. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 7366552 (JP7366552B; KR2021-0116446A) Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a resin composition that is excellent in discharge stability and adhesive strength.

[0006] An object of the present invention is to provide a display device that includes an adhesive member made of a resin composition and having excellent adhesive strength, and that has excellent reliability under various operating conditions. [Means for solving the problem]

[0007] A display device according to one embodiment of the present invention includes a display panel, a window disposed on the display panel, and an adhesive member disposed between the display panel and the window, the adhesive member being derived from a resin composition, the resin composition including a (meth)acrylate oligomer (A) having a siloxane skeleton, a photoinitiator (B), a (meth)acrylate monomer (C) having a surface tension of 20 mN / m or more and 30 mN / m or less and including a first monomer represented by the following chemical formula 1, and a urethane (meth)acrylate oligomer (D), and the shear viscosity of the resin composition at 25°C is 8 mPa·s or more and 50 mPa·s or less.

[0008] <Chemical formula 1> JPEG2025121409000002.jpg4558

[0009] In the above Chemical Formula 1, R1 is a hydrogen atom or a substituted or unsubstituted methyl group, and R2 is a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms.

[0010] The (meth)acrylate oligomer (A) may be synthesized using a first polymerizable monomer represented by the following Chemical Formula 2-1 or Chemical Formula 2-2.

[0011] <Chemical formula 2-1> JPEG2025121409000003.jpg7290

[0012] <Chemical formula 2-2> JPEG2025121409000004.jpg40126

[0013] In Chemical Formula 2-1 and Chemical Formula 2-2, R3 and R5 are each independently a hydrogen atom or a substituted or unsubstituted methyl group, R4 and R6 are each independently a substituted or unsubstituted alkylene group having from 1 to 20 carbon atoms, R7 is a substituted or unsubstituted alkyl group having from 1 to 20 carbon atoms, and n is an integer of from 0 to 20.

[0014] In the above Chemical Formula 2-1, R3 can be an unsubstituted methyl group, R4 can be an unsubstituted n-propylene group, and in the above Chemical Formula 2-2, R5 can be an unsubstituted methyl group, R6 can be an unsubstituted n-propylene group, and R7 can be an unsubstituted n-butyl group.

[0015] The (meth)acrylate oligomer (A) is synthesized using the first polymerizable monomer and a second polymerizable monomer different from the first polymerizable monomer, and the second polymerizable monomer may include any one of methyl methacrylate, isobornyl methacrylate, and 2-hydroxyethyl methacrylate.

[0016] The first monomer may include 2-ethylhexyl acrylate or isodecyl acrylate.

[0017] The (meth)acrylate monomer (C) may further include a second monomer different from the first monomer, and the second monomer may include at least one of 4-hydroxybutyl acrylate, tetrahydrofurfuryl acrylate, and 2-ethylhexyl diglycol acrylate.

[0018] The resin composition may be solvent-free.

[0019] The (meth)acrylate oligomer (A) may have a weight average molecular weight of 4,000 or more and 20,000 or less.

[0020] The (meth)acrylate monomer (C) may have a weight average molecular weight of 400 or more and 1,500 or less.

[0021] The weight average molecular weight of the urethane (meth)acrylate oligomer (D) may be 8,000 or more and 50,000 or less.

[0022] With respect to the total weight of the resin composition, the weight percentage of the (meth)acrylate oligomer (A) may be 1% by weight or more and 7% by weight or less, the weight percentage of the photoinitiator (B) may be 1% by weight or more and 5% by weight or less, the weight percentage of the (meth)acrylate monomer (C) may be 50% by weight or more and 90% by weight or less, and the weight percentage of the urethane (meth)acrylate oligomer (D) may be 1% by weight or more and 15% by weight or less.

[0023] The photoinitiator (B) may include a radical polymerization initiator.

[0024] The adhesive member may have a storage modulus at -20°C of 0.2 MPa or less.

[0025] The adhesive member may have a 180° peel strength of 800 gf / 25 mm or more against a glass substrate or a polyethylene terephthalate (PET) film at a temperature of 25°C.

[0026] The adhesive member may be formed by applying the resin composition directly onto one surface of the window or one surface of the display panel and then curing it with ultraviolet light.

[0027] The display device may further include an input sensing unit disposed on the display panel, and the adhesive member may be disposed between the display panel and the input sensing unit or between the input sensing unit and the window.

[0028] The display panel may include a display element layer and an encapsulation layer disposed on the display element layer, the input sensing unit may be disposed directly on the encapsulation layer, and the adhesive member may be disposed on the input sensing unit.

[0029] The optical adhesive layer may further include a light control layer disposed between the adhesive member and the window, and an optical adhesive layer disposed between the light control layer and the window, and the optical adhesive layer may include a polymer derived from the resin composition.

[0030] The display device may include at least one bending axis, and may be at least partially bendable around the bending axis.

[0031] A resin composition according to one embodiment of the present invention includes a (meth)acrylate oligomer (A) having a siloxane skeleton, a photoinitiator (B), a (meth)acrylate monomer (C) having a surface tension of 20 mN / m or more and 30 mN / m or less and including a first monomer represented by the following chemical formula 1, and a urethane (meth)acrylate oligomer (D), and has a shear viscosity at 25°C of 8 mPa·s or more and 50 mPa·s or less. [Effects of the Invention]

[0032] As described above, the resin composition of the present invention can have excellent discharge stability, coating uniformity, and adhesive strength.

[0033] Furthermore, the display device of the present invention includes an adhesive member having excellent adhesive strength, and therefore can have excellent reliability in various operating states. [Brief explanation of the drawings]

[0034] [Figure 1] 1 is an assembled perspective view showing an unfolded state of a display device according to an embodiment of the present invention; [Figure 2a] 1 is an assembled perspective view showing an inwardly folded state of a display device according to an embodiment of the present invention; [Figure 2b] 1 is an assembled perspective view showing an outer folded state of a display device according to an embodiment of the present invention; [Figure 3] 1 is an exploded perspective view of a display device according to an embodiment of the present invention; [Figure 4] 1 is a cross-sectional view of a display device according to an embodiment of the present invention. [Figure 5a] 3A to 3C are cross-sectional views schematically illustrating a step of a method for manufacturing an adhesive member according to an embodiment of the present invention. [Figure 5b] 3A to 3C are cross-sectional views schematically illustrating a step of a method for manufacturing an adhesive member according to an embodiment of the present invention. [Figure 5c]3A to 3C are cross-sectional views schematically illustrating a step of a method for manufacturing an adhesive member according to an embodiment of the present invention. [Figure 6a] 3A to 3C are cross-sectional views schematically illustrating a step of a method for manufacturing an adhesive member according to an embodiment of the present invention. [Figure 6b] 3A to 3C are cross-sectional views schematically illustrating a step of a method for manufacturing an adhesive member according to an embodiment of the present invention. [Figure 7] 1 is a cross-sectional view showing a display device according to an embodiment of the present invention. [Figure 8] 1 is a cross-sectional view showing a display device according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0035] While the present invention can be modified in various ways and can take various forms, specific embodiments are shown by way of example in the drawings and described in detail herein, but it should be understood that this is not to limit the invention to the particular forms disclosed, but rather to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

[0036] As used herein, when a component (or region, layer, portion, etc.) is referred to as being "on," "connected," or "bonded" to another component, it means that it may be directly positioned, connected, or bonded to the other component, or that a third component may be disposed therebetween.

[0037] On the other hand, in the present application, "directly disposed" may mean that there is no additional layer, film, region, plate, etc. between one layer, film, region, plate, etc. and another portion. For example, "directly disposed" may mean that two layers or two members are disposed without using an additional member such as an adhesive member between them.

[0038] The same reference numerals refer to the same components, and in the drawings, thicknesses, proportions, and dimensions of the components are exaggerated for the purpose of effectively explaining the technical contents.

[0039] "And / or" includes all possible combinations of one or more of the associated elements.

[0040] Terms such as "first" and "second" are used to describe various components, but the components are not limited to these terms. These terms are used only to distinguish one component from another. For example, a first component may be referred to as a "second component," and similarly, a second component may be referred to as a "first component" without departing from the scope of the present invention. A singular expression includes a plural expression unless the context clearly dictates otherwise.

[0041] Furthermore, terms such as "under," "below," "on," and "above" are used to describe the relationship between components shown in the drawings. These terms are relative concepts and are described based on the directions shown in the drawings. In this specification, "disposed on" may refer to being disposed not only above but also below a component.

[0042] It should be understood that the terms "comprise" or "have" and the like specify the presence of any feature, number, step, operation, component, part, or combination thereof set forth above in the specification, but do not preclude the presence or possible addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0043] As used herein, the term "substituted or unsubstituted" means unsubstituted or substituted with one or more substituents selected from the group consisting of a deuterium atom, a halogen atom, a cyano group, a nitro group, an amine group, a silyl group, an oxy group, a thio group, a sulfinyl group, a sulfonyl group, a carbonyl group, a boron group, a phosphine oxide group, a phosphine sulfide group, an alkyl group, an alkenyl group, an alkynyl group, a hydrocarbon ring group, an aryl group, and a heterocyclic group. Each of the substituents listed above may be substituted or unsubstituted. For example, a biphenyl group may be interpreted as an aryl group, or as a phenyl group substituted with a phenyl group.

[0044] In this specification, an alkyl group is straight-chain, branched-chain, or cyclic. The number of carbon atoms in the alkyl group is 1 to 60, 1 to 30, 1 to 20, 1 to 10, or 1 to 6. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an s-butyl group, a t-butyl group, an i-butyl group, a 2-ethylbutyl group, a 3,3-dimethylbutyl group, an n-pentyl group, an i-pentyl group, a neopentyl group, a t-pentyl group, a cyclopentyl group, a 1-methylpentyl group, a 3-methylpentyl group, a 2-ethylpentyl group, a 4-methyl-2-pentyl group, an n-hexyl group, a 1-methylhexyl group, a 2-ethylbutyl group, a 4-methyl-2-pentyl group, a 4-methyl-2-pentyl group, a 4-methylhex ... hexyl, 2-butylhexyl, cyclohexyl, 4-methylcyclohexyl, 4-t-butylcyclohexyl, n-heptyl, 1-methylheptyl, 2,2-dimethylheptyl, 2-ethylheptyl, 2-butylheptyl, n-octyl, t-octyl, 2-ethyloctyl, 2-butyloctyl, 2-hexyloctyl, 3,7-dimethyloctyl, cyclooctyl, n-nonyl, n-decyl, ada Mantyl, 2-ethyldecyl, 2-butyldecyl, 2-hexyldecyl, 2-octyldecyl, n-undecyl, n-dodecyl, 2-ethyldodecyl, 2-butyldodecyl, 2-hexyldodecyl, 2-octyldecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, 2-ethylhexadecyl, 2-butylhexadecyl, 2-hexylhexadecyl, 2-octylhexadecyl Examples of the alkyl groups include, but are not limited to, n-heptadecyl, n-octadecyl, n-nonadecyl, n-icosyl, 2-ethylicosyl, 2-butylicosyl, 2-hexylicosyl, 2-octylicosyl, n-henicosyl, n-docosyl, n-tricosyl, n-tetracosyl, n-pentacosyl, n-hexacosyl, n-heptacosyl, n-octacosyl, n-nonacosyl, and n-triacontyl groups.

[0045] In this specification, a cycloalkyl group may refer to a cyclic alkyl group. The number of carbon atoms in the cycloalkyl group is 3 to 50, 3 to 30, 3 to 20, or 3 to 10. Examples of cycloalkyl groups include, but are not limited to, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a 4-methylcyclohexyl group, a 4-t-butylcyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclononyl group, a cyclodecyl group, a norbornyl group, a 1-adamantyl group, a 2-adamantyl group, an isonorbornyl group, and a bicycloheptyl group.

[0046] In this specification, the above description of the alkyl group is applicable, except that the alkylene group is a divalent group.

[0047] As used herein, the term "alkenyl group" refers to a hydrocarbon group containing one or more carbon-carbon double bonds at the middle or end of an alkyl group having two or more carbon atoms. The alkenyl group may be straight-chain or branched. The number of carbon atoms is not particularly limited, but may be from 2 to 30, from 2 to 20, or from 2 to 10. Examples of alkenyl groups include, but are not limited to, vinyl, 1-butenyl, 1-pentenyl, 1,3-butadienylaryl, styrenyl, and styrylvinyl.

[0048] As used herein, the term "aryl group" refers to any functional group or substituent derived from an aromatic hydrocarbon ring. The aryl group may be a monocyclic aryl group or a polycyclic aryl group. The number of ring carbon atoms in the aryl group is 6 to 30, 6 to 20, or 6 to 15. Examples of aryl groups include, but are not limited to, phenyl, naphthyl, fluorene, anthracene, phenanthrene, biphenyl, terphenyl, quaterphenyl (quaterphenyl), quinquephenyl, sexiphenyl, triphenylenyl, pyrenyl, benzofluoranthene, and chrysene.

[0049] In this specification, the fluorenyl group may be substituted, and two substituents may be bonded to each other to form a spiro structure. Examples of fluorenyl groups that may be substituted include, but are not limited to, the following:

[0050] JPEG2025121409000005.jpg1975

[0051] As used herein, a heterocyclic group refers to any functional group or substituent derived from a ring containing one or more heteroatoms selected from B, O, N, P, Si, and S. Heterocyclic groups include aliphatic heterocyclic groups and aromatic heterocyclic groups. Aromatic heterocyclic groups can be heteroaryl groups. Aliphatic heterocyclic groups and aromatic heterocyclic groups can be monocyclic or polycyclic.

[0052] In this specification, a heteroaryl group may contain one or more heteroatoms selected from B, O, N, P, Si, and S. When a heteroaryl group contains two or more heteroatoms, the two or more heteroatoms may be the same or different. A heteroaryl group may be a monocyclic heterocyclic group or a polycyclic heterocyclic group. The number of ring carbon atoms in a heteroaryl group may be 2 to 30, 2 to 20, or 2 to 10. Examples of heteroaryl groups include a thiophene group, a furan group, a pyrrole group, an imidazole group, a pyridine group, a bipyridine group, a pyrimidine group, a triazine group, a triazole group, an acridyl group, a pyridazine group, a pyridinyl group, a quinoline group, a quinazoline group, a quinoxaline group, a phenoxazine group, a phthalazine group, a pyridopyrimidine group, a pyridopyrazine group, a pyrazinopyrazine group, an isoquinoline group, an indole group, a carbazole group, an N-arylcarbazole group, an N-heteroaryl group, an N-arylphenyl group, an N-phenyl ... Examples of such an alkyl group include, but are not limited to, an arylcarbazole group, an N-alkylcarbazole group, a benzoxazole group, a benzimidazole group, a benzothiazole group, a benzocarbazole group, a benzothiophene group, a dibenzothiophene group, a thienothiophene group, a benzofuran group, a phenanthroline group, a thiazole group, an isoxazole group, an oxazole group, an oxadiazole group, a thiadiazole group, a phenothiazine group, a dibenzosilole group, and a dibenzofuran group.

[0053] In this specification, the above-mentioned explanation regarding the aryl group is applicable to an arylene group, except that the arylene group is a divalent group. The above-mentioned explanation regarding the heteroaryl group is applicable to a heteroarylene group, except that the heteroarylene group is a divalent group.

[0054] As used herein, the term "silyl group" includes alkylsilyl groups and arylsilyl groups. Examples of silyl groups include, but are not limited to, trimethylsilyl, triethylsilyl, t-butyldimethylsilyl, vinyldimethylsilyl, propyldimethylsilyl, triphenylsilyl, diphenylsilyl, and phenylsilyl groups.

[0055] In this specification, the thio group may include an alkylthio group and an arylthio group. The thio group may refer to an alkyl group or an aryl group defined above to which a sulfur atom is bonded. Examples of the thio group include, but are not limited to, a methylthio group, an ethylthio group, a propylthio group, a pentylthio group, a hexylthio group, an octylthio group, a dodecylthio group, a cyclopentylthio group, a cyclohexylthio group, a phenylthio group, and a naphthylthio group.

[0056] As used herein, the term "oxy group" refers to an alkyl group or aryl group defined above to which an oxygen atom is bonded. The oxy group may include an alkoxyoxy group and an aryloxy group. The alkoxy group may be linear, branched, or cyclic. The number of carbon atoms in the alkoxy group is not particularly limited, but may be, for example, 1 to 20 or 1 to 10. Examples of oxy groups include, but are not limited to, methoxy, ethoxy, n-propoxy, isopropoxy, butoxy, pentyloxy, hexyloxy, octyloxy, nonyloxy, decyloxy, benzyloxy, and the like.

[0057] As used herein, the term "boron group" refers to a group in which a boron atom is bonded to the alkyl or aryl group defined above. The boron group includes an alkyl boron group and an aryl boron group. Examples of the boron group include, but are not limited to, a dimethyl boron group, a diethyl boron group, a t-butylmethyl boron group, a diphenyl boron group, and a phenyl boron group.

[0058] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by a person skilled in the art to which the present invention belongs. Furthermore, terms, such as terms defined in commonly used dictionaries, should be interpreted to have a meaning consistent with the meaning they have in the context of the relevant art, and should not be interpreted in an overly ideal or formal sense unless explicitly defined herein.

[0059] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A resin composition according to an embodiment of the present invention and a display device including an adhesive member made of the resin composition will now be described with reference to the drawings.

[0060] Fig. 1 is an assembled perspective view showing a display device DD according to an embodiment of the present invention in an unfolded state, Fig. 2a is an assembled perspective view showing a display device DD according to an embodiment of the present invention in an inward folded state, and Fig. 2b is an assembled perspective view showing a display device DD according to an embodiment of the present invention in an outward folded state.

[0061] The display device DD according to an embodiment of the present invention shown in FIG. 1 may be a device activated by an electrical signal. For example, the display device DD may be, but is not limited to, a mobile phone, a tablet PC, a monitor, a television, a car navigation device, a game console, or a wearable device. FIG. 1 exemplarily illustrates the display device DD as a mobile phone. The display device DD according to an embodiment may be a flexible display device that can be folded, bent, or rolled up.

[0062] 1 and the following drawings, the first direction DR1, the second direction DR2, and the third direction DR3 are shown, but the directions indicated by the first direction DR1, the second direction DR2, and the third direction DR3 described herein are relative concepts and may be converted into other variations. In this specification, the first direction DR1 and the second direction DR2 are orthogonal to each other, and the third direction DR3 may be a normal direction to a plane defined by the first direction R1 and the second direction DR2.

[0063] In this specification, the thickness direction of the display device DD may be a direction along a third direction DR3 that is a normal direction to a surface defined by the first direction DR1 and the second direction DR2. The front (or top) and back (or bottom) surfaces of the members constituting the display device DD may be defined based on the third direction DR3.

[0064] In this specification, "on a plane" may mean viewed from above on a plane parallel to the plane defined by the first direction DR1 and the second direction DR2. In this specification, "overlapping" may mean overlapping on a plane unless otherwise defined.

[0065] Referring to FIG. 1, the display device DD may display an image IM through a display surface FS. The display surface FS may include a display area DA and a non-display area NDA. The display area DA may be an area activated by an electrical signal. The display device DD may display an image IM through the display area DA. The display area DA may also sense various types of external inputs. The non-display area NDA may be adjacent to the display area DA or may surround the display area DA. Accordingly, the shape of the display area DA may be substantially defined by the non-display area NDA. However, this is an exemplary illustration, and the non-display area NDA may be disposed adjacent to only one side of the display area DA or may be omitted. The display surface FS may include a plane defined by a first direction DR1 and a second direction DR2.

[0066] The rear surface RS of the display surface FS may be the surface facing the display surface FS. For example, the rear surface RS may be the outer surface of the display device DD on which no video or images are displayed. Alternatively, the rear surface RS may function as a second display surface on which video or images are displayed.

[0067] The display device DD may be divided into a folding area FA1 and non-folding areas NFA1 and NFA2. A plurality of non-folding areas NFA1 and NFA2 may be defined in the display device DD. The first non-folding area NFA1 and the second non-folding area NFA2 may be spaced apart with the folding area FA1 therebetween.

[0068] 1 to 2b show a display device DD including one folding area FA1, this is merely an example, and the display device DD may have multiple folding areas defined therein. Furthermore, the display device DD may be folded based on multiple folding axes so that portions of the display surface FS face each other. The number of folding axes and the corresponding number of non-folding areas included in the display device DD are not limited to any one embodiment.

[0069] 2a and 2b, the display device DD may be folded based on a first bending axis FX1. The first bending axis FX shown in FIGS. 2a and 2b is a virtual axis extending in a first direction DR1, and the first bending axis FX1 may be aligned with the long side direction of the display device DD. However, this is merely an example, and the extension direction of the first bending axis FX1 is not limited to the first direction DR1.

[0070] The first folding axis FX1 may extend along a first direction DR1 above the display surface FS or may extend along the first direction DR1 below the rear surface RS. Referring to FIG. 2a, the first non-folding region NFA1 and the second non-folding region NFA2 face each other, and the display device DD may be folded inward so that the display surface FS is not exposed to the outside. Referring to FIG. 2b, the display device DD may be folded along the first folding axis FX1 to transform into an outfolding state in which one region overlapping the first non-folding region NFA1 and another region overlapping the second non-folding region NFA2 face each other on the rear surface RS side.

[0071] FIG. 3 is an exploded perspective view of a display device DD according to an embodiment of the present invention.

[0072] 3, the display device DD may include a display module DM, a window WP disposed on the display module DM, and an adhesive member AP disposed between the display module DM and the window WP. The display device DD may further include a support member SM disposed below the display module DM, a protective layer PF disposed on the window WP, and a housing HAU that houses the display module DM, the support member SM, etc.

[0073] The housing HAU may include a material having a relatively high rigidity. For example, the housing HAU may include a plurality of frames and / or plates made of glass, plastic, or metal. The housing HAU may provide a predetermined storage space. The display module DM may be housed in the storage space and protected from external impacts.

[0074] The support member SM may include a metallic material or a polymeric material. For example, the support member SM may include stainless steel, aluminum, or an alloy containing iron or aluminum. Alternatively, the support member SM may be made of carbon fiber reinforced plastic (CFRP) or the like. However, embodiments are not limited thereto, and the support member SM may include a non-metallic material, plastic, glass fiber reinforced plastic, or glass.

[0075] Although not shown, the display device DD may further include a cushioning layer, a shielding layer, etc., disposed below the support member SM. The cushioning layer may include sponge, foam, or an elastomer such as urethane resin. The shielding layer may be an electromagnetic wave shielding layer or a heat dissipation layer.

[0076] The display module DM may be activated by an electrical signal. When activated, the display module DM may display an image IM (FIG. 1) in a display area DA (FIG. 1) of the display device DD. An active area AA-DM and a peripheral area NAA-DM may be defined in the display module DM. The active area AA-DM may be an area activated by an electrical signal. The peripheral area NAA-DM may be an area located adjacent to at least one side of the active area AA-DM. Circuits, wiring, etc. for driving the active area AA-DM may be arranged in the peripheral area NAA-DM.

[0077] An adhesive member AP may be disposed on the display module DM. The adhesive member AP may bond the display module DM and the window WP. The adhesive member AP may be optically transparent. In one embodiment, the adhesive member AP may include a polymer derived from one example of a resin composition RC (see FIGS. 5a and 6a). The adhesive resin AP may be made of one example of a resin composition RC (see FIGS. 5a and 6a). The adhesive member AP made of one example of a resin composition RC (see FIGS. 5a and 6a) may exhibit excellent adhesive reliability. In one embodiment, a display device DD including an adhesive member AP made of the resin composition RC (see FIGS. 5a and 6a) may exhibit excellent reliability in operations such as folding, bending, and rolling.

[0078] The window WP may include a glass substrate. The window WP may protect the display module DM and the like. An image IM (FIG. 1) generated by the display module DM may be provided to a user through the window WP. For example, the window WP may include UTG (Ultra Thin Glass).

[0079] The window WP may include a transparent area TA and a bezel area BZA. The transparent area TA may overlap at least a portion of the active area AA-DM of the display module DM. The transparent area TA may be an optically transparent area. An image IM (FIG. 1) may be provided to a user through the transparent area TA.

[0080] The bezel region BZA may be a region having a relatively low light transmittance compared to the transmissive region TA. The bezel region BZA may define the shape of the transmissive region TA. The bezel region BZA may be adjacent to and surround the transmissive region TA.

[0081] The bezel area BZA may have a predetermined color. The bezel area BZA may cover the peripheral area NAA-DM of the display module DM and may block the peripheral area NAA-DM from being viewed from the outside. However, the embodiment is not limited thereto, and the bezel area BZA may be disposed adjacent to only one side of the transmissive area TA, or at least a portion of the bezel area BZA may be omitted.

[0082] The protective layer PF may be a functional layer that protects one surface (e.g., the top surface) of the window WP. The protective layer PF may include an anti-fingerprint coating, a hard coating, an anti-static agent, etc. Although not shown, an auxiliary adhesive layer may be disposed between the window WP and the protective layer PF. Unlike the illustration, the protective layer PF may be omitted.

[0083] 4 is a cross-sectional view of a display device according to an embodiment of the present invention, which may be a cross-sectional view showing a portion corresponding to line II' in FIG.

[0084] For ease of explanation, FIG. 4 omits the housing HAU from the configuration of FIG. 3, and shows the support member SM, the display module DM, the adhesive member AP, the window WP, and the protective layer PF.

[0085] 4, the support plate SM may include a first support portion MP1 overlapping the first non-folding region NFA1 and a second support portion MP2 overlapping the second non-folding region NFA1. The first support portion MP1 and the second support portion MP2 may be spaced apart from the folding region FA1. The first support portion MP1 and the second support portion MP2 do not overlap the folding region FA1. Unlike the illustration, at least a portion of the first support portion MP1 and at least a portion of the second support portion MP2 may overlap the folding region FA1.

[0086] The display module DM may include a display panel DP and an input sensing unit TP disposed on the display panel DP. The display panel DP may include a base substrate BS, a circuit layer DP-CL disposed on the base substrate BS, a display element layer DP-EL disposed on the circuit layer DP-CL, and a sealing layer TFE disposed to cover the display element layer DP-EL.

[0087] 4 is merely an example, and the configuration of the display panel DP is not limited thereto. For example, the display panel DP may include a liquid crystal display element, in which case the sealing layer TFE may be omitted.

[0088] The base substrate BS may provide a base surface on which the circuit layers DP-CL are disposed. The base substrate BS may be a flexible substrate that can be bent, folded, rolled, etc. The base substrate BS may be a glass substrate, a metal substrate, a polymer substrate, etc. However, embodiments are not limited thereto, and the base substrate BS may include an inorganic layer, an organic layer, or a composite material layer.

[0089] The circuit layer DP-CL may include an insulating layer, a semiconductor pattern, a conductive pattern, a signal line, etc. For example, the circuit layer DP-CL may include a switching transistor and a driving transistor for driving a light-emitting element (not shown) of the display element layer DP-EL.

[0090] The display element layer DP-EL may include a light-emitting element (not shown) that emits light. For example, the display element may be an organic light-emitting element, an inorganic light-emitting element, an organic-inorganic light-emitting element, a micro LED, a nano LED, a quantum dot light-emitting element, an electrophoretic element, an electrowetting element, or the like.

[0091] The encapsulating layer TFE may be disposed above the display element layer DP-EL. The encapsulating layer TFE may protect the light-emitting element layer DP-EL from foreign substances such as moisture, oxygen, and / or dust particles. The encapsulating layer TFE may include at least one inorganic layer. The encapsulating layer TFE may also include at least one organic layer and at least one inorganic layer. For example, the encapsulating layer TFE may include an inorganic layer, an organic layer, and an inorganic layer stacked in sequence.

[0092] The input sensing unit TP may be disposed on the display panel DP. For example, the input sensing unit TP may be disposed directly on the encapsulation layer TFE of the display panel DP. The input sensing unit TP may sense an external input, convert it into a predetermined input signal, and provide the input signal to the display panel DP. For example, in one embodiment of the display device DD, the input sensing unit TP may be a touch sensing unit that senses a touch. The input sensing unit TP may recognize a direct touch by a user, an indirect touch by a user, a direct touch by an object, an indirect touch by an object, or the like.

[0093] The input sensing unit TP may sense at least one of the position and intensity (pressure) of an externally applied touch. In an embodiment, the input sensing unit TP may have various structures or be made of various materials and is not limited to any one embodiment. The input sensing unit TP may include a plurality of sensing electrodes (not shown) for sensing an external input. The sensing electrodes (not shown) may sense the external input in a capacitive manner. The display panel DP may receive an input signal from the input sensing unit TP and generate an image corresponding to the input signal.

[0094] The window WP may include a base layer BL and a print layer BM. The base layer BL may be a glass substrate. Alternatively, the base layer BL may be a plastic substrate. For example, the base layer BL may include polyimide, polyacrylate, polymethyl methacrylate, polycarbonate, polyethylene naphthalate, polyvinylidene chloride, polyvinylidene fluoride, polystyrene, ethylene-vinyl alcohol copolymer, or a combination thereof.

[0095] The print layer BM may be disposed on one surface of the base layer BL. The print layer BM may be provided in at least a partial area of the lower surface of the base layer BL adjacent to the display module DM. The print layer BM may be disposed in an edge area of the base layer BL. The print layer BM may be an ink print layer. The print layer BM may also be a layer formed containing a pigment or dye. The bezel area BZA of the window WP may be the portion where the print layer BM is provided.

[0096] The adhesive member AP may be disposed between the display module DM and the window WP. The thickness T0 of the adhesive member AP may be 50 μm or more and 200 μm or less. For example, the thickness T0 of the adhesive member AP may be 50 μm or more and 100 μm or less. However, this is merely an example, and the thickness T0 of the adhesive member AP is not limited thereto.

[0097] The adhesive member AP of one embodiment includes a polymer derived from a resin composition RC (see FIGS. 5a and 6a) of one embodiment, which will be described later. The resin composition RC (see FIGS. 5a and 6a) of one embodiment includes at least one (meth)acrylate oligomer, at least one photoinitiator, at least one (meth)acrylate monomer, and at least one urethane (meth)acrylate oligomer. The resin composition RC of one embodiment (see FIGS. 5a and 6a) will be described in detail later.

[0098] The adhesive member AP of one embodiment has high peel strength in a humid and hot environment, as described below, and thus can exhibit excellent adhesion reliability and excellent folding reliability. Meanwhile, a humid and hot environment can mean a high temperature and humidity environment. Even in a humid and hot environment, it does not peel from an adherend (e.g., a display module DM or a window WP), and operations such as folding and unfolding can be easily performed. In other words, a display device DD including the adhesive member AP of one embodiment can exhibit excellent reliability in operations such as folding and unfolding, even in a humid and hot environment.

[0099] 5a to 5c are cross-sectional views each showing a schematic step of a method for manufacturing an adhesive member AP according to an embodiment of the present invention.

[0100] In one embodiment, a manufacturing method of an adhesive member AP may include the steps of providing a resin composition RC on a substrate CF, providing UV-L light to a preliminary adhesive member P-AP to form an adhesive member AP, and peeling (detaching) the adhesive member AP from the substrate CF.

[0101] FIG. 5a is a cross-sectional view illustrating an exemplary step of providing a resin composition RC on a substrate CF. Referring to FIG. 5a, the resin composition RC may be applied onto the substrate CF. The resin composition RC may be provided onto the substrate CF through a nozzle NZ. For example, the substrate CF on which the resin composition RC is provided may include polyethylene terephthalate (PET). The substrate CF may be a temporary substrate used to form an adhesive member AP from the resin composition RC. Therefore, the substrate CF may be any substrate that can be easily peeled off (detached) after the resin composition RC is cured. One surface of the substrate CF on which the resin composition RC is provided may be subjected to a release treatment.

[0102] The resin composition RC can be applied by inkjet printing or dispensing. In one embodiment, the resin composition has a shear viscosity of 8 mPa·s or more and 50 mPa·s or less, as measured according to JIS Z8803. The shear viscosity is measured at 25°C and 10 rpm. A resin composition RC having a shear viscosity within this range can exhibit excellent discharge stability. That is, a resin composition RC having a shear viscosity within this range can be smoothly discharged from a device such as a nozzle NZ, and can be applied in a uniform amount and thickness without deviating from the part to which the resin composition RC is to be applied.

[0103] In one embodiment, the resin composition RC may be solvent-free. In one embodiment, the resin composition RC may be solvent-free. The resin composition RC may be provided in a solvent-free form. When the resin composition RC is solvent-free, the ease of ejection of the resin composition RC from the nozzle NZ may be improved. When the resin composition RC contains a volatile organic solvent, the ease of ejection from the nozzle NZ may be reduced by including a heating step for drying the volatile organic solvent in the process for producing an adhesive member containing the resin composition RC.

[0104] In one embodiment, the resin composition RC may be a photocurable resin composition. In one embodiment, the resin composition RC may be a UV-curable resin that is cured by ultraviolet light. In one embodiment, the resin composition RC is in a liquid state before curing and can be crosslinked or cured by receiving light energy such as ultraviolet light.

[0105] In one embodiment, the resin composition RC includes at least one (meth)acrylate oligomer (A), a photoinitiator (B), a (meth)acrylate monomer (C), and a urethane (meth)acrylate oligomer (D).

[0106] In one embodiment, the (meth)acrylate oligomer (A) has a siloxane skeleton. The (meth)acrylate oligomer (A) may be synthesized using a first polymerizable monomer. The (meth)acrylate oligomer (A) may be derived from a first polymerizable monomer represented by the following Chemical Formula 2-1 or 2-2.

[0107] <Chemical formula 2-1> JPEG2025121409000006.jpg7290

[0108] <Chemical formula 2-2> JPEG2025121409000007.jpg40126

[0109] In Chemical Formula 2-1 and Chemical Formula 2-2, R3 and R5 can each independently be a hydrogen atom or a substituted or unsubstituted methyl group. For example, R3 and R5 can be an unsubstituted methyl group.

[0110] In Chemical Formula 2-1 and Chemical Formula 2-2, R4 and R6 can each independently be a substituted or unsubstituted alkylene group having from 1 to 20 carbon atoms. R4 and R6 can each independently be a substituted or unsubstituted linear alkylene group having from 1 to 20 carbon atoms, or a substituted or unsubstituted branched alkylene group having from 1 to 20 carbon atoms. For example, R4 and R6 can be an unsubstituted n-propylene group.

[0111] In Chemical Formula 2-2, R7 can be a substituted or unsubstituted alkyl group having from 1 to 20 carbon atoms. R7 can be a substituted or unsubstituted straight-chain alkyl group having from 1 to 20 carbon atoms or a substituted or unsubstituted branched-chain alkyl group having from 1 to 20 carbon atoms. For example, R7 can be an unsubstituted n-butyl group.

[0112] In Chemical Formula 2-2, n can be an integer of 0 to 20. For example, n can be 1. For example, in Chemical Formula 2-2, n can be n1.

[0113] In one embodiment, the (meth)acrylate oligomer (A) may be a polymer synthesized from a first polymerizable monomer and a second polymerizable monomer different from the first polymerizable monomer. The second polymerizable monomer may include at least one of methyl methacrylate, isobornyl methacrylate, and 2-hydroxyethyl methacrylate. For example, the second polymerizable monomer may include all of methyl methacrylate, isobornyl methacrylate, and 2-hydroxyethyl methacrylate.

[0114] The weight-average molecular weight of the (meth)acrylate oligomer (A) may be 4,000 or more and 20,000 or less. For example, in one embodiment, the weight-average molecular weight of the (meth)acrylate oligomer (A) may be 8,000 or more and 9,500 or less. When the resin composition RC contains the (meth)acrylate oligomer (A) having a weight-average molecular weight within the above range, it can be easily discharged from the nozzle NZ and can be applied in a uniform amount and with a uniform thickness.

[0115] The weight percentage of the (meth)acrylate oligomer (A) may be 1 wt% or more and 20 wt% or less, based on the total weight of the resin composition RC. By including the (meth)acrylate oligomer (A) in this range, the resin composition RC has an appropriate shear viscosity, is easily discharged from a nozzle NZ, and can be provided by an inkjet printing method or a dispensing method. Furthermore, by including the (meth)acrylate polymer (A) in this range, the adhesive member AP made of the resin composition RC has excellent adhesive strength and can be easily folded and unfolded.

[0116] The resin composition RC includes at least one photoinitiator (B). The photoinitiator (B) may include a radical polymerization initiator. When the resin composition RC includes multiple photoinitiators (B), the different photoinitiators may be activated by ultraviolet light having different center wavelengths.

[0117] For example, photoinitiator (B) can include at least one of 2,2-dimethoxy-1,2-diphenylethan-1-one, 1-hydroxy-cyclohexyl-phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, 2-hydroxy-1-[4-(2-hydroxyethoxy)phenyl]-2-methyl-1-propanone, and 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl}-2-methylpropan-1-one.

[0118] Also, the photoinitiator (B) may be 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1, 2-dimethylamino-2-(4-methyl-benzyl)-1-(4-morpholin-4-yl-phenyl)-butan-1-one, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, ethyl(2,4,6-trimethylbenzoyl)phenyl The compound may include at least one of phenyl phosphinate, phenylbis(2,4,6-trimethylbenzoyl)-phosphine oxide, [1-(4-phenylsulfanylbenzoyl)heptylideneamino]benzoate, [1-[9-ethyl-6-(2-methylbenzoyl)carbazol-3-yl]ethylideneamino]acetate, and bis(2,4-cyclopentadienyl)bis[2,6-difluoro-3-(1-pyrryl)phenyl]titanium(IV).

[0119] The weight percentage of the photoinitiator (B) may be 1 wt% or more and 10 wt% or less, based on the total weight of the resin composition RC. For example, the weight percentage of the photoinitiator (B) may be 1 wt% or more and 5 wt% or less, based on the total weight of the resin composition RC. However, this is merely an example, and the weight of the photoinitiator (B) is not limited thereto.

[0120] The resin composition RC includes at least one (meth)acrylate monomer (C). In one embodiment, the (meth)acrylate monomer (C) may include a (meth)acryloyl group. In this specification, the term "(meth)acryloyl group" refers to an acryloyl group or a methacryloyl group, and the term "(meth)acrylic" refers to an acrylic or methacrylic group. For example, the (meth)acrylate monomer may be an acrylate monomer or a methacrylate monomer containing one acryloyl group or one methacryloyl group.

[0121] The (meth)acrylate monomer (C) contains a first monomer. The first monomer contained in the (meth)acrylate monomer (C) is represented by the following chemical formula 1.

[0122] <Chemical formula 1> JPEG2025121409000008.jpg4558

[0123] In Chemical Formula 1, R1 can be a hydrogen atom or a substituted or unsubstituted methyl group. For example, R1 can be an unsubstituted methyl group.

[0124] In Chemical Formula 1, R2 may be a substituted or unsubstituted alkyl group having from 1 to 20 carbon atoms. For example, R2 may be any one of a 4-hydroxybutyl group, a 2-ethylhexyl group, a tetrahydrofurfuryl group, and a 2-ethylhexyldiglycol group.

[0125] The first monomer included in the (meth)acrylate monomer (C) may include 2-ethylhexyl acrylate or isodecyl acrylate.

[0126] The first monomer contained in the (meth)acrylate monomer (C) has a surface tension of 20 mN / m or more and 30 mN / m or less. When the surface tension of the first monomer is 20 mN / m or more and 30 mN / m or less, the resin composition RC can be easily discharged from the nozzle NZ and can be applied in a uniform amount and with a uniform thickness. If the surface tension of the first monomer is less than 20 mN / m, the adhesive member formed using the resin composition RC may have reduced application uniformity to the polyethylene terephthalate film. If the surface tension of the first monomer exceeds 30 mN / m, the resin composition RC may be less easily discharged from the nozzle NZ.

[0127] In one embodiment, the resin composition RC may contain two or more (meth)acrylate monomers (C). The (meth)acrylate monomer (C) may include the first monomer described above and may further include a second monomer different from the first monomer. The second monomer may include any one of 4-hydroxybutyl acrylate, tetrahydrofurfuryl acrylate, and 2-ethylhexyl diglycol acrylate. For example, in one embodiment, the resin composition RC may include 2-ethylhexyl acrylate as the first monomer and 4-hydroxybutyl acrylate, tetrahydrofurfuryl acrylate, and 2-ethylhexyl diglycol acrylate as the second monomer. Alternatively, in one embodiment, the resin composition RC may include isodecyl acrylate as the first monomer and 4-hydroxybutyl acrylate, tetrahydrofurfuryl acrylate, and 2-ethylhexyl diglycol acrylate as the second monomer. However, the embodiments are not limited thereto.

[0128] The weight percentage of the (meth)acrylate monomer (C) may be 50 wt% or more and 90 wt% or less, based on the total weight of the resin composition. For example, the weight percentage of the (meth)acrylate monomer (C) may be 80 wt% or more and 90 wt% or less, based on the total weight of the resin composition. If the weight percentage of the (meth)acrylate monomer (C) is less than 50 wt% based on the total weight of the resin composition, crosslinking within the resin composition may occur, reducing the surface tackiness. As a result, the peel strength of an adhesive member formed using the resin composition to a glass substrate may be reduced. If the weight percentage of the (meth)acrylate monomer (C) is more than 90 wt% based on the total weight of the resin composition, crosslinking within the resin composition may be insufficient, reducing the cohesive strength. As a result, the peel strength of an adhesive member formed using the resin composition to a glass substrate may be reduced.

[0129] When the resin composition RC contains two or more (meth)acrylate monomers (C), the sum of the weight percentages of the two or more (meth)acrylate monomers (C) may be 50 wt% or more and 90 wt% or less, based on the total weight of the resin composition RC. When the resin composition RC contains the (meth)acrylate monomer (C) in this range, the resin composition RC has an appropriate shear viscosity, is easily discharged from a nozzle NZ, and can be provided by an inkjet printing method or a dispensing method. Furthermore, when the resin composition RC contains the (meth)acrylate monomer (C) in this range, an adhesive member AP made of the resin composition RC has excellent adhesive strength and can be easily folded and unfolded.

[0130] The resin composition RC contains at least one urethane (meth)acrylate oligomer (D). For example, the resin composition RC may contain a urethane acrylate oligomer, and the resin composition RC may contain two or more types of urethane acrylate oligomers having different weight-average molecular weights.

[0131] For example, in one embodiment, the weight average molecular weight of the urethane (meth)acrylate oligomer (D) may be 5000 or more and 40000 or less. The urethane (meth)acrylate oligomer (D) having a weight average molecular weight of 5000 or more and 40000 or less is contained in the resin composition RC in the form of an oligomer having a relatively high degree of polymerization, and therefore maintains a high degree of polymerization even after photocuring, thereby making it possible to form an adhesive member AP with excellent adhesive reliability.

[0132] Based on the total weight of the resin composition RC, the weight percentage of the urethane (meth)acrylate oligomer (D) may be 1 wt% or more and 40 wt% or less. Based on the total weight of the resin composition RC, the weight percentage of the urethane (meth)acrylate oligomer (D) may be 1 wt% or more and 15 wt% or less. For example, based on the total weight of the resin composition RC, the weight percentage of the urethane (meth)acrylate oligomer (D) may be about 4 wt%. However, this is merely an example, and the weight of the urethane (meth)acrylate oligomer (D) is not limited thereto.

[0133] FIG. 5b is a cross-sectional view illustrating an exemplary step of applying light to a resin composition RC to form an adhesive member AP. Referring to FIG. 5b, ultraviolet light UV-L can be irradiated onto a preliminary adhesive member P-AP formed by applying the resin composition RC to a uniform thickness. While FIG. 5b illustrates the preliminary adhesive member P-AP being directly irradiated with ultraviolet light UV-L, this is not a limitation. A carrier film (not shown) can be disposed on the preliminary adhesive member P-AP, and the carrier film (not shown) can cover the preliminary adhesive member P-AP during the curing process. The carrier film (not shown) can transmit ultraviolet light UV-L.

[0134] Referring to FIGS. 5a and 5b, ultraviolet light UV-L may be applied to a preliminary adhesive member P-AP in the presence of oxygen. An adhesive member AP (see FIG. 5c) of one embodiment may be formed by curing a resin composition RC of one embodiment in the presence of oxygen. To form the adhesive member AP from the resin composition RC, ultraviolet light UV-L may be applied once or more than once. For example, if ultraviolet light UV-L is applied more than once to form the adhesive member AP (see FIG. 5c) from the resin composition RC, the applied resin composition RC may be pre-cured by applying ultraviolet light UV-L, and the pre-cured resin composition may be finally cured by applying ultraviolet light UV-L. The adhesive member AP (see FIG. 5c) may be formed by final curing of the resin composition RC.

[0135] 5c is a cross-sectional view exemplarily illustrating a step in which the adhesive member AP is peeled (detached) from the substrate CF, which is formed by applying ultraviolet light UV-L (see FIG. 5b) to the preliminary adhesive member P-AP (see FIG. 5b).

[0136] Referring to FIGS. 5a and 5c, an adhesive member AP according to an embodiment may be cured in the presence of oxygen to form an adhesive member AP having a 180° peel strength from a glass substrate of 800 gf / 25 mm to 2000 gf / 25 mm at 25°C. For example, an adhesive member AP according to an embodiment may have a 180° peel strength from a glass substrate of 1000 gf / 25 mm to 1500 gf / 25 mm at 25°C. When a conventional curable resin composition is cured in the presence of oxygen in air, the polymerization reaction of the resin composition is inhibited by the oxygen. Therefore, an adhesive member formed by curing a conventional resin composition in the presence of oxygen has low adhesive strength. The resin composition RC according to an embodiment contains the (meth)acrylate oligomer (A), photoinitiator (B), (meth)acrylate monomer (C), and urethane (meth)acrylate oligomer (D) described above, and therefore can form an adhesive member AP with excellent adhesive reliability even when cured in the presence of oxygen. That is, in one embodiment, the adhesive member AP of the present invention can exhibit excellent peel strength in a humid and hot environment even when photocured in the presence of oxygen.

[0137] The adhesive member AP formed by curing the resin composition RC of one embodiment may have a storage modulus G' of 0.01 MPa or more and 0.2 MPa or less at a temperature of -20°C. In one embodiment, the resin composition RC exhibits excellent adhesive reliability by having a low storage modulus G' even when photocured. Therefore, the adhesive member AP made of the resin composition RC can be easily folded and unfolded without floating at the interface.

[0138] The peeled (detached) adhesive member AP may be provided on one side of the window WP (see FIG. 4) or one side of the display module DM (see FIG. 4). One side of the adhesive member AP may be laminated on one side of the window WP (see FIG. 4) or one side of the display module DM (see FIG. 4), and the remaining side of the adhesive member AP may be attached to the unattached side of the display module DM or the side of the window WP (see FIG. 4).

[0139] 6a and 6b are cross-sectional views each showing a schematic step of a method for manufacturing an adhesive member AP according to an embodiment of the present invention.

[0140] 6a and 6b are cross-sectional views illustrating a manufacturing method of the adhesive member AP that is different from the manufacturing method of the adhesive member AP described with reference to Figs. 6a and 6b, the same content as that described with reference to Figs. 1 to 5c will not be described again, and differences will be mainly described.

[0141] Referring to Figure 6a, the resin composition RC can be applied directly to one surface of the display module DM or to one surface of the window WP (see Figure 6b). Figure 6a shows the resin composition RC applied directly to one surface of the display module DM. The resin composition RC has a shear viscosity of 8 mPa s or more and 50 mPa s or less, as measured according to JIS Z8803 at a temperature of 25°C and 10 rpm, and can be applied while covering the bend in the step portion SP-b of the display module DM.

[0142] Referring to Figure 6b, a window WP may be provided on a pre-adhesive member P-AP formed by applying a resin composition RC to a certain thickness. Next, ultraviolet light UV-L may be applied to the pre-adhesive member P-AP. The ultraviolet light UV-L may be transmitted through the window WP and applied to the pre-adhesive member P-AP. The pre-adhesive member P-AP may be cured to form the adhesive member AP (see Figure 4).

[0143] Alternatively, the adhesive member AP (see FIG. 4) may be formed by directly irradiating the preliminary adhesive member P-AP with ultraviolet light UV-L. Then, a window WP may be provided on the formed adhesive member AP (FIG. 4).

[0144] FIG. 7 is a cross-sectional view showing a display device DD-a according to an embodiment of the present invention.

[0145] In the description of the display device DD-a shown in FIG. 7, the same contents as those described with reference to FIGS. 1 to 6b will not be described again, and differences will be mainly described.

[0146] 3 and 4, the display device DD- shown in FIG. 7 may further include a light control layer PP and an optical adhesive layer AP-a. In one embodiment, the light control layer PP may be disposed between the adhesive member AP and the window WP. In one embodiment, the optical adhesive layer AP-a may be disposed between the light control layer AP and the window WP.

[0147] The light control layer PP is disposed on the display panel DP and can control reflected light from the display panel DP due to external light. The light control layer PP can include, for example, a polarizing plate or a color filter layer.

[0148] The optical adhesive layer AP-a may be made of the resin composition RC according to one embodiment. The optical adhesive layer AP-a may include a polymer derived from the resin composition RC according to one embodiment. The optical adhesive layer AP-a including the polymer derived from the resin composition may have a 180° peel strength of 800 gf / 25 mm or more and 2000 gf / 25 mm or less against a glass substrate or a polyethylene terephthalate (PET) film at a temperature of 25°C. The optical adhesive layer AP-a including the adhesive member AP made of the resin composition RC may have a storage modulus G' of 0.01 MPa or more and 0.2 MPa or less at a temperature of -20°C. As a result, the optical adhesive layer AP-a including the polymer derived from the resin composition RC according to one embodiment has high adhesive properties and flexibility, and does not float at the interface of the optical adhesive layer AP-a even when the display device DD-a is folded or bent, thereby exhibiting excellent adhesion reliability and folding properties.

[0149] The display device DD-a of one embodiment includes an optical adhesive layer AP-a containing a polymer derived from the resin composition RC of one embodiment, and an adhesive member AP. The display device DD-a including the optical adhesive layer AP-a and the adhesive member AP can exhibit excellent reliability during operations such as folding.

[0150] FIG. 8 is a cross-sectional view showing a display device DD-b according to an embodiment of the present invention.

[0151] In the description of the display device DD-b of one embodiment shown in FIG. 8, the same contents as those described with reference to FIGS. 1 to 7 will not be described again, and differences will be mainly described.

[0152] 3 and 4, the display device DD-b shown in FIG. 8 may further include a light control layer PP, an optical adhesive layer AP-a, and an interlayer adhesive layer PIB. In one embodiment, the light control layer PP may be disposed between the adhesive member AP and the window WP. In one embodiment, the optical adhesive layer AP-a may be disposed between the light control layer AP and the window WP.

[0153] In one embodiment of the display device DD-b, the adhesive member AP may be disposed between the display panel DP and the input sensing unit TP. That is, the input sensing unit TP may not be disposed directly on the display panel DP, but may be bonded to the display panel DP by the adhesive member AP. For example, the adhesive member AP may be disposed between the sealing layer TFE (FIG. 4) of the display panel DP and the input sensing unit TP.

[0154] An interlayer adhesive layer PIB may be provided below the light control layer PP. The interlayer adhesive layer PIB may be disposed between the input sensing unit TP and the light control layer PP and may be made of an adhesive material with excellent moisture-proofing properties. For example, the interlayer adhesive layer PIB may include polyisobutylene. The interlayer adhesive layer PIB may be disposed on the input sensing unit TP to prevent corrosion of the sensing electrodes of the input sensing unit TP.

[0155] The display device DD-b of one embodiment may include an optical adhesive layer AP-a and an adhesive member AP containing a polymer derived from the resin composition RC of one embodiment, and the display device DD-b including the optical adhesive layer AP-a and the adhesive member AP may exhibit excellent reliability during operations such as folding.

[0156] Hereinafter, an adhesive member and a display device made of a resin composition according to an embodiment of the present invention will be described in detail with reference to examples and comparative examples. Note that the examples shown below are merely illustrative examples to aid in understanding the present invention, and the scope of the present invention is not limited thereto.

[0157] [Example] 1. Synthesis of (meth)acrylate oligomer (A) The (meth)acrylate oligomers (A) A-1, A-2, A-3, and A-4 used in the resin compositions of the comparative examples and examples were synthesized by the method described below. Each of the (meth)acrylate oligomers (A) A-1, A-2, and A-3 is the (meth)acrylate oligomer (A) of the examples, and the (meth)acrylate oligomer (A) A-4 is the (meth)acrylate oligomer (A) of the comparative example.

[0158] In the synthesis examples, the molecular weight and molecular weight distribution were measured using a gel permeation chromatography (GPC) analyzer HLC-8420GPC manufactured by TOSHO Corporation. A TSKgel SUPER HZM-N was used as the measurement column, and the number average molecular weight (Mn) and molecular weight distribution were obtained in terms of standard polystyrene (PS) from the SEC (size exclusion chromatography) curve detected with a refractive index (RI) detector.

[0159] The composition ratio of the copolymer was measured using a Bruker AVANCE III 300M nuclear magnetic resonance (NMR) analyzer and calculated from the integral ratio of the signals measured from each monomer component in the NMR spectrum. Deuterated chloroform (product of Kanto Chemical Co., Inc.) was used as the intermediate solvent during the measurement.

[0160] (1) Synthesis of (meth)acrylate oligomer (A) A-1 To a round flask equipped with a condenser, a dropping funnel, a nitrogen inlet tube, and a magnetic stirrer, 40 ml of toluene was added, and the mixture was stirred at room temperature (about 25° C.) for 30 minutes while bubbling with nitrogen to deoxygenate the solvent.

[0161] After heating the flask in an oil bath until the internal temperature reached approximately 90°C, a homogeneous solution containing 4 g of siloxane monomer (FM-0711, manufactured by JNC Corporation) as the first polymerizable monomer, 15.2 g of methyl methacrylate (MMA, manufactured by Tokyo Chemical Industry Co., Ltd.) as the second polymerizable monomer, 8.9 g of isobornyl methacrylate (IBXMA, manufactured by Tokyo Chemical Industry Co., Ltd.), and 0.5 g of 2-hydroxyethyl methacrylate (2-HEMA, manufactured by Tokyo Chemical Industry Co., Ltd.), 1.2 g of V-601 (manufactured by Fujifilm Wako Pure Chemical Co., Ltd.) as a thermal polymerization initiator, and 10 ml of toluene was added to the dropping funnel. The stopcock was opened, and the homogeneous solution from the dropping funnel was slowly added dropwise to the flask over 1 hour. The mixture was then stirred for 1 hour, allowing the polymerization reaction to proceed.

[0162] Next, 600 ml of 58 vol% ethanol aqueous solution (FUJIFILM Wako Pure Chemical Co., Ltd.) was added to a 1000 ml beaker and stirred with a magnetic stirrer. The solution after the polymerization reaction in the flask was added dropwise little by little to precipitate a precipitate. The precipitate was suction filtered, washed with 58 vol% ethanol aqueous solution (FUJIFILM Wako Pure Chemical Co., Ltd.) and filtered to remove toluene and unreacted monomer. The precipitate was dried under reduced pressure to obtain a white powder (meth)acrylate oligomer (A) A-1, which is a copolymer.

[0163] The weight average molecular weight of the (meth)acrylate oligomer (A)A-1 was 10,800, the molecular weight distribution was 1.42, and the copolymerization composition ratio of the (meth)acrylate oligomer (A)A-1 was MMA:IBXMA:2-EHMA:FM-0711=76.7:18.5:2.6:2.2.

[0164] (2) Synthesis of (meth)acrylate oligomer (A) A-2 The following process was carried out to introduce a (meth)acrylate group into the terminal of (meth)acrylate oligomer (A)A-1. Specifically, 5 g of (meth)acrylate oligomer (A)A-1, 20 ml of toluene, 2.0 mg of dibutyltin dilaurate (FUJIFILM Wako Pure Chemical Co., Ltd.), and 0.40 g of IEM (2-isocyanatoethyl methacrylate) were placed in a round flask equipped with a condenser and a magnetic stirrer, and the mixture was heated in an oil bath until the internal temperature reached 60°C and allowed to react for 1 hour.

[0165] Next, 600 ml of 58 vol% ethanol aqueous solution (FUJIFILM Wako Pure Chemical Co., Ltd.) was added to a 1000 ml beaker and stirred with a magnetic stirrer. The reaction solution in the flask was added dropwise to precipitate. The precipitate was suction filtered, washed with 58 vol% ethanol aqueous solution (FUJIFILM Wako Pure Chemical Co., Ltd.) and filtered to remove the reaction solvent and unreacted monomer. The precipitate was dried under reduced pressure to obtain a white powder (meth)acrylate oligomer (A) A-2, which is a copolymer.

[0166] The weight average molecular weight of the (meth)acrylate oligomer (A)A-2 was 11,000, and the molecular weight distribution was 1.42. The introduction of the (meth)acrylate group was confirmed by proton nuclear magnetic resonance spectroscopy ( 1 The (meth)acrylate oligomer (A) A-2 was confirmed by 1 H NMR. 1 The peak values confirmed by 1 H NMR are as follows: 1 Tetramethylsilane (TMS) was used as the standard substance for H NMR measurement, and measurements were performed at a resonance frequency of 300 MHz, with chemical shift values reported in δ (ppm).

[0167] A-2 1 H NMR values (TMS, 300 MHz) δ: 5.6 and 6.2

[0168] (3) Synthesis of (meth)acrylate oligomer (A) A-3 To a round flask equipped with a condenser, a dropping funnel, a nitrogen inlet tube, and a magnetic stirrer, 40 ml of toluene was added, and the mixture was stirred at room temperature for 30 minutes while bubbling with nitrogen to deoxygenate the solvent.

[0169] After heating the flask in an oil bath until the internal temperature reached approximately 90°C, 4.2 g of siloxane monomer (TM-0701T, manufactured by JNC Corporation) as the first polymerizable monomer, 15.0 g of methyl methacrylate (MMA, manufactured by Tokyo Seikogyo Co., Ltd.) as the second polymerizable monomer, 8.9 g of isobornyl methacrylate (IBXMA, manufactured by Tokyo Chemical Industry Co., Ltd.), and 0.5 g of 2-hydroxyethyl methacrylate (2-HEMA, manufactured by Tokyo Chemical Industry Co., Ltd.) as the second polymerizable monomer, 1.4 g of V-601 (manufactured by Fujifilm Wako Pure Chemical Co., Ltd.) as a thermal polymerization initiator, and 10 ml of butyl acetate (n-butyl acetate) were added to the dropping funnel. The stopcock was opened, and the solution from the dropping funnel was slowly added dropwise to the flask over 1 hour. The polymerization reaction was then carried out by stirring for 1 hour.

[0170] Next, 600 ml of 58 vol% ethanol aqueous solution (FUJIFILM Wako Pure Chemical Co., Ltd.) was added to a 1000 ml beaker and stirred with a magnetic stirrer. The solution after the polymerization reaction in the flask was added dropwise little by little to precipitate a precipitate. The precipitate was suction filtered, washed with 58 vol% ethanol aqueous solution (FUJIFILM Wako Pure Chemical Co., Ltd.) and filtered to remove butyl acetate and unreacted monomer. The precipitate was dried under reduced pressure to obtain a white powder (meth)acrylate oligomer (A) A-3, which is a copolymer.

[0171] The weight average molecular weight of the (meth)acrylate oligomer (A)A-3 was 10,800, and the molecular weight distribution was 1.42. The copolymerization composition ratio of the (meth)acrylate oligomer (A)A-3 was MMA:IBXMA:2-EHMA:TM-0701T=75.6:18.33:2.1:4.0.

[0172] (4) Synthesis of (meth)acrylate oligomer (A) A-4 To a round flask equipped with a condenser, a dropping funnel, a nitrogen inlet tube, and a magnetic stirrer, 40 ml of toluene was added, and the mixture was stirred at room temperature for 30 minutes while bubbling with nitrogen to deoxygenate the solvent.

[0173] After heating this in an oil bath until the internal temperature reached approximately 90°C, 14.1 g of methyl methacrylate (MMA, manufactured by Tokyo Seikogyo Co., Ltd.), 11.1 g of isobornyl methacrylate (IBXMA, manufactured by Tokyo Chemical Industry Co., Ltd.), 1.1 g of V-601 (manufactured by Fujifilm Wako Pure Chemical Co., Ltd.) as a thermal polymerization initiator, and 10 ml of butyl acetate were added to the dropping funnel. The stopcock was opened, and the homogeneous solution from the dropping funnel was gradually added dropwise to the flask over 1 hour, followed by stirring for 1 hour to carry out the polymerization reaction.

[0174] Next, 600 ml of 58 vol% ethanol aqueous solution (FUJIFILM Wako Pure Chemical Co., Ltd.) was added to a 1000 ml beaker and stirred with a magnetic stirrer. The solution after the polymerization reaction in the flask was added dropwise to precipitate. The precipitate was suction filtered, washed with 58 vol% ethanol aqueous solution (FUJIFILM Wako Pure Chemical Co., Ltd.) and filtered to remove butyl acetate and unreacted monomer. The precipitate was dried under reduced pressure to obtain a white powder of (meth)acrylate oligomer A-4, a copolymer.

[0175] The weight average molecular weight of the (meth)acrylate oligomer A-4 was 6,400, and the molecular weight distribution was 1.49. The copolymerization composition ratio of the (meth)acrylate oligomer (A) A-4 was MMA:IBXMA=76.9:23.1.

[0176] 2. Production of resin composition The resin compositions of the examples were prepared by mixing the materials listed in Table 1. The resin compositions of the comparative examples were prepared by mixing the materials listed in Table 2. Each material was placed in a light-shielding plastic container in the amount (g) shown in Tables 1 and 2 and stirred at room temperature to produce the resin compositions of Examples 1 to 5 and Comparative Examples 1 to 5.

[0177] [Table 1]

[0178] [Table 2]

[0179] [Data for materials in Tables 1 and 2] Omnirad 819: Phenylbis(2,4,6-trimethylbenzoyl)-phosphine oxide (IGM Resins) 4-HBA: 4-hydroxybutyl acrylate (Osaka Organic Chemical Industry Ltd. product) EHDG-AT: 2-Ethylhexyl-diglycol acrylate (KYOEISHA CHEMICAL Co., Ltd. product) 2-EHA: 2-ethylhexyl acrylate (product of Toagosei Co., Ltd.) THF-A: Tetrahydrofurfuryl acrylate (KYOEISHA CHEMICAL Co., Ltd. product) IDAA: Isodecyl acrylate (Osaka Organic Chemical Industry Ltd. product) UF-C051: Urethane acrylate (weight average molecular weight: 35,000, Kyoeisha Chemical Co., Ltd. product) UF-C052: Urethane acrylate (weight average molecular weight: 10,000, Kyoeisha Chemical Co., Ltd. product) UN6304: Urethane acrylate (weight average molecular weight: 10,000, product of Negami Chemical Industrial Co., Ltd.) SAG008: Silicone surfactant (weight average molecular weight: 10,000, product of Nissan Chemical Corporation) S-656: Fluorine-based surfactant (weight average molecular weight: 10,000, AGC SEIMI CHEMICAL product)

[0180] 3. Manufacturing of adhesive members (test pieces) The above-mentioned resin composition was applied to a thickness of 50 μm on a 26 mm×76 mm piece of soda-lime glass (product of Central Glass Co., Ltd.) using an inkjet printer (manufactured by MICROJET).

[0181] In the presence of oxygen, soda lime glass coated with the composition was irradiated with UV LED lamps having peaks of 405 nm and 365 nm, respectively, with an integrated light dose of 220 mJ / cm. 2 , 380 mJ / cm 2 The film was irradiated with ultraviolet light so that

[0182] A PET film (TOYOBO CO.LTD. product name A4360, thickness 50μm) cut to 20mm x 150mm was bonded to the UV-irradiated soda lime glass at a bonding pressure of 0.15MPa. Next, a UV LED lamp with a peak wavelength of 396nm was used to bond the film to an integrated light intensity of 4000mJ / cm. 2 The specimen was then irradiated with ultraviolet light so that the temperature reached 100°C.

[0183] 4. Evaluation of properties of resin compositions and adhesive materials Table 2 below shows the surface tension of the (meth)acrylate monomer (C) in the resin compositions of Examples and Comparative Examples, the shear viscosity of the resin compositions, and the peel strength of adhesive members containing them.

[0184] (Evaluation of Surface Tension of (Meth)acrylate Monomer (C) in Resin Composition) The surface tension of the (meth)acrylate monomer (C) in the resin composition was measured at 25°C by the pendant drop method using a contact angle meter (Kyowa Interface Science Co., Ltd. DMo-601).

[0185] (Evaluation of Shear Viscosity of Resin Composition) The shear viscosity of the resin composition was measured by the JIS Z8803 method at a temperature of 25° C. The shear viscosity of the resin composition was measured using a viscometer TVE-25L (manufactured by TOKISANGYO Co., Ltd.) at a speed of 20 rpm.

[0186] (Evaluation of Spreadability of Resin Composition) The spreadability (spread wettability) of the resin composition was evaluated by dropping a 2 μL droplet onto a PET film (TOYOBO CO. LTD. product name A4360, thickness 50 μm) at 25° C. The droplet was then observed after 60 seconds, and those that maintained their circular shape were marked with "◯" and those that could not maintain their shape were marked with "X."

[0187] (Evaluation of peel strength of adhesive members) The peel strength of the adhesive member was measured using a Universal Testing Machine (Instron Corporation, Model 5965) at a temperature of 25°C, a peel speed of 300 mm / min, and a peel angle of 180°. The peel strength was measured by taking the average value of approximately 50 mm of peeling, and multiplying this average value by 1.25 to evaluate the peel strength per 25 mm width.

[0188] [Table 3]

[0189] Referring to Tables 1 and 3, the resin compositions of Examples 1 to 35 contain A-1, A-2, or A-3 as the (meth)acrylate oligomer (A) of the present invention. Examples 1 to 5 contain a (meth)acrylate oligomer (A) having a siloxane skeleton. The resin compositions of Examples 1 to 5 also contain a (meth)acrylate monomer (C) of the present invention, including a first monomer having a surface tension of 20 mN / m or more and 30 mN / m or less. The shear viscosity at 25°C of the resin compositions of Examples 1 to 5 is 8 mPa·s or more and 50 mPa·s or less. In contrast, referring to Tables 2 and 3, the resin compositions of Comparative Examples 1, 3, and 4 do not contain a (meth)acrylate oligomer (A). The resin composition of Comparative Example 2 contains A-4 as the (meth)acrylate oligomer (A) not corresponding to the present invention. A-4 in Comparative Example 2 does not contain a siloxane skeleton. The resin composition of Comparative Example 5 contains A-1 having a siloxane skeleton as the (meth)acrylate oligomer (A) of the present invention, but does not contain the (meth)acrylate monomer (C) of the present invention. Comparative Example 5 does not contain a first monomer having a surface tension of 20 mN / m or more and 30 mN / m or less, and contains only a (meth)acrylate monomer having a surface tension exceeding 30 mN / m. The shear viscosity of the resin composition of Comparative Example 5 at 25°C exceeds 50 mPa s.

[0190] Referring to Tables 1 to 3, it can be seen that the resin compositions of Examples 1 to 5 having the above material combinations have excellent ejection properties when providing ink, and high coating and adhesive reliability to glass substrates, etc. Therefore, the resin compositions of the examples can improve durability and folding properties when forming adhesive members to be used in flexible display devices.

[0191] The resin compositions of Examples 1 to 5 have shear viscosities of 8 mPa s to 50 mPa s measured according to JIS Z8803 at 25° C. Therefore, if the resin composition according to an embodiment of the present invention is applied using an inkjet printing method, the resin composition can be stably ejected and applied with a uniform thickness.

[0192] It can be seen that the adhesive members made of the resin compositions of Examples 1 to 5 have a 180° peel strength of 800 gf / 25 mm or more and 2000 gf / 25 mm or less at a temperature of 25° C. Therefore, adhesive members containing a resin composition according to an embodiment of the present invention can exhibit excellent adhesive reliability.

[0193] It can be seen that the surface tension of the (meth)acrylate monomer (C) in the resin compositions of Examples 1 to 5 is 20 mN / m or more and 30 mN / m or less. It can also be seen that the spreadability of the resin compositions of Examples 1 to 5 is indicated by "o". Therefore, when the resin composition according to an embodiment of the present invention is applied to a glass substrate or a PET film by inkjet printing, the resin composition according to an embodiment of the present invention maintains excellent adhesive reliability and can be applied with a uniform thickness without deteriorating the coating shape.

[0194] In contrast, Comparative Example 1 does not contain (meth)acrylate oligomer (A), and Comparative Example 2 does not contain a siloxane skeleton in (meth)acrylate oligomer (A). It can be seen that the spreadability of the resin compositions of Comparative Examples 1 and 2 is marked with "x." Because the resin compositions of Comparative Examples 1 and 2 do not contain (meth)acrylate oligomer (A) or the (meth)acrylate oligomer (A) does not contain a siloxane skeleton, it is believed that coating uniformity is reduced when the resin compositions are applied to a glass substrate or a PET film by inkjet printing.

[0195] Comparative Examples 3 and 4 did not contain a (meth)acrylate oligomer (A) but did contain a surfactant. The spreadability of the resin compositions of Comparative Examples 3 and 4 was indicated by "Good," and it was found that the adhesive members made of the resin compositions of Comparative Examples 3 and 4 had a 180° peel strength of less than 800 gf / 25 mm at 25°C. Because the resin compositions of Comparative Examples 3 and 4 contained a surfactant, they could be applied with a uniform thickness when applied to a glass substrate or PET film by inkjet printing. However, the adhesive members made of the resin compositions of Comparative Examples 3 and 4 were determined to have low adhesive strength because they did not contain a siloxane-based (meth)acrylate oligomer (A).

[0196] Comparative Example 5 contains a (meth)acrylate oligomer (A) having a siloxane skeleton but does not contain a first monomer having a surface tension of 20 mN / m or more and 30 mN / m or less. Furthermore, the shear viscosity of the resin composition at 25°C exceeds 50 mPa·s. Therefore, the spreadability of the resin composition of Comparative Example 5 is marked with an "X" and the adhesive member made of the resin composition of Comparative Example 5 has a 180° peel strength of less than 800 gf / 25 mm at 25°C. Since the resin composition of Comparative Example 5 does not contain a (meth)acrylate monomer (C) containing a first monomer, it is determined that coating uniformity is reduced when the resin composition is applied to a glass substrate or PET film by inkjet printing. Furthermore, since the resin composition of Comparative Example 5 has a shear viscosity at 25°C exceeding 50 mPa·s, it is determined that the ease of discharge of the resin composition is reduced and the adhesive reliability of the adhesive member containing the resin composition is reduced.

[0197] A resin composition according to an embodiment of the present invention may include at least one (meth)acrylate polymer (A) containing a siloxane skeleton, at least one surfactant (B), at least one (meth)acrylate monomer (C) having a surface tension of 20 mN / m or more and 30 mN / m or less, and at least one urethane (meth)acrylate oligomer (D). The resin composition according to an embodiment of the present invention may have a shear viscosity of 8 mPa·ss or more and 50 mPa·s or less at 25°C, as measured by JIS Z8803. Therefore, the resin composition according to an embodiment of the present invention may exhibit excellent discharge stability, and an adhesive member made of the resin composition according to an embodiment of the present invention may maintain excellent adhesion and exhibit excellent coating uniformity. A display device according to an embodiment of the present invention may include an adhesive member disposed between a display panel and a window. The adhesive resin may include a polymer derived from the resin composition according to an embodiment of the present invention. Therefore, a display device including the adhesive member according to an embodiment of the present invention may exhibit excellent adhesion reliability even when repeatedly folding / unfolding.

[0198] Although the present invention has been described above with reference to preferred embodiments, it will be understood by those skilled in the art or those with ordinary knowledge in the art that various modifications and variations of the present invention can be made without departing from the spirit and technical scope of the present invention as set forth in the claims below.

[0199] Therefore, the technical scope of the present invention should be determined by the claims, not by the contents of the detailed description of the specification.

[0200] The background and issues of this case are as follows (i) to (v).

[0201] (i) Foldable, rollable, and other display devices using flexible display panels such as organic light-emitting display panels are being used or considered for use in mobile devices, wall-mounted displays, and the like.

[0202] (ii) On the other hand, the adhesive layer or adhesive sheet (especially the pressure-sensitive adhesive layer or adhesive sheet) that bonds the display panel to the touch panel, protective window, polarizing plate, etc., is required to have high optical transparency as well as reliable and durable adhesive performance.

[0203] (iii) In a foldable display device, the adhesive layer or adhesive sheet after curing must maintain a good adhesive state and optical performance even after repeated folding.

[0204] (iv) Patent Document 1 proposes the incorporation of an isocyanate-based crosslinking agent to facilitate rework in the event of poor lamination, and also proposes the further incorporation of a (meth)acrylate oligomer having a silicone chain (siloxane skeleton).

[0205] (v) On the other hand, the curable resin composition must have good fluidity (dischargeability) for application onto display panels, preparation of adhesive sheets, etc. Also, to enable attachment work in the atmosphere, it is required to achieve good adhesion even in the presence of oxygen.

[0206] In a specific embodiment of the present application, at least one of the following A1 to A6 or A1 to A12 is particularly used.

[0207] A1 1 to 7% by weight or 1 to 6% by weight of polysiloxanyl alkyl acrylate (A), 1 to 5 wt % or 1 to 3 wt % of a photoinitiator (specifically, an acylphosphine oxide type) (B); 50 to 90% by weight or 60 to 85% by weight of a low molecular weight (molecular weight less than 1000) mixed (meth)acrylate monomer (C); A resin composition comprising: 1 to 15% by weight or 5 to 15% by weight of a urethane (meth)acrylate oligomer (D).

[0208] A2 The shear viscosity of the resin composition at 25°C is 8 mPa·s or more and 50 mPa·s or less, particularly 10 to 30 mPa·s or 10 to 25 mPa·s.

[0209] A3 The mixed (meth)acrylate monomer (C) consists of the following C1 to C4 (Examples 1 to 4). (C1) Hydroxyl alkyl (carbon number 2-5) acrylate (Specific example is 4-hydroxybutyl acrylate (4-HBA)) (C2) Alkyl (C5-15) (poly)oxyalkylene (meth)acrylate (A specific example is 2-ethylhexyl-diglycol acrylate (EHDG-AT)) (Poly)oxyalkylenes are in particular glycol(oxyethylene), diglycol(dioxyethylene) or triglycol(trioxyethylene). (C3) Alkyl (C5-15) (meth)acrylate (A specific example is 2-ethylhexyl acrylate (2-EHA)) (C4) Oxyalkyl (C4-8) (meth)acrylate (Specific example is tetrahydrofurfuryl acrylate (THF-A))

[0210] A4 In the mixed (meth)acrylate monomer (C) of A3 above, when C2 is 10 parts by weight, C1 is 5 to 10 parts by weight or 6 to 8 parts by weight, C3 is 40 to 70 parts by weight or 50 to 60 parts by weight, and C4 is 8 to 25 parts by weight or 10 to 20 parts by weight.

[0211] A5 In the mixed (meth)acrylate monomer (C), C3 (first monomer) has a surface tension (25° C.) of 20 mN / m or more and 30 mN / m or less, or 24 to 28 mN / m.

[0212] A6 The mixed (meth)acrylate monomer (C) may be composed of the above C3 and the following C5 instead of the above A3 (Example 5). In this case, when the above C5 is 30 parts by weight, the above C3 may be 40 to 70 parts by weight or 50 to 60 parts by weight. (C5) Alkyl (C8-12) (meth)acrylate (A specific example is isodecyl acrylate (IDAA))

[0213] A7 The urethane (meth)acrylate oligomer (D) is composed of a first urethane acrylate (D1) having a large molecular weight (weight average molecular weight of 20,000 to 50,000 or 30,000 to 40,000) and a second urethane acrylate (D2) having a small molecular weight (weight average molecular weight of 5,000 to 15,000 or 8,000 to 13,000).

[0214] A8 The urethane (meth)acrylate oligomer (D) may have a polyester skeleton such as polycaprolactone.

[0215] A9 In the urethane (meth)acrylate oligomer (D), the second urethane acrylate (D2) may be 4 to 10 parts by weight, 5 to 9 parts by weight, or 6 to 8 parts by weight, relative to 6 parts by weight of the first urethane acrylate (D1).

[0216] A10 In the mixed (meth)acrylate monomer (C) of A3, the surface tension (25° C.) of C1, C2 and C4 other than C3 may be 30 to 40 mN / m or 34 to 38 mN / m.

[0217] A11 In the mixed (meth)acrylate monomer (C) of A6, the surface tension (25° C.) of C5 can be 20 to 35 mN / m or 25 to 30 mN / m.

[0218] A12 After adhesion and curing, the storage modulus at -20°C is 0.2 MPa or less, and the 180° peel strength against a glass substrate or polyethylene terephthalate (PET) film at 25°C is 800 gf / 25 mm or more. [Explanation of symbols]

[0219] RC: Resin composition AP: Adhesive material DP: Display panel WP: Window DD:Display device

Claims

1. A display panel; a window disposed above the display panel; an adhesive member disposed between the display panel and the window, The adhesive member is derived from a resin composition, The resin composition comprises a (meth)acrylate oligomer (A) containing a siloxane skeleton; a photoinitiator (B); and a (meth)acrylate monomer (C) having a surface tension of 20 mN / m or more and 30 mN / m or less, the (meth)acrylate monomer (C) including a first monomer represented by the following chemical formula 1; and a urethane (meth)acrylate oligomer (D), A display device, wherein the shear viscosity of the resin composition at 25°C is 8 mPa·s or more and 50 mPa·s or less: <Chemical formula 1> In the above Chemical Formula 1, R １ is a hydrogen atom or a substituted or unsubstituted methyl group, R ２ is a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms.

2. The display device according to claim 1, wherein the (meth)acrylate oligomer (A) is synthesized from a first polymerizable monomer represented by the following chemical formula 2-1 or 2-2: <Chemical formula 2-1> <Chemical formula 2-2> In the chemical formula 2-1 and chemical formula 2-2, R ３ and R ５ are each independently a hydrogen atom or a substituted or unsubstituted methyl group, R ４ and R ６ each independently represents a substituted or unsubstituted alkylene group having from 1 to 20 carbon atoms, R ７ is a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, n is an integer of 0 or more and 20 or less.

3. In the above chemical formula 2-1, R ３ is an unsubstituted methyl group, and R ４ 3. The display device according to claim 2, wherein is an unsubstituted n-propylene group.

4. In the above Chemical Formula 2-2, R ５ is an unsubstituted methyl group, and R ６ is an unsubstituted n-propylene group, and R ７ 3. The display device according to claim 2, wherein is an unsubstituted n-butyl group.

5. The (meth)acrylate oligomer (A) is synthesized using the first polymerizable monomer and a second polymerizable monomer different from the first polymerizable monomer, 3. The display device of claim 2, wherein the second polymerizable monomer comprises any one of methyl methacrylate, isobornyl methacrylate, and 2-hydroxyethyl methacrylate.

6. 2. The display device of claim 1, wherein the first monomer includes 2-ethylhexyl acrylate or isodecyl acrylate.

7. the (meth)acrylate monomer (C) further comprises a second monomer different from the first monomer, 7. The display device of claim 6, wherein the second monomer includes at least one of 4-hydroxybutyl acrylate, tetrahydrofurfuryl acrylate, and 2-ethylhexyl diglycol acrylate.

8. 2. The display device according to claim 1, wherein the resin composition is a solvent-free type.

9. 2. The display device according to claim 1, wherein the weight average molecular weight of the (meth)acrylate oligomer (A) is 4,000 or more and 20,000 or less.

10. 2. The display device according to claim 1, wherein the (meth)acrylate monomer (C) has a weight average molecular weight of 400 or more and 1,500 or less.

11. 2. The display device according to claim 1, wherein the weight average molecular weight of the urethane (meth)acrylate oligomer (D) is 8,000 or more and 50,000 or less.

12. Relative to the total weight of the resin composition, The weight percentage of the (meth)acrylate oligomer (A) is 1% by weight or more and 7% by weight or less, The weight percentage of the photoinitiator (B) is 1% by weight or more and 5% by weight or less, The weight percentage of the (meth)acrylate monomer (C) is 50% by weight or more and 90% by weight or less, 2. The display device according to claim 1, wherein the weight percentage of the urethane (meth)acrylate oligomer (D) is 1% by weight or more and 15% by weight or less.

13. The display device according to claim 1 , wherein the photoinitiator (B) includes a radical polymerization initiator.

14. 2. The display device according to claim 1, wherein the adhesive member has a storage modulus at -20° C. of 0.2 MPa or less.

15. The adhesive member is 2. The display device according to claim 1, wherein the 180° peel strength against a glass substrate or a polyethylene terephthalate (PET) film at a temperature of 25[deg.] C. is 800 gf / 25 mm or more.

16. The display device according to claim 1 , wherein the adhesive member is formed by applying the resin composition directly onto one surface of the window or one surface of the display panel and then curing it with ultraviolet light.

17. further comprising an input sensing unit disposed on the display panel; The display device of claim 1 , wherein the adhesive member is disposed between the display panel and the input sensing unit or between the input sensing unit and the window.

18. the display panel includes a display element layer and a sealing layer disposed on the display element layer; the input sensing portion is disposed directly on the sealing layer; The display device according to claim 17 , wherein the adhesive member is disposed on the input sensing portion.

19. a light control layer disposed between the adhesive member and the window; and an optical adhesive layer disposed between the light control layer and the window; The display device according to claim 1 , wherein the optical adhesive layer contains a polymer derived from the resin composition.

20. the display device includes at least one bending axis; The display device according to claim 1 , wherein at least a portion of the display device is folded around the folding axis.

21. a (meth)acrylate oligomer (A) containing a siloxane skeleton; a photoinitiator (B); and a (meth)acrylate monomer (C) having a surface tension of 20 mN / m or more and 30 mN / m or less, the (meth)acrylate monomer (C) including a first monomer represented by the following chemical formula 1; and a urethane (meth)acrylate oligomer (D), A resin composition having a shear viscosity of 8 mPa s or more and 50 mPa s or less at 25°C: <Chemical formula 1> In the above Chemical Formula 1, R １ is a hydrogen atom or a substituted or unsubstituted methyl group, R ２ is a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms.

Images