Resin composition, adhesive member, and display device including the adhesive member

Abstract

The present application relates to a resin composition, which can include: a (meth)acrylate (A) including a hydroxyl group and having a molecular weight of about 500 or less than 500, and a polymer (B) including polyisoprene or polybutadiene as a main skeleton, having at least one radical-reactive group in one molecule, and having a molecular weight of about 2,000 to about 35,000, wherein the resin composition has a glass transition temperature of about -50℃ to about 0℃ after the resin composition is cured, and the resin composition has a viscosity of about 5 mPa·s to about 50 mPa·s at a temperature of about 30℃ to about 50℃.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority and benefit to Korean Patent Application No. 10-2020-0171104, filed with the Korean Intellectual Property Office on December 9, 2020, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates herein to resin compositions, adhesive components formed from said resin compositions, and display devices including said adhesive components. Background Technology

[0004] Various types of display devices are being developed for multimedia devices such as televisions, mobile phones, tablet computers, navigation systems, and game consoles. Recently, foldable, flexible, or rollable display devices using bendable flexible display components are being developed to achieve portability and increase user-friendliness.

[0005] The individual components used in such flexible display devices need to ensure reliability during folding or bending operations. The adhesive resins used to form the adhesive layers applied to various types of display devices need to have excellent coating properties for the components of various types of display devices.

[0006] It should be understood that this background section is intended to provide some useful context for understanding the art. However, this background section may also include ideas, concepts, or knowledge that were not known or understood by a person skilled in the art prior to the relevant valid application date of the subject matter disclosed herein. Summary of the Invention

[0007] This disclosure provides resin compositions having excellent coating properties and exhibiting a low glass transition temperature after curing, as well as adhesive components prepared therefrom.

[0008] This disclosure also provides a display device that, by including an adhesive component with high flexibility and adhesion, exhibits excellent durability and stability at high and low temperatures, and excellent reliability in operating states such as folding.

[0009] The embodiments provide a resin composition that may comprise: a (meth)acrylate (A) containing hydroxyl groups and having a molecular weight of about 500 or less; and a polymer (B) containing polyisoprene or polybutadiene as a main backbone, having at least one free radical reactive group in one molecule and having a molecular weight of about 2,000 to about 35,000, wherein the resin composition, after being cured, may have a glass transition temperature of about -50°C to about 0°C, and the resin composition may have a viscosity of about 5 mPa·s to about 50 mPa·s at a temperature of about 30°C to about 50°C.

[0010] In an embodiment, the resin composition may further comprise a monofunctional (meth)acrylate (C) different from the (meth)acrylate (A).

[0011] In an embodiment, the resin composition may comprise, relative to the total amount of the resin composition, about 5 wt% to about 30 wt% of the (meth)acrylate (A), about 0.1 wt% to about 5 wt% of the polymer (B), and about 50 wt% to about 88 wt% of the monofunctional (meth)acrylate (C).

[0012] In the embodiments, at least one of the (meth)acrylate (A), the polymer (B), and the monofunctional (meth)acrylate (C) may have two or more types.

[0013] In an embodiment, the resin composition may further comprise a urethane (meth)acrylate oligomer (D) having a molecular weight of about 6,000 or greater.

[0014] In an embodiment, the resin composition may contain about 1 wt% to about 15 wt% of the urethane (meth)acrylate oligomer (D) relative to the total amount of the resin composition.

[0015] In an embodiment, after the resin composition is cured, the resin composition can have a 180° peel strength of about 1000 gf / 25 mm or greater than 1000 gf / 25 mm for polyethylene terephthalate (PET) films and glass.

[0016] In an embodiment, the resin composition may further comprise at least one free radical polymerization initiator.

[0017] In an embodiment, the resin composition may contain an organic solvent, wherein the organic solvent may be contained in an amount of about 1 wt% or less than 1 wt% relative to the total amount of the resin composition.

[0018] In an embodiment, the adhesive component may comprise a polymer derived from a resin composition having a glass transition temperature of about -50°C to about 0°C, wherein the resin composition may comprise: a (meth)acrylate (A) containing hydroxyl groups and having a molecular weight of about 500 or less; and a polymer (B) containing polyisoprene or polybutadiene as a main backbone, having at least one radical reactive group in one molecule and having a molecular weight of about 2,000 to about 35,000, wherein the resin composition has a viscosity of about 5 mPa·s to about 50 mPa·s at a temperature of about 20°C to about 30°C.

[0019] In one embodiment, the polymer can be formed by photocuring the resin composition.

[0020] In an embodiment, the resin composition may further comprise a monofunctional (meth)acrylate (C) different from the (meth)acrylate (A) and the polymer (B), and the resin composition comprises, relative to the total amount of the resin composition, about 5 wt% to about 30 wt% of the (meth)acrylate (A); about 0.1 wt% to about 5 wt% of the polymer (B); and about 50 wt% to about 88 wt% of the monofunctional (meth)acrylate (C).

[0021] In an embodiment, the resin composition may further comprise, relative to the total amount of the resin composition, an amount of about 1 wt% to about 15 wt% of urethane (meth)acrylate oligomer (D) having a molecular weight of about 6,000 or greater.

[0022] In an embodiment, the display device may include a display panel; a window disposed on the display panel; and an adhesive component disposed between the display panel and the window, wherein the adhesive component has a glass transition temperature of about -50°C to about 0°C and is derived from a resin composition, the resin composition may include: a (meth)acrylate (A) containing hydroxyl groups and having a molecular weight of about 500 or less; and a polymer (B) containing polyisoprene or polybutadiene as a main backbone, having at least one free radical reactive group in one molecule and having a molecular weight of about 2,000 to about 35,000, and the resin composition having a viscosity of about 5 mPa·s to about 50 mPa·s at a temperature of about 20°C to about 30°C.

[0023] In an embodiment, the adhesive component may have a thickness of about 50 μm to about 200 μm.

[0024] In one embodiment, the display device may further include an input sensing unit disposed on the display panel, wherein the adhesive member may be disposed between the display panel and the input sensing unit or between the input sensing unit and the window.

[0025] In one embodiment, 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 on the encapsulation layer; and the adhesive component may be disposed on the input sensing unit.

[0026] In one embodiment, the adhesive component can be formed by applying the resin composition to the surface of the window or the surface of the display panel and then UV curing the resin composition.

[0027] In an embodiment, the display device may further include at least one folded region, wherein the at least one folded region may have a radius of curvature of about 5 mm or less than 5 mm.

[0028] In an embodiment, the display device 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, wherein the optical adhesive layer may contain a polymer derived from the resin composition. Attached Figure Description

[0029] The accompanying drawings are included to provide a further understanding of this disclosure, and are incorporated in and form part of this specification. The drawings illustrate embodiments of the disclosure and, together with the description, serve to explain the principles of the disclosure. In the drawings:

[0030] Figure 1 It is a perspective view of the display device according to the implementation plan;

[0031] Figure 2 This is an example. Figure 1 The view shown is of the display device in a folded state;

[0032] Figure 3 It is a perspective view of the display device according to the implementation plan;

[0033] Figure 4 This is an example. Figure 3 The view shown is of the display device in a folded state;

[0034] Figure 5 It is a perspective view of the display device according to the implementation plan;

[0035] Figure 6This is an exploded perspective view of the display device according to the implementation plan;

[0036] Figure 7 This corresponds to the implementation plan. Figure 1 A schematic cross-sectional view of the display device for the portion of line II′;

[0037] Figures 8A to 8C This is a view illustrating a method for manufacturing an adhesive component according to an embodiment;

[0038] Figures 9A to 9B This is a view illustrating a method for manufacturing an adhesive component according to an embodiment;

[0039] Figure 10 It is a schematic cross-sectional view of the display device according to the embodiment; and

[0040] Figure 11 This is a schematic cross-sectional view of the display device according to the implementation scheme. Detailed Implementation

[0041] This disclosure can be modified in many alternative forms, and therefore the embodiments will be described and described in detail in the accompanying drawings. However, it should be understood that this disclosure is not intended to be limited to the form disclosed, but rather to cover all modifications, equivalents, and substitutions that fall within the spirit and scope of this disclosure.

[0042] As used herein, the singular forms “a”, “an”, and “the” are intended to also include the plural forms unless the context clearly indicates otherwise.

[0043] In the specification and claims, for purposes of meaning and interpretation, the term "and / or" is intended to include any combination of the terms "and" and "or". For example, "A and / or B" can be understood to mean "A, B, or A and B". The terms "and" and "or" can be used in the sense of conjunctions or antonymous conjunctions and can be understood as equivalent to "and / or".

[0044] In the specification and claims, for purposes of meaning and interpretation, the phrase "at least one of..." is intended to include the meaning of "at least one selected from the group consisting of...". For example, "at least one of A and B" can be understood to mean "A, B, or A and B".

[0045] In the description, when an element (or area, layer, section, etc.) is referred to as being "on", "connected to", or "linked to" another element, it means that the element can be directly placed on / connected to / linked to the other element, or a third element can be placed therein.

[0046] In the description, "direct installation" can mean that a layer, membrane, zone, plate, etc., is installed without adding a layer, membrane, zone, plate, etc., between other parts. For example, "direct installation" can mean that an installation is carried out without any additional components (such as adhesive components) between two layers or two components.

[0047] The same reference figures refer to the same components. Furthermore, in the accompanying drawings, the thickness, scale, and dimensions of components may be enlarged to effectively depict the technical content.

[0048] It should be understood that although the terms “first,” “second,” etc., may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, without departing from the scope of the exemplary embodiments, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element. Singular terms may include plural forms unless the context clearly indicates otherwise.

[0049] Furthermore, terms such as "below," "under," "above," and "upper" are used to describe the relationships of the configurations shown in the accompanying drawings. These terms are used as relative concepts and are described with reference to the directions indicated in the drawings. In the description, it should be understood that when an element is referred to as "set on," it can be set "above" or "below" other elements.

[0050] The term “overlapping” or “overlapping” means that the first object may be above, below, or to the side of the second object, and vice versa. Additionally, the term “overlapping” may include layers, stacks, surfaces, or facing, extending over, covering, or partially covering, or any other suitable term as would be understood and appreciated by one of ordinary skill in the art.

[0051] When an element is described as “non-overlapping” or “intended not to overlap” with another element, this can include elements spaced apart from each other, offset from each other, or arranged side by side, or any other suitable terminology that would be understood and appreciated by one of ordinary skill in the art.

[0052] The terms "face" and "facing each other" mean that the first element can be directly or indirectly opposite the second element. In the case where a third element is inserted between the first and second elements, the first and second elements can be understood as being indirectly opposite each other, but still facing each other.

[0053] The phrase "in a plan view" means viewing an object from above, and the phrase "in a schematic cross-sectional view" means viewing a cross-section of an object that has been cut vertically from the side.

[0054] As used herein, “about” or “approximately” includes a specified value and means within an acceptable range of deviation from a particular value, as determined by a person skilled in the art taking into account the relevant measurements and the errors associated with the measurement of the particular quantity (i.e., the limits of the measurement system). For example, “about” may mean within one or more standard deviations, or within ±30%, ±20%, ±10%, ±5% of the specified value.

[0055] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. It should also be understood that terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant field, and should not be interpreted in an idealized or overly formal sense, unless expressly defined herein.

[0056] It should be understood that the terms “comprises,” “comprising,” “includes,” and / or “including,” “has,” “have,” and / or “having,” and variations thereof, are intended to indicate the presence of the features, integers, steps, operations, elements, components, or combinations thereof specified in this disclosure, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

[0057] In the following description, the resin composition, adhesive component, and display device according to the embodiments will be described with reference to the accompanying drawings.

[0058] Figure 1 It is a perspective view of the display device according to the implementation plan. Figure 2 This is an example. Figure 1 The view shown is of the display device in a folded state.

[0059] refer to Figure 1 According to the embodiment, the display device DD may have a generally rectangular shape in a plan view, the rectangular shape having a long side extending in a first direction DR1 and a short side extending in a second direction DR2 that intersects or intersects the first direction DR1. However, the embodiment is not limited to this. The display device DD may have various shapes, such as generally circular and generally polygonal shapes. The display device DD may be a flexible display device.

[0060] In the display device DD according to the embodiment, the display surface DS on which the image IM is displayed can be parallel to the plane defined by the first direction DR1 and the second direction DR2. The normal direction of the display surface DS is indicated by the third direction DR3, for example, the thickness direction of the display device DD. The front surface (or upper surface) and the rear surface (or lower surface) of each component can be defined by the third direction DR3. However, the directions indicated by the first to third directions DR1, DR2 and DR3 are relative concepts and can therefore be changed to other directions.

[0061] The display device DD of the embodiment may include at least one folded area FA. (See reference) Figure 1 and Figure 2 The display device DD may include a folded area FA and a non-folded area NFA. The folded area FA may be disposed between the non-folded areas NFA, and the folded area FA and the non-folded area NFA may be arranged or disposed adjacent to each other in the first direction DR1.

[0062] The folded region FA can be a portion that can be folded relative to a folding axis FX extending in a second direction DR2 (which is one direction). The folded region FA can have a radius of curvature RD of about 5 mm or less.

[0063] Figure 1 and Figure 2 The example shown includes one folded region FA and two non-folded regions NFA, but the number of folded regions FA and non-folded regions NFA is not limited to this. For example, the display device DD may include more than two non-folded regions NFA and folded regions FA disposed between the non-folded regions NFA.

[0064] In the display device DD of the embodiment, the non-folding regions NFA can be arranged symmetrically with respect to the folding regions FA. However, the embodiment is not limited to this, and the folding regions FA can be arranged between the non-folding regions NFA, but the areas of the two non-folding regions NFA facing each other with respect to the folding regions FA can be different.

[0065] The display surface DS of the display device DD may include a display area DA and a non-display area NDA surrounding the display area DA. The display area DA may display an image, and the non-display area NDA may not display an image. The non-display area NDA may surround the display area DA or may be adjacent to the display area DA, and may define the edge of the display device DD.

[0066] refer to Figure 2The display device DD can be a foldable display device DD that can be folded or unfolded. For example, the folding area FA can be folded along a folding axis FX that can be parallel to the second direction DR2, so that the display device DD can be folded. The folding axis FX can be defined as a short axis parallel to the short side of the display device DD.

[0067] When the display device DD is folded, the non-folded areas NFA can face each other, and the display device DD can be folded inward so that the display surface DS is not exposed to the outside. However, the embodiment is not limited to this. Unlike the case illustrated in the figures, the display device DD can be folded outward so that the display surface DS can be exposed to the outside.

[0068] Figure 3 It is a perspective view of the display device according to the implementation plan. Figure 4 This is an example. Figure 3 The view shown is of the display device in a folded state.

[0069] In addition to the folding action, Figure 3 The display device DD-a illustrated in the example can have the same characteristics as... Figure 1 The display devices DD illustrated in the example have essentially the same configuration or structure. Therefore, regarding the... Figure 3 and Figure 4 The description of the display device DD-a illustrated herein will describe the folding action.

[0070] refer to Figure 3 and Figure 4 The display device DD-a may include a folded area FA-a and a non-folded area NFA-a. The folded area FA-a may be disposed between the non-folded areas NFA-a, and the folded area FA-a and the non-folded area NFA-a may be arranged or disposed adjacent to each other in the second direction DR2.

[0071] The folding region FA-a can be bent relative to a folding axis FX-a that can be parallel to the first direction DR1, and the display device DD-a can therefore be folded. The folding axis FX-a can be defined as a major axis parallel to the long side of the display device DD-a. Figure 1 The display device DD illustrated in the image can be folded relative to its short axis, while Figure 3 The display device DD-a shown in the example can be folded relative to its long axis. Figure 4 The example shows the display device DD-a folding inward so that the display surface DS is not exposed to the outside, but the implementation is not limited to this, and the display device DD-a can be folded outward relative to the long axis.

[0072] Figure 5This is a perspective view of a display device according to an embodiment. The display device DD-b of the embodiment may include first and second curved regions BA1 and BA2 and a non-curved region NBA, and the first and second curved regions BA1 and BA2 may be curved from one side of the non-curved region NBA.

[0073] refer to Figure 5 The display device DD-b of the embodiment may include a non-curved region NBA displaying an image IM on a front surface, and a first curved region BA1 and a second curved region BA2 displaying the image IM on a side surface. The first curved region BA1 and the second curved region BA2 may each be curved from two sides of the non-curved region NBA.

[0074] refer to Figure 5 The non-curved area NBA can provide image IM in the direction of the third direction DR3, which can be the front surface of the display device DD-b, and the first curved area BA1 and the second curved area BA2 can provide images in the directions of the fifth direction DR5 and the fourth direction DR4, respectively. The fourth direction DR4 and the fifth direction DR5 can intersect or intersect with the first to third directions DR1, DR2 and DR3. However, the directions represented by the first to fifth directions DR1 to DR5 are relative concepts and are not limited to the relationships illustrated in the figures.

[0075] The display device DD-b of the embodiment can be a curved display device, which includes a non-curved region NBA and first and second curved regions BA1 and BA2, respectively disposed on two sides of the non-curved region NBA. Although not illustrated, the display device of the embodiment can be a curved display device including a non-curved region and a curved region. The curved region may be curved only at one side of the non-curved region.

[0076] For example, the above description Figures 1 to 5 Examples of foldable display devices and flexible display devices are shown, but the embodiments are not limited thereto. The display device of the embodiments can be a rollable display device, a flat rigid display device, or a flexible rigid display device.

[0077] In the following description, the display device of the embodiment will be based on the display device DD which is folded relative to the short axis, but the embodiment is not limited thereto, and the following description can be applied to various types of display devices other than the display device DD-a which is folded relative to the long axis and the display device DD-b which includes a curved region.

[0078] Figure 6 This is an exploded perspective view of the display device DD of the implementation scheme. Figure 7 This is a schematic cross-sectional view of the display device DD according to the implementation scheme. Figure 7 It corresponds to Figure 1 A schematic cross-sectional view of the portion of line II′.

[0079] The display device DD of the embodiment may include a display module DM and a window WP disposed on the display module DM. In the display device DD of the embodiment, the display module DM may include a display panel DP having a display element layer DP-EL, and an input sensing unit TP disposed on the display panel DP. The display device DD of the embodiment may include an adhesive component AP disposed between the display panel DP and the window WP. For example, in the display device DD of the embodiment, the adhesive component AP may be disposed between the input sensing unit TP and the window WP. The adhesive component AP may be an optically clear adhesive film (OCA) or an optically clear adhesive resin layer (OCR).

[0080] The adhesive component AP can be formed from the resin composition of the embodiments. The adhesive component AP can comprise a polymer derived from the resin composition of the embodiments.

[0081] The resin composition according to the embodiments may comprise: a (meth)acrylate (A) containing hydroxyl groups and having a molecular weight of about 500 or less, and a polymer (B) having polyisoprene or polybutadiene as the main backbone, having at least one radical reactive group in one molecule, and having a molecular weight of about 2,000 to about 35,000. In the description, (meth)acrylate refers to acrylate or methacrylate.

[0082] In the resin composition of the embodiments, (meth)acrylate (A) is a (meth)acrylate having a weight-average molecular weight (Mw) of about 100 to about 500. (Meth)acrylate (A) is a (meth)acrylate containing at least one hydroxyl group in one molecule. (Meth)acrylate (A) can include different (meth)acrylates. For example, the resin composition of the embodiments can include two or more types of (meth)acrylate (A). For example, in the resin composition of the embodiments, (meth)acrylate (A) can include one type of hydroxypropyl acrylate and one type of hydroxyethyl acrylate.

[0083] (Meth)acrylate (A) may include hydroxybutyl acrylate, hydroxypropyl acrylate, hydroxyethyl acrylate, or mixtures thereof. The resin composition of the embodiments may contain 4-hydroxybutyl acrylate, 3-hydroxypropyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxyethyl acrylate, or mixtures thereof as (meth)acrylate (A).

[0084] Relative to a total of 100 wt% of the resin composition, the resin composition of the embodiments may contain about 5 wt% to about 30 wt% of (meth)acrylate (A). The resin composition of the embodiments contains about 5 wt% to about 30 wt% of (meth)acrylate (A) and therefore can exhibit a low viscosity of about 5 mPa·s to about 50 mPa·s in the resin state, and has a glass transition temperature of about -50°C to about 0°C after photocuring. The resin composition of the embodiments contains about 5 wt% to about 30 wt% of (meth)acrylate (A), and the adhesive component formed by curing the resin composition of the embodiments can therefore have high adhesion to polyethylene terephthalate films and glass, thereby possessing flexibility suitable for folding devices.

[0085] The resin composition of the embodiments may comprise a polymer (B) having a weight-average molecular weight of about 2,000 to about 35,000. The polymer (B) may be a polymer material having at least one radical-reactive group in one molecule and having polyisoprene or polybutadiene as the main backbone. The polymer (B) may comprise different polymer materials. For example, the resin composition of the embodiments may comprise two or more types of polymers (B). For example, the resin composition of the embodiments may comprise one type of polyisoprene compound having radical-reactive groups and one type of polybutadiene compound having radical-reactive groups as polymer (B).

[0086] Polymer (B) may comprise a polyisoprene compound having free radical curable groups, a polybutadiene compound having free radical curable groups, or a mixture thereof. The resin composition of the embodiment may comprise UC-102M (Kuraray company), UC-203M (Kuraray company), TEAI-1000 (Nippon Soda Co., Ltd.) or a mixture thereof as polymer (B).

[0087] Relative to a total of 100 wt% of resin composition, the resin composition of the embodiments may contain about 0.1 wt% to about 5 wt% of polymer (B). The resin composition of the embodiments may contain about 0.1 wt% to about 5 wt% of polymer (B), and therefore may exhibit a low viscosity in the resin state of about 5 mPa·s to about 50 mPa·s, and a glass transition temperature of about -50°C to about 0°C after photocuring. The resin composition of the embodiments contains about 0.1 wt% to about 5 wt% of polymer (B), and the adhesive component formed by curing the resin composition of the embodiments may therefore have high adhesion to polyethylene terephthalate films and glass, thereby possessing flexibility suitable for folding devices.

[0088] The resin composition of the embodiment may further comprise a monofunctional (meth)acrylate (C). The resin composition of the embodiment may further comprise a monofunctional (meth)acrylate (C) different from (meth)acrylate (A) and polymer (B).

[0089] A monofunctional (meth)acrylate (C) refers to a (meth)acrylate having a single functional group. As a non-limiting example, a monofunctional (meth)acrylate (C) refers to a (meth)acrylate in which a (meth)acryloyl group is contained in one molecule. In the resin compositions of the embodiments, the monofunctional (meth)acrylate (C) may comprise different (meth)acrylates. For example, in the resin compositions of the embodiments, the monofunctional (meth)acrylate (C) may comprise at least one monofunctional acrylate and at least one monofunctional methacrylate.

[0090] Monofunctional (meth)acrylates (C) may include, for example, phenoxyethyl (meth)acrylate, phenoxyethoxyethyl (meth)acrylate, phenoxyhydroxypropyl (meth)acrylate, phenylphenoxyethyl (meth)acrylate, bromophenoxyethyl (meth)acrylate, polyoxyethylene nonylphenyl ether (meth)acrylate, isobornyl (meth)acrylate, adamantane (meth)acrylate, methyl adamantane (meth)acrylate, ethyl adamantane (meth)acrylate, borneol (meth)acrylate, tricyclodecyl (meth)acrylate, dicyclopentyl (meth)acrylate, dicyclopentenyl (meth)acrylate, cyclohexyl (meth)acrylate, butylcyclohexyl (meth)acrylate, methyl (meth)acrylate, ethyl (meth)acrylate, and propyl (meth)acrylate. Isopropyl methacrylate, butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, pentyl methacrylate, hexyl methacrylate, heptyl methacrylate, octyl methacrylate, isooctyl methacrylate, ethylhexyl methacrylate, nonyl methacrylate, decyl methacrylate, isodecanyl methacrylate, undecyl methacrylate, dodecyl methacrylate, octadecyl methacrylate, isooctadecyl methacrylate, benzyl methacrylate, ethoxydiethylene glycol methacrylate, polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, methoxyethylene glycol methacrylate, ethoxyethyl methacrylate, or mixtures thereof. In the resin composition of the embodiments, the monofunctional (meth)acrylate (C) may comprise at least one of isodecanyl acrylate and (2-methyl-2-ethyl-1,3-dioxacyclopentan-4-yl)methacrylate. The monofunctional (meth)acrylate (C) may contain at least one of isodecanyl acrylate and medol-10 (Osaka Organic Chemical Industry Ltd.).

[0091] Relative to a total of 100 wt% resin composition, the resin composition of the embodiments may contain about 50 wt% to about 88 wt% of a monofunctional (meth)acrylate (C). The resin composition of the embodiments may contain about 50 wt% to about 88 wt% of a monofunctional (meth)acrylate (C), and therefore may exhibit a low viscosity in the resin state of about 5 mPa·s to about 50 mPa·s, and a glass transition temperature of about -50°C to about 0°C after photocuring. The resin composition of the embodiments contains about 50 wt% to about 88 wt% of a monofunctional (meth)acrylate (C), and the adhesive component formed by curing the resin composition of the embodiments may therefore have high adhesion to polyethylene terephthalate films and glass, thereby possessing flexibility suitable for folding devices.

[0092] The resin composition of the embodiments may further comprise a urethane (meth)acrylate oligomer (D). The urethane (meth)acrylate oligomer (D) may have a weight-average molecular weight of about 6,000 or greater. In the resin composition of the embodiments, the urethane (meth)acrylate oligomer (D) may have a weight-average molecular weight of about 27,000 to about 50,000.

[0093] In embodiments, the urethane (meth)acrylate oligomer (D) may comprise a photocurable compound containing at least one (meth)acryloyl group having a urethane bond. The urethane (meth)acrylate oligomer (D) may comprise at least one of an acrylate having a urethane bond, an urethane acrylate having a polycarbonate backbone, and an urethane acrylate having a polyether backbone. For example, the resin composition of the embodiments may contain at least one of UF-C051 (Kyoeisha Chemical Co., Ltd.) and UN7700 (Negami Chemical Industrial) as a urethane (meth)acrylate oligomer.

[0094] Resin compositions containing urethane (meth)acrylate oligomers (D) having a weight-average molecular weight of about 6,000 or greater can exhibit low viscosity properties and can be applied by methods such as inkjet printing or dispensing coating. The urethane (meth)acrylate oligomers (D) having a weight-average molecular weight of about 6,000 or greater are contained in the resin composition in an oligomeric state with a relatively high degree of polymerization, thereby maintaining a high degree of polymerization even after photocuring, and thus can exhibit low storage modulus (G′) values ​​and high peel strength properties.

[0095] Relative to a total of 100 wt% of the resin composition, the resin composition of the embodiments may contain about 1 wt% to about 15 wt% of urethane (meth)acrylate oligomer (D). The resin composition of the embodiments may contain about 1 wt% to about 15 wt% of urethane (meth)acrylate oligomer (D) having a weight average molecular weight of about 6,000 or greater, and thus exhibits a low viscosity of about 5 mPa·s to about 50 mPa·s in the resin state, and has a glass transition temperature of about -50°C to about 0°C after photocuring. Therefore, if the adhesive component formed from the resin composition of the embodiments is applied to a foldable display device, the display device may have improved folding characteristics.

[0096] The resin composition of the embodiment may further comprise at least one photoinitiator. If the resin composition may comprise a photoinitiator, different photoinitiators may be activated by UV light with different center wavelengths.

[0097] The photoinitiator may be selected from 2,2-dimethoxy-1,2-diphenylethyl-1-one, 1-hydroxy-cyclohexyl-phenyl-one, 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-propanoyl)-benzyl]-phenyl}-2-methylprop-1-one.

[0098] The photoinitiator can be selected from 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinoprop-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1,2-dimethylamino-2-(4-methyl-benzyl)-1-(4-morpholino-4-yl-phenyl)-but-1-one, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, etc. The resin composition of the embodiment may contain any one of acyl-diphenyl phosphite, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, [1-(4-phenylsulfonylbenzoyl)heptylamino]benzoate, [1-[9-ethyl-6-(2-methylbenzoyl)carbazole-3-yl]ethyleneamino]acetate, and bis(2,4-cyclopentadienyl)bis[2,6-difluoro-3-(1-pyrrolidinyl)phenyl]titanium (IV).

[0099] The resin composition of the embodiments may further include other additives, such as curing accelerators. Curing accelerators may include multifunctional amino acrylates and can promote the photocuring reaction of the resin composition of the embodiments. For example, the resin composition of the embodiments may include photomer 4250 (IGM) as a curing accelerator.

[0100] The resin composition of the embodiments may not contain any organic solvent. As an example, the resin composition of the embodiments may contain an organic solvent, but only in an amount of about 1 wt% or less relative to a total of 100 wt% of the resin composition. The resin composition of the embodiments may not contain any organic solvent or may contain an amount of about 1 wt% or less of organic solvent, and thus the processability of the resin composition can be improved, and costs can be reduced when the resin composition of the embodiments is used to form adhesive components.

[0101] To apply adhesive components formed from resin compositions to flexible display devices, it is necessary to ensure the flexibility of the adhesive components. For this purpose, plasticizers are used in existing resin compositions. However, plasticizers typically cause reduced durability at high temperatures after UV curing, poor curing due to delamination, and cloudiness. Furthermore, most plasticizers are high-molecular-weight polymer compounds that increase the viscosity of the resin composition, making them unsuitable for inkjet printing. To apply resin compositions containing plasticizers to inkjet printing processes, organic solvents are required, for example. However, when using organic solvents, processes such as removing the organic solvents after curing can become difficult.

[0102] For example, the resin composition of the embodiment can have high flexibility without the use of plasticizers and organic solvents, form an adhesive component with high stability at low and high temperatures, have excellent processability in the state of the resin composition, and thus can form an adhesive component that can be applied to a flexible display device by inkjet process.

[0103] The resin composition of the embodiment can have a viscosity of about 5 mPa·s to about 50 mPa·s at about 20°C to about 30°C. For example, the resin composition according to the embodiment can have a viscosity of about 5 mPa·s to about 50 mPa·s at about 25°C. The viscosity of the resin composition is measured according to the JIS K 2283 method.

[0104] If the resin composition of the embodiment has a viscosity of less than about 5 mPa·s at about 20°C to about 30°C, the viscosity is low, causing the liquid resin composition supplied for forming the adhesive component to flow, and therefore, it may be difficult to use the resin composition to form a coating film with a uniform thickness. If the resin composition of the embodiment has a viscosity of greater than about 50 mPa·s at about 20°C to about 30°C, it may be difficult to discharge the resin composition from the applicator used to apply the resin composition in an appropriate amount.

[0105] The liquid resin composition is cured by UV irradiation and can be formed into a film or thin film after UV curing. After UV curing, the resin composition of the embodiment can have a 180° peel strength of about 1000 gf / 25 mm or greater than 1000 gf / 25 mm to a glass substrate or polyethylene terephthalate (PET) film.

[0106] Resin compositions cured by UV irradiation can have low glass transition temperatures. After UV curing, the resin compositions of the embodiments can have glass transition temperatures ranging from about -50°C to about 0°C. If the glass transition temperature of the resin compositions of the embodiments is greater than 0°C after UV curing, the cured resin compositions can have reduced durability and flexibility at low temperatures.

[0107] The display panel DP may include a substrate BS, a circuit layer DP-CL disposed on the substrate BS, a display element layer DP-EL disposed on the circuit layer DP-CL, and an encapsulation layer TFE covering or overlapping the display element layer DP-EL. For example, the display panel DP may include organic light-emitting elements or quantum dot light-emitting elements in the display element layer DP-EL.

[0108] Figure 7 The configuration or structure of the display panel DP shown is an example, and the configuration or structure of the display panel DP is not limited to this. Figure 7 The configuration or structure shown is illustrated. For example, a display panel DP may include liquid crystal display elements, and the encapsulation layer TFE may be omitted.

[0109] An input sensing unit TP can be disposed on a display panel DP. For example, the input sensing unit TP can be disposed on or directly disposed on the encapsulation layer TFE of the display panel DP. The input sensing unit TP can detect external input, convert the input into a predetermined input signal, and provide the input signal to the display panel DP. For example, in the display device DD of the embodiment, the input sensing unit TP can be a touch sensing unit for detecting touch. The input sensing unit TP can identify direct touch by a user, indirect touch by a user, direct touch by an object, or indirect touch by an object. The input sensing unit TP can detect at least one of the location of the touch applied externally or the intensity (pressure) of the touch. The input sensing unit TP in the embodiment can have various structures or be formed of various materials, and is not limited to any one embodiment. The input sensing unit TP may include sensing electrodes (not shown) for detecting external input. The sensing electrodes (not shown) can detect external input capacitively. The display panel DP can receive the input signal from the input sensing unit TP and generate an image corresponding to the input signal.

[0110] The window WP protects the display panel DP and the input sensing unit TP. The image IM generated by the display panel DP can be transmitted to the user through the window WP. The window WP provides a touch surface for the display device DD. In a display device DD that includes a folding area FA, the window WP can be a flexible window.

[0111] The window WP may include a substrate layer BL and a printed layer BM. The window WP may include a transmissive region TA and a baffle region BZA. The front surface of the window WP, including the transmissive region TA and the baffle region BZA, corresponds to the front surface of the display device DD.

[0112] The transmissive region TA can be an optically transparent region. The baffle region BZA can be a region with a relatively lower light transmittance than the transmissive region TA. The baffle region BZA can have a predetermined color. The baffle region BZA can be adjacent to the transmissive region TA, and can surround the transmissive region TA or be adjacent to the transmissive region TA. The baffle region BZA can define the shape of the transmissive region TA. However, the embodiments are not limited to the illustrated embodiments; the baffle region BZA can be configured to be adjacent only to one side of the transmissive region TA, and a portion of it can be omitted.

[0113] The substrate layer BL can be a glass substrate or a plastic substrate. For example, the substrate layer BL can be a tempered glass substrate. As an example, the substrate layer BL can be formed from a flexible polymer resin. For example, the substrate layer BL can be formed from polyimide, polyacrylate, polymethyl methacrylate, polycarbonate, polyethylene naphthalate, polyvinylidene chloride, polyvinylidene fluoride, polystyrene, ethylene vinyl alcohol copolymer, or combinations thereof. However, the embodiments are not limited to this, and the general forms of the substrate layer BL used as a window WP in the art can be used without limitation.

[0114] The printed layer BM can be disposed on one surface of the substrate layer BL. In an embodiment, the printed layer BM can be provided or disposed on the lower surface of the substrate layer BL adjacent to the display panel DP. The printed layer BM can be disposed on the edge region of the substrate layer BL. The printed layer BM can be an ink-printed layer. Alternatively, the printed layer BM can be a layer formed by containing pigments or dyes. In the window WP, the baffle region BZA can be the portion in which the printed layer BM is provided or disposed.

[0115] The window WP may further include at least one functional layer (not shown) provided or disposed on the substrate layer BL. For example, the functional layer (not shown) may be, for example, a hard coating or an anti-fingerprint coating, but the implementation is not limited thereto.

[0116] There may be a step between the portion provided with the printed layer BM and the base layer BL without the printed layer BM. The adhesive component AP of the embodiment formed from the resin composition of the above-described embodiment has a low elastic modulus and a high adhesion value to attach to the window WP without lifting at the stepped portion.

[0117] The adhesive component AP of the embodiments may comprise a polymer derived from the resin composition of the embodiments described above. For example, the adhesive component AP according to the embodiments may comprise: a (meth)acrylate (A) containing hydroxyl groups and having a molecular weight of about 500 or less, and a polymer (B) having polyisoprene or polybutadiene as the main backbone, having at least one free radical reactive group in one molecule, and having a molecular weight of about 2,000 to about 35,000. The adhesive component AP of the embodiments may comprise a polymer derived from a resin composition comprising (meth)acrylate (A), polymer (B), and further comprising a monofunctional (meth)acrylate (C), a urethane (meth)acrylate oligomer (D), and a photoinitiator. The description of the resin composition of the embodiments described above can also be applied to (meth)acrylate (A), polymer (B), monofunctional (meth)acrylate (C), urethane (meth)acrylate oligomer (D), and photoinitiator.

[0118] The resin composition for forming the adhesive component AP by polymerization using a photoinitiator can have a viscosity of about 5 mPa·s to about 50 mPa·s at about 20°C to about 30°C, as measured according to the JIS K 2283 method. The glass transition temperature of the adhesive component AP according to the embodiment can be about -50°C to about 0°C.

[0119] The adhesive component AP can have a 180° peel strength of approximately 1000 gf / 25 mm or greater than 1000 gf / 25 mm for glass substrates or polyethylene terephthalate (PET) films.

[0120] The adhesive component AP according to the embodiment can possess high flexibility and adhesive properties, and exhibits high stability and durability at both low and high temperatures. Therefore, applying the adhesive component AP according to the embodiment to a flexible display device ensures excellent folding characteristics.

[0121] The adhesive component AP included in the display device DD of the embodiment can be provided or disposed on one surface of the window WP or the display module DM in the form of a liquid resin composition, and can be formed by providing or disposing of the liquid resin composition between the window WP and the display panel DP through UV curing. In contrast, the adhesive component AP can be provided by: UV curing the liquid resin composition in a separate process; laminating one surface of the adhesive component AP in the cured state as an adhesive film onto one surface of the window WP or the display module DM; and attaching an unattached one surface of the window WP or the display module DM to another or other surface of the adhesive component AP.

[0122] The adhesive component AP can have a thickness of about 50 μm to about 200 μm. For example, the adhesive component AP can have a thickness of about 100 μm to about 150 μm.

[0123] Figures 8A to 8C This is a schematic illustration of a method for preparing an adhesive component AP according to an embodiment. Figure 8A An example is provided of a resin composition RC for forming an adhesive component AP. Figure 8B An example is given of UV irradiation, and Figure 8C An example is shown for removing the carrier membrane CF.

[0124] refer to Figures 8A to 8CThe resin composition RC can be provided on a carrier film CF. For example, a polyethylene terephthalate (PET) film can be used as the carrier film CF, but the embodiments are not limited thereto. The carrier film CF serves as a substrate for applying the liquid resin composition RC and can be used without limitation, as long as it is easily separable from the adhesive component AP after UV curing. For example, a release treatment can be performed on one surface of the carrier film CF on which the resin composition RC is provided.

[0125] The resin composition RC can be provided by methods such as inkjet printing or dispensing. The resin composition RC of the embodiments can be readily expelled from the nozzle NZ, for example, by having a viscosity value of about 5 mPa·s to about 50 mPa·s at about 20°C to about 30°C, and can be provided to maintain a constant coating thickness. As an example, the resin composition RC of the embodiments can have a viscosity value of about 5 mPa·s to about 50 mPa·s at about 25°C.

[0126] Pre-adhesive components P-AP can be provided by applying a resin composition RC to a constant thickness using UV irradiation. Figure 8B An example is shown of a pre-adhesive component P-AP that can be coated by UV irradiation or direct UV irradiation, but the embodiments are not limited thereto. An auxiliary carrier film (not shown) may be further disposed on the pre-adhesive component P-AP, and the auxiliary carrier film (not shown) transmits UV and may cover or overlap the pre-adhesive component P-AP during the UV curing process.

[0127] After UV curing, an adhesive component AP can be formed. The adhesive component AP, which is finally provided by removing the carrier film CF used in the process, can have a glass transition temperature of about -50°C to about 0°C, and a peel strength of about 1000 gf / 25 mm or greater than 1000 gf / 25 mm for a glass substrate or polyethylene terephthalate (PET) film.

[0128] exist Figures 8A to 8C The adhesive component AP prepared in the above steps can be applied to the display device DD described above. For example, one surface of the adhesive component AP can be attached to the display module DM, and the window WP can be sequentially attached to another or other surface of the adhesive component AP facing the surface of the adhesive component AP attached to the display module DM. In contrast, the adhesive component AP can be provided to the display device DD by attaching one surface of the adhesive component AP to one surface of the window WP facing the display module DM, and attaching another or other surface of the adhesive component AP facing the surface of the adhesive component AP attached to the window WP to the display module DM.

[0129] The resin composition provided in a liquid state between the display module DM and the window WP can be cured to form the adhesive component AP. Figure 9A and Figure 9B Examples are shown by referring to Figures 8A to 8C The methods described are different methods for preparing adhesive components AP, which are included in display devices DD.

[0130] Figure 9A An example is provided on a display panel DP with a resin composition RC. Figure 9B An example is a pre-adhesive component P-AP formed from a resin composition RC by UV irradiation.

[0131] The resin composition RC can be provided by methods such as inkjet printing or dispensing. The resin composition RC of the embodiment can be easily dispensed from the nozzle NZ, for example, by having a viscosity value of about 5 mPa·s to about 50 mPa·s at about 25°C, and can be provided to maintain a thin, constant coating thickness. The resin composition has a viscosity value of about 5 mPa·s to about 50 mPa·s, and therefore can be provided while covering or overlapping the unevenness of the stepped SP-a of the display module DM. For example, the resin composition RC has a viscosity value of about 50 mPa·s or less, and therefore can fill unevenness, such as the stepped portion SP-a, without empty spaces. The resin composition RC provided by the nozzle NZ has a viscosity value of about 5 mPa·s or greater than 5 mPa·s, so as to be uniformly applied to a predetermined thickness without overflowing the display module DM.

[0132] A window WP can be provided or formed on a pre-adhesive member P-AP provided by applying a resin composition RC to a constant thickness. UV for curing the resin composition RC can be provided through the window WP. If a window WP is provided or formed on the pre-adhesive member P-AP, the resin composition RC can fill the stepped portion SP-b without empty spaces. For example, the resin composition RC has a low viscosity value of about 50 mPa·s or less, thereby covering or overlapping the curved shape at the curved portion of the stepped portion SP-a, such as between the matrix layer BL and the printed layer BM, to provide the pre-adhesive member P-AP. The pre-adhesive member P-AP can be cured after polymerization by the provided UV to form the adhesive member AP.

[0133] and Figure 9BThe difference shown is that, prior to providing or setting the window WP on the pre-adhesive member P-AP, UV light is applied to the pre-adhesive member P-AP to induce a polymerization reaction in the resin composition RC. The amount of UV irradiation can be the amount of light required for complete curing of the resin composition RC. However, unlike the above, the final adhesive member AP can be formed by partially inducing a polymerization reaction in the resin composition RC in the pre-adhesive member P-AP state and further reacting the unreacted resin composition RC after covering or overlapping the window WP.

[0134] Figures 1 to 5 The display devices DD, DD-a, and DD-b shown in the embodiments include an adhesive member AP comprising a polymer containing a resin composition derived from the embodiments described above, so as to maintain the adhesive member AP in an adhesive state with respect to the window WP and the display panel DP, even when folded or in a curved area, without the adhesive member AP warping.

[0135] Figure 10 This is a schematic cross-sectional view illustrating a display device according to an embodiment. In the following text, in Figure 10 In the description of the display device of the illustrated embodiment, references to the above description are made. Figures 1 to 9B Repeated descriptions will no longer be described, and differences will be described instead.

[0136] Reference Figure 6 and Figure 7 Compared to the described display device DD, Figure 10 The display device DD-1 of the embodiment shown may further include a light control layer PP and an optical adhesive layer AP-a. The display device DD-1 of the embodiment may further include a light control layer PP disposed between the adhesive member AP and the window WP, and an optical adhesive layer AP-a disposed between the light control layer PP and the window WP.

[0137] A light control layer (PP) can be disposed on a display panel (DP) to control reflected light from the display panel (DP) caused by external light. The light control layer (PP) may include, for example, a polarizing layer or a color filter layer.

[0138] The optical adhesive layer AP-a can be an optically clear adhesive film (OCA) or an optically clear adhesive resin layer (OCR). The optical adhesive layer AP-a can be made from the resin composition of the embodiments described above in conjunction with the adhesive component AP of the embodiments described above. Figure 7 Formed in the same manner. For example, the optical adhesive layer AP-a of the embodiment may comprise a polymer derived from a resin composition comprising (meth)acrylate (A), polymer (B), monofunctional (meth)acrylate (C), urethane (meth)acrylate oligomer (D), and a photoinitiator.

[0139] The resin composition for forming the optical adhesive layer AP-a through polymerization using a photoinitiator can have a viscosity of about 5 mPa·s to about 50 mPa·s at about 20°C to about 30°C, as measured according to the JIS K 2283 method. The glass transition temperature of the optical adhesive layer AP-a according to the embodiment can be about -50°C to about 0°C. The optical adhesive layer AP-a according to the embodiment can have a low glass transition temperature value of about -50°C to about 0°C.

[0140] The optical adhesive layer AP-a can have a 180° peel strength of approximately 1000 gf / 25 mm or greater than 1000 gf / 25 mm for glass substrates or polyethylene terephthalate (PET) films.

[0141] The optical adhesive layer AP-a according to the embodiment can possess high flexibility and adhesive properties, and exhibits high stability and durability at both low and high temperatures. Therefore, the optical adhesive layer AP-a according to the embodiment can be applied to flexible display devices, thereby ensuring excellent folding characteristics.

[0142] The display device DD-1 of the embodiment may include an optical adhesive layer AP-a and an adhesive component AP formed from the resin composition of the embodiment. The optical adhesive layer AP-a and the adhesive component AP have a low glass transition temperature, high flexibility and adhesive properties, and high stability and durability at both low and high temperatures. This prevents the interface between the optical adhesive layer AP-a and the adhesive component AP from lifting even when the display device DD-1 is folded or bent, and thus can exhibit excellent reliability characteristics.

[0143] Figure 11 This is a schematic cross-sectional view illustrating a display device according to an embodiment. In the following text, in Figure 11 In the description of the display device of the illustrated embodiment, references to the above description are made. Figures 1 to 10 Repeated descriptions will no longer be described, and differences will be described instead.

[0144] Reference Figure 6 and Figure 7 Compared to the described display device DD, Figure 11 The display device DD-2 of the embodiment shown may further include a light control layer PP, an optical adhesive layer AP-a, and an interlayer adhesive layer PIB. As Figure 10The display device DD-1 of the illustrated embodiment and the display device DD-2 of the illustrated embodiment may further include a light control layer PP disposed between the adhesive member AP and the window WP, and an optical adhesive layer AP-a disposed between the light control layer PP and the window WP.

[0145] In the display device DD-2 according to the embodiment, an adhesive member AP can be provided between the display panel DP and the input sensing unit TP. For example, the input sensing unit TP may not be disposed on or may not be directly disposed on the display panel DP, and the display panel DP and the input sensing unit TP can be bonded to each other by the adhesive member AP. For example, the adhesive member AP can be disposed on the encapsulation layer TFE of the display panel DP. Figure 7 () and the input sensing unit TP.

[0146] An interlayer adhesive layer (PIB) can be provided or disposed beneath the light control layer (PP). The PIB can be disposed between the input sensing unit (TP) and the light control layer (PP), and can be formed of an adhesive material with excellent moisture-proof properties. For example, an interlayer adhesive layer (PIB) containing polyisobutylene can be formed. The PIB can be disposed on the input sensing unit (TP) to prevent corrosion of the sensing electrodes of the input sensing unit (TP).

[0147] The display device DD-2 of the embodiment may include an optical adhesive layer AP-a and an adhesive member AP formed from the resin composition of the embodiment. The optical adhesive layer AP-a and the adhesive member AP exhibit low storage modulus and high elastic recovery force, thereby preventing the interface between the optical adhesive layer AP-a and the adhesive member AP from lifting even when the display device DD-2 is folded or bent, and thus exhibiting excellent reliability characteristics.

[0148] In the following description, resin compositions, adhesive components, and display devices of embodiments will be described with reference to examples and comparative examples. The examples shown below are for understanding the present disclosure only, and the scope of the disclosure is not limited thereto.

[0149] [Example]

[0150] 1. Preparation of curable liquid resin compositions

[0151] The resin compositions of the examples were prepared using the blending ratios listed in Table 1. The resin compositions of the comparative examples were prepared using the blending ratios listed in Table 2. After the forming materials of the examples and comparative examples were provided in a heat-resistant and light-shielding container in the weight ratios disclosed in Tables 1 and 2, a mixture in which Omnirad TPO-H, Esacure 3644, Omnirad 819 and Photomer 4250 were mixed in a weight ratio of 60:10:30:1 was provided in an amount of 2 wt% relative to a total of 100 wt% of the resin composition as a photoinitiator and curing accelerator. The provided materials were then stirred at 1000 rpm for 30 minutes at room temperature using a planetary mixer (manufactured by SHASHIN KAGAKU CO., LTD.) to obtain a curable resin composition.

[0152]

[0153]

[0154] <Data on materials used as components in the examples and comparative examples>

[0155] The data for the materials used in the embodiments and comparative examples disclosed in Tables 1 and 2 are as follows.

[0156] 4-HBA: 4-Hydroxybutyl acrylate

[0157] 3-HPA: 3-Hydroxypropyl Acrylate

[0158] HEA: Hydroxyethyl acrylate

[0159] UC-102M: A polyisoprene compound with free radical curable groups (Kuraray Corporation)

[0160] UC-203M: A polyisoprene compound with free radical curable groups (Kuraray Corporation)

[0161] TEAI-1000: A polybutadiene compound with free radical curable groups (Nippon Soda Co., Ltd.)

[0162] IDAA: Isodecyl acrylate

[0163] Medol-10: (2-Methyl-2-ethyl-1,3-dioxacyclopentan-4-yl)methacrylate (Osaka Organic Chemical Industry Co., Ltd.)

[0164] IBXA: Isoborneol Acrylate

[0165] FA-512AS: Dicyclopentenyloxyethyl acrylate

[0166] LA: Lauryl acrylate

[0167] UF-C051: Carbamate acrylate (Kyoei Chemical Co., Ltd.)

[0168] UN7700: Carbamate acrylates (Genjo Chemical Industry)

[0169] HSA: 12-hydroxystearic acid

[0170] MEK: Methyl Ethyl Ketone

[0171] 2. Evaluation of the physical properties of the resin composition and the adhesive components formed from the resin composition

[0172] Table 3 below measures and displays the viscosity and inkjet printer application characteristics of the resin compositions having the composition ratios of Tables 1 and 2, the glass transition temperature of the cured product formed by curing the resin compositions, curing properties, 180° peel strength, high-temperature durability, low-temperature durability, and flexural adhesion. The viscosity of the resin compositions, inkjet printer application characteristics, glass transition temperature of the cured product, curing properties, 180° peel strength, high-temperature durability, low-temperature durability, and flexural adhesion were measured using the following methods.

[0173] Methods for measuring viscosity

[0174] The viscosity of the resin composition described in the description was measured at 25°C according to JIS K 2283 method and at 10 rpm using a viscometer TVE-25L (TOKI SANGYO, Japan).

[0175] [Measurement of the glass transition temperature of the cured product]

[0176] Using the curable resin compositions prepared in the examples and comparative examples, the integrated light intensity of 4000 mJ / cm was measured using a metal halide lamp (Eye Graphics Co., Ltd., conveyor-type UV irradiation device). 2 Cured resin products (8 mm in diameter and 0.5 mm in thickness) were obtained by UV irradiation, and the glass transition temperature (Tg) of the cured products was measured using a dynamic viscoelasticity measuring device (Anton Paar, MCR302). The measurement conditions were a frequency of 1 Hz, a temperature of -70°C to 80°C, and a heating rate of 10°C / min.

[0177] [Evaluation of curing properties]

[0178] Using the curable resin compositions prepared in the Examples and Comparative Examples, a polyethylene terephthalate film (Toyo Boseki Co., Ltd., Cosmoshine 4100, thickness: 100 μm) and a glass slide (Matsunami Glass Ind., Ltd., S1112) were bonded together to obtain a curable resin composition with a thickness of 100 μm. After bonding, a metal halide lamp (Iwasaki Co., Ltd., conveyor belt UV irradiation device) at 4000 mJ / cm² was used on the glass slide side. 2 UV irradiation is applied at an integrated light intensity to cure the curable resin composition in order to obtain a laminate. By observing the appearance of the laminates obtained above, those without turbidity or poor curing are evaluated as "good", and those with at least one of turbidity or poor curing are evaluated as "defective".

[0179] [Evaluation of the application characteristics of inkjet printers]

[0180] Using the curable resin compositions prepared in the Examples and Comparative Examples, coating and UV curing were performed using an inkjet printer from MICROJET, and the appearance of the cured coatings was observed. Based on the observations, those applicable and without thickness deviation were rated as "good," those applicable but with thickness deviation were rated as "defective," and those not applicable were rated as "not applicable."

[0181] [Measurement of 180° peel strength]

[0182] The curable resin compositions prepared in the examples and comparative examples were applied to a glass slide (Matsunami Glass Industry Co., Ltd., S1112) to obtain a curable resin composition with a thickness of 100 μm. Then, using a UV-LED with a wavelength peak of 365 ± 5 nm, at 100 mW / em... 2 A UV-cured temporary product layer was prepared by irradiating the product with intense UV light for 2 seconds. A polyimide film (DuPont-Toray, [Kapton], thickness: 75 μm) and a glass slide (Matsunami Glass Industry Co., Ltd., [S1112]) were bonded to the prepared UV-cured temporary product layer, and the result was treated at 30°C and 0.5 MPa for 5 minutes using an automated heating and pressure treatment apparatus (Chiyoda Electronics Co., Ltd., [ACS-230]). Then, a UV-LED with a wavelength peak of 395 ± 5 nm was used, with a power of 500 mW / cm². 2The laminate was obtained by subjecting the laminate to intense UV irradiation for 4 seconds. Using the laminate, a 180° peel test was performed using a tensile testing machine (Instron 5965). The measurement conditions were 25°C and a tensile speed of 300 mm / min.

[0183] [Measurement of High-Temperature Durability]

[0184] The polyimide film / cured resin product / glass slide laminate was obtained using the same method as the 180° peel strength measurement. The laminate obtained above was then held at high temperature or high temperature and high humidity (e.g., 85°C, 85% RH) for 72 hours to observe for phenomena such as warping or delamination at the interface with the adherend. Based on the observations, the laminate was rated "good" if there was no change in its appearance, and "defective" if warping or delamination was present.

[0185] [Measurement of Low-Temperature Durability]

[0186] The polyimide film / cured resin product / glass slide laminate was obtained using the same method as the 180° peel strength measurement. The laminate obtained was then held at a low temperature (e.g., -20°C) for 72 hours to observe for phenomena such as warping or delamination at the interface with the adhesive. Based on the observations, the laminate was rated "good" if there was no change in its appearance, and "defective" if warping or delamination was present.

[0187] [Flexibility and Adhesion Test]

[0188] At 23°C and 50% RH, the formulations prepared in the examples and comparative examples were applied to one side of a polyethylene terephthalate film (thickness: 100 μm) and integrated with another polyethylene terephthalate film (thickness: 100 μm) to achieve an integrated light intensity of 4000 mJ / cm. 2 The photoreaction was carried out under UV irradiation. The thickness of the laminate was measured and adjusted to form an adhesive layer with a thickness of 100 μm. The resulting material was placed at 23°C and 50% RH for 24 hours. The PET film / adhesive layer / PET film laminate obtained by this process was cut into samples with a width of 50 mm and a length of 200 mm.

[0189] The samples obtained above were repeatedly bent 30,000 times at 23°C and a bending diameter of 3 mm using a durability tester (Yuasa System Co., Ltd., U-shaped folding tester). Then, the presence or absence of warping and delamination at the interface between the adhesive layer and the adhesive substrate, as well as the presence or absence of adhesive leakage within the adhesive layer, were visually inspected. Durability was evaluated based on the following criteria: Based on the observations, laminates with no change in appearance were rated as "good," while laminates with warping, delamination, or damage were rated as "defective."

[0190] [Table 3]

[0191]

[0192] Referring to the results in Table 3, it was observed that Examples 1 to 11 had low viscosities of about 5 mPa·s to about 50 mPa·s in the resin composition state. The resin compositions of Examples 1 to 11 have low viscosity properties and can therefore be used to form thin, uniform coatings.

[0193] In Examples 1 to 11, approximately 5 wt% to approximately 30 wt% of (meth)acrylate (A), approximately 0.1 wt% to approximately 5 wt% of polymer (B), approximately 50 wt% to approximately 88 wt% of monofunctional (meth)acrylate (C), and approximately 1 wt% to approximately 15 wt% of urethane (meth)acrylate oligomer (D) were used. It was observed that, after photocuring, the resin compositions comprising the above material combinations exhibited low glass transition temperatures, high adhesion properties to glass substrates, excellent durability at both high and low temperatures, and excellent adhesion during repeated folding operations. Therefore, when the resin compositions of the embodiments are used to form adhesive components for flexible display devices, durability and folding characteristics can be improved.

[0194] Compared to the resin compositions of the examples, Comparative Example 1 did not contain polymer (B), and therefore exhibited reduced durability at high temperatures, and showed damaged cured resin in the flexural adhesion test (or bending adhesion test). Compared to the resin compositions of the examples, Comparative Example 2 contained more than 5 wt% of polymer (B), and therefore exhibited reduced adhesion to glass and polyethylene terephthalate, and showed delamination in the flexural adhesion test. It was observed that, compared to the resin compositions of the examples, in Comparative Example 3, the cured product had a glass transition temperature greater than 0°C, and therefore caused the cured resin composition to lose flexibility, resulting in delamination in the durability test at low temperature (-20°C) and damage to the resin in the flexural adhesion test. It was observed that, compared to the resin compositions of the examples, in Comparative Example 4, the cured product had a glass transition temperature less than -50°C, and therefore exhibited reduced durability at high temperatures, and delamination and deformation of the resin were observed in the durability test at 85°C. Unlike the resin compositions of the examples, in Comparative Examples 5 and 6, the viscosity at 25°C exceeded the range of about 5 mPa·s to about 50 mPa·s, indicating failure of precise application on an inkjet printer. As examples, in Comparative Example 5, when the viscosity was less than 5 mPa·s, defects occurred during pattern formation due to ejection defects, and when the viscosity was greater than 50 mPa·s, as in Comparative Example 6, thickness deviations occurred after ejection, indicating failure of uniform application. Compared to the resin compositions of the examples, Comparative Example 7 did not contain (meth)acrylate (A) and therefore had reduced adhesion to glass and polyethylene terephthalate, and exhibited delamination in the flexural adhesion test. It was observed that, compared to the resin compositions of the examples, Comparative Example 8 contained more than 30 wt% of (meth)acrylate (A), and therefore had an increased glass transition temperature, resulting in a loss of flexibility in the cured resin composition, thus exhibiting delamination in the durability test at low temperature (-20°C) and damage to the resin in the flexural adhesion test.

[0195] Compared to the resin compositions of the examples, Comparative Example 9 contains less than 50 wt% of a monofunctional (meth)acrylate (C), and therefore has high viscosity, making it difficult to apply to inkjet printers, and has reduced flexibility, resulting in damage to the resin in the flexural adhesion test. Compared to the resin compositions of the examples, Comparative Example 10 contains more than 15 wt% of a urethane (meth)acrylate oligomer (D), and therefore has high viscosity, making it difficult to apply to inkjet printers, and does not contain (meth)acrylate (A), and therefore has significantly reduced adhesion to glass and ethylene terephthalate and delamination in the flexural adhesion test. Compared to the resin compositions of the examples, Comparative Example 11 has high viscosity, resulting in thickness deviation when applied to inkjet printers, and has a high glass transition temperature, resulting in low flexibility at low temperatures, thus causing delamination in the durability test at -20°C, and does not contain polymer (B), resulting in reduced bendability, thus causing damage to the resin in the flexural adhesion test. Compared to the resin compositions of the examples, Comparative Examples 12 to 15 contain an oil gelling agent and form a gel state, resulting in a viscosity too high to measure the viscosity intended for use in an inkjet printer. They also contain more than 5 wt% of polymer (B), leading to significantly reduced adhesion to glass and polyethylene terephthalate and delamination in flexural adhesion tests. Comparative Example 16 contains 2 wt% of an organic solvent and therefore exhibits turbidity after UV curing, as well as delamination in high-temperature durability and flexural adhesion tests. Comparative Examples 17 to 19 contain 10 wt% of an organic solvent and therefore form a gel state even after UV curing, resulting in poor curing and requiring an additional drying process after curing. Delamination occurs in high- and low-temperature durability and flexural adhesion tests.

[0196] The resin composition of the embodiments has a viscosity of about 5 mPa·s to about 50 mPa·s before curing, indicating advantageous properties for forming a thin, uniform coating film, and exhibiting excellent coating properties even on uneven surfaces due to its low viscosity. The adhesive component of the embodiments formed by curing the resin composition of the embodiments has a low glass transition temperature of about -50°C to about 0°C, and a high 180° peel strength of more than about 1000 gf / 25 mm for polyethylene terephthalate films and glass. Therefore, the display device of the embodiments can include an adhesive component formed from the resin composition of the embodiments to exhibit good reliability without delamination or warping of the adhesive component in bent portions, excellent durability at low and high temperatures, and no delamination between the adhesive component and adjacent components even during bending or folding operations, thus exhibiting excellent operational reliability.

[0197] The resin composition of the embodiment is capable of forming a highly flexible adhesive component without the use of plasticizers and organic solvents, and does not require additional processes, such as organic solvent drying processes, and thus reduces the process cost and time of the adhesive component formed by curing the resin composition and the display device including the adhesive component to increase productivity.

[0198] The resin composition of the embodiment has low viscosity properties and therefore can exhibit excellent coating properties for substrates of various shapes.

[0199] The adhesive component according to the embodiment can have a low glass transition temperature, excellent adhesion properties to glass and polymer films, and exhibit excellent durability and stability at both high and low temperatures.

[0200] The display device of the embodiment may include an adhesive component with high flexibility and adhesion, and thus can exhibit excellent reliability under various operating conditions.

[0201] Although this disclosure has been described with reference to embodiments thereof, it should be understood that this disclosure should not be limited to these embodiments, and various changes and modifications may be made by those skilled in the art without departing from the spirit and scope of this disclosure.

[0202] Therefore, the technical scope of this disclosure is not intended to be limited to what is set forth in the detailed description of the specification, but may also be defined by the appended claims.

Claims

1. A resin composition comprising: (A) meth)acrylates containing hydroxyl groups and having a molecular weight of 500 or less; A polymer (B) comprising polyisoprene or polybutadiene as the main backbone, having at least one free radical reactive group in one molecule and having a molecular weight of 2,000 to 35,000. Monofunctional (meth)acrylates (C) different from the (meth)acrylate (A); and Uraffinate (meth)acrylate oligomers (D) having a molecular weight of 6,000 or greater, wherein The resin composition has a glass transition temperature of -50°C to 0°C after it is cured. The resin composition has a viscosity of 5 mPa·s to 50 mPa·s at a temperature of 30°C to 50°C, and The resin composition comprises, relative to the total amount of the resin composition: The (meth)acrylate (A) in amounts of 5 wt% to 30 wt%; The polymer (B) in amounts ranging from 0.1 wt% to 5 wt%; The monofunctional (meth)acrylate (C) in amounts of 50 wt% to 88 wt%; and The amount of the urethane (meth)acrylate oligomer (D) is from 1 wt% to 15 wt%.

2. The resin composition of claim 1, wherein at least one of the (meth)acrylate (A), the polymer (B), and the monofunctional (meth)acrylate (C) has two or more types.

3. The resin composition of claim 1, wherein, After the resin composition is cured, the resin composition has a 180° peel strength of 1000 gf / 25 mm or greater than 1000 gf / 25 mm for polyethylene terephthalate films and glass.

4. The resin composition of claim 1, further comprising an organic solvent. in, The resin composition contains 1 wt% or less of the organic solvent relative to the total amount of the resin composition.

5. Adhesive components, including: The polymer derived from the resin composition, wherein the adhesive component has a glass transition temperature of -50°C to 0°C, wherein The resin composition comprises: (A) meth)acrylates containing hydroxyl groups and having a molecular weight of 500 or less; A polymer (B) comprising polyisoprene or polybutadiene as the main backbone, having at least one free radical reactive group in one molecule and having a molecular weight of 2,000 to 35,000. Monofunctional (meth)acrylates (C) different from the (meth)acrylate (A); and Oligomers (D) of urethane (meth)acrylates with a molecular weight of 6,000 or greater. The resin composition has a viscosity of 5 mPa·s to 50 mPa·s at a temperature of 20°C to 30°C, and The resin composition comprises, relative to the total amount of the resin composition: The (meth)acrylate (A) in amounts of 5 wt% to 30 wt%; The polymer (B) in amounts ranging from 0.1 wt% to 5 wt%; The monofunctional (meth)acrylate (C) in amounts of 50 wt% to 88 wt%; and The amount of the urethane (meth)acrylate oligomer (D) is from 1 wt% to 15 wt%.

6. A display device, comprising: Display panel; A window is positioned on the display panel; as well as An adhesive component is disposed between the display panel and the window, wherein The adhesive component has a glass transition temperature of -50°C to 0°C and is derived from the resin composition. The resin composition comprises: (A) meth)acrylates containing hydroxyl groups and having a molecular weight of 500 or less; A polymer (B) comprising polyisoprene or polybutadiene as the main backbone, having at least one free radical reactive group in one molecule and having a molecular weight of 2,000 to 35,000. Monofunctional (meth)acrylates (C) different from the (meth)acrylate (A); and Oligomers (D) of urethane (meth)acrylates with a molecular weight of 6,000 or greater. The resin composition has a viscosity of 5 mPa·s to 50 mPa·s at a temperature of 20°C to 30°C, and The resin composition comprises, relative to the total amount of the resin composition: The (meth)acrylate (A) in amounts of 5 wt% to 30 wt%; The polymer (B) in amounts ranging from 0.1 wt% to 5 wt%; The monofunctional (meth)acrylate (C) in amounts of 50 wt% to 88 wt%; and The amount of the urethane (meth)acrylate oligomer (D) is from 1 wt% to 15 wt%.

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