KR102415270B1 - Supporting substrate for flexible display apparatus, method of manufacturing the substrate, and flexible display apparatus having the substrate - Google Patents

Abstract

Disclosed is a substrate for a flexible display device disposed under the flexible display panel to support the same. A substrate for a flexible display device is a restoration layer having a first substrate layer, a second substrate layer disposed to face the first substrate layer, and a restoration pattern layer having a plurality of spaced apart openings formed therebetween to bond them, includes Such a support substrate has a high restoring force, so that flexibility and durability of the flexible display device can be improved.

Description

Support substrate for flexible display device, manufacturing method thereof, and flexible display device including same

The present invention relates to a substrate applied to a flexible display device, a method for manufacturing the same, and a flexible display device having the same.

Recently, many studies have been conducted on flexible display devices in terms of portability and space utilization. Such a flexible display device is developing from a display device that is simply bent to a display device that can be rolled or folded.

In such a flexible display device, since a flexible substrate should be used instead of a conventional glass substrate, a problem in that durability of the display device is deteriorated may occur. In particular, in the case of a display device that can be rolled or folded, the substrate supporting the display device must be able to stably support the display panel despite numerous repeated deformations.

One object of the present invention is to provide a support substrate for a flexible display device having improved resilience and flexibility.

Another object of the present invention is to provide a flexible display device having the support substrate.

The substrate for a flexible display device according to an embodiment of the present invention is disposed under the flexible display panel to support the flexible display panel, and includes a first substrate layer; a second base layer disposed to face the first base layer; and a restoration layer disposed between the first substrate layer and the second substrate layer to adhere them, and having a restoration pattern layer in which a plurality of spaced apart openings are formed. In this case, the flexible display may be disposed on one of the first base layer and the second base layer.

In one embodiment, the strength of the first base layer and the second base layer may be the same, and the first base layer and the second base layer may include polycarbonate, polyethylene tephthalate, polyethylene naphthalate, and polymethyl. It may be formed of one material selected from the group consisting of methacrylates.

In one embodiment, the strength of the second substrate layer may be less than the strength of the first substrate layer, in this case, the first substrate layer is polycarbonate, polyethylene tephthalate, polyethylene naphthalate, and polymethyl methacrylic. It may be formed of one material selected from the group consisting of lattice, and the second base layer may be formed of an elastomeric material. For example, the second base layer may be formed of a silicone resin or a urethane resin.

In an embodiment, the openings may extend in a first direction, have the same shape and be spaced apart from each other at regular intervals in a second direction intersecting the first direction.

In an embodiment, the restoration pattern layer may have a planar shape in the form of a grid.

In an embodiment, the openings may be formed to pass through the restoration pattern layer, or may be formed from one surface of the restoration pattern layer to a depth smaller than a thickness of the restoration layer.

In an embodiment, the restoration pattern layer may be formed of a polymer compound of a first urethane acrylate oligomer compound, a first bifunctional acrylate monomer compound, and a second monofunctional acrylate monomer compound. In this case, the polymer compound may include the chemical structures of Chemical Formulas 1 to 3 below.

[Formula 1]

[Formula 2]

[Formula 3]

In Formulas 1 to 3, X and Y each represent an aliphatic hydrocarbon having 12 to 18 carbon atoms and an aliphatic hydrocarbon having about 6 to 13 carbon atoms, R1 and R2 independently represent hydrogen or a methyl group, Ra, Rb , Rc and Rd each independently represent hydrogen or a methyl group, and n is an integer of 6 or more and 12 or less.

In one embodiment, the first urethane acrylate oligomer compound may be a polymer of a difunctional isocyanate compound and an acrylate compound having one or more hydroxyl groups in the molecule.

In one embodiment, the difunctional isocyanate compound is 4,4'-dicyclohexyldiisocyanate, hexamethylene diisocyanate, 1,4-diisocyanatobutane, 1,6-diisocyanatohexane, 1 , 8-diisocyanatooctane, 1,12-diisocyanatodecane, 1,5-diisocyanato-2-methylpentane, trimethyl-1,6-diisocyanatohexane, 1,3-bis(isocyanato) Methyl) cyclohexane, trans-1,4-cyclohexene diisocyanate, 4,4'-methylenebis (cyclohexyl isocyanate), isophorone diisocyanate, toluene-2,4-diisocyanate, toluene-2,6-di Isocyanate, xylene-1,4-diisocyanate, tetramethylxylene-1,3-diisocyanate, 1-chloromethyl-2,4-diisocyanate, 4,4'-methylenebis(2,6-dimethylphenyl) isocyanate) and at least one selected from the group consisting of trimethanol adduct toluene diisocyanate, wherein the acrylate compound having at least one hydroxyl group in the molecule is hydroxyethyl acrylate, hydroxypropyl acrylate, Hydroxyisopropyl acrylate, hydroxybutyl acrylate, hydroxypentyl acrylate, hydroxyhexyl acrylate, hydroxybutyl vinyl ether, alkylene oxide ring-opened hydroxyacrylate and caprolactone ring-opened hydroxyacrylate It may include one or more selected from the group consisting of.

In one embodiment, the first urethane acrylate oligomer compound may include a compound of Formula 4 below.

[Formula 4]

In Formula 4, X and Y each represent an aliphatic hydrocarbon having 12 to 18 carbon atoms and an aliphatic hydrocarbon having about 6 to 13 carbon atoms, and R1 and R2 each independently represent hydrogen or a methyl group. For example, the first urethane acrylate oligomer compound may include at least one selected from compounds represented by the following Chemical Formulas 5 to 7.

[Formula 5]

[Formula 6]

[Formula 7]

In one embodiment, the bifunctional first acrylate monomer compound is polypropylene glycol diacrylate in which ethylene oxide having 1 to 50 repeating units is ring-opened or propylene oxide having 1 to 50 repeating units is ring-opened. acrylates.

In one embodiment, the monofunctional second acrylate monomer compound may include 2-hydroxyethyl acrylate or 2-hydroxypropyl acrylate.

In one embodiment, the restoration pattern layer may be formed by curing a composition including a photoinitiator and a solvent together with the first urethane acrylate oligomer compound, the first acrylate monomer compound, and the second acrylate monomer compound. .

In one embodiment, the composition comprises 35 to 80% by weight of the first urethane acrylate oligomer compound, 15 to 60% by weight of the first acrylate monomer compound, and 3 to 20% by weight based on the total weight of the acrylate compound. % of the second acrylate monomer compound.

In one embodiment, the photoinitiator may include a radical photoinitiator or a cationic photoinitiator.

In one embodiment, the composition may further include a third acrylate monomer compound having three or more functional groups. In this case, the third acrylate monomer compound may be included in an amount of 10 wt% or less based on the total weight of the acrylate compound.

In one embodiment, the composition may further include a second urethane acrylate oligomer compound having a functional group of 2 or less. In this case, the composition may include the second urethane acrylate oligomer compound in an amount of 35% by weight or less based on the total weight of the acrylate compound.

In one embodiment, the restoration layer may further include a liquid or gel-like filler filling at least a portion of each of the openings. For example, the filler may include a liquid elastomer such as liquid silicone rubber (LSR).

A flexible display device according to an embodiment of the present invention is disposed between a first base layer, a second base layer disposed to face the first base layer, and the first base layer and the second base layer to adhere them and a plurality of a support substrate including a restoration layer having a restoration pattern layer in which openings spaced apart from each other are formed; and a flexible display panel disposed on one of the first base layer and the second base layer.

In an embodiment, the flexible display panel may include an OLED panel, an LCD panel, or E-paper.

In one embodiment, the restoration pattern layer may be formed of a polymer compound of a first urethane acrylate oligomer compound, a first bifunctional acrylate monomer compound, and a second monofunctional acrylate monomer compound. In this case, the polymer The compound may include a chemical structure of Formulas 1 to 3 below.

[Formula 1]

[Formula 2]

[Formula 3]

In Formulas 1 to 3, X and Y each represent an aliphatic hydrocarbon having 12 to 18 carbon atoms and an aliphatic hydrocarbon having about 6 to 13 carbon atoms, R1 and R2 independently represent hydrogen or a methyl group, Ra, Rb , Rc and Rd each independently represent hydrogen or a methyl group, and n is an integer of 6 or more and 12 or less.

According to the substrate for a flexible display device of the present invention and a flexible display device including the same, by forming the opening as described above in the restoration layer, the elongation rate of the support substrate can be increased to significantly improve the folding performance as well as the By absorbing an external shock through the opening, it is possible to remarkably improve the impact resistance of the support substrate and the flexible display device including the same.

In addition, by forming the restoration pattern layer of the restoration layer of a material having a high restoration rate, the restoration force and flexibility of the entire support substrate can be further improved, and as a result, repetitive deformation of the flexible display device such as rolling, folding, or the like It is possible to support the display panel more stably even with a strong external impact.

1 is a cross-sectional view for explaining a substrate for a flexible display device according to an embodiment of the present invention.
2A and 2B are plan views for explaining embodiments of the restoration layer shown in FIG. 1 .
3 is a cross-sectional view for explaining a support substrate for a flexible display device according to another embodiment of the present invention.
4A and 4B are cross-sectional views illustrating a flexible display device according to an embodiment of the present invention.
5A and 5B are cross-sectional views illustrating a flexible display device according to another embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Since the present invention can have various changes and can have various forms, specific embodiments are illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to the specific disclosed form, it should be understood to include all modifications, equivalents and substitutes included in the spirit and scope of the present invention. In describing each figure, like reference numerals have been used for like elements. In the accompanying drawings, the dimensions of the structures are enlarged than the actual size for clarity of the present invention.

Terms such as first, second, etc. may be used to describe various elements, but the elements should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, a first component may be referred to as a second component, and similarly, a second component may also be referred to as a first component.

The terms used in the present application are only used to describe specific embodiments and are not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. In the present application, terms such as “comprise” or “have” are intended to designate that a feature, step, operation, component, part, or combination thereof described in the specification is present, and includes one or more other features or steps. , it should be understood that it does not preclude the possibility of the existence or addition of an operation, a component, a part, or a combination thereof.

Unless defined otherwise, 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 invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related art, and should not be interpreted in an ideal or excessively formal meaning unless explicitly defined in the present application. does not

1 is a cross-sectional view illustrating a substrate for a flexible display device according to an embodiment of the present invention, and FIGS. 2A and 2B are plan views illustrating embodiments of the restoration layer shown in FIG. 1 .

1, 2A and 2B , the support substrate 100 for a flexible display device according to an embodiment of the present invention includes a first base layer 110 , a second base layer 120 and a restoration layer 130 . may include The support substrate 100 is disposed under and supports a flexible display panel such as an OLED panel (see '1200' in FIGS. 4A and 4B and '2200' in FIGS. 5A and 5B), and protects the flexible display panel from external impact. It functions to protect the display panel.

The first base layer 110 may be formed of a polymer material to improve flexibility of the support substrate 100 . For example, the first base layer 110 may be formed of polycarbonate, polyethylene terephthalate, polyethylene naphthalate, polymethyl methacrylate, or the like.

The second base layer 120 may be disposed to face the first base layer 110 , and may be formed of a polymer material that is the same as or different from that of the first base layer 110 .

In one embodiment, the second base layer 120 may have the same strength as the first base layer 110 in order to improve the flexibility of the support substrate 100 . In this case, the second base layer 120 may be formed of the same material as the first base layer 110 . Alternatively, in another embodiment, the second base layer 120 may be formed of a flexible material having lower strength than the first base layer 110 in order to further improve the foldability of the support substrate 100 . have. In this case, the second base layer 120 may be formed of an elastomer material. For example, the second base layer 120 may be formed of a silicone resin, a urethane resin, or the like.

The restoration layer 130 may be disposed between the first base layer 110 and the second base layer 120 to adhere the first base layer 110 and the second base layer 120 to each other. have.

In an embodiment, the restoration layer 130 may include restoration pattern layers 131a and 131b in which a plurality of openings 132a and 132b spaced apart from each other are formed. In an embodiment, the openings 132a and 132b may be formed to pass through the restoration pattern layers 131a and 131b.

In an embodiment, as shown in FIG. 2A , the restoration pattern layer 131a has first openings 132a extending in the first direction Y and having the same shape as the first openings 132a in the first direction Y. ) and may be formed to be spaced apart from each other by a predetermined interval W1 in the second direction X. In this case, in order to prevent the adhesive force between the restoration pattern layer 131a and the first and second base layers 110 and 120 from being reduced, each of the first openings 132a in the second direction ( The width W2 of X) is preferably smaller than the spacing W1 between the openings 132a. Although both ends of the openings 132a are closed in FIG. 2A , both ends of the openings 132a may be open.

In another embodiment, in order to more stably prevent the adhesion between the restoration pattern layer 131b and the first and second base layers 110 and 120 from being lowered, as shown in FIG. 2B , the restoration The pattern layer 131b may have a lattice shape. That is, the openings 132b having the same shape may be formed in a matrix form to be spaced apart from each other at regular intervals in the first direction Y and the second direction X. In this case, the spacing H1 of the openings 132b in the first direction Y and the width H2 of each of the openings 132b in the first direction Y are appropriately adjusted. The width W2 of each of the openings 132b in the second direction X is preferably smaller than the spacing W1 between the openings 132b. Although each of the openings 132b is illustrated in FIG. 2B as having a rectangular shape, the shape of each of the openings 132b may be variously changed, for example, may have a circular shape.

The restoration coating layers 131a and 131b may be formed of a ring material having excellent restoring force. In an embodiment, the restoration coating layers 131a and 131b may be formed of a polymer compound of a first urethane acrylate oligomer compound, a first bifunctional acrylate monomer compound, and a second monofunctional acrylate monomer compound. The first urethane acrylate oligomer compound and the first acrylate monomer compound may improve the restoring force of the restoration coating layers 131a and 131b, and the second acrylate monomer compound may form the restoration coating layers 131a and 131b. Workability and moldability may be improved by lowering the viscosity of the composition for forming, that is, a composition including the first urethane acrylate oligomer compound, the first acrylate monomer compound, and the second acrylate monomer compound.

In one embodiment, the polymer compound of the first urethane acrylate oligomer compound, the bifunctional first acrylate monomer compound, and the monofunctional second acrylate monomer compound has a chemical structure of the following Chemical Formula 1, a chemical structure of the following Chemical Formula 2 and It may include a chemical structure of Formula 3 below. In this case, the chemical structure of Formula 1 below may be derived from the first urethane acrylate oligomer compound, the chemical structure of Formula 2 may be derived from the first acrylate monomer compound, and the chemical structure of Formula 3 below may be derived from the second acrylate monomer compound.

[Formula 1]

[Formula 2]

[Formula 3]

In Formula 1, X represents an aliphatic hydrocarbon having about 12 to 18 carbon atoms, Y represents an aliphatic hydrocarbon having about 6 to 13 carbon atoms, and R1 and R2 may each independently represent hydrogen or a methyl group. Meanwhile, the aliphatic hydrocarbon represented by X may or may not include a hetero atom.

In Formulas 2 and 3, Ra, Rb, Rc and Rd may each independently represent a hydrogen or a methyl group, and n may be an integer of 6 or more and 12 or less.

In one embodiment, the first urethane acrylate oligomer compound may be formed by polymerizing a bifunctional isocyanate compound and an acrylate compound having at least one hydroxyl group in a molecule. In this case, the polymerization method of the bifunctional isocyanate compound and the acrylate compound having at least one hydroxyl group in the molecule is not particularly limited, and for example, they are any polymerization reaction, block polymerization reaction, graft polymerization reaction. It can be polymerized through, etc.

The bifunctional isocyanate compound is, for example, 4,4'-dicyclohexyldiisocyanate, hexamethylene diisocyanate, 1,4-diisocyanatobutane, 1,6-diisocyanatohexane, 1, 8-diisocyanatooctane, 1,12-diisocyanatodecane, 1,5-diisocyanato-2-methylpentane, trimethyl-1,6-diisocyanatohexane, 1,3-bis(isocyanatomethyl) ) Cyclohexane, trans-1,4-cyclohexene diisocyanate, 4,4'-methylenebis (cyclohexyl isocyanate), isophorone diisocyanate, toluene-2,4-diisocyanate, toluene-2,6-diisocyanate , xylene-1,4-diisocyanate, tetramethylxylene-1,3-diisocyanate, 1-chloromethyl-2,4-diisocyanate, 4,4'-methylenebis(2,6-dimethylphenylisocyanate) ), trimethanol adduct toluene diisocyanate, and the like may include at least one selected from the group consisting of.

The acrylate compound having one or more hydroxy groups in the molecule is, for example, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyisopropyl acrylate, hydroxybutyl acrylate, hydroxypentyl acrylate, hydroxy It may include at least one selected from hydroxyhexyl acrylate, hydroxybutyl vinyl ether, ring-opened hydroxyacrylate with alkylene oxide, caprolactone ring-opened hydroxyacrylate, and the like.

In one embodiment, the first urethane acrylate oligomer compound may include a compound of Formula 4 below.

[Formula 4]

In Formula 4, X and Y may represent an aliphatic hydrocarbon having 12 to 18 carbon atoms and an aliphatic hydrocarbon having about 6 to 13 carbon atoms, respectively, and R1 and R2 may each independently represent hydrogen or a methyl group.

For example, the first urethane acrylate oligomer compound may include at least one selected from compounds represented by the following Chemical Formulas 5 to 7.

[Formula 5]

[Formula 6]

[Formula 7]

The compound of Formula 5 can be synthesized by, for example, reacting isophorone diisocyanate and caprolactone acrylate, and the compound of Formula 6 is, for example, reacting isophorone diisocyanate and polyethylene glycol acrylate and the compound of Formula 7 may be synthesized by, for example, reacting isophorone diisocyanate with polypropylene glycol acrylate.

The bifunctional first acrylate monomer compound is from polypropylene glycol diacrylate in which ethylene oxide having a repeating unit of about 1 to 50 ring-opened polyethylene glycol diacrylate, and propylene oxide having a repeating unit of about 1 to 50 ring-opened polypropylene glycol diacrylate. It may include at least one selected type. For example, the bifunctional first acrylate monomer compound is polypropylene glycol diacrylate in which ethylene oxide having a repeating unit of about 6 to 14 ring-opened polyethylene glycol diacrylate or propylene oxide having a repeating unit of about 6 to 14 ring-opened polypropylene glycol diacryl. It may include one or more selected from the rate and the like.

The monofunctional second acrylate monomer compound may include at least one selected from 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, and the like.

Meanwhile, in an embodiment of the present invention, the restoration coating layers 131a and 131b include the first urethane acrylate oligomer compound, the bifunctional first acrylate monomer compound, and the monofunctional second acrylate monomer compound. It can be formed using the composition. In one embodiment, the composition may further include a photoinitiator, a solvent, an additive, etc. together with the first urethane acrylate oligomer compound, the bifunctional first acrylate monomer compound, and the monofunctional second acrylate monomer compound. have. In addition, the composition may further include a polyfunctional third acrylate monomer compound.

The photoinitiator may include a radical photoinitiator, a cationic photoinitiator, and the like, and these may be used alone or in combination of two or more.

As the radical photopolymerization initiator, a known radical photopolymerization initiator compound may be used without limitation, and is not particularly limited. For example, the radical photopolymerization initiator is 1-hydroxycyclohexylphenyl ketone, 2,2'-dimethoxy-2-phenylacetophenone, xanthone, fluorene, fluorenone, benzaldehyde, anthraquinone, triphenylamine, Carbazole, 3-methylacetophenone, 4-chlorobenzophenone, 4,4'-dimethoxybenzophenone, 4,4'-diaminobenzophenone, mihiraketone, benzoylpropyl ether, benzoinethyl ether, benzyldimethyl Ketal, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, thioxanthone, diethyl Thioxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2,4, 6-trimethylbenzoyldiphenylphosphine oxide, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butan-1-one, 1-[4-(2-hydroxyethoxy)-phenyl ]-2-hydroxy-2-methylpropan-1-one and the like may include at least one selected from the group consisting of.

As the cationic photopolymerization initiator, a known cationic photopolymerization initiator compound may be used without limitation, and is not particularly limited. For example, the cationic photopolymerization initiator may include an onium salt, an organometallic salt, and the like. Specifically, the cationic photopolymerization initiator is a diaryliodonium salt, a triarylsulfonium salt, an aryldiazonium salt, an arylsulfonium hexafluoroantimonium salt, an arylsulfonium hexafluorophosphate salt, Diphenyliodonium hexafluoroantimonium salt, diphenyliodonium hexafluorophosphate salt, ditoryliodonium hexafluorophosphate salt, 9-(4-hydroxyethoxyphenyl)cyansrhenium hexa It may include at least one selected from fluorophosphate salts, iron-arene complexes, and the like. However, since the antimonium salt has a problem of environmental pollution, a hexafluorophosphate salt-based compound is preferable as the cationic photopolymerization initiator.

The solvent may improve the applicability of the composition, and may include at least one selected from an alcohol-based compound, a ketone-based compound, a hexane-based compound, a benzene-based compound, and the like. The alcohol-based compound may include at least one selected from methanol, ethanol, isopropanol, butanol, methyl cellulose, and ethyl cellulose. The ketone-based compound may include at least one selected from methyl ethyl ketone, methyl butyl ketone, methyl isobutyl ketone, diethyl ketone, dipropyl ketone, cyclohexanone, and the like. The hexane-based compound may include at least one selected from hexane, heptane, octane, and the like. The benzene-based compound may include at least one selected from benzene, toluene, xylene, and the like.

Meanwhile, the composition may further include additives commonly used in the art to which the present invention pertains, such as surfactants, anti-yellowing agents, and leveling agents. The content of these additives may be included in a ratio of about 0.1 to 10 parts by weight, but may be variously adjusted within a range that does not degrade the physical properties of the present invention.

In one embodiment, the composition may include about 35 to 80% by weight of the first urethane acrylate oligomer compound based on the total weight of the acrylate compound. When the content of the first urethane acrylate oligomer compound is less than 35% by weight, a problem in that the restoration rate of the restoration coating layers 131a and 131b is lowered may occur, and the content of the first urethane acrylate oligomer compound is 80% by weight If it exceeds, the viscosity of the composition is excessively high, which may cause a problem in that the moldability of the composition is lowered.

In one embodiment, the composition may include about 15 to 60% by weight of the bifunctional first acrylate monomer compound based on the total weight of the acrylate compound. When the content of the first acrylate monomer compound is less than 15% by weight, there may be a problem in that the restoration rate of the restoration coating layers 131a and 131b is lowered, and the content of the first acrylate monomer compound exceeds 60% by weight. In this case, the curing shrinkage of the composition may increase, which may cause a problem in that the work processability is deteriorated.

In one embodiment, the composition may include about 3 to 20% by weight of the monofunctional second acrylate monomer compound based on the total weight of the acrylate compound. When the content of the second acrylate monomer compound is less than 3% by weight, the viscosity of the composition is excessively high, which may cause a problem in that the moldability of the composition is deteriorated, and the content of the second acrylate monomer compound is 20% by weight. If it exceeds, a problem in that the restoration rate of the restoration coating layers 131a and 131b is lowered may occur.

In one embodiment, the composition may include the photoinitiator in an amount of about 1 to 3% by weight, and the solvent may include an amount of about 10 to 20% by weight.

Meanwhile, when the composition further includes the polyfunctional third acrylate monomer compound, the composition may include less than about 10% by weight of the third acrylate monomer compound.

In addition, the composition may further include a second urethane acrylate oligomer compound having a functional group of 2 or less independently of the first urethane acrylate oligomer compound, in this case, the composition is based on the total weight of the acrylate compound The second urethane acrylate oligomer compound may be included in an amount of about 35% by weight or less.

Meanwhile, in one embodiment of the present invention, in order to improve the mechanical durability of the support substrate 100 for a flexible display, the restoration layer 130 fills at least a portion of each of the openings 132a and 132b. It may further include a filler (not shown). For example, the filler may include a liquid or gel-like composition. Specifically, the filler may include a liquid elastomer, for example, liquid silicone rubber (LSR).

3 is a cross-sectional view for explaining a support substrate for a flexible display device according to another embodiment of the present invention.

Referring to FIG. 3 together with FIGS. 2A and 2B , the support substrate 200 for a flexible display device according to an embodiment of the present invention includes a first base layer 210 , a second base layer 220 , and a restoration layer 230 . ) may be included. The support substrate 200 according to the present embodiment is substantially the same as the support substrate 100 described with reference to FIGS. 1, 2A and 2B except for the structure of the openings 232 formed in the restoration layer 230 . Since they are the same, detailed overlapping descriptions will be omitted below.

The restoration layer 230 may include a restoration pattern layer 231 having a plurality of openings 232 spaced apart from each other, the restoration pattern layer 231 and the first or second base layer 210; 220 , the openings 232 may be formed so as not to penetrate the restoration pattern layer 231 . For example, the openings 232 may be formed from one surface of the restoration pattern layer 231 to a predetermined depth smaller than the thickness of the restoration layer 230 . Although it is shown in FIG. 3 that the openings 232 are formed at a constant depth from one surface of the restoration pattern layer 231 that is adhered to the second base layer 220 , the openings 232 are formed in the first It may be formed to a predetermined depth from one surface of the restoration pattern layer 231 that is adhered to the base layer 210 .

Since the planar shape of the openings 232 is substantially the same as the shape of the openings 132a and 132b described with reference to FIGS. 2A and 2B , a redundant detailed description thereof will be omitted.

In addition, the restoration layer 230 may further include a filler filling at least a portion of each of the openings 232 . For example, the filler may include a liquid or gel-like composition. Specifically, the filler may include a liquid elastomer, for example, liquid silicone rubber (LSR).

According to the support substrates 100 and 200 for flexible displays according to the embodiment of the present invention, by forming the openings 132 and 232 as described above in the restoration layers 130 and 230, the support substrates 100 and 200 Not only can the folding performance be remarkably improved by increasing the elongation, but also the impact resistance of the support substrates 100 and 200 can be remarkably improved because the openings 132 and 232 absorb external shocks.

In addition, by forming the restoration pattern layers 131 and 132 of the restoration layers 130 and 230 with a material having a high restoration rate, restoration force and flexibility of the entire support substrate 100 can be further improved, and as a result, rolling , it is possible to support the display panel more stably even in the case of repeated deformation or strong external impact of the flexible display device, such as folding.

On the other hand, the flexible display panel may be disposed to be supported by the first base layer (110, 210), it may be disposed to be supported by the second base layer (120, 220).

4A and 4B are cross-sectional views illustrating a flexible display device according to an embodiment of the present invention.

4A and 4B , flexible display apparatuses 1000a and 1000b according to an embodiment of the present invention include a support substrate 1100 and a display panel 1200 .

The support substrate 1100 may include a first base layer 1110 , a second base layer 1120 , and a restoration layer 1130 . Since the support substrate 1100 is substantially the same as the support substrate 100 for a flexible display device described with reference to FIG. 1 , a redundant detailed description thereof will be omitted.

The flexible display panel 1200 may be disposed on the support substrate 1100 . In one embodiment, as shown in FIG. 4A , the flexible display panel 1200 may be disposed on the second base layer 1120 of the support substrate 1100 . In another embodiment, as shown in FIG. 4B , the flexible display panel 1200 may be disposed on the first base layer 1110 of the support substrate 1100 .

As long as it has flexible characteristics, the type of the flexible display panel 1200 is not particularly limited. For example, the flexible display panel 1200 may include an OLED panel, an LCD panel, E-paper, and the like.

For convenience of description, the flexible display panel 1200 will be described as an OLED panel. The flexible display panel 1200 is a panel substrate 1210 disposed on the first substrate layer 1110 or the second substrate layer 1120 of the support substrate 1100 and having a thin film transistor (TFT), the panel An organic light emitting layer 1220 disposed on the substrate 1210 and emitting light according to the operation of the thin film transistor, and a protective layer 1230 disposed on the organic light emitting layer 1220 and protecting the organic light emitting layer 1220 can do. Meanwhile, the flexible display panel 1200 may further include a sealing film, an optical film, etc. disposed between the organic light emitting layer 1220 and the protective layer 1230 .

5A and 5B are cross-sectional views illustrating a flexible display device according to another embodiment of the present invention.

5A and 5B , flexible display apparatuses 2000a and 2000b according to an embodiment of the present invention include a support substrate 2100 and a display panel 2200 .

The support substrate 2100 is substantially the same as the support substrate 200 for a flexible display device described with reference to FIG. 3 , and the flexible display panel 2200 is the flexible display panel 1200 described with reference to FIGS. 4A and 4B . ) and, therefore, redundant detailed descriptions thereof will be omitted.

The flexible display panel 2200 may be disposed on the second base layer 2120 of the support substrate 2100 as shown in FIG. 5A , and as shown in FIG. 5B , the support substrate ( 2100) may be disposed on the first base layer 2110.

According to the substrate for a flexible display device of the present invention and a flexible display device including the same, the supporting substrate has the openings as described above and includes a restoring layer formed of a material having high restoring force, and the flexible display device such as rolling, folding, etc. It is possible to stably support the display panel despite repeated deformation or strong external impact, and as a result, the durability of the flexible display device may be remarkably improved.

Although the above has been described with reference to the preferred embodiments of the present invention, those skilled in the art can variously modify and change the present invention within the scope without departing from the spirit and scope of the present invention as set forth in the following claims. You will understand that you can.

100, 200, 1100: a support substrate for a flexible display device
110, 210: first base layer 120, 220: second base layer
130, 230: restoration layer 1000: display device
1200: display panel

Claims (27)

In the substrate for a flexible display device disposed under the flexible display panel to support the flexible display panel,
a first base layer;
a second base layer disposed to face the first base layer; and
a restoration layer disposed between the first substrate layer and the second substrate layer to adhere them, and a restoration layer having a restoration pattern layer formed with a plurality of spaced apart openings;
The flexible display is disposed on one of the first base layer and the second base layer,
A width of each of the openings in the first direction is smaller than a spacing between the openings in the first direction,
The restoration pattern layer is a substrate for a flexible display device, characterized in that it is formed of a polymer compound of a first urethane acrylate oligomer compound, a first bifunctional acrylate monomer compound, and a second monofunctional acrylate monomer compound. The method of claim 1,
The strength of the first substrate layer and the second substrate layer is the same,
The substrate for a flexible display device, characterized in that the first substrate layer and the second substrate layer are formed of one material selected from the group consisting of polycarbonate, polyethylene terephthalate, polyethylene naphthalate and polymethyl methacrylate. According to claim 1,
The strength of the second substrate layer is smaller than the strength of the first substrate layer,
The first base layer is formed of one material selected from the group consisting of polycarbonate, polyethylene terephthalate, polyethylene naphthalate and polymethyl methacrylate,
The second base layer is a substrate for a flexible display device, characterized in that formed of an elastomeric material. According to claim 1,
The openings are elongated in a second direction intersecting the first direction, have the same shape and are formed to be spaced apart from each other at regular intervals in the first direction, a substrate for a flexible display device. According to claim 1,
The restoration pattern layer is a substrate for a flexible display device, characterized in that it has a planar shape in the form of a grid. 6. The method according to claim 4 or 5,
The substrate for a flexible display device, characterized in that the openings are formed to penetrate the restoration pattern layer. 6. The method according to claim 4 or 5,
The openings are formed from one surface of the restoration pattern layer to a depth smaller than the thickness of the restoration layer, a substrate for a flexible display device. delete According to claim 1,
The polymer compound is a substrate for a flexible display device, characterized in that it comprises a chemical structure of the following Chemical Formulas 1 to 3:
[Formula 1]

[Formula 2]

[Formula 3]

In Formulas 1 to 3, X and Y represent an aliphatic hydrocarbon having 12 to 18 carbon atoms and an aliphatic hydrocarbon having 6 to 13 carbon atoms, respectively, R1 and R2 are each independently hydrogen or a methyl group, Ra, Rb, Rc and Rd each independently represent hydrogen or a methyl group, and n is an integer of 6 or more and 12 or less. 10. The method of claim 9,
The first urethane acrylate oligomer compound is a substrate for a flexible display device, characterized in that it is a polymer of a bifunctional isocyanate compound and an acrylate compound having one or more hydroxyl groups in the molecule. 11. The method of claim 10,
The bifunctional isocyanate compound is 4,4'-dicyclohexyldiisocyanate, hexamethylene diisocyanate, 1,4-diisocyanatobutane, 1,6-diisocyanatohexane, 1,8-diisocyanato Octane, 1,12-diisocyanatodecane, 1,5-diisocyanato-2-methylpentane, trimethyl-1,6-diisocyanatohexane, 1,3-bis(isocyanatomethyl)cyclohexane, trans -1,4-cyclohexene diisocyanate, 4,4'-methylenebis (cyclohexyl isocyanate), isophorone diisocyanate, toluene-2,4-diisocyanate, toluene-2,6-diisocyanate, xylene-1 ,4-diisocyanate, tetramethylxylene-1,3-diisocyanate, 1-chloromethyl-2,4-diisocyanate, 4,4'-methylenebis(2,6-dimethylphenylisocyanate) and trimethanolpropanol Adduct contains at least one selected from the group consisting of toluene diisocyanate,
The acrylate compound having at least one hydroxy group in the molecule is hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyisopropyl acrylate, hydroxybutyl acrylate, hydroxypentyl acrylate, hydroxyhexyl acrylate, A substrate for a flexible display device, comprising at least one selected from the group consisting of hydroxybutyl vinyl ether, ring-opened hydroxyacrylate with alkylene oxide, and caprolactone with ring-opened hydroxyacrylate. According to claim 1,
The first urethane acrylate oligomer compound is a substrate for a flexible display device, characterized in that it comprises a compound of formula (4):
[Formula 4]

In Formula 4, X and Y each represent an aliphatic hydrocarbon having 12 to 18 carbon atoms and an aliphatic hydrocarbon having 6 to 13 carbon atoms, and R1 and R2 each independently represent hydrogen or a methyl group. 13. The method of claim 12,
The first urethane acrylate oligomer compound is a substrate for a flexible display device, characterized in that it comprises at least one selected from the compounds represented by the following Chemical Formulas 5 to 7:
[Formula 5]

[Formula 6]

[Formula 7]

According to claim 1,
The bifunctional first acrylate monomer compound is a polypropylene glycol diacrylate in which ethylene oxide having 1 to 50 repeating units is ring-opened or propylene oxide having 1 to 50 repeating units is ring-opened. Characterized in, a substrate for a flexible display device. According to claim 1,
The monofunctional second acrylate monomer compound is a substrate for a flexible display device, characterized in that it comprises 2-hydroxyethyl acrylate or 2-hydroxypropyl acrylate. According to claim 1,
The restoration pattern layer is characterized in that it is formed by curing a composition comprising a photoinitiator and a solvent together with the first urethane acrylate oligomer compound, the first acrylate monomer compound and the second acrylate monomer compound, for a flexible display device Board. 17. The method of claim 16,
The composition comprises 35 to 80% by weight of the first urethane acrylate oligomer compound, 15 to 60% by weight of the first acrylate monomer compound, and 3 to 20% by weight of the second acrylic based on the total weight of the acrylate compound. A substrate for a flexible display device, characterized in that it contains a rate monomer compound. 17. The method of claim 16,
The photoinitiator is a substrate for a flexible display device, characterized in that it comprises a radical photoinitiator or a cationic photoinitiator. 17. The method of claim 16,
The composition is a substrate for a flexible display device, characterized in that it further comprises a third acrylate monomer compound having three or more functional groups. 20. The method of claim 19,
The third acrylate monomer compound is a substrate for a flexible display device, characterized in that it is included in an amount of 10% by weight or less based on the total weight of the acrylate compound. 17. The method of claim 16,
The composition is a substrate for a flexible display device, characterized in that it further comprises a second urethane acrylate oligomer compound having a functional group of 2 or less. 22. The method of claim 21,
The composition is a substrate for a flexible display device, characterized in that it comprises the second urethane acrylate oligomer compound in an amount of 35% by weight or less based on the total weight of the acrylate compound. The method of claim 1,
The restoration layer is a substrate for a flexible display device, characterized in that it further comprises a liquid or gel-like filler filling at least a portion of each of the openings. 24. The method of claim 23,
The substrate for a flexible display device, characterized in that the filler comprises a liquid elastomer. A first base layer, a second base layer disposed to face the first base layer, and a restoration pattern layer disposed between the first base layer and the second base layer to adhere them and having a plurality of spaced apart openings from each other a support substrate including a restoration layer provided with; and
A flexible display panel disposed on one of the first base layer and the second base layer,
A width of each of the openings in the first direction is smaller than a spacing between the openings in the first direction,
The restoration pattern layer is formed of a polymer compound of a first urethane acrylate oligomer compound, a first bifunctional acrylate monomer compound, and a second monofunctional acrylate monomer compound, a flexible display device. 26. The method of claim 25,
The flexible display panel is characterized in that it comprises an OLED panel, an LCD panel or E-paper, a flexible display device. 26. The method of claim 25,
The polymer compound is a flexible display device, characterized in that it comprises a chemical structure of the following Chemical Formulas 1 to 3:
[Formula 1]

[Formula 2]

[Formula 3]

In Formulas 1 to 3, X and Y represent an aliphatic hydrocarbon having 12 to 18 carbon atoms and an aliphatic hydrocarbon having 6 to 13 carbon atoms, respectively, R1 and R2 are each independently hydrogen or a methyl group, Ra, Rb, Rc and Rd each independently represent hydrogen or a methyl group, and n is an integer of 6 or more and 12 or less.

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