KR20190111633A - Curable resin composition and index matching layer formed the same - Google Patents

Abstract

A curable resin composition of embodiments of the present invention comprises a metal-containing siloxane resin, a cardo-based compound, a polymerization initiator, and a solvent. It is possible to manufacture a high refractive index and high chemical resistance refractive index matching layer from the curable resin composition. The curable resin composition according to embodiments of the present invention can comprise the metal-containing siloxane resin and the cardo-based compound together.

Description

Curable resin composition and the refractive index matching layer formed therefrom {CURABLE RESIN COMPOSITION AND INDEX MATCHING LAYER FORMED THE SAME}

The present invention relates to a curable resin composition and a refractive index matching layer formed therefrom. More specifically, the present invention relates to a photosensitive resin composition comprising a high refractive index component and a refractive index matching layer formed therefrom.

Recently, in an image display device such as a liquid crystal display (LCD) device or an organic light emitting display (OLED) device, an organic component is formed to form various conductive layers, support layers of optical layers, and insulating layers. The resin composition containing is used.

In addition, recently, a touch sensor or a touch screen panel is coupled to the image display device, and image display and information input functions are implemented in one device.

As functional members such as a touch sensor are added to the image display device, for example, visibility of an image may be degraded by conductive structures such as a sensing electrode. Thus, a functional insulating layer can be inserted to improve the optical function.

For example, since the conductive structure has a higher refractive index than the general inorganic insulating layer or the organic insulating layer, the reflectance increases due to the difference in refractive index between the interface of the conductive structure and the insulating layer, and thus the conductive structure may be recognized by the user. And image quality may be degraded.

In order to reduce the difference in refractive index, a method of increasing refractive index by forming insulating layers adjacent to the conductive structure in multiple layers has been applied, but in this case, the thickness of the image display device is increased, and the optical characteristics are rather increased due to the increase in the number of interfaces. It may be degraded.

In addition, adjacent insulating layers may be damaged by a patterning process of a conductive structure such as a sensing electrode. For example, the insulating layer may be damaged by a solution such as an etchant, a developer, and the like.

Therefore, there is a need for a composition for forming an insulating layer capable of improving the optical properties of an image display device while having mechanical and chemical stability.

For example, although Korea Patent Publication No. 2011-0073372 discloses a photosensitive resin composition applied to an image display device, it is difficult to apply to the functional layer for improving the optical properties described above.

Korean Patent Publication No. 10-2011-0073372

One object of the present invention is to provide a curable resin composition capable of forming an insulating layer having improved optical properties and chemical stability.

One object of the present invention is to form a refractive index matching layer formed using the curable resin composition.

One object of the present invention is to provide a touch sensor including the refractive index matching layer.

1. metal-containing siloxane resins; Cardo-based compounds; Polymerization initiator; And a solvent, the curable resin composition.

2. In the above 1, the metal contained in the metal-containing siloxane resin includes zirconium (Zr), titanium (Ti), aluminum (Al), antimony (Sb) or tin (Sn), the metal-containing siloxane resin The curable resin composition which has a structure which the metal atom substituted the some silicon atom contained in a siloxane structure.

3. In the above 2, wherein the metal-containing siloxane resin comprises a structural unit represented by the following structural formula 1, curable resin composition:

[Formula 1]

(In Formula 1, M represents a metal atom selected from zirconium (Zr), titanium (Ti), aluminum (Al), antimony (Sb) or tin (Sn),

R ₁ to R ₆ represent an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or an aromatic group having 6 to 20 carbon atoms, and at least one of R ₁ to R ₆ is the aromatic group. ).

4. In the above 3, at least one of R ₁ to R ₆ comprises a vinyl group, curable resin composition.

5. In the above 1, wherein the cardo-based compound comprises at least one of the compounds represented by the following formula (1) or formula (2), curable resin composition:

[Formula 1]

[Formula 2]

(In Formulas 1 and 2, R ₁ and R ₂ each independently represent a hydrogen atom, a halogen atom, or an organic moiety having 1 to 20 carbon atoms,

At least one of R ₁ or R ₂ is a polymerizable reactive group comprising an unsaturated double bond.

6. In the above 5, wherein the polymerization reactive group is represented by the following formula (3) or formula (4), curable resin composition:

[Formula 3]

[Formula 4]

(N in Formulas 3 and 4 is an integer from 0 to 3).

7. according to the above 1, further comprising inorganic particles, curable resin composition.

8. according to the above 1, further comprising a polymerizable compound, curable resin composition.

9. In the above 8, wherein the polymerizable compound comprises a bifunctional or more acrylate monomer, curable resin composition.

10. In the above 1, in 100 parts by weight of the composition solids,

20 to 80 parts by weight of the metal-containing siloxane resin;

10 to 60 parts by weight of the cardo-based compound;

Curable resin composition containing 0.1-20 weight part of said polymerization initiators.

11. The refractive index matching layer formed of the curable resin composition of any one of the above 1 to 10 and having a refractive index of 1.7 or more.

12. A touch sensor comprising the refractive index matching layer of 11 above.

Curable resin composition according to embodiments of the present invention may include a metal-containing siloxane resin and a cardo-based compound together. Through the combination of the siloxane resin and the cardo-based compound, the refractive index of the insulating film formed from the curable resin composition may increase.

In some embodiments, the siloxane resin may include an aromatic group and / or a vinyl group, whereby the refractive index may be further increased to ensure chemical resistance together. In addition, as the refractive index is further increased through the cardo-based compound including a plurality of aromatic rings, chemical resistance may be further improved.

By using the curable resin composition, for example, a refractive index matching layer having a refractive index of about 1.7 or more can be formed. The refractive index matching layer may be applied to the touch sensor to prevent recognition of the sensing electrode, and to improve the image quality of the image display apparatus to which the touch sensor is applied.

1 is a schematic cross-sectional view illustrating a touch sensor according to example embodiments.

According to embodiments of the present invention, there is provided a curable resin composition comprising a metal-containing siloxane resin, a cardo-based compound and capable of forming a high refractive index insulating layer, and a refractive index matching layer formed from the curable resin composition. In addition, a touch sensor or an image display device including the refractive index matching layer is provided.

Hereinafter, embodiments of the present invention will be described in detail.

<Curable resin composition>

As described above, the curable resin composition according to the exemplary embodiments may include a metal-containing siloxane resin and a cardo-based compound, and may further include a photopolymerizable compound, a photopolymerization initiator, and a solvent. The curable resin composition may further include inorganic particles and other additives.

Metal-containing siloxane resins

The metal-containing siloxane resin (hereinafter may be abbreviated as siloxane resin) may include a siloxane network structure in which siloxane bonds (eg, -Si-O-Si-bonds) are chained repeatedly. The siloxane network structure may have, for example, a two-dimensional or three-dimensional network structure.

According to exemplary embodiments, at least one silicon atom (Si) included in the siloxane resin may be substituted with a metal. In some embodiments, the metal-containing siloxane resin may have a structure in which metal atoms are doped or dispersed in the siloxane network structure.

For example, the metal may include zirconium (Zr), titanium (Ti), aluminum (Al), tin (Sn), antimony (Sb), and the like, and preferably, titanium (Ti) or zirconium (Zr). ) May be combined with the siloxane resin.

In example embodiments, the siloxane resin may include a “? ** group. As the aromatic group is included in the siloxane resin, in addition to the increase in the refractive index through the metal, the refractive index of the insulating film formed from the curable resin composition may be increased. In addition, the chemical resistance and structural reliability of the insulating layer may be enhanced by the aromatic group.

For example, the siloxane resin may include a structural unit represented by Structural Formula 1 below.

[Formula 1]

In Formula 1, M represents a metal atom, R ₁ to R ₆ may represent an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or an aromatic group having 6 to 20 carbon atoms. have.

According to example embodiments, M may be zirconium (Zr), titanium (Ti), aluminum (Al), antimony (Sb), or tin (Sn).

According to exemplary embodiments, at least one of R ₁ to R ₆ may represent the aromatic group. The aromatic group may be substituted with, for example, an alkyl group having 1 to 10 carbon atoms or an alkenyl group having 2 to 10 carbon atoms.

In some embodiments, the siloxane resin may further include a vinyl group. For example, at least one of R ₁ to R ₆ in Formula 1 may include a vinyl group. As the vinyl group is included, for example, the polymerizable compound and the crosslinking property described later may be improved to further improve the refractive index and the mechanical strength.

For example, the metal-containing siloxane resin may be formed by reacting an alkoxy silane compound and a metal-containing compound together. In this case, the siloxane network structure is formed by polycondensation of the alkoxy silane compound, and the metal included in the metal-containing compound may be bonded in a form in which some silicon atoms are substituted.

For example, the alkoxy silane compound may be represented by the following general formula (1).

[Formula 1]

(R _p O) _n -Si- (R _q ) _4-n

In Formula 1, R _p and R _q may each independently be an aromatic group having 6 to 20 carbon atoms, or an alkyl group, alkenyl group or ether group having 1 to 20 carbon atoms. n may be an integer from 1 to 3. In the formula 1, the alkoxy silane compound may include at least one aromatic group. The alkoxy silane compound may further include at least one vinyl group.

The metal-containing compound may be represented by, for example, the following Chemical Formula 2.

[Formula 2]

M (R _a ) _m1 (R _b ) _m2

In Formula 2, M is a metal atom selected from zirconium (Zr), titanium (Ti), aluminum (Al), antimony (Sb) or tin (Sn). R _a may be an alkyl group having 1 to 20 carbon atoms, or an aromatic group having 6 to 20 carbon atoms. R _b may be an alkoxy group having 1 to 10 carbon atoms.

m1 and m2 are integers of 0 to m, respectively, when the valence of the metal M is m, and the sum of m1 and m2 is m.

As described above, according to exemplary embodiments, since the metal atoms are integrated or chemically bonded to the siloxane network structure, the organic and inorganic components may be hybridized to increase the refractive index while maintaining the mechanical properties of the siloxane resin.

In the comparative example, when inorganic particles (for example, titanium oxide and zirconium oxide) are added to and dispersed in an acrylic resin or an epoxy resin to improve the refractive index, the compatibility between the resin and the inorganic particles may be low, thereby decreasing flatness. Can be. In addition, uniform dispersion of the inorganic particles may not be easy, and thus a variation of regions of refractive index and transmittance may occur.

However, according to exemplary embodiments, since the metal atoms are integrated or chemically bonded to the siloxane network structure, the problem due to the decrease in compatibility of the organic resin and the inorganic component can be eliminated.

The metal-containing siloxane resin may include a plurality of Si—O bonds in a molecular structure. In the case of the Si-O bond, it has a larger bond energy and bond angle than the Si-C bond, thereby providing low shrinkage, durability, wear resistance, and flexibility to the refractive index matching layer formed using the composition.

In addition, the metal-containing siloxane resin may form a bulky three-dimensional bulky porous structure by -O-Si-O- bonding. Thus, for example, compared with a resin formed of an acrylate-based monomer, it has better flexibility and can realize an increased degree of crosslinking and / or curing.

In some embodiments, the metal-containing siloxane resin may not include a fluorine atom or a fluorine-containing substituent. When fluorine is included, a space in the resin structure may be caused by the volume or polarization effect of fluorine, thereby decreasing the refractive index.

According to exemplary embodiments, the metal-containing siloxane resin may be included in an amount of about 20 to 80 parts by weight based on 100 parts by weight of the composition solids. When the content of the siloxane resin is less than about 20 parts by weight, a sufficient refractive index increase effect may not be realized, and the hardness of the refractive index matching layer may be excessively lowered. When the content of the siloxane resin is greater than about 80 parts by weight, the coating property of the refractive index matching layer is lowered, solubility of the composition may be lowered.

In consideration of increasing the refractive index, improving chemical resistance and hardness, the content of the siloxane resin may be about 30 to 70 parts by weight.

Cardo-based compounds

The curable resin composition may include a cardo-based compound together with the metal-containing siloxane resin, and may further improve refractive index and chemical resistance of the insulating film formed from the curable resin composition.

According to exemplary embodiments, the cardo-based compound may include a compound represented by Formula 1 or Formula 2.

[Formula 1]

[Formula 2]

In Formulas 1 and 2, R ₁ and R ₂ may each independently represent a hydrogen atom, a halogen atom, or an organic residue having 1 to 20 carbon atoms. The organic residue may include, for example, functional groups such as ether bonds, ester bonds, urethane bonds, carboxyl groups, hydroxyl groups and the like.

In some embodiments, at least one of R ₁ or R ₂ may comprise a polymerizable reactive group. For example, the polymerization reactive group may include an unsaturated double bond such as an acrylate group.

As an example of R <_1> or R <_2> containing the said unsaturated double bond, the substituent of following formula (3) or (4) is mentioned.

[Formula 3]

[Formula 4]

N in Formulas 3 and 4 may be an integer of 0 to 3.

Since the cardo-based compound includes a plurality of aromatic rings in the compound, it is possible to induce an increase in refractive index. Thus, in combination with the metal-containing siloxane resin, it is possible to promote the formation of an insulating film having a further increased refractive index.

In addition, since at least one polymerization reactive group is included as a substituent of the cardo-based compound, crosslinking with a reactive group such as vinyl group included in the metal-containing siloxane resin may improve the etching resistance, chemical resistance, and degree of curing of the insulating film. have. In addition, when the cardo-based compound is further crosslinked with the metal-containing siloxane resin, the refractive index of the insulating film may further increase as the resin structure becomes bulkier.

In one embodiment, both R ₁ and R ₂ may include the polymerization reactive group to improve the chemical resistance, the degree of curing of the insulating film.

As described above, since the cardo-based compound is substantially included as a refractive index enhancer, a high refractive inorganic substance such as inorganic particles may be omitted from the curable resin composition. When the inorganic particles are included in a large amount in the composition, cracks of the insulating film may be caused under high heat conditions, and adhesion to the substrate of the insulating film may be impaired.

However, according to exemplary embodiments, even when the inorganic particles are omitted, sufficient refractive index may be obtained through a cardo-based compound, and cracks and adhesion of the insulating layer may be prevented.

According to exemplary embodiments, the cardo-based compound may be included in an amount of about 10 to 60 parts by weight based on 100 parts by weight of the composition solids. When the content of the cardo-based compound is less than about 10 parts by weight, a sufficient refractive index increase effect may not be realized, and it may be difficult to secure chemical resistance and hardness of the refractive index matching layer. When the content of the cardo-based compound exceeds about 60 parts by weight, it may cause a decrease in compatibility with the metal-containing siloxane resin, thereby deteriorating the transmittance of the refractive index matching layer.

Preferably, in consideration of improving the compatibility with the metal-containing siloxane resin and the refractive index, increase, chemical resistance, preferably the content of the cardo-based compound may be about 20 to 50 parts by weight.

Polymerizable compound

According to exemplary embodiments, the curable resin composition may further include a polymerizable compound for improving the crosslinking density.

The polymerizable compound may include a monomer having at least one functional group having photocurability or thermosetting. For example, monofunctional monomers, difunctional monomers, and other polyfunctional monomers well known in the field of organic compositions can be used.

Examples of the monofunctional monomers are nonylphenylcarbitol acrylate, 2-hydroxy-3-phenoxypropyl acrylate, 2-ethylhexylcarbitol acrylate, 2-hydroxyethyl acrylate, styrene, and N-vinylpi A ralidone etc. are mentioned.

Examples of the bifunctional monomers include 1,4-butanedioldiacrylate, 1,6-hexanedioldi (meth) acrylate, ethylene glycoldi (meth) acrylate, neopentylglycoldi (meth) acrylate, triethylene Glycol di (meth) acrylate, bis (acryloyloxyethyl) ether of bisphenol A, 3-methylpentanediol di (meth) acrylate, and the like.

Specific examples of the polyfunctional monomers include trimethylolpropane tri (meth) acrylate, ethoxylated trimethylolpropane tri (meth) acrylate, propoxylated trimethylolpropane tri (meth) acrylate, and pentaerythritol tree ( Meta) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, ethoxylated dipentaerythritol hexa (meth) acrylate, propoxylated dipentaerythritol hexa (Meth) acrylate, dipentaerythritol hexa (meth) acrylate, etc. are mentioned.

Preferably, the polymerizable compound may include a bifunctional or higher acrylate monomer.

When the polymerizable compound is included, for example, it may range from about 1 to 50 parts by weight of 100 parts by weight of the total composition solids. Within this range, for example, the degree of crosslinking and the degree of curing can be improved without inhibiting the increase in the refractive index from the metal-containing siloxane resin.

Polymerization initiator

The curable resin composition according to exemplary embodiments may further include a polymerization initiator to promote crosslinking or curing of the polymerizable compound. The polymerization initiator may include a thermal polymerizable initiator and / or a photopolymerizable initiator.

For example, the photopolymerization initiator may include an acetophenone compound, a benzophenone compound, a triazine compound, a biimidazole compound, a thioxanthone compound, an oxime ester compound, and the like. These may be used alone or in combination of two or more thereof. An oxime ester type compound can be used.

The thermally polymerizable initiator may include, for example, an azo initiator. For example, azo nitrile based, azo ester based, azo amide based, azo amidine based, macroazo based initiators can be used.

The content of the polymerization initiator may be included, for example, about 0.1 to 20 parts by weight of 100 parts by weight of the composition solids, preferably 0.1 to 10 parts by weight. It is possible to improve the sensitivity of the curing step without inhibiting the adhesiveness and the refractive index of the insulating film within the above range.

solvent

The curable resin composition may include a solvent capable of uniformly dissolving the metal-containing siloxane resin and the cardo-based compound described above.

For example, ethylene glycol monoalkyl ethers; Diethylene glycol dialkyl ethers; Ethylene glycol alkyl ether acetates; Alkylene glycol alkyl ether acetates; Propylene glycol monoalkyl ethers; Propylene glycol dialkyl ethers; Propylene glycol alkyl ether propionates; Butyl diol monoalkyl ethers; Butanediol monoalkyl ether acetates; Butanediol monoalkyl ether propionate; Dipropylene glycol dimethyl ether and dipropylene glycol dialkyl ethers; Aromatic hydrocarbons such as benzene, toluene, xylene and mesitylene; Ketones; Alcohols; Esters; Cyclic ethers such as tetrahydrofuran and pyran; Solvents, such as cyclic esters, such as (gamma) -butyrolactone, can be used. These may be used alone or in combination of two or more thereof.

The solvent may be included in the remaining amount excluding the above-mentioned components, or the remaining amount excluding the above-mentioned components and the additives described below. For example, the solvent may be included in about 60 to 95 parts by weight, preferably 70 to 95 parts by weight of the total weight of the composition. In the above range, the appropriate viscosity and coating property of the composition may be secured to form a coating film having a uniform profile (eg, a refractive index matching layer).

Inorganic particles

In some embodiments, the curable resin composition may further include inorganic particles. The inorganic particles may be dispersed in the composition to further increase the refractive index of the insulating film.

The inorganic particles may include, for example, metal oxide particles. In some embodiments, it may include an oxide of zirconium (Zr), titanium (Ti), aluminum (Al), antimony (Sb), or tin (Sn).

In some embodiments, an oxide of the same metal as the metal bonded to the siloxane resin may be used as the inorganic particles. In this case, a constant refractive index synergy may be realized through optical matching through the inorganic particles and the siloxane resin, and the transmittance may be improved.

Preferably, a zirconium-containing resin may be used as the siloxane resin, and zirconium oxide (zirconia) may be used as the inorganic particles. In this case, the refractive index can be raised more significantly without inhibiting the transmittance of the insulating film.

When the inorganic particles are included, the inorganic particles may be included in an amount of about 1 to 40 parts by weight based on 100 parts by weight of the composition solids. Within this range, the refractive index may be further increased while preventing adhesion of the composition, deterioration of coating properties and cracks.

Other additives

The curable resin composition may further include other additives within a range that does not inhibit the characteristics of the improved refractive index, the degree of curing, the chemical resistance of the insulating film formed therefrom. For example, the additive may include an antioxidant, a leveling agent, a curing accelerator, a surfactant, a filler, an ultraviolet absorber, an anti-agglomerating agent, a chain transfer agent, and the like.

For example, the curable resin composition may use a fluorine-based or silane-based additive for the planarization of the coating surface. Examples of the fluorine- or silane-based additives include aminopropyltriethoxysilane, methacryloxypropylmethyldiethoxysilane, vinyltrimethoxysilane, methacryloxypropyltrimethoxysilane, perfluoroalkyl acrylate copolymer, tri Fluoropropyltrimethoxysilane, heptademfluoro-1,1,2,2-tetrahydrodecyltrimethoxysilane, heptadecafluoro-1,1,2,2-tetrahydrodecyltrimethoxysilane, etc. Can be mentioned. These may be used alone or in combination of two or more.

In some embodiments, the curable resin composition includes only the above-described metal-containing siloxane resin as the resin component, and in this case, it is possible to realize a refractive index synergistic effect while implementing sufficient developability and curing density.

In some embodiments, the curable resin composition may contain other resin components (eg, alkali-soluble resins such as epoxy and / or carboxylic acid group-containing resins) within a range that does not inhibit the refractive index synergistic effect through the siloxane resin. It may also include together.

<Refractive Index Matching Layer, Touch Sensor, Image Display Device>

According to embodiments of the present invention, a touch sensor including the refractive index matching layer and the refractive index matching layer formed using the above-described curable resin composition is provided.

1 is a schematic cross-sectional view illustrating a touch sensor according to example embodiments.

Referring to FIG. 1, the touch sensor may include a base layer 100, a first insulating layer 120, sensing electrodes 130, and a second insulating layer 140.

The base layer 100 is used to mean a film type substrate used as a base layer for forming the sensing electrodes 130, or an object on which the sensing electrodes 130 are formed. In some embodiments, the base layer 100 may refer to a display panel on which a touch sensor is formed or stacked. In some embodiments, the base layer 100 may include a window substrate of the image display device.

For example, the substrate layer 100 may be a substrate or film material commonly used in a touch sensor without particular limitation, and for example, a cyclic olefin polymer (COP), polyethylene terephthalate (PET), polyacryl Rate (PAR), Polyetherimide (PEI), Polyethylenenaphthalate (PEN), Polyphenylenesulfide (PPS), Polyallylate, Polyimide (PI), Cellulose Acetate Propionate (CAP), Poly Ether sulfone (PES), cellulose triacetate (TAC), polycarbonate (PC), cyclic olefin copolymer (COC), polymethyl methacrylate (PMMA) and the like.

In some embodiments, the first insulating layer 120 may be provided as an index matching layer (IML) formed from the curable resin composition described above. As described above, the curable resin composition may provide an increased refractive index through the combination of the siloxane resin and the cardo-based compound. According to example embodiments, the first insulating layer 120 may have a refractive index in a range of about 1.7 or more, for example, about 1.7 to 1.9.

The sensing electrode 130 may include a metal or a transparent conductive oxide. Examples of the metal include silver, gold, copper, aluminum, platinum, palladium, chromium, titanium, tungsten, niobium, tantalum, vanadium, calcium, iron, manganese, cobalt, nickel, zinc, or alloys thereof.

Examples of the transparent conductive oxide include indium tin oxide (ITO), indium zinc oxide (IZO), aluminum zinc oxide (AZO), gallium zinc oxide (GZO), indium tin zinc oxide (ITZO), and zinc tin oxide (ZTO). , Indium gallium oxide (IGO), tin oxide (SnO ₂ ), zinc oxide (ZnO), and the like.

In one embodiment, the sensing electrode 130 may have a multilayer structure including a metal layer and a transparent conductive oxide layer.

The sensing electrode 130 has a relatively high refractive index compared to the organic or inorganic insulating layer, for example, may have a refractive index in the range of about 1.9 to 2.5. In example embodiments, the first insulating layer 120 may serve as a refractive index matching layer to buffer or reduce a difference in refractive index with the sensing electrode 130. Therefore, the sensing electrode 130 may be visually recognized by the user and may prevent the image quality from being impaired.

A second insulating layer 140 may be formed on the first insulating layer 120 to at least partially cover the sensing electrode 130. The second insulating layer 140 may include an organic insulating material such as acrylic or epoxy resin, or an inorganic insulating material such as silicon oxide.

In some embodiments, the sensing electrode 130 may include a first sensing electrode and a second sensing electrode arranged along different directions (for example, the X-axis direction and the Y-axis direction).

For example, the first sensing electrodes may be connected to each other by unit patterns to extend in the form of a sensing line, and the plurality of sensing lines may be arranged. The second sensing electrodes may include unit patterns that are physically spaced apart from each other. For example, a bridge electrode for electrically connecting neighboring second sensing electrodes with the first sensing electrode therebetween may be further included.

In this case, the second insulating layer 140 may be selectively formed at the intersection of the joint portion and the bridge electrode to insulate the first and second sensing electrodes from each other. The bridge electrode may be formed on the second insulating layer 140 to electrically connect the second sensing electrodes through, for example, a contact hole formed in the second insulating layer 140.

In some embodiments, the second insulating layer 140 may be formed from the curable resin composition described above and serve as a refractive index matching layer. In this case, the first insulating layer 120 may be omitted, or may be formed of an organic or inorganic insulating layer. In an embodiment, the first insulating layer 120 may also be provided as a refractive index matching layer formed from the curable resin composition according to the exemplary embodiments together with the second insulating layer 140.

In some embodiments, like the second insulating layer 140 shown in FIG. 1, the refractive index matching layer may be formed as an overcoat layer covering the sensing electrodes 130. Accordingly, the difference in refractive index caused by the exposed surface of the sensing electrode 130 may be reduced or canceled as a whole.

Embodiments of the present invention provide an image display device to which the touch sensor is applied.

The image display device may include various image display devices such as a liquid crystal display (LCD) device, an electroluminescent display device, a plasma display device, an organic light emitting diode (OLED) emitting display device, and may be a flexible display device having flexibility and bending characteristics. have.

For example, the image display device may include a TFT array substrate including a plurality of pixels defined on a TFT array substrate including a thin film transistor (TFT). For example, a liquid crystal layer or an OLED element is formed on the pixel electrode of the TFT array substrate, and a common electrode covering the liquid crystal layer or the OLED element is formed to define a display panel.

The touch sensor described above may be stacked on the display panel, and a protective substrate such as a window substrate or a protective film may be stacked on the touch sensor.

As described above, the touch sensor may include a high refractive index matching layer having improved chemical resistance and reliability. Therefore, it is possible to implement an image display device having improved flexibility and chemical characteristics while suppressing the visibility of the sensing electrode.

Hereinafter, experimental examples including specific examples and comparative examples are provided to help understanding of the present invention, but these are merely illustrative of the present invention and not intended to limit the appended claims, and the scope and spirit of the present invention. It is apparent to those skilled in the art that various changes and modifications to the embodiments can be made within the scope, and such variations and modifications are within the scope of the appended claims.

Examples and Comparative Examples

To the curable resin compositions of Examples and Comparative Examples were prepared by mixing the components in the composition and content (% by weight) shown in Table 1 and stirring, followed by filtering through a polypropylene filter.

Example Comparative example One 2 3 4 5 6 One 2 3 Siloxane resin (A) A-1 4.74 5.74 3.40 - 5.47 3.40 - - 5.99 A-2 - - - 6.63 - - - 4.90 - A-3 - - - - - - 5.71 - - Inorganic particles
(B) - - 3.29 - - - - - - Cardo-based compound
(C) C-1 3.57 - - 2.84 - - - - - C-2 - 2.70 2.64 - - 2.64 - - - C-3 - - - - 3.99 - 3.70 - - Polymerizable
Compound (D) D-1 - - - - - 3.29 - 4.33 - D-2 - - - - - - - - 3.55 Polymerization initiator (E) 0.53 0.72 0.64 0.57 0.73 0.64 0.64 0.90 0.77 Additive (F) 0.22 0.26 0.24 0.20 0.31 0.24 0.25 0.33 0.28 Solvent (G) 90.94 90.58 89.79 89.76 89.50 89.79 89.7 89.54 89.41

Specific compounds used as the components are as follows.

A-1) Zirconium-containing siloxane resin containing phenyl group (DW-Z1, manufactured by Kyungin Corporation)

A-2) Titanium-containing siloxane resin containing phenyl group (DW-T1, manufactured by Kyungin Corporation)

A-3) Metal-free general siloxane resin (DW-OP1, Kyungin Corporation)

B) Zirconia Particles

C-1) a compound of Formula 1-1

[Formula 1-1]

C-2) a compound of Formula 1-2

C-3) a compound of Formula 2-1

D-1) Polyethylene Glycol 200 Diacrylate

D-2) dipentaerythritol hexaacrylate (KAYARAD DPHA, manufactured by Nippon Kayaku)

E) OXE-03 (manufactured by BASF Corporation)

F) Fluorine-based surfactant (F554, manufactured by DIC Corporation)

G) Propylene Glycol Monomethyl Ether Acetate

Experimental Example

A glass substrate (Eagle 2000; manufactured by Corning Corporation) having a length and width of 2 inches was washed sequentially with a neutral detergent, water, and alcohol, and dried. Each of the curable resin compositions prepared in Examples and Comparative Examples was spin coated on the glass substrate, and then heated at 100 ° C. for 3 minutes using a hot plate to form a thin film.

 After cooling the thin film to room temperature, light was irradiated on the entire surface without a mask at an exposure dose of 100 mJ / cm 2 using an exposure machine (MA6; manufactured by SUSS MicroTec Co., Ltd.). Thereafter, the hot plate was maintained at a temperature of 230 ° C. for 30 minutes to form a cured film having a thickness of 1 μm.

(1) refractive index evaluation

The refractive index of the cured film was measured using an ellipsometer (Otsuka Electronics Korea).

(2) chemical resistance evaluation

1) Acid resistance evaluation

The substrate on which the cured film was formed was immersed in an etchant (MA-S02, Dongwoo Fine Chem Co., Ltd.) at 30 ° C. for 1 minute, and the thickness change was observed using a surface change before and after immersion and a film thickness meter (DEKTAK, Veeco).

2) Base resistance evaluation

The substrate on which the cured film was formed was immersed in a strip solution (SAM-S19, Dongwoo Fine Chem Co., Ltd.) at 50 ° C. for 5 minutes, and the thickness change was observed using a surface change before and after immersion and a film thickness meter (DEKTAK, Veeco).

3) Development of developer

The substrate on which the cured film was formed was immersed in a developer (tetraammonium hydroxide 2.38%) for 2 minutes at room temperature, and the change in thickness was observed using a surface change before and after immersion and a film thickness gauge (DEKTAK, Veeco).

Evaluation criteria of surface change are as follows.

○: practically no surface damage was observed

Δ: local surface damage observed

X: cured film thickness decreased substantially

The evaluation results are shown in Table 2 below.

Refractive index Chemical resistance Acid resistance Base resistance Developability Surface change △ film thickness
(Μm) Surface change △ film thickness
(Μm) Surface change △ film thickness
(Μm) Example 1 1.73 ○ 0.001 ○ 0.001 ○ 0.000 Example 2 1.74 ○ 0.002 ○ 0.001 ○ 0.000 Example 3 1.78 ○ 0.001 ○ 0.001 ○ 0.000 Example 4 1.74 ○ 0.002 ○ 0.001 ○ 0.000 Example 5 1.75 ○ 0.002 ○ 0.001 ○ 0.000 Example 6 1.75 ○ 0.000 ○ 0.000 ○ 0.000 Comparative Example 1 1.64 X 0.242 X 0.189 X 0.075 Comparative Example 2 1.61 X 0.368 X 0.264 X 0.145 Comparative Example 3 1.65 ○ 0.002 ○ 0.000 ○ 0.000

Referring to Table 2, in the case of using the metal-containing siloxane resin and the cardo-based compound together in both examples, when the high refractive index of about 1.7 or more is secured, the chemical resistance was improved together.

In the comparative examples in which the metal-containing siloxane resin and / or the cardo-based compound were omitted, a high refractive index of 1.7 or more was not obtained, and the chemical resistance was also lowered.

100: substrate layer
120: first insulating layer
130: sensing electrode
140: second insulating layer

Claims (12)

Metal-containing siloxane resins;
Cardo-based compounds;
Polymerization initiator; And
Curable resin composition containing a solvent.
The method of claim 1, wherein the metal included in the metal-containing siloxane resin includes zirconium (Zr), titanium (Ti), aluminum (Al), antimony (Sb) or tin (Sn),
The said metal containing siloxane resin has the structure which the metal atom substituted the some silicon atom contained in siloxane structure, curable resin composition.
The curable resin composition according to claim 2, wherein the metal-containing siloxane resin comprises a structural unit represented by the following Structural Formula 1:
[Formula 1]

(In Formula 1, M represents a metal atom selected from zirconium (Zr), titanium (Ti), aluminum (Al), antimony (Sb) or tin (Sn),
R ₁ to R ₆ represent an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or an aromatic group having 6 to 20 carbon atoms, and at least one of R ₁ to R ₆ is the aromatic group. ).
The curable resin composition according to claim 3, wherein at least one of R ₁ to R ₆ comprises a vinyl group.
The curable resin composition of claim 1, wherein the cardo-based compound includes at least one of compounds represented by the following Chemical Formula 1 or Chemical Formula 2:
[Formula 1]

[Formula 2]

(In Formulas 1 and 2, R ₁ and R ₂ each independently represent a hydrogen atom, a halogen atom, or an organic moiety having 1 to 20 carbon atoms,
At least one of R ₁ or R ₂ is a polymerizable reactive group comprising an unsaturated double bond.
The curable resin composition according to claim 5, wherein the polymerization reactive group is represented by the following Chemical Formula 3 or Chemical Formula:
[Formula 3]

[Formula 4]

(N in Formulas 3 and 4 is an integer from 0 to 3).
The curable resin composition of Claim 1 which further contains an inorganic particle.
The curable resin composition of Claim 1 which further contains a polymeric compound.
The curable resin composition of Claim 8 in which the said polymeric compound contains the bifunctional or more than acrylate-type monomer.
The method according to claim 1, in 100 parts by weight of the composition solids,
20 to 80 parts by weight of the metal-containing siloxane resin;
10 to 60 parts by weight of the cardo-based compound;
Curable resin composition containing 0.1-20 weight part of said polymerization initiators.
A refractive index matching layer formed of the curable resin composition of any one of claims 1 to 10 and having a refractive index of 1.7 or more.
A touch sensor comprising the refractive index matching layer of claim 11.

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