KR20190089651A - Adhesive Composition and Optical Laminate Using the Same - Google Patents

Abstract

The present invention relates to an adhesive composition comprising a polyfunctional (meth)acrylate compound having an amide group-containing monomer, a photocurable (meth)acrylate oligomer, a photoinitiator and an amine group, and to an optical laminate comprising an adhesive layer formed by the adhesive composition. The adhesive composition according to the present invention can bond an optical layer comprising a UV transmissive region and a UV impermeable region at the same time in a UV impermeable substrate with excellent adhesion.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an adhesive composition and optical laminate using the same,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive composition and an optical laminate using the same, and more particularly, to an adhesive composition capable of bonding an optical layer including an ultraviolet ray transmitting region and an ultraviolet ray opaque region with excellent adhesive strength and an optical laminate will be.

The touch sensor is a device that grasps a touch point in response to a touch when a user touches an image displayed on the screen with a finger or a touch pen. The touch sensor is a liquid crystal display (LCD), an organic light- Emitting diodes (OLEDs), and the like.

Such a touch sensor can be applied to various substrates via a UV curable adhesive. However, when the base material is a UV-impermeable base material, the adhesive should be cured by irradiating UV light toward the touch sensor side. However, since the touch sensor includes a UV-impermeable region together with a UV-transparent region, sufficient ultraviolet rays do not reach the adhesive located under the UV-impermeable region of the touch sensor in conventional UV-curable adhesives, resulting in insufficient curing. Thereby adversely affecting their adhesion.

Japanese Patent Registration No. 4,711,354 discloses a technique for containing an organic peroxide in an adhesive and heating after UV irradiation to cure the adhesive in the UV-impermeable region as a technique for improving the curing of the adhesive present in the UV-impermeable region . However, the heating process has a limitation because it can damage the substrate or the like.

Accordingly, there is a demand for development of an adhesive composition capable of bonding an optical layer simultaneously including a UV-transparent region and a UV-impermeable region to a UV-impermeable base with an excellent adhesive force.

Japanese Patent Registration No. 4,711,354

It is an object of the present invention to provide an adhesive composition capable of bonding an optical layer including a UV-transparent region and a UV-impermeable region with excellent adhesive force.

Another object of the present invention is to provide an optical laminate formed using the adhesive composition.

On the other hand, the present invention provides an adhesive composition comprising a monomer having the following formula (1) or (2), a photo-curable (meth) acrylate oligomer, a photoinitiator and a polyfunctional (meth) acrylate compound having an amine group.

[Chemical Formula 1]

(2)

In this formula,

R ₁ and R ₂ are each independently hydrogen or a methyl group,

R ₃ is hydrogen or a C ₁ -C ₄ alkyl group,

R ₄ is a C ₂ -C ₆ alkylene group,

X ₁ and X ₂ are each independently O or NR ₅ ,

R ₅ is a C ₁ -C ₄ alkyl group.

In one embodiment of the present invention, the polyfunctional (meth) acrylate compound having an amine group may be a compound represented by the following general formula (3).

(3)

In this formula,

R ⁶ and R ⁷ are each independently a C ₁ -C ₆ alkylene group,

R ⁸ is a hydroxy group, a C ₁ -C ₆ alkyl group or a C ₁ -C ₆ hydroxyalkyl group.

In one embodiment of the present invention, the adhesive composition may be one for bonding an optical layer comprising an ultraviolet transparent region and an ultraviolet opaque region.

In one embodiment of the present invention, the adhesive composition may be for bonding an ultraviolet-opaque substrate with an optical layer comprising an ultraviolet-transparent region and an ultraviolet-opaque region.

On the other hand, the present invention relates to a substrate; An adhesive layer formed of the adhesive composition laminated on the substrate; And an optical layer laminated on the adhesive layer.

The adhesive composition according to the present invention can bond an optical layer containing a UV-transparent region and a UV-impermeable region at the same time to various substrates including a UV-impermeable substrate with excellent adhesive force, It can be used effectively.

1 is a structural cross-sectional view of an optical laminate according to an embodiment of the present invention.
2 is a structural cross-sectional view of a touch sensor included in an optical laminate according to an embodiment of the present invention.

Hereinafter, the present invention will be described in more detail.

An embodiment of the present invention relates to an adhesive composition comprising a monomer having the following formula (1) or (2), a photo-curable (meth) acrylate oligomer, a photoinitiator and a polyfunctional (meth) acrylate compound having an amine group.

[Chemical Formula 1]

(2)

In this formula,

R ₁ and R ₂ are each independently hydrogen or a methyl group,

R ₃ is hydrogen or a C ₁ -C ₄ alkyl group,

R ₄ is a C ₂ -C ₆ alkylene group,

X ₁ and X ₂ are each independently O or NR ₅ ,

R ₅ is a C ₁ -C ₄ alkyl group.

As used herein, the C ₁ -C ₄ alkyl group means a linear or branched monovalent hydrocarbon having 1 to 4 carbon atoms, for example, methyl, ethyl, n-propyl, i-propyl, i-butyl, t-butyl, and the like.

As used herein, the term C ₂ -C ₆ alkylene group means a linear or branched divalent hydrocarbon having 2 to 6 carbon atoms and includes, for example, ethylene, propylene, and butylene, but is not limited thereto .

In one embodiment of the present invention, the monomer of Formula 1 may be a compound wherein R ₁ is hydrogen or a methyl group, X ₁ is O or NR ₅ , and R ₅ is a methyl group.

In one embodiment of the present invention, the monomer of Formula 2 may be a compound wherein R ₂ is hydrogen or a methyl group, R ₃ is hydrogen, R ₄ is an ethylene group, and X ₂ is O.

The monomer of the above formula (1) or (2) is a photopolymerizable monomer, and the radical quenching due to oxygen is suppressed by the nitrogen of the amide group thereof. That is, the radical can reach the deep part, The curing can sufficiently proceed to the UV-impermeable region even if ultraviolet rays are irradiated.

The monomers of the above formula (1) or (2) have a high glass transition temperature (Tg) and an elastic modulus, which are advantageous for exhibiting an adhesive strength.

The monomer of Formula 1 or Formula 2 may be used in an amount of 20 to 70% by weight based on 100% by weight of the adhesive composition. If the content of the monomer of the formula (1) or (2) is less than 20% by weight, the radical quenching inhibiting effect by the nitrogen of the amide group is insufficient and the curing of the UV-impermeable region may not be sufficient. , The monomers may not be polymerized by hydrogen donation from the amine, and the reaction may terminate in a state where the molecular weight is small, and the degree of crosslinking may be lowered, so that sufficient curing may not be obtained.

In one embodiment of the present invention, a photopolymerizable monomer other than the monomer of the above formula (1) or (2) may further include a (meth) acrylate monomer ordinarily used in the art.

The (meth) acrylate monomer may be a (meth) acrylate monomer having one (meth) acryloyloxy group in the molecule (hereinafter referred to as "monofunctional (meth) acrylate monomer"), (Meth) acrylate monomer having at least three (meth) acryloyloxy groups in the molecule (hereinafter referred to as " bifunctional (meth) acrylate monomer " (Hereinafter referred to as "multifunctional (meth) acrylate monomer"), or a mixture thereof. The (meth) acrylate monomers may be used alone or in combination of two or more.

In the present invention, (meth) acrylate means acrylate and / or methacrylate.

Examples of the monofunctional (meth) acrylate monomers include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) Butyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, isobutyl (meth) acrylate, (Meth) acrylate, dicyclopentenyl (meth) acrylate, benzyl (meth) acrylate, isobornyl (meth) acrylate, phenoxyethyl (Meth) acrylate, trimethylolpropane mono (meth) acrylate, pentaerythritol mono (meth) acrylate, phenoxypolyethylene glycol (meth) acrylate, ) Acrylate and the like The can.

As the monofunctional (meth) acrylate monomer, a carboxyl group-containing (meth) acrylate monomer may also be used. Specific examples thereof include 2- (meth) acryloyloxyethylphthalic acid, 2- (meth) acryloyloxyethylhexahydrophthalic acid, carboxyethyl (meth) acrylate, 2- (meth) acryloyloxyethylsuccinic acid, N- (meth) acryloyloxy-N ', N'-dicarboxy-p-phenylenediamine and 4- (meth) acryloyloxyethyltrimellitic acid. Further, a (meth) acryloylamino group-containing monomer such as 4- (meth) acryloylamino-1-carboxymethylpiperidine and the like may also be used.

Examples of the bifunctional (meth) acrylate monomers include alkylene glycol di (meth) acrylates, polyoxyalkylene glycol di (meth) acrylates, halogen-substituted alkylene glycol di (meth) acrylates, aliphatic polyols (Meth) acrylates of di (meth) acrylates, hydrogenated dicyclopentadiene or tricyclodecanedialanol, di (meth) acrylates of dioxane glycol or dioxanedialcohol, bisphenol A or Di (meth) acrylates of alkylene oxide adducts of bisphenol F, and epoxy di (meth) acrylates of bisphenol A or bisphenol F, but are not limited thereto.

More specific examples of the bifunctional (meth) acrylate monomers include ethylene glycol di (meth) acrylate, 1,3-butanediol di (meth) acrylate, 1,4-butanediol di (meth) (Meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, neopentyl glycol di Acrylate, diethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, diethylene glycol di (Meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, polytetramethylene glycol di (Meth) acryloyloxyethoxyethoxyphenyl] propane, 2,2-bis [4- (meth) acryloyloxy (meth) acrylate, (Meth) acrylate, tricyclodecane dimethanol di (meth) acrylate, 1,3-dioxane-2,5-diyl di (meth) acrylate, Acrylate [alias dioxane glycol di (meth) acrylate], acetal compound of hydroxypivalaldehyde and trimethylol propane [Compound: 2- (2-hydroxy-1,1-dimethylethyl) Di (meth) acrylate of 1,3,5-tris (2-hydroxyethyl) isocyanurate, and di (meth) .

Examples of the polyfunctional (meth) acrylate monomer include glycerin tri (meth) acrylate, trimethylol propane tri (meth) acrylate, ditrimethylol propane tri (meth) acrylate, ditrimethylol propane tetra (Meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta Poly (meth) acrylates of trifunctional or higher aliphatic polyols such as trimethylolpropane tri (meth) acrylate and lithol hexa (meth) acrylate, and poly (meth) acrylates of trifunctional or higher halogen- Tri (meth) acrylate, tri (meth) acrylate of an alkylene oxide adduct of trimethylolpropane, 1,1,1-tris [(meth) Tri (meth) acrylate, and silicon hexa (meth) acrylate of 1,3,5-tris (2-hydroxyethyl) isocyanurate.

The additional (meth) acrylate monomer may be used in an amount ranging from 5 to 50% by weight based on the total 100% by weight of the adhesive composition.

In one embodiment of the present invention, the photocurable (meth) acrylate oligomer may be a urethane (meth) acrylate oligomer, a polyester (meth) acrylate oligomer, or a mixture thereof. The photocurable (meth) acrylate oligomer may be used alone or in combination of two or more. In particular, when a urethane (meth) acrylate oligomer is used, adhesion can be increased.

The urethane (meth) acrylate oligomer is a compound having a urethane bond (-NHCOO-) and at least two (meth) acryloyloxy groups in the molecule. Specifically, a urethane-forming reaction product of a (meth) acrylate monomer having at least one (meth) acryloyloxy group and at least one hydroxyl group in a molecule with a polyisocyanate, a terminal isocyanate obtained by reacting a polyol with a polyisocyanate Group-containing urethane compound and a (meth) acrylate monomer having at least one (meth) acryloyloxy group and at least one hydroxy group in the molecule, respectively.

Examples of the hydroxyl group-containing (meth) acrylate monomer used in the urethanization reaction include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) (Meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, pentaerythritol tri Methacrylate, and the like.

Examples of the polyisocyanate used in the urethane formation reaction with such a hydroxy group-containing (meth) acrylate monomer include hexamethylene diisocyanate, lysine diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, tolylene diisocyanate, Isocyanates, diisocyanates obtained by hydrogenating aromatic isocyanates in these diisocyanates (for example, diisocyanates such as hydrogenated tolylene diisocyanate and hydrogenated xylylene diisocyanate), triphenylmethane triisocyanate, dimethylentriphenyl Di- or triisocyanates such as triisocyanate and dibenzylbenzene triisocyanate, and polyisocyanates obtained by mass-increasing diisocyanate.

Examples of the polyol used for producing the terminal isocyanate group-containing urethane compound by reaction with the polyisocyanate include aromatic, aliphatic and alicyclic polyols, polyester polyols and polyether polyols. Examples of the aliphatic and alicyclic polyols include 1,4-butanediol, 1,6-hexanediol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, neopentyl glycol, trimethylolethane, , Ditrimethylol propane, pentaerythritol, dipentaerythritol, dimethylolheptane, dimethylolpropionic acid, dimethylolbutanoic acid, glycerin, hydrogenated bisphenol A and the like.

The polyester polyol may be one obtained by a condensation reaction of the polyol and a polyvalent carboxylic acid or anhydride thereof. Examples of the polycarboxylic acid or its anhydride include succinic acid, adipic acid, (maleic anhydride) maleic acid, (anhydride) itaconic acid, (anhydrous) trimellitic acid, (anhydrous) pyromellitic acid, (Anhydrous) phthalic acid, (anhydrous) phthalic acid, isophthalic acid, terephthalic acid and the like.

Examples of the polyether polyols include polyalkylene glycols, and polyoxyalkylene-modified polyols obtained by reacting the polyols or dihydroxybenzenes with alkylene oxides.

The polyester (meth) acrylate oligomer is a compound having an ester bond in the molecule and at least two (meth) acryloyloxy groups. Specifically, it can be obtained by a condensation reaction of (meth) acrylic acid, a polycarboxylic acid or an anhydride thereof and a polyol. Examples of the polycarboxylic acid or its anhydride used in the condensation reaction include succinic acid, adipic acid, (maleic anhydride) maleic acid, (anhydride) itaconic acid, (anhydrous) trimellitic acid, (Anhydrous) phthalic acid, (anhydrous) phthalic acid, isophthalic acid, terephthalic acid, and the like. Examples of the polyol used in the condensation reaction include 1,4-butanediol, 1,6-hexanediol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, neopentyl glycol, trimethylolethane, Dipentaerythritol, dimethylolheptane, dimethylolpropionic acid, dimethylolbutanoic acid, glycerin, hydrogenated bisphenol A, and the like.

The photocurable (meth) acrylate oligomer may have a number average molecular weight of 500 to 20,000, preferably 500 to 5,000, more preferably 500 to 2,000. When the number average molecular weight of the photocurable (meth) acrylate oligomer is less than 500, the brittleness of the adhesive composition is too strong and may be vulnerable to cracks. When the number average molecular weight exceeds 20,000, the viscosity of the oligomer increases It may be difficult to realize an adhesive composition having a low viscosity, and the movement speed of the radical is slowed, so that hardening of the UV-impermeable region may become difficult.

The photocurable (meth) acrylate oligomer may be used in an amount of 20 to 70% by weight based on 100% by weight of the adhesive composition. If the content of the photocurable (meth) acrylate oligomer is less than 20% by weight, the degree of crosslinking may be low and the curing may not be sufficiently performed. If the content is more than 70% by weight, have.

In one embodiment of the present invention, the photoinitiator can be used without limitation as long as it is used in the art. In particular, as the photoinitiator, a long-wavelength photoinitiator having an absorption wavelength of 380 to 450 nm may be used. Specifically, as the photoinitiator, a phosphine oxide-based photoinitiator may be used. Examples of commercially available phosphine oxide-based photoinitiators include bis (2,4,6-trimethylbenzoyl) -4-methylphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) (2,4,6-trimethylbenzoyl) -2-methylphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -4-methylphenylphosphine oxide, bis 4,6-trimethylbenzoyl) -2,5-diethylphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -2,3,5,6-tetramethylphenylphosphine oxide, 2,4,6 (DERACURE TPO), bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide (IGACURE 819), and the like. Particularly, in the case of using 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (DAROCURE TPO) and bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide (IGACURE 819) as the photoinitiator , Excellent deep-part curing characteristics and excellent luminance characteristics.

The photoinitiator may be used in an amount ranging from 1 to 10% by weight based on 100% by weight of the adhesive composition. When the content of the photoinitiator is less than 1% by weight, sufficient radicals are not generated and the curing rate may be slow. When the content exceeds 10% by weight, the reliability of the unreacted photoinitiator is lowered, There is a problem that the cohesion is lowered due to the non-enlargement.

In one embodiment of the present invention, the polyfunctional (meth) acrylate compound having an amine group may be a compound represented by the following general formula (3).

(3)

In this formula,

R ⁶ and R ⁷ are each independently a C ₁ -C ₆ alkylene group,

R ⁸ is hydrogen, a C ₁ -C ₆ alkyl group or a C ₁ -C ₆ hydroxyalkyl group.

As used herein, a C ₁ -C ₆ alkylene group means a linear or branched divalent hydrocarbon having 1 to 6 carbon atoms, and includes, for example, methylene, ethylene, propylene, butylene, hexylene and the like But is not limited thereto.

As used herein, a C ₁ -C ₆ alkyl group means a linear or branched monovalent hydrocarbon group having 1 to 6 carbon atoms, and examples thereof include methyl, ethyl, n-propyl, i-propyl, i-butyl, t-butyl, n-pentyl, n-hexyl, and the like.

As used herein, the term " C ₁ -C ₆ hydroxyalkyl group " means a linear or branched hydrocarbon having 1 to 6 carbon atoms substituted with a hydroxy group, and includes, for example, hydroxymethyl, hydroxyethyl, However, the present invention is not limited thereto.

In one embodiment of the present invention, R ⁶ and R ⁷ are a hexylene group, and R ⁸ may be a hydroxyethyl group.

The polyfunctional (meth) acrylate compound having an amine group acts as a hydrogen donor, and is effective in overcoming the photoinhibition reaction by oxygen, thereby transferring radicals to the deep portion. Even if ultraviolet rays are irradiated only in the UV transmissive region, It is possible to induce the curing to sufficiently proceed to the region.

The amine functional group-containing polyfunctional (meth) acrylate compound may be used in an amount ranging from 1 to 20% by weight based on 100% by weight of the adhesive composition. If the content of the amine group-containing polyfunctional (meth) acrylate compound is less than 1% by weight, the effect of overcoming the oxygen barrier of the polyfunctional (meth) acrylate compound having an amine group is insufficient and the curing of the UV- If the content exceeds 20% by weight, the monomers may not be polymerized due to hydrogen donation from excess amine, and the reaction may terminate in a state where the molecular weight is small, and the adhesion may be lowered.

The adhesive composition according to one embodiment of the present invention may further include additives known in the art as needed. The kind of the additive is not particularly limited, and examples thereof include a photosensitizer, a silane coupling agent, an adhesion promoter, a leveling agent, an ultraviolet absorber, an antioxidant, a dye, a processing aid, an ion trap agent, an antioxidant, , A plasticizer, a foaming inhibitor, an antistatic agent, a fragrance, and a surfactant. These may be used alone or in combination of two or more.

The content of the additive is not particularly limited and may be, for example, 0.01 to 3% by weight, preferably 0.5 to 1% by weight based on 100% by weight of the total adhesive composition.

The adhesive composition according to one embodiment of the present invention can be suitably used for bonding an optical layer including a UV-transparent region and a UV-impermeable region. In particular, the adhesive composition according to one embodiment of the present invention may be suitably used for bonding a UV-impermeable substrate with an optical layer comprising a UV-transparent region and a UV-impermeable region.

Referring to Figure 1, one embodiment of the present invention is directed to a substrate 100; An adhesive layer (200) formed of the adhesive composition laminated on the substrate; And an optical layer (300) laminated on the adhesive layer.

The optical laminate according to one embodiment of the present invention can be produced, for example, by a coating process for forming an adhesive coated surface by applying the adhesive composition of the present invention in an uncured state to a substrate, An adhesive process, and a curing process for curing the adhesive composition.

There is no particular limitation on the coating method of the adhesive composition, and various coating methods such as a doctor blade, a wire bar, a die coater, a comma coater, and a gravure coater can be used.

After the adhesive composition of the present invention is coated on the substrate, the optical layer is adhered to the adhesive coated surface, and then the active energy ray is irradiated to cure the adhesive composition to fix the optical layer on the substrate.

Although a light source of an active energy ray is not particularly limited, an active energy ray having a light emission distribution with a wavelength of 400 nm or less is preferable. Specific examples thereof include low pressure mercury lamp, medium pressure mercury lamp, high pressure mercury lamp, ultra high pressure mercury lamp, Mercury lamp, metal halide lamp and the like are preferable. The light irradiation intensity for the adhesive composition is appropriately determined according to the composition of the adhesive composition and is not particularly limited, but the irradiation intensity in the wavelength range effective for activating the photoinitiator is preferably 0.1 to 6000 mW / cm 2. When the irradiation intensity is 0.1 mW / cm 2 or more, the reaction time does not become too long. When the irradiation intensity is 6000 mW / cm 2 or less, the heat radiated from the light source and the yellowing due to heat generation during curing of the adhesive composition and the deterioration of the substrate and / There is less concern. The light irradiation time for the adhesive composition is controlled for each adhesive composition to be cured, and is not particularly limited, but it is preferable that the accumulated light amount as a product of the irradiation intensity and irradiation time is set to 10 to 10,000 mJ / cm 2. When the accumulated amount of light for the adhesive is 10 mJ / cm 2 or more, a sufficient amount of the active agent derived from the photoinitiator can be sufficiently generated to promote the curing reaction more surely. If the amount is less than 10000 mJ / cm 2, the irradiation time does not become too long, .

The thickness of the adhesive layer 200 can be adjusted according to the adhesive strength, preferably 0.01 to 10 mu m, more preferably 0.1 to 5 mu m. When the thickness of the adhesive layer 200 is less than 0.01 탆, there is a high possibility of incorporation of air bubbles at the time of bonding, and when the thickness of the adhesive layer is more than 10 탆, the price increases.

In one embodiment of the present invention, the substrate 100 may be ultraviolet (UV) impermeable. For example, the substrate 100 may be a polarizing plate or a polyimide film.

In one embodiment of the present invention, the optical layer 300 may comprise a UV transmissive region and a UV impermeable region. For example, the optical layer 300 may be a touch sensor.

The touch sensor may be a touch sensor that forms a separation layer on a carrier substrate to perform a touch sensor formation process and uses the separation layer as a wiring coating layer when separated from the carrier substrate. For example, the touch sensor may be a film touch sensor having a film shape.

2, the touch sensor includes an isolation layer 310; An electrode pattern layer 330 formed on the isolation layer; And an insulating layer 340 formed on the electrode pattern layer and covering the electrode pattern layer.

The separation layer 310 is a polymer organic film, which is coated on a carrier substrate, an electrode pattern layer or the like is formed thereon, and finally, the separation layer 310 is separated from the carrier substrate.

The separation force of the separation layer 310 is preferably 1 N / 25 mm or less, and more preferably 0.1 N / 25 mm or less. That is, it is preferable that the separation layer 310 is formed of a material such that the physical force applied when the separation layer 310 is separated from the carrier substrate does not exceed 1 N / 25 mm, especially 0.1 N / 25 mm.

When the peeling force of the separation layer 310 is more than 1 N / 25 mm, the separation layer 310 may not be cleanly separated when separated from the carrier substrate, and the separation layer 310 may remain on the carrier substrate. The protective layer 320, the electrode pattern layer 330, and the insulating layer 340 may be cracked.

Particularly, the peeling force of the separating layer 310 is more preferably 0.1 N / 25 mm or less, more preferably 0.1 N / 25 mm or less in view of controllability of the curl after peeling from the carrier substrate. Although the curl does not cause any problems in terms of the function of the touch sensor, it is advantageous to minimize the curl since the process efficiency in the joining process, the cutting process, and the like may be lowered.

The thickness of the separation layer 310 is preferably 10 to 1000 nm, more preferably 50 to 500 nm. If the thickness of the separation layer 310 is less than 10 nm, the uniformity of the separation layer may deteriorate and the electrode pattern may be unevenly formed. In addition, the separation layer 310 may be locally peeled and torn, curl) is not controlled. If the thickness exceeds 1000 nm, the peeling force is not lowered further, and flexibility is lowered.

An electrode pattern layer 330 is formed on the isolation layer 310. The isolation layer 310 functions as a covering layer covering the electrode pattern layer 330 after being separated from the carrier substrate, ) Functioning as a protective layer for protecting from external contact.

At least one protective layer 320 may be further formed on the isolation layer 310. At least one protective layer 320 may be formed on the isolation layer 310 since the isolation layer 310 alone may be difficult to protect the electrode pattern against external contact or impact.

The protective layer 320 includes at least one of an organic insulating film and an inorganic insulating film, and may be formed by a method of coating and hardening or by deposition.

An electrode pattern layer 330 is formed on the isolation layer 310 or the protection layer 320. The electrode pattern layer 330 includes a sensing electrode for sensing the touch and a pad electrode formed at one end of the sensing electrode. Here, the sensing electrode may include not only an electrode for sensing a touch but also a wiring pattern connected to the electrode.

The electrode pattern layer 330 may be formed of at least one material selected from a metal, a metal nanowire, a metal oxide, a carbon nanotube, a graphene, a conductive polymer, and a conductive ink.

The pattern structure of the electrode pattern layer is preferably an electrode pattern structure used for the electrostatic capacity method, and mutual-capacitance or self-capacitance may be applied.

In case of mutual-capacitance, it may be a lattice electrode structure having a horizontal axis and a vertical axis. Bridge electrodes may be formed at the intersections of the electrodes on the horizontal axis and the vertical axis, or the horizontal axis electrode pattern layer and the vertical axis electrode pattern layer may be formed and electrically separated from each other.

In the case of a self-capacitance type, it may be an electrode layer structure in which a change in capacitance is read using one electrode at each point.

An insulating layer 340 is formed on the electrode pattern layer 330. The insulating layer may prevent corrosion of the electrode pattern and protect the surface of the electrode pattern. It is preferable that the insulating layer 340 is formed to have a constant thickness by filling the gap between the electrode and the wiring. That is, it is preferable that the surface opposite to the surface in contact with the electrode pattern layer 330 is formed to be flat so as not to expose the irregularities of the electrode.

The insulating layer is not particularly limited as long as it is an organic insulating material, but is preferably a thermosetting or UV curable organic polymer.

The pad electrode of the touch sensor may be electrically connected to the circuit board. The circuit board is, for example, a flexible printed circuit board (FPCB), and functions to electrically connect the touch control circuit and the touch sensor.

The optical laminate according to an embodiment of the present invention may be in the form that the separation layer 310 of the touch sensor is attached to the adhesive layer 200.

Hereinafter, the present invention will be described more specifically with reference to Examples, Comparative Examples and Experimental Examples. It should be apparent to those skilled in the art that these examples, comparative examples and experimental examples are only for illustrating the present invention, and the scope of the present invention is not limited thereto.

Example  1 to 3 and Comparative Example  1 to 5: Preparation of adhesive composition

Each component was mixed with the composition shown in Table 1 (unit: parts by weight) to prepare an adhesive composition.

Example Comparative Example One 2 3 One 2 3 4 5 Photopolymerizable monomer Photopolymerizable monomer 1 50 50 30 50 50 Photopolymerizable monomer 2 20 Photopolymerizable monomer 3 50 Photopolymerizable monomer 4 50 Photopolymerizable monomer 5 50 The photocurable (meth) acrylate oligomer 50 50 50 50 50 50 50 50 Photoinitiator Photoinitiator 1 4 2 2 4 4 4 4 Photo initiator 2 2 2 Photoinitiator 3 4 A polyfunctional (meth) acrylate compound having an amine group 5 5 5 5 5 5

Photopolymerizable monomer 1: acryloylmorpholine

Photopolymerizable monomer 2: isobornyl acrylate

Photopolymerizable monomer 3: benzyl acrylate

Photopolymerizable monomer 4: Phenoxyethyl acrylate

Photopolymerizable monomer 5: 1,6-hexanediol diacrylate

Photocurable (meth) acrylate oligomer: Ebecryl 270 (Entis, number average molecular weight: 1,500)

Photoinitiator 1: DARACURE TPO (BASF, absorption wavelength: 395 to 420 nm)

Photoinitiator 2: IGACURE 819 (BASF, absorption wavelength: 395 to 440 nm)

Photoinitiator 3: IGACURE 184 (BASF)

(AM 102, Ion Nanochem), which is a polyfunctional (meth) acrylate compound having an amine group: R ⁶ and R ⁷ are a hexylene group and R ⁸ is a hydroxyethyl group,

Experimental Example  One:

The properties of the adhesive compositions prepared in the above Examples and Comparative Examples were measured by the methods described below, and the results are shown in Table 2 below.

(One) UV  Impermeable region Unscaled width

The adhesive composition prepared in the above Examples and Comparative Examples was applied in a thickness of 5 탆 between a 100 탆 PET film and a 50 탆 release film and masked so as to prevent UV transmission at a width of 18.5 mm on the release film, Curable coating film was prepared by UV curing with a metal halide lamp (UV intensity 600 mJ / cm 2, irradiation intensity 40 mW / cm 2).

The release film was removed and the length of the uncured width was measured.

(2) Peel force

The adhesive composition prepared in the above Examples and Comparative Examples was applied in a thickness of 5 탆 between two 100 탆 PET films and UV-cured by a metal halide lamp (UV intensity 600 mJ / cm 2, irradiation intensity 40 mW / cm 2) , Cut into a width of 25 mm, and peeled off force was measured with a 180 degree peel peeler.

division Unscaled width (mm) Peel force
(N / 25 mm) Example 1 5 9 Example 2 3 11 Example 3 8 10 Comparative Example 1 10 7 Comparative Example 2 10 7 Comparative Example 3 10 7 Comparative Example 4 12 6 Comparative Example 5 17 6

As shown in Table 2, it was confirmed that the adhesive compositions of Examples 1 to 3 according to the present invention were further cured in the UV impermeable region as compared with the adhesive compositions of Comparative Examples 1 to 5.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Do. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Accordingly, the actual scope of the invention is defined by the appended claims and their equivalents.

100: substrate 200: adhesive layer
300: optical layer 310: separation layer
320: protective layer 330: electrode pattern layer
340: insulating layer

Claims (15)

An adhesive composition comprising a monomer of formula (1) or (2), a photo-curable (meth) acrylate oligomer, a photoinitiator and a polyfunctional (meth)
[Chemical Formula 1]

(2)

In this formula,
R ₁ and R ₂ are each independently hydrogen or a methyl group,
R ₃ is hydrogen or a C ₁ -C ₄ alkyl group,
R ₄ is a C ₂ -C ₆ alkylene group,
X ₁ and X ₂ are each independently O or NR ₅ ,
R ₅ is a C ₁ -C ₄ alkyl group. The adhesive composition according to claim 1, wherein the monomer of Formula 1 is a compound wherein R ₁ is hydrogen or a methyl group, X ₁ is O or NR ₅ , and R ₅ is a methyl group. The adhesive composition according to claim 1, wherein the monomer of Formula 2 is a compound wherein R ₂ is hydrogen or a methyl group, R ₃ is hydrogen, R ₄ is an ethylene group, and X ₂ is O. The adhesive composition according to claim 1, wherein the amine functional group-containing polyfunctional (meth) acrylate compound is a compound represented by the following formula (3):
(3)

In this formula,
R ⁶ and R ⁷ are each independently a C ₁ -C ₆ alkylene group,
R ⁸ is a hydroxy group, a C ₁ -C ₆ alkyl group or a C ₁ -C ₆ hydroxyalkyl group. The adhesive composition according to claim 4, wherein R ⁶ and R ⁷ are hexylene groups and R ⁸ is a hydroxyethyl group. The adhesive composition of claim 1, wherein the photocurable (meth) acrylate oligomer is a urethane (meth) acrylate oligomer, a polyester (meth) acrylate oligomer, or a mixture thereof. The adhesive composition according to claim 1, wherein the photoinitiator has an absorption wavelength of 380 to 450 nm. 8. The adhesive composition of claim 7, wherein the photoinitiator comprises 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide. The adhesive composition according to claim 1, wherein the adhesive layer comprises an ultraviolet-transmissive region and an ultraviolet-opaque region. The adhesive composition according to claim 1, wherein the adhesive composition is for bonding an optical layer containing an ultraviolet ray-transparent region and an ultraviolet ray-opaque region to an ultraviolet-opaque substrate. materials;
An adhesive layer formed of the adhesive composition according to any one of claims 1 to 10 laminated on the substrate; And
And an optical layer laminated on the adhesive layer. The optical laminate according to claim 11, wherein the substrate is ultraviolet-opaque. The optical laminate according to claim 11, wherein the substrate is a polarizing plate or a polyimide film. 12. The optical stack of claim 11, wherein the optical layer comprises an ultraviolet transparent region and an ultraviolet opaque region. The optical laminate according to claim 11, wherein the optical layer is a touch sensor.

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