KR20140085299A - Adhesive film and optical display comprising the same - Google Patents

Abstract

The present invention relates to an adhesive film of which the strain is 5%, the tan δ in the frequency sweep test under 30°C and 1 rad/s is 0.12-0.38, and the tan δ in the frequency sweep test under 30°C and 100 rad/s is 0.2-0.7 and to an optical display device including the same.

Description

TECHNICAL FIELD [0001] The present invention relates to an adhesive film, and an optical display device including the adhesive film.

The present invention relates to an adhesive film and an optical display device including the same.

The capacitive touch pad has a transparent adhesive film adhered to a window or a film positioned on the upper surface of the touch pad and operates by sensing a change in capacitance in the window or film. The dielectric constant of the unipolar detection plate is changed or the human hand or a predetermined object (conductor or liquid) or the like is brought into proximity to or brought into contact with the monopole detection plate and the capacitance due to the change in the dielectric constant of the monopole detection plate is changed to generate the switching signal do.

Recently, a flexible type optical display device has been developed, and the adhesive film used therefor should have excellent bending characteristics. However, if the bending property is good, there is a problem that a floating phenomenon, a bubble generation, or a dragging mark may occur.

(A) a (meth) acrylate monomer having a hydrocarbon group of 1-12 carbon atoms, (b) a hydroxy group-containing (meth) acrylate monomer, (c) an amide group (D) a monomer component comprising a vinyl ester monomer, and discloses an acrylic polymer used for a pressure-sensitive adhesive composition for a touch panel having a resin acid value of 0.1 mgKOH / g or less and a dielectric constant of 3-6 have.

An object of the present invention is to provide an adhesive film having a good stress relaxation property in bending.

Another object of the present invention is to provide an adhesive film free from lifting, bubbling, or dragging marks under bending conditions.

Another object of the present invention is to provide an adhesive film with increased endurance reliability and minimized resistance.

It is still another object of the present invention to provide an adhesive film excellent in transparency.

Another object of the present invention is a composition for the above-mentioned pressure-sensitive adhesive film and an optical member comprising the same.

The adhesive film of the present invention has a strain of 5%, a tan δ of 0.12-0.38 at a frequency sweep test of 30 ° C. and 1 rad / s, a strain of 5%, a temperature of 30 ° C. and a velocity of 100 rad / s In the frequency sweep test, tan δ can be 0.2-0.7.

The pressure-sensitive adhesive composition of the present invention may comprise 100 parts by weight of a photocurable monomer, 0.01-0.15 parts by weight of a crosslinking agent, and 0.1-10 parts by weight of an initiator.

An optical display device of the present invention includes a substrate, an OLED element formed on the substrate, a sealing layer sealing the OLED element, a first adhesive film formed on the sealing layer, a substrate formed on the first adhesive film, A transparent conductive material comprising a first transparent conductive layer formed on an upper portion of the substrate and a second transparent conductive layer formed on a lower portion of the substrate, a polarizing plate formed on the first transparent conductive layer, a second adhesive film formed on the polarizing plate, And a window formed on the second adhesive film, wherein at least one of the first adhesive film and the second adhesive film may include the adhesive film.

The present invention provides a transparent pressure-sensitive adhesive film which has good bending properties and is free of lifting, bubbling, or trailing marks under bending conditions, and capable of securing high endurance reliability and minimized resistance.

1 is a cross-sectional view of an OLED display device according to an embodiment of the present invention.
2 is a cross-sectional view of an OLED display device according to another embodiment of the present invention.

The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. The present invention may be embodied in many different forms and is not limited to the embodiments described herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and the same or similar components are denoted by the same reference numerals throughout the specification. In the present specification, 'upper' and 'lower' are defined with reference to the drawings, and 'upper' may be changed to 'lower' and 'lower' 'May mean acrylate and / or methacrylate.

The adhesive film of the present invention has a strain of 5%, a tan δ of 0.12-0.4 at a frequency sweep test of 30 ° C. and 1 rad / s, a strain of 5% In the frequency sweep test, tan δ can be 0.2-0.7. When the tan delta of the adhesive film is out of the above range, the adhesive film can not exhibit the bending property, and the "bending property" may mean that the transparent adhesive film can be folded without being lifted or bubbled, At this time, the number of repetitions of folding of the adhesive film may be more than 1000 times.

The adhesive film had a strain of 5%, a frequency sweep test at 30 캜 and 1 rad / s, tan δ of the adhesive film was specifically 0.12-0.38, more specifically 0.14-0.38, such as 0.14, 0.15, 0.0 > The adhesive film may have a strain of 5%, a frequency sweep test at 30 占 폚 and 100 rad / s, tan? May be specifically 0.3-0.7, more specifically 0.3-0.65. In this range, the pressure-sensitive adhesive film can realize the bending property, and there may be no lifting, bubbling, or trailing marks upon bending.

tan δ may refer to the ratio (G "/ G ') of the loss modulus (G") to the storage modulus (G') measured in the frequency sweep test as in Equation 1:

<Formula 1>

tan δ = loss modulus / storage modulus.

The adhesive film may have a strain of 5%, a storage modulus at 30 ° C and ¹ rad / s of ⁷ x 10 ⁴ -1 x 10 ⁷ dyne / cm ² , and a loss modulus of ¹ x 10 ⁴ - 8 x 10 ⁶ dyne / cm ² . Within this range, it is possible to increase the bending property of the adhesive film by having the tan delta.

The adhesive film has a storage elastic modulus at a strain of 5%, 30 ℃ and ^{100rad / s 1x10 5 -5x10 7 dyne} / cm 2, specifically, 1x10 ⁵ - 3x10 to ^6, more preferably ^{3x10 5 - 3x10 6 dyne / cm} 2 , And the loss elastic modulus may be ¹ x ^{10 4} - 3 x 10 ⁷ dyne / cm ² , preferably 3 x 10 ⁴ - 3 x 10 ⁷ dyne / cm ² . Within the above range, the tan delta can be provided to enhance the bending property of the adhesive film.

The adhesive film has a storage modulus at a strain of 5%, 80 ℃ and frequency sweep test of ^{1rad / s 1x10 3 - 5x10 6} dyne / cm 2, preferably from 6x10 ⁴ - 5x10 ⁶ dyne / cm ² , preferably 7 x 10 ⁴ - ⁹ x ^{10 5} dyne / cm ² . Within the above range, the reliability of endurance of the pressure-sensitive adhesive film can be enhanced.

The adhesive film may have a gel fraction of 40-90%, preferably 50-85%. Within the above range, reliability of the pressure-sensitive adhesive film can be secured.

The rate of change in resistance represented by the following formula (2) may be 5% or less, preferably 2-5%

<Formula 2>

(Where P ₁ is an initial resistance measured for a sample in which electrodes are formed at both ends of an adhesive film, and P ₂ is a resistance measured after the sample is left at 60 ° C / 90% RH for 240 hours to be). The resistance change rate of the adhesive film is 5% or less, thereby lowering the capacitance value when used in a touch panel, and reducing the occurrence of time delay in the signal, thereby raising the sensing sensitivity.

The adhesive film may have good transparency. In the specific example, the adhesive film may have a haze of 1% or less, preferably 0.1-0.9%, and a total light transmittance of 90% or more, preferably 95-99% in the visible light region.

Accordingly, the adhesive film can be used as an adhesive film included in a flexible display, and can also be used as an OCA (optical clear adhesive) film included in a cellular phone, a TV, a monitor, and a tablet PC, but is not limited thereto.

The adhesive film may be formed of a pressure sensitive adhesive composition comprising a (meth) acrylic copolymer, an initiator, and a crosslinking agent. For example, the pressure sensitive adhesive composition may be coated on a release film (e.g., polyester, polyethylene terephthalate film) Followed by curing. In the specific examples, the UV curing can be carried out under the conditions of 50 mW / cm ² or less and 20 to 240 seconds. Preferably, oxygen can be cured in the blocked state. The coating thickness is not particularly limited, and an adhesive layer having a thickness of 50 to 2 mm, for example, 50 to 1.5 mm, can be formed.

The thickness of the adhesive film (thickness excluding the release film) is not particularly limited, but may be 10 탆 to 1 mm, for example, 50 탆 to 1.5 mm.

The pressure sensitive adhesive composition of the present invention may comprise a (meth) acrylic copolymer. (Meth) acrylic copolymer is a copolymer of a mixture of photo-curable monomers, and the photo-curable monomer is a monomer having a glass transition temperature (Tg) of 80 ° C or higher, preferably 80-150 ° C, a glass transition temperature of less than 80 ° C Lt; RTI ID = 0.0 &gt; 30 C &lt; / RTI &gt; In one embodiment, the photocurable monomer comprises 0-40 wt% (preferably 0.0001-40 wt%) of a monomer having a glass transition temperature of 80 캜 or higher and 60-100 wt% of a monomer having a glass transition temperature of lower than 80 캜 0.0001-99.9999% by weight).

Preferably, the photocurable monomer may comprise 0 to 30% by weight of a monomer having a glass transition temperature of not lower than 80 캜 and 70 to 100% by weight of a monomer having a glass transition temperature of lower than 80 캜. More preferably, the monomer having a glass transition temperature of 80 캜 or higher 0-25% by weight, 75 to 100% by weight of a monomer having a glass transition temperature of lower than 80 占 폚.

The monomer having a glass transition temperature of 80 캜 or higher may include, but is not limited to, at least one of (meth) acrylic monomers having an alicyclic group, vinyl monomers having a carboxylic acid group, and (meth) acrylic monomers having an alicyclic hetero group.

The (meth) acrylic monomer having an alicyclic group may include a (meth) acrylic acid ester having a single ring or a heterocyclic alicyclic ring having 4 to 20 carbon atoms. (Meth) acrylic acid esters having a monocyclic or heterocyclic alicyclic ring of 6 to 20 carbon atoms, such as isobornyl (meth) acrylate, cyclopentyl (meth) acrylate Cyclohexyl (meth) acrylate, and the like. The (meth) acrylic monomer having an alicyclic group may be contained in an amount of 0 to 30% by weight in the (meth) acrylic copolymer. Within the above range, the durability of the pressure-sensitive adhesive film may be improved.

The vinyl monomer having a carboxylic acid group may include a carboxylic acid having a vinyl group or a (meth) acrylic acid ester having a carboxylic acid group. For example, the monomer may mean at least one member selected from the group consisting of? -Carboxyethyl (meth) acrylate, (meth) acrylic acid, itaconic acid, maleic acid, fumaric acid and vinyl acetic acid, . The vinyl monomer having a carboxylic acid group may be contained in an amount of less than 3% by weight and 0-2% by weight in the (meth) acrylic copolymer. Within the above range, the adhesive force of the adhesive film can be increased.

The (meth) acrylic monomer having an alicyclic hetero group may include (meth) acrylic monomers having 4 to 6 carbon atoms and having a single alicyclic heterocycle having nitrogen, oxygen or sulfur. For example, the monomer may include (meth) acryloylmorpholine and the like. The (meth) acrylic monomer having an alicyclic hetero group may be contained in the (meth) acrylic copolymer in an amount of 0-10 wt%, preferably 0-5 wt%. Within this range, there may be an effect of improving the adhesion to the glass substrate.

The monomer having a glass transition temperature lower than 80 占 폚 may include, but not limited to, at least one of (meth) acrylic monomers having an alkyl group and (meth) acrylic monomers having a hydroxy group.

The (meth) acrylic monomer having an alkyl group may include a (meth) acrylic acid ester having a linear or branched alkyl group having 1 to 20 carbon atoms. For example, the monomer may be selected from the group consisting of methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, (Meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, ethylhexyl (meth) acrylate, octyl (Meth) acrylate, decyl (meth) acrylate, and lauryl (meth) acrylate. The (meth) acrylic monomer having an alkyl group may be contained in an amount of 40 to 70% by weight based on the solid content of the (meth) acrylic copolymer. Within this range, there can be an effect of excellent adhesive strength.

The (meth) acrylic monomer having a hydroxy group may be a (meth) acrylic acid ester having at least one hydroxyl group, an alkyl group having from 1 to 20 carbon atoms, a cycloalkyl group having from 5 to 20 carbon atoms, or an aryl group having from 6 to 20 carbon atoms. For example, the monomer may be selected from the group consisting of 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxypropyl (meth) (Meth) acrylate, 1-chloro-2-hydroxypropyl (meth) acrylate, diethylene glycol mono (meth) acrylate, (Meth) acrylate, neopentyl glycol mono (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, neopentyl glycol mono (Meth) acrylate, trimethylolethane di (meth) acrylate, 2-hydroxy-3-phenyloxypropyl (meth) acrylate, 4-hydroxycyclopentyl - phenyloxy (meth) acrylate, 4-hydro Sisayi claw-hexyl (meth) may be one or more of the acrylate, but are not necessarily limited thereto. The (meth) acrylic monomer having a hydroxy group may be contained in an amount of 20 to 50% by weight based on the solid basis in the (meth) acrylic copolymer. Within this range, durability and adhesive strength may be improved.

(Meth) acryl-based copolymer comprises 40 to 70 wt% of a (meth) acrylic monomer having an alkyl group, 20 to 50 wt% of a (meth) acrylic monomer having a hydroxy group, 0 to 30 wt% of a (meth) acrylic monomer having an alicyclic group 0-5% by weight (preferably 0.01-5% by weight) of a (meth) acrylic monomer having an alicyclic heterocycle, 0-2% by weight of a (meth) acrylic monomer having a carboxylic acid group (Preferably 0.01 to 2% by weight) of a photo-curable monomer mixture.

In one embodiment, the (meth) acrylic copolymer is a copolymer of 40-60% by weight of a (meth) acrylic monomer having an alkyl group (e.g., 40,41,42,43,44,45,46,47,48,49,50 , 20 to 50% by weight of a (meth) acrylic monomer having a hydroxy group (for example, 20, 21, 22, 23, 24 , 25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49 , 50% by weight), 1 to 30% by weight of a (meth) acrylic monomer having an alicyclic group (e.g., 1,2,3,4,5,6,7,8,9,10,11,12,13, 2, 2, 3, 24, 25, 26, 27, 28, 29, 30 weight%), 1-2 weight% of a (meth) acrylic monomer having a carboxylic acid group (E.g., 1, 1.5, 2.0 wt%). Preferably 54 to 60% by weight (e.g., 54, 55, 56, 57, 58, 59 and 60% by weight) of a (meth) acrylic monomer having an alkyl group, 15-20% by weight (e.g., 15,16,17,18,19,20 weight%) of a (meth) acrylic monomer having an alicyclic group (for example, 20,21,22,23,24,25% %), And a (meth) acrylic monomer having a carboxylic acid group in an amount of 1 to 2 wt% (e.g., 1,1.5 and 2.0 wt%).

In another embodiment, the (meth) acrylic copolymer is a copolymer of 60-65 wt% (e.g., 60, 61, 62, 63, 64 or 65 wt%) of a (meth) acrylic monomer having an alkyl group, 30 to 35% by weight (for example, 30, 31, 32, 33, 34 and 35% by weight) of an acrylic monomer, 1 to 5% by weight of a (meth) acrylic monomer having an alicyclic heterocycle 3,4, 5% by weight).

In another embodiment, the (meth) acrylic copolymer is a copolymer of 60-70% by weight of a (meth) acrylic monomer having an alkyl group (e.g., 60,61,62,63,64,66,66,67,68,69, 30 to 40% by weight (for example, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40% by weight) of a (meth) acrylic monomer having a hydroxyl group have.

The pressure-sensitive adhesive composition may further include at least one of an initiator and a crosslinking agent.

The initiator may comprise a photoinitiator. The photoinitiator may be activated by ultraviolet rays or electron beams to activate a carbon-carbon double bond in the adhesive film to generate a radical reaction.

Specific examples include, but are not limited to, acetophenone compounds or mixtures thereof. Specific examples thereof include 2,2-dimethoxy-2-phenylacetophenone, 2,2'-diethoxyacetophenone, 2,2'-dibutoxyacetophenone, 2-hydroxy-2-methylpropiophenone, pt Dichloro-4-phenoxyacetophenone, 2-methyl-1- (4- (methylthio) phenyl) - 2-morpholinopropane-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one or mixtures thereof.

The initiator may be contained in an amount of 0.1 to 10 parts by weight, specifically 0.1 to 1 part by weight, based on 100 parts by weight of the mixture of the (meth) acrylic copolymer or the photopolymerizable monomer. Within this range, there can be an effect as a fully cured and adhesive film.

The crosslinking agent may comprise a multifunctional (meth) acrylate capable of curing with an active energy beam.

In an embodiment, the crosslinking agent is selected from the group consisting of 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, polyethylene glycol di Neopentylglycol adipate di (meth) acrylate, dicyclopentanyl di (meth) acrylate, caprolactone modified dicyclopentenyl di (meth) acrylate, ethylene oxide modified di Acrylate, di (meth) acryloxyethyl isocyanurate, allyl cyclohexyl di (meth) acrylate, tricyclodecane dimethanol (meth) acrylate, dimethylol dicyclopentanedi (meth) Ethylene oxide modified hexahydrophthalic acid di (meth) acrylate, tricyclodecane dimethanol (meth) acrylate, neopentyl glycol modified trimethylpropane di (meth) acrylate, Bifunctional acrylates such as adamantane di (meth) acrylate or 9,9-bis [4- (2-acryloyloxyethoxy) phenyl] fluorene; (Meth) acrylate, dipentaerythritol tri (meth) acrylate, propionic acid modified dipentaerythritol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, propylene oxide Trifunctional acrylates such as modified trimethylolpropane tri (meth) acrylate, trifunctional urethane (meth) acrylate or tris (meth) acryloxyethylisocyanurate; Tetrafunctional acrylates such as diglycerin tetra (meth) acrylate or pentaerythritol tetra (meth) acrylate; Pentafunctional acrylates such as dipentaerythritol penta (meth) acrylate; (Meth) acrylate, dipentaerythritol hexa (meth) acrylate, caprolactone modified dipentaerythritol hexa (meth) acrylate or urethane (meth) acrylate (ex. Isocyanate monomer and trimethylol propane tri (Meth) acrylates of polyhydric alcohols may be used as the cross-linking agent. The cross-linking agent may be selected from polyfunctional have.

An isocyanate-based, epoxy-based, aziridine-based, melamine-based, amine-based, imide-based, carbodiimide-based, amide-based cross-linking agent or a combination thereof may be used.

The cross-linking agent is used in an amount of 0.01-0.15 parts by weight, specifically 0.01-0.1 parts by weight (e.g., 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1). Within the above range, solvent resistance and moderate crosslinking in UV reaction can be achieved to improve durability.

The pressure-sensitive adhesive composition may further include a silane coupling agent.

As the silane coupling agent, those conventionally known to those skilled in the art can be used. For example, there can be mentioned 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyl tri A silicon compound having an epoxy structure such as methoxysilane; A polymerizable unsaturated group-containing silicon compound such as vinyltrimethoxysilane, vinyltriethoxysilane and (meth) acryloxypropyltrimethoxysilane; Containing silicon compounds such as 3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane and N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane. ; And 3-chloropropyltrimethoxysilane, and the like, but are not limited thereto. Preferably, a silane coupling agent having an epoxy structure can be used.

The silane coupling agent may be contained in an amount of 0.01-1 parts by weight, preferably 0.01-0.5 parts by weight, based on 100 parts by weight of the mixture of the (meth) acrylic copolymer or the photo-curable monomer. Within this range, there is an effect that the reliability is excellent and the adhesive force is increased.

The pressure-sensitive adhesive composition may optionally contain a curing accelerator, an ionic liquid, a lithium salt, an inorganic filler, a softening agent, an antioxidant, an antioxidant, a stabilizer, a tackifier resin, a modified resin (polyol resin, phenol resin, acrylic resin, (Coloring pigments, extender pigments, etc.), treating agents, ultraviolet light blocking agents, fluorescent whitening agents, dispersing agents, heat stabilizers, antioxidants, antioxidants, Light stabilizers, ultraviolet absorbers, antistatic agents, lubricants, and solvents.

The additive may be added in an amount of 0.01-5 parts by weight, preferably 0.03-3 parts by weight, more preferably 0.05-2 parts by weight, based on 100 parts by weight of the copolymer.

The pressure-sensitive adhesive composition is prepared by mixing the above-mentioned copolymer and initiator and partially polymerizing the composition by ultraviolet irradiation to obtain a viscous liquid. The crosslinking agent and the initiator can then be further added with an additive.

The optical display device of the present invention may include the above-mentioned pressure-sensitive adhesive film. In an embodiment, the optical display device may include a capacitive or resistive touch panel structure including the pressure-sensitive adhesive film. In an embodiment, the optical display device comprises an optical film; And an adhesive film formed on the optical film. The optical film may be a polarizing plate, a color filter, a retardation film, an elliptically polarizing film, a reflective film, an antireflection film, a compensating film, a brightness enhancement film, , A glass shatterproof film, a surface protective film, a plastic LCD substrate, a transparent conductive film including an ITO film, and the like. The method for producing the optical film can be easily manufactured by a person having ordinary skill in the art to which the present invention belongs. For example, a touch panel can be formed by attaching a touch pad to a window or an optical film using the adhesive film. Or may be applied to an ordinary polarizing film as an adhesive film as in the prior art. In an embodiment, the optical display device may include, but is not limited to, an organic light emitting diode display, a liquid crystal display, and the like.

1 is a cross-sectional view of an OLED display device according to an embodiment of the present invention.

1, an organic light emitting diode display 100 according to an embodiment of the present invention includes a substrate 10, an OLED element 15 formed on the substrate 10, a sealing layer 15 for sealing the OLED element 15, A first adhesive film 25 formed on the sealing layer 20, a substrate 35 formed on the first adhesive film 25, a first transparent conductive layer 40 formed on the top of the substrate 35, And a second transparent conductive layer 30 formed on the lower portion of the substrate 35. The polarizing plate 45 formed on the upper portion of the first transparent conductive layer 40 and the second transparent conductive layer 40 formed on the upper portion of the polarizing plate 45. [ And a window 55 formed on the top of the adhesive film 50 and the second adhesive film 50. One or more of the first adhesive film 25 and the second adhesive film 50 may be used in the present invention It can be an example of an adhesive film.

The substrate 10 may be a substrate (e.g., a TFT substrate) commonly used in an organic light emitting diode display device. Specifically, the substrate 10 may be a glass substrate, a plastic polyimide, an epoxy, an acrylic, It may be a substrate having flexibility.

Although not shown in FIG. 1, the OLED element 15 includes a first electrode, a second electrode, an organic light emitting layer formed between the first electrode and the second electrode, The organic light-emitting film may be formed by sequentially laminating a hole injection layer, a hole transporting layer, a light emitting layer, an electron transporting layer, and an electron injecting layer, but is not limited thereto.

The sealing layer 20 protects the OLED element 15 from external moisture or oxygen and may be formed of an inorganic, organic or inorganic / organic mixture.

The transparent conductor includes a base material 35 and a first transparent conductive layer 40 formed on both surfaces of the base material 35 and a second transparent conductive layer 30 can do. The first transparent conductive layer 40 and the second transparent conductive layer 30 may be the same or different from each other. The substrate 35 may be an optical transparent film (e.g., a polyester including polycarbonate, polyethylene terephthalate or the like) And may be an indium tin oxide (ITO) film, or a film containing a metal nanowire. Although not shown in FIG. 1, the first transparent conductive layer 40 and / Or the second transparent conductive layer 30 may be patterned.

The first adhesive film 25 adheres the sealing layer 20 and the second transparent conductive layer 30 and the second adhesive film 50 adheres the first transparent conductive layer 40 and the window 55, May be the same or different, and may include, but not limited to, an adhesive film of one embodiment of the present invention.

The polarizing plate 45 has an anti-reflection function in the organic light emitting display and may include, but not limited to, a polarizer, a protective film formed on the polarizer and / or a retardation film, though not shown in FIG.

The window 55 serves as a display, and may be formed of glass or a plastic material, or may be formed of a material having flexibility.

2 is a cross-sectional view of an OLED display device according to another embodiment of the present invention

2, an OLED display 200 according to another embodiment of the present invention includes a substrate 10, an OLED element 15 formed on the substrate 10, a sealing layer 15 for sealing the OLED element 15, A first adhesive film 25 formed on the sealing layer 20, a substrate 35 formed on the first adhesive film 25, a first transparent conductive layer 40 formed on the top of the substrate 35, A polarizing plate 45 formed on the upper portion of the first transparent conductive layer 40, a second adhesive film 50 formed on the upper portion of the polarizing plate 45, and a second adhesive film 50 formed on the upper portion of the polarizing plate 45 And one or more of the first adhesive film 25 and the second adhesive film 50 may be the adhesive film of the embodiment of the present invention.

Except that the second transparent conductive layer 30 is not included in the organic light emitting diode display device of FIG.

In addition, the OLED display according to embodiments of the present invention can be omitted if there is no seal layer 20 and / or a polarizer 45, and the device can be driven and the display is not damaged.

Hereinafter, the present invention will be described in more detail by way of examples, but these examples are for illustrative purposes only and should not be construed as limiting the present invention.

Specific specifications of the components used in the following examples and comparative examples are as follows:

(A) photo-curable monomers: (A1) ethylhexyl acrylate (EHA), (A2) isobornyl acrylate (IBOA), (A3) 2-hydroxyethyl acrylate (HEA) ), (A5) acryloylmorpholine (ACMO)

(B) Initiator: IGACURE TM651 (2,2-dimethoxy-2-phenylacetophenone) (manufactured by Shiba Japan K.K.)

(C) Crosslinking agent: 1,6-hexanediol diacrylate (HDDA)

(D) Silane coupling agent: epoxy silane (KBM-403, manufactured by Shinetsu)

Example  1 to 4 and Comparative Example  1 to 3

(A) and (B) of 0.04 parts by weight in terms of the content (unit: parts by weight) shown in the following Table 1 were mixed well in a glass container, the dissolved oxygen was replaced with nitrogen gas, To partially polymerize the mixture to obtain a viscous liquid. 0.26 parts by weight of initiator (B) and the components (C) and (D) shown in Table 1 were added to the resulting composition, followed by thorough mixing to prepare a pressure-sensitive adhesive composition.

The resulting pressure-sensitive adhesive composition was applied on a release film polyester film having a thickness of 50 占 퐉 to perform a release treatment with a film thickness of 150 占 퐉. In order to remove oxygen adversely affecting the polymerization, the release film was covered, and ultraviolet rays were irradiated from the two surfaces using a low-pressure lamp (Sylvania BL Lamp) for about 3 minutes to obtain a transparent pressure-sensitive adhesive sheet.

Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 (A)



(A1) EHA 54 59 60 65 57 54 84 (A2) IBOA 20 18 - - 18 20 - (A3) HEA 25 22 35 35 22 25 15 (A4) AA One One - - 3 One One (A5) ACMO - - 5 - - - - (B) 0.3 0.3 0.3 0.3 0.3 0.3 0.3 (C) 0.1 0.075 0.05 0.01 0.05 0.2 0.3 (D) 0.1 0.1 0.1 0.1 0.1 0.1 0.1 Hardening method UV curing UV curing UV curing UV curing UV curing UV curing UV curing

The pressure-sensitive adhesive sheet thus prepared was evaluated for the following physical properties and shown in Table 2.

(1) Change in resistance: The pressure-sensitive adhesive sheets prepared in Examples and Comparative Examples were attached to ITO PET, and electrodes were formed on both sides using silver paste to prepare samples. Thereafter, the initial resistance (P1) was measured for the prepared sample. The sample was allowed to stand at 60 DEG C / 90% RH for 240 hours and the resistance (P2) was measured. At this time, the resistance was measured using a Checkman portable resistance, voltage and current measuring device (TaeKwang Electronics Co., Ltd.). Thereafter, the resistance value measured in each of the above conditions was substituted into the formula (2), and the rate of change in resistance was measured.

(2) Peel strength: The above-prepared pressure-sensitive adhesive sheet was attached to a PET film (backing film, thickness: 50 占 퐉). The pressure-sensitive adhesive sheet was attached to the ITO film. The peeling force was measured when the pressure-sensitive adhesive sheet and the ITO film were peeled off at a peeling rate of 300 mm / min using a TA.XT_Plus Texture Analyzer (Stable Micro System) at 30 minutes after attachment.

(3) Durability: After bonding the PC film / ITO film / glass and the PET film with the adhesive sheet, they were allowed to stand at 60 ° C / 90% relative humidity for 500 hours. Whether lifting or peeling off of the adhered surface or occurrence of bubbles was visually observed and evaluated according to the following criteria.

Good: Good (no bubbles or peeling)

X: poor (large amount of bubbles or peeling occurred)

(4) Storage elastic modulus, loss elastic modulus, and tan delta: A pressure sensitive adhesive sheet on which a plurality of cured adhesive layers are stacked and a 1 mm thick cured adhesive layer is formed is cut into a circle having a diameter of 8 mm. Using a storage elasticity tester (ARES, TA), frequency sweep tests were carried out at 5% strain, 30 ° C and 80 ° C, 10 ^-1 to 10 ² rad / ') And loss elastic modulus (G''), and obtain tan δ.

(5) Gel fraction: The adhesive film was immersed in an ethyl acetate solution at 23 캜 for 72 hours, and the change in weight was measured and calculated from the following equation (3).

[Formula 3]

(Where A is the mass of the adhesive film dissolved in ethyl acetate at 23 ° C for 72 hours and dried after 1 hour at 150 ° C, and B is the initial mass of the adhesive film)

(6) Lifting when bending:

Test I: It was composed of PET film / transparent adhesive film / ITO PET / transparent adhesive film / PET, and tested for stripes and bubbles.

Test II: PET film / transparent adhesive film / ITO PET / transparent adhesive film / polarizing plate was composed and tested for strips and bubbles.

Test III: PET film / transparent adhesive film / ITO PET / transparent adhesive film / PC film.

The bending test was carried out in the above order and bending was performed. At this time, the bending radius was set to 3 mm (radius), and a state of delamination (unbonded) was observed at the bending part or the vicinity thereof. Respectively. "X" for bubbles and streaks when bending, "O" for at least one of bubbles and streaks.

Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Rate of change in resistance (%) 3% 3% 2% 2% 5% 3% 3% Peel strength (gf / 25 mm) 1900 2030 2700 1700 2400 1930 2000 durability O O O O O O O G '(x 10 ⁵ dyne / cm ² , 1 rad / s, 30 ° C) 3.15 2.66 1.7 3.4 2.38 3.15 4.8 G "(x 10 ⁴ dyne / cm ² , 1 rad / s, 30 ° C) 5.82 4.24 2.44 5.4 5.6 7.36 15.6 tanδ
(30 DEG C, 1 rad / s) 0.18 0.159 0.14 0.159 0.235 0.234 0.325 G '(x 10 ⁵ dyne / cm ² , 100 rad / s, 30 ° C) 5.4 4.3 3.2 5.98 7.01 9.55 18.5 G "(x 10 ⁵ dyne / cm ² , 100 rad / s, 30 ° C) 1.87 1.47 1.76 3.65 6.25 8.63 19.2 tanδ
(30 DEG C, 100 rad / s) 0.34 0.34 0.55 0.61 0.89 0.9 1.04 G '(x 10 ⁵ dyne / cm ² , 1 rad / s, 80 ° C) 3.15 2.66 3.55 1.9 1.99 3.17 2.46 Gel fraction (%) 85 75 74 74 74 91 92 Bending I X X X X O O O Lifting Bending II X X X X O O O Lifting Bending III X X X X O O O

As shown in Table 2 above, the pressure-sensitive adhesive films of the present invention exhibited a strain rate of 5%, a frequency sweep test of 30 캜 and 1 rad / s, tan δ and a strain of 5%, a frequency sweep test at 30 캜 and 100 rad / δ has an appropriate range, and therefore has excellent bending characteristics, excellent adhesive strength, and excellent endurance reliability.

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.

Claims (17)

A frequency sweep test at 30 DEG C and 1 rad / s of 5% strain shows that tan < RTI ID = 0.0 > 8 &lt; / RTI &
An adhesive film having a tan δ of 0.2-0.7 in the following formula 1 in a frequency sweep test at a strain rate of 5% at 30 ° C and 100 rad / s:
<Formula 1>
tan δ = loss modulus / storage modulus. According to claim 1, wherein the storage elastic modulus at a strain of 5%, 30 ℃ and 1rad / s in the above adhesive film ^{7x10 4 - 1x10 7 dyne / cm} 2, the loss modulus is ^{1x10 4 - 8x10 6 dyne / cm} 2 of pressure-sensitive adhesive film. According to claim 1, wherein the adhesive film is a strain of 5%, 30 ℃ and a storage modulus at 100rad / s 1x10 ⁵ to - 3x10 ⁶ dyne / cm ^2, the loss modulus is ^{1x10 4 - 3x10 7 dyne / cm} 2 of pressure-sensitive adhesive film . The pressure-sensitive adhesive film according to claim 1, wherein the pressure-sensitive adhesive film has a storage modulus of 1x10 &lt; ³ &gt; - 5x10 &lt; ⁶ &gt; dyne / cm &lt; ² &gt; in a frequency sweep test at 80 DEG C and 1 rad / The adhesive film according to claim 1, wherein the adhesive film has a gel fraction of 40-90%. The pressure-sensitive adhesive film according to claim 1, wherein the pressure-sensitive adhesive film has a resistance change rate of 5% or less,
<Formula 2>

(Where P ₁ is an initial resistance measured on a sample where electrodes are formed at both ends of an adhesive film, and P ₂ is a resistance measured after the sample is left at 60 ° C / 90% relative humidity for 240 hours). The pressure-sensitive adhesive film according to claim 1, wherein the pressure-sensitive adhesive film is formed from a pressure-sensitive adhesive composition comprising a photo-curable monomer, an initiator and a crosslinking agent. 8. The composition of claim 7, wherein the composition comprises
100 parts by weight of the photocurable monomer,
0.01 to 0.15 parts by weight of the crosslinking agent, and
0.1 to 10 parts by weight of the initiator. The pressure-sensitive adhesive film according to claim 8, wherein the photocurable monomer comprises less than 3% by weight of a vinyl monomer having a carboxylic acid group. 8. The composition of claim 7, wherein the photocurable monomer has a glass transition temperature (Tg) 60 to 100% by weight of a monomer having a glass transition temperature Monomers at 80 占 폚 or higher 0-40% by weight of the adhesive film. The composition according to claim 7, wherein the photocurable monomer is a copolymer of 40-60 wt% of a (meth) acrylic monomer having an alkyl group, 20-50 wt% of a (meth) acrylic monomer having a hydroxy group, By weight of a (meth) acrylic monomer having a carboxylic acid group. 8. The composition according to claim 7, wherein the photocurable monomer comprises 60-65 wt% of a (meth) acrylic monomer having an alkyl group, 30-35 wt% of a (meth) acrylic monomer having a hydroxy group, To 5% by weight. The pressure-sensitive adhesive film according to claim 7, wherein the photocurable monomer comprises 60-70% by weight of a (meth) acrylic monomer having an alkyl group and 30-40% by weight of a (meth) acrylic monomer having a hydroxy group. 8. The adhesive film of claim 7, wherein the composition further comprises a silane coupling agent. 15. The adhesive film according to claim 14, wherein the silane coupling agent has an epoxy structure. 15. The adhesive film according to claim 14, wherein the silane coupling agent is contained in an amount of 0.01 to 1 part by weight based on 100 parts by weight of the photocurable monomer. An OLED device comprising: a substrate; an OLED element formed on the substrate; a sealing layer sealing the OLED element; a first adhesive film formed on the sealing layer; a substrate formed on the first adhesive film; A first transparent conductive layer formed on the first transparent conductive layer, a second transparent conductive layer formed on the transparent conductive layer, and a second transparent conductive layer formed on the transparent conductive layer, And a window formed on the substrate,
Wherein at least one of the first adhesive film and the second adhesive film comprises the adhesive film of any one of claims 1 to 16.

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