KR101908182B1 - Adhesive film, optical member comprising the same and optical display apparatus comprising the same - Google Patents

Abstract

(Meth) acryl-based copolymer having a hydroxyl group and organic nanoparticles, wherein the ratio of the shear strength of formula (1) is 1 to 2, an optical member including the adhesive film, and an optical display device comprising the adhesive film.

Description

TECHNICAL FIELD [0001] The present invention relates to an adhesive film, an optical member including the adhesive member, and an optical display device including the adhesive member. [0002]

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

The optical display device includes a display element including a window film, a conductive film, and an organic light emitting element. In an optical display device, various display devices can be adhered by an optical clear adhesive (OCA). Recently, a flexible optical display device has been developed as an optical display device.

The adhesive film should have good foldability, and should not have bubbles or peeling even at room temperature, at high temperature and high humidity, for a predetermined period of time or even during repeated folding. The adhesive film should have high peel strength not only at room temperature but also at high temperature. However, the higher the peel strength of the adhesive film, the better the foldability of the adhesive film is. On the other hand, a pressure-sensitive adhesive film having a high storage modulus difference between high temperature, normal temperature or low temperature may deteriorate the reliability of the optical display device.

The background art of the present invention is disclosed in Korean Patent Publication No. 2007-0055363.

A problem to be solved by the present invention is to provide an adhesive film excellent in reliability not only at room temperature but also repeatedly folded at high temperature and high humidity.

Another problem to be solved by the present invention is to provide a pressure-sensitive adhesive film having a small difference in storage modulus between high temperature, room temperature or low temperature and having excellent reliability.

Another object of the present invention is to provide a pressure-sensitive adhesive film having good foldability.

Another object of the present invention is to provide an adhesive film that is optically transparent and can be used in an optical display device.

The adhesive film of the present invention comprises a (meth) acrylic copolymer having hydroxyl groups and organic nanoparticles, and the ratio of the shear strength of the following formula 1 may be 1 to 2:

<Formula 1>

Ratio of Shear Strength = B / A

(In the above formula 1, A and B are as defined in the detailed description of the present invention).

The optical member of the present invention may include an optical film and an adhesive film of the present invention formed on at least one side of the optical film.

The optical display device of the present invention may include the pressure-sensitive adhesive film of the present invention.

The present invention provides an adhesive film excellent in reliability not only at room temperature but also repeatedly folded at high temperature and high humidity.

The present invention provides a pressure-sensitive adhesive film having a low storage modulus difference between high temperature, normal temperature or low temperature and having excellent reliability.

The present invention provides a pressure-sensitive adhesive film having good foldability.

The present invention provides an adhesive film which is optically transparent and can be used in an optical display device.

1 is a cross-sectional view of an optical display device according to an embodiment of the present invention.
2 is a plan view for preparing a specimen for measuring the shear strength.
3 is a cross-sectional view of a specimen for peel strength measurement.

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.

The terms "upper" and "lower" in this specification are defined with reference to the drawings, wherein "upper" may be changed to "lower", "lower" What is referred to as " on " may include not only superposition, but also intervening other structures in the middle. On the other hand, what is referred to as " directly on " or " directly above "

As used herein, " (meth) acrylic " may mean acrylic and / or methacrylic. As used herein, " copolymer " may include oligomers, polymers or resins.

The " average particle diameter " of the organic nanoparticles in the present specification is the particle diameter of the organic nanoparticles expressed by the Z-average value measured by a Zetasizer nano-ZS instrument using Malvern's water or organic solvent and confirmed by SEM / TEM.

In the present specification, the "shear strength" of the pressure-sensitive adhesive film is the maximum value of shear stress, and an adhesive film (thickness: 20) (length x width, 2 cm x 2 cm) is lapped with a 2 kg roll as shown in Fig. 2 (a). 2 (b), the STN (super twisted nematic) LCD glass 30 is laminated on the lower portion of the portion where the adhesive film 20 and the ITO film 10 are joined together. The joint area is the same as the area of the adhesive film 20. The shear strength at 25 캜 is measured by measuring the shear strength at 25 캜 at a rate of 3 mm / min after the specimen is left at 25 캜 for 2 hours. The shear strength at 80 캜 was measured by measuring the shear strength at a rate of 3 mm / min at 80 캜 after leaving the specimen at 25 캜 for 1 hour and leaving it at 80 캜 for 30 minutes. The shear strength can be measured using UTM (SHIMADZU AGS-X).

The " modulus " of the pressure-sensitive adhesive film in this specification is the storage modulus (G '). A specimen having a thickness of 500 탆 and a diameter of 8 mm was prepared by laminating a plurality of adhesive films of the prepared sample and punched to prepare a specimen having a shear rate of 1 rad / sec and strain of 1% under an auto strain condition using an 8 mm jig. The measurement was carried out while increasing the temperature at a temperature rise rate of 5 ° C / min at -60 ° C to 90 ° C under the load, and the modulus was obtained at -20 ° C, 25 ° C and 80 ° C, respectively.

In the present specification, the " folding conditions " are lamination in the order of PET film (thickness: 50 to 125 m) / adhesive film (thickness: 20 to 150 m) / PET film The PET film and the adhesive film were adhered to each other and aged at room temperature (for example, 25 DEG C) for 12 hours and cut into a size of width x length (70 mm x 140 mm) to prepare specimens. , Tesa) to a flexural evaluation equipment (CFT-2000, Covotech). At this time, the PET film was subjected to corona treatment, and then the adhesive film and the corona-treated surface were adhered to each other. Bending the specimen in the longitudinal direction at 60 ° C and 93% relative humidity, bending the specimen at a radius of curvature of 3 mm, 30 cycles per minute, wherein one cycle means bending and spreading the specimen at the radius of curvature, bending and holding for 1 second And 50,000 cycles of bending under a straightening condition. As used herein, " good foldability " means that no peeling or bubbling has occurred at the folding site when the folding condition is applied.

Hereinafter, an adhesive film according to an embodiment of the present invention will be described.

The adhesive film according to the present embodiment (hereinafter referred to as the 'adhesive film') may have a ratio of the shearing strength of the following formula 1 to 1 or 2. In the above range, the adhesive film may be excellent in reliability and good folding property, not only at room temperature but also repeatedly bending at high temperature and high humidity. Specifically, the ratio of the shear strength of the following formula 1 may be from 1 to 1.9:

<Formula 1>

Ratio of Shear Strength = B / A

(In the above formula (1), A is the shear strength (unit: kgf / 4 cm ² ) of the adhesive film at 80 ° C,

B is the shear strength at 25 캜 (unit: kgf / 4 cm ² ) of the adhesive film.

The ratio of the shearing strength of the above formula (1) can evaluate whether the adhesive film is excellent in reliability not only at room temperature but also in repeated bending at high temperature and / or high humidity. When the ratio of the shearing strength of formula (1) is 1 to 2, the adhesive film is excellent in reliability not only at room temperature but also in repeated bending at high temperature and / or high humidity. In particular, when the pressure-sensitive adhesive film has the following storage modulus, when the pressure-sensitive adhesive film has the shearing strength ratio of Formula 1, the pressure-sensitive adhesive film can be reliably bent even at a high temperature and / or high humidity.

Thus, the pressure-sensitive adhesive film was obtained by adhering an adhesive film (thickness 100 占 퐉) between two corona-treated PET films having a thickness of 50 占 퐉 so that the pressure-sensitive adhesive film had a curvature radius of 3 mm at 60 占 폚 and 93% (one cycle in which the adhesive film is bent and bent once in half) at the speed of a cycle of 50,000 cycles, the number of cycles in which lifting or bubbles are not generated is 50,000 cycles or more, for example, 50,000 to 200,000 Cycle.

In one embodiment, the difference between the shearing strengths of the adhesive film of the following formula 2 is 8 kgf / 4 cm ² or less, specifically 0 kgf / 4 cm ² to 7 kgf / 4 cm ² : There can be excellent effects:

<Formula 2>

Difference in Shear Strength = B - A

(In the above formula 2, A and B are as defined in the above formula 1).

The adhesive film has a shear strength can be 10kgf / 4cm ² to 25kgf / 4cm ^2, specifically 10kgf / 4cm ² to 20kgf / 4cm ² at 25 ℃. The adhesive film has a shear strength can be 8kgf / 4cm ² to 20kgf / 4cm ^2, specifically 10kgf / 4cm ² to 20kgf / 4cm ² eseo 80 ℃.

The adhesive film may have a modulus at a modulus of -20 캜 at 80 캜 of from 1: 1 to 1:10, specifically from 1: 1 to 1: 8, more specifically from 1: 1 to 1: 6. In the above range, the adhesive film does not deteriorate the adhesive force between the adherends in a wide temperature range (-20 DEG C to 80 DEG C) and can be used for a flexible optical member. The pressure-sensitive adhesive film may have a modulus of 10 kPa to 500 kPa, specifically 12 kPa to 300 kPa at 80 ° C. Within this range, high temperature reliability improvement effects can be obtained. The pressure-sensitive adhesive film may have a modulus of 25 kPa to 500 kPa, specifically 30 kPa to 300 kPa at 25 ° C. Within the above range, the viscoelastic characteristics are exhibited at room temperature in the above-mentioned range, and not only the resilience is excellent but also the number of cycles of the foldable test can be increased. The pressure-sensitive adhesive film may have a modulus of 25 kPa to 500 kPa, specifically 30 kPa to 300 kPa, more specifically 20 kPa to 150 kPa at -20 ° C. Within the above-mentioned range, viscoelastic characteristics are exhibited at low temperatures, which is advantageous in that the restoring force is excellent. The pressure-sensitive adhesive film showing good folding property at low temperature can have good folding property even at room temperature and high temperature.

The adhesive film may have a peel strength at 25 ° C of 700 gf / in or more, specifically 900 gf / in, specifically 900 gf / in to 3000 gf / in. The peel strength at 60 캜 of the pressure-sensitive adhesive film may be 900 gf / in or more, specifically 900 gf / in to 3000 gf / in. Within the above range, the durability and the like of the pressure-sensitive adhesive film can be improved.

The adhesive film may have a glass transition temperature (Tg) of -100 캜 to -10 캜, specifically, -70 캜 to -35 캜. Within this range, folding reliability can be improved. The adhesive film may have a haze of 2% or less, specifically 0.1% to 1% and a total light transmittance of 90% or more, specifically 95% to 99% in a visible light region (e.g., a wavelength of 380 nm to 780 nm). Within this range, optical transparency is good and can be used in optical display devices. The thickness of the adhesive film may be 10 탆 to 300 탆, specifically 15 탆 to 175 탆. In the above range, it can be used in an optical display device.

The adhesive film may include a (meth) acrylic copolymer having a hydroxyl group and organic nanoparticles. The adhesive film can be produced by photo-curing a pressure-sensitive adhesive composition. The pressure-sensitive adhesive composition may include a monomer mixture for a (meth) acrylic copolymer having a hydroxyl group or a (meth) acrylic copolymer prepared by partial polymerization thereof, organic nanoparticles, and an initiator. The monomer mixture may be contained in the pressure-sensitive adhesive composition in the state of a monomer mixture in which polymerization is not carried out at all, but the monomer mixture may be contained as a partially polymerized partial polymer.

The monomer mixture may form a (meth) acrylic copolymer having a hydroxyl group. The (meth) acrylic copolymer having a hydroxyl group forms a matrix of the pressure-sensitive adhesive film and can exhibit adhesiveness. The (meth) acrylic copolymer having a hydroxyl group may have a glass transition temperature of -100 ° C to -10 ° C, specifically -70 ° C to -30 ° C. Within the above range, the pressure-sensitive adhesive film has an excellent adhesive strength and reliability in a wide temperature range. The (meth) acrylic copolymer having a hydroxyl group may have a refractive index of 1.40 to 1.70, specifically 1.45 to 1.60. Within this range, transparency can be maintained when laminated with other optical films.

The monomer mixture may include a hydroxyl group-containing (meth) acrylate and an alkyl group-containing (meth) acrylate.

The hydroxyl group-containing (meth) acrylate can provide the adhesive force of the adhesive film. The hydroxyl group-containing (meth) acrylate may be a (meth) acrylate containing at least one hydroxyl group. For example, the hydroxyl group-containing (meth) acrylate may be at least one selected from the group consisting of 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) (Meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, (Meth) acrylate, diethylene glycol mono (meth) acrylate, 1,6-hexanediol mono (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol penta (Meth) acrylate, trimethylolethane di (meth) acrylate, 2-hydroxy-3-phenyloxypropyl (meth) acrylate, 4- Hydroxycyclopentyl (meth) acrylate (Meth) acrylate, cyclohexanedimethanol mono (meth) acrylate, and the like. The hydroxyl group-containing (meth) acrylate is used in an amount of 5 to 40% by weight, for example, 10 to 30% by weight, 10 to 25% by weight, based on the sum of hydroxyl group-containing (meth) acrylate and alkyl group- %, And 15 wt% to 25 wt%. The adhesive strength and durability reliability of the adhesive film can be further improved in the above range and the ratio of the aforementioned shearing strength can be ensured.

The alkyl group-containing (meth) acrylate can form a matrix of an adhesive film. The alkyl group-containing (meth) acrylate may include an unsubstituted linear or branched alkyl (meth) acrylate having 1 to 20 carbon atoms. (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, lauryl (meth) acrylate, and isobonyl (meth) acrylate. The alkyl group-containing (meth) acrylate contains 60 to 95% by weight, such as 70 to 90% by weight, 75 to 90% by weight, of the sum of hydroxyl group-containing (meth) acrylate and alkyl group- %, And 75 wt% to 85 wt%. The adhesive strength and durability reliability of the adhesive film can be further improved in the above range and the ratio of the aforementioned shearing strength can be ensured.

In one embodiment, the monomer mixture contains 5% by weight to 40% by weight, more specifically 12% by weight to 35% by weight, of the hydroxyl group-containing (meth) acrylate in the total of the hydroxyl group-containing (meth) (Meth) acrylate, more specifically from 65% by weight to 85% by weight, more specifically from 15% by weight to 35% by weight, %. &Lt; / RTI &gt; Within this range, folding reliability can be improved.

The monomer mixture may further comprise copolymerizable monomers.

The copolymerizable monomer may be contained in the (meth) acrylic copolymer to provide additional effects to the (meth) acrylic copolymer, the pressure sensitive adhesive composition or the pressure sensitive adhesive film. The copolymerizable monomer is a monomer having an ethylene oxide, a monomer having propylene oxide, a monomer having an amine group, a monomer having an alkoxy group, a monomer having a phosphoric acid group, or a monomer having an alkyl group (meth) , A monomer having a sulfonic acid group, a monomer having a phenyl group, a monomer having a silane group, a monomer having a carboxylic acid group, and an amide group-containing (meth) acrylate.

As the monomer having an ethylene oxide, one or more (meth) acrylate monomers containing an ethylene oxide group (-CH ₂ CH ₂ O-) may be used. (Meth) acrylate, polyethylene oxide monoethyl ether (meth) acrylate, polyethylene oxide monopropyl ether (meth) acrylate, polyethylene oxide monobutyl ether (meth) acrylate, polyethylene oxide mono (Meth) acrylate, polyethylene oxide monoisobutyl ether (meth) acrylate, polyethylene oxide diethyl ether (meth) acrylate, polyethylene oxide monoisopropyl ether (meth) acrylate, polyethylene oxide monoisobutyl ether (Meth) acrylate such as polyethylene oxide mono-t-butyl ether (meth) acrylate, but is not limited thereto.

The monomer having propylene oxide is at least one monomer selected from the group consisting of polypropylene oxide monomethyl ether (meth) acrylate, polypropylene oxide monoethyl ether (meth) acrylate, polypropylene oxide monopropyl ether (meth) acrylate, polypropylene oxide monobutyl ether (Meth) acrylate, polypropylene oxide diethyl ether (meth) acrylate, polypropylene oxide monoisopropyl ether (meth) acrylate, polypropylene oxide dimethyl ether (Meth) acrylate such as polypropylene oxide monoisobutyl ether (meth) acrylate, polypropylene oxide mono butyl ether (meth) acrylate, and the like, but is not limited thereto no All.

Monomers having an amine group include monomethylaminoethyl (meth) acrylate, monoethylaminoethyl (meth) acrylate, monomethylaminopropyl (meth) acrylate, monoethylaminopropyl (meth) acrylate, dimethylaminoethyl Acrylic acid-containing (meth) acrylate such as diethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, N-tert- butylaminoethyl (meth) acrylate, and methacryloxyethyltrimethylammonium chloride But are not necessarily limited to, monomers.

Examples of the monomer having an alkoxy group include 2-methoxyethyl (meth) acrylate, 2-methoxypropyl (meth) acrylate, 2-ethoxypropyl (meth) (Meth) acrylate, methoxypentyl (meth) acrylate, 3-ethoxypentyl (meth) acrylate, 2-ethoxypentyl ) Acrylate, 3-butoxyhexyl (meth) acrylate, and the like.

Monomers having a phosphoric acid group include monomers such as 2-methacryloyloxyethyldiphenyl phosphate (meth) acrylate, trimethacryloyloxyethylphosphate (meth) acrylate, triacryloyloxyethylphosphate (meth) Acrylic monomer having a phosphoric acid group, but the present invention is not limited thereto.

The monomer having a sulfonic acid group may be an acrylic monomer having a sulfonic acid group such as sodium sulfopropyl (meth) acrylate, sodium 2-sulfoethyl (meth) acrylate, and sodium 2-acrylamido-2-methylpropane sulfonate But is not necessarily limited thereto.

The monomer having a phenyl group can be an acrylic vinyl monomer having a phenyl group such as p-tert-butylphenyl (meth) acrylate, o-biphenyl (meth) acrylate and phenoxyethyl (meth) acrylate, It is not.

The monomer having a silane group may be selected from the group consisting of 2-acetoacetoxyethyl (meth) acrylate, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (2-methoxyethyl) silane, vinyltriacetoxysilane, Butoxypropyltrimethoxysilane, and the like, but is not limited thereto.

The monomer having a carboxylic acid group may be at least one monomer selected from the group consisting of (meth) acrylic acid, 2-carboxyethyl (meth) acrylate, 3-carboxypropyl (meth) acrylate, 4-carboxybutyl (meth) acrylate, itaconic acid, Maleic anhydride, and the like, but are not necessarily limited thereto.

The amide group-containing (meth) acrylate is at least one compound selected from the group consisting of (meth) acrylamide, N-methyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methoxymethyl (Meth) acrylamide, N-hydroxyethyl (meth) acrylamide and N, N-diethyl (meth) acrylamide. Particularly, N-hydroxyethyl (meth) acrylamide and N, N-diethyl (meth) acrylamide are excellent in the effect of the present invention and can be obtained by reacting an alkyl group- containing (meth) May have an excellent effect of compatibility with the water.

The copolymerizable monomer may be contained in the monomer mixture in an amount of 10 wt% or less, specifically 7 wt% or less, more specifically 0.1 wt% to 10 wt%. The copolymerizable monomer may be contained in an amount of 10 parts by weight or less, 7 parts by weight or less, and 0.1 parts by weight to 10 parts by weight, based on 100 parts by weight of the total of the hydroxyl group-containing (meth) acrylate and the alkyl group-containing (meth) acrylate. In the above range, the pressure-sensitive adhesive composition can further improve the adhesive strength and durability of the pressure-sensitive adhesive film. In particular, the monomer having a carboxylic acid group may be contained in an amount of not more than 5% by weight, specifically not more than 3% by weight, more specifically not more than 1% by weight in the monomer mixture. Within this range, the pressure-sensitive adhesive composition can further improve the adhesion and durability of the pressure-sensitive adhesive film without corrosion of the metal adherend.

The organic nanoparticles may have an average particle diameter of 10 nm to 400 nm, specifically 10 nm to 300 nm, more specifically 10 nm to 250 nm, more specifically 50 nm to 250 nm. Within this range, it is possible to prevent the organic nanoparticles from being clumped, do not affect the folding of the adhesive film, and the transparency of the adhesive film may be good even within the range of difference in refractive index as described below.

The refractive index difference between the organic nanoparticles and the (meth) acrylic copolymer having a hydroxyl group may be 0.1 or less, specifically 0 or more and 0.05 or less, specifically 0 or more and 0.02 or less. In the above range, the transparency of the adhesive film can be excellent. The refractive index of the organic nanoparticles may be 1.40 to 1.70, specifically 1.45 to 1.60. Within the above range, the transparency of the adhesive film may be excellent.

The organic nanoparticles may include, but are not limited to, core-shell nanoparticles such as a bead type as well as core-shell nanoparticles. In the case of a core-shell type, the core and the shell may satisfy the following formula 3: that is, both the core and the shell may be nanoparticles that are organic materials. When such a particle type is used, the adhesive property of the adhesive film is good, and the balance property of elasticity and flexibility can be effective.

<Formula 3>

Tg (c) < Tg (s)

(Unit: 占 폚), and Tg (s) is the glass transition temperature (unit: 占 폚) of the shell.

As used herein, the term " shell " means the outermost layer of the organic nanoparticles. The core may be a single spherical particle. However, the core may further comprise additional layers surrounding the spherical particles if they have the above glass transition temperature.

Specifically, the glass transition temperature of the core may be -150 ° C to 10 ° C, specifically -150 ° C to -5 ° C, more specifically -150 ° C to -20 ° C. Within this range, there may be a low temperature and / or room temperature viscoelastic effect of the adhesive film. The core may comprise at least one of polyalkyl (meth) acrylate, polybutadiene or polysiloxane having the above glass transition temperature.

The polyalkyl (meth) acrylate may be at least one selected from the group consisting of polymethyl acrylate, polyethylacrylate, polypropyl acrylate, polybutyl acrylate, polyisopropyl acrylate, polyhexyl acrylate, polyhexyl methacrylate, polyethylhexyl acrylate And polyethylhexyl methacrylate, polysiloxane, and is not necessarily limited thereto.

The polysiloxane can be, for example, an organosiloxane (co) polymer. The organosiloxane (co) polymer may be one which is not cross-linked, or a cross-linked (co) polymer may be used. In order to impart impact resistance and colorability, an organosiloxane (co) polymer in a crosslinked state can be used. It is a crosslinked form of organosiloxane, specifically crosslinked dimethylsiloxane, methylphenylsiloxane, diphenylsiloxane or a mixture of two or more thereof. By using a copolymerized form of two or more organosiloxanes, the refractive index can be adjusted from 1.41 to 1.50.

The crosslinking state of the organosiloxane (co) polymer can be determined by the degree of dissolution by various organic solvents. As the crosslinking state deepens, the degree of dissolution by the solvent becomes smaller. As the solvent for determining the crosslinking state, acetone, toluene and the like can be used. Specifically, the organosiloxane (co) polymer may have a portion which is not dissolved by acetone or toluene. The insoluble matter to the toluene of the organosiloxane copolymer may be 30% or more.

Additionally, the organosiloxane (co) polymer may further comprise an alkyl acrylate crosspolymer. The alkyl acrylate crosslinked polymer may be selected from the group consisting of methyl acrylate, ethyl acrylate, n-butyl acrylate, and 2-ethylhexyl acrylate. For example, n-butyl acrylate or 2-ethylhexyl acrylate having a low glass transition temperature may be used.

Specifically, the glass transition temperature of the shell may be from 15 캜 to 150 캜, specifically from 35 캜 to 150 캜, more specifically from 50 캜 to 140 캜. In the above range, the dispersibility of the organic nanoparticles in the (meth) acrylic copolymer may be excellent. The shell may comprise a polyalkyl methacrylate having said glass transition temperature. For example, it is possible to use polymethylmethacrylate (PMMA), polyethylmethacrylate, polypropylmethacrylate, polybutylmethacrylate, polyisopropylmethacrylate, polyisobutylmethacrylate and polycyclohexylmethacrylate Rate, &lt; / RTI &gt; but is not necessarily limited thereto.

The core may comprise from 30 wt% to 99 wt%, specifically from 40 wt% to 95 wt%, and more specifically from 50 wt% to 90 wt%, of the organic nanoparticles. Within the above range, the folding property of the pressure-sensitive adhesive film may be good in a wide temperature range. The shell may comprise from 1 wt% to 70 wt%, specifically from 5 wt% to 60 wt%, more specifically from 10 wt% to 50 wt%, of the organic nanoparticles. Within the above range, the folding property of the pressure-sensitive adhesive film may be good in a wide temperature range.

The organic nanoparticles are added in an amount of 0.1 to 20 parts by weight, specifically 0.5 to 10 parts by weight, specifically 0.5 to 8 parts by weight, based on 100 parts by weight of the total of the monomer mixture constituting the (meth) acrylic copolymer . Within the above-mentioned range, the modulus of the pressure-sensitive adhesive film at high temperature can be increased within the above-mentioned range, the folding property of the pressure-sensitive adhesive film at room temperature and high temperature can be improved, and the low temperature and / or room temperature viscoelasticity of the pressure- The ratio of the shear strength can be ensured. Particularly, in the range of from 0.5 parts by weight to 8 parts by weight, the effect described above can be remarkable.

The organic nanoparticles can be prepared by conventional emulsion polymerization, suspension polymerization, or solution polymerization.

Initiators can be used to cure (partially polymerize) the monomer mixture into a (meth) acrylic copolymer or to cure a viscous liquid into a film. The initiator may include at least one of a photopolymerization initiator and a thermal polymerization initiator.

As the photopolymerization initiator, any of them can be used as long as it can induce the polymerization reaction of the radically polymerizable compound described below in a curing process by light irradiation or the like to realize the second crosslinking structure. For example, benzoin, hydroxy ketone, amino ketone or phosphine oxide photoinitiators can be used. Specific examples thereof include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether , Benzoin n-butyl ether, benzoin isobutyl ether, 2,2-dimethoxy-2-phenylacetophenone, 2,2'-diethoxyacetophenone, 2,2'-dibutoxyacetophenone, Acetophenone compounds such as hydroxy-2-methylpropiophenone, pt-butyl trichloroacetophenone, pt-butyldichloroacetophenone, 4-chloroacetophenone, 2,2'-dichloro-4- phenoxyacetophenone, Diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2- 2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2- - (2-hydroxyethoxy) phenyl-2- (hydroxy-2-propyl) ketone, benzophenone, p-phenylbenzophenone, 4,4- 2-ethyl anthraquinone, 2-t-butyl anthraquinone, 2-amino anthraquinone, thioxanthone, 2-ethylthioxanthone, 2- 2-methyl-1 - [(2-hydroxy-2-methyl-1- &lt; / RTI &gt; methyl) benzoic acid ester, 4- (1-methylvinyl) phenyl] propanone] and 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide. In the present application, one kind or more kinds of the above can be used, but the present invention is not limited thereto.

The thermal polymerization initiator is not particularly limited as long as it has the above-mentioned physical properties, and for example, ordinary initiators such as an azo-based compound, a peroxide-based compound or a redox-based compound can be used. Examples of the azo compound include 2,2-azobis (2-methylbutyronitrile), 2,2-triyl azo bis (isobutyronitrile), 2,2-triazabis 2-methyl azo bis (2-methylpropionate) and 2,2-phylazobis (4- (4-methoxyphenyl) Methoxy-2,4-dimethylvaleronitrile), and the like, and examples of the peroxide compound include inorganic peroxides such as potassium persulfate, ammonium persulfate or hydrogen peroxide; Or peroxydicarbonate, peroxydicarbonate, peroxy ester, tetramethyl butyl peroxyneodecanoate, bis (4-butylcyclohexyl) peroxydicarbonate, di (2-ethylhexyl) peroxycarbonate, Hexyl peroxy dicarbonate, dimethoxy butyl peroxy dicarbonate, hexyl peroxy dicarbonate, hexyl peroxy dicarbonate, diisopropyl peroxy dicarbonate, diethoxy ethyl peroxy dicarbonate, diethoxyhexyl peroxy dicarbonate, , Bis (3-methoxy-3-methoxybutyl) peroxy dicarbonate, dibutyl peroxy dicarbonate, dicetyl peroxy dicarbonate, dimyristyl peroxy dicarbonate, 1,1 , 3,3-tetramethylbutyl peroxypivalate, hexyl peroxypivalate, butyl peroxypivalate, trimethylhexanoyl peroxide, dimethylhydroxybutyl peroxy Amyl peroxyneodecanoate, t-butyl peroxyneoheptanoate, amyl peroxy pivalate, t-butyl peroxy pivalate, t-amyl peroxide, Organic peroxides such as peroxy-2-ethylhexanoate, lauryl peroxide, dilauroyl peroxide, didecanoyl peroxide, benzoyl peroxide or dibenzoyl peroxide, Examples of the system compound include, but are not limited to, a mixture of a peroxide compound and a reducing agent in combination. In the present application, one kind or a mixture of two or more kinds of azo type, peroxide type or redox type compound as described above can be used.

The initiator is contained in an amount of 0.001 to 5 parts by weight, specifically 0.001 to 3 parts by weight, more specifically 0.005 to 1 part by weight per 100 parts by weight of the total of the monomer mixture constituting the (meth) acrylic copolymer . In the above range, the curing reaction can be completely carried out, and the remaining amount of the initiator remains, the permeability can be prevented from being lowered, the bubble generation can be lowered, and the reactivity can be improved.

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. Specifically, the epoxy group-containing silane coupling agent having a glycidoxidation period includes 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane . The silane coupling agent may be contained in an amount of 0.01 to 5 parts by weight, specifically 0.05 to 1 part by weight based on 100 parts by weight of the total of the monomer mixture constituting the (meth) acrylic copolymer. In the above range, reliability can be secured in the bending state at the high temperature and high humidity described above, and not only the peel strength is high even at a high temperature, but also the modulus difference between low temperature, normal temperature and high temperature can be low.

The pressure-sensitive adhesive composition may further include a crosslinking agent. The cross-linking agent can increase the degree of crosslinking of the pressure-sensitive adhesive composition and increase the mechanical strength of the pressure-sensitive 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 (Meth) acrylate, dicyclopentanyl di (meth) acrylate, caprolactone modified dicyclopentenyl di (meth) acrylate, ethylene oxide modified di (meth) acrylate, di (Meth) acrylate, trimethylolpropane di (meth) acrylate, acryloyloxyethyl isocyanurate, allyl cyclohexyl di (meth) acrylate, tricyclodecane dimethanol Di (meth) acrylate, tricyclodecane dimethanol (meth) acrylate, neopentyl glycol modified trimethylpropane di (meth) acrylate, adamantane di (meth) Bifunctional acrylates such as 9,9-bis [4- (2-acryloyloxyethoxy) phenyl] fluorene and the like; (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 can be used as the crosslinking agent. The polyfunctional (meth) acrylates of polyhydric alcohols may be used alone or in combination of two or more. The crosslinking agent is contained in an amount of 0.001 to 5 parts by weight, specifically 0.003 to 3 parts by weight, specifically 0.005 to 1 part by weight, based on 100 parts by weight of the total of the monomer mixture constituting the (meth) acrylic copolymer There is an effect of excellent adhesion and reliability in the above range.

The pressure-sensitive adhesive composition may optionally contain a curing accelerator, an ionic liquid, a lithium salt, an inorganic filler, a softener, a molecular weight modifier, an antioxidant, an antioxidant, a stabilizer, a tackifier resin, a modifying resin (polyol resin, phenol resin, (Coloring pigments, extender pigments, etc.), treating agents, ultraviolet light blocking agents, fluorescent whitening agents, dispersing agents, heat stabilizers, antioxidants, antioxidants, A light stabilizer, an ultraviolet absorber, an antistatic agent, a coagulant, a lubricant and a solvent.

The pressure-sensitive adhesive composition may have a viscosity at 25 ° C ranging from 300 cPs to 50,000 cPs, and may have an effect of obtaining excellent coating and thickness uniformity in the above range.

The pressure-sensitive adhesive composition can be prepared by partially polymerizing a monomer mixture for a (meth) acrylic copolymer having a hydroxyl group as an initiator, and further comprising an initiator and organic nanoparticles. Mentioned cross-linking agent, additives, and the like. Alternatively, the pressure-sensitive adhesive composition may be prepared by partially polymerizing a mixture comprising a monomer mixture, a initiator and a silane coupling agent for a (meth) acrylic copolymer having a hydroxyl group, and further containing an initiator. Mentioned cross-linking agent, additives, and the like. Partial polymerization may include solution polymerization, suspension polymerization, photopolymerization, bulk polymerization, or emulsion polymerization. Specifically, the solution polymerization can be carried out at 50 to 100 캜 by adding an initiator to the monomer mixture. As the initiator, a photopolymerization initiator such as acetophenone-based and 1-hydroxycyclohexyl phenyl ketone including 2,2-dimethoxy-2-phenylacetophenone and the like can be used. Partial polymerization can be carried out at 25 DEG C with a viscosity of from 1,000 cPs to 10,000 cPs, specifically from 4,000 cPs to 9,000 cPs. The adhesive film can be produced by a conventional method. For example, the pressure-sensitive adhesive composition may be coated on a release film and cured. Curing may include irradiation of the irradiation dose 400mJ / cm ² to 3000mJ / cm ² at a wavelength of 300nm to 400nm into a low-pressure lamp in an oxygen-free state.

The optical member according to an embodiment of the present invention includes an optical film and an adhesive film formed on at least one side of the optical film, and the adhesive film may include an adhesive film according to embodiments of the present invention. Thus, the optical member has good bending and / or good folding properties and can be used in a flexible display device.

The optical film may be at least one selected from the group consisting of a window film, a window, a polarizing plate, a color filter, a retardation film, an elliptically polarizing film, a reflective polarizing film, an antireflection film, OLED device barrier layers, plastic LCD substrates, indium tin oxide (ITO), fluorinated tin oxide (FTO), aluminum doped zinc oxide (AZO), carbon nanotubes (CNT), nanowires such as Ag nanowires and graphene , And the like. The method for producing an optical film can be easily manufactured by a person having ordinary skill in the art to which the present invention belongs.

For example, the touch panel can be formed by attaching the touch pad to a window or an optical film using an adhesive film. Or may be applied to an ordinary polarizing film as an adhesive film as in the prior art.

The optical display device of the present invention may include the pressure-sensitive adhesive film of the present invention. The optical display device may include an organic light emitting diode display, a liquid crystal display, and the like. The optical display device may include a flexible display device. However, the optical display device may include a non-flexible display device.

Hereinafter, a flexible display device according to an embodiment of the present invention will be described with reference to FIG. 1 is a cross-sectional view of a flexible display device according to an embodiment of the present invention.

1, a flexible display device 100 according to an exemplary embodiment of the present invention includes a display unit 110, an adhesive layer 120, a polarizer 130, a touch screen panel 140, and a flexible window film 150, and the adhesive layer 120 may include an adhesive film according to an embodiment of the present invention.

The display unit 110 is for driving the flexible display device 100 and may include an optical element including an OLED, an LED, a quantum dot light emitting diode (QLED) formed on a substrate and a substrate, or an LCD device. Although not shown in FIG. 1, the display unit 110 may include a lower substrate, a thin film transistor, an organic light emitting diode, a planarization layer, a protective layer, and an insulating layer.

The polarizing plate 130 may implement polarizing of the inner light or prevent reflection of the external light to realize the display or increase the contrast ratio of the display. The polarizing plate may be composed of a polarizer alone. Or the polarizing plate may include a polarizing film and a protective film formed on one or both sides of the polarizing film. Or the polarizing plate may include a polarizer and a protective coating layer formed on one or both sides of the polarizer. The polarizer, the protective film, and the protective coating layer may be conventional ones known to those skilled in the art.

The touch screen panel 140 senses a change in capacitance caused when a conductor such as a human body or a stylus touches, and generates an electrical signal. The display unit 110 can be driven by this signal. The touch screen panel 140 may include a first sensor electrode and a second sensor electrode formed between the first sensor electrode and the first sensor electrode, which are formed by patterning a conductive conductive material. have. The conductors for the touch screen panel 340 may include, but are not limited to, metal nanowires, conductive polymers, carbon nanotubes, and the like.

1 illustrates a polarizing plate 130 and a touch screen panel 140 stacked by an adhesive film or an adhesive film or a polarizer or a polarizing plate on a touch screen panel 140 to form a polarizing plate 130 and a touch screen panel 140. [ 140 may be integrated.

The flexible window film 150 may be formed at the outermost portion of the flexible display device 300 to protect the display device.

Although not shown in FIG. 1, the pressure sensitive adhesive film of the present invention is further formed between the polarizer 130 and the touch screen panel 140 and / or between the touch screen panel 140 and the flexible window film 150, Screen panel, and flexible window film.

Hereinafter, the configuration and operation of the present invention will be described in more detail with reference to preferred embodiments of the present invention. It should be understood, however, that the same is by way of illustration and example only and is not to be construed in any way as limiting the invention.

Manufacturing example

Organic nanoparticles were prepared by emulsion polymerization. The core is polybutyl acrylate, the shell is polymethyl methacrylate, the shell is 35 weight% of the organic nanoparticles, the core is 65 weight% of the organic nanoparticles, the average particle diameter is 100 nm and the refractive index is 1.48 .

Example  One

5 parts by weight of butyl acrylate (n-BA), 75 parts by weight of 2-ethylhexyl acrylate (2-EHA), 15 parts by weight of 4-hydroxybutyl acrylate (4-HBA) 5 parts by weight of diethylaminoethyl acrylate (DEAA), 5 parts by weight of the organic nanoparticles of the preparation example, and 0.005 part by weight of initiator Irgacure 651 were mixed well in the reactor. The dissolved oxygen in the reactor was replaced with a nitrogen gas, and the mixture was partially polymerized by irradiation with ultraviolet rays using a low-pressure mercury lamp for several minutes to prepare a viscous liquid having a viscosity of 5,000 cps at 25 ° C. 0.3 part by weight of Irgacure 184, 0.01 part by weight of crosslinking agent hexanediol diacrylate (HDDA) and 0.1 part by weight of silane coupling agent 3-glycidoxypropyltrimethoxysilane (KBM-403) were mixed well in a viscous liquid in a reactor to prepare a pressure- . (Polyethylene terephthalate) film as a releasing film, and irradiated with ultraviolet light at a light quantity of 2000 mJ / cm ² to produce a pressure-sensitive adhesive sheet of 50 탆 thick adhesive film and PET film.

Example  2 to Example  5

A pressure-sensitive adhesive sheet of a pressure-sensitive adhesive film and a PET film having a thickness of 50 탆 was prepared in the same manner as in Example 1, except that the composition of the pressure-sensitive adhesive composition was changed as shown in Table 1 below.

Comparative Example  1 and Comparative Example  2

A pressure-sensitive adhesive sheet of a pressure-sensitive adhesive film and a PET film having a thickness of 50 탆 was prepared in the same manner as in Example 1, except that the composition of the pressure-sensitive adhesive composition was changed as shown in Table 1 below.

The properties of the pressure-sensitive adhesive sheets prepared in Examples and Comparative Examples were evaluated in the following Table 1, and the results are shown in Table 1 below.

(1) Ratio of Shear Strength and Shear Strength: An adhesive film (length x width, 2 cm x 2 cm) and ITO film (length x width, 6 cm x 2 cm) were lapped with a 2 kg roll as shown in Fig. 2 . In FIG. 2 (a), reference numeral 10 denotes an ITO film portion, and reference numeral 20 denotes a portion where an adhesive film and an ITO film are laminated. After removing the heavy film, the STN glass is laminated to the bottom of the portion where the adhesive film and the ITO film are joined using a laminating machine as shown in FIG. 2 (b). In FIG. 2 (b), reference numeral 10 denotes an ITO film portion, reference numeral 20 denotes a portion where an adhesive film and an ITO film are laminated, and reference numeral 30 denotes an STN LCD glass. The joint area is the same as the area of the adhesive film. The specimens were allowed to stand at 25 占 폚 for 2 hours, and the shear strength at 25 占 폚 was measured at 25 占 폚 using a UTM (SHIMADZU AGS-X) at a rate of 3 mm / min. The specimens were left at 25 DEG C for 1 hour and left at 80 DEG C for 30 minutes. Then, the shear strength at 80 DEG C was measured at 80 DEG C at a rate of 3 mm / min using UTM (SHIMADZU AGS-X).

(2) Modulus (G '): The viscoelasticity was measured at a shear rate of 1 rad / sec using a Rheometer (Anton Paar MCR-501) as a dynamic viscoelasticity measuring device under an auto strain condition at a strain of 1%. After removing the release film from the pressure-sensitive adhesive sheet, a plurality of pressure-sensitive adhesive films each having a thickness of 50 占 퐉 were laminated, laminated to a thickness of 500 占 퐉, and the laminate was perforated with a perforator having a diameter of 8 mm. Using a jig of 8 mm, the specimens were subjected to measurement while raising the temperature at a temperature rising rate of 5 DEG C / min in a temperature range of -60 DEG C to 90 DEG C under a load of 300 gf, The modulus was determined at 80 ° C.

(3) Folding evaluation: A PET film (thickness: 50 탆) / an adhesive film (thickness: 100 탆) / a PET film (thickness: 50 탆) were laminated in this order and adhered with a roller. (70 mm x 140 mm), and the prepared specimens were fixed to a flexural evaluation apparatus (CFT-2000, manufactured by Covotech) using an adhesive (4965, Tesa). At this time, the PET film was subjected to corona treatment, and then the adhesive film and the corona-treated surface were adhered to each other. Bending the specimen in the longitudinal direction at 60 ° C and 93% relative humidity, bending the specimen at a radius of curvature of 3 mm, 30 cycles per minute, wherein one cycle means bending and spreading the specimen at the radius of curvature, bending and holding for 1 second And 50,000 cycles of bending under a straightening condition. X when peeling or bubbling occurred after 100,000 cycles, and when the peeling and bubbling did not occur, it was indicated with.

(4) Peel Strength: PET (polyethylene terephthalate) film of length x width x thickness (150 mm x 25 mm x 75 m) was treated with corona twice at a dose of 78 doses (total dose: 156 dose) using a corona processor. The corona-treated surfaces of the PET film were laminated on both sides of an adhesive film (length x width x thickness, 100 mm x 25 mm x 50 m) to prepare the specimen shown in Fig. 3 (a). The specimen was autoclaved at a pressure of 3.5 bar at 50 ° C for 1000 seconds and the specimens were fixed on a TA.XT_Plus Texture Analyzer (Stable Micro System). Referring to FIG. 3 (b), the T-Peel peel strength was measured at a temperature of 25 ° C in a TA.XT_Plus Texture Analyzer when one PET film was fixed and the other PET film was pulled at a speed of 50 mm / min .

Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 Comparative Example 2 Monomer
(Parts by weight) n-BA 5 10 0 0 0 0 0 2-EHA 75 75 80 80 80 57 55 4-HBA 15 10 10 20 20 0 0 2-HEA 0 0 0 0 0 23 45 3-HPA 5 5 10 0 0 0 0 DEAA One One One 0 0 0 0 ACMO 0 0 0 0 0 2 0 IBOA 0 0 0 0 0 20 0 Organic nanoparticles
(Parts by weight) 5 5 5 3 3 0 0 Cross-linking agent
(Parts by weight) HDDA 0.01 0 0.01 0 0 0.1 0.1 DPHA 0 0 0 0.01 0 0 0 SR610 0 0 0 0 0.03 0 0 Silane coupling agent
(Parts by weight) 0.1 0.1 0 0 0.1 0.1 0.1 Shear strength
(kgf / 4 cm ² ) @ 25 ℃ 17.59 12.94 16.22 13.07 16.73 28.75 17.66 @ 80 ℃ 12.34 9.69 11.70 12.95 10.44 9.03 7.15 The ratio of the shear strength of Equation 1 1.43 1.34 1.39 1.01 1.60 3.18 2.47 The difference in shear strength (kgf / 4 cm ² ) 5.25 3.25 4.52 0.12 6.29 19.72 10.51 Modulus
(kPa) @ -20 ℃ 92 98 95 85 82 14500 180 @ 25 ℃ 35 30 35 32.2 32.5 65.00 39.6 @ 80 ℃ 25 18 23 21.4 21.9 46.80 29.6 @ 80 ℃ Modulus: @ -20 ℃ Modulus 1: 3.68 1: 5.44 1: 4.13 1: 3.97 1: 3.74 1: 309.83 1: 6.08 Folding evaluation
@ 60 ° C and 93% relative humidity ○ ○ ○ ○ ○ × × Peel strength (gf / in, @ 25 ℃) 1320 1230 1280 1450 1430 1150 850

2-EHA: 2-ethylhexyl acrylate, 4-HBA: 4-hydroxybutyl acrylate, ACMO: acryloylmorpholine, 2-HEA: 2-hydroxyethyl acrylate 3-hydroxypropyl acrylate, DEAA: diethylaminoethyl acrylate, IBOA: isobornyl acrylate, HDDA: hexanediol diacrylate, DPHA: dipentaerythritol hexa (meth) acrylate, DIPENTAERYTHRITOL HEXAACRYLATE, SR610: Polyethylene glycol (600) diacrylate.

As shown in Table 1, the adhesive film of the present invention exhibited a specific ratio between the shear strength at 25 ° C and the shear strength at 80 ° C, so that the adhesive film had good foldability even at high temperature and high humidity.

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 (16)

(Meth) acryl-based copolymer having a hydroxyl group and organic nanoparticles, wherein the ratio of the shear strength of the following formula (1) is 1 to 2,
<Formula 1>
Ratio of Shear Strength = B / A
(In the above formula 1,
A is the shear strength (unit: kgf / 4 cm ² ) of the adhesive film at 80 ° C,
(B) is the shear strength (unit: kgf / 4 cm &lt; ² &gt;) of the adhesive film at 25 DEG C)
The pressure-sensitive adhesive film preferably has a modulus ratio of 1: 1 to 1:10 at a modulus of -20 DEG C at 80 DEG C,
The (meth) acrylic copolymer having a hydroxyl group is a copolymer of a monomer mixture containing a hydroxyl group-containing (meth) acrylate and an alkyl group-containing (meth) acrylate,
Wherein the monomer mixture comprises 5 to 40% by weight of the hydroxyl group-containing (meth) acrylate and 60 to 95% by weight of the alkyl group-containing (meth) acrylate.
The adhesive film according to claim 1, wherein the adhesive film has a difference in shear strength of 8 kgf / 4 cm ² or less in the following formula (2):
<Formula 2>
Difference in Shear Strength = B - A
(In the above formula 2, A and B are as defined in the above formula 1).
The method of claim 1 wherein the adhesive film is from 25 ℃ shear strength is 10kgf / 4cm ² more than 25kgf / 4cm ² or less, the adhesive film is the shear strength is more than 8kgf / 4cm ² at 80 ℃ 25kgf / 4cm ² or less , An adhesive film.
The pressure-sensitive adhesive film according to claim 1, wherein the pressure-sensitive adhesive film has a modulus of 10 kPa to 500 kPa at 80 캜.
delete The pressure-sensitive adhesive film according to claim 1, wherein the pressure-sensitive adhesive film has a glass transition temperature of -100 캜 to -10 캜.
The pressure-sensitive adhesive film according to claim 1, wherein the pressure-sensitive adhesive film is a pressure-sensitive adhesive film having a thickness of 100 占 퐉 bonded between two corona-treated PET films having a thickness of 50 占 퐉 and having a curvature radius of 3 mm at 60 占 폚 and 93% Wherein the number of cycles in which no bending or bubbling is generated when bending (one cycle of bending and spreading the adhesive film once in half) at a rate of 30 cycles per minute is 50,000 cycles or more.
delete The adhesive film according to claim 1, wherein the monomer mixture further comprises a monomer having an amine group.
The adhesive film according to claim 1, wherein the organic nanoparticles have an average particle diameter of 10 nm to 400 nm.
11. The method of claim 10, wherein the organic nanoparticles are core-
Wherein the core and the shell satisfy the following formula 3:
<Formula 3>
Tg (c) < Tg (s)
(Unit: 占 폚), and Tg (s) is the glass transition temperature (unit: 占 폚) of the shell.
The adhesive film according to claim 1, wherein the organic nanoparticles are contained in an amount of 0.1 to 20 parts by weight based on 100 parts by weight of the monomer mixture constituting the (meth) acrylic (meth) acrylic copolymer having a hydroxyl group.
The pressure-sensitive adhesive film according to claim 1, wherein the pressure-sensitive adhesive film has a haze of 2% or less at a wavelength of 380 nm to 780 nm.
The pressure-sensitive adhesive film according to claim 1, wherein the pressure-sensitive adhesive film further comprises at least one of an initiator, a crosslinking agent, and a silane coupling agent.
An optical film, and an adhesive film formed on at least one side of the optical film,
Wherein the adhesive film comprises the adhesive film of any one of claims 1 to 4, 6, 7, 9 to 14.
An optical display device comprising the optical member of claim 15.

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