KR102020889B1 - Adhesive film, optical member comprising the same and optical display apparatus comprising the same - Google Patents

Abstract

A pressure-sensitive adhesive film formed of a monomer mixture containing a hydroxyl group-containing (meth) acrylate and an alkyl group-containing (meth) acrylate, wherein the pressure-sensitive adhesive film is a polyethylene terephthalate film (thickness: 50 mu m) and the pressure-sensitive adhesive film (thickness: 100 mu m) And a polyethylene terephthalate film (thickness: 100 μm) of three-layered specimens sequentially stacked (width x length: 13 cm x 3 cm) between the frame of 1 cm spacing so that the horizontal length of the specimen is 1/2 A pressure-sensitive adhesive film having a bubble area of 0% when bent in the direction of a terephthalate film (thickness: 50 µm) and repeated 10 cycles of 1 cycle of 24 hours, which is the following sequential execution, an optical member including the same and the same An optical display device is provided.

Description

Adhesive film, optical member including the same, and optical display including the same {ADHESIVE FILM, OPTICAL MEMBER COMPRISING THE SAME AND OPTICAL DISPLAY APPARATUS COMPRISING THE SAME}

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 device including a window film, a conductive film, an organic light emitting device, and the like. Various display elements in the optical display device may be adhered by an optical clear adhesive (OCA). Recently, a flexible optical display device has been developed as an optical display device. Thus, the pressure-sensitive adhesive film should be good in reliability and good folding property because there is no peeling or bubble generation at high temperature, normal temperature, low temperature change or heat shock.

Since the pressure-sensitive adhesive film is used in an optical display device, the peel strength should be high at high temperature as well as at room temperature. However, in general, even if the pressure-sensitive adhesive film has a high peel strength at room temperature, the peel strength is reduced. In addition, an adhesive film having a large difference in peel strength or modulus between high temperature and room temperature may reduce the reliability of the optical display device.

Background art of the present invention is disclosed in Korean Patent Laid-Open No. 2007-0055363.

The problem to be solved by the present invention is to provide a pressure-sensitive adhesive film that is excellent in durability and reliability and can extend the life of the display is low bubble generation area in the temperature change or heat shock between high temperature, room temperature, low temperature.

Another problem to be solved by the present invention is to provide a pressure-sensitive adhesive film that can lower the peel strength reduction at high temperatures compared to room temperature.

Another problem to be solved by the present invention is to provide a pressure-sensitive adhesive film with low durability and reliability at low to high temperatures.

Another problem to be solved by the present invention is to provide an adhesive film having good folding properties.

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

The pressure-sensitive adhesive film of the present invention is formed of a monomer mixture containing a hydroxyl group-containing (meth) acrylate and an alkyl group-containing (meth) acrylate, the pressure-sensitive adhesive film is a polyethylene terephthalate film (thickness: 50㎛), the pressure-sensitive adhesive film (thickness : 100 μm), and the three-layered specimens (width x length: 13 cm x 3 cm), in which the polyethylene terephthalate film (thickness: 100 μm) was sequentially laminated, had a horizontal length of 1 / t between the frames having a spacing of 1 cm. When it is bent in the direction of the polyethylene terephthalate film (thickness: 50 mu m) to 2 and repeated one cycle of 24 hours, which is the following sequential execution, 10 times, the bubble generation area may be 0%:

<1 cycle> Slowly warming for 2 hours from 25 ° C to 60 ° C while maintaining 93% relative humidity → 3.5 hours at constant temperature and humidity of 60 ° C and 93% relative humidity → Slowly for 2 hours while maintaining 93% relative humidity to 25 ° C Decreased temperature slowly while maintaining 93% relative humidity for 2 hours from 25 ℃ to 60 ℃ → 3.5 hours at constant temperature and humidity of 60 ℃ and 93% relative humidity → Slowly decelerated for 2 hours while maintaining 93% relative humidity to 25 ℃ 2 hours left at constant temperature and humidity of 25 ° C and 93% RH → 0.5 hour deceleration to -10 ° C → 3.5 hours at constant temperature of -10 ° C → Temperature rise for 1 hour while maintaining 93% relative humidity to 25 ° C → 25 ° C And left for 2 hours at constant temperature and humidity of 93% relative humidity.

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

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

The present invention provides a pressure-sensitive adhesive film that is excellent in durability and reliability and can extend the life of the display is low bubble generation area at high temperature, room temperature, low temperature change or thermal shock.

The present invention provides a pressure-sensitive adhesive film that can lower the peel strength decrease at high temperatures compared to room temperature.

The present invention provides a pressure-sensitive adhesive film that does not change even in temperature changes due to a small difference in modulus at low to high temperatures.

The present invention provides an adhesive film having good folding properties.

The present invention provides an adhesive film that 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 exemplary embodiment of the present invention.
Figure 2 is a schematic diagram for measuring the peel strength in the experimental example.
3 is a schematic diagram for creep measurement in an experimental example.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. The drawings and description are to be regarded as illustrative in nature and not restrictive. Like reference numerals designate like elements throughout the specification.

In the present specification, "upper" and "lower" are defined based on the drawings, and according to a viewpoint, "upper" may be changed to "lower" and "lower" to "upper", and "on" or What is referred to as “on” may include not only the above but also intervening other structures in the middle. On the other hand, what is referred to as "directly on" or "directly on" means that there is no intervening structure in between. As used herein, "(meth) acryl" may mean acrylic and / or methacryl.

As used herein, "copolymer" may include oligomers, polymers or resins.

In the present specification, the "average particle diameter" of the organic nanoparticles is the particle size of the organic nanoparticles expressed in Z-average values and the SEM / TEM observations measured in an aqueous or organic solvent using a Zetasizer nano-ZS device manufactured by Malvern. .

In this specification, "modulus" is a storage modulus (G ').

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

The adhesive film according to the present embodiment (hereinafter, 'adhesive film') is formed of a monomer mixture containing a hydroxyl group-containing (meth) acrylate and an alkyl group-containing (meth) acrylate, and a polyethylene terephthalate film (thickness: 50 μm) , The pressure-sensitive adhesive film (thickness: 100㎛), and the polyethylene terephthalate film (thickness: 100㎛) of the three-layered specimen (layer x length: 13cm x 3cm) sequentially laminated the specimen between the frame of 1cm interval When bent in the direction of the polyethylene terephthalate film (thickness: 50㎛) so that the lateral length of 1/2, the bubble generation area may be 0% when 1 cycle of 24 hours, 10 cycles of the following sequential execution is repeated. In the above range, when used in a flexible display, it is possible to prolong the life of the display even at temperature changes of high temperature, room temperature, and low temperature:

<1 cycle> Gradually elevated temperature for 2 hours from 25 ° C to 60 ° C while maintaining 93% relative humidity → 3.5 hours at constant temperature and humidity of 60 ° C and 93% RH for 2 hours while maintaining 93% relative humidity to 25 ° C Gradually decrease temperature → slowly increasing temperature while maintaining 93% relative humidity for 2 hours from 25 ℃ to 60 ℃ and leaving it for 3.5 hours at constant temperature and humidity of 60 ℃ and 93% relative humidity → Slowly decreasing temperature for 2 hours while maintaining 93% relative humidity to 25 ℃ → 2 hours at constant temperature and humidity of 25 ° C and relative humidity of 93% → Decreased for 0.5 hours to -10 ° C → 3.5 hours at constant temperature of -10 ° C → Temperature for 1 hour while maintaining 93% relative humidity to 25 ° C → 25 It is left to stand for 2 hours at constant temperature and humidity of ℃ and relative humidity of 93%.

In addition, the pressure-sensitive adhesive film of this embodiment may have a bubble generation area of 0% when one cycle of the following sequential performance is repeated 30 cycles. Within this range, the life of the display can be extended even under thermal shock when used in a flexible display:

<1 cycle> 2 hours at a constant temperature of -40 ℃ → 2 hours at a constant temperature of 85 ℃

In addition, the pressure-sensitive adhesive film according to the present embodiment may not only have high peel strength at room temperature but also lower the peel strength reduction ratio compared to the peel strength at room temperature at high temperature, thereby improving durability and reliability without peeling or lifting. Specifically, the pressure-sensitive adhesive film according to this embodiment may be 60% or less, specifically, 0% to 60% of the reduction rate of the peel strength of the following formula 1. In the above range, the adhesive film can be used in a flexible device because of its excellent reliability and durability:

<Equation 1>

Peel Strength Reduction Ratio = ｜ B-A ｜ / A x 100

(In Formula 1, A is the peel strength at 25 ° C. of the adhesive film (unit: gf / in),

B is the peel strength (unit: gf / in) of the adhesive film at 60 ℃.

In addition, the pressure-sensitive adhesive film of the present embodiment may be a difference in peel strength of the following formula 2 1200gf / in or less, specifically 50gf / in to 1000gf / in. In the above range, the adhesive film has high reliability and durability and can be used in flexible devices:

<Equation 2>

Peel Strength Difference = ｜ B-A ｜

(In Formula 2, A and B are as defined in Formula 1). In Equations 1 and 2, B≤A, where "peel strength" is the T-PEEL peel strength.

In the adhesive film according to the present embodiment, the peel strength defined as A in Equations 1 and 2 may be 700gf / in or more, specifically 900gf / in or more, specifically 900gf / in to 3000gf / in. In the adhesive film according to the present embodiment, the peel strength defined by B in Equations 1 and 2 may be 500gf / in or more, specifically 500gf / in to 3000gf / in. In the above range, the durability of the pressure-sensitive adhesive film and the like can be improved.

In the pressure-sensitive adhesive film, the ratio of modulus at 80 ° C. to modulus: −20 ° C. may be 1: 1 to 1:10, specifically 1: 1 to 1: 8, and more particularly, 1: 1 to 1: 6. In the above range, the adhesive film has a low ratio of modulus at a low temperature to a high temperature, and thus has high durability and reliability, and does not degrade adhesion between the adhesives in a wide temperature range (-20 ° C. to 80 ° C.) and can be used for flexible optical members. have. In particular, the above-described effect may be better when the modulus ratio is 1: 1 to 1: 6. The adhesive film may have a modulus of 10 kPa to 500 kPa, specifically 12 kPa to 300 kPa at 80 ° C. In the above range, there may be an effect of improving the high temperature reliability. The adhesive film may have a modulus of 15 kPa to 500 kPa, specifically 20 kPa to 300 kPa at 25 ° C. In the above range, viscoelastic properties are expressed at room temperature, not only excellent restoring force but also good folding properties can be expressed. The adhesive film may have a modulus of 20 kPa to 500 kPa, specifically 30 kPa to 500 kPa at -20 ° C. In the above range, the viscoelastic properties are expressed at low temperatures, there is an advantage that the restoring force is excellent.

The adhesive film may have a glass transition temperature (Tg) of -100 ° C to -10 ° C, specifically -70 ° C to -35 ° C. In the above range, there may be an effect of improving the folding reliability at low temperature to high temperature. The adhesive film may have a creep of 10 μm to 400 μm, specifically 30 μm to 300 μm at 25 ° C. Within this range, the foldability, adhesion, and reliability under low conditions (low bubble generation area) may be excellent.

The adhesive film may have a haze of 2% or less, specifically 0.1% to 1%, total light transmittance of 90% or more, and specifically 95% to 99% in a visible light region (for example, a wavelength of 380 nm to 780 nm). Within this range, the optical transparency is good and can be used for the optical display device. The adhesive film may have a thickness of 10 μm to 300 μm, specifically 12 μm to 175 μm. Within this range, it can be used for an optical display device.

The pressure-sensitive adhesive film according to an embodiment of the present invention may be prepared by photocuring the pressure-sensitive adhesive composition. The pressure-sensitive adhesive composition may be a monomer mixture for a (meth) acrylic copolymer having a hydroxyl group; Initiator; And macromonomers and organic nanoparticles. The monomer mixture may be included in the pressure-sensitive adhesive composition in a state in which the monomer mixture is not polymerized at all, but the monomer mixture may be included 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 adhesive film and may 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 0 ° C. In the above range, the adhesive film has the effect of having excellent adhesive strength and reliability in a wide temperature range. The (meth) acrylic copolymer having a hydroxyl group may have a refractive index of 1.35 to 1.70, specifically 1.40 to 1.60. Within this range, transparency can be maintained when laminating with other optical films. The monomer mixture may be composed of hydroxyl group-containing (meth) acrylate and 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 one or more hydroxyl groups. For example, the hydroxyl group-containing (meth) acrylate is 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (Meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 1,4-cyclohexanedimethanol mono (meth) acrylate, 1-chloro-2-hydrate Oxypropyl (meth) acrylate, diethylene glycol mono (meth) acrylate, 1,6-hexanediol mono (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, Neopentylglycol mono (meth) acrylate, trimethylolpropane di (meth) acrylate, trimethylolethane di (meth) acrylate, 2-hydroxy-3-phenyloxypropyl (meth) acrylate, 4- Hydroxycyclopentyl (meth) acrylate Y, 4-hydroxycyclohexyl (meth) acrylate and cyclohexanedimethanol mono (meth) acrylate. The hydroxyl group-containing (meth) acrylate is 5% to 40% by weight, for example, 8% to 30% by weight, 10% to 30% by weight of the total of the hydroxyl group-containing (meth) acrylate and the alkyl group-containing (meth) acrylate. It may be included in weight percent. The adhesion and durability of the pressure-sensitive adhesive film in the above range can be further improved.

The alkyl group-containing (meth) acrylate can be a copolymer to form a matrix of the adhesive film. The alkyl group-containing (meth) acrylate may include an unsubstituted linear or branched alkyl (meth) acrylic acid ester having 1 to 20 carbon atoms. For example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, t-butyl (meth) acrylate, iso-butyl (meth) acrylic Latex, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, ethylhexyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, nonyl (meth) And at least one of acrylate, decyl (meth) acrylate, lauryl (meth) acrylate and isobornyl (meth) acrylate. The alkyl group-containing (meth) acrylate is 60% to 95% by weight, for example, 65% to 92%, 68% to 90% by weight of the total of the hydroxyl group-containing (meth) acrylate and the alkyl group-containing (meth) acrylate. It may be included in the weight percent, 70% to 90% by weight. The adhesion and durability of the pressure-sensitive adhesive film in the above range can be further improved.

The monomer mixture may further include a copolymerizable monomer. The copolymerizable monomer may be included 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 different from the hydroxyl group-containing (meth) acrylate and the alkyl group-containing (meth) acrylate, and includes a monomer having 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 , 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.

Monomers having ethylene oxide may be at least one (meth) acrylate monomer containing an ethylene oxide group (-CH ₂ CH ₂ O-). For example, polyethylene oxide monomethyl ether (meth) acrylate, polyethylene oxide monoethyl ether (meth) acrylate, polyethylene oxide monopropyl ether (meth) acrylate, polyethylene oxide monobutyl ether (meth) acrylate, polyethylene oxide mono Pentyl ether (meth) acrylate, polyethylene oxide dimethyl ether (meth) acrylate, polyethylene oxide diethyl ether (meth) acrylate, polyethylene oxide monoisopropyl ether (meth) acrylate, polyethylene oxide monoisobutyl ether (meth) It may be a polyethylene oxide alkyl ether (meth) acrylate, such as acrylate, polyethylene oxide monotertbutyl ether (meth) acrylate, but is not necessarily limited thereto.

Monomers with propylene oxide include 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 monopentyl ether (meth) acrylate, polypropylene oxide dimethyl ether (meth) acrylate, polypropylene oxide diethyl ether (meth) acrylate, polypropylene oxide monoisopropyl ether (meth) acrylic Polypropylene oxide alkylether (meth) acrylates, such as latex, polypropylene oxide monoisobutyl ether (meth) acrylate, polypropylene oxide monotertbutyl ether (meth) acrylate, but are not necessarily limited thereto. no All.

Monomers having an amine group include monomethylaminoethyl (meth) acrylate, monoethylaminoethyl (meth) acrylate, monomethylaminopropyl (meth) acrylate, monoethylaminopropyl (meth) acrylate, dimethylaminoethyl (meth Amine group containing (meth), such as an acrylate, diethylaminoethyl (meth) acrylate, N-tert- butylaminoethyl (meth) acrylate, and (meth) acryloxyethyl trimethylammonium chloride (meth) acrylate It may be an acrylic monomer, but is not necessarily limited thereto.

Monomers having an alkoxy group include 2-methoxy ethyl (meth) acrylate, 2-methoxypropyl (meth) acrylate, 2-ethoxypropyl (meth) acrylate, 2-butoxypropyl (meth) acrylate, 2 -Methoxypentyl (meth) acrylate, 2-ethoxypentyl (meth) acrylate, 2-butoxyhexyl (meth) acrylate, 3-methoxypentyl (meth) acrylate, 3-ethoxypentyl (meth ), 3-butoxyhexyl (meth) acrylate, but is not necessarily limited thereto.

Monomers having a phosphoric acid group include 2-methacryloyloxyethyldiphenyl phosphate (meth) acrylate, trimethacryloyloxyethyl phosphate (meth) acrylate, triacryloyloxyethyl phosphate (meth) acrylate, and the like. It may be an acrylic monomer having a phosphoric acid group, but is not necessarily 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. However, the present invention is not limited thereto.

The monomer having a phenyl group may be an acrylic vinyl monomer having a phenyl group such as p-tert-butylphenyl (meth) acrylate, o-biphenyl (meth) acrylate, phenoxyethyl (meth) acrylate, but is not limited thereto. It doesn't happen.

Monomers having a silane group include 2-acetoacetoxyethyl (meth) acrylate, vinyltrimethoxysilane, vinyltriethoxysilane, vinyl tris (2-methoxyethyl) silane, vinyltriacetoxysilane, and (meth) acryl It may be a vinyl monomer having a silane group such as royloxypropyl trimethoxysilane, but is not necessarily limited thereto.

Monomers having a carboxylic acid group include (meth) acrylic acid, 2-carboxyethyl (meth) acrylate, 3-carboxypropyl (meth) acrylate, 4-carboxybutyl (meth) acrylate, itaconic acid, crotonic acid, maleic acid, and fumaric acid. And maleic anhydride, and the like, but are not necessarily limited thereto.

Amide group-containing (meth) acrylates include (meth) acrylamide, N-methyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methoxymethyl (meth) acrylamide, and N, N-methylene Bis (meth) acrylamide, N-hydroxyethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide.

The copolymerizable monomer may be included in an amount of 15 parts by weight or less, specifically 10 parts by weight or less, and more specifically 0.05 parts by weight to 8 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. Can be. The pressure-sensitive adhesive composition in the above range can further improve the adhesion and recovery of the adhesive film. The monomer having a carboxylic acid group is 5 parts by weight or less, specifically 3 parts by weight or less, and more specifically 1 part by weight or less based on 100 parts by weight of the total of the hydroxyl group-containing (meth) acrylate and the alkyl group-containing (meth) acrylate. May be included. The pressure-sensitive adhesive composition in the above range can further improve the adhesive strength and durability of the adhesive film.

The initiator can be used to cure (partial polymerization) the monomer mixture into a (meth) acrylic copolymer or to cure a viscous liquid into a film. The initiator may comprise one or more of a photopolymerization initiator and a thermal polymerization initiator.

As a photoinitiator, as long as it can induce the polymerization reaction of the radically polymerizable compound mentioned above in the hardening process by light irradiation etc., any can be used. For example, a benzoin type, a hydroxy ketone type, an amino ketone type, or a phosphine oxide type photoinitiator etc. can be used, Specifically, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether , Benzoin n-butyl ether, benzoin isobutyl ether, 2,2-dimethoxy-2-phenylacetophenone, 2,2'-diethoxy acetophenone, 2,2'-dibutoxy acetophenone, 2-hydride Acetophenone compounds such as oxy-2-methyl propiophenone, pt-butyl trichloro acetophenone, pt-butyl dichloro acetophenone, 4-chloro acetophenone, 2,2'-dichloro-4-phenoxy acetophenone, Dimethylanino acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropane-1one, 2 -Benzyl-2-dimethyl amino-1- (4-morpholino phenyl) -butan-1-one, 1-hydroxycyclohexylphenylketone, 2-methyl-1- [4- (methylthio) phenyl]- 2- PORINO-PROPAN-1-ON, 4- (2-hydroxyethoxy) phenyl-2- (hydroxy-2-propyl) ketone, benzophenone, p-phenylbenzophenone, 4,4-nonsidiethylaminobenzo Phenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-t-butylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chloro Thioxanthone, 2,4-dimethyl thioxanthone, 2,4-diethyl thioxanthone, benzyldimethyl ketal, acetophenone dimethyl ketal, p-dimethylamino benzoic acid ester, oligo [2-hydroxy-2-methyl-1- [ 4- (1-methylvinyl) phenyl] propanone], 2,4,6-trimethylbenzoyl- diphenyl-phosphine oxide, etc. are mentioned. In the present application, one or more of the above may be used, but is not limited thereto.

The thermal polymerization initiator is not particularly limited as long as it has the above-described physical properties. For example, a common initiator such as an azo compound, a peroxide compound, or a redox compound can be used. Examples of the azo compound in the above are 2,2-azobis (2-methylbutyronitrile), 2,2-triazobis (isobutyronitrile), 2,2-triazobis (2,4-dimethyl Valeronitrile), 2,2-nitazobis-2-hydroxymethylpropionitrile, dimethyl-2,2-methylazobis (2-methylpropionate) and 2,2-piazobis (4- Methoxy-2,4-dimethylvaleronitrile) and the like, and examples of the peroxide-based compound include inorganic peroxides such as potassium peroxide, ammonium persulfate or hydrogen peroxide; Or diacyl peroxide, peroxy dicarbonate, peroxy ester, tetramethylbutylperoxy neodecanoate, bis (4-butylcyclohexyl) peroxydicarbonate, di (2-ethylhexyl) peroxy carbonate, butylper Oxy neodecanoate, dipropyl peroxy dicarbonate, diisopropyl peroxy dicarbonate, diethoxyethyl peroxy dicarbonate, diethoxyhexyl peroxy dicarbonate, hexyl peroxy dicarbonate, dimethoxybutyl 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 peroxy pivalate, butyl peroxy pivalate, trimethyl hexanoyl peroxide, dimethyl hydroxybutyl peroxy Odecanoate, amyl peroxyneodecanoate, butyl peroxyneodecanoate, t-butylperoxy neoheptanoate, amylperoxy pivalate, t-butylperoxy pivalate, t-amyl Organic peroxides such as peroxy-2-ethylhexanoate, lauryl peroxide, dilauuroyl peroxide, didecanoyl peroxide, benzoyl peroxide or dibenzoyl peroxide, and the like. Examples of the compound include, but are not limited to, a mixture using a peroxide compound and a reducing agent in combination. In the present application, one kind or a mixture of two or more kinds of the azo-based, peroxide-based or redox-based compounds may be used.

 The initiator is 0.0001 parts by weight to 5 parts by weight, specifically 0.001 parts by weight to 3 parts by weight based on 100 parts by weight of the total of the hydroxyl group-containing (meth) acrylate and alkyl group-containing (meth) acrylate constituting the (meth) acrylic copolymer. More specifically, the content may be included in an amount of 0.001 part by weight to 1 part by weight. In this range, the curing reaction can proceed completely, remaining amount of initiator can remain to prevent the transmittance from decreasing, and also it is possible to lower the bubble generation and have excellent reactivity.

The macromonomer may be polymerized with the monomer mixture to form a hydroxyl group-containing (meth) acrylic copolymer, thereby increasing the strength of the pressure-sensitive adhesive film. The macromonomer may be included in the pressure-sensitive adhesive film to increase the peel strength of the pressure-sensitive adhesive film.

Macromonomers have functional groups curable by active energy rays and can be polymerized with hydroxyl group-containing (meth) acrylates and alkyl group-containing (meth) acrylates. Specifically, the macromonomer may be represented by the following Chemical Formula 1:

<Formula 1>

(In Formula 1, R ¹ is hydrogen or methyl group, X is a single bond or a divalent bond group, Y is methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, iso-butyl Polymer chain obtained by polymerizing one or two or more selected from (meth) acrylate, t-butyl (meth) acrylate, styrene and (meth) acrylonitrile).

The macromonomer may have a number average molecular weight of 2,000 to 20,000, specifically 2,000 to 10,000, more specifically 4,000 to 8,000. In the said range, sufficient adhesive strength can be obtained, it is excellent in heat resistance, and the fall of the workability by the viscosity raise of an adhesive composition can be suppressed. Macromonomer may have a glass transition temperature of 40 ℃ to 150 ℃, specifically 60 ℃ to 140 ℃, more specifically 80 ℃ to 130 ℃. In the above range, the pressure-sensitive adhesive film can exhibit sufficient cohesion, and can suppress a decrease in stickiness or adhesion.

The divalent bond group is C1 to C10 alkylene group, C7 to C13 arylalkylene group, C6 to C12 arylene group, -NR ^2- (wherein R ² is hydrogen or C1 to C5 alkyl group), COO-,- O-, -S-, -SO ₂ NH-, -NHSO _2- , -NHCOO-, -OCONH, or a group derived from a heterocycle.

In addition, the divalent linking group may be represented by the following Formula 1a to Formula 1d:

<Formula 1a>

<Formula 1b>

<Formula 1c>

<Formula 1d>

(In Formula 1a to Formula 1d, * is a linking site of the element)

Macromonomer can use a commercial item. For example, a macromonomer whose terminal is a methacryloyl group and the segment corresponding to Y is methyl methacrylate, the macromonomer where the segment corresponding to Y is the styrene segment, and the segment of the segment Y is the styrene / acryl The macromonomer which is ronitrile, the macromonomer whose segment is butylacrylate, etc. can be used.

The macromonomer is 20 parts by weight or less, specifically 0.1 parts by weight to 20 parts by weight, 0.1 parts by weight to 10 parts by weight, 0.5 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. It may be included from 5 parts by weight. In the above range, it is possible to balance the viscoelasticity and modulus and the restoring force of the pressure-sensitive adhesive film, it is possible to prevent the haze rise of the pressure-sensitive adhesive film.

The organic nanoparticles may further increase the modulus of the pressure-sensitive adhesive film at high temperature, thereby preventing the pressure-sensitive adhesive film from peeling and / or lifting and / or generating bubbles at high temperature, thereby further increasing reliability at high temperature. The organic nanoparticles may have a high glass transition temperature, thereby increasing modulus at a high temperature of the adhesive film.

  The organic nanoparticles may have an average particle diameter of 10 nm to 400 nm, specifically 10 nm to 300 nm, more specifically 30 nm to 280 nm, and more specifically 50 nm to 280 nm. In the above range, it does not affect the folding of the pressure-sensitive adhesive film, the transparency of the pressure-sensitive adhesive film may be good as a total light transmittance of 90% or more in the visible light region.

The organic nanoparticles may have a refractive index difference of 0.1 or less, specifically 0 or more and 0.05 or less, specifically 0 or more and 0.02 or less, with a (meth) acrylic copolymer having a hydroxyl group. In the above range, the transparency of the pressure-sensitive adhesive film may be excellent. The organic nanoparticles may have a refractive index of 1.35 to 1.70, specifically 1.40 to 1.60. In the above range, the transparency of the adhesive film may be excellent.

The organic nanoparticles may include, but are not limited to, simple nanoparticles such as a bead type as well as a core-shell type. In the case of the core-shell type, the core and the shell may satisfy the following Equation 3: That is, both the core and the shell may be nanoparticles which are organic materials. When having a particle form as described above, the folding property of the pressure-sensitive adhesive film is good, it may be effective in the balance physical properties of elasticity and flexibility.

<Equation 3>

Tg (c) <Tg (s)

(In Formula 3, Tg (c) is the glass transition temperature of the core (unit: ℃),

Tg (s) is the glass transition temperature (unit: ° C) of the shell.

As used herein, "shell" refers to the outermost layer of organic nanoparticles. The core may be one spherical particle. However, the core may further comprise an additional layer surrounding the spherical particles if it has the above glass transition temperature.

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

Polyalkyl (meth) acrylates are polymethylacrylate, polyethylacrylate, polypropylacrylate, polybutylacrylate, polyisopropylacrylate, polyhexyl acrylate, polyhexyl methacrylate, polyethylhexyl acrylate And polyethylhexyl methacrylate, polysiloxane, but are not necessarily limited thereto.

The polysiloxane can be, for example, an organosiloxane (co) polymer. The organosiloxane (co) polymer may be one which is not crosslinked, or a crosslinked (co) polymer may be used. Crosslinked organosiloxane (co) polymers can be used for impact resistance and colorability. This is a crosslinked organosiloxane, specifically, crosslinked dimethylsiloxane, methylphenylsiloxane, diphenylsiloxane or a mixture of two or more thereof may be used. The refractive index of 1.41 to 1.50 can be adjusted by using a form in which two or more organosiloxanes are copolymerized.

The crosslinking state of the organosiloxane (co) polymer can be judged with the degree of dissolution by various organic solvents. The deeper the crosslinking state, the smaller the degree of dissolution by the solvent. Acetone, toluene, or the like may be used as a solvent for determining the crosslinking state. Specifically, the organosiloxane (co) polymer may have a portion that is not dissolved by acetone or toluene. The insoluble component of the organosiloxane copolymer to toluene may be 30% or more.

Additionally, the organosiloxane (co) polymer may further include an alkylacrylate crosspolymer. As the alkyl acrylate crosspolymer, methyl acrylate, ethyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate and the like can be used. For example, n-butyl acrylate or 2-ethylhexyl acrylate having a low glass transition temperature can be used.

Specifically, the glass transition temperature of the shell may be 15 ℃ to 150 ℃, specifically 35 ℃ to 150 ℃, more specifically 50 ℃ to 140 ℃. 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 the glass transition temperature. For example, polymethyl methacrylate (PMMA), polyethyl methacrylate, polypropyl methacrylate, polybutyl methacrylate, polyisopropyl methacrylate, polyisobutyl methacrylate and polycyclohexyl methacrylate It may include one or more of the rate, but is not necessarily limited thereto.

The core may be included in 30 to 99% by weight, specifically 40 to 95% by weight, more specifically 50 to 90% by weight of the organic nanoparticles. In the above range, the folding property of the adhesive film in a wide temperature range may be good. The shell may comprise 1% to 70% by weight, specifically 5% to 60% by weight, more specifically 10% to 50% by weight of the organic nanoparticles. In the above range, the folding property of the adhesive film in a wide temperature range may be good.

The organic nanoparticles are 0.1 parts by weight to 20 parts by weight, specifically 0.5 parts by weight to 10 parts by weight, specifically 0.5 parts by weight to 100 parts by weight of the total amount of the hydroxyl group-containing (meth) acrylate and the alkyl group-containing (meth) acrylate. It may be included in 8 parts by weight. In the above range, the modulus of the pressure-sensitive adhesive film at a high temperature can be made high, the folding property at room temperature and high temperature of the pressure-sensitive adhesive film can be improved, and the low-temperature and / or room temperature viscoelasticity of the pressure-sensitive adhesive film can be excellent.

Organic nanoparticles can be prepared by conventional emulsion polymerization, suspension polymerization, solution polymerization method.

The pressure-sensitive adhesive composition may further include a silane coupling agent. The silane coupling agent can be made reliable because there is no bubble or peeling even if the pressure-sensitive adhesive film is left for a predetermined time at a high temperature and high humidity in a frame having a predetermined radius of curvature. Silane coupling agents can be used conventionally known to those skilled in the art. For example, 3-glycidoxy propyl trimethoxysilane, 3-glycidoxy propyl triethoxysilane, 3-glycidoxy propylmethyl dimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltri Silicon compounds having an epoxy structure such as methoxysilane; Polymerizable unsaturated group-containing silicon compounds such as vinyl trimethoxy silane, vinyl triethoxy silane, and (meth) acryloxy propyl trimethoxysilane; Amino group-containing silicon compounds such as 3-aminopropyl trimethoxysilane, N- (2-aminoethyl) -3-aminopropyl trimethoxysilane, N- (2-aminoethyl) -3-aminopropyl methyl dimethoxysilane ; And 3-chloro propyl trimethoxysilane and the like may include one or more selected from the group consisting of, but is not limited thereto. Preferably, a silane coupling agent having an epoxy structure can be used. The silane coupling agent may be included in an amount of 0.01 to 3 parts by weight, specifically 0.01 to 1 part by weight, based on 100 parts by weight of the total of the hydroxyl group-containing (meth) acrylate and alkyl group-containing (meth) acrylate. In the above range, reliability can be ensured in the bending state at the high temperature and high humidity described above, and the difference in peeling force between low temperature, room temperature, and high temperature can be low.

The pressure-sensitive adhesive composition may further include a crosslinking agent. The crosslinking agent may increase the degree of crosslinking of the pressure-sensitive adhesive composition to increase the mechanical strength of the pressure-sensitive adhesive film. The crosslinking agent may comprise a polyfunctional (meth) acrylate that is curable with active energy rays. In an embodiment, the crosslinking agent is 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentylglycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, Neopentylglycol adipate di (meth) acrylate, dicyclopentanyl di (meth) acrylate, caprolactone modified dicyclopentenyl di (meth) acrylate, ethylene oxide modified di (meth) acrylate, di (meth ) Acryloxy ethyl isocyanurate, allylated cyclohexyl di (meth) acrylate, tricyclodecane dimethanol (meth) acrylate, dimethylol dicyclopentanedi (meth) acrylate, ethylene oxide modified hexahydrophthalic acid Di (meth) acrylate, tricyclodecane dimethanol (meth) acrylate, neopentylglycol modified trimethylpropane di (meth) acrylate, adamantane di (meth) acrylic Bifunctional acrylates such as late or 9,9-bis [4- (2-acryloyloxyethoxy) phenyl] fluorene and the like; Trimethylolpropane tri (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) acryloxyethyl isocyanurate; Tetrafunctional acrylates such as diglycerin tetra (meth) acrylate or pentaerythritol tetra (meth) acrylate; 5-functional acrylates, such as dipentaerythritol penta (meth) acrylate; And dipentaerythritol hexa (meth) acrylate, caprolactone-modified dipentaerythritol hexa (meth) acrylate or urethane (meth) acrylate (ex. Isocyanate monomers and trimethylolpropane tri (meth) acrylate 6 functional acrylates such as reactants, etc., but are not limited thereto.They may be used singly or in mixture of two or more. Preferably, the crosslinking agent may be a polyfunctional (meth) acrylate of a polyhydric alcohol. The crosslinking agent is 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 hydroxyl group-containing (meth) acrylate and alkyl group-containing (meth) acrylate. It can be included in parts by weight There is an effect of excellent adhesion and increased reliability in the above range.

The pressure-sensitive adhesive composition may optionally include a curing accelerator, an ionic liquid, a lithium salt, an inorganic filler, a softener, a molecular weight regulator, an antioxidant, an antioxidant, a stabilizer, a tackifying resin, a modified resin (polyol resin, a phenol resin, an acrylic resin, a polyester resin). , Polyolefin resins, epoxy resins, epoxidized polybutadiene resins, etc.), leveling agents, antifoaming agents, plasticizers, dyes, pigments (colored pigments, sieving pigments, etc.), treatment agents, sunscreen agents, fluorescent brighteners, dispersants, thermal stabilizers Conventional additives such as light stabilizers, ultraviolet absorbers, antistatic agents, flocculants, lubricants and solvents may be further included.

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

The pressure-sensitive adhesive composition may be prepared by partially polymerizing a monomer mixture for a (meth) acrylic copolymer having a hydroxyl group with an initiator and including one or more of additional initiators, macromonomers, and organic nanoparticles. The crosslinking agent, additive, etc. which were mentioned above may also be included. Alternatively, the pressure-sensitive adhesive composition may be prepared by partially polymerizing a mixture comprising a monomer mixture and an initiator for a (meth) acrylic copolymer having a hydroxyl group, and including one or more of additional initiators, macromonomers, and organic nanoparticles. The crosslinking agent, additive, etc. which were mentioned above may also be included. Partial polymerization can include solution polymerization, suspension polymerization, photopolymerization, bulk polymerization, or emulsion polymerization. Specifically, solution polymerization may be performed at 50 ° C. to 100 ° C. by adding an initiator to the monomer mixture. As an initiator, photoinitiators, such as an acetophenone type and 1-hydroxycyclohexyl phenyl ketone containing 2, 2- dimethoxy- 2-phenylacetophenone etc. can be used. The partial polymerization can be polymerized at 25 ° C. with a viscosity of 300 cPs to 50,000 cPs, specifically, at a viscosity of 500 cPs to 9,000 cPs. The adhesive film can be manufactured by a conventional method. For example, the pressure-sensitive adhesive composition may be prepared by coating a release film and curing the same. 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.

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

In one embodiment, the optical film provides certain optical functions of the display device, such as polarization, optical compensation, display quality improvement, and / or conductivity, wherein the optical film is a window film, a window, a polarizer, a color filter, a retardation film. , Elliptical polarizing film, reflective polarizing film, antireflection film, compensation film, brightness enhancement film, alignment film, light diffusion film, glass scattering prevention film, surface protection film, OLED element barrier layer, plastic LCD substrate, ITO (indium tin oxide) And transparent electrode films including fluorinated tin oxide (FTO), aluminum dopped zinc oxide (AZO), carbon nanotube (CNT), Ag nanowires, graphene, and the like. The manufacturing method of the optical film can be easily manufactured by those skilled in the art to which the present invention pertains.

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

In another embodiment, the optical film is an optically transparent optical film, the optical member including the optical film and the adhesive film may serve as a support layer of the display element. For example, the display element may include a window film or the like. The window film may include the optical member and a window coating layer (eg, a silicon based coating layer) formed on the optical member. The window film can be a flexible window film. Specifically, the optical film has a total light transmittance of 90% or more in the visible region, and includes a cellulose resin including triacetyl cellulose, polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polybutylene naphthalate, and the like. Formed of at least one of a poly (meth) acrylate resin, a cyclic olefin polymer resin, an acrylic resin, a polyamide resin, including a polyester resin, a polycarbonate resin, a polyimide resin, a polystyrene resin, a polymethylmethacrylate, and the like It may be a film. The optical film may have a thickness of 10 μm to 100 μm, specifically 20 μm to 75 μm, and more specifically 30 μm to 50 μm. It can be used as the support layer of the display element in the above range.

The optical member may be an optical member having two layers including an optical film and an adhesive film formed on one surface of the optical film. Alternatively, the optical member may include two or more optical films, and at least two or more of the optical films may be three or more film laminates laminated by the adhesive film of the present invention.

In one embodiment, the optical member may be a first optical film, a second optical film, and a three-layer film laminate in which the first optical film and the second optical film are laminated by the adhesive film of the present invention. Each of the first optical film and the second optical film may be a film formed of at least one of polyethylene terephthalate resin, polycarbonate resin, polyimide resin, poly (meth) acrylate resin, cyclic olefin polymer resin, and acrylic resin. Can be. Each of the first optical film and the second optical film has a thickness of 10 μm to 100 μm, specifically 20 μm to 75 μm, more specifically 30 μm to 50 μm, and the adhesive film has a thickness of 10 μm to 100 μm. This can be In the above range, it can be effective to maximize the impact resistance while maintaining good folding properties. The first optical film and the second optical film may be the same or different in thickness and material, respectively.

The optical display device of the present invention may include the adhesive film of the present invention. The optical display device may include an organic light emitting display device, a liquid crystal display device 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 exemplary embodiment of the present invention will be described with reference to FIG. 1. 1 is a cross-sectional view of a flexible display device according to an embodiment of the present invention.

Referring to FIG. 1, the flexible display apparatus 100 according to an exemplary embodiment of the present invention may include a display unit 110, an adhesive layer 120, a polarizing plate 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 apparatus 100 and may include a substrate and an optical element including an OLED, an LED, a quantum dot light emitting diode (QLED), or an LCD element formed on the substrate. 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 film, and an insulating film.

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

The touch screen panel 140 generates an electrical signal by detecting a change in capacitance generated when a human body or a conductor such as a stylus touches the touch screen panel. The display 110 may be driven by the signal. The touch screen panel 140 is formed by patterning a flexible and conductive conductor, and may include a second sensor electrode formed between the first sensor electrode and the first sensor electrode to cross the first sensor electrode. have. The conductor for the touch screen panel 340 may include, but is not limited to, metal nanowires, conductive polymers, carbon nanotubes, and the like.

1 illustrates that the polarizing plate 130 and the touch screen panel 140 are laminated by an adhesive film or an adhesive film, but the polarizing plate 130 and the touch screen panel (including the polarizer or the polarizing plate in the touch screen panel 140). 140 may be integrated.

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

Although not shown in FIG. 1, the adhesive film of the embodiment of the present invention is further formed between the polarizing plate 130 and the touch screen panel 140 and / or between the touch screen panel 140 and the flexible window film 150. Bonding between the screen panel and the flexible window film can be strengthened.

Hereinafter, the configuration and operation of the present invention through the preferred embodiment of the present invention will be described in more detail. However, this is presented as a preferred example of the present invention and should not be construed as limiting the present invention by any means.

Production Example

By emulsion polymerization method, organic nanoparticles were prepared. The core is polybutylacrylate, the shell is polymethylmethacrylate, the shell is 35% by weight of the organic nanoparticles, the core is 65% by weight of the organic nanoparticles, the average particle diameter is 100nm, the organic nanoparticles having a refractive index of 1.48 Was prepared.

Example  One

To 100 parts by weight of the mixture of hydroxyl group-containing (meth) acrylate and alkyl group-containing (meth) acrylate in Table 1, 5 parts by weight of organic nanoparticles of the preparation, 0.005 parts by weight of the initiator Irgacure651 was well mixed in the reactor. The monomer mixture was partially polymerized by exchanging dissolved oxygen in the reactor with nitrogen gas and then irradiating with ultraviolet light using a low pressure mercury lamp for a few minutes to prepare a viscous liquid having a viscosity of 5,000 cps at 25 ° C. 0.3 weight part of initiator Irgacure184, 0.01 weight part of crosslinking agents hexanediol diacrylate, and 0.1 weight part of silane coupling agents 3-glycidoxy propyl trimethoxysilane (KBM-403) were added to the viscous liquid, and the adhesive composition was prepared. The pressure-sensitive adhesive composition was applied to a PET (polyethylene terephthalate) film which is a release film, and irradiated with an ultraviolet light amount of 2000 mJ / cm ² to prepare a pressure-sensitive adhesive sheet of the pressure-sensitive adhesive film and PET film.

Example  2 to Example  6

Except for changing the configuration of the pressure-sensitive adhesive composition in Example 1 to prepare a pressure-sensitive adhesive sheet of the pressure-sensitive adhesive film and PET film in the same manner.

Comparative example  1 lesson Comparative example  2

Except for changing the configuration of the pressure-sensitive adhesive composition in Example 1 to prepare a pressure-sensitive adhesive sheet of the pressure-sensitive adhesive film and PET film in the same manner.

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

(1) Bubble generation area during durability life evaluation: A PET film was obtained by releasing a PET film from the pressure sensitive adhesive sheets of Examples and Comparative Examples. Rectangular cross-section of a three-layer structure in which a polyethylene terephthalate film (thickness: 50 mu m), the adhesive film (thickness: 100 mu m), and a polyethylene terephthalate film (thickness: 100 mu m) are sequentially stacked. : 13 cm x 3 cm), and the specimen was bent in the direction of the polyethylene terephthalate film (thickness: 50 μm) so that the horizontal length of the specimen was 1/2 between the molds having a spacing of 1 cm. The bubble generation area was evaluated when 1 cycle of 24 hours was repeated 10 cycles. The bubble generation area was analyzed by an optical microscope (Olympus, EX-51) image of Mountech's Mac-view software to calculate the ratio of the total bubble generation area to the total area of the adhesive film.

 <1 cycle> Gradually elevated temperature for 2 hours from 25 ° C to 60 ° C while maintaining 93% relative humidity → 3.5 hours at constant temperature and humidity of 60 ° C and 93% RH for 2 hours while maintaining 93% relative humidity to 25 ° C Gradually decrease temperature → slowly increasing temperature while maintaining 93% relative humidity for 2 hours from 25 ℃ to 60 ℃ and leaving it for 3.5 hours at constant temperature and humidity of 60 ℃ and 93% relative humidity → Slowly decreasing temperature for 2 hours while maintaining 93% relative humidity to 25 ℃ → 2 hours at constant temperature and humidity of 25 ° C and relative humidity of 93% → Decreased for 0.5 hours to -10 ° C → 3.5 hours at constant temperature of -10 ° C → Temperature for 1 hour while maintaining 93% relative humidity to 25 ° C → 25 It is left to stand for 2 hours at constant temperature and humidity of ℃ and relative humidity of 93%.

(2) Area of bubble generation at the evaluation of thermal shock: Specimens were prepared in the same manner as in (1), and bubble area was evaluated. The specimen was bent in the direction of the polyethylene terephthalate film (thickness: 50 μm) so that the horizontal length of the specimen was 1/2 between the molds having a spacing of 1 cm, and repeated 30 cycles of one cycle of the following sequential execution (1 Bubble generation area was evaluated in the same manner as

<1 cycle> 2 hours at a constant temperature of -40 ℃ → 2 hours at a constant temperature of 85 ℃

(3) Peeling strength: The PET film was released from the adhesive sheets of Examples and Comparative Examples to obtain an adhesive film (width x length x thickness: 100 mm x 25 mm x 100 µm). One side of the PET film (width x length x thickness: 150 mm x 25 mm x 75 μm) was corona treated with two corona treatments (total dose: 156 dose) while discharging at a dose of 78 doese per dose using a corona treatment machine. The specimens of FIG. 2 (a) were prepared by laminating the corona treated surfaces of the PET film on both sides of the adhesive film. The specimens were autoclaved at pressure of 3.5 bar at 50 ° C. for 1000 seconds and fixed in a TA.XT _- Plus Texture Analyzer (Stable Micro System). Referring to FIG. 2 (b), one PET film was fixed at 25 ° C. or 60 ° C. using TA.XT _- Plus Texture Analyzer, and the other PET film was pulled at a rate of 50 mm / min to measure peel strength. .

(4) Modulus: Viscoelasticity was measured under auto strain conditions at a shear rate of 1 rad / sec and strain of 1% using a rheometer (Anton Paar MCR-501). Using the pressure-sensitive adhesive composition prepared in Examples and Comparative Examples to prepare a pressure-sensitive adhesive sheet of 50㎛ thickness of the adhesive film and PET film. A plurality of 50 μm thick adhesive films were laminated and laminated to a thickness of 500 μm, and the laminate was punched out using an 8 mm diameter perforator to be used as a specimen. The measurement was performed while raising the temperature at a temperature rising rate of 5 ° C./min at a temperature of −60 ° C. to 90 ° C. with a load of 300 gf applied to the specimen using an 8 mm jig. The temperature was -20 ° C., 25 ° C. and 80 ° C. The modulus was calculated at 占 폚, respectively.

모양인 시편을 제조하였다. PET 필름과 점착필름 간의 접촉 면적은 점착필름(길이x 폭, 15 mm x 15 mm)의 면적과 동일하다. 상기 시편을 TA(TA.XT Plus Texture Analyzer (Stable Micro System 제조))에 고정하고, 25℃에서 하중(W) 500gf로 0.6mm/min의 속도로 한쪽 PET 필름을 잡아당겼을 때 점착 필름이 PET필름으로부터 600 초 동안 움직인 거리를 측정하였다.(5) Creep: Referring to Figure 3, PET (polyethylene terephthalate) film (length x width, 45mm x 15mm) each end portion of each other via an adhesive film (length x width, 15mm x 15mm) Stick the cross section

A specimen in shape was prepared. The contact area between the PET film and the adhesive film is equal to the area of the adhesive film (length x width, 15 mm x 15 mm). When the specimen was fixed to TA (TA.XT Plus Texture Analyzer (manufactured by Stable Micro System)) and pulled on one PET film at a speed of 0.6 mm / min at a load (W) of 500 gf at 25 ° C, the adhesive film was PET. The distance traveled for 600 seconds from the film was measured.

(6) Glass transition temperature: Measured using DSC Q20 from TA Instrument. For example, after raising the temperature of the pressure-sensitive adhesive film to about 100 ℃ at a rate of 10 ℃ / min, the equilibrium state is maintained for 5 minutes, the temperature is lowered to about -120 ℃ at a rate of 10 ℃ / min and maintained for 10 minutes. After the data of the endothermic transition curve when the temperature was raised from −120 ° C. to about 160 ° C. at a rate of 10 ° C./min was obtained, the inflection point of the endothermic transition curve was determined as the glass transition temperature.

(7) Folding evaluation: laminated in the order of PET film (thickness: 50 μm) / adhesive film (thickness: 100 μm) / PET film (thickness: 50 μm), aged with a roller, and aged at room temperature for 12 hours. , A specimen was prepared by cutting to a width x length (70 mm x 140 mm) size, and the prepared specimen was fixed to a flexibility evaluation equipment (CFT-2000, Covotech) using an adhesive (4965, Tesa). At this time, the PET film was corona-treated and then the adhesive film and the corona-treated side were adhered. Bending in the longitudinal direction of the specimen at 60 ° C. and 93% relative humidity, the bending radius of curvature is 3 mm, bending 30 cycles per minute, where 1 cycle means bending the specimen to the radius of curvature and straightening it to 180 °. 100,000 seconds for stretching after holding for a second It means the conditions for cycle bending. When peeling or foaming generate | occur | produced after 100,000 cycles, it marked with (circle) when no peeling and foaming occurred.

Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Comparative Example 1 Comparative Example 2 n-BA
(Part by weight) 5 5 10 10 - - 24 15 2-EHA
(Part by weight) 75 78 75 75 80 80 75 65 4-HBA
(Part by weight) 15 15 10 5 20 20 One 15 3-HPA
(Part by weight) 5 2 5 10 - - - 5 DEAA
(Part by weight) - - - One - One One One Organic nanoparticles
(Part by weight) 5 5 3 3 5 - 5 - Macromonomer
(Part by weight) - - - - - 5 - - Crosslinking agent
(Part by weight) 0.01 0.01 - - 0.01 0.01 0.01 - Silane coupling agent
(Part by weight) 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 bubble
Occur
area
(%) Endurance Life Assessment 0 0 0 0 0 0 15.3 4.6 Thermal shock 0 0 0 0 0 0 6.8 2.7 Peel strength
(gf / in) ＠ 25 ℃ 1428 1372 1324 1464 1570 1333 862 1401 ＠ 60 ℃ 974 773 579 670 742 653 268 476 Peel Strength Reduction Ratio of Equation 1 (%) 31.7 43.6 56.2 54.2 52.7 51.0 68.9 66.0 Peel Strength Difference of Equation 2 (gf / in) 454 599 745 794 828 680 594 925 Modulus
(kPa) ＠ -20 ℃ 140 132 105 124 84 97 65 118 ＠ 25 ℃ 42 35 27 30 35 34 19 37 ＠ 80 ℃ 30 28 18 21 23 18 9 15 Creep
(Μm) 65 77 119 36 93 43 85 69 Glass transition temperature
(℃) -56.1 -57.3 -57.2 -55.5 -57.7 -53.2 -59.4 -54.2 Folding rating ○ ○ ○ ○ ○ ○ × ×

n-BA: n-butylacrylate, 2-EHA: 2-ethylhexylacrylate, 4-HBA: 4-hydroxybutylacrylate, 3-HPA: 3-hydroxybutylacrylate, DEAA: diethyl Aminoethyl acrylate, macromonomer: AA-6 (Toakosei), crosslinking agent: 1,6-hexanediol diacrylate, silane coupling agent: 3-glycidoxypropyltrimethoxysilane

As shown in Table 1, the pressure-sensitive adhesive film of the present embodiment has a low bubble generation area at high temperature, room temperature, low temperature change or heat shock, which is excellent in durability and reliability and extends the life of the display. The reduction in peel strength of the can be lowered, the ratio of modulus between low temperature and high temperature provided a durable, reliable adhesive film.

Simple modifications and variations of the present invention can be easily made by those skilled in the art, and all such modifications or changes can be seen to be included in the scope of the present invention.

Claims (25)

It is an adhesive film formed of the monomer mixture containing a hydroxyl group containing (meth) acrylate and an alkyl group containing (meth) acrylate,
The pressure-sensitive adhesive film is a polyethylene terephthalate film (thickness: 50 μm), the pressure-sensitive adhesive film (thickness: 100 μm), and a specimen of a three-layer structure in which a polyethylene terephthalate film (thickness: 100 μm) is sequentially stacked. : 13cm x 3cm) was bent in the direction of the polyethylene terephthalate film (thickness: 50㎛) so that the horizontal length of the specimen is 1/2 between the frame of 1cm intervals, 1 cycle of 24 hours, the following sequential execution When repeated 10 cycles, the bubble generation area is 0%,
<1 cycle> Gradually elevated temperature for 2 hours from 25 ° C to 60 ° C while maintaining 93% relative humidity → 3.5 hours at constant temperature and humidity of 60 ° C and 93% RH for 2 hours while maintaining 93% relative humidity to 25 ° C Gradually decrease temperature → 2 hours while maintaining 93% relative humidity from 25 ℃ to 60 ℃ Slowly increase the temperature for 2 hours while standing at 3.5 ℃ in constant temperature and humidity of 60 ℃ and 93% RH → Slowly decrease temperature for 2 hours while maintaining 93% relative humidity to 25 ℃ → 2 hours at constant temperature and humidity of 25 ° C and relative humidity of 93% → Decreased for 0.5 hours to -10 ° C → 3.5 hours at constant temperature of -10 ° C → Temperature increased for 1 hour while maintaining 93% relative humidity to 25 ° C → 2 hours at constant temperature and humidity of 25 ℃ and 93% relative humidity,
5% by weight to 40% by weight of the hydroxyl group-containing (meth) acrylate and 60% by weight of the alkyl group-containing (meth) acrylate in the total of the hydroxyl group-containing (meth) acrylate and the alkyl group-containing (meth) acrylate. 95 wt%,
The pressure-sensitive adhesive film further comprises one or more of organic nanoparticles, macromonomers,
The pressure-sensitive adhesive film is an adhesive modulus of the modulus: -1 to 1: 10 at 80 ° C: 1 to 1:10.
According to claim 1, wherein the pressure-sensitive adhesive film is bent in the direction of the polyethylene terephthalate film (thickness: 50㎛) so that the horizontal length of the specimen is half between the frame of 1cm intervals, the following sequential performance Pressure-sensitive adhesive film having a bubble generation area of 0% when phosphorus 1 cycle is repeated 30 cycles:
<1 cycle> 2 hours at constant temperature of -40 degreeC → 2 hours at constant temperature of 85 degreeC.
The pressure-sensitive adhesive film of claim 1, wherein the pressure-sensitive adhesive film has a reduction ratio of peeling strength of Formula 1 below 60%:
<Equation 1>
Rate of decrease in peel strength = ｜ B-A ｜ / A x 100
(In Formula 1, A is the peel strength at 25 ° C. of the adhesive film (unit: gf / in),
B is the peel strength (unit: gf / in) of the adhesive film at 60 ℃.
The pressure-sensitive adhesive film of claim 3, wherein the pressure-sensitive adhesive film has a B value of 500 gf / in or more in Formula 1.
The pressure-sensitive adhesive film of claim 1, wherein the pressure-sensitive adhesive film has a glass transition temperature of -100 ° C to -10 ° C.
The pressure-sensitive adhesive film of claim 1, wherein the pressure-sensitive adhesive film has a creep of 10 µm to 400 µm at 25 ° C.
The pressure-sensitive adhesive film of claim 1, wherein the pressure-sensitive adhesive film has a modulus of 10 kPa to 500 kPa at 80 ° C.
The pressure-sensitive adhesive film of claim 1, wherein the pressure-sensitive adhesive film has a modulus of 20 kPa to 500 kPa at -20 ° C.
delete delete The pressure-sensitive adhesive film of claim 1, wherein the monomer mixture further comprises at least one of a monomer having an ethylene oxide and a monomer having an amine group.
According to claim 1, wherein the adhesive film further comprises a silane coupling agent,
The silane coupling agent is a pressure-sensitive adhesive film, comprising a silane coupling agent having an epoxy group.
The pressure-sensitive adhesive film of claim 1, wherein the pressure-sensitive adhesive film further comprises an initiator or a crosslinking agent.
The pressure-sensitive adhesive film of claim 1, wherein the organic nanoparticles have an average particle diameter of 10 nm to 400 nm.
The method of claim 1, wherein the organic nanoparticles are core-shell particles,
The core and the shell to satisfy the following formula 3, the adhesive film:
<Equation 3>
Tg (c) <Tg (s)
(In Formula 3, Tg (c) is the glass transition temperature (unit: ° C) of the core, Tg (s) is the glass transition temperature (unit: ° C) of the shell).
The pressure-sensitive adhesive film of claim 14, wherein the organic nanoparticles are included in an amount of 0.1 to 20 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.
The pressure-sensitive adhesive film of claim 1, wherein the macromonomer is included in an amount of 0.1 to 20 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.
The pressure-sensitive adhesive film of claim 1, wherein the pressure-sensitive adhesive film has a haze of 2% or less at a wavelength of 380 nm to 780 nm.
An optical film, and an adhesive film formed on at least one surface of the optical film,
The adhesive film is to include the adhesive film of claim 1, the optical member.
The optical member according to claim 19, wherein the optical member is a first optical film, a second optical film, and a three-layer film laminate in which the first optical film and the second optical film are laminated by the adhesive film. .
21. The method of claim 20, wherein the first optical film and the second optical film are each one of polyethylene terephthalate resin, polycarbonate resin, polyimide resin, poly (meth) acrylate resin, cyclic olefin polymer resin, acrylic resin Optical member which is a film formed from the above resin.
The optical member of claim 20, wherein the first optical film and the second optical film have a thickness of 10 μm to 100 μm, respectively, and the adhesive film has a thickness of 10 μm to 100 μm.
The optical member of claim 20, wherein the optical member is for a window film.
An optical display device comprising the optical member of claim 19.
The optical member according to any one of claims 19 to 23; And a window coating layer formed on the optical member.

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