KR101385042B1 - Adhesive Composition, Adhesive Film Comprising the Same, Method for Preparing the Adhesive Film and Display Member Using the Same - Google Patents

Abstract

(상기에서, R1, R2 및 R3는 각각 독립적으로 탄소수 1~5의 알킬기이고, R4 및 R5는 각각 독립적으로 탄소수 1~6의 알킬기 또는 탄소수 6~12의 아릴기이며, n은 3~25의 정수이고, m은 1~10의 정수임) The adhesive composition of this invention is a (meth) acryl-type copolymer; An oligomeric siloxane represented by Formula 1 below; And a crosslinking agent, wherein the (meth) acrylic copolymer comprises alicyclic, aromatic or combinations thereof:
[Chemical Formula 1]

(In the above, R1, R2 and R3 are each independently an alkyl group having 1 to 5 carbon atoms, R4 and R5 are each independently an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms, n is a 3-25 Integer, m is an integer from 1 to 10)

Description

Adhesive composition, adhesive film, manufacturing method thereof and display member using the same {Adhesive Composition, Adhesive Film Comprising the Same, Method for Preparing the Adhesive Film and Display Member Using the Same}

The present invention relates to a pressure-sensitive adhesive composition, pressure-sensitive adhesive film, a manufacturing method thereof and an optical member using the same. More specifically, the present invention introduces an oligomeric siloxane having a specific structure into the acrylic copolymer to improve the durability and cutting properties of the pressure-sensitive adhesive, minimize ITO corrosion, and at the same time improve the amount of overfilling properties and re-peelable pressure-sensitive adhesive composition, adhesive A film, a manufacturing method thereof, and an optical member using the same.

The capacitive touch pad is attached to a window or film positioned on an upper surface of the capacitive touch pad and a light-transparent adhesive to detect a change in capacitance in the window or film to exhibit characteristics. Glass, PMMA, PC, etc. may be used as the window, and problems such as lifting, bubble generation, warpage, and ITO patterns may occur when the environment changes depending on the type of the material.

In general, the light-transparent pressure-sensitive adhesive is composed of an acrylic monomer, and includes an acid component such as acrylic acid. Accordingly, various acids present in the light transparent adhesive oxidize ITO on the touch pad side, thereby increasing the resistance of the ITO, thereby lowering the characteristics of the touch pad.

Therefore, there is a demand for development of a pressure-sensitive adhesive suitable for a pressure-sensitive adhesive for touch screens, while having excellent durability and cutting property and effectively suppressing resistance change of the electrode layer under severe conditions.

Recently, various attempts have been made to solve problems such as lifting, bubble generation, warpage, and ITO patterns. However, even if the problems such as lifting, bubble generation, warpage, ITO pattern is revealed, it is difficult to peel off, there is a problem that the ITO film, ITO Glass, or touch panel must be disposed together.

Accordingly, there is a need for development of a pressure-sensitive adhesive that can be easily peeled off, easy to remove the light-transparent pressure-sensitive adhesive due to defects, and solves problems such as lifting, bubble generation, warpage, and ITO pattern.

One object of the present invention is to provide a pressure-sensitive adhesive composition which is excellent in durability and cutting properties and can minimize excessive ITO corrosion and at the same time improve the amount of landfill properties.

Another object of the present invention is to provide an adhesive composition having excellent reworkability.

Another object of the present invention is to provide a pressure-sensitive adhesive composition that can effectively suppress the resistance change of the electrode layer under severe conditions.

Still another object of the present invention is to provide a pressure-sensitive adhesive composition which does not cause end lifting, bubbles, warpage, or light leakage.

Still another object of the present invention is to provide a pressure-sensitive adhesive composition which can be easily coated with a solvent-free type and can thicken a film thickness.

Still another object of the present invention is to provide an acid free type adhesive film and a method of manufacturing the same, which are excellent in durability using the pressure-sensitive adhesive composition.

Still another object of the present invention is to provide a display member using the adhesive film.

One aspect of the present invention relates to an adhesive composition. In one embodiment the pressure-sensitive adhesive composition is a (meth) acrylic copolymer; An oligomeric siloxane represented by Formula 1 below; And a crosslinking agent, wherein the (meth) acrylic copolymer contains alicyclic, aromatic or combinations thereof:

[Chemical Formula 1]

(In the above, R1, R2 and R3 are each independently an alkyl group having 1 to 5 carbon atoms, R4 and R5 are each independently an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms, n is a 3-25 Integer, and m is an integer of 1 to 10).

The (meth) acrylic copolymer may have a glass transition temperature of -50 to 0 ° C.

The (meth) acrylic copolymer may be a C _{1 -20} alkyl (meth) acrylate, alicyclic or aromatic (meth) acrylates and copolymers of hydroxy monomers mixture comprising a lock group-containing monomer.

In embodiments wherein the (meth) acrylic copolymer is 60 to 95% by weight of a C _{1 -20} alkyl (meth) acrylate, alicyclic or aromatic (meth) acrylate, 0.1 to 20% by weight, and hydroxyl group-containing monomer 0.5 It may be a copolymer of a monomer mixture comprising ˜25% by weight.

Monomers containing the (meth) acrylic copolymers in time 60 to 95% by weight of a C _{1 -20} alkyl (meth) acrylate, cycloaliphatic-containing (meth) acrylate, 0.5 to 20% by weight, a hydroxyl in another embodiment from 0.5 to It may be a copolymer of a monomer mixture comprising 25% by weight and 0.1-10% by weight of aromatic (meth) acrylate.

The (meth) acrylic copolymer may have a viscosity of 1000 to 2500 cp at 25 ℃.

The oligomeric siloxane may have a refractive index of 1.4 to 1.5.

The oligomeric siloxane may have an alkoxy group content in the molecule of 30 to 60% by weight.

The oligomeric siloxane may have an epoxy equivalent of 250 to 450 g / mol.

In an embodiment, the pressure-sensitive adhesive composition may have an acid value of zero.

The pressure-sensitive adhesive composition is 100 parts by weight of the (meth) acrylic copolymer; 0.01 to 5 parts by weight of the oligomeric siloxane; And 0.01 to 5 parts by weight of a crosslinking agent.

Another aspect of the present invention relates to an adhesive film formed by curing the pressure-sensitive adhesive composition.

In one embodiment, the adhesive film may contain an oligomeric siloxane represented by Chemical Formula 1 and have a modulus of 1 Hz 1 × 10 ⁵ to 1 × ^{10 7} dyne / cm ² by a frequency sweep test at 30 ° C. In an embodiment, the adhesive film contains an alicyclic group.

The adhesive film may have a resistance change ΔR of less than 5% represented by Equation 1 below:

[Equation 1]

In the above formula, P ₂ is the resistance after standing for 240 hours at 60 ℃ / 90% relative humidity conditions, P ₁ is the initial resistance.

The adhesive film may have a thickness of 100 μm to 2 mm.

The adhesive film may have a peel strength of 1950 to 3000 gf / 25 mm.

Another aspect of the present invention relates to a method for producing an adhesive film. The method comprises polymerizing a (meth) acrylic copolymer by polymerizing a monomer mixture comprising a (meth) acrylate containing a C _1-20 alkyl (meth) acrylate, an alicyclic, aromatic, or a combination thereof and a hydroxy group-containing monomer. To prepare; Preparing a pressure-sensitive adhesive composition by mixing a crosslinking agent and an oligomeric siloxane represented by the following Formula 1 to the (meth) acrylic copolymer; And UV curing the pressure-sensitive adhesive composition.

The (meth) acrylic copolymer does not include a solvent and may have a viscosity of 25 to 1000 to 2500 cp.

Another aspect of the present invention relates to a display member. Wherein the display member comprises: an optical film; And the adhesive film attached to one or both surfaces of the optical film.

In an embodiment, the optical film may be a polarizing film.

In an embodiment, the optical film may be an ITO film.

The present invention is excellent in durability and cutting property, excellent in reworkability, and can minimize ITO corrosion and at the same time effectively suppress the resistance change of the electrode layer under severe conditions, and do not cause end lifting, bubbles, warpage and light leakage. By using the pressure-sensitive adhesive composition and the pressure-sensitive adhesive composition which can be easily coated with a solvent-free type, and the pressure-sensitive adhesive composition, durability can be provided and an acid-free type pressure-sensitive adhesive film and a manufacturing method thereof can be provided. The present invention can also provide a display member using the adhesive film.

Unless stated otherwise in the specification, "(meth) acryl" means that both "acryl" and "methacryl" are possible.

The adhesive composition of this invention is a UV curing type, and contains a (meth) acrylic-type copolymer. In a specific embodiment, the pressure-sensitive adhesive composition is the (meth) acrylic copolymer; And crosslinkers. Hereinafter, each component of the present invention will be described in detail below.

(Meth) acrylic copolymer

In a specific embodiment, the (meth) acrylic copolymer is a monomer mixture comprising a C _1-20 alkyl (meth) acrylate, an alicyclic, aromatic, or a combination containing (meth) acrylate and a hydroxy group-containing monomer. It may be a copolymer of.

Examples of the C _1-20 alkyl (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, pentyl (Meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, nonyl (meth) acrylate, decyl And is not necessarily limited thereto. These may be used alone or in combination of two or more. Here, (meth) acrylate means both acrylate and methacrylate. The alkyl (meth) acrylate of C _1-20 may be included in 60 to 95% by weight of the (meth) acrylic copolymer. In the above-mentioned range, bubbles and floating are not generated under heat and humidity conditions, and durability is excellent.

Examples of the alicyclic containing (meth) acrylate include isobornyl (meth) acrylate, carbonyl (meth) acrylate, cyclohexyl (meth) acrylate, and the like, but are not necessarily limited thereto. These may be used alone or in combination of two or more. The alicyclic containing (meth) acrylate may be included in 0.1 to 20% by weight, preferably 0.5 to 20% by weight, more preferably 5 to 18% by weight in the (meth) acrylic copolymer. Excellent durability in the above range, there is an advantage that the adhesive force increases.

In specific embodiments, the aromatic (meth) acrylate may include phenyl (meth) acrylate, phenoxy (meth) acrylate, 2-ethylphenoxy (meth) acrylate, benzyl (meth) acrylate, 2-phenylethyl ( Meth) acrylate, 3-phenylpropyl (meth) acrylate, 4-phenylbutyl (meth) acrylate, 2-2-methylphenylethyl (meth) acrylate, 2-3-methylphenylethyl (meth) acrylate, 2 4-methylphenylethyl (meth) acrylate, 2- (4-propylphenyl) ethyl (meth) acrylate, 2- (4- (1-methylethyl) phenyl) ethyl (meth) acrylate, 2- (4 -Methoxyphenyl) ethyl (meth) acrylate, 2- (4-cyclohexylphenyl) ethyl (meth) acrylate, 2- (2-chlorophenyl) ethyl (meth) acrylate, 2- (3-chlorophenyl ) Ethyl (meth) acrylate, 2- (4-chlorophenyl) ethyl (meth) acrylate, 2- (4-bromophenyl) ethyl (meth) acrylate, 2- (3-phenylphenyl) ethyl (meth ) Acrylate, benzyl (meth) acrylate and 2- (4-benzyloxy-phenyl and the like), ethyl (meth) acrylate may be used, it not limited to these. These may be used alone or in combination of two or more. The aromatic (meth) acrylate may be included in 0.1 to 20% by weight, preferably 0.1 to 10% by weight, more preferably 0.5 to 7% by weight of the (meth) acrylic copolymer. Excellent durability in the above range, there is an advantage that the adhesive force increases.

When the alicyclic (meth) acrylate and the aromatic (meth) acrylate are applied simultaneously, it is preferable to use more content of the alicyclic (meth) acrylate. In this case, the modulus and peel strength are excellent.

Examples of the monomer having a hydroxy group include 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and 2-hydroxybutyl (meth). Acrylate, 6-hydroxyhexyl (meth) acrylate, 1,4-cyclohexanedimethanol mono (meth) acrylate, chloro-2-hydroxypropyl acrylate, diethylene glycol mono (meth) acrylate, allyl Alcohol, and the like, but is not necessarily limited thereto. These may be used alone or in combination of two or more. The monomer having a hydroxyl group may be included in 0.5 to 25% by weight of the (meth) acrylic copolymer. In the above range, there is an advantage that the adhesive strength is increased, and the durability reliability at high temperature and high humidity is improved.

The (meth) acrylic copolymer may be polymerized by adding other copolymerizable monomers in addition to the above-mentioned monomers. For example, monomers having a birefringence in an amount other than the aromatic (meth) acrylate may also be added and polymerized as necessary.

In other embodiments acrylic acid may be used in the range of 3% by weight or less, preferably 2% by weight or less.

The (meth) acrylic copolymer is polymerized after the initiator is added to the monomer components, and the polymerization produces a viscous liquid having a viscosity of about 1000 to 2500 cp at 25 ° C. of the (meth) acrylic copolymer. Coating is easy in the viscosity range, there is an advantage in forming the coating film.

The (meth) acrylic copolymer may have a weight average molecular weight of 1.5 million to 3 million g / mol. There is an advantage of showing excellent durability in the above range.

The (meth) acrylic copolymer may have a glass transition temperature (Tg) of -50 to 0 ° C, preferably -40 to -15 ° C. There is an advantage in the adhesive strength and durability in the above range.

The (meth) acrylic copolymer of the present invention does not require a step of dissolving in a separate solvent during the coating step. That is, since it is applied as a solvent-free process, not only the process is easy and the coating process is easy, but also the manufacture of the adhesive film of the thick thickness of 100 micrometers-2 mm is possible.

The initiator may preferably be applied to a photoinitiator. The photoinitiator is activated by ultraviolet rays or electron beams to activate a carbon-carbon double bond in the adhesive film to generate a radical reaction. Specific examples include, but are not limited to, alpha-hydroxy ketone type compounds, benzyl ketal type compounds, and mixtures thereof. Hydroxy-2-methyl-1-phenyl-1-propanone, 2-hydroxy-1- [4- (2-hydroxyethoxy) phenyl] -2-methyl-1-propanone, and the like. These photoinitiators may be used alone or in combination of two or more. The photoinitiator may be applied to 0.01 to 3 parts by weight, preferably 0.1 to 1 parts by weight based on 100 parts by weight of the (meth) acrylic copolymer. Excellent durability in the above range can be obtained.

Cross-linking agent

The (meth) acrylic copolymer may be mixed with a crosslinking agent to form an adhesive composition.

As the crosslinking agent, a polyfunctional (meth) acrylate capable of curing with an active energy ray may be preferably used.

In a specific example, the polyfunctional (meth) acrylate is 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol 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, tricyclodecanedimethanol (meth) acrylate, dimethylol Dicyclopentanedi (meth) acrylate, ethylene oxide modified hexahydrophthalic acid di (meth) acrylate, tricyclodecane dimethanol (meth) acrylate, neopentylglycol modified trimeth Bifunctional such as propane di (meth) acrylate, adamantane di (meth) acrylate or 9,9-bis [4- (2-acryloyloxyethoxy) phenyl] fluorene Sex acrylates; 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; Pentafunctional acrylates such as dipentaerythritol penta (meth) acrylate; And dipentaerythritol hexa (meth) acrylate, caprolactone-modified dipentaerythritol hexa (meth) acrylate or urethane (meth) acrylate (e.g., an isocyanate monomer and trimethylolpropane tri Hexafunctional acrylates such as acrylonitrile-butadiene-acrylonitrile-butadiene-acrylonitrile, and the like, but are not limited thereto. They may be used alone or in combination of two or more.

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

In the present invention, the content of the crosslinking agent is 0.01 to 5 parts by weight, preferably 0.1 to 3 parts by weight, more preferably 0.5 to 2 parts by weight based on 100 parts by weight of the (meth) acrylic copolymer.

Since the pressure-sensitive adhesive composition prepared as above does not contain an acid component such as (meth) acrylic acid, the acid value is zero.

Oligomeric siloxane

The oligomeric siloxane used in the present invention has a structure represented by the following general formula (1):

[Chemical Formula 1]

(In the above, R1, R2 and R3 are each independently an alkyl group having 1 to 5 carbon atoms, R4 and R5 are each independently an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms, n is a 3-25 Integer, m is an integer from 1 to 10)

Preferably R 1, R 2 and R 3 may be methyl, ethyl or propyl groups.

The oligomeric siloxane may have a viscosity of 25 to 15 cps, preferably 20 to 35 cps.

The oligomeric siloxane may have a refractive index of 1.4 to 1.5. It can be suitably applied to the optical member in the above range.

In addition, the oligomeric siloxane may have an alkoxy group content in the molecule of 30 to 60% by weight, preferably 35 to 55% by weight. It has excellent durability, adhesion and reworkability in the above range.

The oligomeric siloxane may have an epoxy equivalent of 250 to 450 g / mol, preferably 300 to 400 g / mol. It has excellent adhesion and re-peelability in the above range.

In the present invention, the content of the oligomeric siloxane is 0.01 to 5 parts by weight, more preferably 0.1 to 1 part by weight based on 100 parts by weight of the (meth) acrylic copolymer. In the above range, the substrate adhesion and durability, long-term storage characteristics are good.

The pressure-sensitive adhesive composition may optionally contain a silane coupling agent, a curing accelerator, an ionic liquid, a lithium salt, an inorganic filler, a softener, an antioxidant, an antioxidant, a stabilizer, a tackifying resin, and a modified resin (polyol resin, phenol resin, acrylic). Resins, polyester resins, polyolefin resins, epoxy resins, epoxidized polybutadiene resins, and the like), leveling agents, antifoaming agents, plasticizers, dyes, pigments (colored pigments, extender pigments, etc.), treatment agents, sunscreen agents, fluorescent whitening agents, Conventional additives such as dispersants, heat stabilizers, light stabilizers, ultraviolet absorbers, antistatic agents, lubricants and solvents may be further included.

The pressure-sensitive adhesive film of the present invention may be formed by curing the pressure-sensitive adhesive composition. For example, the pressure-sensitive adhesive composition may be coated on a release film and then UV cured. In embodiments, the UV curing may be performed at 1 ~ 50mw / cm 2 conditions.

The coating thickness is not particularly limited, and may form an adhesive layer having a thickness of 100 μm to 2 mm, for example, 150 μm to 1.5 mm. In addition, it may be preferably cured in a state in which oxygen is blocked during curing.

The adhesive film has a resistance change (ΔR) represented by the following Equation 1 is less than 5%, preferably less than 2%:

[Equation 1]

In the above formula, P ₂ is the resistance after standing for 240 hours at 60 ℃ / 90% relative humidity conditions, P ₁ is the initial resistance.

The adhesive film may contain an oligomeric siloxane represented by Chemical Formula 1 and have a modulus of 1 × 10 ⁵ to 1 × 10 ⁷ dyne / cm ² by a frequency sweep test at 30 ° C. and 1 Hz.

The adhesive film may have a peel strength of 1950 to 3000 gf / 25 mm.

Another aspect of the present invention relates to a display member. Wherein the display member comprises: an optical film; And the adhesive film attached to one or both surfaces of the optical film. The optical film may include a polarizing plate, a color filter, a retardation film, an elliptical polarizing film, a reflection film, an antireflection film, a compensation film, a brightness enhancement film, an alignment film, a light diffusion film, a glass scattering prevention film, a surface protection film, a plastic LCD substrate, ITO film etc. are mentioned. 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 can be formed by attaching a touch pad to a window or an optical film using the adhesive film.

Or it may be applied as an adhesive film to a conventional polarizing film as in the prior art.

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

Example

Example  One

75 parts by weight of ethylhexyl acrylate, 10 parts by weight of isobornyl acrylate, 15 parts by weight of hydroxy ethyl acrylate, and Irgacure ™ 651 (2,2-dimethoxy-2-phenylacetophenone) as a photopolymerization initiator ( 0.3 parts by weight of Shiva Japan was mixed in a glass vessel to prepare a mixture. After replacing the dissolved oxygen with nitrogen gas, the mixture was polymerized by irradiation with ultraviolet light using a low pressure lamp (sylvania Lamp BL360) to obtain a (meth) acrylic copolymer having a viscosity of about 1,500 cP. 0.2 parts by weight of HDDA (1,6-hexanediol diacrylate), 0.2 parts by weight of oligomeric siloxane (manufactured by X-41-1059A: Shintsu) as a crosslinking agent, and a polymerization initiator (irga) in the resulting (meth) acrylic copolymer 0.3 weight part of cure 651) was added, and the adhesive composition was prepared. The resulting pressure-sensitive adhesive composition was coated onto a 50 μm thick polyester film (release film) to form an adhesive film with a thickness of 175 μm. In order to remove oxygen which adversely affects the polymerization, a 50 μm thick polyester film (release film) was covered on the adhesive film, and then irradiated with a low pressure lamp (sylvania Lamp BL360) for about 3 minutes on both sides of the release film. To obtain a transparent adhesive film.

Example  2

76 parts by weight of ethylhexyl acrylate, 8 parts by weight of phenoxy ethyl acrylate, and 16 parts by weight of hydroxy ethyl acrylate were used as monomers for preparing the acrylic copolymer, and the content of oligomeric siloxane (X-41-1059A: manufactured by Shintsu) was determined. Except for changing to 1 part by weight, it was carried out in the same manner as in Example 1.

Example  3

As the monomer for producing the acrylic copolymer, 65 parts by weight of ethylhexyl acrylate, 15 parts by weight of isobornyl acrylate, 15 parts by weight of hydroxy ethyl acrylate and 5 parts by weight of phenoxy ethyl acrylate (Adrich Ardrich) were used. It carried out similarly to Example 1 except having changed the content of (X-41-1059A: Shininetsu) to 0.5 weight part.

Comparative Example  One

The same procedure as in Example 1 was performed except that an epoxy silane coupling agent (KBM-403: manufactured by Shintetsu) was applied instead of an oligomeric siloxane (manufactured by X-41-1059A: manufactured by Shintetsu).

Comparative Example  2

The same procedure as in Example 1 was carried out except that acrylic acid was used instead of isobornyl acrylate.

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Acrylic copolymer EHA 75 76 65 75 75 IBOA 10 - 15 10 - HEA 15 16 15 15 15 Aromatic Acryl Monomer - 8 5 - - AA - - - - 10 HDDA 0.2 0.2 0.5 0.2 0.2 Oligomeric siloxane 0.2 One 0.5 - 0.2 Silane coupling agent - - - 0.2 - Manufacturing method UV curing UV curing UV curing UV curing UV curing Resistance change (△%)  <2 <2  <2  <2 5% or more Peel strength 2100 2400 2500 1930 3500 durability O O O △ O Modulus 3 * 10 ⁵ 5 * 10 ⁵ 1 * 10 ⁶ 3 * 10 ⁵ 6 * 10 ⁵

Property evaluation

(1) Resistance change: The prepared adhesive film was attached to ITO PET, and a sample was prepared by forming electrodes using silver paste on both sides. Thereafter, the initial resistance (P1) was measured on the prepared sample, and the sample was left for 240 hours under the condition of 60 ° C / 90% RH, and then the resistance (P2) was measured. At this time, the resistance was measured using a Checkman portable resistance, voltage, and current measuring instrument (made by Taekwang Electronics). Then, the resistance change rate (ΔR) was measured by substituting the resistance value measured under each condition as shown in Equation 1 below:

[Equation 1]

In the above formula, P ₂ is the resistance after standing for 240 hours at 60 ℃ / 90% relative humidity conditions, P ₁ is the initial resistance.

(2) Using a PET film (backing film) having a thickness of 50 μm in peeling strength (gf / 25 mm), the prepared adhesive film was attached to the ITO film, and at 30 minutes after the attachment, TA.XT_Plus Texture Analyzer Peeling force was measured at 300 mm / min speed | rate using (Stable Micro System (made)).

(3) Durability: After bonding PC film / ITO film / Glass and PET film, it is allowed to stand at 60 ^o C / 90% relative humidity for 500 hours, and then there is no lifting or peeling or bubbles on the surface. Observed visually and evaluated by the following criteria.

Good: Good (no bubbles or peeling)

?: Good (bubbles or peeling phenomenon somewhat)

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

(4) Modulus (dyne / cm ² ): by laminating the adhesive layer to prepare a specimen with a diameter of 8mm, 1mm in thickness and the storage elastic modulus was measured by a frequency sweep test at 30 ℃ using a rheometer.

As shown in Table 1, in Examples 1 to 3, while the resistance change is low and the peel strength, durability and modulus are excellent, Comparative Example 1 without applying the oligomeric siloxane was inferior in durability and peel strength, and IBOA Instead, Comparative Example 2 containing acrylic acid can be seen that the resistance change significantly increased.

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 (22)

(Meth) acrylic copolymers;
An oligomeric siloxane represented by Formula 1 below; And
A crosslinking agent;
Wherein the (meth) acrylic copolymer comprises an alicyclic, aromatic, or a combination thereof;
[Chemical Formula 1]

(In the above, R1, R2 and R3 are each independently an alkyl group having 1 to 5 carbon atoms, R4 and R5 are each independently an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms, n is a 3-25 Integer, and m is an integer of 1 to 10).

The pressure-sensitive adhesive composition of claim 1, wherein the (meth) acrylic copolymer has a glass transition temperature of -50 to 0 ° C.
The method of claim 1, wherein the (meth) acrylic copolymer is the copolymer of a monomer mixture comprising a C _{1 -20} alkyl (meth) acrylate, alicyclic or aromatic (meth) acrylate and hydroxyl group-containing monomer Adhesive composition characterized by.
4. The method of claim 3 wherein the (meth) acrylic copolymers are (meth) acrylate 60 to 95% by weight, and alicyclic or aromatic (meth) acrylate, 0.1 to 20% by weight, and the hydroxyl groups of C _{1 -20} It is a copolymer of the monomer mixture containing 0.5-25 weight% of monomer containing, The adhesive composition characterized by the above-mentioned.
The method of claim 1, wherein the (meth) acrylic copolymers are (meth) acrylate 60 to 95% by weight of C _{1 -20,} cycloaliphatic-containing (meth) acrylate, 0.5 to 20% by weight, hydroxyl group-containing monomer A pressure-sensitive adhesive composition, characterized in that it is a copolymer of a monomer mixture comprising 0.5 to 25% by weight and 0.1 to 10% by weight of aromatic-containing (meth) acrylate.
The pressure-sensitive adhesive composition of claim 1, wherein the (meth) acrylic copolymer has a viscosity of 1000 to 2500 cps at 25 ° C.
The pressure-sensitive adhesive composition of claim 1, wherein the oligomeric siloxane has a refractive index of 1.4 to 1.5.
The pressure-sensitive adhesive composition of claim 1, wherein the oligomeric siloxane has an alkoxy group content in the molecule of 30 to 60 wt%.
The pressure-sensitive adhesive composition of claim 1, wherein the oligomeric siloxane has an epoxy equivalent weight of 250 to 450 g / mol.
The pressure-sensitive adhesive composition of claim 1, wherein the pressure-sensitive adhesive composition has an acid value of zero.
According to claim 1, wherein the pressure-sensitive adhesive composition is a (meth) acrylic copolymer 100 parts by weight; 0.01 to 5 parts by weight of the oligomeric siloxane; And 0.01 to 5 parts by weight of a crosslinking agent.
The adhesive film formed by hardening | curing the adhesive composition of any one of Claims 1-11.
An adhesive film containing an oligomeric siloxane represented by the following Chemical Formula 1 and having a modulus of 1 × 10 ⁵ to 1 × 10 ⁷ dyne / cm ² at 30 ° C. and 1 Hz:
[Chemical Formula 1]

(In the above, R1, R2 and R3 are each independently an alkyl group having 1 to 5 carbon atoms, R4 and R5 are each independently an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms, n is a 3-25 Integer, and m is an integer of 1 to 10).
The pressure-sensitive adhesive film of claim 13, wherein the pressure-sensitive adhesive film contains (meth) acrylate containing alicyclic, aromatic, or a combination thereof.
The pressure-sensitive adhesive film of claim 13, wherein the pressure-sensitive adhesive film has a resistance change ΔR of less than 5% represented by Equation 1 below:

[Equation 1]

In the above formula, P ₂ is the resistance after standing for 240 hours at 60 ℃ / 90% relative humidity conditions, P ₁ is the initial resistance.
The pressure-sensitive adhesive film of claim 13, wherein the pressure-sensitive adhesive film has a thickness of 100 μm to 2 mm.
The pressure-sensitive adhesive film of claim 13, wherein the pressure-sensitive adhesive film has a peel strength of 1950 to 3000 gf / 25 mm.
By polymerizing the alkyl (meth) acrylate, cycloaliphatic, aromatic or a monomer mixture comprising a (meth) acrylate and hydroxyl group-containing monomer containing a combination of the C _{1 -20} (meth) acrylic copolymer Preparation of and;
Preparing a pressure-sensitive adhesive composition by mixing a crosslinking agent and an oligomeric siloxane represented by the following Formula 1 to the (meth) acrylic copolymer; And
UV curing the pressure-sensitive adhesive composition;
Method of producing an adhesive film comprising the steps:
[Chemical Formula 1]

(In the above, R1, R2 and R3 are each independently an alkyl group having 1 to 5 carbon atoms, R4 and R5 are each independently an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms, n is a 3-25 Integer, and m is an integer of 1 to 10).
19. The method according to claim 18, wherein the (meth) acrylic copolymer does not include a solvent and has a viscosity of 1000 to 2500 cps at 25 ° C.
Optical film; And
The pressure-sensitive adhesive film of any one of claims 13 to 17 attached to one or both sides of the optical film;
Display member comprising a.
The display member of claim 20, wherein the optical film is a polarizing film.
21. The display member according to claim 20, wherein the optical film is an ITO film.