KR20170099441A - Adhesive composition for optical use and the adhesive film for optical use - Google Patents

Abstract

The present invention relates to an adhesive composition for optical uses, showing high barrier performance with respect to moisture and oxygen based on low vapor permeability by being applied to optical devices or display devices, and realizing excellent adhesive performance and optical properties. More specifically, provided is an adhesive composition for optical uses, comprising: isobutyrene-isoprene rubber containing a polar functional group; and a silane coupling agent chemically coupled to the polar functional group. Moreover, provided is an adhesive film for optical uses comprising an adhesive layer containing cured material of the adhesive composition for optical uses.

Description

TECHNICAL FIELD [0001] The present invention relates to a pressure-sensitive adhesive composition for optical use and a pressure-

The present invention relates to a pressure-sensitive adhesive composition for optical use and a pressure-sensitive adhesive film for optical use, wherein the pressure-sensitive adhesive composition for optical use and the pressure-sensitive adhesive film for optical use are capable of curing sulfur- or halogen- , Moisture permeability and adhesive performance, and consequently impart excellent optical characteristics and durability to the optical device.

Touch materials, including packaged electronic devices or transparent conductive films, require excellent touch sensitivity for excellent operation. Further, in recent years, much attention has been focused on the development of pressure-sensitive adhesive compositions for improving the durability and optical characteristics of devices such as OLED or touch screen panels.

Generally, a pressure-sensitive adhesive used for an OLED or a touch screen panel should have optical properties such as transparency and visibility. To this end, a pressure sensitive adhesive containing acrylic resin as a base resin has been generally used. However, it needs to be supplemented in terms of touch sensitivity, and at the same time, it is important to secure suitable modulus and optical properties.

Also, pressure-sensitive adhesives using a rubber-based resin have been developed to compensate for the disadvantages of acrylic resins. For example, Korean Patent Laid-Open Publication No. 2014-0050956 discloses a pressure-sensitive adhesive composition comprising a rubber- No. 2014-0049278 also discloses the use of a butyl rubber-based polymer to lower the moisture permeability.

However, in the case of a pressure-sensitive adhesive containing a rubber-based resin as a base resin, it is difficult to perform chemical crosslinking through a curing process, and physical crosslinking must be used. As a result, it is difficult to form a cured or crosslinked structure for ensuring sufficient durability. Also, application of the final product may thus be limited.

One embodiment of the present invention provides an optical pressure-sensitive adhesive composition comprising a rubber capable of chemically crosslinking through an appropriate curing process, resulting in excellent long-term durability, moisture resistance and chemical resistance, and excellent optical properties .

Another embodiment of the present invention provides an adhesive film for optical use which is capable of chemical crosslinking and curing of the rubber itself, realizing excellent durability when applied to an electronic device, excellent in optical characteristics, and improved in adhesive property and moisture permeability.

In one embodiment of the invention, the polar functional group-containing isobutylene-isoprene rubber; And a silane coupling agent chemically bonded to the polar functional group.

In another embodiment of the present invention, there is provided an optical adhesive film having a pressure-sensitive adhesive layer containing a cured product of the optical pressure-sensitive adhesive composition.

The optical pressure-sensitive adhesive composition for optical application imparts excellent moisture resistance and chemical resistance to optical devices or electronic devices to which the optical pressure-sensitive adhesive composition is applied, and can realize excellent long-term durability and optical characteristics.

In addition, the optical adhesive film can be applied to various electronic devices as compared with the conventional adhesive film using an acrylic resin or a rubber-based resin as a base resin, and can exhibit excellent adhesion and long-term reliability.

1 schematically shows a cross section of an optical adhesive film according to an embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other features and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which: These embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art to which the invention pertains. Only. Like reference numerals refer to like elements throughout the specification.

In the drawings, the thickness is enlarged to clearly represent the layers and regions. In the drawings, for the convenience of explanation, the thicknesses of some layers and regions are exaggerated.

It will also be understood that when a layer, film, region, plate, or the like is referred to as being "on" or "over" another portion, . Conversely, when a part is "directly over" another part, it means that there is no other part in the middle. In addition, when a layer, film, region, plate, or the like is referred to as being "under" or "under" another portion, . Conversely, when a part is "directly underneath" another part, it means that there is no other part in the middle.

In one embodiment of the invention, the polar functional group-containing isobutylene-isoprene rubber; And a silane coupling agent chemically bonded to the polar functional group.

The pressure-sensitive adhesive composition for optical use is a pressure-sensitive adhesive composition used in an optical device, and can be used, for example, in an organic light emitting device (OLED) or the like to perform a sealing function for blocking moisture and oxygen introduced from the outside. Thus, the ability to block moisture and oxygen is referred to as barrier performance. In general, an optical adhesive uses an acrylate resin as a base resin rather than a rubber for optical properties, and a rubber resin may be more advantageous in terms of improving barrier performance.

The rubber used in conventional pressure sensitive adhesives proceeds through physical crosslinking through thermosetting or photo-curing based on sulfur, or by substituting halogen in the rubber itself. Alternatively, the rubber is contained as a method of mixing the photo-curable monomer together with rubber in the pressure-sensitive adhesive and curing the photo-curable monomer by light irradiation.

When sulfur or halogen components are used in the pressure-sensitive adhesive, problems such as corrosion may be caused when the pressure-sensitive adhesive is applied to the final electronic product, so that the application range is narrow. In the case of using the photo-curable monomer, There was a problem in that the durability was not good.

On the other hand, the optical pressure-sensitive adhesive composition for optical use can be thermally cured by itself by using a chemically modified rubber, and the above-mentioned problems can be solved.

The optical pressure-sensitive adhesive composition for optical use includes a rubber having a polar functional group through chemical modification, and may specifically include an isobutylene-isoprene rubber having a polar functional group. The optical pressure-sensitive adhesive composition for optical use can further improve the barrier performance by using an isobutylene-isoprene rubber, and by using an isobutylene-isoprene rubber containing a polar functional group per se, Or a halogen component, there is no risk of corrosion, and as a result, excellent long-term durability and optical characteristics can be realized.

In addition, the optical pressure-sensitive adhesive composition for optical use includes a silane coupling agent chemically bonded to the polar functional group together with a polar functional group-containing isobutylene-isoprene rubber.

Generally, the silane coupling agent used in the pressure-sensitive adhesive is simply dispersed and mixed in the pressure-sensitive adhesive composition. In this case, the silane coupling agent is free to move in the pressure-sensitive adhesive composition and causes the durability of the pressure-sensitive adhesive to move to the surface of the pressure-sensitive adhesive within a relatively low glass transition temperature. Therefore, there has been a limitation that only a very small amount can be used in order to prevent durability deterioration.

In one embodiment, the optical pressure-sensitive adhesive composition includes the silane coupling agent chemically bonded to the polar functional group of the isobutylene-isoprene rubber, so that the silane coupling agent, which is simply dispersed and mixed in the composition, It is possible to prevent the durability from being lowered even if a large amount is used, and at the same time, the moisture permeation preventing effect and the adhesive force improving effect can be greatly improved.

The polar functional group-containing isobutylene-isoprene rubber is a rubber modified such that the isobutylene-isoprene rubber has a polar functional group. For example, the polar functional group may be a hydroxyl group, a carboxyl group, an amine group, An aldehyde group, an epoxy group, a maleic anhydride group, an amide group, and combinations thereof.

In one embodiment, the polar functional group may comprise a hydroxy group or a carboxyl group, in which case it is easy to chemically bond with the silane coupling agent and can greatly improve barrier performance.

The polar functional group may be grafted to the isoprene unit of the isobutylene-isoprene rubber. That is, the polar functional group is introduced not in an isobutylene unit but in an isoprene unit, thereby minimizing the degree of unsaturation of the rubber component. As a result, the moisture resistance and viscoelastic property can be improved, and the yellowing phenomenon can be prevented .

In addition, the polar functional group can be evenly distributed in the rubber chain by being grafted to the isoprene unit, and as a result, efficient crosslinking is possible, and long-term durability and stable physical properties of the final film can be realized.

Specifically, the polar functional group-containing isobutylene-isoprene rubber may have a degree of unsaturation of from 0 to 30, and may be, for example, from 0 to 3, for example, . The 'degree of unsaturation' refers to the degree to which multiple bonds are included in the chemical structure, and can be measured using NMR or IR. More specifically, the degree of unsaturation may be determined by measuring the degree of unsaturation of a multiple bond in the chemical structure of the isobutylene- Means number. The optical pressure-sensitive adhesive composition for optical use can improve moisture resistance and viscoelastic property by using a rubber having an unsaturation degree in the above range, and can prevent yellowing, and can realize excellent weather resistance and durability.

The isobutylene-isoprene rubber may be a copolymer formed from a monomer mixture comprising about 70 mole% to about 99 mole% of isobutylene and about 1 mole% to about 30 mole% of isoprene. In addition, the polar functional groups may be introduced via chemical modification to such isobutylene-isoprene rubber. In the isobutylene-isoprene rubber, when the content of isobutylene is less than about 70 mol% and the content of isoprene is more than about 30 mol%, the moisture permeability and gas permeability of the optical pressure- There is a possibility of corrosion of the electronic device to which this is applied. When the content of isobutylene is more than about 99 mol% and the content of isoprene is less than about 1 mol%, it is difficult to sufficiently introduce a polar functional group into the isobutylene-isoprene rubber. Therefore, There is a fear that it will not improve sex.

The isobutylene-isoprene rubber having a polar functional group may have a weight average molecular weight (Mw) of about 10,000 to about 100, for example, about 200,000 to about 70. [ Since the optical pressure-sensitive adhesive composition for optical use contains a rubber having a weight average molecular weight (Mw) in the above range, a physical entanglement site due to the crosslinking structure after curing can be sufficiently secured, Can be provided to provide excellent compatibility. In addition, the optical pressure-sensitive adhesive composition for optical use can be obtained by using a rubber having a weight average molecular weight (Mw) within the above range as a base component, thereby securing an appropriate viscosity and producing an adhesive film or an adhesive sheet without problems such as dewetting Coating properties can be exhibited.

The isobutylene-isoprene rubber having polar functional groups may contain from about 0.5% to about 30% by weight of polar functional groups. That is, the polar functional group-containing isobutylene-isoprene rubber may comprise from about 0.5% to about 30% by weight of polar functional groups in its total weight, for example from about 1% to about 5% have. By introducing the polar functional group into the isobutylene-isoprene rubber in the above range, it is possible to form an appropriate crosslinking density in the curing process of the optical pressure-sensitive adhesive composition and to realize excellent durability.

The optical pressure-sensitive adhesive composition includes a silane coupling agent chemically bonded to the polar functional group together with the polar functional group-containing isobutylene-isoprene rubber. The silane coupling agent can significantly improve the moisture permeability of the optical pressure-sensitive adhesive composition.

Specifically, the silane coupling agent includes a reactive functional group that chemically bonds with the polar functional group; And alkoxy groups. The silane coupling agent is chemically bonded to the polar functional isobutylene-isoprene rubber contained in the optical pressure-sensitive adhesive composition by containing both the reactive functional group and the alkoxy group, and at the same time, chemically bonded to the substrate to which the optical pressure- It is possible to realize a greatly improved moisture permeability.

The reactive functional group of the silane coupling agent is a functional group that chemically reacts with and reacts with the polar functional group of the isobutylene-isoprene rubber. Examples of the functional group include an isocyanate group, a mercapto group, a vinyl group, an epoxy group, an amino group, Time, and combinations thereof.

In one embodiment, the reactive functional group of the silane coupling agent may comprise an isocyanate group, and the polar functional group of the isobutylene-isoprene rubber may include a hydroxy group or a carboxyl group.

In another embodiment, the reactive functional group of the silane coupling agent may comprise an epoxy group, and the polar functional group of the isobutylene-isoprene rubber may comprise an amino group or a hydroxy group.

In another embodiment, the reactive functional group of the silane coupling agent may comprise a (meth) acryloxy group, and the polar functional group of the isobutylene-isoprene rubber may comprise a (meth) acrylate group.

In addition, the silane coupling agent includes an alkoxy group having an -OR chemical structure together with the reactive functional group. R in the alkoxy group may be a straight or branched alkyl group of C1 to C10, and may be, for example, a methyl group, an ethyl group, an isopropyl group, a propyl group, a butyl group or a pentyl group. The alkoxy group of the silane coupling agent serves to catch moisture introduced into the interface between the optical pressure-sensitive adhesive composition and the substrate to which it is applied, thereby greatly enhancing the moisture permeability. The pressure-sensitive adhesive layer formed by the optical pressure- Thereby improving the adhesion between the substrate and the substrate.

That is, the optical pressure-sensitive adhesive composition for optical use can improve interfacial adhesion with an adherend by including an isobutylene-isoprene rubber modified to contain a polar functional group and a silane coupling agent chemically bonded to the polar functional group, It is possible to realize excellent barrier performance.

The optical pressure-sensitive adhesive composition for optical use may contain about 0.02 to about 8 parts by weight of the silane coupling agent per 100 parts by weight of the isobutylene-isoprene rubber containing the polar functional group. For example, about 1 to about 4 parts by weight . The optical pressure-sensitive adhesive composition of the present invention contains the silane coupling agent in a content ratio within the above range, so that the polar functional group of the rubber and the reactive functional group of the silane coupling agent can form a chemical bond with an appropriate distribution, The effect of improving the property can be maximized.

The optical pressure-sensitive adhesive composition for optical use may further comprise, if necessary, one selected from the group consisting of a curing agent, a reaction promoter, a curing retarder, an adhesion promoter, an oxidation stabilizer, and combinations thereof.

The curing agent is a compound capable of chemically bonding with the polar functional group of the isobutylene-isoprene rubber, whereby the optical pressure-sensitive adhesive composition can be cured to have a proper degree of curing. For example, when the isobutylene-isoprene rubber contains a hydroxy group or a carboxyl group as a polar functional group, the curing agent may include an isocyanate curing agent, and in this case, a chemical reaction with the isobutylene- .

When the optical pressure-sensitive adhesive composition comprises a curing agent, the curing agent may be included in an amount of about 0.05 to about 5 parts by weight based on 100 parts by weight of the isobutylene-isoprene rubber having the polar functional group. By incorporating the curing agent in the above range in the content of the optical pressure-sensitive adhesive composition for optical, it is possible to realize a suitable crosslinking density and curing degree at the time of curing.

The reaction promoter is used for rapidly promoting the chemical reaction between the curing agent and the polar functional group of the isobutylene-isoprene rubber. Specifically, the reaction promoter includes a tin catalyst, a bismuth catalyst, . ≪ / RTI > When the reaction accelerator of the above kind is used, the crosslinking reaction between the curing agent and the polar functional group of the rubber can proceed rapidly, and the curing efficiency of the optical pressure-sensitive adhesive composition can be improved.

When the optical pressure-sensitive adhesive composition comprises the reaction promoter, the reaction promoter may be included in an amount of about 0.01 to about 5 parts by weight based on 100 parts by weight of the polar functional group-containing isobutylene-isoprene rubber. By including the reaction promoter in the above range, the crosslinking reaction rate between the silane coupling agent and the polar functional group can be efficiently improved without causing unnecessary side reactions, which can be economically advantageous. For example, when the reaction accelerator is used in an excessive amount, the reaction speed is excessively fast, resulting in partial gelation and difficulty in producing a uniform film.

The curing retarder serves to inhibit the reaction of the final pressure-sensitive adhesive composition to the stage before the film coating, and may specifically include a ketone-based curing retardant. When the above-mentioned curing retardant is used, the stability of the final pressure-sensitive adhesive composition can be maintained, and an advantage that the pot-life to the stage before film coating is sufficiently secured can be obtained.

When the optical pressure-sensitive adhesive composition comprises the curing retarder, the curing retardant may be included in an amount of about 0.01 to about 5 parts by weight based on 100 parts by weight of the polar functional group-containing isobutylene-isoprene rubber. By incorporating the curing retarder in the above range, it is possible to obtain an effect of preventing gelation of the final blended composition. Further, when the curing retardant is used in an excessive amount There is a fear that the curing reaction of the pressure-sensitive adhesive composition is disturbed and effective crosslinking can not be achieved.

Since the optical pressure-sensitive adhesive composition for optical use contains a rubber component, moisture permeability is low and excellent barrier performance can be achieved, but sufficient peeling force and adhesive force can not be secured. Therefore, if necessary, it may further include a tackifier.

 For example, the adhesion promoter may be selected from the group consisting of hydrogenated dicyclopentadiene compounds, hydrogenated terpene compounds, hydrogenated rosin compounds, hydrogenated aromatic compounds, hydrogenated petroleum based compounds, and combinations thereof . ≪ / RTI > The adhesion-promoting agent can be advantageous for realizing transparency by including a compound having a hydrogenated structure, and is less influenced by thermal energy at the time of thermal curing, so that excellent adhesion and peeling force can be realized.

For example, the adhesion-promoting agent may include a hydrogenated dicyclopentadiene-based compound or a hydrogenated rosin-based compound, and in this case, particularly, an effect that tack performance is imparted and optical properties such as light transmittance and haze are improved Can be obtained.

The hydrogenated tackifier may be partially hydrogenated or fully hydrogenated. Specifically, the hydrogenated tackifier can have a hydrogenation rate of about 60% or more, for example, 100%. When the hydrogenation rate is less than about 60%, the pressure-sensitive adhesive layer containing a large amount of double bonds in the molecule may lower the visibility and transparency of the pressure-sensitive adhesive composition. As the tendency of the double bonds to absorb heat energy increases There is a problem that when the thermal energy for curing is irradiated, it is absorbed and, as a result, the tackiness and the peeling force become uneven.

Further, the tackifier may have a softening point of about 80 캜 to about 150 캜, specifically about 80 캜 to about 130 캜, and more specifically about 100 캜 to about 120 캜. 'Softening point' refers to the temperature at which, when heat is applied to a material, it begins to deform or soften by heat. If the softening point of the pressure-sensitive adhesive is less than about 80 캜, the pressure-sensitive adhesive may soften at a relatively low temperature, thereby deteriorating the high-temperature reliability of the pressure-sensitive adhesive containing the pressure-sensitive adhesive. And if it exceeds 150 ° C, it is difficult to realize the effect of improving the tackiness of the pressure-sensitive adhesive at room temperature, and there is a concern that the pressure-sensitive adhesive may become hard due to the addition of a small amount of the pressure- have.

When the optical pressure-sensitive adhesive composition includes the tackifier, the tackifier may be included in an amount of about 10 to about 70 parts by weight based on 100 parts by weight of the polar functional group-containing isobutylene-isoprene rubber. By using the tackifier in the content within the above range, the peeling force to the substrate can be effectively improved without lowering the moisture permeability of the optical pressure-sensitive adhesive composition.

In another embodiment of the present invention, there is provided an optical adhesive film comprising a pressure-sensitive adhesive layer containing a cured product of the optical pressure-sensitive adhesive composition.

The optical adhesive film is applied to an optical device such as a display, an electronic device, and an organic light emitting diode (OLED), and can realize excellent optical characteristics and barrier performance simultaneously through a pressure-sensitive adhesive layer containing a cured product of the optical pressure- .

The pressure-sensitive adhesive layer may include a cured product of the optical pressure-sensitive adhesive composition, and the cured product may be a thermosetting product produced by applying heat energy to the optical pressure-sensitive adhesive composition for curing.

The gel content of the pressure-sensitive adhesive layer may be about 55 wt% to about 100 wt%, for example, about 60 wt% to about 90 wt%. When the gel content satisfies the above range, the pressure-sensitive adhesive layer can exhibit excellent level difference absorbability and adhesion, and can be applied to an optical device to realize excellent durability and barrier performance.

The pressure-sensitive adhesive layer can be produced from the optical pressure-sensitive adhesive composition for a high degree of peeling force against the substrate and exhibit low moisture permeability. For example, the pressure-sensitive adhesive layer may have a peel force with respect to the glass substrate of about 1000 g / in or more, specifically about 1500 g / in to about 2800 g / in, and more specifically about 1900 g / Lt; / RTI >

At the same time, the pressure-sensitive adhesive layer may have a water vapor permeability (WVTR) of 10 g / m 2 24 hr or less, for example, about 5 g / m 2 24 hr or less, for example, about 3 g / m 2 24 hr or less, For example, it may be less than about 0 g / m < 2 > 24hr and less than about 3 g / m < 2 > The pressure-sensitive adhesive layer can simultaneously exhibit the peeling force and the moisture-permeability in the above-described range through the optical pressure-sensitive adhesive composition. As a result, the optical pressure-sensitive adhesive film containing the pressure-sensitive adhesive layer is applied to a display or an electronic device or the like to provide excellent barrier performance and durability Can be displayed at the same time.

Further, the pressure-sensitive adhesive layer may have a light transmittance of not less than about 90%, for example, not less than about 92%, and a haze of less than about 2%, for example, less than about 1%. The pressure-sensitive adhesive layer satisfies the light transmittance and haze in the above-described range, and thus can be usefully applied to parts requiring a visibility of a display or an electronic device, and visibility can be improved based on excellent optical characteristics.

The pressure-sensitive adhesive layer is formed from the optical pressure-sensitive adhesive composition, and may be most preferable when the gel content, the peeling force for the glass substrate, the moisture permeability, the light transmittance and the haze are all satisfied simultaneously in the respective ranges described above. This can be achieved by controlling the interaction of the rubber and the silane coupling agent contained in the optical pressure-sensitive adhesive composition.

1 schematically shows a cross section of an optical adhesive film 100 according to an embodiment of the present invention. Referring to FIG. 1, the optical adhesive film 100 may include a release film layer 110 including the pressure-sensitive adhesive layer 120 and laminated on one side or both sides of the pressure-sensitive adhesive layer 120 .

The release film layer may be formed on both sides or one side of the pressure-sensitive adhesive layer depending on the position of the pressure-sensitive adhesive layer in the final product when the optical pressure-sensitive adhesive film is applied to the final product .

The release film layer may have a structure in which a releasing agent is coated on one side of the base film. At this time, the release film layer may be disposed so that the surface coated with the release agent is in contact with the pressure-sensitive adhesive layer.

Here, the base film is not particularly limited. For example, a polyethylene terephthalate (PET) film may be used to facilitate the distribution and cutting of the optical pressure-sensitive adhesive film without being damaged during curing of the optical pressure- Can be used.

The releasing agent is not particularly limited, and for example, a releasing agent having a releasing force of about 7 g / 2 in to about 50 g / 2 in for the pressure-sensitive adhesive layer may be used. In this case, the releasing film layer can secure a sufficient peeling force with the pressure-sensitive adhesive layer formed from the optical pressure-sensitive adhesive composition, and can be peeled off without residue from the surface of the pressure-sensitive adhesive layer, .

Hereinafter, specific embodiments of the present invention will be described. However, the embodiments described below are only intended to illustrate or explain the present invention, and thus the present invention should not be limited thereto.

< Manufacturing example >

Manufacturing example  1: Preparation of isobutylene-isoprene rubber having a hydroxy group

An isobutylene-isoprene rubber which is a copolymer formed from a monomer mixture comprising 1.7 mol% of isoprene and 98.3 mol% of isobutylene was prepared. 3 parts by weight of peroxide (mCPBA) relative to 100 parts by weight of the isobutylene-isoprene rubber was charged into a 2 L reactor equipped with a cooling device to easily regulate the temperature of the nitrogen gas, and the mixture was stirred at 30 ° C for 6 hours. Then, 3.1 parts by weight of a 1N hydrochloric acid aqueous solution was added to 100 parts by weight of the rubber, and the mixture was stirred at 30 ° C for 1 hour, then heated to 90 ° C and stirred for 1 hour. Thus, an isobutylene-isoprene rubber (IIR-OH) having a hydroxyl group grafted to an isoprene unit in the main chain was prepared.

Manufacturing example  2: Preparation of isobutylene-isoprene rubber having carboxyl group

An isobutylene-isoprene rubber which is a copolymer formed from a monomer mixture comprising 1.7 mol% of isoprene and 98.3 mol% of isobutylene was prepared. 3 parts by weight of maleic anhydride and 3 parts by weight of dibenzoyl peroxide were added to 100 parts by weight of the isobutylene-isoprene rubber in a 2 L reactor equipped with a cooling device to regulate the temperature of the nitrogen gas, , And the mixture was stirred at 60 ° C to 80 ° C for 5 hours. Then, 3.1 parts by weight of a 1N hydrochloric acid aqueous solution was added to 100 parts by weight of the rubber, and the mixture was stirred at 30 ° C for 1 hour, then heated to 90 ° C and stirred for 1 hour. Thus, an isobutylene-isoprene rubber (IIR-COOH) having a carboxyl group grafted to an isoprene unit in the main chain was prepared.

< Example  And Comparative Example >

Example  One

3 parts by weight of a silane coupling agent containing an isocyanate group and an ethoxy group was mixed with 100 parts by weight of an isobutylene-isoprene rubber having a hydroxy group of the preparation example 1, 1.0 part by weight of a Tin catalyst as a reaction accelerator, 1.5 parts by weight of an isocyanate-based curing agent (Duranate, TKA-100), 1.0 part by weight of acetylacetone (Sigma-Aldrich, Acetylacetone) as a curing retarder and 25 parts by weight of a hydrogenated terpene compound (Yasuhara chemical Co., Clearon P125) By weight were mixed to prepare a pressure-sensitive adhesive composition.

Example  2

A pressure-sensitive adhesive composition was prepared in the same manner as in Example 1, except that the isobutylene-isoprene rubber having the carboxyl group of Preparation Example 2 was used.

Example  3

3 parts by weight of a silane coupling agent containing an epoxy group and an ethoxy group was mixed with 100 parts by weight of an isobutylene-isoprene rubber having a hydroxy group of the above Production Example 1, and 1.0 part by weight of a Tin catalyst as a reaction promoter, 1 part by weight of an isocyanate-based curing agent (Duranate, TKA-100;), 1.0 part by weight of acetylacetone (Sigma-Aldrich, Acetylacetone) as a curing retarder, And 25 parts by weight of a hydrogenated terpene compound (Yasuhara chemical Co., Clearon P125) as an enhancer were mixed to prepare a pressure-sensitive adhesive composition.

Comparative Example  One

A pressure-sensitive adhesive composition was prepared in the same manner as in Example 1, except that a silane coupling agent containing an isocyanate group and an ethoxy group and a reaction promoter were not included.

Comparative Example  2

Isobutylene-isoprene rubber as a copolymer formed from a monomer mixture containing 1.7 mol% of isoprene and 98.3 mol% of isobutylene, wherein isobutylene-isoprene rubber having an isocyanate group And 3 parts by weight of a silane coupling agent containing an ethoxy group were mixed, and 10 parts by weight of a dicyclopentadiene diacrylate monomer as a photocurable component, 0.5 part by weight of a photoinitiator (Igacure 651) and a hydrogenated terpene compound (Yasuhara chemical Ltd., Clearon P125) were mixed to prepare a pressure-sensitive adhesive composition.

Comparative Example  3

Wasobutylene-isoprene rubber as a copolymer formed from a monomer mixture containing 1.7 mol% of isoprene and 98.3 mol% of isobutylene, with respect to 100 parts by weight of the isobutylene-isoprene rubber not modified to have a polar functional group, , 10 parts by weight of a dicyclopentadiene diacrylate monomer, 0.5 part by weight of a photoinitiator (Igacure 651), and 10 parts by weight of a hydrogenated terpene compound (Yasuhara chemical Co., Clearon P125) as an adhesion promoter were mixed to prepare a pressure sensitive adhesive composition.

Comparative Example  4

0.5 part by weight of a photoinitiator (Igacure 651) and 5 parts by weight of a urethane acryl-based curing agent (SUAT-1020, manufactured by Shin-TAT & Co.) were mixed with 100 parts by weight of an acrylic resin to prepare a pressure-sensitive adhesive composition.

<Evaluation>

The pressure-sensitive adhesive composition of Example 1-3 and the pressure-sensitive adhesive composition of Comparative Example 1 were coated in a film form and dried to form a thermoset at a temperature of 120 ° C, and a pressure-sensitive adhesive layer having a thickness of 50 μm was prepared.

In the case of Comparative Example 2-4, a photo-cured product was formed by irradiating ultraviolet light energy of 2500 mJ / cm 2, and a pressure-sensitive adhesive layer having a thickness of 50 μm was prepared.

Experimental Example  One: Moisture-permeable  Measure

Each of the pressure-sensitive adhesive layers of the examples and comparative examples was immersed in a certain amount of water in a cup at a temperature of 38 DEG C and a relative humidity of 90%, and then the pressure-sensitive adhesive layer was loaded thereon and capped. (WVTR) was measured with a measuring device (Labthink TSY-T3) using the weight of the water evaporated and blown off. The results are shown in Table 1 below.

Experimental Example  2: Exfoliation  Measure

For each of the pressure-sensitive adhesive layers of the examples and comparative examples, the peel force on the glass substrate was measured at a peeling speed of 300 mm / min using a UTM (Universal Testing Machine). The results are shown in Table 1 below.

Experimental Example  3: Measurement of optical properties

1) Measurement of light transmittance (T)

Each of the pressure-sensitive adhesive layers of the examples and comparative examples was adhered to a transparent glass substrate, and then the light transmittance was measured using a UV-Vis spectrometer at 20 ° C to 30 ° C at room temperature.

2) Measurement of haze (H)

Each of the pressure-sensitive adhesive layers of the examples and comparative examples was attached to a transparent glass substrate, and haze was measured with a haze meter (BYK) apparatus at a room temperature of 20 to 30 캜.

Experimental Example  4: Measurement of durability

The structure of the barrier COP film / pressure-sensitive adhesive layer / glass base material was formed for each of the pressure-sensitive adhesive layers of the examples and the comparative examples and left for 500 hours at a temperature of 85 ° C and a relative humidity of 85% The durability was evaluated according to bubble generation, yellowing, and whether or not the substrate was lifted. The results are shown in Table 1 below. No bubble was observed, no yellowing phenomenon was observed, no exfoliation occurred, and excellent (○) was indicated. When any one of them was unsatisfactory, insufficient (×) was indicated.

Moisture permeability
[g / ㎡ · 24 hr] Peel force
[g / in] Optical properties [%] durability T H Example 1 3.9 2353 92.1 0.84 ○ Example 2 3.8 2566 92.1 0.85 ○ Example 3 3.5 2297 92.1 0.82 ○ Comparative Example 1 6.1 2162 92.5 0.78 ○ Comparative Example 2 4.8 1186 92.4 0.58 × Comparative Example 3 5.2 987 92.3 0.52 ○ Comparative Example 4 43.1 1788 92.7 0.18 ○

Referring to the results of Table 1, Comparative Example 1, which did not contain the silane coupling agent chemically bonded to the polar functional group of the rubber, had better moisture permeability and peel strength than the pressure-sensitive adhesive layer of Examples 1 to 3 I can see that I can not.

In the case of Comparative Example 2, a rubber containing no silane coupling agent but no polar functional group was used, and a silane coupling agent was simply dispersed and mixed. In this case, the durability is poor, the moisture permeability and the peeling force are also inferior to those of Examples 1 to 3.

In addition, in the case of Comparative Example 3, rubber having no polar functional group was used, and it was found that the rubber was not included in the silane coupling system and was considerably inferior to Examples 1 to 3 in terms of the peeling force.

Furthermore, Comparative Example 4 is a pressure-sensitive adhesive layer made of a general photo-curable acrylic pressure-sensitive adhesive, which is not significantly better in moisture permeability than Examples 1 to 3, and inferior in terms of peel strength.

That is, the optical pressure-sensitive adhesive composition according to the embodiments of the present invention imparts excellent moisture permeability to an optical device or an electronic device to which the optical pressure-sensitive adhesive composition is applied, and can realize excellent long-term durability and optical characteristics.

In addition, the optical adhesive film can be applied to various electronic devices as compared with the conventional adhesive film using an acrylic resin or a rubber-based resin as a base resin, and can exhibit excellent adhesion and long-term reliability.

100: Adhesive film
110: release film layer
120: pressure-sensitive adhesive layer

Claims (10)

Polar functional group-containing isobutylene-isoprene rubber; And
And a silane coupling agent chemically bonded to the polar functional group
Sensitive adhesive composition for optics.
The method according to claim 1,
Wherein the polar functional group comprises one selected from the group consisting of a hydroxyl group, a carboxyl group, an amine group, an acrylic group, a methacrylic group, an aldehyde group, an epoxy group, a maleic anhydride group,
Sensitive adhesive composition for optics.
The method according to claim 1,
The polar functional group is introduced into the isoprene unit of the isobutylene-isoprene rubber
Sensitive adhesive composition for optics.
The method according to claim 1,
The isobutylene-isoprene rubber is a copolymer formed from a monomer mixture comprising 70 mol% to 99 mol% of isobutylene and 1 mol% to 30 mol% of isoprene
Sensitive adhesive composition for optics.
The method according to claim 1,
The polar functional group-containing isobutylene-isoprene rubber has a weight average molecular weight (Mw) of 10,000 to 1,000,000
Sensitive adhesive composition for optics.
The method according to claim 1,
Wherein the silane coupling agent is a reactive functional group that chemically bonds with the polar functional group; And alkoxy groups,
The reactive functional group includes one selected from the group consisting of an isocyanate group, a mercapto group, a vinyl group, an epoxy group, an amino group, a (meth) acryloyl group, and combinations thereof
Sensitive adhesive composition for optics.
The method according to claim 1,
And 0.02 to 8 parts by weight of the silane coupling agent relative to 100 parts by weight of the polar functional group-containing isobutylene-isoprene rubber
Sensitive adhesive composition for optics.
The method according to claim 1,
Further comprising one selected from the group consisting of a curing agent, a reaction promoter, a curing retarder, an adhesion promoter, an oxidation stabilizer, and combinations thereof
Sensitive adhesive composition for optics.
9. The method of claim 8,
Wherein the adhesion promoter comprises one selected from the group consisting of hydrogenated dicyclopentadiene compounds, hydrogenated terpene compounds, hydrogenated rosin compounds, hydrogenated aromatic compounds, hydrogenated petroleum based compounds, and combinations thereof
Sensitive adhesive composition for optics.
A pressure-sensitive adhesive composition comprising a pressure-sensitive adhesive layer comprising a cured product of the optical pressure-sensitive adhesive composition according to any one of claims 1 to 9
Optical adhesive film.

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