KR102111963B1 - Adhesive composition for optical use and the adhesive film for optical use - Google Patents

Abstract

It is applied to an optical device or a display device, and exhibits a high barrier performance against moisture and oxygen based on low moisture permeability, and at the same time, relates to an optical pressure-sensitive adhesive composition that realizes excellent adhesion performance and optical properties. Having isobutylene-isoprene rubber; And it provides an optical pressure-sensitive adhesive composition comprising; organic and inorganic particles comprising organic particles or inorganic particles. In addition, it provides an optical pressure-sensitive adhesive film comprising a pressure-sensitive adhesive layer containing a cured product of the optical pressure-sensitive adhesive composition.

Description

Optical adhesive composition and optical adhesive film {ADHESIVE COMPOSITION FOR OPTICAL USE AND THE ADHESIVE FILM FOR OPTICAL USE}

This specification claims the benefit of the filing date of Korean Patent Application No. 10-2015-0155175 filed with the Korean Intellectual Property Office on November 5, 2015, all of which is included in the present invention.

The present invention relates to an optical pressure-sensitive adhesive composition and an optical pressure-sensitive adhesive film, the optical pressure-sensitive adhesive composition and the optical pressure-sensitive adhesive film is capable of curing sulfur (sulfur-) or halogen-free and excellent chemical resistance , It is to implement moisture resistance, optical properties and durability.

Touch materials, including packaged electronic devices or transparent conductive films, require good touch sensitivity for excellent operation. Furthermore, in recent years, much attention has been paid to the development of an adhesive composition for improving the durability and optical properties of devices such as OLEDs or touch screen panels.

In general, an adhesive used in an OLED or a touch screen panel should secure optical properties such as transparency and visibility. To this end, in the prior art, an adhesive having an acrylic resin as a base resin was generally used, but this requires supplementation in terms of touch sensitivity, and at the same time, it is an important problem to secure suitable modulus and optical properties.

In addition, adhesives using rubber-based resins are also being developed to compensate for the disadvantages of acrylic resins. For example, Korean Patent Publication No. 2014-0050956 discloses an adhesive composition comprising a rubber-based polymer, and the Republic of Korea Patent Publication No. 2014-0049278 also discloses the use of a butyl rubber-based polymer to lower the moisture permeability.

However, in the case of an adhesive containing a rubber-based resin as a base resin, chemical crosslinking is difficult through a curing process, physical crosslinking must be used, and as a result, it is difficult to form a cured or crosslinked structure to ensure sufficient durability. In addition, the application of the final product may be limited accordingly.

As an optical pressure-sensitive adhesive composition containing a rubber capable of chemical crosslinking through an appropriate curing process, as a result, excellent long-term durability, moisture resistance, and chemical resistance can be secured, and excellent optical properties can be provided.

Another embodiment of the present invention provides a chemical adhesive crosslinking and curing of the rubber itself, thereby realizing excellent durability when applied to an electronic device, providing an optical adhesive film having excellent optical properties, improved adhesion performance and moisture resistance.

In one embodiment of the present invention, isobutylene-isoprene rubber having a polar functional group; And it provides an optical pressure-sensitive adhesive composition comprising; organic and inorganic particles comprising organic particles or inorganic particles.

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

The optical pressure-sensitive adhesive composition imparts excellent moisture resistance and chemical resistance to the optical device or electronic device to which it is applied, and can realize excellent long-term durability and optical properties.

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

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

Advantages and features of the present invention, and a method of achieving them will become apparent with reference to embodiments described below. However, the present invention will not be limited to the embodiments disclosed below, but will be implemented in various different forms, Only the present embodiments are provided to make the disclosure of the present invention complete, and to provide those who have ordinary knowledge in the art to which the present invention pertains, to fully disclose the scope of the invention, and the invention is defined by the scope of the claims. It just works. The same reference numerals refer to the same components throughout the specification.

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

Also, in the present specification, when a part such as a layer, film, region, plate, etc. is said to be "above" or "above" another part, this is not only when the other part is "directly above" but also when there is another part in the middle. Also includes. Conversely, when one part is "just above" another part, it means that there is no other part in the middle. In addition, when a part such as a layer, film, region, plate, etc. is said to be "below" or "below" another part, it is not only when the other part is "just below" but also when there is another part in the middle. Includes. Conversely, when one part is "just below" another part, it means that there is no other part in the middle.

In one embodiment of the present invention, isobutylene-isoprene rubber having a polar functional group; And it provides an optical pressure-sensitive adhesive composition comprising; organic and inorganic particles comprising organic particles or inorganic particles.

The optical pressure-sensitive adhesive composition is used in an organic light emitting device (OLED) or the like to perform a sealing function to block moisture and oxygen flowing from outside. As such, the ability to block moisture and oxygen is referred to as barrier performance. In general, the optical pressure-sensitive adhesive uses an acrylate-based resin as a base resin for optical properties, but a rubber-based resin may be more advantageous in view of improving the barrier performance.

In addition, organic or inorganic particles may be mixed with the optical pressure-sensitive adhesive composition in order to further improve the barrier performance of moisture and oxygen. However, in the case of a general rubber-based resin, the compatibility with organic or inorganic particles is not good, so it is difficult to improve the barrier performance, and the optical properties are also deteriorated.

In contrast, the optical pressure-sensitive adhesive composition can improve compatibility with organic or inorganic particles by using a chemically modified rubber-based resin, and as a result, it is possible to obtain an advantage of simultaneously securing excellent optical properties and barrier performance.

In addition, the rubber used in the conventional pressure-sensitive adhesive was subjected to physical crosslinking through heat curing or photocuring based on sulfur, or crosslinking by replacing halogen in the rubber itself. Alternatively, the rubber was added to the pressure-sensitive adhesive by mixing the photocurable monomer with rubber and curing the photocurable monomer by light irradiation.

When a sulfur or halogen component is used in the adhesive, when the adhesive is applied to the final electronic product, problems such as corrosion of the skin complex can be caused, so the application range is narrow and the photocurable monomer In the case of using the rubber itself, there was a problem in that durability is not good because it does not participate in curing.

On the other hand, the optical pressure-sensitive adhesive composition can secure the heat-curable properties by itself by using a chemically modified rubber, and can obtain the advantage of solving the above-mentioned problems.

The optical pressure-sensitive adhesive composition 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 may further improve barrier performance by using isobutylene-isoprene rubber, and sulfur or halogen for curing by using isobutylene-isoprene rubber containing polar functional groups in itself. Since there is no need to use a (halogen) component, there is no risk of corrosion, and as a result, excellent long-term durability and optical properties can be realized.

According to an embodiment of the present invention, the polar functional group may include one selected from the group consisting of hydroxy group, carboxyl group, amine group, acrylic group, methacryl group, aldehyde group, epoxy group, maleic anhydride group, amide group and combinations thereof. Can be. In one embodiment, the polar functional group may include a hydroxy group or a carboxyl group, and in this case, it is advantageous to improve compatibility with the organic-inorganic particles, thereby greatly improving barrier performance.

According to an embodiment of the present invention, the polar functional group may be grafted to an isoprene unit of isobutylene-isoprene rubber. Specifically, the polar functional group may be one attached to the main chain of the isobutylene-isoprene rubber. More specifically, the polar functional group may be a graft bond to an isoprene unit in the main chain of the isobutylene-isoprene rubber.

According to an embodiment of the present invention, the polar functional group is a carboxyl group, and the carboxyl group may be a straight chain or branched alkylene group having a carboxyl group attached to its terminal, which is bound to an isoprene unit.

According to an embodiment of the present invention, the polar functional group is a hydroxy group, and the hydroxy group may be a unit of isoprene in the form of isopropanol.

That is, the polar functional group is introduced into the isoprene unit, not the isobutylene unit, thereby minimizing the degree of unsaturation of the rubber component, thereby improving the moisture permeability and viscoelastic properties, and at the same time obtain the advantage of preventing yellowing Can be. In addition, the polar functional group can be randomly distributed in the rubber chain by grafting on the isoprene unit, and as a result, it is possible to obtain an advantage of enabling efficient crosslinking and realizing long-term durability and stable physical properties of the final film.

Specifically, the isobutylene-isoprene rubber having a polar functional group may have a degree of unsaturation (0 to 1), for example, 0 to 0.5, for example, 0 (zero) days Can be. The 'unsaturation degree' indicates the degree to which multiple bonds are included in the chemical structure and can be measured using NMR or IR. The higher the degree of unsaturation, the more multiple bonds are included. Specifically, the degree of unsaturation may mean the number of units including multiple bonds to the number of isoprene units. For example, when there are no multiple bonds in the repeating unit of the isobutylene-isoprene rubber having the carboxyl group, the degree of unsaturation may be 0. Further, with respect to the isoprene unit of the isobutylene-isoprene rubber having the carboxyl group, when the number of repeat units having multiple bonds is half, the degree of unsaturation may be 0.5.

The optical pressure-sensitive adhesive composition can implement excellent weather resistance and durability by using rubber having an unsaturation in the above range.

According to an embodiment of the present invention, the content of the isoprene unit of the isobutylene-isoprene rubber may be 1 mol% or more and 30 mol% or less, based on the total number of moles of the isobutylene unit and the isoprene unit. In addition, the content of the isoprene unit may be 1% or more and 30% or less with respect to the total unit of the isobutylene-isoprene. The content of the isoprene unit may be the same as the content of the isoprene monomer with respect to the entire copolymerized monomer in the production of the isobutylene-isoprene rubber.

When the content of isoprene is adjusted to 1 mol% or more with respect to the total number of moles of isoprene units and isoprene units, the introduction of carboxyl or hydroxy groups may be easy, and crosslinking of the rubber itself through heat curing It can be done smoothly. Furthermore, when the content of the isoprene is adjusted to 30 mol% or less with respect to the total number of moles of the isobutylene unit and the isoprene unit, the moisture permeability and the gas permeability of the optical pressure-sensitive adhesive composition can be low, and the electronic device to which it is applied Corrosion can be prevented.

In this specification, isobutylene units and isoprene units may mean isobutylene repeat units and isoprene repeat units in isobutylene-isoprene rubber, respectively.

Specifically, the isobutylene-isoprene rubber may be a copolymer formed from a monomer mixture containing about 70 mol% to about 99 mol% of isobutylene and about 1 mol% to about 30 mol% of isoprene, and the polar functional group Can be introduced through the chemical modification of such isobutylene-isoprene rubber. In the isobutylene-isoprene rubber, when the content of the isobutylene is less than about 70 mol% and the content of the isoprene is greater than about 30 mol%, the water and gas permeability of the optical pressure-sensitive adhesive composition is increased. There is a fear of causing corrosion of the electronic device to which it is applied. In addition, when the content of isobutylene is greater 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, so it is compatible with the organic / inorganic particles. There is a fear that sex cannot be improved.

According to one embodiment of the invention, the isobutylene-isoprene rubber having the polar functional group may have a weight average molecular weight (Mw) of about 10,000 to about 1 million, for example, about 200,000 to about 700,000 have. The optical pressure-sensitive adhesive composition can sufficiently secure a physical entanglement site by a crosslinked structure after curing by containing rubber having a weight average molecular weight (Mw) in the above range, and organic and inorganic particles are evenly distributed. It is possible to secure excellent compatibility by providing sites. In addition, the optical pressure-sensitive adhesive composition ensures an appropriate viscosity by using a rubber having a weight average molecular weight (Mw) in the above range as a base component, so that it is excellent without problems such as dewetting when manufacturing into an adhesive film or an adhesive sheet. It can exhibit coating properties.

According to an embodiment of the present invention, when the isobutylene-isoprene rubber has a hydroxy group as a polar functional group, the content of the hydroxy group of the isobutylene-isoprene rubber having the hydroxy group is the total number of moles of isobutylene units and isoprene units With respect to, it may be 1 mol% or more and 30 mol% or less. That is, the isobutylene-isoprene rubber having the hydroxy group may contain 1 mol% to 30 mol% of hydroxy groups relative to the total number of moles of the repeating unit. By introducing a hydroxyl group into the isobutylene-isoprene rubber in an amount in the above range, an appropriate crosslink density can be formed through curing, and excellent durability can be achieved through an appropriate gel content.

Further, according to an embodiment of the present invention, when the isobutylene-isoprene rubber has a carboxyl group as a polar functional group, the content of the carboxyl group of the isobutylene-isoprene rubber having the carboxyl group is an isobutylene unit and an isoprene unit With respect to the total number of moles, it may be 1 mol% or more and 30 mol% or less. That is, the isobutylene-isoprene rubber having the carboxyl group may contain 1 mol% to 30 mol% of carboxyl groups based on the total number of moles of repeating units. A carboxyl group is introduced into the isobutylene-isoprene rubber in an amount in the above range to form an appropriate crosslink density through curing, and excellent durability can be achieved through an appropriate gel content.

According to an embodiment of the present invention, the optical pressure-sensitive adhesive composition has organic-inorganic particles including organic particles or inorganic particles together with the isobutylene-isoprene rubber having the polar functional group. The organic / inorganic particles impart more improved barrier properties to the optical pressure-sensitive adhesive composition, and those having excellent compatibility with isobutylene-isoprene rubber having the polar functional group may be used.

The organic / inorganic particles include organic particles or inorganic particles, and may be composed of only organic particles, or may be composed of only inorganic particles, or may be mixed with them.

The organic-inorganic particles may be dispersed in a cross-linked structure formed by isobutylene-isoprene rubber having a polar functional group as a grain of a predetermined shape, for example, a spherical shape, to improve barrier performance.

According to an embodiment of the present invention, the particle diameter of the organic-inorganic particles may be about 2 nm to about 100 nm, and specifically about 5 nm to about 50 nm. In addition, when the organic-inorganic particles are organic particles, the particle diameter may be 5 nm to 20 nm, and when the organic-inorganic particles are inorganic particles, the particle diameter may be 10 nm to 50 nm. Furthermore, the organic-inorganic particles may be used in a mixture of various sizes in the above range. The particle diameter of the organic-inorganic particles can be derived by measuring the diameter of the projected image when the organic-inorganic particles are projected with parallel light in a certain direction. By using organic-inorganic particles having a particle diameter in the above range, compatibility with the isobutylene-isoprene rubber having the polar functional group can be improved, and the optical pressure-sensitive adhesive composition not only has excellent barrier performance but also secures a certain level of optical properties or more. can do.

According to an embodiment of the present invention, the organic particles are made of graphene oxide, partially crosslinked polyacrylic acid, polyvinyl alcohol, ascorbate, glucose, acetic anhydride, propionic anhydride, and combinations thereof It may include one selected from the group. In one embodiment, the optical pressure-sensitive adhesive composition may include graphene oxide as organic-inorganic particles, and in this case, an advantage of improving both optical properties and barrier properties may be obtained.

According to one embodiment of the invention, the inorganic particles are sodium oxide, iron oxide, calcium oxide, nano zeolite, calcium chloride, montmorillonite, bentonite, lithium sulfate, magnesium sulfate, aluminum acetylacetonate and combinations thereof It may include one selected from the group consisting of.

The optical pressure-sensitive adhesive composition may include both the organic-inorganic particles and the isobutylene-isoprene rubber having the polar functional group in an appropriate content, thereby improving both barrier performance and optical properties based on their excellent compatibility.

Specifically, according to one embodiment of the present invention, the optical pressure-sensitive adhesive composition may contain about 0.5 to about 20 parts by weight of the organic-inorganic particles with respect to 100 parts by weight of isobutylene-isoprene rubber having the polar functional group. And, for example, may include about 1 to about 10 parts by weight, for example, about 1 to about 5 parts by weight. The optical pressure-sensitive adhesive composition can ensure excellent optical properties and barrier performance at the same time by including the organic-inorganic particles in the above-mentioned content, and if the content of the organic-inorganic particles is excessive, there is a fear that the optical properties are deteriorated. .

According to one embodiment of the present invention, the optical pressure-sensitive adhesive composition may further include one selected from the group consisting of a crosslinking agent, a reaction accelerator, a curing retarder, an adhesion promoter, an oxidation stabilizer, and combinations thereof, as necessary.

The crosslinking agent is a compound that can be chemically bonded to the polar functional group of the isobutylene-isoprene rubber, through which the optical pressure-sensitive adhesive composition can be cured to have an appropriate degree of curing. For example, when the isobutylene-isoprene rubber includes a hydroxy group or a carboxyl group as a polar functional group, the crosslinking agent may include an isocyanate-based crosslinking agent, in which case chemical reactions occur well to obtain excellent curing efficiency. .

When the optical pressure-sensitive adhesive composition includes a crosslinking agent, the crosslinking agent may be included in an amount of about 0.05 to about 5 parts by weight based on 100 parts by weight of isobutylene-isoprene rubber having the polar functional group. When the optical pressure-sensitive adhesive composition contains a crosslinking agent in an amount within the above range, a crosslinking density and a degree of curing suitable for curing may be realized.

The reaction accelerator is to accelerate the chemical reaction between the crosslinking agent and the polar functional group of the isobutylene-isoprene rubber, and specifically, from a group consisting of a tin catalyst, a bismuth catalyst, and combinations thereof. It may include a selected one. When the reaction accelerator of this type is used, a crosslinking reaction between the heat crosslinking agent and a hydroxy group or a carboxyl group may be rapidly progressed, and curing efficiency of the optical pressure-sensitive adhesive composition may be improved.

When the optical pressure-sensitive adhesive composition includes the reaction accelerator, the reaction accelerator may be included in an amount of about 0.01 to about 5 parts by weight based on 100 parts by weight of the thermosetting rubber. Since the reaction accelerator is included in the content in the above range, the crosslinking reaction rate between the crosslinking agent and the polar functional group can be efficiently improved without causing unnecessary side reactions, and it can be economically advantageous. For example, when the reaction accelerator is used in an excessive amount, the reaction rate proceeds too fast and partial gelation may occur, resulting in difficulty in uniform film production.

The curing retarder serves to suppress the reaction up to the step before coating the film after the final adhesive composition is blended, and may specifically include a ketone-based curing retarder. When using this type of curing retarder, it is possible to maintain the stability of the final pressure-sensitive adhesive composition, it is possible to obtain the advantage of sufficiently securing the pot life (pot-life) until the film coating step.

When the optical pressure-sensitive adhesive composition includes the curing retarder, the curing retarder may be included in an amount of about 0.01 to about 5 parts by weight based on 100 parts by weight of the thermosetting rubber. Since the curing retarder is included in the above-mentioned content, an effect of preventing gelation of the final blended composition can be obtained. In addition, when the curing retarder is used in an excessive amount, There is a concern that the curing reaction of the pressure-sensitive adhesive composition may be prevented to achieve effective crosslinking.

Since the optical pressure-sensitive adhesive composition includes a rubber component, it may implement excellent barrier performance due to low moisture permeability, but it is difficult to secure sufficient peel strength and adhesion. Therefore, if necessary, it may further include an adhesion promoter.

According to an embodiment of the present invention, the adhesion promoter is a hydrogenated dicyclopentadiene-based compound, a hydrogenated terpene-based compound, a hydrogenated rosin-based compound, a hydrogenated aromatic-based compound, a hydrogenated petroleum-based compound, and combinations thereof. It may include one selected from the group consisting of. The tackifier may be advantageous for realizing transparency by including a compound having a hydrogenated structure, and may be excellent in adhesion and peel strength under the influence of thermal energy during thermal curing.

For example, the adhesion promoter may include a hydrogenated dicyclopentadiene-based compound or a hydrogenated rosin-based compound, in which case, in particular, the effect of improving tack performance and improving optical properties such as light transmittance and haze Can get

The hydrogenated tackifier may be partially hydrogenated or fully hydrogenated. Specifically, the hydrogenated adhesion promoter may have a hydrogenation rate of about 60% or more, for example, 100%. When the hydrogenation rate is less than about 60%, there are fears that visibility and transparency of the pressure-sensitive adhesive layer formed of the pressure-sensitive adhesive composition may decrease due to a large amount of double bonds in the molecule. As the tendency for the double bond to absorb thermal energy increases, When irradiating thermal energy for curing, it may absorb it, resulting in a problem in which adhesiveness and peeling force become non-uniform.

In addition, the adhesion promoter may have a softening point of about 80 ° C to about 150 ° C, specifically about 80 ° C to about 130 ° C, and more specifically about 100 ° C to about 120 ° C. The term 'softening point' generally refers to the temperature at which a substance starts to deform or soften by heat. When the softening point of the pressure-sensitive adhesive is less than about 80 ℃, since the pressure-sensitive adhesive is softened at a relatively low temperature may cause a problem that the high-temperature reliability of the pressure-sensitive adhesive containing it may decrease, when the pressure-sensitive adhesive film is prepared using the pressure-sensitive adhesive, high temperature In distribution and storage, there may be a difficult problem, and when it exceeds about 150 ° C, there is a problem in that it is difficult to implement the adhesion promoting effect at room temperature, and there is a concern that the adhesive becomes hard even by adding a small amount. have.

When the optical pressure-sensitive adhesive composition includes the pressure-sensitive adhesive, the pressure-sensitive adhesive may be included from about 10 to about 70 parts by weight based on 100 parts by weight of isobutylene-isoprene rubber having the polar functional group. Peeling power to the substrate of the optical pressure-sensitive adhesive composition may be improved by using the adhesion promoter in an amount in the above range.

In another embodiment of the present invention, there is provided an optical adhesive film comprising an adhesive layer containing a cured product of the optical adhesive composition. The optical pressure-sensitive adhesive film is applied to a display, an electronic device, and the like, and through the pressure-sensitive adhesive layer containing a cured product of the optical pressure-sensitive adhesive composition can achieve excellent optical properties and barrier performance at the same time.

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

The gel content of the pressure-sensitive adhesive layer may be about 55% to about 100% by weight, for example, about 60% to about 90% by weight. When the gel content satisfies the above range, the pressure-sensitive adhesive layer can exhibit excellent step absorbency and adhesion, and can be applied to displays, electronic devices, and the like to realize excellent durability and barrier performance.

The pressure-sensitive adhesive layer may be prepared from the pressure-sensitive adhesive composition for optical use, exhibiting high peel strength to a glass substrate and low moisture permeability. For example, the pressure-sensitive adhesive layer may have a peel strength to a glass substrate of about 1,200 g / in or more, specifically about 1,200 g / in to about 2,500 g / in, and more specifically about 1,800 g / in to About 2,500 g / in.

At the same time, the pressure-sensitive adhesive layer may have a moisture permeability (WVTR) of 10 g / m 2 · 24 hr or less, for example, about 7.5 g / m 2 · 24 hr or less, or 7 g / m 2 · 24 hr or less, for example, about 3 g / m 2 • 24 hr or less, or 2.5 hr or less, for example, greater than about 0 g / m 2 · 24 hr and less than about 3 g / m 2 · 24 hr. The pressure-sensitive adhesive layer can simultaneously exhibit the peeling force and moisture permeability of the above range through the optical pressure-sensitive adhesive composition, and as a result, an optical pressure-sensitive adhesive film containing the pressure-sensitive adhesive layer is applied to a display or an electronic device to provide excellent barrier performance and durability. Can be represented at the same time.

Further, the pressure-sensitive adhesive layer may have a light transmittance of about 80% or more, about 85% or more, or 90% or more, for example, about 92% or more, and haze of less than about 4.5%, less than about 2%, or less than about 1.5% , For example, less than about 1%. The pressure-sensitive adhesive layer can be usefully applied to parts requiring visibility of a display or electronic device by satisfying the light transmittance and haze of the above range, and improve visibility based on excellent optical properties.

The pressure-sensitive adhesive layer is formed from the pressure-sensitive adhesive composition for the optical, it may be most preferable when the gel content, the peeling force to the glass substrate, moisture permeability, light transmittance, and haze are all satisfied at the same time in each of the aforementioned ranges. This can be achieved by controlling the compatibility of rubber and organic / inorganic particles contained in the optical pressure-sensitive adhesive composition, specifically, the compatibility of rubber and organic / inorganic particles with chemical modification of isobutylene-isoprene rubber and suitable organic / inorganic It can be controlled through the formulation of the particles.

According to one embodiment of the present invention, it may include a release film layer laminated on one or both sides of the pressure-sensitive adhesive layer.

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 includes the adhesive layer 120 and may include a release film layer 110 laminated on one or both sides of the adhesive layer 120. .

The release film layer is a layer that is peeled and removed when the optical adhesive film is applied to the final product, and may be formed on both sides or one side of the adhesive layer depending on where the adhesive layer is disposed in the final product. .

The release film layer may have a structure in which a release agent is applied to one surface 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.

At this time, the base film is not particularly limited, but, for example, a polyethylene terephthalate (PET) film in order to advantageously distribute and cut the optical adhesive film without being damaged upon curing of the optical adhesive composition. Can be used.

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

Hereinafter, specific embodiments of the present invention are presented. However, the examples described below are only for specifically illustrating or explaining the present invention, and the present invention is not limited thereto.

< Manufacturing example >

Manufacturing example  One: Backbone  Preparation of isobutylene-isoprene rubber with hydroxy group

An isobutylene-isoprene rubber, a copolymer formed from a monomer mixture containing 1.7 mol% isoprene and 98.3 mol% isobutylene, was prepared. Nitrogen gas was refluxed, and 3 parts by weight of peroxide (mCPBA) was added to 100 parts by weight of the isobutylene-isoprene rubber in a 2L reactor equipped with a cooling device to facilitate temperature control, followed by stirring at 30 ° C for 6 hours. Subsequently, 3.1 parts by weight of an aqueous 1N hydrochloric acid solution was added to 100 parts by weight of the rubber, stirred at 30 ° C for 1 hour, and then heated to 90 ° C and stirred for 1 hour. Thus, isobutylene-isoprene rubber (IIR-OH) having a hydroxy group grafted onto the main chain isoprene unit was prepared.

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

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

Manufacturing example  3: Backbone  Preparation of isobutylene-isoprene rubber with hydroxy group

Preparation Example 3 is a copolymer formed from a monomer mixture containing 0.5 mol% isoprene and 99.5 mol% isobutylene, and proceeds in the same manner as in Production Example 1, except that the copolymer is used to graft to the main chain isoprene unit. Isobutylene-isoprene rubber (IIR-OH) having a hydroxy group was prepared.

Preparation Example 4: Preparation of isobutylene-isoprene rubber having a hydroxy group in the main chain

Preparation Example 4 is a graft to the main chain of isoprene units proceeding in the same manner as in Preparation Example 1, except that isobutylene-isoprene rubber, which is a copolymer formed from a monomer mixture containing 28 mole% of isoprene and 72 mole% of isobutylene, was used. Isobutylene-isoprene rubber (IIR-OH) having a hydroxy group was prepared.

Manufacturing example  5: Backbone  Preparation of isobutylene-isoprene rubber with hydroxy group

Preparation Example 5 is a copolymer formed from a monomer mixture containing 35 mol% of isoprene and 65 mol% of isobutylene, and proceeds in the same manner as in Production Example 1, except that the copolymer is used to graft the main chain of isoprene units. Isobutylene-isoprene rubber (IIR-OH) having a hydroxy group was prepared.

Manufacturing example 6: on the side chain  Preparation of isobutylene-isoprene rubber with hydroxy group

An isobutylene-isoprene rubber, a copolymer formed from a monomer mixture containing 1.7 mol% isoprene and 98.3 mol% isobutylene, was prepared. Nitrogen gas was refluxed, and 3 parts by weight of peroxide (mCPBA) was added to 100 parts by weight of the isobutylene-isoprene rubber in a 2L reactor equipped with a cooling device to facilitate temperature control, followed by stirring at 30 ° C for 6 hours. Thus, an epoxy group was introduced into the isoprene unit of the isobutylene-isoprene rubber. Subsequently, 1 part by weight of periodic acid was added to 100 parts by weight of the rubber, followed by stirring at 30 ° C for 2 hours, and then 3 parts by weight of sodium borohydride (NaBH4), followed by stirring for 6 hours. Thus, isobutylene-isoprene rubber having hydroxy in the side chain (terminal) was prepared.

< Example  And Comparative example >

Example  1 to 5

With respect to 100 parts by weight of isobutylene-isoprene rubber having a hydroxy group of Preparation Example 1, graphene oxide particles having a particle diameter of 5 to 20 nm are mixed in 3, 5, 10, 15 and 20 parts by weight, respectively, and a trifunctional isocyanate system 1.2 parts by weight of a crosslinking agent (Duranate, TKA-100), 1.0 parts by weight of a tin catalyst as a reaction accelerator, 1.0 parts by weight of acetylacetone (Sigma-Aldrich, Acetylacetone) as a curing retarder and hydrogenated terpene as an adhesion promoter A pressure-sensitive adhesive composition was prepared by mixing 15 parts by weight of a compound (Yasuhara Chemical, Clearon P125).

Example  6

A pressure-sensitive adhesive composition was prepared in the same manner as in Example 1, except that isobutylene-isoprene rubber having a carboxyl group of Preparation Example 2 and 5 parts by weight of graphene oxide particles having a particle diameter of 5 to 20 nm were mixed.

Example  7

A pressure-sensitive adhesive composition was prepared in the same manner as in Example 6, except that montmorillonite particles having a particle diameter of 10 to 50 nm were added to 100 parts by weight of isobutylene-isoprene rubber having a hydroxy group of Preparation Example 1 above. Did.

Example  8

An adhesive composition was prepared in the same manner as in Example 1, except that 5 parts by weight of graphene oxide particles having a particle diameter of 5 to 20 nm were mixed with respect to 100 parts by weight of isobutylene-isoprene rubber having a hydroxy group of Preparation Example 4 Did.

Reference example  1 to 3

With respect to 100 parts by weight of isobutylene-isoprene rubber having a hydroxy group of Preparation Example 1, graphene oxide particles having a particle diameter of 5 to 20 nm are mixed in 25, 30 and 40 parts by weight, respectively, and a trifunctional isocyanate crosslinking agent (Duranate Co., Ltd.) , TKA-100) 1.2 parts by weight, 1.0 part by weight of a tin catalyst as a reaction accelerator, 1.0 part by weight of acetylacetone (Sigma-Aldrich, Acetylacetone) as a curing retarder, and a hydrogenated terpene compound (Yasuhara chemical) as an adhesion promoter社, Clearon P125) to prepare an adhesive composition by mixing 15 parts by weight.

Comparative example  One

5 parts by weight of graphene oxide particles having a particle diameter of 5 to 20 nm, based on 100 parts by weight of isobutylene-isoprene rubber, which is a copolymer formed from a monomer mixture containing 1.7 mol% isoprene and 98.3 mol% isobutylene having no polar functional group Mix, 10 parts by weight of dicyclopentadiene diacrylate monomer as a photocurable component, 0.5 parts by weight of photoinitiator (Igacure651) and 15 parts by weight of a hydrogenated terpene compound (Yasuhara Chemical, Clearon P125) as an adhesion promoter to prepare an adhesive composition It was prepared.

Comparative example  2

With respect to 100 parts by weight of the acrylic resin, 0.5 parts by weight of a photoinitiator (Igacure651) and 5 parts by weight of a urethane acrylic curing agent (Shin-T & C, SUO-1020) were mixed to prepare an adhesive composition.

Comparative example  3

A pressure-sensitive adhesive composition was prepared in the same manner as in Example 1, except that the graphene oxide particles were not included.

Reference example  4

A pressure-sensitive adhesive composition was prepared in the same manner as in Comparative Example 1, except that isobutylene-isoprene rubber having a hydroxy group was used in the main chain prepared from Preparation Example 3 above.

Reference example  5

An adhesive composition was prepared in the same manner as in Comparative Example 1, except that isobutylene-isoprene rubber having a hydroxy group was used in the main chain prepared from Preparation Example 5 above.

Reference example  6

An adhesive composition was prepared in the same manner as in Comparative Example 1, except that 100 parts by weight of isobutylene-isoprene rubber having a hydroxy group was used in the side chain (terminal) prepared from Preparation Example 6.

Table 2 below shows the compositions of the examples, reference examples, and comparative examples.

<Evaluation>

After preparing the pressure-sensitive adhesive composition of Examples 1 to 8, Reference Examples 1 to 3, and Comparative Example 3 in the form of a film, while drying, a thermosetting was formed at a temperature of 50 ° C., and a 50 μm thick pressure-sensitive adhesive layer containing the same Was prepared.

In the case of Comparative Examples 1 and 2 and Reference Examples 4 to 6, an ultraviolet light energy of 2500 mJ / cm 2 was irradiated to form a photocured product, and an adhesive layer having a thickness of 50 μm was prepared.

Experimental Example  One: Moisture-permeable  Measure

For each of the pressure-sensitive adhesive layers of the Examples and Comparative Examples, after soaking a certain amount of water in a cup at a temperature of 38 ° C and a relative humidity of 90%, 24 hours after capping by loading the pressure-sensitive adhesive layer thereon Using the reduced weight of the water evaporated during the while, the moisture permeability (WVTR) was measured with a measuring device (Labthink TSY-T3), and the results are shown in Table 1 below.

Experimental Example  2: Peeling  Measure

For each of the pressure-sensitive adhesive layers of the Examples and Comparative Examples, the peel force to the glass substrate was measured at a peeling speed of 300 mm / min using a universal testing machine (UTM), and the results are shown in Table 1 below.

Experimental Example  3: Measurement of optical properties

1) Measurement of light transmittance (T)

After attaching each of the pressure-sensitive adhesive layers of Examples and Comparative Examples to a transparent glass substrate, light transmittance was measured using an ultraviolet-visible spectrometer (UV-Vis spectrometer) at room temperature of 20 ° C to 30 ° C.

2) Measurement of haze (H)

After attaching each of the pressure-sensitive adhesive layers of Examples and Comparative Examples to a transparent glass substrate, haze was measured with a Haze meter (BYK) apparatus at room temperature conditions of 20 ° C to 30 ° C.

Experimental Example 4: Measurement of reliability

For each of the pressure-sensitive adhesive layers of the Examples, Reference Examples and Comparative Examples, a glass substrate was attached to one side, and the release film on the back side was removed to replace it with an ITO film. Time was left. Subsequently, air bubbles and excitation were observed with the naked eye to measure durability. The measurement results are listed in Table 1 below, and specifically, when bubbles and excitations are not generated at all, they are indicated by ○, and when bubbles and excitations are generated, they are indicated by ×.

Basic composition Moisture permeability
[g / ㎡ · 24hr] Peeling force
[g / in] responsibility Optical characteristics (%) T H Example 1 IIR-OH (IP 1.7 mol%) + 3 parts by weight graphene 7.15 1827 ○ 92.5 0.41 Example 2 IIR-OH (IP 1.7 mol%) + 5 parts by weight graphene 2.12 1978 ○ 92.5 0.45 Example 3 IIR-OH (IP 1.7 mol%) + 10 parts by weight graphene 1.96 1632 ○ 90.3 0.99 Example 4 IIR-OH (IP 1.7 mol%) + 15 parts by weight graphene 1.42 1548 ○ 86.3 1.45 Example 5 IIR-OH (IP 1.7 mol%) + 20 parts by weight graphene 0.92 1211 ○ 80.0 4.22 Example 6 IIR-COOH (IP 1.7 mol%) + 5 parts by weight graphene 1.98 2837 ○ 92.7 0.85 Example 7 IIR-OH (IP 1.7 mol%) + 5 parts by weight MMNT 2.08 1754 ○ 92.3 0.67 Example 8 IIR-OH (IP 28 mol%) + 5 parts by weight graphene 2.08 1724 ○ 92.5 0.59 Reference Example 1 IIR-OH (IP 1.7 mol%) + 25 parts by weight graphene 0.88 872 × 77.5 11.38 Reference Example 2 IIR-OH (IP 1.7 mol%) + 30 parts by weight graphene 0.89 605 × 53.2 15.54 Reference Example 3 IIR-OH (IP 1.7 mol%) + 40 parts by weight graphene 0.86 403 × 50.1 22.76 Comparative Example 1 IIR + 5 parts by weight graphene 5.12 972 × 92.5 1.54 Comparative Example 2 Acrylic resin 180 2766 × 92.7 0.22 Comparative Example 3 IIR-OH + Graphene X 8.3 2125 ○ 92.9 0.27 Reference Example 4 IIR-OH (IP 0.5 mol%) + 5 parts by weight graphene 6.03 220 × 92.5 1.69 Reference Example 5 IIR-OH (IP 35 mol%) + 5 parts by weight graphene 14.3 830 × 90.4 0.63 Reference Example 6 IIR-OH side chain (IP 1.7 mol%) + 5 parts by weight graphene 9.03 677 × 92.5 1.46

Referring to the results of Table 1, it can be seen that Comparative Example 1, in which the polar functional groups were not bonded, significantly lowered the peel strength and reliability. Furthermore, it can be seen that in the case of Comparative Example 2 using only acrylic resin without organic and inorganic particles, the reliability was inferior to that of Example. Furthermore, in the case of Comparative Example 3 using isobutylene-isoprene rubber having polar functional groups without organic and inorganic particles, it was found that there was a problem in that the moisture permeability was higher than in Examples.

In the case of Reference Examples 1 to 3 containing the content of graphene in excess of 20 parts by weight, the moisture permeability is low, but there is a problem of exhibiting low peel strength and low reliability, and the optical adhesive has high transmittance and haze value in optical properties. There is a problem difficult to use.

Furthermore, in the case of Reference Example 4 using isobutylene-isoprene rubber having an isoprene content of 0.5 mol% and Reference Example 5 using isobutylene-isoprene rubber having an isoprene content of 35 mol%, relatively high moisture permeability and low reliability And low peel strength. In addition, in the case of Reference Example 6 using isobutylene-isoprene rubber having a hydroxy group bonded to a side chain, it exhibited high moisture permeability, low reliability, and low peeling force.

100: adhesive film
110: release film layer
120: adhesive layer

Claims (12)

Isobutylene-isoprene rubber having polar functional groups; And
Organic and inorganic particles comprising organic particles or inorganic particles; containing
The polar functional group is grafted to the isoprene unit of the isobutylene-isoprene rubber,
The polar functional group includes one selected from the group consisting of hydroxy group, carboxyl group and combinations thereof,
The content of the isoprene unit of the isobutylene-isoprene rubber is 1 mol% or more and 30 mol% or less of the optical pressure-sensitive adhesive composition, based on the total number of moles of the isobutylene unit and the isoprene repeating unit. delete delete delete According to claim 1,
The isobutylene-isoprene rubber having the polar functional group has an optical pressure-sensitive adhesive composition having a weight average molecular weight (Mw) of 10,000 to 1 million. According to claim 1,
The organic / inorganic particles have an optical pressure-sensitive adhesive composition having a particle diameter of 2 nm to 100 nm. According to claim 1,
The organic particle is for optical, including one selected from the group consisting of graphene oxide, partially cross-linked polyacrylic acid, polyvinyl alcohol, ascorbate, glucose, acetic anhydride, propionic anhydride, and combinations thereof Adhesive composition. According to claim 1,
The inorganic particles are optical, including one selected from the group consisting of sodium oxide, iron oxide, calcium oxide, nanozeolite, calcium chloride, montmorillonite, bentonite, lithium sulfate, magnesium sulfate, aluminum acetylacetonate, and combinations thereof Pressure-sensitive adhesive composition. According to claim 1,
The optical pressure-sensitive adhesive composition containing 0.5 to 20 parts by weight of the organic-inorganic particles, based on 100 parts by weight of the isobutylene-isoprene rubber having the polar functional group. According to claim 1,
The optical pressure-sensitive adhesive composition is an optical pressure-sensitive adhesive composition further comprising one selected from the group consisting of a crosslinking agent, a reaction accelerator, a curing retarder, an adhesion promoter, an oxidation stabilizer, and combinations thereof. The method of claim 10,
The tackifier is optical including one selected from the group consisting of hydrogenated dicyclopentadiene-based compounds, hydrogenated terpene-based compounds, hydrogenated rosin-based compounds, hydrogenated aromatic-based compounds, hydrogenated petroleum-based compounds, and combinations thereof. Pressure-sensitive adhesive composition. An optical pressure-sensitive adhesive film having a pressure-sensitive adhesive layer containing a cured product of the optical pressure-sensitive adhesive composition according to any one of claims 1 to 5 to 11.

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