KR102109909B1 - The adhesive composition and the adhesive film - Google Patents

Abstract

It is formed from a mixed monomer component comprising a first alkyl (meth) acrylate having an alkyl group having 4 to 15 carbon atoms, a second alkyl (meth) acrylate having an alkyl group having 1 to 3 carbon atoms, and acrylic acid, and has a weight average molecular weight (Mw ) Is 5 to 10 million photopolymerizable resin; And a crosslinkable monomer, wherein the crosslinkable monomer is provided with a pressure-sensitive adhesive composition comprising a glycidyl group-containing (meth) acrylate.

Description

Adhesive composition and adhesive tape {THE ADHESIVE COMPOSITION AND THE ADHESIVE FILM}

It relates to an adhesive composition and an adhesive tape.

Demand for an image display device that inputs, manipulates, and displays information through a touch screen, such as a television, computer, and mobile communication terminal, is increasing. The image display device includes a protection unit such as a glass substrate or a transparent plastic substrate on an image display unit such as a liquid crystal display (LCD), and an image, image, or the like is not transmitted through the border area of the image display device because light is not transmitted It can be formed from the portion where the display does not appear, including the distal portion of the body of the image display device.

The edge region of the image display device is called a bezel, and in this bezel, the image display unit and the protection unit of the image display device may be adhered via an adhesive tape, that is, a double-sided adhesive tape.

In addition, while the demand for expanding the size of the image display unit continues to increase these days, there are many demands for the device itself not to grow. To meet this demand, attempts have been made to reduce the size or width of the bezel. As such, the need for an adhesive tape for application to a narrow bezel is also increasing. In order to be applied to a narrow bezel, the adhesive tape must be easily processed and cut so as to correspond to the shape of the narrow bezel, and despite a small area, it must exhibit excellent adhesive performance during the manufacturing process and after use.

An embodiment of the present invention, when applied to a narrow bezel, provides excellent processability and cutability, and provides a pressure-sensitive adhesive composition having excellent durability and adhesion even in a small area, and excellent repulsion resistance.

Another embodiment of the present invention is an adhesive tape prepared using the adhesive composition, and is applied to a narrow bezel to provide an adhesive tape having excellent reliability and adhesive performance in a high temperature and high humidity environment.

In one embodiment of the present invention, from a mixed monomer component comprising a first alkyl (meth) acrylate having an alkyl group having 4 to 15 carbon atoms, a second alkyl (meth) acrylate having an alkyl group having 1 to 3 carbon atoms, and acrylic acid It is formed, the weight average molecular weight (Mw) of 5 to 10 million photopolymerizable resin; And a crosslinkable monomer, wherein the crosslinkable monomer provides a pressure-sensitive adhesive composition comprising a glycidyl group-containing (meth) acrylate.

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

The pressure-sensitive adhesive composition is applied to a narrow bezel area, exhibits excellent repulsion resistance and adhesion retention under a high temperature and high humidity environment, and implements appropriate adhesion to a plastic substrate to improve processability and cutability.

The adhesive tape exhibits excellent cutability in the process of forming and processing to be applied to a narrow bezel area, reducing the defect rate of mass production based on proper adhesion to a plastic substrate, and having excellent repulsion resistance and high temperature and high humidity reliability. Can be implemented.

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

Advantages and features of the present invention, and a method of achieving them will be apparent with reference to embodiments described below. However, the present invention is not limited to the embodiments disclosed below, but may 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, from a mixed monomer component comprising a first alkyl (meth) acrylate having an alkyl group having 4 to 15 carbon atoms, a second alkyl (meth) acrylate having an alkyl group having 1 to 3 carbon atoms, and acrylic acid It is formed, the weight average molecular weight (Mw) of 5 to 10 million photopolymerizable resin; And a crosslinkable monomer, wherein the crosslinkable monomer provides a pressure-sensitive adhesive composition comprising a glycidyl group-containing (meth) acrylate.

The pressure-sensitive adhesive composition includes a photopolymerizable resin, and the weight average molecular weight (Mw) of the photopolymerizable resin may be about 5 million to about 10 million. For example, it may be from about 6 million to about 10 million, or from about 7 million to about 10 million. The pressure-sensitive adhesive composition can improve the initial adhesion to the plastic substrate by including a photopolymerizable resin having a weight average molecular weight in the above range, exhibits excellent durability under a high temperature and high humidity environment, and can increase adhesion retention.

In addition, unlike the resin having a weight average molecular weight (Mw) of less than about 5 million, which has been used in an adhesive, the photopolymerizable resin having the weight average molecular weight has a high cohesive force and can exhibit high resistance to heat, thereby improving initial adhesion. It is possible to increase the adhesive holding power under a high temperature and high humidity environment.

Typically in the bezel of the display, for example, glass and plastic; Or glass and metal; The image display unit and the protection unit, which are formed of different materials, are adhered via an adhesive tape, and the adhesive tape may be formed of, for example, an acrylic adhesive.

However, the acrylic adhesive that is commonly used may have a problem of lifting or foaming under high temperature and high humidity conditions or even desorption when the components of different materials are adhered to each other due to low repulsion resistance.

The pressure-sensitive adhesive composition, including the crosslinkable monomer together with the photopolymerizable resin, can realize excellent repulsion resistance and excellent high temperature and high humidity reliability, and can prevent lifting, bubble generation, and desorption. Specifically, the crosslinkable monomer may react with the photopolymerizable resin to form a crosslinking structure connecting photopolymerizable resins. For example, the crosslinkable monomer may react with the acrylic acid structure of the photopolymerizable resin to connect photopolymerizable resins to each other.

More specifically, the crosslinkable monomer may be a material having no crosslinking reactivity at room temperature and crosslinking reactivity under high temperature and high humidity. In the present specification, the term 'crosslinking reactivity' refers to physical properties in which both ends react chemically to form a bond in the chemical structure of a crosslinkable monomer. That is, the crosslinkable monomer does not crosslink at either end or both ends at room temperature, and both ends react chemically at high temperatures to exhibit crosslinking reactivity.

The crosslinking monomer does not undergo a crosslinking reaction at room temperature, and both ends of the crosslinkable monomer are reacted with the photopolymerizable resin to form a crosslinking structure under conditions of high temperature and high humidity, thereby providing an appropriate crosslinking density and excellent flexibility to the pressure-sensitive adhesive composition. can do. As a result, the pressure-sensitive adhesive tape made of the pressure-sensitive adhesive composition can achieve high repulsion resistance and excellent high-temperature and high-humidity reliability, thereby preventing lifting, bubble generation and desorption.

.

The crosslinkable monomer includes a glycidyl group-containing (meth) acrylate, and the glycidyl group-containing (meth) acrylate is a glycidyl group-containing (meth) acrylate having a triangular ring, and is a tetragonal or more ring It has the advantage of excellent crosslinking reactivity than (meth) acrylate having a structural functional group. Specifically, the glycidyl group-containing (meth) acrylate having a triangular ring has excellent ring-opening reactivity under conditions of high temperature and high humidity, and can easily react with a photopolymerization resin to better form a crosslinking structure connecting photopolymerization resins. have. Accordingly, excellent repulsion resistance and excellent high temperature and high humidity reliability can be realized.

For example, the glycidyl group-containing (meth) acrylate may have the structure of Formula 1 below. In this case, R ₁ is hydrogen or a methyl group, and m may be an integer from 0 to 10.

[Formula 1]

The glycidyl group-containing (meth) acrylate contains a glycidyl group having a triangular ring, as in Chemical Formula 1, and as described above, under conditions of high temperature and high humidity, the ring of the glycidyl group is opened. , Reacting with the photopolymerizable resin may form a crosslinking structure connecting the photopolymerizable resins.

At this time, m may be an integer from 0 to 10. When m satisfies the above range, the crosslinkable monomer can achieve an appropriate level of crosslink density, whereby the pressure-sensitive adhesive composition can realize excellent flexibility, repulsion resistance, and high temperature and high humidity reliability.

The crosslinkable monomer may further include (meth) acrylate having a glycidyl group-containing (meth) acrylate and another oxygen-containing heterocycloalkyl group.

For example, the crosslinkable monomer may further include an oxetane group-containing (meth) acrylate or a tetrahydrofurfuryl group-containing (meth) acrylate.

As described above, the crosslinkable monomer is a material having no crosslinking reactivity at room temperature and crosslinking reactivity under high temperature and high humidity, specifically, about 60 ° C to about 90 ° C and a relative humidity of about 50% to about 90% In can have a crosslinking reactivity.

The crosslinkable monomer is a material having crosslinking reactivity under high temperature and high humidity, and is distinct from the monomer of the mixed monomer component constituting the photopolymerization resin, and is present as an unreacted monomer in the adhesive composition.

The crosslinkable monomer is a material having crosslinking reactivity under high temperature and high humidity, and is a separate component distinct from the monomer of the mixed monomer component constituting the photopolymerization resin, and is present as an unreacted monomer in the adhesive composition.

As described below, the pressure-sensitive adhesive composition may form a photocured product by irradiating light energy, wherein the crosslinkable monomer does not exhibit crosslinking reactivity. Specifically, when irradiating light energy, at least some of the crosslinkable monomers may have a photocuring reaction with an acrylate group of the photopolymerizable resin, but the oxygen-containing heterocycloalkyl group of the crosslinkable monomer does not crosslink. That is, the oxygen-containing heterocyclo alkyl group of the crosslinkable monomer is present in a free state even after curing of the pressure-sensitive adhesive composition. This may be possible by appropriately controlling the chemical structure and composition of the crosslinkable monomer and setting the curing conditions, temperature, and humidity appropriately in the curing step of the pressure-sensitive adhesive composition.

The crosslinkable monomer is capable of imparting appropriate crosslinking density and excellent flexibility by crosslinking with the photopolymerizable resin when the pressure-sensitive adhesive composition is photocured and the photocured product is placed under conditions of high temperature and high humidity, resulting in high temperature and high humidity. It can show excellent adhesion and reliability under the environment.

The crosslinkable monomer constitutes an adhesive composition together with a photopolymerizable resin formed by photopolymerization, thereby exhibiting high cohesiveness and high resistance to heat, consequently improving the initial adhesion, and improving the adhesion retention under an environment of high temperature and high humidity. Excellent repulsion resistance and high temperature and high humidity reliability can be realized.

The pressure-sensitive adhesive composition includes a photopolymerization resin, and the photopolymerization resin is a polymer synthesized from one or more monomers by irradiating light energy such as ultraviolet rays as being distinguished from a thermal polymerization resin. In the process of manufacturing the photopolymerizable resin, a resin having a high weight average molecular weight can be prepared as described above by appropriately adjusting the light amount and temperature conditions, and through this, excellent physical properties as described above can be realized.

Specifically, the photopolymerizable resin is formed from a mixed monomer component comprising a first alkyl (meth) acrylate having an alkyl group having 4 to 15 carbon atoms, a second alkyl (meth) acrylate having an alkyl group having 1 to 3 carbon atoms, and acrylic acid. Can be. For example, the photopolymerizable resin may be formed from a mixed monomer component composed of only the first alkyl (meth) acrylate, the second alkyl (meth) acrylate, and acrylic acid.

The mixed monomer component forming the photopolymerizable resin may include about 20% to about 40% by weight of the second alkyl (meth) acrylate. Specifically, it may include about 20% to about 30% by weight. Since the photopolymerizable resin is prepared from a mixed monomer component containing a second alkyl (meth) acrylate in the above range, high peel strength to a plastic substrate can be realized, and as a result, excellent processability in the process of cutting and forming an adhesive tape Can represent In addition, low repulsion resistance, it is possible to prevent the occurrence of excitation, air bubbles, etc. in an environment of high temperature and high humidity.

The second alkyl (meth) acrylate has an alkyl group having 1 to 3 carbon atoms, and specifically, may have a linear or pulverized alkyl group having 1 to 3 carbon atoms. Since the second alkyl (meth) acrylate has a linear or pulverized alkyl group in the carbon number range, it is possible to easily control the initial adhesive strength and peel strength to the plastic substrate of the adhesive to a required level.

The second alkyl (meth) acrylate may have, for example, a glass transition temperature (Tg) of about 5 ° C to about 20 ° C, and specifically about 5 ° C to about 15 ° C. By including the second alkyl (meth) acrylate having the glass transition temperature in the above range of the mixed monomer component, it is possible to realize a high peeling force to the plastic substrate, and as a result, excellent processability in the cutting and molding process of the adhesive tape. Can be represented. In addition, low repulsion resistance, it is possible to prevent the occurrence of excitation, air bubbles, etc. in an environment of high temperature and high humidity.

Specifically, the second alkyl (meth) acrylate may include one selected from the group consisting of methyl (meth) acrylate, ethyl (meth) acrylate, and combinations thereof. The shorter the length of the alkyl group in the second alkyl (meth) acrylate, the easier it is to adjust the cohesive force, glass transition temperature and adhesion of the photocured product. For example, the second alkyl (meth) acrylate may include methyl acrylate (MA), and in this case, the length of the alkyl group is short, thereby providing excellent cohesion to the cured product. In this case, it may be particularly advantageous in terms of increasing the peel strength to the plastic substrate.

The second alkyl (meth) acrylate has an alkyl group having a relatively short length, and in some cases, a problem that causes a peculiar fragrance may occur. For example, the methyl acrylate (MA) has an intrinsic fragrance, and there is a limitation that the adhesive is not contained in a certain amount or more. In one embodiment, the pressure-sensitive adhesive composition is used for application to a bezel of a small area, thereby minimizing the effect of this scent, and by using the second alkyl (meth) acrylate at a required level, excellent Advantages of realizing physical properties can be secured.

The mixed monomer component may include about 6% to about 8% by weight of the acrylic acid. By adjusting the content of the acrylic acid to the appropriate range, the pressure-sensitive adhesive composition may have excellent adhesion and excellent repellency under high temperature and high humidity environments.

Specifically, the pressure-sensitive adhesive composition comprises both a photopolymerizable resin formed from a mixed monomer component containing acrylic acid in the above-described range, thereby providing both initial adhesion suitable for application to a narrow bezel portion, adhesion retention under a high temperature and high humidity environment, and excellent repellency. Can be secured.

The acrylic acid is a monomer having high polarity, and can improve adherend and adhesion. Specifically, the acrylic acid interacts with a functional group on the surface of the adherend to increase the adhesive force over time, and the peelability of the adhesive tape formed from the pressure-sensitive adhesive composition may decrease. Thus, by containing the acrylic acid in the content of the above range, the pressure-sensitive adhesive composition can impart initial adhesion suitable for application to a narrow bezel portion and adhesion retention under a high temperature and high humidity environment.

Further, the acrylic acid may react with the crosslinkable monomer. Specifically, the pressure-sensitive adhesive composition may include a glycidyl group-containing (meth) acrylate that is a crosslinkable monomer in addition to the photopolymerization resin formed from the mixed monomer component containing the acrylic acid. At this time, the glycidyl group-containing (meth) acrylate may form a cross-linking structure connecting the photopolymerizable resins by reacting with the photopolymerizable resin while the ring of the glycidyl group is opened under conditions of high temperature and high humidity. As a result, the pressure-sensitive adhesive composition can implement an appropriate crosslinking density and excellent flexibility.

In addition, the pressure-sensitive adhesive composition, the mixed monomer component contains acrylic acid in the content of the above range, and at the same time, the photopolymerized resin prepared from the mixed monomer component has a weight average molecular weight of the above-described range and the initial adhesive strength of the required level and Adhesion holding power and excellent repellency can be secured.

The mixed monomer component for preparing the photopolymerizable resin may include the first alkyl (meth) acrylate together with the second alkyl (meth) acrylate and the acrylic acid. For example, the mixed monomer component may be composed of only the first alkyl (meth) acrylate, the second alkyl (meth) acrylate, and acrylic acid. At this time, the mixed monomer component includes about 6% by weight to about 8% by weight of acrylic acid as described above, and at the same time may include a second alkyl (meth) acrylate in the above-described range of content, furthermore, The content of the first alkyl (meth) acrylate may be determined so that the total sum is 100% by weight.

The first alkyl (meth) acrylate has an alkyl group having 4 to 15 carbon atoms, and provides excellent initial adhesion of the pressure-sensitive adhesive through its type and content, and can easily control the adhesion to a required level.

Specifically, the first alkyl (meth) acrylate may have a straight or pulverized alkyl group having 4 to 15 carbon atoms. Since the first alkyl (meth) acrylate has a straight or pulverized alkyl group in the carbon number range, it is possible to easily control the initial adhesive strength and peel strength to the plastic substrate of the adhesive to a required level.

More specifically, the first alkyl (meth) acrylate may include one selected from the group consisting of ethylhexyl (meth) acrylate, butyl (meth) acrylate, isooctyl (meth) acrylate, and combinations thereof. have.

The pressure-sensitive adhesive composition may contain 8 to 12% by weight of the photopolymerizable resin. Specifically, the photopolymerizable resin is formed by photopolymerization of a mixed monomer component comprising a first alkyl (meth) acrylate, a second alkyl (meth) acrylate, and acrylic acid, and by including a photopolymerization resin in a content within the above range, While implementing a sufficiently good level of adhesion, the viscosity may not be excessively increased.

The pressure-sensitive adhesive composition may further include one selected from the group consisting of a photo-curable monomer, a photo-curing agent, a photo-initiator, and combinations thereof, apart from the photopolymerizable resin and the crosslinkable monomer.

The photo-curable monomer is different from the cross-linkable monomer, and is a compound capable of chemically bonding to the photo-polymerizable resin by irradiation of light energy at room temperature or performing a polymerization reaction between photo-curable monomers, through which the adhesive composition Silver photocuring can achieve an appropriate gel content.

The photocurable monomer may include the same type of monomer as the monomer of the mixed monomer component constituting the photopolymerization resin. More specifically, the photocurable monomer may be derived from a mixed monomer component used in the production of the photopolymerizable resin, but both are distinguished from each other, and unlike the mixed monomer component, exist in a monomer form in the pressure-sensitive adhesive composition. . At this time, the photo-curable monomers play a different role from the mixed monomer components constituting the photopolymerization resin in the process of curing the pressure-sensitive adhesive composition by light energy. Therefore, even if the monomer of the mixed monomer component and the photocurable monomer are the same compound, both have different influences on related properties, such as the adhesion retention performance, initial adhesion, and repellency of the pressure-sensitive adhesive composition.

In addition, the photo-curable monomer is from the group consisting of other alkyl (meth) acrylate, hydroxyl group-containing (meth) acrylate, carboxyl group-containing (meth) acrylate, and combinations thereof, in addition to the mixed monomer component used in the production of the photopolymerizable resin. It may further include a selected one.

For example, the alkyl (meth) acrylate is the first alkyl (meth) acrylate having an alkyl group having 4 to 15 carbon atoms, the second alkyl (meth) acrylate having an alkyl group having 1 to 3 carbon atoms, 16 carbon atoms It may include one selected from the group consisting of alkyl (meth) acrylate and a combination thereof having the above alkyl group, but is not limited thereto.

Examples of the hydroxy group-containing (meth) acrylate include one selected from the group consisting of 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxyethylacrylamide, and combinations thereof. It may include, but is not limited thereto.

Examples of the carboxyl group-containing (meth) acrylate include β-carboxyethyl (meth) acrylate, (meth) acrylic acid, itaconic acid, maleic acid, fumaric acid, vinyl acetate, acrylic acid, methacrylic acid, fumaric acid, maleic acid and their It may include one selected from the group consisting of a combination, but is not limited thereto.

In addition, the photocuring agent is 2,4-trilene diisocyanate, 2,6-triene diisocyanate, hydrogenated trilene diisocyanate, 1,3-xylene diisocyanate, 1,4-xylene diisocyanate, diphenyl methane- 4,4-diisocyanate, 1,3-bisisocyanatomethyl cyclohexane, tetra methyl xylene diisocyanate, 1,5-naphthalene diisocyanate, 2,2,4-trimethyl hexamethylene diisocyanate, 2,4,4- Selected from the group consisting of trimethyl hexamethylene diisocyanate, trimethylene diisocyanate adduct of trimethylolpropane, xylene diisocyanate adduct of trimethylolpropane, toriphenylmethanetoriisocyanato, methylene bis triisocyanate, and combinations thereof. It may include one, but is not limited thereto. The photocuring agent can increase the degree of crosslinking of the photocurable resin, and can easily control the initial adhesion and peel strength to required levels.

The photoinitiator is an alpha-ketone-based compound, acetophenone-based compound, ketal-based compound, aromatic sulfonyl chloride-based compound, photoactive oxime-based compound, benzophenone-based compound, thioxanthone-based compound, campoquinone-based compound, halogenated ketone-based compound , Acylphosphinoxide-based compounds, acylphosphonate-based compounds, and combinations thereof, may or may not include one selected from the group, but is not limited thereto. The photoinitiator is activated by radiation or ultraviolet rays, and acts to initiate a curing reaction by activating a double bond between carbons.

The pressure-sensitive adhesive composition may be applied to the bezel portion of the display, wherein the width of the bezel portion may be about 2 mm to about 5 mm.

In a device including a display, a bezel portion corresponding to an edge of a display screen is gradually narrowing in line with a recent trend to expand a display. At this time, the pressure-sensitive adhesive composition may be applied to a bezel portion having a narrow width of about 2 mm to about 5 mm, and may exhibit excellent adhesion performance to an area.

In addition, excellent processability can be realized in a process in which the adhesive tape manufactured using the adhesive composition is molded and cut into a shape suitable for a bezel portion having a narrow width. In the case of a general adhesive tape, when cutting to have a narrow shape, there is a problem in that the adhesive is stuck to the cutting tool and difficult to manufacture in a desired shape. However, although the adhesive composition is cut to have a narrow width shape of the adhesive tape prepared using the adhesive composition, the cutting interface may be cut with a clean contour. In addition, the part that is cut and released is attached to the plastic substrate and is released. By using the pressure-sensitive adhesive composition, it can exhibit a high peel strength to the plastic substrate, which can help accurate release, and as a result, a defective rate in the manufacturing process of the adhesive tape. Can be reduced.

In addition, the pressure-sensitive adhesive composition may be applied to a narrow bezel portion of a display to exhibit excellent adhesion retention and excellent repulsion resistance under a high temperature and high humidity environment, and implement excellent adhesion performance to an area.

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

The pressure-sensitive adhesive layer is prepared using the pressure-sensitive adhesive composition, may be specifically formed of a photocured product of the pressure-sensitive adhesive composition. As a result, the adhesive layer can secure initial adhesion to a plastic substrate and adhesion retention under a high temperature and high humidity environment in an appropriate range, and at the same time, excellent repellency. As a result, the adhesive tape can secure properties suitable for application to the display bezel portion as described above.

The photocured product may be formed by irradiating light energy to the pressure-sensitive adhesive composition, and may be formed by curing the photopolymerization resin in the pressure-sensitive adhesive composition by specifically irradiated light energy. In this case, the photocured product may include a crosslinkable monomer containing a glycidyl group-containing (meth) acrylate. For example, the glycidyl group of the crosslinkable monomer contained in the photocured product may exist in a free state.

Specifically, the photocured product may be formed by photocuring the pressure-sensitive adhesive composition at room temperature. The room temperature may be about 23 ℃ to about 25 ℃. At this time, the glycidyl group-containing (meth) acrylate, which is a crosslinkable monomer included in the pressure-sensitive adhesive composition, is a material having crosslinking reactivity under high temperature and high humidity as described above, and does not crosslink in a photocuring reaction in the temperature range. . Specifically, in the photocuring reaction in the above temperature range, the ring of the glycidyl group-containing (meth) acrylate is not opened and does not react with the photopolymerization resin, and thus does not form a crosslinking structure connecting the photopolymerization resins. That is, the glycidyl group-containing (meth) acrylate is present as a monomer in the photocured product.

The adhesive tape may be placed in an environment of high temperature and high humidity during or after the process of being applied to the final product. At this time, the conventional acrylic adhesive tape may have problems such as low adhesion and low rebound resistance in high temperature and high humidity environments, such as excitation, air bubbles, and the like.

In one embodiment, the adhesive tape may realize excellent physical properties by a crosslinking reaction of the crosslinkable monomer under a high temperature and high humidity environment by including an adhesive layer composed of a photocured product containing a crosslinkable monomer. That is, the crosslinkable monomer can be imparted with excellent flexibility and tackiness to the adhesive layer by performing a crosslinking reaction with the photopolymerizable resin in an environment of high temperature and high humidity.

Further, the pressure-sensitive adhesive layer containing a photocured product of the pressure-sensitive adhesive composition may have a gel content of about 40% to about 50%, for example, about 42% to about 45%. The 'gel content' may be calculated by Equation 1 below.

[Equation 1]

Gel content (%) = W ₂ / W ₁ * 100

In Equation 1, the W ₁ refers to the 'first mass' obtained by measuring the mass of the target hardened material specimen to measure the gel content, and the W ₂ is immersed in the solvent in the initial mass of the hardened specimen specimen at room temperature. It means 'later mass', which is the mass (mass) of a specimen obtained by leaving it for a certain period of time, filtering it using a strainer, and drying the remaining specimen at a constant temperature for a period of time.

The solvent may be, for example, chloroform, ethyl acetate, acetone, methanol, ethanol, isopropanol, butanol, dimethylformamide, and the like, and the filtering device may use, for example, about 200 mesh wire mesh, but is not limited thereto. It does not work.

The time for immersing the specimen in a solvent and allowing it to stand can be left for, for example, about 24 to about 48 hours, but it is sufficient as long as other components except the gel can be dissolved and separated in the solvent, and is not particularly limited. .

In addition, the conditions of the temperature and time for drying the specimen obtained by the filtering device may be, for example, from about 100 ° C to about 150 ° C, for about 1 hour to about 2 hours, but a temperature sufficient to dry the specimen. And under conditions of time, it is not particularly limited.

The gel content of the adhesive layer satisfies the above range, thereby maintaining an appropriate cohesive force, and may have an effect of maintaining an adhesive force in an environment of high temperature and high humidity. Through this, it is possible to realize excellent adhesion and at the same time to secure repellency and processability.

1 is a cross-sectional view schematically showing a cross-section of an adhesive tape according to an embodiment. When referring to this, the adhesive tape 100 may be, for example, a double-sided adhesive tape. In this case, specifically, the adhesive tape may have a structure including a core material 10 and an adhesive layer 20 obtained by photocuring the pressure-sensitive adhesive composition on both sides of the core material.

As described above, it is formed from a mixed monomer component comprising a first alkyl (meth) acrylate, a second alkyl (meth) acrylate and acrylic acid contained in the pressure-sensitive adhesive composition, the weight average molecular weight (Mw) is 5 million to Due to the photopolymerization resin of 10 million, the adhesive tape can secure an appropriate adhesive force in an environment of high temperature and high humidity. In addition, the glycidyl group-containing (meth) acrylate, which is a crosslinkable monomer included in the pressure-sensitive adhesive composition, may react with the photopolymerizable resin to form a crosslinked structure connecting photopolymerizable resins. As a result, appropriate crosslinking density and excellent flexibility can be imparted to the pressure-sensitive adhesive composition.

Accordingly, the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition can secure an appropriate adhesion under an environment of high temperature and high humidity, and at the same time, flexibility can be increased to an appropriate level to realize excellent repulsion resistance and excellent high temperature and high humidity reliability, thereby generating excitation, air bubbles and There is an advantage that can prevent the desorption phenomenon.

As described above, the adhesive tape may be applied to the display bezel portion, and the bezel portion may have a width of about 2 mm to about 5 mm.

For the core material, for example, a foamed substrate such as acrylic foam, polyethylene foam, polyurethane foam, or the like may be used, and plastics such as polyethylene terephthalate (PET) film, polycarbonate (PC) film, and polyvinyl chloride (PVC) film may be used. Films can also be used.

At this time, the thickness of the core material may be about 50 μm to about 55 μm. Further, the thickness of the adhesive layer may be about 100 μm to about 110 μm. Since the core material and the adhesive layer have a thickness in the above range, the entire thickness of the device including the display may be applied to the bezel portion without excessively thick, thereby exhibiting proper adhesive performance and adhesive retention. In addition, high efficiency of the process for manufacturing the adhesive tape can be secured.

Hereinafter, specific embodiments of the present invention are presented. However, the examples described below are only for specifically illustrating or describing the present invention, and the present invention should not be limited thereby.

< Example  And Comparative example >

Example  One

A mixed monomer component was prepared by mixing 5% by weight of acrylic acid (AA), 25% by weight of methyl acrylate (MA), and 70% by weight of ethylhexyl acrylate (EHA). A photopolymerizable resin having a weight average molecular weight (Mw) of 8 million was prepared from the mixed monomer component through photopolymerization. 10 parts by weight of the photopolymerizable resin, 90 parts by weight of a photocurable monomer compared to 100 parts by weight of a photopolymerizable resin, 0.1 parts by weight of HDDA as a photocuring agent, 0.3 parts by weight of Irg651 as a photoinitiator, and glycidyl methacrylate as a crosslinkable monomer (glycidyl methacrylate, GMA) was prepared in an adhesive composition containing 0.1 parts by weight.

Example  2

A mixed monomer component was prepared by mixing 6% by weight of acrylic acid (AA), 25% by weight of methyl acrylate (MA), and 69% by weight of ethylhexyl acrylate (EHA). A photopolymerizable resin having a weight average molecular weight (Mw) of 8 million was prepared from the mixed monomer component through photopolymerization. 10% by weight of the photopolymerizable resin, 90 parts by weight of a photocurable monomer compared to 100 parts by weight of the photopolymerizable resin, 0.1 parts by weight of HDDA as a photocuring agent, 0.3 parts by weight of Irg651 as a photoinitiator, and m = 0 in Chemical Formula 1 An adhesive composition comprising 0.1 parts by weight of glycidyl methacrylate (GMA) was prepared.

[Formula 1]

Example  3

A mixed monomer component was prepared by mixing 7% by weight of acrylic acid (AA), 25% by weight of methyl acrylate (MA), and 68% by weight of ethylhexyl acrylate (EHA). A photopolymerizable resin having a weight average molecular weight (Mw) of 8 million was prepared from the mixed monomer component through photopolymerization. 10 parts by weight of the photopolymerizable resin, 90 parts by weight of a photocurable monomer compared to 100 parts by weight of a photopolymerizable resin, 0.1 parts by weight of HDDA as a photocuring agent, 0.3 parts by weight of Irg651 as a photoinitiator, and glycidyl methacrylate as a crosslinkable monomer (glycidyl methacrylate, GMA) was prepared in an adhesive composition containing 0.1 parts by weight.

Example  4

A mixed monomer component was prepared by mixing 8% by weight of acrylic acid (AA), 25% by weight of methyl acrylate (MA), and 67% by weight of ethylhexyl acrylate (EHA). A photopolymerizable resin having a weight average molecular weight (Mw) of 8 million was prepared from the mixed monomer component through photopolymerization. 10 parts by weight of the photopolymerizable resin, 90 parts by weight of a photocurable monomer compared to 100 parts by weight of a photopolymerizable resin, 0.1 parts by weight of HDDA as a photocuring agent, 0.3 parts by weight of Irg651 as a photoinitiator, and glycidyl methacrylate as a crosslinkable monomer (glycidyl methacrylate, GMA) was prepared in an adhesive composition containing 0.1 parts by weight.

Example  5

A mixed monomer component was prepared by mixing 10% by weight of acrylic acid (AA), 25% by weight of methyl acrylate (MA), and 65% by weight of ethylhexyl acrylate (EHA). An adhesive composition comprising 0.1 parts by weight of glycidyl methacrylate (GMA) having a weight average molecular weight (Mw) of 8 million was prepared from the mixed monomer component through photopolymerization.

Example  6

The same as in Example 1, except that an adhesive composition comprising 0.1 parts by weight of 1,2 epoxy-9-decene (1,2 Epoxy-9-decene) having m = 1 in Chemical Formula 1 as a crosslinkable monomer was prepared. A pressure-sensitive adhesive composition was prepared by the method.

Example  7

Except for preparing a pressure-sensitive adhesive composition comprising 0.1 parts by weight of 4-hydrobutyl acrylate glycidyl ether (4HBAGE) of m = 2 in formula 1 as a crosslinkable monomer, Example 1 The pressure-sensitive adhesive composition was prepared in the same manner as.

Comparative example  One

An adhesive composition was prepared in the same manner as in Example 1, except that an adhesive composition containing 0.1 parts by weight of oxetane methacrylate (OMA) as a crosslinkable monomer was prepared.

Comparative example  2

A pressure-sensitive adhesive composition was prepared in the same manner as in Example 1, except that a pressure-sensitive adhesive composition comprising 0.1 parts by weight of tetrahydrofurfuryl methacrylate (THFMA) as a crosslinkable monomer was prepared.

Comparative example  3

A pressure-sensitive adhesive composition was prepared in the same manner as in Example 1, except that a photopolymerization resin having a weight average molecular weight (Mw) of 2 million was prepared from the monomer composition through photopolymerization.

Mixed monomer component Photopolymerization resin
[Mw] Adhesive composition MA [% by weight] AA [% by weight] EHA [% by weight] Photopolymerization resin [% by weight] Crosslinkable monomer Kinds Content [parts by weight] / 100 parts by weight of photopolymerizable resin Example 1 25 5 70 8 million 10 GMA 0.1 Example 2 25 6 69 8 million 10 GMA 0.1 Example 3 25 7 68 8 million 10 GMA 0.1 Example 4 25 8 67 8 million 10 GMA 0.1 Example 5 25 10 65 8 million 10 GMA 0.1 Example 6 25 6 69 8 million 10 m = 1 0.1 Example 7 25 6 69 8 million 10 m = 2 0.1 Comparative Example 1 25 6 69 8 million 10 OMA 0.1 Comparative Example 2 25 6 69 8 million 10 THFMA 0.1 Comparative Example 3 25 6 69 2 million 10 GMA 0.1

<Evaluation>

The pressure-sensitive adhesive compositions of Examples 1-7 and Comparative Examples 1-3 were applied on both sides of a substrate made of polyethylene terephthalate (PET) material, and under a temperature condition of 30 ° C., UV irradiation of about 1,800 mJ / cm ² was applied. UV curing was performed to form a photocured product. Thus, an adhesive tape including an adhesive layer containing a photocured product was prepared. Specifically, the pressure-sensitive adhesive tape is a double-sided pressure-sensitive adhesive tape in which the pressure-sensitive adhesive layers on both sides of the substrate are formed to a thickness of 100 μm, respectively.

Experimental Example  1: Curing degree (= gel content) (%)

With respect to the pressure-sensitive adhesive layer prepared from the pressure-sensitive adhesive composition of the Examples and Comparative Examples, the gel content [%] was measured by the following calculation formula 1.

<Calculation formula 1>

Curing degree (GEL,%) = (W ₂ / W ₁ ) × 100

In the above equation 1, the mass of the target hardened specimen to measure the degree of curing is measured to obtain the 'first mass (W ₁ )'. The mass (dry mass) of the specimen obtained by immersing the specimen of the cured product of the first weight in ethyl acetate solvent and standing at room temperature for 24 hours, after filtering using 200 mesh wire, and drying the remaining specimen at 110 ° C. for 2 hours It is referred to as 'later mass (W ₂ )' and the gel content was measured after storing the target hardened specimen at 50 ° C for 1 day, and the results are as shown in Table 2 below.

Experimental Example  2: Repulsion resistance

Measurement method: For each adhesive tape prepared with the adhesive composition of Examples 1-7 and Comparative Examples 1-3, the time at which each adhesive layer was peeled from plates of different materials was measured by the method described below. It was evaluated as repulsion resistance.

1) Prepare a first plate of size 155Ⅹ30Ⅹ0.5mm from aluminum material, prepare a second plate size of 170Ⅹ35Ⅹ2mm from polycarbonate material, and prepare them once with isopropyl acetate (IPA), as heptanes. Washed 3 times.

2) Each adhesive tape was cut to a size of 150 mm to 20 mm to prepare each specimen.

3) On the one side of the first plate, the vertical edges are aligned with each other to position the specimen, and then pressed and pressed twice with a 7kg roller, and then the vertical edges are aligned with each other on one side of the specimen. After the second plate was positioned, it was reciprocated and pressed twice with a 7 kg roller to form a laminated body specimen having a laminated structure of the second plate / the specimen / the first plate.

c) After aging the laminate specimen for 30 minutes at 60 ° C., a direction in which the horizontal (170 mm) of the second plate and the vertical (165 mm) of the test jig are parallel to a test jig made of aluminum having a size of 210Ⅹ165Ⅹ5mm. With both ends fitted, the laminate specimen was bent accordingly.

Accordingly, one of the both ends includes each layer (the second plate / the specimen / the first plate) of the laminate specimen, and the other is such that only the second plate is included.

d) The laminated specimen in the bent state was placed in a high-temperature and high-humidity chamber at 85 ° C / 85% condition and left for 2 hours, and at the end side including only the second plate, the laminated specimen on the second plate was 10. Observing at minute intervals, the specimen; and the time taken for at least one of the first plate and the second plate to be peeled were measured, and the results are shown in Table 2 below.

Experimental Example  3: Measurement of initial adhesion

In the pressure-sensitive adhesive layers prepared from the pressure-sensitive adhesive composition of Examples 1-3 and Comparative Examples 1-3, 20 minutes were maintained at room temperature after each pressure-sensitive adhesive layer was attached to a polycarbonate (PC) substrate. Subsequently, the peel strength was measured at a speed of 300 mm / min to measure the initial adhesive force [kgf / in ² ], and the results are as shown in Table 2 below.

Experimental Example  4: adhesion Retention  Measure

For each pressure-sensitive adhesive tape made of the pressure-sensitive adhesive composition of the Examples and Comparative Examples, two 60 mm × 25 mm rectangular SUS substrates are prepared, and then specimens corresponding to 1 inch * 1 inch are attached to both sides. After leaving for 2 hours, it was placed in a high-temperature / high-humidity chamber at 85 ° C / 85%, and the time to drop off was measured. The results are shown in Table 2 below.

Hardening degree
[%] Repulsion resistance (time) adhesiveness Initial adhesion (kgf / in2) Adhesion holding power (time) Example 1 38 24 hours 3.5 1 hours Example 2 42 24 hours 3.0 24 hours Example 3 48 6 hours 2.8 24 hours Example 4 50 4 hours 2.5 24 hours Example 5 56 1 hours 2.0 24 hours Example 6 42 24 hours 3.0 12 hours Example 7 42 24 hours 3.2 6 hours Comparative Example 1 45 1 hours 3.0 2 hours Comparative Example 2 43 30 minutes 3.0 1 hours Comparative Example 3 42 24 hours 2.8 2 hours

When referring to the results of Table 2, it can be seen that the adhesive tape prepared from the example satisfies both excellent repellency and high initial adhesive strength, and excellent adhesive retention strength, compared to the adhesive tape prepared from the comparative example. .

100: adhesive tape
10: heartwood
20: adhesive layer

Claims (17)

It is formed from a mixed monomer component comprising a first alkyl (meth) acrylate having an alkyl group having 4 to 15 carbon atoms, a second alkyl (meth) acrylate having an alkyl group having 1 to 3 carbon atoms, and acrylic acid, and has a weight average molecular weight (Mw ) Is 5 to 10 million photopolymerizable resin; And a crosslinkable monomer,
The crosslinkable monomer includes a glycidyl group-containing (meth) acrylate,
8 to 12% by weight of the photopolymerizable resin
Adhesive composition.
According to claim 1,
The crosslinkable monomer has a crosslinking reactivity at 60 ° C to 90 ° C and a relative humidity of 50% to 90%.
Adhesive composition.
According to claim 1,
The glycidyl group-containing (meth) acrylate has the structure of Formula 1
Adhesive composition.
[Formula 1]

(R ₁ is hydrogen or a methyl group, m is an integer from 0 to 10)
According to claim 1,
The mixed monomer component comprises 20% to 40% by weight of the second alkyl (meth) acrylate
Adhesive composition.

According to claim 1,
The mixed monomer component contains 6% to 8% by weight of the acrylic acid
Adhesive composition.
According to claim 1,
The first alkyl (meth) acrylate comprises one selected from the group consisting of ethyl hexyl (meth) acrylate, butyl (meth) acrylate, isooctyl (meth) acrylate, and combinations thereof
Adhesive composition.
According to claim 1,
The second alkyl (meth) acrylate comprises one selected from the group consisting of methyl (meth) acrylate, ethyl (meth) acrylate, and combinations thereof
Adhesive composition.
delete According to claim 1,
Photocurable monomer, photocuring agent, photoinitiator, and further comprising one selected from the group consisting of combinations thereof
Adhesive composition.
The method of claim 9,
The photocurable monomer includes one selected from the group consisting of alkyl (meth) acrylate, hydroxyl group-containing (meth) acrylate, carboxyl group-containing (meth) acrylate, and combinations thereof.
Adhesive composition.
The method of claim 9,
The photocuring agent is 2,4-trilene diisocyanate, 2,6-triene diisocyanate, hydrogenated trilene diisocyanate, 1,3-xylene diisocyanate, 1,4-xylene diisocyanate, diphenyl methane-4, 4-diisocyanate, 1,3-bisisocyanatomethyl cyclohexane, tetra methyl xylene diisocyanate, 1,5-naphthalene diisocyanate, 2,2,4-trimethyl hexamethylene diisocyanate, 2,4,4-trimethyl hexa One selected from the group consisting of methylene diisocyanate, trimethylene diisocyanate adduct of trimethyrolpropane, xylene diisocyanate adduct of trimethyrolpropane, toriphenylmethanetoriisocyanato, methylene bis triisocyanate, and combinations thereof. Containing
Adhesive composition.
The method of claim 9,
The photoinitiator is an alpha-ketone-based compound, acetophenone-based compound, ketal-based compound, aromatic sulfonyl chloride-based compound, photoactive oxime-based compound, benzophenone-based compound, thioxanthone-based compound, campoquinone-based compound, halogenated ketone-based compound , Acyl phosphoxide-based compound, acyl phosphonate-based compound and one selected from the group consisting of a combination thereof
Adhesive composition.
According to claim 1,
The pressure-sensitive adhesive composition is applied to the bezel portion of the display, and the bezel portion has a width of 2 mm to 5 mm.
Adhesive composition.
An adhesive tape having an adhesive layer comprising a photocured product of the adhesive composition according to any one of claims 1 to 7 or 9 to 13.
The method of claim 14,
The photocured product is formed by photocuring the pressure-sensitive adhesive composition at room temperature.
Adhesive tape.
The method of claim 14,
The photocured product comprises a crosslinkable monomer containing a glycidyl group-containing (meth) acrylate
Adhesive tape.
The method of claim 14,
The gel content of the adhesive layer is 40% to 50%
Adhesive tape.

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