KR102131180B1 - 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 a carboxyl group-containing (meth)acrylate , Photopolymerizable resin having a weight average molecular weight (Mw) of 5 to 10 million; Crosslinkable monomers; And a urethane oligomer which is a crosslinking agent, wherein the crosslinkable monomer is provided with an 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 easy to process and cut so as to correspond to the shape of the narrow bezel, and despite the small area, it must exhibit excellent adhesion performance during the manufacturing process and after use.

One embodiment of the present invention, when applied to a narrow bezel, exhibits excellent processability and cutability, excellent durability and adhesion to a small area, has excellent repellency, and provides an adhesive composition having high adhesion at high temperatures do.

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, 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 and the carboxyl group-containing (meth)acrylate A photopolymerizable resin formed from a mixed monomer component containing and having a weight average molecular weight (Mw) of 5 to 10 million; Crosslinkable monomers; And a urethane oligomer which is a crosslinking agent, and 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 to show excellent repulsion resistance and adhesion retention under a high temperature and high humidity environment, and it is possible to improve processability and cutability by implementing appropriate adhesion to a plastic substrate, and can realize improved adhesion at high temperatures. have.

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 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, thicknesses are enlarged to clearly represent 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 of 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, 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 and the carboxyl group-containing (meth)acrylate A photopolymerizable resin formed from a mixed monomer component containing and having a weight average molecular weight (Mw) of 5 to 10 million; Crosslinkable monomers; And a urethane oligomer which is a crosslinking agent, and 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 adhesion retention under high temperature and high humidity environments.

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 respectively formed of different materials, are adhered through an adhesive tape, and the adhesive tape may be formed of, for example, an acrylic adhesive.

However, acrylic adhesives that are commonly used have low rebound resistance when sticking parts of different materials, resulting in excitement, bubbles, etc. in high temperature and high humidity conditions, and reduced adhesion in high temperature environments, and even there is a problem of detachment. Can.

The pressure-sensitive adhesive composition includes a crosslinkable monomer and a urethane oligomer which is a crosslinking agent together with the photopolymerizable resin, so that excellent repulsion resistance and excellent high temperature and high humidity reliability can be achieved, preventing lifting and foaming, and significantly improved adhesion even in a high temperature environment You can implement

The pressure-sensitive adhesive composition includes a urethane oligomer that is a crosslinking agent, and as described below, a curing reaction may occur due to irradiated light energy, and at this time, it reacts with a photopolymerization resin to increase the degree of crosslinking of the photocured product and impart excellent flexibility. .

Specifically, the urethane oligomer, which is a crosslinking agent, may be a photocurable urethane acrylic oligomer obtained by reacting a polyol and a polyisocyanate compound as a complex of an acrylic monomer and a urethane acrylate compound. For example, the crosslinking agent may be a bifunctional aliphatic urethane acrylate having two acrylate groups at the ends. The urethane oligomer crosslinking agent can improve the adhesion of the adhesive tape formed from the pressure-sensitive adhesive composition containing it.

The urethane oligomer has a large molecular weight and a long chain structure. The pressure-sensitive adhesive composition, by including the urethane oligomer, has a long chain between cross-linking points, and its molecular weight is large, so it is possible to increase the degree of hardening without significantly increasing the cohesive force, and accordingly, the stress relaxation characteristics are improved, thereby lowering the peel strength. It is possible to increase the high-temperature shear strength without being carried out. In addition, excellent flexibility can be imparted to the pressure-sensitive adhesive prepared from the pressure-sensitive adhesive composition.

The urethane oligomer may have a weight average molecular weight (Mw) of about 1,200 to about 1,800. The urethane oligomer, which is a crosslinking agent included in the pressure-sensitive adhesive composition, has a weight average molecular weight in the above range, thereby providing excellent flexibility to the pressure-sensitive adhesive prepared therefrom.

In addition, the pressure-sensitive adhesive composition containing the urethane oligomer that is the cross-linking agent can easily control the cross-linking reaction, form an appropriate degree of cross-linking, and realize high adhesion even at room temperature and high durability even at high temperatures. ,

The pressure-sensitive adhesive composition may include about 0.1% to about 0.5% by weight of urethane oligomer. By adjusting the content of the urethane oligomer to the appropriate range, the urethane oligomer can appropriately control the crosslinking reaction and the degree of curing with the photopolymerizable resin and the like, thereby curing the pressure-sensitive adhesive composition to have an appropriate crosslinking density, narrow bezel portion It is possible to secure both initial adhesion suitable for application to, adhesion retention under high temperature and high humidity environments, and excellent repellency.

The pressure-sensitive adhesive composition includes a crosslinkable monomer in addition to the photopolymerization resin and a urethane oligomer which is a crosslinking agent. The crosslinkable monomer may react with the photopolymerizable resin to form a crosslinking structure connecting photopolymerizable resins. The photopolymerizable resin is formed from a mixed monomer component containing a carboxyl group-containing (meth)acrylate as described above, and contains a carboxyl group in the structure. For example, the crosslinkable monomer reacts with the carboxyl group of the photopolymerizable resin to form a photopolymerizable resin. It can play a role of crosslinking.

Specifically, the crosslinkable monomer does not have crosslinking reactivity at room temperature, and may be a material having 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 show crosslinking reactivity.

The crosslinkable monomer does not undergo a crosslinking reaction at room temperature, and both ends of the crosslinkable monomer react with the photopolymerizable resin to form a crosslinked 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 and foaming, and having improved adhesion at high temperatures.

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 can 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 crosslinking 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% Can have crosslinking reactivity at

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, an acrylate group thereof, which is at least a part of the crosslinkable monomer, may undergo a photocuring reaction with the photopolymerizable resin, but the oxygen-containing heterocycloalkyl group of the crosslinkable monomer does not undergo a crosslinking reaction. 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 curing conditions, temperature, and humidity appropriately in the curing step of the pressure-sensitive adhesive composition.

The crosslinkable monomer is capable of imparting an appropriate crosslinking density and excellent flexibility by crosslinking with a photopolymerizable resin when the photosensitive material is placed under conditions of high temperature and high humidity after the adhesive composition is photocured, and as a result, high temperature and high humidity It can show excellent adhesion and reliability under the environment.

The cross-linkable monomer constitutes an adhesive composition together with a photopolymerizable resin and urethane oligomer formed by photopolymerization, thereby exhibiting high cohesion and high resistance to heat, realizing improved initial adhesion, and further improved adhesion and high adhesion under high temperature and high humidity environments. It can have, and at the same time it is possible to implement excellent repulsion resistance and high temperature and high humidity reliability.

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 preparing 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 includes 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 a carboxyl group-containing (meth)acrylate Can be formed from mixed monomer components. For example, the photopolymerizable resin may be formed from a mixed monomer component composed of only the first alkyl (meth)acrylate, second alkyl (meth)acrylate, and carboxyl group-containing (meth)acrylate.

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-described 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, the repellency is low, and it is possible to prevent the occurrence of excitation, 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 straight 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, specifically about 5 °C to about 15 °C. Since the mixed monomer component includes a second alkyl (meth)acrylate having a glass transition temperature in the above range, it is possible to realize a high peel strength 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, the repellency is low, and it is possible to prevent the occurrence of excitation, 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 narrow-area bezel, thereby minimizing the effect of this scent, and by using the second alkyl (meth)acrylate in a required level of content. Advantages of realizing physical properties can be secured.

The mixed monomer component may include about 6% to about 8% by weight of the carboxyl group-containing (meth)acrylate. By adjusting the content of the carboxyl group-containing (meth)acrylate to the appropriate range, the pressure-sensitive adhesive composition can have excellent adhesion and excellent repellency under a high temperature and high humidity environment.

Specifically, the pressure-sensitive adhesive composition comprises a photopolymerization resin formed from a mixed monomer component containing a carboxyl group-containing (meth)acrylate in an amount in the above range, and is suitable for being applied to a narrow bezel part, and maintains adhesion under a high temperature and high humidity environment, and All excellent repulsion resistance can be secured.

The carboxyl group-containing (meth)acrylate is a monomer having high polarity, and can improve adherend and adhesion. Specifically, the carboxyl group-containing (meth)acrylate interacts with a functional group on the surface of the adherend to increase the adhesive strength over time, so that the peelability of the adhesive tape formed from the pressure-sensitive adhesive composition may decrease. Thus, by containing the carboxyl group-containing (meth)acrylate in an amount in 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.

And, the carboxyl group-containing (meth)acrylate can also react with the crosslinkable monomer. Specifically, the pressure-sensitive adhesive composition may include a photopolymerizable resin formed from a mixed monomer component containing the carboxyl group-containing (meth)acrylate, a urethane oligomer, and a glycidyl group-containing (meth)acrylate that is a crosslinkable monomer. 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, in the pressure-sensitive adhesive composition, the mixed monomer component contains the carboxyl group-containing (meth)acrylate in an amount in the above range, and at the same time, the photopolymerizable resin prepared from the mixed monomer component has a weight average molecular weight in the above-mentioned range. It is possible to secure both the initial adhesive strength and adhesive holding strength of the required level and excellent repulsion resistance.

Specifically, the carboxyl group-containing (meth)acrylate is one selected from the group consisting of (meth)acrylic acid, crotonic acid, maleic acid, fumaric acid, and combinations thereof. Can be

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 carboxyl group-containing (meth)acrylate. For example, the mixed monomer component may be composed of only the first alkyl (meth)acrylate, the second alkyl (meth)acrylate, and the carboxyl group-containing (meth)acrylate. At this time, the mixed monomer component includes from about 6% by weight to about 8% by weight of the carboxyl group-containing (meth)acrylate as described above, and at the same time, the second alkyl (meth)acrylate in the above-mentioned range In addition, the content of the first alkyl (meth)acrylate may be determined such 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 adhesive strength of the pressure-sensitive adhesive through its type and content, and can easily control the peel strength 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 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.

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 a carboxyl group-containing (meth)acrylate, with a content within the above range By including a photopolymerizable resin, it is possible to implement a sufficiently good level of tackiness while not excessively increasing the viscosity.

The pressure-sensitive adhesive composition can implement a high adhesion strength without containing a tackifier. While the general pressure-sensitive adhesive composition includes a tackifier to enhance adhesion, the pressure-sensitive adhesive composition can implement a higher adhesion at room temperature by including urethane oligomers and crosslinkable monomers together with a photopolymerizable resin, except for the tackifier, , Excellent repulsion resistance and excellent high temperature and high humidity reliability can be prevented, lifting and bubble generation are prevented, and remarkably improved adhesion can be realized even at high temperatures. In addition, it is economical because a high tackiness can be realized at the same time without including an expensive tackifier.

The pressure-sensitive adhesive composition may further include one selected from the group consisting of a photocurable monomer, a photoinitiator, a silane coupling agent, and combinations thereof, separately from the photopolymerizable resin, urethane oligomer, and crosslinkable monomer.

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

The photocurable monomer may include a monomer of the same type as the monomer of the mixed monomer component constituting the photopolymerization resin. More specifically, the photocurable monomer may be derived from the 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 monomer plays a different role from the mixed monomer component 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 photocurable monomer may further include one selected from the group consisting of other alkyl (meth)acrylates, hydroxyl group-containing (meth)acrylates, and combinations thereof, in addition to the mixed monomer components used in the production of the photopolymerizable resin. .

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 is 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.

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 may be selected from the group consisting of a combination thereof, may or may not include, 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 silane coupling agent is γ-glycidoxypropyl trimethoxy silane, γ-glycidoxypropyl methyl diethoxy silane, γ-glycidoxy propyl triethoxy silane, 3-mercaptopropyl trimethoxy silane, vinyl tree Methoxy silane, vinyl triethoxy silane, γ-methacryloxypropyl trimethoxy silane, γ-methacryloxypropyl triethoxy silane, γ-aminopropyl trimethoxy silane, γ-aminopropyl triethoxy silane, 3-isocyanatepropyltriethoxy silane, γ-acetoacetatepropyltrimethoxy silane, and combinations thereof. The silane coupling agent may improve adhesion and adhesion stability between the cured product and the adherend, thereby improving heat resistance and moisture resistance. In addition, when appropriately added, the silane coupling agent can improve the adhesion reliability of the cured product under high temperature and/or high humidity.

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, the bezel part corresponding to the edge of the display screen is gradually narrowing in line with the recent trend to expand the 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 and released to the plastic substrate, and by using the pressure-sensitive adhesive composition, it can exhibit high peel strength to the plastic substrate to 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 an initial adhesive strength to a plastic substrate and a higher adhesive strength and adhesive 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 urethane oligomer contained in the pressure-sensitive adhesive composition has a long chain structure with a long distance between the cross-linking reaction sites, as described above, to easily control the cross-linking reaction, and can have a high adhesion at room temperature.

In addition, the pressure-sensitive adhesive composition is a crosslinkable monomer, a glycidyl group-containing (meth)acrylate is a material having crosslinking reactivity under high temperature and high humidity as described above, and does not have crosslinking reactivity in the 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, so that a crosslinking structure connecting the photopolymerization resins is not formed. That is, the glycidyl group-containing (meth)acrylate is present in the monomer state 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 be detached due to a decrease in adhesive strength in an environment of high temperature and high humidity, or may have problems such as excitation, air bubbles, etc. due to low repulsion resistance.

In one embodiment, the adhesive tape may implement excellent physical properties by crosslinking reaction of the crosslinkable monomer under a high temperature and high humidity environment by including an adhesive layer composed of a urethane oligomer and 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 under a high temperature and high humidity environment.

In addition, 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 the specimen obtained by leaving it for a 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 can be left for about 24 hours to about 48 hours, for example, but it is sufficient as long as the components other than 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 adhesiveness 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, formed from a mixed monomer component comprising a first alkyl (meth) acrylate, a second alkyl (meth) acrylate and a carboxyl group-containing (meth) acrylate included in the pressure-sensitive adhesive composition, the weight average molecular weight ( Due to the photopolymerization resin having a Mw) of 5 to 10 million, the adhesive tape can secure improved adhesive strength in an environment of high temperature and high humidity. In addition, the urethane oligomer contained in the pressure-sensitive adhesive composition improves the adhesion, and the cross-linking structure in which the crosslinkable monomer-containing glycidyl group (meth)acrylate contained in the pressure-sensitive adhesive composition reacts with the photopolymerization resin to connect the photopolymerization resins to each other Can form. 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 ensure adequate adhesion in 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.

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

For the core material, for example, a foamed substrate such as acrylic foam, polyethylene foam, or polyurethane foam 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 from 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 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 wt% of the photopolymerizable resin, 80 wt% of a photocurable monomer, 0.3 wt% of an urethane oligomer, an aliphatic urethane acrylate (SUO 1020, Mw 1800), and glycidyl methacrylate as a crosslinkable monomer (glycidyl methacrylate, GMA) to prepare an adhesive composition containing 0.1% by weight.

Comparative example One

A pressure-sensitive adhesive composition was prepared in the same manner as in Example 1, except that a pressure-sensitive adhesive composition was prepared without containing glycidyl methacrylate (GMA) as a crosslinkable monomer.

Comparative example 2

A pressure-sensitive adhesive composition was prepared in the same manner as in Comparative Example 1, except that a pressure-sensitive adhesive composition containing 0.3% by weight of aziridine crosslinking agent (Mw 200) instead of the urethane oligomer was prepared.

Comparative example 3

A pressure-sensitive adhesive composition was prepared in the same manner as in Example 1, except that a pressure-sensitive adhesive composition containing 0.3% by weight of aziridine crosslinking agent (Mw 200) instead of the urethane oligomer was prepared.

Comparative example 4

A pressure-sensitive adhesive composition was prepared in the same manner as in Comparative Example 2, except that a pressure-sensitive adhesive composition containing 10% by weight of a rosin-based tackifier (SP 560) as a photocurable monomer 70% and a tackifier was prepared.

Adhesive composition Photopolymer resin
[weight%] Crosslinker Crosslinkable monomer Tackifier Kinds Content [% by weight] Kinds Content [% by weight] Type (content) Example 1 10 SUO 1020 0.3 GMA 0.1 - Comparative Example 1 10 SUO 1020 0.3 GMA - - Comparative Example 2 10 Aziridine crosslinker 0.3 GMA - - Comparative Example 3 10 Aziridine crosslinker 0.3 GMA 0.1 - Comparative Example 4 10 Aziridine crosslinker 0.3 GMA - SP560
(10% by weight)

<Evaluation>

The pressure-sensitive adhesive composition of Example 1 and Comparative Example 1-4 was applied on both surfaces of a polyethylene terephthalate (PET) material substrate, 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 each formed to a thickness of 100 μm.

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 cured product 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 leaving it 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 results are as shown in Table 2 below.

Experimental Example 3: Measurement of adhesive force

In the pressure-sensitive adhesive layer prepared from the pressure-sensitive adhesive composition of Example 1 and Comparative Example 1-4, after each pressure-sensitive adhesive layer was attached to a polycarbonate (PC) substrate, 20 minutes were maintained at room temperature (25° C.). Subsequently, the peel strength was measured at a speed of 300 mm/min to measure the adhesive strength [kgf/in ² ].

In addition, after each adhesive layer was attached to the polycarbonate (PC) substrate, 20 minutes were maintained at a high temperature of 80°C. Subsequently, the peel strength was measured at a rate of 300 mm/min to measure the adhesive force [kgf/in ² ], and the results are shown in Table 2 below.

Curing degree
[%] Adhesion (kgf/in2) Room temperature (25 ℃) High temperature (80 ℃) Example 1 47 2600 3100 Comparative Example 1 47 2600 1500 Comparative Example 2 48 1800 1050 Comparative Example 3 48 1800 2500 Comparative Example 4 40 1900 1100

When referring to the results of Table 2, Example 1, which contains urethane oligomer and crosslinkable monomer, glycidyl methacrylate (GMA), exhibits high adhesion even at room temperature, and unlike Comparative Examples 1 to 4, at high temperatures It can be seen that the adhesive strength does not decrease, and rather, the adhesive strength is further improved.

100: adhesive tape
10: heartwood
20: adhesive layer

Claims (16)

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 a carboxyl group-containing (meth)acrylate , Photopolymerizable resin having a weight average molecular weight (Mw) of 5 to 10 million; Crosslinkable monomers; And a urethane oligomer which is a crosslinking agent,
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 urethane oligomer has a weight average molecular weight (Mw) of 1,200 to 1,800
Adhesive composition.
According to claim 1,
0.1 to 0.5% by weight of the urethane oligomer
Adhesive composition.
According to claim 1,
The crosslinkable monomer has crosslinking reactivity at 60°C to 90°C and 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 contains the second alkyl (meth) acrylate 20% to 40% by weight
Adhesive composition.
According to claim 1,
The mixed monomer component contains 6 to 8% by weight of the carboxyl group-containing (meth)acrylate
Adhesive composition.
According to claim 1,
The carboxyl group-containing (meth)acrylate includes one selected from the group consisting of (meth)acrylic acid, crotonic acid, maleic acid, fumaric acid, and combinations thereof.
Adhesive composition.
delete According to claim 1,
Without tackifier
Adhesive composition.
According to claim 1,
Photocurable monomer, photoinitiator, silane coupling agent, and further comprising one selected from the group consisting of combinations thereof
Adhesive composition.
The method of claim 11,
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.
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 8 or 10 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 gel content of the adhesive layer is 40% to 50%
Adhesive tape.

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