KR102099961B1 - The adhesive composition and the adhesive tape - Google Patents

Abstract

Applied to the narrow bezel area of the mobile, it exhibits excellent reliability and repulsion resistance under a high temperature and high humidity environment, and implements proper initial adhesion to a plastic substrate to improve processability and cutability. It is formed from a mixed monomer component containing 8% by weight, the weight average molecular weight (Mw) of 5 to 10 million photopolymerizable resin; And it provides a pressure-sensitive adhesive composition comprising a curing agent having a weight average molecular weight (Mw) of 1000 to 6000. In addition, as an adhesive tape having an adhesive layer containing a photocured product of the pressure-sensitive adhesive composition, it is applied to a narrow bezel, has excellent reliability and adhesion performance in a high temperature and high humidity environment, and is cuttable and flowable in a process processed to suit a narrow bezel. This excellent adhesive tape is provided.

Description

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

Regarding the pressure-sensitive adhesive composition and the pressure-sensitive adhesive tape, specifically, it can be applied to a bezel part such as a display, exhibits excellent adhesion retention under a high temperature and high humidity environment, and is manufactured using the pressure-sensitive adhesive composition capable of realizing repellency of a certain level or more It relates to an adhesive tape.

2. Description of the Related Art In recent years, in the field of portable information terminal devices such as smart phones, the demand for expanding the size of a display continues to increase. When the size of the display increases, it can be very useful for viewing video content or reading an e-book. However, although the screen is expanded by increasing the size of the display, there are many demands for the device itself not to be large. In order to meet these needs, attempts have been made to reduce the size or width of the bezel located at the peripheral edge of the display. As such, the demand for the implementation of a narrow bezel is increasing, and the need for an adhesive film or an adhesive tape to be applied to the narrow bezel in accordance with this trend is also increasing. In order to be applied to a narrow bezel, it must be easy to process and cut so that the adhesive film or adhesive tape corresponds to the shape of the narrow bezel, and despite the small area, it is necessary to secure various physical properties during the manufacturing process and use after manufacturing.

An embodiment of the present invention exhibits excellent processability and cutability when applied to a narrow bezel, and has excellent adhesion retention under a high temperature and high humidity environment even for a small area, and may exhibit repellency of a certain level or higher.

Another embodiment of the present invention is a pressure-sensitive adhesive tape prepared using the pressure-sensitive adhesive composition, when applied to a narrow bezel, it has excellent reliability and adhesion performance in a high temperature and high humidity environment, and can secure repulsion resistance, and is suitable for a narrow bezel. It provides an adhesive tape excellent in cutability and distribution in the process of being processed.

In one embodiment of the present invention, it is formed from a mixed monomer component containing 6% to 8% by weight of acrylic acid, the weight average molecular weight (Mw) of 5 to 10 million photopolymerization resin; And it provides a pressure-sensitive adhesive composition comprising a curing agent having a weight average molecular weight (Mw) of 1000 to 6000.

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 can exhibit excellent processability and cutability when applied to a narrow bezel, and provides a pressure-sensitive adhesive composition capable of exhibiting excellent adhesion retention under a high temperature and high-humidity environment and exhibiting repellency over a certain level even in a small area.

The adhesive tape exhibits excellent cutability in the process of forming and processing to apply to a narrow bezel area of a mobile device, and can reduce the defect rate of mass production based on proper initial adhesive strength to a plastic substrate, and finally apply area Compared to this, it exhibits excellent repulsion resistance and can realize excellent adhesion retention performance in a high temperature and high humidity environment.

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 present 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 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, it is formed from a mixed monomer component containing 6% to 8% by weight of acrylic acid, the weight average molecular weight (Mw) of about 5 to about 8 million photopolymerization resin; And it provides a pressure-sensitive adhesive composition comprising a curing agent having a weight average molecular weight (Mw) of about 1000 to about 6000.

The pressure-sensitive adhesive composition includes a photopolymerizable resin, and the photopolymerizable resin may have a weight average molecular weight (Mw) of about 5 million to about 10 million. For example, the weight average molecular weight (Mw) of the photopolymerizable resin may be about 8 million to about 10 million. The pressure-sensitive adhesive composition by containing a photopolymerizable resin having a weight average molecular weight in the above range, compared to the resin having a weight average molecular weight (Mw) of about 4 million or less that has been used in the conventional pressure-sensitive adhesive, adhesion under a high temperature and high humidity environment with initial adhesion to a plastic substrate The holding power is improved, and may have the advantage of improving high temperature durability when curing.

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

The pressure-sensitive adhesive composition includes a curing agent having a weight average molecular weight (Mw) of about 1000 to about 6000 together with a photopolymerizable resin having a weight average molecular weight (Mw) in the above range. The pressure-sensitive adhesive composition, while including a curing agent having a weight average molecular weight (Mw) in the above range with the photopolymerizable resin, while at the same time ensuring excellent initial adhesion performance, at the same time can further improve the adhesion retention performance in a high temperature and high humidity environment, Resilience can also be secured by raising the level.

The 'resistance resistance' of the pressure-sensitive adhesive composition refers to a degree of preventing a lift-off phenomenon between the adherend and the pressure-sensitive adhesive when the pressure-sensitive adhesive composition is applied to an adherend having an uneven shape or a curved portion. It is excellent in resilience.

The weight average molecular weight (Mw) of the curing agent may be about 1000 to about 6000, for example, about 1000 to about 2000, for example, about 1000 to about 1500. The pressure-sensitive adhesive composition may improve repulsion resistance to a certain level or higher in a high temperature and high humidity environment through a curing agent having a weight average molecular weight (Mw) in the above range, and may be applied to a small area such as, for example, a bezel part of a display. Nevertheless, it is possible to effectively prevent the problem of deterioration over time or deterioration of durability due to excitation.

For example, the pressure-sensitive adhesive composition may include about 0.1% to about 10% by weight of the curing agent, specifically, about 0.1% to about 1.0% by weight. When the pressure-sensitive adhesive composition includes a curing agent in an amount within the above range, it is possible to maximize the effect of improving the resilience, and also secure excellent adhesion retention performance in a high temperature and high humidity environment.

 The curing agent may include an aliphatic urethane acrylate-based curing agent as a material that undergoes a crosslinking reaction with the photopolymerization resin by light energy. The aliphatic urethane acrylate-based curing agent is a structural unit of the formula (1); And an acrylate group at both ends of the main chain including a linear or branched alkylene structural unit having 1 to 20 carbon atoms.

 [Formula 1]

The aliphatic urethane acrylate-based curing agent may contain a large amount of oxygen atoms (O) in the chemical structure to impart soft physical properties to the pressure-sensitive adhesive composition, and can realize the effect of improving adhesion. That is, the aliphatic urethane acrylate-based curing agent can achieve an appropriate gel content together with the photopolymerizable resin, and can improve the effect of improving the resilience and adhesion retention performance.

As described above, the pressure-sensitive adhesive composition may include a photopolymerizable resin having a weight average molecular weight (Mw) of 5 to 10 million and a curing agent having a weight average molecular weight (Mw) of 1000 to 6000, thereby providing the required level of repulsion resistance. And adhesion retention performance.

The photopolymerizable resin is prepared from a mixed monomer component containing about 6% to about 8% by weight of acrylic acid as described above, and the acrylic acid content of the mixed monomer component is adjusted to the above range, under the high temperature and high humidity environment of the pressure-sensitive adhesive composition The adhesive holding force and the initial adhesive force can be controlled to a desired level.

That is, in the case of the pressure-sensitive adhesive composition, the higher the content of acrylic acid, the higher the cohesive force, the lower the initial adhesive strength, and the higher the high temperature and high humidity environment, the adhesion retention performance is improved. At this time, the pressure-sensitive adhesive composition according to one embodiment includes both a photopolymerization resin formed from a mixed monomer component containing acrylic acid in the above range of content, so that both the initial adhesive strength suitable for application to the bezel portion of the display and the adhesive retention strength under a high temperature and high humidity environment Can be secured.

In addition, the pressure-sensitive adhesive composition includes the acrylic monomer in the content of the above range of the mixed monomer component, and at the same time, the initial adhesive strength of the level required by the photopolymerized resin prepared from the mixed monomer component having a weight average molecular weight in the above range, and It is possible to secure all of the adhesive holding power.

The mixed monomer component for preparing the photopolymerizable resin may further include the first alkyl (meth) acrylate and the second alkyl (meth) acrylate together with the acrylic acid. The first alkyl (meth) acrylate having an alkyl group having 4 to 15 carbon atoms can appropriately control the soft properties of the pressure-sensitive adhesive through its type and content, and increase the initial adhesion when applied to the bezel part. Can play a role. In addition, the second alkyl (meth) acrylate has an alkyl group having 1 to 3 carbon atoms and can control the initial adhesive strength and peel strength of the adhesive to the plastic substrate through its type and content.

In one embodiment, the photopolymerizable resin may be formed from a mixed monomer component composed of only the first alkyl (meth) acrylate, second alkyl (meth) acrylate, and acrylic acid.

For example, the mixed monomer component may include about 20% to about 40% by weight of the second alkyl (meth) acrylate, specifically, about 30% to about 40% by weight, More specifically, it may include about 35% to about 40% by weight. When the content of the second alkyl (meth) acrylate exceeds about 40% by weight, there is a fear that curing of the pressure-sensitive adhesive composition does not occur well. Since the photopolymerizable resin is prepared from a mixed monomer component containing a second alkyl (meth) acrylate in a content in the above range, high initial adhesion to a plastic substrate can be achieved, and in the process of cutting and forming an adhesive tape such as a punching process It can show excellent workability.

For example, when the mixed monomer component is composed of only the first alkyl (meth) acrylate, the second alkyl (meth) acrylate, and acrylic acid, the mixed monomer component is from about 6% to about 8% by weight as described above It includes a weight% acrylic acid, and at the same time, the second alkyl (meth) acrylate may be included in a content in the aforementioned range, and further, the content of the first alkyl (meth) acrylate so that the total sum is 100% by weight. Can decide.

The first alkyl (meth) acrylate has an alkyl group having 4 to 15 carbon atoms, and specifically, may have a linear or pulverized alkyl group having 4 to 15 carbon atoms. Thus, an acrylate having an appropriate glass transition temperature (Tg) can be used as the first alkyl (meth) acrylate, which gives soft properties to the pressure-sensitive adhesive composition and gives initial adhesion when applying the bezel part. It can contribute greatly to improvement.

Specifically, the first alkyl (meth) acrylate may have a glass transition temperature (Tg) of about -80 ° C to about -20 ° C, for example, about -50 ° C to about -20 ° C.

Specifically, the first alkyl (meth) acrylate may include one selected from the group consisting of ethyl hexyl (meth) acrylate, butyl (meth) acrylate, isooctyl (meth) acrylate, and combinations thereof. .

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 0 ° C to about 15 ° C, specifically about 8 ° C to about 11 ° C, and more specifically, about It may be 10 ℃. The mixed monomer component may include a second alkyl (meth) acrylate having a glass transition temperature in the above range, thereby realizing high temperature durability during curing.

In addition, the second alkyl (meth) acrylate may have a weight average molecular weight of about 100 or less, for example, about 20 to about 60. Through the weight average molecular weight range, the second alkyl (meth) acrylate may implement excellent durability.

Specifically, the second alkyl (meth) acrylate may include one selected from the group consisting of methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, and combinations thereof. For example, the second alkyl (meth) acrylate may include methyl acrylate (MA), and 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 small area, thereby minimizing the influence of this scent, and by using the second alkyl (meth) acrylate at a required level, excellent physical properties. It is possible to secure the advantages to be implemented.

Specifically, 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 portion 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 in the above range, and may exhibit excellent adhesion performance despite application to a small area.

In addition, the pressure-sensitive adhesive composition can implement excellent processability in the process of molding and cutting the shape of the pressure-sensitive adhesive tape manufactured using it in a shape suitable for a bezel portion having a narrow width. In the case of a general adhesive film or an adhesive tape, when cutting to have a narrow width, 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 manufactured 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, by using the pressure-sensitive adhesive composition can exhibit a high peel strength to the plastic substrate can help the accurate release, as a result of the defect 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 the display to exhibit excellent adhesion retention under a high temperature and high humidity environment, and implement excellent adhesion performance and repulsion resistance to an area.

The pressure-sensitive adhesive composition may further include a photocurable monomer together with the photopolymerizable resin.

The photocurable monomer is a compound capable of performing a curing reaction by being combined with the photopolymerizable resin by light energy, or curing reaction between photocurable monomers, through which the pressure-sensitive adhesive composition may be cured to have an appropriate gel content.

The photocurable monomer is a monomer distinct from the monomers constituting the photopolymerizable resin, and when the pressure-sensitive adhesive composition is finally cured, its position and chemical bonding structure in the curing structure are different from each other, and as a result, the pressure-sensitive adhesive composition is formed. The influence on the final properties of the adhesive layer is different from each other. Therefore, even if the monomers belonging to the mixed monomer component constituting the photopolymerizable resin and the photocurable monomer are the same compound, both have different influences on the final physical properties of the pressure-sensitive adhesive composition.

That is, the photopolymerizable resin is prepolymerized by a predetermined photopolymerization condition from a mixed monomer component whose composition is properly controlled as described above, and the photocurable monomer is subsequently mixed with the photopolymerizable resin to form the photopolymerizable resin. It is a component that is clearly distinguished from monomers.

If the monomers for forming the photopolymerizable resin and the photocurable monomer are not initially distinguished, all of them are mixed to polymerize some monomers under a certain photopolymerization condition from a raw material composition composed of only monomers to form a photopolymerizable resin, and in the polymerization reaction. In the case where the monomer remaining without participation is a photocurable monomer, it is almost impossible to control the final properties to meet the purpose according to one embodiment of the present invention.

That is, in the process of forming a photopolymerization resin under a certain photopolymerization condition from the raw material composition, a photocurable monomer that is partially cured under the light energy condition may occur, and thus it is difficult to control the content ratio of the partially pre-cured photocurable monomer. Therefore, control of the final cured structure is practically impossible.

Specifically, the pressure-sensitive adhesive composition may include about 5% to about 20% by weight of the photopolymerizable resin, and about 80% to about 95% by weight of the photocurable monomer. The adhesive composition may include a photopolymerizable resin and a photocurable monomer in an amount within the above range to form a cured product having an appropriate gel content through an appropriate time curing process. In addition, the pressure-sensitive adhesive composition may secure an appropriate viscosity to ensure uniform coating properties required in the process of being manufactured with an adhesive tape.

The photocurable monomer is a monofunctional (meth) acrylate, and any monomer containing one (meth) acrylate group may be used without limitation, for example, ethylhexyl (meth) acrylate, butyl (meth) acrylic Rate, isooctyl (meth) acrylate, methyl (meth) acrylate, ethyl (meth) acrylate, acrylic acid, and combinations thereof.

That is, in one embodiment, the photocurable monomer may be made of a monomer of the same type as the monomer of the mixed monomer component for forming the photopolymerizable resin.

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 the initial adhesive strength to the plastic substrate and the adhesive retention strength under a high temperature and high humidity environment in an appropriate range. 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. When the pressure-sensitive adhesive composition further comprises a photocurable monomer, the photopolymerizable resin and the photocurable monomer may be cured together by irradiation of light energy.

The adhesive layer through the photocured product of the pressure-sensitive adhesive composition may have a gel content of about 10% to about 60%, for example about 15% to about 55%, for example about 25% to about 50 %. The 'gel content' is a value derived by Equation 1 below, and by controlling the gel content of the adhesive layer within the above range, it is possible to simultaneously implement excellent adhesion and high temperature durability. When the gel content is too high, it may be advantageous in terms of high temperature durability, but there is a problem that the adhesive strength is significantly lowered, and when the gel content is too low, it may be advantageous in terms of adhesive strength, but there is a fear that high temperature durability is significantly lowered.

[Equation 1]

Gel content (%) = B / A × 100

In Equation 1, A is the specimen of the adhesive layer, soaked in an ethyl acetate solvent and left at room temperature for 24 hours, filtered using a 200 mesh wire mesh, and the expanded mass, which is the mass of the remaining sample, and B is 110 ° C. Is the dry mass, which is the mass of the specimen obtained by drying for 2 hours.

1, the adhesive tape 100 may be, for example, a double-sided adhesive tape. In this case, specifically, the adhesive tape may have a structure of a core material 10 and an adhesive layer 20 formed on both sides of the core material.

The adhesive tape of the double-sided 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㎛ to about 55㎛. In addition, the thickness of the adhesive layer may be from about 100㎛ to about 110㎛. Process having a thickness of the above range of the core material and the adhesive layer can be applied to the bezel portion without making the overall thickness of the device including the display too thick, and can exhibit proper adhesive performance and adhesive retention, and the process of manufacturing the adhesive tape High efficiency of 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 is not limited thereto.

< Example  And Comparative example >

Example  One

A mixed monomer component was prepared by mixing 6% by weight of acrylic acid (AA), 35% by weight of methyl acrylate (MA), and 59% 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. Subsequently, the photopolymerizable resin containing 10% by weight of ethylhexyl acrylate (EHA), methyl acrylate (MA) and acrylic acid (AA) in a weight ratio of 59: 35: 6 contains 89.85% by weight of a photocurable monomer, weight An adhesive composition comprising 0.15% by weight of an aliphatic urethane acrylate-based curing agent (Shin-T & C, SUO-1020) having an average molecular weight (Mw) of 1800 was prepared.

Example  2

A mixture monomer component was prepared by mixing 7% by weight of acrylic acid (AA), 35% by weight of methyl acrylate (MA), and 58% by weight of ethylhexyl acrylate (EHA), from which the weight average molecular weight (Mw) was obtained through photopolymerization. 8 million photopolymerizable resins were prepared. Subsequently, the photopolymerizable resin containing 10% by weight of ethylhexyl acrylate (EHA), methyl acrylate (MA) and acrylic acid (AA) in a weight ratio of 58: 35: 7 as a photocurable monomer containing 89.85% by weight Except, the pressure-sensitive adhesive composition was prepared in the same manner as in Example 1.

Example  3

A mixed monomer component was prepared by mixing 8% by weight of acrylic acid (AA), 35% by weight of methyl acrylate (MA), and 57% by weight of ethylhexyl acrylate (EHA), from which the weight average molecular weight (Mw) was obtained through photopolymerization. 8 million photopolymerizable resins were prepared. Subsequently, except that it contains 89.85% by weight of the photo-curable monomer in which the photopolymerizable resin is mixed in a weight ratio of 57: 35: 8 and 10% by weight of ethylhexyl acrylate (EHA), methyl acrylate (MA) and acrylic acid (AA). And in the same manner as in Example 1 to prepare an adhesive composition.

Example  4

An adhesive composition was prepared in the same manner as in Example 1, except that the adhesive composition contained 0.3% by weight of the curing agent and 89.7% by weight of the photocurable monomer.

Example  5

The pressure-sensitive adhesive composition was prepared in the same manner as in Example 1, except that the weight-average molecular weight (Mw) of the isocyanate-based curing agent having a weight of 3000 was 0.3% by weight, and the photocurable monomer was 89.7% by weight.

Comparative example  One

A mixed monomer component was prepared by mixing 5% by weight of acrylic acid (AA), 35% by weight of methyl acrylate (MA), and 60% by weight of ethylhexyl acrylate (EHA), from which the weight average molecular weight (Mw) was obtained through photopolymerization. 8 million photopolymerizable resins were prepared. Subsequently, except that it contains 89.85% by weight of the photo-curable monomer mixed with the weight ratio of the photopolymerization resin 10% by weight of ethyl hexyl acrylate (EHA), methyl acrylate (MA) and acrylic acid (AA) in a weight ratio of 60: 35: 5 And in the same manner as in Example 1 to prepare an adhesive composition.

Comparative example  2

A mixed monomer component was prepared by mixing 10% by weight of acrylic acid (AA), 35% by weight of methyl acrylate (MA), and 55% by weight of ethylhexyl acrylate (EHA), from which the weight average molecular weight (Mw) was obtained through photopolymerization. 8 million photopolymerizable resins were prepared. Subsequently, except that it contains 89.85% by weight of the photo-curable monomer in which the photopolymerizable resin is mixed in a weight ratio of 55:35:10 with 10% by weight and ethylhexyl acrylate (EHA), methyl acrylate (MA) and acrylic acid (AA). And in the same manner as in Example 1 to prepare an adhesive composition.

Comparative example  3

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

Comparative example  4

Except that the pressure-sensitive adhesive composition comprises 0.3% by weight of a hexanediol diacrylate curing agent (sigma-aldrich) having a weight average molecular weight (Mw) of 200, and 89.7% by weight of the photocurable monomer. The pressure-sensitive adhesive composition was prepared in the same way.

Comparative example  5

The pressure-sensitive adhesive composition and the weight average molecular weight (Mw) of the polyethylene glycol diacrylate curing agent (sigma-aldrich company) containing 0.3% by weight, except for containing the photocurable monomer 89.7% by weight of Example 1 and The pressure-sensitive adhesive composition was prepared in the same way.

For each of the pressure-sensitive adhesive composition of the above Examples and Comparative Examples, matters related to the mixed monomer component, the photopolymerizable resin, and the curing agent are listed in Table 1 below.

Mixed monomer component [% by weight] Adhesive composition Photopolymer resin Photocurable monomer Hardener MA AA EHA Mw weight% EHA: MA: AA content Mw weight% Example 1 35 6 59 8 million 10 59: 35: 6 89.85 1800 0.15 Example 2 35 7 58 8 million 10 58: 35: 7 89.85 1800 0.15 Example 3 35 8 57 8 million 10 57: 35: 8 89.85 1800 0.15 Example 4 35 6 59 8 million 10 59: 35: 6 89.7 1800 0.3 Example 5 35 6 59 8 million 10 59: 35: 6 89.7 3000 0.3 Comparative Example 1 35 5 60 8 million 10 60: 35: 5 89.85 1800 0.15 Comparative Example 2 35 10 55 8 million 10 55:35:10 89.85 1800 0.15 Comparative Example 3 35 6 59 2 million 10 59: 35: 6 89.85 1800 0.15 Comparative Example 4 35 6 59 8 million 10 59: 35: 6 89.7 200 0.3 Comparative Example 5 35 6 59 8 million 10 59: 35: 6 89.7 500 0.3

<Evaluation>

Each of the adhesive compositions of Examples and Comparative Examples was irradiated with UV energy to perform photo-curing, thereby preparing an adhesive tape comprising an adhesive layer comprising the photocured product thus formed. Specifically, the pressure-sensitive adhesive tape is a double-sided pressure-sensitive adhesive tape in which the pressure-sensitive adhesive layer is formed on both sides of a core material of 50 μm thick PET film material to a thickness of 100 μm.

Experimental example  1: Measurement of gel content

With respect to the pressure-sensitive adhesive layer made of the pressure-sensitive adhesive composition of the Examples and Comparative Examples, the gel content [%] was measured by the formula 1, and the results are as shown in Table 2 below.

Experimental example  2: Measurement of initial adhesion

In the adhesive films of Examples and Comparative Examples, each adhesive layer was attached to a polycarbonate (PC) substrate, and then maintained at room temperature for 20 minutes. Subsequently, the peel strength was measured at a rate 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  3: adhesion Retention  Measure

With respect to the adhesive tapes of Examples and Comparative Examples, after preparing two SUS substrates of 60 mm × 25 mm (horizontal × vertical) size, adhesive tape specimens corresponding to 1 inch × 1 inch were attached therebetween. After standing at room temperature for 2 hours, in a high temperature and high humidity chamber at a temperature of 85 ° C. and a relative humidity of 85%, one SUS substrate is fixed to the chamber wall, and a weight of 500 g is suspended from the other SUS substrate to be detached. The time taken until it was measured. The results are shown in Table 2 below.

Experimental example  4: Evaluation of processability

The adhesive tapes of the examples and the comparative examples are each processed into a frame shape having a border portion of a width of 2 mm to 5 mm through a punching process. At this time, in the punching process, after the adhesive tape is attached to the polyvinyl chloride (PVC) substrate, a punching is performed about 3 times per second, and after processing into a desired shape, the punched portion is cut into a polyvinyl chloride (PVC) substrate. Peel off. At this time, the workability of the punching process is about the length (mm) and the polyvinyl chloride (PVC) substrate protruding out of the interface of the plate by placing an adhesive tape between two rigid 1 mm thick plates of SUS material and applying a weight of about 5 kg. It can be evaluated by measuring the peel strength. The peel strength [kgf / in ² ] of the adhesive tape to the polyvinyl chloride (PVC) substrate was measured at a rate of 300 mm / min. The results are shown in Table 2 below.

Experimental example  5: Repulsive  Measure

For the adhesive tapes of the Examples and Comparative Examples, the repellency was measured by the following measurement procedures of ① to ⑤, and the results are as shown in Table 2 below.

① Prepare a first plate of size 155mm × 30mm × 0.5mm with aluminum material, prepare a second plate of size 170mm × 35mm × 2mm with polycarbonate material, and prepare them once with isopropyl acetate (IPA), It was washed three times with heptanes.

② Each double-sided adhesive tape of each of the above Examples and Comparative Examples was cut to a size of 150 mm × 20 mm to prepare each specimen.

③ Position the specimen by aligning the longitudinal rims on one side of the first plate, then press and reciprocate twice with a 7kg roller, and then align the vertical plates on one side of the specimen to match the second plate. After positioning, pressing and reciprocating twice with a 7 kg roller to form a laminate specimen having a stacked structure of a second plate / specimen / first plate.

④ After aging the laminated specimen for 30 minutes at 60 ° C, both ends are parallel to the horizontal (170mm) of the second plate and the vertical (165mm) of the test jig to the test jig of aluminum size of 210 × 165 × 5mm. , And the laminate specimen was bent accordingly.

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

⑤ The laminated specimen in the bent state was left at room temperature for 2 hours, and then placed in a high temperature / high humidity chamber at 85 ° C / 85% RH condition, and at the end side including only the second plate, the specimen laminated on the second plate was 10. The time required for peeling of at least one of the specimen and the first plate and the second plate was measured by observing at minute intervals.

Gel content
[%] Initial adhesion
[kgf / in ² ] Adhesion holding power
[hr] Processability evaluation Repulsion resistance [hr] Length [㎜] PVC peel force
[kgf / in ² ] Example 1 25 44 3 12 1580 24 Example 2 32 35 6 8 1540 12 Example 3 48 30 12 5 1470 8 Example 4 38 34 24 5 1500 6 Example 5 25 50 2 18 1600 24 Comparative Example 1 18 50 One 15 1600 24 Comparative Example 2 53 18 24 2 1400 2 Comparative Example 3 23 52 One 25 1680 2 Comparative Example 4 63 20 3 4 1300 3 Comparative Example 5 48 30 3 8 1400 12

When referring to the results of Table 2, Examples 1 to 5 are adhesive layers formed from the adhesive composition according to one embodiment of the present invention, the gel content satisfies 25% to 50%, and the initial adhesive strength is 30kgf / in ² At the same time, at the same time, the adhesion retention time under a high temperature and high humidity environment is applied to a small area, such as a bezel part, for more than 2 hours, and thus can exhibit adhesive properties for realizing excellent adhesion performance.

In addition, the length of the adhesive tapes of Examples 1 to 5 pushed out was 18 mm or less, for example, less than 15 mm, for example, 10 mm or less, and at the same time, the peeling force to the polyvinyl chloride (PVC) substrate was 1400 kgf / in. ^{As it is more} than ² , it can be seen that it is controlled to satisfy these two conditions at the same time, thereby realizing excellent punchability.

In addition, the adhesive tapes of Examples 1 to 5 have a repellency of 6 hours or more, for example, 8 hours or more, for example, 12 hours or more, for example, 24 according to the measurement procedure of ① to ⑤ above. As it is time, it can be seen that it is applied to an adherend having a curved or uneven structure to realize excellent adhesion performance.

100: adhesive tape
10: heartwood
20: adhesive layer

Claims (12)

A photopolymerizable resin formed from a mixed monomer component containing 6% to 8% by weight of acrylic acid, and having a weight average molecular weight (Mw) of 5 to 10 million; Photocurable monomers consisting of monofunctional (meth) acrylates; And a curing agent having a weight average molecular weight (Mw) of 1000 to 6000.
Adhesive composition.
According to claim 1,
0.1 to 10% by weight of the curing agent
Adhesive composition.
According to claim 1,
The curing agent comprises an aliphatic urethane acrylate-based curing agent
Adhesive composition.
According to claim 1,
The mixed monomer component includes a first alkyl (meth) acrylate having an alkyl group having 4 to 15 carbon atoms; And a second alkyl (meth) acrylate having an alkyl group having 1 to 3 carbon atoms.
Adhesive composition.
According to claim 4,
The mixed monomer component contains the second alkyl (meth) acrylate 20 to 40% by weight
Adhesive composition.
According to claim 4,
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 4,
The second alkyl (meth) acrylate includes one selected from the group consisting of methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, and combinations thereof.
Adhesive composition.
delete delete According to claim 1,
The 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 and 10.
The method of claim 11,
The gel content of the adhesive layer is 10% to 60%,
The gel content of the adhesive layer is defined by [Equation 1] below
Adhesive tape;
[Equation 1]
Gel content (%) = B / A × 100
In Equation 1, A is the specimen of the adhesive layer, soaked in an ethyl acetate solvent and left at room temperature for 24 hours, filtered using a 200 mesh wire mesh, and the expanded mass, which is the mass of the remaining sample, and B is 110 ° C. Is the dry mass, which is the mass of the specimen obtained by drying for 2 hours.

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