KR101860387B1 - Adhesive Tape containing elastic layer and display device using the same - Google Patents

Abstract

The present invention relates to a pressure-sensitive adhesive tape, in which an elastic layer is disposed between two pressure-sensitive adhesive layers and a substrate made of a foamed resin having elasticity is used to remarkably improve reworkability and effectively prevent bending phenomenon in a high temperature and high humidity environment The present invention relates to a pressure-sensitive adhesive tape.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive tape having an elastic layer and a display device using the adhesive tape,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure-sensitive adhesive tape and a display device using the pressure-sensitive adhesive tape. More particularly, the present invention relates to a pressure-sensitive adhesive tape comprising an adhesive layer between adhesive layers of an adhesive tape to remarkably improve reworkability, And an application of the adhesive tape to a display device.

Adhesive tapes are used in various fields such as automobiles and textiles. Typically, double-sided adhesive tapes are used to bond a panel and a back cover of a display. At this time, the adhesive tape may be a double-sided foam tape including a foam substrate.

In particular, organic light emitting diodes (OLEDs), which are widely illuminated and displayable because of their natural color, fast response speed, low power consumption, wide viewing angle and thinness, Unlike conventional LCDs, it does not require a backlight unit because it emits light.

However, since the glass substrate of the OLED can not have sufficient structural strength and safety, a back cover in the form of a plate is often adhered to the backside using an adhesive material in order to improve the strength of the glass substrate. In this case, double-sided adhesive tape is used as an adhesive material, and double-sided adhesive tape serves to zero the gap between the back cover and the OLED panel.

On the other hand, in the OLED display panel, since the OLED display panel has a structure in which the glass substrate and the back cover are closely contacted with each other without any gap, heat energy converted from light energy and light energy of the OLED light emitting device is transmitted to the back cover, Resulting in an increase in the temperature of the liquid.

Further, if the parts are defective after assembling the parts with the adhesive tape, or if the adhesive is wrong during the assembly, the adhesive tape must be removed again. However, in the case of the conventional adhesive tape, it has been very difficult to remove it from the parts from the parts. While the tensile strength of the foamed resin of the adhesive tape is low and can easily be broken, the adhesive is relatively cohesive, so it took a considerable amount of time to remove it because it was difficult to remove the parts at once without leaving residues .

Further, the pressure-sensitive adhesive tape has been problematic in that the display panel that is adhered in a high-temperature environment is jammed, thereby increasing the defect rate of the panel.

Therefore, there is a need for research and development of an adhesive tape which is excellent in adhesive strength, excellent in reworkability, and effectively prevents jamming in a high temperature environment.

As described above, in order to solve the problems of the conventional adhesive tape, the present invention provides an adhesive tape having an elastic layer which is easy to remove after adhesion, excellent in reworkability, and effectively prevents jamming in a high temperature environment For that purpose.

It is another object of the present invention to provide a pressure-sensitive adhesive tape having the above-described elastic layer in a display device.

In order to achieve the above object, the present invention provides an elastic layer having a structure in which a foamed resin layer, a first elastic pressure-sensitive adhesive layer formed on an upper portion of a foamed resin layer, and a second elastic pressure- A pressure-sensitive adhesive tape is provided.

The first adhesive layer of the adhesive tape having the elastic layer according to an embodiment of the present invention includes a first adhesive layer, a first elastic layer formed under the first adhesive layer, and a second elastic layer formed under the first elastic layer The second elastic adhesive layer of the adhesive tape having the elastic layer of the present invention is laminated with the second adhesive layer, and the second elastic adhesive layer comprises the third adhesive layer, the second elastic layer formed under the third adhesive layer, And a fourth adhesive layer formed on the adhesive layer.

The adhesive tape having the elastic layer according to an embodiment of the present invention provides an adhesive tape having an elastic layer further comprising a polyethylene terephthalate layer on the lower portion of the foamed resin layer

The first elastic layer of the adhesive tape having an elastic layer according to an embodiment of the present invention may include at least one of a urethane-based elastomer, an acrylic-based elastomer, a rubber-based elastomer, and a silicone-based elastomer.

The second elastic layer of the adhesive tape having the elastic layer according to an embodiment of the present invention may include at least one or more of urethane elastomer, acrylic elastomer, rubber elastomer, silicone elastomer, polyethylene terephthalate and nonwoven fabric.

The first adhesive layer to the fourth adhesive layer of the adhesive tape having the elastic layer according to an embodiment of the present invention may include at least one of an acrylic adhesive, a silicone adhesive and a rubber adhesive.

The foamed resin layer of the adhesive tape having an elastic layer according to an embodiment of the present invention may include at least one of urethane foam, silicone foam, acryl foam and polyolefin foam.

The dynamic tensile strength of the adhesive tape having the elastic layer according to an embodiment of the present invention may be 5.5 to 30 kgf / inch ² .

The static tensile strength at 80 DEG C of the adhesive tape having the elastic layer according to an embodiment of the present invention can be maintained for 1 hour or more when a force of 700 gf / (15 mm * 15 mm) is applied.

The static shear strength at 80 DEG C of the adhesive tape having the elastic layer according to an embodiment of the present invention may not cause any swelling when a force of 1 kgf / inch ² is applied.

The 180 ° peel strength of the first and second elastic adhesive layers of the adhesive tape according to an embodiment of the present invention may be 1000 to 3000 gf / inch.

The display according to an embodiment of the present invention includes a display panel, an adhesive tape having an elastic layer disposed on one side of the display panel, and a back cover disposed on the adhesive tape having the elastic layer, Wherein the adhesive tape comprises a foamed resin layer, a first elastic pressure sensitive adhesive layer formed on the foamed resin layer, and a second elastic pressure sensitive adhesive layer formed on a lower portion of the foamed resin layer, And the second elastic adhesive layer comprises a first adhesive layer, a first elastic layer formed under the first adhesive layer, and a second adhesive layer formed under the first elastic layer, A second elastic layer formed on a lower portion of the third adhesive layer, and a fourth adhesive layer formed on a lower portion of the second elastic layer, wherein the first adhesive layer contacts the display panel, The adhesive layer And it may be in contact.

The adhesive tape of the present invention is characterized in that when the elastic layer is disposed between the adhesive layers to be removed after adhesion, the adhesive tape including the elastic layer is stretched to weaken the adhesive strength of the adhesive layer, So that the reworkability is excellent.

Further, since the adhesive tape of the present invention is to remove the adhesive tape by lengthening the adhesive tape by stretching the adhesive tape due to the elastic layer of the adhesive tape, the adhesive tape is left in a high temperature and high humidity environment, The effect is excellent.

On the other hand, even if the effects are not explicitly mentioned here, the effects described in the following specification which are expected by the technical features of the present invention and their potential effects can be handled as described in the specification of the present invention.

1 is a cross-sectional view showing one embodiment of the adhesive tape of the present invention.
2 (a) and 2 (b) are sectional views showing the first elastic pressure sensitive adhesive layer and the second elastic pressure sensitive adhesive layer of the pressure sensitive adhesive tape of the present invention, respectively.
3 is a cross-sectional view showing that an adherend is adhered to both sides of the adhesive tape of the present invention.
4 is a view showing a process of removing the adhesive tape from the adherend when the adherend is adhered to both sides of the adhesive tape of the present invention.
5 is a photograph showing a test procedure for measuring the dynamic tensile strength of the adhesive tape having the elastic layer of Experimental Example 2. FIG.
Fig. 6 is a photograph showing a test procedure for measuring the static tensile strength of the adhesive tape having the elastic layer at 80 캜 in Experimental Example 3. Fig.
7 is a photograph showing a test procedure for measuring the static shear strength of an adhesive tape having an elastic layer at 80 ° C in Experimental Example 4. FIG.
8 is a view showing an example of using the adhesive tape of the present invention in a display device.

The following description of the invention refers to the accompanying drawings, which illustrate, by way of example, specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. . ≪ / RTI >

The following detailed description is not to be taken in a limiting sense, and the scope of the present invention is to be limited only by the appended claims, along with the full scope of equivalents to which the claims are entitled, if properly explained. In the drawings, like reference numerals refer to the same or similar functions throughout the several views.

Throughout the specification, when an element is referred to as "including" an element, it means that it may include other elements of the element, not the exclusion of other elements unless specifically stated otherwise.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, so that those skilled in the art can easily carry out the present invention.

1 is a cross-sectional view schematically showing an adhesive tape according to an embodiment of the present invention. Referring to FIG. 1, the adhesive tape 100 of the present invention includes a foamed resin layer 200, a first elastic pressure-sensitive adhesive layer 300 formed on the upper portion of the foamed resin layer, And an adhesive layer (400).

Referring to FIG. 2, the first elastic adhesive layer 300 of the present invention includes a first adhesive layer 320, a first elastic layer 310 formed under the first adhesive layer 310, And a second adhesive layer 330 formed on the second adhesive layer 330.

The second elastic pressure sensitive adhesive layer 400 of the present invention has a third adhesive layer 420, a second elastic layer 410 formed below the third adhesive layer, and a fourth adhesive layer 420 formed below the second elastic layer 410 Layer 430 as shown in FIG.

The first adhesive layer may further include a first release film 510 formed on the first adhesive layer.

And a second release film 520 layer formed under the fourth adhesive layer of the present invention.

The lower part of the foamed resin layer of the present invention may further include a polyethylene terephthalate (PET) layer. This serves to support the adhesive tape provided with the elastic layer, and thus it is possible to facilitate handling and workability of the adhesive tape provided with the elastic layer

The first adhesive layer to the fourth adhesive layer of the adhesive tape having the elastic layer may include at least one or more of an acrylic adhesive, a silicone adhesive and a rubber adhesive, and preferably the first adhesive layer to the fourth adhesive layer The layer may include, but is not limited to, an acrylic adhesive.

At this time, the acrylic resin may be at least one selected from the group consisting of methyl methacrylate, methyl acrylate, ethyl acrylate, butyl acrylate, hexyl acrylate, n-octyl acrylate, isooctyl acrylate, Acrylic acid, acrylic acid, acrylamide, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, methacrylic acid, itaconic acid, maleic acid and the like May be a polymer containing one or more monomers, but preferably a polymer resin containing the above-mentioned 2-ethylhexyl acrylate monomer may be used.

When the polymer resin containing the 2-ethylhexyl acrylate monomer is used, the cohesive force of the pressure-sensitive adhesive layer is excellent and the excessive increase in the adhesion strength can be suppressed, so that the good adhesion to the display panel as well as various electronic devices, housings, metals, It is possible to form an adhesive layer excellent in adhesion, re-peeling property and reworkability.

The first elastic layer of the adhesive tape having the elastic layer may include at least one of a urethane-based elastomer, an acrylic-based elastomer, a rubber-based elastomer and a silicone-based elastomer, and is preferably a urethane-based elastomer.

The second elastic layer of the adhesive tape having the elastic layer may include at least one or more of a urethane-based elastomer, an acrylic-based elastomer, a rubber-based elastomer, a silicone-based elastomer, polyethylene terephthalate (PET) and a nonwoven.

The foamed resin layer of the adhesive tape having the elastic layer may include at least one of elastic urethane foam, silicone foam, acrylic foam and polyolefin foam, but is not limited thereto.

The material of the first release film layer and the second release film layer may be, for example, a synthetic resin film such as polyethylene, polypropylene or polyester film, a substrate such as paper, a nonwoven fabric, a cloth, a foamed sheet or a metal foil, A silicon-based treatment, a long-chain alkyl-based treatment, or a fluorine-based treatment may be applied to at least one surface of the pressure-sensitive adhesive to enhance the releasability (releasability) from the pressure-sensitive adhesive.

Referring to FIG. 3, the adhesive tape 100 having the elastic layer of the present invention includes a first adhesive layer 300 on one surface of the first adhesive layer to which the first elastic layer is not adhered, The adhesive material 620 can be adhered to one side of the fourth adhesive layer in which the second elastic layer is not adhered to the structure of the second elastic adhesive layer 400, So that the adherend can be adhered.

4, both sides of an adhesive tape having an elastic layer of the present invention are adhered to adherends 610 and 620 as shown in FIG. 4 (a). 4 (b), the foamed resin layer 200 of the adhesive tape having the elastic layer is first separated on the basis of the perforated line using a machine, and then the foamed resin layer is separated from the separated elastic layers And pulls the adhered materials 610 and 620 in a direction in which the adhered materials 610 and 620 form a 5 to 25 ° degree in a direction in which the adhered materials 610 and 620 are not adhered. Of course, the angle formed with the adherend is not limited to the above-described angle, but any angle can be used as long as it can weaken the adhesive strength by increasing the elastic pressure sensitive adhesive layer and the foamed resin layer. In Fig. 4, the direction is indicated by an arrow. At this time, as the first elastic layer and the separated foamed resin layer 200 are stretched, the first adhesive layer adhered to the adherend 610 is stretched together. The second elastic layer and the separated foamed resin layer 200 are stretched in the same manner as described above, and the fourth adhesive layer adhered to the adherend 620 is also stretched.

 As the first and fourth adhesive layers are stretched together, the adhesive force acting on the surface is converted to acting on the wire, thereby weakening the adhesive force. When the adhesive force continues to weaken, the adhesive tape 100 having the elastic layer of the present invention can be removed from the adherend materials 610 and 620 as shown in Fig. 4 (c). As the tape is stretched, the adhesive force is weakened and removed. Therefore, even if the adhesive tape having the elastic layer of the present invention is left in a high temperature and high humidity environment, the residue may not remain.

The composition of the foamed resin layer of the adhesive tape having the elastic layer of the present invention may contain carbon black, iron oxide, copper oxide, tin oxide, azo dye, nigrosine, perylene, anilene black, etc. And at least one of the known black pigments selected from the group consisting of black pigments.

The composition of the foamed resin layer may contain additives such as surface lubricants, leveling agents, antioxidants, light stabilizers, corrosion inhibitors, polymerization inhibitors, organic fillers, inorganic fillers, metal powders, coupling agents, At least one additive selected from the group consisting of dyes, pigments, ultraviolet screening agents, processing oils, and tackifiers may be suitably added depending on the use or purpose of the user.

The thicknesses of the first elastic adhesive layer and the second elastic adhesive layer in the present invention may independently be 0.01 to 0.3 mm, preferably 0.125 mm, but are not limited thereto.

Further, the foamed resin layer of the present invention may have a thickness of 0.2 to 3 mm. When the thickness of the foamed resin layer exceeds 3 mm when the adhesive tape having the elastic layer is used for an OLED substrate, the thickness of the OLED panel can not be reduced. On the contrary, when the thickness of the foamed resin layer is less than 0.2 mm, It is difficult to structurally support the elastic pressure sensitive adhesive layers disposed on the upper and lower portions of the resin layer and reworkability may be deteriorated.

In addition, when the first adhesive layer and the fourth adhesive layer are peeled from the adherend, an antistatic agent may be further added to prevent peeling electrification that may occur between each adhesive layer and the adherend.

The 180 ° peel strength of the first elastic pressure sensitive adhesive layer and the second elastic pressure sensitive layer of the present invention may be independently from 1000 to 2000 gf / inch for 30 minutes after the adhesion, and when 48 hours have passed after the adhesion 1800 to 3000 gf / inch. The peel strength measurement described above is a measurement according to ASTM D3330 in an environment of a temperature of 23 캜 and a humidity of 50%.

In this case, if the peeling strength is out of the above range, if the maximum peeling strength range is exceeded, the adhesive strength of the adhesive tape of the present invention is strong and the peeling strength is not easy to remove and the reworkability effect is reduced. On the other hand, , The adhesive force is insufficient and the phenomenon of being detached from the adhesive surface may occur.

ASTM is a standard name according to the American Society for Testing and Materials (ASTM). 1) Definition of a common term in the field, 2) 3) a method for making a given measurement; 4) a criterion for dividing an object or a concept into groups; 5) determining the range or limit of the characteristics of a product or material; Sharing.

The dynamic tensile strength of the adhesive tape having the elastic layer may be 5.5 to 30 kgf / inch ² . If the dynamic tensile strength of the adhesive tape is less than 5.5 kgf / inch ^{2, the} adherend can not be properly supported. Therefore, when used in the manufacturing process of the display panel, a panel distortion may occur during or after the operation of the panel. kgf / inch ² , the adhesive strength is so high that the adhesive tape having the elastic layer of the present invention can not be automatically separated from the adherend using a machine.

In addition, the adhesive tape having the above-mentioned elastic layer can be used as a pressure-sensitive adhesive tape having an elastic layer attached to an adhering material when a force is applied toward the center of the globe in a direction perpendicular to the adhering surface in a high temperature environment (static tensile strength test) May be attached for an hour or more without separation, and preferably may be attached for 1 to 12 hours.

The static tensile strength test is a test to evaluate how well the adherend is held in a high temperature environment.

Further, when the static shear strength is measured in a high temperature environment by using an adhesive tape having an elastic layer, no jarring phenomenon appears at all, and it can be utilized very stably in applications such as displays.

The static shear strength test is a test for evaluating how well the adhesive tape with the elastic layer of the present invention holds the adherend in a high temperature environment. Since the direction of applying the force is different from the above static tensile strength, There is a difference in the direction in which the provided adhesive tape stays.

In the above-mentioned static tensile strength and static shear strength measurement, the same adhesive force can be maintained even in an environment where the adhesive layer having the elastic layer of the present invention, which can be adhered to the adherend even in a high temperature environment, Of course.

The application of the adhesive tape of the present invention is not particularly limited and may be used for various purposes depending on the constitutional characteristics of the adhesive tape. For example, it can be used in display devices such as televisions, mobile phones, etc., and more specifically, it can be used to adhere panels and back covers of OLED or LCD.

Here, since the back cover is difficult to maintain its shape by the substrate alone such as the glass substrate of the panel, the plate material is often adhered to the back surface of the panel in order to improve the strength of the substrate.

For example, as shown in FIG. 8, after the adhesive tape 100 having the above-described elastic layer is attached to the back cover 720 of the display, the adhesive tape 100 having the elastic layer is adhered The display panel 710 can be adhered to the back cover 720 by adhering the display panel 710 to the other surface. The gap between the display panel 710 and the back cover 720 can be zeroed when the adhesive tape 100 having the above-described elastic layer is used.

In this case, the process of attaching the adhesive tape 100 to the display panel 710 and attaching the back cover 720 to one side of the non-adhesive tape can be changed.

The display is not limited to the CRT, the PDP, the LED, the LCD, and the OLED, but may be preferably used for the LCD and the OLED.

The panel of the OLED may include a substrate, a first electrode disposed on the substrate, an organic light emitting layer disposed on the first electrode, and a second electrode disposed on the organic light emitting layer.

The panel of the LCD may include a first substrate, a second substrate disposed to face the first substrate, and a liquid crystal layer interposed between the first substrate and the second substrate.

In addition, as the method of forming the first to fourth adhesive layers, any known coating method that can be used for the production of the adhesive tape can be applied without limitation, and more specifically, for example, a roll coating, a gravure coating, A roll brush, a spray coating, an air knife coating, a die coating method or the like can be used. However, the method of coating the pressure-sensitive adhesive layer is not particularly limited.

Example

Example  One

First, a pressure-sensitive adhesive was prepared, and the process was as follows.

58 parts by weight of butyl acrylate, 40 parts by weight of butyl methacrylate, 2 parts by weight of acrylic acid, 2 parts by weight of polyoxyethylene alkyl ether as an emulsifying agent, and 5 parts by weight of a polymerization initiator were added to a reaction vessel equipped with a stirrer, And 0.1 part by weight of zero 2,2-azobis (2-amidinopropane) dihydrochloride were charged to prepare a polymer emulsion.

Thereafter, polyoxyethylene nonylphenyl ether as a surfactant and 2-isopropenyl-2-oxazoline as a water-soluble oxazoline crosslinking agent were mixed in the polymer emulsion to prepare a pressure-sensitive adhesive composition.

Then a pressure-sensitive adhesive composition of the thermoplastic polyurethane (Thermoplastic (NBR 30D) composed of an elastic pressure-sensitive adhesive layer was applied on both upper and lower surfaces of the polyurethane (TPU) (first or second elastic layer) so that the total thickness after drying was 0.125 mm and then dried at 80 ° C for 5 minutes. Gt;

Experimental Example 1: 180 DEG peel strength  exam( Peel test )

Example 1 was cut into lengths of 25 mm * 300 mm in length and width, respectively, to prepare specimens. After that, the surfaces to be attached, that is, the surface of Inva and the surface of aluminum, are washed once with IPA (Isopropyl alcohol) and then once with heptane.

Then, 0.025 mm thick PET was laminated on one side of the prepared specimen, and the other side was adhered to the in-plane or aluminum side, and then the 4.5-lb roller was reciprocated once based on ASTM D3330 to completely adhere the specimen .

The completely adhered specimens were allowed to stand for 30 minutes at a temperature of 23 ° C and a humidity of 50%, and the 180-degree peel strength was evaluated at a rate of 300 mm / min using UTM.

After standing for 48 hours under the same temperature and humidity conditions as above, the 180 degree peel strength was evaluated in the same manner as described above, and the results are shown in Table 1.

At this time, the invar surface was an alloy having 63.5% of iron and 36.5% of nickel and having a small coefficient of thermal expansion, and was used as a substrate to which the adhesive was applied in the experiments 1 to 4 along with the aluminum surface.

In fact, the inside surface of the panel of the display is an invar material, and the back cover surface is an aluminum material.

30 minutes later After 48 hours NBR 30D Inva cotton 1494 2135 Aluminum face 1625 2322

[Unit: gf / inch]

According to the above Table 1, the peel strength after 1000 minutes was 1000 to 2000 gf / inch after 30 minutes, and the peel strength after 48 hours was 1800 to 3000 gf / inch. Thus, the pressure sensitive adhesive of Example 1 exhibited an adhesive force suitable for application to the display panel and the back cover . If it has a peeling strength exceeding the above numerical range, it may be difficult to remove because of too strong a cohesive force, and if it has a peeling strength lower than the numerical value range, the cohesive force is too weak, Can occur.

Example  2

In Example 2, a 0.5 mm thick polyurethane foam (manufactured by Utis, trade name SSL) was used as a foamed resin layer, and a PET resin was disposed under the foamed resin layer. A reworkable foam pad was prepared by attaching the 0.125 mm thick elastic adhesive layer of Example 1 to both the upper and lower surfaces of the foamed resin layer including the PET resin layer.

Comparative Example  One

In Comparative Example 1, a double-sided foam tape (manufactured by 3M Company, trade name: 4734FP-86) was used. The foamed resin layer and the foamed resin layer were provided on both upper and lower surfaces thereof with an adhesive layer made of an adhesive. The 4734FP-86 of 3M proved to be a solution that can adequately hold the panel, and it has already been proven that it is separated when the panel is separated from the machine

Experimental Example  2: Dynamic tensile strength test ( Dynamic tensile strength test )

Example 2 and Comparative Example 1 were cut to an area of 1 inch * 1 inch to prepare respective specimens. Thereafter, the method for producing the specimen is carried out in the same manner as in the first embodiment.

The prepared specimens were tested at a speed of 12.7 mm / min using UTM. The results are shown in Table 2 below.

At this time, UTM is abbreviation of universal test machine. It can measure not only tensile strength but also compressive strength, flexural strength or bending strength.

Test 1 Test 2 Test 3 Average Remarks Example 2 6.82 6.92 6.74 6.83 Foam separation Comparative Example 1 6.46 6.32 6.53 6.44 Foam separation

[Unit: kgf / inch ² ]

According to the above Table 2, it can be seen that foam separation occurs in both of Comparative Example 1 and Example 2, which were proved to be separated when the panel was separated from the conventional machine. In particular, the dynamic tensile strength Was relatively large. Therefore, it can be seen that the display panel can be well supported without being detached or pushed when the adhesive tape according to the present invention is adhered to the display panel.

Experimental Example  3: Static tensile strength test in high temperature environment ( Static tensile strength  test)

Example 2 and Comparative Example 1 were cut to lengths of 15 mm * 15 mm in length and 15 mm, respectively, to prepare respective specimens. The subsequent method of producing the specimen is carried out in the same manner as in the first embodiment.

The prepared specimens were weighed so as to apply a force of 700 gf in the direction perpendicular to the attached surface and in the direction of the center of the globe at a temperature of 80 ° C, and the dropping time was evaluated. The results are shown in Table 3 below .

Test 1 Test 2 Test 3 Test 4 Example 2 90 minutes 170 minutes 130 minutes 240 minutes Comparative Example 1 21 minutes foam separation - - -

In Table 3, the static tensile strength is evaluated, which is an evaluation of the degree of holding the adherend well in a high temperature environment. As shown in Table 3, in the case of Example 2, the foams were not separated even after hanging for at least one hour. However, in Comparative Example 1, the foams were separated and torn to cause breakage of the foam. As a result, it can be confirmed that the adhesive force of Example 2 is not adversely affected even at a high temperature of room temperature or higher, and adhered to the adherend for a long time.

Experimental Example  4: Static shear strength test in a high temperature environment ( Static shear strength  test)

A specimen was prepared in the same manner as in Experimental Example 2, except that Comparative Example 1 was omitted.

The specimens were suspended at a temperature of 80 ° C in a direction perpendicular to the center of the specimen so that a force of 1 kgf was applied. The static shear strength was measured and the measured values were shown in Table 4 below. As in Experimental Example 3, the test was performed to measure how well Example 2 adhered to the adherend. However, in Experimental Example 3, since the adhered surface was vertical, the direction of additional hanging was changed, There is a difference in the direction in which it stays different.

result Example 2 No jungling occurred at all.

In Example 2, it was confirmed that no shrunk phenomenon occurred at high temperature. Accordingly, when the above Example 2 is used in the display manufacturing process, the adhesive tape adhered to the panel and the back cover does not show a problem in adhesive force even at high temperature, does not show any jarring phenomenon, Respectively.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be understood by those skilled in the art that various changes may be made and equivalents may be resorted to without departing from the scope of the appended claims.

100: adhesive tape 200: foamed resin layer
300: first elastic adhesive layer 310: first elastic layer
320: first adhesive layer 330: second adhesive layer
400: second elastic adhesive layer 410: second elastic layer
420: third adhesive layer 430: fourth adhesive layer
510: first release film layer 520: second release film layer
610, 620: Adhesive material 710: Display panel
720: Display back cover

Claims (16)

Foamed resin layer;
A first elastic adhesive layer formed on the foamed resin layer;
And a second elastic pressure sensitive adhesive layer formed under the foamed resin layer,
Wherein the first elastic adhesive layer comprises: a first adhesive layer; A first elastic layer formed under the first adhesive layer; And a second adhesive layer formed under the first elastic layer,
The second elastic adhesive layer comprises a third adhesive layer; A second elastic layer formed under the third adhesive layer; And a fourth adhesive layer formed under the second elastic layer,
Wherein the foamed resin layer comprises at least one selected from the group consisting of urethane foam, silicone foam, acryl foam and polyolefin foam, and is at least one selected from the group consisting of carbon black, iron oxide, copper oxide, tin oxide, azo dye, nigrosine, perylene and aniline And at least one black pigment selected from the group consisting of red black,
The thickness of the first elastic pressure sensitive adhesive layer and the second elastic pressure sensitive adhesive layer is 0.01 to 0.3 mm, the 180 ° peeling strength is 1000 to 3000 gf / inch, and the thickness of the foamed resin layer is 0.2 to 3 mm Wherein the adhesive layer has an elastic layer. The method according to claim 1,
Wherein the first elastic layer comprises at least one selected from the group consisting of a urethane-based elastomer, an acrylic-based elastomer, a rubber-based elastomer, and a silicone-based elastomer. The method according to claim 1,
Wherein the second elastic layer comprises at least one selected from the group consisting of a urethane-based elastomer, an acrylic-based elastomer, a rubber-based elastomer, a silicone-based elastomer, a polyethylene terephthalate and a nonwoven fabric. The method according to claim 1,
Wherein the first to fourth adhesive layers each independently comprise at least one selected from the group consisting of an acrylic adhesive, a silicone adhesive, and a rubber adhesive. delete The method according to claim 1,
Wherein the foamed resin layer further comprises a polyethylene terephthalate resin layer. delete The method according to any one of claims 1 to 4 and 6,
Wherein the adhesive tape having the elastic layer has a dynamic tensile strength of 5.5 to 30 kgf / inch ² . The method according to any one of claims 1 to 4 and 6,
Wherein the adhesive tape having the elastic layer has a static tensile strength at 80 DEG C for at least 1 hour when a force of 700 gf / (15 mm * 15 mm) is applied. The method according to any one of claims 1 to 4 and 6,
The static shear strength at 80 ℃ of a pressure-sensitive adhesive tape having an elastic layer is an adhesive tape having an elastic layer, characterized in that it does not advance at all occurs when a force of 1 kgf / inch ^2.
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