CN110878191A

CN110878191A - Bonding sheet for display and display including the same

Info

Publication number: CN110878191A
Application number: CN201910826883.4A
Authority: CN
Inventors: 李相雨; 金珍赫; 白英彬; 李瑟基
Original assignee: Innox Corp
Current assignee: Innox Corp
Priority date: 2018-09-04
Filing date: 2019-09-03
Publication date: 2020-03-13
Anticipated expiration: 2039-09-03
Also published as: JP6880129B2; JP2020037690A; CN110878191B; KR102152295B1; KR20200027218A

Abstract

The present invention relates to an adhesive sheet for a display, and more particularly, to an adhesive sheet for a display and a display including the same, the adhesive sheet for a display including: the antistatic treatment can prevent static electricity from being generated, the mobility of the adhesive layer is low, no air bubbles are generated during bonding, and the adhesive layer has excellent adhesive force with a display device, impact resistance and bending performance, so that the adhesive layer can be applied to a display with a height difference or a flexible display, and can show an effect of low reduction rate of the adhesive force even when placed in an environment with high temperature and high humidity.

Description

Bonding sheet for display and display including the same

Technical Field

Background

Recently, with the dramatic development of information communication technology and the expansion of the market, Flat panel displays (Flat panel displays) have been attracting attention as display devices. Representative examples of such flat Panel displays include liquid crystal displays (liquid crystal displays), Plasma Display panels (Plasma Display panels), Organic Light Emitting Diodes (Organic Light Emitting Diodes), and the like.

Organic light emitting diodes have advantages such as fast response speed, light weight, small size, low power consumption, self-light emitting devices, flexibility, and the like, and thus, recently, demands for next-generation display devices, displays, illumination, and the like are increasing.

The organic light emitting diode is formed by sequentially evaporating a transparent electrode, a hole injection layer, a hole transport layer, an organic light emitting layer, an electron transport layer, an electron injection layer, and a metal electrode on a glass substrate, and its principle is that electrons and holes supplied from both side electrodes are recombined in the organic light emitting layer and emit light by using energy emitted from the organic light emitting layer.

The organic light emitting diode is deteriorated by external factors such as moisture and oxygen or ultraviolet rays, and thus a packaging (packing) technique for sealing the organic light emitting device is important, and the organic light emitting display needs to be made thin in order to apply the organic light emitting device to various applications.

On the other hand, the lower portion of the display device includes an adhesive sheet for protecting the display device from external force and preventing static electricity from being generated, but the conventional adhesive sheet for a display device has problems that static electricity cannot be prevented from being generated and adhesion to the display device is poor.

Therefore, the following adhesive sheets for display use are urgently needed to be studied: the antistatic treatment can prevent static electricity from being generated, the mobility of the adhesive layer is low, no air bubbles are generated during bonding, and the adhesive layer has excellent adhesive force with a display device, impact resistance and bending performance, so that the adhesive layer can be applied to a display with a height difference or a flexible display, and can show an effect of low reduction rate of the adhesive force even when placed in an environment with high temperature and high humidity.

Documents of the prior art

Patent document

Patent document 1: KR 10-0252953B 1 (grant date: 2000, 01, 21).

Disclosure of Invention

The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a display adhesive sheet and a display including the same, the display adhesive sheet including: the antistatic treatment can prevent static electricity from being generated, the mobility of the adhesive layer is low, no air bubbles are generated during bonding, and the adhesive layer has excellent adhesive force with a display device, impact resistance and bending performance, so that the adhesive layer can be applied to a display with a height difference or a flexible display, and can show an effect of low reduction rate of the adhesive force even when placed in an environment with high temperature and high humidity.

In order to achieve the above object, the present invention provides a display adhesive sheet comprising a base film including a base material and an adhesive layer formed on an upper surface of the base material, the adhesive layer being composed of a base resin and a composition having an antistatic agent in a solid phase at a temperature of 25 ℃, the antistatic agent containing a cationic salt including a diazonium salt having a substituted or unsubstituted aryl group, and the adhesive layer having a gel fraction (gel fraction) of 50 to 88% as measured by the following equation 1.

Mathematical formula 1:

however, in the above mathematical formula 1, the weight of the adhesive layer after dissolution is a weight measured by extracting a predetermined weight of the adhesive layer before dissolution and surrounding the extracted adhesive layer with a 200 mesh screen (mesh), then placing methyl ethyl ketone in a thermostat at 40 ℃ for 24 hours, immersing Methyl Ethyl Ketone (MEK) for 3 times, then drying the remaining adhesive layer remaining on the screen with hot air at 100 ℃ for 24 hours, and measuring the weight.

According to an embodiment of the present invention, the antistatic agent may include a cationic salt represented by the following chemical formula 1.

Chemical formula 1:

in the above chemical formula 1, R¹、R²、R³Are each independently C₁～C₄Linear or C₃～C₅A branched alkyl group of (3).

Also, the antistatic agent may include a cationic salt represented by the following chemical formula 2.

Chemical formula 2:

and, the antistatic agent may further comprise an anionic salt comprising a compound selected from the group consisting of Cl^－、Br^－、I^－、AlCl₄ ^－、Al₂Cl₇ ^－、BF₄ ^－、PF₆ ^－、ClO₄ ^－、NO₃ ^－、CH₃COO^－、CF₃COO^－、CH₃SO₃ ^－、CF₃SO₃ ^－、(CF₃SO₂)₂N^－、(CF₃SO₂)₃C^－、AsF₆ ^－、SbF₆ ^－、NbF₆ ^－、TaF₆ ^－、(CN)₂N^－、C₄F₉SO₃ ^－、(C₂F₅SO₂)₂N^－、C₃F₇COO^－、(FSO₂)₂N^－、(CF₃SO₂)(CF₃CO)N^－And N (SO)₂F)₂ ^－One or more of the group consisting of.

Also, the antistatic agent may be a compound represented by the following chemical formula 3.

Chemical formula 3:

the antistatic agent may be contained in an amount of 0.01 to 5 parts by weight based on 100 parts by weight of the main resin.

The base resin may be an acrylic copolymer.

The weight average molecular weight of the base resin may be 200000 to 1000000.

The composition may further include 0.02 to 0.35 parts by weight of a curing agent per 100 parts by weight of the base resin.

The substrate may be a polyethylene terephthalate (PET) substrate.

Further, at least one surface of the base material may be subjected to antistatic treatment.

The present invention may further include a release film disposed on an upper surface of the adhesive layer and adhered thereto by the adhesive layer, wherein one surface of the release film is subjected to an antistatic treatment.

Further, the lower surface of the release film may be subjected to a silicon release treatment.

And, the release force between the base film and the release film may be 1 to 7 gf/in.

The base film may have a transmittance of 88% or more and a Haze (Haze) of 0.5 to 2.0%.

The adhesion of the base film may be 1300gf/in or more, which is measured by the following measuring method.

The detection method comprises the following steps:

after a base film was attached to glass (glass) and 24 hours had elapsed, the adhesion was measured at a peeling speed of 5mm per second at 180 degrees.

In another aspect, the present invention provides a display comprising the base film as described above.

The adhesive sheet for display and the display including the same according to the present invention have the effects of preventing generation of static electricity by antistatic treatment, having low fluidity of the adhesive layer, not generating bubbles during bonding, and having excellent adhesion to a display device, impact resistance, and bending properties, and thus can be applied to a display having a height difference or a flexible display, and can exhibit an effect of reducing the adhesion even when placed in an environment of high temperature and high humidity.

Drawings

Fig. 1 is a cross-sectional view of an adhesive sheet for a display according to an embodiment of the present invention.

Fig. 2 is a separated sectional view of an adhesive sheet for a display according to an embodiment of the present invention.

Fig. 3 is a schematic cross-sectional view of a display according to an embodiment of the invention.

Description of reference numerals

110. 111:

release film

120, 120', 120 ": base film

121. 121', 121 ":

bonding layers

122, 122', 122 ": base material

300: a display.

Detailed Description

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art to which the present invention pertains can easily carry out the present invention. The present invention may be embodied in various forms and is not limited to the embodiments described herein. In the drawings, portions that are not related to the description are omitted in order to clearly explain the present invention, and the same reference numerals are given to the same or similar components throughout the specification.

As shown in fig. 1, the adhesive sheet for a display according to an embodiment of the present invention includes a base film 120, and the base film 120 includes a base material 122 and an adhesive layer 121 formed on an upper surface of the base material 122.

The base film 120 is directly attached to the display to protect the lower portion of the display and to function as a supporting means.

As described above, the base film 120 includes the base material 122 and the adhesive layer 121 formed on the upper surface of the base material 122.

In this case, the gel fraction (gel fraction) of the adhesive layer 121 measured by the following equation 1 is 50 to 88%, preferably 65 to 84%.

Mathematical formula 1:

however, in the above mathematical formula 1, the weight of the adhesive layer after dissolution is a weight measured by extracting a predetermined weight of the adhesive layer before dissolution and surrounding the extracted adhesive layer with a 200-mesh screen (mesh), then placing the adhesive layer in Methyl Ethyl Ketone (MEK), placing the adhesive layer in a thermostat at 40 ℃ for 24 hours, immersing the adhesive layer in Methyl Ethyl Ketone (MEK) for 3 times, and then drying the remaining adhesive layer remaining on the screen with hot air at 100 ℃ for 24 hours to measure the weight.

If the gel content measured by the above equation 1 is less than 50%, the fluidity of the adhesive layer becomes high, and bubbles may be generated during bonding, and therefore, the adhesive performance may be reduced, and if the gel content is more than 88%, the adhesive force and the bending performance may be reduced.

The adhesive layer 121 is formed from a composition containing a main resin and an antistatic agent.

The base resin is not particularly limited as long as it is a resin that can be generally used in the art to form an adhesive layer having sufficient adhesive strength, and preferably, it may be an acrylic copolymer.

The weight average molecular weight of the base resin may be 200000 to 1000000, and preferably 400000 to 800000. When the weight average molecular weight of the base resin is less than 200000, flexibility of the adhesive, wettability with the adhesive material, adhesion and bending property are excellent, but when peeling is performed, the adhesive layer may be damaged due to a decrease in cohesive force, and when the weight average molecular weight is more than 1000000, excellent cohesive force and adhesion may be maintained, and when the weight average molecular weight is more than a predetermined molecular weight, the adhesive force may be decreased, and wettability with the adhesive material and bending property may not be good due to formation of a hard adhesive layer.

The antistatic agent is an antistatic agent which is in a solid phase at a temperature of 25 ℃, and the antistatic agent contains a cationic salt and may further contain an anionic salt. The antistatic agent is an antistatic agent which is in a solid phase at a temperature of 25 ℃, has excellent adhesion of the base film 120, can maintain appropriate surface resistance, and has an effect of low reduction rate of adhesion even when placed in an environment of high temperature and high humidity.

The cationic salt of the above antistatic agent comprises a azonium salt having a substituted or unsubstituted aryl group, and preferably, may be a cationic salt represented by the following chemical formula 1, and more preferably, may be a cationic salt represented by the following chemical formula 2.

Chemical formula 1:

Chemical formula 2:

also, the anionic salt of the above antistatic agent may comprise a salt selected from the group consisting of Cl^－、Br^－、I^－、AlCl₄ ^－、Al₂Cl₇ ^－、BF₄ ^－、PF₆ ^－、ClO₄ ^－、NO₃ ^－、CH₃COO^－、CF₃COO^－、CH₃SO₃ ^－、CF₃SO₃ ^－、(CF₃SO₂)₂N^－、(CF₃SO₂)₃C^－、AsF₆ ^－、SbF₆ ^－、NbF₆ ^－、TaF₆ ^－、(CN)₂N^－、C₄F₉SO₃ ^－、(C₂F₅SO₂)₂N^－、C₃F₇COO^－、

(FSO₂)₂N^－、(CF₃SO₂)(CF₃CO)N^－And N (SO)₂F)₂ ^－More than one selected from the group consisting of PF may be preferably included₆ ^－、BF₄ ^－、I^－And (CF)₃SO₂)₂N^－One or more of the group consisting of.

Also, most preferably, the antistatic agent may be a compound represented by the following chemical formula 3.

Chemical formula 3:

the composition may include the antistatic agent in an amount of 0.01 to 5 parts by weight, preferably 0.1 to 4.5 parts by weight, based on 100 parts by weight of the main agent resin. If the antistatic agent is included in an amount of less than 0.01 parts by weight based on 100 parts by weight of the main agent resin, there is a possibility that an electrical short circuit may occur and a glass voltage may be increased, and if the antistatic agent is included in an amount of more than 5 parts by weight, there is a possibility that the adhesion of the base film 120 may be reduced, and there is a problem that the adhesion may be significantly reduced after being placed in an environment of high temperature and high humidity conditions.

The composition may further contain a curing agent.

Among the above curing agents, there is no particular limitation as long as it is a curing agent generally used for forming an adhesive layer having a sufficient adhesive force, and preferably, an epoxy-based curing agent is used, more preferably, an epoxy-amine-based curing agent is used, and even more preferably, N' -tetraglycidyl-m-xylylenediamine may be used.

The curing agent may be contained in an amount of 0.02 to 0.35 parts by weight, preferably 0.1 to 0.3 parts by weight, based on 100 parts by weight of the base resin. If the curing agent is contained in an amount of less than 0.02 parts by weight based on 100 parts by weight of the main agent resin, the adhesive layer cannot be cured at a desired level, and the fluidity of the adhesive layer increases due to the decrease in the gel content, so that bubbles are not generated during bonding, and the adhesive performance is lowered. If the curing agent is contained in an amount of more than 0.35 parts by weight, the adhesive layer may be excessively cured, the gel content may be saturated, and the adhesive strength and bending property may be deteriorated, and the unreacted curing agent may remain.

The thickness of the adhesive layer 121 is not limited as long as it is a thickness of an adhesive layer generally included in an adhesive sheet, and may be preferably 10 to 30 μm, and more preferably 11 to 27 μm.

The material of the base material 122 is not limited as long as it is a material generally used for an adhesive sheet in the art, and preferably, it may be a polyethylene terephthalate (PET) base material. The thickness of the base material 122 is not limited as long as it is a thickness of a base material generally used for an adhesive sheet, and may be preferably 50 to 150 μm, and more preferably 70 to 130 μm.

On the other hand, at least one side, preferably, a lower side, of the base material 122 included in the base film 120 of the present invention may be subjected to an antistatic treatment to prevent generation of static electricity. The generation of static electricity can be prevented by the antistatic treatment.

The transmittance of the base film 120 may be 88% or more, preferably 90% or more, and more preferably 91% or more. The haze of the base film 120 is 0.5 to 2%, and preferably, the haze may be 0.7 to 1.5%.

Also, the adhesive force of the base film 120 should be high enough not to be peeled from the lower portion of the display, and preferably, the adhesive force of the base film is 1300gf/in or more, and more preferably, the adhesive force may be 1400gf/in or more, which is measured by the following measuring method.

Detection method

After a base film was attached to glass (glass) and 24 hours had elapsed, the adhesion when 180 was peeled off at a rate of 5mm per second was examined.

If the adhesive force of the base film 120 detected by the above-described detection method is less than 1300gf/in, the above-described problem of peeling the base film 120 from the display may occur.

On the other hand, the adhesive sheet for display according to an embodiment of the present invention may further include a release film 110, the release film 110 is disposed on an upper surface of the adhesive layer 121 and is adhered by the adhesive layer 121, and one surface of the release film 110 is antistatic-treated.

The release film 110 has a function of protecting the base film 120. The adhesive sheet for display according to the present invention may be applied to a display for attachment, and in this case, the release film 110 may be peeled off first and then the base film 120 may be attached to the display. In this case, the release force of the release film 110 is 1 to 7gf/in, and more preferably, 2 to 6 gf/in. If the release force of the release film 110 is less than 1gf/in, the release film is excessively peeled from the base film 120 even with a small physical stimulus, and thus the base film 120 cannot be easily protected, and if the release force is greater than 7gf/in, the release film is not easily peeled when applied to a display, and thus the defective rate is increased, which is not suitable.

As shown in fig. 2, in order to make the release film 110 exhibit the release force as described above, the lower surface of the release film 110 may be subjected to a release treatment (a). In the above-mentioned release treatment, any substance generally used in the art for release treatment may be used without limitation, and preferably, the release treatment is performed using silicon, and a suitable level of release force can be exhibited.

On the other hand, at least one side, preferably, the upper and lower sides of the release film 110 of the present invention may be subjected to antistatic treatment to prevent generation of static electricity. The generation of static electricity can be prevented by the antistatic treatment.

The material of the release film 110 is not limited as long as it can be generally used for a release film in the art, and preferably, may be a polyethylene terephthalate (PET) substrate. The thickness of the release film 110 is not limited as long as it is a thickness of a release film generally used for an adhesive sheet, and may be preferably 30 to 90 μm, more preferably 35 to 85 μm, but is not limited thereto.

The bonding sheet for display as described above can be prepared by a preparation method described later, but is not limited thereto, and the same portions as those described above will be omitted for explanation.

The bonding sheet for display of the present invention can be prepared by the steps comprising: a step of applying a composition containing a main agent resin and an antistatic agent to the upper surface of the base material 122 to form a temporary bonding layer; and a step of bonding the release film 110 to the upper surface of the base material 122 on which the temporary bonding layer is formed, and curing the temporary bonding layer to prepare the bonded release film 110 and the base film 120.

First, a step of applying a composition containing a main agent resin and an antistatic agent to the upper surface of the base material 122 to form a temporary adhesive layer will be described.

The composition comprises a main agent resin and an antistatic agent, and the composition can also comprise a curing agent and a solvent.

The solvent is not limited as long as it is a solvent generally used for an adhesive composition for forming an adhesive layer, and may preferably include one or more selected from the group consisting of water-based solvents, alcohol-based solvents, ketone-based solvents, amine-based solvents, ester-based solvents, acetic acid-based solvents, amide-based solvents, halogenated hydrocarbon-based solvents, ether-based solvents, and furan-based solvents, more preferably include one or more selected from the group consisting of alcohol-based solvents, ketone-based solvents, amine-based solvents, ester-based solvents, acetic acid-based solvents, and ether-based solvents, and most preferably methyl ethyl ketone. The solvent may be contained in an amount of 20 to 60 parts by weight, preferably 25 to 55 parts by weight, based on 100 parts by weight of the base resin, but is not limited thereto.

Next, a procedure of bonding the release film 110 to the upper surface of the base material 122 on which the temporary bonding layer is formed, and curing the temporary bonding layer to prepare the bonded release film 110 and the base film 120 will be described.

The method of bonding the release film 110 to the upper surface of the base material 122 on which the temporary bonding layer is formed may be used without limitation as long as it is a method and/or conditions generally used in the art, and it is preferable that bonding is performed by a roll laminator under normal temperature conditions, but is not limited thereto.

The curing may be performed under any curing conditions generally used in the art for forming an adhesive layer, and preferably, the curing may be performed at a temperature of 30 to 80 ℃ for 30 to 60 hours, and more preferably, at a temperature of 40 to 70 ℃ for 40 to 55 hours, but the curing is not limited thereto.

In another aspect, the present invention includes a display comprising the base film as described above.

As shown in fig. 3, the base film 120 ″ may be attached to a lower portion of the display 300. Specifically, the lower portion of the display can be protected and static electricity can be prevented from being generated in the display device by including the base film 120 ″ including the adhesive layer 121 'having sufficient adhesive force and the substrate 122' for protecting the display.

The present invention is more specifically illustrated by the following examples, which do not limit the scope of the present invention but assist understanding thereof.

Example 1

A composition was prepared by mixing a main agent resin having a weight average molecular weight of 600000 and a copolymer obtained by randomly copolymerizing acrylic acid, butyl acrylate, ethyl acrylate, and vinyl acetate, a curing agent, an antistatic agent, and a solvent, and using 0.22 parts by weight of N, N' -tetraglycidyl-m-xylylenediamine as the curing agent and 4.25 parts by weight of a compound which is in a solid phase at a temperature of 25 ℃ and is represented by the following chemical formula 3, i.e., 39 parts by weight of methyl ethyl ketone as the solvent, based on 100 parts by weight of the main agent resin.

Further, a temporary adhesive layer was formed by coating the composition on the upper surface of a substrate subjected to antistatic treatment by coating poly (3, 4-ethylenedioxythiophene)/polystyrene sulfonate (PEDOT/PSS) on the lower surface of a polyethylene terephthalate (PET) substrate having a thickness of 75 μm in a thin film manner, antistatic treatment was performed by coating poly (3, 4-ethylenedioxythiophene)/polystyrene sulfonate (PEDOT/PSS) on the upper surface and the lower surface of the polyethylene terephthalate (PET) substrate having a thickness of 75 μm in a covering manner, a silicon release agent was coated on the lower surface in a thin film manner so that the lower surface of the release film subjected to silicon release treatment was placed in contact with the temporary adhesive layer, and then the substrate was bonded by a roll laminator under normal temperature conditions and cured at a temperature of 50 ℃ for 48 hours, thus, a base film on which an adhesive layer having a thickness of 14 μm was formed and a release film laminated on the upper surface of the base film were prepared, thereby preparing an adhesive sheet for a display.

Chemical formula 3

Examples 2 to 11 and comparative examples 1 to 2

Prepared in the same manner as in example 1, as in the following tables 1 to 3, bonding sheets for display use as shown in tables 1 to 3 were prepared by changing the weight average molecular weight of the main agent resin, the content of the curing agent, the content of the antistatic agent, and the like.

Comparative example 3

Prepared in the same manner as in example 1, except that N-hexyl-4-methylpyridinium hexafluorophosphate (N-hexyl-4-methylpyridinium hexafluorophosphate, CAS No.929897-32-5), which is represented by the following chemical formula 4 and is in a liquid phase under a temperature condition of 25 ℃, is used as an antistatic agent, a bonding sheet for a display was prepared in the same manner as in example 1.

Chemical formula 4

Comparative examples 4 to 7

Prepared in the same manner as in the above comparative example 3, bonding sheets for display use as shown in table 3 were prepared by changing the content of the antistatic agent represented by the above chemical formula 4 and having a liquid phase under a temperature condition of 25 ℃.

Examples of the experiments

1. Determination of gel content of adhesive layer

For the adhesive sheets for display prepared according to examples and comparative examples, an adhesive layer having a weight of 0.2g was extracted, and then put into and surrounded by a 200 mesh screen (mesh). Further, a Polyethylene (PE) bottle having a capacity of 500ml containing Methyl Ethyl Ketone (MEK) was put into a mesh (mesh) surrounding the adhesive layer, and left to stand in a constant temperature water tank at 40 ℃ for 24 hours, and the mesh (mesh) was soaked in Methyl Ethyl Ketone (MEK) for 3 times. The weight was measured by completely removing Methyl Ethyl Ketone (MEK) by hot air drying the residual adhesive layer remaining on the mesh for 24 hours under the temperature condition of 100 ℃, and the gel content was measured by the following numerical formula 1 and shown in the following tables 1 to 3.

Mathematical formula 1

2. Evaluation of Release force of Release film, adhesive force of base film, and glass Voltage

The adhesive sheets for display prepared according to examples and comparative examples were cut to a width of 1 inch, and then peeled at a speed of 40mm per second to measure the release force of the release film, the adhesive sheets for display were cut to a width of 1 inch to remove the release film, and then the Glass (Glass) adhered to the cleaned surface was peeled at a speed of 5mm per second to measure the adhesive force of the adhesive layer after 24 hours, and the adhesive sheets for display were cut to a size of 100 × 100mm, and then the release film was peeled at a speed of 80mm per second to measure the Glass voltage (V) of the adhesive layer, the above steps were repeated 5 times, and when the average value was 0.05kV or less, the adhesive sheets were marked with ○, and when the average value was greater than 0.05kV, the adhesive sheets for display were marked with × and are shown in tables 1 to 3 below.

3. Evaluation of adhesive Properties of adhesive sheets for display

The base film of the adhesive sheet for display prepared according to the examples and comparative examples was attached to the lower part of the display using a roll laminator under normal temperature conditions, and after 24 hours, the sheet was left to stand at a temperature of 60 ℃ and a relative humidity of 90% for 500 hours to confirm whether or not the peeling phenomenon occurred in the attached lower adhesive sheet, and the adhesive performance of the base film was evaluated by marking ○ when the peeling phenomenon did not occur and marking x when the peeling phenomenon occurred, and tables 1 to 3 below.

4. Measuring the change rate of the adhesive force after the adhesive material is placed in the environment with high temperature and high humidity

The base films of the adhesive sheets for display prepared according to examples and comparative examples were attached to alkali-free glass (Non-alkali glass), left to stand at a temperature of 60 ℃ and a relative humidity of 95% for 500 hours, and after being left to stand in an environment sufficiently at normal temperature, the base films were peeled at a speed of 180 degrees at a rate of 5mm per second to measure the adhesive strength of the adhesive layers, and the rate of change of the adhesive strength was measured with each initial adhesive strength as a reference of 100%.

5. Evaluation of impact resistance

For the adhesive sheets for display prepared according to examples and comparative examples, base films were attached to glass (glass) using a roll laminator, and after 24 hours, when a spherical weight having a weight of 100g was dropped from a height of 10cm to the surface of the base film, the impact resistance was evaluated by marking ○ in the case where no bubble was generated between the adhesive layer and the glass (glass) and marking x in the case where a bubble was generated, and shown in tables 1 to 3 below.

6. Evaluation of bending Properties

After polyimide films each prepared according to examples and comparative examples were cut in a size of 25mm × 150mm in the horizontal and vertical directions, 10000 times were performed with the curvature radius set to 3R in a french setting in which both ends of the polyimide film to which the base film was attached were brought into contact, and without any abnormality, it was marked with ○, and in the case where any abnormality occurred such as interlayer peeling and/or peeling from the adhesive surface in the base film, it was marked with × to evaluate the bending performance, and shown in the following tables 1 to 3.

TABLE 1

TABLE 2

TABLE 3

As is apparent from tables 1 to 3, examples 1, 3, 4, 6, 7, 9 and 10, which satisfy all the conditions of the weight average molecular weight of the main agent resin of the present invention, the content of the curing agent, the kind and content of the antistatic agent, and the like, can simultaneously achieve the effects of appropriate release force of the release film, excellent adhesion force of the base film, excellent adhesion property evaluation results of the adhesive sheet for display, excellent impact resistance and bending property, and low change rate of the adhesion force after being left in a high temperature and high humidity condition environment, as compared to examples 2, 5, 8, 11 and comparative examples 1 to 7, which omit any one of the weight average molecular weight of the main agent resin of the present invention, the content of the curing agent, the kind and content of the antistatic agent, and the like.

While one embodiment of the present invention has been described above, the concept of the present invention is not limited to the embodiments proposed in the present specification, and a person having ordinary skill in the art understanding the concept of the present invention can easily propose other embodiments by adding, changing, deleting, adding components, etc., within the scope of the same concept, and this is included in the scope of the concept of the present invention.

Claims

1. An adhesive sheet for a display, characterized in that,

comprising a base film comprising a base material and an adhesive layer formed on the upper surface of the base material, wherein the adhesive layer is composed of a main resin and a composition having an antistatic agent in a solid phase at a temperature of 25 ℃ and the antistatic agent comprises a cationic salt comprising an onium salt having a substituted or unsubstituted aryl group,

the adhesive layer has a gel content of 50 to 88% as measured by the following equation 1,

mathematical formula 1:

however, in the above mathematical formula 1, the weight of the adhesive layer after dissolution is a weight measured by extracting a predetermined weight of the adhesive layer before dissolution and surrounding the extracted adhesive layer with a 200-mesh screen, then placing the adhesive layer in methyl ethyl ketone, placing the adhesive layer in a constant temperature water tank at 40 ℃ for 24 hours, immersing the methyl ethyl ketone for 3 times, and then drying the residual adhesive layer remaining on the screen with hot air at 100 ℃ for 24 hours to measure the weight.

2. The bonding sheet for display use according to claim 1,

the above antistatic agent comprises a cationic salt represented by the following chemical formula 1:

chemical formula 1:

3. The bonding sheet for display use according to claim 1,

the above antistatic agent comprises a cationic salt represented by the following chemical formula 2:

chemical formula 2:

4. the bonding sheet for display use according to claim 1, wherein the antistatic agent further comprises an anionic salt comprising a compound selected from the group consisting of Cl^－、Br^－、I^－、AlCl₄ ^－、Al₂Cl₇ ^－、BF₄ ^－、PF₆ ^－、ClO₄ ^－、NO₃ ^－、CH₃COO^－、CF₃COO^－、CH₃SO₃ ^－、CF₃SO₃ ^－、(CF₃SO₂)₂N^－、(CF₃SO₂)₃C^－、AsF₆ ^－、SbF₆ ^－、NbF₆ ^－、TaF₆ ^－、(CN)₂N^－、C₄F₉SO₃ ^－、(C₂F₅SO₂)₂N^－、C₃F₇COO^－、(FSO₂)₂N^－、(CF₃SO₂)(CF₃CO)N^－And N (SO)₂F)₂ ^－One or more of the group consisting of.

5. The bonding sheet for display use according to claim 1,

the above antistatic agent is a compound represented by the following chemical formula 3:

chemical formula 3:

6. the bonding sheet for display use according to claim 1, wherein the composition comprises 0.01 to 5 parts by weight of the antistatic agent per 100 parts by weight of the base resin.

7. The bonding sheet for display use according to claim 1, wherein the main agent resin is an acrylic copolymer.

8. The bonding sheet for display use according to claim 1, wherein the weight average molecular weight of the main agent resin is 200000 to 1000000.

9. The bonding sheet for display use according to claim 1, wherein the composition further comprises 0.02 to 0.35 parts by weight of a curing agent per 100 parts by weight of the base resin.

10. The bonding sheet for display use according to claim 1, wherein the substrate is a polyethylene terephthalate substrate.

11. The bonding sheet for display use according to claim 1, wherein at least one surface of the base material is subjected to antistatic treatment.

12. The adhesive sheet for display use according to claim 1, further comprising a release film provided on an upper surface of the adhesive layer and bonded thereto by the adhesive layer, wherein one surface of the release film is subjected to antistatic treatment.

13. The bonding sheet for display use according to claim 12, wherein a lower surface of the release film is subjected to a silicon release treatment.

14. The bonding sheet for display use according to claim 12, wherein a release force between the base film and the release film is 1 to 7 gf/in.

15. The bonding sheet for display use according to claim 1, wherein the base film has a transmittance of 88% or more and a haze of 0.5 to 2%.

16. The bonding sheet for display use according to claim 1, wherein after 24 hours, the base film is adhered to glass, and the adhesion force is measured when the sheet is peeled by 180 degrees at a speed of 5 mm/second, and the measured adhesion force is 1300gf/in or more.

17. A display comprising the base film of any one of claims 1 to 16.