KR102542730B1 - Adhesive film, manufacturing method of same and plastic organic light emitting display comprising same - Google Patents

Abstract

The present application relates to an adhesive film, a manufacturing method thereof, and a plastic organic light emitting display including the same.

Description

Adhesive film, manufacturing method thereof, and plastic organic light emitting display including the same

The present application relates to an adhesive film, a manufacturing method thereof, and a plastic organic light emitting display including the same.

With the recent development of display-related technologies, display devices that can be deformed during use, such as folding, rolling in a roll shape, or stretching like a rubber band, have been researched and developed. Since these displays can be deformed into various shapes, they can satisfy both the demand for a larger display in the use stage and the demand for a smaller display for portability.

The deformable display device may not only be deformed into a preset shape, but also may be deformed into various shapes according to a user's request or a situation in which the display device is used. Therefore, it is necessary to recognize the deformed shape of the display and control the display device in response to the recognized shape.

Meanwhile, since the deformable display device has a problem in that each component of the display device is damaged due to deformation, each component of the display device must satisfy folding reliability and stability.

In particular, recently, demand for a foldable display is increasing, and demand for a plastic organic light emitting display, which is a type of deformable foldable display, is also increasing. Since the foldable display involves folding and unfolding operations, it is essential to attach a supporter that serves as a guideline for the operation to the bottom of the substrate of the foldable display. In the case of a backplate for a conventional display, an adhesive is coated on the end surface of a base material, so a process of forming an additional adhesive or adhesive is required to attach a support that serves as a guideline to the lower portion.

In the process of attaching semiconductor chips (DIC (driver IC) bonding) used to drive pixels constituting the display during the manufacturing process of plastic organic light emitting displays, the display panel itself is made flexible PI in the existing COF (Chip On FPC) process. It is changing to a COP (Chip On Plastic) process that uses (polyimide) and attaches a semiconductor chip to the extended part of PI at the same time.

The COP process is carried out under high temperature and specific pressure conditions, and in the case of existing adhesive products, a large amount of air bubbles are generated around the semiconductor chip (DIC Chip) during the COP process.

In addition, air bubbles or unexpected foreign substances generated in the process of bonding the adhesive sheet to the substrate may flow in, which is undesirable from the viewpoint of aesthetics or adhesiveness, and re-adhesion of the adhesive sheet may be required. However, in the case of an adhesive sheet having high adhesive strength, such re-adhesion work is difficult.

Then, a technique for reducing such bubbles has been devised. For example, a technique of forming a concavo-convex surface shape on the adhesive surface of a pressure-sensitive adhesive using an embossed liner has been devised. In this case, when the pressure-sensitive adhesive is bonded to the substrate, even if air bubbles are mixed between the two, air easily flows out through the grooves on the surface of the pressure-sensitive adhesive, so that air bubbles can be easily removed without re-adhesion. However, the pressure-sensitive adhesive described above requires a certain thickness in order to form grooves. In addition, when this pressure-sensitive adhesive is lightly adhered to a base material, the adhesion area is reduced due to the presence of grooves, making it easy to perform operations such as rework and repositioning, but sufficient adhesive strength cannot be obtained. There is a possibility.

In order to enhance the rework characteristics, recently, an adhesive sheet having low adhesive strength in the initial stage of the adhesive sheet and increasing the adhesive strength after a specific process has been developed.

Therefore, in view of this situation, the adhesive force is maintained low in the initial stage of adhesion, and at the same time, the ability to develop sufficient adhesive force necessary for fixing the substrate to be adhered thereafter, and in the display COP process, due to the generation of adhesive bubbles due to exposure to high temperatures, It is necessary to develop an adhesive sheet capable of preventing the decrease in adhesive force due to

Japanese Patent Laid-Open No. 2006-299283

The present application is intended to provide an adhesive film, a manufacturing method thereof, and a plastic organic light emitting display including the same.

An exemplary embodiment of the present application is a base film; And an adhesive film comprising an adhesive sheet provided on one side of the base film,

After bonding the opposite side of the surface in contact with the base film of the pressure-sensitive adhesive sheet to stainless steel (SUS304 substrate), the initial adhesive strength after leaving it at 23 ° C for 2 hours is 100 gf / inch or less, and then heat-treated at 50 ° C for 20 minutes. Adhesion is over 300gf/inch,

The pressure-sensitive adhesive sheet is measured at a frequency of 1Hz and a heating rate of 5°C/min in the range of -20°C to 250°C, and the storage modulus (G1) at 210°C satisfies Equation 1 below.

[Equation 1]

1x10 ^4Pa ≤ G1 ≤ 9.9x10 ^4Pa

Another exemplary embodiment of the present application includes preparing a base film; and forming a pressure-sensitive adhesive sheet by applying and curing a pressure-sensitive adhesive composition on one surface of the base film,

After bonding the opposite side of the surface in contact with the base film of the pressure-sensitive adhesive sheet to stainless steel (SUS304 substrate), the initial adhesive strength after leaving it at 23 ° C for 2 hours is 100 gf / inch or less, and then heat-treated at 50 ° C for 20 minutes. Adhesion is over 300gf/inch,

The adhesive sheet is measured at a frequency of 1 Hz and a heating rate of 5 ° C / min in the range of -20 ° C to 250 ° C, and the storage modulus (G1) at 210 ° C satisfies Equation 1. want to do

Another exemplary embodiment of the present application is an adhesive film according to the present application; and a plastic organic light emitting display provided on the adhesive sheet side of the adhesive film.

Finally, an exemplary embodiment of the present application includes a liquid crystal display provided on a surface opposite to a surface of the plastic substrate in contact with the adhesive film; and an organic light emitting layer on a surface opposite to a surface of the liquid crystal display in contact with the plastic substrate.

The adhesive film according to an exemplary embodiment of the present application includes a polymer having a melting temperature (Tm) of 30° C. or more and a (meth)acrylate-based resin in the adhesive sheet, and the adhesive sheet including the same has initial adhesive strength with the substrate to be adhered. have these low characteristics.

In particular, in the case of the adhesive sheet included in the adhesive film according to one embodiment of the present application, the initial adhesive strength with the adherend substrate is low, and at the same time, the adhesive strength increases after a specific process to develop sufficient adhesive strength to fix the adherend substrate. have

That is, in the adhesive film according to the present application, the adhesive strength of the adhesive sheet to the adherend substrate is initially maintained low, and no dirt remains even when it is removed in case of erroneous attachment, and then the adhesive strength is increased through a specific process to increase the adhesive strength characterized by being maintained.

In the adhesive film according to an exemplary embodiment of the present application, the specific content of the curing agent and the specific (meth)acrylate-based resin are appropriately adjusted in the adhesive sheet, so that the adhesive sheet has a frequency of 1 Hz and a temperature increase rate of 5 in the range of -20 ° C to 250 ° C Measured in ° C / min, as the storage modulus (G1) value at 210 ° C satisfies the range of Equation 1 above, it has a feature that can prevent the occurrence of lifting due to high temperature and high pressure pressing during the COP process of the display do.

That is, in the adhesive film according to an exemplary embodiment of the present application, as the storage modulus value of the adhesive sheet satisfies the range of Equation 1 at a high temperature, no lifting occurs even when a high temperature and high pressure process is performed, and It has a feature capable of minimizing the generation of air bubbles in the adhered adhesive sheet.

1 is a diagram showing a schematic laminated structure of an adhesive film according to an exemplary embodiment of the present application.
2 is a diagram showing a laminated structure of an adhesive film including a release film according to an exemplary embodiment of the present application.
3 is a diagram showing the size of bubbles according to an exemplary embodiment of the present application.
4 is a side view illustrating an organic light emitting display according to an exemplary embodiment of the present application.
5 is a side view illustrating an organic light emitting display according to an exemplary embodiment of the present application.
6 is a diagram showing a DSC graph of a polymer showing glass transition temperature behavior.
7 is a diagram showing a DSC graph of a polymer showing melting temperature behavior.

Hereinafter, this specification will be described in more detail.

In the present specification, when a part "includes" a certain component, it means that it may further include other components, not excluding other components unless otherwise stated.

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. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein.

An exemplary embodiment of the present application is a base film; And an adhesive film comprising an adhesive sheet provided on one side of the base film,

After bonding the opposite side of the surface in contact with the base film of the pressure-sensitive adhesive sheet to stainless steel (SUS304 substrate), the initial adhesive strength after leaving it at 23 ° C for 2 hours is 100 gf / inch or less, and then heat-treated at 50 ° C for 20 minutes. Adhesion is over 300gf/inch,

The pressure-sensitive adhesive sheet is measured at a frequency of 1Hz and a heating rate of 5°C/min in the range of -20°C to 250°C, and the storage modulus (G1) at 210°C satisfies Equation 1 below.

[Equation 1]

1x10 ^4Pa ≤ G1 ≤ 9.9x10 ^4Pa

In the case of the adhesive film according to the present application, the initial adhesive strength of the adhesive sheet has a range of 100 gf / inch or less, and the late adhesive strength after heat treatment has a value of 300 gf / inch or more, and the adhesive strength to the adherend substrate is initially maintained low, It is characterized in that no dirt is left even if it is removed in case of erroneous attachment, and then the adhesive force is increased through a specific process to maintain the adhesive force with the adherend substrate.

In addition, in the adhesive film according to an exemplary embodiment of the present application, the specific content of the curing agent and the specific (meth)acrylate-based resin are appropriately adjusted to the adhesive sheet, and the adhesive sheet is heated at a frequency of 1 Hz and in the range of -20 ° C to 250 ° C. Measured at a speed of 5 ° C / min, as the storage modulus (G1) value at 210 ° C satisfies the range of Equation 1 above, the occurrence of lifting due to high temperature and high pressure pressing during the COP process of the display is prevented. will have

The initial adhesive force and the late adhesive force were measured using a texture analyzer (Stable Micro Systems Co.) at an angle of 180° and a peeling speed of 300 mm/min, and the adhesive sheet according to the present invention was measured at a size of 1 inch. After cutting it into , it was reciprocated once with a 2kg rubber roller, attached to the SUS304 substrate, and then measured.

That is, the initial adhesive strength is obtained by cutting the adhesive sheet according to the present invention to a size of 1 inch, reciprocating once with a 2kg rubber roller, attaching it to a SUS304 substrate, leaving it for 2 hours at 23 ° C, It refers to the value measured using a texture analyzer (Stable Micro Systems Inc.) while peeling at a peeling speed of 10 min.

The late adhesive strength is measured by cutting the adhesive sheet according to the present invention to a size of 1 inch, reciprocating once with a 2kg rubber roller, attaching it to a SUS304 substrate, leaving it at 23 ° C for 2 hours, and then at 50 ° C for 20 minutes. It refers to the value measured using a texture analyzer (Stable Micro Systems Inc.) while peeling at an angle of 180° and a peeling speed of 300 mm/min after heat treatment.

When a sine-shaped shear strain is applied to an elastic body, the stress has the same phase, but in the case of a Newtonian fluid, it is delayed by pi/2, and in the case of a viscoelastic material, the stress is delayed in an intermediate form. Expressing this mathematically, one component is in phase and the other component is delayed by pi/2. Here, the portion in the same phase is called the storage modulus, and the portion delayed by pi/2 is the loss modulus. That is, the storage modulus means energy stored without loss by elasticity.

In one embodiment of the present application, the storage modulus can be measured using TA Instrument's ARES G2, and specifically, the pressure-sensitive adhesive sheet is heated in the range of -20 ° C to 250 ° C under a condition of a frequency of 1 Hz in a shear mode. It means the value of the shear storage modulus at 210 ° C, measured at a rate of 5 ° C / min.

The term "storage modulus" refers to the pressure-sensitive adhesive sheet obtained by manufacturing the pressure-sensitive adhesive sheet to a thickness of 1 mm and punching it with a punch having a diameter of 8 mm, using TA Instrument's ARES G2, under a chuck pressure of 100 g. and a value obtained by measuring under conditions of a frequency of 1 Hz.

In the case of the adhesive film according to an exemplary embodiment of the present application, the storage elastic modulus at a high temperature (210 ° C.) satisfies the above range, so that the adhesive strength is maintained constant even at a high temperature.

A high storage modulus at a high temperature means that the pressure-sensitive adhesive sheet has a high elasticity. As the storage modulus increases, the resistance against external pressure can be exerted. Specifically, the pressure-sensitive adhesive sheet maintains a storage modulus of 1.0x10 ⁴ Pa to 9.9x10 ⁴ Pa at a high temperature of 210° C., thereby minimizing deformation caused by external stimuli, thereby preventing the generation of bubbles during the COP process.

In one embodiment of the present application, when the storage modulus is less than the above range, a pressure phenomenon easily occurs and bubbles may be generated during the COP process. At the time of the film, it is not completely attached to the base film, and a lifting phenomenon occurs, resulting in the generation of air bubbles.

In one embodiment of the present application, the initial adhesive force after bonding the opposite surface of the surface of the adhesive sheet in contact with the base film to the SUS304 substrate and leaving it at 23 ° C for 2 hours is 100 gf / inch or less, preferably 95 gf / inch inch or less, more preferably 90 gf / inch or less.

In another exemplary embodiment, the initial adhesive strength after bonding the opposite side of the surface of the adhesive sheet in contact with the base film to the SUS304 substrate and leaving it at 23° C. for 2 hours is 5 gf/inch or more, preferably 10 gf/inch or more. , More preferably, it may be 15 gf / inch or more.

In another exemplary embodiment, after bonding the opposite side of the surface in contact with the base film of the pressure-sensitive adhesive sheet to the SUS304 substrate, leaving it at 23° C. for 2 hours and heat-treating at 50° C. for 20 minutes, the adhesive strength at the end is 300 gf/inch or more. , Preferably it may be 400 gf / inch or more, more preferably 500 gf / inch or more.

In another exemplary embodiment, after bonding the opposite surface of the surface in contact with the base film of the adhesive sheet to the SUS304 substrate, leaving it at 23 ° C for 2 hours and heat-treating at 50 ° C for 20 minutes, the adhesive strength at the end is 5000 gf / inch or less , preferably 4000 gf/inch or less, more preferably 3000 gf/inch or less.

In one embodiment of the present application, after bonding the opposite surface of the surface of the adhesive sheet in contact with the base film to the SUS304 substrate, the intermediate adhesive strength after leaving at 23 ° C. for 24 hours is 120 gf / inch or less, preferably 115 gf / inch inch or less, more preferably 110 gf / inch or less.

In another exemplary embodiment, after bonding the opposite surface of the surface in contact with the base film of the pressure-sensitive adhesive sheet to the SUS304 substrate, the medium-term adhesive strength after leaving at 23 ° C. for 24 hours is 10 gf / inch or more, preferably 15 gf / inch or more , More preferably, it may be 20 gf / inch or more.

The adhesive film according to the present application includes a polymer having a melting temperature of 30 ° C or more as described above in the adhesive sheet, so that the adhesive strength is maintained at a constant low level even after leaving for 2 hours / 24 hours at room temperature (23 ° C). It is characterized in that it has a characteristic that it does not leave dirt even when it is removed in case of incorrect attachment, and then, through a specific process, the adhesive force is increased to maintain the adhesive force with the adherend substrate.

In one embodiment of the present application, the storage modulus (G1) at 210 ° C is 1x10 ⁴ Pa ≤ G1 ≤ 9.9x10 ⁴ Pa, preferably 1.3x10 ⁴ Pa ≤ G1 ≤ 9.5x10 ⁴ Pa, more preferably 1.5x10 ⁴ Pa ≤ G1 ≤ 8.0x10 ⁴ Pa.

In the adhesive film according to an exemplary embodiment of the present application, the specific content of the curing agent and the specific (meth)acrylate-based resin are appropriately adjusted in the adhesive sheet, so that the adhesive sheet has a frequency of 1 Hz and a temperature increase rate of 5 in the range of -20 ° C to 250 ° C Measured in ° C / min, as the storage modulus (G1) value at 210 ° C satisfies the range of Equation 1 above, it has a feature that can prevent the occurrence of lifting due to high temperature and high pressure pressing during the COP process of the display do.

That is, in the case of the adhesive film according to the present application, as the storage modulus value of the adhesive sheet satisfies the range of Equation 1 even when it is subsequently attached to the adherend substrate and subjected to a high temperature (210 ° C) process, the high temperature and high pressure Even if the process proceeds, no lifting occurs, and it has a feature that can minimize the generation of air bubbles in the adhesive sheet adhered to the substrate to be adhered.

That is, in the case of the adhesive film according to an exemplary embodiment of the present application, even after being left for 2 hours/24 hours at room temperature (23° C.), the adhesive strength is maintained at a constant level at a low level, so even if it is incorrectly attached, dirt is removed. does not remain, and then the adhesive force is increased through a specific process to maintain the adhesive force with the adherend substrate, and as the storage modulus at high temperature maintains the range of Equation 1 above, the adhesive due to high temperature exposure during the COP process of the display It is possible to prevent a decrease in adhesive strength, so that it has characteristics capable of maintaining adhesive strength with the PI substrate and suppressing the generation of air bubbles.

In one embodiment of the present application, an adhesive film having a value of 3 or more and 100 or less is provided for the late adhesive strength/initial adhesive strength.

In one embodiment of the present application, the value of the late adhesive strength/initial adhesive strength may be 3 or more and 100 or less, preferably 10 or more and 80 or less.

In one embodiment of the present application, an adhesive film having a value of 0.8 or more and 1.2 or less of the mid-term adhesive strength/initial adhesive strength is provided.

In one embodiment of the present application, a polyimide substrate is laminated on the opposite surface of the adhesive sheet in contact with the base film, and an IC chip (width x mm, After attaching vertical y mm, height z mm, 5 mm ≤ x ≤ 100 mm, 0.1 mm ≤ y ≤ 10 mm, 0.01 mm ≤ z ≤ 1 mm),

Size of bubbles measured by analyzing the image of the adhesive sheet measured with an optical microscope (30 magnification) after applying pressure to the IC chip for 5 seconds at 210°C and 50 mPa in the thickness direction (ZD) of the adhesive sheet (D1) is intended to provide an adhesive film that satisfies the following formula 2.

[Equation 2]

D1 ≤ 160 μm

D1 is the size of the bubble,

The direction in which the pressure is applied to the IC chip is the observation direction,

The longest distance of the bubble from the long side of the IC chip is d1;

The shortest distance of the bubble from the long side of the IC chip is d2,

The above D1 is d1-d2.

In an exemplary embodiment of the present application, Equation 2 may satisfy D1 ≤ 160 μm, preferably D1 ≤ 155 μm, and more preferably D1 ≤ 150 μm.

In another exemplary embodiment, Equation 2 may be 0 μm ≤ D1 ≤ 160 μm, preferably 0 μm ≤ D1 ≤ 155 μm, and more preferably 0 μm ≤ D1 ≤ 150 μm.

Specifically, it can be seen in Figure 3 the size of the bubble according to the present application. 3 illustrates a side view and a top view of a structure in which a PI substrate 50 and an IC chip 60 are laminated on an adhesive film 40 according to an exemplary embodiment of the present application.

That is, in Equation 2, the fact that the direction in which the pressure is applied to the IC chip is the observation direction means that the observation is made in the top view direction in FIG. 3, and the longest distance (d1) of the bubble from the long side of the IC chip and, for the shortest distance d2 of the bubble from the long side of the IC chip, when a virtual extension line perpendicular to the long side of the IC chip is drawn, the shortest distance in contact with the bubble is d2, and the longest distance in contact with the bubble is d1. In this case, the size of the bubble may be expressed as d1-d2.

In one embodiment of the present application, when a plurality of bubbles are generated, the size of the bubbles may be defined based on the bubble having the maximum value of d1 for each bubble.

In one embodiment of the present application, the longest distance of the bubble from the long side of the IC chip and the shortest distance of the bubble from the long side of the IC chip are defined based on a direction perpendicular to the long side of the IC chip.

That is, in the case of the adhesive film according to the present application, as the specific adhesive composition is included in the adhesive sheet, it has a feature that can suppress the generation of bubbles even under high temperature conditions. In the case of the adhesive film according to the present application, high temperature and In the process of bonding the high-pressure IC chip, it has a feature capable of preventing air bubbles from spreading from the IC chip.

In one embodiment of the present application, the IC chip refers to a Display Driver Integrated Circuit (IC) chip, which is used to drive pixels constituting a display such as an organic light emitting diode (OLED) or a liquid crystal display (LCD). means a semiconductor chip.

In one embodiment of the present application, the IC chip may be expressed as width x mm, length y mm, height z mm, 5 mm ≤ x ≤ 100 mm, 0.1 mm ≤ y ≤ 10 mm, 0.01 mm ≤ z ≤ 1 mm may be satisfied.

In one embodiment of the present application, x may satisfy 5 mm ≤ x ≤ 100 mm, 10 mm ≤ x ≤ 90 mm, 20 mm ≤ x ≤ 50 mm, and x may be 30 mm.

In one embodiment of the present application, y may satisfy 0.1 mm ≤ y ≤ 10 mm, 0.5 mm ≤ y ≤ 5 mm, 0.5 mm ≤ y ≤ 3 mm, and y may be 1 mm.

In an exemplary embodiment of the present application, z may satisfy 0.01 mm ≤ z ≤ 1 mm, 0.05 mm ≤ z ≤ 0.9 mm, 0.1 mm ≤ z ≤ 0.5 mm, and z may be 0.2 mm.

In one embodiment of the present application, a polyimide substrate is laminated on the opposite surface of the adhesive sheet in contact with the base film, and an IC chip (width x mm, After attaching vertical y mm, height z mm, 5 mm ≤ x ≤ 100 mm, 0.1 mm ≤ y ≤ 10 mm, 0.01 mm ≤ z ≤ 1 mm),

Bubble generation area measured by analyzing the image of the adhesive sheet measured with an optical microscope (30 magnification) after applying pressure to the IC chip for 5 seconds at 210°C and 50 mPa in the thickness direction (ZD) of the adhesive sheet The ratio (%) provides an adhesive film that satisfies Equation 3 below.

[Equation 3]

0 % ≤ (V2/V1) x 100 ≤ 30 %

In the above formula 3,

The direction in which the pressure is applied to the IC chip is the observation direction,

V1 is the area (mm ² ) on the pressure-sensitive adhesive sheet expressed as (x mm + 2 mm) x (y mm + 2 mm), and means an area including the entire area of the IC chip,

V2 means the total area (mm ² ) of bubbles in the pressure-sensitive adhesive sheet.

Equation 3 means the area ratio of bubbles generated in the pressure-sensitive adhesive sheet, which means the area ratio of bubbles generated with respect to the area of a specific pressure-sensitive adhesive sheet. , In the end, in the case of the adhesive film according to an exemplary embodiment of the present application, the size of bubbles generated is less than a specific range (satisfying Equation 2), and the area ratio of bubbles generated is less than a specific range (satisfying Equation 3) Accordingly, it is possible to prevent a decrease in adhesive strength even under conditions of high temperature and high pressure, thereby having a feature capable of suppressing the generation of air bubbles in the adhesive sheet.

In an exemplary embodiment of the present application, Equation 3 is 0% ≤ (V2 / V1) x 100 ≤ 30%, preferably 0.5% ≤ (V2 / V1) x 100 ≤ 15%, more preferably 1% ≤ (V2/V1) x 100 ≤ 10%.

In one embodiment of the present application, V1 means a specific area within the pressure-sensitive adhesive sheet, and is an area (mm ² ) on the pressure-sensitive adhesive sheet represented by a value of (x mm + 2mm) x (y mm + 2 mm). , means an area including the entire area of the IC chip.

In an exemplary embodiment of the present application, V1 is an area (mm ² ) on the pressure-sensitive adhesive sheet expressed as (x mm + 2 mm) x (y mm + 2 mm), which includes the entire area of the IC chip. In detail, V1 is the area (mm 2 ) on the adhesive sheet expressed as (x mm + 2 mm) x (y mm + ² mm), and the center of V1 and the center of gravity of the IC chip are It means the area on the matching adhesive sheet.

In one embodiment of the present application, V2 means the total area of bubbles generated in the pressure-sensitive adhesive sheet, and the shape of bubbles is not limited to a circle, an ellipse, or a polygon.

In one embodiment of the present application, a polyimide substrate is laminated on the opposite surface of the adhesive sheet in contact with the base film, and an IC chip (width x mm, After attaching vertical y mm, height z mm, 5 mm ≤ x ≤ 100 mm, 0.1 mm ≤ y ≤ 10 mm, 0.01 mm ≤ z ≤ 1 mm),

Bubble generation area measured by analyzing the image of the adhesive sheet measured with an optical microscope (30 magnification) after applying pressure to the IC chip for 5 seconds at 210°C and 50 mPa in the thickness direction (ZD) of the adhesive sheet The ratio (%) provides an adhesive film that satisfies Equations 4 and 5 below.

[Equation 4]

0 % ≤ (V2/M1) x 100 ≤ 30 %

[Equation 5]

5 cm ² ≤ M1 ≤ 100 m ²

In the above formulas 4 and 5,

The direction in which the pressure is applied to the IC chip is the observation direction,

M1 means the total area of the pressure-sensitive adhesive sheet,

V2 means the total area of air bubbles generated in the pressure-sensitive adhesive sheet.

In one embodiment of the present application, M1 means the entire area of the pressure-sensitive adhesive sheet, and when the pressure-sensitive adhesive sheet has a rectangular parallelepiped shape, it means a value of a x b (a: horizontal length, b: vertical length), The shape of the adhesive sheet is not limited thereto.

In an exemplary embodiment of the present application, M1 means the entire area of the pressure-sensitive adhesive sheet, and may satisfy a range of 5 cm ² ≤ M1 ≤ 100 m ² , preferably 10 cm ² ≤ M1 ≤ 1 m ² .

A PI (Polyimide) substrate is laminated on the opposite side of the adhesive sheet in contact with the base film, and an IC chip (width x mm) is placed on the opposite side of the PI (Polyimide) substrate in contact with the adhesive sheet. , length y mm, height z mm, 5 mm ≤ x ≤ 100 mm, 0.1 mm ≤ y ≤ 10 mm, 0.01 mm ≤ z ≤ 1 mm), and then attaching the IC chip in the thickness direction (ZD) of the adhesive sheet The condition of applying pressure for 5 seconds under the conditions of 210 ℃ and 50 mPa is the condition of attaching the IC chip to the adhesive film of the present application using the TAB bonding machine equipment in the actual COP process (pressure for 5 seconds under the conditions of 210 ℃ and 50 mPa ), and the bubble size and bubble area ratio are used as evaluation criteria to indicate that the pressure-sensitive adhesive sheet according to the present application contains a specific pressure-sensitive adhesive composition and minimizes the generation of bubbles in the actual COP process.

1 shows a side view of the adhesive film according to the present application, and specifically, it can be confirmed that the adhesive film 40 has a form in which the base film 10 / the adhesive sheet 20 are sequentially stacked.

In one embodiment of the present application, the pressure-sensitive adhesive sheet includes a pressure-sensitive adhesive composition or a cured product thereof, and the pressure-sensitive adhesive composition includes a (meth)acrylate-based resin; A polymer having a melting temperature (Tm) of 30° C. or higher; And a curing agent, wherein the polymer is a copolymer of a monofunctional polysiloxane and one or more monomers, and the curing agent is included in an amount of 0.2 parts by weight or more and 1.3 parts by weight or less based on 100 parts by weight of the (meth)acrylate-based resin. An adhesive film is provided.

The melting temperature according to the present application means the temperature at which a phase transition of a material from a solid state to a liquid state occurs. A change corresponding to can be observed, and the temperature at this time can be defined as the melting temperature.

The melting temperature can be measured by differential thermal analysis (DSC). Specifically, it is a value measured by drawing the endothermic and calorific value of a material according to temperature as a phase transition occurs when a sample of about 10 mg is sealed in a dedicated pen and heated in a certain elevated temperature environment.

That is, since the pressure-sensitive adhesive composition according to an exemplary embodiment of the present application includes a polymer exhibiting melting temperature (Tm) behavior, it has excellent variable properties compared to the case of including a polymer exhibiting glass transition temperature (Tg) behavior, and , especially at room temperature (25 ° C), it has excellent stability over time without an increase in adhesive strength.

6 shows a DSC graph for a polymer exhibiting glass transition temperature (Tg) behavior, and FIG. 7 below shows a DSC graph for a polymer exhibiting melting temperature (Tm) behavior.

As can be seen in FIG. 6, in the case of a polymer showing glass transition temperature behavior, it can be confirmed that a phase transition occurs as the temperature is gradually increased with respect to a stable period (Glassy), and a phase transition (Glassy-> Rubbery) can be confirmed. That is, in the case of including a polymer exhibiting glass transition temperature behavior, variable characteristics may occur, but the phase transition temperature range is wide, and when stored at room temperature (25 ℃) for a long time, some phase transition occurs, increasing the adhesive strength of the pressure-sensitive adhesive layer and stability over time This may lead to poor results, and the variable characteristics may not be excellent in the phase transition state to the rubbery state.

Conversely, as can be seen in FIG. 7, in the case of polymers showing melting temperature behavior, when the temperature is gradually increased with respect to the stable period (Solid), it can be seen that a rapid phase transition (Solid->liquid) occurs at a specific temperature (melting). there is. That is, in the case of including a polymer exhibiting melting temperature behavior, a rapid phase transition occurs at a specific temperature value, so that the phase transition does not occur at a temperature below the melting temperature, thereby suppressing the increase in adhesive strength (excellent stability over time), and higher than the melting temperature. At the above temperature, a phase transition occurs, resulting in a rapid increase in adhesive strength (excellent variable properties).

In one embodiment of the present application, the pressure-sensitive adhesive sheet may include the pressure-sensitive adhesive composition as it is.

In one embodiment of the present application, the pressure-sensitive adhesive sheet may include the dried pressure-sensitive adhesive composition.

In one embodiment of the present application, the pressure-sensitive adhesive sheet may include a cured product of the pressure-sensitive adhesive composition.

In one embodiment of the present application, the monomer provides an adhesive film represented by Formula 1 below.

[Formula 1]

In Formula 1,

X is N or O;

R ₁ is hydrogen or a methyl group;

n is an integer from 1 to 30;

In an exemplary embodiment of the present application, n in Formula 1 may be an integer from 1 to 30.

In another exemplary embodiment, n in Formula 1 may be an integer of 10 to 25.

In another exemplary embodiment, n in Formula 1 may be an integer of 16 to 22.

In one embodiment of the present application, the X may be N.

In one embodiment of the present application, the X may be O.

In Formula 1, in particular, when the value of n has the above range, some crystallization begins to occur due to entanglement between side chains of carbon, so that the polymer including it can exhibit melting temperature (Tm) behavior do.

The polymer having a melting temperature of 30° C. or higher means that the final polymer has a melting temperature of 30° C. or higher when the monofunctional polysiloxane and one or more monomers represented by Formula 1 are copolymerized.

In one embodiment of the present application, the melting temperature of the polymer may be 30 ° C or higher, 70 ° C or lower, preferably 60 ° C or lower, more preferably 50 ° C or lower.

In one embodiment of the present application, the components of the polymer included in the pressure-sensitive adhesive composition can be identified through GC (Gas chromatography) analysis, and the composition can be identified through NMR (Nuclear magnetic resonance) analysis.

The copolymerization means a polymer obtained by polymerizing two or more different types of units, and in the copolymer, two or more types of units may be arranged irregularly or regularly.

The copolymer is a random copolymer in which monomers are mixed with each other without regularity, a block copolymer in which blocks arranged in a certain section are repeated, or an alternating copolymer in which monomers are alternately repeated and polymerized. There may be an alternating copolymer, and the polymer having a melting temperature of 30° C. or higher according to an exemplary embodiment of the present application may be a random copolymer, a block copolymer, or an alternating copolymer.

In one embodiment of the present application, the monomer represented by Chemical Formula 1 provides an adhesive film in which at least one selected from the group consisting of STA (Stearyl acrylate) and STMA (Stearyl methacrylate).

As the monofunctional polysiloxane according to the present application, Chisso's FM-0721, Shin-Etsu's KF2012, etc. may be used, but is not limited thereto.

In one embodiment of the present application, the polymer having a melting temperature of 30 ° C or higher may have a weight average molecular weight of 30,000 g / mol to 200,000 g / mol.

In another embodiment, the polymer having a melting temperature of 30 ° C or higher may have a weight average molecular weight of 30,000 g / mol to 150,000 g / mol, preferably 30,000 g / mol to 100,000 g / mol .

When the polymer having a melting temperature of 30° C. or higher according to the present application has a weight average molecular weight value within the above range, the arrangement of molecules in the polymer is excellent, resulting in a low initial adhesive strength when a pressure-sensitive adhesive sheet is subsequently manufactured.

The weight average molecular weight is one of the average molecular weights in which the molecular weight of a certain polymer material is used as a standard and the molecular weight is not uniform, and is a value obtained by averaging the molecular weights of component molecular species of a polymer compound having a molecular weight distribution by weight fraction.

The weight average molecular weight may be measured through Gel Permeation Chromatography (GPC) analysis.

In one embodiment of the present application, the polymer having a melting temperature of 30 ° C or higher is the monofunctional polysiloxane; said one or more monomers; And it can be prepared by including a thermal polymerization initiator in a polymer composition containing a solvent.

Although toluene may be used as the solvent, it is not limited thereto as long as it can dissolve the monofunctional polysiloxane and the at least one monomer, and a general organic solvent may be used accordingly.

In one embodiment of the present application, the polymer having a melting temperature of 30 ° C or higher is based on 100 parts by weight of the polymer having a melting temperature of 30 ° C or higher, 10 parts by weight or more and 40 parts by weight or less of the monofunctional polysiloxane, and 60 parts by weight of the monomer It provides an adhesive film comprising more than 90 parts by weight or less.

In an exemplary embodiment of the present application, the polymer having a melting temperature of 30 ° C or higher is 10 parts by weight or more and 40 parts by weight or less, preferably 15 parts by weight of the monofunctional polysiloxane based on 100 parts by weight of the polymer having a melting temperature of 30 ° C or higher. It may contain more than 30 parts by weight or less, more preferably 18 parts by weight or more and 25 parts by weight or less.

In an exemplary embodiment of the present application, the polymer having a melting temperature of 30 ° C or higher is 60 parts by weight or more and 90 parts by weight or less, preferably 65 parts by weight or more 85 parts by weight based on 100 parts by weight of the polymer having a melting temperature of 30 ° C or higher. It may include 85 parts by weight or less, more preferably 70 parts by weight or more and 85 parts by weight or less.

When the polymer having a melting temperature of 30 ° C or higher according to the present application includes the monofunctional polysiloxane and the monomer by weight, the melting temperature value of the entire polymer may be appropriately formed, and accordingly, at room temperature of the adhesive sheet later The initial adhesive strength can be maintained low, and stability over time at room temperature also has excellent characteristics.

In one embodiment of the present application, the pressure-sensitive adhesive composition provides an adhesive film containing 1 part by weight or more and 10 parts by weight or less of a polymer having a melting temperature of 30 ° C. or higher based on 100 parts by weight of a (meth)acrylate-based resin.

In another embodiment, the pressure-sensitive adhesive composition is based on 100 parts by weight of (meth)acrylate-based resin, 1 part by weight or more and 7 parts by weight or less, preferably 3 parts by weight or more 7 parts by weight of a polymer having a melting temperature of 30 ° C or higher. may be included below.

When the polymer having a melting temperature of 30 ° C. or higher is included in the pressure-sensitive adhesive composition in a weight part within the above range, the amount of the polymer present is suitable and the stability over time at room temperature is excellent, so that the adhesive strength can be maintained constant, When applied to a plastic organic light emitting display in the future, in a variable process, it has excellent variable performance.

The pressure-sensitive adhesive composition according to an exemplary embodiment of the present application includes the curing agent in an amount of 0.2 parts by weight or more and 1.3 parts by weight or less based on 100 parts by weight of the (meth)acrylate-based resin, so in the case of a pressure-sensitive adhesive sheet produced by curing the curing agent, The adhesive force at high temperature is not lowered, and the generation of air bubbles can be suppressed.

In one embodiment of the present application, the curing agent is 0.2 parts by weight or more and 1.3 parts by weight or less based on 100 parts by weight of the (meth)acrylate-based resin, preferably 0.3 parts by weight or more and 1.0 parts by weight or less, more preferably 0.3 parts by weight or more. It may be included in more than 0.7 parts by weight or less by weight.

In an exemplary embodiment of the present application, the curing agent may be an isocyanate-based curing agent, and specifically may be Samyoung Ink DR7030HD.

In one embodiment of the present application, the glass transition temperature (Tg, glass transition temperature) of the pressure-sensitive adhesive composition provides an adhesive film of -80 ℃ or more and 0 ℃ or less.

In another embodiment, the glass transition temperature (Tg, glass transition temperature) of the pressure-sensitive adhesive composition is -80 ° C or more and 0 ° C or less, preferably -70 ° C or more and 0 ° C or less, more preferably -70 ° C or more It may be below 0°C.

The glass transition temperature of the pressure-sensitive adhesive composition refers to the glass transition temperature of the entire pressure-sensitive adhesive composition including both the (meth)acrylate-based resin and the curing agent of the pressure-sensitive adhesive composition. Since the glass transition temperature value of the pressure-sensitive adhesive composition has the above range Accordingly, the storage elastic modulus at high temperature of the adhesive film according to the present application has the range of Equation 1, so that the adhesive strength is not reduced even in a high-temperature process and the generation of bubbles can be suppressed.

In one embodiment of the present application, the (meth)acrylate-based resin may include a (meth)acrylate-based resin having a weight average molecular weight of 100,000 g/mol to 5 million g/mol.

In this specification, (meth)acrylate is meant to include both acrylate and methacrylate. The (meth)acrylate-based resin may be, for example, a copolymer of a (meth)acrylic acid ester-based monomer and a crosslinkable functional group-containing monomer.

The copolymer refers to a polymer obtained by polymerizing two or more different types of units, and in the copolymer, two or more types of units may be arranged irregularly or regularly.

The copolymer is a random copolymer in which monomers are mixed with each other without regularity, a block copolymer in which blocks arranged in a certain section are repeated, or an alternating copolymer in which monomers are alternately repeated and polymerized. There may be alternating copolymers.

The weight average molecular weight is one of the average molecular weights in which the molecular weight of a certain polymer material is used as a standard and the molecular weight is not uniform, and is a value obtained by averaging the molecular weights of component molecular species of a polymer compound having a molecular weight distribution by weight fraction.

The weight average molecular weight may be measured through Gel Permeation Chromatography (GPC) analysis.

In one embodiment of the present application, the (meth)acrylate-based resin provides an adhesive film having a glass transition temperature of less than 0°C.

The glass transition temperature of the (meth)acrylate-based resin means the glass transition temperature of the entire final (meth)acrylate-based resin in which the monomers are polymerized, and in the present specification, the glass transition temperature is a differential scanning calorimeter (DSC, Mettler Co.), a value measured by drawing the endothermic and calorific value of the material according to the temperature as the phase transition occurs when about 10 mg of the sample is sealed in a dedicated pen and heated in a certain elevated temperature environment.

Specifically, the glass transition temperature is a nominal value described in literature, catalogs, etc., or a value calculated based on the following general formula (1) (Fox formula).

[general formula (1)]

1/Tg=W1/Tg1+W2/Tg2+... +Wn/Tgn

In the above general formula (1), Tg is the glass transition temperature of polymer A (unit: K), Tgi (i = 1, 2, ... n) is the glass transition temperature when monomer i forms a homopolymer (unit: : K), Wi (i = 1, 2, ... n) represents the mass fraction of monomer i in all monomer components.

In the above general formula (1), polymer A is monomer 1, monomer 2, . . . , means a calculation formula in the case of including n types of monomer components of monomer n.

In another exemplary embodiment, the (meth)acrylate-based resin has a glass transition temperature of -110°C or more and less than 0°C, preferably -90°C or more and less than 0°C, more preferably -70°C or more and less than 0°C. may be less than

As the glass transition temperature of the (meth)acrylate-based resin satisfies the above range, the adhesive film according to the present application can maintain a certain level of adhesive strength even under conditions of high temperature and high pressure, and can also minimize the generation of air bubbles. characteristics, and the storage modulus value at high temperature may satisfy a specific range.

That is, in the case of the adhesive film according to the present application, the storage modulus at high temperature can satisfy a specific range by controlling the glass transition temperature of the (meth)acrylate-based resin and adjusting the specific content of the curing agent. .

The (meth)acrylic acid ester-based monomer is not particularly limited, but examples thereof include alkyl (meth)acrylate, and more specifically, as a monomer having an alkyl group having 1 to 12 carbon atoms, pentyl (meth)acrylate, n-butyl (meth)acrylate, ethyl (meth)acrylate, methyl (meth)acrylate, hexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethyl One or more of hexyl (meth)acrylate, dodecyl (meth)acrylate, and decyl (meth)acrylate may be included.

The crosslinkable functional group-containing monomer is not particularly limited, but may include, for example, one or more of a hydroxy group-containing monomer, a carboxyl group-containing monomer, and a nitrogen-containing monomer.

Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, ) acrylate, 8-hydroxyoctyl (meth)acrylate, 2-hydroxyethylene glycol (meth)acrylate, or 2-hydroxypropylene glycol (meth)acrylate.

Examples of the carboxyl group-containing monomer include (meth)acrylic acid, 2-(meth)acryloyloxyacetic acid, 3-(meth)acryloyloxypropyl acid, 4-(meth)acryloyloxybutyric acid, and acrylic acid. doublet, itaconic acid, maleic acid, or maleic anhydride; and the like.

Examples of the nitrogen-containing monomer include (meth)acrylonitrile, N-vinyl pyrrolidone, or N-vinyl caprolactam.

In view of improving other functionalities such as compatibility, at least one of vinyl acetate, styrene, and acrylonitrile may be additionally copolymerized with the (meth)acrylate-based resin.

In one embodiment of the present application, the (meth) acrylate-based resin includes at least one monomer selected from the group consisting of an alkyl (meth) acrylate monomer, a hydroxyalkyl acrylate monomer, and a nitrogen-containing monomer An adhesive film is provided.

The alkyl acrylate and alkyl methacrylate are monomers having an alkyl group having 1 to 12 carbon atoms, pentyl (meth) acrylate, n-butyl (meth) acrylate, ethyl (meth) acrylate, methyl (meth) acrylate rate, hexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, dodecyl (meth)acrylate and decyl (meth)acrylate One or more of them may be included.

As the hydroxyalkyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, 6-hydroxyhexyl acrylate, 8-hydroxyoctyl acrylate, 2 -Hydroxyethylene glycol acrylate or 2-hydroxypropylene glycol acrylate.

Examples of the nitrogen-containing monomer include VP (N-vinyl pyrrolidone, N-vinyl pyrrolidone).

In one embodiment of the present application, the (meth) acrylate-based resin is based on 100 parts by weight of the (meth) acrylate-based resin, 70 to 99 parts by weight of an alkyl acrylate monomer, 1 to 15 parts by weight of a hydroxyalkyl acrylate monomer and 0.5 to 10 parts by weight of the nitrogen-containing monomer.

It means that the (meth)acrylate-based resin includes 70 to 99 parts by weight of an alkyl acrylate monomer, 1 to 10 parts by weight of a hydroxyalkyl acrylate monomer, and 0.5 to 7 parts by weight of a nitrogen-containing monomer, an alkyl acrylate monomer, It means that the hydroxyalkyl acrylate monomer and the nitrogen-containing monomer are polymerized in the above weight ratio.

In an exemplary embodiment of the present application, the (meth) acrylate-based resin is 70 to 99 parts by weight, preferably 80 to 99 parts by weight, more preferably 80 to 99 parts by weight of an alkyl acrylate based on 100 parts by weight of the (meth) acrylate-based resin. It may include 80 to 95 parts by weight.

In one embodiment of the present application, the (meth) acrylate-based resin is hydroxyalkyl acrylate based on 100 parts by weight of the (meth) acrylate-based resin 1 to 15 parts by weight, preferably 5 to 13 parts by weight, More preferably, it may include 7 to 10 parts by weight.

In one embodiment of the present application, the (meth)acrylate-based resin is 0.5 to 10 parts by weight, preferably 1 to 8 parts by weight, more preferably 1 to 8 parts by weight of nitrogen-containing monomer based on 100 parts by weight of the (meth)acrylate-based resin. It may include 3 to 8 parts by weight.

In one embodiment of the present application, the (meth) acrylate-based resin is a first (meth) acrylate-based monomer having a glass transition temperature of 0 ° C or higher, a second (meth) acrylate-based monomer having a glass transition temperature of less than 0 ° C, and It provides an adhesive film comprising one or more monomers selected from the group consisting of functional group-containing third (meth)acrylate-based monomers.

When the (meth)acrylate-based resin has the above composition and content, as the storage modulus (G1) of the adhesive sheet at a high temperature (210 ° C) satisfies Equation 1, the adhesive film can be obtained even in a high temperature COP process. Since the adhesive strength is not lowered, it has a characteristic capable of suppressing the generation of air bubbles.

In one embodiment of the present application, the pressure-sensitive adhesive composition may further include at least one selected from the group consisting of a crosslinking agent, a solvent, a dispersing agent, a photoinitiator, a thermal initiator, and a tackifier.

According to an exemplary embodiment of the present specification, the crosslinking agent is hexanedioldi(meth)acrylate, ethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate having 2 to 14 ethylene groups, and trimethylolpropane. Di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, 2-trisacryloyloxymethylethylphthalic acid, the number of propylene groups 2 to 14 propylene glycol di(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, acidic variants of dipentaerythritol penta(meth)acrylate and dipentaerythritol Compounds obtained by esterifying polyhydric alcohols such as mixtures of hexa(meth)acrylates (trade names: TO-2348 and TO-2349 manufactured by Toga Synthetic Co., Ltd., Japan) with α,β-unsaturated carboxylic acids; compounds obtained by adding (meth)acrylic acid to compounds containing a glycidyl group, such as trimethylolpropane triglycidyl ether acrylic acid adducts and bisphenol A diglycidyl ether acrylic acid adducts; Ester compounds of polyhydric carboxylic acids with compounds having hydroxyl groups or ethylenically unsaturated bonds, such as phthalic acid diesters of β-hydroxyethyl (meth)acrylate and toluene diisocyanate adducts of β-hydroxyethyl (meth)acrylates , or adducts with polyisocyanates; (meth)acrylic acid alkyl esters such as methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate; And 9,9'-bis [4- (2-acryloyloxyethoxy) phenyl] may include one or more selected from the group consisting of fluorene, but is not limited to these, known in the art Common ones can be used.

According to an exemplary embodiment of the present specification, the photoinitiator is a triazine-based compound, a biimidazole compound, an acetophenone-based compound, an O-acyloxime-based compound, a thioxanthone-based compound, a phosphine oxide-based compound, a coumarin-based compound and benzophenone It may be substituted with one or two or more substituents selected from the group consisting of paddy-based compounds.

Specifically, according to an exemplary embodiment of the present specification, the photoinitiator is 2,4-trichloromethyl-(4'-methoxyphenyl)-6-triazine, 2,4-trichloromethyl-(4'-methoxyphenyl) Toxystyryl) -6-triazine, 2,4-trichloromethyl- (fiplonil) -6-triazine, 2,4-trichloromethyl- (3', 4'-dimethoxyphenyl) -6 -triazine, 3-{4-[2,4-bis(trichloromethyl)-s-triazin-6-yl]phenylthio}propanoic acid, 2,4-trichloromethyl-(4'-ethyl ratio) triazine compounds such as phenyl)-6-triazine or 2,4-trichloromethyl-(4'-methylbiphenyl)-6-triazine; 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetraphenyl biimidazole or 2,2'-bis(2,3-dichlorophenyl)-4,4',5 Biimidazole compounds, such as 5'-tetraphenyl biimidazole; 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one, 4-(2-hydroxy Toxy)-phenyl (2-hydroxy)propyl ketone, 1-hydroxycyclohexyl phenyl ketone, 2,2-dimethoxy-2-phenyl acetophenone, 2-methyl-(4-methylthiophenyl)-2-mol Acetopes such as polyno-1-propan-1-one (Irgacure-907) or 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one (Irgacure-369) paddy field compound; O-acyloxime compounds such as Ciba Geigy's Irgacure OXE 01 and Irgacure OXE 02; benzophenone compounds such as 4,4'-bis(dimethylamino)benzophenone or 4,4'-bis(diethylamino)benzophenone; thioxanthone-based compounds such as 2,4-diethyl thioxanthone, 2-chloro thioxanthone, isopropyl thioxanthone, or diisopropyl thioxanthone; 2,4,6-trimethylbenzoyl diphenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentyl phosphine oxide or bis(2,6-dichlorobenzoyl) propyl phosphine oxide phosphine oxide compounds such as the like; 3,3'-carbonylvinyl-7-(diethylamino)coumarin, 3-(2-benzothiazolyl)-7-(diethylamino)coumarin, 3-benzoyl-7-(diethylamino)coumarin, 3-benzoyl-7-methoxy-coumarin or 10,10'-carbonylbis[1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H,11H-Cl] A coumarin-based compound such as -benzopyrano[6,7,8-ij]-quinolizin-11-one may be used alone or in combination of two or more, but is not limited thereto.

In addition, as the thermal initiator, those known in the art may be used.

Although toluene may be used as the solvent, it is not limited thereto as long as it can dissolve a specific substance, and a general organic solvent may be used accordingly.

In one embodiment of the present application, the base film is PET (polyethylene terephthalate), polyester (polyester), PC (polycarbonate), PI (polyimide), PEN (polyethylene naphthalate), PEEK (polyether ether ketone), PAR ( polyarylate), polycylicolefin (PCO), polynorbornene, polyethersulphone (PES), and cycloolefin polymer (COP).

In another exemplary embodiment, the base film may be polyethylene terephthalate (PET).

In one embodiment of the present application, the thickness of the base film is 25 μm or more and 300 μm or less, preferably 30 μm or more and 270 μm or less, more preferably 40 μm or more and 250 μm or less.

Also, the base film is preferably transparent. The meaning here that the base film is transparent indicates that the light transmittance of visible light (400 to 700 nm) is 80% or more.

When the base film has the above range, the laminated adhesive film has characteristics capable of being thinned.

In one embodiment of the present application, the thickness of the adhesive sheet is 3 μm or more and 100 μm may be below.

In another exemplary embodiment, the thickness of the adhesive sheet is 3 μm or more and 100 μm or less, preferably 5 μm or more and 80 μm or less, more preferably 10 μm or more and 50 μm may be below.

When the thickness of the pressure-sensitive adhesive sheet is within the above range, the rate of bubbles generated inside the pressure-sensitive adhesive sheet may be lowered under high-temperature conditions, and later, adhesion to the adherend substrate may also have excellent characteristics.

In one embodiment of the present application, the thickness of the adhesive film is 110 ㎛ or more and 700 ㎛ The adhesive film which is the following is provided.

In another embodiment, the thickness of the adhesive film is 120 ㎛ or more and 600 ㎛ or less, preferably 125 μm or more and 550 μm or less, more preferably 130 μm or more and 500 μm may be below.

When the adhesive film has the above range, the thickness is suitable when applied to a plastic organic light emitting display later, and the adhesive strength is not reduced in a high-temperature COP process.

In one embodiment of the present application, the pressure-sensitive adhesive sheet may be stacked in plurality.

In one embodiment of the present application, an adhesive film further comprising a release film is provided on the opposite side of the adhesive sheet in contact with the base film.

The release film may be a hydrophobic film and is a layer for protecting an adhesive sheet having a very thin thickness, and refers to a transparent layer attached to one surface of the adhesive sheet, and is a film having excellent mechanical strength, thermal stability, moisture barrier properties, and isotropy. can be used. For example, acetate-based, polyester-based, polyethersulfone-based, polycarbonate-based, polyamide-based, polyimide-based, polyolefin-based, cycloolefin-based, polyurethane-based and acrylic resin films such as triacetyl cellulose (TAC), etc. It can be used, but if it is a commercially available silicon-treated release film, it is not limited thereto.

2 is a diagram showing a laminated structure of an adhesive film including a release film according to an exemplary embodiment of the present application. Specifically, it can be confirmed that the adhesive film 40 has a structure in which the base film 10 / the adhesive sheet 20 / the release film 30 are sequentially stacked.

All of the release film may be removed when applied to a display.

An exemplary embodiment of the present application includes preparing a base film; and forming a pressure-sensitive adhesive sheet by applying and curing a pressure-sensitive adhesive composition on one surface of the base film,

After bonding the opposite side of the surface in contact with the base film of the pressure-sensitive adhesive sheet to stainless steel (SUS304 substrate), the initial adhesive strength after leaving it at 23 ° C for 2 hours is 100 gf / inch or less, and then heat-treated at 50 ° C for 20 minutes. Adhesion is over 300gf/inch,

The adhesive sheet is measured at a frequency of 1 Hz and a heating rate of 5 ° C / min in the range of -20 ° C to 250 ° C, and the storage modulus (G1) at 210 ° C satisfies Equation 1. want to do

In the manufacturing method, the base film, the pressure-sensitive adhesive composition, the initial adhesive strength, the late adhesive strength, the adhesive sheet, and the definitions of Equation 1 are the same as described above.

In the present application, the pressure-sensitive adhesive sheet may be prepared by applying a pressure-sensitive adhesive composition on a base film with a bar coater.

In one embodiment of the present application, the pressure-sensitive adhesive composition is a (meth) acrylate-based resin; A polymer having a melting temperature (Tm) of 30° C. or higher; And a curing agent, wherein the polymer is a copolymer of a monofunctional polysiloxane and one or more monomers, and the curing agent is included in an amount of 0.2 parts by weight or more and 1.3 parts by weight or less based on 100 parts by weight of the (meth)acrylate-based resin. A method for producing an adhesive film is provided.

An exemplary embodiment of the present application is an adhesive film according to the present application; and a plastic organic light emitting display provided on the adhesive sheet side of the adhesive film.

An exemplary embodiment of the present application is an adhesive film according to the present application; a plastic substrate provided on the side of the adhesive sheet of the adhesive film; and an IC chip provided on a surface opposite to a surface of the plastic substrate in contact with the adhesive film.

An exemplary embodiment of the present application includes a thin film transistor (TFT) provided on a surface opposite to a surface of the plastic substrate in contact with the adhesive film; and an organic light emitting layer on a surface opposite to a surface of the thin film transistor (TFT) in contact with the plastic substrate.

An exemplary embodiment of the present application includes a liquid crystal display provided on a surface opposite to a surface of the plastic substrate in contact with the adhesive film; and an organic light emitting layer on a surface opposite to a surface of the liquid crystal display in contact with the plastic substrate.

In FIG. 4 , a laminated structure of a plastic organic light emitting display according to an exemplary embodiment of the present application can be confirmed.

In the plastic organic light emitting display according to an exemplary embodiment of the present application, an anisotropic conductive film (ACF Anisotropic Conductive Film) may be further included on a surface of the IC chip in contact with the plastic substrate.

The anisotropic conductive film is a material for circuit connection in which conductive fine particles are uniformly dispersed in a film-like adhesive and has electrical anisotropy of conductivity in the thickness direction and insulation in the plane direction through a thermal compression bonding process.

In FIG. 5 , a laminated structure of a plastic organic light emitting display according to an exemplary embodiment of the present application can be confirmed.

The organic light emitting layer may be selected from the group consisting of an organic photoelectric device, an organic transistor, an organic solar cell, an organic light emitting device, and a micro LED device.

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the present invention. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein.

< manufacturing example >

< Example 1>

1) polymerization of the first polymer (( met ) acrylate type polymerization of resin)

Ethylhexylacrylate (EHA, Ehylhexylacrylate) / Methylmethacrylate (MMA, Methylmethacrylate) / N-vinylpyrrolidone (VP, N-Vinylpyrrolidone) / Hydroxyethylacrylate (HEA, hydroxyethylacrylate) 65/20/5 After adding ethyl acetate (EA, Ethyl Acetate) at a weight ratio of / 10, azobisisobutyronitrile (AIBN), a thermal polymerization initiator, was added to form a (meth)acrylate-based resin with a weight average molecular weight of 1 million g/mol. manufactured.

2) Polymerization of the second polymer (polymerization of a polymer having a melting temperature of 30 ° C or higher)

A second polymer having a weight average molecular weight of 60,000 g / mol was prepared by adding a material having a composition and weight ratio of the second polymer of Table 1 to toluene, and then adding AIBN (azobisisobutyronitrile) as a thermal polymerization initiator. did

In Table 1, FM0721 is a monofunctional polysiloxane manufactured by Chisso, and FM0721 is a (meth)acrylate containing polysiloxane.

3) Manufacture of adhesive film

An isocyanate curing agent (Samyoung Ink DR7030HD) was added in an amount of 0.3 parts by weight based on 100 parts by weight of the (meth)acrylate-based resin, and then diluted with a toluene solution to have a solid content of 20%.

The prepared adhesive composition was coated on a polyethylene terephthalate (PET) film (T91455) treated with MPI's double-sided anti-static (AS) treatment to a thickness of 15 μm, and double-sided anti-static (Anti-static) , AS) treated polyethylene terephthalate (PET) (RF12AS) was applied, and then aged at 40° C. for 2 days to prepare an adhesive film.

< Example 2>

In Example 1, an adhesive film was prepared in the same manner as in Example 1, except that 0.7 parts by weight of the curing agent was used.

< comparative example 1>

In Example 1, an adhesive film was prepared in the same manner as in Example 1, except that 1.5 parts by weight of the curing agent was used.

< comparative example 2>

In Example 1, an adhesive film was prepared in the same manner as in Example 1, except that 0.1 part by weight of the curing agent was used.

< comparative example 3>

In Example 1, an adhesive film was prepared in the same manner as in Example 1 except that the second polymer was not used.

Table 1 below shows the composition and weight ratio of the first polymer, the second polymer, and the curing agent included in the adhesive films of Example 1, Example 2, and Comparative Examples 1 to 3.

first polymer
(weight ratio) second polymer curing agent
(DR-7030HD) monomer
(weight ratio) parts by weight Example 1 EHA/MMA/VP/HEA
=65/20/5/10 FM0721/STMA/STA
=20/60/20 5 0.3 Example 2 EHA/MMA/VP/HEA=65/20/5/10 FM0721/STMA/STA
=20/60/20 5 0.7 Comparative Example 1 EHA/MMA/VP/HEA=65/20/5/10 FM0721/STMA/STA
=20/60/20 5 1.5 Comparative Example 2 EHA/MMA/VP/HEA=65/20/5/10 FM0721/STMA/STA
=20/60/20 5 0.1 Comparative Example 3 EHA/MMA/VP/HEA=65/20/5/10 - - 0.3

With respect to the adhesive films of Example 1, Example 2 and Comparative Examples 1 to 3, evaluation data for initial adhesive strength, intermediate adhesive strength, late adhesive strength, storage modulus (210 ° C) and bubble evaluation are shown in Table 2 below. .

initial adhesion
(gf/inch) medium term adhesion
(gf/inch) Late adhesion
(gf/inch) storage modulus
(210℃) bubble evaluation
(occurrence level) Example 1 72 78 1632 2x10 ^4Pa 48 μm Example 2 65 66 1515 5x10 ^4Pa 144 μm Comparative Example 1 58 59 1212 1x10 ^5Pa 215 μm Comparative Example 2 101 109 1753 7x10 ^3Pa 202 μm Comparative Example 3 1602 1623 1641 2x10 ^4Pa 50 µm

1. Initial adhesive strength: One of the adhesive films prepared in Examples 1, 2, and Comparative Examples 1 to 3 was laminated by reciprocating once with a 2kg rubber roller on stainless steel (SUS304 substrate) and laminated at 23 ° C. After leaving it for 2 hours, the film was measured on the stainless steel (SUS304 substrate) using a texture analyzer (Stable Micro Systems) at an angle of 180 ° and a peeling speed of 300 mm / min.

2. Medium-term adhesive strength: One of the adhesive films prepared in Examples 1, 2, and Comparative Examples 1 to 3 was laminated on stainless steel (SUS304 substrate) by reciprocating once with a 2kg rubber roller and laminating at 23 ° C. After leaving it for 24 hours, the film was measured on the stainless steel (SUS304 substrate) using a texture analyzer (Stable Micro Systems) at an angle of 180 ° and a peeling speed of 300 mm / min.

3. Late adhesive strength: One of the adhesive films prepared in Examples 1, 2, and Comparative Examples 1 to 3 was laminated on stainless steel (SUS304 substrate) by reciprocating once with a 2kg rubber roller and laminating at 50 ° C. After standing for 20 minutes, the film was measured on the stainless steel (SUS304 substrate) using a texture analyzer (Stable Micro Systems) at an angle of 180 ° and a peeling speed of 300 mm / min.

4. Storage modulus: The shear storage modulus at 210 ° C was calculated in shear mode, measured at a heating rate of 5 ° C / min in the range of -20 to 250 ° C under conditions of a frequency of 1 Hz. At this time, TA Instrument's ARES G2 was used as the measurement equipment.

5. Bubble evaluation: Regarding the PI (polyimide) substrate laminated adhesive sheet, an IC chip (width 30mm x length 1mm x height 0.2 mm), the size of bubbles generated when pressure was applied to the IC chip for 5 seconds at 210° C. and 50 mPa in the thickness direction (ZD) of the pressure-sensitive adhesive sheet was shown.

As can be seen from Table 2, in the case of the adhesive film according to the present application, it was confirmed that the adhesive strength at high temperature was maintained within a certain range as the specific adhesive composition was included in the adhesive sheet.

That is, in the case of the adhesive film according to the present application, it was confirmed that it has a feature capable of preventing a decrease in the adhesive strength of the adhesive sheet due to exposure to high temperatures during the COP process of the display, and it was confirmed that the size of generated air bubbles was also minimized. Accordingly, it was confirmed that the adhesive strength did not decrease even under high temperature conditions.

In the case of the adhesive films of Comparative Examples 1 and 2, it can be seen that the adhesive strength decreases when high temperature conditions are applied, and accordingly, in the actual COP process, the size of bubbles generated in the adhesive sheet increases, resulting in a decrease in adhesive strength was able to confirm

Specifically, in the case of Comparative Examples 1 and 2, the content of the curing agent included in the pressure-sensitive adhesive composition exceeds a specific range (Comparative Example 1) or is less than a specific range (Comparative Example 2), corresponding to high temperature and high pressure conditions. It was confirmed that the adhesive strength was reduced upon application.

In addition, as can be seen in Examples 1 and 2 of Table 1, the adhesive film according to an exemplary embodiment of the present application includes a polymer and (meth)acrylic acid having a melting temperature (Tm) of 30° C. or higher in the adhesive sheet. Including the late-based resin, it was confirmed that the pressure-sensitive adhesive sheet including the same had low initial adhesive strength with the adherend substrate.

In particular, in the case of the adhesive sheet included in the adhesive film according to one embodiment of the present application, the initial adhesive strength with the adherend substrate is low, and at the same time, the adhesive strength increases after a specific process to develop sufficient adhesive strength to fix the adherend substrate. In the adhesive film according to the present application, the adhesive strength of the adhesive sheet to the adherend substrate is initially maintained low, and no dirt is left even if it is removed in case of erroneous attachment, and then the adhesive strength is increased through a specific process to increase the adhesive strength with the adherend substrate. It was confirmed that this was maintained.

In the case of Comparative Example 3 of Table 2, as the storage modulus at a high temperature (210° C.) satisfies a specific range, the adhesive strength does not fall when a high temperature condition is applied, and accordingly, in the actual COP process, the adhesive sheet Although the size of the bubbles generated was small, the adhesive force did not decrease, but the initial adhesive force and the intermediate adhesive force were high, so it was confirmed that the rework characteristics were not good when attached incorrectly.

10: base film
20: adhesive sheet
25: PI substrate
30: release film
40: adhesive film
50: plastic substrate
55: ACF Anisotropic Conductive Film
60: IC chip
80: thin film transistor (TFT)
90 organic light emitting layer
d1: Longest distance of bubbles from the long side of the IC chip
d2: The shortest distance of bubbles from the long side of the IC chip

Claims (21)

base film; and
an adhesive sheet provided on one surface of the base film;
As an adhesive film containing,
After bonding the opposite side of the surface in contact with the base film of the pressure-sensitive adhesive sheet to stainless steel (SUS304 substrate), the initial adhesive strength after leaving it at 23 ° C for 2 hours is 100 gf / inch or less, and then heat-treated at 50 ° C for 20 minutes. Adhesion is over 300gf/inch,
After bonding the opposite surface of the surface in contact with the base film of the pressure-sensitive adhesive sheet to stainless steel (SUS304 substrate), the medium-term adhesive strength after leaving at 23 ° C. for 24 hours is 110 gf / inch or less,
The pressure-sensitive adhesive sheet is measured at a frequency of 1 Hz and a heating rate of 5 ° C / min in the range of -20 ° C to 250 ° C, and the storage modulus (G1) at 210 ° C satisfies the following formula 1:
[Equation 1]
1x10 ^4Pa ≤ G1 ≤ 9.9x10 ^4Pa The method of claim 1,
An adhesive film having a value of the late adhesive force/initial adhesive force of 3 or more and 100 or less. delete delete The method of claim 1,
A polyimide substrate was laminated on the opposite surface of the adhesive sheet in contact with the base film, and an IC chip (width x mm, length y mm, height z mm, 5 mm ≤ x ≤ 100 mm, 0.1 mm ≤ y ≤ 10 mm, 0.01 mm ≤ z ≤ 1 mm),
Bubble generation area measured by analyzing the image of the adhesive sheet measured with an optical microscope (30 magnification) after applying pressure to the IC chip for 5 seconds at 210°C and 50 mPa in the thickness direction (ZD) of the adhesive sheet The ratio (%) is an adhesive film that satisfies the following formula 3:
[Equation 3]
0 % ≤ (V2/V1) x 100 ≤ 30 %
In the above formula 3,
The direction in which the pressure is applied to the IC chip is the observation direction,
V1 is the area (mm ² ) on the pressure-sensitive adhesive sheet expressed as (x mm + 2 mm) x (y mm + 2 mm), and means an area including the entire area of the IC chip;
V2 means the total area (mm ² ) of bubbles in the pressure-sensitive adhesive sheet. The method of claim 1,
The pressure-sensitive adhesive sheet includes a pressure-sensitive adhesive composition or a cured product thereof,
The pressure-sensitive adhesive composition is a (meth) acrylate-based resin; A polymer having a melting temperature (Tm) of 30° C. or higher; and a curing agent;
The polymer is a copolymer of a monofunctional polysiloxane and one or more monomers,
The curing agent is included in an amount of 0.2 parts by weight or more and 1.3 parts by weight or less based on 100 parts by weight of the (meth)acrylate-based resin. The method of claim 6,
The monomer is an adhesive film represented by the following formula (1):
[Formula 1]

In Formula 1,
X is N or O;
R ₁ is hydrogen or a methyl group;
n is an integer from 1 to 30; The method of claim 7,
The monomer represented by Chemical Formula 1 is at least one selected from the group consisting of STA (Stearyl acrylate) and STMA (Stearyl methacrylate). The method of claim 6,
The polymer having a melting temperature of 30 ° C or higher is based on 100 parts by weight of the polymer having a melting temperature of 30 ° C or higher,
10 parts by weight or more and 40 parts by weight or less of the monofunctional polysiloxane, and
An adhesive film comprising 60 parts by weight or more and 90 parts by weight or less of the monomer. The method of claim 6,
The pressure-sensitive adhesive composition is based on 100 parts by weight of (meth) acrylate-based resin,
An adhesive film comprising 1 part by weight or more and 10 parts by weight or less of a polymer having a melting temperature of 30 ° C or higher. The method of claim 6,
The (meth) acrylate-based resin includes at least one monomer selected from the group consisting of an alkyl (meth) acrylate monomer, a hydroxyalkyl acrylate monomer, and a nitrogen-containing monomer. The pressure-sensitive adhesive film of claim 6, wherein the pressure-sensitive adhesive composition has a glass transition temperature (Tg) of -80°C or more and 0°C or less. The pressure-sensitive adhesive film of claim 6, wherein the pressure-sensitive adhesive composition further comprises at least one selected from the group consisting of a crosslinking agent, a solvent, a dispersing agent, a photoinitiator, a thermal initiator, and a tackifier. The method according to claim 1, wherein the thickness of the pressure-sensitive adhesive sheet is 3 μm or more and 100 μm The adhesive film which is the following. The method according to claim 1, wherein the thickness of the base film is 25 ㎛ or more 300 ㎛ The adhesive film which is the following. The method according to claim 1, wherein the base film is PET (polyethylene terephthalate), polyester (polyester), PC (polycarbonate), PI (polyimide), PEN (polyethylene naphthalate), PEEK (polyether ether ketone), PAR (polyarylate), PCO An adhesive film selected from the group consisting of (polycylicolefin), polynorbornene, polyethersulphone (PES), and cycloolefin polymer (COP). The adhesive film of claim 1, further comprising a release film on the opposite side of the adhesive sheet in contact with the base film. Preparing a base film; and
Forming a pressure-sensitive adhesive sheet by applying and curing a pressure-sensitive adhesive composition on one surface of the base film;
As a method for producing an adhesive film comprising a,
After bonding the opposite side of the surface in contact with the base film of the pressure-sensitive adhesive sheet to stainless steel (SUS304 substrate), the initial adhesive strength after leaving it at 23 ° C for 2 hours is 100 gf / inch or less, and then heat-treated at 50 ° C for 20 minutes. Adhesion is over 300gf/inch,
After bonding the opposite surface of the surface in contact with the base film of the pressure-sensitive adhesive sheet to stainless steel (SUS304 substrate), the medium-term adhesive strength after leaving at 23 ° C. for 24 hours is 110 gf / inch or less,
The pressure-sensitive adhesive sheet is measured at a frequency of 1 Hz and a heating rate of 5 ° C / min in the range of -20 ° C to 250 ° C, and the storage modulus (G1) at 210 ° C satisfies the following formula 1 Method for producing an adhesive film:
[Equation 1]
1x10 ^4Pa ≤ G1 ≤ 9.9x10 ^4Pa The method of claim 18
The pressure-sensitive adhesive composition is a (meth) acrylate-based resin; A polymer having a melting temperature (Tm) of 30° C. or higher; and a curing agent;
The polymer is a copolymer of a monofunctional polysiloxane and one or more monomers,
The curing agent is included in 0.2 parts by weight or more and 1.3 parts by weight or less based on 100 parts by weight of the (meth) acrylate-based resin. The pressure-sensitive adhesive film according to any one of claims 1, 2 and 5 to 17; and
a plastic substrate provided on the side of the adhesive sheet of the adhesive film;
A plastic organic light emitting display comprising a. in claim 20
a liquid crystal display provided on a surface opposite to the surface of the plastic substrate in contact with the adhesive film; and
an organic light emitting layer on a surface opposite to the surface of the liquid crystal display in contact with the plastic substrate;
A plastic organic light emitting display comprising a.

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