KR20200105049A - Heat-radiation complex sheet having improved heat-radiation ability, display device including the same and impact-absorbing ability and method for manufacturing the same - Google Patents

Abstract

Disclosed is a heat radiating composite sheet including: an impact-resistant foamed layer comprising foam particles and a crosslinked binder resin surrounding the foam particles; a polymer film directly bonded to one side of the foam layer; and a metal foil directly bonded to the other surface of the foam layer. The crosslinkable binder resin is formed by crosslinkage of an acrylic binder resin. The acrylic binder resin is formed through an addition reaction of a monomer mixture, wherein the monomer mixture includes 15-35 wt% of ethyl acrylate (EA), 15-35 wt% of methyl methacrylate (MMA), 15-30 wt% of n-butyl acrylate (n-BA), 10-20 wt% of methoxy polyethylene glycol methacrylate (MPEGMA); and 1-5 wt% of acrylamide, and the acrylic binder resin has a glass transition temperature of -50°C to 30°C.

Description

Heat-radiation composite sheet with improved heat dissipation and shock absorption performance, display device including the same, and manufacturing method thereof SAME}

The present invention relates to a heat radiation composite sheet. More specifically, it relates to a heat radiation composite sheet having improved heat radiation performance and shock absorption performance, a display device including the same, and a manufacturing method thereof.

Recently, as high-performance, multifunctional, and miniaturized electronic devices such as mobile phones, tablet PCs, and notebook computers have progressed, the importance of improving the heat dissipation function of electronic devices is increasing.

In order to improve the heat dissipation function of such an electronic device, a heat dissipation member including a material having high thermal conductivity such as copper is used, and in order to improve the impact resistance of a portable electronic device, a composite sheet form combined with a shock absorbing foam, etc. The heat dissipation member of is being developed.

In the case of the composite heat dissipation sheet as described above, there is a problem in that heat dissipation performance is deteriorated according to the composite, which is composed of several functional layers to impart various functions.

The present invention is to solve the above problems, to provide a heat dissipation composite sheet having improved heat dissipation performance and shock absorption performance.

Another object of the present invention is to provide a display device including the heat dissipation composite sheet.

Another object of the present invention is to provide a method for producing the heat-dissipating composite sheet.

However, the problem to be solved by the present invention is not limited to the above-mentioned problems, and may be variously extended without departing from the spirit and scope of the present invention.

The heat dissipation composite sheet according to exemplary embodiments of the present invention for achieving the object of the present invention described above is an impact-resistant foam layer comprising foam particles and a crosslinked binder resin bonded to the foam particles, and one surface of the foam layer It includes a polymer film directly bonded to and a metal foil directly bonded to the other surface of the foam layer. The crosslinked binder resin is formed by crosslinking of an acrylic binder resin, and the acrylic binder resin is ethyl acrylate (EA) 15% to 35% by weight, methyl methacrylate (MMA) 15 Wt% to 35 wt%, n-butyl acrylate (n-BA) 15 wt% to 30 wt%, methoxy polyethylene glycol methacrylate (MPEGMA) 10 wt% to 20 It is formed by addition reaction of a monomer mixture containing 1% to 5% by weight of acrylamide and 1% to 5% by weight of acrylamide, and has a glass transition temperature of -50°C to 30°C.

According to an embodiment, the monomer mixture is ethyl acrylate 20% to 30% by weight, methyl methacrylate 25% to 30% by weight, n-butyl acrylate 15% to 25% by weight, methoxypolyethylene 10% to 20% by weight of glycol methacrylate, 1% to 5% by weight of acrylamide, and 1% to 3% by weight of styrene, and the glass transition temperature of the acrylic binder resin is -20°C to 0°C .

According to an embodiment, the heat dissipation composite sheet further includes an embossed adhesive layer coupled to one surface of the polymer film and having an embossed pattern.

According to an embodiment, the polymer film includes a light blocking material or a black colored layer.

According to an embodiment, the metal foil includes at least one selected from the group consisting of copper, aluminum, silver, and nickel.

According to an embodiment, the metal foil includes a metal layer and a carbon-based heat dissipation layer, and the carbon-based heat dissipation layer is disposed between the metal layer and the foam layer, and includes graphene or graphite.

A display device according to exemplary embodiments of the present invention includes the heat dissipation composite sheet and a display panel coupled to the heat dissipation composite sheet.

The method of manufacturing a heat-dissipating composite sheet according to exemplary embodiments of the present invention includes forming a coating layer by applying a foaming composition including an acrylic binder resin, a foaming agent, a curing agent, and a solvent on a polymer film, and applying the coating layer to 40° C. Forming a pre-foamed layer by heating at 115°C to remove the solvent, laminating a metal foil on the pre-foaming layer, and heating the pre-foaming layer at 120°C to 160°C to expand the expanded particles and the expanded particles It includes the step of forming an impact-resistant foam layer comprising a crosslinked binder resin combined with.

As described above, according to exemplary embodiments of the present invention, the polymer film, the impact-resistant foam layer, and the metal foil are not bonded using a pressure-sensitive adhesive, and an impact-resistant foam composition is provided on the polymer film, and the solvent is removed. After laminating the and metal foil, a foaming step is performed to form an impact resistant foam layer. Therefore, by increasing the adhesion between the impact-resistant foam layer and the polymer film, and the impact-resistant foam layer and the metal foil, the impact-resistant foam layer and the polymer film, and the impact-resistant foam layer and the metal foil can be directly bonded without an adhesive layer using a pressure-sensitive adhesive. . Accordingly, it is possible to provide a heat dissipating composite sheet integrally formed without an adhesive layer and a lamination process using the same.

Accordingly, it is possible to prevent deterioration in heat dissipation performance occurring at the adhesive layer and the interface thereof, and greatly improve the efficiency of the heat dissipation composite sheet manufacturing process.

In addition, through the combination of monomers constituting the acrylic binder resin of the foam composition, not only can the impact absorption performance be improved, but also the bonding strength with the adhesive layer in a high temperature/high humidity environment can be increased, thereby improving the reliability of the adhesive tape. I can.

1 to 4 are cross-sectional views illustrating a method of manufacturing a heat-dissipating composite sheet according to an embodiment of the present invention.
5 is a cross-sectional view of a heat dissipation composite sheet according to another embodiment of the present invention.
6 is an enlarged cross-sectional view of an adhesive layer and a release layer of the heat dissipation composite sheet of FIG.
7 is an enlarged plan view of an adhesive layer of the heat dissipation composite sheet of FIG. 5.
8 is a cross-sectional view illustrating a display device according to an exemplary embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. The present invention is intended to illustrate specific embodiments and describe in detail in the text, as various changes may be made and various forms may be applied. However, this is not intended to limit the present invention to a specific form disclosed, it should be understood to include all changes, equivalents, or substitutes included in the spirit and scope of the present invention. In the accompanying drawings, the dimensions of the structures are shown to be enlarged compared to the actual size for clarity of the present invention.

The terms used in the present application are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In the present application, terms such as "comprise" or "have" are intended to designate the existence of features, numbers, steps, actions, elements, or combinations thereof described in the specification, and one or more other features or numbers It is to be understood that the possibility of the presence or addition of, steps, actions, components, or combinations thereof, is not preliminarily excluded.

Unless otherwise defined, all terms, including technical and scientific terms, used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. Terms such as those defined in a commonly used dictionary should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and should not be interpreted as an ideal or excessively formal meaning unless explicitly defined in this application. Does not.

1 to 4 are cross-sectional views illustrating a method of manufacturing a heat-dissipating composite sheet according to an embodiment of the present invention.

Referring to FIG. 1, a coating layer 20 is formed by providing a foaming composition on a substrate 10.

According to an embodiment, the substrate 10 may be a polymer film. For example, the substrate 10 may include a polymer such as polyethylene terephthalate (PET), polycarbonate, polyimide, and polyamide.

The substrate 10 may serve to evenly transmit the impact to the impact resistant foam layer by dispersing the external impact in the heat dissipating composite sheet. In addition, according to an embodiment, the polymer film 10 may include a light blocking material such as a black pigment or a black dye, or may include a black blocking layer combined by a method such as printing. When the heat-dissipating composite sheet including the colored polymer film as described above is applied to a display device, it may block light leakage.

The foaming composition may include a foaming agent, an acrylic binder resin, a curing agent, and a solvent.

According to an embodiment, the blowing agent may include pre-expanded particles. The pre-expanded particles may have a microsphere shape. For example, the pre-expanded particles may have a microsphere shape having a diameter ranging from about 5 micrometers (μm) to about 15 μm.

For example, the pre-expanded particles may include a foam seed and an elastic shell coating the surface of the foam seed.

According to an embodiment, the foam seed may include a hydrocarbon-based material such as butane or pentane. In one embodiment, the foam seed may include the hydrocarbon-based material in liquid form. The elastic shell may comprise a polymeric material such as an acrilonitrile copolymer.

According to another embodiment, the blowing agent may include a chemical blowing agent. The chemical blowing agent can form hollow expanded particles by generating gas by heating or by reaction with other components.

For example, the chemical foaming agent may include inorganic foaming agents such as ammonium carbonate, sodium carbonate, sodium bicarbonate, potassium hydroxide, sodium hydroxide, etc., organic foaming agents such as azo compounds, nitro compounds, sulfonyl compounds, and the like. The chemical blowing agent may generate gas such as carbon dioxide gas, ammonia gas, nitrogen gas, and the like.

The acrylic binder resin is obtained by addition polymerization of monomers. The monomer mixture forming the acrylic resin is ethyl acrylate (EA), methyl methacrylate (MMA), n-butyl acrylate (n-BA), methoxypolyethylene Glycol methacrylate (MPEGMA) and acrylamide.

The ethyl acrylate increases the softness of the foam structure formed from the foam composition, thereby increasing the shock absorption performance at room temperature. However, when the content of the ethyl acrylate is excessive, the reliability of the foam structure at high temperature may be deteriorated. For example, the content of ethyl acrylate is preferably 15% to 35% by weight of the total weight of the monomer mixture.

The methyl methacrylate may increase the hardness of the foam structure, thereby increasing the reliability of the foam structure at high temperatures. However, when the content of the methyl methacrylate is excessive, the shock absorption performance of the foam structure may be deteriorated. For example, the content of the methyl methacrylate is preferably 15% to 35% by weight of the total weight of the monomer mixture.

The n-butyl acrylate may increase the flexibility of the foam structure and increase bonding strength between the binder and the foam. However, when the content of the n-butyl acrylate is excessive, high-temperature adhesion between the foamed structure and the adhesive layer may decrease. For example, the content of the n-butyl acrylate is preferably 15% to 30% by weight of the total weight of the monomer mixture.

The methoxypolyethylene glycol methacrylate may increase repulsion and resilience against impact of the foamed structure. However, when the content of the methoxypolyethylene glycol methacrylate is excessive, the shock absorbing performance of the foam structure and the bonding strength with the adhesive layer at room temperature may decrease. For example, the content of the methoxypolyethylene glycol methacrylate is preferably 10% to 20% by weight of the total weight of the monomer mixture. The methoxypolyethylene glycol methacrylate is a polymer monomer, and if the molecular weight is excessively large, the high temperature adhesion between the foam structure and the adhesive layer may be lowered, and if insufficient, the shock absorption performance of the foam structure and at room temperature The bonding strength with the adhesive layer may be lowered. Preferably, the weight average molecular weight of the methoxypolyethylene glycol methacrylate may be about 30,000 to 50,000.

The acrylamide may increase the elasticity of the foamed structure, but if the content is excessive, the shock absorbing performance of the foamed structure and the adhesion at room temperature may decrease. For example, the content of the acrylamide is preferably 1% to 5% by weight of the total weight of the monomer mixture.

According to an embodiment, the monomer mixture may further include styrene. The styrene may increase the high temperature/high humidity reliability of the foamed structure, but if the content is excessive, the shock absorbing performance of the foamed structure and the bonding strength with the adhesive layer at room temperature may be reduced. For example, the content of styrene is preferably 1% to 3% by weight of the total weight of the monomer mixture.

Thus, according to one embodiment, the monomer mixture, ethyl acrylate 15% to 35% by weight, methyl methacrylate 15% to 35% by weight, n-butyl acrylate 15% to 30% by weight, It may include 10% to 20% by weight of oxypolyethylene glycol methacrylate, 1% to 5% by weight of acrylamide, and 1% to 3% by weight of styrene.

The molecular weight of the acrylic binder resin may be controlled by polymerization temperature and reaction time. For example, it is preferable that the weight average molecular weight of the acrylic binder resin is 200,000 to 300,000. When the weight average molecular weight of the acrylic binder resin exceeds 200,000, the viscosity is excessively increased, thereby reducing fairness, and when it is less than 300,000, mechanical properties may decrease.

For example, the acrylic binder resin may have a glass transition temperature of about -50°C to 30°C depending on the composition. When the glass transition temperature of the acrylic binder resin is excessively low, the compressive load decreases to reduce the resilience, and the high-temperature adhesion to the adhesive layer may decrease. When it is excessively high, the shock absorption performance decreases, and the adhesive layer Room temperature adhesion of the fruit may decrease. Preferably, the glass transition temperature of the acrylic binder resin may be -30°C to 0°C, more preferably, -20°C to 0°C. For example, the monomer mixture for obtaining the glass transition temperature of -20°C to 0°C, 20% to 30% by weight of ethyl acrylate, 25% to 30% by weight of methyl methacrylate, n-butyl acrylic It may include 15% to 25% by weight of rate, 10% to 20% by weight of methoxypolyethylene glycol methacrylate, 1% to 5% by weight of acrylamide, and 1% to 3% by weight of styrene.

As the curing agent, an epoxy-based compound, a melamine-based compound, an isocyanate compound, a metal salt, or an amine-based compound may be used. These may be used alone or in combination of two or more. In one embodiment, an isocyanate compound may be used as the curing agent.

The solvent may be an organic solvent such as toluene, methyl ethyl ketone (MEK), ethyl acrylate (EA), or the like. The foaming composition may be adjusted to have an appropriate viscosity by the solvent, for example, the foaming composition may have a viscosity of about 1,600 cps to about 2,400 cps.

According to an embodiment, the foaming composition comprises 1 part by weight to 10 parts by weight of the foaming agent, 0.5 parts by weight to 5 parts by weight of the curing agent, and 20 parts by weight to 30 parts by weight of the solvent based on 100 parts by weight of the acrylic binder resin. can do.

According to an embodiment, the foaming composition may further include a pigment material such as carbon black and graphite powder. For example, the pigment may be mixed in an amount of 1 to 5 parts by weight based on 100 parts by weight of the acrylic binder resin.

In addition, the foaming composition may further include additional components for improving mechanical and physical reliability of the foamed structure, such as a silane coupling agent and an antifoaming agent.

For example, the foaming composition may be obtained by mixing the foaming agent and the binder. For example, the foaming composition can be obtained by preparing a binder composition including the binder, the curing agent, the solvent, and the like, and gradually stirring the foaming agent by adding the foaming agent to the binder composition.

Referring to FIG. 2, the coating layer 20 is heated to form a pre-foaming layer 22. The heating is for drying the solvent of the coating layer 20 and may be performed at a temperature lower than the foaming start temperature of the foaming agent.

For example, the heating temperature may be 30 ℃ to 120 ℃, preferably 40 ℃ to 115 ℃. More preferably, the heating temperature may be 45 ℃ to 110 ℃.

Referring to FIG. 3, a metal foil 30 is laminated on the preliminary foam layer 22. The metal foil 30 may include a metal having high thermal conductivity, for example, copper, aluminum, silver, nickel, or a combination thereof. For example, the thickness of the metal foil 30 may be 20 μm to 200 μm.

According to an embodiment, the metal foil 30 may include a metal layer and a carbon-based heat dissipation layer. The carbon-based heat dissipation layer may improve adhesion and heat transfer capability at the interface. For example, the carbon-based heat dissipation layer may include a two-dimensional carbon-based structure such as graphene and graphite. The carbon-based heat dissipation layer may be disposed on the attachment surface of the metal foil 30. Accordingly, the carbon-based heat dissipation layer may be disposed between the preliminary foam layer 22 and the metal layer.

Referring to FIG. 4, the pre-foaming layer 22 is heated to form an impact-resistant foaming layer 24.

For example, through the heating, the chemical foaming agent in the pre-foaming layer 22 generates gas, or the pre-expanded particles are expanded, thereby forming the hollow foamed particles 25. In addition, by curing the acrylic binder resin in the pre-foaming layer 22, a crosslinked structure surrounding the expanded particles 25 may be formed.

According to an embodiment, the heating of the pre-expanded layer 22 may be performed at a temperature equal to or higher than the expansion start temperature of the pre-expanded particles, for example, in the range of 120°C to 160°C, and preferably, 120°C to 150°C. It can be carried out at temperatures in the range of °C.

According to an embodiment, the heat treatment may be performed by being divided into a plurality of temperature sections. For example, the substrate 10 on which the preliminary foam layer 22 is formed may sequentially pass through a plurality of chambers and a foaming process may be performed, and each of the chambers may sequentially increase the internal temperature along the moving direction of the conveyor. Can be set.

For example, the expanded particles 25 may be expanded by 2 to about 5 times the diameter of the pre-expanded particles. In addition, the thickness of the impact resistant foam layer 24 may be increased by about 2 to 5 times compared to the thickness of the preliminary foam layer 22. For example, the impact-resistant foam layer 24 may be expanded to a thickness of about 50 μm to 200 μm.

According to an embodiment of the present invention, a polymer film, an impact resistant foam layer and a metal foil are not bonded using an adhesive, and an impact resistant foam composition is provided on the polymer film, and a preliminary foam layer from which the solvent is removed and a metal foil are laminated. After performing the foaming step to form an impact resistant foam layer. Therefore, by increasing the adhesion between the impact-resistant foam layer and the polymer film, and the impact-resistant foam layer and the metal foil, the impact-resistant foam layer and the polymer film, and the impact-resistant foam layer and the metal foil can be directly bonded without an adhesive layer using a pressure-sensitive adhesive. . Accordingly, it is possible to provide a heat dissipating composite sheet integrally formed without an adhesive layer and a lamination process using the same.

Accordingly, it is possible to prevent deterioration in heat dissipation performance occurring at the adhesive layer and the interface thereof, and greatly improve the efficiency of the heat dissipation composite sheet manufacturing process.

In addition, through the combination of monomers constituting the acrylic binder resin of the foam composition, not only can the impact absorption performance be improved, but also the bonding strength with the adhesive layer in a high temperature/high humidity environment can be increased, thereby improving the reliability of the adhesive tape. I can.

5 is a cross-sectional view of a heat dissipation composite sheet according to another embodiment of the present invention.

Referring to FIG. 5, the heat dissipation composite sheet includes an impact-resistant foam layer 24 disposed between the polymer film 10 and the metal foil 30. The polymer film 10 and the metal foil 30 are directly bonded to the impact-resistant foam layer 24, respectively, without an adhesive layer. An adhesive layer 40 may be coupled to one surface of the polymer film 10, and a release layer 50 may be coupled to the adhesive layer 40.

The adhesive layer 40 may serve as an adhesive layer for bonding the heat dissipation composite sheet to another device, for example, a display device.

For example, the adhesive layer 40 may be formed by applying a pressure sensitive adhesive (PSA). As the pressure-sensitive adhesive, those known in the art may be used. For example, the pressure-sensitive adhesive may be an acrylic pressure-sensitive adhesive, and specifically, may include a pressure-sensitive adhesive including an acrylic copolymer-based material. More specifically, the pressure-sensitive adhesive may include an acrylic copolymer, a crosslinking agent, and a solvent. The crosslinking agent may include an epoxy compound, a melamine compound, an isocyanate compound, and the like. The solvent may include acetone, toluene, methyl ethyl ketone, and the like.

For example, the pressure-sensitive adhesive may be cured to form an adhesive layer 40 including a crosslinked structure of the acrylic resin.

For example, the release layer 50 may be a polymer film including a polymer such as polyethylene terephthalate or polycarbonate.

According to an embodiment, the adhesive layer 40 may be an embossed adhesive layer having an uneven pattern formed on a surface thereof. An uneven pattern corresponding to an inverse phase of the uneven pattern may be formed on the adhesive surface of the release layer 50.

6 is an enlarged cross-sectional view of an adhesive layer and a release layer of the heat dissipation composite sheet of FIG. 5. 7 is an enlarged plan view of an adhesive layer of the heat dissipation composite sheet of FIG. 5.

According to an embodiment, the adhesive layer 40 may have protrusions 42 extending along a first direction D1 and a second direction D2 perpendicular to the first direction D1 on a plan view. . The height H1 of the protrusion may be about 5 to 10 μm, and the width of the protrusions 42 may be about 130 to 180 μm. In addition, the width W1 of the channel 44 corresponding to the gap between the protrusions may be about 15 to 30 μm. Further, a distance between adjacent protrusions along the first direction D1 or the second direction D2 may be about 130 to 180 μm.

Through the channel 44 of the adhesive layer 40, a discharge passage for air bubbles that may be generated in the bonding process of the heat dissipating composite sheet may be provided.

In addition, the adhesive layer 40 may have a high profile reliability within the numerical range. Accordingly, when provided in a display device or the like, the shock absorbing performance and reliability thereof of the adhesive tape can be improved.

8 is a cross-sectional view illustrating a display device according to an exemplary embodiment of the present invention.

The display device according to the exemplary embodiment of the present invention may include a heat dissipation composite sheet coupled to the display panel 200 as illustrated in FIG. 8. For example, after removing the release layer 50 from the heat dissipation composite sheet shown in FIG. 5, the heat dissipation composite sheet and the display panel 200 are in contact with the adhesive layer 40 to the lower surface of the display panel 200. Can be combined. The display panel 200 may include a liquid crystal display, an organic light-emitting display, an inorganic LED display, and the like.

The display device may be combined with the heat radiation composite sheet to improve impact resistance and heat radiation performance.

Hereinafter, characteristics of the heat dissipation composite sheet according to exemplary embodiments will be described in more detail with reference to specific experimental examples.

Experimental example

Synthesis Example 1

About 30% by weight of ethyl acrylate, about 30% by weight of methyl methacrylate, about 20% by weight of n-butyl acrylate, about 15% by weight of methoxypolyethylene glycol methacrylate, about 3% by weight of acrylamide and about 2% by weight of styrene %, and using azo-bis-isobutyrylnitrile (AIBN) as an initiator (about 0.002 parts by weight based on 100 parts by weight of the mixture), reaction at about 40°C for about 1 hour, at about 55°C for about 6 hours Then, an acrylic copolymer having a glass transition temperature of about -10°C was obtained.

Example 1

With respect to 100 parts by weight of each of the acrylic copolymer of Synthesis Example 1, 2.6 parts by weight of an isocyanate curing agent, 3 parts by weight of a black pigment, 0.5 parts by weight of a silane coupling agent (product name: KBM-403) and 0.5 parts by weight of a defoaming agent (product name: BYK-333) A foaming composition was prepared by mixing parts by weight and 25 parts by weight of toluene, and 2 parts by weight of the pre-expanded particles were slowly mixed with the foaming composition while stirring to prepare a foamed composition.

After applying the foaming composition on the PET film printed with black ink, a heat drying process was performed while moving at a speed of 12 m/min using a heating line under the temperature conditions shown in Table 1 below.

Table 1

Next, after pressing the rolled copper foil (thickness 50 µm, 70 µm, 90 µm) on the dried pre-foaming layer, it moves at a speed of 12 m/min using a heating line under the temperature conditions shown in Table 2 below. While performing the foaming process, a heat-dissipating composite sheet was obtained.

Table 2

Comparative example One

After applying the same foaming composition as in Example 1 on a PET substrate, a pre-heat treatment and foaming process were performed while moving at a speed of 12 m/min using a foam line under the temperature conditions shown in Table 3 below.

Table 3

Next, on the foam layer, a PSA adhesive was coated, and a rolled copper foil (50 µm in thickness) was pressed to obtain a heat dissipating composite sheet.

Experiment 1-Measurement of adhesion

On the SUS plate, using a Nitto 5000NS double-sided tape, the heat dissipation composite sheet of Example 1 was fixed, and a PET film was affixed thereon using a Nitto 5000NS double-sided tape, and then pressurized with a roller, and at room temperature and high temperature (85℃). At the time of peeling (300 mm/min, peeling angle: 180 degrees) at (left for 30 minutes), the adhesion was measured at the time of peeling of the heat dissipating composite sheet of Comparative Example 1 by the same method, and the results are shown in Table 4 below. Done.

Table 4

Referring to Table 4, the heat dissipation composite sheet according to the embodiment of the present invention had high adhesion at both room temperature and high temperature without using a separate adhesive, and as a result, structural destruction was observed at the foam layer or its interface during the peeling test. Could.

On the other hand, in the case of bonding the foam layer and the copper foil with an adhesive according to the prior art, the adhesion was relatively low, and in particular, the adhesion was greatly reduced at high temperatures, so that interlayer separation was observed without interfacial destruction. Therefore, it can be seen that the heat resistance of the heat radiation composite tape is low.

Although the above has been described with reference to embodiments of the present invention, those skilled in the art will be able to variously modify and change the present invention without departing from the spirit and scope of the present invention described in the following claims. You will understand that you can.

The heat dissipation composite tape according to the above-described exemplary embodiments is combined with various display panels such as, for example, a liquid crystal display panel and an organic light emitting display panel, and can be used in portable electronic devices such as mobile phones, tablet PCs, and notebook computers. have.

Claims (13)

An impact-resistant foam layer comprising expanded particles and a crosslinked binder resin surrounding the expanded particles;
A polymer film directly bonded to one surface of the foam layer; And
Including a metal foil directly bonded to the other surface of the foam layer,
The crosslinked binder resin is formed by crosslinking of an acrylic binder resin, and the acrylic binder resin is ethyl acrylate (EA) 15% to 35% by weight, methyl methacrylate (MMA) 15 Wt% to 35 wt%, n-butyl acrylate (n-BA) 15 wt% to 30 wt%, methoxy polyethylene glycol methacrylate (MPEGMA) 10 wt% to 20 A heat dissipating composite sheet formed by addition reaction of a monomer mixture containing 1% to 5% by weight of acrylamide and 1% to 5% by weight of acrylamide and having a glass transition temperature of -50°C to 30°C. The method of claim 1, wherein the monomer mixture is ethyl acrylate 20% to 30% by weight, methyl methacrylate 25% to 30% by weight, n-butyl acrylate 15% to 25% by weight, methoxypolyethylene 10% to 20% by weight of glycol methacrylate, 1% to 5% by weight of acrylamide, and 1% to 3% by weight of styrene,
The heat dissipation composite sheet, characterized in that the glass transition temperature of the acrylic binder resin is -20 ℃ to 0 ℃. The heat dissipation composite sheet of claim 1, further comprising an embossed adhesive layer bonded to one surface of the polymer film and having an embossed pattern. The heat dissipation composite sheet according to claim 1, wherein the polymer film comprises a light blocking material or a black colored layer. The heat dissipation composite sheet of claim 1, wherein the metal foil comprises at least one selected from the group consisting of copper, aluminum, silver, and nickel. The heat dissipation of claim 5, wherein the metal foil comprises a metal layer and a carbon-based heat dissipation layer, and the carbon-based heat dissipation layer is disposed between the metal layer and the foam layer, and comprises graphene or graphite. Composite sheet. The heat dissipation composite sheet of any one of claims 1 to 6; And
A display device including a display panel coupled to the heat dissipation composite sheet. Forming a coating layer by applying a foaming composition comprising an acrylic binder resin, a foaming agent, a curing agent, and a solvent on a polymer film;
Heating the coating layer at 40°C to 115°C to remove the solvent to form a pre-foaming layer;
Laminating a metal foil on the pre-foam layer; And
Heating the pre-foaming layer at 120°C to 160°C to form an impact-resistant foamed layer comprising expanded particles and a crosslinked binder resin surrounding the expanded particles. The method of claim 8, wherein the crosslinked binder resin is formed by crosslinking of an acrylic binder resin, and the acrylic binder resin comprises 15% to 35% by weight of ethyl acrylate (EA), and methyl methacrylate ( methyl methacrylate, MMA) 15% to 35% by weight, n-butyl acrylate (n-BA) 15% to 30% by weight, methoxy polyethylene glycol methacrylate (MPEGMA) ) Formed by the addition reaction of a monomer mixture containing 10% to 20% by weight and 1% to 5% by weight of acrylamide, characterized in that it has a glass transition temperature of -50 ℃ to 30 ℃ Method for producing a heat-dissipating composite sheet. The method of claim 9, wherein the monomer mixture is ethyl acrylate 20% to 25% by weight, methyl methacrylate 25% to 30% by weight, n-butyl acrylate 20% to 30% by weight, methoxypolyethylene 10% to 20% by weight of glycol methacrylate, 1% to 5% by weight of acrylamide, and 1% to 3% by weight of styrene,
The glass transition temperature of the acrylic binder resin is a method of manufacturing a heat radiation composite sheet, characterized in that -20 ℃ to 0 ℃. The method of claim 8, wherein the foaming agent comprises at least one chemical foaming agent selected from the group consisting of inorganic foaming agents, organic foaming agents, and water. The method of claim 8, wherein the foaming agent comprises pre-expanded particles including a foam seed and an elastic shell coating a surface of the foam seed. The method of claim 8, wherein the metal foil comprises at least one selected from the group consisting of copper, aluminum, silver, and nickel.

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