KR101622508B1 - Composite sheet comprising polymer nano composite layer and method for producing thereof - Google Patents

Abstract

The present invention relates to a composite sheet including a polymer nanocomposite layer and a method for producing the same. The method of the present invention includes the steps of: preparing a clay solution and a graphene oxide solution; generating a mixture by mixing the clay solution and the graphene oxide solution with a polymer binder; producing a coating liquid by adding a fluorine-based additive and an antifoamer to the mixture; and forming a polymer nanocomposite layer by application of the coating liquid onto a substrate. The composite sheet including a polymer nanocomposite layer which is produced according to an aspect of the present invention has excellent heat conduction characteristics and is capable of efficiently discharging to the outside heat generated in electronic equipment. Accordingly, the lifespan of the electronic equipment can be extended and efficiency of the electronic equipment can be improved. In addition, the composite sheet including a polymer nanocomposite layer which is produced according to an aspect of the present invention is capable of preventing moisture penetration from the outside by containing clay, and thus is capable of extending the lifespan of the electronic equipment. Furthermore, the composite sheet according to the present invention is subjected to no significant decline in optical properties, such as optical transmittance and haze, while containing both graphene oxide and the clay, and thus can be applied in various ways to a field requiring transparency.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite sheet comprising a polymer nanocomposite layer and a method for manufacturing the composite sheet.

To a composite sheet comprising a polymer nanocomposite layer and a method for producing the composite sheet.

BACKGROUND ART [0002] In recent years, with the development of electronic devices and the demand for complex functions, the weight, thickness, and miniaturization of printed circuit boards have been progressively increasing. In order to meet such a demand, the wiring of the printed circuit becomes more complicated, the density becomes higher, and the function becomes higher. In addition, a lightweight, thin, and flexible electronic device such as a wearable device, which is attracting much attention from many people, is required to have high integration in order to provide many functions. However, the problem of heat generation inside the electronic device due to such high integration has become a technical problem that must be solved.

In addition, as the use of incandescent lamps is totally prohibited for improving energy efficiency and reducing carbon dioxide emission, it is expected that the demand for LED light sources to replace them is expected to increase rapidly. In order to improve the economical efficiency of LED light sources, Instead of reducing the number, a high current drive is required to improve the output, and the heat dissipation problem is still a technical challenge.

Therefore, there is a need for a technique for releasing a considerable amount of heat that is inevitably generated for economical utilization of semiconductor devices and high-efficiency LEDs requiring high integration.

In addition, in order to realize light weight shortening of electronic devices, materials composing the electronic devices can be small and integrated, and at the same time, high efficiency should be exhibited. However, due to the accompanying heat, the characteristics of the material and further the characteristics of the electronic device are deteriorated. For this reason, it is necessary to develop a material for exhibiting excellent heat radiation characteristics.

For this purpose, thermally conductive polymer materials have been recognized as important materials. In particular, carbon composite materials such as polymer composite materials including ceramic or metal filler, graphite, carbon nanotube, and carbon fiber Many polymer composite materials are being developed. Of these carbon composite materials, graphene, which has received much attention recently, is a thin film structure in which carbon atoms having a thickness of about 0.35 nm are honeycomb. Many studies have been conducted due to high electrical conductivity and excellent heat conduction characteristics. In order to ensure dispersion stability in polymer complexes, they are manufactured in the form of complexes through changes in surface properties and are applied in various ways as well as thermoconductive polymer composite materials . Especially, it is known that the thermal conductivity is particularly superior to other carbon composite materials. In order to solve such a problem, recently, a heat radiation sheet using a polymer composite containing nanoparticles is increasingly applied.

In view of this situation, there is a growing interest in composite sheets that can prolong the lifetime of electronic devices by providing new functions in addition to heat-radiating sheets using polymer complexes. In particular, in order to prolong life, It is necessary to provide a composite sheet capable of preventing this.

There is provided a composite sheet including a polymer nanocomposite layer in which graphene nanoparticles are dispersed and clay is contained to prevent moisture permeation and improve thermal conductivity characteristics and a method for manufacturing the same.

The composite sheet including the polymer nanocomposite layer according to an embodiment of the present invention includes a polymer nanocomposite layer containing graphene oxide and clay.

In a composite sheet comprising a polymer nanocomposite layer according to one aspect of the present invention, the polymer nanocomposite layer is formed on a substrate, and the substrate is made of a material selected from the group consisting of polyethylene terephthalate (PET), polyethylene naphthalate (PEN) (PES), polycarbonate (PC), polyimide, and polyimide substrates.

In the composite sheet comprising the polymer nanocomposite layer according to one aspect of the present invention, the clay is montmorillonite.

In the composite sheet comprising the polymer nanocomposite layer according to one aspect of the present invention, the graphene oxide is contained in an amount of 2 wt% to 5 wt% with respect to the total weight of the polymer nanocomposite layer.

In the composite sheet comprising the polymer nanocomposite layer according to one aspect of the present invention, the clay is contained in an amount of 2 wt% to 5 wt% with respect to the total weight of the polymer nanocomposite layer.

In the composite sheet comprising the polymer nanocomposite layer according to one aspect of the present invention, the polymer nanocomposite layer has a thickness of 10 mu m to 20 mu m.

According to another embodiment of the present invention, there is provided a method for preparing a composite sheet comprising a polymer nanocomposite layer, comprising: preparing a clay solution and a graphine oxide solution; Mixing the clay solution and the graphene oxide solution with a polymeric binder to form a mixture; Adding a fluorine-based additive and a defoaming agent to the mixture to prepare a coating solution; And coating the coating solution on a substrate to form a polymer nanocomposite layer.

In the method for producing a composite sheet comprising a polymer nanocomposite layer according to one aspect of the present invention, the graphene oxide solution is prepared by mixing graphene oxide with deionized water and ultrasonication.

In the method for producing a composite sheet comprising a polymer nanocomposite layer according to one aspect of the present invention, the polymeric binder is selected from the group consisting of a polyurethane resin, a polyacrylic resin and a polyester resin.

In the method for producing a composite sheet comprising a polymer nanocomposite layer according to one aspect of the present invention, the mixing ratio of the polymer binder and the graphene oxide solution is 2: 0.5 to 2: 1.5.

In the method for producing a composite sheet comprising a polymer nanocomposite layer according to one aspect of the present invention, the mixing ratio of the polymer binder and the clay solution is 6: 0.5 to 6: 1.5.

In the method for producing a composite sheet comprising a polymer nanocomposite layer according to one aspect of the present invention, the polymer nanocomposite layer is formed to a thickness of 10 mu m to 20 mu m.

In the method for producing a composite sheet comprising a polymer nanocomposite layer according to one aspect of the present invention, the substrate is selected from the group consisting of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethersulfone (PES), polycarbonate (PC, Polycarbonate), and a polyimide substrate.

In the method for producing a composite sheet comprising a polymer nanocomposite layer according to one aspect of the present invention, the step of separating the polymer nanocomposite layer from the substrate is further included.

The composite sheet including the polymer nanocomposite layer produced according to one aspect of the present invention exhibits excellent heat conduction characteristics and can efficiently release heat generated inside the electronic device to the outside. As a result, the lifetime of the electronic device can be extended and the efficiency of the electronic device can be improved. In addition, the composite sheet including the polymer nanocomposite layer produced according to one aspect of the present invention can prevent the moisture from being transmitted from the outside including the clay, thereby increasing the lifetime of the electronic device. . Further, since the composite sheet of the present invention contains both graphene oxide and clay, its optical properties such as light transmittance and haze are not significantly lowered, and thus it can be applied to various fields where transparency is required.

The method for producing a composite sheet comprising a polymer nanocomposite layer according to one aspect of the present invention uses graphene oxide and a clay to separate a composite sheet capable of preventing moisture permeation from the outside, And can be provided as a standing sheet.

1 is a flowchart illustrating a method for fabricating a composite sheet including a polymer nanocomposite layer according to an embodiment of the present invention.
2 is a TEM (Transmission Electron Microscope) photograph of a composite sheet including a polymer nanocomposite layer according to an embodiment of the present invention.

In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may unnecessarily obscure the subject matter of the present invention. In addition, the terms described below are established in consideration of the functions of the present invention, and these may vary depending on the intention of the manufacturer or custom in the industry, and the definition should be based on the contents throughout the specification.

Hereinafter, a composite sheet including a polymer nanocomposite layer according to one aspect of the present invention and a method of manufacturing the composite sheet will be described in detail with reference to FIG.

The method for preparing a composite sheet comprising a polymer nanocomposite layer according to the present invention comprises the steps of: (i) preparing a clay solution and a graphine oxide solution (S100); Mixing the clay solution and the graphene oxide solution with a polymer binder to produce a mixture (S200); Adding a fluorine-based additive and a defoaming agent to the mixture to prepare a coating solution (S300); And coating the coating solution on the substrate to form a polymer nanocomposite layer (S400).

First, in a step (S100) of preparing a clay solution and a graphine oxide solution, a clay solution is prepared by mixing clay particles in deionized water, For a period of time. Here, the clay particles may be montmorillonite, but are not limited thereto. The graphene oxide solution is also prepared by mixing graphene oxide with deionized water. The graphene oxide solution is ultrasonically treated for 15 to 20 minutes using a bath type ultrasonic equipment to maintain the dispersibility of the graphene oxide do

In the step (S200) of mixing the clay solution and the graphene oxide solution with a polymeric binder to form a mixture, the polymeric binder may be a polyurethane resin or a polyacrylic resin. The polymeric binder may be any one selected from water-soluble binders such as polyester resins.

The polymeric binder according to the present invention has excellent merits such as ease of processing and variety of forms, but it is disadvantageous in that the thermal energy transferred through the inside is dispersed due to the characteristics of the polymer, and the thermal conductivity is low. Accordingly, when a composite material is appropriately mixed with a material having excellent heat conduction characteristics such as graphene oxide, it can be used in a variety of fields requiring relatively good heat dissipation properties.

Graphenoxide serves as an inorganic filler to lower the coefficient of thermal expansion of the polymeric binder and to enhance the heat dissipation properties of the coating layer prepared from the coating solution.

The mixing ratio of the polymer binder and the graphene oxide solution may be varied depending on the required properties in consideration of the use of the coating solution to be prepared. In one aspect of the present invention, the blending ratio of the polymer binder and the graphene oxide solution is 2: 2: 1.5.

That is, when the blending ratio of the polymer binder and the graphene oxide is less than 2: 0.5, the thermal conductivity of the composite material due to the graphene oxide blending is lowered. If the blending ratio of the polymer binder and the graphene oxide is greater than 2: 1.5 The content of the solid content is increased and the dispersibility may be deteriorated, resulting in a decrease in the uniformity of the coating. Therefore, preferably, the mixing ratio of the polymer binder and the graphene oxide solution may be from 2: 0.5 to 2: 1.5.

The mixing ratio of the polymer binder and the clay solution may vary depending on the properties required in consideration of the use of the coating solution to be prepared and the like. In one aspect of the present invention, the mixing ratio of the polymer binder and the clay solution is 6: 0.5 to 6: .

That is, when the blending ratio of the polymer binder and the graphene oxide is less than 6: 0.5, the waterproofing property of the composite material due to the mixing of the clay solution is lowered. When the blending ratio of the polymer binder and the clay solution is greater than 6: 1.5 Resulting in poor uniformity of the coating. Therefore, preferably, the mixing ratio of the polymer binder and the clay solution may be 6: 0.5 to 6: 1.5.

Then, a fluorine-based additive and a defoaming agent are added to a mixture of the polymer binder, the clay solution and the graphene oxide solution to prepare a coating solution (S300). The fluorine-based additive is a non-ionic fluorosurfactant. The defoamer is an organic modified polysiloxane emulsion, a dimethyl polysiloxane, a polyether siloxane copolymer emulsion, a polyether siloxane copolymer and an organic polymer. Polymers, polymers of hydrophobic silica and organic polymers.

The fluorine-based additive is added in an amount of 0.01 to 0.05% by weight based on the total weight of the mixture, and the defoaming agent may be added in an amount of 0.1% by weight based on the total weight of the mixture.

The fluorine-based additives and antifoaming agents are used to improve the surface tension reduction and leveling of the solution in subsequent coating processes in the course of preparing the composite material solution. When the mixing ratio of the fluorine-based additive and the defoaming agent is less than the above ratio, it is difficult to achieve the object of the present invention such that the coating is not easy. If the mixing ratio is larger than the mixing ratio, the compatibility of the coating solution is deteriorated, There is a possibility that the properties of the back coating layer itself may be deteriorated.

Add a fluorine-based additive and defoamer and mix for about 10 minutes using a magnetic stirrer. Then, it is treated at 2000 rpm for 10 minutes by using a high-speed rotary mixer and treated at 1000 rpm for 20 minutes to remove bubbles and the like which may be present in the coating liquid.

Thereafter, the prepared coating solution is coated on the substrate to form a polymer nanocomposite layer (S400). In this specification, the polymer nanocomposite layer is the same as the coating layer or the coating film coated on the substrate. The coating liquid was uniformly applied on the substrate using an applicator at a thickness of about 10 탆 to 20 탆 and then dried at 80 캜 for about 12 hours to form a polymer nanocomposite layer.

The polymer nanocomposite layer may have a thickness of 10 [mu] m to 20 [mu] m. That is, since the shape of electronic apparatuses and the like is pursuing the tendency of light and thin chips, the thickness of the applied composite sheet should be as thin as possible and exhibit excellent heat radiation property and moisture permeation prevention property. That is, when the thickness of the composite sheet is too thin, it may be difficult to handle the coating film. As a result of the experiment of the present invention, the coating film has excellent heat radiation effect and moisture permeation prevention effect when the thickness of the coating film is 10 탆 to 20 탆 .

The substrate may be a PET (polyethylene terephthalate) film, a polyethylene naphthalate (PEN), a polyethersulfon (PES), a polycarbonate (PC), a polycarbonate or a polyimide substrate. In the method for producing a composite sheet according to one aspect of the present invention, the polymer nanocomposite layer may be separated from the substrate and provided in the form of a free standing sheet.

In the polymer nanocomposite layer, the clay may be contained in an amount of 2 wt% to 5 wt% with respect to the total weight of the polymer nanocomposite layer, and the graphene oxide may be contained in the polymer nanocomposite layer in an amount of 2 wt% to 5 wt% % ≪ / RTI >

The composite sheet produced according to one aspect of the present invention includes graphene oxide and a polymer nanocomposite layer containing clay, thereby improving thermal conductivity characteristics due to graphene oxide, and allowing the clay to permeate moisture from the outside Can be prevented. Thus, the life span of the electronic device using the composite sheet of the present invention can be extended, and the efficiency of the electronic device can be improved. In addition, the composite sheet of the present invention includes graphene oxide and clay, and optical properties such as light transmittance and haze are not significantly deteriorated, so that the composite sheet can be applied to various fields requiring transparency.

The present invention can provide the composite sheet produced by the above production method in the form of a free standing composite sheet separated from the substrate together with the substrate or in the form of a free standing composite sheet, It is possible to improve the thermal conductivity and moisture permeation preventing property of the substrate, and the like.

Hereinafter, comparative examples and examples of a method for producing a composite sheet comprising a polymer nanocomposite layer according to one aspect of the present invention will be described.

Comparative Example

A substrate of polyethylene naphthalate (PEN) before the polymer nanocomposite layer of the following examples was coated.

Example 1

Preparation of a composite sheet comprising a polymer nanocomposite layer (including both graphene oxide and clay)

A graphene oxide solution was prepared by mixing 2 g of graphene oxide with 100 mL of DI water, and the solution was sonicated for 15 minutes using a bath type ultrasonic equipment. Add 5 g of clay particles (montmorillonite) to 200 mL of deionized water (DI water) and mix with an impeller mixer at 85 ° C for 3 hours to make a clay solution.

6 g of the graphene oxide solution and 2 g of the clay solution were mixed, and the resultant mixture was mixed with a rod magnet for 30 minutes. 12 g of a polyurethane resin was added thereto and mixed with a homogenizer for 10 minutes. Then, 0.04 g of a fluorine-based additive and 0.1 g of a defoaming agent were added, and the mixture was stirred for 10 minutes using a bar magnet to prepare a coating solution. The prepared coating liquid is treated at 2000 rpm for 10 minutes and at 1000 rpm for 20 minutes using a high-speed rotary mixer to remove bubbles.

Thereafter, the prepared coating solution was applied on the PEN film by using an applicator at 28 to 30 탆 and dried at about 80 캜 for 12 hours to form a 17 탆 -thick polymer nanocomposite layer.

Example 2

Preparation of a composite sheet comprising a polymer nanocomposite layer (including graphene oxide alone)

A graphene oxide solution was prepared by mixing 2 g of graphene oxide with 100 mL of DI water, and the solution was sonicated for 15 minutes using a bath type ultrasonic equipment.

Then, 6 g of the graphene oxide solution and 12 g of the polyurethane resin were added and mixed by a homogenizer for 10 minutes. Then, 0.04 g of a fluorine-based additive and 0.1 g of a defoaming agent were added, and the mixture was stirred for 10 minutes using a bar magnet to prepare a coating solution. The prepared coating liquid is treated at 2000 rpm for 10 minutes and at 1000 rpm for 20 minutes using a high-speed rotary mixer to remove bubbles.

Thereafter, the prepared coating solution was applied on a PEN film in an applicator using an applicator in a range of 28 to 30 μm and dried at about 80 ° C. for 12 hours to form a 16 μm thick polymer nanocomposite layer.

Example 3

Preparation of a composite sheet comprising a polymer nanocomposite layer (including clay only)

Add 5 g of clay particles (montmorillonite) to 200 mL of deionized water (DI water) and mix with an impeller mixer at 85 ° C for 3 hours to make a clay solution.

Then, 2 g of the clay solution and 12 g of the polyurethane resin were added and mixed for 10 minutes using a homogenizer. Then, 0.04 g of a fluorine-based additive and 0.1 g of a defoaming agent were added, and the mixture was stirred for 10 minutes using a bar magnet to prepare a coating solution. The prepared coating liquid is treated at 2000 rpm for 10 minutes and at 1000 rpm for 20 minutes using a high-speed rotary mixer to remove bubbles.

Thereafter, the prepared coating solution was applied on the PEN film by using an applicator at 28 to 30 탆 and dried at about 80 캜 for 12 hours to form a 17 탆 -thick polymer nanocomposite layer.

In the present invention, the water vapor transmission rate (WVTR) was measured using a PERMATRAN-W 3/33 MA (MOCON, USA) equipment on the composite sheet comprising the polymer nanocomposite layer prepared in the above Comparative Examples and Examples The thermal conductivity was measured using a Thermal Diffusivity Measurements (NETZSCH, LFA 447 Nanoflach, Germany). The light transmittance was measured using MCPD-3000 (Otsuka, Japan) and haze was measured with NDH-5000 (Nippon Denshoku, Japan).

Experimental results and discussion

The results of the composite sheet produced in the above Examples and Comparative Examples are shown in Table 1 below.

Water permeability
(m ² / g · day) Thermal conductivity
(W / mK) Light transmittance
(% @ 550 nm) Hayes
(Haze) Comparative Example 2 - 86.60 0.89 Example 1 0.9 6.19 77.17 5.74 Example 2 2 13.98 81.10 3.54 Example 3 0.9 - 86.40 2.34

2, which is a TEM photograph of the composite sheet prepared in Example 1, it can be seen that a polymer nanocomposite layer containing graphene oxide and clay particles (referred to as clay particles) is formed, It can be confirmed that the graphene oxide and clay particles are uniformly dispersed therein.

As can be seen in Table 1, the moisture permeability and thermal conductivity of the PEN substrate before coating in the comparative example are compared with those of Examples 1 to 3, The moisture permeability of the composite sheet including the polymer nanocomposite layer is decreased, and the thermal conductivity is increased. From this, it is confirmed that the clay particles have an effect of preventing moisture permeation, and that the graphene oxide improves the thermal conductivity.

As shown in the results of Example 2, the composite sheet on which the polymer nanocomposite layer composed of only graphene oxide was formed had relatively good thermal conductivity characteristics compared to the other Examples. However, the water permeability was almost the same as that of Comparative Example, The effect of preventing permeation is relatively low.

As shown in the results of Example 3, the composite sheet on which the polymer nanocomposite layer composed of only clay particles was formed had a relatively good water permeability as compared with Comparative Examples and Example 2, but the thermal conductivity was almost the same The improvement effect of the thermal conductivity characteristics is relatively low.

As a result, according to one aspect of the present invention, a composite sheet comprising a polymer nanocomposite layer containing graphene oxide and clay particles exhibits excellent heat conduction characteristics and moisture permeation prevention effect, and efficiently generates heat inside the electronic device So that it is possible to prevent the moisture from permeating from the outside. As a result, the lifetime of the electronic device can be extended and the efficiency of the electronic device can be improved. In addition, the composite sheet of the present invention includes graphene oxide and clay, and optical properties such as light transmittance and haze are not significantly deteriorated, so that the composite sheet can be applied to various fields requiring transparency.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be understood that various modifications and applications are possible. For example, each component specifically shown in the embodiments can be modified and implemented. It is to be understood that all changes and modifications that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Claims (14)

delete delete delete delete delete delete Preparing a clay solution and a graphine oxide solution;
Mixing the clay solution and the graphene oxide solution with a polymeric binder to form a mixture;
Adding a fluorine-based additive and a defoaming agent to the mixture to prepare a coating solution; And
And coating the coating solution on a substrate to form a polymer nanocomposite layer,
Wherein the graphene oxide solution is prepared by mixing graphene oxide with deionized water and then ultrasonically treating the graphene oxide.
delete 8. The method of claim 7,
Wherein the polymeric binder is selected from the group consisting of a polyurethane resin, a polyacrylic resin, and a polyester resin.
8. The method of claim 7,
Wherein the mixing ratio of the polymer binder and the graphene oxide solution is from 2: 0.5 to 2: 1.5.
8. The method of claim 7,
Wherein the mixing ratio of the polymer binder to the clay solution is from 6: 0.5 to 6: 1.5.
8. The method of claim 7,
Wherein the polymer nanocomposite layer is formed to a thickness of 10 mu m to 20 mu m.
8. The method of claim 7,
The substrate is selected from the group consisting of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethersulfone (PES), polycarbonate (PC), and polyimide Of the composite sheet.
8. The method of claim 7,
And separating the polymer nanocomposite layer from the substrate.

Images