KR102192902B1 - Manufacturing method of multi function sheet - Google Patents

Abstract

The present invention comprises the steps of (a) preparing a metal mesh, (b) removing impurities present on the surface of the prepared metal mesh, (c) including 80wt% or more graphite powder on at least one surface of the metal mesh Pressing after spraying the powder in the form of a slurry mixture of water; (d) primary rolling using a rolling roller after pressing; (e) drying heat treatment after the first rolling; And (f) secondary rolling with a rolling roller after dry heat treatment.
Since the composite functional sheet manufactured by the above manufacturing method does not contain an adhesive or the like, it has excellent electromagnetic wave shielding performance and high heat dissipation function.

Description

Manufacturing method of multifunctional sheet {MANUFACTURING METHOD OF MULTI FUNCTION SHEET}

The present invention relates to a method of manufacturing a composite functional sheet.

In recent years, as electronic devices become slippery, complex, lightweight, and compact, noise and disturbances caused by electromagnetic waves are more easily generated as electric circuits become highly functional, high-density, highly integrated, and complex. Such electromagnetic waves not only disturb mutual propagation between electronic devices, but also cause a decrease in efficiency and a shortened lifespan of electronic products, and have a problem of having a harmful effect on the human body.

Therefore, in order to solve this problem, research on a method of manufacturing a composite functional sheet for shielding electromagnetic waves generated from electronic devices and dissipating heat generated is being conducted.

An example of such a technique is disclosed in Patent Document 1 and Patent Document 2 below.

That is, the following Patent Document 1 relates to a composite material for shielding electromagnetic waves, comprising a plate-shaped polymer sheet made of a non-conductive material, a conductive pattern portion attached to one or both top and bottom surfaces of the polymer sheet, and the conductive pattern portion is a conductive material It is formed as a thin film having a predetermined pattern and reflects the incident electromagnetic wave and simultaneously absorbs and shields the electromagnetic wave.

In addition, the following Patent Document 2 relates to a heat dissipation sheet, provided with an insulating heat dissipating layer, a heat dissipating layer, and an insulating layer, and the insulating heat dissipating layer, heat dissipating layer and insulating layer are thermoplastic elastomers (TPE), thermally conductive fillers, flame retardant additives, and process It discloses that the oil and additives are mixed and provided.

However, among the conventional technologies as described above, Patent Document 1 simply acts as an electromagnetic wave shield, and requires an additional heat dissipation sheet to radiate the generated heat, making it difficult to thin and slim, and increase the cost, and Patent Document 2, since it is necessary to additionally use an electromagnetic shielding sheet for shielding electromagnetic waves, it is difficult to thin and slim, and the manufacturing process is complicated.

Republic of Korea Patent Publication No. 10-2013-0111870 Korean Patent Registration No. 10-1831595

An object of the present invention is to provide a method of manufacturing a composite functional sheet having improved electromagnetic shielding performance and high heat dissipation function.

The object of the invention is not limited to the object mentioned above. The objects of the present invention will become more apparent from the following description, and will be realized by means and combinations described in the claims.

A method of manufacturing a composite functional sheet according to an embodiment of the present invention includes (a) preparing a metal mesh, (b) removing impurities present on the surface of the prepared metal mesh, (c) Pressing after spraying in the form of a slurry in which water is mixed with a functional powder containing 80 wt% or more of graphite powder on at least one surface; (d) primary rolling using a rolling roller after pressing; (e) drying heat treatment after the first rolling; And (f) secondary rolling with a rolling roller after dry heat treatment.

In an embodiment of the present invention, the slurry in step (c) is preferably mixed with 10 to 60 g of water per 100 g of the functional powder.

In an embodiment of the present invention, the pressing in step (c) may be performed at a pressure of 10 to 100 kg/cm ² .

In one embodiment of the present invention, the size of the powder in step (c) may be 10 μm or less.

In an embodiment of the present invention, the dry heat treatment in step (e) may be performed at a temperature of 180°C to 220°C.

According to an embodiment of the present invention, electromagnetic wave shielding performance and high heat dissipation function are maximized by attaching graphite powder and heat radiation powder to the metal mesh without the use of a chemical adhesive.

1 is a process diagram illustrating a method of manufacturing a composite functional sheet according to an embodiment of the present invention.
2 is a schematic diagram showing a method of manufacturing a composite functional sheet according to an embodiment of the present invention.
3 and 4 are schematic diagrams showing cross-sections in order to compare the case where pressing is performed and the case where rolling is performed.

The above objects, other objects, features, and advantages of the present invention will be easily understood through the following preferred embodiments related to the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided so that the disclosed contents may be thorough and complete, and the spirit of the present invention may be sufficiently conveyed to those skilled in the art.

In describing each drawing, similar reference numerals have been used for similar elements. In the accompanying drawings, the dimensions of the structures are shown to be enlarged than actual for clarity of the present invention. Terms such as first and second may be used to describe various components, but the components should not be limited by the terms. These terms are used only for the purpose of distinguishing one component from another component. For example, without departing from the scope of the present invention, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element. Singular expressions include plural expressions unless the context clearly indicates otherwise.

In the present specification, terms such as "comprise" or "have" are intended to designate the presence of features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, but one or more other features. It is to be understood that the presence or addition of elements or numbers, steps, actions, components, parts, or combinations thereof, does not preclude in advance the possibility of being added. Further, when a part such as a layer, film, region, plate, etc. is said to be "on" another part, this includes not only the case where the other part is "directly above", but also the case where there is another part in the middle. Conversely, when a part such as a layer, a film, a region, or a plate is said to be "under" another part, this includes not only the case where the other part is "directly below", but also the case where there is another part in the middle.

Unless otherwise specified, all numbers, values, and/or expressions expressing quantities of ingredients, reaction conditions, polymer compositions, and formulations used herein are those that occur in obtaining such values, among other things essentially. Since they are approximations that reflect the various uncertainties of the measurement, it should be understood as being modified in all cases by the term "about". In addition, when numerical ranges are disclosed herein, these ranges are continuous and, unless otherwise indicated, include all values from the minimum value of this range to the maximum value including the maximum value. Furthermore, when this range refers to an integer, all integers from the minimum value to the maximum value including the maximum value are included, unless otherwise indicated.

In the present specification, when a range is described for a variable, it will be understood that the variable includes all values within the stated range, including the stated endpoints of the range. For example, a range of "5 to 10" includes values of 5, 6, 7, 8, 9, and 10, as well as any subranges such as 6 to 10, 7 to 10, 6 to 9, 7 to 9, etc. Inclusive, and it will be understood to include any values between integers that are reasonable in the scope of the stated range, such as 5.5, 6.5, 7.5, 5.5 to 8.5 and 6.5 to 9, and the like. Also, for example, the range of "10% to 30%" is 10% to 15%, 12% to 10%, 11%, 12%, 13%, etc., as well as all integers including up to 30%. It will be understood to include any subranges such as 18%, 20% to 30%, and the like, and include any values between reasonable integers within the scope of the stated range, such as 10.5%, 15.5%, 25.5%, and the like.

Hereinafter, a method of manufacturing a composite functional sheet according to the present invention will be described in detail with reference to the drawings.

1 is a process diagram illustrating a method of manufacturing a composite functional sheet according to an embodiment of the present invention, and FIG. 2 is a schematic diagram showing a method of manufacturing a composite functional sheet according to an embodiment of the present invention.

1 and 2, first, a metal mesh is prepared (S10).

As shown in FIG. 2, the metal mesh 10 is fixed and connected to one side of the device while being wound on a roller, and is provided by rotating the roller in the moving direction of the metal mesh.

The material of the metal mesh can be applied in various ways, and it is recommended to use a copper material or aluminum material having excellent heat dissipation performance and ductility. And it is better to have a size of 80 to 120 mesh.

Next, impurities existing on the surface of the metal mesh are removed (S20).

Impurities such as dust present on the surface of the metal mesh provided in step S10 are removed by passing through the air shower device 20 through which air is injected.

The air of the air shower device 20 is sprayed onto the upper or lower surface of the metal mesh in a direction horizontal to the metal mesh conveyed by the roller.

If impurities present on the surface of the metal mesh are not removed, it is difficult to attach the functional powder to be described later to the surface due to foreign substances on the contact surface, and even if attached, a phenomenon in which the functional powder to be described later is easily separated and separated may occur.

After that, the functional powder is evenly sprayed on one surface of the metal mesh in the form of a slurry and then pressed (S30).

The metal mesh from which the impurities have been removed in step S20 is passed through the spraying device 30. The spraying device 30 sprays 10 to 60 g of water per 100 g of functional powder, preferably 35 g of water in a slurry state. The spraying device 30 sprays the slurry from one surface, preferably the upper surface of the metal mesh, so that the functional heat dissipation powder contained in the slurry fills the pores of the metal mesh and covers the upper surface of the metal mesh.

The spraying device 30 sprays the slurry in a direction horizontal to the upper surface of the metal mesh. At this time, the functional powder contains at least 80 wt% or more of graphite powder, and a heat radiation powder may be used together, and the size of the powder is preferably 10 μm or less in consideration of heat radiation and electromagnetic wave shielding performance. The heat dissipation powder may be a heat dissipation filler powder such as aluminum powder or heat dissipation ceramic powder. The mixing ratio of the graphite powder and the heat dissipation powder may be adjusted in the range of 100:0 to 80:20 depending on the required function.

Thereafter, the slurry is pressed against the surface covered with the metal mesh at a pressure of 10 to 100 kg/cm ² to form a flat shape. At this time, the pressure applied by pressing is compacting, which makes the gaps between the powders compact, but since it is not a strong pressure, basic compacting is performed.

Next, the functional powder slurry and the metal mesh are first rolled (S40).

The metal mesh covered with the slurry pressed in step S30 is passed through the upper and lower rolling rollers 40. At this time, the pressure applied by the rolling roller is in the range of 70 to 200 kg/cm ² , which is stronger than the pressing in step S30, and as the functional powders of the slurry are compressed, more powders are additionally pushed between the through holes of the metal mesh. The rolling process can be applied to both cold rolling and hot rolling.

3 and 4 are schematic diagrams showing cross-sections in order to compare the case where pressing is performed and the case where rolling is performed.

Specifically, as shown in FIG. 3, in the preceding pressing process, the slurry powder 220 is filled in the through hole, which is the space between the metal mesh 100 together with the powders 210 covering the upper portion of the metal mesh 100. The metal mesh 100 is not filled to the extent that force is applied in the horizontal direction.

When the rolling process is performed, as shown in FIG. 4, some of the powders 210 covering the upper surface of the metal mesh 100 are additionally filled in the through hole, which is the space between the metal mesh 100, The powders 220 are filled so as to apply a force in the horizontal direction to the metal mesh 100 in the through hole. In this case, since the metal mesh 100 has elasticity due to the characteristics of the material, the powders 220 filled in the through holes may be additionally accommodated in a state compressed by a fine value. As described above, when a metal mesh having a size of 80 to 120 mesh is applied to the size of the functional powder of 10 μm or less in consideration of the function, sufficient powders are located in the through-holes formed in the metal mesh to obtain a mechanical bonding force.

After that, dry heat treatment is performed (S50).

In the step S40, the first rolled metal mesh is dried and heat treated for 3 to 7 minutes in a heater 50 set to a temperature of 180°C to 220°C, preferably 200°C to remove moisture from the slurry. It is preferable to leave less than 3% moisture, and even if moisture is removed, functional powders remain attached to the metal mesh without an adhesive due to mechanical bonding force due to compression in the first rolling process.

Finally, secondary rolling is performed (S60).

In the step S50, the metal mesh filled with the functional powders from which moisture is removed by heat treatment is passed through the upper and lower rolling rollers 60 so as to have a desired thickness, and secondly rolled in the range of 70 to 200 kg/cm ² .

The rolling process can be applied to both cold rolling and hot rolling.

In this way, the secondary rolled metal mesh may be wound on a roller.

When the process as described above is completed, a composite functional sheet (S70) formed to a desired thickness is obtained. The composite functional sheet manufactured by the above manufacturing method has more excellent heat dissipation effect since graphite powder and heat dissipation powder are attached to the metal mesh without using an adhesive such as resin.

Although the invention made by the present inventor has been described in detail according to the above embodiment, the invention is not limited to the above embodiment, and can be changed in various ways without departing from the gist of the invention.

10: metal mesh
20: air shower device
30: spraying device
40, 60: rolling roller
50: heater
100: metal mesh
210, 220: slurry powder

Claims (5)

(a) preparing a metal mesh;
(b) removing impurities present on the surface of the prepared metal mesh;
(c) spraying a functional powder containing 80 wt% or more of graphite powder on at least one surface of the metal mesh in the form of a slurry in which water is mixed, followed by pressing;
(d) primary rolling using a rolling roller after pressing;
(e) drying heat treatment after the first rolling; And
(f) secondary rolling with a rolling roller after dry heat treatment,
In the first rolling process, functional powders filled in the through holes, which are spaces between the metal meshes, are filled to the extent that force is applied in the horizontal direction toward the metal mesh, and functional powders filled to the extent that force is applied in the horizontal direction by the elasticity of the metal mesh. A method for manufacturing a composite functional sheet, characterized in that the functional powders remain attached to the metal mesh without an adhesive by generating a mechanical bonding force between them.
The method of claim 1,
In the step (c), the slurry is a method for producing a composite functional sheet in which 10 to 60 g of water are mixed per 100 g of the functional powder.
The method of claim 1,
The pressing in step (c) is a method of manufacturing a composite functional sheet that is carried out at a pressure of 10 to 100 kg/cm ² .
The method of claim 1,
In the step (c), the size of the powder is 10㎛ or less manufacturing method of the composite functional sheet.
The method of claim 1,
The drying heat treatment in step (e) is performed at a temperature of 180°C to 220°C.

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