KR20100064841A - Composite sheet having noise, vibration and thermal insulation function - Google Patents

Abstract

The present invention relates to a composite sheet comprising a first layer comprising rubber and a second layer comprising a nonwoven fabric interwoven with carbon fibers.

The composite sheet according to the present invention has a heat insulation function in addition to the noise and / or vibration blocking function to protect the transportation equipment or electrical and electronic equipment from heat, noise and vibration.

Description

COMPOSITE SHEET HAVING NOISE, VIBRATION AND THERMAL INSULATION FUNCTION}

The present invention relates to a composite sheet capable of blocking noise and / or vibration while simultaneously blocking heat.

In general, as a sound insulation and / or insulation to reduce the noise generated from cars, ships, electrical and electronic devices or to prevent the noise from leaking to the outside, fiber members such as glass wool, mineral wool, etc. (Fibrous material), urethane foam (urethane foam), foamed synthetic resin such as sponge is used.

However, in the case of such conventional soundproofing and / or heat insulating materials, there have been cases where the use of these materials is restricted due to the generation of toxic substances or for safety reasons. Particularly, in the case of a foamed synthetic resin such as urethane foam, it is flammable, and thus harmful toxic substances are produced during manufacture or fire, and in the case of vitrified fibers such as glass wool, glass microfiber is scattered during its use due to low mechanical strength, thereby working There was a difficulty.

In particular, the conventional soundproofing materials were effective in reducing noise generated from noise sources due to the structure of sound absorption in the application of automobiles, ships, electrical and electronic devices, and the like. However, in the case of sound insulation and / or vibration suppression which blocks noise and / or vibration generated from the noise source from reaching the neighboring spaces, the conventional soundproofing materials have not been sufficiently effective.

Therefore, there is a need for the development of new thermal insulation and / or sound insulation materials having excellent thermal insulation performance and / or noise / vibration blocking performance without generating toxic substances harmful to the human body, and particularly for the development of effective thermal insulation and / or sound insulation materials. In addition to the selection of a suitable material, economic aspects such as the weight, thickness, etc. of the material should be fully considered.

The present inventors are not harmful to the human body because no toxic substances are produced during the use of a nonwoven fabric with a densely interwoven carbon fiber instead of a mineral wool sheet or a foamed synthetic resin. It was found that excellent insulation performance and sound absorption performance can be achieved. However, the non-woven fabric is somewhat low noise and vibration blocking performance was not able to properly block the noise and / or vibration.

Accordingly, the present invention is to provide a composite sheet capable of laminating a rubber sheet to a nonwoven fabric in which carbon fibers are densely interlaced to block heat and at the same time block noise and / or vibration.

The present invention comprises a first layer comprising a rubber; And a second layer laminated on a major sied of the first layer, the second layer including a nonwoven fabric in which carbon fibers are entangled.

The composite sheet according to the present invention may not only reduce or block noise and / or vibration, but also block heat by laminating a second layer including a nonwoven fabric in which carbon fibers are interwoven with a first layer including rubber. It can protect transportation equipment such as ships, automobiles, electric and electronic devices from heat, noise and vibration.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

The composite sheet 1 according to the present invention comprises a first layer 10 comprising rubber; And a second layer 20 comprising a nonwoven fabric in which carbon fibers are entangled (see FIG. 1). Here, the first layer may block noise and / or vibration, and the second layer may absorb noise while blocking heat. The composite sheet may be arranged such that the first layer 10 is in contact with a site where noise or vibration occurs in a transportation device such as a ship or an automobile, or an electric / electronic device. The heating device may be disposed to be in contact with a heating device such as a vehicle or an electric or electronic device. Such a composite sheet 1 can protect transportation equipment, such as ships and automobiles, electrical and electronic equipment from heat, noise and / or vibration.

In general, as a means for removing noise of transportation equipment such as ships, automobiles, aircraft, and electric and electronic devices, for example, sheets made of fiber members such as mineral wool and glass wool, or sheets made of foamed synthetic resin in the form of urethane foam, etc. This was widely used. However, damage caused by the use of these sound insulation and / or heat insulating materials has recently been pointed out, and its use is limited.

Specifically, in the case of a sheet made of a foamed synthetic resin, a flammable material may cause toxic substances in a fire and may damage the human body. In the case of a sheet made of glass fiber or mineral wool, the blowing of fibers during work (splashing, 飛散) ), The fibers can be harmful to the eyes or skin, and also difficult to remove when in contact with the skin. In addition, in the case of the sheet made of glass fibers, the sound absorption performance and the like gradually decreases as moisture is absorbed, and the durability is low due to the low mechanical strength. Moreover, conventional sound insulation and / or thermal insulation materials, in particular mineral wool sheets or fiberglass sheets, were thickened to about 25 mm to 75 mm in order to block noise and / or vibration, and thus were not available for slimming products.

Thus, in the present invention, by using a non-woven fabric made of carbon fibers, instead of mineral wool sheets or foamed synthetic resin, it effectively blocks heat regardless of changes in the surrounding environment without generating toxic substances during manufacture, use or fire. At the same time, noise was reduced. However, in the case of the nonwoven fabric made of carbon fiber, it was effective in sound absorption and heat insulation, but there was a problem in that noise and / or vibration blocking properties were somewhat inferior.

Thus, in the present invention, by laminating the layer 10 including rubber to the layer 20 including the nonwoven fabric made of carbon fiber, it is possible to effectively block heat and at the same time reduce or block noise and / or vibration, It is possible to protect the equipment mounted in transportation equipment such as ships, automobiles and electric and electronic equipment from noise and vibration.

Specifically, in the present invention, heat can be effectively blocked by the second layer 20 including the nonwoven fabric made of carbon fiber, and at the same time, noise and / or vibration can be blocked by the first layer 10 including rubber. Can be.

For example, when the composite sheet 1 of the present invention is disposed such that the first layer 10 including rubber is in contact with a noise generating part or a vibration generating part in a transport device such as a ship, an automobile, or an electric / electronic device, Noise and / or vibration generated at the site of noise and / or vibration is reached on one side of the first layer in contact with the site. Then, the rubber of the first layer vibrates and is transmitted therein by the reached noise and / or vibration, but the amplitude of the noise and / or vibration being transmitted through the rubber is due to the characteristics of the rubber itself (ex. Elasticity, etc.). Due to the continuous reduction, the amplitude of the oscillating rubber and the amplitude of the noise and / or vibration are superimposed and the amplitude of the vibration transmitted to the rubber gradually decreases. As the amplitude of the noise and vibration reached to one side of the first layer is continuously reduced, the noise and / or vibration are hardly transmitted to the part or air in contact with the opposite side of the first layer.

In addition, when the composite sheet 1 of the present invention is disposed such that the second layer 20 including the nonwoven fabric is in contact with a heating element portion in a transport device such as a ship or an automobile, and an electric / electronic device, Thermal energy is transferred to the second layer in contact with the heating element site. Then, when the heat energy transferred to one side of the second layer is moved to the opposite side of the second layer, the ventilation layer formed by the carbon fiber in the nonwoven fabric is dispersed to adjust the heat energy, thereby suppressing the movement of the heat energy. Can be.

In addition, in the present invention, when the amount of air filled in the space between the carbon fibers is too large, it is known that the heat energy can be transferred to the side of the lower temperature, that is, the opposite side of the second layer by the convection phenomenon, to prevent this In order to achieve this, the bulk density of the nonwoven fabric made of carbon fiber was adjusted to about 0.1 g / cm 3 or more.

In addition, when noise or vibration reaches the second layer 20, the air filled in the spaces between the carbon fibers is vibrated by the reached noise or vibration, and at this time, due to the viscous friction of the air, Some may be converted to heat energy and consumed. That is, the second layer 20 including the nonwoven fabric can absorb noise or vibration. Therefore, the composite sheet of this invention containing the 2nd layer containing a nonwoven fabric can reduce noise and vibration more effectively compared with the sheet | seat which consists only of rubber | gum.

As described above, the composite sheet 1 (see FIGS. 1 and 2) of the present invention includes a first layer 10 including rubber and a second layer 20 including a nonwoven fabric in which carbon fibers are interwoven. Since transfer of heat, noise and / or vibration from one side of the seat to the opposite side can be suppressed, it is possible to protect transportation equipment such as ships, automobiles, and electric / electronic devices from heat, noise and vibration.

According to one embodiment of the present invention, as shown in FIG. 1, the composite sheet 1 includes a first layer 10 including rubber and a second layer 20 including a nonwoven fabric in which carbon fibers are entangled. Include.

The first layer 10 includes rubber, such as natural rubber and synthetic rubber, to block or reduce noise and / or vibration as described above. Examples of the synthetic rubber include, but are not limited to, silicone rubber, butyl rubber, styrene-butadiene rubber, ethylene vinyl acetate rubber, and the like.

Moreover, in this invention, synthetic rubbers, such as a silicone type rubber, a butyl type rubber, styrene butadiene rubber, and ethylene vinyl acetate rubber; And a rubber made of a composition for rubber containing an inorganic filler can be used. The inorganic filler is for improving vibration damping, and non-limiting examples thereof include talc, clay, mica, silica, zinc oxide, iron oxide, aluminum hydroxide, and the like. Although these can be used individually or in mixture of 2 or more types.

The content of the inorganic filler may be about 10 to 150 parts by weight, preferably about 30 to 100 parts by weight, and more preferably about 50 to 70 parts by weight, based on 100 parts by weight of the rubber.

In addition, the rubber used in the present invention, if necessary, vulcanizing agents (ex. Sulfur, organic peroxides, metal oxides, etc.) (about 1 to 10 parts by weight), vulcanization accelerators (ex. Diphenyl Guanidine, 2-Mercapto benzo thiazole, etc.) And other additives such as organic accelerators, inorganic accelerators such as ZnO, MgO, etc.) (about 1 to 10 parts by weight), anti-aging agents (about 1 to 10 parts by weight), and the like.

The thickness of the first layer 10 including such rubber is not particularly limited, and may be appropriately adjusted according to the type of rubber used, the site where the composite sheet is used, the amplitude of noise or vibration generated, and the like. However, if the thickness of the first layer 10 is too thick, noise or vibration may be better blocked, but may not be used in slim devices such as electric and electronic devices. On the other hand, if the thickness of the first layer is too thin, it may not be able to properly absorb noise or vibration. Therefore, it is appropriate that the thickness of the first layer is about 1 to 4 mm.

In the composite sheet 1 of the present invention, the second layer 20 includes a nonwoven fabric in which carbon fibers are entangled in order to effectively block heat (see FIG. 4).

The nonwoven fabric is made by mechanically or physically intertwining a web obtained from carbon fibers. For example, the nonwoven fabric may include supplying carbon fibers to a carding machine to form a web; And entangle the web using at least one of a needle-punch method and a water jet method to increase the physical or mechanical strength of the web. Can be. Specifically, by repeatedly moving up and down the needle with a hook on a web formed by mixing carbon fibers, a part of the carbon fibers arranged in multiple layers in a plane is arranged in the thickness direction. At the same time, the carbon fibers are entangled and strongly bound to each other. In addition, high pressure water flow may be used instead of the needle to entangle the carbon fibers of the web with each other.

In the inside of the nonwoven fabric prepared as described above, the ventilation layer formed by the entangled carbon fibers controls the thermal energy, thereby suppressing the movement of the thermal energy, thereby exhibiting excellent thermal insulation performance. Accordingly, the nonwoven fabric of the present invention may have a weight per unit area of about 200 g / m 2 to 1000 g / m 2, preferably about 500 to 1000 g / m 2, in order to exert heat insulating performance. In addition, the nonwoven fabric may have a bulk density of about 0.1 g / cm 3 or more, preferably about 0.1 to 0.2 g / cm 3, more preferably about 0.1 to 0.16 g / cm 3. In addition, the nonwoven fabric may have an air permeability of about 30 cm 3 / cm 2 / s or less, preferably about 15 to 30 cm 3 / cm 2 / s. The second layer 20 made of such a nonwoven fabric not only provides excellent heat insulating property to the composite sheet of the present invention, but can also impart excellent sound absorption in a low frequency region.

In addition, the carbon fiber of the nonwoven fabric is a heat resistant fiber, has high strength and high modulus in the fiber axis direction, and can effectively block heat. In addition, since the nonwoven fabric is made of pure microfiber carbon fibers, it exhibits light and excellent sound absorption properties. Non-limiting examples of such carbon fibers include, but are not limited to, carbon fibers derived from polyacrylonitrile, carbon fibers derived from pitch, carbon fibers derived from rayon, and the like.

The fiber length of the carbon fiber is not particularly limited. However, when the nonwoven fabric is manufactured by interlacing carbon fibers having a fiber length of about 10 mm or more, the carbon fibers do not fall off well from the nonwoven fabric, while the longer the fiber length, the better the sound absorption. In view of this, it is appropriate to use carbon fibers having a fiber length of about 10 to 100 mm, preferably about 20 to 80 mm. According to one example of the present invention, the fiber length of the carbon fibers was about 50 mm.

Further, the median diameter of the carbon fiber is suitably about 10 to 50 mu m, preferably about 10 to 20 mu m (see FIGS. 5 and 6). If the carbon fiber is too thin, the workability is lowered, while if the carbon fiber is too thick, the heat insulation and sound absorption may be lowered.

In addition, in this invention, it can use individually or in mixture of 2 or more types of carbon fiber. As the same or different types of carbon fibers, carbon fibers having different median diameters and fiber lengths can be mixed and used. The mixing ratio of the two or more carbon fibers can be appropriately adjusted according to the application site of the composite sheet.

As the thickness of the second layer 20 formed of such a nonwoven fabric is thicker, the insulation is better, but in consideration of economical efficiency, ease of handling, and space for the composite sheet, it is about 2 to 100 mm, preferably about 2 to 50 mm. Can be.

Meanwhile, according to another embodiment of the present invention, as shown in FIG. 2, the composite sheet 1 may include a nonwoven fabric laminated on a first layer 100 including rubber and a major side of the first layer. In addition to the second layer 20, the third layer may further include a third layer, which is laminated on the opposite side of the first layer 10 and includes a metal. The third layer 30 may not only prevent the surface of the first layer including rubber from being contaminated or scratches, but also may be generated inside a transport device such as a ship or an automobile, or an electric / electronic device. It can shield electromagnetic waves.

The third layer 30 may be a metal film, a metal wire mesh, a glass cloth, or the like, but is not limited thereto. According to an example of the present invention, the third layer was an aluminum film.

Although the thickness of this 3rd layer is not specifically limited, It is suitable that it is about 0.05-0.2 mm.

The composite sheet according to the present invention can be produced by various methods.

According to one embodiment of the invention, the composite sheet 1 is a step of forming a nonwoven fabric 20 by intertwining carbon fibers; And laminating the nonwoven fabric on the major side of the rubber sheet 10.

In addition, according to another embodiment of the present invention, the composite sheet 1 is to form a nonwoven fabric 20 by interweaving carbon fibers; Laminating the nonwoven fabric to a major side of a rubber sheet (10); And laminating at least one selected from the group consisting of a metal film, a metal wire mesh, and a glass cloth to the opposite side of the rubber sheet. In this case, the step of laminating the nonwoven fabric and the rubber sheet and the step of laminating the rubber sheet with at least one selected from the group consisting of a metal film, a metal wire mesh, and a glass cloth may be performed simultaneously or sequentially.

In addition, according to another embodiment of the present invention, the composite sheet 1 is a step of forming a nonwoven fabric 20 by intertwining carbon fibers; Laminating the nonwoven fabric to a main surface of a rubber sheet (10); And it may be produced by a method comprising the step of forming a metal film 30 on the opposite side of the rubber sheet.

1) In the present invention, a nonwoven fabric made of carbon fibers is prepared and used as the second layer 20.

First, a web is formed according to a conventional web forming method using a web forming apparatus using carbon fibers having the same or different median diameter or fiber length. For example, carbon fibers may be fed to a carding machine to form a web. At this time, the carbon fibers of the web are arranged in multiple layers in a plane and are irregularly arranged in various directions.

Thereafter, the formed web is formed by the mechanical or physical method such as the needle-punch method or the water jet method. The fibers are entangled and strongly bound to each other.

Here, it is appropriate to adjust the needle punch density when using the needle punching machine so that the air permeability of the nonwoven fabric is about 15 to 30 cm 3 / cm 2 / s. If the density of the needle punch is too small, the entanglement of the carbon fibers may not be sufficiently made, so that the mechanical strength and durability of the nonwoven fabric may be low. On the other hand, if the density of the needle punch is too high, the air permeability in the nonwoven fabric is low, the heat insulation effect or sound absorption effect may not be properly exhibited.

Moreover, when binding a web using a water jet, it is preferable to adjust the airflow of a nonwoven fabric by adjusting the water pressure of a water jet, the diameter, the space | interval, etc. of a nozzle hole.

2) Thereafter, the prepared nonwoven fabric is laminated with rubber, preferably uncured rubber. In this case, since the rubber has adhesiveness or tacky property, the nonwoven fabric may be laminated to the rubber by using a pair of pressing rollers known in the art without using a separate adhesive means such as an adhesive. However, in order to prevent the nonwoven fabric and the rubber from separating in the future when using the composite sheet, it is preferable to laminate the prepared nonwoven fabric using a pair of compression rollers before the rubber is completely cured.

The rubber may be prepared by methods known in the art.

3) On the other hand, in the present invention, the vacuum film deposition method, the ion plating method, and the electron beam vacuum are formed so that the metal film used as the surface protection layer 30 is formed on the main surface of the rubber sheet on which the nonwoven fabric is laminated on the opposite side. A metal can be deposited on the main surface of the rubber sheet using a vapor deposition method, a sputtering method, or the like.

Alternatively, at least one selected from the group consisting of a prefabricated metal film, a metal wire mesh, and a glass cloth when laminating the nonwoven fabric on the main surface of the rubber sheet, or laminating the nonwoven fabric on the main surface of the rubber sheet, It can be joined to the opposite side of the sheet. In this case, the metal film may be obtained by depositing a metal material on the surface of a release film by a known thin film forming method such as vacuum deposition, ion plating, electron beam vacuum deposition, sputtering, or the like. Alternatively, the metal film may be obtained by a metal foil manufacturing method known in the art, such as a method of dissolving a metal (ex. Aluminum) ingot, which is a raw material, in a melting furnace and extruding it into a desired shape.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. However, the present invention is not limited thereto.

Example 1

Using a PAN-based carbon fiber (Toho Tenax, Pyromex) having a fiber length of 10 mm and a median dimeter of about 14 μm as a raw material, the fibers are entangled using heat and pressure. A nonwoven fabric having a thickness of about 4 mm and a weight per unit volume of 600 g / m 2 was prepared. The average density of the obtained nonwoven fabric was 0.15 kg / cm <3>, and air permeability was about 27 cm <3> / cm <2> / s.

The nonwoven fabric prepared above and a rubber sheet (Namyang Novitek, Zerony Series) having a thickness of 2 mm were laminated using a pair of compression rollers.

Example 2 to Example 10

As shown in Table 1, a nonwoven fabric and a composite sheet using the nonwoven fabric were prepared in the same manner as in Example 1, except that the thickness of the nonwoven fabric and the thickness of the rubber sheet were changed.

Example 2 3 4 5 6 7 8 9 10 Thickness of Nonwoven Fabric (mm) 3.87 5.60 7.20 24.60 5.23 10.09 21.88 10 50 Thickness of rubber sheet (mm) 2 2 2 2 2 2 2 - -

Comparative example  One

Glass wool (3M Fire barrier Packing material, PM4) having a thickness of 8 mm was used.

Comparative Example 2

Mineral wool having a thickness of 25 mm (mineral wool blanket of Byucksan, average density: 80 kg / m 3) was used.

Experimental Example  1-insulation performance measurement

In order to confirm the thermal insulation performance of the composite sheet according to the present invention, the heat transfer characteristics were measured as follows.

1) First, in order to measure the heat transfer characteristics of the composite sheet (thickness; 4.8 mm) prepared in Example 1, a heat transfer meter (MTS Alliance RT / 5) was used. First, a 50 mm × 50 mm specimen was inserted between a heating plate and a cold plate of a heat transfer meter, but the nonwoven surface of the specimen contacted the heating plate, and the rubber surface of the specimen contacted the cold plate. At this time, the temperature of the heating plate was about 300 ℃, the temperature of the cold plate was about room temperature (that is, the heating temperature is 300 ℃). After a lapse of about 120 minutes, the temperature of the cold plate in contact with the rubber surface of the composite sheet was measured, and the measurement results are shown in Table 2 and FIG. 7.

Temperature of Heating Plate (℃) 300 Cold Plate Temperature (℃) 80

As can be seen in Table 2 and Figure 7, the temperature of the heating plate was 300 ℃, while the temperature of the cold plate was 80 ℃. From this, it was found that the heat transfer rate of the composite sheet according to the present invention is low.

In addition, even though heat was continuously transferred to the composite sheet of Example 1 for 120 minutes, the temperature of the cold plate was maintained at about 80 ° C.

2) Heat transfer performance measurement according to the thickness change of nonwoven fabric

In order to measure the heat transfer degree according to the thickness change of the nonwoven fabric used in the composite sheet of the present invention, it was measured using a heat transfer meter (MTS Alliance RT / 5) in the same manner as in Experimental Example 1-1. However, the heating time was 90 minutes. In this case, as the specimens 1 to 4, the nonwoven fabrics prepared in Examples 2 to 5 were used, respectively. Glass wool of Comparative Example 1 (thickness; 8 mm) was used as Control 1, and mineral wool (thickness; 25 mm) of Comparative Example 2 was used as Control 2. In addition, the weight loss and appearance change of each specimen were also measured. Its measurement results are shown in Table 3 below.

Psalm 1 Psalm 2 Psalm 3 Psalm 4 Control group 1 Control 2 size 50 mm × 50 mm Thickness (mm) 3.87 5.60 7.20 24.31 8.27 25 Weight loss Initial weight (g) 1.693 2.395 2.620 7.904 5.713 6.064 Weight after 90 minutes (g) 1.549 2.237 2.378 7.236 5.581 5.870 % Remaining 92 93 91 92 98 97 Heat
relay Temperature of Heating Plate (℃) 300 Cold Plate Temperature (℃) 84 74 66 35 60 39 Change in appearance No No No No - -

As a result of the measurement, the thicker the specimens 1 to 4, the lower the temperature of the cold plate in contact with the bottom surface of each specimen. From this, it turned out that the thicker the nonwoven fabric is, the more insulated it is.

In addition, the temperature of the cold plate in contact with the bottom surface of Specimen 3 (thickness; 7.20 mm) was about 66 ° C., while the temperature of the cold plate was 60 ° C. for the control 1 (thickness; 8.27 mm). Therefore, even when using the nonwoven fabric made of carbon fiber of the present invention, it was confirmed that the heat insulating performance is similar to the glass wool used as a conventional heat insulating material.

In addition, in the case of specimen 4 (thickness; 24.31 mm), the temperature of the cold plate in contact with the bottom surface was 35 ° C, and in the case of control 2 (thickness; 25 mm), the temperature of the cold plate was 39 ° C. From this, it can be seen that the nonwoven fabric used in the present invention is similar in heat insulation performance to the mineral wool used as a conventional heat insulating material.

3) Measurement of heat transfer performance of nonwoven fabric according to heat energy change

When the heat energy was changed, in order to measure the heat transfer degree of the nonwoven fabric according to the present invention, it was measured using a heat transfer meter (MTS Alliance RT / 5) in the same manner as in Experimental Example 1-1. However, the heating temperature was changed from 150 ° C. to 300 ° C. to 500 ° C., and the heating times were about 90 minutes, 120 minutes and 120 minutes, respectively. In this case, as the specimens 5 to 7, a nonwoven fabric prepared in Examples 6 to 8 was used. The measurement results thereof are shown in Table 4 and FIG. 8.

Psalm 5
(5 mm) Temperature of Heating Plate (℃) 150 300 500 Cold Plate Temperature (℃) 45 75 122 Psalm 6
(10 mm) Temperature of Heating Plate (℃) 150 300 500 Cold Plate Temperature (℃) 38 66 88 Psalm 7
(20 mm) Temperature of Heating Plate (℃) 150 300 500 Cold Plate Temperature (℃) 29 41 56

As a result of the measurement, when the temperature of the heating plate in contact with the top surface of the specimens 5 to 7 was heated to 150 → 500 ° C., the temperature of the cold plate in contact with the bottom surface of each specimen also slightly increased. In addition, with the change in the thickness of the specimen (5 mm → 10 mm → 20 mm), the temperature of the cold plate in contact with the bottom surface of each specimen was lowered.

4) In order to check whether the nonwoven fabric blocks heat in the composite sheet of the present invention, it was measured using a heat transfer meter (MTS Alliance RT / 5) in the same manner as in Experimental Example 1-1. At this time, the nonwoven fabrics prepared in Examples 2 and 3 were used as specimens 8 and 9, and the composite sheets prepared in Examples 2 and 3 were used as controls 3 and 4. Its measurement results are shown in FIG.

As a result of the measurement, the temperature of the cold plate in contact with the bottom surface of specimen 8 or the temperature of the cold plate in contact with the bottom surface of control 2 was similar, and also the temperature of the cold plate in contact with the bottom surface of specimen 9 or the bottom of control 3 The temperature of the cold plate in contact with the surface was similar. From this, it turned out that a nonwoven fabric provides the heat insulation performance in the composite sheet of this invention.

Experimental Example  2-sound absorption performance measurement

In order to measure the sound absorption performance of the composite sheet according to the present invention, noise reduction coefficient (NRC) was measured according to the ISO standard method. In this case, as specimens 10 and 11, nonwoven fabrics prepared in Examples 9 and 10 were used. The measurement results thereof are shown in Table 5 and FIG. 10.

thickness
(Mm) Sound absorption coefficient (α) by frequency band NRC 250 ㎐ 500 ㎐ 1000 ㎐ 2000 ㎐ Psalm 10 10 0.05 0.18 0.50 0.81 0.4 Psalm 11 50 0.93 1.01 1.03 1.0 1.0

As a result of the measurement, the sound absorption rate of specimens 10 and 11 generally satisfied the requirement for use as a sound absorption material (absorption rate; 0.3 or more), and particularly in the case of specimen 11, the sound absorption rate was 1.0. In addition, as shown in Figure 6, it can be seen that the composite sheet of the specimens 10 and 11 absorbs sound having a 1/3 Octave center frequency of less than 500 Hz ~ 5000 Hz.

1 is a cross-sectional view of a composite sheet according to an embodiment of the present invention.

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

3 is an optical micrograph showing a cross section of the composite sheet according to another embodiment of the present invention.

4 and 5 are electron micrographs showing the surface of the nonwoven fabric prepared in Example 1 of the present invention.

6 is an electron micrograph showing a cross section of the carbon fiber used in the nonwoven fabric prepared in Example 1 of the present invention.

7 is a graph showing heat transfer characteristics of the composite sheet prepared in Example 1.

8 is a graph showing the heat transfer characteristics of the nonwoven fabric prepared in Examples 6 to 8.

9 is a graph showing the heat transfer characteristics of the nonwoven fabric and composite sheet prepared in Examples 2 and 3.

10 is a graph showing the sound absorption characteristics of the composite sheets prepared in Examples 9 and 10.

&Lt; Description of reference numerals &

1: composite sheet, 10: first layer comprising rubber,

20: second layer comprising nonwoven fabric, 30: third layer comprising metal

Claims (17)

One layer comprising rubber; And a second layer laminated on a major side of the first layer, the second layer comprising a nonwoven fabric in which carbon fibers are entangled. The composite sheet according to claim 1, wherein the nonwoven fabric has a weight per unit area of 200 to 1000 g / m 2, a bulk density of 0.1 or more g / cm 3, and an air permeability of 30 cm 3 / cm 2 / s or less. The composite sheet of claim 1, wherein the carbon fiber is derived from polyacrylonitrile. The composite sheet of claim 1, wherein the carbon fiber has a median diameter of 10 to 50 μm. The composite sheet of claim 1, wherein the nonwoven fabric is manufactured using at least one of a needle-punch method and a water jet method. The composite sheet according to claim 1, wherein the second layer has a thickness of 2 to 100 mm. The composite sheet according to claim 1, wherein the rubber is natural rubber or synthetic rubber. The composite sheet according to claim 7, wherein the rubber is a synthetic rubber selected from the group consisting of silicone rubber, butyl rubber, styrene-butadiene rubber and ethylene vinyl acetate rubber. The composite sheet of claim 8, wherein the rubber further comprises an inorganic filler. The method of claim 9, wherein the inorganic filler is selected from the group consisting of talc, clay, BaSO ₄ , SiO ₂ , MgSO ₄ , CaCO ₃ , Al ₂ O ₃ , mica and mixtures thereof. Composite sheet characterized by. The composite sheet according to claim 1, wherein the first layer has a thickness of 1 to 5 mm. The method of claim 1, further comprising a third layer laminated on the major side of the first layer on which the second layer is laminated, wherein the third layer comprises a metal film, a metal wire mesh, and a glass cloth. A composite sheet comprising at least one material selected from the group consisting of Glass cloth. The composite sheet according to any one of claims 1 to 12, wherein the composite sheet is used for noise isolation, vibration isolation, insulation, or both. Interlacing the carbon fibers to form a nonwoven fabric; And Laminating the nonwoven to the major side of the rubber sheet Method of manufacturing a composite sheet comprising a. The method of claim 14, wherein the forming of the nonwoven fabric is performed using a needle punching machine or a water jet. 15. The composite sheet of claim 14, further comprising laminating at least one material selected from the group consisting of a metal film, a metal wire mesh, and a glass cloth to the main surface of the rubber sheet having the nonwoven fabric on the opposite side. Manufacturing method. 15. The method of claim 14, further comprising the step of forming a metal film by depositing a metal on the main surface of the rubber on which the non-woven fabric is laminated on the opposite side.

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