KR100898900B1 - Conductive composites and method for manufacturing the same - Google Patents

Abstract

The present invention relates to a conductive composite and a method for manufacturing the same, which include metal particles, metal flakes, metal-nanofiber composites, metal-polymer composites, nanofiber-polymer composites, metal-nanofiber-polymer composites, In addition, by compositely dispersing two or three or more various additives selected from nanofibers or nanotubes, the composite material and the method of manufacturing the composite material further improve the conductivity by securing a flow path of direct thermal and electrical conductivity between the additives It is about.

Conductive composites, mechanical milling, metal particles, metal flakes, single molecules, polymers, nanofibers, nanotubes, carbon nanotubes, carbon nanofibers, metal fibers, dispersion

Description

Conductive composites and method for manufacturing the same

1 is a view schematically showing a manufacturing process of an additive used in the production of a conductive composite according to the present invention,

2 is a view schematically showing a conductive composite manufacturing process according to the present invention,

3 is an actual view taken with a scanning electron microscope the shape change of the metal flakes with the mechanical milling time,

Figure 4 is a photogram taken with a scanning electron microscope of the shape change of the composite with the mechanical milling time in manufacturing a metal-nanofiber composite;

5 is a photo-realistic view taken with an optical microscope of the shape of the metal-polymer composite prepared by the mechanical milling method,

6 is a photogram of a shape change of a composite according to the content of carbon nanotubes in the preparation of a nanofiber-polymer composite using a mechanical milling method with a scanning electron microscope;

7 is a photo-realistic view taken with an optical microscope of the shape of the metal-nanofiber-polymer composite prepared by the mechanical milling method,

8 is a photo-realistic view of a mixed material of metal particles and metal flakes dispersed in a polymer matrix and then the mixed shape with an optical microscope;

9 is a photo-realistic view of the mixed particles of the metal particles, metal flakes, and metal-nanofiber composites in the polymer matrix and then the mixed shape with an optical microscope;

10 is a photo-realistic view taken with an optical microscope of a shape in which an additive of a metal foil is dispersed in a polymer matrix;

FIG. 11 is an optical view taken with an optical microscope of a shape in which an additive of a metal-nanofiber composite is dispersed in a polymer matrix; FIG.

<Explanation of symbols for the main parts of the drawings>

10 metal particles 12 metal flakes

14 metal-carbon nanotube composite 20 carbon nanotube

30: Monomolecule and Polymer Particles 40: Monomolecule and Polymer Bases

The present invention relates to a conductive composite material and a method for manufacturing the same, and more particularly, to a conductive composite material and a method for manufacturing the same in which various additives are dispersed in a single molecule and a polymer matrix.

In general, research has been conducted since 2000 to manufacture single-molecule and polymer-based conductive composites using nanofibers such as metal particles, metal flakes or carbon nanotubes, carbon nanofibers, and metal fibers.

Domestic patents include "Carbon Fiber-Containing Resins" by Published Patent No. 1997-74867 (1997.12.10) filed by Advanced Ceramics Corporation under the name of "High Thermal Conductive Composite and Manufacturing Method thereof", and Showa Denko Corporation. Patent Application Publication No. 2006-13512 (2006.2.10) entitled "Dispersion and Resin Composite Materials."

International patents include U.S. Patent No. 6,162,849, filed by Ferro Corporation under the name "Thermally conductive thermoplastic," which discloses thermal conductivity by dispersing metal particles, metal flakes, metal fibers and carbon nanofibers in single molecules and polymers. The raw material was manufactured and its characteristic evaluated.

However, the above patent is made by adding only a single shape of additives such as metal particles, metal flakes, and nanofibers to a single molecule and a polymer matrix, which has direct thermal conductivity and It was difficult to see the excellent effect because the flow path of electric conduction was not secured enough.

In other words, when only a single additive is dispersed in a single molecule and a polymer in the process of forming and integrating a conductive material, the spherical metal particles do not form a connection network in the matrix. There is not enough connectivity between them.

Carbon nanotubes also exhibit a phenomenon of low conductivity due to inability to uniformly disperse, which causes defects and deteriorates the physical properties of monomolecular and polymeric materials.

In addition, as a conventional method for imparting conductivity to monomolecules and polymers, there is a method of thin-film plating alloys on solid polymer particle surfaces using a chemical plating method in the process of preparing polymer-metal composite particles. Because it is a main ingredient, it has a disadvantage of high material cost and poor adhesiveness, neutralization process, mechanical roughening, and chemical etching (for hydrophilicity on the surface of the plastic to make a flaw so that the flaw is plated for good adhesion) and to give susceptibility. It has the disadvantage of having to go through several complicated processes such as treatment (treatment in liquid to give hydrophilic plastic surface sensitivity), activation treatment, plating, etc., which results in low efficiency in terms of mass production.

Accordingly, the present invention has been invented to solve the above problems, and in the method of dispersing metal and nanofibers in a matrix, the metal and nanofibers, a single molecule, and a polymer material are uniformly distributed between particles and particles. Unlike conventional methods, by adding mechanical energy such as mechanical milling method to produce additives with excellent dispersibility, and by dispersing various additives in combination to produce conductive composites, it secures the flow path of direct thermal and electrical conduction in the base. The purpose is to provide a method for improving conductivity.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

In order to achieve the above object, the present invention comprises the steps of milling the metal particles using a mechanical milling method to produce a metal foil; Mixing metal particles with nanofibers or nanotubes and then milling them using mechanical milling to produce a metal-nanofiber composite; Preparing a metal-polymer composite by mixing the metal particles with the solid monomolecule and the polymer particles and milling the same using a mechanical milling method; Preparing a nanofiber-polymer composite by mixing nanofibers or nanotubes with solid monomolecules and polymer particles and then milling them by mechanical milling; Preparing a metal-nanofiber-polymer composite by mixing nanofibers or nanotubes with the metal-polymer composite and milling the same using a mechanical milling method; The metal particles, metal flakes, metal-nanofiber composites, metal-polymer composites, nanofiber-polymer composites, metal-nanofiber-polymer composites, and a mixture of two or three or more additives selected from nanofibers or nanotubes It is then added to the monomolecular and polymer matrix of the liquid phase, and then dispersing the additives in the matrix using a dispersion method by mechanical milling to provide a conductive composite of the liquid phase.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

1 is a view schematically showing a manufacturing process of the additive used in the production of the conductive composite according to the present invention. In addition, FIG. 2 is a view schematically illustrating a process of manufacturing a conductive composite according to the present invention, and illustrates a process of manufacturing a single molecule and a polymer matrix-based conductive composite using various additives of FIG. 1.

As shown, the present invention relates to a method for producing a liquid or solid conductive composite in which various additives are dispersed in a mono- and polymer matrix, in particular, metal particles, Two or three selected from metal-flakes, metal-nano-fibers composites, metal-polymer composites, nanofiber-polymer composites, metal-nanofiber-polymer composites, and nanofibers or nanotubes The main focus is to produce a mixture of two or more additives and then dispersed in a single molecule and a polymer matrix using a mechanical dispersion method.

First, a material used as an additive will be described with reference to FIG. 1.

The metal particles are spherical metal powders and are materials used to impart conductivity.

The metal particles may be metal materials that are elastically deformed or plastically deformed by mechanical milling (for example, ball milling) and have excellent thermal conductivity and electrical conductivity at the same time, for example, aluminum powder or copper powder, or other thermal conductivity and Known metal particles known to be excellent in electrical conductivity at the same time may be used, and may be known metal particles which have been used to prepare existing thermally conductive and electrically conductive composite materials.

In addition, the metal flakes are manufactured by milling the metal particles using a mechanical milling method (for example, ball milling) and deforming them into flakes. By applying mechanical impact energy, the metal particles cause elastic deformation or plastic deformation, and by this deformation, metal flakes can be produced from the metal particles.

In addition, the metal-nanofiber composite is a composite in which nanofibers or nanotubes are partially inserted into the metal particles, and after mixing the nanofibers or nanotubes with the metal particles, mechanical milling (eg, ball milling) is performed. It is manufactured by milling using In the manufacturing process, when mechanical impact energy is applied to the metal particles by mechanical milling, the nanofibers or nanotubes penetrate into the metal particles while the metal particles cause elastic deformation or plastic deformation.

In addition, the metal-polymer composite is a composite material in which metal particles are thinly bonded to the surface of solid monomolecules and polymer particles, and the metal particles are mixed with solid monomolecules and polymer particles, followed by mechanical milling (ball milling). It is manufactured by milling using In the manufacturing process, the metal particles are coated on the surface of the monomolecular and polymer particles by mechanical milling, thereby joining.

In addition, the nanofiber-polymer composite is a composite material in which nanofibers or nanotubes are bonded to or partially inserted into the solid monomolecular and polymer particle surfaces, and the nanofibers or nanotubes are mixed with the monomolecular and polymer particles in the solid phase. It is then milled using mechanical milling methods (eg ball milling). In the manufacturing process, the nanofibers or nanotubes are coated on the surface of monomolecules and polymer particles by mechanical milling, and are bonded or partially inserted into monomolecules and polymer particles.

In addition, the metal-nanofiber-polymer composite is a composite in which nanofibers or nanotubes are bonded to or partially inserted into the metal-polymer composite surface, wherein nanofibers or nanotubes are mixed with the metal-polymer composite. It is then milled using mechanical milling methods (eg ball milling). In the manufacturing process, the nanofibers or nanotubes are coated on the surface of the metal-polymer composite by the mechanical milling or are partially inserted into the metal-polymer composite.

In the present invention, the nanofibers may be metal fibers or carbon nanofibers, and the nanotubes may be carbon nanotubes. In order to manufacture the additives, one or two selected from metal fibers, carbon nanofibers, and carbon nanotubes may be used in combination. As the metal fibers, known metal fibers that have been used to manufacture conventional conductive composites may be used. Can be.

In the present invention, the nanofibers or nanotubes are used to prepare additives for producing conductive composites, that is, the metal-nanofiber composites and nanofiber-polymer composites, and metal-nanofiber-polymer composites. Although also a material used for manufacturing, nanofibers or nanotubes themselves can be used as additives for producing conductive composites.

In addition, the monomolecular and polymer particles may be used by selecting one of various types of monomolecular and polymer particles, including thermoplastics, thermosets, elastomers, thermoplastic elastomers, and the like. Can be.

And, in the process of manufacturing the additive using the metal particles, that is, the metal flakes, metal-nanofiber composite, metal-polymer composite, metal-nanofiber-polymer composite, mechanical milling time, that is, time to apply mechanical energy May vary depending on the composite to be prepared, and may also vary according to the type of metal particles used. For example, it is desirable to increase the time for alloy composites than to produce pure metal composites.

In manufacturing the metal flakes in the present invention, the mechanical milling time is preferably about 0.7 to 1 hour.

If the time is shorter than the above-described time, the metal flakes formed are too small, and thus, even when dispersed in a matrix, a direct path in the conduction flow cannot be secured, and a significant increase in conductivity is expected. Becomes difficult.

On the other hand, after 1 hour, as the mechanical milling time becomes longer, additional mechanical impact energy is applied to the metal flakes forming the cold-weld, resulting in a crack and cracking as the gap is formed in the metal flakes.

The smaller size and the gaps in the metal flakes become resistance elements that prevent the flow of conduction, so that good conductivity cannot be obtained.

In addition, in manufacturing the metal-nanofiber composite, the mechanical milling time is preferably about 0.5 to 1 hour.

If the time is shorter than the above time, it is difficult to insert the nanofibers or nanotubes to the proper length inside the metal particles to be deformed, whereas if the time is longer than 1 hour, the nanofibers or nanotubes are deformed by mechanical impact energy. As it is completely inserted into the metal particles, it does not play a conductive role.

In addition, in the preparation of the metal-polymer composite, the metal particles may be used in an amount of 6 to 15 vol.% Based on the total volume of the solid monomolecular and polymer particles, and the milling time is preferably 3 to 6 hours.

Here, when the metal particles are used at less than 6 vol.% Or the milling time is less than 3 hours, it is impossible to prepare a desired composite material in which a sufficient amount of the metal particles are bonded to the solid monomolecular and polymer particle surfaces. In addition, when used in excess of 15 vol.% There is a problem that the remaining metal particles of more than 15 vol.% Is not bonded to the surface of the solid monomolecule and polymer particles do not see the milling effect.

In addition, the content of the nanofibers or nanotubes used in manufacturing the nanofiber-polymer composite is preferably 4 wt.% Or more, and the mechanical milling time should be 12 hours or more.

Preferably, the nanofibers or nanotubes are 4 to 10 wt.% And the remainder are mixed with solid monomolecules and polymer particles, followed by mechanical milling for 12 to 24 hours, and less than 4 wt.%. In the case of use, it is difficult to obtain a desired conductivity property because a sufficient amount of nanofibers or nanotubes cannot be bonded or partially inserted. When milling for less than 12 hours, the nanofibers or nanotubes may be It becomes difficult to bond to or partially insert into the surface of molecules and polymer particles.

In addition, in the production of metal-nanofiber-polymer composites, as in the nanofiber-polymer composite, the content of nanofibers or nanotubes is preferably 4 wt.% Or more, and the mechanical milling time should be 12 hours or more.

Preferably, 4 to 10 wt.% Of the nanofibers or nanotubes are mixed with the remainder of the metal-polymer composite, and then subjected to mechanical milling for 12 to 24 hours. In this case, it is difficult to obtain a desired conductivity property because it is impossible to bond a sufficient amount of nanofibers or nanotubes, and when milling for less than 12 hours, the nanofibers or nanotubes are formed on the surface of solid monomolecules and polymer particles. It becomes difficult to join or partially insert therein.

Meanwhile, referring to FIG. 2, a process of manufacturing the conductive composite is described. In the present invention, the additives prepared as described above are mixed and then added and dispersed in a single molecule and a polymer matrix.

First, two or three or more additives selected from the above metal particles, metal flakes, metal-nanofiber composites, metal-polymer composites, nanofiber-polymer composites, metal-nanofiber-polymer composites and nanofibers used as additives Mixed and mixed into the liquid monomolecular and polymer resin, and then dispersed by mechanical dispersion method to prepare a liquid conductive composite.

Next, in order to manufacture a solid conductive composite, by pressing the liquid conductive composite as described above through a one-way pressing method to prepare a solid conductive composite having a specific shape.

Here, the monomolecular and polymer materials are selected from a variety of monomolecular and polymeric materials, including thermoplastics, thermosets, elastomers, thermoplastic elastomers, and the like. In addition, known monomolecular and polymeric materials that have been used to manufacture conventional conductive composite materials, such as unsaturated polyester resins (UPR) that can be produced in liquid form, can be used.

In addition, the mechanical dispersion method is one of dispersion methods using various energies such as ultrasonic and roll milling, ball milling, jet milling, screw mixing, and the like. Select the method to carry out.

And, the one-way pressing method is a mechanical processing method using one method selected, for example, during extrusion, rolling and injection.

When the additives of the metal-nanofiber composite, the nanofiber-polymer composite, and the metal-nanofiber-polymer composite are used in the above additives, nanofibers or nanotubes may be formed in the monomolecular and polymer materials even by applying a conventional dispersion process. It can be uniformly dispersed, and it is possible to prevent segregation of nanofibers or nanotubes in subsequent processing such as extrusion or injection.

Hereinafter, a method for preparing each additive according to the present invention and a method for preparing a single molecule and a polymer matrix conductive composite in which these additives are dispersed in detail will be described and described in detail by way of examples. It is not limited by.

Example 1

According to the method proposed in the present invention as an additive to the spherical metal particles (metal powder) by applying a mechanical impact energy using a mechanical milling method to produce a metal flakes, Figure 3 attached to the shape change of the metal flakes with milling time Indicated.

Aluminum powder was used as the metal particles, and the metal particles were milled by a ball milling method.

3 is a photogram taken of a scanning electron microscope of the shape change of the metal flakes (aluminum flakes) 10 according to the mechanical milling time.

3 is a photograph with a milling time of 0.5 hours, the metal particles form the metal foil 10, but because the size is measured from the photograph and the size is too small, even if dispersed in the base of the conduction It is difficult to expect a significant increase in conductivity because there is no direct path in the flow.

The photograph of 2) is a photograph with a milling time of 1 hour. In this case, the metal foil 10 having the cold weld (cold-weld) formed as the contact between the metal due to the mechanical impact energy was confirmed. As a result of measuring the size from the photograph, it was confirmed that the size of the metal foil 10 was increased by about three times than in the case of 0.5 hour, and the implementation of the desired characteristic is possible.

However, as shown in the photo of 3), as the mechanical milling time becomes longer after 1 hour, more mechanical impact energy is applied to the metal foil 10 on which cold-weld is formed, so that a gap is formed in the metal foil. It was cracked and cracked as a result, and as a result, it was possible to identify non-uniform and reduced size metal flakes.

The smaller size and the gaps in the metal flakes become resistance elements that prevent the flow of conduction, so that good conductivity cannot be obtained.

The milling time in the production of metal flakes was good even if the milling time was within 0.7 to 1 hour even if the metal particles such as aluminum and copper were different.

Example 2

According to the method proposed in the present invention as an additive, the carbon nanotube and the metal particles were mixed, and mechanical impact energy was applied by using a mechanical milling method to prepare a metal-carbon nanotube composite.

Aluminum powder was used as the metal particles, and a mixture of carbon nanotubes and aluminum particles was milled by a ball milling method.

FIG. 4 is an actual view taken with a scanning electron microscope of the shape change of the composite according to the mechanical milling time in manufacturing the aluminum-carbon nanotube composite.

When mechanical impact energy is applied to the metal particles by the mechanical milling method, the metal particles (aluminum particles) cause elastic deformation or plastic deformation, and carbon nanotubes penetrate into the metal particles whose shape is deformed. As shown in the photograph, when the mechanical milling time is 1 hour, the length in which the carbon nanotubes 20 are inserted into the deformed metal particles 10 and the length of the non-insertion of the metal nanoparticles 10 can be appropriately implemented, thereby realizing the desired characteristics. .

However, when the mechanical milling time is longer than 1 hour as shown in the photographs of 2), 3) and 4), the carbon nanotubes are completely inserted into the metal particles 10 and thus do not play a conductive role.

The milling time in the production of aluminum-carbon nanotubes, even if the metal particles such as aluminum and copper were different within 0.5 to 1 hour, good results were obtained regardless of the milling method.

Example 3

The metal-polymer composite was prepared by mixing the metal particles with the solid polymer particles as an additive and applying mechanical impact energy using a mechanical milling method.

Aluminum powder was used as the metal particles, polycarbonate (PC) particles were used as the solid polymer material, and a mixture of the metal particles and the polymer material was milled by a ball milling method.

In preparing the additive, the metal particles (aluminum particles) were 6 vol.% Based on the total volume of the polymer particles, and the milling time was 3 hours.

When milling by applying mechanical impact energy in a state in which the two materials are mixed, an additive of a metal-polymer composite having metal particles (metal powder) bonded to the surface of the polymer particles is made.

FIG. 5 is an optical view showing the shape of the metal-polymer composite prepared by the mechanical milling method using an optical microscope. Particularly, after the additive of the metal-polymer composite is prepared, the additive is added to a liquid polymer resin. It is a photograph taken of the solid conductive composite prepared by dispersing by mechanical dispersion method and then molded by one-way pressing method, and showing the dispersion state of the metal-polymer composite used as an additive in the conductive composite.

Referring to FIG. 5, although the size of the polymer particles 30 is not uniform, it can be seen that the polymer particles 30 bonded to the surface of the metal particles 10 are dispersed in a matrix, and the metal is not more than 3 hours in milling time. It can also be confirmed that the particles can be produced in a composite material bonded to the surface of the polymer particles.

Example 4

The carbon nanotube-polymer composite was prepared by mixing solid polymer particles with carbon or nanotubes as an additive and applying mechanical impact energy using a mechanical milling method.

Polycarbonate (PC) particles were used as the solid polymer material, and a mixture of the polymer material and the carbon nanotubes was milled by a ball milling method.

When milling by applying mechanical impact energy in a state in which the two materials are mixed, an additive of a carbon nanotube-polymer composite in which carbon nanotubes are bonded to the surface of the polymer particles or partially inserted into the polymer particles is made.

6 is a photogram taken by scanning electron microscopy of the shape change of the composite material according to the content of the carbon nanotubes in the production of carbon nanotube-polymer composites using a mechanical milling method.

When the mechanical milling time is 12 hours or more, it can be confirmed through FIG. 6 that a carbon nanotube-polymer composite material in which carbon nanotubes are bonded or partially inserted into the surface of solid monomolecules and polymer particles is possible.

In addition, as a result of observing the composite surface shape according to the content of the carbon nanotubes through Figure 6, the picture of 1) is the case of the content of the carbon nanotubes 3 wt.%, The carbon nanotubes inside the solid polymer (PC) It can be seen that 20 is almost inserted so that the remaining uninserted portion is compressed to the surface under mechanical impact energy.

The photo of 2) shows that the content of the carbon nanotubes is 4 wt.%, And that the carbon nanotubes 20 are more firmly compressed on the particle surface than in the case of 1).

Photograph 3 shows that the content of carbon nanotubes is 5 wt.%. After the carbon nanotubes 20 are inserted into the polymer, the remaining carbon nanotubes 20 are bonded to the surface.

The photo of 4) shows that the content of carbon nanotubes is 8 wt.%, And more residual carbon nanotubes 20 are bonded to the surface than in the case of 3).

Example 5

The metal-aluminum-polymer composite prepared by mixing the metal (aluminum) -polymer composite prepared in Example 3 with the carbon nanotube according to the method of the present invention as an additive and then applying mechanical impact energy using a mechanical milling method Was prepared.

Here, the mixed material of the metal-polymer composite and carbon nanotubes was milled by a ball milling method.

When the milling is applied with mechanical impact energy while the two materials are mixed, additives of the metal-carbon nanotube-polymer composite, in which carbon nanotubes are coated on the metal-polymer composite surface and bonded or partially inserted into the metal-polymer composite, Is made.

FIG. 7 is an optical view taken with an optical microscope of the shape of the metal-carbon nanotube-polymer composite prepared by the mechanical milling method.

When the mechanical milling time is 12 hours or more, it can be seen from FIG. 7 that it is possible to produce a metal-carbon nanotube-polymer composite in which carbon nanotubes are bonded or partially inserted into the metal-polymer composite surface.

Example 6

According to the method of the present invention, the metal particles and the metal flakes of Example 1 are mixed in a weight ratio of 1: 1, and then the mixture is introduced into a liquid polymer matrix, and then dispersed by a mechanical dispersion method, so that the liquid and Solid phase conductive composites were prepared.

The change in thermal conductivity according to the shape of the mixture of 'metal particles + metal flakes' used as a composite additive in the polymer matrix and the amount of 'metal particles + metal flakes' added is explained through Table 1 and FIG. do.

As a composite additive, a mixture of the 'metal particles + metal flakes' was added to an unsaturated polyester resin (UPR) to prepare a conductive composite, and 20 to 40 vol.% Of the total volume of the resin was added (usually an additive of 40 As a result of measuring the thermal conductivity according to the vol.%), it was confirmed that the measurement result was improved than that of the existing unsaturated polyester resin.

8 is a photogram of the mixed material of the metal particles and the metal flakes dispersed in the polymer matrix, and the mixed shape is taken with an optical microscope.

Metallic foil using the property that the additive of the spherical metal particles 10 is uniformly dispersed in the matrix 40, and that the additive of the metal foil 12 is aligned and dispersed in a predetermined direction in the matrix 40, mostly By dispersing the metal particles 10 between the (12) to strengthen the connection between the additives in the base 40, it can be seen through Figure 8 that the disadvantages of the single additive can be compensated.

Example 7

According to the method proposed in the present invention, the metal particles, the metal flakes of Example 1, and the metal-carbon nanotube composite of Example 2 were mixed in a weight ratio of 2: 1: 1, and then the mixture was mixed with a liquid polymer matrix. And then dispersed by mechanical dispersion to prepare liquid and solid conductive composites.

The shape of the mixture of 'metal particles + metal flakes + metal-carbon nanotube composites' used as a composite additive in the polymer matrix and the thermal conductivity according to the addition amount of 'metal particles + metal flakes + metal-carbon nanotube composite' The change will be described with reference to Table 2 below and FIG. 9.

As a composite additive, a mixture of the 'metal particles + metal flakes + metal-carbon nanotube composite' was added to an unsaturated polyester resin (UPR) to prepare a conductive composite, and 20 to 40 vol.% Of the total volume of the resin was added. As a result of measuring the thermal conductivity according to the result, it was confirmed that the measurement result is improved than the thermal conductivity of the existing unsaturated polyester resin.

9 is a photogram of the mixed particles of the metal particles, the metal flakes, and the metal-carbon nanotube composite in the polymer matrix, and the mixed shapes are taken with an optical microscope.

The additives of the spherical metal particles 10 and the disc-shape metal-carbon nanotube composite material 14 are uniformly dispersed in the matrix 40, and the additives of the metal foil 12 By using the property of being mostly aligned in a predetermined direction and dispersed in the base 40, by dispersing the metal particles 10 between the metal flakes 12 to strengthen the connection between the additives in the base, the disadvantages of a single additive can be compensated It can be confirmed through Figure 9.

Comparative example  One

A conductive composite was prepared using a single additive, wherein the additive of the metal flake of Example 1 was introduced into a liquid polymer matrix and then dispersed by a mechanical dispersion method to prepare a liquid and solid conductive composite.

The shape of the metal flakes used as the additive mixed in the polymer matrix and the change in thermal conductivity according to the amount of the metal flakes added will be described with reference to Table 3 and FIG. 10.

In Example 1, an additive of an aluminum flake prepared using aluminum was added to an unsaturated polyester resin (UPR) to prepare a conductive material, and the thermal conductivity was measured according to the addition amount of 20 to 40 vol.% Based on the total volume of the resin. As a result, the measurement result was improved than the thermal conductivity of the existing unsaturated polyester resin, but the degree of improvement was so small that satisfactory characteristics were not obtained.

10 is a photogram taken with an optical microscope of the shape of the additive of the metal flakes dispersed in the polymer matrix.

The metal foil 12 is dispersed in most of the substrate 40 while being aligned in a predetermined direction, so that the network is not well formed between the additives, and it can be confirmed through FIG. 10 that the flow path of direct conduction is not sufficiently secured.

This hindered the flow of evangelism, making it difficult to expect outstanding effects.

Comparative Example 2

A conductive composite was prepared using a single additive, wherein the additive of the metal-carbon nanotube composite of Example 2 was charged into a polymer matrix of a liquid phase, and then dispersed by a mechanical dispersion method to prepare a liquid and solid conductive composite. .

The shape of the metal-carbon nanotube composite used as an additive mixed in the polymer matrix and the change in thermal conductivity according to the amount of the metal-carbon nanotube composite added are described with reference to Table 4 below and FIG. 11.

The conductive material was prepared by adding the aluminum-carbon nanotube composite prepared in Example 2 to an unsaturated polyester resin (UPR) and measuring the thermal conductivity according to the addition amount of 20 to 40 vol.% Relative to the total volume of the resin. Although the measurement result was improved than the thermal conductivity of the existing unsaturated polyester resin, it rose slightly to a lower level than Comparative Example 1.

FIG. 11 is an optical view taken with an optical microscope of a shape in which an additive of a metal-carbon nanotube composite is dispersed in a polymer matrix. FIG.

As a result of observing the shape of the metal-carbon nanotube composite material 14 dispersed in the matrix 40, it can be seen from FIG. 11 that the connection between the additives is lower than that of the additive of the metal flake of Comparative Example 1, and eventually, the additives It can be seen that the lower the connection, the lower the thermal conductivity.

On the other hand, Figure 12 is a graph showing a change in the thermal conductivity of the conductive material according to the volume content of the additives in the monomolecular and polymer matrix according to the present invention, referring to Example 6 ('Al Flake + Al Spherical') And it can be seen that the thermal conductivity of Example 7 ('Al Flake + Al Spherical + Al-CNTs') is significantly improved compared to the thermal conductivity of Comparative Example 1 ('Al Flake') and Comparative Example 2 ('Al-CNTs') Can be.

In addition, electrical conductivity was measured for the conductive composites prepared in Example 7 and Comparative Examples 1 and 2, and the change in electrical conductivity according to the volume content of the additive in the polymer matrix was shown in Table 5 below.

As a result of measuring the electrical conductivity of the conductive composites prepared in Example 7 and Comparative Examples 1 and 2 according to the additive content (20 to 40 vol.%), It was confirmed that the electrical conductivity was greatly improved in the case of Example 7. Could.

Composite material of Comparative Example 1 prepared using only the metal foil convenience single additive was lower conductivity as not be able to measure the electrical conductivity of the conductive composite material of Example 7 was added to the carbon nanotube is confirmed that the electric conductivity of 10 ² Improved Could.

As described above, according to the conductive composite according to the present invention and a method for manufacturing the same, metal particles, metal flakes, metal-nanofiber composites, metal-polymer composites, nanofiber-polymer composites, metal-nanofiber-polymer composites and By dispersing two or three or more various additives selected from the nanofibers in the matrix, it is possible to manufacture a composite material having further improved conductivity by securing a flow path of direct thermal and electrical conduction between the additives. It is possible to effectively solve the problem of connectivity between the additives in the matrix, which has been a problem in the conventional conductive material.

When manufacturing a conductive material utilizing the properties of various additives as in the present invention can be expected to improve the mechanical properties in addition to the improvement of thermal conductivity and electrical conductivity.

In addition, since the dispersion process is dependent on mechanical energy, there is an advantage that the manufacturing process is simplified, and thus, an improvement in production efficiency can be expected in an industrial aspect. As the necessity of excellent conductive polymer material is expanded in the modern industry, economical process development is absolutely required, and the present invention can not only dramatically improve the current industrial process, but also when using the present invention, airplanes and electronic materials In the field, you can expect a dramatic effect.

By using various additives in combination with the properties as in the present invention, it is possible to prepare liquid and solid conductive materials having improved conductivity without being affected by the properties of single molecules and polymers and subsequent processing. Industrial applications can be greatly expanded.

The monomolecular and polymer matrix conductive composites prepared by the present invention can be usefully applied to the prevention of lightning strikes or secondary batteries in airplanes, and are used in various industrial fields such as constant temperature heaters, thermal sensors, overcurrent control and low current circuit protectors, and electromagnetic interference shielding. It can be applied to.

Claims (18)

delete delete delete delete delete delete delete delete delete delete delete delete Metal flakes as an essential component and metal particles; Metal-nanofiber composites; Metal-polymer composites; Nanofiber-polymer composites; Metal-nanofiber-polymer composites; Nanofibers or nanotubes; Conductive composite material, characterized in that the additive made of one or more of the metal flakes is mixed and dispersed in the liquid monomolecule and the polymer matrix. The method according to claim 13, The metal-nanofiber composite is mechanically milled in a state where metal particles and nanofibers or nanotubes are mixed so that the nanofibers or nanotubes are penetrated into the metal particles. The method according to claim 13, The metal-polymer composite is mechanically milled in a state in which metal particles are mixed with solid monomolecules and polymer particles, and the conductive composites are bonded while metal particles are coated on the surface of the monomolecules and polymer particles. The method according to claim 13, The nanofiber-polymer composite is mechanically milled in a state in which nanofibers or nanotubes are mixed with solid monomolecules and polymer particles, and bonded or partially inserted while nanofibers or nanotubes are coated on the surface of the monomolecules and polymer particles. Conductive composite, characterized in that. The method according to claim 15 or 16, The solid monomer and polymer particles are any one of a thermoplastic resin, a thermosetting resin, an elastomer and a thermoplastic elastomer. The method according to claim 13, The metal-nanofiber-polymer composite is mechanically milled in a state where nanofibers or nanotubes are mixed with the metal-polymer composite, and is bonded or partially inserted while nanofibers or nanotubes are coated on the metal-polymer composite surface. Characterized by a conductive composite.

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