KR20180034149A - Conductive film and manufacturing method of the same - Google Patents

Abstract

Provided is a conductive film which contains a thermoplastic resin and a conductive material, wherein the content of the conductive material is at least 65 wt% or more. Moreover, provided is a production method thereof. According to the present invention, it is possible to secure excellent and uniform electrical conductivity.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a conductive film,

Conductive film and a method of manufacturing the same.

These properties can easily be imparted by attaching conductive films to components or products that generally require conductive properties. Conductive property is a so-called electric conductivity, which means that heat or electricity can move through a predetermined substance or object, which can be used to give various performances such as, for example, antistatic performance, heat radiation performance and the like.

In general, a film having conductive properties is molded into a film by extruding a polymer resin and a conductive material into an extruder.

However, when a product such as a film is molded by using the extruder, the viscosity of the molten polymer resin including the conductive material increases during extrusion processing, so that a high pressure is generated in the discharging portion, In addition, there is a problem that the viscoelasticity increases and processing is not smoothly performed in a desired form, or the defect rate increases.

In one embodiment of the present invention, there is provided a conductive film capable of realizing excellent yet uniform electrical conductivity and capable of re-molding.

In another embodiment of the present invention, there is provided a method of manufacturing a conductive film which can achieve excellent yet uniform electrical conductivity and can be re-formed.

However, the technical problem to be solved by the present invention is not limited to the above-mentioned problems, and other matters not mentioned can be clearly understood by those skilled in the art from the following description.

In one embodiment of the invention, there is provided a conductive film comprising a thermoplastic resin and a conductive material, wherein the content of the conductive material is at least 65% by weight or more.

The conductive film can be re-formed using a thermoplastic resin, and at the same time, as described in another embodiment of the present invention, a mixture containing the conductive film in the form of powder is molded by a press die to produce a conductive material having a higher content But also there is an advantage that the dispersibility can be realized at a superior level because there is little possibility of aggregation or aggregation.

As a result, the electroconductive film can provide excellent but uniform electrical conductivity, and can be re-molded, and since it does not use an organic solvent in the manufacturing process, excellent eco-friendliness and safety can be achieved.

The conductive film may have an average electrical conductivity of about 0.1 X ¹⁰ S / cm to about 5 X 10 ² S / cm.

By having a high average electric conductivity within the above range, for example, when it is applied to an antistatic film or a heat radiation film, its performance can be further improved.

In one embodiment, the relative standard deviation (RSD) of the electrical conductivity for the conductive film can be, for example, about 15% or less, and specifically about 0% to about 10%.

As described above, the relative standard deviation is calculated to the small range, as described above, so that the conductive film has an advantage that it can realize a more uniform level of electrical conductivity as a whole on one side thereof.

In another embodiment of the present invention, there is provided a method for producing a thermoplastic resin composition, comprising: (S1) preparing a thermoplastic resin powder; (S2) mixing the thermoplastic resin powder and the solid conductive material to prepare a mixture containing at least 65 wt% of the conductive material; And (S4) fabricating a conductive film by applying heat and pressure to the mixture.

In the above manufacturing method, a conductive film is produced by using a mixture of a thermoplastic resin in the form of powder and a conductive material, so that the conductive film can be re-molded and heat and pressure can be applied without using an extruder Since the conductive film can be manufactured, there is an advantage that the conductive material can be contained in a high content.

Each thermoplastic resin particle forming the thermoplastic resin powder may have an average diameter of, for example, about 1 탆 to about 500 탆, and specifically about 10 탆 to about 50 탆.

By having a small diameter within the above range, the conductive material can be more uniformly mixed with the conductive material, thereby realizing excellent dispersibility.

The electrically conductive film and the method of manufacturing the same may achieve excellent but uniform electrical conductivity and re-formability.

1 is a schematic process flow diagram of a method for manufacturing an electrically conductive film according to another embodiment of the present invention.

In the present specification, it is to be understood that when certain embodiments and / or certain components included therein are referred to as "comprising ", it is understood that they do not exclude other components, It can mean that it can include more.

Hereinafter, the formation or position of any structure in the top (or bottom) or top (or bottom) of the substrate means that any structure is formed or positioned in contact with the top (or bottom) But is not limited to not including other configurations between the substrate and any structure formed on (or under) the substrate.

As used herein, the term " step "or" step "does not mean " step for.

As used herein, the terms "about", "substantially", and the like are used herein to refer to the manufacturing and material tolerances inherent in the meanings mentioned, May be used to prevent unauthorized exploitation by an unscrupulous infringer of precise or absolute disclosures in order to aid in the disclosure.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, which will be readily apparent to those skilled in the art to which the present invention pertains. It should be understood, however, that the present invention may be embodied in many different forms and should not be construed as limited to the exemplary embodiments set forth herein.

In one embodiment of the invention, there is provided a conductive film comprising a thermoplastic resin and a conductive material, wherein the content of the conductive material is at least 65% by weight or more.

Typically, a film having conductive properties is produced as a film by extruding a raw material in the form of a pellet formed from a thermoplastic resin and a conductive material into an extruder, or by thermally curing a conductive composition containing a thermosetting resin and a conductive material.

When the film is produced using an extruder, if the content of the conductive material is high, the molten raw material is stuck to the extruder during the extrusion process and the processing is not smoothly performed or the defective ratio is increased. Therefore, the conductive material can not be contained in a high content When a thermosetting resin is used, there is a problem in that it can not be melted again after the molding is completed, so that it is impossible to re-mold.

In addition, conductive compositions include organic solvents, which are environmentally harmful.

Accordingly, in one embodiment of the present invention, the conductive film can be remolded using a thermoplastic resin. At the same time, as described in another embodiment of the present invention, a mixture containing the conductive film in the form of powder is pressed by a press die The conductive material can be contained in a higher amount, and there is no fear of aggregation or aggregation, so that the dispersibility of the conductive material can be realized at an excellent level.

As a result, the electroconductive film can provide excellent but uniform electrical conductivity and can be remolded.

In addition, since no organic solvent is used in the manufacturing process, excellent environmental friendliness and safety can be achieved.

The conductive film may include a thermoplastic resin.

Accordingly, the conductive film not only realizes excellent flexibility but also can be re-molded according to a predetermined case, so that the conductive film can be recycled for various purposes without increasing the cost.

The thermoplastic resin may be, for example, a polyurethane resin, a polyester resin, a phenol resin, an acrylic resin, a polysiloxane resin, a polystyrene resin, a polyvinyl resin, a polyether amide resin, a cellulose acetate resin, a styrene acrylonitrile resin, Nitrile resin, ethylene vinyl acetate resin, ethylene acrylate resin, and combinations thereof, and may specifically include a polyurethane resin.

The polyurethane resin in the thermoplastic resin can be made by, for example, conducting a polymerization reaction on a composition comprising a diisocyanate compound, a polyol, and optionally a chain extender.

Examples of the diisocyanate compound include 1,4-butylene diisocyanate, 1,6-hexamethylene diisocyanate, cyclopentylene 1,3-diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, Isophorone diisocyanate, cyclohexylene 1,4-diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate. A mixture of isomers of 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate, 4,4'-methylenebis (phenyldiisocyanate), 2,2-diphenylpropane, 4,4'-diisocyanate , p-phenylene diisocyanate, m-phenylene diisocyanate, xylene diisocyanate, 1,4-naphthylene diisocyanate, and combinations thereof, but is not limited thereto No.

Examples of the polyol include polyols such as 1,2-ethanediol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, But are not limited to, at least one selected from the group consisting of 1,4-cyclohexanediol, ethylene glycol, propylene glycol, glycerol, and combinations thereof.

The chain extender may be of any kind known in the art without any particular limitation.

The thermoplastic resin may, for example, comprise less than about 35 weight percent, and may also include, for example, from about 5 weight percent to about 30 weight percent, but is not limited thereto.

The conductive film may include a conductive material in an amount of at least 65 wt% or more.

Specifically, the conductive material may be included in an amount of about 70% by weight to about 95% by weight, thereby effectively improving the electrical conductivity. For example, when the conductive film is applied as an antistatic film, It is possible to realize excellent antistatic performance, and furthermore, when it is applied to, for example, a heat radiation film, it is possible to realize a better heat radiation performance.

The conductive material may be, for example, in the form of particles, and the average diameter thereof may be about 1 [mu] m to about 100 [mu] m.

In addition, the conductive material may include at least one selected from the group consisting of, for example, a metal, graphite, graphene, carbon nanotube, and combinations thereof, and specifically includes graphite, Can be implemented.

The conductive film may further include at least one additive selected from the group consisting of a pigment, an antioxidant, a UV stabilizer, a defoamer, a thickener, a flame retardant, a coupling agent, a foaming agent, It is not limited.

The conductive film may have a thickness of about 50 탆 to about 2000 탆. By having the thickness within the above range, the mechanical properties such as durability required for the conductive film can be sufficiently realized without increasing the total thickness thereof excessively.

In the present specification, each electric conductivity described below can be measured by, for example, a 4 minute probe method, but is not limited thereto.

The conductive film may have an average electrical conductivity of about 0.1 X ¹⁰ S / cm to about 5 X 10 ² S / cm.

By having a high average electric conductivity within the above range, the performance of the antistatic film or the heat dissipation film can be further improved, for example, as described above.

In one embodiment, the relative standard deviation (RSD) of the electrical conductivity for the conductive film can be, for example, about 15% or less, and specifically about 0% to about 10%.

The relative standard deviation (RSD,%) can be calculated, for example, according to the following equation:

[Equation 1]

) Ⅹ 100Relative standard deviation (RSD) = standard deviation (S) / average (

) Ⅹ 100

The relative standard deviation may be an arbitrary point on the entire surface of the conductive film and may indicate the degree of difference between the electric conductivities at the respective points so that the electric conductivity of the conductive film becomes smaller as the relative standard deviation becomes smaller More uniformity can be shown.

) 및 상기 표준편차(S)은 이 기술분야에서 공지된 방법에 따라 계산될 수 있고, 예를 들어, 하기 계산식 2 및 3에 따라 각각 계산될 수 있다:The average (

) And the standard deviation S may be calculated according to methods known in the art and may be calculated respectively according to the following equations 2 and 3, for example:

[Equation 2]

, S/cm) = (x₁+x₂+ +X_n)/nAverage(

, S / cm) = (x 1 + x 2 + + X n) / n

[Equation 3]

In the above equations, x ₁ , x ₂ , and X _n mean electrical conductivity at a predetermined point arbitrarily selected from the entire one surface of the conductive film, and n can mean the number of points.

 As described above, the relative standard deviation is calculated to the small range, as described above, so that the conductive film has an advantage that it can realize a more uniform level of electrical conductivity as a whole on one side thereof.

Fig. 1 schematically shows a process flow chart of a method for producing a conductive film according to another embodiment of the present invention.

The manufacturing method includes: (S1) preparing a thermoplastic resin powder; (S2) mixing the thermoplastic resin powder and the solid conductive material to prepare a mixture containing at least 65 wt% of the conductive material; And (S4) applying heat and pressure to the mixture to produce a conductive film.

The conductive film described above in one embodiment can be produced by the above production method.

In the above manufacturing method, a conductive film is produced by using a mixture of a thermoplastic resin in the form of powder and a conductive material, so that the conductive film can be re-molded and heat and pressure can be applied without using an extruder Since the conductive film can be manufactured, there is an advantage that the conductive material can be contained in a high content.

When a conductive film is formed by using a conventional extruder, if a molten raw material containing a high content of conductive material is used, the viscosity of the molten raw material is high, resulting in a problem of sticking to the extruder, Respectively.

That is, unlike the case where a film is formed by conventional extrusion processing, the above-mentioned manufacturing method uses a mixture of a solid phase containing a thermoplastic resin in powder form as a raw material and applies heat and pressure without using an extruder, It is possible to form a film stably, and there is less fear that the film is aggregated or aggregated with each other, so that the dispersibility of the film can be realized at an excellent level.

In addition, since no organic solvent is used in the manufacturing process, excellent environmental friendliness and safety can be achieved.

In the above production method, a thermoplastic resin powder can be prepared, and the thermoplastic resin is as described above in one embodiment.

The thermoplastic resin powder may be prepared by a method known in the art and may be prepared by any method known in the art including, for example, powder slush molding, spray drying, hydrogrinding, ball milling, cryogenic grinding ) Method, but is not limited thereto.

Each thermoplastic resin particle forming the thermoplastic resin powder may have an average diameter of, for example, about 1 탆 to about 500 탆, and specifically about 10 탆 to about 50 탆.

In the present specification, the average diameter of the particles can be measured using a TEM / SEM apparatus or a particle size analyzer, but is not limited thereto.

By having a small diameter within the above range, the conductive material can be more uniformly mixed with the conductive material, thereby realizing excellent dispersibility.

In the above production method, the thermoplastic resin powder and the solid phase conductive material may be mixed to prepare a mixture containing at least 65 wt% of the conductive material, for example, about 70 wt% % To about 95% by weight. The conductive material is as described above in one embodiment.

Further, the mixture does not contain a solvent. The solvent includes all kinds known in the art, for example, organic solvents and the like.

As described above, unlike a conventional method in which a conductive film is produced by an extruder using a pellet-shaped raw material, a mixture of a powdery thermoplastic resin and a conductive material is mixed with a mixture containing only a solid phase material, And pressure, it is possible to realize excellent processability, low defect rate and excellent dispersibility, thereby realizing even higher electrical conductivity at a uniform level.

The electrical conductivity of the conductive film can be effectively improved by preparing the conductive material to have a high content within the above range. For example, when the conductive film is applied as the antistatic film, more excellent antistatic performance can be realized In addition, when applied to, for example, a heat-radiating film, a superior heat-radiating performance can be realized.

The thermoplastic resin powders may be mixed to include, for example, less than about 35 weight percent, and may also be mixed to include, for example, from about 5 weight percent to less than about 30 weight percent.

In one embodiment, the mixture can be mixed using a homogenizer or a ball mill apparatus, thereby achieving even better dispersibility.

Further, in the above production method, heat and pressure may be applied to the mixture to produce a conductive film.

For example, when heat and pressure are applied to the mixture, the thermoplastic resin powder is melted, and when the application of heat and pressure is subsequently terminated and dried or cooled, the melted thermoplastic resin is hardened again, A film of a thermoplastic resin material in which the conductive material is uniformly impregnated can be produced.

In the step of producing the conductive film, the heat and pressure are applied using a plate-shaped press die and not applied using an extruder. The press mold may be a hot press mold.

The mixture may be placed in a plate-shaped press mold and heat and pressure may be applied thereto to produce the conductive film.

When the extruder is used, the pellet-shaped raw material is added to produce a film. If the content of the conductive material is high, it is difficult to form the raw material in the form of pellets. In addition, since the viscosity of the raw material is high during melting, It is impossible or the equipment may be damaged.

Accordingly, in another embodiment, as described above, by using the thermoplastic resin in the form of powder and applying the heat and pressure using the plate-shaped press die, the conductive material including the conductive material containing a high amount of the conductive material The film can be easily produced.

For the mixture, heat can be applied, for example, at a temperature of from about 80 [deg.] C to about 300 [deg.] C. Also, a pressure of, for example, from about 1 MPa to about 300 MPa may be applied to the mixture.

In the preparation of the mixture, an additive comprising at least one selected from the group consisting of, for example, a pigment, an antioxidant, a UV stabilizer, a defoamer, a thickener, a flame retardant, a coupling agent, a foaming agent, But not limited to,

The conductive film may be manufactured to have a thickness of about 50 탆 to about 2000 탆. By making the thickness within the above range, it is possible to sufficiently realize the mechanical properties such as durability required for the conductive film without increasing the total thickness thereof excessively.

The conductive film may be made to have an average electrical conductivity of about 0.1 X ¹⁰ S / cm to about 3 X 10 ² S / cm.

By having such a high average electric conductivity within the above range, the performance of the antistatic film or the heat dissipation film can be further improved, for example, as described above.

In this manufacturing method, the relative standard deviation (RSD) of the electrical conductivity for the conductive film may be made to be, for example, about 15% or less, and specifically about 0% to about 10% have.

)은 일 구현예에서 전술한 바와 같다. The relative standard deviation (RSD,%), the standard deviation (S) and the average (

) Are as described above in one embodiment.

The relative standard deviation is calculated to be in the small range, so that the conductive film has an advantage that it can realize a more uniform level of electrical conductivity as a whole on one surface.

Hereinafter, specific embodiments of the present invention will be described. However, the embodiments described below are only intended to illustrate or explain the present invention, and the present invention should not be limited thereto.

Example

Example 1 (press working, graphite content: 70% by weight)

Powders containing thermoplastic polyurethane resin particles having an average diameter of 1 to 500 mu m were prepared by the melt spray method.

Then, the mixture was prepared by mixing the powder with graphite having an average diameter of 10 mu m to 50 mu m, and the content of the graphite in the mixture was 70 wt%.

The mixture was heated and pressurized to 180 占 폚 and 200 MPa against a press mold (Carver Inc., AutoFour / 3012H) to prepare a conductive film having a thickness of 1700 占 퐉.

Example 2 (Content of graphite: 80% by weight)

A conductive film was prepared under the same conditions and in the same manner as in Example 1 except that the content of graphite in the mixture was 80 wt%.

Example 3 (content of graphite: 85% by weight)

A conductive film was produced under the same conditions and in the same manner as in Example 1, except that the graphite content in the mixture was adjusted to 85 wt%.

Comparative Example 1 (press working, graphite content: 10% by weight)

A mixture prepared by mixing 90 weight% of thermoplastic polyurethane resin powder and 10 weight% graphite in a stirrer (Brabender Mixer W 50 EHT) was prepared, and the mixture was subjected to heat and pressure in a press mold under the conditions of 180 ^° C and 200 MPa To prepare a conductive film having a thickness of 1000 mu m.

Comparative Example 2 (extrusion processing, graphite content: 65% by weight)

The conductive film was prepared under the same conditions and the same method as in Comparative Example 1 except that the pellet raw material containing 35% by weight of the thermoplastic polyurethane resin and 65% by weight of the graphite was used.

Comparative Example 3 (content of thermosetting epoxy resin and graphite: 80% by weight)

A 2,000 탆 thick conductive film was formed by applying a resin composition containing 18.2% by weight of a liquid thermosetting epoxy resin, 80% by weight of graphite, 1.8% by weight of a curing agent and an organic solvent and applying a pressure of 150 캜 and a pressure of 200 MPa, .

Experimental Example

Various properties of the conductive films according to Examples 1-3 and Comparative Examples 1-3 were evaluated and described in Table 1 below.

Experimental Example  1: Electrical conductivity and its uniformity

Measurement methods: The electrical conductivities of all the conductive films according to Examples 1-3 and Comparative Examples 1-3 were measured on the entire one surface, and the average, standard deviation, and relative standard deviation of the electrical conductivity were measured Lt; RTI ID = 0.0 > formula. ≪ / RTI >

The electrical conductivity was measured by a 4 minute probe method using a sheet resistance meter (Loresta-GP, MCP-T610).

Experimental Example  2: Reformation

Measurement method: The conductive films according to Examples 1-3 and Comparative Examples 1-3 were subjected to 180 ° C and 200 MPa pressure to observe whether they were fused to form a single film, The case where the film was formed as a single film was evaluated as being capable of re-molding and indicated as "? &Quot;, and the case of burning was evaluated as being impossible to re-mold and evaluated as " X ".

, S/cm)Average electrical conductivity
(

, S / cm) Relative standard deviation of electrical conductivity
(RSD,%) Reformation Example 1 5.3 7 ○ Example 2 48.8 8 ○ Example 3 191 4 ○ Comparative Example 1 6.3x10 ^-4 8 ○ Comparative Example 2 - - - Comparative Example 3 322 8 X

As shown in Table 1, it can be clearly expected that each of the conductive films according to Examples 1 to 3 has an excellent average electric conductivity and therefore has excellent antistatic performance and heat radiation performance, and the relative standard deviation of electrical conductivity is small It is clearly confirmed that uniform electrical conductivity can be realized and re-formation is also excellent.

On the other hand, the conductive film according to Comparative Example 1 was significantly inferior in the average electrical conductivity, and in Comparative Example 2, extrusion was difficult because of extruder, and the conductive film according to Comparative Example 3 could not be re-formed.

Claims (14)

A thermoplastic resin, and a conductive material, wherein the content of the conductive material is at least 65% by weight or more.
The method according to claim 1,
Wherein the content of the conductive material is 70 wt% to 95 wt%
Conductive film.
The method according to claim 1,
Having an average electric conductivity of 0.1 X ¹⁰ S / cm to 5 X 10 ² S / cm
Conductive film.
The method according to claim 1,
The relative standard deviation (RSD,%) of the electrical conductivity of the conductive film is not more than 15%
Conductive film.
The method according to claim 1,
The conductive material is in the form of particles and has an average diameter of 1 to 100 mu m
Conductive film.
The method according to claim 1,
Wherein the conductive material comprises at least one selected from the group consisting of metal, graphite, graphene, carbon nanotube, and combinations thereof
Conductive film.
Preparing a thermoplastic resin powder;
Preparing a mixture containing at least 65 wt% of the conductive material by mixing the thermoplastic resin powder and the solid phase conductive material; And
Applying heat and pressure to the mixture to form a conductive film;
≪ / RTI >
8. The method of claim 7,
The mixture is prepared to contain 70 wt% to 95 wt% of the conductive material
A method for producing a conductive film.
8. The method of claim 7,
Each of the thermoplastic resin particles forming the thermoplastic resin powder has an average diameter of 1 to 500 mu m
A method for producing a conductive film.
8. The method of claim 7,
The conductive film is made to have an average electric conductivity of 0.1 X ¹⁰ S / cm to 3 X 10 ² S / cm
A method for producing a conductive film.
8. The method of claim 7,
And the relative standard deviation (RSD) of the electrical conductivity for the conductive film is 15% or less
A method for producing a conductive film.
8. The method of claim 7,
In the step of producing the conductive film, the heat and pressure are applied using a press mold of a plate shape, and not applied using an extruder
A method for producing a conductive film.
13. The method of claim 12,
Applying heat at a temperature of 80 < 0 > C to 300 &
A method for producing a conductive film.
14. The method of claim 13,
Applying a pressure of from 1 MPa to 300 MPa
A method for producing a conductive film.

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