KR20170088234A - Anisotropic thermally conductive film, laminate sheet using same and method of preparing same - Google Patents
Anisotropic thermally conductive film, laminate sheet using same and method of preparing same Download PDFInfo
- Publication number
- KR20170088234A KR20170088234A KR1020160008366A KR20160008366A KR20170088234A KR 20170088234 A KR20170088234 A KR 20170088234A KR 1020160008366 A KR1020160008366 A KR 1020160008366A KR 20160008366 A KR20160008366 A KR 20160008366A KR 20170088234 A KR20170088234 A KR 20170088234A
- Authority
- KR
- South Korea
- Prior art keywords
- polyamic acid
- film
- organic solvent
- porous
- acid solution
- Prior art date
Links
Images
Classifications
-
- C08J7/047—
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B38/00—Ancillary operations in connection with laminating processes
- B32B38/08—Impregnating
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B9/00—Layered products comprising a layer of a particular substance not covered by groups B32B11/00 - B32B29/00
- B32B9/005—Layered products comprising a layer of a particular substance not covered by groups B32B11/00 - B32B29/00 comprising one layer of ceramic material, e.g. porcelain, ceramic tile
- B32B9/007—Layered products comprising a layer of a particular substance not covered by groups B32B11/00 - B32B29/00 comprising one layer of ceramic material, e.g. porcelain, ceramic tile comprising carbon, e.g. graphite, composite carbon
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B9/00—Layered products comprising a layer of a particular substance not covered by groups B32B11/00 - B32B29/00
- B32B9/04—Layered products comprising a layer of a particular substance not covered by groups B32B11/00 - B32B29/00 comprising such particular substance as the main or only constituent of a layer, which is next to another layer of the same or of a different material
- B32B9/045—Layered products comprising a layer of a particular substance not covered by groups B32B11/00 - B32B29/00 comprising such particular substance as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G73/00—Macromolecular compounds obtained by reactions forming a linkage containing nitrogen with or without oxygen or carbon in the main chain of the macromolecule, not provided for in groups C08G12/00 - C08G71/00
- C08G73/06—Polycondensates having nitrogen-containing heterocyclic rings in the main chain of the macromolecule
- C08G73/10—Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
- C08G73/1003—Preparatory processes
- C08G73/1007—Preparatory processes from tetracarboxylic acids or derivatives and diamines
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
- C08J5/18—Manufacture of films or sheets
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
- C09D179/00—Coating compositions based on macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing nitrogen, with or without oxygen, or carbon only, not provided for in groups C09D161/00 - C09D177/00
- C09D179/04—Polycondensates having nitrogen-containing heterocyclic rings in the main chain; Polyhydrazides; Polyamide acids or similar polyimide precursors
- C09D179/08—Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B37/00—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding
- B32B37/14—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding characterised by the properties of the layers
- B32B37/24—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding characterised by the properties of the layers with at least one layer not being coherent before laminating, e.g. made up from granular material sprinkled onto a substrate
- B32B2037/243—Coating
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2313/00—Elements other than metals
- B32B2313/04—Carbon
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Materials Engineering (AREA)
- Health & Medical Sciences (AREA)
- Ceramic Engineering (AREA)
- Polymers & Plastics (AREA)
- Manufacturing & Machinery (AREA)
- Wood Science & Technology (AREA)
- Life Sciences & Earth Sciences (AREA)
- Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)
- Laminated Bodies (AREA)
Abstract
Description
The present invention relates to an anisotropic heat conductive film and a method of manufacturing the same, and more particularly, to an anisotropic heat conductive film comprising the steps of: (1) preparing a polyamic acid solution by mixing polyamic acid (PAA) prepared by reacting dianhydride with an organic solvent; (2) coating the polyamic acid solution on one side of the release film; (3) immersing and curing the coated release film in a mixture of water and the organic solvent, wherein the concentration of the organic solvent in the mixed solution is lower than the concentration of the organic solvent in the polyamic acid solution; And (4) drying the coated release film. By controlling the size and density of the pores while maintaining excellent thermal conductivity in the horizontal direction, the porous polyamic acid film selectively has a thermal conductivity in the vertical direction The present invention also relates to an anisotropic heat conductive film and a method of manufacturing the same.
[0002] With the recent trend toward higher performance and slimmer and thinner electrical and electronic devices, demand for heat-radiating sheets capable of effectively dissipating heat generated from heat sources such as semiconductor components and light emitting parts built therein has been steadily increasing. The release of heat generated by the heat source is important because it is closely related to the reliability and service life of electrical and electronic equipment, and various heat-radiating materials capable of efficiently emitting heat have been developed.
As the heat dissipation material, heat dissipation pads, heat dissipation sheets, heat dissipation paints, and the like have been developed and supplemented or replaced existing heat dissipation fans, heat dissipation fins, and heat founts.
Particularly, the heat-radiating sheet is manufactured in the form of a graphite sheet, a polymer-ceramic composite sheet, a multilayer coating metal thin film sheet, and the like. In addition to the thermal conductivity in the horizontal direction (that is, The heat radiation sheet having excellent heat conductivity is developed.
However, in recent years, there has been a tendency to reduce the thermal conductivity in the vertical direction while maintaining an excellent thermal conductivity in the horizontal direction, as the types and usage times of electronic devices directly contacting the user's skin have increased recently, Demand is increasing. In fact, when the smartphone is used for a long period of time, the internal temperature rises above 45 ° C, and heat is conducted in the vertical direction, which causes the user to directly feel the skin.
However, in the case of conventional heat dissipation materials, in general, when the thermal conductivity in the vertical direction is lowered, not only the thermal conductivity in the horizontal direction is lowered, but also the thermal conductivity in the vertical direction is difficult to control There is a problem.
Accordingly, an object of the present invention is to provide a method and apparatus for selectively reducing the thermal conductivity in the vertical (i.e., thickness direction) direction while controlling the size and density of the pores while maintaining an excellent thermal conductivity in the horizontal And an object of the present invention is to provide an anisotropic heat conductive film capable of controlling the thermal conductivity in the vertical direction, a laminated sheet using the same, and a method of manufacturing the same.
In order to achieve the above object, the present invention provides a method for producing a polyamic acid solution, comprising the steps of: (1) preparing a polyamic acid solution by mixing polyamic acid (PAA) prepared by reacting dianhydride with an organic solvent; (2) coating the polyamic acid solution on one side of the release film; (3) immersing and curing the coated release film in a mixture of water and the organic solvent, wherein the concentration of the organic solvent in the mixed solution is lower than the concentration of the organic solvent in the polyamic acid solution; And (4) drying the coated release film. The present invention also provides a method for producing a porous polyamic acid film.
The present invention also provides a process for producing a porous polyimide film comprising the step of imidizing the porous polyamic acid film.
In addition, the present invention provides a method for producing a porous graphite film, comprising carbonizing and graphitizing the porous polyimide film.
The anisotropic heat conductive film of the present invention can reduce the thermal conductivity in the vertical direction while maintaining the excellent thermal conductivity in the horizontal direction by including the pores therein and also can control the size and density of the inner pores and the like, There is an advantage that the thermal conductivity of the heat sink can be controlled.
1 schematically shows a method for producing a porous polyamic acid film, a porous polyimide film and a porous graphite film according to the present invention.
(1) preparing a polyamic acid solution by mixing polyamic acid or PAA prepared by reacting dianhydride with dianhydride in an organic solvent; (2) coating the polyamic acid solution on one side of the release film; (3) immersing and curing the coated release film in a mixture of water and the organic solvent, wherein the concentration of the organic solvent in the mixed solution is lower than the concentration of the organic solvent in the polyamic acid solution; And (4) drying the coated release film. The present invention also provides a method for producing a porous polyamic acid film.
In the method of producing a porous polyamic acid film according to the present invention, the step (1) is a step of preparing a polyamic acid solution by mixing polyamic acid prepared by reacting dianhydride with dianhydride in an organic solvent.
The polyamic acid polymer in the step (1) can be prepared by copolymerizing dianhydride and diamine by a conventional method. For example, (i) reacting an aromatic tetracarboxylic acid dianhydride and an under-molar amount of an aromatic diamine compound in an organic polar solvent to obtain a prepolymer having an acid anhydride group at both ends, and then reacting the aromatic tetracarboxylic acid dianhydride with an aromatic tetracarboxylic acid dianhydride A method of preparing a polyamic acid polymer having a desired molecular weight by adding an aromatic diamine compound so that the aromatic diamine compound is substantially equimolar; Or an aromatic tetracarboxylic acid dianhydride and (ii) an aromatic tetracarboxylic dianhydride and an excessive molar amount of an aromatic diamine compound are reacted in an organic polar solvent to obtain a prepolymer having amine groups at both ends, and then an aromatic tetracarboxylic acid dianhydride and an aromatic diamine compound The polyamic acid polymer may be prepared by adding aromatic tetracarboxylic dianhydride so as to be substantially equimolar to produce a polyamic acid polymer having a desired molecular weight, but is not limited thereto.
Also, the dianhydride used in the present invention can be used without limitation as long as it can be commonly used in the production of polyamic acid. For example, biphenyltetracarboxylic dianhydride (3,3 ', 4,4'-biphenyltetracarboxylic dianhydride (BPDA), pyromellitic dianhydride (1,2,4,5-benzenetetracarboxylic dianhydride, PMDA), 12-oxo-phytodienoic acid (OPDA) , But is not limited thereto.
The diamine used in the present invention can be used without limitation as long as it can be commonly used in the production of polyamic acid. Examples thereof include para-phenylene diamine (pPDA), aminophenylaminobenzazole (2 - (4-aminophenyl) -5-aminobenzoxazole, APAB), diisocyanate, and the like.
The dianhydrides and diamines used in the present invention may be used in a molar ratio of 1: 0.9 to 0.9: 1, and one or more dianhydrides and diamines may be used.
The organic solvent of the polyamic acid solution in the step (1) may be any solvent that dissolves the polyamic acid. For example, the organic solvent may be selected from the group consisting of m-cresol, N-methyl-2-pyrrolidone (NMP), dimethylformamide (DMF), dimethylacetamide (DMAc), dimethylsulfoxide (DMSO) Acetate, and the like can be used.
The content of the organic solvent in the polyamic acid solution is not particularly limited, but may be in the range of 75 to 99 parts by weight, preferably 80 to 90 parts by weight in the total polyamic acid solution to obtain the appropriate molecular weight and viscosity of the polyamic acid solution. have.
In the method of manufacturing a porous polyamic acid film according to the present invention, the step (2) is a step of forming a polyamic acid coating layer by coating the polyamic acid solution on one surface of a release film.
The release film in the step (2) may be a commonly used release film, preferably polyethylene terephthalate (PET), polymethylpentene, polypropylene (OPP, CPP), polyethylene (PE) Mixed layer. In addition, the thickness of the release film may be 10 to 400 탆, but is not limited thereto. In addition, the thickness of the polyamic acid coating layer may be 10-400 탆, but is not limited thereto.
In the method for producing a porous polyamic acid film according to the present invention, the step (3) is a step of immersing and curing the coated release film in a mixture of water and the organic solvent, wherein the concentration of the organic solvent in the mixed liquid is Is lower than the concentration of the organic solvent in the polyamic acid solution.
Since the concentration of the organic solvent in the mixed liquid is lower than the concentration of the organic solvent in the polyamic acid solution in the step (3), the organic solvent in the polyamic acid coating layer flows out by the diffusion due to the concentration difference, Water in the mixed liquid flows into the polyamic acid coating layer. In the step (3), the polyamic acid coating layer is cured. In this case, the curing of the polyamic acid coating layer does not mean imidization but refers to a phenomenon in which the morphology is changed by evaporating the solvent.
In other words, when the coated release film is immersed, diffusion is caused by the difference in concentration of the organic solvent from the surface of the polyamic acid coating layer. At this time, the generated diffusion can be visually confirmed by whether or not the haze occurs. At the same time, holes are generally formed on the surface of the polyamic acid coating layer, and water of the mixed solution is introduced into the pores.
The content of the organic solvent in the mixed solution is not particularly limited, but may be 30 to 75 parts by weight, preferably 40 to 60 parts by weight, of the total mixed solution in order to achieve proper diffusion by the difference in concentration.
The immersion in the step (3) may be performed one or more times, preferably two or more times, or three or more times. When the immersion is carried out two or more times, the content of the organic solvent in the mixed solution may be different, and the content of organic solvent in the second immersion mixed solution may be lower than the content of organic solvent in the first immersion mixed solution.
For example, as shown in FIG. 1, when the first immersion is performed in a mixed solution having an organic solvent content of 65 to 75 parts by weight, the second immersion may be performed in a mixed solution having an organic solvent content of 40 to 50 parts by weight. More specifically, the mixture is immersed in a mixture of DMF and water at a ratio of 65:35 parts by weight to 75:25 parts by weight for 5 minutes to 10 minutes at a temperature of 25 ° C. Then, a mixture of DMF and water in a ratio of 40:60 parts by weight to 50:50 parts by weight For 5 to 10 minutes at a temperature of 25 占 폚 and immersed in water for 5 to 10 minutes at a temperature of 25 占 폚.
In the method of manufacturing a porous polyamic acid film according to the present invention, the step (4) is a step of drying the coated release film, wherein the water introduced into the polyamic acid coating layer is evaporated to form pores. Specifically, the drying may be performed in a hot air drying oven at a temperature of 80 ° C to 120 ° C for 2 hours to 10 hours, and then the release film may be removed to produce a porous polyamic acid film.
The average particle diameter of the pores formed in the polyamic acid film may be 100 to 500 nm, preferably 300 to 400 nm. The pores formed in the polyamic acid film may be 10 to 40% by volume, preferably 20 to 30% by volume, based on the entire polyamic acid film. In the step (3), the pore size and density formed inside the polyamic acid film can be controlled by controlling the concentration of the organic solvent in the mixed solution and the immersion holding time.
(1) preparing a polyamic acid solution by mixing polyamic acid prepared by reacting dianhydride with dianhydride in an organic solvent; (2) coating the polyamic acid solution on one side of the release film; (3) immersing and curing the coated release film in a mixture of water and the organic solvent, wherein the concentration of the organic solvent in the mixed solution is lower than the concentration of the organic solvent in the polyamic acid solution; (4) drying the coated release film to produce a porous polyamic acid film; And (5) imidizing the prepared porous polyamic acid film. The present invention also provides a method for producing a porous polyimide film.
In the method for producing a porous polyimide film according to the present invention, the step (5) is a step of imidizing the porous polyamic acid film. As the imidation method applicable to the formation of the polyimide film, a thermal imidation method, a chemical imidization method, or a thermal imidation method and a chemical imidization method may be used in combination, and preferably a thermal imidation method is applied .
When the thermal imidation method is used, the porous polyimic acid film may be heated at 200 to 700 ° C, preferably 250 to 500 ° C for 1 hour to 5 hours to obtain a porous polyimide film. Specifically, the porous polyamic acid film is dried in a hot-air drying oven at a temperature of 200 ° C to 300 ° C for 2 hours to 10 hours, then at 350 ° C to 450 ° C for 1 hour to 5 hours And then dried to obtain a porous polyimide film.
The average particle size of pores formed in the polyimide film may be 100 to 500 nm, preferably 300 to 400 nm. The pores formed in the polyimide film may be 2 to 20% by volume, and preferably 5 to 10% by volume based on the total polyimide film. The size of the pores can be controlled according to the heat treatment temperature and the application time of the heat treatment.
(1) preparing a polyamic acid solution by mixing polyamic acid prepared by reacting dianhydride with dianhydride in an organic solvent; (2) coating the polyamic acid solution on one side of the release film; (3) immersing and curing the coated release film in a mixture of water and the organic solvent, wherein the concentration of the organic solvent in the mixed solution is lower than the concentration of the organic solvent in the polyamic acid solution; (4) drying the coated release film to produce a porous polyamic acid film; (5) Imidizing the prepared porous polyamic acid film to prepare a porous polyimide film; And (6) carbonizing and graphitizing the prepared porous polyimide film. The present invention also provides a method for producing a porous graphite film.
In the method for producing a porous graphite film according to the present invention, the step (6) is a step of carbonizing and graphitizing the porous polyimide film.
In the carbonization step, the porous polyimide film is carbonized by heating at 700 to 1,500 ° C, preferably 800 to 1,400 ° C, more preferably about 1,000 ° C for about 1 to 10 hours to prepare a porous carbonized film have. Specifically, the prepared porous polyimide film may be put into a vacuum tube and carbonized at a temperature of 800 to 1400 ° C by a resistance heating method while maintaining a nitrogen atmosphere.
In the graphitization step, the porous carbon film is graphitized by heating at 2,000 to 3,000 DEG C, preferably 2,500 to 3,000 DEG C, and more preferably about 2,600 DEG C for about 5 to 20 hours to obtain a porous graphite film have. Specifically, the carbonized porous polyimide film may be put into a graphitization furnace, maintained in a nitrogen atmosphere, and maintained at 2500 to 3000 ° C for 5 to 20 hours by an induction heating method to produce a porous graphite film.
Thereafter, flexibility can be imparted to the porous graphite film through a post-treatment process. For example, flexibility can be imparted to the porous graphite film through a rolling process by a roll mill at 20 to 100 ° C, preferably 20 to 50 ° C. Specifically, the produced porous graphite film can be provided with flexibility through a rolling process in which a load of 10 to 50 tons is applied while the rolling roll number of the roll is supplied at a film feed rate of 1 rpm to 5 rpm, A porous graphite film having a thickness of 25 mu m to 40 mu m can be produced.
The average particle diameter of pores formed in the graphite film may be 100 to 500 nm, preferably 100 to 200 nm. The pores formed in the graphite film may be 2 to 10% by volume, preferably 2 to 5% by volume, based on the entire graphite film. The size of the pores can be controlled according to the number of times of rolling after the production of the graphite film and application load.
The present invention also provides a laminated sheet in which the porous polyamic acid film is laminated on one surface of a conventional graphite sheet. The present invention also provides a laminated sheet in which the porous polyimide film is laminated on one surface of a conventional graphite sheet. The present invention also provides a laminated sheet in which the porous graphite film is laminated on one surface of a conventional graphite sheet.
(1) preparing a polyamic acid solution by mixing polyamic acid prepared by reacting dianhydride with dianhydride in an organic solvent; (2) coating the polyamic acid solution on one surface of the base film; (3) a step of immersing and curing the coated substrate film in a mixture of water and the organic solvent, wherein the concentration of the organic solvent in the mixed solution is lower than the concentration of the organic solvent in the polyamic acid solution; And (4) drying the coated base film. The present invention also provides a method for producing a laminated sheet composed of a porous polyamic acid film and a base film.
In the method for producing a laminated sheet composed of a porous polyamic acid film and a base film according to the present invention, the base film may be a commonly used base film, and may be a polyimide film or a graphite film.
The vertical heat conductivity of the laminated sheet according to the present invention may be 5 W / m · K or less, preferably 3 W / m · K or less, and more preferably 2 W / m · K or less.
Further, the present invention provides a display device comprising the laminated sheet.
Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the following examples are intended to illustrate the present invention, but the scope of the present invention is not limited thereto.
[Example]
Example 1 - Preparation of porous polyamic acid film
≪ Preparation step of polyamic acid solution >
The polyamic acid solution was prepared from polyamic acid solution (product name: PI Varnish) available from SKC Kolon PI having a dimethylformamide (DMF) content of 82 wt%.
<Coating Step>
The polyamic acid solution was coated on the PET release film to a thickness of 300 mu m using a coating applicator.
≪ Immersion and curing step >
The coated PET release film was immersed in a mixture of about 70:30 parts by weight of DMF and water at a temperature of 25 DEG C for about 8 minutes. Subsequently, the mixture was immersed in a mixture of about 45:55 parts by weight of DMF and water at a temperature of 25 DEG C for about 8 minutes and immersed in water at a temperature of 25 DEG C for about 8 minutes. Curing progressed sequentially during the immersion.
<Drying step>
The coated PET release film was dried in a hot air drying oven at a temperature of about 100 캜 for about 6 hours, and then the release film was removed to prepare a porous polyamic acid film.
Example 2 - Preparation of porous polyimide film
<Imide step>
The prepared porous polyamic acid film was sandwiched in a pin tenter and dried in a hot air drying oven at a temperature of about 250 ° C. for about 6 hours and then dried in a hot air drying oven at a temperature of about 400 ° C. for about 3 hours To prepare a porous polyimide film.
Example 3 - Preparation of porous graphite film
<Carbonization step>
The prepared porous polyimide film was put into a vacuum tube, and the temperature was carbonized at a temperature of about 1000 ° C by a resistance heating method while maintaining a nitrogen atmosphere.
≪ Graphitization step &
The carbonized porous polyimide film was placed in a graphitization furnace, and maintained at a temperature of about 2600 ° C. for about 10 hours by maintaining the atmosphere of nitrogen under an induction heating system to prepare a porous graphite film.
<Rolling step>
The prepared porous graphite film was subjected to a rolling process in which a load of 10 to 50 tons was applied. The film feed rate of the rolling process is a rolling roll speed of 1 rpm to 5 rpm, and the temperature of the rolling roll is maintained at 20 캜 to 50 캜. Through this rolling process, a porous graphite film having a thickness of 25 mu m to 40 mu m was produced.
Experimental Example - Measurement of thermal conductivity (or thermal diffusivity)
The thermal conductivity of porous graphite films having thicknesses of 25 μm, 30 μm and 40 μm prepared in Examples 1 to 3 was measured by the following method. The results are shown in Table 1 below.
Thermal Conductivity Measurement-The LFA-447 (model name) device from Netzsch was used to measure the flash conductivity using a flash method. The flashing method is a non-contact type measuring method, which can measure the thermal diffusion coefficient without contact resistance with the sample, can measure in a short time, and can reduce the size of the sample.
Thermal conductivity (W / mK)
Thermal conductivity (W / mK)
As shown in Table 1, it can be seen that as the thickness of the graphite film becomes smaller, the thermal conductivity in the horizontal direction becomes larger, and conversely, the thermal conductivity in the vertical direction becomes smaller. In other words, the horizontal and vertical thermal conductivities according to the thickness of the graphite film are inversely proportional to each other, indicating that the graphite film has an anisotropic effect. In addition, it can be seen that the graphite film maintains an excellent thermal conductivity in the horizontal direction and a low thermal conductivity in the vertical direction.
Also, the graphite film is a porous film containing pores therein, and can be effectively used even in the case where impact absorption is required because the impact resistance is excellent.
Claims (12)
(2) coating the polyamic acid solution on one side of the release film;
(3) immersing and curing the coated release film in a mixture of water and the organic solvent, wherein the concentration of the organic solvent in the mixed solution is lower than the concentration of the organic solvent in the polyamic acid solution; And
(4) drying the coated release film
Wherein the porous polyamic acid film is a porous polyamic acid film.
(2) coating the polyamic acid solution on one side of the release film;
(3) immersing and curing the coated release film in a mixture of water and the organic solvent, wherein the concentration of the organic solvent in the mixed solution is lower than the concentration of the organic solvent in the polyamic acid solution;
(4) drying the coated release film to produce a porous polyamic acid film; And
(5) Imaging the prepared porous polyamic acid film
≪ / RTI >
(2) coating the polyamic acid solution on one side of the release film;
(3) immersing and curing the coated release film in a mixture of water and the organic solvent, wherein the concentration of the organic solvent in the mixed solution is lower than the concentration of the organic solvent in the polyamic acid solution;
(4) drying the coated release film to produce a porous polyamic acid film;
(5) Imidizing the prepared porous polyamic acid film to prepare a porous polyimide film; And
(6) Carbonizing and graphitizing the prepared porous polyimide film
≪ / RTI >
A porous polyamic acid film having 20 to 30% by volume of pores.
A porous polyimide film having 5 to 10% by volume of pores.
A porous graphite film having 2 to 5 volume percent pores.
(2) coating the polyamic acid solution on one surface of the base film;
(3) a step of immersing and curing the coated substrate film in a mixture of water and the organic solvent, wherein the concentration of the organic solvent in the mixed solution is lower than the concentration of the organic solvent in the polyamic acid solution; And
(4) drying the coated substrate film
Wherein the porous polyamic acid film comprises a porous polyamic acid film and a base film.
Wherein the base film is a polyimide film.
Wherein the base film is a graphite film.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1020160008366A KR101778739B1 (en) | 2016-01-22 | 2016-01-22 | Anisotropic thermally conductive film, laminate sheet using same and method of preparing same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1020160008366A KR101778739B1 (en) | 2016-01-22 | 2016-01-22 | Anisotropic thermally conductive film, laminate sheet using same and method of preparing same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| KR20170088234A true KR20170088234A (en) | 2017-08-01 |
| KR101778739B1 KR101778739B1 (en) | 2017-09-14 |
Family
ID=59650189
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| KR1020160008366A KR101778739B1 (en) | 2016-01-22 | 2016-01-22 | Anisotropic thermally conductive film, laminate sheet using same and method of preparing same |
Country Status (1)
| Country | Link |
|---|---|
| KR (1) | KR101778739B1 (en) |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4110669B2 (en) | 1999-05-13 | 2008-07-02 | 宇部興産株式会社 | Porous insulating material and laminate thereof |
| JP6330261B2 (en) | 2013-05-29 | 2018-05-30 | 宇部興産株式会社 | Method for producing polymer porous membrane and polymer porous membrane |
-
2016
- 2016-01-22 KR KR1020160008366A patent/KR101778739B1/en active IP Right Grant
Also Published As
| Publication number | Publication date |
|---|---|
| KR101778739B1 (en) | 2017-09-14 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10946617B2 (en) | Graphite laminated body | |
| JP6423633B2 (en) | Polyimide film for graphite sheet and method for producing the same | |
| TWI714971B (en) | Polyimide film, manufacturing method thereof, graphite sheet prepared by using the same and electronic device | |
| JP7015934B2 (en) | A polyimide film for a graphite sheet containing a spherical PI-based filler containing graphene, a manufacturing method thereof, and a graphite sheet manufactured using the same. | |
| JP6121168B2 (en) | Polyimide film and method for producing the same | |
| TWI613149B (en) | Manufacturing method of polyimide film and manufacturing method of graphite film using the same | |
| KR102346587B1 (en) | Polyimide Film with Improved Dimensional Stability and Method for Preparing the Same | |
| KR20230157271A (en) | Polyimide film | |
| JP7474846B2 (en) | Polyimide film for graphite sheet, its manufacturing method and graphite sheet manufactured therefrom | |
| JP2023550619A (en) | Polyimide film for graphite sheets, method for producing the same, and graphite sheets produced therefrom | |
| JP6403389B2 (en) | Method for producing imide-based porous film and imide-based porous film | |
| JP4406764B2 (en) | Gas barrier polyimide film and metal laminate using the same | |
| JPWO2018070476A1 (en) | Method of producing graphite film | |
| KR101778739B1 (en) | Anisotropic thermally conductive film, laminate sheet using same and method of preparing same | |
| JP2006269558A (en) | Method of producing flexible laminate substrate | |
| CN114144390B (en) | Graphite flake and electronic device comprising same | |
| JP7385028B2 (en) | Polyimide film for graphite sheets, its manufacturing method, and graphite sheets manufactured from it | |
| TWI549907B (en) | Graphite film and manufacturing method thereof | |
| JP5709018B2 (en) | Metal laminate | |
| TW202204477A (en) | Polyimide film, and metal-clad laminate | |
| JP2011131456A (en) | Gas-barrier polyimide film and metal layered product using the same | |
| WO2011030860A1 (en) | Polyimide precursor and polyimide | |
| KR102414419B1 (en) | Method for preparing polyimide film for graphite sheet and method for preparing graphite sheet | |
| JP5069844B2 (en) | Method for producing insulating film for printed wiring board, polyimide / copper laminate and printed wiring board | |
| JP2006274040A (en) | Polyimide film and flexible circuit board using the same |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A201 | Request for examination | ||
| E902 | Notification of reason for refusal | ||
| E701 | Decision to grant or registration of patent right | ||
| GRNT | Written decision to grant |