TWI613149B - Manufacturing method of polyimide film and manufacturing method of graphite film using the same - Google Patents

Abstract

A method for manufacturing a graphite film using a method for manufacturing a polyfluoreneimide film, first mixing a diamine, a solvent, and a catalyst to form a catalyst-containing diamine solution. Next, a tetracarboxylic dianhydride is mixed with a catalyst-containing diamine solution to form a catalyst-containing polyamine solution. Next, the polyamine solution containing the catalyst is heated to form a polyamino acid film containing the catalyst. Next, the polyimide film containing the catalyst is imidized to form a polyimide film. Finally, the polyimide film is heated to form a graphite film. The step of imidizing a polyfluorinated acid film containing a catalyst to form a polyfluorinated imine film is catalyzed by a catalyst, and the catalyst is a tertiary amine.

Description

Method for producing polyimide film and method for producing graphite film using the same

The present invention relates to a method for manufacturing a polyfluorene film and a method for manufacturing a graphite film using the same, and in particular, to a method for manufacturing a polyfluorene film that can be used for manufacturing a graphite film with excellent thermal conductivity, and uses thereof. This polyimide film is a method for producing a graphite film having excellent thermal conductivity.

With the rapid improvement of the efficiency of electronic products, how to meet the heat dissipation requirements of electronic products has become an important issue. The heat dissipation material or heat conducting material used in general electronic products is copper, and the thermal conductivity of copper is about 400 W / m-K. Aluminum is often used as a heat-dissipating material or heat-conducting material in electronic products with light weight requirements, and the thermal conductivity of aluminum is about 200 W / m-K. Since the graphite film made of natural graphite is a low density material with high thermal conductivity, flexibility, and electromagnetic shielding, its thermal conductivity is about 300 W / m-K. Therefore, the graphite film is widely used as a heat dissipation material or a thermally conductive material in various electronic products. The graphite film made of natural graphite is mainly made of natural graphite flakes or other natural graphite materials. After screening, acidification, high-temperature expansion, and rolling processes, the graphite film made of natural graphite is pressed one by one by natural graphite. The structure of the graphite layer is loose and discontinuous, with many lattice defects and pores easily absorbing water, so that its thermal conductivity is only between 200 and 400 W / mk, and its structural strength is not good and it is easy to crack or fall. This situation increases the risk of short circuits in electronic products.

In view of the disadvantages of using the aforementioned natural graphite film, the industry began to replace the natural graphite film with an artificial graphite film as a heat dissipation component of electronic products. There are obvious differences in the raw materials, overall crystallinity, mechanical properties and thermal conductivity of artificial graphite flakes and natural graphite flakes. Artificial graphite flakes usually use polyimide (PI) as a raw material for manufacturing, and the carbon atoms are left by thermal cracking of the polyimide through a carbonization and graphitization process. Then, the carbon atoms are rearranged at high temperature to form a continuous, ordered and nearly perfect layered graphite crystal structure. In this way, artificial graphite flakes have superior mechanical properties and thermal conductivity than natural graphite flakes.

However, with the rapid improvement of the efficiency of electronic products and the significant reduction in the volume of electronic products, the thermal conductivity of graphite films made of copper, aluminum, and general natural graphite, and the thermal conductivity of artificial graphite films made of polyimide films currently used. The ability can no longer meet the heat dissipation requirements of miniaturized electronic products. Therefore, how to improve the thermal conductivity of graphite film is one of the problems that need to be solved urgently.

The invention provides a method for manufacturing a polyimide film and a method for manufacturing a graphite film using the same, particularly a method for manufacturing a polyimide film, and the use of the polyimide film to produce graphite with excellent thermal conductivity. The manufacturing method of the film is used to solve the problem of insufficient thermal conductivity of the heat dissipation material in the current electronic products.

An embodiment of the present invention discloses a method for manufacturing a polyfluoreneimide film, which comprises mixing a diamine, a solvent and a catalyst to form a catalyst-containing diamine solution; mixing a tetracarboxylic dianhydride and a catalyst-containing diamine A solution to form a polyamic acid solution containing a catalyst; heating the polyamino acid solution containing a catalyst to form a polyamino acid film containing a catalyst; and imidizing a polyamino acid film containing a catalyst to form a polyamino acid film containing a catalyst Polyimide film. In the step of imidizing a polyamine film containing a catalyst to form a polyimide film, the polyamine film containing a catalyst in a solid state is catalyzed by heating and dehydration together with the catalyst to perform imidization to form a solid polymer.醯 imine membrane, and the catalyst is tertiary amine.

Another embodiment of the present invention discloses a method for manufacturing a polyfluorene imide film, which comprises mixing a diamine, a tetracarboxylic dianhydride, a solvent, and a catalyst to form a polyfluorinated acid solution containing a catalyst; heating the catalyst And a polyimide film containing a catalyst to form a polyimide film containing a catalyst; and a polyamidate film containing a catalyst to form a polyimide film. In the step of imidizing a polyamine film containing a catalyst to form a polyimide film, the polyamine film containing a catalyst in a solid state is catalyzed by heating and dehydration together with the catalyst to perform imidization to form a solid polymer.醯 imine membrane, and the catalyst is tertiary amine.

Another embodiment of the present invention discloses a method for manufacturing a graphite film, which includes preparing a polyimide film using the method for manufacturing a polyimide film of any of the foregoing embodiments; and heating the polyimide film to form a graphite film. .

According to the method for manufacturing a polyimide film disclosed in the present invention and the method for manufacturing a graphite film using the same, the polyimide film is catalyzed by heating and dehydration together with a tertiary amine to obtain a better imidization. The imidization effect of polyimide results in a polyimide film composed of continuous and ordered polyimide molecules. In this way, in the graphite film obtained by graphitizing a polyfluorene imide film composed of continuous and ordered polyfluorene imine molecules according to the present invention, the graphite molecules have a continuous and ordered layered structure, so the graphite film has excellent The heat conduction performance solves the problem of insufficient thermal conductivity of the heat dissipation material in the electronic product.

Furthermore, the catalyst has been uniformly dispersed in the diamine solution containing the catalyst before being contacted with the polyamic acid, which improves the effective contact area and collision frequency between the polyamic acid and the catalyst, so that the imine is completed within a predetermined time. The amount of catalyst required for the chemical reaction is reduced. In this way, the present invention uses less catalyst to complete the imidization reaction within a predetermined time, so that the manufacturing cost of the present invention is reduced.

The above description of the contents of this disclosure and the description of the following embodiments are used to demonstrate and explain the spirit and principle of the present invention, and provide a further explanation of the scope of the patent application of the present invention.

The detailed features and advantages of the present invention are described in detail in the following embodiments. The content is sufficient for any person skilled in the art to understand and implement the technical content of the present invention, and according to the content disclosed in this specification, the scope of patent applications and the drawings. Anyone skilled in the relevant art can easily understand the related objects and advantages of the present invention. The following examples further illustrate the viewpoints of the present invention in detail, but do not limit the scope of the present invention in any way.

First, a method for manufacturing a graphite film according to an embodiment of the present invention is described, please refer to FIG. 1. FIG. 1 is a flowchart of a graphite film manufacturing method according to an embodiment of the present invention. The method for manufacturing a graphite film in this embodiment includes a method for manufacturing a polyimide film according to an embodiment of the present invention. Specifically, steps S101 to S104 are a method for manufacturing a polyimide film according to an embodiment of the present invention.

First, a diamine, a solvent, and a catalyst are mixed to form a catalyst-containing diamine solution (S101).

In detail, a diamine and a catalyst are added to a polar solvent and stirred, so that the diamine and the catalyst are uniformly dissolved in the polar solvent to form a diamine solution containing the catalyst. The catalyst is a tertiary amine, such as triethylenediamine (DABCO, Triethylenediamine, CAS. No .: 280-57-9), N, N-Dimethylcyclohexylamine, CAS. No .: 98-94-2), 1,2-Dimethylimidazole, trimethylamine, triethylamine, tripropylamine, tributylamine, triethanolamine, N, N-dimethylethanolamine, N , N-diethylethanolamine, triethylenediamine, N-methylpyrrolidine, N-ethylpyrrolidine, N-methylhexahydropyridine, N-ethylhexahydropyridine, imidazole, pyridine, quinoline or Isoquinoline. In order to uniformly dissolve the diamine and the catalyst in the solvent and reduce the required mixing time, the solvent can be quickly stirred at a frequency of 20 Hertz (Hz) to 100 Hertz to accelerate the dispersion of the diamine and the catalyst in the solvent.

Next, the tetracarboxylic dianhydride and the catalyst-containing diamine solution are mixed to form a catalyst-containing polyamine solution (S102).

Specifically, tetracarboxylic dianhydride is slowly added to a catalyst-containing diamine solution and stirred at room temperature, so that the tetracarboxylic dianhydride and the diamine in the catalyst-containing diamine solution are reacted to form polyfluorene amine. Acid (PAA, Polyamic acid) solution. At this time, the catalyst was uniformly dispersed in the polyamino acid solution containing the catalyst. The ratio of the molar number of tetracarboxylic dianhydride to the molar number of diamine is from 0.98: 1 to 1.05: 1. The weight percentage of the catalyst relative to the total weight of the diamine and the tetracarboxylic dianhydride is 1 to 50%.

In some embodiments of the present invention, the weight percentage of the catalyst relative to the total weight of the diamine and the tetracarboxylic dianhydride is 1 to 50%, but not limited thereto. In still another embodiment of the present invention, the weight percentage of the catalyst relative to the total weight of the diamine and the tetracarboxylic dianhydride is 1 to 10%. In another embodiment of the present invention, the weight percentage of the catalyst relative to the total weight of the diamine and the tetracarboxylic dianhydride is 1 to 5%.

In some embodiments of the present invention, when the viscosity of the polyamine solution containing the catalyst reaches between 10,000 cps and 50,000 cps, that is, between 100 poise (ps) and 500 poise, the addition of tetracarboxylic acid di Anhydride and stop stirring. In this way, the viscosity of the polyamic acid solution containing the catalyst can be prevented from being too high, which makes it difficult to spread the polyamino acid solution containing the catalyst on the surface of the carrier plate for heating to form a film during subsequent processing.

Next, the catalyst-containing polyamine solution is heated to form a catalyst-containing polyamino acid film (S103).

In detail, a polyamine solution containing a catalyst is coated on a carrier material, and then the carrier material coated with the polyamino acid solution containing a catalyst is placed in a high-temperature environment of 120 ° C to 200 ° C and dried. . In this way, the solvent in the polyamine solution containing the catalyst is vaporized by heat and leaves the polyamine solution containing the catalyst, and the non-gasified catalyst and the polyamine in the polyamine solution containing the catalyst are caused to evaporate. The acid forms a polyamine film containing the catalyst, while the unvaporized catalyst is uniformly distributed in the polyamine film containing the catalyst. After the solvent in the catalyst-containing polyamine solution is heated and vaporized, a catalyst-containing polyamine film attached to a carrier is obtained. Next, the polyamine film containing the catalyst is peeled from the support material for subsequent steps. The temperature of heating and drying can be matched to the boiling point of the solvent. In some embodiments of the present invention, the drying temperature is 120 ° C to 200 ° C, but it is not limited thereto.

Next, the polyimide film containing the catalyst is imidized to form a polyimide film (S104).

In detail, the polyamidate film containing the catalyst is heated at a temperature higher than the heating and drying temperature, that is, at a temperature of 250 ° C. to 400 ° C., and the imidization reaction of the following two reaction mechanisms is simultaneously performed. The first is a catalyst that uniformly disperses in a polyacrylic acid mold in a solid state to catalyze the imidization reaction of the polyacid acid, dehydrating and closing the polyacid acid to form a polyimide. The second is to imidize the solid polyamidic acid film by high temperature catalysis to dehydrate and ring-close the polyamidic acid to form polyimide. Through the imidization reaction of the above two reaction mechanisms, a polyfluorinated acid film in a solid state and containing a catalyst achieves a better imidization effect and obtains a polymer composed of a continuous and ordered array of polyimide molecules.醯 imine film. The higher the heating temperature, the shorter the time required for the polyimide film containing the catalyst to undergo imidization reaction to form the polyimide film. However, if the reaction temperature is too high or the heating time is too long, the bonding between the atoms in the polyfluorene imine molecule may be broken, so that the polyfluorene imine is degraded due to high temperature. In some embodiments of the present invention, the temperature at which the polyamidoacid film containing the catalyst is subjected to imidization by heating is 270 ° C to 450 ° C, but it is not limited thereto. In still another embodiment of the present invention, the temperature for heating the polyimide acid film containing the catalyst to carry out the imidization reaction is 270 ° C to 350 ° C, but it is not limited thereto. In addition, in some embodiments of the present invention, the polyamino acid film containing the catalyst is fixed with a jig and heated to carry out the imidization reaction, but it is not limited thereto. In another part of the embodiment of the present invention, the polyamino acid film containing the catalyst is uniaxially stretched and heated to carry out the imidization reaction.

Next, the carbonized polyfluorene film is heated at a carbonization temperature to form a carbonized polyfluorene film (S105).

In detail, the polyimide film is placed in a low-pressure environment, a nitrogen atmosphere, or an inert gas atmosphere, and heat-treated at a carbonization temperature of 800 ° C to 1500 ° C to make the polyimide film on the surface of the polyimide film. The amine was carbonized to obtain a carbonized polyfluorene film. For example, the polyfluorene film can be placed in a heating chamber with an internal pressure below one atmosphere for heating and carbonization, or the polyfluorene film can be placed in a heating chamber filled with nitrogen for heating and carbonization.

Finally, the graphitized carbonized polyfluorene film is heated at a graphitization temperature higher than the carbonization temperature to form a graphite film (S106).

In detail, the carbonized polyfluorene imide film is placed in a low-pressure environment or an inert gas atmosphere, and heated at a graphitization temperature of 2500 ° C to 3000 ° C to make the carbonized polyfluorene on the surface of the carbonized polyfluorene film The imine begins to graphitize to obtain a graphite film, and the preparation of the graphite film is completed. For example, the carbonized polyfluorene imide film can be placed in a heating chamber filled with argon or helium for heating and graphitization to obtain a graphite film.

The carbonization of the polyfluorene imide film and the graphitization of the carbonized polyfluorene imide film in some embodiments of the present invention can be performed in different heating chambers, but not limited thereto. In other embodiments of the present invention, the carbonization of the polyimide film and the graphitization of the carbonized polyimide film may also be performed by first carbonizing the polyimide film at the carbonization temperature in the same heating chamber, and then increasing the heating temperature. High to graphitization temperature to graphitize the carbonized polyfluorene film.

Next, a method for manufacturing a graphite film according to another embodiment of the present invention is described, please refer to FIG. 2. FIG. 2 is a flowchart of a graphite film manufacturing method according to another embodiment of the present invention. The method for manufacturing a graphite film of this embodiment includes a method for manufacturing a polyimide film according to another embodiment of the present invention. In detail, steps S201 to S203 are a method for manufacturing a polyimide film according to another embodiment of the present invention.

First, a diamine, a tetracarboxylic dianhydride, a solvent, and a catalyst are mixed to form a polyphosphonic acid solution containing a catalyst (S201).

In detail, the diamine, tetracarboxylic dianhydride and catalyst are added to a polar solvent and stirred at room temperature, so that the diamine, tetracarboxylic dianhydride and catalyst are uniformly dissolved in the polar solvent, and the diamine and tetracarboxylic acid are dissolved in the polar solvent. The carboxylic dianhydride reacts to form a polyamic acid (PAA, Polyamic acid) solution. At this time, the catalyst was uniformly dispersed in the polyamino acid solution containing the catalyst. The ratio of the molar number of tetracarboxylic dianhydride to the molar number of diamine is from 0.98: 1 to 1.05: 1. The weight percentage of the catalyst relative to the total weight of the diamine and the tetracarboxylic dianhydride is 1 to 50%. In this embodiment, diamine, tetracarboxylic dianhydride and catalyst are added to the polar solvent at the same time, but it is not limited thereto. The catalyst is a tertiary amine, such as triethylenediamine (DABCO, Triethylenediamine, CAS. No .: 280-57-9), N, N-Dimethylcyclohexylamine, CAS. No .: 98-94-2), 1,2-Dimethylimidazole, trimethylamine, triethylamine, tripropylamine, tributylamine, triethanolamine, N, N-dimethylethanolamine, N , N-diethylethanolamine, triethylenediamine, N-methylpyrrolidine, N-ethylpyrrolidine, N-methylhexahydropyridine, N-ethylhexahydropyridine, imidazole, pyridine, quinoline or Isoquinoline. In order to uniformly dissolve the diamine, tetracarboxylic dianhydride and catalyst and form a polyamine solution containing the catalyst, and reduce the required mixing time, the solvent can be rapidly stirred at a frequency of 20 Hertz (Hz) to 100 Hertz , Accelerate the dissolution of diamine, tetracarboxylic dianhydride and catalyst uniformly and form a polyfluorinated acid solution containing catalyst.

In some embodiments of the present invention, the weight percentage of the catalyst relative to the total weight of the diamine and the tetracarboxylic dianhydride is 1 to 50%, but not limited thereto. In still another embodiment of the present invention, the weight percentage of the catalyst relative to the total weight of the diamine and the tetracarboxylic dianhydride is 1 to 10%. In another embodiment of the present invention, the weight percentage of the catalyst relative to the total weight of the diamine and the tetracarboxylic dianhydride is 1 to 5%.

In some embodiments of the present invention, when the viscosity of the polyamic acid solution containing the catalyst reaches between 10,000 cps and 50,000 cps, that is, between 100 poise (ps) and 500 poise, the stirring is stopped. In this way, the viscosity of the polyamic acid solution containing the catalyst can be prevented from being too high, which makes it difficult to spread the polyamino acid solution containing the catalyst on the surface of the carrier plate for heating to form a film during subsequent processing.

Next, the polyamine solution containing the catalyst is sequentially heated to form a polyamine film containing the catalyst (S202), and the polyamidate film containing the catalyst is imidized to form a polyimide film (S203). The carbonized polyfluorene imide film is heated at a carbonization temperature to form a carbonized polyfluorene imide film (S204), and the graphitized carbonized polyfluorene imide film is heated at a graphitization temperature higher than the carbonization temperature to form a graphite film (S205).

Since the detailed operation modes of steps S202 to S205 are the same as steps S103 to S106, the detailed operation modes of steps S202 to S205 will not be repeated here.

The polyfluorene acid film undergoes amidation reaction to form a polyfluorine film. The high-temperature fluorene amination method or the chemical fluorene amination method can be used alone. In the high-temperature imidization method, it is necessary to use a high temperature of 350 ° C or higher to make the polyacid film amidation reaction. In the chemical imidization method, excess chemical reagents, such as acetic anhydride and pyridine, are required to make the imidization reaction of the polyimide film. In the present invention, a small amount of tertiary amine is used as a catalyst, and a lower arsonization temperature is used to obtain a better arsonization effect, thereby obtaining a polyarylene formed by continuous and ordered polyarylene imine molecules. Amine film. In this way, in the graphite film formed by the carbonization and graphitization of the polyimide film formed by the continuous and ordered polyimide molecules, the graphite molecules formed by the carbonization and graphitization of the polyimide molecules are continuous. The ordered layered structure makes the graphite film have excellent thermal conductivity. Moreover, in the process of the present invention for manufacturing a graphite film with excellent thermal conductivity, the total amount of catalyst used is lower than the total amount of catalyst required to prepare a polyfluorene imine film by using a chemical imidization method alone, and heating the polyfluorene The temperature of the amine film to carry out the imidization reaction is also lower than the heating temperature required for preparing the polyfluorene imide film by using the high-temperature sulfide amination method alone.

In the present invention, the catalyst is mixed with the diamine and the solvent to form a diamine solution containing the catalyst before the polyamine acid solution containing the catalyst is formed. Therefore, the catalyst was uniformly dispersed in the diamine solution containing the catalyst before being contacted with the polyamic acid. As the catalyst catalyzes the chemical reaction, the more the contact area between the reactant and the catalyst or the higher the collision frequency, the faster and more average the chemical reaction speed, and the lower the demand for the catalyst. Therefore, by improving the uniformity of mixing between polyamic acid and the catalyst, increasing the contact area and collision frequency between the polyamic acid and the catalyst, quickly obtaining a better amidation effect with fewer catalysts, and then obtaining quality Preferred polyfluorene imide film. In this way, the graphite film obtained from the graphitization of a polyimide film of better quality according to the present invention has better thermal conductivity, and solves the problem of insufficient thermal conductivity of a heat dissipation material in an electronic product.

Furthermore, since the present invention is a graphite film graphitized from a polyimide film of better quality, the graphite molecules in the graphite film have a continuous and ordered layered structure, so that the graphite film also has excellent conductive properties and can be As a conductive material. Therefore, the graphite film of the present invention can be applied as a thermally conductive material, a heat dissipation material, and a conductive material, but is not limited thereto.

Furthermore, the catalyst has been uniformly dispersed in the diamine solution containing the catalyst before being contacted with the polyamidic acid, so that the amount of catalyst required to complete the imidization reaction within a predetermined time is reduced. In this way, the present invention uses less catalyst to complete the imidization reaction within a predetermined time, so that the manufacturing cost of the present invention is reduced.

Furthermore, the catalyst has been uniformly dispersed in the diamine solution containing the catalyst before contacting the polyamic acid, so that the viscosity of the polyamino acid solution containing the catalyst can be controlled between 10,000 cps and 50,000 cps, that is, 100 Poise (ps) to 500 poises. In this way, the thickness of the catalyst-containing polyamine film obtained by subsequent heating and drying of the catalyst-containing polyamino acid solution coated on the carrier plate is relatively uniform, and the film forming property is better. In contrast, if the catalyst is added after the polyamine solution containing the catalyst is formed and the polyamine solution containing the catalyst is stirred to dissolve the catalyst, the viscosity of the polyamino acid solution containing the catalyst increases rapidly and is not easy to control. . In this way, the catalyst-containing polyamine film obtained by heating and drying the catalyst-containing polyamino acid solution coated on the carrier plate has poor film thickness uniformity, and shrinkage during graphitization due to uneven film thickness. Even conditions will result in poor film formation of graphite films.

In the above embodiments, the diamine includes, but is not limited to, p -phenylenediamine (PPDA, p- Phenylenediamine), 2,2'-bis (trifluoromethyl) benzidine (TFMB, 2,2'-Bis (trifluoromethyl) benzidine, CAS. No .: 341-58-2), HFBAPP (2,2-Bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, CAS. No .: 69563-88-8), BTFDPE (4,4 '-oxybis [3- (trifluoromethyl) benzeneamine], CAS. No .: 344-48-9), FAPQ (4,4'-[1,4-phenylenebis (oxy)] Bis [3- (trifluoromethyl)] benzenamine , CAS. No .: 94525-05-0), FFDA (9,9-Bis (4-amino-3-fluorophenyl) fluorine, CAS. No .: 127926-65-2), 9,9-Bis [4 -(4-amino-3-fluorophenyl) bezene] fluorine, BAFL (9,9-Bis (aminophenyl9fluorene)), 4,4'-diaminodiphenyl ether (ODA, 4,4'-Oxydianiline, CAS. No. : 101-80-4).

In the above embodiment, the tetracarboxylic dianhydride includes but is not limited to pyromellitic dianhydride (PMDA, 1, 2, 4, 5 benzenetetracarboxylic dianhydride), biphenyltetracarboxylic dianhydride (BPDA, 3, 3 ', 4,4'-biphenyl tetracarboxylic dianhydride), biphenyltetracarboxylic dianhydride, 2,3,3 ', 4'-biphenyltetracarboxylic dianhydride (2,3,3 ', 4'-biphenyl tetracarboxylic dianhydride), diphenyl ether tetracarboxylic dianhydride (4,4'-oxydiphthalic anhydride), 3,4'-diphenyl ether tetracarboxylic dianhydride (3,4' -oxydiphthalic anhydride), benzophenonetetracarboxylic dianhydride, 2,2-bis [(4- (3,4-dicarboxyphenoxy) phenyl)] propane dianhydride (BPADA, 2, 2-bis [4- (3,4dicarboxyphenoxy) phenyl] propane dianhydride), 4,4 '-(hexafluoroisopropene) diphthalic anhydride (6FDA, 2,2-bis (3,4-anhydrodicarboxyphenyl) hexafluoropropane), two Phenyl maple tetracarboxylic dianhydride (3,3 ', 4,4'-diphenyl sulfonetetracarboxylic dianhydride), 9,9-bis (3,4-dicarboxyphenyl) fluorene dianhydride, CAS. No .: 135876-30-1, 9,9-bis [4- (3,4-dicarboxyphenoxt) phenyl] fluorene dianhydride, CAS. No .: 59507-08-3, Naphthalenetetracarboxylic dianhydride, Naphthalenetetracaboxylic dianhydride, Bis- (3,4-phthalic anhydride) dimethyl (Bis (3,4-dicarboxyphenyl) dimethylsilane dianhydride), 1,3-bis (3,4-dicarboxyphenyl) -1,1,3,3-tetramethyldisiloxane dianhydride (1 , 3-bis (4'-phthalic anhydride) -tetramethyldisiloxane), BPAF (9,9-Bis (3,4-dicarboxyphenyl) fluorine dianhydride), BP-TME (Bis (1,3-dioxo-1,3-dihydroisobenzofuran -5-carboxylic acid) biphenyl-3,3'-diyl ester).

In the above embodiment, the polar solvent includes, but is not limited to, N, N-Dimethyl formamide (DMF), Dimethylacetamide (DMAc), Dimethyl sulfoxide, DMSO), N-methyl-2-pyrrolidone (NMP), gamma-butyrolactone (GBL).

In the following, several examples and comparative examples are used to explain the graphite film disclosed in this proposal, and experimental tests are performed to compare the difference in properties.

Example one

First, 24.06 g of 4,4'-diaminodiphenyl ether (ODA) and 1.5 g of N, N-dimethylcyclohexylamine as a catalyst were added to 198.5 g of dimethylacetamide (DMAc) and stirred for 0.5 After hours, ODA and N, N-dimethylcyclohexylamine were uniformly dissolved in DMAc to form a diamine solution containing a catalyst.

Next, 25.94 grams of pyromellitic dianhydride (PMDA) was slowly added to the catalyst-containing diamine solution and stirred at room temperature for 6 hours, so that PMDA and ODA were reacted to form a catalyst-containing polyamine solution. The weight percentage of the catalyst N, N-dimethylcyclohexylamine to the total weight of ODA and PMDA is 3%.

Next, the catalyst-containing polyamic acid solution was coated on a support plate, and the catalyst-containing polyamino acid solution was dried by heating at 120 ° C. for 10 minutes to form a catalyst-containing polyamino acid film on the support plate, and The polyamic acid film containing the catalyst was peeled from the carrier plate.

Next, the polyamine film containing the catalyst was heated at 320 ° C. for 10 minutes, and the polyamine film containing the catalyst was imidized to form a polyimide film.

Next, the carbonized polyimide film was heated in a heating chamber filled with a nitrogen atmosphere at a carbonization temperature of 1000 ° C. for 60 minutes to form a carbonized polyimide film.

Finally, the graphitized carbonized polyfluorene imide film was heated in a heating chamber filled with an argon atmosphere at a graphitization temperature of 2800 ° C. for 30 minutes to form a graphite film.

Example two

The second embodiment is similar to the first embodiment, except that the weight of the catalyst N, N-dimethylcyclohexylamine is 2.5 g, and the total ODA and PMDA of the catalyst N, N-dimethylcyclohexylamine The weight percentage is 5%, and the weight of the solvent DMAc is 197.5 g.

Example three

The third embodiment is similar to the first embodiment, except that the weight of the catalyst triethylenediamine (DABCO) is 1.5 g, the weight percentage of the catalyst DABCO relative to the total weight of ODA and PMDA is 3%, and the weight of the solvent DMAc 200 grams.

Embodiment 4

The fourth embodiment is similar to the first embodiment, except that in the fourth embodiment, 15.84 g of ODA, 5.7 g of p-phenylenediamine (PPDA) and 0.5 g of N, N-dimethylcyclohexylamine as a catalyst are added to 200 g The solution was stirred in DMAc for 0.5 hours, so that ODA, PPDA and N, N-dimethylcyclohexylamine were uniformly dissolved in DMAc to form a diamine solution containing a catalyst. Next, 28.46 g of pyromellitic dianhydride (PMDA) was slowly added to the catalyst-containing diamine solution and stirred at room temperature for 6 hours, so that PMDA reacted with ODA and PPDA to form a catalyst-containing polyamine solution. The weight percentage of the catalyst N, N-dimethylcyclohexylamine to the total weight of ODA, PPDA and PMDA is 1%.

Example 5

The fifth embodiment is similar to the fourth embodiment, except that in the fifth embodiment, the weight of the catalyst N, N-dimethylcyclohexylamine is 1.5 g, and the catalyst N, N-dimethylcyclohexylamine relative to ODA, PPDA and The total weight of PMDA is 3% by weight, and the weight of the solvent DMAc is 200 grams.

Example Six

The sixth embodiment is similar to the fourth embodiment, except that the weight of the catalyst DABCO is 1.5 g, the weight percentage of the catalyst DABCO relative to the total weight of ODA, PPDA and PMDA is 3%, and the weight of the solvent DMAc is 200 g.

Example Seven

Example 7 is similar to Example 1, except that in Example 7, 14.4 g of ODA, 5.19 g of p-phenylenediamine (PPDA), and 2.5 g of DABCO as a catalyst were added to 200 g of DMAc and stirred for 0.5 hours to make ODA , PPDA and DABCO are uniformly dissolved in DMAc to form a diamine solution containing a catalyst. Next, 12.95 g of PMDA and 17.46 g of biphenyltetracarboxylic dianhydride (BPDA) were slowly added to the catalyst-containing diamine solution and stirred at room temperature for 6 hours, so that PMDA and BPDA reacted with ODA and PPDA to form a catalyst-containing solution. Polyamine solution. The weight percentage of the catalyst DABCO to the total weight of ODA, PPDA, PMDA and BPDA is 5%.

Example eight

The eighth embodiment is similar to the first embodiment, except that in the eighth embodiment, 10.11 g of ODA, 5.46 g of p-phenylenediamine (PPDA), and 1.5 g of N, N-dimethylcyclohexylamine as a catalyst are added to 200 g The solution was stirred in DMAc for 0.5 hours, so that ODA, PPDA and N, N-dimethylcyclohexylamine were uniformly dissolved in DMAc to form a diamine solution containing a catalyst. Next, 13.08 g of PMDA and 21.35 g of BP-TME (Bis (1,3-dioxo-1,3-dihydroisobenzofuran-5-carboxylic acid) biphenyl-3,3'-diyl ester) were slowly added to the catalyst-containing diamine The solution was stirred at room temperature for 6 hours, and PMDA and BP-TME were reacted with ODA and PPDA to form a polyamine solution containing a catalyst. The weight percentage of the catalyst N, N-dimethylcyclohexylamine to the total weight of ODA, PPDA, PMDA and BP-TME is 3%.

Comparative example one

Comparative Example 1 is similar to Example 1, except that catalyst is not added in Comparative Example 1.

Comparative Example Two

Comparative Example 2 is similar to Example 4, except that no catalyst was added in Comparative Example 2.

Comparative example three

Comparative Example 3 is similar to Example 7, except that no catalyst was added in Comparative Example 3.

Comparative Example 4

Comparative Example 4 is similar to Example 8 except that no catalyst was added in Comparative Example 4.

Please refer to Table 1 for the formulation of Examples 1 to 8 and Comparative Examples 1 to 4.

Table I         <TABLE border = "1" borderColor = "# 000000" width = "85%"> <TBODY> <tr> <td> </ td> <td> Catalyst (%) </ td> <td> Diamine ( G) </ td> <td> Tetracarboxylic dianhydride (g) </ td> </ tr> <tr> <td> </ td> <td> </ td> <td> ODA </ td> <td> PPDA </ td> <td> PMDA </ td> <td> BPDA </ td> <td> BP-TME </ td> </ tr> <tr> <td> Example 1 </ td > <td> N, N-dimethylcyclohexylamine 3% (1.5 g) </ td> <td> 24.06 </ td> <td>-</ td> <td> 25.94 </ td> <td >-</ td> <td>-</ td> </ tr> <tr> <td> Example 2 </ td> <td> N, N-dimethylcyclohexylamine 5% (2.5 g) </ td> <td> 24.06 </ td> <td>-</ td> <td> 25.94 </ td> <td>-</ td> <td>-</ td> </ tr> <tr > <td> Example 3 </ td> <td> DABCO 3% (1.5 g) </ td> <td> 24.06 </ td> <td>-</ td> <td> 25.94 </ td> < td>-</ td> <td>-</ td> </ tr> <tr> <td> Example 4 </ td> <td> N, N-dimethylcyclohexylamine 1% (0.5 g ) </ td> <td> 15.84 </ td> <td> 5.7 </ td> <td> 28.46 </ td> <td>-</ td> <td>-</ td> </ tr> < tr> <td> Example 5 </ td> <td> N, N-dimethylcyclohexylamine 3% (1.5 g) </ td> <td> 15.84 </ td> <td> 5.7 </ td > <td> 28.46 </ td> <td>-</ td> <td>-</ td> </ tr> <tr> <td> Embodiment 6 </ td> td> <td> DABCO 3% (1.5 g) </ td> <td> 15.84 </ td> <td> 5.7 </ td> <td> 28.46 </ td> <td>-</ td> <td >-</ td> </ tr> <tr> <td> Example 7 </ td> <td> DABCO 5% (2.5 g) </ td> <td> 14.4 </ td> <td> 5.19 < / td> <td> 12.95 </ td> <td> 17.46 </ td> <td>-</ td> </ tr> <tr> <td> Example 8 </ td> <td> N, N -Dimethylcyclohexylamine 3% (1.5 g) </ td> <td> 10.11 </ td> <td> 5.46 </ td> <td> 13.08 </ td> <td>-</ td> < td> 21.35 </ td> </ tr> <tr> <td> Comparative Example 1 </ td> <td> None </ td> <td> 24.06 </ td> <td>-</ td> <td > 25.94 </ td> <td>-</ td> <td>-</ td> </ tr> <tr> <td> Comparative Example 2 </ td> <td> None </ td> <td> 15.84 </ td> <td> 5.7 </ td> <td> 28.46 </ td> <td>-</ td> <td>-</ td> </ tr> <tr> <td> Comparative example three </ td> <td> None </ td> <td> 14.4 </ td> <td> 5.19 </ td> <td> 12.95 </ td> <td> 17.46 </ td> <td>-</ td> </ tr> <tr> <td> Comparative Example 4 </ td> <td> None </ td> <td> 10.11 </ td> <td> 5.46 </ td> <td> 13.08 </ td > <td>-</ td> <td> 21.35 </ td> </ tr> </ TBODY> </ TABLE>

Please refer to Table 2 for the collation of the measurement results of the graphite films of Examples 1 to 8 and Comparative Examples 1 to 4.

Table II         <TABLE border = "1" borderColor = "# 000000" width = "85%"> <TBODY> <tr> <td> </ td> <td> Graphite film formation status </ td> <td> Graphite film Film thickness (μm) </ td> <td> Thermal conductivity (W / mK) </ td> <td> Thermal diffusivity α (cm <sup> 2 </ sup> / sec) </ td> </ tr > <tr> <td> Example 1 </ td> <td> Film formation </ td> <td> 59 </ td> <td> 1184.3 </ td> <td> 6.482 </ td> </ tr > <tr> <td> Example 2 </ td> <td> Film formation </ td> <td> 52 </ td> <td> 1332.2 </ td> <td> 7.292 </ td> </ tr > <tr> <td> Example 3 </ td> <td> Film formation </ td> <td> 58 </ td> <td> 1228 </ td> <td> 6.721 </ td> </ tr > <tr> <td> Example 4 </ td> <td> Film formation </ td> <td> 56.5 </ td> <td> 1257.4 </ td> <td> 6.882 </ td> </ tr > <tr> <td> Example 5 </ td> <td> Film formation </ td> <td> 55 </ td> <td> 1334.2 </ td> <td> 7.303 </ td> </ tr > <tr> <td> Example 6 </ td> <td> Film formation </ td> <td> 53 </ td> <td> 1406.6 </ td> <td> 7.699 </ td> </ tr > <tr> <td> Example 7 </ td> <td> Film formation </ td> <td> 52.5 </ td> <td> 1152.6 </ td> <td> 6.309 </ td> </ tr > <tr> <td> Example 8 </ td> <td> Film formation </ td> <td> 54 </ td> <td> 1302.5 </ td> <td> 7.129 </ td> </ tr > <tr> <td> ratio Example 1 </ td> <td> Fragile </ td> <td>-</ td> <td>-</ td> <td>-</ td> </ tr> <tr> <td> Compare Example 2 </ td> <td> Filming </ td> <td> 48-56 </ td> <td> 1092.4 </ td> <td> 5.979 </ td> </ tr> <tr> <td > Comparative Example 3 </ td> <td> Fragile </ td> <td>-</ td> <td>-</ td> <td>-</ td> </ tr> <tr> <td > Comparative Example 4 </ td> <td> Film formation </ td> <td> 58 </ td> <td> 982.8 </ td> <td> 5.379 </ td> </ tr> </ TBODY> < / TABLE>

Comparative Examples 1 to 4 did not use a catalyst to catalyze the imidization reaction, but only used a high temperature to catalyze the polyimidation reaction in the polyacid film. Therefore, affected by the different heating and heating speeds of the various parts of the polyimide film, the speed and degree of the imidization reaction of the polyimide film are uneven, which makes the degree of imidization of the polyimide film at different parts inconsistent. It is not possible to obtain a polyfluorene imide film in which continuous polyamine molecules are aligned. Furthermore, during the subsequent graphitization, the speed of dehydration and carbonization of the polyimide films of different degrees of imidization were not consistent, resulting in the failure to obtain a graphite film composed of continuous and ordered layered graphite molecules. Therefore, the thermal conductivity and thermal diffusivity of the graphite films of Comparative Examples 2 and 4 are not good, the thickness of the films of Comparative Example 2 is not uniform, and Comparative Examples 1 and 3 even break up and fail to form a film.

Compared to Comparative Examples 1 to 4, Examples 1 to 8 of the present invention use a catalyst to catalyze a polyfluorinated acid film for amidation reaction to form a polyfluorinated imine film. Under the catalysis of the catalyst which is uniformly mixed with the polyamidic acid, the imidization reaction is carried out at a similar reaction rate, thereby obtaining a polyimide film having the same degree of imidization. In this way, when the polyimide film with the same degree of imidization is subsequently graphitized, the speed of dehydration and carbonization of the polyimide film at each part is relatively consistent, and a better-quality graphite film can be obtained. Therefore, the graphite film of the first to eighth embodiments of the present invention has a thermal conductivity higher than 1100 W / mK and a thermal diffusivity higher than 6.3 mm ² / sec, and its thermal conductivity is sufficient to be applied to heat dissipation elements in electronic products.

Furthermore, the catalyst has been uniformly dispersed in the diamine solution containing the catalyst before being contacted with the polyamidic acid, so that the amount of catalyst required to complete the imidization reaction within a predetermined time is reduced. In this way, the present invention uses less catalyst to complete the imidization reaction within a predetermined time, so that the manufacturing cost of the present invention is reduced.

Furthermore, in the first to eighth embodiments of the present invention, the catalyst is dissolved and uniformly dispersed in the diamine solution containing the catalyst before forming the polyamidic acid solution containing the catalyst. In this way, it is easy to control the polymerization reaction rate of the diamine and the tetracarboxylic dianhydride, so that the viscosity of the polyamine solution containing the catalyst is controlled between 10,000 cps and 50,000 cps, that is, 100 poise (ps) to 500 Berth. Therefore, the catalyst-containing polyamine solution is coated on a carrier plate and heated and dried to obtain a catalyst-containing polyamine film having a uniform film thickness, and a flat graphite film can be obtained.

To sum up, in the method for manufacturing a polyimide film of the present invention and the method for manufacturing a graphite film using the same, the use of a tertiary amine as a catalyst catalyzes the amidation reaction of a polyamidic acid, and through the improvement The mixing uniformity between the polyamic acid and the catalyst can increase the contact area and the collision frequency between the polyamic acid and the catalyst, obtain a better imidization effect and obtain a better quality polyimide film. In this way, the graphite film obtained from the graphitization of a polyimide film of better quality according to the present invention has better thermal conductivity, and solves the problem of insufficient thermal conductivity of a heat dissipation material in an electronic product.

Furthermore, the catalyst has been uniformly dispersed in the diamine solution containing the catalyst before being contacted with the polyamidic acid, so that the amount of catalyst required to complete the imidization reaction within a predetermined time is reduced. In this way, the present invention uses less catalyst to complete the imidization reaction within a predetermined time, so that the manufacturing cost of the present invention is reduced.

In addition, the catalyst has been uniformly dispersed in the diamine solution containing the catalyst before being contacted with the polyamic acid, so that the polymerization reaction rate of the diamine and the tetracarboxylic dianhydride can be easily controlled, thereby making the polyamino acid solution containing the catalyst The viscosity is controlled between 10,000 cps and 50,000 cps, that is, between 100 poise (ps) and 500 poise. In this way, the thickness of the catalyst-containing polyamine film obtained by subsequent heating and drying of the catalyst-containing polyamino acid solution coated on the carrier plate is relatively uniform, and a flat graphite film can be obtained. In this way, when the graphite film produced by the manufacturing method of the present invention is used as a heat dissipation material of an electronic product, it can be closely adhered to the heat source of the electronic product to obtain a better heat transfer effect, thereby improving the heat dissipation effect of the electronic product.

Although the present invention is disclosed in the foregoing embodiments, it is not intended to limit the present invention. Changes and modifications made without departing from the spirit and scope of the present invention belong to the patent protection scope of the present invention. For the protection scope defined by the present invention, please refer to the attached patent application scope.

no

FIG. 1 is a flowchart of a graphite film manufacturing method according to an embodiment of the present invention. FIG. 2 is a flowchart of a graphite film manufacturing method according to another embodiment of the present invention.

Claims (15)

A method for manufacturing a polyfluoreneimide film includes: mixing a diamine, a solvent, and a catalyst to form a catalyst-containing diamine solution; mixing a tetracarboxylic dianhydride and the catalyst-containing diamine solution to form a Catalyst-containing polyamine solution; heating the catalyst-containing polyamino acid solution to form a catalyst-containing polyamino acid film; and imidizing the catalyst-containing polyamino acid film to form a polyfluorene Imine film; wherein, in the step of imidizing the polyamine film containing the catalyst to form the polyimide film, the catalyst-containing polyamine film is catalyzed by heating and dehydration together with the catalyst The imidization is performed to form the polyimide film in a solid state, and the catalyst is a tertiary amine. A method for manufacturing a polyimide film, comprising: mixing a diamine, a tetracarboxylic dianhydride, a solvent, and a catalyst to form a polyamic acid solution containing a catalyst; and heating the polyamino acid containing the catalyst. A solution to form a polyamine film containing a catalyst; and amidating the polyamine film containing a catalyst to form a polyimide film; wherein the polyamine containing the catalyst is imidized. In the step of forming a polyimide film by heating, dehydration and catalysis with the catalyst to catalyze the solid polyamidic acid film containing the catalyst in a solid state through heating and dehydration to form the polyimide film in a solid state, and the The catalyst is a tertiary amine. The weight percentage of the catalyst relative to the total weight of the diamine and the tetracarboxylic dianhydride is 1 to 50%, and the viscosity of the polyamine solution containing the catalyst is 10,000 to 50,000 cps. The method for manufacturing a polyimide film according to claim 1, wherein the weight percentage of the catalyst relative to the total weight of the diamine and the tetracarboxylic dianhydride is 1 to 50%. The method for manufacturing a polyimide film according to claim 3, wherein the weight percentage of the catalyst relative to the total weight of the diamine and the tetracarboxylic dianhydride is 1 to 10%. The method for manufacturing a polyfluoreneimide film according to claim 4, wherein the weight percentage of the catalyst relative to the total weight of the diamine and the tetracarboxylic dianhydride is 1 to 5%. The method for producing a polyimide film according to claim 1, wherein the viscosity of the polyamidic acid solution containing the catalyst is 10,000 to 50,000 cps. The method for producing a polyfluoreneimide film according to claim 1 or 2, wherein the diamine includes p-phenylenediamine (PPDA, p-Phenylenediamine), 2,2'-bis (trifluoromethyl) benzidine ( TFMB, 2,2'-Bis (trifluoromethyl) benzidine, CAS.No.:341-58-2), HFBAPP (2,2-Bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, CAS.No.69563- 88-8), BTFDPE (4,4'-oxybis [3- (trifluoromethyl) benzeneamine], CAS.No.344-48-9), FAPQ (4,4 '-[1,4-phenylenebis (oxy)] Bis [3- (trifluoromethyl)] benzenamine, CAS. No. 94525-05-0), FFDA (9,9-Bis (4-amino-3-fluorophenyl) fluorine, CAS. No. 127926-65-2), 9,9-Bis [4- (4-amino-3-fluorophenyl) bezene] fluorine, BAFL (9,9-Bis (aminophenyl9fluorene)), or 4,4'-diaminodiphenyl ether (ODA, 4,4 ' -Oxydianiline, CAS. No .: 101-80-4). The method for producing a polyfluoreneimide film according to claim 1 or 2, wherein the tetracarboxylic dianhydride comprises pyromellitic dianhydride (PMDA, 1,2,4,5 benzenetetracarboxylic dianhydride), biphenyltetracarboxylic acid Acid dianhydride (BPDA, 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride), biphenyltetracarboxylic dianhydride (3,4,3', 4'-biphenyltetracarboxylic dianhydride), 2,3,3 ', 4 '-Biphenyltetracarboxylic dianhydride (2,3,3 ', 4'-biphenyltetracarboxylic dianhydride), diphenyl ether tetracarboxylic dianhydride (4,4'-oxydiphthalic anhydride), 3,4'-diphenyl ether tetracarboxylic dianhydride (3,4'- oxydiphthalic anhydride), benzophenonetetracarboxylic dianhydride, 2,2-bis [(4- (3,4-dicarboxyphenoxy) phenyl)] propane dianhydride (BPADA, 2,2 -bis [4- (3,4-dicarboxyphenoxy) phenyl] propane dianhydride), 4,4 '-(hexafluoroisopropene) diphthalic anhydride (6FDA, 2,2-bis (3,4-anhydrodicarboxyphenyl) hexafluoropropane), Diphenyl maple tetracarboxylic dianhydride (3,3 ', 4,4'-diphenylsulfonetetracarboxylic dianhydride), 9,9-bis (3,4-dicarboxyphenyl) fluorene dianhydride, CAS. No. 135876-30-1, 9 , 9-bis [4- (3,4-dicarboxyphenoxt) phenyl] fluorene dianhydride, CAS. No. 59507-08-3, naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, naphthalene di Acid anhydride (naphthalenetetracaboxylic dianhydride), bis- (3,4-diphthalic anhydride) dimethyl silane (bis (3,4-dicarboxyphenyl) dimethylsilane dianhydride), 1,3-bis (3,4-dicarboxyphenyl) -1,1,3,3-tetramethyldisiladian dianhydride (1,3-bis (4'-phthalic anhydr ide) -tetramethyldisiloxane), BPAF (9,9-Bis (3,4-dicarboxyphenyl) fluorine dianhydride) or BP-TME (Bis (1,3-dioxo-1,3-dihydroisobenzofuran-5-carboxylic acid) biphenyl-3 3'-diyl ester). The method for producing a polyfluoreneimide film according to claim 1 or 2, wherein the combination of the diamine and the tetracarboxylic dianhydride is 4,4'-diaminodiphenyl ether (ODA, 4,4'- Oxydianiline, CAS. No .: 101-80-4) in combination with pyromellitic dianhydride (PMDA, 1,2,4,5 benzenetetracarboxylic dianhydride), or 4,4'-diaminodiphenyl ether (ODA) , A combination of p-phenylenediamine (PPDA, p-Phenylenediamine) and pyromellitic dianhydride (PMDA), or 4,4'-diaminodiphenyl ether (ODA), p-phenylenediamine (PPDA), cumene Tetracarboxylic dianhydride (PMDA) and biphenyltetracarboxylic dianhydride (BPDA, 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride), or 4,4'-diaminodiphenyl ether (ODA), p-phenylenediamine (PPDA), pyromellitic dianhydride (PMDA) and BP -TME (Bis (1,3-dioxo-1,3-dihydroisobenzofuran-5-carboxylic acid) biphenyl-3,3'-diyl ester). The method for manufacturing a polyfluoreneimide film according to claim 1 or 2, wherein the catalyst comprises triethylenediamine (DABCO, Triethylenediamine), N, N-Dimethylcyclohexylamine, 1,2-Dimethylimidazole, trimethylamine, triethylamine, tripropylamine, tributylamine, triethanolamine, N, N-dimethylethanolamine, N, N-diethylethanolamine , Triethylenediamine, N-methylpyrrolidine, N-ethylpyrrolidine, N-methylhexahydropyridine, N-ethylhexahydropyridine, imidazole, pyridine, quinoline or isoquinoline. A method for manufacturing a graphite film, comprising: preparing a polyimide film according to the method for manufacturing a polyimide film according to any one of claim 1 to claim 10; and heating the polyimide film to form a graphite. membrane; The method for manufacturing a graphite film according to claim 11, wherein a thermal conductivity of the graphite film is greater than 1100 W / m-K. The method for manufacturing a graphite film according to claim 11, wherein the graphite film has a thermal diffusivity higher than 6.3 cm ² / sec. The method for manufacturing a graphite film according to any one of claim 11 to claim 13, wherein the step of heating the polyimide film to form the graphite film includes heating and carbonizing the polyimide film at a carbonization temperature. To form a carbonized polyfluorene film; and The carbonized polyfluorene film is heated and graphitized at a graphitization temperature to form the graphite film, and the graphitization temperature is higher than the carbonization temperature. The method for manufacturing a graphite film according to claim 14, wherein the carbonization temperature is 900 to 1500 ° C, and the graphitization temperature is 2500 to 3000 ° C.