KR20200051261A - Ultra-Thin Polyimide Film with Improved Dimensional Stability and Method for Preparing the Same - Google Patents

Abstract

The present invention provides a polyimide film having a thickness of at most 10.0 μm, a modulus of at least 4 GPa and a coefficient of thermal expansion of 8-10 ppm/°C.

Description

Ultra-Thin Polyimide Film with Improved Dimensional Stability and Method for Preparing the Same}

The present invention relates to an ultra-thin polyimide film having improved dimensional stability and a method for manufacturing the same.

Polyimide (PI) is a polymer material having thermal stability based on a rigid aromatic backbone, and has excellent mechanical strength, chemical resistance, weather resistance, and heat resistance based on the chemical stability of the imide ring.

In addition, polyimide is highly regarded as a high-functional material that can be used in microelectronics and optical fields based on excellent electrical properties such as insulation properties and low dielectric constant.

Examples of the microelectronic field include highly integrated circuits included in portable electronic devices and communication devices. The polyimide can be used as a film that is attached to or added to a circuit to provide electrical insulation to the circuit, while protecting the circuit against moisture, light sources, and shocks.

Although various examples may exist as a film for protecting the circuit as described above, in the case of a composite film in which an adhesive layer is formed on one side or both sides of the film, it may be referred to as a coverlay in a narrow sense. It can be preferably used for the coverlay.

Recently, flexible circuit boards in which circuit shapes can be flexibly deformed have been widely used as electronic devices have become thinner, smaller, and more diversified in design, and the polyimide film is also thicker to be used as a coverlay for such circuit boards. It is manufactured in an ultra-thin form of thin, for example, 10 µm or less.

However, such an ultra-thin polyimide film has a disadvantage of poor dimensional stability due to a relatively low modulus and a rather high thermal expansion coefficient unsuitable for the coverlay.

Accordingly, there is a high need for a polyimide film having an ultra-thin film shape and excellent dimensional stability.

According to an aspect of the present invention, despite the first polyamic acid and the second polyamic acid having different properties and an inorganic filler, in particular, a polyimide film prepared using nano silica is in the form of an ultra-thin film of 10 μm or less, While satisfying the required mechanical properties, it is possible to develop very good dimensional stability.

According to another aspect of the present invention, when preparing a polyimide film by preparing a mixed solution comprising a second polyamic acid and nano silica and mixing it with the first polyamic acid, mixing and / or dispersion of nano silica is improved. A high quality polyimide film can be obtained.

According to these aspects, the above-mentioned conventional problems can be solved, and the present invention has a practical purpose in providing a specific embodiment thereof.

In one embodiment, the present invention provides a first polyamic acid prepared by polymerization of a first dianhydride and a first diamine;

A second polyamic acid prepared by polymerization of a second dianhydride and a second diamine; And

It provides a polyimide film having a thickness of 10.0 μm or less by imidizing a precursor composition including an inorganic filler.

In one embodiment, the present invention provides a method of making the polyimide film.

In one embodiment, the present invention provides a coverlay comprising the polyimide film and an electronic device including the coverlay.

Hereinafter, embodiments of the present invention will be described in more detail in the order of "polyimide film" and "polyimide film production method" according to the present invention.

Prior to this, the terms or words used in the present specification and claims should not be interpreted as being limited to ordinary or dictionary meanings, and the inventor appropriately explains the concept of terms in order to explain his or her invention in the best way. Based on the principle that it can be defined, it should be interpreted as meanings and concepts consistent with the technical spirit of the present invention.

Therefore, the configuration of the embodiments described herein is only one of the most preferred embodiments of the present invention and does not represent all of the technical spirit of the present invention, and various equivalents and modifications that can replace them at the time of this application It should be understood that examples may exist.

In this specification, a singular expression includes a plural expression unless the context clearly indicates otherwise. In this specification, the terms "comprises", "haves" or "have" are intended to indicate the presence of implemented features, numbers, steps, elements or combinations thereof, one or more other features or It should be understood that the existence or addition possibilities of numbers, steps, elements, or combinations thereof are not excluded in advance.

As used herein, "dianhydride (dianhydride)" is intended to include its precursors or derivatives, which may not technically be dianhydrides, but nevertheless react with diamines to form polyamic acids. And this polyamic acid can be converted back to polyimide.

“Diamine” as used herein is intended to include precursors or derivatives thereof, which may not technically be diamines, but will nevertheless react with dianhydrides to form polyamic acids, which are polyamic The acid can be converted back to polyimide.

Where an amount, concentration, or other value or parameter herein is given as an enumeration of ranges, preferred ranges, or preferred upper and lower limits, any upper limit of any pair of any pair, regardless of whether the ranges are disclosed separately or It should be understood to specifically disclose all ranges that can be formed with preferred values and any lower range limits or desirable values. When a range of numerical values is referred to herein, unless stated otherwise, that range is intended to include the endpoints and all integers and fractions within the range. It is intended that the scope of the invention not be limited to the specific values recited when defining a range.

Polyimide film

The polyimide film according to the present invention,

A first polyamic acid prepared by polymerization of the first dianhydride and the first diamine;

A second polyamic acid prepared by polymerization of a second dianhydride and a second diamine; And

As a polyimide film prepared by imidizing a precursor composition containing an inorganic filler,

The second dianhydride is 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride (s-BPDA) and 2,3,3', 4'-biphenyltetracarboxylic dianhydride Ride (a-BPDA) contains at least one selected from,

The second diamine is 1 selected from paraphenylenediamine (PPD), metaphenylenediamine (MPD), 3,3'-dimethylbenzidine (o-tolidine) and 2,2'-dimethylbenzidine (m-tolidine). Includes more than species,

The first dianhydride includes at least one dianhydride different from the second dianhydride,

The first diamine includes at least one diamine different from the second diamine,

The thickness may be 10.0 μm or less, the modulus may be 4 GPa or more, and the coefficient of thermal expansion may be 8 to 10 ppm / ° C. or less.

In one specific example, the first polyamic acid may form a first polyimide chain through imidization, and the second polyamic acid may form a second polyimide chain through imidization, and the inorganic system The filler may be dispersed in the first polyimide chain and the second polyimide chain.

In some aspects, at least a portion of the first polyimide chain and the second polyimide chain may be cross-linked through imidization.

The inorganic filler dispersed as described above may advantageously act to improve the chemical resistance and strength of the polyimide film. However, the excessive use of the inorganic filler may serve as a direct cause of the rapid elongation of the polyimide film, and, on the contrary, the use of too little is advantageous for improving the thermal properties and strength of the polyimide film. It does not work and is not preferred. The preferred content range of the inorganic filler will be described in detail later.

The inorganic filler is, without limitation, silica, alumina, titania, zinc oxide, tantalum oxide, zirconia, silicon nitride, boron nitride, calcium sulfate, calcium carbonate, barium carbonate, gallium oxide, talc, barium silicate, magnesium titanate, titanium It may include at least one selected from barium acid and aluminum titanate. Specifically, spherical nano-silica having an average particle diameter of 10 to 20 nm with excellent dispersibility and relatively small particle size distribution variation with respect to polyamic acid. It may include.

When the average particle diameter of the nano-silica is less than the above range, the specific surface area based on the entire nano-silica is increased, and particles constituting the nano-silica may be aggregated. Aggregation of the particles constituting the nano-silica can lead to defects in the form protruding from the polyimide surface.

If, when the average particle diameter of the nano-silica exceeds the above range, the smoothness of the polyimide film may be lowered. In another aspect, nano silica having a relatively large average particle diameter exceeding the above range may cause a phenomenon in which particles settling in the polyamic acid are increased by gravity. The nano-silica particles which have been precipitated and partially biased may form protrusions while being exposed through the surface of the polyimide film.

The second polyamic acid may be a material having a rigid structure and a flexible structure together at an appropriate level in molecular structure, so that the second polyimide chain derived from the second polyamic acid is rigid at an appropriate level while a part is relatively It can have a flexible molecular structure.

Such a second polyimide chain can contribute to intrinsicly required tensile strength and / or modulus of the polyimide film, in particular, so that the polyimide film has a predetermined strength.

In addition, properties such as elongation may generally be difficult to be compatible with the desired modulus at a desired level, but the second polyimide chain of the present invention allows the polyimide film to express a desired level of strength based on its molecular structure and at the same time elongation. It can play a major role in suppressing the expression of the decrease.

The first polyimide chain formed from the first polyamic acid may be present in excess of the second polyimide chain. Accordingly, the first polyimide chain can achieve most of the content of the polymer chain constituting the polyimide film. Such a first polyimide chain can have a major function in the polyimide film having a desirable level of tensile strength and modulus, and an appropriate level of glass transition temperature and chemical resistance.

Also, it should be noted that in the polyimide film of the present invention, the first polyimide chain and the second polyimide chain act complementarily to have an appropriate level of thermal expansion coefficient.

In general, in order to suppress the occurrence of thermal distortion of the polyimide film in the temperature range of 100 to 200 ° C, which is formed in the production of the coverlay, it may be preferable that the thermal expansion coefficient of the polyimide film is 10 ppm / ° C.

When the polyimide film is applied as a coverlay, it may be a thermal expansion coefficient suitable for reflecting a compensation value according to a difference in thermal expansion coefficient between an adhesive layer having adhesiveness between the polyimide film and the metal foil, and the polyimide film within the scope of the present invention Based on the thickness of the thermal expansion coefficient can be controlled. If there is no correction of the coefficient of thermal expansion according to the thickness of the polyimide film, a poor appearance of the coverlay may be caused.

Accordingly, the polyimide film according to the present invention is characterized by a combination of a first polyimide chain and a second polyimide chain, and despite being an ultra-thin type, it is 10 ppm / ℃ or less, in particular 8 ppm / ℃ to 10 ppm / ℃ , More specifically, it may have a thermal expansion coefficient of 9 ppm / ℃ to 10 ppm / ℃.

As a result, the polyimide film of the present invention has the advantage of having dimensional stability suitable for being applied as a coverlay with an inherently high level of modulus, elongation and thermal expansion coefficient while being ultra-thin.

However, when the contents of the first polyimide chain and the second polyimide chain in the polyimide film are harmonized in a predetermined range, various physical properties-related advantages described above may be exhibited, but outside the range, the first polyimide chain And when the exquisite balance in which the second polyimide chain can act complementarily collapses, the thermal expansion coefficient may be excessively increased or seriously deteriorated.

In addition, even if the content of the second polyimide chain is relatively excessive, the tensile strength and modulus of the polyimide film are not significantly improved, while the coefficient of thermal expansion may rapidly decrease, and the glass transition temperature and adhesion may be lowered. As such, it may be desirable for the second polyimide chain to be used limitedly to achieve the desired polyimide film.

Particularly, this phenomenon may be more prominent in an ultra-thin film having a thickness of 10 μm or less, and particularly 8.0 μm or less.

Accordingly, the present invention provides a desirable content of the first polyimide chain and the second polyimide chain. In a specific example of this, the polyimide film of the present invention, based on its total weight, 60 to 90% by weight of the first polyimide chain, 5 to 20% by weight of the second polyimide chain and 5 to 20% by weight of the inorganic system It may include a filler, and more specifically, the polyimide has a thickness of 8.0 µm or less, and in particular 7.5 µm or less, based on the total weight thereof, 74 to 86 wt% of the first polyimide chain, 7 to 13 And 2 to 7% by weight of the second polyimide chain and an inorganic filler.

When the first polyimide chain and the second polyimide chain are combined in an exquisite balance in such a predetermined content range, the polyimide film can inherently possess both the desired level of mechanical properties and dimensional stability as described above. have.

Such a polyimide film,

The tensile strength may be 30 kgf / cm ³ or more, specifically 30 kgf / cm ³ to 50 kgf / cm ³ ,

Elongation may be 40% or more, specifically 50% to 80%,

Modulus can be from 4 GPa to 7 Gpa,

The glass transition temperature may be 380 ° C or higher, and specifically 380 ° C to 450 ° C.

In one specific example, the first polyamic acid has a viscosity of 50,000 cP to 300,000 cP measured at 23 ° C when the solid content is 15% by weight, and the second polyamic acid is 23 ° C when the solid content is 15% by weight The viscosity measured at may be 5,000 cP to 20,000 cP.

When the viscosity of the first polyamic acid is less than 50,000 cP, the polyimide film may significantly deteriorate heat resistance and mechanical properties. When the viscosity of the first polyamic acid is more than 300,000 cP, there may be a problem in terms of the manufacturing process of the film. Specifically, as the precursor composition has a high viscosity, there is a possibility that a problem occurs in the film forming process of the film, and further, it may be difficult to produce a film of 10 μm or less.

When the viscosity of the second polyamic acid is less than 5,000 cP, the formation of the second polyimide chain may not be sufficient. This is not desirable from the viewpoint of improving various properties of the polyimide film described above. When the viscosity of the second polyamic acid exceeds 20,000 cP, the dispersibility of the inorganic filler in the precursor composition may be lowered, which is not preferable in view of the processability of the polyimide film.

In one specific example, the second dianhydride may include 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, and the second diamine is 2,2'-dimethylbenzidine It may include.

In another specific example, the second dianhydride may include 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, and the second diamine may include paraphenylenediamine Can be.

In one specific example, the first diamine,

The first diamine is paraphenylenediamine, metaphenylenediamine, 3,3'-dimethylbenzidine, 2,2'-dimethylbenzidine, 2,4-diaminotoluene, 2,6-diaminotoluene, 3, 5-diaminobenzoic acid (DABA), 4,4'-diaminodiphenyl ether (ODA), 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane (methylenediamine) , 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2'-bis (trifluoromethyl) -4, 4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminodiphenylmethane, 3,3'-dicarboxy-4,4'-diaminodiphenylmethane, 3,3 ', 5,5'-tetramethyl-4,4'-diaminodiphenylmethane, bis (4-aminophenyl) sulfide, 4,4'-diaminobenzanilide, 3,3'-dimethoxybenzidine, 2, 2'-dimethoxybenzidine, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl sulfide , 3,4'-diaminodiphenyl Fide, 4,4'-diaminodiphenylsulfide, 3,3'-diaminodiphenylsulfone, 3,4'-diaminodiphenylsulfone, 4,4'-diaminodiphenylsulfone, 3,3 ' -Diaminobenzophenone, 4,4'-diaminobenzophenone, 3,3'-diamino-4,4'-dichlorobenzophenone, 3,3'-diamino-4,4'-dimethoxybenzophenone , 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 2,2-bis (3-aminophenyl) propane, 2,2 -Bis (4-aminophenyl) propane, 2,2-bis (3-aminophenyl) -1,1,1,3,3,3-hexafluoropropane, 2,2-bis (4-aminophenyl) -1,1,1,3,3,3-hexafluoropropane, 3,3'-diaminodiphenylsulfoxide, 3,4'-diaminodiphenylsulfoxide, 4,4'-diaminodi Phenyl sulfoxide, 1,3-bis (3-aminophenyl) benzene, 1,3-bis (4-aminophenyl) benzene, 1,4-bis (3-aminophenyl) benzene, 1,4-bis (4 -Amino phenyl) benzene, 1,3-bis (4-aminophenoxy) benzene (TPE-R), 1,4-bis (3-aminophenoxy) bene (TPE-Q) 1,3-bis (3-aminophenoxy) -4-trifluoromethylbenzene, 3,3'-diamino-4- (4-phenyl) phenoxybenzophenone, 3,3 ' -Diamino-4,4'-di (4-phenylphenoxy) benzophenone, 1,3-bis (3-aminophenylsulfide) benzene, 1,3-bis (4-aminophenylsulfide) benzene, 1, 4-bis (4-aminophenylsulfide) benzene, 1,3-bis (3-aminophenylsulfone) benzene, 1,3-bis (4-aminophenylsulfone) benzene, 1,4-bis (4-aminophenyl) Sulfone) benzene, 1,3-bis [2- (4-aminophenyl) isopropyl] benzene, 1,4-bis [2- (3-aminophenyl) isopropyl] benzene, 1,4-bis [2- (4-aminophenyl) isopropyl] benzene, 3,3'-bis (3-aminophenoxy) biphenyl, 3,3'-bis (4-aminophenoxy) biphenyl, 4,4'-bis ( 3-aminophenoxy) biphenyl, 4,4'-bis (4-aminophenoxy) biphenyl, bis [3- (3-aminophenoxy) phenyl] ether, bis [3- (4-aminophenoxy) ) Phenyl] ether, bis [4- (3-aminophenoxy) phenyl] ether , Bis [4- (4-aminophenoxy) phenyl] ether, bis [3- (3-aminophenoxy) phenyl] ketone, bis [3- (4-aminophenoxy) phenyl] ketone, bis [4- (3-aminophenoxy) phenyl] ketone, bis [4- (4-aminophenoxy) phenyl] ketone, bis [3- (3-aminophenoxy) phenyl] sulfide, bis [3- (4-aminophenoxy Si) phenyl] sulfide, bis [4- (3-aminophenoxy) phenyl] sulfide, bis [4- (4-aminophenoxy) phenyl] sulfide, bis [3- (3-aminophenoxy) phenyl] sulfone , Bis [3- (4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] sulfone, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [3- (3-aminophenoxy) phenyl] methane, bis [3- (4-aminophenoxy) phenyl] methane, bis [4- (3-aminophenoxy) phenyl] methane, bis [4- (4-aminophenoxy City) phenyl] methane, 2,2-bis [3- (3-aminophenoxy) phenyl] propane, 2,2-bis [3- (4-aminophenoxy) phenyl] propane, 2,2- Bis [4- (3-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] propane (BAPP), 2,2-bis [3- (3-aminophenoxy) C) phenyl] -1,1,1,3,3,3-hexafluoropropane, 2,2-bis [3- (4-aminophenoxy) phenyl] -1,1,1,3,3, 3-hexafluoropropane, 2,2-bis [4- (3-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane and 2,2-bis [4- (4-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane.

In one specific example, the first dianhydride,

Pyromellitic dianhydride (PMDA), oxydiphthalic dianhydride (ODPA), 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride (s-BPDA), 2,3,3 ', 4'-biphenyltetracarboxylic dianhydride (a-BPDA), diphenylsulfone-3,4,3', 4'-tetracarboxylic dianhydride (DSDA), bis (3,4 -Dicarboxyphenyl) sulfide dianhydride, 2,2-bis (3,4-dicarboxyphenyl) -1,1,1,3,3,3-hexafluoropropane dianhydride, 2,3,3 ', 4'-benzophenonetetracarboxylic dianhydride, 3,3', 4,4'-benzophenonetetracarboxylic dianhydride (BTDA), bis (3,4-dicarboxyphenyl) methane dian Hydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, p-phenylenebis (trimeric monoester acid anhydride), p-biphenylenebis (trimeric mono Ester acid anhydride), m-terpe Neil-3,4,3 ', 4'-tetracarboxylic dianhydride, p-terphenyl-3,4,3', 4'-tetracarboxylic dianhydride, 1,3-bis (3 , 4-dicarboxyphenoxy) benzene dianhydride, 1,4-bis (3,4-dicarboxyphenoxy) benzene dianhydride, 1,4-bis (3,4-dicarboxyphenoxy) biphenyl Dianhydride, 2,2-bis [(3,4-dicarboxy phenoxy) phenyl] propane dianhydride (BPADA), 2,3,6,7-naphthalenetetracarboxylic acid dianhydride, 1,4,5 , 8-naphthalenetetracarboxylic dianhydride and 4,4 '-(2,2-hexafluoroisopropylidene) diphthalic acid dianhydride.

Manufacturing method of polyimide film

The method for producing the polyimide film of the present invention,

Polymerizing the first polyamic acid from the first dianhydride and the first diamine;

Polymerizing the second polyamic acid from the second dianhydride and the second diamine;

Preparing a mixed solution by mixing the nano-silica prepared using a mill with the second polyamic acid;

Preparing a precursor composition by mixing the mixed solution with a first polyamic acid; And

It may include the step of imidizing the precursor composition to obtain a polyimide film.

In general, inorganic fillers, such as nano-silica, tend to aggregate rather than disperse easily upon simple mixing with polyamic acid. On the other hand, the first polyamic acid and the second polyamic acid sharing similar chemical properties can be relatively easily mixed.

Thus, in the manufacturing method of the present invention, the dispersion of nano silica can be primarily easily induced by mixing the nano silica with a relatively low viscosity second polyamic acid.

Then, when the second polyamic acid containing nano-silica is mixed with the first polyamic acid, the second polyamic acid is easily mixed with the first polyamic acid, and thus the previously dispersed nano-silica together with the second polyamic acid is the first polyamic acid. It can be rapidly mixed and / or dispersed throughout the mixed acid. The above may be the main advantage of the manufacturing method according to the present invention.

In one specific example, an organic solvent may be used in the step of preparing the first polyamic acid, the second polyamic acid, and the mixed solution.

A non-limiting example of an organic solvent that can be used in these steps may be an aprotic polar solvent.

As a non-limiting example of the aprotic polar solvent, amide solvents such as N, N'-dimethylformamide (DMF), N, N'-dimethylacetamide (DMAc), p-chlorophenol, o-chloro And phenol-based solvents such as phenol, N-methyl-pyrrolidone (NMP), gamma brotirolactone (GBL) and digrime, and these may be used alone or in combination of two or more.

The method for polymerizing the first polyamic acid and the second polyamic acid is, for example,

(1) a method in which the total amount of the diamine monomer is placed in an organic solvent, and then the dianhydride monomer is added to be substantially equimolar with the diamine monomer and polymerized;

(2) a method in which the total amount of the dianhydride monomer is placed in an organic solvent, and then the diamine monomer is added to be substantially equimolar with the dianhydride monomer to polymerize;

(3) After adding some components of the diamine monomer in an organic solvent, after mixing some components of the dianhydride monomer with respect to the reaction component at a ratio of about 95 mol% to 105 mol%, the remaining diamine monomer components are added thereto. A method in which the remaining dianhydride monomer components are added successively to make the diamine monomer and the dianhydride monomer substantially equimolar;

(4) After placing the dianhydride monomer in an organic solvent, after mixing some components of the diamine compound with respect to the reaction component in a ratio of 95 mol% to 105 mol, other dianhydride monomer components are added and successively the remaining diamine A method of polymerization by adding a monomer component such that the diamine monomer and the dianhydride monomer become substantially equimolar; And

(5) Some diamine monomer components and some dianhydride monomer components are reacted in an organic solvent so as to be in excess, thereby forming a first polymer, and some diamine monomer components and some dianhydride monomer components in another organic solvent. Is a method of reacting such that one is in excess to form a second polymer, and then mixing the first and second polymers to complete polymerization, wherein the diamine monomer component is excessive when forming the first polymer, In the second polymerized product, an excess of the dianhydride monomer component is present, and when the dianhydride monomer component is excessive in the first polymerized product, in the second polymerized product, the diamine monomer component is added in excess. All diamine monomer components and dianhydride monomer components used in the reaction are substantially equimolar. And a method of polymerizing as much as possible.

However, the above method is an example for helping the implementation of the present invention, and the scope of the present invention is not limited to them, and any known method can be used.

Meanwhile, the first polyamic acid, the second polyamic acid, and / or the mixed solution for the purpose of improving various properties of the film, such as sliding property, thermal conductivity, conductivity, corona resistance, and loop hardness of the polyimide film derived from the precursor composition In the manufacturing step, carbon-based materials such as carbon black and graphene may be further added.

Meanwhile, the step of obtaining the polyimide film may include forming a polyimide film by imidizing the gel film after forming the precursor composition on a support and drying the gel film.

Specific examples of the imidization method include a thermal imidization method, a chemical imidization method, or a complex imidization method using a combination of the thermal imidization method and a chemical imidization method, and examples thereof include the following non-limiting examples. This will be described in more detail.

<Thermal imidization method>

The thermal imidization method is a method of excluding chemical catalysts and inducing an imidization reaction with a heat source such as hot air or an infrared dryer.

Drying the precursor composition to form a gel film; And

The heat treatment of the gel film may include a process of obtaining a polyimide film.

Here, the gel film can be understood as a film intermediate having self-supporting properties in an intermediate step for conversion from polyamic acid to polyimide.

In the process of forming the gel film, the precursor composition is cast in a film form on a support such as a glass plate, aluminum foil, endless stainless belt, or stainless drum, and then the precursor composition on the support is 50 ° C to 200 ° C, Specifically, it may be to dry at a variable temperature in the range of 80 ℃ to 200 ℃.

Accordingly, a gel film may be formed by partial curing and / or drying of the precursor composition. Then, the gel film can be obtained by peeling from the support.

In some cases, a process of stretching the gel film may be performed in order to control the thickness and size of the polyimide film obtained in the subsequent heat treatment process and to improve the orientation, and the stretching is performed in the machine transport direction (MD) and the machine transport direction. It may be performed in at least one of the lateral direction for (TD).

The gel film thus obtained is fixed to a tenter and then heat-treated at a variable temperature in the range of 50 ° C to 700 ° C, specifically 150 ° C to 650 ° C, to remove water, residual solvent, etc. remaining in the gel film, and remaining By imidizing almost all the amic acid groups, the polyimide film of the present invention can be obtained.

In some cases, the polyimide film obtained as described above may be heated to a temperature of 400 ° C to 650 ° C for 5 seconds to 400 seconds to further harden the polyimide film, and may remain inside the obtained polyimide film. It can also be done under a given tension to relieve stress.

<Chemical imidation method>

The chemical imidization method is a method of promoting imidization of the amic acid group by adding a dehydrating agent and / or an imidizing agent to the precursor composition.

Here, the term “dehydrating agent” refers to a substance that promotes a cyclization reaction through dehydration of a polyamic acid, and as a non-limiting example, an aliphatic acid anhydride, an aromatic acid anhydride, N, N ' -Dialkyl carbodiimide, lower halogenated aliphatic, lower halogenated patty acid anhydride, aryl phosphonic dihalide, thionyl halide, and the like. Aliphatic acid anhydrides may be preferred from the viewpoint of ease of availability, and cost, and non-limiting examples thereof include acetic anhydride (or acetic anhydride, AA), propion acid anhydride, and lactic Acid anhydride etc. are mentioned, These can be used individually or in mixture of 2 or more types.

In addition, "imide agent" means a substance having an effect of promoting a ring-closure reaction to a polyamic acid, for example, an imine-based component such as an aliphatic tertiary amine, an aromatic tertiary amine, and a heterocyclic tertiary amine. Can be. Of these, heterocyclic tertiary amines may be preferable from the viewpoint of reactivity as a catalyst. Non-limiting examples of heterocyclic tertiary amines include quinoline, isoquinoline, β-picoline (BP), pyridine and the like, and these may be used alone or in combination of two or more.

It is preferable that the addition amount of a dehydrating agent is in the range of 0.5 to 5 mol with respect to 1 mol of the amic acid group in polyamic acid, and it is particularly preferable to be in the range of 1.0 mol to 4 mol. Further, the amount of the imidizing agent added is preferably in the range of 0.05 mol to 2 mol with respect to 1 mol of the amic acid group in the polyamic acid, and particularly preferably in the range of 0.2 mol to 1 mol.

When the dehydrating agent and the imidizing agent fall below the above range, chemical imidization is insufficient, cracks may be formed in the polyimide film to be produced, and mechanical strength of the film may also be lowered. In addition, if these addition amounts exceed the above range, imidization may proceed excessively rapidly, and in this case, it is difficult to cast in the form of a film, or the prepared polyimide film may exhibit brittle characteristics, which is not preferable. not.

<Composite imidization method>

In conjunction with the chemical imidization method described above, a complex imidization method in which a thermal imidization method is further performed can be used for the production of a polyimide film.

Specifically, the complex imidization method includes a chemical imidation process of adding a dehydrating agent and / or an imidizing agent to a precursor composition at a low temperature; And drying the precursor composition to form a gel film and heat-treating the gel film.

When performing the chemical imidization process, the type and amount of the dehydrating agent and the imidizing agent may be appropriately selected as described in the previous chemical imidization method.

In the process of forming the gel film, a precursor composition containing a dehydrating agent and / or an imidizing agent is cast in a film form on a support such as a glass plate, aluminum foil, endless stainless belt, or stainless drum, and then on the support. The precursor composition is dried at variable temperatures ranging from 50 ° C to 200 ° C, specifically 80 ° C to 200 ° C. In this process, chemical converting agents and / or imidizing agents can act as catalysts to rapidly convert the amic acid groups to imide groups.

In some cases, a process of stretching the gel film may be performed in order to control the thickness and size of the polyimide film obtained in the subsequent heat treatment process and to improve the orientation, and the stretching is performed in the machine transport direction (MD) and the machine transport direction. It may be performed in at least one of the lateral direction for (TD).

The gel film thus obtained is fixed to a tenter and then heat-treated at a variable temperature in the range of 50 ° C to 700 ° C, specifically 150 ° C to 650 ° C to remove water, catalyst, residual solvent, and the like remaining in the gel film, By imidizing almost any remaining amic acid group, the polyimide film of the present invention can be obtained. In such a heat treatment process, a dehydrating agent and / or an imidizing agent acts as a catalyst, so that the amic acid group can be rapidly converted to an imide group, thereby realizing a high imidization rate.

In some cases, the polyimide film obtained as described above may be heated to a temperature of 400 ° C to 650 ° C for 5 seconds to 400 seconds to further harden the polyimide film, and may remain inside the obtained polyimide film. It can also be done under a given tension to relieve stress.

The polyimide film according to the present invention includes a first polyimide chain, a second polyimide chain and nano silica. Although such a polyimide film has an ultra-thin form of 10 μm or less, as the properties of each polyimide chain act complementarily, mechanical properties such as tensile strength and dimensional stability such as modulus, elongation and thermal expansion coefficient are related. Physical properties can be inherent to the desired level.

The advantage of the manufacturing method according to the present invention is to include a method that can facilitate the dispersion of nano-silica.

Specifically, the manufacturing method of the present invention, by mixing the nano-silica with a relatively low-viscosity second polyamic acid, it is possible to primarily easily induce dispersion of the nano-silica, and then a second polyamic acid containing nano-silica When mixed with the first polyamic acid, as the second polyamic acid is easily mixed with the first polyamic acid, nano-silica which has already been dispersed can be rapidly mixed and / or dispersed throughout the first polyamic acid together with the second polyamic acid. have.

Hereinafter, the operation and effects of the invention will be described in more detail through specific examples of the invention. However, these examples are only presented as examples of the invention, and the scope of the invention is not thereby determined.

<Example 1>

Production Example 1-1: Polymerization of first polyamic acid

425 g of DMF was added as a solvent to a 1 L reactor under a nitrogen atmosphere.

Subsequently, after setting the temperature to 25 ° C., 30.04 g of ODA was added as one component of the first diamine, and after stirring for about 30 minutes, it was confirmed that the monomer was dissolved, followed by dividing 31.9 g of PMDA as the first dianhydride. Input. When the reaction is completed, 4.1 g of PPD is added as another component of the first diamine, and after stirring for about 30 minutes to confirm that the monomer is dissolved, 7.8 g of PMDA is added as the first dianhydride, and finally the viscosity is 250,000. The final dose was adjusted and adjusted to be from cP to 300,000 cP.

After the addition, the mixture was stirred for 1 hour while maintaining the temperature to obtain a first polyamic acid having a final viscosity of 260,000 cP.

Preparation Example 1-2: polymerization of second polyamic acid

425 g of DMF was added as a solvent to a 1 L reactor under a nitrogen atmosphere.

Subsequently, after setting the temperature to 25 ° C., 26.3 g of PPD was added as the second diamine, and after stirring for about 30 minutes to confirm that the monomer was dissolved, 47.5 g of s-BPDA as the second dianhydride was added in portions and finally Viscosity was added in small amounts from 8,000 cP to 12,000 cP.

After the addition, the mixture was stirred for 2 hours while maintaining the temperature to obtain a second polyamic acid having a final viscosity of about 10,000 cP.

Preparation Example 1-3: Preparation of mixed solution

After 15 g of nano silica was mixed with 85 g of DMF and 0.5 g of dispersant Shin-Etsu 'APTES', a filler crude solution containing nano silica having an average particle diameter of 15 μm was prepared using a milling machine.

50 g of the second polyamic acid prepared in Preparation Example 1-2 and 50 g of the filler crude liquid were mixed to prepare a mixed liquid. For reference, the mixed solution may be prepared by adjusting the contents of each of the second polyamic acid and nanosilica based on the total weight of the polyimide film.

Production Example 1-4: Preparation of ultra-thin polyimide film

9.1 g of the mixed solution prepared in Preparation Example 1-3 was mixed with 40 g of the first polyamic acid prepared in Preparation Example 1-1, and 4.35 g of isoquinoline (IQ), 12.03 g of acetic anhydride (AA) as a catalyst, And 8.61 g of DMF was added, then uniformly mixed to prepare a precursor composition, and the precursor composition was cast to 80 μm using a doctor blade on a SUS plate (100SA, Sandvik) and in a temperature range of 100 ° C. to 200 ° C. It was dried.

Then, the film was peeled from the SUS Plate and fixed to a pin frame and transferred to a high-temperature tenter.

The film was heated from 200 ° C to 500 ° C in a high-temperature tenter, cooled at 25 ° C, and then separated from the pin frame to about 80% by weight of the first polyimide chain and 10% by weight of the second polyimide to the total weight of the polyimide film. An 8 μm thick polyimide film was prepared comprising mid-chain and 10% by weight of nano silica.

<Examples 2 to 6>

Example 1, except that the input amount of at least one of the first polyamic acid, the second polyamic acid, and the nano silica was adjusted so that the first polyimide chain, the second polyimide chain, and the nano-silica form the weight ratios shown in Table 1. A polyimide film having a thickness of 8 μm was prepared in the same manner as.

<Example 7>

Preparation Example 1-2 was changed as follows, except that a second polyamic acid was prepared, in the same manner as in Example 1, about 80% by weight of the first polyimide chain, 10% by weight, based on the total weight of the polyimide film. A polyimide film of 8 μm thickness was prepared comprising a second polyimide chain of and 10% by weight of nano silica:

-As a polymerization process of the second polyamic acid, 425 g of DMF was added as a solvent to a 1 L reactor under a nitrogen atmosphere. After setting the temperature to 25 ° C., 31.44 g of m-tolidine was added as the second diamine, and after stirring for about 30 minutes, it was confirmed that the monomer was dissolved, and then 43.5 g of s-BPDA as the second dianhydride was added in portions and finally Viscosity was added in small amounts from 5,000 cP to 20,000 cP. After the addition, the mixture was stirred for 1 hour while maintaining the temperature to obtain a second polyamic acid having a final viscosity of about 10,000 cP.

<Example 8 to Example 12>

At least one of the first polyamic acid, the second polyamic acid, and the nano silica was used so that the second polyamic acid described in Example 7 was used, and the first polyimide chain, the second polyimide chain, and the nano-silica form the weight ratios shown in Table 1. A polyimide film having a thickness of 8 μm was prepared in the same manner as in Example 1, except that one input amount was adjusted.

<Comparative Example 1>

Preparation Example 1-2 and Preparation Example 1-3 are omitted, and a precursor composition containing only the first polyamic acid in Preparation Example 1-4 is used so that the polyimide film contains 100% by weight of the first polyimide chain. A polyimide film having a thickness of 8 μm was prepared in the same manner as in Example 1, except that the polyimide film was prepared.

<Comparative Example 2 to Comparative Example 6>

Example 1, except that the input amount of at least one of the first polyamic acid, the second polyamic acid, and the nano silica was adjusted so that the first polyimide chain, the second polyimide chain, and the nano-silica form the weight ratios shown in Table 1. A polyimide film having a thickness of 8 μm was prepared in the same manner as.

<Comparative Example 7 to Comparative Example 11>

At least one of the first polyamic acid, the second polyamic acid, and the nano silica was used so that the second polyamic acid described in Example 7 was used, and the first polyimide chain, the second polyimide chain, and the nano-silica form the weight ratios shown in Table 1. A polyimide film having a thickness of 8 μm was prepared in the same manner as in Example 1, except that one input amount was adjusted.

<Experimental Example: Evaluation of physical properties of polyimide film>

For the polyimide films prepared in Examples 1 to 12 and Comparative Examples 1 to 11, the thermal expansion coefficient, modulus, tensile strength and elongation were measured in the following manner, and the results are summarized in Table 1 below. .

1) Coefficient of thermal expansion

The coefficient of thermal expansion was measured using a TMA (TA) from the temperature profile of 100 ° C to 200 ° C under the method given in ASTM D696-98.

2) Modulus

Modulus was measured using the Instron 5564 model, using the method set forth in ASTM D882.

3) Tensile strength and elongation

It was measured using the method described in ASTM D882 using Instron UTM.

Weight ratio ^* Second PAA ** monomer thickness
(㎛) CTE
(ppm / ℃) Modulus
(GPa) The tensile strength
(kgf / cm ³ ) Elongation
(%) Example 1 80:10:10 BPDA; PPD 8 9.5 4.5 32 55 Example 2 70:20:10 BPDA; PPD 8 8.3 5.2 36 52 Example 3 85: 10: 5 BPDA; PPD 8 9.6 4.3 33 60 Example 4 90: 5: 5 BPDA; PPD 8 10.0 4.1 34 65 Example 5 60:20:20 BPDA; PPD 8 8.0 5.5 30 41 Example 6 65:20:15 BPDA; PPD 8 8.0 5.4 32 46 Example 7 80:10:10 BPDA; m-tolidine 8 9.6 4.6 30 52 Example 8 70:20:10 BPDA; m-tolidine 8 8.3 5.3 35 50 Example 9 85: 10: 5 BPDA; m-tolidine 8 8.4 4.5 33 58 Example 10 90: 5: 5 BPDA; m-tolidine 8 9.9 4.2 34 63 Example 11 60:20:20 BPDA; m-tolidine 8 8.1 5.8 30 40 Example 12 65:20:15 BPDA; m-tolidine 8 8.1 5.7 31 42 Comparative Example 1 100: 0: 0 none 8 13 3.5 30 70 Comparative Example 2 65:25:10 BPDA; PPD 8 7.8 6.0 25 30 Comparative Example 3 65:10:25 BPDA; PPD 8 9.4 5.0 22 25 Comparative Example 4 50:25:25 BPDA; PPD 8 7.5 6.2 21 20 Comparative Example 5 90: 10: 0 BPDA; PPD 8 9.8 3.8 30 65 Comparative Example 6 87: 10: 3 BPDA; PPD 8 9.7 3.9 30 62 Comparative Example 7 65:25:10 BPDA; m-tolidine 8 7.7 6.2 21 20 Comparative Example 8 65:10:25 BPDA; m-tolidine 8 9.2 5.1 20 19 Comparative Example 9 50:25:25 BPDA; m-tolidine 8 7.2 6.5 21 18 Comparative Example 10 90: 10: 0 BPDA; m-tolidine 8 9.5 3.8 29 62 Comparative Example 11 87: 10: 3 BPDA; m-tolidine 8 9.3 3.9 28 58

* 1st polyimide chain: 2nd polyimide chain: nano silica weight ratio

** Second PAA = Second polyamic acid

As shown in Table 1, the polyimide film prepared according to the example has a thickness of 10.0 μm or less and satisfies all of the following properties, but the comparative example shows that at least one of the following properties is not satisfied.

-4 GPa or higher modulus

Thermal expansion coefficient of -8 to 10 ppm / ℃

Tensile strength over -30 kgf / cm ³

Elongation over -40%

Comparative Example 1 relates to a polyimide film containing only the first polyimide chain, and exhibits an excessively high coefficient of thermal expansion, which can be expected to have poor dimensional stability when used as an insulating film of a coverlay.

Comparative Examples 2, 4, 7 and 9 relate to polyimide films comprising an excess of second polyimide chains outside the scope of the present invention, which express good modulus, while their degree of improvement is minimal compared to Examples , Since it shows a very low coefficient of thermal expansion, it can also be expected that the dimensional stability is poor. In addition, the tensile strength and elongation were also found to be poor compared to the examples.

From this, it is understood that when the contents of each of the first polyimide chain and the second polyimide chain included in the polyimide film are harmonized within the limits defined in the present invention, the advantages of the aforementioned physical properties can be simultaneously expressed. Can be.

In addition, since Comparative Examples 3, 4, 8, and 9 in which nano-silica was included in an excessive amount as an inorganic filler had very poor elongation, it can be seen that it is important that the content of nano-silica falls within the scope of the present invention.

On the other hand, the comparative examples 5, 6, 10 and 11, which did not contain nano silica at all, or were included in a small amount outside the scope of the present invention, exhibited good elongation, but exhibited relatively low modulus and tensile strength.

This suggests that in order for the tensile strength, modulus, and elongation to be compatible to an appropriate level, it is preferable to include an inorganic filler in a content range selected in the present invention.

Although described above with reference to embodiments of the present invention, those of ordinary skill in the art to which the present invention pertains will be able to make various applications and modifications within the scope of the present invention based on the above.

Claims (16)

A first polyamic acid prepared by polymerization of the first dianhydride and the first diamine;
A second polyamic acid prepared by polymerization of a second dianhydride and a second diamine; And
As a polyimide film prepared by imidizing a precursor composition containing an inorganic filler,
The second dianhydride is 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride (s-BPDA) and 2,3,3', 4'-biphenyltetracarboxylic dianhydride Ride (a-BPDA) contains at least one selected from,
The second diamine is 1 selected from paraphenylenediamine (PPD), metaphenylenediamine (MPD), 3,3'-dimethylbenzidine (o-tolidine) and 2,2'-dimethylbenzidine (m-tolidine). Includes more than species,
The first dianhydride includes at least one dianhydride different from the second dianhydride,
The first diamine includes at least one diamine different from the second diamine,
A polyimide film having a thickness of 10.0 µm or less, a modulus of 4 GPa or more, and a thermal expansion coefficient of 8 to 10 ppm / ° C. According to claim 1,
The first polyamic acid forms a first polyimide chain through imidization,
The second polyamic acid forms a second polyimide chain through imidization,
The inorganic filler is a polyimide film dispersed in the first polyimide chain and the second polyimide chain. According to claim 2,
With respect to the total weight of the polyimide film,
60 to 90% by weight of the first polyimide chain,
5 to 20% by weight of the second polyimide chain, and
A polyimide film comprising 5 to 20% by weight of an inorganic filler. According to claim 2,
The polyimide film has a thickness of 8.0 μm or less,
With respect to the total weight of the polyimide film,
74 to 86% by weight of the first polyimide chain,
7 to 13% by weight of the second polyimide chain, and
A polyimide film comprising 7 to 13% by weight of an inorganic filler. According to claim 1,
The second dianhydride comprises 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, and the second diamine comprises 2,2'-dimethylbenzidine. According to claim 1,
The second dianhydride comprises 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, and the second diamine comprises paraphenylenediamine. According to claim 1,
The inorganic filler is silica, alumina, titania, zinc oxide, tantalum oxide, zirconia, silicon nitride, boron nitride, calcium sulfate, calcium carbonate, barium carbonate, gallium oxide, talc, barium silicate, magnesium titanate, barium titanate, and A polyimide film comprising at least one selected from aluminum titanate. According to claim 1,
The inorganic filler is a polyimide film containing nano-silica having an average particle diameter of 10 to 20 nm. According to claim 1,
The first polyamic acid has a viscosity of 50,000 cP to 300,000 cP measured at 23 ° C when the solid content is 15% by weight,
The second polyamic acid is a polyimide film having a viscosity of 5,000 cP to 20,000 cP measured at 23 ° C when the solid content is 15% by weight. According to claim 1,
The first dianhydride is pyromellitic dianhydride (PMDA), oxydiphthalic dianhydride (ODPA), 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride (s-BPDA) ), 2,3,3 ', 4'-biphenyltetracarboxylic dianhydride (a-BPDA), diphenylsulfone-3,4,3', 4'-tetracarboxylic dianhydride (DSDA) ), Bis (3,4-dicarboxyphenyl) sulfide dianhydride, 2,2-bis (3,4-dicarboxyphenyl) -1,1,1,3,3,3-hexafluoropropane dianhydride Ride, 2,3,3 ', 4'-benzophenonetetracarboxylic dianhydride, 3,3', 4,4'-benzophenonetetracarboxylic dianhydride (BTDA), bis (3,4 -Dicarboxyphenyl) methane dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, p-phenylenebis (trimeric monoester acid anhydride), p-biphenyl Renbis (Trimellitic Monoester) Seed anhydride), m-terphenyl-3,4,3 ', 4'-tetracarboxylic dianhydride, p-terphenyl-3,4,3', 4'-tetracarboxylic dianhydride Ride, 1,3-bis (3,4-dicarboxyphenoxy) benzene dianhydride, 1,4-bis (3,4-dicarboxyphenoxy) benzene dianhydride, 1,4-bis (3, 4-dicarboxyphenoxy) biphenyl dianhydride, 2,2-bis [(3,4-dicarboxy phenoxy) phenyl] propane dianhydride (BPADA), 2,3,6,7-naphthalenetetracarboxylic acid One or more selected from dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride and 4,4 '-(2,2-hexafluoroisopropylidene) diphthalic acid dianhydride A polyimide film containing. According to claim 1,
The first diamine is paraphenylenediamine, metaphenylenediamine, 3,3'-dimethylbenzidine, 2,2'-dimethylbenzidine, 2,4-diaminotoluene, 2,6-diaminotoluene, 3, 5-diaminobenzoic acid (DABA), 4,4'-diaminodiphenyl ether (ODA), 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane (methylenediamine) , 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2'-bis (trifluoromethyl) -4, 4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminodiphenylmethane, 3,3'-dicarboxy-4,4'-diaminodiphenylmethane, 3,3 ', 5,5'-tetramethyl-4,4'-diaminodiphenylmethane, bis (4-aminophenyl) sulfide, 4,4'-diaminobenzanilide, 3,3'-dimethoxybenzidine, 2, 2'-dimethoxybenzidine, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl sulfide , 3,4'-diaminodiphenyl Fide, 4,4'-diaminodiphenylsulfide, 3,3'-diaminodiphenylsulfone, 3,4'-diaminodiphenylsulfone, 4,4'-diaminodiphenylsulfone, 3,3 ' -Diaminobenzophenone, 4,4'-diaminobenzophenone, 3,3'-diamino-4,4'-dichlorobenzophenone, 3,3'-diamino-4,4'-dimethoxybenzophenone , 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 2,2-bis (3-aminophenyl) propane, 2,2 -Bis (4-aminophenyl) propane, 2,2-bis (3-aminophenyl) -1,1,1,3,3,3-hexafluoropropane, 2,2-bis (4-aminophenyl) -1,1,1,3,3,3-hexafluoropropane, 3,3'-diaminodiphenylsulfoxide, 3,4'-diaminodiphenylsulfoxide, 4,4'-diaminodi Phenyl sulfoxide, 1,3-bis (3-aminophenyl) benzene, 1,3-bis (4-aminophenyl) benzene, 1,4-bis (3-aminophenyl) benzene, 1,4-bis (4 -Amino phenyl) benzene, 1,3-bis (4-aminophenoxy) benzene (TPE-R), 1,4-bis (3-aminophenoxy) bene (TPE-Q) 1,3-bis (3-aminophenoxy) -4-trifluoromethylbenzene, 3,3'-diamino-4- (4-phenyl) phenoxybenzophenone, 3,3 '-Diamino-4,4'-di (4-phenylphenoxy) benzophenone, 1,3-bis (3-aminophenylsulfide) benzene, 1,3-bis (4-aminophenylsulfide) benzene, 1, 4-bis (4-aminophenylsulfide) benzene, 1,3-bis (3-aminophenylsulfone) benzene, 1,3-bis (4-aminophenylsulfone) benzene, 1,4-bis (4-aminophenyl) Sulfone) benzene, 1,3-bis [2- (4-aminophenyl) isopropyl] benzene, 1,4-bis [2- (3-aminophenyl) isopropyl] benzene, 1,4-bis [2- (4-aminophenyl) isopropyl] benzene, 3,3'-bis (3-aminophenoxy) biphenyl, 3,3'-bis (4-aminophenoxy) biphenyl, 4,4'-bis ( 3-aminophenoxy) biphenyl, 4,4'-bis (4-aminophenoxy) biphenyl, bis [3- (3-aminophenoxy) phenyl] ether, bis [3- (4-aminophenoxy) ) Phenyl] ether, bis [4- (3-aminophenoxy) phenyl] ether , Bis [4- (4-aminophenoxy) phenyl] ether, bis [3- (3-aminophenoxy) phenyl] ketone, bis [3- (4-aminophenoxy) phenyl] ketone, bis [4- (3-aminophenoxy) phenyl] ketone, bis [4- (4-aminophenoxy) phenyl] ketone, bis [3- (3-aminophenoxy) phenyl] sulfide, bis [3- (4-aminophenoxy Si) phenyl] sulfide, bis [4- (3-aminophenoxy) phenyl] sulfide, bis [4- (4-aminophenoxy) phenyl] sulfide, bis [3- (3-aminophenoxy) phenyl] sulfone , Bis [3- (4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] sulfone, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [3- (3-aminophenoxy) phenyl] methane, bis [3- (4-aminophenoxy) phenyl] methane, bis [4- (3-aminophenoxy) phenyl] methane, bis [4- (4-aminophenoxy City) phenyl] methane, 2,2-bis [3- (3-aminophenoxy) phenyl] propane, 2,2-bis [3- (4-aminophenoxy) phenyl] propane, 2,2- Bis [4- (3-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] propane (BAPP), 2,2-bis [3- (3-aminophenoxy) C) phenyl] -1,1,1,3,3,3-hexafluoropropane, 2,2-bis [3- (4-aminophenoxy) phenyl] -1,1,1,3,3, 3-hexafluoropropane, 2,2-bis [4- (3-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane and 2,2-bis [4- (4-aminophenoxy) phenyl] A polyimide film comprising at least one member selected from 1,1,1,3,3,3-hexafluoropropane. According to claim 1,
A polyimide film having a tensile strength of 30 kgf / cm ³ or more and an elongation of 40% or more. A method for manufacturing the polyimide film according to claim 1,
Polymerizing the first polyamic acid from the first dianhydride and the first diamine;
Polymerizing the second polyamic acid from the second dianhydride and the second diamine;
Preparing a mixed solution by mixing the nano-silica prepared using a mill with the second polyamic acid;
Preparing a precursor composition by mixing the mixed solution with a first polyamic acid; And
The method comprising the step of obtaining a polyimide film by imidizing the precursor composition. The method of claim 13,
The step of obtaining the polyimide film includes forming the polyimide film by imidizing the gel film after forming the precursor composition on a support and drying the gel film. A coverlay comprising the polyimide film according to claim 1. An electronic device comprising the coverlay according to claim 15.