WO2020040527A1

WO2020040527A1 - Polyimide film comprising crystalline polyimide resin and thermal conductive filler and manufacturing method therefor

Info

Publication number: WO2020040527A1
Application number: PCT/KR2019/010587
Authority: WO
Inventors: 김기훈; 이길남; 최정열
Original assignee: 에스케이씨코오롱피아이 주식회사
Priority date: 2018-08-24
Filing date: 2019-08-20
Publication date: 2020-02-27
Also published as: CN112585198A; KR20200022902A; KR102153508B1; CN112585198B

Abstract

The present invention provides a polyimide film, comprising: 100 parts by weight of a first polyimide resin; 3-10 parts by weight of a second polyimide resin; and 2-8 parts by weight of a thermal conductive filler, wherein the second polyimide resin has higher crystallinity than the first polyimide resin and the polyimide film has a degree of crystallization of 50% or higher, a thermal conductivity of 0.8 W/m•K or higher in the thickness direction, and a thermal conductivity of 3.2 W/m•K or higher in the plane direction.

Description

Polyimide film comprising crystalline polyimide resin and thermally conductive filler and method for preparing same

The present invention relates to a polyimide film comprising a crystalline polyimide resin and a thermally conductive filler and a method for producing the same.

In general, the polyimide (PI) resin refers to a high heat-resistant resin prepared by solution polymerization of an aromatic dianhydride and an aromatic diamine or an aromatic diisocyanate to prepare a polyamic acid derivative, and then imidization by cyclization of the ring at a high temperature.

Polyimide resin is an insoluble and insoluble ultra high heat resistant resin that has excellent properties such as heat oxidation resistance, heat resistance, radiation resistance, low temperature, chemical resistance, and so on. It is used for electronic materials in a wide range of fields such as coatings, insulating films, semiconductors, and electrode protective films for TFT-LCDs.

In accordance with the recent trend of high informatization, the polyimide resin used in electronic devices for accumulating a large amount of information and processing and transmitting such information at high speed has to have high electrical insulation and to effectively release heat generated from electronic devices. To improve the thermal conductivity is required.

In detail, in order to further improve heat dissipation performance, it is necessary to ensure the desired thermal conductivity not only in the planar direction but also in the thickness direction of the polyimide film.

By the way, the polyimide resin is different from other configurations, but generally has an amorphous structure, so the thermal conductivity is not high. As a method for improving the thermal conductivity of such a polyimide resin, a method is known in which a thermally conductive filler is dispersed in a precursor solution and then a film is formed using the dispersion.

However, it is difficult to achieve a desired degree of thermal conductivity only by adding a thermally conductive filler in this way, and in the case where the content of the filler is excessively administered to improve the thermal conductivity, an excess of filler forms an aggregate to form a filler aggregate. Protruding from the film surface may cause a poor appearance.

In addition, as the content of the filler in the film is increased, a problem may occur that the mechanical properties of the polyimide film are degraded or the filming process itself is impossible.

Therefore, there is a high need for a technology that can fundamentally solve these problems.

It is an object of the present invention to provide a polyimide film comprising a crystalline polyimide resin and a thermally conductive filler.

According to an aspect of the present invention, the polyimide film is configured to include a first polyimide resin, a second polyimide resin having a higher crystallinity and a thermally conductive filler than the first polyimide resin, thereby forming a planar surface of the polyimide film Directional thermal conductivity and thickness direction thermal conductivity can be improved.

According to another aspect of the present invention, by adjusting the viscosity of the second polyamic acid which is a precursor of the second polyimide resin, it is possible to improve the crystallinity of the polyimide film produced therefrom.

Therefore, the present invention has a practical purpose to provide a specific embodiment thereof.

The present invention, 100 parts by weight of the first polyimide resin,

3 to 10 parts by weight of the second polyimide resin, and

2 to 8 parts by weight of the thermally conductive filler,

The second polyimide resin is more crystalline than the first polyimide resin,

The polyimide film whose crystallinity of a polyimide film is 50% or more, thickness direction thermal conductivity is 0.8 W / m * K or more, and planar direction thermal conductivity is 3.2 W / m * K or more.

The present invention has found that the thermal conductivity of the polyimide film is improved by the second polyimide resin and the thermally conductive filler having greater crystallinity than the first polyimide resin.

Therefore, specific content for implementation thereof is described herein.

Prior to this, terms or words used in the present specification and claims should not be construed as having a conventional or dictionary meaning, and the inventors should properly explain the concept of terms in order to best explain their own invention. It should be interpreted as meaning and concept corresponding to the technical idea of the present invention based on the principle that it can be defined.

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 idea of the present invention, various equivalents and modifications that can replace them at the time of the present application It should be understood that examples may exist.

As used herein, the singular forms "a", "an" and "the" include plural forms unless the context clearly indicates otherwise. As used herein, the terms "comprise", "comprise" or "have" are intended to indicate that there is a feature, number, step, component, or combination thereof, that is, one or more other features, It is to be understood that the present invention does not exclude the possibility of adding or presenting numbers, steps, components, or combinations thereof.

As used herein, "dianhydride" is intended to include precursors or derivatives thereof, which technically may not be dianhydride, but nevertheless will react with the diamine to form a polyamic acid. This polyamic acid can be converted back to polyimide.

As used herein, "diamine" 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 in turn Can be converted to mid.

Where an amount, concentration, or other value or parameter is given herein as an enumeration of ranges, preferred ranges, or preferred upper and preferred lower values, any pair of any upper range thresholds, whether or not a range is disclosed separately, or It is to be understood that this disclosure specifically discloses all ranges formed with a desired value and any lower range limit or desired value.

When a range of numerical values is mentioned herein, unless stated otherwise, the range is intended to include the endpoint and all integers and fractions within that range.

It is intended that the scope of the invention not be limited to the particular values mentioned when defining the range.

제1 양태: 폴리이미드 필름First Embodiment: Polyimide Film

Polyimide film according to the present invention, 100 parts by weight of the first polyimide resin,

3 to 10 parts by weight of the second polyimide resin, and

2 to 8 parts by weight of the thermally conductive filler,

The second polyimide resin is more crystalline than the first polyimide resin,

The polyimide film has a crystallinity of 50% or more, a thickness direction thermal conductivity of 0.8 W / m · K or more, and a planar direction thermal conductivity of 3.2 W / m · K or more.

Generally used polyimide resins are amorphous polymers, and polyimide films prepared therefrom also exhibit low or no crystallinity. In contrast, in the present invention, the polyimide film comprises a second polyimide resin having a higher crystallinity than the first polyimide resin in the polyimide film so as to exhibit crystallinity. The crystallinity may be at least 50%.

Although it is not easy to measure the crystallinity of each polyimide resin having a different composition in the polyimide film and compare the size of the crystallinity between the polyimide resins, it is possible to measure the crystallinity of the polyimide film itself. Therefore, when the crystallinity of the polyimide film increases as the content of the second polyimide resin increases in the polyimide film, it can be confirmed that the second polyimide resin has greater crystallinity than the first polyimide resin. have.

The crystallinity of the polyimide resin is greatly influenced by the composition of the monomers constituting the polyimide resin, but the crystallinity may vary depending on the polymerization method in addition to the composition. For example, in the process of preparing a polyimide resin, in the process of polymerizing a polyamic acid as its precursor, some molecular structures may be arranged in a regular state depending on the viscosity to form a degree of crystal formation.

In summary, in the present invention, the crystallinity of the polyimide film may vary according to the content of the second polyimide resin in the polyimide film, and also according to the viscosity of the second polyamic acid which is a precursor of the second polyimide resin. The degree of crystallinity of the polyimide film produced from may vary.

Meanwhile, at least a part of the second polyimide resin may form a crystal, and the crystal and the thermally conductive filler may have a structure of forming a heat transfer path in a thickness direction and / or a planar direction in the film.

In the present invention, the crystal is a structure in which a part of the polyimide chain included in the second polyimide resin is regularly arranged, for example, radially regular arrangements in the two-dimensional or three-dimensional direction from the central nucleus of the crystal A structure in which the polyimide chain is regularly arranged in the form of a circle or sphere in the form of a crystal is grown, but a specific shape or form is not limited.

Such a crystal may be present in a myriad of numbers in the polyimide film, may include a portion of the amorphous portion between the crystalline portion and the crystalline portion, it is also possible that the amorphous portion, the crystal portion may be present separately.

This structure is different from the structure of a general polyimide film in which a thermally conductive filler is dispersed between amorphous polyimide resins in a polyimide film, and the crystals have a thickness as well as the planar direction of the thermally conductive filler and film in the polyimide film. The heat transfer path can also be formed in the direction, and thus the planar thermal conductivity and / or thickness thermal conductivity of the polyimide film according to the present invention can be improved.

However, despite the above advantages, it is not preferable that the second polyimide resin is unconditionally contained in the polyimide film unconditionally.

Specifically, the above advantages may be expressed when the content of the second polyimide resin in the polyimide film is a certain level, but if it exceeds this, the advantages in terms of improving the thermal conductivity may be enhanced, but as described above in the polyimide film It is because elongation of a polyimide film may fall rapidly because too much crystal | crystallization exists.

That is, it is important that the polyimide film contains an appropriate amount of the first polyimide resin and the second polyimide resin so that the mechanical properties and the thermal conductivity of the polyimide film are compatible.

As described above, the polyimide film of the present invention comprises 100 parts by weight of the first polyimide resin, 3 to 10 parts by weight of the second polyimide resin, and 2 to 8 parts by weight of the thermally conductive filler and the crystallinity of the polyimide film Is 50% or more, the thickness thermal conductivity is 0.8 W / m · K or more, and the planar thermal conductivity may be 3.2 W / m · K or more.

More specifically, the polyimide film of the present invention may include 5 to 10 parts by weight of the second polyimide resin.

On the other hand, the first polyimide resin may be prepared by imidizing the first polyamic acid formed by the reaction of the first dianhydride and the first diamine.

The first dianhydride that may be used to prepare the first polyamic acid of the present invention may be an aromatic tetracarboxylic dianhydride.

The aromatic tetracarboxylic dianhydride is pyromellitic dianhydride (or PMDA), oxydiphthalic dianhydride (or ODPA), diphenylsulfone-3,4,3 ', 4'-tetracarboxylic Dianhydride (or 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 (or BTDA), bis (3,4-dicarboxyphenyl) methane dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, p-phenylenebis (trimelitic monoester Acid anhydride), p-biphenylenebis (trimelitic monoester acid anhydride), m-terphenyl-3,4,3 ', 4'-tetracarboxylic dianhydride Id, 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, 4,4'- (2,2-hexafluoroisopropylidene) diphthalic acid dianhydride etc. are mentioned. These can be used individually or in combination of 2 or more types as desired.

These may be used alone or in combination of two or more as desired, but dianhydrides which may be particularly preferably used as the first dianhydride in the present invention are pyromellitic dianhydride (PMDA), oxydiphthalic Anhydride (ODPA) and benzophenone tetracarboxylic dianhydride (BTDA) may be one or more selected from the group consisting of.

The 1st diamine which can be used for manufacture of the 1st polyamic-acid solution of this invention is an aromatic diamine, classified as follows, for example.

1) 1,4-diaminobenzene (or paraphenylenediamine, PDA), 1,3-diaminobenzene, 2,4-diaminotoluene, 2,6-diaminotoluene, 3,5-diaminobenzo Diamines having one benzene nucleus in structure, such as Ik acid (or DABA) and the like, diamines having a relatively rigid structure;

2) diaminodiphenyl ethers such as 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane (methylenediamine), 3,3'-dimethyl-4,4'-diamino Biphenyl, 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'-dichlorobenzidine, 3,3'-dimethylbenzidine (or o-tolidine), 2,2'-dimethylbenzidine (or m-tolidine), 3,3'-dimethoxybenzidine, 2,2'-dimethoxybenzidine, 3,3'-diaminodiphenylether, 3,4'-dia Minodiphenylether, 4,4'-diaminodiphenylether, 3,3'-diaminodiphenylsulfide, 3,4'-diaminodiphenylsulfide, 4,4'-diaminodiphenylsulfide, 3 , 3'-diaminodiphenylsulfone, 3,4'-dia Nodiphenylsulfone, 4,4'-diaminodiphenylsulfone, 3,3'-diaminobenzophenone, 4,4'-diaminobenzophenone, 3,3'-diamino-4,4'-dichlorobenzo Phenone, 3,3'-diamino-4,4'-dimethoxybenzophenone, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-dia Minodiphenylmethane, 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'-dia Diamines having two benzene nuclei in structure, such as minodiphenylsulfoxide, 3,4'-diaminodiphenylsulfoxide, 4,4'-diaminodiphenylsulfoxide and the like;

3) 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 (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- Diamines having three benzene nuclei in structure, such as (4-aminophenyl) isopropyl] benzene;

4) 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-amino phenoxy) phenyl] ketone, bis [3- (3-amino phenoxy) phenyl] sulfide , Bis [3- (4-aminophenoxy) 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-ami) Phenoxy) phenyl] sulfone, bis [3- (3-aminophenoxy) phenyl] methane, bis [3- (4-aminophenoxy) phenyl] methane, bis [4- (3-aminophenoxy) Phenyl] methane, bis [4- (4-aminophenoxy) 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) 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, Like 3,3,3-hexafluoropropane, 2,2-bis [4- (4-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane, and the like, Diamine with four benzene nuclei in structure.

These may be used alone or in combination of two or more as desired, but diamines which may be particularly preferably used as the first diamine in the present invention include phenylenediamine (PPD), 2,2-bis [4 '-( 4-aminophenoxy) phenyl] propane (BAPP) and methylenedianiline (MDA) may be one or more selected from the group consisting of.

On the other hand, the second polyimide resin may be prepared by imidizing the second polyamic acid formed by the reaction of the second dianhydride and the second diamine.

Specifically, the second dianhydride may include biphenyltetracarboxylic dianhydride (BPDA), and the second diamine may be oxydianiline (ODA), 1,3-bis (4-aminophenoxy). C) benzene (TPE-R) and 1,4-bis (3-aminophenoxy) benzene (TPE-Q).

In the present invention, the second diamine may be used alone or in combination of two or more as desired, but the diamine which may be particularly preferably used as the second diamine is 1,3-bis (4-aminophenoxy) benzene. (TPE-R).

On the other hand, the thermally conductive filler may include one or more selected from the group consisting of graphene, alumina, boron nitride, but is not limited thereto.

Specifically, the thermally conductive filler may include 1 to 3 parts by weight of graphene and 1 to 5 parts by weight of alumina.

If the graphene or alumina content is less than the above range, the desired level of thermal conductivity cannot be achieved. On the contrary, if the graphene or alumina content is above the above range, the excess graphene or alumina particles form agglomerates so that the particle agglomerates can be formed. It is not preferable because it may protrude from the surface of the film, resulting in a poor appearance, a problem that the mechanical properties of the produced polyimide film may be degraded or the film forming process itself is impossible.

The thermally conductive filler particle size can be appropriately adjusted to achieve the effect of the present invention, for example, the average long diameter of the graphene may be 5 to 15 ㎛, the average particle diameter of the alumina is 5 to 25 ㎛ Can be.

When the size of the graphene or alumina particles is less than the range, a desired level of thermal conductivity may not be achieved. On the contrary, when the size of the graphene or alumina particles is larger than the range, When mixed with the first polyamic acid or the second polyamic acid, the dispersibility is low, and the particles may protrude from the surface of the film, causing appearance defects.

As described above, the polyimide film of the present invention may have a crystallinity of 50% or more, a thickness thermal conductivity of 0.8 W / m · K or more, a planar thermal conductivity of 3.2 W / m · K or more, and an elongation of 30% or more. .

제2 양태: 폴리이미드 필름의 제조방법Second Embodiment: Manufacturing Method of Polyimide Film

Method for producing a polyimide film according to the present invention,

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

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

Preparing a precursor composition by mixing the first polyamic acid, the second polyamic acid, and the thermally conductive filler; And

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

Production of the polyamic acid in the present invention is, for example,

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

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

(3) After putting some components of the diamine monomer in the solvent, and mixing some components of the dianhydride monomer in the ratio of about 95 to 105 mol% with respect to the reaction component, the remaining diamine monomer component is added and the rest Adding a dianhydride monomer component so that the diamine monomer and the dianhydride monomer are substantially equimolar and polymerized;

(4) After putting the dianhydride monomer in a solvent, after mixing some components of a diamine compound in the ratio of 95-105 mol% with respect to a reaction component, another dianhydride monomer component is added and it continues, and the remaining diamine monomer component is carried out. Adding a diamine monomer and a dianhydride monomer to substantially equimolar polymerization;

(5) Some of the diamine monomer component and some of the dianhydride monomer component are reacted to an excess in one solvent to form a first composition, and some of the diamine monomer component and some dianhydride monomer component in another solvent are either Reacting with excess to form a second composition, and then mixing the first and second compositions and completing the polymerization, wherein the second composition is excessive when the diamine monomer component is excessive when the first composition is formed. In the case where the dianhydride monomer component is in excess and the dianhydride monomer component in the first composition is in excess, in the second composition, the diamine monomer component is in excess, and the first and second compositions are mixed and used for these reactions. The total diamine monomer component and the dianhydride monomer component to be substantially equimolar It can be joined to the methods.

The solvent is not particularly limited as long as it is an organic solvent in which the polyamic acid may be dissolved. However, the solvent may be an aprotic polar solvent.

Non-limiting examples of the aprotic polar solvent include amide solvents such as N, N'-dimethylformamide (DMF) and N, N'-dimethylacetamide (DMAc), p-chlorophenol, o-chloro Phenol solvents such as phenol, N-methyl-pyrrolidone (NMP), gamma butyrolactone (GBL), diglyme, and the like, and the like, and these may be used alone or in combination of two or more thereof.

In some cases, the solubility of the polyamic acid may be adjusted by using auxiliary solvents such as toluene, tetrahydrofuran, acetone, methyl ethyl ketone, methanol, ethanol and water.

In one example, the organic solvents that can be particularly preferably used for preparing the precursor compositions of the present invention may be amide solvents N, N'-dimethylformamide and N, N'-dimethylacetamide.

The polymerization method is not limited only to the above examples, and any known method may be used.

In addition, the polymerization method may be applied to the first polyamic acid and the second polyamic acid polymerization, respectively.

In the step of polymerizing the second polyamic acid, when the solid content is 15% by weight, the second polyamic acid may have a viscosity measured at 23 ° C. from 100,000 cP to 150,000 cP.

If the viscosity of the second polyamic acid exceeds the above range, a higher pressure must be applied by friction with the pipe when the second polyamic acid is moved through the pipe during the manufacturing process of the polyimide film, so that the process cost This may increase and the handleability may decrease. In addition, the higher the viscosity, the more time and cost the mixing process can take.

Moreover, the filming process itself may be impossible due to the excessively high viscosity, and even if the filming process is possible, the elongation of the polyimide film produced therefrom may be lowered, which is not preferable.

On the other hand, when the viscosity of the said second polyamic acid is less than the said range, the crystallinity of the 2nd polyimide resin contained in the polyimide film manufactured from this will fall, and the crystal and thermoelectric of a 2nd polyimide resin will fall. The conductive filler cannot exert the effect of the present invention to form a heat transfer path in the film to improve the thermal conductivity.

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

As a specific method of such imidation, the thermal imidation method, the chemical imidation method, or the composite imidation method which uses the said thermal imidation method and the chemical imidation method together is mentioned as an example, About these the following non-limiting examples It will be described in more detail through.

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

Drying the precursor composition to form a gel film; And

The gel film may be heat-treated to obtain a polyimide film.

Here, a gel film can be understood as a film intermediate which has self-support at an intermediate stage with respect to the conversion from polyamic acid to polyimide.

Forming the gel film, the precursor composition is cast in the form of a film on a support such as glass plate, aluminum foil, endless stainless belt, or stainless drum, and then the precursor composition on the support 50 ℃ to 200 ℃, Specifically, the drying may be performed at a variable temperature ranging from 80 ° C to 150 ° C.

This may result in the formation of a gel film by partial curing and / or drying of the precursor composition. It can then peel off from the support to obtain a gel film.

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

The gel film thus obtained is fixed in a tenter and then heat-treated at a variable temperature in the range of 50 ° C to 500 ° C, specifically 150 ° C to 500 ° C, to remove water, residual solvents, and the like remaining in the gel film. Nearly all amic acid groups can be imidated to obtain the polyimide film of the present invention.

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 cure the polyimide film, and may remain in the obtained polyimide film. This may be done under a predetermined tension to relieve stress.

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

As used herein, the term "dehydrating agent" refers to a substance that promotes a ring-closure reaction through dehydration to polyamic acid, and includes, but is not limited to, aliphatic acid anhydrides, aromatic acid anhydrides, and N, N '. -Dialkylcarbodiimide, halogenated lower aliphatic, halogenated lower patty acid anhydride, aryl phosphonic dihalide, thionyl halide and the like. Of these, aliphatic acid anhydrides may be preferred in view of ease of availability and cost, and non-limiting examples thereof include acetic anhydride (AA), propion acid anhydride, and lactic acid anhydride. These etc. are mentioned, These can be used individually or in mixture of 2 or more types.

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

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

When the dehydrating agent and the imidating agent are less than the above range, chemical imidization is insufficient, cracks may be formed in the polyimide film to be produced, and the mechanical strength of the film may be lowered. In addition, if the amount of these additions exceeds the above range, the imidization may proceed excessively rapidly, and in this case, it is difficult to cast in the form of a film or the produced polyimide film may exhibit brittle characteristics, which is not preferable. not.

In connection with the above-mentioned chemical imidation method, the composite imidation method which further performs the thermal imidation method can be used for manufacture of a polyimide film.

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

In performing the chemical imidization process, the type and amount of the dehydrating agent and the imidizing agent may be appropriately selected according to the above-described chemical imidization method.

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

The gel film thus obtained is fixed in a tenter and then heat treated at a variable temperature ranging from 50 ° C. to 600 ° C., specifically 150 ° C. to 500 ° C. to remove water, catalyst, residual solvent, etc. remaining in the gel film, Nearly all remaining amic acid groups can be imidated to obtain the polyimide film of the present invention. In such a heat treatment process, the dehydrating agent and / or the imidating agent may act as a catalyst, thereby rapidly converting the amic acid group into the imide group, thereby enabling high imidization rate.

The present invention can also provide an electronic device including the polyimide film.

Hereinafter, the operation and effects of the invention will be described in more detail with reference to specific examples of the invention. However, these embodiments are only presented as an example of the invention, whereby the scope of the invention is not determined.

Preparation Example 1 Preparation of First Polyamic Acid Solution

407.5 g of DMF was added to a 500 ml reactor equipped with a stirrer and a nitrogen inlet / outlet tube, and the temperature of the reactor was set at 25 ° C., followed by 35.1 g of ODA and 6.3 g of PPD. After confirming, 51.0 g of PMDA was added in portions, and a first polyamic acid solution having a solid content of 18.5 wt% and a viscosity at 23 ° C. of 250,000 to 300,000 cP was prepared.

Preparation Example 2 Preparation of Second Polyamic Acid Solution

425 g of DMF was added to a 500 ml reactor equipped with a stirrer and a nitrogen inlet / outlet tube, and the temperature of the reactor was set at 30 ° C., followed by 37.53 g of TPE-R and 97 g of BPDA to dissolve completely. It was confirmed. After stirring was continued for 120 minutes while heating to 40 ° C. under a nitrogen atmosphere, a second polyamic acid solution having a solid content of 15 wt% and a viscosity at 23 ° C. of 130,000 to 150,000 cP was prepared.

Preparation Example 3 Preparation of Precursor Composition and Polyimide Film

After setting the temperature of the reactor at 50 ° C., 0.05 g of graphene having a long diameter of 10 μm was added to 30 g of the polyamic acid solution of Preparation Example 1 and 1.04 g of the polyamic acid solution of Preparation Example 2 as a thermally conductive filler. 0.26 g of this 16 μm alumina was added, followed by stirring for 1 hour while maintaining the temperature to prepare a precursor composition.

The precursor composition was bubbled through a high speed rotation of at least 1,500 rpm. Thereafter, the degassed polyimide precursor composition was applied to the glass substrate using a spin coater. After drying for 30 minutes in a nitrogen atmosphere and at a temperature of 120 ℃ to prepare a gel film, the gel film is heated to 450 ℃ at a rate of 2 ℃ / min, heat treatment at 450 ℃ 60 minutes, up to 30 ℃ Cooling at a rate of 2 ° C./min gave a polyimide film. Thereafter, the polyimide film was peeled off from the glass substrate by dipping in distilled water.

The polyimide film prepared contained 100 parts by weight of the first polyimide resin, 3 parts by weight of the second polyimide resin, 1 part by weight of graphene and 5 parts by weight of alumina and had a thickness of 15 μm.

The thickness of the produced polyimide film was measured using an Anritsu Electric Film thickness tester.

In Preparation Example 2, a polyimide film was prepared in the same manner as in Example 1, except that the viscosity of the second polyamic acid solution was changed as in Table 1 below.

In Preparation Example 3, a polyimide film was prepared in the same manner as in Example 1, except that the amount of the polyamic acid solution was changed to have a content of the polyimide resin of Table 1 below.

In Preparation Example 2, except that the viscosity of the second polyamic acid solution was changed as shown in Table 1, and in Preparation Example 3, the amount of the polyamic acid solution was changed to have a content of the polyimide resin of Table 1 below. A polyimide film was prepared in the same manner as in Example 1.

Example 5

In Preparation Example 2, a polyimide film was prepared in the same manner as in Example 1 except that 30.51 g of ODA was added instead of TPE-R.

Comparative Example 1

A polyimide film was prepared in the same manner as in Example 1, except that no second polyamic acid was added.

Comparative Example 2

Comparative Example 3

Comparative Example 6

Comparative Example 7

In Preparation Example 2, a polyimide film was prepared in the same manner as in Example 1 except that a second polyamic acid was prepared using 29.40 g of MDA instead of TPE-R and 44.63 g of ODPA instead of BPDA. Prepared.

	그래핀 함량(중량부)Graphene content (parts by weight)	알루미나 함량(중량부)Alumina content (parts by weight)	제2 폴리이미드 수지 함량(중량부)Second polyimide resin content (parts by weight)	제2 폴리아믹산에 사용된 단량체Monomer used in the second polyamic acid	제2 폴리아믹산 점도(cP)Second polyamic acid viscosity (cP)
실시예 1Example 1	1One	55	33	BPDA; TPE-RBPDA; TPE-R	130,000130,000
실시예 2Example 2	1One	55	33	BPDA; TPE-RBPDA; TPE-R	150,000150,000
실시예 3Example 3	1One	55	55	BPDA; TPE-RBPDA; TPE-R	130,000130,000
실시예 4Example 4	1One	55	55	BPDA; TPE-RBPDA; TPE-R	150,000150,000
실시예 5Example 5	1One	55	1010	BPDA; TPE-RBPDA; TPE-R	130,000130,000
실시예 6Example 6	1One	55	1010	BPDA; TPE-RBPDA; TPE-R	150,000150,000
실시예 7Example 7	1One	55	33	BPDA; ODABPDA; ODA	130,000130,000
비교예 1Comparative Example 1	1One	55	--	--	--
비교예 2Comparative Example 2	1One	55	1One	BPDA; TPE-RBPDA; TPE-R	130,000130,000
비교예 3Comparative Example 3	1One	55	1313	BPDA; TPE-RBPDA; TPE-R	130,000130,000
비교예 4Comparative Example 4	1One	55	33	BPDA; TPE-RBPDA; TPE-R	80,00080,000
비교예 5Comparative Example 5	1One	55	33	BPDA; TPE-RBPDA; TPE-R	170,000170,000
비교예 6Comparative Example 6	1One	55	33	BPDA; TPE-RBPDA; TPE-R	200,000200,000
비교예 7Comparative Example 7	1One	55	33	ODPA; MDAODPA; MDA	130,000130,000

Experimental Example 1: Evaluation of Crystallinity

About the polyimide films produced in Examples 1 to 7, and Comparative Examples 1 to 7, respectively, the crystallinity was analyzed using XRD (Rigaku Corporation, Ultima IV).

At this time, the degree of crystallinity was calculated by the following equation (1), the results are shown in Table 2 below.

(One)

In Formula (1), X _c is the degree of crystallinity (%),

I _a is the area of amorphous scattering,

I _c is the area of crystalline scattering peaks.

	결정화도(%)Crystallinity (%)
실시예 1Example 1	5353
실시예 2Example 2	5656
실시예 3Example 3	5858
실시예 4Example 4	6060
실시예 5Example 5	6363
실시예 6Example 6	6666
실시예 7Example 7	5252
비교예 1Comparative Example 1	1515
비교예 2Comparative Example 2	2020
비교예 3Comparative Example 3	8080
비교예 4Comparative Example 4	3030
비교예 5Comparative Example 5	6262
비교예 6Comparative Example 6	6565
비교예 7Comparative Example 7	3535

Referring to Table 2, in the case of the polyimide film of Examples 1 to 7, the crystallinity of the polyimide film is included by including 3 to 10 parts by weight of the second polyimide resin with respect to 100 parts by weight of the first polyimide resin. It can be confirmed that 50% or more are satisfied.

On the other hand, Comparative Examples 1 and 2 in which the content of the second polyimide resin is lower than the range of the present invention, it can be seen that the crystallinity is lower than the polyimide film of the examples, the viscosity is lower than the range of the present invention in the manufacturing process Comparative Example 4 in which the second polyamic acid was added, Comparative Example 7 in which the second polyamic acid without the crystalline monomer was added, it was also confirmed that the crystallinity is lower than the polyimide film of the examples.

From this, it can be seen that the crystallinity of the polyimide film varies according to the content of the second polyimide resin included in the polyimide film, and in the case of using a second polyamic acid having a relatively low viscosity in the manufacturing process, the polyimide film Although manufactured to include the same amount of the second polyimide resin, it can be seen that the crystallinity of the polyimide film is different.

Experimental Example 2: Evaluation of Thermal Conductivity

About the polyimide films produced in Examples 1 to 7, and Comparative Examples 1 to 7, respectively, the thickness direction of the polyimide film by the laser flash method using a thermal diffusivity measuring instrument (Model LFA 447, Netsch) And the thermal diffusivity in the planar direction was measured, and the thermal conductivity was calculated by multiplying the measured thermal diffusivity by density (weight / volume) and specific heat (specific heat measured value using DSC), and the results are shown in Table 3 below.

Experimental Example 3: Elongation Evaluation

For the polyimide films prepared in Examples 1 to 7, and Comparative Examples 1 to 7, respectively, each polyimide film was cut into a width of 10 mm and a length of 40 mm, followed by Instron 5564 UTM equipment of Instron. Elongation was measured using ASTM D-882 method, and the results are shown in Table 3 below.

	열전도율(W/m·K)Thermal Conductivity (W / mK)		신율(%)% Elongation
	두께방향Thickness direction	평면방향Planar direction	신율(%)% Elongation
실시예 1Example 1	0.90.9	3.53.5	3737
실시예 2Example 2	1.01.0	3.93.9	3636
실시예 3Example 3	1.151.15	4.34.3	3535
실시예 4Example 4	1.251.25	4.64.6	3434
실시예 5Example 5	1.351.35	5.55.5	3333
실시예 6Example 6	1.51.5	6.36.3	3131
실시예 7Example 7	0.850.85	3.23.2	4040
비교예 1Comparative Example 1	0.650.65	2.42.4	4545
비교예 2Comparative Example 2	0.690.69	2.52.5	4545
비교예 3Comparative Example 3	1.71.7	7.57.5	1515
비교예 4Comparative Example 4	0.660.66	2.452.45	4646
비교예 5Comparative Example 5	1.301.30	5.355.35	2222
비교예 6Comparative Example 6	1.431.43	5.925.92	1919
비교예 7Comparative Example 7	0.650.65	2.42.4	4747

Referring to Table 3, in the case of the polyimide films of Examples 1 to 7, the thermal conductivity in the planar direction is 3.2 W / m · K or more, the thermal conductivity in the thickness direction is 0.8 W / m · K or more, and the elongation is 30%. It can be confirmed that the above are satisfied.

On the other hand, Comparative Examples 1 and 2 in which the content of the second polyimide resin is lower than the range of the present invention, and Comparative Example 4 in which a second polyamic acid having a viscosity lower than the range of the present invention are used in the preparation process are used. In the case of Comparative Example 7 in which a second polyamic acid was added, it was confirmed that the thermal conductivity, in particular, the thermal conductivity in the thickness direction was less than 0.8 W / m · K.

On the other hand, in the case of Comparative Example 3 in which the content of the second polyimide resin is higher than the range of the present invention, and Comparative Examples 5 and 6 in which the second polyamic acid having a viscosity higher than the range of the present invention is added in the manufacturing process, the thermal conductivity in the thickness direction Although it is excellent in 0.8 W / m * K or more, it can be confirmed that elongation is 30% or less compared with the Example.

Although described above with reference to embodiments of the present invention, those of ordinary skill in the art, it will be possible to perform various applications and modifications within the scope of the present invention based on the above contents.

The polyimide film according to the present invention includes a first polyimide resin, a second polyimide resin having a higher crystallinity than the first polyimide resin, and a thermally conductive filler, so that the crystals and the thermal conductivity of the second polyimide resin are By forming the heat transfer path in the film in the thickness direction and / or the planar direction in the film, the planar thermal conductivity and the thickness direction thermal conductivity of the polyimide film can be improved.

In the production method according to the present invention, by adjusting the viscosity of the second polyamic acid that is a precursor of the second polyimide resin, it is possible to increase the crystallinity of the polyimide film produced therefrom.

Claims

100 parts by weight of the first polyimide resin,

3 to 10 parts by weight of the second polyimide resin, and

2 to 8 parts by weight of the thermally conductive filler,

The second polyimide resin is more crystalline than the first polyimide resin,

The method of claim 1,

The first polyimide resin is prepared by imidating a first polyamic acid formed by the reaction of a first dianhydride and a first diamine,

The second polyimide resin is produced by imidating a second polyamic acid formed by the reaction of a second dianhydride and a second diamine.

The method of claim 2,

The first dianhydride comprises one or more selected from the group consisting of pyromellitic dianhydride (PMDA), oxydiphthalic hydride (ODPA) and benzophenone tetracarboxylic dianhydride (BTDA) ,

The first diamine is at least one selected from the group consisting of phenylenediamine (PPD), 2,2-bis [4 '-(4-aminophenoxy) phenyl] propane (BAPP) and methylenedianiline (MDA). Polyimide film containing.

The method of claim 2,

The second dianhydride comprises biphenyltetracarboxylic dianhydride (BPDA),

The second diamine is oxydianiline (ODA), 1,3-bis (4-aminophenoxy) benzene (TPE-R), 1,4-bis (3-aminophenoxy) benzene (TPE-Q) Polyimide film containing one or more selected from the group consisting of.

The method of claim 4, wherein

Wherein said second diamine comprises 1,3-bis (4-aminophenoxy) benzene (TPE-R).

The method of claim 1,

The thermally conductive filler includes at least one selected from the group consisting of graphene, alumina and boron nitride, polyimide film.

The method of claim 6,

The thermally conductive filler includes 1 to 3 parts by weight of graphene and 1 to 5 parts by weight of alumina, polyimide film.

The method of claim 6,

The graphene is an average long diameter of 5 to 15 ㎛ polyimide film.

The method of claim 6,

The alumina has a mean particle size of 5 to 25 ㎛ polyimide film.

The method of claim 1,

At least a portion of the second polyimide resin forms a crystal, and the crystal and the thermally conductive filler form a heat transfer path in a thickness direction and / or in a planar direction in the film.

The method of claim 1,

The polyimide film, the polyimide film, the elongation is 30% or more.

As a method of manufacturing the polyimide film according to claim 1,

Imidizing the precursor composition to obtain a polyimide film.

The method of claim 12,

Obtaining the polyimide film includes forming a polyimide film by forming the precursor composition on a support and drying to prepare a gel film, and then imidating the gel film.

The method of claim 12,

The second polyamic acid has a viscosity of 100,000 cP to 150,000 cP measured at 23 ° C. when the solid content is 15% by weight.

An electronic device comprising the polyimide film of claim 1.