WO2024085591A1 - Polyimide film and method for producing same - Google Patents

Abstract

The present invention provides: a polyimide film having excellent heat resistance and mechanical properties, such as a yield strength of at least 138 MPa and a glass transition temperature of at least 370°C; and a method for producing same.

Description

Polyimide film and its manufacturing method

The present invention relates to a polyimide film having excellent heat resistance and mechanical properties (yield strength and yield point) and a method of manufacturing the same.

Polyimide (PI) is a polymer material that has the highest level of heat resistance, chemical resistance, electrical insulation, chemical resistance, and weather resistance among organic materials, based on an imide ring with a rigid aromatic main chain and excellent chemical stability. am.

Polyimide film is attracting attention as a material for various electronic devices that require the above-mentioned properties.

Examples of micro-electronic components to which polyimide film is applied include thin, flexible circuit boards with high circuit integration to cope with the weight reduction and miniaturization of electronic products. Polyimide film is especially widely used as an insulating film for thin circuit boards. there is.

The thin circuit board generally has a structure in which a circuit including metal foil is formed on an insulating film. In a broad sense, such a thin circuit board is referred to as a flexible metal foil clad laminate and is made of a thin copper plate with metal foil. When used, it is sometimes referred to as Flexible Copper Clad Laminate (FCCL) in a narrower sense.

Methods for manufacturing flexible metal foil laminates include, for example, (i) casting or applying polyamic acid, a precursor of polyimide, onto metal foil and then imidizing it, (ii) sputtering. (iii) a metalizing method in which a metal layer is directly installed on a polyimide film; and (iii) a laminating method in which a polyimide film and a metal foil are bonded through heat and pressure through thermoplastic polyimide.

In particular, the metallization method produces a flexible metal foil laminate by, for example, sputtering a metal such as copper on a polyimide film with a thickness of 20 to 38 ㎛ and sequentially depositing a tie layer and a seed layer. This method has the advantage of forming ultrafine circuits with a circuit pattern pitch of 35 ㎛ or less, and is widely used to manufacture flexible metal foil laminates for COF (chip on film).

Since the polyimide film used in such flexible metal foil laminates must have high heat resistance and mechanical properties, there is an urgent need for a polyimide film that has both excellent heat resistance and mechanical properties.

The matters described in the above background technology are intended to aid understanding of the background of the invention, and may include matters that are not prior art already known to those skilled in the art in the field to which this technology belongs.

[Prior art literature]

[Patent Document]

(Patent Document 1) Republic of Korea Patent No. 10-1375276

(Patent Document 2) Republic of Korea Patent Publication No. 2016-0002402

Accordingly, the purpose of the present invention is to provide a polyimide film that has both excellent heat resistance and mechanical properties (yield strength and yield point) and a method for manufacturing the same.

However, the problem to be solved by the present invention is not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the description below.

One aspect of the present invention for achieving the above object is that the yield strength is 138 MPa or more,

With a glass transition temperature of 370℃ or higher,

A polyimide film is provided.

Another aspect of the present invention provides a flexible metal foil laminate including the polyimide film and an electrically conductive metal foil.

Another aspect of the present invention provides an electronic component including the flexible metal foil laminate.

The present invention provides a polyimide film in which the composition ratio and reaction ratio of dianhydride and diamine components are adjusted, thereby improving the processability of the polyimide film by providing a polyimide film with excellent heat resistance, yield point, and yield strength characteristics. .

This polyimide film can be applied to various fields that require a polyimide film with excellent properties, for example, to a flexible metal foil laminate manufactured by a metallizing method or to electronic components including such a flexible metal foil laminate.

Terms or words used in this specification and claims should not be construed as limited to their common or dictionary meanings, and the inventor may appropriately define the concept of terms in order to explain his or her invention in the best way. It must be interpreted with meaning and concept consistent with the technical idea of the present invention based on the principle that it is.

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

In this specification, singular expressions include plural expressions, unless the context clearly dictates otherwise. In this specification, terms such as “comprise,” “comprise,” or “have” are intended to designate the presence of implemented features, numbers, steps, components, or a combination thereof, and are intended to indicate the presence of one or more other features or It should be understood that this does not exclude in advance the possibility of the presence or addition of numbers, steps, components, or combinations thereof.

As used herein, “dianhydride acid” is intended to include precursors or derivatives thereof, which may not technically be dianhydride acids, but which will nonetheless react with diamines to form polyamic acids, which in turn will form polyamic acids. It can be converted to mead.

As used herein, “diamine” is intended to include precursors or derivatives thereof, which may not technically be diamines, but which will nonetheless react with dianhydride to form polyamic acids, which in turn will form polyamic acids. Can be converted to mead

When amounts, concentrations, or other values or parameters are given herein as ranges, preferred ranges, or enumerations of upper preferred values and lower preferred values, any pair of upper range limits or It is to be understood that the preferred values and any lower range limits or all ranges formed from the preferred values are specifically disclosed.

When a range of numerical values is stated herein, unless otherwise stated, the range is intended to include the endpoints and all integers and fractions within the range. The scope of the invention is not intended to be limited to the specific values recited when defining the scope.

In this specification, “a to b” and “a to b” that indicate numerical ranges, “to” and “~” are defined as ≥ a and ≤ b.

The polyimide film according to one embodiment of the present invention may have a yield strength of 138 MPa or more and a glass transition temperature of 370°C or more.

Meanwhile, the yield strength of the polyimide film may be 150 MPa or less, and the glass transition temperature may be 380°C or less.

For example, the yield strength of the polyimide film may be 138 MPa or more, 140 MPa or more, or 145 MPa or more.

In one embodiment, the yield point of the polyimide film may be 2.4% or more.

Meanwhile, the yield point of the polyimide film may be 2.6% or less.

In one embodiment, the polyimide film is a dianhydride containing biphenyltetracarboxylic dianhydride (BPDA), pyromellitic dianhydride (PMDA), and benzophenone tetracarboxylic dianhydride (BTDA). It can be obtained by imidizing a polyamic acid solution containing a component and a diamine component including paraphenylene diamine (PPD), m-tolidine (m-tolidine), and oxydianiline (ODA).

That is, the polyimide film is a polymer composed of biphenyltetracarboxylic dianhydride, pyromellitic dianhydride, benzophenone tetracarboxylic dianhydride, paraphenylene diamine, m-tolidine, and oxydianiline. It can be obtained by subjecting the derived polyamic acid to an imidization reaction.

In one embodiment, based on a total content of 100 mol% of the dianhydride component, the content of the biphenyltetracarboxylic dianhydride is 15 mol% or more and 30 mol% or less, and the pyromellitic dianhydride The content of may be 30 mol% or more and 50 mol% or less, and the content of the benzophenone tetracarboxylic dianhydride may be 25 mol% or more and 45 mol% or less.

For example, based on the total content of the dianhydride component of 100 mol%, the content of the biphenyltetracarboxylic dianhydride is 20 mol% or more and 25 mol% or less, and the content of the pyromellitic dianhydride is It may be 35 mol% or more and 45 mol% or less, and the content of the benzophenone tetracarboxylic dianhydride may be 30 mol% or more and 45 mol% or less.

In one embodiment, based on a total content of 100 mol% of the diamine component, the paraphenylene diamine content is 45 mol% or more and 60 mol% or less, and the m-tolidine content is 10 mol% or more, It is 25 mol% or less, and the content of oxydianiline may be 20 mol% or more and 40 mol% or less.

For example, based on a total content of 100 mol% of the diamine component, the paraphenylene diamine content is 50 mol% or more and 60 mol% or less, and the m-tolidine content is 10 mol% or more and 15 mol%. % or less, and the content of oxydianiline may be 25 mol% or more and 35 mol% or less.

Paraphenylene diamine of the present invention is a rigid monomer, and as the content of paraphenylene diamine increases, the synthesized polyimide has a more linear structure, which can contribute to improving the mechanical properties and heat resistance of the polyimide.

also. In particular, m-tolidine contains a benzene ring structure containing a methyl group, so it can contribute to improving the mechanical properties and heat resistance of the polyimide film.

The polyimide chain derived from biphenyltetracarboxylic dianhydride of the present invention has a structure named charge transfer complex (CTC), that is, an electron donor and an electron acceptor. It has a regular straight structure located close to each other and intermolecular interaction is strengthened, affecting the heat resistance and mechanical properties of the polyimide film.

In addition, pyromellitic dianhydride is a dianhydride component with a relatively rigid structure and can provide appropriate elasticity to the polyimide film.

In order for a polyimide film to have excellent mechanical properties and heat resistance, the content ratio of dianhydride is important. For example, as the content ratio of biphenyltetracarboxylic dianhydride decreases, mechanical properties and heat resistance due to the CTC structure may decrease.

In addition, biphenyltetracarboxylicdianhydride and benzophenonetetracarboxylicdianhydride contain two benzene rings corresponding to the aromatic portion, while pyromellitic dianhydride contains a benzene ring corresponding to the aromatic portion. Includes 1.

The increase in the content of pyromellitic dianhydride in the dianhydride component can be understood as an increase in the imide group within the molecule based on the same molecular weight, which means that the imide group derived from the pyromellitic dianhydride is added to the polyimide polymer chain. It can be understood that the ratio of groups increases relative to the imide group derived from biphenyltetracarboxylicdianhydride and/or benzophenonetetracarboxylicdianhydride.

In other words, an excessive increase in the pyromellitic dianhydride content can be seen as a relative increase in imide groups in the entire polyimide film, which makes it difficult to expect improvements in mechanical properties and heat resistance.

Conversely, if the content ratio of pyromellitic dianhydride is excessively reduced, the relatively rigid structural components are reduced, and the elasticity of the polyimide film may be lowered below a desired level.

For this reason, when the content of biphenyltetracarboxylic dianhydride is above the above range or the content of pyromellitic dianhydride is below the above range, the mechanical properties and heat resistance of the polyimide film may be reduced. .

Conversely, even if the content of the biphenyltetracarboxylic dianhydride is below the above range or the content of pyromellitic dianhydride is above the above range, the mechanical properties and heat resistance of the polyimide film may be adversely affected. You can.

Therefore, the content range of each of biphenyltetracarboxylic dianhydride, pyromellitic dianhydride, and benzophenone tetracarboxylic dianhydride, which are dianhydride components of the polyimide film of the present application, and paraphenylene, which is a diamine component. If the respective content ranges of diamine, m-tolidine, and oxydianiline are above or below the content ranges herein, heat resistance (glass transition temperature) and/or mechanical properties (yield point, yield strength) may be reduced.

In one embodiment, the polyimide of the polyimide film is a first polymer obtained by imidizing a dianhydride component containing the biphenyltetracarboxylic dianhydride and a diamine component containing the m-tolidine. It may be a block copolymer containing blocks.

That is, the polyimide may be a block copolymer containing two or more blocks.

Meanwhile, the first block can be obtained by imidizing a polyamic acid derived from a polymer of a dianhydride component made of biphenyltetracarboxylic dianhydride and a diamine component made of m-tolidine.

In one embodiment, based on a total content of 100 mol% of the polyimide, the content of the first block may be 10 mol% or more and 16 mol% or less.

If the content of the first block is below the range of the present application, the glass transition temperature of the polyimide film may be lowered and heat resistance may be reduced. Additionally, if the content of the first block exceeds the range described herein, the yield point and/or yield strength of the polyimide film may decrease.

In the present invention, the production of polyamic acid is, for example,

(1) A method of polymerizing the entire amount of the diamine component in a solvent, and then adding the dianhydride component in substantially equimolar amounts to the diamine component;

(2) A method of polymerizing the entire amount of the dianhydride component in a solvent, and then adding the diamine component in substantially equimolar amounts to the dianhydride component;

(3) After adding some of the diamine components into the solvent, mixing some of the dianhydride components in a ratio of about 95 to 105 mol% with respect to the reaction components, adding the remaining diamine components, and then adding the remaining dianhydride components continuously. A method of polymerizing by adding components such that the diamine component and the dianhydride component are substantially equimolar;

(4) After adding the dianhydride component into the solvent, mixing some components of the diamine compound in a ratio of 95 to 105 mol% with respect to the reaction components, adding another dianhydride component, and then adding the remaining diamine component, A method of polymerizing the diamine component and the dianhydride component in substantially equimolar amounts;

(5) Reacting some diamine components and some dianhydride components in a solvent so that either one is in excess to form a first composition, and reacting some diamine components with some dianhydride components in another solvent so that either one is in excess. A method of forming a second composition, mixing the first and second compositions, and completing polymerization. In this case, if the diamine component is excessive when forming the first composition, the dianhydride component is added to the second composition. If the dianhydride component is excessive in the first composition, the diamine component is in excess in the second composition, and the first and second compositions are mixed so that the total diamine component and dianhydride component used in these reactions are substantially A method of polymerizing them by making them equimolar.

In the present invention, the polymerization method of the polyamic acid as described above can be defined as a random polymerization method, and the polyimide film manufactured from the polyamic acid of the present invention manufactured through the above process maximizes the effect of the present invention. It can be preferably applied in terms of ordering.

However, since the above polymerization method produces a relatively short length of the repeating unit in the polymer chain described above, there may be limitations in demonstrating each of the excellent properties of the polyimide chain derived from the dianhydride component. Therefore, the polymerization method of polyamic acid that can be particularly preferably used in the present invention may be a block polymerization method.

In one specific example, the method for producing a polyimide film according to the present invention includes,

It may include preparing a polyamic acid containing the first block of the block copolymer by polymerizing biphenyltetracarboxylic dianhydride and m-tolidine in an organic solvent.

In addition, the method for producing the polyimide film is to combine the remaining dianhydride component and diamine component in addition to the biphenyltetracarboxylic dianhydride and m-tolidine forming the first block to form the polyimide film in addition to the first block. It may include preparing a polyamic acid containing additional blocks necessary to realize the properties.

Meanwhile, the polyamic acid containing the first block of the block copolymer may be manufactured earlier than the polyamic acid containing other blocks, and the polyamic acid containing the other blocks may be manufactured first, and then the polyamic acid containing the first block may be produced first. Acids can also be manufactured.

For example, after preparing a polyamic acid containing a first block by adding biphenyltetracarboxylic dianhydride and m-tolidine together, the remaining blocks are formed in the polyamic acid containing the prepared first block. Polyimide, a block copolymer, can also be produced by additionally adding the dianhydride component and diamine component in a given order and imidizing them.

In addition, after first manufacturing the polyamic acid containing a block other than the first block or during manufacturing the polyamic acid containing a block other than the first block, the polyamic acid containing a block other than the manufactured first block is compared to the polyamic acid containing a block other than the first block. A polyamic acid containing the first block can also be prepared by adding phenyltetracarboxylic dianhydride and m-tolidine together.

On the other hand, the solvent for synthesizing polyamic acid is not particularly limited, and any solvent can be used as long as it dissolves polyamic acid, but it is preferable that it is an amide-based solvent.

Specifically, the organic solvent may be an organic polar solvent, and in particular, may be an aprotic polar solvent, for example, N,N-dimethylformamide (DMF), N,N - It may be one or more selected from the group consisting of dimethylacetamide, N-methyl-pyrrolidone (NMP), gamma butyrolactone (GBL), and Diglyme, but is not limited thereto, and may be used alone as needed. Or, two or more types can be used in combination.

In one example, N,N-dimethylformamide and N,N-dimethylacetamide may be particularly preferably used as the organic solvent.

Additionally, in the polyamic acid manufacturing process, fillers may be added to improve various properties of the film such as sliding properties, thermal conductivity, corona resistance, and loop hardness. The added filler is not particularly limited, but preferred examples include silica, titanium oxide, alumina, silicon nitride, boron nitride, calcium hydrogen phosphate, calcium phosphate, and mica.

The particle size of the filler is not particularly limited and may be determined depending on the film properties to be modified and the type of filler to be added. Generally, the average particle diameter is 0.05 to 100 μm, preferably 0.1 to 75 μm, more preferably 0.1 to 50 μm, and particularly preferably 0.1 to 25 μm.

If the particle size is below this range, it becomes difficult to achieve a reforming effect, and if the particle size is above this range, the surface properties may be greatly damaged or the mechanical properties may be greatly reduced.

Additionally, the amount of filler added is not particularly limited and may be determined based on the film properties to be modified, the particle size of the filler, etc. Generally, the amount of filler added is 0.01 to 100 parts by weight, preferably 0.01 to 90 parts by weight, and more preferably 0.02 to 80 parts by weight, based on 100 parts by weight of polyimide.

If the amount of filler added is less than this range, it is difficult to achieve a reforming effect due to the filler, and if it is more than this range, the mechanical properties of the film may be significantly damaged. The method of adding the filler is not particularly limited, and any known method may be used.

In the production method of the present invention, the polyimide film can be produced by thermal imidization and chemical imidization.

In addition, it may be manufactured by a complex imidization method in which thermal imidization and chemical imidization are combined.

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

The thermal imidization method can imidize the amic acid group present in the gel film by heat treating the gel film at a variable temperature in the range of 100 to 600 ℃, specifically 200 to 500 ℃, more specifically, The amic acid group present in the gel film can be imidized by heat treatment at 300 to 500°C.

However, even in the process of forming a gel film, some of the amic acid (about 0.1 mol% to 10 mol%) may be imidized, and for this purpose, the polyamic acid composition is dried at a variable temperature in the range of 50 ℃ to 200 ℃. It can also be included in the scope of the thermal imidization method.

In the case of chemical imidization, a polyimide film can be produced using a dehydrating agent and an imidizing agent according to methods known in the art.

As an example of a complex imidization method, a dehydrating agent and an imidizing agent are added to a polyamic acid solution, then heated at 80 to 200°C, preferably 100 to 180°C, partially cured and dried, and then heated to 5 to 400°C at 200 to 400°C. A polyimide film can be produced by heating for a few seconds.

The present invention provides a multilayer film comprising the polyimide film described above.

The multilayer film may include additional polyimide films, such as thermoplastic polyimide films.

The present invention provides a flexible metal foil laminate including the above-described polyimide film and an electrically conductive metal foil.

There is no particular limitation on the metal foil to be used, but when the flexible metal foil laminate of the present invention is used for electronic components, electronic devices, etc., copper or copper alloy, stainless steel or its alloy, nickel or nickel alloy ( 42 alloy), aluminum, or aluminum alloy.

In general flexible metal foil laminates, copper foils such as rolled copper foil and electrolytic copper foil are widely used, and can also be preferably used in the present invention. Additionally, a rust-prevention layer, a heat-resistant layer, or an adhesive layer may be applied to the surface of these metal foils.

In the present invention, the thickness of the metal foil is not particularly limited, and may be sufficient to provide sufficient function depending on the intended use.

The flexible metal foil laminate according to the present invention may have a structure in which metal foil is laminated to at least one side of the polyimide film.

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

Manufacturing example: Preparation of polyimide film

The polyimide film of the present invention can be manufactured by conventional methods known in the art as follows. First, a polyamic acid solution is obtained by reacting the dianhydride and diamine components described above in an organic solvent.

At this time, the solvent is generally an amide-based solvent, such as an aprotic polar solvent (Aprotic solvent), such as N,N'-dimethylformamide, N,N'-dimethylacetamide, N-methyl-pyrrolidone, or A combination of these can be used.

The dianhydride and diamine components can be added in the form of powder, lump, and solution. It is preferable to add them in the form of powder at the beginning of the reaction to proceed with the reaction, and then add them in the form of a solution to control the polymerization viscosity. .

The obtained polyamic acid solution can be mixed with an imidization catalyst and a dehydrating agent and applied to a support.

Examples of catalysts used include tertiary amines (eg, isoquinoline, β-picoline, pyridine, etc.), and examples of dehydrating agents include, but are not limited to, anhydrous acid. In addition, the support used above may include, but is not limited to, a glass plate, aluminum foil, a circular stainless steel belt, or a stainless drum.

The film applied on the support is gelled on the support by drying air and heat treatment.

The gelated film is separated from the support and heat-treated to complete drying and imidization.

The film that has completed the heat treatment can be heat treated under a certain tension to remove residual stress inside the film generated during the film forming process.

Specifically, 500 ml of DMF was added while nitrogen was injected into a reactor equipped with a stirrer and nitrogen injection/discharge pipes, the temperature of the reactor was set to 25°C, and biphenyltetracarboxylic dianhydride (BPDA) and pyrogen were added. Melitic dianhydride (PMDA), benzophenone tetracarboxylic dianhydride (BTDA), paraphenylene diamine (PPD), m-tolidine, oxydianiline (ODA) and 4,4' -Add diaminobenzanilide (4,4'-Diaminobenzanilide, 4,4'-DABA) in the adjusted composition ratio and order and completely dissolve it.

When added, biphenyltetracarboxylicdianhydride and m-tolidine are continuously added to imidize the dianhydride component containing biphenyltetracarboxylicdianhydride and the diamine component containing m-tolidine. The first block obtained by reacting can be obtained.

Afterwards, the temperature of the reactor was raised to 30°C under a nitrogen atmosphere and stirring was continued for 120 minutes while heating to prepare polyamic acid with a first reaction viscosity of 800 to 1,200 cP.

The polyamic acid prepared in this way was stirred to a final viscosity of 140,000 to 160,000 cP.

The contents of the catalyst and dehydrating agent were adjusted and added to the prepared final polyamic acid, and then a polyimide film was manufactured using an applicator.

Examples and Comparative Examples

As shown in Table 1 below, the contents of the dianhydride component and the diamine component in Examples 1 to 4 and Comparative Examples 1 to 5 were adjusted to prepare a polyimide film according to the preparation example.

In addition, by controlling the order and amount of addition of the dianhydride component and the diamine component, the polyimide films of Examples 1 to 4 and Comparative Examples 1 to 3 were prepared by controlling the dianhydride component containing biphenyltetracarboxylic dianhydride and m -It contains a first block obtained by imidating a diamine component containing tolidine, but the polyimide films of Comparative Examples 4 and 5 are composed of a dianhydride component containing biphenyltetracarboxylic dianhydride and m-tol. It does not include the first block obtained by subjecting a diamine component containing lydine to an imidation reaction.

In addition, the content of the first block obtained by imidizing the dianhydride component containing biphenyltetracarboxylic dianhydride and the diamine component containing m-tolidine of the polyimide films of Comparative Examples 1 to 3 is as follows. Based on the total content of 100 mol% of the polyimide film, it was included in an amount of 5 mol% or more and 8 mol% or less.

Meanwhile, the content of the first block obtained by imidizing the dianhydride component containing biphenyltetracarboxylic dianhydride and the diamine component containing m-tolidine of the polyimide films of Examples 1 to 4 is as above. Based on the total content of 100 mol% of the polyimide film, it was all included in an amount of 10 mol% or more and 16 mol% or less.

	Dianhydride product			diamine
	PMDA	BPDA	BTDA	O.D.A.	PPD	m-Tolidine	4,4'-DABA
Example 1	40	20	40	30	58	12	-
Example 2	40	25	35	30	58	12	-
Example 3	40	23	37	34	54	12	-
Example 4	40	20	40	34	56	10	-
Comparative Example 1	40	20	40	42	53	5	-
Comparative example 2	42	20	38	45	50	5	-
Comparative example 3	40	20	40	34	58	8	-
Comparative example 4	40	20	40	34	50	8	8

The glass transition temperature (Tg), yield point, and yield strength of the produced polyimide film were measured and shown in Table 2 below.

	Properties
	Tg (℃)	yield point (%)	yield strength (MPa)
Example 1	370	2.53	140.4
Example 2	373	2.48	145.1
Example 3	370	2.46	138.2
Example 4	371	2.43	141.2
Comparative Example 1	365	2.47	114.8
Comparative example 2	364	2.70	142.7
Comparative Example 3	369	2.54	138.7
Comparative example 4	358	2.72	152.8
Comparative Example 5	353	2.86	149.1

(1) Glass transition temperature measurement

For the glass transition temperature (T _g ) in Table 2, the loss modulus and storage modulus of each film were obtained using DMA, and the inflection point was measured as the glass transition temperature in their tangent graph.

(2) Yield point and yield strength measurement

The yield point and yield strength in Table 2 were determined by cutting the polyimide film into 15 mm Х 50 mm to prepare a specimen and using a tensile tester (Instron 5564, Instron) at a tensile speed of 200 mm/min according to ASTM D 882 standards. ) was measured at room temperature (room temp.).

As a result of the measurement, the polyimide films of Examples 1 to 4 had a glass transition temperature of 370°C or higher, a yield point of 2.4% or higher, and a yield strength of 138 MPa or higher.

When comparing the polyimide films of Examples 1 and 2, which had the same content of diamine component and different content of dianhydride component, as the content of BPDA increased and the content of BTDA decreased, the glass transition temperature of the polyimide film slightly decreased. It was confirmed that the yield rises, the yield point slightly decreases, and the yield strength slightly increases.

Comparing the polyimide films of Example 1 and Example 3, it was confirmed that the yield point and yield strength of the polyimide film were slightly lowered as the contents of BPDA and ODA increased and the contents of PPD and BTDA decreased.

In addition, when comparing Examples 1 and 4 in which the content of the dianhydride component is the same and the content of the diamine component is different, as the content of ODA increases and the content of PPD and m-tolidine decreases, the glass transition temperature slightly increases. , it was confirmed that the yield point was slightly lowered and the yield strength was slightly increased.

On the other hand, compared to the polyimide film of Example 1, the polyimide film of Comparative Example 1, in which the ODA content was increased and the PPD and m-tolidine content were reduced, had a glass transition temperature of less than 370°C and a yield strength of less than 138 MPa. It has been degraded.

In addition, compared to the polyimide film of Example 1, the polyimide film of Comparative Example 3, in which the ODA content was increased and the m-tolidine content was reduced, had a glass transition temperature of less than 370°C.

Compared to the polyimide film of Comparative Example 1, the polyimide film of Comparative Example 2, in which the contents of PMDA and ODA were further increased and the contents of BTDA and PPD were further reduced, had both improved yield point and yield strength, but still had a glass transition temperature of 370°C. It was less than

The polyimide film of Comparative Example 3 had all improved glass transition temperature, yield point, and yield strength compared to the polyimide film of Comparative Example 1, but the glass transition temperature was still less than 370°C.

Comparative Example 4, which does not contain a block obtained by imidating a dianhydride component containing 4,4'-DABA and biphenyltetracarboxylic dianhydride and a diamine component containing m-tolidine, and The polyimide film of Comparative Example 5 had a lower glass transition temperature (less than 370°C) compared to the polyimide films of Examples 1 and 4 having the same dianhydride component composition ratio.

Accordingly, the polyimide films of Examples 1 to 4 manufactured within the appropriate range of the present application were excellent in both heat resistance (glass transition temperature) and mechanical properties (yield strength and yield point), but when outside the appropriate range of the present application, the heat resistance and It was confirmed that it was difficult to achieve both mechanical properties.

In other words, it was confirmed that a polyimide film that has heat resistance and mechanical properties and can be applied to a variety of applications is a polyimide film manufactured within the appropriate scope of the present application.

The examples of the polyimide film and the manufacturing method of the polyimide film of the present invention are only preferred embodiments that allow those skilled in the art to easily practice the present invention, and the above-described examples Since it is not limited to this, the scope of rights of the present invention is not limited. Therefore, the true scope of technical protection of the present invention should be determined by the technical spirit of the attached patent claims. In addition, it will be clear to those skilled in the art that various substitutions, modifications and changes can be made without departing from the technical spirit of the present invention, and it is obvious that parts that can be easily changed by those skilled in the art are also included in the scope of rights of the present invention. .

The present invention provides a polyimide film in which the composition ratio and reaction ratio of dianhydride and diamine components are adjusted, thereby improving the processability of the polyimide film by providing a polyimide film with excellent heat resistance, yield point, and yield strength characteristics. .

This polyimide film can be applied to various fields that require a polyimide film with excellent properties, for example, to a flexible metal foil laminate manufactured by a metallizing method or to electronic components including such a flexible metal foil laminate.

Claims (9)

1. Yield strength is greater than 138 MPa,

   A glass transition temperature of 370°C or higher,

   Polyimide film.
2. According to paragraph 1,

   With a yield point of 2.4% or more,

   Polyimide film.
3. According to paragraph 1,

   Dianhydride components including biphenyltetracarboxylic dianhydride (BPDA), pyromellitic dianhydride (PMDA), and benzophenone tetracarboxylic dianhydride (BTDA), paraphenylene diamine (PPD), Obtained by imidizing a polyamic acid solution containing a diamine component including m-tolidine and oxydianiline (ODA),

   Polyimide film.
4. According to paragraph 3,

   Based on the total content of the dianhydride component of 100 mol%, the content of the biphenyltetracarboxylic dianhydride is 15 mol% or more and 30 mol% or less, and the content of the pyromellitic dianhydride is 30 mol%. It is 50 mol% or less, and the content of the benzophenone tetracarboxylic dianhydride is 25 mol% or more and 45 mol% or less,

   Polyimide film.
5. According to paragraph 3,

   Based on the total content of the diamine component of 100 mol%, the paraphenylene diamine content is 45 mol% or more and 60 mol% or less, and the m-tolidine content is 10 mol% or more and 25 mol% or less, The content of oxydianiline is 20 mol% or more and 40 mol% or less,

   Polyimide film.
6. According to paragraph 3,

   The polyimide is a block copolymer comprising a first block obtained by imidizing a dianhydride component containing the biphenyltetracarboxylic dianhydride and a diamine component containing the m-tolidine,

   Polyimide film.
7. According to clause 6,

   Based on the total content of 100 mol% of the polyimide, the content of the first block is 10 mol% or more and 16 mol% or less,

   Polyimide film.
8. A flexible metal foil laminate comprising the polyimide film according to any one of claims 1 to 7 and an electrically conductive metal foil.
9. Electronic components comprising the flexible metal foil laminate according to claim 8