TWI843190B - Polyimide film, method for manufacturing the same, multilayer film and electronic component including the same - Google Patents

Abstract

The present invention relates to a polyimide film and a method for producing the same. The polyimide film is produced by imidizing a polyamide solution. The polyamide solution comprises: a dianhydride component including biphenyltetracarboxylic dianhydride (BPDA), pyromellitic dianhydride (PMDA) and benzophenonetetracarboxylic dianhydride (BTDA); and a diamine component including diaminodiphenyl ether (ODA), p-phenylenediamine (PPD) and 4,4'-diaminobenzanilide (DABA).

Description

Polyimide film, method for producing the same, multilayer film and electronic component comprising the same

The present invention relates to a polyimide film having excellent mechanical strength and heat resistance and a method for manufacturing the same.

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

In particular, due to its excellent insulation properties, such as low dielectric constant and excellent electrical properties, it has attracted much attention as a high-functional polymer material in the electrical, electronic and optical fields.

Recently, with the trend toward lighter and smaller electronic products, the development of highly integrated, flexible, and thin circuit boards is being actively pursued.

The trend of this type of thin circuit board is to use a structure in which a circuit including a metal foil is formed on a polyimide film that has excellent heat resistance, low temperature resistance, and insulation characteristics and is easily bendable.

As such thin circuit boards, flexible metal clad laminates are mainly used, and as an example, there is a flexible copper clad laminate (FCCL) using a thin copper plate as the metal foil. In addition, polyimide can also be used as a protective film, insulating film, etc. of the thin circuit board.

In particular, recently, as a variety of functions are built into electronic devices, these electronic devices require faster computing speeds and communication speeds. In order to meet this demand, thin circuit boards that can communicate at high frequencies are being developed.

However, conventional polyimide films have a disadvantage of relatively low heat resistance when used in the latest circuit boards. Although various studies have been conducted to improve heat resistance, the improvement in heat resistance is accompanied by a decrease in mechanical strength or thermal properties such as glass transition temperature.

Therefore, there is still an urgent need to develop a polyimide film that improves heat resistance while maintaining the original mechanical strength of polyimide or thermal properties such as glass transition temperature.

[Prior art document] [Patent document] (Patent document 1) Korean patent No. 10-1004429.

[Technical issues]

The object of the present invention is to provide a polyimide film having both excellent high heat resistance and mechanical properties and a method for manufacturing the same.

In particular, the present invention aims to provide a polyimide film having high high temperature thermal stability, excellent elastic modulus, tensile strength and elongation properties, and a method for producing the same.

Therefore, the essential purpose of the present invention is to provide a specific embodiment thereof. [Technical Solution]

In order to achieve the above-mentioned purpose, one embodiment of the present invention provides a polyimide membrane, which is manufactured by imidizing a polyamide solution, wherein the polyamide solution comprises: dianhydride components including biphenyltetracarboxylic dianhydride (3,3′,4,4′-Biphenyltetracarboxylic dianhydride, BPDA), pyromellitic dianhydride (PMDA) and benzophenonetetracarboxylic dianhydride (3,3',4,4'-Benzophenonetetracarboxylic dianhydride, BTDA); and diamine components including diaminodiphenyl ether (4,4′-Oxydianiline, ODA), p-Phenylenediamine (PPD) and 4,4'-Diaminobenzanilide (4,4'-Diaminobenzanilide, DABA).

In one embodiment, based on 100 mol% of the total content of the diamine components, the content of the diaminodiphenyl ether may be greater than 23 mol% and less than 43 mol%, the content of the p-phenylenediamine may be greater than 50 mol% and less than 60 mol%, and the content of the 4,4-diaminobenzanilide may be greater than 10 mol% and less than 30 mol%.

In addition, based on the total content of the aforementioned dianhydride components as 100 mol %, the content of the aforementioned biphenyltetracarboxylic dianhydride may be greater than 15 mol % and less than 30 mol %, the content of the aforementioned pyromellitic dianhydride may be greater than 50 mol % and less than 65 mol %, and the content of the aforementioned benzophenone tetracarboxylic dianhydride may be greater than 10 mol % and less than 35 mol %.

On the other hand, the polyimide film may include a block copolymer composed of two or more blocks.

In one embodiment, the polyimide film may have an elastic modulus of 5 GPa or more, a strength of 340 MPa or more, a glass transition temperature (Tg) of 360° C. or more, and an elongation of 60% or more.

Another embodiment of the present invention provides a method for producing a polyimide film, comprising: (a) a step of polymerizing a dianhydride component including biphenyltetracarboxylic dianhydride (BPDA), pyromellitic dianhydride (PMDA) and benzophenonetetracarboxylic dianhydride (BTDA) with a diamine component consisting of diaminodiphenyl ether (ODA), p-phenylenediamine (PPD) and 4,4'-diaminobenzanilide (DABA) in an organic solvent to produce polyimide; and (b) a step of subjecting the polyimide to imidization.

Another embodiment of the present invention provides a multilayer film including the polyimide film or a multilayer film including the polyimide film and a thermoplastic resin layer.

Another embodiment of the present invention provides a flexible metal foil laminate including the aforementioned polyimide film and a conductive metal foil, and an electronic component including the aforementioned flexible metal foil laminate. [Effect of the invention]

The polyimide film of the embodiment of the present invention can have excellent high heat resistance and mechanical properties by using a specific dianhydride component and a specific diamine component in combination at a specific molar ratio. In addition, the adhesion can be improved.

On the other hand, the present invention includes the polyimide film as described above and can be usefully applied to electronic components such as flexible metal foil laminates.

The following describes the embodiments of the present invention in more detail according to the order of "polyimide film" and "method for producing polyimide film" of the present invention.

Prior to this, the terms or words used in this specification and the scope of the patent application shall not be interpreted in a limited manner as having the usual or dictionary meanings, but shall only be interpreted as meanings and concepts that are consistent with the technical ideas of the present invention based on the principle that "the inventor may appropriately define the concepts of the terms in order to explain his own invention in the best way."

Therefore, the embodiments described in this specification are merely the best embodiments of the present invention and do not fully represent the technical ideas of the present invention. Therefore, it should be understood that at the time of the present invention, there will be multiple equivalents and modifications that can replace them.

Unless the context clearly indicates otherwise, singular expressions in this specification include plural expressions. In this specification, terms such as "including", "having" or "having" are intended to specify the existence of features, numbers, steps, constituent elements or combinations thereof of the implementation, and should be understood as not excluding the existence or additional possibility of one or more other features or numbers, steps, constituent elements or combinations thereof in advance.

In this specification, when an amount, concentration or other value or parameter is given by listing a range, a preferred range, or a preferred upper limit and a preferred lower limit, it should be understood that all ranges formed by any pair of any range upper limit or preferred value and any range lower limit or preferred value are specifically disclosed, regardless of whether the range is disclosed separately.

When a range of numerical values is mentioned in this specification, unless otherwise stated, the range is intended to include its endpoints and all integers and fractions within the range, which means that the scope of the present invention is not limited to the specific values mentioned when defining the range.

In this specification, "dianhydride" is meant to include precursors or derivatives thereof, which may not technically be dianhydrides but will nevertheless react with diamines to form polyamides which can in turn be converted into polyimines.

In this specification, "diamine" is meant to include precursors or derivatives thereof, which may not technically be diamines but will nevertheless react with dianhydrides to form polyamides, which in turn can be converted into polyimines.

The polyimide film of the present invention is prepared by imidizing a polyimide solution including a dianhydride component and a diamine component, wherein the dianhydride component includes biphenyltetracarboxylic dianhydride (3,3',4,4'-Biphenyltetracarboxylic dianhydride; BPDA), pyromellitic dianhydride (PMDA) and benzophenonetetracarboxylic dianhydride (3,3',4,4'-Benzophenonetetracarboxylic dianhydride; BTDA), and the diamine component includes diaminodiphenyl ether (4,4'-Oxydianiline; ODA), p-phenylenediamine (PPD) and 4,4'-diaminobenzanilide (DABA).

In one embodiment, based on the total content of the aforementioned diamine components being 100 mol%, the content of the aforementioned diaminodiphenyl ether may be greater than 23 mol% and less than 43 mol%, the content of the aforementioned p-phenylenediamine may be greater than 50 mol% and less than 60 mol%, and the content of the aforementioned 4,4-diaminobenzanilide may be greater than 10 mol% and less than 30 mol%.

The aforementioned 4,4'-diaminobenzanilide contains an amide group, and therefore within the content range of the present invention, it greatly helps to improve the excellent heat resistance and mechanical properties of the polyimide film of the present invention.

In one embodiment, based on the total content of the dianhydride components being 100 mol %, the content of the biphenyltetracarboxylic dianhydride may be greater than 15 mol % and less than 30 mol %, the content of the pyromellitic dianhydride may be greater than 50 mol % and less than 65 mol %, and the content of the benzophenone tetracarboxylic dianhydride may be greater than 10 mol % and less than 35 mol %.

The polyimide chain derived from biphenyltetracarboxylic dianhydride has a structure called a charge transfer complex (CTC), that is, a regular linear structure in which electron donors and electron acceptors are arranged close to each other, which strengthens the intermolecular interaction.

In addition, benzophenone tetracarboxylic dianhydride, which has a carbonyl group, also contributes to the expression of CTC, just like biphenyltetracarboxylic dianhydride.

In particular, pyromellitic dianhydride may be additionally contained as the dianhydride component. Pyromellitic dianhydride is a dianhydride component having a relatively rigid structure and is highly recommended in that it can impart appropriate elasticity to the polyimide film.

In addition, biphenyltetracarboxylic dianhydride and benzophenonetetracarboxylic dianhydride contain two benzene rings corresponding to the aromatic moiety, whereas pyromellitic dianhydride contains one benzene ring corresponding to the aromatic moiety.

In the dianhydride component, the increase in the content of pyromellitic dianhydride can be understood as an increase in the imide groups in the molecule when the molecular weight is the same. This can be understood as the ratio of the imide groups derived from the aforementioned pyromellitic dianhydride to the imide groups derived from biphenyltetracarboxylic dianhydride and dibenzophenonetetracarboxylic dianhydride in the polyimide polymer chain is relatively increased.

If the content of pyromellitic dianhydride is excessively reduced, the relatively rigid structural components are reduced, and thus the mechanical properties of the polyimide film are reduced and cannot reach the desired level.

For this reason, when the content of the biphenyltetracarboxylic dianhydride and the benzophenonetetracarboxylic dianhydride exceeds the above range, the mechanical properties of the polyimide film are deteriorated.

In one implementation example, the polyimide film may include a block copolymer composed of two or more blocks.

At least one block of the aforementioned block copolymer may include a combination of pyromellitic dianhydride and 4,4'-diaminobenzanilide.

By adjusting the block structure of this block copolymer, the glass transition temperature of the polyimide film can be increased, ensuring the high-temperature thermal stability of the polyimide film.

In one implementation example, the elastic modulus of the polyimide film may be greater than 5 GPa, and the strength may be greater than 340 MPa.

In addition, the glass transition temperature (Tg) of the polyimide film may be 360° C. or higher, and the elongation may be 60% or higher.

In particular, properties such as elongation are generally difficult to achieve at an optimal level together with strength, but the components and proportions of the present invention including 4,4'-diaminobenzanilide containing an amide group can play a major role in suppressing the decrease in elongation while expressing an optimal level of strength.

In the present invention, polyamine can be produced by, for example, the following method.

(1) Method, the entire amount of the diamine component is added to a solvent, and then the dianhydride component is added so that the molar amount is substantially equimolar with the diamine component and polymerization is carried out.

(2) Method, the entire amount of the dianhydride component is added to the solvent, and then the diamine component is added so that the molar amount is substantially equimolar with the dianhydride component and polymerization is carried out.

(3) A method comprising adding a portion of the diamine component to a solvent, mixing a portion of the dianhydride component at a ratio of about 95 to 105 mol% relative to the reaction component, adding the remaining diamine component, and then adding the remaining dianhydride component so that the diamine component and the dianhydride component are substantially equimolar and polymerizing.

(4) A method comprising adding a dianhydride component to a solvent, mixing a portion of the diamine compound at a ratio of 95 to 105 mol% relative to the reaction components, adding the other dianhydride component, and then continuing to add the remaining diamine component until the diamine component and the dianhydride component are substantially equimolar and polymerizing.

(5) A method comprising reacting a part of a diamine component with a part of a dianhydride component in a solvent so that one of them is in excess to form a first composition, and reacting a part of a diamine component with a part of a dianhydride component in another solvent so that one of them is in excess to form a second composition, and then mixing the first and second compositions to complete polymerization. In this case, when the diamine component is in excess when forming the first composition, the dianhydride component is in excess in the second composition, and when the dianhydride component is in excess in the first composition, the diamine component is in excess in the second composition. The first and second compositions are mixed so that the total amount of the diamine component and the dianhydride component used in the reaction is substantially equimolar and then polymerization is carried out.

However, the polymerization method is not limited to the above examples, and polyamine can be produced by any known method.

In a specific example, the method for manufacturing the polyimide film of the present invention may include: (a) polymerizing a dianhydride component including biphenyltetracarboxylic dianhydride (BPDA), pyromellitic dianhydride (PMDA) and benzophenonetetracarboxylic dianhydride (BTDA) with a diamine component consisting of diaminodiphenyl ether (ODA), p-phenylenediamine (PPD) and 4,4'-diaminobenzanilide (DABA) in an organic solvent to produce polyimide; and (b) subjecting the aforementioned polyimide to imidization.

In one implementation example, based on 100 mol % of the total content of the diamine components, the content of the diaminodiphenyl ether may be greater than 23 mol % and less than 43 mol %, the content of the p-phenylenediamine may be greater than 50 mol % and less than 60 mol %, the content of the 4,4'-diaminobenzanilide may be greater than 10 mol % and less than 30 mol %, based on 100 mol % of the total content of the dianhydride components, the content of the biphenyltetracarboxylic dianhydride may be greater than 15 mol % and less than 30 mol %, the content of the pyromellitic dianhydride may be greater than 50 mol % and less than 65 mol %, and the content of the benzophenonetetracarboxylic dianhydride may be greater than 10 mol % and less than 35 mol %.

The polyimide film may have an elastic modulus of 5 GPa or more, a strength of 340 MPa or more, a glass transition temperature (Tg) of 360° C. or more, and an elongation of 60% or more.

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 made of polyamic acid of the present invention manufactured by the process as described above is preferably applicable due to the effects of improving mechanical properties and heat resistance of the present invention.

On the other hand, the solvent used for synthesizing polyamine is not particularly limited, and any solvent can be used as long as it can dissolve polyamine, but an amide solvent is preferred.

Specifically, the aforementioned solvent may be an organic polar solvent, more specifically, an aprotic polar solvent, for example, one or more selected from the group consisting of N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), N-methylpyrrolidone (NMP), p-chlorophenol, o-chlorophenol, N-methylpyrrolidone (NMP), γ-butyrolactone (GBL) and diglyme (Diglyme), but is not limited thereto and may be used alone or in combination of two or more as needed.

In one example, N,N-dimethylformamide and N,N-dimethylacetamide are particularly preferably used as the aforementioned solvent.

In addition, fillers other than nanosilicon dioxide can be added during the polyamide manufacturing process to improve various properties of the film, such as slip, thermal conductivity, corona resistance, and ring hardness. The added filler material is not particularly limited, and preferred examples include titanium oxide, aluminum oxide, silicon nitride, boron nitride, calcium hydrogen phosphate, calcium phosphate, mica, and the like.

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

If the particle size is below this range, the modification effect is difficult to show, and if it exceeds this range, the surface properties may be greatly damaged or the mechanical properties may be greatly reduced.

In addition, the amount of filler added is not particularly limited and can be determined according to the film properties to be modified or the filler particle size, 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, relative to 100 parts by weight of polyimide.

If the amount of filler added is below this range, the modifying effect of the filler is difficult to be exhibited, and if it exceeds this range, there is a possibility that the mechanical properties of the film will be greatly damaged. The method of adding the filler is not particularly limited, and any known method can be used.

In the manufacturing method of the present invention, the polyimide membrane can be manufactured by thermal imidization and chemical imidization.

In addition, it can also be produced by a composite imidization method that combines thermal imidization and chemical imidization.

The so-called thermal imidization method is a method that uses a heat source such as hot air or an infrared dryer to induce the imidization reaction without using a chemical catalyst.

The aforementioned thermal imidization method can heat-treat the aforementioned gel film at a variable temperature in the range of 100°C to 600°C to imidize the amide groups present in the gel film. Specifically, the heat treatment can be performed at 200°C to 500°C, and more specifically, at 300°C to 500°C to imidize the amide groups present in the gel film.

However, during the process of forming the gel film, a portion of the polyamine (about 0.1 mol% to 10 mol%) will also be imidized. For this purpose, the polyamine composition can be dried at a variable temperature in the range of 50°C to 200°C, which can also be included in the scope of the aforementioned thermal imidization method.

As for the chemical imidization method, a polyimide membrane can be produced by using a dehydrating agent and an imidizing agent according to a method known in the industry. The so-called "dehydrating agent" refers to a substance that promotes the ring-closing reaction by dehydrating the polyamide. As non-limiting examples, aliphatic anhydrides, aromatic anhydrides, N,N'-dialkylcarbodiimide, halogenated lower aliphatic anhydrides, halogenated lower Pater anhydrides, aromatic phosphonic acid dihalides and sulfinyl halides can be used. Among them, from the perspective of availability and cost, aliphatic anhydrides are preferred. As non-limiting examples, acetic anhydride (or anhydrous acetic acid, AA), propionic anhydride and lactic anhydride can be used, and they can be used alone or in combination of two or more.

In addition, the so-called "imide agent" means a substance that has the effect of promoting the ring-closing reaction of polyamide, and can be, for example, an imine component such as an aliphatic tertiary amine, an aromatic tertiary amine, and a heterocyclic tertiary amine. Among them, from the perspective of reactivity as a catalyst, a heterocyclic tertiary amine is preferred. Non-limiting examples of heterocyclic tertiary amines include quinoline, isoquinoline, β-methylpyridine (BP), and pyridine, which can be used alone or in combination of two or more.

The amount of the dehydrating agent added is preferably in the range of 0.5 mol to 5 mol, and more preferably in the range of 1.0 mol to 4 mol, relative to 1 mol of amine groups in the polyamine. In addition, the amount of the imidizing agent added is preferably in the range of 0.05 mol to 2 mol, and more preferably in the range of 0.2 mol to 1 mol, relative to 1 mol of amine groups in the polyamine.

If the amount of the dehydrating agent and the imidizing agent is below the above range, the chemical imidization will be insufficient, cracks will occur in the manufactured polyimide film, and the mechanical strength of the film will also be reduced. On the other hand, if the amount of the addition exceeds the above range, the imidization will proceed too quickly, and at this time, it will be difficult to cast into a film form or the manufactured polyimide film will show brittleness, so it is not recommended.

As an example of the composite imidization method, a dehydrating agent and an imidizing agent may be added to a polyamide solution, and then heated at 80°C to 200°C, preferably 100°C to 180°C. After partial curing and drying, the solution may be heated at 200°C to 400°C for 5 to 400 seconds to produce a polyimide film.

The present invention provides a multilayer film comprising the polyimide film and a thermoplastic resin layer and a flexible metal-clad laminate comprising the polyimide film and a conductive metal foil.

As the aforementioned thermoplastic resin layer, for example, a thermoplastic polyimide resin layer or the like can be applied.

The metal foil used is not particularly limited, but when the flexible metal-clad foil laminate of the present invention is used for electronic equipment or electrical equipment, it can be, for example, a metal foil including copper or a copper alloy, stainless steel or an alloy thereof, nickel or a nickel alloy (including 42 alloy), aluminum or an aluminum alloy.

In common flexible metal foil laminates, copper foils called rolled copper foils and electrolytic copper foils are often used, and they can also be preferably used in the present invention. In addition, the surfaces of these metal foils can also be coated with a rust-proof layer, a heat-resistant layer or an adhesive layer.

In the present invention, the thickness of the metal foil is not particularly limited, and may be any thickness that can fully exert its function depending on its application.

The flexible metal foil-clad laminate of the present invention may be a structure in which a metal foil is laminated on one side of the polyimide film or an adhesive layer containing thermoplastic polyimide is attached to one side of the polyimide film and the metal foil is laminated in a state where the metal foil is attached to the adhesive layer.

The present invention also provides an electronic component comprising the above-mentioned flexible metal-clad foil laminate as an electrical signal transmission circuit.

The following is a more detailed description of the functions and effects of the invention through specific embodiments of the invention. However, such embodiments are only proposed as examples of the invention, and the scope of the invention is not limited thereby.

＜Manufacturing example＞

Nitrogen was injected into a 500 ml reactor equipped with a stirrer, a nitrogen injection tube, and a discharge tube, and DMF was added at the same time. After the reactor temperature was set to 30°C, diaminodiphenyl ether (ODA), p-phenylenediamine (PPD), and 4,4'-diaminobenzanilide (DABA) as diamine components, and biphenyltetracarboxylic dianhydride (BPDA), pyromellitic dianhydride (PMDA), and benzophenonetetracarboxylic dianhydride (BTDA) as dianhydride components were added, and complete dissolution was confirmed.

Then, under a nitrogen atmosphere, the reactor temperature was heated to 40°C and stirred for 120 minutes to produce polyamine.

A catalyst and a dehydrating agent are added to the polyamine thus produced, and after being spun at a high speed of more than 1500 rpm to remove air bubbles, the polyamine is coated on a glass substrate using a spin coater.

Then, the adhesive film was manufactured by drying at 120°C for 30 minutes in a nitrogen atmosphere, heating it to 450°C at a rate of 2°C/min, heat-treating it at 450°C for 60 minutes, and then cooling it back to 30°C at a rate of 2°C/min to obtain the final polyimide film, which was then peeled off from the glass substrate by dipping in distilled water.

The thickness of the manufactured polyimide film was 15 μm. The thickness of the manufactured polyimide film was measured using an electric film thickness tester manufactured by Anritsu.

<Example 1 to Example 4 and Comparative Example 1 to Comparative Example 3>

The production was carried out according to the above-mentioned production example, but the contents of the diamine monomer and the dianhydride monomer were adjusted as shown in Table 1.

[Table 1] Diamine monomer (mol %) Dianhydride monomer (mol %) PPD ODA 4,4-DABA PMDA BTDA BPDA Embodiment 1 55 25 20 55 27 18 Embodiment 2 55 30 15 55 27 18 Embodiment 3 55 35 10 55 27 18 Embodiment 4 55 35 10 63 10 27 Comparison Example 1 55 45 0 63 10 27 Comparison Example 2 55 45 0 58 20 twenty two Comparison Example 3 67.5 22.5 10 40 35 25

＜Experimental example＞ Evaluation of elastic modulus, strength, elongation and glass transition temperature

As shown in Table 1 above, for the polyimide films manufactured in Examples 1 to 4 and Comparative Examples 1 to 3, respectively, elastic modulus, strength, elongation, and glass transition temperature were measured and shown in Table 2.

(1) Elastic modulus, strength and elongation

The elastic modulus, strength and elongation were measured using Instron 3365SER equipment according to ASTM D 882.

(2) Glass transfer temperature measurement

The glass transition temperature (T _g ) is obtained by using DMA to determine the loss elasticity and storage elasticity of each film, and then measuring the inflection point in the tangent graph as the glass transition temperature.

[Table 2] Elastic modulus (GPa) Strength (MPa) Elongation (%) Tg（℃） Embodiment 1 5.1 370 85 364 Embodiment 2 5.4 370 80 377 Embodiment 3 5.7 375 77 369 Embodiment 4 5.3 350 65 369 Comparison Example 1 6.2 330 40 371 Comparison Example 2 6.0 325 45 346 Comparison Example 3 6.1 330 56 357

As shown in Table 2, the polyimide film produced according to the embodiment of the present invention has an elastic modulus of 5 GPa or more and a strength of 340 MPa or more, and not only has excellent mechanical strength, but also has a glass transition temperature (Tg) of 360°C or more, and accordingly, excellent thermal stability.

In addition, corresponding to an elongation of more than 60%, excellent mechanical strength and excellent elongation can be achieved at the same time.

This result is achieved through the specific ingredients and ratios of the present invention, and it can be seen that the content of each ingredient plays a decisive role.

In contrast, the polyimide films of Comparative Examples 1 to 3 were measured to have higher elastic moduli than the polyimide films of Examples 1 to 4.

However, it was confirmed that the strength and elongation of the polyimide films of Comparison Examples 1 to 3 were lower than those of the polyimide films of Examples 1 to 4, and in particular, the glass transition temperature of the polyimide films of Comparison Examples 2 and 3 was lower than that of the polyimide films of Examples 1 and 4.

Therefore, it can be expected that the polyimide film of the comparative example is difficult to be practically applied to electronic components.

The above description is made with reference to the embodiments of the present invention. However, anyone skilled in the art in the field to which the present invention belongs can make various applications and modifications within the scope of the present invention based on the above contents.

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Claims (10)

A polyimide film is prepared by imidizing a polyamide solution, wherein the polyamide solution comprises: a dianhydride component including biphenyltetracarboxylic dianhydride (BPDA), pyromellitic dianhydride (PMDA) and benzophenonetetracarboxylic dianhydride (BTDA); and a diamine component including diaminodiphenyl ether (ODA), p-phenylenediamine (PPD) and 4,4'-diaminobenzanilide (DABA), wherein the content of the biphenyltetracarboxylic dianhydride is 15 mol% or more and 30 mol% or less based on the total content of the dianhydride components being 100 mol%. The content of the aforementioned pyromellitic dianhydride is 50 mol% or more and 65 mol% or less, the content of the aforementioned benzophenone tetracarboxylic dianhydride is 10 mol% or more and 35 mol% or less, wherein, based on the total content of the aforementioned diamine component of 100 mol%, the content of the aforementioned diaminodiphenyl ether is 23 mol% or more and 43 mol% or less, the content of the aforementioned p-phenylenediamine is 50 mol% or more and 60 mol% or less, the content of the aforementioned 4,4-diaminobenzylaniline is 10 mol% or more and 30 mol% or less, wherein the elongation of the aforementioned polyimide film is 60% or more. The polyimide membrane as described in claim 1, wherein the polyimide membrane comprises a block copolymer composed of two or more blocks. The polyimide film as described in claim 1, wherein the elastic modulus of the polyimide film is greater than 5 GPa and the strength is greater than 340 MPa. The polyimide film as described in claim 1, wherein the glass transition temperature (Tg) of the polyimide film is above 360°C. A method for preparing a polyimide film comprises the following steps: (a) polymerizing a dianhydride component comprising biphenyltetracarboxylic dianhydride (BPDA), pyromellitic dianhydride (PMDA) and benzophenonetetracarboxylic dianhydride (BTDA) with a diamine component consisting of diaminodiphenyl ether (ODA), p-phenylenediamine (PPD) and 4,4'-diaminobenzanilide (DABA) in an organic solvent to prepare polyimide; and (b) subjecting the polyimide to imidization, wherein the content of the biphenyltetracarboxylic dianhydride is 15 mol% based on the total content of the dianhydride component being 100 mol%. % or more and 30 mol% or less, the content of the aforementioned pyromellitic dianhydride is 50 mol% or more and 65 mol% or less, the content of the aforementioned benzophenone tetracarboxylic dianhydride is 10 mol% or more and 35 mol% or less, wherein, based on the total content of the aforementioned diamine component of 100 mol%, the content of the aforementioned diaminodiphenyl ether is 23 mol% or more and 43 mol% or less, the content of the aforementioned p-phenylenediamine is 50 mol% or more and 60 mol% or less, the content of the aforementioned 4,4-diaminobenzylaniline is 10 mol% or more and 30 mol% or less, wherein the elongation of the aforementioned polyimide film is 60% or more. The method for manufacturing a polyimide film as described in claim 5, wherein the elastic modulus of the polyimide film is greater than 5 GPa, the strength is greater than 340 MPa, and the glass transition temperature (Tg) is greater than 360°C. A multilayer film comprising a polyimide film as described in any one of claims 1 to 4. A multi-layer film comprising: a polyimide film as described in any one of claims 1 to 4; and a thermoplastic resin layer. A flexible metal foil laminate comprising: a polyimide film as described in any one of claims 1 to 4; and a conductive metal foil. An electronic component comprising a flexible metal foil laminate as described in claim 9.