Polyimide film with excellent heat resistance and mechanical property and method for preparing same

Abstract

The present invention provides a polyimide film comprising a copolymer of a dianhydric acid monomer including pyromellitic dianhydride (PMDA) and a diamine monomer including 4,4'-diaminodiphenyl ether (ODA) and m-toluidine (m-TD), wherein the coefficient of thermal expansion CTETD in the width direction (TD) of the film, measured under conditions of a measurement temperature range of 50 to 200°C and a heating rate of 10°C / min, is -5 to 2.5 ppm / °C and the modulus is 8 GPa or more.

Description

Technology Field

[0001] The present invention relates to a polyimide film having excellent heat resistance and mechanical properties and a method for manufacturing the same. More specifically, the invention relates to a polyimide film having excellent heat resistance and mechanical properties without using paraphenylenediamine (p-phenylenediamine, PPD) and a method for manufacturing the same. Background Technology

[0002] Polyimide (PI) is a polymer material based on an imide ring with excellent chemical stability and a rigid aromatic main chain, and possesses the highest level of heat resistance, chemical resistance, electrical insulation, chemical resistance, and weather resistance among organic materials.

[0003] Generally, polyimide (PI) film refers to a polyimide resin formed into a film. Polyimide resin refers to a high-heat-resistant resin produced by solution polymerizing an aromatic dianhydride with an aromatic diamine or an aromatic diisocyanate to produce a polyamic acid derivative, and then dehydrating it at high temperatures to form an imid.

[0004] Conventional polyimide resins primarily used p-phenylenediamine (PPD) as the aromatic diamine; however, the use of PPD caused bubble formation and gel development during film manufacturing, resulting in low productivity and process efficiency. Additionally, while large amounts of PPD were used to meet requirements for a low coefficient of thermal expansion, problems such as poor chemical resistance persisted.

[0005] Accordingly, there is a need to develop polyimide films that do not use paraphenylenediamine while possessing excellent heat resistance and mechanical properties after imidization. The problem to be solved

[0006] The present invention aims to provide a polyimide film having excellent heat resistance and mechanical properties after imidization without using paraphenylenediamine (p-phenylenediamine, PPD), and a method for manufacturing the same.

[0007] In addition, the present invention aims to provide a display device comprising the polyimide film. means of solving the problem

[0008] The present invention is capable of various modifications and may have various embodiments, and specific embodiments are to be illustrated and described in detail. However, this is not intended to limit the invention to specific embodiments, and it should be understood that the invention includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the invention.

[0009] The terms used in this application are used merely to describe specific embodiments and are not intended to limit the invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, terms such as "comprising" or "having" are intended to specify the presence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0010] Where in this specification, when a quantity, concentration, or other value or parameter is given as an enumeration of a range, a preferred range, a preferred upper limit, and a preferred lower limit, it should be understood that any pair of any upper range limit or preferred value and any lower range limit or preferred value are specifically disclosed, regardless of whether the range is disclosed separately.

[0011] Where a range of numerical values ​​is mentioned in this specification, unless otherwise stated, the range and the scope of the parent invention within that range are not intended to be limited to the specific value mentioned when defining the range.

[0012] In this specification, "dianhydride" is intended to include its precursor or derivative, and is also referred to as "dianhydride acid," "dianhydride," or "acid dianhydride." Although these may not technically be dianhydrides, they will nevertheless react with a diamine to form a polyamic acid, which can then be converted into a polyimide.

[0013] In this specification, "diamine" is intended to include its precursors or derivatives, which may not technically be diamines but nevertheless will react with dianhydric acid to form a polyamic acid, which can then be converted into a polyimide.

[0014] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the present invention pertains. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in this application. Specific details for the implementation of the above invention are described below.

[0015] The present invention relates to a polyimide film with excellent heat resistance and mechanical properties and a method for manufacturing the same.

[0016] polyimide film

[0017] The present invention comprises a copolymer comprising a dianhydric acid monomer including pyromellitic dianhydride (PMDA) and a diamine monomer including 4,4'-diaminodiphenyl ether (ODA) and m-toluidine (m-TD), and the coefficient of thermal expansion (CTE) in the width direction (TD) of the film measured under conditions of a measurement temperature range of 50 to 200°C and a heating rate of 10°C / min. TD A polyimide film having a temperature of -5 to 2.5 ppm / ℃ and a modulus of 8 GPa or more is provided.

[0018] Specifically, the thermal expansion coefficient CTE in the width direction (TD) of the polyimide film measured under conditions of a measurement temperature range of 50–200°C and a heating rate of 10°C / min. TD The pH may be -5 to 2.5 ppm / ℃, and preferably -4.5 to 1.5 ppm / ℃.

[0019] Specifically, the polyimide film may have a modulus of 8 GPa or more. For example, the lower limit of the modulus may be 9 GPa or more, 9.5 GPa or more, or 10 GPa or more. In addition, the upper limit of the modulus is not specifically limited but may be 18 GPa or less, 17 GPa or less, 16 GPa or less, or 15 GPa or less. The modulus was measured using an INSTRON Instron 5564 UTM instrument at a speed of 20 mm / min on samples with a length of 80 mm and a width of 15 mm, and the average of 10 samples was calculated.

[0020] The above polyimide film has a coefficient of thermal expansion CTE in the machine transport direction (MD). MD and thermal expansion coefficient CTE in the width direction (TD) TD The difference value of (CTE MD -CTE TD ) may be -3 to 3 ppm / ℃, preferably -2 to 2 ppm / ℃, more preferably -1.8 to 1.8 ppm / ℃.

[0021] The above polyimide film has an average thermal expansion coefficient CTE Ave The value may be -4.25 to 3.0 ppm / ℃, and preferably -4.35 to 2.0 ppm / ℃. The average coefficient of thermal expansion CTE Ave is the coefficient of thermal expansion CTE of the above polyimide film in the machine transport direction (MD). MD and thermal expansion coefficient CTE in the width direction (TD) TD It may be the average value of calculated.

[0022] The coefficient of thermal expansion CTE in the machine conveying direction (MD) mentioned above MD and thermal expansion coefficient CTE in the width direction (TD) TD These are the slopes measured in the 50 to 200 ℃ range at 10 ℃ / min 50 mN, respectively, using TA company's TMA equipment (Q400).

[0023] The above polyimide film may have a glass transition temperature (Tg) of 380°C or higher. For example, the lower limit of the glass transition temperature may be 385°C or higher, 395°C or higher, or 398°C or higher. In addition, the upper limit of the glass transition temperature is not specifically limited, but may be 500°C or lower, 495°C or lower, or 490°C or lower. The glass transition temperature was measured using DMA under conditions of 10°C / min.

[0024] The above polyimide film may have a chemical resistance of -25 to -13% based on thickness, and preferably -24.5 to -13.5%.

[0025] In one embodiment, the above polyimide film may have a chemical resistance of -25 to -10% by weight, and preferably -23.5 to -11%.

[0026] The chemical resistance based on thickness and the chemical resistance based on weight were each measured based on ASTM D570 absorption rate. The impregnation and storage criteria were measured by immersing in a 15% NaOH solution at 60°C for 30 minutes and then checking the change in weight and thickness.

[0027] The polyimide film may have a hygroscopic expansion coefficient (CHE) of 3 to 6 ppm / RH%, and preferably 3.5 to 5 ppm / RH%. The hygroscopic expansion coefficient was measured by performing stabilization using a PMIC device under humidity conditions of 3 to 90% RH until no dimensional change occurred.

[0028] The thickness of the above polyimide film can be appropriately selected considering the application, usage environment, physical properties, etc. of the polyimide film. For example, the thickness of the polyimide film may be 1 to 100 μm, 15 to 70 μm, 25 to 50 μm, or 30 to 45 μm, but is not limited thereto.

[0029] Another embodiment of the present invention provides a multilayer film comprising the polyimide film and a thermoplastic resin layer.

[0030] Another embodiment of the present invention provides a flexible metal foil laminate comprising the polyimide film and an electrically conductive metal foil.

[0031] Another embodiment of the present invention provides an electronic component comprising the flexible metal foil laminate.

[0032] Another embodiment of the present invention provides a display element comprising the polyimide film.

[0033] copolymer

[0034] The copolymer is a copolymer of a dianhydric acid monomer containing pyromellitic dianhydride (PMDA) and a diamine monomer containing 4,4'-diaminodiphenyl ether (ODA) and m-tolydine (m-TD).

[0035] The copolymer may be a block copolymer having two or more blocks.

[0036] The above block copolymer may be composed of: a first block copolymerized with a dianhydric acid monomer composed of pyromellitic dianhydride (PMDA) and a diamine monomer composed of m-tolydine (m-TD); and a second block copolymerized with a dianhydric acid monomer composed of pyromellitic dianhydride (PMDA) and a diamine monomer composed of 4,4'-diaminodiphenyl ether (ODA).

[0037] The content of the m-tolydine (m-TD) among the total diamine monomers of the copolymer may be 40 to 80 mol%, preferably 45 to 75 mol%, more preferably 50 to 70 mol%, and even more preferably 55 to 65 mol%. If the m-tolydine content is less than 40 mol%, the low hygroscopicity and low dielectric properties of the polyimide film are negligible and the chemical resistance is very low, which is undesirable, and if it exceeds 80 mol%, it is difficult to form a polyimide film thereafter, which is undesirable.

[0038] The content of the 4,4'-diaminodiphenyl ether (ODA) among the total diamine monomers of the copolymer may be 20 to 60 mol%, preferably 25 to 55 mol%, more preferably 30 to 50 mol%, and even more preferably 35 to 45 mol%. If the content of the 4,4'-diaminodiphenyl ether is less than 20 mol%, it is undesirable because it is difficult to form a polyimide film thereafter, and if it exceeds 60 mol%, it is undesirable because the low hygroscopicity and low dielectric properties resulting from the inclusion of m-tolydine are negligible.

[0039] The molar ratio of the above dianhydric acid monomer and the above diamine monomer may be 1:2 to 2:1, and preferably 1:1.

[0040] The copolymer may contain 90 to 110 mol% of the diamine monomer, preferably 95 to 105 mol%, more preferably 98 to 102 mol%, and even more preferably 99 to 101 mol%.

[0041] The copolymer may contain 90 to 110 mol% of the dianhydride monomer, preferably 95 to 105 mol%, more preferably 98 to 102 mol%, and even more preferably 100 mol%.

[0042] Based on 100 mol% of the diamine monomer, the copolymer may contain 95 to 105 mol% of the dianhydride monomer, for example, the lower limit may be 95.5 mol% or more, 96 mol% or more, 96.5 mol% or more, 97 mol% or more, 97.5 mol% or more, 98 mol% or more, 98.5 mol% or more, 99 mol% or more, or 99.5 mol% or more, and the upper limit may be 105 mol% or less, 104 mol% or less, 103 mol% or less, 102 mol% or less, 101 mol% or less, or 100 mol% or less.

[0043] Method for manufacturing polyimide film

[0044] The present invention relates to a method for manufacturing a polyimide film comprising the step of copolymerizing a dianhydric acid monomer comprising pyromellitic dianhydride (PMDA) with a diamine monomer comprising 4,4'-diaminodiphenyl ether (ODA) and m-toluidine (m-TD), wherein the coefficient of thermal expansion in the width direction (TD) of the polyimide film is measured under conditions of a measurement temperature range of 50 to 200°C and a heating rate of 10°C / min. TD A method for manufacturing a polyimide film is provided, wherein the temperature is -5 to 2.5 ppm / ℃ and the modulus of the polyimide film is 8 GPa or higher.

[0045] Specifically, the thermal expansion coefficient CTE in the width direction (TD) of the polyimide film measured under conditions of a measurement temperature range of 50–200°C and a heating rate of 10°C / min. TD The pH may be -5 to 2.5 ppm / ℃, and preferably -4.5 to 1.5 ppm / ℃.

[0046] Specifically, the polyimide film may have a modulus of 8 GPa or more. For example, the lower limit of the modulus may be 9 GPa or more, 9.5 GPa or more, or 10 GPa or more. In addition, the upper limit of the modulus is not specifically limited but may be 18 GPa or less, 17 GPa or less, 16 GPa or less, or 15 GPa or less. The modulus was measured using an INSTRON Instron 5564 UTM instrument at a speed of 20 mm / min on samples with a length of 80 mm and a width of 15 mm, and the average of 10 samples was calculated.

[0047] The copolymerizing step may include: a step of polymerizing a dianhydric acid monomer containing pyromellitic dianhydride (PMDA) and a diamine monomer containing m-tolydine (m-TD) to produce a first block; and a step of polymerizing a dianhydric acid monomer containing pyromellitic dianhydride (PMDA) and a diamine monomer containing 4,4'-diaminodiphenyl ether (ODA) to produce a second block.

[0048] In the step of generating the first block, the content of the diamine monomer containing m-tolydine (m-TD) may be greater than the content of the dianhydride monomer containing pyromellitic dianhydride (PMDA).

[0049] More specifically, in the step of generating the first block, the content of the diamine monomer containing m-tolydine (m-TD) is 40 to 80 mol%, the content of the dianhydric acid monomer containing pyromellitic dianhydride (PMDA) is 20 to 70 mol%, and the content of the dianhydric acid monomer containing pyromellitic dianhydride (PMDA) (M 1st PMDA The content of the diamine monomer containing the above m-toluidine (m-TD) relative to ) (M m-TD ) ratio(M m-TD / M 1st PMDA ) may be greater than 1 and less than 2.

[0050] The above ratio (M m-TD / M 1st PMDA If ) is 1 or less, or 2 or more, it is difficult to form a block copolymer of the desired shape, which is undesirable.

[0051] In the step of producing the second block above, the content of the diamine monomer containing the 4,4'-diaminodiphenyl ether (ODA) may be less than the content of the dianhydride monomer containing the pyromellitic dianhydride (PMDA).

[0052] More specifically, in the step of generating the second block, the content of the diamine monomer containing 4,4'-diaminodiphenyl ether (ODA) is 20 to 60 mol%, the content of the dianhydric acid monomer containing pyromellitic dianhydride (PMDA) is 30 to 80 mol%, and the content of the dianhydric acid monomer containing pyromellitic dianhydride (PMDA) (M 2nd PMDA The content of the diamine monomer containing the 4,4'-diaminodiphenyl ether (ODA) relative to ) (M ODA ) ratio(M ODA / M 2nd PMDA ) may be greater than 0 and less than 1.

[0053] The above ratio (M ODA / M 2nd PMDAIf ) is 0 or 1 or more, it is difficult to form a block copolymer of the desired shape, which is undesirable.

[0054] Each of the above first block and second block can be produced in the presence of a solvent.

[0055] The above solvent may include one or more selected from the group consisting of N,N'-dimethylacetamide (DMAc), N-methyl-2-pyrrolidone (NMP), N,N'-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), diethylacetamide (DEAc), N-ethyl-2-pyrrolidone (NEP), N,N'-diethylformamide (DEF), dimethylpropanamide (DMPA), and gamma-butyrolactone (GBL), and preferably N,N'-dimethylformamide (DMF) may be used.

[0056] Another embodiment of the present invention provides a multilayer film comprising a polyimide film produced by the method for producing the polyimide film and a thermoplastic resin layer.

[0057] Another embodiment of the present invention provides a flexible metal foil laminate comprising a polyimide film produced by the method for producing the polyimide film and an electrically conductive metal foil.

[0058] Another embodiment of the present invention provides an electronic component comprising the flexible metal foil laminate.

[0059] Another embodiment of the present invention provides a display element comprising the polyimide film. Effects of the invention

[0060] The polyimide film and the method for manufacturing the same according to the present invention do not use paraphenylenediamine (p-phenylenediamine, PPD), thereby increasing price competitiveness and providing excellent productivity and process efficiency.

[0061] In addition, the polyimide film according to the present invention has the effect of excellent heat resistance and mechanical properties.

[0062] In addition, the polyimide film according to the present invention has the effect of being applicable to a display device. Specific details for implementing the invention

[0063] Examples are provided to aid in understanding the present invention. The following examples are provided merely to facilitate a better understanding of the invention, and the scope of the invention is not limited by these examples.

[0064] <Example>

[0065] Example 1. Preparation of Polyimide Film

[0066] Example 1-1

[0067] A solution containing a first block (m-TD / PMDA block) was prepared by mixing 80 mol% of the diamine monomer m-tolydine (m-TD) and 60 mol% of the dianhydric acid monomer pyromellitic dianhydride (PMDA) with 100 mol% of dimethylformamide (DMF) and polymerizing them.

[0068] 20 mol% of 4,4'-diaminodiphenyl ether (ODA), a diamine monomer, and 37 mol% of pyromellitic dianhydride (PMDA), a dianhydric acid monomer, were mixed in the above solution and polymerized to form a second block (ODA / PMDA block).

[0069] Finally, 3 mol% of PMDA was added to produce a polyamic acid containing a first block (m-TD / PMDA block) and a second block (ODA / PMDA block).

[0070] The above polyamic acid was mixed with a catalyst and the degassed polyamic acid was coated onto a glass plate. Subsequently, the solvent-to-solid ratio was calculated using an applicator and the mixture was pushed to uniformly distribute the surface. Afterward, the polyimide film was obtained by curing under a nitrogen atmosphere under conditions of 130°C (4 min) → 280°C (4 min) → 420°C (4 min). At this time, the film thickness was prepared to be 33.5 μm.

[0071] Examples 1-2 to 1-6

[0072] A polyimide film was prepared in the same manner as in Example 1-1, except that the ratios of m-tolydine, ODA, and PMDA content were adjusted as shown in Table 1 below.

[0073] Comparative Example 1-1

[0074] A polyimide film was prepared in the same manner as in Example 1-1, except that the ratios of m-tolydine, ODA, and PMDA content were adjusted as shown in Table 1 below.

[0075] Comparative Example 1-2

[0076] A random copolymerized polyimide film was prepared by mixing 100 mol% of dimethylformamide (DMF), 50 mol% of m-tolidine (m-TD), 50 mol% of 4,4'-diaminodiphenyl ether (ODA), and 97 mol% of pyromellitic dianhydride (PMDA), which is a dianhydride compound, and finally adding 3 mol% of PMDA.

[0078] Table 1 below lists the composition and content of the dianhydride monomer and diamine monomer used when preparing the polyimide films according to Examples 1-1 to 1-6 and Comparative Example 1-1.

[0079] m-TD (mol%) 1st PMDA (Moll%) ODA (mol%) 2nd PMDA (Moll%) 3rd PMDA (Moll%) Types of copolymers Example 1-1 80 60 20 37 3 block Examples 1-2 70 52.5 30 44.5 3 block Examples 1-3 60 45.0 40 52.0 3 block Examples 1-4 65 48.8 35 48.2 3 block Examples 1-5 50 37.5 50 59.5 3 block Examples 1-6 40 30.0 60 67.0 3 block Comparative Example 1-1 30 22.5 70 74.5 3 block

[0081] Table 2 below lists the composition and content of the dianhydride monomer and diamine monomer used to manufacture the polyimide film according to Comparative Example 1-2.

[0082] m-TD (mol%) ODA (mol%) 1st PMDA (Moll%) 2nd PMDA (Moll%) Types of copolymers Comparative Example 1-2 50 50 97 3 Random

[0084] <Experimental Example>

[0085] Experimental Example 1. Evaluation of Physical Properties of Polyimide Film

[0086] (1) Coefficient of thermal expansion (CTE)

[0087] For the polyimide films of Examples 1-1 to 1-6 and Comparative Examples 1-1 and 1-2, the slope in the 50–200 ℃ range was measured in the machine transport direction (MD) and width direction (TD) respectively using a TA TMA equipment (Q400) under conditions of 10 ℃ / min and 50 mN. Subsequently, the coefficient of thermal expansion CTE in the machine transport direction (MD) MD and thermal expansion coefficient CTE in the width direction (TD) TD Average coefficient of thermal expansion CTE from the value Ave Wow, MD thermal expansion coefficient CTE MD and TD thermal expansion coefficient CTE TD The difference value of (CTE MD -CTE TD ) was calculated. The coefficient of thermal expansion CTE of the polyimide film in the machine-side (MD) direction. MD , coefficient of thermal expansion in the width direction (TD) CTE TD , average coefficient of thermal expansion CTE Ave and MD thermal expansion coefficient CTE MD and TD thermal expansion coefficient CTE TD The difference value of (CTE MD -CTE TD The results of each measurement are shown in Table 3 below.

[0088] (2) Glass transition temperature (Tg)

[0089] The glass transition temperature of the polyimide films of Examples 1-1 to 1-6 and Comparative Examples 1-1 and 1-2 was measured using DMA at a rate of 10°C / min. The results are shown in Table 3 below.

[0090] (3) Modulus

[0091] For the polyimide films of Examples 1-1 to 1-6 and Comparative Examples 1-1 and 1-2 above, samples with a length of 80 mm and a width of 15 mm were prepared and measured at a speed of 20 mm / min using an INSTRON Instron 5564 UTM instrument, and the average of 10 samples was calculated. The results are shown in Table 3 below.

[0092] (4) Chemical resistance

[0093] Chemical resistance based on thickness and chemical resistance based on weight were measured for the polyimide films of Examples 1-1 to 1-6 and Comparative Examples 1-1 and 1-2, respectively, and the results are shown in Table 3 below.

[0094] The chemical resistance based on thickness and the chemical resistance based on weight were each measured based on ASTM D570 absorption rate. The impregnation and storage criteria were measured by immersing in a 15% NaOH solution at 60°C for 30 minutes and then checking the change in weight and thickness.

[0095] (5) Moisture absorption expansion coefficient (CHE)

[0096] For the polyimide films of Examples 1-2, 1-3, 1-5 and Comparative Examples 1-1 and 1-2 above, stabilization was performed using a PMIC device under humidity conditions of 3 to 90% RH until no dimensional changes occurred, and the coefficient of moisture expansion was measured. The results are shown in Table 3 below.

[0098] Table 3 below summarizes the results of the physical property evaluation of the polyimide films of Examples 1-1 to 1-6 and Comparative Examples 1-1 and 1-2.

[0099] division CTE (ppm / ℃) Tg (°C) Modulus (GPa) Chemical resistance (%) CHE (ppm / RH%) MD TD average Difference value thickness weight Example 1-1 -3.07 -4.50 -3.79 1.43 412 12.9 -14.5 -13.3 - Examples 1-2 -3.19 -3.55 -3.37 0.36 413 11.8 -13.9 -11.8 4.0 Examples 1-3 -1.55 -1.78 -1.67 0.23 406 10.3 -16.2 -13.9 4.4 Examples 1-4 -3.03 -2.40 -2.72 -0.63 409 12.6 -14.4 -14.4 - Examples 1-5 -0.30 -0.73 -0.5 0.43 402 9.8 -18.9 -20.1 5.7 Examples 1-6 3.8 2.0 2.9 1.8 402 8.1 -25.0 -24.6 - Comparative Example 1-1 9.4 4.8 7.1 4.6 400 6.2 -32.1 -34.2 7.2 Comparative Example 1-2 3.1 3.4 3.2 -0.3 400 8.8 -34.0 -32.9 6.7

[0101] According to Table 3, when a block copolymer is included, the example with an m-TD content of 40 to 80 mol% has superior chemical resistance compared to Comparative Example 1-1 with an m-TD content of 30 mol%, and it can be confirmed that CTE and CHE are also superior.

[0102] In addition, when comparing physical properties with and without the block at the same content (Examples 1-5 and Comparative Example 1-2), it can be seen that while other physical properties are similar, heat resistance and chemical resistance are significantly superior when the block is included.

[0103] From these results, it can be confirmed that the polyamic acid of the present invention and the polyimide film prepared therefrom have excellent heat resistance, chemical resistance, moisture resistance, and mechanical properties without using paraphenylenediamine (p-phenylenediamine, PPD).

[0104] In addition, since the polyimide film of the present invention does not use paraphenylenediamine (p-phenylenediamine, PPD), it has relatively higher price competitiveness and offers excellent productivity and process efficiency.

[0106] The specification omits detailed descriptions of matters that can be sufficiently recognized and inferred by those skilled in the art of the present invention, and various modifications are possible within the scope of not altering the technical concept or essential configurations of the present invention, in addition to the specific examples described in this specification. Accordingly, the present invention may be implemented in a manner different from that specifically described and exemplified in this specification, and this is a matter that can be understood by those skilled in the art.

Claims

Claim 1 A copolymer comprising a dianhydric acid monomer including pyromellitic dianhydride (PMDA) and a diamine monomer including 4,4'-diaminodiphenyl ether (ODA) and m-toluidine (m-TD), wherein the copolymer is a block copolymer having two or more blocks, and the coefficient of thermal expansion in the width direction (TD) of the film measured under conditions of a measurement temperature range of 50 to 200°C and a heating rate of 10°C / min is CTE TD A polyimide film having a temperature of -5 to 2.5 ppm / ℃ and a modulus of 8 GPa or more. Claim 2 In claim 1, the thermal expansion coefficient CTE of the polyimide film in the machine transport direction (MD) MD and coefficient of thermal expansion in the width direction (TD) CTE TD The difference value of (CTE MD -CTE TD Polyimide film having -3 to 3 ppm / ℃. Claim 3 In claim 1, the average thermal expansion coefficient CTE of the polyimide film Ave α is -4.25 to 3.0 ppm / ℃, and the average thermal expansion coefficient CTE is Ave is the coefficient of thermal expansion CTE in the machine-transport direction (MD) of the above polyimide film MD and coefficient of thermal expansion in the width direction (TD) CTE TD Polyimide film, which is the calculated average value of Claim 4 delete Claim 5 A polyimide film according to claim 1, wherein the block copolymer comprises: a first block copolymerized with a dianhydric acid monomer composed of pyromellitic dianhydride (PMDA) and a diamine monomer composed of m-toluidine (m-TD); and a second block copolymerized with a dianhydric acid monomer composed of pyromellitic dianhydride (PMDA) and a diamine monomer composed of 4,4'-diaminodiphenyl ether (ODA). Claim 6 A polyimide film according to claim 1, wherein the m-tolydine (m-TD) content among the total diamine monomers of the copolymer is 40 to 80 mol%. Claim 7 A polyimide film according to claim 1, wherein the content of the 4,4'-diaminodiphenyl ether (ODA) among the total diamine monomers of the copolymer is 20 to 60 mol%. Claim 8 A polyimide film according to claim 1, wherein the glass transition temperature (Tg) of the polyimide film is 380°C or higher. Claim 9 A polyimide film according to claim 1, wherein the chemical resistance based on thickness of the polyimide film is -25 to -13% and the chemical resistance based on weight is -25 to -10%. Claim 10 The polyimide film according to claim 1, wherein the polyimide film has a moisture absorption expansion coefficient of 3 to 6 ppm / RH%. Claim 11 A polyimide film according to claim 1, wherein the thickness of the polyimide film is 1 to 100 μm. Claim 12 A method for manufacturing a polyimide film comprising the step of copolymerizing a dianhydric acid monomer containing pyromellitic dianhydride (PMDA) with a diamine monomer containing 4,4'-diaminodiphenyl ether (ODA) and m-toluidine (m-TD) to produce a block copolymer having two or more blocks, wherein the coefficient of thermal expansion in the width direction (TD) of the polyimide film measured under conditions of a measurement temperature range of 50 to 200°C and a heating rate of 10°C / min is CTE TD A method for manufacturing a polyimide film having a temperature of -5 to 2.5 ppm / ℃ and a modulus of 8 GPa or more. Claim 13 A method for manufacturing a polyimide film according to claim 12, wherein the copolymerizing step comprises: a step of polymerizing a dianhydric acid monomer containing pyromellitic dianhydride (PMDA) and a diamine monomer containing m-tolydine (m-TD) to produce a first block; and a step of polymerizing a dianhydric acid monomer containing pyromellitic dianhydride (PMDA) and a diamine monomer containing 4,4'-diaminodiphenyl ether (ODA) to produce a second block. Claim 14 In claim 13, in the step of generating the first block, the content of the diamine monomer containing m-tolydine (m-TD) is 40 to 80 mol%, the content of the dianhydric acid monomer containing pyromellitic dianhydride (PMDA) is 20 to 70 mol%, and the content of the dianhydric acid monomer containing pyromellitic dianhydride (PMDA) (M 1st PMDA The content of the diamine monomer containing the above m-toluidine (m-TD) relative to ) (M m-TD ) Mollar ratio (M m-TD / M 1st PMDA A method for manufacturing a polyimide film in which ) is greater than 1 and less than 2. Claim 15 In claim 13, in the step of generating the second block, the content of the diamine monomer containing the 4,4'-diaminodiphenyl ether (ODA) is 20 to 60 mol%, the content of the dianhydric acid monomer containing the pyromellitic dianhydride (PMDA) is 30 to 80 mol%, and the content of the dianhydric acid monomer containing the pyromellitic dianhydride (PMDA) (M 2nd PMDA The content of the diamine monomer containing the 4,4'-diaminodiphenyl ether (ODA) relative to ) (M ODA ) Mollar ratio (M ODA / M 2nd PMDA A method for manufacturing a polyimide film in which ) is greater than 0 and less than 1.

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