Polyimide film and laminate containing the same

Abstract

The present invention provides a polyimide film and a laminate containing the same that exhibit excellent thermal properties, mechanical properties, and adhesive strength, even without a primer layer. [Solution] The polyimide film contains 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA), pyromellitic anhydride (PMDA), p-phenylenediamine (p-PDA), 2,2'-dimethyl-4,4'-diaminobiphenyl (m-TB), and 4,4'-diaminodiphenyl ether (ODA), and further contains copolymer chain segments composed of BPDA and p-PDA.

Description

Technical Field

[0001] The present invention relates to a polyimide film and a laminate containing the same, and particularly to a polyimide film whose composition contains 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA), pyromellitic dianhydride (PMDA), p-phenylenediamine (p-PDA), 2,2'-dimethyl-4,4'-diaminobiphenyl (m-TB), and 4,4'-diaminodiphenyl ether (ODA) and contains a copolymer chain segment composed of BPDA and p-PDA. The polyimide film and the laminate containing the same have excellent thermal properties, mechanical properties, and adhesion.

Background Art

[0002] A flexible printed circuit board is a laminate including a metal layer and a polyimide film, and most flexible printed circuit boards have an adhesive layer as a medium for adhering them between the metal layer and the polyimide film. In recent years, due to the progress of the fine line formation of flexible printed circuit boards, the thickness of the metal layer has become thinner, and a laminate directly connecting the polyimide film and the metal layer has been developed.

[0003] Generally, when adhering a polyimide film to a metal layer, a plastic polyimide layer can be attached as an adhesive medium on the polyimide film. However, during the adhesion process with the metal layer, since it has a manufacturing step that requires a high-temperature hot press, it is difficult to manufacture a thin laminate of the polyimide film and the metal layer. Another method is to directly adhere the metal layer and the polyimide film through metallization. However, since it is difficult for a general polyimide to ensure the adhesion force with the metal layer, in order to impart a predetermined adhesiveness between the polyimide and the metal, it is necessary to perform surface treatment and then metallization.

[0004] The invention described in Patent Document 1 (TWI695865) relates to a method for improving the adhesive strength after metallization. This method improves the adhesive strength between the metal layer and the polyimide film by applying a primer to the polyimide film. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Taiwan Patent No. I695865 Specification [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] However, the inventors discovered that the poor thermal properties of the primer layer can lead to problems such as a decrease in the overall thermal properties of the polyimide film, an increased tendency for the primer layer to become unnecessarily sticky, and difficulties in subsequent processing.

[0007] Therefore, the present inventors have provided a polyimide film with excellent adhesive strength even without a primer layer. The polyimide film efficiently improves its adhesive strength after metallization and can maintain an adhesive strength greater than 0.5 kgf / cm after roasting at 150°C for 24 hours. [Means for solving the problem]

[0008] To solve the above problems, the polyimide film of one embodiment of the present invention is It contains copolymer polyimides formed from dianhydrides and diamines, The dianhydride comprises 60 to 80 mol% of 3,3',4,4'-biphenyltetracarboxylic acid dianhydride (BPDA) and 20 to 40 mol% of pyromellitic anhydride (PMDA) relative to 100 mol% of the dianhydride. The diamine comprises 10 to 40 mol% of p-phenylenediamine (p-PDA), 30 to 60 mol% of 2,2'-dimethyl-4,4'-diaminobiphenyl (m-TB), and 10 to 40 mol% of 4,4'-diaminodiphenyl ether (ODA), relative to 100 mol% of the diamine. The copolymerized polyimide contains copolymer chain segments consisting of BPDA and p-PDA, with the content of the copolymer chain segments being 25 to 40 mol% relative to 100 mol% of the copolymerized polyimide, and the polyimide film has a linear thermal expansion coefficient (CTE) of less than 15 ppm / °C and a Young's modulus greater than 7 GPa. [Effects of the Invention]

[0009] The present invention has been made in view of the above-mentioned conventional problems, and its objective is to provide a polyimide film and a laminate containing the same that have excellent thermal properties, mechanical properties, and adhesive strength. [Modes for carrying out the invention]

[0010] The following describes how the present invention can be implemented through specific examples, and those skilled in the art will be able to understand other advantages and effects of the present invention from the disclosure herein. The present invention can also be implemented or applied through different examples, and the details herein can be modified and changed in various ways based on different viewpoints and uses, without departing from the spirit of the invention.

[0011] <Production of polyimide film> Polyimide films are produced from copolymerized polyamic acid via chemical cyclization or thermocyclization. The copolymerized polyamic acid is formed by polymerizing a dianhydride and a diamine. The dianhydride contains 60 to 80 mol% of 3,3',4,4'-biphenyltetracarboxylic acid dianhydride (BPDA) and 20 to 40 mol% of pyromellitic anhydride (PMDA) per 100 mol% of the dianhydride.

[0012] The diamine comprises 10 to 40 mol% of p-phenylenediamine (p-PDA), 30 to 60 mol% of 2,2'-dimethyl-4,4'-diaminobiphenyl (m-TB), and 10 to 40 mol% of 4,4'-diaminodiphenyl ether (ODA), relative to 100 mol% of the diamine. The copolymerized polyimide has copolymer chain segments consisting of BPDA and p-PDA.

[0013] In the examples, in order to ensure better thermal properties, BPDA and p-PDA were reacted in a solvent for 1 to 3 hours, and the content of the copolymer chain segment was 25 to 40 mol% relative to 100 mol% of the copolymerized polyimide.

[0014] In the preparation of polyimides, solvents such as dimethylacetamide (DMAc), N-methylpyrrolidone (NMP), N-ethyl-2-pyrrolidone (NEP), γ-butyrolactone (GBL), and N,N-dimethylformamide (DMF) can be used. In the examples, dimethylacetamide is used as the solvent.

[0015] After the polymerization of the BPDA and p-PDA copolymer segment is complete, the remaining diamine is added. By adding all or part of the diamine, a second or third copolymer segment can be formed.

[0016] The diamine may be any of mTB, ODA, or p-PDA. After adding the diamine so that the ratio of the total number of moles of anhydrous to the total number of moles of diamine is 0.95 or higher, PMDA or BPDA is added, and the reaction is stirred for at least 1 hour, preferably 2 hours or more.

[0017] Next, a small amount of BPDA or PMDA is used to adjust the viscosity, and finally the viscosity of the solution is adjusted to 100,000 cps to 600,000 cps, preferably 150,000 to 400,000 cps. In this case, the solid content in the solution can be made 10 to 25 wt%, and in this way, the preparation of the polyimide precursor is completed.

[0018] In addition, for the purpose of improving various properties such as winding property, sliding property, thermal conductivity, hardness, color and luster of the above polyimide precursor, inorganic material particles or organic material particles may be added. Examples of the inorganic material particles include silicon oxide, boron nitride, aluminum oxide, titanium oxide, zirconium oxide, zinc oxide, calcium phosphate, etc.

[0019] Examples of the organic material particles include tetrafluoroethylene·perfluoroalkoxy vinyl ether copolymer (PFA), polytetrafluoroethylene (PTFE), liquid crystal polymer (LCP), polyimide (PI), etc.

[0020] The average particle diameter of the inorganic material particles and the organic material particles is usually 0.01 μm to 100 μm, preferably 0.03 μm to 10 μm, and more preferably 0.05 μm to 5 μm.

[0021] The addition amount of the inorganic material particles and the organic material particles is 0.5 to 10% by weight, preferably 1 to 3% by weight based on the polyimide precursor.

[0022] In order to produce a polyimide film by imidizing the above polyimide precursor (copolymer polyamic acid), a thermal cyclization method or a chemical cyclization method can be used.

[0023] The thermal cyclization method is a cyclization method that does not use a dehydrating agent or a catalyst. The copolymer polyamic acid and a solvent are mixed to adjust the viscosity to 8,000 to 20,000 cps, coated on a glass or metal carrier, and heated in a temperature range of 350 to 400 °C and baked for 1 to 8 hours to obtain a polyimide film.

[0024] The chemical cyclization method is a method in which a copolymer polyamic acid is mixed with a solvent to adjust the viscosity, and then a catalyst and a dehydrating agent are added to perform chemical cyclization. Here, the dehydrating agent may be acetic anhydride or benzoic anhydride, and in the examples, acetic anhydride may be used as the dehydrating agent. As the catalyst, pyridine, 3-methylpyridine, 2-methylpyridine, 4-methylpyridine, isoquinoline, quinoline, triethylamine, etc. may be used, and preferably, pyridine, 3-methylpyridine, 2-methylpyridine, 4-methylpyridine are used. In the examples, 3-methylpyridine may be used as the catalyst.

[0025] The above-mentioned catalyst and dehydrating agent can be used alone or can be used after being diluted with a solvent.

[0026] In the chemical cyclization method, after adding a dehydrating agent and a catalyst to a mixed solution of a copolymer polyamic acid and a solvent and stirring uniformly, degassing is performed using a centrifugal degassing device, and the degassed solution is applied to a glass plate with a scraper. The gap of the scraper can be adjusted according to the required thickness of the film. The coated sample is baked at 40°C to 120°C for 10 to 40 minutes, preferably at 60°C to 100°C for 20 to 30 minutes. Then, it is baked at 170°C to 200°C for 10 minutes, and then baked at 230°C to 280°C for 5 to 25 minutes, preferably at 240°C to 260°C for 10 to 20 minutes. Finally, as the final treatment, it is baked at 330°C to 400°C for 10 to 30 minutes, preferably at 350°C to 370°C for 15 to 20 minutes.

[0027] In the above film manufacturing process, in addition to the glass plate, a metal plate can also be used as a substrate. When producing a polyimide film using a metal plate, after baking and drying in the temperature range of 40°C to 120°C, it is necessary to peel the film from the metal plate. The peeled semi-dry film is fixed to a metal frame, baked at 170°C for 20 minutes, and then, as the final treatment, heated to 350°C and baked for 20 minutes to obtain a polyimide film.

[0028] <Manufacture of Laminated Board> The method for manufacturing the laminated board includes the steps of forming a nickel metal layer (also referred to as a nickel layer) on the surface of a polyimide film in contact with the polyimide film by electroplating, and after the nickel metal layer has been formed, performing heat treatment to form a copper layer thereon by electroplating.

[0029] In embodiments of the present invention, the nickel layer is formed on one or both sides of the polyimide substrate by electroplating. Conventional electroplating methods can be cited as examples of the electroplating method, and are not particularly limited. Furthermore, as a specific example of the electroplating method, the surface of the polyimide film may first be subjected to a hydrophilic treatment, and known surface treatments can be cited as examples, and are not particularly limited.

[0030] The surface treatment used in this invention involves hydrophilizing the surface of a polyimide film using a roll-to-roll plasma treatment machine (model number: R2RP03) purchased from Creating Nano Technologies. The operating conditions are described below.

[0031] The polyimide film is fixed to the unwinding roll, the guide film is connected, the cavity is closed, nitrogen (N2) is introduced, power is turned on to draw in gas, and after the device has finished preheating, the manufacturing stage begins. The tension is set to 2 kg, the operating pressure to 300 mTorr, and the power supply to 10 kW, and the type and flow rate of the gas are adjusted.

[0032] Here, there are four types of gases: nitrogen (N2), oxygen (O2), carbon tetrafluoride (CF4), and argon (Ar), which can be combined as needed. The total gas flow rate is controlled between 1900 sccm and 2700 sccm. The length of the plasma zone is 11 m. The processing time can be controlled by adjusting the linear velocity of the device within the range of 0.5 m / min to 6.0 m / min. After processing is complete, oxygen (O2) and argon (Ar) are sequentially introduced to clean the cavity, the vacuum is released, the power is turned off, the cavity is opened and the polyimide film is removed, thus completing the plasma modification of the surface.

[0033] This invention, while referring to the SLP metallization process (SLP process) of Nippon Okuno Pharmaceutical Co., Ltd., uses the SLP series of electroplating reagents and sequentially performs steps such as charge adjustment, pre-immersion, catalyst activation, accelerated and reduced nickel plating. The operating conditions are described below.

[0034] The hydrophilized polyimide film is immersed in SLP-200 solution at 65°C for 75 seconds to adjust its charge, then removed and rinsed with water.

[0035] The polyimide film is continuously immersed in a 25°C SLP-300 solution for 25 seconds and then in an SLP-400 solution for 75 seconds to deposit a catalyst (e.g., palladium) onto its surface, after which it is removed and washed with water.

[0036] Next, the catalyst is activated by immersing it in a 35°C SLP-500 solution for 75 seconds, then removed and washed with water.

[0037] Subsequently, the material is immersed in an SLP-660 solution at 40°C to control the pH value to 8.5±0.1, and after carrying out the reducing nickel plating reaction for 250 seconds, it is removed and washed with water to complete the composite film of nickel metal layer / polyimide film, with a thickness of 0.08~0.10 μm for the nickel layer on one side.

[0038] The copper layer of the present invention is not particularly limited, as long as it is a copper layer capable of forming subsequent etched lines. In one embodiment of the present invention, the copper layer is preferably formed on a nickel metal layer by electroplating. The electroplating solution that can be used for the copper layer may be a commercially available product, for example, a copper sulfate electroplating solution (purchased from ALL-IN-LINE-CHEMICALS ENTERPRISE, Inc.) can be used.

[0039] The operating conditions for electroplating the copper layer are described below. First, the nickel metal layer / polyimide film composite film is heat-treated at 120°C for 24 hours to roast it, and then the oxide layer on the surface of the nickel metal layer is removed using 2 wt% sulfuric acid. Next, the copper is electroplated in an electroplating tank. The electroplating solution contains 150 g / L of H2SO4, 120 g / L of CuSO4, and 50 ppm of chloride ions, and may optionally contain appropriate amounts of electroplating additives such as brighteners and planarizers. The current density is 4 A / dm². 2 The average plating speed is approximately 0.5 μm / min, and by controlling the current application time, a copper metal layer with a thickness of 0.2 to 20 μm can be deposited on the surface of the nickel layer as needed. [Examples]

[0040] The present invention will be further described below through examples and comparative examples, but the present invention is not limited to these examples and comparative examples.

[0041] <Detection Method> The thermal and electrical properties of the polyimide films obtained in the following examples are detected by the following method.

[0042] (1) Young's modulus A Hounsfield H10K-S tensile testing machine will be used, and measurements will be performed according to the ASTM D882 standard specifications.

[0043] (2) Linear thermal expansion coefficient (CTE) Measurements will be performed using a TA Instruments Q400 TMA instrument, in accordance with the ASTM D696 standard specification. When measuring the coefficient of thermal expansion of polyimide film at 50-200°C, the heating rate will be set to 10°C / min. To remove stress caused by heat treatment, residual stress will be removed by the first measurement, and the result of the second measurement will be used as the actual value.

[0044] (3) Adhesive strength Measurements are performed using a Hounsfield H10K-S tensile testing machine, in accordance with the standard specification of IPC-TM-6502.4.9.

[0045] (4) Calculation of the molar ratio of dianhydride to the diamine in the copolymer chain segment. After calculating the number of moles of diamine and dianhydride in the copolymer chain segment solution, the molar ratio of dianhydride to diamine in the copolymer chain segment can be obtained by dividing the number of moles of dianhydride by the number of moles of diamine (dianhydride / diamine).

[0046] (5) Molar ratio of copolymer chain segment to copolymer polyimide By calculating the number of moles of diamine and dianhydride in the copolymerized segment solution, summing them up, and then dividing by the number of moles of copolymerized polyimide solution, the molar ratio of copolymerized chain segments to copolymerized polyimide can be obtained.

[0047] <Example 1> Production of polyimide film 7.139 g of p-phenylenediamine (p-PDA, 0.066 mol) is added to 400 g of N,N-dimethylacetamide (DMAc), and after dissolving completely, 15.538 g of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA, 0.165 mol) is added, and the mixture is stirred for 1 hour while maintaining the temperature at 25°C to form a copolymer chain segment solution.

[0048] To the copolymer chain segment solution described above, 25.694 g of 2,2'-dimethyl-4,4'-diaminobiphenyl (m-TB, 0.121 mol) is added and stirred until completely dissolved. Then, 11.999 g of pyromellitic anhydride (PMDA, 0.055 mol) is slowly added while stirring for 0.5 hours, maintaining the solution temperature at 25°C, until it dissolves and reacts.

[0049] Next, 12.301 g of BPDA was added and reacted for 1 hour, after which 6.609 g of 4,4'-diaminodiphenyl ether (ODA, 0.033 mol) was added to completely dissolve it. Then, 19.747 g of BPDA (0.0671 mol) was added and reacted for 2 hours, after which the viscosity was adjusted to 250,000 ± 300,000 cps using a small amount of BPDA to finally obtain a copolymer polyamide solution with a solid content of 20 wt%.

[0050] Take 33 g of the above copolymer polyamide solution and add 17 g of N,N-dimethylacetamide (DMAc) to dilute it so that the solid content is 13.2 wt%. Next, stir the diluted copolymer polyamide solution for 10 minutes, and then add 7.12 g of diluted acetic anhydride (the weight ratio of acetic anhydride to DMAc is 5:1) and 5.41 g of diluted 3-methylpyridine (the weight ratio of 3-methylpyridine to DMAc is 1:1) to dilute it further.

[0051] After uniform stirring, the solution is degassed using a centrifugal degasser, and the degassed solution is applied to a glass plate. The application is then carried out using a scraper with a gap of 600 μm. The applied sample is roasted in an 80°C oven for 30 minutes, then the temperature is increased to 170°C at a heating rate of 3.6°C / min for 10 minutes. Furthermore, the temperature is increased to 260°C at a heating rate of 5.9°C / min for 10 minutes, and as a final treatment, the temperature is increased to 350°C at a heating rate of 8.13°C / min for 20 minutes.

[0052] Laminate manufacturing A nickel metal layer is formed on the surface of a polyimide film by electroless plating, and this nickel metal layer is brought into contact with the polyimide film. After the nickel metal layer is formed, a heat treatment is performed to form a copper layer on top of it by electrolytic plating.

[0053] In this embodiment, a nickel layer is formed on one or both sides of a polyimide film by electroless plating. Examples of electroless plating methods include those described above.

[0054] In this embodiment, the nickel layer is formed on one or both sides of the polyimide film by electroless plating. In this embodiment, referring to the SLP metallization process (SLP process) of Nippon Okuno Pharmaceutical Co., Ltd., the SLP series electroless nickel plating reagents are used, and steps such as charge adjustment, pre-immersion, catalyst activation, accelerated and reduced nickel plating are performed in order, with the operating conditions as described above.

[0055] In this embodiment, the fabrication conditions for the copper layer are as described above. This allows for the production of a laminate of copper layer / nickel metal layer / polyimide film. The thickness of the nickel metal layer on one side is 0.08 to 0.10 μm, and the thickness of the copper layer on the other side is 0.2 to 20 μm.

[0056] <Example 2> Production of polyimide film 7.167 g of p-phenylenediamine (p-PDA, 0.0663 mol) was added to 400 g of N,N-dimethylacetamide (DMAc), and after dissolving all of it, 17.551 g of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA, 0.165 mol) was added, and the mixture was stirred for 1 hour while maintaining the temperature at 25°C to form a copolymer chain segment solution.

[0057] To the copolymer chain segment solution described above, 18.762 g of 2,2'-dimethyl-4,4'-diaminobiphenyl (m-TB, 0.088 mol) is added and stirred until completely dissolved. Then, 12.047 g of pyromellitic anhydride (PMDA, 0.055 mol) is slowly added while stirring for 0.5 hours, maintaining the solution temperature at 25°C, until it dissolves and reacts.

[0058] Next, 7.150 g of BPDA is added and reacted for 1 hour, then 13.272 g of 4,4'-diaminodiphenyl ether (ODA, 0.066 mol) is added to completely dissolve it. Subsequently, 23.076 g of BPDA (0.0784 mol) is added and reacted for 2 hours, and then a small amount of BPDA is used to adjust the viscosity to 250,000 ± 300,000 cps, finally obtaining a copolymer polyamide solution with a solid content of 20 wt%.

[0059] Take 33 g of the above copolymer polyamide solution and add 17 g of N,N-dimethylacetamide (DMAc) to dilute it so that the solid content is 13.2 wt%. Next, stir the diluted copolymer polyamide solution for 10 minutes, and then add 7.15 g of diluted acetic anhydride (the weight ratio of acetic anhydride to DMAc is 5:1) and 5.41 g of diluted 3-methylpyridine (the weight ratio of 3-methylpyridine to DMAc is 1:1) to dilute it further.

[0060] After uniform stirring, the solution is degassed using a centrifugal degasser, and the degassed solution is applied to a glass plate. The application is then carried out using a scraper with a gap of 600 μm. The applied sample is roasted in an 80°C oven for 30 minutes, then the temperature is increased to 170°C at a heating rate of 3.6°C / min for 10 minutes. Furthermore, the temperature is increased to 260°C at a heating rate of 5.9°C / min for 10 minutes, and as a final treatment, the temperature is increased to 350°C at a heating rate of 8.13°C / min for 20 minutes.

[0061] Laminate manufacturing This is the same as in Example 1.

[0062] <Example 3> Production of polyimide film 7.167 g of p-phenylenediamine (p-PDA, 0.0663 mol) was added to 400 g of N,N-dimethylacetamide (DMAc), and after dissolving all of it, 18.526 g of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA, 0.0552 mol) was added, and the mixture was stirred for 1 hour while maintaining the temperature at 25°C to form a copolymer chain segment solution.

[0063] To the copolymer chain segment solution described above, 18.762 g of 2,2'-dimethyl-4,4'-diaminobiphenyl (m-TB, 0.0884 mol) is added and the mixture is stirred until completely dissolved. Then, 12.047 g of pyromellitic anhydride (PMDA, 0.0552 mol) and 8.45 g of BPDA are slowly added and the mixture is stirred for 1 hour, after which 13.272 g of 4,4'-diaminodiphenyl ether (ODA, 0.0663 mol) is added.

[0064] After dissolving all the components, 20.801 g of BPDA (0.0707 mol) is slowly added, and the solution is stirred for 12 hours while maintaining the temperature at 25°C until it dissolves and reacts. Then, the viscosity is adjusted to 250,000 ± 300,000 cps using a small amount of BPDA to obtain a copolymer polyamide solution with a solid content of 20 wt%.

[0065] Take 33 g of the above copolymer polyamide solution and add 17 g of N,N-dimethylacetamide (DMAc) to dilute it so that the solid content is 13.2 wt%. Next, stir the diluted copolymer polyamide solution for 10 minutes, and then add 7.15 g of diluted acetic anhydride (the weight ratio of acetic anhydride to DMAc is 5:1) and 5.43 g of diluted 3-methylpyridine (the weight ratio of 3-methylpyridine to DMAc is 1:1) to dilute it further.

[0066] After uniform stirring, the solution is degassed using a centrifugal degasser, and the degassed solution is applied to a glass plate. The application is then carried out using a scraper with a gap of 600 μm. The applied sample is roasted in an 80°C oven for 20 minutes, then the temperature is increased to 170°C at a heating rate of 1.8°C / min and roasted for another 20 minutes. As a final treatment, the temperature is increased to 350°C at a heating rate of 2.0°C / min and roasted for another 20 minutes.

[0067] Laminate manufacturing This is the same as in Example 1.

[0068] <Example 4> Production of polyimide film 7.228 g of p-phenylenediamine (p-PDA, 0.0668 mol) was added to 400 g of N,N-dimethylacetamide (DMAc), and after dissolving all of it, 18.683 g of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA, 0.0635 mol) was added, and the mixture was stirred for 1 hour while maintaining the temperature at 25°C to form a copolymer chain segment solution.

[0069] To the copolymer chain segment solution described above, 18.921 g of 2,2'-dimethyl-4,4'-diaminobiphenyl (m-TB, 0.209 mol) is added and stirred until completely dissolved. Then, 14.579 g of pyromellitic anhydride (PMDA, 0.0668 mol) is slowly added, and the solution is stirred for 0.5 hours while maintaining the temperature at 25°C until it dissolves and reacts.

[0070] Next, 5.244 g of BPDA is added and reacted for 1 hour, after which 13.384 g of 4,4'-diaminodiphenyl ether (ODA, 0.0668 mol) is added to completely dissolve it. Then, 20.977 g of BPDA (0.0713 mol) is added and reacted for 2 hours, after which the viscosity is adjusted to 250,000 ± 300,000 cps using a small amount of BPDA to finally obtain a copolymer polyamide solution with a solid content of 20 wt%.

[0071] Take 33 g of the above copolymer polyamide solution and add 17 g of N,N-dimethylacetamide (DMAc) to dilute it so that the solid content is 13.2 wt%. Next, stir the diluted copolymer polyamide solution for 10 minutes, and then add 7.21 g of diluted acetic anhydride (the weight ratio of acetic anhydride to DMAc is 5:1) and 5.48 g of diluted 3-methylpyridine (the weight ratio of 3-methylpyridine to DMAc is 1:1) to dilute it further.

[0072] After uniform stirring, the solution is degassed using a centrifugal degasser, and the degassed solution is applied to a glass plate. The application is then carried out using a scraper with a gap of 600 μm. The applied sample is roasted in an 80°C oven for 40 minutes, then the temperature is increased to 170°C at a heating rate of 3.6°C / min for 10 minutes. Furthermore, the temperature is increased to 260°C at a heating rate of 5.9°C / min for 10 minutes, and as a final treatment, the temperature is increased to 350°C at a heating rate of 8.13°C / min for 20 minutes.

[0073] Laminate manufacturing This is the same as in Example 1.

[0074] <Example 5> Production of polyimide film This is the same as in Example 4. Laminate manufacturing A polyimide film is subjected to surface modification using plasma. The polyimide film is fixed to an unwinding roll and a guide film is connected. The tension is set to 2 kg, the operating pressure to 300 mTorr, the power supply to 10 kW, and the nitrogen flow rate to 2000 sccm. The length of the plasma zone is 11 m, and the linear velocity is 5.0 m / min. After the process is complete, oxygen (O2) and argon (Ar) are sequentially introduced to clean the cavity. After releasing the vacuum, the power is turned off, the cavity is opened, and the polyimide film is removed, completing the plasma modification of the surface. The subsequent steps are the same as in Example 1.

[0075] <Example 6> Production of polyimide film 7.290 g of p-phenylenediamine (p-PDA, 0.0674 mol) is added to 400 g of N,N-dimethylacetamide (DMAc), and after dissolving all of it, 18.842 g of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA, 0.064 mol) is added, and the mixture is stirred for 1 hour while maintaining the temperature at 25°C to form a copolymer chain segment solution.

[0076] To the copolymer chain segment solution described above, 19.082 g of 2,2'-dimethyl-4,4'-diaminobiphenyl (m-TB, 0.0899 mol) is added and stirred until completely dissolved. Then, 17.155 g of pyromellitic anhydride (PMDA, 0.0786 mol) is slowly added while stirring for 0.5 hours, maintaining the solution temperature at 25°C, until it dissolves and reacts.

[0077] Next, 1.983 g of BPDA is added and reacted for 0.5 hours, after which 13.499 g of 4,4'-diaminodiphenyl ether (ODA, 0.0674 mol) is added to completely dissolve it. Then, 21.156 g of BPDA (0.0719 mol) is added and reacted for 2 hours, after which the viscosity is adjusted to 250,000 ± 300,000 cps using a small amount of BPDA to finally obtain a copolymer polyamide solution with a solid content of 20 wt%.

[0078] Take 33 g of the above copolymer polyamide solution and add 17 g of N,N-dimethylacetamide (DMAc) to dilute it so that the solid content is 13.2 wt%. Next, stir the diluted copolymer polyamide solution for 10 minutes, and then add 7.27 g of diluted acetic anhydride (the weight ratio of acetic anhydride to DMAc is 5:1) and 5.52 g of diluted 3-methylpyridine (the weight ratio of 3-methylpyridine to DMAc is 1:1) to dilute it further.

[0079] After uniform stirring, the solution is degassed using a centrifugal degasser, and the degassed solution is applied to a glass plate. The application is then carried out using a scraper with a gap of 600 μm. The applied sample is roasted in an 80°C oven for 40 minutes, then the temperature is increased to 170°C at a heating rate of 3.6°C / min for 10 minutes. Furthermore, the temperature is increased to 260°C at a heating rate of 5.9°C / min for 10 minutes, and as a final treatment, the temperature is increased to 350°C at a heating rate of 8.13°C / min for 20 minutes.

[0080] Laminate manufacturing This is the same as in Example 1.

[0081] <Example 7> Production of polyimide film This is the same as in Example 6. Laminate manufacturing This is the same as in Example 5.

[0082] <Example 8> Production of polyimide film This is the same as in Example 6. Laminate manufacturing A polyimide film is subjected to surface modification using plasma. The polyimide film is fixed to an unwinding roll and a guide film is connected. The tension is set to 2 kg, the operating pressure to 300 mTorr, the power supply to 10 kW, and the argon (Ar) flow rate is adjusted to 2000 sccm. The length of the plasma zone is 11 m, and the linear velocity is 5.0 m / min. After the process is complete, oxygen (O2) and argon (Ar) are sequentially introduced to clean the cavity, the vacuum is released, the power is turned off, the cavity is opened, and the polyimide film is removed, thus completing the plasma modification of the surface. The subsequent steps are the same as in Example 1.

[0083] <Example 9> Production of polyimide film 9.925 g of p-phenylenediamine (p-PDA, 0.0918 mol) was added to 400 g of N,N-dimethylacetamide (DMAc), and after dissolving all of it, 24.304 g of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA, 0.0826 mol) was added, and the mixture was stirred for 2 hours while maintaining the temperature at 25°C to form a copolymer chain segment solution.

[0084] To the copolymer chain segment solution described above, 19.486 g of 2,2'-dimethyl-4,4'-diaminobiphenyl (m-TB, 0.0918 mol) is added and stirred until completely dissolved. Then, 17.517 g of pyromellitic anhydride (PMDA, 0.0803 mol) is slowly added, and the solution is stirred for 1 hour while maintaining the temperature at 25°C until it dissolves and reacts.

[0085] Next, 9.189 g of 4,4'-diaminodiphenyl ether (ODA, 0.0459 mol) is added and completely dissolved. Then, 18.566 g of BPDA (0.0631 mol) is added and reacted for 2 hours, after which the viscosity is adjusted to 250,000 ± 300,000 cps using a small amount of BPDA to obtain a copolymer polyamide solution with a solid content of 20 wt%.

[0086] Take 33 g of the above copolymer polyamide solution and add 17 g of N,N-dimethylacetamide (DMAc) to dilute it so that the solid content is 13.2 wt%. Next, stir the diluted copolymer polyamide solution for 10 minutes, and then add 7.42 g of diluted acetic anhydride (the weight ratio of acetic anhydride to DMAc is 5:1) and 5.64 g of diluted 3-methylpyridine (the weight ratio of 3-methylpyridine to DMAc is 1:1) to dilute it further.

[0087] After uniform stirring, the solution is degassed using a centrifugal degasser, and the degassed solution is applied to a glass plate. The application is then carried out using a scraper with a gap of 600 μm. The applied sample is roasted in an 80°C oven for 40 minutes, then the temperature is increased to 170°C at a heating rate of 3.6°C / min for 10 minutes. Furthermore, the temperature is increased to 260°C at a heating rate of 5.9°C / min for 10 minutes, and as a final treatment, the temperature is increased to 350°C at a heating rate of 8.13°C / min for 20 minutes.

[0088] Laminate manufacturing This is the same as in Example 1.

[0089] <Comparative Example 1> Production of polyimide film 11.090 g of p-phenylenediamine (p-PDA, 0.1025 mol) was added to 400 g of N,N-dimethylacetamide (DMAc), and after dissolving all of it, 24.138 g of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA, 0.082 mol) was added, and the mixture was stirred for 1 hour while maintaining the temperature at 25°C to form a copolymer chain segment solution.

[0090] To the copolymer chain segment solution described above, 19.352 g of 2,2'-dimethyl-4,4'-diaminobiphenyl (m-TB, 0.0912 mol) is added and stirred until completely dissolved. Then, 12.427 g of pyromellitic anhydride (PMDA, 0.057 mol) is slowly added while stirring for 0.5 hours, maintaining the solution temperature at 25°C, until it dissolves and reacts.

[0091] Next, 6.845 g of 4,4'-diaminodiphenyl ether (ODA, 0.0342 mol) is added and completely dissolved. Then, 25.143 g of BPDA (0.0855 mol) is added and reacted for 2 hours, after which the viscosity is adjusted to 250,000 ± 300,000 cps using a small amount of BPDA to obtain a copolymer polyamide solution with a solid content of 20 wt%.

[0092] Take 33 g of the above copolymer polyamide solution and add 17 g of N,N-dimethylacetamide (DMAc) to dilute it so that the solid content is 13.2 wt%. Next, stir the diluted copolymer polyamide solution for 10 minutes, and then add 7.37 g of diluted acetic anhydride (the weight ratio of acetic anhydride to DMAc is 5:1) and 5.6 g of diluted 3-methylpyridine (the weight ratio of 3-methylpyridine to DMAc is 1:1) to dilute it further.

[0093] After uniform stirring, the solution is degassed using a centrifugal degasser, and the degassed solution is applied to a glass plate. The application is then carried out using a scraper with a gap of 600 μm. The applied sample is roasted in an 80°C oven for 40 minutes, then the temperature is increased to 170°C at a heating rate of 3.6°C / min for 10 minutes. Furthermore, the temperature is increased to 260°C at a heating rate of 5.9°C / min for 10 minutes, and as a final treatment, the temperature is increased to 350°C at a heating rate of 8.13°C / min for 20 minutes.

[0094] Laminate manufacturing This is the same as in Example 1.

[0095] <Comparative Example 2> Production of polyimide film 7.167 g of p-phenylenediamine (p-PDA, 0.0663 mol) is added to 400 g of N,N-dimethylacetamide (DMAc), and after dissolving completely, 11.565 g of pyromellitic anhydride (PMDA, 0.0530 mol) is added, and the mixture is stirred for 1 hour while maintaining the temperature at 25°C to form a copolymer chain segment solution.

[0096] To the copolymer chain segment solution described above, 18.762 g of 2,2'-dimethyl-4,4'-diaminobiphenyl (m-TB, 0.0884 mol) is added and stirred until completely dissolved. Then, 0.482 g of pyromellitic anhydride (PMDA, 0.0786 mol) and 20.151 g of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA, 0.0685 mol) are slowly added, and the solution is stirred for 0.5 hours while maintaining the temperature at 25°C until dissolved and reacted.

[0097] Next, 13.272 g of 4,4'-diaminodiphenyl ether (ODA, 0.0663 mol) is added and completely dissolved. Then, 27.626 g of BPDA (0.0939 mol) is added and reacted for 2 hours, after which the viscosity is adjusted to 250,000 ± 300,000 cps using a small amount of BPDA to finally obtain a copolymer polyamide solution with a solid content of 20 wt%.

[0098] Take 33 g of the above copolymer polyamide solution and add 17 g of N,N-dimethylacetamide (DMAc) to dilute it so that the solid content is 13.2 wt%. Next, stir the diluted copolymer polyamide solution for 10 minutes, and then add 7.15 g of diluted acetic anhydride (the weight ratio of acetic anhydride to DMAc is 5:1) and 5.43 g of diluted 3-methylpyridine (the weight ratio of 3-methylpyridine to DMAc is 1:1) to dilute it further.

[0099] After uniform stirring, the solution is degassed using a centrifugal degasser, and the degassed solution is applied to a glass plate. The application is then carried out using a scraper with a gap of 600 μm. The applied sample is roasted in an 80°C oven for 40 minutes, then the temperature is increased to 170°C at a heating rate of 3.6°C / min for 10 minutes. Furthermore, the temperature is increased to 260°C at a heating rate of 5.9°C / min for 10 minutes, and as a final treatment, the temperature is increased to 350°C at a heating rate of 8.13°C / min for 20 minutes.

[0100] Laminate manufacturing This is the same as in Example 1.

[0101] <Comparative Example 3> Production of polyimide film 13.272 g of 4,4'-diaminodiphenyl ether (ODA, 0.0663 mol) was added to 400 g of N,N-dimethylacetamide (DMAc), and after dissolving all of it, 11.565 g of pyromellitic anhydride (PMDA, 0.0393 mol) was added, and the mixture was stirred for 1 hour while maintaining the temperature at 25°C to form a copolymer chain segment solution.

[0102] To the copolymer chain segment solution described above, 18.762 g of 2,2'-dimethyl-4,4'-diaminobiphenyl (m-TB, 0.0884 mol) is added and stirred until completely dissolved. Then, 0.482 g of pyromellitic anhydride (PMDA, 0.0022 mol) and 20.801 g of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA, 0.0707 mol) are slowly added, and the solution is stirred for 0.5 hours while maintaining the temperature at 25°C until dissolved and reacted.

[0103] Next, 13.272 g of p-phenylenediamine (p-PDA, 0.0663 mol) is added and completely dissolved. Then, 26.976 g of BPDA (0.0917 mol) is added and reacted for 2 hours. After that, a small amount of BPDA is used to adjust the viscosity to 250,000 ± 300,000 cps, finally obtaining a copolymerized polyamide solution with a solid content of 20 wt%.

[0104] Take 33 g of the above copolymer polyamide solution and add 17 g of N,N-dimethylacetamide (DMAc) to dilute it so that the solid content is 13.2 wt%. Next, stir the diluted copolymer polyamide solution for 10 minutes, and then add 7.15 g of diluted acetic anhydride (the weight ratio of acetic anhydride to DMAc is 5:1) and 5.43 g of diluted 3-methylpyridine (the weight ratio of 3-methylpyridine to DMAc is 1:1) to dilute it further. After uniform stirring, the solution is degassed using a centrifugal degasser, and the degassed solution is applied to a glass plate. The application is then carried out using a scraper with a gap of 600 μm. The applied sample is roasted in an 80°C oven for 40 minutes, then the temperature is increased to 170°C at a heating rate of 3.6°C / min for 10 minutes. Furthermore, the temperature is increased to 260°C at a heating rate of 5.9°C / min for 10 minutes, and as a final treatment, the temperature is increased to 350°C at a heating rate of 8.13°C / min for 20 minutes.

[0105] Laminate manufacturing This is the same as in Example 1.

[0106] <Comparative Example 4> Production of polyimide film 13.272 g of 4,4'-diaminodiphenyl ether (ODA, 0.0663 mol) was added to 400 g of N,N-dimethylacetamide (DMAc), and after dissolving all of it, 15.601 g of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA, 0.0530 mol) was added, and the mixture was stirred for 1 hour while maintaining the temperature at 25°C to form a copolymer chain segment solution.

[0107] To the copolymer chain segment solution described above, 18.762 g of 2,2'-dimethyl-4,4'-diaminobiphenyl (m-TB, 0.0884 mol) is added and stirred until completely dissolved. Then, 12.047 g of pyromellitic anhydride (PMDA, 0.0552 mol) and 4.550 g of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA, 0.0155 mol) are slowly added, and the solution is stirred for 0.5 hours while maintaining the temperature at 25°C until dissolved and reacted.

[0108] Next, 7.167 g of p-phenylenediamine (p-PDA, 0.0552 mol) is added and completely dissolved. Then, 27.626 g of BPDA (0.0939 mol) is added and reacted for 2 hours, after which the viscosity is adjusted to 250,000 ± 300,000 cps using a small amount of BPDA to obtain a copolymer polyamide solution with a solid content of 20 wt%.

[0109] Take 33 g of the above copolymer polyamide solution and add 17 g of N,N-dimethylacetamide (DMAc) to dilute it so that the solid content is 13.2 wt%. Next, stir the diluted copolymer polyamide solution for 10 minutes, and then add 7.15 g of diluted acetic anhydride (the weight ratio of acetic anhydride to DMAc is 5:1) and 5.43 g of diluted 3-methylpyridine (the weight ratio of 3-methylpyridine to DMAc is 1:1) to dilute it further.

[0110] After uniform stirring, the solution is degassed using a centrifugal degasser, and the degassed solution is applied to a glass plate. The application is then carried out using a scraper with a gap of 600 μm. The applied sample is roasted in an 80°C oven for 40 minutes, then the temperature is increased to 170°C at a heating rate of 3.6°C / min for 10 minutes. Furthermore, the temperature is increased to 260°C at a heating rate of 5.9°C / min for 10 minutes, and as a final treatment, the temperature is increased to 350°C at a heating rate of 8.13°C / min for 20 minutes.

[0111] Laminate manufacturing This is the same as in Example 1.

[0112] <Comparative Example 5> Production of polyimide film 12.985 g of p-phenylenediamine (p-PDA, 0.120 mol) was added to 400 g of N,N-dimethylacetamide (DMAc), and after dissolving all of it, 31.797 g of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA, 0.1081 mol) was added, and the mixture was stirred for 2 hours while maintaining the temperature at 25°C to form a copolymer chain segment solution.

[0113] To the copolymer chain segment solution described above, 25.493 g of 2,2'-dimethyl-4,4'-diaminobiphenyl (m-TB, 0.120 mol) is added and the mixture is stirred until completely dissolved. Then, 26.192 g of pyromellitic anhydride (PMDA, 0.120 mol) and 2.473 g of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA, 0.0084 mol) are slowly added, and the mixture is stirred for 0.5 hours while maintaining the solution temperature at 25°C until the components dissolve and react.

[0114] Next, after stirring for 2 hours to allow the reaction to proceed, a small amount of BPDA was used to adjust the viscosity to 250,000 ± 300,000 cps, finally obtaining a copolymerized polyamide solution with a solid content of 20 wt%.

[0115] Take 33 g of the above copolymer polyamide solution and add 17 g of N,N-dimethylacetamide (DMAc) to dilute it so that the solid content is 13.2 wt%. Next, stir the diluted copolymer polyamide solution for 10 minutes, and then add 7.77 g of diluted acetic anhydride (the weight ratio of acetic anhydride to DMAc is 5:1) and 5.90 g of diluted 3-methylpyridine (the weight ratio of 3-methylpyridine to DMAc is 1:1) to dilute it further.

[0116] After uniform stirring, the solution is degassed using a centrifugal degasser, and the degassed solution is applied to a glass plate. The application is then carried out using a scraper with a gap of 600 μm. The applied sample is roasted in an 80°C oven for 40 minutes, then the temperature is increased to 170°C at a heating rate of 3.6°C / min for 10 minutes. Furthermore, the temperature is increased to 260°C at a heating rate of 5.9°C / min for 10 minutes, and as a final treatment, the temperature is increased to 350°C at a heating rate of 8.13°C / min for 20 minutes.

[0117] Laminate manufacturing This is the same as in Example 1.

[0118] <Comparative Example 6> Production of polyimide film 25.493 g of 2,2'-dimethyl-4,4'-diaminobiphenyl (m-TB, 0.120 mol) was added to 400 g of N,N-dimethylacetamide (DMAc), and after dissolving all of it, 31.797 g of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA, 0.1081 mol) was added, and the mixture was stirred for 2 hours while maintaining the temperature at 25°C to form a copolymer chain segment solution.

[0119] To the copolymer chain segment solution described above, 12.985 g of p-phenylenediamine (p-PDA, 0.120 mol) is added and the mixture is stirred until completely dissolved. Then, 26.192 g of pyromellitic anhydride (PMDA, 0.120 mol) and 2.473 g of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA, 0.0084 mol) are slowly added, and the mixture is stirred for 0.5 hours while maintaining the solution temperature at 25°C until it dissolves and reacts.

[0120] Next, after stirring for 2 hours to allow the reaction to proceed, a small amount of BPDA was used to adjust the viscosity to 250,000 ± 300,000 cps, finally obtaining a copolymerized polyamide solution with a solid content of 20 wt%.

[0121] Take 33 g of the above copolymer polyamide solution and add 17 g of N,N-dimethylacetamide (DMAc) to dilute it so that the solid content is 13.2 wt%. Next, stir the diluted copolymer polyamide solution for 10 minutes, and then add 7.77 g of diluted acetic anhydride (the weight ratio of acetic anhydride to DMAc is 5:1) and 5.90 g of diluted 3-methylpyridine (the weight ratio of 3-methylpyridine to DMAc is 1:1) to dilute it further.

[0122] After uniform stirring, the solution is degassed using a centrifugal degasser, and the degassed solution is applied to a glass plate. The application is then carried out using a scraper with a gap of 600 μm. The applied sample is roasted in an 80°C oven for 40 minutes, then the temperature is increased to 170°C at a heating rate of 3.6°C / min for 10 minutes. Furthermore, the temperature is increased to 260°C at a heating rate of 5.9°C / min for 10 minutes, and as a final treatment, the temperature is increased to 350°C at a heating rate of 8.13°C / min for 20 minutes.

[0123] Laminate manufacturing This is the same as in Example 1.

[0124] <Comparative Example 7> Production of polyimide film 22.954 g of 2,2'-dimethyl-4,4'-diaminobiphenyl (m-TB, 0.108 mol) was added to 400 g of N,N-dimethylacetamide (DMAc), and after dissolving all of it, 28.631 g of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA, 0.108 mol) was added, and the mixture was stirred for 2 hours while maintaining the temperature at 25°C to form a copolymer chain segment solution.

[0125] To the copolymer chain segment solution described above, 21.650 g of 4,4'-diaminodiphenyl ether (ODA, 0.108 mol) is added and the mixture is stirred until completely dissolved. Then, 23.584 g of pyromellitic anhydride (PMDA, 0.108 mol) and 2.227 g of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA, 0.0076 mol) are slowly added, and the mixture is stirred for 0.5 hours while maintaining the solution temperature at 25°C until the components dissolve and react.

[0126] Next, after stirring for 2 hours to allow the reaction to proceed, a small amount of BPDA was used to adjust the viscosity to 250,000 ± 300,000 cps, finally obtaining a copolymerized polyamide solution with a solid content of 20 wt%.

[0127] Take 33 g of the above copolymer polyamide solution and add 17 g of N,N-dimethylacetamide (DMAc) to dilute it so that the solid content is 13.2 wt%. Next, stir the diluted copolymer polyamide solution for 10 minutes, and then add 6.99 g of diluted acetic anhydride (the weight ratio of acetic anhydride to DMAc is 5:1) and 5.32 g of diluted 3-methylpyridine (the weight ratio of 3-methylpyridine to DMAc is 1:1) to dilute it further.

[0128] After uniform stirring, the solution is degassed using a centrifugal degasser, and the degassed solution is applied to a glass plate. The application is then carried out using a scraper with a gap of 600 μm. The applied sample is roasted in an 80°C oven for 40 minutes, then the temperature is increased to 170°C at a heating rate of 3.6°C / min for 10 minutes. Furthermore, the temperature is increased to 260°C at a heating rate of 5.9°C / min for 10 minutes, and as a final treatment, the temperature is increased to 350°C at a heating rate of 8.13°C / min for 20 minutes.

[0129] Laminate manufacturing This is the same as in Example 1.

[0130] <Comparative Example 8> Production of polyimide film 4.860 g of p-phenylenediamine (p-PDA, 0.0449 mol) is added to 400 g of N,N-dimethylacetamide (DMAc), and after dissolving completely, 11.901 g of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA, 0.0404 mol) is added, and the mixture is stirred for 1 hour while maintaining the temperature at 25°C to form a copolymer chain segment solution.

[0131] To the copolymer chain segment solution described above, 19.082 g of 2,2'-dimethyl-4,4'-diaminobiphenyl (m-TB, 0.0899 mol) and 2.430 g of p-phenylenediamine (0.0225 mol) are added, and the mixture is stirred until completely dissolved. Then, 17.155 g of pyromellitic anhydride (PMDA, 0.0786 mol) and 6.611 g of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA, 0.0225 mol) are slowly added, and the mixture is stirred for 1 hour until dissolved and reacted.

[0132] Next, 13.499 g of 4,4'-diaminodiphenyl ether (ODA, 0.0674 mol) is added and completely dissolved. Then, while maintaining the solution temperature at 25°C, 23.470 g of BPDA (0.0798 mol) is added and reacted for 2 hours. After that, a small amount of BPDA is used to adjust the viscosity to 250,000 ± 300,000 cps, finally obtaining a copolymer polyamide solution with a solid content of 20 wt%.

[0133] Take 33 g of the above copolymer polyamide solution and add 17 g of N,N-dimethylacetamide (DMAc) to dilute it so that the solid content is 13.2 wt%. Next, stir the diluted copolymer polyamide solution for 10 minutes, and then add 7.27 g of diluted acetic anhydride (the weight ratio of acetic anhydride to DMAc is 5:1) and 5.52 g of diluted 3-methylpyridine (the weight ratio of 3-methylpyridine to DMAc is 1:1) to dilute it further.

[0134] After uniform stirring, the solution is degassed using a centrifugal degasser, and the degassed solution is applied to a glass plate. The application is then carried out using a scraper with a gap of 600 μm. The applied sample is roasted in an 80°C oven for 40 minutes, then the temperature is increased to 170°C at a heating rate of 3.6°C / min for 10 minutes. Furthermore, the temperature is increased to 260°C at a heating rate of 5.9°C / min for 10 minutes, and as a final treatment, the temperature is increased to 350°C at a heating rate of 8.13°C / min for 20 minutes.

[0135] Laminate manufacturing This is the same as in Example 1.

[0136] Finally, the compositions used in the above examples and comparative examples, and the physical properties of the resulting polyimide films are summarized in Table 1 below.

[0137] [Table 1]

[0138] First, as shown in Table 1 above, in Comparative Example 1, the p-phenylenediamine content and copolymer chain segment content in the polyimide are not within the required range, resulting in a low adhesive strength value that does not meet the needs.

[0139] Next, as shown in Table 1 above, Comparative Example 2 does not have a copolymer chain segment consisting of BPDA and p-PDA, resulting in a low adhesive strength value after roasting, which does not meet the needs.

[0140] As shown in Table 1 above, Comparative Example 3 does not have a copolymer chain segment consisting of BPDA and p-PDA, resulting in a low Young's modulus and not meeting the needs.

[0141] Furthermore, as shown in Table 1 above, Comparative Example 4 does not have a copolymer chain segment consisting of BPDA and p-PDA, resulting in a high coefficient of linear thermal expansion (CTE) and a low Young's modulus, which does not meet the needs.

[0142] Furthermore, as shown in Table 1 above, Comparative Example 5 does not have the specific dianhydride and diamine composition claimed by this application, resulting in a low adhesive strength value that does not meet the needs.

[0143] Furthermore, as shown in Table 1 above, Comparative Example 6 does not have the specific dianhydride and diamine composition claimed by the present application, and does not have a copolymer chain segment consisting of BPDA and p-PDA, resulting in a low adhesive strength value and not meeting the needs.

[0144] Furthermore, as shown in Table 1 above, Comparative Example 7 does not have the specific dianhydride and diamine composition claimed by the present application, and does not have a copolymer chain segment consisting of BPDA and p-PDA. As a result, it has a low adhesive strength, a high coefficient of linear thermal expansion (CTE), and a low Young's modulus, and does not meet the needs.

[0145] As shown in Table 1 above, in Comparative Example 8, the content of copolymer chain segments in the polyimide is not within the required range, resulting in a low Young's modulus value that does not meet the needs.

[0146] The present invention is not limited to the embodiments described above, and various modifications can be made within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included within the technical scope of the present invention.

Claims

1. A polyimide film comprising a copolymerized polyimide formed from a dianhydride and a diamine, The dianhydride comprises 60 to 80 mol% of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA) and 20 to 40 mol% of pyromellitic anhydride (PMDA) relative to 100 mol% of the dianhydride. The diamine comprises 10 to 40 mol% of p-phenylenediamine (p-PDA), 30 to 60 mol% of 2,2'-dimethyl-4,4'-diaminobiphenyl (m-TB), and 10 to 40 mol% of 4,4'-diaminodiphenyl ether (ODA), relative to 100 mol% of the diamine. The copolymerized polyimide comprises copolymer chain segments consisting of BPDA and p-PDA, and the content of the copolymer chain segments is 25 to 40 mol% relative to 100 mol% of the copolymerized polyimide. The polyimide film has a linear thermal expansion coefficient (CTE) of less than 15 ppm / °C and a Young's modulus greater than 7 GPa. Polyimide film.

2. In the copolymer chain segment, the molar ratio of the dianhydride to the diamine is greater than 0.

9. The polyimide film according to claim 1.

3. The polyimide film according to claim 1, wherein the polyimide film is manufactured by a chemical cyclization method in which the firing temperature is 350°C to 380°C.

4. A laminate comprising a polyimide film according to claim 1 and a metal layer attached to the polyimide film, The adhesive strength between the metal layer and the polyimide film is greater than 0.65 kgf / cm. After roasting at 150°C for 24 hours, the adhesive strength between the metal layer and the polyimide film is greater than 0.5 kgf / cm. Laminated board.

5. The polyimide film, through surface treatment using plasma, achieves an adhesive strength between the metal layer and the polyimide film greater than 0.8 kgf / cm. The laminate according to claim 4.

6. The plasma is an atmospheric plasma and uses a gas containing at least one of the group consisting of nitrogen, argon, oxygen, and carbon tetrafluoride. The laminate according to claim 5.

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