Low dielectric black polyimide film and method for producing the same

Abstract

The present invention relates to a polyimide film having a transmittance of 1.0% or less, a glossiness of 50% or less, and a dielectric loss factor of 0.01 or less, and a manufacturing method thereof. The polyimide film, in which the types and composition ratios of dianhydride acid components, diamine components, and carbon black are adjusted, has the effect of simultaneously having excellent optical properties, dielectric properties, and chemical resistance properties.

Description

[Technical Field]

[0001] The present invention relates to a polyimide film having excellent optical properties, dielectric properties, and chemical resistance properties at the same time, and a method for producing the same. [Background technology]

[0002] Polyimide (PI) is a polymeric material based on imide rings, which have excellent chemical stability along with a rigid aromatic main chain, and has the highest levels of heat resistance, chemical resistance, electrical insulation, chemical resistance, and weather resistance among organic materials. Polyimide films have been attracting attention as materials for a variety of electronic devices that require the above-mentioned properties. In particular, they have recently been widely used as coverlays in portable electronic devices and communication devices. Coverlays are used to protect electronic components such as printed wiring boards and lead frames of semiconductor integrated circuits, and require physical properties such as thinness and slimness. Recently, optical properties, including security, portability, visual effects, and the ability to conceal electronic components and mounted parts, have also been required.

[0003] In order to satisfy such optical properties, carbon black or the like is mixed into the polyimide film. However, conventional polyimide films containing carbon black have poor dielectric properties for use in high-speed transmission, making them difficult to apply to 5G electronic devices. Therefore, there is a strong demand for the development of polyimide films that simultaneously have excellent optical properties and dielectric properties. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Republic of Korea Patent No. 10-1045823 Summary of the Invention [Problem to be solved by the invention]

[0005] Therefore, an object of the present invention is to provide a polyimide film that simultaneously has excellent optical properties, dielectric properties, and chemical resistance properties. However, the problems to be solved by the present invention are not limited to those mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description. [Means for solving the problem]

[0006] In order to achieve the above object, one aspect of the present invention is a glass substrate having a transmittance of 1.0% or less, a glossiness of 50% or less, and a dielectric loss factor of 0.01 or less. A polyimide film is provided. Another aspect of the present invention is a process for producing a polyamic acid by polymerizing, in an organic solvent, a dianhydride acid component including two or more selected from the group consisting of biphenyltetracarboxylic dianhydride (BPDA), pyromellitic dianhydride (PMDA), oxydiphthalic anhydride (ODPA), and benzophenonetetracarboxylic dianhydride (BTDA), and a diamine component including two or more selected from the group consisting of paraphenylenediamine (PPD), m-tolidine, oxydianiline (ODA), and 1,3-bisaminophenoxybenzene (TPE-R); (b) mixing and dispersing carbon black in the polyamic acid; (c) imidizing the polyamic acid; The carbon black is at least one selected from the group consisting of bone black, lamp black, and thermal black. A method for producing a polyimide film is provided. Yet another aspect of the present invention includes a polyimide film, Provide coverlay. [Effects of the Invention]

[0007] The present invention provides a polyimide film in which the types and composition ratios of a dianhydride acid component, a diamine component, and carbon black are controlled, thereby providing a polyimide film having excellent optical properties, dielectric properties, and chemical resistance properties. Such polyimide films are applicable to a variety of fields requiring polyimide films with excellent optical properties, dielectric properties, and chemical resistance, such as coverlays. DETAILED DESCRIPTION OF THE INVENTION

[0008] The terms and words used in this specification and claims should not be interpreted in a limited way to their ordinary or dictionary meanings, but should be interpreted in a way that is consistent with the technical idea of the present invention, in accordance with the principle that the inventor can appropriately define the concept of the term in order to best describe his or her invention. Therefore, it should be understood that the configuration of the embodiment described in this specification is merely one of the most preferred embodiments of the present invention and does not represent the entire technical idea of the present invention, and that there may be various equivalents and modifications that can replace them at the time of this application. In this specification, the singular includes the plural unless the context clearly indicates otherwise. It should be understood that in this specification, the terms "comprise," "comprise," or "have" are intended to specify the presence of embodied features, numbers, steps, components, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, numbers, steps, components, or combinations thereof.

[0009] As used herein, "dianhydride acid" is intended to include precursors or derivatives thereof, which may not technically be dianhydrides, but which nevertheless must react with diamines to form polyamic acids, which are then converted back to polyimides. As used herein, "diamine" is intended to include precursors or derivatives thereof, which may not technically be diamines, but which nevertheless must react with dianhydrides to form polyamic acids, which are then converted back to polyimides. Whenever an amount, concentration, or different value or parameter is given herein as a range, a preferred range, or a list of upper and lower preferred values, it should be understood to specifically disclose all ranges formed by any pair of any upper range limit or preferred value, and any lower range limit or preferred value, regardless of whether ranges are otherwise disclosed.

[0010] Where a range of numerical values is recited herein, unless otherwise stated, the range is intended to include the endpoints thereof, and all integers and fractions within the range. It is not intended that the scope of the invention be limited to the specific values recited when defining a range. A polyimide film according to an embodiment of the present invention may have a transmittance of 1.0% or less, a glossiness of 50% or less, and a dielectric loss factor of 0.01 or less. In addition, the polyimide film has a dielectric constant of 4.0 or less and a chemical resistance index of 90% or more. may be.

[0011] In one embodiment, the polyimide film is obtained by an imidization reaction of a polyamic acid solution containing a dianhydride acid component including two or more selected from the group consisting of biphenyltetracarboxylic dianhydride (BPDA), pyromellitic dianhydride (PMDA), oxydiphthalic anhydride (ODPA), and benzophenonetetracarboxylic dianhydride (BTDA), and a diamine component including two or more selected from the group consisting of paraphenylenediamine (PPD), m-tolidine, oxydianiline (ODA), and 1,3-bisaminophenoxybenzene (TPE-R). In particular, the polyimide film is obtained by imidizing a polyamic acid solution containing a dianhydride acid component consisting of two or more selected from the group consisting of biphenyltetracarboxylic dianhydride, pyromellitic dianhydride, and benzophenonetetracarboxylic dianhydride, and a diamine component including two or more selected from the group consisting of paraphenylenediamine, m-tolidine, and oxydianiline.

[0012] On the other hand, based on 100 mol% of the total content of the dianhydride acid components, the content of the biphenyltetracarboxylic dianhydride may be 20 mol% or more and 50 mol% or less, the content of the pyromellitic dianhydride may be 25 mol% or more and 70 mol% or less, and the content of the benzophenonetetracarboxylic dianhydride may be 50 mol% or less. Furthermore, based on 100 mol% of the total content of the diamine components, the content of the paraphenylenediamine may be 5 mol% or more and 75 mol% or less, the content of the m-tolidine may be 25 mol% or more and 80 mol% or less, and the content of the oxydianiline may be 25 mol% or less. The paraphenylenediamine of the present invention is a rigid monomer, and by increasing the content of paraphenylenediamine, the synthesized polyimide has a more linear structure, which contributes to improving the mechanical properties of the polyimide.

[0013] Furthermore, m-tolidine has a methyl group that exhibits hydrophobicity, which contributes to the low moisture absorption property related to the dimensional stability of the polyimide film against moisture. In the present invention, the polyimide chain derived from biphenyltetracarboxylic dianhydride has a structure called a charge transfer complex (CTC), i.e., a regular linear structure in which an electron donor and an electron acceptor are located close to each other, thereby enhancing intermolecular interactions. This structure has the effect of preventing hydrogen bonding with moisture, which has an effect of reducing the moisture absorption rate, thereby maximizing the effect of reducing the moisture absorption of the polyimide film.

[0014] In particular, the dianhydride component may further include pyromellitic dianhydride, which is preferred because it is a dianhydride component having a relatively rigid structure and can impart appropriate elasticity to the polyimide film. For a polyimide film to simultaneously satisfy appropriate elasticity and moisture absorption, the content ratio of the dianhydride is particularly important. For example, as the content ratio of biphenyltetracarboxylic dianhydride decreases, it becomes difficult to expect low moisture absorption due to the CTC structure. In addition, biphenyltetracarboxylic dianhydride, oxydiphthalic anhydride, and benzophenonetetracarboxylic dianhydride are aromatic compounds. The pyromellitic dianhydrides contain two benzene rings corresponding to the aromatic moiety, whereas the pyromellitic dianhydrides contain one benzene ring corresponding to the aromatic moiety.

[0015] An increase in the content of pyromellitic dianhydride in the dianhydride acid component can be understood as an increase in the number of imide groups in the molecule based on the same molecular weight, which can be understood as a relative increase in the ratio of imide groups derived from the pyromellitic dianhydride to the imide groups derived from biphenyltetracarboxylic dianhydride in the polyimide polymer chain. That is, an increase in the content of pyromellitic dianhydride is seen as a relative increase in imide groups relative to the entire polyimide film, which makes it difficult to expect a low moisture absorption rate. Conversely, if the content ratio of the pyromellitic dianhydride is reduced, the amount of the relatively rigid structural component is reduced, and the mechanical properties of the polyimide film may be reduced below the desired level. For this reason, if the content of the biphenyltetracarboxylic dianhydride exceeds the above range, the mechanical properties of the polyimide film are reduced, and it is not possible to ensure a level of heat resistance appropriate for manufacturing a flexible metal foil laminate.

[0016] Conversely, if the content of the biphenyltetracarboxylic dianhydride is below the above range or the content of the pyromellitic dianhydride is above the above range, it is difficult to achieve appropriate levels of dielectric constant, dielectric loss factor, and moisture absorption rate, which is undesirable. The m-tolidine has a methyl group, which is particularly hydrophobic, and contributes to the low moisture absorption properties of the polyimide film, and the low moisture absorption derived from m-tolidine contributes to the low dielectric loss factor of the polyimide film.

[0017] In one embodiment, the polyimide film includes carbon black, and the carbon black may be any one or more selected from the group consisting of bone black, lamp black, and thermal black. Bone black is typically made by carbonizing animal bones and has a warm black color. Lamp black is made by collecting soot from burning mineral oils such as petroleum and tar, and has a bluish color. It is used as a special printing ink for printing banknotes, etc. Thermal black is produced by the thermal decomposition of natural gas and acetylene. On the other hand, the polyimide film does not contain furnace black.

[0018] In one embodiment, the polyimide film may contain only bone black, or may contain both bone black and lamp black, or may contain both bone black and thermal black. Furthermore, when the polyimide film contains bone black together with lamp black or thermal black, the weight ratio of bone black to lamp black or thermal black (weight % of bone black:weight % of lamp black or thermal black) may be 4:1 to 1.5:1. In one embodiment, the carbon black is contained in an amount of 1% by weight to 15% by weight based on 100% by weight of the polyimide film. In one embodiment, the polyimide film may have a thickness of 7.5 μm or more and 75 μm or less.

[0019] In the present invention, the polyamic acid can be produced, for example, by (1) A method in which the entire amount of the diamine component is placed in a solvent, and then the dianhydride acid component is added in an amount substantially equimolar to the diamine component to polymerize it; (2) A method in which the entire amount of the dianhydride acid component is placed in a solvent, and then the diamine component is added in an amount substantially equimolar to the dianhydride acid component to polymerize it; (3) A method in which a part of the diamine component is placed in a solvent, and then a part of the dianhydride component is mixed with the reaction components in a ratio of about 95 to 105 mol %, and then the remaining diamine component is added, and then the remaining dianhydride component is added successively to this, so that the diamine component and the dianhydride component are substantially equimolar, thereby polymerizing; (4) A method in which a dianhydride acid component is placed in a solvent, and then a portion of the components in the diamine compound is mixed in a ratio of 95 to 105 mol % relative to the reactants, and then another dianhydride acid component is added, followed by the remaining diamine component, so that the diamine component and the dianhydride acid component are substantially equimolar, thereby polymerizing the mixture; (5) A method of forming a first composition by reacting some diamine components and some dianhydride acid components in a solvent so that one of them is in excess, and then forming a second composition by reacting some diamine components and some dianhydride acid components in another solvent so that one of them is in excess, and then mixing the first and second compositions to complete the polymerization, in which if the diamine component is in excess when forming the first composition, the dianhydride acid component is made in excess in the second composition, and if the dianhydride acid component is in excess in the first composition, the diamine component is made in excess in the second composition, and the first and second compositions are mixed to polymerize the diamine components and dianhydride acid components used in the reactions in total so that they are substantially equimolar.

[0020] In one embodiment, the method for producing a polyimide film according to the present invention comprises the steps of: (a) producing a polyamic acid by polymerizing, in an organic solvent, a dianhydride component including two or more selected from the group consisting of biphenyltetracarboxylic dianhydride (BPDA), pyromellitic dianhydride (PMDA), oxydiphthalic anhydride (ODPA), and benzophenonetetracarboxylic dianhydride (BTDA), and a diamine component including two or more selected from the group consisting of paraphenylenediamine (PPD), m-tolidine, oxydianiline (ODA), and 1,3-bisaminophenoxybenzene (TPE-R); (b) mixing and dispersing carbon black in the polyamic acid; (c) imidizing the polyamic acid. In the present invention, the polymerization method of the polyamic acid can be defined as a random polymerization method, and the polyimide film prepared from the polyamic acid of the present invention prepared by the above process can be preferably applied in terms of maximizing the effect of the present invention, which is to improve dimensional stability. However, since the above polymerization method produces a polymer chain with a relatively short repeating unit length, there may be a limit to the excellent properties of the polyimide chain derived from the dianhydride acid component. Therefore, the polyamic acid polymerization method that is particularly preferably used in the present invention is block polymerization.

[0021] On the other hand, the solvent for synthesizing the polyamic acid is not particularly limited, and any solvent that can dissolve the polyamic acid can be used, but an amide-based solvent is preferred. Specifically, the organic solvent may be an organic polar solvent, more specifically, an aprotic polar solvent, and may be, for example, one or more selected from the group consisting of N,N-dimethylformamide (DMF), N,N-dimethylacetamide, N-methyl-pyrrolidone (NMP), gamma-butyrolactone (GBL), and diglyme, but is not limited thereto, and may be used alone or in combination of two or more kinds as needed. In one example, N,N-dimethylformamide and N,N-dimethylacetamide are particularly preferably used as the organic solvent.

[0022] Furthermore, in the production process of polyamic acid, a filler may be added for the purpose of improving various film properties such as sliding properties, thermal conductivity, corona resistance, loop hardness, etc. The filler to be added is not particularly limited, but preferred examples include silica, titanium oxide, alumina, silicon nitride, boron nitride, calcium hydrogen phosphate, calcium phosphate, mica, etc. The particle size of the filler is not particularly limited and may be determined depending on the film properties to be modified and the type of filler to be added. Generally, the average particle size is 0.05 to 100 μm, preferably 0.1 to 75 μm, more preferably 0.1 to 50 μm, and particularly preferably 0.1 to 25 μm. If the particle size is below this range, the modifying effect is less likely to be achieved, whereas if it exceeds this range, the surface properties may be significantly damaged and the mechanical properties may be significantly reduced.

[0023] The amount of filler to be added is not particularly limited and may be determined depending on the film properties to be modified, the particle size of the filler, etc. Generally, the amount of filler to be 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, per 100 parts by weight of polyimide. If the amount of filler added is below this range, the modifying effect of the filler will be difficult to achieve, and if it exceeds this range, the mechanical properties of the film may be significantly impaired. The method of adding the filler is not particularly limited, and any known method may be used.

[0024] In the production method of the present invention, the polyimide film is produced by a thermal imidization method and a chemical imidization method. Alternatively, the imidation layer may be produced by a hybrid imidation method in which thermal imidization and chemical imidization are performed in parallel. The thermal imidization method is a method in which a chemical catalyst is not used and the imidization reaction is induced by a heat source such as hot air or an infrared dryer. The thermal imidization method involves heat-treating the gel film at a variable temperature in the range of 100 to 600°C to imidize the amic acid groups present in the gel film, specifically at 200 to 500°C, and more specifically at 300 to 500°C to imidize the amic acid groups present in the gel film.

[0025] However, even during the process of forming the gel film, a portion of the amic acid (approximately 0.1 mol % to 10 mol %) is imidized. For this reason, the polyamic acid composition can be dried at a variable temperature ranging from 50°C to 200°C, which also falls within the category of the thermal imidization method. In the case of chemical imidization, a polyimide film can be produced using a dehydrating agent and an imidizing agent by methods known in the art. As an example of the composite imidization method, a polyimide film can be produced by adding a dehydrating agent and an imidization agent to a polyamic acid solution, heating the solution at 80 to 200°C, preferably 100 to 180°C, partially curing and drying the solution, and then heating the solution at 200 to 400°C for 5 to 400 seconds. The present invention provides a coverlay including the above-described polyimide film. [Example]

[0026] The functions and effects of the present invention will be described in more detail below through specific manufacturing examples and examples of the present invention, however, these manufacturing examples and examples are presented only as examples of the present invention and do not limit the scope of the invention.

[0027] Manufacturing example: Manufacturing of polyimide film The polyimide film of the present invention can be produced by the following conventional methods known in the art. First, the dianhydride acid and the diamine component are reacted in an organic solvent to obtain a polyamic acid solution. In this case, the solvent is generally an aprotic polar solvent such as an amide solvent. solvent), such as N,N'-dimethylformamide, N,N'-dimethylacetamide, N-methyl-pyrrolidone, or a combination thereof, can be used. The dianhydride and diamine components may be added in the form of powder, lump, or solution. Preferably, they are added in the form of powder at the beginning of the reaction to allow the reaction to proceed, and then added in the form of a solution to control the polymerization viscosity. The resulting polyamic acid solution is mixed with carbon black, an imidization catalyst, and a dehydrating agent, and then coated onto a support.

[0028] Examples of catalysts used include, but are not limited to, tertiary amines (e.g., isoquinoline, β-picoline, pyridine, etc.), and examples of dehydrating agents include, but are not limited to, acid anhydride. Furthermore, examples of supports used include, but are not limited to, glass plates, aluminum foils, rotating stainless steel belts, and stainless steel drums. The film coated on the support is gelled on the support by dry air and heat treatment. The gelled film is separated from the support and heat treated to complete drying and imidization. After the heat treatment, the film is further heat treated under a certain tension to remove residual stress inside the film that has occurred during the film formation process.

[0029] Specifically, 500ml of DMF was added to a reactor equipped with a stirrer and nitrogen inlet / outlet tubes while injecting nitrogen. The reactor temperature was then set to 30°C, and biphenyltetracarboxylic dianhydride (BPDA), pyromellitic dianhydride (PMDA), benzophenonetetracarboxylic dianhydride (BTDA), paraphenylenediamine (PPD), m-tolidine, and oxydianiline (ODA) were added in the specified ratio and order and completely dissolved. The reactor temperature was then raised to 40°C under a nitrogen atmosphere, and stirring was continued for 120 minutes to produce a polyamic acid with a primary reaction viscosity of 1,500 cP. The polyamic acid thus produced was stirred to a final viscosity of 100,000 to 120,000 cP. The contents of carbon black, catalyst and dehydrating agent were adjusted and added to the prepared final polyamic acid, and then a polyimide film was produced using an applicator.

[0030] Examples and Comparative Examples In Examples 1 to 8 and Comparative Examples 1 to 6, polyimide films were prepared according to the preparation examples by adjusting the contents of the dianhydride acid component and the diamine component, and the type and content of carbon black, as shown in Tables 1 and 2 below. [Table 1] [Table 2] The carbon black content in Tables 1 and 2 is the weight percent of the carbon black contained in the polyimide film based on 100 weight percent of the polyimide film.

[0031] The transmittance, gloss, dielectric constant (Dk), dielectric loss factor (Df) and chemical resistance index of the prepared polyimide film were measured and are shown in Tables 3 and 4 below. [Table 3] [Table 4]

[0032] (1) Transmittance measurement The polyimide films produced in Examples 1 to 8 and Comparative Examples 1 to 6 were measured for transmittance in the visible light region according to ASTM D1003 using a transmittance measuring device (model name: ColorQueset XE, manufacturer: HunterLab).

[0033] (2) Gloss measurement The gloss of each of the polyimide films produced in Examples 1 to 8 and Comparative Examples 1 to 6 was measured at an angle of 60° using a gloss measuring device (model name: E406L, manufacturer: Elcometer) based on the ASTM D523 method.

[0034] (3) dielectric constant The dielectric constant (Dk) of each of the polyimide films produced in Examples 1 to 8 and Comparative Examples 1 to 6 was measured at 10 GHz using an SPDR measuring instrument manufactured by Keysight Corporation.

[0035] (4) Measurement of dielectric loss factor The dielectric loss factor (Df) of each of the polyimide films produced in Examples 1 to 8 and Comparative Examples 1 to 6 was measured using an Agilent 4294A resistance meter after leaving the flexible metal foil laminate for 72 hours.

[0036] (5) Chemical resistance index measurement The polyimide films produced in Examples 1 to 8 and Comparative Examples 1 to 6 were each subjected to corona treatment on both sides, and then the polyimide film + bonding sheet (adhesive) + copper foil structure was bonded using a hot press at a pressure of 50 kgf and a temperature of 160°C for 30 minutes to prepare FCCL samples. FCCL cut into a size of 4 × 10 cm was exposed to a 10% NaOH solution at 55°C for 3 minutes, then to a desmear solution (10% NaMnO4 + 4% NaOH) at 55°C for 5 minutes, and then washed. This process was repeated twice, and the thickness of the film was measured and compared with the thickness before exposure to the NaOH solution and desmear solution. The degree of change in thickness after exposure relative to the thickness before exposure was expressed as a percentage. As a result of the measurements, the polyimide films of Examples 1 to 8 had a transmittance of 1.0% or less, a glossiness of 50% or less, a dielectric loss factor of 0.01 or less, a dielectric constant of 4.0 or less, and a chemical resistance index of 90% or more.

[0037] When bone black and thermal black are used together as in the examples, it was confirmed that as the content of thermal black in carbon black increases, the gloss, dielectric constant, and dielectric loss factor of the polyimide film increase, while the chemical resistance index decreases. In addition, it was confirmed that the gloss, dielectric constant, and dielectric loss factor of the polyimide film increased, and the chemical resistance index decreased, when bone black and lamp black were used together compared to when bone black was used alone.

[0038] On the other hand, the polyimide film of Comparative Example 1, which had the same dianhydride acid and diamine component and their contents as the polyimide films of Examples 1 to 4 but contained no carbon black, had very high transmittance and gloss. It was also confirmed that the polyimide film of Comparative Example 2, which contained only furnace black as carbon black, had significantly higher transmittance and gloss than the polyimide films of Examples 1 to 4, and also had a higher dielectric constant. In addition, it was confirmed that the polyimide film of Comparative Example 3, which used a mixture of bone black and furnace black, had a significantly higher dielectric loss factor than the polyimide films of Examples 1 to 4.

[0039] On the other hand, the polyimide film of Comparative Example 4, which had the same dianhydride acid and diamine component and their contents as the polyimide films of Examples 5 to 8 but contained no carbon black, had very high transmittance and gloss. It was also confirmed that the polyimide film of Comparative Example 5, which contained only furnace black as carbon black, had significantly higher transmittance and gloss than the polyimide films of Examples 5 to 8, and also had a higher dielectric constant. In addition, it was confirmed that the polyimide film of Comparative Example 6, which used a mixture of bone black and furnace black, had a significantly higher dielectric loss factor than the polyimide films of Examples 5 to 8.

[0040] Therefore, the polyimide films of Examples 1 to 8, which were produced within the appropriate range of the present application, all had excellent optical properties (transmittance, gloss), dielectric properties (dielectric constant, dielectric loss factor), and chemical resistance. However, it was confirmed that it was difficult to achieve both optical properties and dielectric properties when the appropriate range of the present application was exceeded. That is, it was confirmed that the polyimide film that has both optical and dielectric properties and excellent chemical resistance and is applicable to various fields of application is the polyimide film manufactured within the appropriate range of the present invention. The examples of the polyimide film and method for manufacturing the polyimide film of the present invention are merely preferred examples that will enable those skilled in the art to easily practice the present invention, and the present invention is not limited to the above examples, and the scope of the present invention is not limited by these examples. Therefore, the true technical scope of the present invention must be determined by the technical spirit of the appended claims. Furthermore, it is obvious to those skilled in the art that various substitutions, modifications, and alterations are possible within the scope of the present invention, and it is obvious that parts that can be easily modified by those skilled in the art are also included in the scope of the present invention. [Industrial Applicability]

[0041] The present invention provides a polyimide film in which the types and composition ratios of a dianhydride acid component, a diamine component, and carbon black are controlled, thereby providing a polyimide film having excellent optical properties, dielectric properties, and chemical resistance properties. Such polyimide films are applicable to a variety of fields requiring polyimide films with excellent optical properties, dielectric properties, and chemical resistance, such as coverlays.

Claims

1. The transmittance is 1.0% or less, the gloss is 50% or less, and the dielectric loss factor is 0.01 or less. A polyimide film, the polyimide film is obtained by an imidization reaction of a polyamic acid solution, the polyamic acid solution containing a dianhydride acid component including two or more selected from the group consisting of biphenyltetracarboxylic dianhydride (BPDA), pyromellitic dianhydride (PMDA), oxydiphthalic anhydride (ODPA) and benzophenonetetracarboxylic dianhydride (BTDA), and a diamine component including two or more selected from the group consisting of paraphenylenediamine (PPD), m-tolidine, oxydianiline (ODA) and 1,3-bisaminophenoxybenzene (TPE-R); the polyimide film contains carbon black; The carbon black is at least one selected from the group consisting of bone black, lamp black, and thermal black; A polyimide film, wherein the carbon black does not include furnace black.

2. The dielectric constant is 4.0 or less, The chemical resistance index is 90% or more. The polyimide film according to claim 1 .

3. a polyamic acid solution containing a dianhydride acid component consisting of two or more selected from the group consisting of biphenyltetracarboxylic dianhydride, pyromelic dianhydride, and benzophenonetetracarboxylic dianhydride, and a diamine component containing two or more selected from the group consisting of paraphenylenediamine, m-tolidine, and oxydianiline, which is obtained by imidizing the polyamic acid solution; The polyimide film according to claim 1 .

4. the content of the biphenyltetracarboxylic dianhydride is 20 mol% or more and 50 mol% or less, the content of the pyromellitic dianhydride is 25 mol% or more and 70 mol% or less, and the content of the benzophenonetetracarboxylic dianhydride is 50 mol% or less, based on 100 mol% of the total content of the dianhydride acid components; The polyimide film according to claim 3 .

5. the content of the paraphenylenediamine is 5 mol % or more and 75 mol % or less, the content of the m-tolidine is 25 mol % or more and 80 mol % or less, and the content of the oxydianiline is 25 mol % or less, based on 100 mol % of the total content of the diamine components; The polyimide film according to claim 3 .

6. The carbon black is contained in an amount of 1% by weight or more and 15% by weight or less based on 100% by weight of the polyimide film. The polyimide film according to claim 1 .

7. The thickness of the polyimide film is 7.5 μm or more and 75 μm or less. The polyimide film according to claim 1 .

8. (a) producing a polyamic acid by polymerizing, in an organic solvent, a dianhydride acid component including two or more selected from the group consisting of biphenyltetracarboxylic dianhydride (BPDA), pyromellitic dianhydride (PMDA), oxydiphthalic anhydride (ODPA), and benzophenonetetracarboxylic dianhydride (BTDA), and a diamine component including two or more selected from the group consisting of paraphenylenediamine (PPD), m-tolidine, oxydianiline (ODA), and 1,3-bisaminophenoxybenzene (TPE-R); (b) mixing and dispersing carbon black in the polyamic acid; (c) imidizing the polyamic acid; The carbon black is at least one selected from the group consisting of bone black, lamp black, and thermal black; The carbon black does not include furnace black. A method for producing polyimide film.

9. The polyimide film according to any one of claims 1, 2, 3, 4, 5, 6 and 7 is included. Coverlay.

Images