Polyamic acid composition for preparing soluble polyimide solution and soluble polyimide solution prepared therefrom

Abstract

The present invention provides a polyamic acid composition for preparing a soluble polyimide solution, and a soluble polyimide solution prepared therefrom, the polyamic acid composition comprising polyamic acid comprising dianhydride monomers and diamine monomers as polymerization units, wherein the dianhydride monomers comprise 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA), and the diamine monomers comprise 4,4'-methylenebis (2,6-diethylaniline) (MEDA) and 4,4'-diaminodiphenyl ether (4,4'-ODA).

Description

Polyamic acid composition for preparing an available polyimide solution and an available polyimide solution prepared therefrom

[0001] The present invention relates to a polyamic acid composition for preparing a soluble polyimide solution and a soluble polyimide solution prepared therefrom. More specifically, the present invention relates to a polyamic acid composition for preparing a soluble polyimide solution having excellent thermal and mechanical properties while simplifying the process, and a soluble polyimide solution prepared therefrom.

[0002] Polyimide (PI) is a polymer material characterized by excellent heat resistance, chemical resistance, electrical insulation, chemical resistance, and weather resistance among organic materials, based on a rigid aromatic backbone and an imide ring with excellent chemical stability. It can be manufactured into various forms, such as films, fibers, and membranes. These properties make polyimide widely used in advanced materials and insulating coatings for electrical and electronic applications, semiconductors, displays, automobiles, aviation, and space applications.

[0003] Polyimide can be manufactured by dissolving an acid dianhydride having two acid anhydride groups per molecule and a diamine having two amino groups per molecule in a solvent, synthesizing a polyimide precursor called polyamic acid (PAA), and then applying, drying, and heat-treating at approximately 350°C to imidize the polyimide. There has been a growing demand for handling polyimides in a solution state, and extensive development is underway on solvent-soluble polyimides.

[0004] However, polyimides manufactured by imidization through dehydration and ring closure reactions using conventional chemical methods or thermal (high temperature) methods have the problem of being difficult to process due to their insolubility in solvents. In addition, in order to manufacture polyimides that are soluble in solvents, it is generally necessary to use monomers with high solubility, but since these monomers generally have low heat resistance, the resulting polyimides have the problem of low heat resistance and chemical resistance. On the other hand, in order to use polyimides in the form of solutions while having heat or chemical resistance, there is a method of manufacturing polyimides by forming a film with a polyamic acid solution, which is a polyimide precursor, and then imidizing the film.

[0005] However, polyamic acid solutions are easily affected by humidity, are difficult to handle or store, and have the problem of requiring a high-temperature heat treatment process to imidize the polyamic acid or a complex and long-term treatment process.

[0006] Against this backdrop, there is a need to develop a polyimide that maintains the high heat resistance and insulating properties of polyimide, is easily soluble in organic solvents, and enables the manufacture of polyimide-based products through a simple process.

[0007] The present invention aims to provide a polyamic acid composition for preparing a polyimide solution having soluble properties in an organic solvent after the polyimide is fully imidized, and a soluble polyimide solution prepared therefrom.

[0008] In addition, the present invention aims to provide a polyamic acid composition for preparing a soluble polyimide solution for preparing a polyimide having excellent thermal and mechanical properties while simplifying the manufacturing process by omitting the purification, filtration and drying processes for removing by-products (impurities), and a soluble polyimide solution prepared therefrom.

[0009] In addition, the present invention aims to provide a polyamic acid composition for preparing the above-described soluble polyimide solution and a soluble polyimide solution prepared therefrom in various forms such as a film, a hollow fiber membrane, a varnish, a powder, etc.

[0010] The present invention is susceptible to various modifications and embodiments. Therefore, specific embodiments are illustrated and described in detail. However, this is not intended to limit the present invention to specific embodiments, but rather to encompass all modifications, equivalents, and alternatives falling within the spirit and technical scope of the present invention.

[0011] The terminology used in this application is only used to describe specific embodiments and is not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, it should be understood that the terms "comprise" or "have" indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but do not exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0012] When amounts, concentrations, or other values ​​or parameters are given herein as a range, preferred range, or enumeration of an upper preferred value and a lower preferred value, it should be understood that this specifically discloses any range 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 separately disclosed.

[0013] When a range of numerical values ​​is mentioned in this specification, unless otherwise stated, it is intended that the endpoints of the range and the scope of the invention within the range are not limited to the specific values ​​mentioned in defining the range.

[0014] As used herein, "dianhydride" is intended to include precursors or derivatives thereof, also referred to as "dianhydric acids," "dianhydrides," or "acid dianhydrides." While these may not technically be dianhydrides, they will nonetheless react with diamines to form polyamic acids, which can then be converted to polyimides.

[0015] As used herein, "diamine" is intended to include precursors or derivatives thereof, which may not technically be diamines, but which will nonetheless react with a dianhydride acid to form a polyamic acid, which in turn can be converted to a polyimide.

[0016] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and shall not be construed in an idealized or overly formal sense unless explicitly defined herein. Specific details for implementing the invention are described below.

[0017] The present invention relates to a polyamic acid composition for preparing an available polyimide solution and a soluble polyimide solution prepared therefrom.

[0018] In the present invention, the available polyimide solution means a varnish (solution) in which a fully imidized solid polyimide is dissolved in an organic solvent.

[0019] Polyamic acid composition for preparing available polyimide solution

[0020] The present invention provides a polyamic acid composition for preparing a soluble polyimide solution, which comprises a polyamic acid comprising a dianhydride monomer and a diamine monomer as polymerization units, wherein the dianhydride monomer comprises 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA), and the diamine monomer comprises 4,4'-methylenebis(2,6-diethylaniline) (MEDA) and 4,4'-diaminodiphenyl ether (ODA).

[0021] The polyamic acid composition for preparing the above-mentioned available polyimide solution may additionally contain carbonyl diimidazole.

[0022] In the past, when chemical imidization was performed using both a catalyst and a dehydrating agent, a powder was obtained through purification processes such as purification, washing, filtration, and drying to remove by-products, and then dissolved in a polar organic solvent for use. However, the present invention uses an additive CDI having both a catalyst and a dehydrating agent function, so that a purification process including purification, filtration, and drying processes can be omitted and the product can be used directly in the form of a varnish, thereby having the advantage of reducing costs.

[0023] The polyamic acid composition for preparing the above-described available polyimide solution may contain 0.5 to 1.5 mol% of the carbonyl diimidazole based on 1 molar equivalent of the polyamic acid. For example, the upper limit may be 1.4 mol%, 1.3 mol%, 1.25 mol%, 1.2 mol%, 1.15 mol%, 1.12 mol%, 1.11 mol%, 1.1 mol%, 1.09 mol%, 1.08 mol%, 1.07 mol%, 1.06 mol%, or 1.05 mol% or less, and the lower limit may be 0.5 mol%, 0.6 mol%, 0.7 mol%, 0.8 mol%, 0.85 mol%, 0.87 mol%, 0.88 mol%, 0.89 mol%, or 0.9 mol% or more. The polyamic acid composition for preparing the above-mentioned soluble polyimide solution contains 0.5 to 1.5 mol% of the carbonyl diimidazole based on 1 molar equivalent of the polyamic acid, so that the mechanical and thermal properties of the polyimide film finally prepared therefrom are excellent, and an additional purification process is not required after preparing the soluble polyimide solution.

[0024] The polyamic acid composition for preparing the above-mentioned available polyimide solution may additionally include a catalyst and a dehydrating agent.

[0025] The catalyst may include at least one tertiary amine selected from the group consisting of pyridine, isoquinoline, α-picoline, β-picoline, γ-picoline, imidazole, 1-methylimidazole, benzimidazole, triethylamine, and triethylenediamine (DABCO), and more preferably, may include pyridine.

[0026] The polyamic acid composition for preparing the above-described available polyimide solution may contain 0.1 to 1.5 mol% of the catalyst based on 1 molar equivalent of the polyamic acid. For example, the upper limit may be 1.2 mol%, 1.0 mol%, 0.9 mol%, 0.8 mol%, 0.7 mol%, 0.6 mol%, 0.55 mol%, 0.5 mol%, 0.48 mol%, 0.47 mol%, 0.46 mol%, or 0.45 mol% or less, and the lower limit may be 0.1 mol%, 0.15 mol%, 0.18 mol%, 0.2 mol%, 0.22 mol%, 0.23 mol%, 0.24 mol%, or 0.25 mol% or more.

[0027] The dehydrating agent may include at least one selected from the group consisting of acetic anhydride, trifluoroacetic anhydride, sulfoxide chloride, and N,N'-dicyclohexylcarbodiimide, and preferably may include acetic anhydride.

[0028] The polyamic acid composition for preparing the above-described available polyimide solution may contain 0.5 to 1.5 mol% of the dehydrating agent based on 1 molar equivalent of the polyamic acid. For example, the upper limit may be 1.4 mol%, 1.3 mol%, 1.25 mol%, 1.2 mol%, 1.15 mol%, 1.12 mol%, 1.11 mol%, 1.1 mol%, 1.09 mol%, 1.08 mol%, 1.07 mol%, 1.06 mol%, or 1.05 mol% or less, and the lower limit may be 0.5 mol%, 0.6 mol%, 0.7 mol%, 0.8 mol%, 0.85 mol%, 0.87 mol%, 0.88 mol%, 0.89 mol%, or 0.9 mol% or more.

[0029] The content of 4,4'-methylenebis(2,6-diethylaniline) (MEDA) among the total diamine monomers may be 5 mol% to 100 mol%. For example, the upper limit may be 100 mol%, 99 mol%, 98 mol%, 97 mol%, 96 mol%, or 95 mol% or less, and the lower limit may be 5 mol%, 10 mol%, 15 mol%, 20 mol%, 25 mol%, 30 mol%, 35 mol%, 40 mol%, 45 mol%, 50 mol%, 55 mol%, 58 mol%, 60 mol%, 61 mol%, 62 mol%, 63 mol%, 64 mol%, or 65 mol% or more. When the above 4,4'-methylenebis(2,6-diethylaniline) (MEDA) content is outside the above range (5 mol% to 100 mol%), it is difficult to manufacture a polyimide (film, hollow fiber membrane, powder, etc.) having the desired mechanical and thermal properties, which is not preferable.

[0030] Among the total diamine monomers, the content of 4,4'-diaminodiphenyl ether (4,4'-ODA) may be greater than 0 mol% and less than or equal to 50 mol%. For example, the upper limit may be less than or equal to 50 mol%, 45 mol%, 42 mol%, 40 mol%, 39 mol%, 38 mol%, 37 mol%, 36 mol%, or 35 mol%, and the lower limit may be greater than or equal to 1 mol%, 2 mol%, 3 mol%, 4 mol%, or 5 mol%. When the content of 4,4'-diaminodiphenyl ether (4,4'-ODA) is included outside the above range (more than 0 mol% and less than or equal to 50 mol%), it is difficult to manufacture a polyimide (film, hollow fiber membrane, powder, etc.) having desired mechanical and thermal properties, which is not preferable.

[0031] The polyamic acid composition for preparing the above-mentioned available polyimide solution may contain 90 to 110 mol% of the above-mentioned dianhydride monomer, preferably 95 to 105 mol%, and more preferably 100 mol%.

[0032] The polyamic acid composition for preparing the above-mentioned available polyimide solution may contain 90 to 110 mol% of the above-mentioned diamine monomer, preferably 95 to 105 mol%, and more preferably 100 mol%.

[0033] The polyamic acid composition for preparing the above-mentioned available polyimide solution may contain the above-mentioned dianhydride monomer and the above-mentioned diamine monomer in a molar ratio of 6:4 to 4:6, and preferably in a molar ratio of 5:5.

[0034] Available polyimide solution

[0035] The present invention provides a soluble polyimide solution prepared from the polyamic acid composition for preparing the above soluble polyimide solution.

[0036] Specifically, the present invention provides a soluble polyimide solution comprising a polyimide comprising a dianhydride monomer and a diamine monomer as polymerization units, wherein the dianhydride monomer comprises 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA), and the diamine monomer comprises 4,4'-methylenebis(2,6-diethylaniline) (MEDA) and 4,4'-diaminodiphenyl ether (4,4'-ODA).

[0037] The polyimide described above has excellent solubility in organic solvents for solids content of 30 wt% or less. In one embodiment, the presence of floating matter in the soluble polyimide solution was visually confirmed. If no floating matter was present in the solution, it was judged to be soluble, and if floating matter was present in the solution, it was judged to be insoluble.

[0038] The above organic solvent may be an aprotic polar organic solvent, and specifically may include at least one selected from the group consisting of N-methyl-pyrrolidone (NMP), N,N'-dimethylformamide (DMF), N,N'-diethylformamide (DEF), N,N'-dimethylacetamide (DMAc), N,N'-dimethylpropionamide (DMPA), and N,N-diethylacetamide (DEAc).

[0039] The content of 4,4'-methylenebis(2,6-diethylaniline) (MEDA) among the total diamine monomers may be 5 mol% to 100 mol%. For example, the upper limit may be 100 mol%, 99 mol%, 98 mol%, 97 mol%, 96 mol%, or 95 mol% or less, and the lower limit may be 5 mol%, 10 mol%, 15 mol%, 20 mol%, 25 mol%, 30 mol%, 35 mol%, 40 mol%, 45 mol%, 50 mol%, 55 mol%, 58 mol%, 60 mol%, 61 mol%, 62 mol%, 63 mol%, 64 mol%, or 65 mol% or more. When the above 4,4'-methylenebis(2,6-diethylaniline) (MEDA) content is outside the above range (5 mol% to 100 mol%), it is difficult to manufacture a polyimide (film, hollow fiber membrane, powder, etc.) having the desired mechanical and thermal properties, which is not preferable.

[0040] Among the total diamine monomers, the content of 4,4'-diaminodiphenyl ether (4,4'-ODA) may be greater than 0 mol% and less than or equal to 50 mol%. For example, the upper limit may be less than or equal to 50 mol%, 45 mol%, 42 mol%, 40 mol%, 39 mol%, 38 mol%, 37 mol%, 36 mol%, or 35 mol%, and the lower limit may be greater than or equal to 1 mol%, 2 mol%, 3 mol%, 4 mol%, or 5 mol%. When the content of 4,4'-diaminodiphenyl ether (4,4'-ODA) is included outside the above range (more than 0 mol% and less than or equal to 50 mol%), it is difficult to manufacture a polyimide (film, hollow fiber membrane, powder, etc.) having desired mechanical and thermal properties, which is not preferable.

[0041] The above-mentioned soluble polyimide solution may additionally contain imidazole. The above-mentioned soluble polyimide solution does not contain imidazole partially substituted with a substituent.

[0042] Specifically, a soluble polyimide solution prepared from a polyamic acid composition for preparing a soluble polyimide solution containing carbonyl diimidazole includes an imidazole compound, wherein the imidazole compound is a byproduct of the carbonyl diimidazole. The imidazole compound exists between the polyimide polymer chains and forms hydrogen bonds with the polyimide polymer chains, thereby improving intermolecular force and enhancing mechanical properties.

[0043] Meanwhile, when forming a film from an available polyimide solution, the imidazole compound is easily removed by heat and therefore does not remain in the finished polyimide product.

[0044] This has the advantage of easy removal of by-products compared to the chemical imidization method using a conventional catalyst (tertiary amine) and dehydrating agent (acetic anhydride) and the process of purifying, washing, filtering, and drying.

[0045] The above-mentioned available polyimide solution may contain the imidazole compound in an amount of more than 0 parts by weight and less than or equal to 75 parts by weight, based on 100 parts by weight of the polyimide. For example, the upper limit may be less than or equal to 75 parts by weight, 55 parts by weight, or 50 parts by weight, and the lower limit may be more than 0 parts by weight, 15 parts by weight, or 20 parts by weight or more.

[0046] In the present invention, the thermal decomposition temperature (Td), which is mainly used as a standard for judging the thermal properties of polyimide, and the glass transition temperature (Tg), which can predict thermal properties while also ensuring mechanical properties, were confirmed.

[0047] The glass transition temperature (Tg) of the film manufactured from the above-mentioned soluble polyimide solution may be 270°C or higher, and for example, the lower limit of the glass transition temperature may be 273°C, 275°C, 276°C, or 277°C or higher, and the upper limit is not particularly limited but may be 500°C or lower. The above-mentioned glass transition temperature may be measured using DMA at 5°C / min for the film manufactured from the above-mentioned soluble polyimide solution.

[0048] The 5 wt% thermal decomposition temperature (Td) of the film manufactured from the above-mentioned soluble polyimide solution may be 485°C or higher, and for example, the lower limit of the thermal decomposition temperature may be 487°C, 488°C, 489°C, or 490°C or higher, and the upper limit is not particularly limited but may be 600°C or lower. The thermal decomposition temperature may be measured using a TA thermogravimetric analysis Q50 model. In a specific example, the polyimide film manufactured from the above-mentioned soluble polyimide solution is heated to 100°C at a rate of 10°C / min in a nitrogen atmosphere and then isothermally maintained for 1 hour to remove moisture. Thereafter, the temperature may be measured by increasing the temperature to 600°C at a rate of 10°C / min and causing a 5% weight loss.

[0049] In addition, the film manufactured from the above-mentioned available polyimide solution may have a modulus of 2.5 GPa or more, preferably 2.6 GPa or more, and the upper limit may be 30.0 GPa or less, although not particularly limited thereto. The modulus may be measured using an Instron 5564 UTM device from INSTRON.

[0050] The film manufactured from the above-mentioned available polyimide solution may have a tensile strength of 70 MPa or more, preferably 72 MPa or more, and the upper limit may be 400 MPa or less, although there is no particular limitation thereon. The tensile strength may be measured using an Instron 5564 UTM device manufactured by INSTRON.

[0051] The film manufactured from the above-mentioned available polyimide solution may have an elongation of 6% or more, preferably 6.4% or more, and the upper limit may be 30% or less, although there is no particular limitation thereon. The elongation may be measured using an Instron 5564 UTM device from INSTRON.

[0052] A film manufactured from the available polyimide solution of the present invention has the characteristics of excellent solubility in organic solvents while maintaining excellent mechanical and thermal properties.

[0053] The above-mentioned soluble polyimide solution can be in the form of a varnish, and the above-mentioned soluble polyimide solution has the advantage of being readily usable in polyimide films, fibers or coatings by being used directly in the form of a varnish without a purification process including purification, filtration and drying steps.

[0054] The present invention provides a polyimide prepared from a soluble polyimide solution, wherein the polyimide may be in the form of a film, a hollow fiber membrane, or a powder, and specifically, may be a polyimide film, a polyimide hollow fiber membrane, or a polyimide powder comprising the polyimide. The thickness of the polyimide film or the polyimide hollow fiber membrane may be appropriately selected in consideration of the intended use, use environment, physical properties, etc. For example, the thickness of the polyimide film or the polyimide hollow fiber membrane may be 1 to 100 μm, 5 to 50 μm, 10 to 40 μm, or 15 to 25 μm, but is not limited thereto.

[0055] In another aspect, a part comprising a molded body formed from the available polyimide solution of the present invention is provided.

[0056] Specifically, the above components may include, but are not limited to, electronic circuit board components, semiconductor devices, lithium ion battery components, solar cell components, fuel cell components, motor windings, engine peripheral components, paints, optical components, heat dissipating materials, electromagnetic shielding materials, surge components, dental materials, slide coatings, and electrostatic chucks.

[0057] The polyamic acid composition for preparing a polyimide solution according to the present invention and the polyimide solution prepared therefrom have the property of being soluble in an organic solvent, and can be prepared into various products such as films and fibers simply by drying the solvent without an imidization process at high temperatures, thereby improving the ease of the process.

[0058] In addition, the polyamic acid composition for preparing a polyimide solution according to the present invention and the polyimide solution prepared therefrom exhibit excellent solubility characteristics in organic solvents and have excellent mechanical and thermal properties.

[0059] In addition, the polyamic acid composition for preparing an available polyimide solution according to the present invention and the available polyimide solution prepared therefrom have the effect of being provided in various forms such as films, varnishes, and powders according to the intended use.

[0060] In addition, the polyamic acid composition for preparing an available polyimide solution according to the present invention and the available polyimide solution prepared therefrom have the effect of being applicable to various fields such as insulation coating, fiber, and membrane.

[0061] To aid in understanding the present invention, examples are presented. The following examples are provided solely to facilitate a better understanding of the present invention, and the scope of the present invention is not limited by the examples.

[0062] <Example 1: Preparation of polyimide solution>

[0063] Example 1-1

[0064] 65 mol% of 4,4'-methylenebis(2,6-diethylaniline) (MEDA) and 35 mol% of 4,4'-diaminodiphenyl ether (4,4'-ODA) were dissolved in N-methyl-pyrrolidone (NMP) organic solvent in a nitrogen / room temperature atmosphere. Then, 100 mol% of 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA) was added, and the MEDA, 4,4'-ODA, and BTDA were randomly polymerized for 1 hour to obtain a polyamic acid.

[0065] 1.0 molar equivalent of carbonyl diimidazole (CDI) was added as an additive to the obtained polyamic acid, and a chemical imidization process was performed in a continuous polymerization batch process at 40°C for 2.5 hours to prepare a polyimide solution containing polyimide (solid content 20 wt%).

[0066] The above polyimide solution additionally contains an imidazole compound, which is a by-product of the above carbonyl diimidazole, and can be used in the form of a varnish without purification, filtration, and drying processes.

[0067] Examples 1-2 to 1-4

[0068] A polyimide solution was prepared in the same manner as in Example 1-1, except that the monomer components and content, and additive components and content ratio were adjusted as shown in Table 1 below.

[0069] Comparative Examples 1-1 to 1-5

[0070] A polyimide solution was prepared in the same manner as in Example 1-1, except that the monomer components and content, and additive components and content ratio were adjusted as shown in Table 1 below.

[0071] However, the polyimide solutions manufactured according to Comparative Examples 1-1 to 1-5 were additionally subjected to purification, filtration, and drying processes by using a catalyst (pyridine) and a dehydrating agent (acetic anhydride).

[0072]

[0073] The monomer types and contents, additive types and contents, and solubility of the examples and comparative examples are described in Table 1 below. To evaluate solubility, the presence of floating matter in the polyimide solutions prepared according to the examples and comparative examples was visually confirmed. If no floating matter was present in the solution, the solvent solubility was recorded as O, and if floating matter was present in the solution, the solvent solubility was recorded as X.

[0074] Distinction Anhydride Monomer (mol%) Diamine Monomer (mol%) Additive (Molar Equivalent to Polyamic Acid, mol%) Solvent Solubility BTDABPDAMEDA2,4-TDAODAmTBCDIPyridine / AA Example 1-1100-65-35-1.0-O Example 1-2100-80-20-1.0-O Example 1-3100-90-10-1.0-O Example 1-4100-95-5-1.0-O Comparative Example 1-1100-40455101.0-X Comparative Example 1-2100-4045510-0.3 / 1.0X Comparative Example 1-3100-4545551.0-X Comparative Example 1-4100-4545551.00.3 / 1.0X Comparison Example 1-584.5515.4565305-1.0-X

[0075] The abbreviations for the substances used in Table 1 above are as follows.

[0076] BTDA: 3,3',4,4'-Benzophenonetetracarboxylic dianhydride

[0077] BPDA: Biphenyl tetracarboxylic dianhydride

[0078] MEDA: 4,4'-methylenebis(2,6-diethylaniline)

[0079] 2,4-TDA: 2,4-diaminotoluene

[0080] ODA: 4,4'-diaminodiphenyl ether

[0081] mTB: m-tolidine

[0082] CDI: Carbonyl diimidazole

[0083] AA: Acetic anhydride

[0084]

[0085] As shown in Table 1 above, it was confirmed that the polyimide solutions of Examples 1-1 to 1-4 according to the present invention exhibited solubility properties in organic solvents.

[0086] However, it was confirmed that the polyimide solutions of Comparative Examples 1-1 to 1-5 were insoluble in a gel state.

[0087]

[0088] <Example 2: Preparation of polyimide film>

[0089] Examples 2-1 to 2-4

[0090] The soluble polyimide solutions prepared according to Examples 1-1 to 1-4 were coated onto a glass substrate using a spin coater (MSB200, Mikasa) to a thickness of 20 μm and dried at 250°C for 20 minutes. The coating method is not particularly limited. After cooling to 25°C, the solution was separated from the glass substrate to produce a polyimide film with a thickness of approximately 20 μm.

[0091]

[0092] <Example 3: Preparation of polyimide powder>

[0093] Examples 3-1 to 3-4

[0094] For the polyamic acid manufactured in Examples 1-1 to 1-4, 1.0 molar equivalent of carbonyl diimidazole (CDI) was added, and a chemical imidization process was performed in a continuous polymerization batch process at 60°C. Next, after completion of the reaction, the polymer was precipitated in an ethanol non-solvent to remove impurities (unreacted substances), and a purification process was performed to dry this in a vacuum oven at a temperature of less than 150°C for 24 hours, thereby manufacturing a polyimide powder (solid content 20 wt%).

[0095]

[0096] <Experimental Example: Characteristic Evaluation of Polyimide Film>

[0097] The mechanical and thermal properties of the polyimide films of Examples 2-1 to 2-4 were evaluated.

[0098] Experimental Example 1: Mechanical Properties Evaluation

[0099] (1) Modulus (Young's modulus)

[0100] The polyimide films of Examples 2-1 to 2-4 were prepared as samples of 400 mm in length and 10 mm in width using an Instron 5564 UTM device from INSTRON, and the modulus was measured at a speed (20 mm / min). The average of 10 samples was calculated. The results are shown in Table 2 below.

[0101] (2) Tensile strength

[0102] The tensile strength of the polyimide films of Examples 2-1 to 2-4, each measuring 400 mm in length and 10 mm in width, was measured at a speed (20 mm / min) using an Instron 5564 UTM device manufactured by INSTRON, and the average of 10 samples was calculated. The results are shown in Table 2 below.

[0103] (3) Elongation

[0104] The elongation of the polyimide films of Examples 2-1 to 2-4 was measured under room temperature conditions using an Instron 5564 UTM device manufactured by INSTRON according to the ASTM D882 method. The results are shown in Table 2 below.

[0105] Experimental Example 2: Thermal Characteristics Evaluation

[0106] (1) Glass transition temperature (Tg)

[0107] For the polyimide films of Examples 2-1 to 2-4, the point at which rapid expansion occurred was measured as the on-set point using DMA at 5°C / min. The results are shown in Table 2.

[0108] (2) Thermal decomposition temperature of 5 wt% (Td 5 wt%)

[0109] A TA thermogravimetric analysis Q50 model was used, and the polyimide films of Examples 2-1 to 2-4 were heated to 100°C at a rate of 10°C / min in a nitrogen atmosphere, and then maintained isothermally for 1 hour to remove moisture. Thereafter, the temperature was increased to 600°C at a rate of 10°C / min, and the temperature at which a 5% weight loss occurred was measured, and the results are shown in Table 2 below.

[0110] ClassificationMechanical propertiesThermal propertiesModulus (GPa)Tensile strength (MPa)Elongation (%)Tg (℃)Td 5wt% (℃)Example 2-14.172.57.51277491Example 2-23.877.37.14279496Example 2-33.684.26.7277500Example 2-42.693.56.41282504

[0111]

[0112] According to Table 2, it can be confirmed that the film manufactured from the available polyimide solution according to the present invention has excellent mechanical and thermal properties, such as a modulus of 2.5 GPa or more, a tensile strength of 70 MPa or more, an elongation of 6.0% or more, a glass transition temperature of 277°C or more, and a 5 wt% thermal decomposition temperature of 490°C or more.

[0113] Meanwhile, the polyimide solutions of Comparative Examples 1-1 to 1-5 were insoluble in a gel state (see Table 1 above), so films could not be manufactured and thus mechanical / thermal properties could not be measured.

[0114]

[0115] The specification omits detailed descriptions of matters that would be readily apparent and inferred by those skilled in the art. Furthermore, various modifications, other than the specific examples described herein, are possible without altering the technical spirit or essential configuration of the invention. Therefore, the present invention may be practiced in ways other than those specifically described and exemplified herein, as will be apparent to those skilled in the art.

Claims

1. Contains a polyamic acid containing an dianhydride monomer and a diamine monomer as polymerization units, The above dianhydride monomer comprises 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA), A polyamic acid composition for preparing a soluble polyimide solution, wherein the diamine monomer comprises 4,4'-methylenebis(2,6-diethylaniline) (MEDA) and 4,4'-diaminodiphenyl ether (4,4'-ODA).

2. In paragraph 1, A polyamic acid composition for preparing an available polyimide solution, wherein the polyamic acid composition for preparing an available polyimide solution further comprises carbonyl diimidazole.

3. In paragraph 2, A polyamic acid composition for preparing an available polyimide solution, wherein the polyamic acid composition for preparing an available polyimide solution comprises 0.5 to 1.5 mol% of the carbonyl diimidazole with respect to 1 molar equivalent of the polyamic acid.

4. In paragraph 1, A polyamic acid composition for preparing a soluble polyimide solution, wherein the content of 4,4'-methylenebis(2,6-diethylaniline) (MEDA) among the total diamine monomers is 5 mol% to 100 mol%.

5. In paragraph 4, A polyamic acid composition for preparing a soluble polyimide solution, wherein the content of 4,4'-methylenebis(2,6-diethylaniline) (MEDA) among the total diamine monomers is 65 mol% to 95 mol%.

6. In paragraph 1, A polyamic acid composition for preparing a soluble polyimide solution, wherein the content of 4,4'-diaminodiphenyl ether (4,4'-ODA) among the total diamine monomers is greater than 0 mol% and less than or equal to 50 mol%.

7. In paragraph 6, A polyamic acid composition for preparing a soluble polyimide solution, wherein the content of 4,4'-diaminodiphenyl ether (4,4'-ODA) among the total diamine monomers is greater than 5 mol% and less than or equal to 35 mol%.

8. A polyimide comprising an dianhydride monomer and a diamine monomer as polymerization units, The above dianhydride monomer comprises 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA), A soluble polyimide solution, wherein the diamine monomer comprises 4,4'-methylenebis(2,6-diethylaniline) (MEDA) and 4,4'-diaminodiphenyl ether (4,4'-ODA).

9. In paragraph 8, The above polyimide is a soluble polyimide solution that exhibits solubility properties in organic solvents for a solid content of 30 wt% or less.

10. In paragraph 9, A soluble polyimide solution, wherein the organic solvent comprises at least one selected from the group consisting of N-methyl-pyrrolidone (NMP), N,N'-dimethylformamide (DMF), N,N'-diethylformamide (DEF), N,N'-dimethylacetamide (DMAc), N,N'-dimethylpropionamide (DMPA), and N,N-diethylacetamide (DEAc).

11. In paragraph 8, A soluble polyimide solution having a content of 4,4'-methylenebis(2,6-diethylaniline) (MEDA) of 5 mol% to 100 mol% among the total diamine monomers.

12. In paragraph 11, A soluble polyimide solution having a content of 4,4'-methylenebis(2,6-diethylaniline) (MEDA) of 65 mol% to 95 mol% among the total diamine monomers.

13. In paragraph 8, A soluble polyimide solution, wherein the content of 4,4'-diaminodiphenyl ether (4,4'-ODA) among the total diamine monomers is greater than 0 mol% and less than or equal to 50 mol%.

14. In paragraph 13, A soluble polyimide solution, wherein the content of 4,4'-diaminodiphenyl ether (4,4'-ODA) among the total diamine monomers is greater than 5 mol% and less than or equal to 35 mol%.

15. In paragraph 8, A soluble polyimide solution, wherein the above soluble polyimide solution further comprises an imidazole compound.

16. In paragraph 15, A soluble polyimide solution, wherein the above-mentioned soluble polyimide solution contains the imidazole compound in an amount of more than 0 parts by weight and less than or equal to 75 parts by weight based on 100 parts by weight of the polyimide.

17. Polyimide manufactured from the available polyimide solution of Article 8.

18. In paragraph 17, The glass transition temperature (Tg) of the above polyimide is 270°C or higher, The above glass transition temperature is a polyimide, which is measured as the on-set point at which the polyimide rapidly expands under 5°C / min conditions using dynamic mechanical analysis (DMA).

19. In paragraph 17, The 5 wt% thermal decomposition temperature (Td) of the above polyimide is 485°C or higher, The above thermal decomposition temperature is a polyimide that is heated to 100°C at a rate of 10°C / min in a nitrogen atmosphere, maintained at an isothermal temperature for 1 hour to remove moisture, and then heated to 600°C at a rate of 10°C / min to measure the temperature at which a weight loss of 5% occurs.

20. In paragraph 17, The above polyimide is, Modulus is 2.5 GPa or more, Tensile strength is 70 MPa or more, Elongation is 6% or more, Polyimide, wherein the above modulus, tensile strength and elongation are each measured using a universal testing machine (UTM).