Solvent-soluble polyimide with simplified preparation process and preparation method therefor

Abstract

The present invention provides a preparation method for polyamide, comprising the steps of: (a) preparing polyamic acid by polymerizing a dianhydride monomer and a diamine monomer; and (b) preparing soluble polyimide by reacting the polyamic acid with carbonyl diimidazole, wherein the soluble polyimide is in a varnish form.

Description

Solvent-soluble polyimide with simplified manufacturing process and method for manufacturing the same

[0001] The present invention relates to a solvent-soluble polyimide and a method for producing the same. More specifically, the present invention relates to a polyimide with excellent thermal and mechanical properties and a method for producing the same while simplifying the process.

[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 purpose of the present invention is to provide a method for manufacturing 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).

[0008] In addition, the present invention aims to provide a method for producing a polyimide having fully imidized polyimide and having soluble properties in an organic solvent.

[0009] In addition, the present invention aims to provide a polyimide manufactured according to the above polyimide manufacturing method.

[0010] In addition, the present invention aims to provide various forms of a separator, binder, insulating coating, coating material, etc. containing the polyimide.

[0011] In addition, the present invention aims to provide a composition for manufacturing polyimide that can be used in the method for manufacturing the polyimide.

[0012] 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.

[0013] 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.

[0014] 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.

[0015] 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.

[0016] 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.

[0017] 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.

[0018] 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.

[0019] The present invention relates to a method for manufacturing a polyimide having excellent thermal and mechanical properties while simplifying the manufacturing process by omitting purification, filtration and drying processes for removing by-products (impurities).

[0020] Polyimide manufacturing method

[0021] The present invention provides a method for producing a polyimide, comprising the steps of (a) polymerizing an dianhydride monomer and a diamine monomer to produce a polyamic acid; and (b) reacting the polyamic acid with carbonyl diimidazole to produce a soluble polyimide; wherein the soluble polyimide is in the form of a varnish.

[0022] The method for manufacturing the above polyimide may not perform a purification process including purification, filtration and drying steps after step (b).

[0023] In the past, in order to remove by-products during chemical imidization, a powder was obtained through a purification process such as purification, washing, filtration, and drying, 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, thereby omitting the purification process including purification, filtration, and drying, and allowing direct use in the form of a varnish.

[0024] In step (a), the carbonyl diimidazole may be reacted in an amount of 0.5 to 1.5 molar equivalents relative to 1 molar equivalent of the polyamic acid. For example, the upper limit may be 1.5, 1.4, 1.3, 1.2, 1.1 molar equivalents or less, and the lower limit may be 0.5, 0.6, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95 molar equivalents or more. If the carbonyl diimidazole is reacted in an amount less than 0.5 molar equivalents, the physical properties of the produced polyimide deteriorate, which is undesirable, and if it is reacted in an amount exceeding 1.5 molar equivalents, an additional purification process becomes necessary, which is undesirable.

[0025] The above purification process may refer to a series of processes such as purification, washing, filtration, and drying to remove by-products (impurities, catalysts, unreacted substances, etc.) after performing the imidization process.

[0026] Additionally, the above purification may include a purification method commonly used in polymer synthesis, such as reprecipitation, such as an alcohol precipitation method.

[0027] The above step (b) can be performed at a temperature of 20 to 60°C. For example, the upper limit can be 60°C, 58°C, 55°C, 52°C, 50°C, 48°C, 45°C, 44°C, 43°C, 42°C, 41°C or less, and the lower limit can be 20°C, 22°C, 25°C, 28°C, 30°C, 32°C, 35°C, 36°C, 37°C, 38°C or more.

[0028] The above step (b) may be performed for 0.5 to 5 hours. For example, the upper limit may be 5, 4.5, 4, 3.5, 3, 2.7 hours or less, and the lower limit may be 0.5, 0.8, 1, 1.2, 1.5, 2.0, 2.3 hours or more.

[0029] The reaction of the above step (b) is an imidization reaction, and the imidization rate may be 97 to 100%, preferably 98 to 100%, more preferably 99 to 100%, and most preferably 100%.

[0030] In the above step (a), the polymerization may be random polymerization or block polymerization.

[0031] Specifically, when polymerizing by random polymerization, a random copolymer can be produced, and a copolymer composed of two or more types of polymerization units (repeating units) can be produced. For example, the expression “-(A)a-(B)b-(C)c-(D)d-”, which is a random copolymer of polymerization units A to D, means that the polymerization units are randomly connected in various forms such as -(ABADABABC)-, -(AACCCBBDB)-, -(AADABADABACC)-, and a, b, c, and d represent the ratios of polymerization units A, B, C, and D.

[0032] In addition, step (a) may include (a-1) a step of adding the entire dianhydride monomer to the entire diamine monomer; and (a-2) a step of randomly polymerizing the entire diamine monomer and the entire dianhydride monomer. For example, the random polymerization may be performed by dissolving the entire diamine monomer in an organic solvent, then adding and dissolving the entire dianhydride monomer, and then polymerizing to produce a polyamic acid.

[0033] Specifically, when polymerizing by block polymerization, a block copolymer can be produced, and a copolymer composed of two or more types of polymerization units (repeating units) can be produced. For example, the expression “-(A)a-(B)b-(C)c-(D)d-”, which is a block copolymer of polymerization units A to D, means that the same polymerization units are continuously connected in the form of -(AAABBBBBCCCCDDD)-, and a, b, c, and d represent the ratios of polymerization units A, B, C, and D.

[0034] In addition, step (a) includes (a-1) a step of introducing any one dianhydride monomer into any one diamine monomer; and (a-2) a step of block polymerizing any one diamine monomer and any one dianhydride monomer; and steps (a-1) and (a-2) may be repeated multiple times. For example, the block polymerization may be performed by repeating the steps of dissolving one diamine monomer in an organic solvent, then introducing one dianhydride monomer and polymerizing it, introducing another diamine monomer and polymerizing it, and then introducing another dianhydride monomer and polymerizing it, thereby producing a polyamic acid.

[0035] The above dianhydride monomer may include at least one selected from the group consisting of pyromellitic dianhydride (PMDA), 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA), oxydiphthalic dianhydride (ODPA), 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (6FDA), biphenyltetracarboxylic dianhydride (BPDA), 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride (DSDA), and 2,2-bis(4-(3,4-dicarboxyphenoxy)phenyl)propane dianhydride. More specifically, it may be any one or a combination of any one or more of the above-mentioned dianhydride monomers. More specifically, it is preferable that the above-mentioned dihydric acid monomer is composed of one type, and more specifically, it is preferable that it includes 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA).

[0036] The above diamine monomer may include at least one selected from the group consisting of 4,4'-methylenebis(2,6-diethylaniline) (MEDA), 2,4-diaminotoluene (2,4-TDA), 2,6-diaminotoluene (2,6-TDA), m-phenylenediamine (m-PD), p-phenylenediamine (p-PD), 3,3''-diaminodiphenyl sulfone (3,3''-DDS), 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (6FAP), 3,5-diethyltoluene-2,6-diamine, 3,5-diethyltoluene-2,4-diamine, 4,4'-methylenebis(2-ethyl-6-methylaniline) (MEMA). More specifically, it may be a combination including any one or more of the above-mentioned diamine monomers. More specifically, it is preferable that the diamine monomer includes at least one type, and more specifically, it is preferable that it includes 4,4'-methylenebis(2,6-diethylaniline) (MEDA) and 2,4-diaminotoluene (2,4-TDA).

[0037] In one embodiment, the polyamic acid may be a polymerization of the dianhydride monomer 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA); and the diamine monomers 4,4'-methylenebis(2,6-diethylaniline) (MEDA) and 2,4-diaminotoluene (2,4-TDA).

[0038] The content of 4,4'-methylenebis(2,6-diethylaniline) (MEDA) among the total diamine monomers 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%, 40 mol%, 30 mol%, 20 mol%, 18 mol%, 17 mol%, 15 mol%, 13 mol%, or 12 mol%, and the lower limit may be greater than or equal to 0.1 mol%, 1 mol%, 2 mol%, 3 mol%, or 4 mol%.

[0039] Among the total diamine monomers, the content of 2,4-diaminotoluene (2,4-TDA) may be less than 100 mol% and greater than 50 mol%. For example, the upper limit may be 99.9 mol%, 99 mol%, 98 mol%, 97 mol%, or 96 mol% or less, and the lower limit may be 50 mol%, 60 mol%, 70 mol%, 80 mol%, 72 mol%, 73 mol%, 75 mol%, or 78 mol% or more.

[0040] The above polyimide may contain 90 to 110 mol% of the diamine monomer, preferably 95 to 105 mol%, and more preferably 100 mol%.

[0041] The above polyimide may contain 90 to 110 mol% of the above dianhydride monomer, preferably 95 to 105 mol%, and more preferably 100 mol%.

[0042] The above polyimide may contain the dianhydride monomer and the diamine monomer in a molar ratio of 1:2 to 2:1, and preferably in a molar ratio of 1:1.

[0043] The above polyimide may be a soluble polyimide having excellent solubility in an organic solvent for a solid content of 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%, 20 wt%, 21 wt%, 22 wt%, 23 wt%, 24 wt%, or 25 wt% or more. The upper limit is not particularly limited, but may be 50 wt% or less.

[0044] 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), dimethylpropanamide (DMPA), and N,N-diethylacitamide (DEAc).

[0045] In the present invention, the thermal decomposition temperature (Td), which is mainly used as a standard for judging the thermal properties of the polyimide, and the glass transition temperature (Tg), which can predict the thermal properties while also ensuring the mechanical properties, were confirmed.

[0046] The 5 wt% thermal decomposition temperature (Td) of the polyimide may be 485°C or higher, and for example, the lower limit of the thermal decomposition temperature may be 487±1°C, 490±1°C, 493±1°C, or 495±1°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 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 increased to 600°C at a rate of 10°C / min to measure the temperature at which a 5% weight loss occurs.

[0047] The glass transition temperature (Tg) of the above polyimide may be 300°C or higher, and for example, the lower limit of the glass transition temperature may be 305±1°C, 310±1°C, 312±1°C, 315±1°C, 317±1°C, or 318±1°C or higher, and the upper limit is not particularly limited but may be 500°C or lower. The glass transition temperature may be measured for the polyimide using DMA at 5°C / min.

[0048] In addition, the polyimide may have a modulus of 3.0 GPa or more, preferably 3.3 GPa or more, and the upper limit is not particularly limited, but may be 30.0 GPa or less. The modulus was measured using an Instron 5564 UTM device manufactured by INSTRON.

[0049] The above polyimide may have a tensile strength of 110 MPa or more, preferably 115 MPa or more, and the upper limit is not particularly limited but may be 400 MPa or less. The tensile strength was measured using an Instron 5564 UTM device from INSTRON.

[0050] The above polyimide may have an elongation of 5% or more, preferably 5.2% or more, and the upper limit is not particularly limited but may be 30% or less. The elongation was measured using an Instron 5564 UTM device manufactured by INSTRON.

[0051] In general, in order to imidize polyamic acid, a dehydrating agent and a catalyst are used in the polyamic acid, and then steps of purification, filtration, and drying are performed to remove impurities. However, the method for manufacturing polyimide according to the present invention simplifies the manufacturing process by using the additive CDI, thereby omitting purification processes such as purification, filtration, and drying to remove by-products (impurities), and at the same time, it is possible to manufacture a polyimide having excellent thermal and mechanical properties as well as excellent solubility in a solvent.

[0052] In another aspect, the present invention provides a polyimide manufactured according to the method for manufacturing the polyimide. In this case, the polyimide may be a solvent-soluble polyimide.

[0053] The above polyimide can be in the form of a varnish, and the polyimide has the advantage of being able to be easily used in a polyimide film, fiber, or coating by being used directly in the form of a varnish without a purification process including purification, filtration, and drying steps.

[0054] In another aspect, a polyimide film including the polyimide is provided.

[0055] The thickness of the above polyimide film may be appropriately selected in consideration of the purpose, usage environment, physical properties, etc. of the polyimide film. For example, the thickness of the polyimide film may be 1 to 100 μm, 5 to 50 μm, 10 to 40 μm, or 15 to 25 μm, but is not limited thereto.

[0056] In another aspect, a component including a molded body formed from the polyimide is provided.

[0057] 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.

[0058] In another aspect, the present invention provides a separator, fiber, insulating layer or coating layer comprising a polyimide according to the above description.

[0059] In another aspect, the present invention provides a composition for producing a soluble polyimide, comprising: a polyamic acid comprising a dianhydride monomer and a diamine monomer as polymerization units; and carbonyl diimidazole.

[0060] The method for manufacturing polyimide according to the present invention simplifies the manufacturing process by omitting the purification, filtration, and drying processes for removing by-products (impurities), while also manufacturing polyimide having excellent thermal and mechanical properties.

[0061] In addition, a polyimide can be manufactured that is fully imidized and has soluble properties in an organic solvent.

[0062] In addition, the polyimide according to the present invention has the effect of being applicable to various fields such as membranes, binders, insulating coatings, coating materials, and fibers.

[0063] Figure 1 is an optical image of a polyimide film manufactured according to Example 5-1 and Comparative Examples 9 and 10.

[0064] 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.

[0065] <Example>

[0066] Example 1: Preparation of polyimide (random copolymer)

[0067] Example 1-1

[0068] 5 mol% of 4,4'-methylenebis(2,6-diethylaniline) (MEDA) and 95 mol% of 2,4-diaminotoluene (2,4-TDA) were dissolved in dimethylformamide (DMF) organic solvent under a nitrogen / room temperature atmosphere. Then, 100 mol% of 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA) was added, and the MEDA, 2,4-TDA, and BTDA were randomly polymerized for 1 hour to obtain a polyamic acid composition.

[0069] To the obtained polyamic acid composition, 1.0 molar equivalent of carbonyl diimidazole (CDI) was added, and a chemical imidization process was performed in a continuous polymerization batch process at 40°C for 2.5 hours to produce a soluble polyimide (solid content 20 wt%), which was used in the form of a varnish without purification, filtration, or drying processes. This means that it has solubility properties for an organic solvent (DMF).

[0070] Example 1-2

[0071] A soluble polyimide was prepared in the same manner as in Example 1-1, except that 0.9 molar equivalents of carbonyl diimidazole (CDI) were added instead of 1.0 molar equivalents of carbonyl diimidazole (CDI) in Example 1-1.

[0072] Example 1-3

[0073] A soluble polyimide was prepared in the same manner as in Example 1-1, except that 10 mol% of methylenebis(2,6-diethylaniline)(MEDA) and 90 mol% of 2,4-diaminotoluene(2,4-TDA) were used instead of 5 mol% of methylenebis(2,6-diethylaniline)(MEDA) and 95 mol% of 2,4-diaminotoluene(2,4-TDA) in Example 1-1.

[0074] Example 2: Preparation of polyimide (block copolymer)

[0075] Example 2-1

[0076] 10 mol% of 4,4'-methylenebis(2,6-diethylaniline) (MEDA) was dissolved in dimethylformamide (DMF) organic solvent under a nitrogen / room temperature atmosphere. Then, 100 mol% of 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA) was added and block polymerization was performed for 1 hour. Next, 90 mol% of 2,4-diaminotoluene (2,4-TDA) was added and block polymerization was performed for 1 hour to obtain a polyamic acid composition.

[0077] To the obtained polyamic acid composition, 1.0 molar equivalent of carbonyl diimidazole (CDI) was added, and a chemical imidization process was performed in a continuous polymerization batch process at 40°C for 2.5 hours to produce a soluble polyimide (solid content 20 wt%), which was used in the form of a varnish without purification, filtration, and drying processes.

[0078] Example 2-2

[0079] A soluble polyimide was manufactured in the same manner as in Example 2-1, except that instead of adding 10 mol% of 4,4'-methylenebis(2,6-diethylaniline)(MEDA) and 90 mol% of 2,4-diaminotoluene(2,4-TDA) in Example 2-1, 20 mol% of 4,4'-methylenebis(2,6-diethylaniline)(MEDA) and 80 mol% of 2,4-diaminotoluene(2,4-TDA) were added.

[0080] Example 3: Preparation of polyimide (random copolymer)

[0081] Examples 3-1 to 3-3

[0082] As shown in Table 1 below, a soluble polyimide was manufactured using the same method as Example 1-1, but with different types and contents of monomers and additives.

[0083] Example 4: Preparation of polyimide (block copolymer)

[0084] Examples 4-1 to 4-3

[0085] As shown in Table 1 below, a soluble polyimide was manufactured using the same method as Example 2-1, but with different types and contents of monomers and additives.

[0086] Comparative Example 1: Production of polyimide (using catalyst and dehydrating agent)

[0087] 5 mol% of 4,4'-methylenebis(2,6-diethylaniline) (MEDA) and 95 mol% of 2,4-diaminotoluene (2,4-TDA) were dissolved in dimethylformamide (DMF) organic solvent under a nitrogen / room temperature atmosphere. Then, 100 mol% of 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA) was added, and the MEDA, 2,4-TDA, and BTDA were randomly polymerized for 1 hour to obtain a polyamic acid composition.

[0088] To the obtained polyamic acid composition, 0.3 molar equivalents of pyridine (catalyst, Py) and 1.0 molar equivalents of acetic anhydride (dehydrating agent, AA) were 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, catalyst, AA, etc.), 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%).

[0089] Comparative Example 2: Manufacturing of polyimide (including purification process)

[0090] The polyimide prepared according to Example 1-1 was precipitated in an ethanol non-solvent to remove impurities (unreacted substances, catalyst, AA, etc.), and then further subjected to a purification process of drying in a vacuum oven at a temperature of less than 150°C for 24 hours to prepare polyimide powder.

[0091] Comparative Examples 3 and 4: Preparation of polyimide

[0092] Polyimide powder was manufactured using the same method as Comparative Example 1, but with different types and contents of monomers and additives and polymerization methods, as shown in Table 1 below.

[0093] Comparative Examples 5 to 8: Preparation of polyimide

[0094] Polyimide powder was manufactured using the same method as Comparative Example 2, but with different types and contents of monomers and additives and polymerization methods, as shown in Table 1 below.

[0095]

[0096] The monomer types and contents, polymerization methods, additive types and contents, whether a purification process was performed, and solubility of the examples and comparative examples are described in Table 1 below. To evaluate solubility, the polyimide powder of the comparative example was added to the organic solvent N,N'-dimethylformamide (DMF), stirred for 30 minutes, and the degree of turbidity of the solution was visually confirmed.

[0097] ClassificationAnhydride (mol%)Diamine (mol%)Polymerization methodAdditive (molar equivalent to polyamic acid)Whether purification process is performedSolubility (solvent availability)BTDAMEDA2,4-TDAExample 1-1100595Random polymerizationCDI (1.0 molar equivalent)XsolubleExample 1-2100595Random polymerizationCDI (0.9 molar equivalent)XsolubleExample 1-31001090Random polymerizationCDI (1.0 molar equivalent)XsolubleExample 2-11001090Block polymerizationCDI (1.0 molar equivalent)XsolubleExample 2-21002080Block polymerizationCDI (1.0 molar equivalent)XsolubleExample 3-11001585Random polymerizationCDI (1.0 Molar equivalent) X soluble Example 3-21002575 Random polymerization CDI (0.9 molar equivalent) X soluble Example 3-31003070 Random polymerization CDI (1.0 molar equivalent) X soluble Example 4-11003070 Block polymerization CDI (1.0 molar equivalent) X soluble Example 4-21003575 Block polymerization CDI (1.0 molar equivalent) X soluble Example 4-31004060 Block polymerization CDI (0.9 molar equivalent) X soluble Comparative Example 1100595 Random polymerization Py (0.3 molar equivalent) AA (1.0 molar equivalent) ○ soluble Comparative Example 2100595 Random polymerization CDI (1.0 molar equivalent) ○ soluble Comparative Example 31002080 Block polymerization Py (0.3 molar equivalent) AA (1.0 molar equivalent) ○solubleComparative example 41003575 Block polymerization Py (0.3 molar equivalent) AA (1.0 molar equivalent) ○solubleComparative example 51002080 Block polymerization CDI (1.0 molar equivalent) ○solubleComparative example 61002575 Random polymerization CDI (0.9 molar equivalent) ○solubleComparative example 71003070 Random polymerization CDI (1.0 molar equivalent) ○solubleComparative example 81004060 Block polymerization CDI (0.9 molar equivalent) ○soluble

[0098] Example 5: Preparation of polyimide (random copolymer) film

[0099] Example 5-1

[0100] The polyimide varnish manufactured according to Example 1-1 was coated on a glass substrate using a spin coater (MS-B200, Mikasa) to a thickness of 20 μm and dried at 250°C for 20 minutes. The coating method is not particularly limited. Subsequently, the film was cooled at 25°C and separated from the glass substrate to manufacture a polyimide film with a thickness of approximately 20 μm.

[0101] Examples 5-2 and 5-3

[0102] A polyimide film was manufactured in the same manner as in Example 5-1, except that polyimide varnishes manufactured according to Examples 1-2 and 1-3 were used instead of the polyimide varnish manufactured according to Example 1-1 in Example 5-1.

[0103] Example 6: Preparation of polyimide (block copolymer) film

[0104] Examples 6-1 and 6-2

[0105] A polyimide film was manufactured in the same manner as in Example 5-1, except that polyimide varnishes manufactured according to Examples 2-1 and 2-2 were used instead of the polyimide varnish manufactured according to Example 1-1 in Example 5-1.

[0106] Example 7: Preparation of polyimide (random copolymer) film

[0107] Examples 7-1 to 7-3

[0108] A polyimide film was manufactured in the same manner as in Example 5-1, except that polyimide varnishes manufactured according to Examples 3-1 to 3-3 were used instead of the polyimide varnish manufactured according to Example 1-1 in Example 5-1.

[0109] Example 8: Preparation of polyimide (block copolymer) film

[0110] Examples 8-1 to 8-3

[0111] A polyimide film was manufactured in the same manner as in Example 5-1, except that polyimide varnishes manufactured according to Examples 4-1 to 4-3 were used instead of the polyimide varnish manufactured according to Example 1-1 in Example 5-1.

[0112] Comparative Example 9: Manufacturing of polyimide film

[0113] The polyimide powder manufactured according to Comparative Example 1 was dissolved in an organic solvent (DMF) to obtain a solution having a solid content of 20 wt%, and the solution thus obtained was coated on a glass substrate using a spin coater (MS-B200, Mikasa) to a thickness of 20 μm and dried at 250°C for 20 minutes. The coating method is not particularly limited. After cooling at 25°C, the solution was separated from the glass substrate to produce a polyimide film having a thickness of approximately 20 μm.

[0114] Comparative Examples 10 to 16: Production of polyimide film

[0115] A polyimide film was manufactured in the same manner as in Comparative Example 9, except that instead of using the polyimide powder manufactured according to Comparative Example 1 in Comparative Example 9, the polyimide powder manufactured according to Comparative Examples 2 to 8 was used.

[0116] <Experimental Example>

[0117] Experimental Example 1: Comparison of the Appearance of Polyimides

[0118] Figure 1 is an optical image of a polyimide film manufactured according to Example 5-1 and Comparative Examples 9 and 10.

[0119] According to Fig. 1, it was confirmed that the polyimide film of Example 5-1 had a darker color than Comparative Examples 9 and 10. The existing polyimide with availability implements availability by imparting flexibility to the molecular chain in order to lower the CTC (charge transfer complex) of the imide group, or by introducing a bulky substituent to the side chain in order to increase the three-dimensional effect. In this case, the color of the film was transparent and the mechanical properties were reduced. However, judging from the darker color of the polyimide film according to the present invention, it was found that this is because the presence of imidazole between the polyimide polymer chains improves the intermolecular force due to hydrogen bonding, and the mechanical properties are improved compared to the existing polyimide with availability due to the CTC.

[0120] Therefore, it was found that the present invention can manufacture a polyimide film with excellent physical properties using CDI without performing purification, filtration, and drying processes.

[0121] Experimental Example 2: Evaluation of the physical properties of polyimide

[0122] (1) Glass transition temperature (Tg)

[0123] The point at which the polyimide films manufactured according to the examples and comparative examples rapidly expanded was measured as the on-set point using DMA at 5°C / min. The results are shown in Table 2.

[0124] (2) Thermal decomposition temperature (Td) of 5 wt%

[0125] A TA Q50 model thermogravimetric analysis was used, and the polyimide films manufactured according to the examples and comparative examples 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.

[0126] (3) Modulus (Young's modulus)

[0127] The polyimide films manufactured according to the examples and comparative examples were prepared by preparing 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 3 below.

[0128] (4) Tensile strength

[0129] The tensile strength of polyimide films manufactured according to the examples and comparative examples was measured using an Instron 5564 UTM device from INSTRON, using samples measuring 400 mm in length and 10 mm in width at a speed of 20 mm / min. The average of 10 samples was calculated. The results are shown in Table 3 below.

[0130] (5) Elongation

[0131] The elongation of polyimide films according to the examples and comparative examples was measured under room temperature conditions using an Instron 5564 UTM device from INSTRON according to the ASTM D882 method. The results are shown in Table 3 below.

[0132] Classification Tg (℃) Td 5wt% (℃) Example 5-1 332 533 Example 5-2 330 495 Example 5-3 32 5516 Example 6-1 32 6516 Example 6-2 31 8510 Example 7-1 32 0 506 Example 7-2 31 2 500 Example 8-2 31 1 501 Comparative Example 9 32 5529 Comparative Example 10 331 533 Comparative Example 12 310 486 Comparative Example 132 94 480 Comparative Example 14 312 487 Comparative Example 152 94 480 Comparative Example 162 95 480

[0133] ClassificationModulus (Gpa)Tensile strength (Mpa)Elongation (%)Example 5-13.971535.26Example 5-23.421355.41Example 5-33.661265.46Example 6-13.511215.36Example 6-23.451195.37Example 7-13.031124.44Example 7-23.581304.82Example 8-23.251284.25Comparative Example 93.731355.24Comparative Example 102.41954.55Comparative Example 123.011215.07Comparative Example 163.011085.56

[0134] According to Table 2, it was found that the polyimide films manufactured according to Examples 5-1 to 7-2 and 8-2 had similar or improved glass transition temperatures (Tg 310°C or higher) and thermal decomposition temperatures (Td 5 wt% 495°C or higher) compared to Comparative Examples 9, 10 and 12 to 16.

[0135] Specifically, the heat resistance characteristics of the polyimide film according to Example 5-1 were the best, and through this, it was found that it is desirable to add the additive CDI so as to be substantially equimolar with the polyamic acid. In addition, although both Examples 5-1 to 5-3, which were randomly polymerized, and Examples 6-1 to 6-2, which were block polymerized, had excellent heat resistance characteristics, it was found that the heat resistance characteristics of Examples 5-1 to 5-3, in which the polymerization units were randomly arranged, were better. That is, it was confirmed that the present invention has excellent heat resistance characteristics (Tg and Td 5 wt %) even when CDI is used and purification, filtration, and drying processes are not performed.

[0136] In addition, according to Table 3, it was found that the polyimide films manufactured according to Examples 5-1 to 7-2 and 8-2 had similar or improved modulus (3.03 GPa or more), tensile strength (110 MPa) and elongation (4.2% or more) compared to Comparative Examples 9, 10, 12 and 16.

[0137] Specifically, it was confirmed that the polyimide film of Example 5-1 had improved mechanical properties such as Young's modulus, strength, and elongation compared to Comparative Examples 9 and 10. That is, as mentioned in Experimental Example 1, it was found that the present invention can produce a polyimide film with excellent mechanical properties using CDI without performing purification, filtration, and drying processes.

[0138] Therefore, the present invention can achieve process simplification by using the additive CDI, thereby omitting the purification, filtration, and drying processes, and can manufacture a polyimide film having excellent heat resistance characteristics (Tg and Td 5 wt %) and mechanical properties.

[0139]

[0140] 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 readily apparent to those skilled in the art.

Claims

1. (a) a step of manufacturing polyamic acid by polymerizing an ionic acid monomer and a diamine monomer; and (b) a step of producing a soluble polyimide by reacting carbonyl diimidazole with the polyamic acid; A method for producing polyimide, wherein the above-mentioned available polyimide is in the form of a varnish.

2. In paragraph 1, A method for producing polyimide, wherein the above method for producing polyimide does not perform purification, filtration and drying steps after step (b).

3. In paragraph 1, A method for producing a polyimide, wherein 0.5 to 1.5 molar equivalents of the above carbonyl diimidazole are reacted with 1 molar equivalent of the above polyamic acid.

4. In paragraph 1, A method for producing polyimide, wherein the above step (b) is performed at a temperature of 20 to 60°C.

5. In paragraph 1, A method for producing polyimide, wherein the above step (b) is performed for 0.5 to 5 hours.

6. In paragraph 1, A method for producing a polyimide, wherein the polymerization in step (a) is random polymerization or block polymerization.

7. In paragraph 1, A method for producing a polyimide, wherein the above dianhydride monomer comprises at least one selected from the group consisting of pyromellitic dianhydride (PMDA), 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA), oxydiphthalic dianhydride (ODPA), 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (6FDA), biphenyltetracarboxylic dianhydride (BPDA), 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride (DSDA), and 2,2-bis(4-(3,4-dicarboxyphenoxy)phenyl)propane dianhydride.

8. In paragraph 1, A method for producing a polyimide, wherein the above diamine monomer comprises at least one selected from the group consisting of 4,4'-methylenebis(2,6-diethylaniline) (MEDA), 2,4-diaminotoluene (2,4-TDA), 2,6-diaminotoluene (2,6-TDA), m-phenylenediamine (m-PD), p-phenylenediamine (p-PD), 3,3''-diaminodiphenylsulfone (3,3''-DDS), 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (6FAP), 3,5-diethyltoluene-2,6-diamine, 3,5-diethyltoluene-2,4-diamine, and 4,4'-methylenebis(2-ethyl-6-methylaniline) (MEMA).

9. In paragraph 8, A method for producing a polyimide, wherein the content of 4,4'-methylenebis(2,6-diethylaniline) (MEDA) among the total diamine monomers is greater than 0 mol% and less than or equal to 50 mol%.

10. In paragraph 8, A method for producing a polyimide, wherein the content of 2,4-diaminotoluene (2,4-TDA) among the total diamine monomers is 50 mol% or more and less than 100 mol%.

11. In paragraph 1, A method for producing a polyimide, wherein the above-mentioned available polyimide exhibits solubility properties in an organic solvent for a solid content of 15 wt% or more.

12. In paragraph 1, A method for producing a polyimide, wherein the above-mentioned available polyimide has a 5 wt% thermal decomposition temperature (Td) of 485°C or higher.

13. In paragraph 1, A method for manufacturing a polyimide, wherein the above-mentioned available polyimide has a glass transition temperature (Tg) of 300°C or higher.

14. In paragraph 1, The above available polyimide Modulus is 3.0 GPa or more, Tensile strength is 110 MPa or more, A method for manufacturing polyimide having an elongation of 5% or more.

15. A soluble polyimide manufactured according to a method for manufacturing a polyimide according to any one of claims 1 to 14.

16. Polyamic acid containing an dianhydride monomer and a diamine monomer as polymerization units; and Carbonyl diimidazole; A composition for producing an available polyimide comprising:

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