WO2015190645A1 - Method for preparing polyimide using water as dispersion medium and method for recovering water - Google Patents

Abstract

The present invention relates to a method for preparing a polyimide using water as a dispersion medium for reaction and, more particularly, to a method for preparing a polyimide by dispersing a dianhydride compound and a diamine compound in water and reacting the compounds in a pressurized state within a sealed pressure vessel under temperature conditions of 5°C or above. The present invention also provides a method for recovering water by discharging vapor generated during the preparation of the polyamide and cooling and condensing the vapor. By using water as a dispersion medium, the method according the present invention does not generate organic-based waste fluid and is thus environmentally-friendly, reduces production costs, minimizes residual solvents after drying and thus does not have a problem that physical properties are degraded due to the residual solvents, and is advantageous in that the reaction temperature is lower, reaction steps are reduced, and the reaction time is shortened compared to conventional methods. Since water can be recovered after the reaction is completed, the method also allows recycling of water and is thus economical and very environmentally-friendly. In addition, the polyimide prepared by the method according to the present invention has the advantage of increasing thermal stability and molecular weight compared to polyimides prepared by conventional synthesis methods.

Description

Method for producing polyimide using water as a dispersion medium and method for recovering water

The present invention relates to a method for producing polyimide, and more particularly, by using water as a dispersion medium, organic waste liquid does not occur, which is environmentally friendly, low in manufacturing cost, and minimizes residual solvent after drying. It relates to a method for producing polyamide used as a method and to recover water used as a dispersion medium.

High heat-resistant polymer materials are essential materials for miniaturization, high performance, and high reliability of products according to the development of advanced technology. In the form of film, molded products, textiles, paints, adhesives, and composites, aerospace, aviation, electricity / electronics, automobiles And a wide range of industrial fields such as precision instruments. Among them, films have been mainly developed as electronic materials and packaging materials, and they are classified into general purpose engineering plastic films centered on polyester films, and are used as flexible circuit boards because of their high heat resistance, chemical resistance and electrical properties. It can be divided into a polyimide film, an aramid film having high elastic properties, a fluorine film, a super-engineering thermoplastic film, and the like, and these may be classified into special films for various purposes according to heat resistance and use. The use of these materials is steadily increasing with the development of the IT industry.

The polyimide in the material has excellent mechanical strength, chemical resistance, weather resistance and heat resistance based on the chemical stability of the imide ring. In addition, it is easy to synthesize, can make a thin film, and has the advantage that no crosslinking group for curing. In addition, due to its excellent electrical properties, it has been spotlighted as a high functional polymer material in the field of microelectronics and optics.

More specifically, the use of the polyimide is used as a surface protection material such as a flexible circuit board or an integrated circuit, or as a base resin, to form an interlayer insulating film or a protective film of a semiconductor ultrafine circuit. In recent years, weight reduction and miniaturization of products have been important in the display field. However, glass substrates that are currently used have a disadvantage of being heavy, broken and difficult to process continuously. For this reason, research is being conducted to utilize a polyimide substrate having a merit of being lightweight, flexible, and continuous process in place of a glass substrate for flexible display fabrication.

There are largely four methods for producing a polyimide reported to date. As a first method, a polyamic acid precursor is first synthesized by the reaction of dianhydride and diamine, and the second step is to prepare a polyimide by imidizing the polyamic acid in the next step.

In the above manufacturing method, the first step is a step of preparing a polyamic acid. Diane hydride is added to a reaction solution in which diamine is dissolved to form a polyamic acid by ring opening and polyaddition reaction. The reaction solvent to be used is N, N - dimethylacetamide, N, N - a polar organic solvent such as dimethylformamide, N- methyl-2-pyrrolidone are mainly used.

In the second step, the polyamic acid prepared in step 1 is imidized by dehydration and ring-closure reaction by chemical or thermal method to synthesize polyimide.

The chemical imidization method is a method in which a chemical dehydrating agent represented by acid anhydrides such as acetic anhydride and tertiary amines such as pyridine are added to a solution of polyamic acid as a precursor and heated at 160 ° C or higher. On the other hand, the thermal imidization method is a method of thermally imidating by applying a solution of polyamic acid as a precursor to a substrate, evaporating the solvent and heating to 250 ~ 350 ℃ without chemical dehydrating agent and catalyst.

In the production of polyimide using the polyimide production method described above, especially when aliphatic diamine is used, the high molecular weight of the amino group of the diamine is high, so that the diamine forms a salt with amic acid instead of participating in the polymerization reaction. Polyimide of is not obtained. Therefore, fully aliphatic polyimide and partially aliphatic polyimide synthesized using aliphatic diamine are generally low in molecular weight and thus poor in mechanical properties.

The second method uses a N-silylation reaction to increase the molecular weight of the polyimide by preventing the formation of amic acid and diamine salts, which is a disadvantage of the first method. Diamine and chlorotrimethylsilane are reacted to synthesize diamine protected with N-trimethylsilyl group, and then polyimide is synthesized using the protected diamine via polyamic acid protected with N-trimethylsilyl group. In this method as well, organic solvents are used for the synthesis of diamines protected with N-trimethylsilyl groups and for the synthesis of polyimides.

The disadvantage of the N-silylation method is that the chlorotrimethylsilane reagent for synthesizing N-trimethylsilyl group-protected aliphatic diamine is expensive and very sensitive to moisture, which makes it difficult to handle. The disadvantage is that it becomes more complex than the first synthesis method.

The third method is to use meta-cresol as a solvent, add meta-cresol as a solvent, add dianhydride and diamine, and send the reaction for a long time by raising the temperature step by step.

The method using the meta-cresol has the disadvantage that the reaction time is longer than 64 hours and the reaction time is long and still has an unsatisfactory molecular weight and the drying time is long and the irritating smell is severe because of the use of the meta-cresol solvent.

The fourth method is an in-situ silylation method, and the second method, N-silylation method, is intended to solve the disadvantages sensitive to moisture. Diamine was added to the reactor containing the organic solvent, followed by chlorotrimethylsilane at low temperature, followed by dianhydride to synthesize polyamic acid protected with N-trimethylsilyl group, followed by chemical imidization or thermal imidization reaction. Synthesize polyimide.

Disadvantages of the in-situ silylation synthesis method are long reaction times, improved molecular weight but high chlorotrimethylsilane reagents, high imidization catalysts, long drying times and protecting groups in polyamic acids protected with N-trimethylsilyl groups. In order to synthesize the removed polyamic acid, a reprecipitation process may be required, and even in the case of an all-aliphatic polyimide, sufficient transparency cannot be obtained.

Regarding the above polyimide synthesis method using an organic solvent, a full aromatic polyimide synthesis method is disclosed in High Performance Polymers, 15: 269-279, 2003 and High Performance Polymers, 18: 31-44, 2006. In this method, dianhydride is first added to water and heated at reflux to hydrolyze to synthesize tetracarboxylic acid. Diamine is added to this solution to form a salt precipitate of tetracarboxylic acid and diamine. The mixture of sediment and water is then transferred to the glassliner of the pressure device, followed by the operation of bleeding air and filling with nitrogen several times to make a nitrogen atmosphere. Nitrogen was added to the mixture to raise the pressure to 20 psi and then heated at 135 ° C. for 1 hour and 180 ° C. for 2 hours. The resulting product is filtered and washed with water to obtain a powder, which is in turn washed with hot water, methanol, acetone and dichloromethane. The obtained product is placed in a vacuum oven and heated at 40 ° C. overnight to obtain a polyimide powder. However, this method has a disadvantage of being cumbersome and costly to manufacture due to multiple synthesis steps.

On the other hand, the solvent used in the normal polyimide manufacturing process is often difficult to recycle because it is mixed with impurities even if it must be removed or recovered. In this regard, there is a patent related to a system for circulating distilled water, but in this case, a filter part for filtering raw water, a filter part for adsorption filtration of filtered water, a sewage bucket for recovering sewage generated after the reaction, and a filter part for filtering the same. In addition, since it consists of a device of a very complicated structure such as a sterilizer to sterilize it, there is a disadvantage that is not economical in terms of cost.

[Preceding technical literature]

[Patent Documents] Korean Patent 1,004,096, Korean Patent 449,798, Korean Patent 0717377, US Patent 7,053,168, International Patent Application 2012-091231 (WO2012 / 91231), International Patent Application PCT / JP2011 / 066144 ( WO 2012/008543), Korean Patent No. 826,294

[Non-Patent Document] Polymer Science and Technology Vol. 24, No. 1, pp. 3-9, Jin Young Park et al., Preparation and application of polyimide based particles; Macromolecules 2002, 35, 2277-2281 Yasufumi Watanabe, Yoshimasa Sakai, Yuji Shibasaki, Shinji Ando, and Mitsuru Ueda Synthesis of Wholly Alicyclic Polyimides from N-Silylated Alicyclic Diamines and Alicyclic Dianhydrides; Journal of photopolymer Science and Technology Volume 16, Number 2 (2003) Youshiyuki Oishi, Shu Ondera, Jan Oravec, Kunio Mori, Shinji Ando, Yoshiharu Terui, and kazuhiko Maeda Synthesis of Fluorine-Containing wholly Alicyclic Polyimide by In Situ Silylation Method; Macromolecules 2009, 42, 5892-5894 Dulce M. Munoz, Mariola Calle, Jose G. de la Campa, Javier de Abajo, and Angel E. Lozano An Improved Method for Preparing Very High Molecular Weight Polyimides; Macromolecular Research, Vol. 15, No. 2, pp 114-128 (2007) Anu Stella Mathews, Il Kim, and Chang-Sik Ha Synthesis, Characterization, and Properties of Fully Aliphatic Polyimides and Their Derivatives for Microelectronics and Optoelectronics Applications; High Performance Polymers, 15: 269-279, 2003 John Chiefari, Buu Dao, Andrew M. Groth and Jonathan H. Hodgkin Water as Solvent in Polyimide Synthesis: Thermoset and Thermoplastic Examlpes; High Performance Polymers, 18: 31-44, 2006 John Chiefari, Buu Dao, Andrew M. Groth and Jonathan H. Hodgkin Water as Solvent in Polyimides Synthesis II: Processable Aromatic Polyimide

The present invention proposes a new production method using water as a dispersion medium in order to solve problems such as environmental pollution, an increase in manufacturing cost, residual solvent, and the like caused by using an organic solvent in a conventional method for producing polyimide. In addition, compared to the conventional polyimide manufacturing method, the reaction temperature and time, the reaction reagents, the synthesis step is reduced to propose a new manufacturing method which is very simple and reduced manufacturing costs. In addition, the present invention is to provide a polyimide having a very high molecular weight and excellent mechanical properties compared to the polymer prepared by the conventional synthesis method having a high thermal properties.

In addition, the present invention is to provide a method for recovering the water used as a dispersion medium.

The present invention provides a method for preparing a polyimide by dispersing a dianhydride compound and a diamine compound in water and then reacting in a sealed pressure vessel under a temperature condition of 5 ° C. or higher and producing a polyimide. Compared to the polyimide produced by the conventional synthesis method, there is no problem of residual solvent and very high molecular weight. can do. In addition, by easily recovering and recycling the water used in the reaction, more economical manufacturing is possible and resources can be saved to reduce environmental pollution.

In the present invention, by using water as the reaction dispersion medium in the production of polyimide, there is an advantage that the organic waste solution does not occur, which is environmentally friendly, inexpensive to manufacture, and the residual solvent is minimized after drying so that there is no problem such as deterioration of physical properties due to the residual solvent. In addition, by easily recovering and recycling the water used in the reaction, the purchase cost of the water is reduced to reduce the polyimide manufacturing cost, thereby making it more economical and saving resources to reduce environmental pollution. In addition, the present invention has the advantage that the reaction temperature is low, the reaction step is short and the reaction time is short compared to the conventional manufacturing method by applying a pressure in the production of polyimide, the prepared polyimide is a polyimide prepared by the conventional method Compared with the thermal stability, the molecular weight is large. In addition, there is an advantage that can be easily prepared a fully aromatic polyimide, partially aliphatic polyimide and fully aliphatic polyimide.

1 is an FT-IR spectrum of a pyromellitic dianhydride and a 4,4'-oxydianiline polyimide according to Example 1; 2 is an FT-IR spectrum of 1,2,4,5-cyclocyclotetracarboxylic dianhydride and 4,4′-oxydianiline polyimide according to Example 2; 3 is an FT-IR spectrum of 1,2,4,5-cyclocyclotetracarboxylic dianhydride and 4,4-methylenebis (2-methylcyclohexylamine) polyimide according to Example 3; 4 is an FT-IR spectrum of 5.9605 g of 1,2,4,5-cyclocyclotetracarboxylic dianhydride and 4,4-methylenebis (2-methylcyclohexylamine) polyimide according to Example 5; 5 is an FT-IR spectrum of 1,2,3,4-cyclopentane-tetracarboxylic dianhydride and 3- (aminomethyl) -3,5,5-trimethylcyclohexanamine polyimide according to Comparative Example 1 FIG. ; 6 is an FT-IR spectrum of 3- (aminomethyl) -3,5,5-trimethylcyclohexanamine and 3- (aminomethyl) -3,5,5-trimethylcyclohexaneamine polyimide according to Comparative Example 2. FIG. ; 7 is an FT-IR spectrum of 3- (aminomethyl) -3,5,5-trimethylcyclohexanamine and 3- (aminomethyl) -3,5,5-trimethylcyclohexanamine polyimide according to Comparative Example 3. ; 8 is an FT-IR spectrum of 1,2,3,4-cyclopentane-tetracarboxylic dianhydride and 3- (aminomethyl) -3,5,5-trimethylcyclohexanamine polyimide according to Comparative Example 4. FIG. to be.

The present invention is to prepare a polyimide by dispersing the dianhydride compound and the diamine compound in water and then placing the mixture in a pressure vessel and sealing the reaction under a pressure applied in the reaction temperature range of 5 ℃ to 400 ℃ It is a manufacturing method of a polyimide.

More specifically, the present invention comprises the steps of: a) dispersing the dianhydride compound and the diamine compound in water; And b) sealing the dispersion in a pressure vessel, and reacting the dianhydride compound with the diamine compound at a temperature of 5 ° C. to 400 ° C. and pressurization conditions.

The present invention also provides a method for preparing a hydride compound comprising: a) dispersing a dianhydride compound and a diamine compound in water; b) after the dispersion is put in a pressure vessel and sealed, reacting the dianhydride compound and the diamine compound at a temperature of 5 ℃ to 400 ℃ and pressurized conditions; And (c) recovering water by cooling and condensing water vapor generated in step (b) from the pressure vessel after the completion of step (b).

In one aspect according to the invention, steam may occur during step (b), and water may be recovered by cooling and condensing the steam, wherein the water may be distilled water.

In one aspect according to the present invention, the polyimide prepared according to the method may be a fully aromatic polyimide, a partially aliphatic polyimide or a fully aliphatic polyimide.

Dianehydride compounds that can be used in the present invention are substituted or unsubstituted aromatic or aliphatic dianhydride compounds.

In one embodiment according to the present invention, a substituted or unsubstituted aromatic or aliphatic dianhydride represented by the following formula (1) may be used as the dianhydride.

<Formula 1>

R ₁ in Formula 1,

It may be selected from the group consisting of.

In one embodiment according to the present invention, the dianhydride compound may use one or two or more dianhydrides.

In one aspect according to the invention, the diamine may be substituted or unsubstituted aromatic or aliphatic diamine.

In one embodiment according to the present invention, the diamine may be a substituted or unsubstituted aromatic or aliphatic diamine represented by the following formula (2).

<Formula 2>

H ₂ NR ₂ -NH ₂

R ₂ in Formula 2,

It may be selected from the group consisting of. And, x may be an integer satisfying 1≤x≤50, preferably an integer satisfying 3≤x≤20. In the above formula, n is a natural number in the range of 1 to 20, W, X, Y are each an alkyl group or an aryl group having 1 to 30 carbon atoms, and Z is selected from an ester group, an amide group, an imide group, and an ether group.

In one aspect according to the present invention, the diamine compound may use one kind or two or more kinds of diamines.

In one embodiment according to the present invention, water may be water in any state, such as distilled water, deionized water, tap water.

In one embodiment according to the invention, the reaction temperature preferably has a range of 5 ℃ to 400 ℃. More specifically, it is 20 degreeC-250 degreeC. If the reaction temperature is less than 5 ℃ the reaction rate is too slow to make polyimide practically difficult, if the temperature exceeds 400 ℃ may cause thermal decomposition of the monomer or polymer.

In one embodiment according to the invention, the reaction time of step b) is preferably in the range of 5 minutes to 5 days. More specifically, the reaction may be performed for 10 minutes to 10 hours, even more specifically for 10 minutes to 5 hours. If the reaction time is less than 5 minutes, the reaction does not proceed well, if more than 5 days may cause hydrolysis of the polymer.

In one aspect according to the invention, the pressing conditions of step b) is preferably in the range of 1 bar to 1000 bar. More specifically, it is 1 bar to 500 bar. If the reaction pressure is less than 1 bar, the reaction does not proceed well, and if it is more than 1000 bar may cause damage to the reaction vessel.

In one aspect according to the present invention, the method of pressurizing is composed of one or two or more methods selected from the method of forming water vapor pressure in the pressure vessel, injecting an inert gas into the pressure vessel, or compressing the pressure vessel. do. Wherein the inert gas is at least one gas selected from the group consisting of nitrogen, argon, helium, neon, krypton and xenon.

In one embodiment according to the invention, the reaction product of step b) may further comprise the step of filtration and drying to obtain a polyimide.

In still another aspect according to the present invention, there is provided a polyimide film prepared by dissolving a polyimide prepared according to the above method in an organic solvent and applying the solution to a substrate. Here, as the organic solvent, N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, N-vinylpyrrolidone, N-methylcaprolactam, dimethyl sulfoxide Seed, tetramethylurea, pyridine, dimethylsulfone, hexamethylsulfoxide, meta-cresol, gamma-butyrolactone, ethylcellosolve, butylcellosolve, ethylcarbitol, butylcarbitol, ethylcarbitol acetate, butyl One or more solvents selected from the group consisting of carbitol acetate, ethylene glycol, ethyl lactate, butyl lactate, cyclohexanone and cyclopentanone can be used. Also here, the concentration of polyimide in the solution may be from 1 to 90 wt%. If the solubility of the polyimide is low and it is difficult to prepare a polyimide solution, the polyamic acid is dissolved in an organic solvent and applied to a substrate, thereby producing a polyimide film by thermal imidization.

In one aspect according to the present invention, a small amount of an additive such as a wetting enhancer may be added if necessary for the polyimide or polyamic acid solution. The additive is preferably added 0.001 to 5% by weight based on the polyimide or polyamic acid. More specifically, 0.01 to 2% by weight can be added.

In one aspect according to the present invention, as a coating method of a polyimide or polyamic acid composition for forming a polyimide film, spin coating method, dipping method, flexo printing method, inkjet printing method, spraying method, potting method, screen A printing method or the like can be used. Among these methods, as a method for obtaining a thick film of 10 µm or more, the bar coat coating method, the slit coating coating method, the screen printing method, the spin coating method and the like are preferable.

In another aspect according to the present invention, there is provided a molded article formed by compression molding, injection molding, slush molding, blow molding, extrusion molding or spinning method of the polyimide prepared according to the above method.

Polyimide synthesized by the manufacturing method of the present invention is a wide range of industries such as space, aviation, electrical / electronics, semiconductors, transparent / flexible displays, liquid crystal alignment film, automotive, precision equipment, packaging, medical materials, separators, fuel cells, secondary batteries It can be used in the field.

Hereinafter, the present invention will be described in more detail with reference to Examples and Experimental Examples. However, the following Examples and Experimental Examples are intended to help the understanding of the present invention and are not intended to limit the scope of the present invention thereto.

Example 1-1 Preparation of Whole Aromatic Polyimide

22.6 g of pyromellitic dianhydride and 21.13 g of 4,4'-oxydianiline were dispersed in 200 mL of distilled water. The reaction solution was transferred to a 500 mL pressure vessel equipped with a stirrer, a nitrogen injector, and a temperature controller. Substitute the air of the pressure vessel with nitrogen gas, adjust the temperature to 135 ° C, and stir for 3 hours at a pressure of 60 bar. Mead was synthesized. After the reaction was completed, the water vapor was discharged from the pressure vessel and passed through the transfer tube and the cooler sequentially to cool and condense the steam to recover about 180 mL of distilled water. Nuclear magnetic resonance analysis (NMR) of the recovered distilled water confirmed that no impurities were present. In the infrared absorption spectrum of the synthesized polymer (FIG. 1), the C = O absorption band of the imide group was observed at 1775 cm ⁻¹ and 1715 cm ⁻¹ , and the CN absorption band of the imide group was observed at 1367 cm ⁻¹ .

Example 1-2. Preparation of Whole Aromatic Polyimide

11.106 g of 4,4 '-(hexafluoroisopropylidene) dianiline and 8.005 g of 2,2'-bis (trifluoromethyl) -4,4'-diaminobiphenyl were dispersed in 200 mL of distilled water. The reaction solution was transferred to a 500 mL pressure vessel equipped with a stirrer, a nitrogen injector, and a temperature controller. Substitute the air of the pressure vessel with nitrogen gas, adjust the temperature to 135 ° C, and stir for 3 hours at a pressure of 60 bar. Mead was synthesized. After the reaction was completed, the water vapor was discharged from the pressure vessel and passed through the transfer tube and the cooler sequentially to cool and condense the steam to recover about 180 mL of distilled water. Nuclear magnetic resonance analysis (NMR) of the recovered distilled water confirmed that no impurities were present. In the infrared absorption spectrum of the synthesized polymer, the C = O absorption band of the imide group was observed at 1780 cm ⁻¹ and 1718 cm ⁻¹ , and the CN absorption band of the imide group was observed at 1369 cm ⁻¹ .

Example 2-1: Preparation of partially alicyclic polyimide

5.604 g of 1,2,4,5-cyclohexanetetracarboxylic dianhydride and 5.006 g of 4,4'-oxydianiline were dispersed in 200 mL of distilled water. The reaction solution was transferred to a 500 mL pressure vessel equipped with a stirrer, a nitrogen injector, and a temperature controller. Substitute the air of the pressure vessel with nitrogen gas, adjust the temperature to 135 ° C, and stir for 3 hours at a pressure of 60 bar. Mead was synthesized. After the reaction was completed, the water vapor was discharged from the pressure vessel and passed through the transfer tube and the cooler sequentially to cool and condense the steam to recover about 180 mL of distilled water. Nuclear magnetic resonance analysis (NMR) of the recovered distilled water confirmed that no impurities were present. In the infrared absorption spectrum of the synthesized polymer (FIG. 2), the C = O absorption band of the imide group was observed at 1778 cm ⁻¹ and 1716 cm ⁻¹ , and the CN absorption band of the imide group was observed at 1365 cm ⁻¹ .

Example 2-2: Preparation of partially alicyclic polyimide

8.3565 g of 4,4 '-(hexafluoroisopropylidene) dianiline and 5.604 g of 4,4'-oxydianiline were added to 200 mL of distilled water and dispersed. The reaction solution was transferred to a 500 mL pressure vessel equipped with a stirrer, a nitrogen injector, and a temperature controller. Substitute the air of the pressure vessel with nitrogen gas, adjust the temperature to 135 ° C, and stir for 3 hours at a pressure of 60 bar. Mead was synthesized. After the reaction was completed, the water vapor was discharged from the pressure vessel and passed through the transfer tube and the cooler sequentially to cool and condense the steam to recover about 180 mL of distilled water. Nuclear magnetic resonance analysis (NMR) of the recovered distilled water confirmed that no impurities were present. In the infrared absorption spectrum of the synthesized polymer, the C = O absorption band of the imide group was observed at 1779 cm ^-1 and 1718 cm ^-1 , and the CN absorption band of the imide group was observed at 1362 cm ^-1 1.

Example 2-3: Preparation of partially alicyclic polyimide

5.604 g of 1,2,4,5-cyclohexanetetracarboxylic dianhydride and 5.006 g of 4,4'-oxydianiline were dispersed in 200 mL of distilled water. The reaction solution was transferred to a 500 mL pressure vessel equipped with a stirrer, a nitrogen injector, and a temperature controller. Substitute the air of the pressure vessel with nitrogen gas, adjust the temperature to 180 ° C, and stir for 10 minutes at a pressure of 100 bar. Mead was synthesized. After the reaction was completed, the water vapor was discharged from the pressure vessel and passed through the transfer tube and the cooler sequentially to cool and condense the steam to recover about 180 mL of distilled water. Nuclear magnetic resonance analysis (NMR) of the recovered distilled water confirmed that no impurities were present. In the infrared absorption spectrum of the synthesized polymer, the C = O absorption band of the imide group was observed at 1778 cm ⁻¹ and 1714 cm ⁻¹ , and the CN absorption band of the imide group was observed at 1365 cm ⁻¹ .

Example 2-4: Preparation of partially alicyclic polyimide

5.604 g of 1,2,4,5-cyclohexanetetracarboxylic dianhydride and 5.006 g of 4,4'-oxydianiline were dispersed in 200 mL of distilled water. The reaction solution was transferred to a 500 mL pressure vessel equipped with a stirrer, a nitrogen injector, and a temperature controller. Substitute the air of the pressure vessel with a nitrogen gas, adjust the temperature to 50 ° C., and stir at a pressure of 1.3 bar for 3 days. Mead was synthesized. After the reaction was completed, the water vapor was discharged from the pressure vessel and passed through the transfer tube and the cooler sequentially to cool and condense the steam to recover about 180 mL of distilled water. Nuclear magnetic resonance analysis (NMR) of the recovered distilled water confirmed that no impurities were present. In the infrared absorption spectrum of the synthesized polymer, the C = O absorption band of the imide group was observed at 1776 cm ^{−1 and} 1716 cm ⁻¹ , and the CN absorption band of the imide group was observed at 1364 cm ⁻¹ .

Example 2-5: Preparation of partially alicyclic polyimide

5.604 g of 1,2,4,5-cyclohexanetetracarboxylic dianhydride and 5.006 g of 4,4'-oxydianiline were dispersed in 200 mL of distilled water. The reaction solution was transferred to a 500 mL pressure vessel equipped with a stirrer, a nitrogen injector, and a temperature controller. Then, a high pressure nitrogen gas was injected into the pressure vessel to form a pressure of 50 bar, and the temperature was adjusted to 10 ° C., followed by stirring for 5 days. To synthesize a polyimide. After the reaction was completed, the water vapor was discharged from the pressure vessel and passed through the transfer tube and the cooler sequentially to cool and condense the steam to recover about 180 mL of distilled water. Nuclear magnetic resonance analysis (NMR) of the recovered distilled water confirmed that no impurities were present. In the infrared absorption spectrum of the synthesized polymer, the C = O absorption band of the imide group was observed at 1775 cm ^-1 and 1717 cm ^-1 , and the CN absorption band of the imide group was observed at 1364 cm ^-1 .

Example 3 Preparation of Full Cyclic Polyimide

5.9605 g of 1,2,4,5-cyclohexanetetracarboxylic dianhydride and 5.604 g of 4,4-methylenebis (2-methylcyclohexylamine) MMCA were added to 200 mL of distilled water and dispersed. The reaction solution was transferred to a 500 mL pressure vessel equipped with a stirrer, a nitrogen injector, and a temperature controller. Substitute the air of the pressure vessel with nitrogen gas, adjust the temperature to 135 ° C, and stir for 3 hours at a pressure of 60 bar. Mead was synthesized. After the reaction was completed, the water vapor was discharged from the pressure vessel and passed through the transfer tube and the cooler sequentially to cool and condense the steam to recover about 180 mL of distilled water. Nuclear magnetic resonance analysis (NMR) of the recovered distilled water confirmed that no impurities were present. In the infrared absorption spectrum of the synthesized polymer (FIG. 3), the C = O absorption band of the imide group was observed at 1773 cm ⁻¹ and 1712 cm ⁻¹ , and the CN absorption band of the imide group was observed at 1368 cm ⁻¹ .

Example 4 Preparation of Thin Films of Polyimide

Prior to thin film fabrication, a cleaning process of a silicon wafer to be used as a substrate was performed. This process removes various contaminants such as particles, organic contaminants, metal contaminants and natural oxide films. Contaminants were removed by heating at 120 ° C. for 3 hours using a Piranha solution in which sulfuric acid and hydrogen peroxide were mixed at a ratio of 7: 3. Thereafter, 0.20 g of the synthesized polyimide was dissolved in 2.0 mL of N, N-dimethylacetamide or N, N-dimethylformamide, filtered through a microfilter having a pore size of 0.2 μm, and then washed at 500 rpm. A polyimide thin film was prepared by annealing after removing the solvent after performing a two-stage spin coating of 10 seconds and 1500 rpm for 50 seconds. As another method, a polyimide thin film was prepared by casting a polyimide solution on a substrate and removing the solvent and annealing.

Example 5 Recycling and Recovery of Water

5.961 g of 1,2,4,5-cyclocyclohexanedicarboxylic dianhydride and 5.604 g of 4,4-methylenebis (2-methylcyclohexylamine) were added and dispersed in 200 mL of distilled water recovered in Example 3. The reaction solution was transferred to a 500 mL pressure vessel equipped with a stirrer, a nitrogen injector, and a temperature controller. Substitute the air of the pressure vessel with nitrogen gas, adjust the temperature to 135, and stir at a pressure of 60 bar for 3 hours. Was synthesized. After the reaction was completed, the water vapor was discharged from the pressure vessel and passed through the transfer tube and the cooler sequentially to cool and condense the steam to recover about 180 mL of distilled water. Nuclear magnetic resonance analysis (NMR) of the recovered distilled water confirmed that no impurities were present. In the infrared absorption spectrum of the synthesized polymer (FIG. 4), the C = O absorption band of the imide group was observed at 1785 cm ⁻¹ and 1718 cm ⁻¹ , and the CN absorption band of the imide group was observed at 1394 cm ⁻¹ .

Comparative Example 1 Preparation of Two Stages of Battery Cyclic Polyimide

4.2028 g (2.00 mmol) of 1,2,3,4-cycloclotane-tetracarboxylic dianhydride was added to 10 mL of N-methyl-2-pyrrolidone in a 50-mL two-neck round-bottom flask substituted with nitrogen gas. And 3.406 g (2.00 mmol) of 3- (aminomethyl) -3,5,5-trimethylcyclohexanamine were added and reacted at room temperature for 24 hours.

As a chemical imidization method, 5 mL of acetic anhydride and 3 mL of pyridine were added to the solution, and the mixture was refluxed at 170 ° C. for 5 hours, cooled to room temperature, and reprecipitated using an excess of ice water. After washing with 100 mL of water and 100 mL of methyl alcohol, vacuum drying was performed to synthesize an all-cyclic polyimide.

As a thermal imidization method, a polyimide was obtained by heating the synthesized polyamic acid solution step by step in an oven or a hot plate at 250 to 300 ° C. and heating it for 12 hours. In the infrared absorption spectrum of the synthesized polymer (FIG. 5), the C = O absorption band of the imide group at 1774 cm ⁻¹ and 1713 cm ⁻¹ , and the CN absorption band of the imide group at 1368 cm ⁻¹ .

Comparative Example 2: Preparation by N-silylation method of full cyclic polyimide

To synthesize aliphatic diaminopolysiloxane, 25 mL of purified toluene was added to a 100 mL three-necked round bottom flask substituted with nitrogen gas, and 8.515 g (5.00 of 3- (aminomethyl) -3,5,5-trimethylcyclohexanamine was added. mmol) and 1.0864 g (10.0 mmol) of chlorotrimethylsilane were added and reacted at 5 ° C for 30 minutes. 0.5911 g (10.0 mmol) of trimethylamine was slowly added dropwise to this solution. After reacting at 5 ° C. for 2 hours, the reaction mixture was heated up to 60 ° C. for 24 hours, and then dried under vacuum to synthesize aliphatic diaminopolysiloxane. 4.2028 g (2.00 mmol) of 1,2,3,4-cycloclotane-tetracarboxylic dianhydride was added to 10 mL of N-methyl-2-pyrrolidone in a 50-mL two-neck round-bottom flask substituted with nitrogen gas. And aliphatic diaminopolysiloxane (2.00 mmol) synthesized above were added thereto and reacted at room temperature for 24 hours. The synthesized polyimide-siloxane was reprecipitated using distilled water. After filtration and vacuum drying, a polyamic acid was synthesized.

In the chemical imidization method, 5 mL of acetic anhydride and 3 mL of pyridine were added to the solution, refluxed at 170 ° C. for 5 hours, cooled to room temperature, and reprecipitated using an excess of ice water. After washing with 100 mL of water and 100 mL of methyl alcohol, vacuum drying was performed to synthesize an all-cyclic polyimide.

As a method of thermal imidization, a polyimide was obtained by heating the synthesized polyamic acid solution step by step in an oven or a hot plate at 250 to 300 ° C. and heating it for 12 hours. In the infrared absorption spectrum of the synthesized polymer (FIG. 6), the C = O absorption band of the imide group was observed at 1778 cm ⁻¹ and 1714 cm ⁻¹ , and the CN absorption band of the imide group was observed at 1368 cm ⁻¹ .

Comparative Example 3: Preparation of in-situ silylation method of full cyclic polyimide

10 mL of N-methyl-2-pyrrolidone (NMP) was added to a 50-mL two-necked round bottom flask substituted with nitrogen gas, and 3.406 g of 3- (aminomethyl) -3,5,5-trimethylcyclohexanamine 2.00 mmol) was added, and 0.43456 g (4.0 mmol) of chlorotrimethylsilane was added at 0 ° C., followed by stirring for 2 hours. After that, 4.2028 g (2.00 mmol) of 1,2,3,4-cyclopentane-tetracarboxylic dianhydride were added thereto, and the reaction was performed at room temperature for 24 hours. The synthesized diaminopolysiloxane was reprecipitated using distilled water. After filtration and vacuum drying, a polyamic acid was synthesized.

In chemical imidization, 5 mL of acetic anhydride and 3 mL of pyridine were added to the solution, and the mixture was refluxed at 170 ° C. for 5 hours, cooled to room temperature, and reprecipitated using excess ice water. After washing with 100 mL of water and 100 mL of methyl alcohol, vacuum drying was performed to synthesize an all-cyclic polyimide.

As a method of thermal imidization, a polyimide was obtained by heating the synthesized polyamic acid solution step by step in an oven or a hot plate at 250 to 300 ° C. and heating it for 12 hours. In the infrared absorption spectrum of the synthesized polymer (FIG. 7), the C = O absorption band of the imide group was observed at 1776 cm ⁻¹ and 1714 cm ⁻¹ , and the CN absorption band of the imide group was observed at 1367 cm ⁻¹ .

Comparative Example 4: Preparation by Meta-Cresol Synthesis of Battery Cyclic Polyimide

10 mL of meta-cresol was added to a 50 mL-2 neck round bottom flask substituted with nitrogen gas, and 4.2028 g (2.00 mmol) and 3- (aminomethyl 1,2,3,4-cyclopentane-tetracarboxylic dianhydride were added. 3.406 g (2.00 mmol) of 3,5,5-trimethylcyclohexanamine were added thereto, and the reaction was carried out at 100 ° C. for 12 hours at 150 ° C. for 4 hours and at 200 ° C. for 48 hours. The synthesized solution was cooled down to room temperature, washed with 100 mL of meta-cresol and 100 mL of methyl alcohol, filtered, and dried in vacuo at 60 ° C. to synthesize a cycloaliphatic polyimide. 8), the C = O absorption band of the imide group was observed at 1773 cm ^-1 and 1712 cm ^-1 , and the CN absorption band of the imide group was observed at 1367 cm ^-1 .

Table 1

	Example 1-1	Example 1-2	Example 2-1	Example 2-2	Example 2-3	Example 3	Comparative Example 1	Comparative Example 2	Comparative Example 3	Comparative Example 4
Imidization	135 ℃	135 ℃	135 ℃	135 ℃	180 ℃	135 ℃	300 ℃	300 ℃	300 ℃	200 ℃
Reaction time	3 hours	3 hours	3 hours	3 hours	10 minutes	3 hours	36 hours	36 hours	36 hours	64 hours
Use of catalyst	not used	not used	not used	not used	not used	not used	Used	Used	Used	not used
Dispersant or solvent type	water	water	water	water	water	water	NMP	NMP	NMP	m -cresol
Reaction step	1 step	1 step	1 step	1 step	1 step	1 step	2 step	4 step	2 step	1 step
Synthesized Polyimide Pyrolysis Temperature	> 500 ℃	> 500 ℃	490 ℃	490 ℃	490 ℃	450 ℃	403 ℃	407 ℃	428 ℃	434 ℃
Synthesized Polyimide Molecular Weight (GPC)	Not measurable	285941	302381	342514	304513	198726	3054	9567	78265	10213

As shown in Table 1, in Examples 1 to 3 of the present invention, the maximum imidization temperature is lower, the reaction time is shorter, and the reaction step is less than that of Comparative Examples 1 to 4, which is a conventional method. In addition, there is an advantage that the reaction proceeds in water without using a catalyst and an organic solvent. It was confirmed that the polyimide synthesized in Examples 1 to 3 had a higher pyrolysis temperature and a very high molecular weight than the polyimide synthesized in Comparative Examples 1 to 4. In addition, as illustrated in Example 5, it was possible to recover and recycle the water used to prepare the polyimide.

Therefore, the polyimide synthesis method of the present invention is simpler, less expensive to manufacture and environmentally friendly than the conventional method, and the polyimide synthesized by the method of the present invention has a very high molecular weight compared to the polyimide prepared by the conventional synthesis method. It can be seen that it has mechanical properties and high thermal properties.

Polyimide synthesized by the manufacturing method of the present invention is a wide range of industries such as space, aviation, electrical / electronics, semiconductors, transparent / flexible displays, liquid crystal alignment film, automotive, precision equipment, packaging, medical materials, separators, fuel cells, secondary batteries It can be used in the field.

Claims (24)

1. a) dispersing the dianhydride compound and the diamine compound in water; And b) sealing the dispersion in a pressure vessel and reacting the dianehydride compound with the diamine compound at a temperature of 5 ° C. to 400 ° C. and pressurization conditions.
2. a) dispersing the dianhydride compound and the diamine compound in water;

   b) after the dispersion is put in a pressure vessel and sealed, reacting the dianhydride compound and the diamine compound at a temperature of 5 ℃ to 400 ℃ and pressurized conditions; And

   c) recovering water by cooling and condensing the water vapor generated in step b) from the pressure vessel.
3. The method according to claim 1 or 2,

   The polyimide is a wholly aromatic polyimide, a partially alicyclic polyimide or an all-cyclic polyimide.
4. The method according to claim 1 or 2,

   The dianhydride compound is a method for producing a polyimide, characterized in that the substituted or unsubstituted aromatic or aliphatic dianhydride.
5. The method of claim 4, wherein

   Substituted or unsubstituted aromatic or aliphatic dianhydride is a process for producing a polyimide, characterized in that the dianhydride of formula (I):

   <Formula 1>

   

   Where R ₁ is

   

   

   

   It is selected from the group consisting of.
6. The method according to claim 1 or 2,

   A dianhydride compound is a manufacturing method of the polyimide characterized by using 1 type (s) or 2 or more types of dianhydrides.
7. The method according to claim 1 or 2,

   The diamine compound is a method for producing a polyimide, characterized in that the substituted or unsubstituted aromatic or aliphatic diamine.
8. The method of claim 7, wherein

   Substituted or unsubstituted aromatic or aliphatic diamine is a method for producing a polyimide, characterized in that the diamine of the formula (2):

   <Formula 2>

   H ₂ NR ₂ -NH ₂

   Where R ₂ is

   

   

   

   

   

   

   

   Is selected from the group consisting of

   Here, x is an integer satisfying 1≤x≤50, n is a natural number of 1 to 20, W, X, Y are each independently an alkyl group or an aryl group having 1 to 30 carbon atoms, Z is an ester group , Amide group, imide group, and ether group.
9. The method according to claim 1 or 2,

   The diamine compound uses the 1 type, or 2 or more types of diamine, The manufacturing method of the polyimide characterized by the above-mentioned.
10. The method according to claim 1 or 2,

    b) the reaction of the step of producing a polyimide, characterized in that carried out at a temperature condition of 20 ℃ to 250 ℃.
11. The method according to claim 1 or 2,

    The reaction of step b) is a method for producing a polyimide, characterized in that performed for 5 minutes to 5 days.
12. The method according to claim 1 or 2,

    The reaction of step b) is a method for producing a polyimide, characterized in that carried out for 10 minutes to 10 hours.
13. The method according to claim 1 or 2,

    The reaction of step b) is a method for producing a polyimide, characterized in that carried out for 10 minutes to 5 hours.
14. The method according to claim 1 or 2,

    Pressing conditions of step b) is a method for producing a polyimide, characterized in that the pressure conditions in the range of 1 bar to 1000 bar.
15. The method according to claim 1 or 2,

    Pressing conditions of step b) is a method for producing a polyimide, characterized in that the pressure conditions in the range of 1 bar to 500 bar.
16. The method according to claim 1 or 2,

    Pressurization conditions, the production of polyimide, characterized in that the water vapor pressure is formed in the pressure vessel, inert gas is injected into the pressure vessel, or by one or two or more methods selected from the method of compressing the pressure vessel. Way.
17. The method of claim 16,

    The inert gas is at least one gas selected from the group consisting of nitrogen, argon, helium, neon, krypton and xenon.
18. The method according to claim 1 or 2,

    after b), further comprising filtering and drying the reaction product of step b) to obtain a polyimide.
19. Polyimide prepared according to the method of claim 1.
20. Preparing a solution by dissolving the polyimide according to claim 19 in an organic solvent; And

    Method of producing a polyimide film comprising the step of applying the solution to a substrate.
21. The method of claim 20,

    The organic solvent is N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, N-vinylpyrrolidone, N-methylcaprolactam, dimethyl sulfoxide, tetra Methyl urea, pyridine, dimethyl sulfone, hexamethyl sulfoxide, meta-cresol, gamma-butyrolactone, ethyl cellosolve, butyl cellosolve, ethyl carbitol, butyl carbitol, ethyl carbitol acetate, butyl carbitol acetate And at least one solvent selected from the group consisting of ethylene glycol, ethyl lactate, butyl lactate, cyclohexanone and cyclopentanone.
22. The method of claim 20,

    Method for producing a polyimide film, characterized in that the concentration of polyimide in the solution is 1 to 90wt%.
23. A polyimide film prepared according to the method of claim 20.
24. A molded article molded by the method according to claim 19, wherein the polyimide is selected from the group consisting of compression molding, injection molding, slush molding, blow molding, extrusion molding and spinning methods.

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