KR101709378B1 - Preparation method of polyimide under high pressure - Google Patents

Abstract

The present invention relates to a process for preparing a pressure vessel, comprising the steps of: a) introducing a dispersion prepared by dispersing a dianhydride compound and a diamine compound in an organic solvent or a dispersion prepared by dispersing a polyamic acid compound in an organic solvent into a pressure vessel; And b) imidizing the inside of the pressure vessel under a pressurizing condition to produce a polyimide, wherein the polyimide preparation reaction is carried out at a relatively low temperature The produced polyimide is colorless and transparent so that industrial applications can be expanded and a wholly aromatic polyimide, a partially aliphatic polyimide and a pre-aliphatic polyimide having a high molecular weight can be produced. The recovered solvent can be recycled, making it economical and environmentally friendly.

Description

Preparation method of polyimide under high pressure < RTI ID = 0.0 >

The present invention relates to a process for producing polyimide which is carried out under pressurized conditions.

High heat-resistant polymer materials are essential materials for miniaturization, high performance, and high reliability of products in accordance with the development of advanced technology. They are used in the form of film, molded product, fiber, paint, adhesive and composite materials. And precision instruments.

Polyimide (PI), which is a typical high heat-resistant polymer, 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 be made into a thin film film, has a merit that it does not need a crosslinking agent for curing, and is attracting attention as a high functional polymer material ranging from microelectronics and optical fields due to its excellent electrical properties.

There are four major methods for producing polyimide reported so far.

The first method is a method in which polyamic acid, which is a precursor, is first synthesized (step 1) by reaction of dianhydride and diamine, and then polyimide is imidized (step 2) . The first step is a step of preparing polyamic acid, in which dianhydride is added to the reaction solution in which diamine is dissolved, and polyamic acid is formed by a ring opening reaction and a middle part reaction. The reaction solvent to be used is N, N - dimethylacetamide, N, N - dimethylformamide, N - polar organic solvents such as methyl-2-pyrrolidone are mainly used. In the subsequent step 2, the polyamic acid prepared in the above step 1 is imidated by dehydration and ring-closing reaction through a chemical method or a thermal method to synthesize a polyimide.

The chemical imidization method is a method in which a imidization catalyst typified by a chemical dehydrating agent typified by an acid anhydride such as acetic anhydride and a tertiary amine such as pyridine is added to a solution of polyamic acid as a precursor and heated at 160 ° C or higher. The thermal imidization method is a method of applying a solution of polyamic acid, which is a precursor, to a substrate, evaporating the solvent, and then thermally imidizing the solution at 250 to 350 ° C without a chemical dehydrating agent and a catalyst.

According to the above polyimide production method, when an aliphatic diamine is used in the production of a polyimide, the basicity of the amino group of the diamine is high and the diamine forms a salt with an amic acid instead of participating in the polymerization reaction. Of polyimide can not be obtained. Therefore, fully aliphatic polyimide and partially aliphatic polyimide synthesized by using an aliphatic diamine generally have a low molecular weight and have poor mechanical properties.

The second method is to use N - silylation reaction to increase the molecular weight of polyimide by preventing the formation of ammic acid and diamine salt, which are disadvantages of the first method. Diamine and chlorotrimethylsilane are reacted to synthesize a diamine protected with N - trimethylsilyl group. Then, the protected diamine is used to synthesize a polyimide through a polyamic acid protected with an N - trimethylsilyl group. In this method, an organic solvent is used for the synthesis of the diamine protected by the N - trimethylsilyl group and for the polyimide synthesis.

As a disadvantage of the N -silylation method, the chlorotrimethylsilane reagent for synthesizing an aliphatic diamine protected with an N -trimethylsilyl group is expensive and very difficult to handle due to its high water content, It is more complicated than the first synthesis method.

The third method is a method of using meta-cresol as a solvent, in which meta-cresol is added as a solvent, dianhydride and diamine are added, and the temperature is increased stepwise to react for a long time. The meta-cresol method has a disadvantage in that the reaction time is longer than 64 hours and the reaction time is long and still has unsatisfactory molecular weight and the meta-cresol solvent is used so that the drying time is long and the irritating odor is severe.

The fourth method is an in-situ method for solving the drawback that the second method, the N -seal relation method, is sensitive to moisture. After adding diamine to the reactor containing organic solvent, chlorotrimethylsilane was added at low temperature, and then dianhydride was added to synthesize a polyamic acid protected with N - trimethylsilyl group, followed by chemical imidization or thermal imidization reaction Polyimide is synthesized. Disadvantages of the in situ silylation synthesis method are that the reaction time is long and the molecular weight is improved but the chlorotrimethylsilane reagent is expensive, the imidization catalyst is needed, the drying time is long and the protecting group is protected from the polyamic acid protected with N -trimethylsilyl group A reprecipitation process may be required to synthesize the removed polyamic acid, and sufficient transparency can not be secured even in the case of the aliphatic polyimide.

Korean Patent No. 1,004,096 (December 20, 2010)

Disclosure of the Invention The present invention has been conceived to solve the above-mentioned problems, and provides a method of producing a colorless transparent polyimide under a relatively low temperature condition by producing a polyimide under a pressurized condition using a pressure vessel during the production of the polyimide do.

According to one embodiment of the present invention, there is provided a process for preparing a pressure-sensitive adhesive composition, comprising the steps of: a) dispersing a dispersion prepared by dispersing a dianhydride compound and a diamine compound in an organic solvent or a dispersion prepared by dispersing a polyamic acid compound in an organic solvent, Inputting; And b) imidizing the inside of the pressure vessel under a pressurizing condition, thereby producing a polyimide.

Also in an exemplary embodiment, there is provided a polyimide produced according to the method, wherein the polyimide is a wholly aromatic polyimide, a partially aliphatic polyimide or a prealiphatic polyimide.

Also, in an exemplary embodiment, a polyimide solution is prepared by dissolving polyimide prepared according to the above method in an organic solvent to prepare a polyimide solution, and then the polyimide solution is applied to a substrate to prepare a polyimide film. A method for producing a film is provided.

Also in an exemplary embodiment, there is provided a polyimide film produced according to the method.

According to the present invention, since the polyimide production reaction is carried out at a relatively low temperature, the produced polyimide is colorless and transparent and has a wide industrial application range.

Further, according to the present invention, wholly aromatic polyimides, partial aliphatic polyimides, and all aliphatic polyimides having a high molecular weight can be produced.

Further, according to the present invention, the solvent used in the polyimide manufacturing process can be recovered and recycled, which is economical and environmentally friendly.

1 is an FT-IR spectrum of pyromellitic dianhydride and 4,4'-oxydianiline polyimide according to Example 1.
2 is an FT-IR spectrum of 1,2,4,5-cyclohexanetetracarboxylic dianhydride and 4,4'-oxydianiline polyimide according to Example 2. Fig.
3 is an FT-IR spectrum of 1,2,4,5-cyclohexanetetracarboxylic dianhydride and 4,4-methylenebis (2-methylcyclohexylamine) polyimide according to Example 3.
4 is a graph showing the FT-IR spectra of 1,2,3,4-cyclopentane-tetracarboxylic dianhydride and 3- (aminomethyl) -3,5,5-trimethylcyclohexaneamine polyimide according to Comparative Example 1 to be.
5 shows the FT-IR spectra of 3- (aminomethyl) -3,5,5-trimethylcyclohexaneamine and 3- (aminomethyl) -3,5,5-trimethylcyclohexaneamine polyimide according to Comparative Example 2 to be.
6 shows the FT-IR spectra of 3- (aminomethyl) -3,5,5-trimethylcyclohexaneamine and 3- (aminomethyl) -3,5,5-trimethylcyclohexaneamine polyimide according to Comparative Example 3 to be.
7 is a graph showing the FT-IR spectrum of 1,2,3,4-cyclopentane-tetracarboxylic dianhydride and 3- (aminomethyl) -3,5,5-trimethylcyclohexaneamine polyimide according to Comparative Example 4 to be.

The present invention relates to a process for producing polyimide which is carried out under pressurized conditions.

The method for producing a polyimide according to the present invention provides a method for producing a colorless transparent polyimide under a relatively low temperature condition by producing a polyimide under a pressurized condition using a pressure vessel in the production of the polyimide.

Hereinafter, the present invention will be described in more detail.

Polyimide manufacturing

In order to accomplish the object of the present invention, there is provided a process for producing a polyimide according to one embodiment, which comprises the steps of: a) preparing a dispersion liquid prepared by dispersing a dianhydride compound and a diamine compound in an organic solvent or a dispersion prepared by dispersing a polyamic acid compound in an organic solvent Into a pressure vessel; And b) imidizing the inside of the pressure vessel under a pressurizing condition to produce a polyimide.

The method may further include discharging the solvent vapor generated in the step b) from the pressure vessel, and cooling and condensing the solvent vapor.

Further, the method may further include filtering and drying the reaction product produced by the imidization reaction in the step b).

In addition, the method may further include a step of sequentially re-precipitating, filtering and drying the reaction products produced by the imidization reaction in the step b).

First, a dispersion liquid prepared by dispersing a dianhydride compound and a diamine compound in an organic solvent or a polyamic acid compound dispersed in an organic solvent is introduced into a pressure vessel (step a).

According to one embodiment of the present invention, when a dispersion prepared by dispersing a dianhydride compound and a diamine compound in an organic solvent is used, the polyimide can be directly prepared from the dispersion in which the reactants are mixed.

Meanwhile, when polyimide is prepared using a dispersion prepared by dispersing a polyamic acid compound in an organic solvent according to another embodiment of the present invention, the polyamic acid compound may be one prepared by a general technique in the related art And the production method thereof is not particularly limited.

In one embodiment of the present invention, the dianhydride compound may be substituted or unsubstituted at least one dianhydride, and the dianhydride compound may be aromatic or aliphatic.

Meanwhile, in one embodiment of the present invention, the dianhydride may include a compound represented by the following formula (1).

≪ Formula 1 >

(R ₁ in the formula 1 is a compound of the following

. ≪ / RTI >

In one embodiment of the present invention, the diamine compound may be a substituted or unsubstituted diamine, and the diamine compound may be aromatic or aliphatic.

Meanwhile, in one embodiment of the present invention, the diamine may include a compound represented by the following formula (2).

(2)

(Wherein R < 2 _> represents the following compound

. ≪ / RTI >

Meanwhile, the organic solvent in step a) may be at least one selected from the group consisting of N -methylpyrrolidone, N, N -dimethylacetamide, N, N -dimethylformamide, N -vinylpyrrolidone, N -methylcaprolactam, But are not limited to, ethyl acetate, ethyl acetate, butyl acetate, ethyl acetate, butyl acetate, ethyl lactate, ethyl lactate, ethyl lactate, ethyl lactate, ethyl lactate, It may be a single solvent selected from the group consisting of carbitol acetate, ethylene glycol, ethyl lactate, butyl lactate, cyclohexanone and cyclopentanone, or a mixture of two or more thereof.

The pressure vessel to be used may be a pressure vessel generally used in the related art, and its material or shape is not particularly limited, and the size may be varied as necessary.

Next, after the dispersion liquid is put into a pressure vessel, imidation reaction is performed under pressure conditions in the pressure vessel to produce polyimide (step b).

Meanwhile, in one embodiment of the present invention, the pressing condition of step b) may be a pressure of 1.1 to 1000 bar, more specifically 1.1 to 500 bar, more specifically 1.5 to 500 bar It may be pressurized under a pressure condition, and further pressurized under a pressure condition in the range of 2 to 200 bar.

When the pressure vessel is pressurized to a pressure of less than 1.1 bar, the reaction does not progress well at a relatively low temperature. If the pressure vessel is pressurized to a pressure higher than 1000 bar, the pressure vessel may be damaged.

On the other hand, the pressurizing condition may be achieved by the vapor pressure formed inside the pressure vessel, or by the inert gas injected into the pressure vessel, or by compression of the pressure vessel, It is possible.

Meanwhile, the inert gas may be one or more gases selected from the group consisting of oxygen, argon, helium, neon, krypton, and xenon.

Meanwhile, the temperature condition in the step b) may be a temperature condition ranging from 20 to 300 ° C. More specifically, it may be a temperature condition ranging from 40 to 250 占 폚, and more specifically, a temperature condition ranging from 60 to 200 占 폚. When the temperature is lower than 20 ° C, the reaction rate is too slow to effectively manufacture the polyimide. When the temperature is higher than 300 ° C, not only the thermal decomposition of the monomer or the polymer can occur, but also the polyimide May not be colorless and transparent.

Meanwhile, in one embodiment of the present invention, the reaction time of the step b) may be 10 minutes to 3 days, more specifically 10 minutes to 10 hours, more specifically 10 minutes to 5 hours. If the reaction time is less than 10 minutes, the reaction may not proceed well. If the reaction time exceeds 3 days, gelation may occur, which may be undesirable from the economical point of view.

Meanwhile, in step b), solvent vapor may be generated. After the solvent vapor is discharged from the pressure vessel, the solvent vapor may be cooled, condensed and recovered. Since the organic solvent can be recovered through the above steps, the economical efficiency can be improved.

In one embodiment of the present invention, the step (b) may further comprise filtering and drying the reaction product produced by the imidization reaction. In yet another embodiment, the imidization reaction may be performed in step b) And then sequentially reprecipitating, filtering and drying the reaction product produced by the reaction product.

In one embodiment of the present invention, the solvent used for washing in the reprecipitation and filtration is water, ethanol, methanol, isopropanol, n-butanol, n-hexane, acetone, ether, ethyl acetate, tetrahydrofuran, Foam, or a mixture of two or more kinds thereof.

The polyimide prepared through the series of processes may be a fully aromatic polyimide having a number average molecular weight of 50,000 to 2,000,000, a partially aliphatic polyimide or a fully aliphatic polyimide.

Production of polyimide film

If the polyimide is dissolved in an organic solvent used as a reaction solvent, a polyimide film may be prepared by directly applying the polyimide to a substrate without being subjected to a filtration-drying step or a re-precipitation-filtration-drying step.

On the other hand, if the polyimide produced according to the above-described polyimide production method is in a dried state, it is dissolved in an organic solvent to prepare a polyimide solution, and then the polyimide solution is applied to a substrate to produce a polyimide film can do.

In one embodiment of the present invention, the organic solvent used to dissolve the polyimide is N -methylpyrrolidone, N, N -dimethylacetamide, N, N -dimethylformamide, N- money, N-methyl caprolactam, dimethyl sulfoxide, tetramethylurea, pyridine, dimethyl sulfone, hexamethyl sulfoxide, meta-cresol, gamma-butyrolactone, cellosolve, butyl cellosolve, ethyl cells, ethyl carbitol, It may be one single solvent selected from the group consisting of butyl carbitol, ethyl carbitol acetate, butyl carbitol acetate, ethylene glycol, ethyl lactate, butyl lactate, cyclohexanone, and cyclopentanone, or a mixture of two or more thereof. . Meanwhile, the polyimide concentration in the polyimide solution may be 1 to 90 wt%.

On the other hand, a small amount of additives such as a wettability improver may be added to the polyimide solution, if necessary. The additive may be added in an amount of 0.001 to 5% by weight, more preferably 0.01 to 2% by weight, based on the polyimide.

The polyimide film produced by the above method exhibits a light transmittance of 80% or more with respect to light having a yellow index of 5 or less and a thickness of 20 탆 and a wavelength of 450 nm.

Meanwhile, in one embodiment of the present invention, the method of applying the polyimide solution onto a substrate includes a spin coating method, a dipping method, a flexographic printing method, an inkjet printing method, a spraying method, a potting method, Can be used. Among these methods, a bar coating method, a slit coating method, a screen printing method, a spin coating method and the like may be preferable as a method of obtaining a thick film of 10 탆 or more.

On the other hand, the polyimide of the present invention can be molded into a molded product through compression molding, injection molding, slush molding, blow molding, extrusion molding, spinning or the like.

As described above, according to the present invention for producing polyimide under pressurized conditions, since the reaction proceeds under the pressurizing condition using the pressure vessel, the temperature at which the reaction is carried out corresponds to a relatively low temperature condition in comparison with the prior art, Polyimide is colorless and transparent and has a wide range of industrial applications. Meanwhile, according to the present invention, the solvent used in the polyimide manufacturing process can be recovered and recycled, which is economical and environmentally friendly.

On the other hand, the polyimide prepared according to the present invention can be used in a wide range of industries such as space, aviation, electric / electronic, semiconductor, transparent / flexible display, liquid crystal alignment film, automobile, precision instrument, packaging, medical material, separator, Can be used in the field.

Hereinafter, the present invention will be described in more detail with reference to Examples and Experimental Examples. It should be understood, however, that the following examples and experimental examples are provided to aid understanding of the present invention and are not intended to limit the scope of the present invention thereto.

Example

Example 1: Preparation of wholly aromatic polyimide

22.6 g of pyromellitic dianhydride and 21.1 g of 4,4'-oxydianiline were dispersed in 200 mL of N -methylpyrrolidone. The reaction solution was transferred to a 500-mL pressure vessel equipped with a stirrer, a nitrogen-introducing apparatus and a temperature controller. The air in the pressure vessel was replaced with nitrogen gas and the temperature was adjusted to 135 ° C. The mixture was stirred at a pressure of 60 bar for 3 hours, Were synthesized. The reaction mixture was filtered to obtain a solid, which was then dried to obtain a polymer powder.

The infrared absorption spectrum (Fig. 1), 1777cm ^-1 and 1725cm ^-1 C = O absorption band of the already deugi, already CN absorption band of deugi at 1378cm ^-1 in the synthesized polymer was observed.

After completion of the polyimide production reaction, water vapor was discharged from the pressure vessel and the water vapor was cooled and condensed by sequentially passing through a transfer pipe and a cooler to recover about 180 mL of N - methylpyrrolidone. Nuclear magnetic resonance (NMR) analysis of the recovered N - methylpyrrolidone showed no impurities.

Example 2: Preparation of partial aliphatic polyimide

5.60 g of 1,2,4,5-cyclohexanetetracarboxylic dianhydride and 5.00 g of 4,4'-oxydianiline were dispersed in 200 mL of N -methylpyrrolidone. The reaction solution was transferred to a 500-mL pressure vessel equipped with a stirrer, a nitrogen-introducing apparatus and a temperature controller. The air in the pressure vessel was replaced with nitrogen gas and the temperature was adjusted to 135 ° C. The mixture was stirred at a pressure of 60 bar for 3 hours to obtain polyimide Were synthesized. The reaction mixture was put in water, reprecipitated, and filtered to obtain a solid, which was then dried to obtain a polymer powder.

The infrared absorption spectrum (Fig. 2), 1785cm ^-1 and 1718cm ^-1 C = O absorption band of the already deugi, already CN absorption band of deugi at 1394cm ^-1 in the synthesized polymer was observed.

After completion of the polyimide production reaction, water vapor was discharged from the pressure vessel and the water vapor was cooled and condensed by sequentially passing through a transfer pipe and a cooler to recover about 180 mL of N - methylpyrrolidone. Nuclear magnetic resonance (NMR) analysis of the recovered N - methylpyrrolidone showed no impurities.

Example 3: Preparation of all aliphatic polyimide

5.96 g of 1,2,4,5-cyclohexanetetracarboxylic dianhydride and 5.60 g of 4,4-methylenebis (2-methylcyclohexylamine) were added to 200 mL of N -methylpyrrolidone and dispersed. The reaction solution was transferred to a 500-mL pressure vessel equipped with a stirrer, a nitrogen-introducing apparatus and a temperature controller. The air in the pressure vessel was replaced with nitrogen gas and the temperature was adjusted to 135 ° C. The mixture was stirred at a pressure of 60 bar for 3 hours, Were synthesized. The reaction mixture was put in water, reprecipitated, and filtered to obtain a solid, which was then dried to obtain a polymer powder.

The infrared absorption spectrum (Fig. 3), 1782cm ^-1 and 1700cm ^-1 C = O absorption band of the already deugi, already CN absorption band of deugi at 1377cm ^-1 in the synthesized polymer was observed.

After completion of the polyimide production reaction, water vapor was discharged from the pressure vessel, and the water vapor was cooled and condensed by sequentially passing through a transfer pipe and a cooler to recover about 180 mL of N-methylpyrrolidone. Nuclear magnetic resonance analysis (NMR) of the recovered N-methylpyrrolidone showed no impurities.

Example 4: Preparation of polyimide thin film

Prior to the production of the thin film, a cleaning process of a silicon wafer to be used as a substrate was carried out. This process removes various contaminants such as particles, organic contaminants, metal contaminants, and natural oxide films. The contaminants were removed by heating at 120 ° C for 3 hours using a Piranha solution containing sulfuric acid and hydrogen peroxide in a ratio of 7: 3.

0.20 g of the synthesized polyimide was added to 2.0 mL of N, N - dimethylacetamide or N, N - dimethylformamide to prepare a polyimide solution. Alternatively, the polyimide solution obtained after the polyimide production reaction can be used as it is without being subjected to reprecipitation or filtration. The polyimide solution was filtered with a fine filter having a pore size of 0.2 mu m, spin-coated on the substrate in two steps of 500 rpm for 10 seconds and 1500 rpm for 50 seconds, and then the solvent was removed. Thin films were prepared.

As another method, a polyimide thin film was prepared by casting a polyimide solution on a substrate, removing a solvent and annealing.

Comparative Example 1: Two-step preparation of all aliphatic polyimide

10 mL of N -methyl-2-pyrrolidone was added to a 50-mL 2-neck round bottom flask substituted with nitrogen gas, and 4.20 g (2.00 mmol) of 1,2,3,4-cyclopentane-tetracarboxylic dianhydride was added thereto, And 3.41 g (2.00 mmol) of 3- (aminomethyl) -3,5,5-trimethylcyclohexanamine were added thereto, followed by reaction at room temperature for 24 hours.

5 mL of acetic anhydride and 3 mL of pyridine were added to the solution by chemical imidization method, and the mixture was refluxed at 170 ° C. for 5 hours. After the temperature was lowered to room temperature, reprecipitation was performed using an excessive amount of ice water. The solid obtained through filtration was washed with 100 mL of water and 100 mL of methyl alcohol, and vacuum-dried to synthesize all aliphatic polyimide. (On the other hand, in the thermal imidation method, the synthesized polyamic acid solution was cast on a substrate, Alternatively, the polyimide may be obtained by heating the mixture in a stepwise manner with a hot plate, followed by heating at this temperature for 12 hours).

The infrared absorption spectrum (Fig. 4), 1774cm ^-1 and 1713cm C = O absorption band, already CN absorption band at 1368cm ^{-1 -1} of deugi this imide group in the synthesized polymer was observed.

Comparative Example 2: Synthesis of all aliphatic polyimide N - Manufacture by seal relation method

To the aliphatic diaminopolysiloxane, 25 mL of purified toluene was added to a 100 mL 3-necked round bottom flask substituted with nitrogen gas, and 8.52 g (5.00 mmol) of 3- (aminomethyl) -3,5,5-trimethylcyclohexaneamine And 1.09 g (10.0 mmol) of chlorotrimethylsilane were placed and reacted at 5 ° C for 30 minutes. 0.591 g (10.0 mmol) of trimethylamine was slowly added dropwise to this solution. After reacting at 5 ° C for 2 hours, the temperature was raised to 60 ° C, and the reaction was carried out for 24 hours, followed by vacuum drying to synthesize an amino-protected aliphatic diaminopolysiloxane.

N -methyl-2-pyrrolidone (10 mL) was added to a 50-mL 2-neck round bottom flask substituted with nitrogen gas, and 4.20 g (2.00 mmol) of 1,2,3,4-cyclopentane-tetracarboxylic dianhydride and The aliphatic diaminopolysiloxane synthesized above was added and reacted at room temperature for 24 hours.

The synthesized polyimide-siloxane was reprecipitated using distilled water. After filtration and vacuum drying, polyamic acid was synthesized.

5 mL of acetic anhydride and 3 mL of pyridine were added to the solution by chemical imidization method, and the mixture was refluxed at 170 ° C. for 5 hours. After the temperature was lowered to room temperature, reprecipitation was performed using an excessive amount of ice water. The solid obtained through filtration was washed with 100 mL of water and 100 mL of methyl alcohol, and vacuum-dried to synthesize all aliphatic polyimide. (On the other hand, in the thermal imidation method, the synthesized polyamic acid solution was cast on a substrate, Alternatively, the polyimide may be obtained by heating stepwise with a hot plate and then heating at this temperature for 12 hours).

The infrared absorption spectrum (Fig. 5), 1778cm ^-1 and 1714cm ^-1 C = O absorption band of the already deugi, already CN absorption band of deugi at 1368cm ^-1 in the synthesized polymer was observed.

Comparative Example 3: Preparation of a pre-aliphatic polyimide by an in-situ silylation method

10 mL of N -methyl-2-pyrrolidone (NMP) was added to a 50-mL 2-necked round bottom flask substituted with nitrogen gas, and 3.406 g of 3- (aminomethyl) -3,5,5-trimethylcyclohexaneamine 2.00 mmol) was added thereto, and then 0.435 g (4.00 mmol) of chlorotrimethylsilane was added at 0 ° C, followed by stirring for 2 hours. Then, 4.20 g (2.00 mmol) of 1,2,3,4-cyclopentane-tetracarboxylic dianhydride was added and the mixture was reacted at room temperature for 24 hours. The synthesized diaminopolysiloxane was reprecipitated using distilled water. After filtration and vacuum drying, polyamic acid was synthesized.

5 mL of acetic anhydride and 3 mL of pyridine were added to the solution by chemical imidization, and the mixture was refluxed at 170 DEG C for 5 hours. After the temperature was lowered to room temperature, re-precipitation was performed using excess ice water. The solid obtained through filtration was washed with 100 mL of water and 100 mL of methyl alcohol and vacuum-dried to synthesize a pre-aliphatic polyimide. (On the other hand, in the thermal imidation method, the polyamic acid solution was cast on a substrate, The polyimide may be obtained by heating the mixture in a stepwise manner with a hot plate and then heating at this temperature for 12 hours).

Deugi already in the C = O absorption band, 1367cm ^-1 1776cm ^-1 and 1714cm ^-1 in the infrared absorption spectrum (Fig. 6) of the synthesized polymers are already CN absorption band of deugi was observed.

Comparative Example 4: Preparation of a prealiphatic polyimide by meta-cresol synthesis

10 mL of meta-cresol was added to a 50 mL-2-neck round bottom flask substituted with nitrogen gas, and 4.20 g (2.00 mmol) of 1,2,3,4-cyclopentane-tetracarboxylic dianhydride and 3- (aminomethyl) 3.41 g (2.00 mmol) of 3,5,5-trimethylcyclohexaneamine was added and the mixture was reacted at 60 DEG C for 8 hours at 100 DEG C for 12 hours at 150 DEG C for 4 hours and at 200 DEG C for 48 hours. The synthesized solution was cooled to room temperature, washed with 100 mL of methacresol and 100 mL of methyl alcohol, filtered, and vacuum dried at 60 ° C. to synthesize all aliphatic polyimide.

The infrared absorption spectrum (Fig. 7), 1773cm ^-1 and 1712cm ^-1 C = O absorption band of the already deugi, already CN absorption band of deugi at 1367cm ^-1 in the synthesized polymer was observed.

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Immediate maximum temperature 135 ℃ 135 ℃ 135 ℃ 300 ° C 300 ° C 300 ° C 200 ℃ Reaction time 3 hours 3 hours 3 hours 36 hours 36 hours 36 hours 72 hours Presence or absence of catalyst not used not used not used Used (at chemical imidization) Used (at chemical imidization) Used (at chemical imidization) not used Dispersion medium or solvent type NMP NMP NMP NMP NMP NMP m -cresol Reaction step 1 step 1 step 1 step 2 step 4 step 2 step 1 step Synthesis of polyimide pyrolysis temperature > 500 ° C 497 ° C 440 ° C 403 DEG C 407 ° C 428 ° C 434 ° C The synthesized polyimide molecular weight (GPC) Not measurable 221226 1023546 3054 9567 78265 10213

As shown in Table 1, in Examples 1 to 3 of the present invention, the maximum imidization temperature is low, the reaction time is short, and the reaction step is small as compared with Comparative Examples 1 to 4 which are conventional methods. It also has the advantage of not using a catalyst, and the solvent used in the production of polyimide can be recovered and recycled. Therefore, the polyimide synthesis method of the present invention is simple, inexpensive and environmentally friendly compared to the conventional method.

Claims (22)

A dispersion liquid prepared by dispersing a dianhydride compound and a diamine compound in an organic solvent is introduced into a pressure vessel and subjected to imidization reaction at a temperature of 60 to 300 DEG C under the pressure condition inside the pressure vessel to produce a polyimide Step, comprising a single step,
Wherein the polyimide is a wholly aromatic polyimide, a partially aliphatic polyimide, or a wholly aliphatic polyimide having a number average molecular weight of 50,000 to 2,000,000. The method according to claim 1,
Withdrawing the produced solvent vapor from the pressure vessel, and then cooling and condensing it to recover the polyimide. The method according to claim 1,
Filtering and drying the reaction product produced by the imidization reaction, or sequentially reprecipitating, filtering and drying the reaction products produced by the imidation reaction. delete The method according to claim 1,
Wherein the dianhydride compound is at least one substituted or unsubstituted dianhydride, and the diamine compound is at least one substituted or unsubstituted diamine. 6. The method of claim 5,
Wherein the dianhydride compound is an aromatic or aliphatic dianhydride. The method according to claim 6,
Wherein the dianhydride is a dianhydride of the following formula (1).

≪ Formula 1 >
(R ₁ in the formula 1 is a compound of the following

. ≪ / RTI > 6. The method of claim 5,
Wherein the diamine compound is an aromatic or aliphatic diamine. 9. The method of claim 8,
Wherein the diamine is a diamine of the following formula (2).

(2)
(Wherein R < 2 _> represents the following compound

. &Lt; / RTI &gt; The method according to claim 1,
Wherein the pressurizing condition is a pressure condition in the range of 1.1 to 1000 bar. The method according to claim 1,
Wherein the temperature condition is a temperature condition in a range of 60 to 250 占 폚. The method according to claim 1,
The reaction is carried out for 10 minutes to 3 days. The method according to claim 1,
Wherein the pressurizing conditions are formed by at least one factor selected from the group consisting of a vapor pressure formed inside the pressure vessel, an inert gas injected into the pressure vessel, and a pressure vessel compression. 14. The method of claim 13,
Wherein the inert gas is at least one gas selected from the group consisting of oxygen, argon, helium, neon, krypton, and xenon. The method according to claim 1,
The organic solvent may be selected from the group consisting of N -methylpyrrolidone, N, N -dimethylacetamide, N, N -dimethylformamide, N -vinylpyrrolidone, N -methylcaprolactam, dimethylsulfoxide, But are not limited to, pyridine, dimethyl sulfone, hexamethyl sulfoxide, meta-cresol, gamma-butyrolactone, ethyl cellosolve, butyl cellosolve, ethyl carbitol, butyl carbitol, ethyl carbitol acetate, butyl carbitol acetate, , Ethyl lactate, butyl lactate, cyclohexanone, and cyclopentanone, or a mixed solvent of two or more kinds. delete A process for producing a polyimide film, comprising the step of directly coating a polyimide prepared according to the process of claim 1 on a substrate in the state that the polyimide is dissolved in an organic solvent used as a reaction solvent. A process for producing a polyimide film comprising the steps of dissolving polyimide prepared according to the production method of claim 1 in an organic solvent to prepare a polyimide solution, and then applying the polyimide solution to a substrate to produce a polyimide film. 19. The method of claim 18,
The organic solvent may be selected from the group consisting of N -methylpyrrolidone, N, N -dimethylacetamide, N, N -dimethylformamide, N -vinylpyrrolidone, N -methylcaprolactam, dimethylsulfoxide, But are not limited to, pyridine, dimethyl sulfone, hexamethyl sulfoxide, meta-cresol, gamma-butyrolactone, ethyl cellosolve, butyl cellosolve, ethyl carbitol, butyl carbitol, ethyl carbitol acetate, butyl carbitol acetate, , Ethyl lactate, butyl lactate, cyclohexanone, and cyclopentanone, or a mixed solvent of two or more kinds. 19. The method of claim 18,
Wherein the polyimide concentration in the polyimide solution is 1 to 90 wt%. The method for producing a polyimide film according to claim 17 or 18, wherein the polyimide film has a yellow index of 5 or less and a light transmittance of 80% or more with respect to light having a wavelength of 450 nm at a thickness of 20 탆 . delete

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