KR100548634B1 - Unsymetric diamine monomer having trifluoromethyl and benzimidazol ring - Google Patents

Abstract

The present invention relates to a diamine compound having an asymmetric structure having a trifluoromethyl group and a benzimidazole ring, which is a compound represented by the following formula (1), and has a monomer having a diamine compound having an asymmetric structure having a trifluoromethyl group and a benzimidazole ring. The aromatic polyimide of formula (6) prepared by using is a rigid structure, exhibits toughness, yet has sufficient solubility in the final polymer state, and has excellent processability, low refractive index, and adhesion to a substrate including a metal such as copper. This is excellent and there is an effect that can be used in electrical and electronic, optical, separator machine.

[Formula 1]

[Formula 6]

Trifluoromethyl group, benzimidazole ring, asymmetric structure, diamine monomer, aromatic polyimide

Description

Asymmetric diamine compound having trifluoromethyl group and benzimidazole ring {Unsymetric diamine monomer having trifluoromethyl and benzimidazol ring}

1 is a 1H Nuclear Magnetic Resonance spectrum (1H NMR) of the diamine compound synthesized in Example 1 of the present invention,

FIG. 2 is an infrared spectrum (Infrared spectrum) of the diamine compound synthesized in Example 1 of the present invention.

3 is an infrared spectroscopic analysis spectrum of the aromatic polyimide prepared in Example 3 of the present invention,

4 is a hydrogen atom nuclear magnetic resonance spectroscopy spectrum of the aromatic polyimide prepared in Example 3 of the present invention,

5 is a view showing the results of the thermogravimetric analysis (TGA) for the aromatic polyimide prepared in Example 3 of the present invention,

6 is a view showing the results of differential scanning calorimetry (DSC) of the aromatic polyimide prepared in Examples 2, 3, 4 and 5 of the present invention.

The present invention relates to a diamine compound having an asymmetric structure having a trifluoromethyl group and a benzimidazole ring. More specifically, it is a diamine monomer having a trifluoromethyl group for inhibiting various interactions between molecules, and a benzimidazole ring for imparting adhesion and toughness, solubilizing even after complete imidation and toughness. The present invention relates to a diamine compound having an asymmetric structure having a trifluoromethyl group and a benzimidazole ring which can be used in the production of a polyimide having excellent general properties.

The polyimide obtained by polymerizing a diamine monomer and a tetracarboxylic dianhydride monomer is excellent in heat resistance, mechanical strength, dimensional stability, and excellent in flame retardancy and electrical insulation. Due to such excellent physical properties, polyimide has been used in various applications such as electrical and electronic devices, aerospace equipment, transportation equipment, and various forms of research are being conducted according to the intended use.

Among the above polyimides, aromatic polyimides have excellent physical properties such as thermal stability, mechanical properties, electrical insulation, chemical resistance, and the like. It is a typical high performance polymer used for applications such as adhesives and coating agents.

In general, the aromatic polyimide is not dissolved in organic solvents at all in the final stage of imidization and is decomposed before being melted and cannot be processed. Therefore, it is processed in the form of an intermediate polyamic acid, followed by heat treatment to terminate imidization. The final product is manufactured through a two-step process. However, the method of manufacturing the final molded article by curing in the state of the processable intermediate polyamic acid and then curing by heat and chemical treatment is formed by instability of the intermediate polyamic acid and the formation of by-products such as water generated during curing. There is a problem that causes deformation and defects.

Therefore, studies have been actively conducted to develop soluble polyimides that can be easily processed even in the final stage after the imidization is fully performed while minimizing the deterioration of the physical properties of the aromatic polyimide. . The method for preparing soluble polyimide may include introducing a flexible functional group or a bulky substituent into the polymer backbone, twisting the flat plate shape of the polymer chain, using a monomer having an alicyclic structure, A method of introducing an asymmetric structure to reduce the regularity of the molecular structure, and a method of copolymerizing components having good solubility in an organic solvent together.

Another method for preparing soluble polyimides is to introduce perfluoroalkyl groups, including trifluoromethyl groups, into the polyimide backbone, in which case the bonds between carbon-fluorine are stronger than those between carbon-hydrogen. It does not significantly reduce the heat resistance of the polyimide, but suppresses the various interactions of the conventional polyimide, which not only increases the solubility of the polyimide but also increases the water absorption rate, dielectric constant, refractive index, etc. due to the low polarization of the fluorine atom. Brings about a significant decrease.

On the other hand, when the heterocyclic ring is included in the polymer chain, it is possible to increase the toughness of the polymer material by increasing the attractive force between molecules while maintaining the existing rigid structure, and also improves adhesion to various substrates including metals such as copper. It can greatly improve.

In order to solve the above problems, the present invention is to suppress various interactions of the polyimide, and asymmetric diamond having a trifluoromethyl group and benzimidazole ring as a monomer for imparting toughness and adhesion to the polyimide Provides a min compound.

In addition, the present invention provides a method for producing a diamine compound having an asymmetric structure having a trifluoromethyl group and a benzimidazole ring as a monomer for inhibiting various interactions of the polyimide and imparting toughness and adhesion to the polyimide. to provide.

In addition, the present invention provides a diamine compound capable of producing an aromatic polyimide having excellent solubility, toughness and adhesion after the imidation is fully performed using a diamine compound having an asymmetric structure having a trifluoromethyl group and a benzimidazole ring. to provide.

In addition, the present invention is an electro-electro-optic prepared by using an aromatic polyimide having excellent solubility, toughness and adhesion after complete imidation using a diamine compound having an asymmetric structure having a trifluoromethyl group and a benzimidazole ring. Provided is a diamine compound capable of producing a film for use.

The above and other objects of the present invention can be achieved by the present invention described below.

In order to achieve the above object, the present invention provides a diamine compound characterized in that the compound of formula 1 as an asymmetric structure having a trifluoromethyl group and a benzimidazole ring.

[Formula 1]

In addition, the present invention comprises the steps of synthesizing 4-nitro-2-trifluoromethyl benzoic acid of the formula (3) from 2-bromo-5-nitrobenzotrifluoride of the formula (2); Reacting the 4-nitro-2-trifluoromethyl benzoic acid with 4-nitro-1,2-phenylene diamine of the following formula (4) and then cyclizing to synthesize a compound of the dynate of the following formula (5) step; And reducing the nitro group in the compound with the dynamite; It provides a method for producing a diamine compound of claim 1 comprising a.

[Formula 2]

[Formula 3]

[Formula 4]

[Formula 5]

The present invention also provides an aromatic polyimide, which is prepared from the diamine compound and tetracarboxylic dianhydride, and is a compound represented by the following Chemical Formula 6.

[Formula 6]

In addition, the present invention comprises the steps of dissolving the diamine compound and tetracarboxylic dianhydride in an organic solvent to form a polyamic acid of formula (7); And it provides a method for producing the aromatic polyimide of claim 3 comprising the step of imidizing the polyamic acid.

[Formula 7]

The diamine compound may be 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 2,4'-diaminodiphenyl ether, 2 , 2'-diaminodiphenyl ether, 2,3'-diaminodiphenyl ether, 1,4-bis (4-aminophenoxy) benzene, 1,4-bis (3-aminophenoxy) benzene, 1 , 3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, p-phenylenediamine, m-phenylenediamine, o-phenylenediamine, p- Aminobenzylamine, m-aminobenzylamine, 4,4'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 2,2-bis [4 -(4-aminophenoxy) phenyl] propane, 2,2-bis [4- (3-aminophenoxy) phenyl] propane, bis (4-aminophenyl) sulfide, bis (3-aminophenyl) sulfide, 3 , 4-diaminophenylsulfide, bis (4-aminophenyl) sulfoxide, bis (3-aminophenyl) sulfoxide Id, 3,4-diaminophenylsulfoxide, bis (4-aminophenyl) sulfone, bis (3-aminophenyl) sulfone, 3,4-diaminophenylsulfone, 4,4'-diaminobenzophenone, 3 , 4'-diaminobenzophenone, 3,3'-diaminobenzophenone, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] sulfone, bis [4- (4-aminophenoxy) phenyl] ether, 1,4-bis [4- (3-aminophenoxy) benzoyl] benzene, 1,3-bis [4- (3-aminophenoxy) benzoyl] Benzene, 4,4'-bis [3- (4-aminophenoxy) benzoyl] diphenyl ether, 4,4'-bis [3- (3-aminophenoxy) benzoyl] diphenyl ether, 4,4 ' -Bis [4- (4-amino-a, a-dimethylbenzyl) phenoxy] benzophenone, 4,4'-bis [4- (4-amino-a, a-dimethylbenzyl) phenoxy] di Phenylsulfone, bis [4- {4- (4-aminophenoxy) phenoxy} phenyl] sulfone, 1,4-bis [4- (4-aminophenoxy) -a, a-dimethylbenzyl] benzene, 1,3-bis [4- (4-aminophenoxy) -a, a-dimethylbenzyl] benzene, 2,2-bis [4- (4 -Aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane, 2,2-bis [4- (3-aminophenoxy) phenyl] -1,1,1,3 It can be used in admixture with at least one diamine monomer selected from the group consisting of, 3 and 3-hexafluoropropane.

The tetracarboxylic dianhydride is 1,2,4,5-benzenetetracarboxylic dianhydride, 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride, 2,2', 3, 3'-benzophenone tetracarboxylic dianhydride, 3,3 ', 4,4'- diphenyl ether carboxylic dianhydride, 2,2'.3,3'- diphenyl ether carboxylic dianhydride, 3,3'-oxyphthalic acid dianhydride, 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, 2,2', 3,3'-biphenyltetracarboxylic dianhydride, 3, 3 ', 4,4'-tetracarboxydiphenylsulfide dianhydride, 2,2', 3,3'-tetracarboxydiphenylsulfide dianhydride, 3,3 ', 4,4'-tetracarboxyldi Phenylsulfone dianhydride, 2,2 ', 3,3'-tetracarboxylic diphenylsulfone dianhydride, 4,4'-hexafluoroisopropylidenediphthalic anhydride, 1,4,5,8-naphthalenetetracar Acid dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride and 2,3,6,7-naphthalenetetracarboxylic dianhydride The paper may be selected from one or more from the group.

The step of imidizing the polyamic acid may be stirred for 6 to 10 hours at a temperature of 170 to 200 ℃.

In the step of imidizing the polyamic acid, chlorobenzene may be added to remove water as a reaction byproduct.

In addition, the present invention provides a film which is prepared by dissolving the aromatic polyimide prepared by the above method in a polar aprotic organic solvent or a phenol solvent.

The polar aprotic organic solvent is N, N-dimethylformamide (N, N-dimethylformide, DMF), N, N-dimethylacetamide (N, N-dimethylacetamide, DMAc), N-methylpyrrolidone (N-methylpyrrolidone, NMP) and dimethylsulfoxide (dimethylsulfoxide, DMSO) may be selected from the group consisting of, the phenolic solvent may be m -cresol.

Hereinafter, the present invention will be described in detail.

The present invention, in order to have a solubility in an organic solvent even after the aromatic polyimide is imidized, and further to exhibit adhesion and toughness, to suitably control the molecular structure of the monomer that is a raw material of the aromatic polyimide, It is characterized by introducing trifluoromethyl groups and benzimidazole rings in the diamine monomers to provide aromatic polyimides of toughness and adhesion.

That is, the present invention provides a diamine compound characterized in that the compound of formula 1 as an asymmetric structure having a trifluoromethyl group and a benzimidazole ring.

[Formula 1]

The diamine compound having the structure of Formula 1 has a trifluoromethyl group of a suitable size on one side of the benzene ring to inhibit various interactions of the polyimide, thereby increasing the solubility of the polyimide, as well as low polarization of the fluorine atom. Due to this, a significant decrease in moisture absorption, dielectric constant, refractive index, and the like is brought about. In addition, the molecule contains a benzimidazole ring, which is a heterocyclic ring, to increase the toughness of the polymer material by increasing the attractive force between molecules while maintaining the rigid structure of the plate-like structure, as well as various metals such as copper Adhesion to the substrate can be greatly improved. In addition, the functional groups introduced into the molecular structure are introduced asymmetrically to offset the symmetry between the polyimide chains, thereby further reducing the interaction, thereby greatly improving the solubility of the polyimide in the organic solvent.

In addition, the diamine compound of the present invention may be prepared according to the following Scheme 1. That is, 4-nitro-2-trifluoromethyl benzoic acid is synthesized from 2-bromo-5-nitrobenzotrifluoride, and 4-nitro-2-trifluoromethyl benzoic acid and 4-nitro Diamine compounds can be prepared by reacting -1,2-phenylene diamine, followed by cyclization to synthesize dinitro compounds, and reduction of nitro groups in the dinitro compounds.

Scheme 1

The present invention also provides an aromatic polyimide, which is prepared from the diamine compound and tetracarboxylic dianhydride as described above, and is a compound represented by the following Chemical Formula 6.

[Formula 6]

The aromatic polyimide as described above, as shown in Scheme 2, after the diamine compound of Formula 1 and tetracarboxylic dianhydride monomer is dissolved in an organic solvent to form a polyamic acid of the formula (7), the polyamic acid It can be prepared by imidization.

Scheme 2

[Formula 7]

An example of a specific method for producing an aromatic polyimide as described above is as follows.

Diamine monomer and tetracarboxylic dianhydride monomer are dissolved in N-methylpyrrolidone (NMP) as a reaction solvent. At this time, the concentration of the solution is preferably set to 10 to 20% (monomer weight (g) / amount of solvent (mL)). The solution is stirred at room temperature for 2 to 6 hours to form a polyamic acid, the solution is diluted to 5 to 10%, then heated to a temperature of 170 to 200 ° C. and stirred for 6 to 10 hours to imidize. In order for the imidation reaction to proceed effectively, it is preferable to continuously add a small amount of chlorobenzene to remove the water generated during the reaction. When the reaction is complete, the reaction solution is precipitated in a mixture of excess methanol and water, washed with hot water, alcohol, acetone and dried in a vacuum oven.

In the method for producing an aromatic polyimide, the polyamic acid prepared using a diamine monomer may be obtained in a powder state, or a film may be obtained in a polyamic acid state, and then imidized at 200 to 400 ° C.

The diamine compound of formula 1 for producing the aromatic polyimide can be used in combination with other diamines in a range that does not reduce the solubility depending on the intended use. Diamines which can be used in admixture include 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 2,4'-diaminodi Phenyl ether, 2,2'-diaminodiphenyl ether, 2,3'-diaminodiphenyl ether, 1,4-bis (4-aminophenoxy) benzene, 1,4-bis (3-aminophenoxy ) Benzene, 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, p-phenylenediamine, m-phenylenediamine, o-phenylenedia Min, p-aminobenzylamine, m-aminobenzylamine, 4,4'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 2,2 -Bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (3-aminophenoxy) phenyl] propane, bis (4-aminophenyl) sulfide, bis (3-aminophenyl ) Sulfide, 3,4-diaminophenylsulfide, bis (4-aminophenyl) sulfoxide, bis (3- Minophenyl) sulfoxide, 3,4-diaminophenyl sulfoxide, bis (4-aminophenyl) sulfone, bis (3-aminophenyl) sulfone, 3,4-diaminophenyl sulfone, 4,4'-diamino Benzophenone, 3,4'-diaminobenzophenone, 3,3'-diaminobenzophenone, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl ] Sulfone, bis [4- (4-aminophenoxy) phenyl] ether, 1,4-bis [4- (3-amino phenoxy) benzoyl] benzene, 1,3-bis [4- (3-aminophenoxy Benzoyl] benzene, 4,4'-bis [3- (4-aminophenoxy) benzoyl] diphenyl ether, 4,4'-bis [3- (3-aminophenoxy) benzoyl] diphenyl ether, 4,4'-bis [4- (4-amino-a, a-dimethylbenzyl) phenoxy] benzophenone, 4,4'-bis [4- (4-amino-a, a-dimethylbenzyl) Phenoxy] diphenylsulfone, bis [4- {4- (4-aminophenoxy) phenoxy} phenyl] sulfone, 1,4-bis [4- (4-aminophenoxy) -a, a-dimethyl Benzyl] benzene, 1,3-bis [4- (4-aminophenoxy) -a, a-dimethylbenzyl] Benzene, 2,2-bis [4- (4-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane, 2,2-bis [4- (3-aminophenoxy C) phenyl] -1,1,1,3,3 and 3-hexafluoropropane.

In addition, tetracarboxylic dianhydrides that can be used to react with the diamine monomers to prepare aromatic polyimides include 1,2,4,5-benzenetetracarboxylic dianhydride, 3,3'4, 4'-benzophenonetetracarboxylic dianhydride, 2,2 ', 3,3'-benzophenonetetracarboxylic dianhydride, 3,3', 4,4'- diphenylethercarboxylic dianhydride, 2,2 ', 3,3'-diphenylethercarboxylic acid dianhydride, 3,3'-oxyphthalic acid dianhydride, 3,3', 4,4'-biphenyltetracarboxylic dianhydride, 2, 2 ', 3,3'-biphenyltetracarboxylic dianhydride, 3,3', 4,4'-tetracarboxylic diphenylsulfide dianhydride, 2,2 ', 3,3'-tetracarboxylic die Phenylsulfide dianhydride, 3,3 ', 4,4'-tetracarboxylic diphenylsulfone dianhydride, 2,2', 3,3'-tetracarboxylic diphenyl sulfone dianhydride, 4,4'-hexafluoro Leusopropylidenediphthalic anhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 1,2,5,6- Program talren and the like tetracarboxylic dianhydride and 2,3,6,7-naphthalene tetracarboxylic dianhydride. In the present invention, the above-mentioned tetracarboxylic dianhydrides may be used alone or in combination.

In addition, polyimide prepared using tetracarboxylic dianhydride except for benzene tetracarboxylic dianhydride among the tetracarboxylic dianhydride is N, N-dimethylformamide (DMF), N, N- A tough film can be prepared by dissolving in polar aprotic organic solvents such as dimethylacetamide (DMAc), N-methylpyrrolidone (NMP) and dimethyl sulfoxide (DMSO) or phenols such as m -cresol. have.

Hereinafter, the present invention will be described in more detail with reference to the following examples, but the scope of the present invention is not limited to the examples.

In addition, the structure and physical properties of the monomers and polymers according to Examples and Comparative Examples were confirmed and measured by the following method.

The structure of the synthesized material was confirmed by IR (Infrared spectroscopy, UV spectroscopy, Bruker, FT-IR spectrophotometer) and NMR (Magnetic Resonance spectroscopy), nuclear magnetic resonance spectroscopy, Bruker's Fourier Transform AVANCE400 spectrometer (400MHz). IR was used for KBr or a film, and NMR was used by dissolving a sample in chloroform- d or dimethyl sulfoxide- d6 .

Inherent Viscosity of the synthesized polymer was measured by dissolving the sample in N, N-dimethylacetamide (DMAc) solvent at a concentration of 0.5 g / dL, and then using a Canon-Ubeloide viscometer (30 ° C). Cannon-Ubbelohde type Viscometer).

Thermal analysis was performed through TGA (Thermogravimetric Analysis), Differential Scanning Calrorimetry (DSC), and TMA (Thermomechanical Analysis) .The TA 2200 thermal analysis system (TA Instrument's TA 2200 thermal analyzer system, TGA 2050, DSC 2010, TMA 2940). In the case of TGA and DSC, it was measured at a temperature rise rate of 10oC / min, and in the case of TMA, it was measured at a temperature rise rate of 5oC / min. In all cases it was carried out under a constant nitrogen stream and TGA was carried out under a constant air stream. The temperature at which the weight loss of 5% was obtained was obtained from TGA, and the glass transition temperature (T g ) was selected as the middle point of the portion where the slope of the curve changed in the drawing showing the DSC result, and the coefficient of thermal expansion (CTE) was TMA. It was measured in the temperature range from 50 ° C to 250 ° C.

* 72 refractive index was measured by the prism coupling method (Prism Coupling Method) using a light source of 633nm wavelength after producing a thin polyimide film coated on a suitable glass.

Solubility of N-methylpyrrolidone (NMP), N, N-dimethylacetamide (DMAc), N, N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) When added to m-cresol, tetrahydrofuran (THF), chloroform and acetone, it melts well at room temperature ++, melts at elevated temperature +, melts partially at elevated temperature +-, raises temperature If it does not melt, it is marked with-.

Example 1 Synthesis of Diamine Compound of Formula 1 as an Asymmetric Structure Having Trifluoromethyl Group and Benzimidazole Ring

Example 1 Synthesis of 6,4'-Diamino-2'-trifluoromethyl-2-phenylbenzimidazole

27.0 g (100 mmol) of 2-bromo-5-nitrobenzotrifluoride was dissolved in 100 mL of N, N-dimethylformamide (DMF), and then 10.0 g (112 mmol) of cyanocopper (CuCN) was added and 150 ° C. Stirred for 8 h. After stirring, the reaction solution was cooled to room temperature, diluted with addition of 300 mL of dichloromethane, extracted with distilled water several times to remove DMF and salts, water was removed with anhydrous magnesium sulfate, and the solvent was distilled off under reduced pressure. As a result, 2-bromo-5-nitrobenzonitrile, a pale yellow viscous liquid, was synthesized. (19.8g, 91.6mmol; yield = 91.6%)

19.0 g (87.9 mmol) of 2-bromo-5-nitrobenzonitrile and 200 mL of 70% concentrated sulfuric acid were put in a 500 mL reaction vessel, and the reaction was carried out at reflux for 1 hour at 100 ° C and 30 minutes at 170 ° C. After the reaction, the mixture was precipitated in 1 L of water to synthesize colorless 4-nitro-2-trifluoromethylbenzoic acid. (18.0 g, 76.6 mmol; yield = 87.1%)

16.5 g (70.2 mmol) of 4-nitro-2-trifluoromethylbenzoic acid and 80 mL of thionyl chloride (SOCl 2) were added to a 250 mL reaction vessel, and reacted under reflux for 4 hours. After the reaction, SOCl2 was distilled off under reduced pressure to obtain 4-nitro-2-trifluoromethylbenzoyl chloride (70.2 mmol), and then triethylamine as a base in 100 mL of N, N-dimethylacetamide (DMAc) solvent. 7.8 g (77 mmol) was added and 90 mL of a solution of 10.7 g (69.9 mmol) of 4-nitro-1,2-phenylenediamine was slowly added dropwise, followed by stirring at room temperature for 8 hours. After stirring, the precipitate was precipitated in 1 L of water to obtain a pale brown, powdery 2'-amino-4,5'-dytro-2-trifluoromethylbenzamide. (24.1 g, 65.1 mmol; yield = 93.1%)

* 79 18.5 g (50.0 mmol) of synthesized 2'-amino-4,5'-dynitro-2-trifluoromethylbenzamide, together with 250 mL of glacial acetic acid, were placed in a 500 mL reaction vessel for 12 hours at an external temperature of 150 ° C. Reaction at reflux. After the reaction, the precipitate was precipitated in 1.2 L of water to synthesize yellow, powdery 6,4'-dytro-2'-trifluoromethyl-2-phenylbenzimidazole. (12.9g, 36.6mmol; Yield = 73.2%)

12.5 g (35.5 mmol) of 6,4'-dynitro-2'-trifluoromethyl-2-phenylbenzimidazole, a dynamite compound, were added together with 160 mL of ethanol into a 500 mL reaction vessel and anhydrous tin chloride (SnCl2 41.0 g (216 mmol) was added. 80 mL of concentrated hydrochloric acid was slowly added dropwise to the reaction solution, and the reaction mixture was reacted under reflux for 8 hours. After the reaction, ethanol was evaporated, mixed with 300 mL of water, and 10% sodium hydroxide solution was added to give a pale yellow diamine monomer as a precipitate. This was recrystallized in ethanol / water to give a pale yellow 6,4'-diamino-2'-trifluoromethyl-2-phenylbenzimidazole. (8.49 g, 29.0 mmol; yield = 81.7%)

1H NMR and IR results of the prepared 6,4'-diamino-2'-trifluoromethyl-2-phenylbenzimidazole are shown in FIGS. 1 and 2, respectively.

Examples 2 to 5: Preparation of Aromatic Polyimide Using Diamine Compound of Formula 1

Example 2

0.7924 g (27.11 mmol) of diamine monomer was completely dissolved in purified 10 mL of N-methylpyrrolidone (NMP), followed by the same equivalent of 3,3 ', 4,4'-diphenylethercarboxylic acid dianhydride ( ODPA) 0.8410 g (27.11 mmol) was added in a solid state and stirred at room temperature for 4 hours to form a polyamic acid. After 5 mL of N-methylpyrrolidone was further added to the polyamic acid-formed solution, the temperature was raised to 190 ° C., and 5 mL of chlorobenzene was added thereto, followed by stirring for 8 hours while removing water, a by-product generated during imidization. At this time, no precipitation or gelation phenomenon occurred during the reaction. After 8 hours, the resulting viscous solution was cooled to room temperature and precipitated with a mixture of methanol and water and filtered. The filtered white precipitate was washed twice with excess water, hot methanol, and hot acetone, respectively, and then dried at a temperature of 70 ° C. and vacuum to prepare an aromatic polyimide. The prepared aromatic polyimide was dissolved in a DMAc solvent, at which time the concentration of the solution was 10 wt%. 10 wt% of DMAc solution was applied to the glass plate, and then solvent was removed at a temperature of 70 ° C. and vacuum for 24 hours to prepare a pale yellow transparent and tough film.

The kind, viscosity, glass transition temperature, temperature at 5% weight loss, coefficient of thermal expansion, solubility, refractive index, birefringence and film thickness of tetracarboxylic dianhydride used to prepare aromatic polyimide are shown in Table 1. .

In addition, the DSC results performed on the prepared aromatic polyimide are shown in FIG. 5.

Example 3

Aromatic polyimide was carried out in the same manner as in Example 2, except that 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride (BTDA) was used instead of ODPA used as tetracarboxylic dianhydride. Was prepared and a light brown transparent and tough film was obtained.

Example 3 was also the same as in Example 2, no precipitation or gelation phenomenon occurred during the reaction.

The type, viscosity, glass transition temperature, temperature at 5% weight loss, coefficient of thermal expansion, solubility, refractive index, birefringence and film thickness of tetracarboxylic dianhydride used to prepare aromatic polyimides are shown in Table 1. .

In addition, IR, 1H NMR, TGA and DSC results of the prepared aromatic polyimide are shown in FIGS. 2, 3, 4 and 5, respectively.

Example 4

An aromatic polyimide was prepared using 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride (BPDA) instead of ODPA used as tetracarboxylic dianhydride, and instead of 10wt% DMAc solution. An orange transparent and tough film was obtained in the same manner as in Example 2, except that the film was prepared with a 10 wt% N-methylpyrrolidone (NMP) solution.

Example 4 Like Example 2, no precipitation or gelation phenomenon occurred during the reaction.

The type, viscosity, glass transition temperature, temperature at 5% weight loss, coefficient of thermal expansion, solubility, refractive index, birefringence and film thickness of tetracarboxylic dianhydride used to prepare aromatic polyimides are shown in Table 1. .

In addition, the DSC results performed on the prepared aromatic polyimide are shown in FIG. 5.

Comparative example

In order to compare the physical properties of the above examples are commonly known under the trade name Kapton (TM), a polyimide having the structure of Formula 8 was purchased. The polyimide is insoluble and 4,4'-diaminodiphenyl ether (ODA) and 1,2,4,5-benzenetetracarboxylic acid (1,2,4,5- bnezenetetracarboxylic acid (PMDA), and their general properties are shown in Table 1.

[Formula 8]

As shown in Table 1, the general physical properties represented by the polyimide prepared in Examples 2, 3 and 4, namely, viscosity, glass transition temperature, temperature at 5% weight loss and glass expansion coefficient compared to the comparative example It can be seen that similar (Example 2) to excellent (Examples 3 and 4) physical properties. Therefore, even when the aromatic polyimide is prepared from the diamine monomer having the trifluoromethyl group and the benzimidazole ring introduced according to the present invention, general physical properties are not deteriorated, so that it is still applicable to the industrial field in which the conventional polyimide was used. do.

In addition, the polyimides prepared in Examples 2, 3 and 4 exhibit excellent solubility in the solvents of NMP, DMAc, DMF, and DMSO, wherein the polyimide according to the present invention is a trifluoromethyl group and a benzimidazole ring. In spite of being introduced and having a rigid structure, the introduction of the trifluoromethyl group and various interactions with the overall asymmetric structure are suppressed, thereby providing a soluble polymer.

On the other hand, it shows that the polyimide of the present invention is selectively dissolved in a solvent such as NMP, DMAc, DMF, DMSO by showing insolubility in chloroform or acetone, which are common organic solvents, and low solubility in m-cresol and THF. Can be.

In addition, the refractive index and birefringence of the aromatic polyimide films of Examples 2, 3 and 4 prepared using the solvents described above are lower than those of the comparative examples, which indicates that the low polarization of the fluorine atoms of the trifluoromethyl group is low. This is because the polyimide of the present invention can be usefully used as an electro-electro-optic material.

As described above, the diamine compound having an asymmetric structure having the trifluoromethyl group and the benzimidazole ring according to the present invention, and the aromatic polyimide prepared by using the monomer as a monomer exhibits toughness as a rigid structure, It has a good solubility in the polymer state, has excellent workability, low refractive index, and good adhesion to substrates including metals such as copper, which can be used in electric and electronic, optical and separator machines. Invention.

While the invention has been described in detail above with reference to the described embodiments, it will be apparent to those skilled in the art that various modifications and variations are possible within the scope and spirit of the invention, and such modifications and variations fall within the scope of the appended claims. It is also natural.

Claims (2)

Diamine compound characterized in that the compound of formula 1 as an asymmetric structure having a trifluoromethyl group and a benzimidazole ring. [Formula 1]

(A) synthesizing 4-nitro-2-trifluoromethyl benzoic acid of Formula 3 from 2-bromo-5-nitrobenzotrifluoride of Formula 2; (B) reacting the 4-nitro-2-trifluoromethyl benzoic acid with 4-nitro-1,2-phenylene diamine of the following Chemical Formula 4 and then cyclizing the compound to give a dynamite of the following Chemical Formula 5. Synthesizing; And (C) reducing the nitro group in the compound to the dynamite; Method for producing a diamine compound of claim 1 comprising a. [Formula 2]

[Formula 3]

[Formula 4]

[Formula 5]

Images