CN1261407C - A kind of fluorine-containing aromatic diamine containing azo structure and its preparation method and application - Google Patents

Abstract

The fluorine-containing aromatic diamine containing azo structure of the present invention is prepared according to the following steps: (1) by weight, 1-80 parts of trifluoromethyl-substituted aniline and 1-160 parts of HCl/H ₂ O are mixed solution and 1-40 parts of sodium nitrite aqueous solution to make diazonium salt solution; (2) slowly dropwise add 1-80 parts of m-phenylenediamine and 1-160 parts of HCl/H ₂ O mixed solution in the above diazonium salt solution The prepared solution is filtered, washed with water, dried and recrystallized to obtain the fluorine-containing aromatic diamine containing an azo structure. The fluorine-containing aromatic diamine containing azo structure described in the present invention is used for synthesizing polyimide liquid crystal aligning agent.

Description

A kind of fluorine-containing aromatic diamine containing azo structure and its preparation method and application

technical field

The invention relates to a class of fluorine-containing aromatic diamines containing an azo structure and its preparation method and use.

Background technique

Aromatic diamines are widely used in the synthesis of polyimides. In recent years, with the rapid development of the microelectronics industry, the demand for functional polyimide materials has become more and more extensive. Standard polyimide materials are generally insoluble and infusible due to their rigid backbone structure. Therefore, in practical applications, it is mostly used in the form of its precursor, that is, polyamic acid (Edited by Ding Mengxian and He Tianbai, New Polyimide Materials, Science Press, 1998, 1). Polyamic acid can be converted into polyimide after imidization at high temperature. The imidization temperature is usually 250-300°C. Such a high temperature is unbearable for many temperature-sensitive fields in the microelectronics industry. . In view of this, extensive modification work has been carried out on standard polyimide materials. Among them, the preparation of organic soluble polyimides by synthesizing novel monomers is a hot topic of current research (Huang S.J., Hoyt A.E., The synthesis of soluble polyimides, TRIP, 1995, 3(8), 262-271).

There are a wide variety of diamine monomers for the synthesis of soluble polyimides, among which introducing fluorine-containing substituents in diamines is one of the most effective means of synthesizing soluble polyimides (Ghosh M.K., Mittal K.L., Polyimide: fundamentals and applications, Marcel Dekker, 1996, p71). There are many reports about fluorine-containing diamine monomers in the literature. For example, Ichino et al. reported fluorine-containing diamine monomers with long fluoroalkyl side chains (Ichino T., Sasaki S., Matsuura T. and Nishi S., J. Polym. Sci., Part A: Polym Chem., 1990, 28, p323). Auman et al. have synthesized the fluorine-containing diamine monomer (Auman B.C., Higley D.P., Scherer K.V, Polym.Prepr., 1993,34 (1) with two (trifluoromethyl) heptafluoroalkyl substituents in the side chain , p389). Yusa et al studied the polymerization behavior of diamine monomers with perfluorononenyl ether in the side chain (Yusa M., Takeda S., and Miyadera Y, Polym.Prepr.Japan, 1990, 39, p897) and so on .

Although the above-mentioned fluorine-containing monomers are used in the synthesis of polyimides, the synthesis routes of these fluorine-containing diamines are relatively complicated, and the raw materials are not easy to obtain, especially the purification of the monomers is relatively difficult, and it is difficult to obtain high-purity products and achieve mass production. purpose, which largely limits the application.

Contents of the invention

The invention provides a novel fluorine-containing diamine monomer, its preparation method and application. The synthetic route of this monomer is simple, the raw material is easy to obtain, and it is easy to purify, so it can be produced in large quantities.

The fluorine-containing aromatic diamine of the present invention has the structure shown in general formula (1):

Among them, ^R1 is: or

Wherein, R _f is: -CF ₃ or -(CF ₃ ) ₂ .

The fluorine-containing aromatic diamine represented by the general formula (1) particularly includes a diamine monomer of the following structure:

The fluorine-containing aromatic diamine containing azo structure of the present invention is synthesized according to the following steps:

(1) In parts by weight, dissolve 1-80 parts of trifluoromethyl-substituted aniline in 1-160 parts of HCl/H ₂ O mixed solution, add 1-40 parts of sodium nitrite aqueous solution dropwise at 0-5°C, and stir After 0.5-3 hours, make diazonium salt solution A;

(2) Dissolving 1-80 parts of m-phenylenediamine in 1-160 parts of HCl/H ₂ O mixed solution by weight to prepare solution B;

(3) Slowly add solution B to solution A at 0-5°C, and after the dropwise addition, stir the mixture at 0-5°C for 1-3 hours, then raise the temperature to 25°C. Add 1-60 parts (parts by weight) of ammonia solution dropwise to the system to adjust the pH value to about 7. The mixed system was filtered, washed with water repeatedly, and dried in vacuum to obtain a crude product. The crude product is recrystallized from ethanol to obtain the fluorine-containing aromatic diamine containing an azo structure.

The fluorine-containing aromatic diamine containing azo structure of the present invention is tested by analysis means such as Fourier transform infrared spectrum (FT-IR), nuclear magnetic resonance (NMR), mass spectrometry (MS), elemental analysis, chromatogram-mass spectrometry, etc. The diamine structure was invented, and its purity can reach 99.5%. The ion analysis test shows that the ion content of the monomer of this structure is as follows: Na ⁺ <1-2ppm, Cl ^- <1-2ppm, K ⁺ <1ppm. In addition, the raw materials of this type of monomer are easy to obtain, and the yield is as high as 80-85%, which is suitable for large-scale production.

The fluorine-containing aromatic diamine containing an azo structure of the present invention is used for preparing a polyimide liquid crystal aligning agent.

Detailed ways

Example 1 In a three-neck flask equipped with a stirrer and a thermometer, 33.52 g (0.208 mol) of m-trifluoromethylaniline was dissolved in 52.5 ml of 37% HCl and 20 ml of H ₂ O. The system was cooled to 0-5°C with ice water, and a 14.1g NaNO ₂ /30ml H ₂ O solution was added dropwise. Stirring was continued for 1 hr after the dropwise addition was completed. 21.8g (0.202mol) of m-phenylenediamine was dissolved in 18.0ml of 37% HCl and 150ml of H ₂ O, and the solution was added dropwise to the above system. After the dropwise addition was complete, the mixture was stirred for 2 hours, and 46 g of sodium acetate was added. After cooling with ice water for 1 hour, the temperature was raised to room temperature. Add 20% NaOH solution dropwise to the system to adjust the pH value to about 7. The resulting red powder precipitate was filtered, washed with water repeatedly, and dried in vacuum. The crude product was recrystallized from ethanol to obtain crystal 2,4-diamino-3'-trifluoromethylazobenzene with a yield of 39.8 g (84%), and its structure is shown in formula (2). FT-IR (KBr, cm ^-1 ): 3501.7, 3439.4, 3362.7, 1632.8, 1576.1; ¹ H-NMR (300MHz, DMSO-d ₆ , ppm): 5.93(s; 1H); 6.08-6.11(d; 1H ); 6.17(s; 2H); 7.37(s; 2H); 7.42-7.47(d; 1H); 7.57-7.62(m; 1H); 7.65-7.67(m; 1H); 7.97-8.00(d; 1H ); 8.02 (s; 1H). ¹³ C-NMR (300MHz, DMSO-d ₆ , ppm): 96.5, 106.8; 117.3; 119.3, 122.9, 126.5, 131.0; 123.5; 154.4. Mass spectrum: 280 (M+, 36.6). Elemental analysis: C ₁₃ H ₁₁ F ₃ N ₄ : Calculated: C, 55.71%; H, 3.96%; N, 19.99%. Found: C, 55.54%; H , 3.95%; N, 19.95%.

Example 2 In a three-neck flask equipped with a stirrer and a thermometer, 33.52 g (0.208 mol) of p-trifluoromethylaniline was dissolved in 52.5 ml of 37% HCl and 20 ml of H ₂ O. The system was cooled to 0-5°C with ice water, and a 14.1g NaNO ₂ /30ml H ₂ O solution was added dropwise. Stirring was continued for 1 hr after the dropwise addition was completed. 21.8g (0.202mol) of m-phenylenediamine was dissolved in 18.0ml of 37% HCl and 150ml of H ₂ O, and the solution was added dropwise to the above system. After the addition was complete, the mixture was stirred for 2 hrs, and 46 g of sodium acetate was added. After cooling with ice water for 1 hr, the temperature was raised to room temperature. Add 20% NaOH solution dropwise to the system to adjust the pH value to about 7. The resulting red powder precipitate was filtered, washed with water repeatedly, and dried in vacuum. The crude product was recrystallized from ethanol to obtain crystalline 2,4-diamino-4'-trifluoromethylazobenzene with a yield of 40.7 g (86%). Its structure is shown in formula (3). FT-IR (KBr, cm ^-1 ): 3496.7, 3432.4, 3369.7, 1630.8, 1570.1; ¹ H-NMR (300MHz, DMSO-d ₆ , ppm): 5.96(s; 1H); 6.06-6.11(d; 1H ); 6.20(s, 2H), 7.44(s; 2H); 7.67-7.70(m; 2H); 7.87-7.92(d; 2H); 8.05(s; 2H). Mass Spectrum: 280(M+, 36.6). Elemental analysis: C ₁₃ H ₁₁ F ₃ N ₄ : Calculated: C, 55.71%; H, 3.96%; N, 19.99%. Found: C, 55.54%; H, 3.95%; N, 19.95%.

Example 3 In a three-neck flask equipped with a stirrer and a thermometer, 52.60 g (0.208 mol) of 4-(4'-trifluoromethyl)phenoxyaniline was dissolved in 52.5 ml of 37% HCl and 50 ml of H ₂ O. The system was cooled to 0-5°C with ice water, and a 14.1g NaNO ₂ /50ml H ₂ O solution was added dropwise. Stirring was continued for 1.5 hr after the dropwise addition was completed. 21.8g (0.202mol) of m-phenylenediamine was dissolved in 18.0ml of 37% HCl and 150ml of H ₂ O, and the solution was added dropwise to the above system. After the addition was complete, the mixture was stirred for 1 hr and 46 g of sodium acetate was added. After cooling with ice water for 1 hr, the temperature was raised to room temperature. Add 20% NaOH solution dropwise to the system to adjust the pH value to about 7. The resulting red powder precipitate was filtered, washed with water repeatedly, and dried in vacuum. The crude product is recrystallized with ethanol to obtain crystal 2,4-diamino-4'-[4"-(trifluoromethyl)phenoxy]azobenzene, yield 63.93g (85%), and its structure is shown in formula (4 ). FT-IR (KBr, cm ^-1 ): 3442.4, 3369.2, 1630.8, 1570.1; ¹ H-NMR (300MHz, DMSO-d ₆ , ppm): 5.92 (s; 1H); 6.07-6.10 (d ; 1H); 6.19(s; 2H); 6.92-6.96(d, 2H), 7.20-7.25(d, 2H), 7.37(s; 2H); 7.42-7.47(d; 1H); 7.57-7.62(m ; 2H); 7.97-8.00 (d; 2H). Mass spectrum: 372 (M+, 36.6). Elemental analysis: C ₁₉ H ₁₅ F ₃ N ₄ O: Calculated: C, 61.29%; H, 4.06%; N, 15.05%. Found: C, 61.24%; H, 4.05%; N, 15.02%.

Example 4 In a three-necked flask equipped with a stirrer and a thermometer, 66.81g (0.208mol) of 4-(3',5'-bistrifluoromethyl)phenoxyaniline was dissolved in 52.5ml of 37% HCl and 60ml of H ₂ O middle. The system was cooled to 0-5°C with ice water, and 14.1g NaNO ₂ /60ml H ₂ O solution was added dropwise. Stirring was continued for 1.5 hours after the dropwise addition was complete. 21.8g (0.202mol) of m-phenylenediamine was dissolved in 18.0ml of 37% HCl and 150ml of H ₂ O, and the solution was added dropwise to the above system. After the dropwise addition was complete, the mixture was stirred for 2.5 hours, and 46 g of sodium acetate was added. After cooling with ice water for 1 hr, the temperature was raised to room temperature. Add 20% NaOH solution dropwise to the system to adjust the pH value to about 7. The resulting red powder precipitate was filtered, washed with water repeatedly, and dried in vacuum. The crude product was recrystallized with ethanol to obtain crystal 2,4-diamino-4'-[3", 5"-bis(trifluoromethyl)phenoxy]azobenzene, yield 71.16g (80%), its structure As shown in formula (5). FT-IR (KBr, cm ^-1 ): 3440.6, 3354.2, 1640.8, 1572.7; ¹ H-NMR (300MHz, DMSO-d ₆ , pprr): 5.94 (s; 1H); 6.07-6.10 (d; 1H); 6.19(s; 2H); 7.23-7.26(m, 2H), 7.27-7.31(m; 2H); 7.40(s; 1H); 7.96-8.03(d; 2H). Mass Spectrum: 440(M+, 36.6). Elemental analysis: C ₂₀ H ₁₄ F ₆ N ₄ O: Calculated: C, 54.55%; H, 3.20%; N, 12.72%. Found: C, 54.52%; H, 3.22%; N, 12.69%.

Claims (4)

1. azo structure contained fluorinated aromatic diamines is characterized in that described azo structure contained fluorinated aromatic diamines general formula is as follows:

Wherein, R ¹For Or

Wherein, R _fFor :-CF ₃Or-(CF ₃) ₂

2. azo structure contained fluorinated aromatic diamines according to claim 1 is characterized in that described azo structure contained fluorinated aromatic diamines is:

3. the method for making of azo structure contained fluorinated aromatic diamines according to claim 1 is characterized in that step is carried out in the following order:

(1) by weight, 1-80 part trifluoromethyl substituted aniline is dissolved in 1-160 part HCl/H ₂In the O mixing solutions, 0-5 ℃ drips 1-40 part sodium nitrite in aqueous solution down, stirs after 0.5-3 hour, makes diazonium salt solution;

(2) under 0-5 ℃, in above-mentioned solution, slowly drip by 1-80 part mphenylenediamine and 1-160 part HCl/H ₂The solution that the O mixed solution is made into obtains mixture;

(3) said mixture is warming up to 25 ℃ in stirring under 0-5 ℃ after 1-3 hour.Drip 1-60 part ammonia soln again, adjust about pH value to 7, with the suspension filtered that obtains, filter cake is washed repeatedly, vacuum-drying and recrystallization obtain described azo structure contained fluorinated aromatic diamines.

4. the purposes of azo structure contained fluorinated aromatic diamines according to claim 1 is characterized in that being used to prepare orientation agent of polyimide liquid crystal.