The invention relates to an electronic grade 4, 4apos; refining and purifying method of-bis (4-aminophenoxy) biphenyl

Abstract

The invention discloses a method for refining and purifying electronic-grade 4, 4 '-di (4-aminophenoxy) biphenyl, and aims to obtain a diamine monomer with low metal impurity content. The method comprises the following treatment steps: (1) dissolving a BAPB diamine crude product in an acetonitrile solvent under a heating condition; (2) adding pretreated activated aluminum oxide powder particles or an activated carbon adsorbent into an acetonitrile solution of BAPB, starting stirring, refluxing for 2 hours at 90 DEG C, and carrying out hot filtration; (3) adding pretreated ion exchange resin into the filtrate under a heating condition, starting stirring, refluxing for 2 hours at 90 DEG C, and carrying out hot filtration; (4) slowly cooling the filtrate to room temperature, separating out a BAPB diamine solid, and carrying out suction filtration; and (5) washing the filtered BAPB with ultrapure water, and drying to obtain a final product. The BAPB diamine monomer obtained by the invention meets the requirements of downstream applications of electronic-grade polyimide films, electronic-grade polyimide resin, flexible printed circuit boards, liquid crystal PI orientation agents, photosensitive PI adhesives and the like.

Description

Technical Field

[0001] The invention belongs to the field of fine chemicals, and specifically relates to a method for refining and purifying electronic-grade 4,4'-di(4-aminophenoxy)biphenyl. Background Art

[0002] 4,4′-bis(4-aminophenoxy)biphenyl, abbreviated as BAPB, is a diamine with an aromatic ring. Its structure is shown in the figure below. Because of its low thermal expansion coefficient and dielectric constant, excellent chemical resistance and radiation resistance, it is widely used in high-temperature resistant insulating materials, microelectronic layer isolation films, liquid crystal displays, resistance conversion memories, etc.

[0003]

[0004] 4,4′-bis(4-aminophenoxy)biphenyl is a white solid. Its preparation method has been reported in literature or patents (Insulating Materials, Issue 41, 2008, Yu Xinhai, page 10; CN101293842B). It first uses 4,4′-dihydroxybiphenyl, 4-chloronitrobenzene and potassium carbonate as raw materials to reflux in a mixed solvent system of N,N-dimethylformamide (DMF) and toluene to generate 4,4′-bis(4-nitrophenoxy)biphenyl, and then further reduces it to 4,4′-bis(4-aminophenoxy)biphenyl in a Pd / C-hydrazine hydrate reduction system. The purity of the obtained product is 99.2%. The literature does not mention a method for removing residual metal impurities in 4,4′-bis(4-aminophenoxy)biphenyl diamine.

[0005] 4,4′-bis(4-aminophenoxy)biphenyl can be used to react with common PMDA pyromellitic anhydride, BPDA biphenyl tetracarboxylic anhydride, etc. to prepare polyamic acid solution, and then prepare polyimide film materials. As a diamine monomer raw material, the organic purity of 4,4′-bis(4-aminophenoxy)biphenyl directly affects the viscosity and molecular weight of polyamic acid. The Pd introduced during its synthesis and preparation and the content of common metal impurities such as Na, Mg, and Ca will also affect the electrical properties of the final polyimide film. Therefore, in order to ensure the quality of polyimide film, it is necessary to find an effective purification method to obtain electronic grade high-purity 4,4′-bis(4-aminophenoxy)biphenyl diamine monomer. Summary of the invention

[0006] In order to solve the problems mentioned in the above background technology, the present invention provides a relatively simple purification method, which uses acetonitrile as a recrystallization solvent, alumina or activated carbon as an adsorbent, and an ion exchange resin for a displacement reaction, thereby obtaining high-purity 4,4′-di(4-aminophenoxy)biphenyl and effectively reducing the content of metal impurities in the sample.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] A method for refining and purifying electronic-grade 4,4'-bis(4-aminophenoxy)biphenyl comprises the following steps: adding a crude 4,4'-bis(4-aminophenoxy)biphenyl raw material and acetonitrile into a reaction container, heating, stirring and dissolving, successively adding an activated alumina / activated carbon adsorbent and an ion exchange resin to carry out an impurity removal reaction, then filtering while hot, cooling the filtrate to recrystallize and precipitate a solid, filtering by suction, washing with water, and then drying to obtain a final product.

[0009] The further technical scheme is as follows: the specific implementation steps are as follows: adding crude 4,4′-di(4-aminophenoxy)biphenyl raw material and acetonitrile into a reaction container; heating to 90°C and stirring to dissolve; adding pretreated activated alumina or activated carbon adsorbent into the reaction solution, refluxing at high temperature for 2 hours, and hot filtering; adding pretreated ion exchange resin into the filtrate, refluxing at high temperature for 2 hours, and hot filtering; slowly cooling the filtrate to room temperature, recrystallizing to obtain 4,4′-di(4-aminophenoxy)biphenyl solid, filtering with suction, rinsing with ultrapure water, and drying to obtain the final product.

[0010] Preferably, the mass ratio of the crude 4,4′-bis(4-aminophenoxy)biphenyl raw material, acetonitrile, adsorbent, and ion exchange resin is 1:(10-20):(2-5):(2-5);

[0011] Preferably, the adsorbent is one of activated alumina and activated carbon; the adsorbent needs to be cleaned three times with 4% hydrochloric acid and ultrapure water before use, and then dehydrated with acetonitrile;

[0012] Preferably, the ion exchange resin is a chelating ion exchange resin or a strong acid cation exchange resin; the ion exchange resin needs to be activated and cleaned with 4% hydrochloric acid, ultrapure water, and acetonitrile before use, and then cleaned with ultrapure water and acetonitrile;

[0013] Preferably, the filter membrane used for heat filtration is made of PTFE polytetrafluoroethylene or PVDF polyvinylidene fluoride, with a pore size of 5 μm;

[0014] Preferably, the final drying temperature in S5 is 60-70° C. and the drying time is 4-12 hours.

[0015] The beneficial effects of the present invention are:

[0016] 1. During the purification process of 4,4′-bis(4-aminophenoxy)biphenyl samples, only acetonitrile is used as the recrystallization solvent and water is used as the cleaning solvent. The solvent is easy to obtain and recycle, and the obtained sample has a high purity.

[0017] 2. After the 4,4′-bis(4-aminophenoxy)biphenyl sample was treated with the two impurity removal processes of alumina / activated carbon adsorbent and ion exchange resin replacement, the metal impurity content in the sample decreased significantly. It can be seen from the results of the embodiment that the alumina adsorbent can significantly reduce the Pd and Fe contents in the sample, and the ion exchange resin can reduce the Na, Mg, Ca and other contents; when the metal impurity content in the sample is known, these two impurity removal processes can be used selectively;

[0018] 3. The method for removing metal impurities mentioned in the present invention can be extended to the electronic grade purification of other compounds, and only the recrystallization solvent and the cleaning solvent need to be re-screened.

[0019] 4. The method of the present invention uses alumina and activated carbon as adsorbents and replaces them through ion exchange resin to finally obtain BAPB diamine monomer with a purity of 99.9%. The metal impurity content is reduced to below 0.5 ppm, which can be used for the synthesis and preparation of electronic grade polyimide and meet the requirements of downstream applications such as electronic grade polyimide film, electronic grade polyimide resin, flexible printed circuit board, liquid crystal PI orientation agent, photosensitive PI glue, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 It is a process flow chart of the present invention;

[0022] Figure 2 It is the HPLC test result of Example 1 in the present invention. DETAILED DESCRIPTION

[0023] Example 1

[0024] Weigh crude 4,4′-di(4-aminophenoxy)biphenyl (3 g) and acetonitrile (60 mL) into a three-necked round-bottom flask, add a magnet and a thermometer, and heat to 90°C. After the sample is completely dissolved, add 6 g of pretreated activated alumina, reflux at 90°C for 2 hours, and then filter while hot; add 6 g of pretreated D401 chelating ion exchange resin to the filtrate, reflux at 90°C for 2 hours, and then filter while hot; the filtrate is slowly cooled to room temperature, and a solid sample is recrystallized. Wash the solid sample with ultrapure water and bake it in an oven at 60°C for 10 hours to obtain the final sample.

[0025] According to liquid chromatography (HPLC) analysis, the purity of 4,4′-bis(4-aminophenoxy)biphenyl diamine obtained in this embodiment is 99.9%; according to inductively coupled plasma mass spectrometry ICP-MS detection, the total content of metal impurities such as Na, Mg, Al, K, Ca, Fe, Cu, Zn, Pd, etc. in the sample is 1.31 ppm, compared with Comparative Example 1 and Comparative Example 2, the content of metal impurities such as K, Ca, Zn, Pd, etc. is significantly reduced.

[0026] Example 2

[0027] Weigh crude 4,4′-di(4-aminophenoxy)biphenyl (3 g) and acetonitrile (60 mL) into a three-necked round-bottom flask, add a magnet and a thermometer, and heat to 90°C. After the sample is completely dissolved, add 6 g of pretreated activated alumina, reflux at 90°C for 2 hours, and then filter while hot; add 6 g of pretreated activated alumina to the filtrate. IRC120H strong acid cation exchange resin was refluxed at 90°C for 2 hours, and then filtered while hot; the filtrate was slowly cooled to room temperature, and a solid sample was recrystallized. The solid sample was washed with ultrapure water and baked in an oven at 60°C for 10 hours to obtain the final sample.

[0028] According to liquid chromatography (HPLC) analysis, the purity of 4,4′-bis(4-aminophenoxy)biphenyl diamine obtained in this embodiment is 99.9%; according to inductively coupled plasma mass spectrometry ICP-MS detection, the total content of metal impurities such as Na, Mg, Al, K, Ca, Fe, Cu, Zn, Pd, etc. in the sample is 1.32ppm, compared with Comparative Example 1 and Comparative Example 3, the content of metal impurities such as Na, Ca, Zn, Pd, etc. is significantly reduced.

[0029] Comparative Example 1

[0030] Weigh crude 4,4′-di(4-aminophenoxy)biphenyl (3 g) and acetonitrile (50 mL) in a three-necked round-bottom flask, add a magnet and a thermometer, and heat to 90°C. After the sample is completely dissolved, add 6 g of pretreated activated alumina, reflux at 90°C for 2 hours, and then filter while hot. The filtrate is slowly cooled to room temperature, and a solid sample is recrystallized. Wash the solid sample with ultrapure water and bake it in an oven at 60°C for 10 hours to obtain the final sample.

[0031] According to liquid chromatography (HPLC) analysis, the purity of 4,4′-bis(4-aminophenoxy)biphenyl diamine obtained in this embodiment is 99.9%. According to inductively coupled plasma mass spectrometry ICP-MS detection, the total content of metal impurities such as Na, Mg, Al, K, Ca, Fe, Cu, Zn, and Pd in ​​the sample is 1.96 ppm.

[0032] Comparative Example 2

[0033] Weigh crude 4,4′-di(4-aminophenoxy)biphenyl (3 g) and acetonitrile (50 mL) in a three-necked round-bottom flask, add a magnet and a thermometer, and heat to 90°C. After the sample is completely dissolved, add 6 g of pretreated D401 chelating ion exchange resin, reflux at 90°C for 2 hours, and then filter while hot. The filtrate is slowly cooled to room temperature, and a solid sample is precipitated by recrystallization. Wash the solid sample with ultrapure water and bake it in an oven at 60°C for 10 hours to obtain the final sample.

[0034] According to liquid chromatography (HPLC) analysis, the purity of 4,4′-di(4-aminophenoxy)biphenyl diamine obtained in this embodiment is 99.9%. According to inductively coupled plasma mass spectrometry ICP-MS detection, the total content of metal impurities such as Na, Mg, Al, K, Ca, Fe, Cu, Zn, and Pd in ​​the sample is 2.5 ppm.

[0035] Comparative Example 3

[0036] Weigh crude 4,4′-di(4-aminophenoxy)biphenyl (3 g) and acetonitrile (50 mL) into a three-necked round-bottom flask, add a magnet and a thermometer, and heat to 90°C. After the sample is completely dissolved, add 6 g of pretreated IRC120H strong acid cation exchange resin was refluxed at 90°C for 2 hours, then filtered while hot, and the filtrate was slowly cooled to room temperature to recrystallize and precipitate a solid sample. The solid sample was washed with ultrapure water and baked in an oven at 60°C for 10 hours to obtain the final sample.

[0037] According to liquid chromatography (HPLC) analysis, the purity of 4,4′-bis(4-aminophenoxy)biphenyl diamine obtained in this embodiment is 99.9%. According to inductively coupled plasma mass spectrometry ICP-MS detection, the total content of metal impurities such as Na, Mg, Al, K, Ca, Fe, Cu, Zn, and Pd in ​​the sample is 1.88 ppm.

[0038] Table 1 is the test results of the metal impurity content of each embodiment of the present invention;

[0039] Table 1

[0040]

[0041] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for refining and purifying electronic grade 4,4'-bis(4-aminophenoxy)biphenyl, characterized in that: The following steps are involved: S1, dissolving the crude BAPB raw material in acetonitrile solvent under heating conditions; S2. Add the pretreated adsorbent to the acetonitrile solution of BAPB, wherein the pretreatment method is washing with hydrochloric acid and ultrapure water and dehydrating with acetonitrile, start stirring, reflux at 90° C. for 2 hours, and hot filter to obtain a filtrate; S3, under heating conditions, add the pretreated ion exchange resin to the S2 filtrate, start stirring, reflux at 90°C for 2 hours, and hot filter to obtain a filtrate; The filtrate in S4 and S3 slowly cooled to room temperature to precipitate BAPB diamine solid, which was then filtered; S5. Rinse the BAPB obtained after filtration with ultrapure water and dry it to obtain the final product.

2. The method for refining and purifying electronic grade 4,4'-bis(4-aminophenoxy)biphenyl according to claim 1, characterized in that: The adsorbent is activated alumina or activated carbon.

3. The method for refining and purifying electronic grade 4,4'-bis(4-aminophenoxy)biphenyl according to claim 2, characterized in that: The pretreatment method of the adsorbent includes: washing with 4% hydrochloric acid and ultrapure water for 3 times before use, and then dehydrating with acetonitrile.

4. The method for refining and purifying electronic grade 4,4'-bis(4-aminophenoxy)biphenyl according to claim 1, characterized in that: The ion exchange resin is a chelate ion exchange resin or a strong acid cation exchange resin.

5. The method for refining and purifying electronic grade 4,4'-bis(4-aminophenoxy)biphenyl according to claim 4, characterized in that: The pretreatment method of the ion exchange resin comprises: activating and washing with 4% hydrochloric acid, ultrapure water and acetonitrile before use, and then washing with ultrapure water and acetonitrile.

6. The method for refining and purifying electronic grade 4,4'-bis(4-aminophenoxy)biphenyl according to claim 1, characterized in that: The mass ratio of the crude BAPB raw material, acetonitrile, adsorbent and ion exchange resin is 1:(10-20):(2-5):(2-5).

7. The method for refining and purifying electronic grade 4,4'-bis(4-aminophenoxy)biphenyl according to claim 1, characterized in that: The filter membrane used for the hot filtration is made of PTFE polytetrafluoroethylene or PVDF polyvinylidene fluoride, with a pore size of 5 μm.

8. The method for refining and purifying electronic grade 4,4'-bis(4-aminophenoxy)biphenyl according to claim 1, characterized in that: The drying temperature in S5 is 60-70° C. and the drying time is 4-12 hours.

Images