CN116693481B - Purification method of electronic grade hexafluorodianhydride - Google Patents
Purification method of electronic grade hexafluorodianhydride Download PDFInfo
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- CN116693481B CN116693481B CN202310983112.2A CN202310983112A CN116693481B CN 116693481 B CN116693481 B CN 116693481B CN 202310983112 A CN202310983112 A CN 202310983112A CN 116693481 B CN116693481 B CN 116693481B
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- 238000000034 method Methods 0.000 title claims abstract description 37
- 238000000746 purification Methods 0.000 title claims abstract description 21
- 238000002425 crystallisation Methods 0.000 claims abstract description 123
- 230000008025 crystallization Effects 0.000 claims abstract description 123
- 239000012452 mother liquor Substances 0.000 claims abstract description 113
- 239000012528 membrane Substances 0.000 claims abstract description 107
- 239000011347 resin Substances 0.000 claims abstract description 67
- 229920005989 resin Polymers 0.000 claims abstract description 67
- 238000001914 filtration Methods 0.000 claims abstract description 18
- 239000002253 acid Substances 0.000 claims abstract description 4
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims description 58
- 239000013078 crystal Substances 0.000 claims description 46
- 239000007788 liquid Substances 0.000 claims description 44
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 claims description 42
- WEVYAHXRMPXWCK-UHFFFAOYSA-N Acetonitrile Chemical compound CC#N WEVYAHXRMPXWCK-UHFFFAOYSA-N 0.000 claims description 36
- 239000002904 solvent Substances 0.000 claims description 36
- 239000000047 product Substances 0.000 claims description 22
- 238000000926 separation method Methods 0.000 claims description 16
- 239000000725 suspension Substances 0.000 claims description 16
- KRKNYBCHXYNGOX-UHFFFAOYSA-N citric acid Chemical compound OC(=O)CC(O)(C(O)=O)CC(O)=O KRKNYBCHXYNGOX-UHFFFAOYSA-N 0.000 claims description 15
- 238000001035 drying Methods 0.000 claims description 15
- 239000012466 permeate Substances 0.000 claims description 15
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 claims description 10
- CTQNGGLPUBDAKN-UHFFFAOYSA-N O-Xylene Chemical group CC1=CC=CC=C1C CTQNGGLPUBDAKN-UHFFFAOYSA-N 0.000 claims description 6
- ZMXDDKWLCZADIW-UHFFFAOYSA-N N,N-Dimethylformamide Chemical compound CN(C)C=O ZMXDDKWLCZADIW-UHFFFAOYSA-N 0.000 claims description 5
- 229910000147 aluminium phosphate Inorganic materials 0.000 claims description 5
- 238000004064 recycling Methods 0.000 claims description 5
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 claims description 4
- BDAGIHXWWSANSR-UHFFFAOYSA-N methanoic acid Natural products OC=O BDAGIHXWWSANSR-UHFFFAOYSA-N 0.000 claims description 4
- 239000002033 PVDF binder Substances 0.000 claims description 3
- 239000012510 hollow fiber Substances 0.000 claims description 3
- 229940078552 o-xylene Drugs 0.000 claims description 3
- 229920002981 polyvinylidene fluoride Polymers 0.000 claims description 3
- OSWFIVFLDKOXQC-UHFFFAOYSA-N 4-(3-methoxyphenyl)aniline Chemical compound COC1=CC=CC(C=2C=CC(N)=CC=2)=C1 OSWFIVFLDKOXQC-UHFFFAOYSA-N 0.000 claims description 2
- 235000019253 formic acid Nutrition 0.000 claims description 2
- 238000005086 pumping Methods 0.000 claims description 2
- 229910021645 metal ion Inorganic materials 0.000 abstract description 11
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 abstract description 4
- 238000005265 energy consumption Methods 0.000 abstract description 4
- 229910052731 fluorine Inorganic materials 0.000 abstract description 4
- 239000011737 fluorine Substances 0.000 abstract description 4
- 230000008878 coupling Effects 0.000 abstract 1
- 238000010168 coupling process Methods 0.000 abstract 1
- 238000005859 coupling reaction Methods 0.000 abstract 1
- 238000004519 manufacturing process Methods 0.000 abstract 1
- 238000001953 recrystallisation Methods 0.000 abstract 1
- 239000000243 solution Substances 0.000 description 81
- 230000008929 regeneration Effects 0.000 description 26
- 238000011069 regeneration method Methods 0.000 description 26
- 238000004321 preservation Methods 0.000 description 25
- 239000002245 particle Substances 0.000 description 17
- 230000000052 comparative effect Effects 0.000 description 15
- 238000011084 recovery Methods 0.000 description 13
- 238000003756 stirring Methods 0.000 description 13
- 125000004122 cyclic group Chemical group 0.000 description 12
- 238000004821 distillation Methods 0.000 description 12
- 239000000463 material Substances 0.000 description 7
- 239000004642 Polyimide Substances 0.000 description 4
- 229920001721 polyimide Polymers 0.000 description 4
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 3
- 238000001514 detection method Methods 0.000 description 3
- 239000012535 impurity Substances 0.000 description 3
- 150000002500 ions Chemical class 0.000 description 3
- 239000000178 monomer Substances 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 2
- 239000010413 mother solution Substances 0.000 description 2
- 238000000859 sublimation Methods 0.000 description 2
- 230000008022 sublimation Effects 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 239000012141 concentrate Substances 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000012043 crude product Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 239000007791 liquid phase Substances 0.000 description 1
- 238000010899 nucleation Methods 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 238000010587 phase diagram Methods 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 230000008092 positive effect Effects 0.000 description 1
- 239000012264 purified product Substances 0.000 description 1
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- 230000002194 synthesizing effect Effects 0.000 description 1
- 238000002834 transmittance Methods 0.000 description 1
- 239000010887 waste solvent Substances 0.000 description 1
Classifications
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D307/00—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom
- C07D307/77—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom ortho- or peri-condensed with carbocyclic rings or ring systems
- C07D307/87—Benzo [c] furans; Hydrogenated benzo [c] furans
- C07D307/89—Benzo [c] furans; Hydrogenated benzo [c] furans with two oxygen atoms directly attached in positions 1 and 3
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The invention belongs to the technical field of fluorine-containing industry, and particularly discloses a purification method of electronic grade hexafluorodianhydride, which comprises the steps of firstly adding ion chelating exchange resin into 25-50wt% of hexafluorodianhydride solution, adjusting pH to 2-6 by using an acid regulator, carrying out pretreatment, and filtering to obtain hexafluorodianhydride crystallization mother liquor; and then conveying the hexafluorodianhydride crystallization mother liquor into a membrane assembly at a flow rate of 10-20L/h, and performing membrane crystallization at 60-90 ℃. According to the invention, through the coupling of resin pretreatment, membrane crystallization and fluidized bed crystallization, the electronic grade hexafluorodianhydride with purity more than or equal to 99.5%, metal ion content less than or equal to 1ppm and uniform granularity is obtained, and compared with the traditional recrystallization purification process, the energy consumption is lower, the production cost is reduced, and the requirement of industrial purification is met.
Description
Technical Field
The invention belongs to the technical field of fluorine-containing industry, and particularly relates to a purification method of electronic grade hexafluorodianhydride.
Background
The hexafluorodianhydride is used as an important monomer for synthesizing polyimide, and the fluorine-containing polyimide prepared by the method can improve certain properties of materials, such as lightening of the materials, improvement of light transmittance, improvement of solubility and the like; in addition, the free volume of the material can be increased, and the gas permeability of the material is improved, which is beneficial to expanding the application of polyimide materials in various fields.
Fluorine-containing polyimide has two large application fields, one is a gas separation membrane and the other is an electronic field. In particular to the application in the electronic field, the quality requirement is high, the impurity content control is more strict, the metal ion content is required to be less than or equal to 1ppm, and the product purity is required to be more than or equal to 99.5 percent. Therefore, the quality of the monomer will be more strict, and the quality of the monomer will be more demanding.
At present, the industrial purification of the hexafluorodianhydride mainly adopts the crystallization of a traditional crystallization kettle (CN 109678826A), a large amount of waste solvent is generated in the crystallization process, the energy consumption is high, the batches are different, the metal ion content of the purified product is higher, and the electronic grade requirement of less than or equal to 1ppm is not met. Chinese patent document CN204840995U discloses a sublimation purification device for hexafluorodianhydride, can guarantee that hexafluorodianhydride is at sublimation purification's in-process, and the temperature is controllable, and material flow is controllable, and easy and simple to handle moreover, simple structure can not introduce impurity in the air and make the material purity influenced, has adduction device, can not cause the pollution to the environment. However, the method has low purification efficiency, cannot reach the scale of industrial treatment, and has higher operation temperature and high energy consumption.
Disclosure of Invention
The invention provides a purification method of electronic grade hexafluorodianhydride in order to overcome the defects of the prior art.
In order to achieve the above purpose, the invention adopts the following technical scheme:
the purifying process of electronic grade hexafluorodianhydride includes the following steps:
(1) Pretreatment of resin: adding 2-4wt% ion chelating exchange resin to 25-50wt% of hexafluorodianhydride solution, adjusting pH to 2-6 with an acid regulator, pre-treating for 0.5-3 h at 60-90 ℃, and filtering to obtain hexafluorodianhydride crystallization mother liquor;
(2) And (3) film crystallization: conveying the hexafluorodianhydride crystallization mother liquor obtained in the step (1) into a membrane assembly at a flow rate of 10-20L/h, condensing the solvent in the mother liquor into liquid at the other side of the membrane for recycling after the solvent in the mother liquor is distilled by the membrane and permeates the membrane in a steam form, and concentrating the crystallization mother liquor to supersaturate; and then sending supersaturated crystallization mother liquor into a fluidized bed crystallizer, pumping the crystallization mother liquor at the upper layer of the crystallizer into a membrane assembly for internal circulation, enabling crystals to flow in the circulating crystallization mother liquor for suspension growth, leading out a crystallization product from the lower part of the crystallizer, and carrying out solid-liquid separation and drying to obtain the hexafluorodianhydride crystal.
Preferably, the resin particles obtained by filtering in the step (1) are subjected to regeneration treatment, and sulfuric acid solution accounting for 10-20wt% of the resin is introduced to carry out countercurrent regeneration of the resin, so that the resin is recycled. Preferably 12 to 16wt%.
Preferably, the pretreatment temperature in step (1) is not higher than the boiling point of the solvent used. The pretreatment time is 1-2 h. The configuration conditions of the hexafluorodianhydride solution in the step (1) are as follows: the normal pressure, the temperature of 50-100 ℃ and the rotating speed of 500-1000 r/min.
Preferably, the solvent of the hexafluorodianhydride solution in the step (1) is one or a combination of several of acetonitrile, N-dimethylformamide and o-xylene.
Preferably, the acid regulator in the step (1) is one or a combination of more of citric acid, formic acid, acetic acid, phosphoric acid, hydrochloric acid and sulfuric acid. Further preferred is one or a combination of several of citric acid, acetic acid and phosphoric acid. The proper acidity regulator can improve the metal ion removal rate, the stability of the membrane component and the product yield.
Preferably, the concentration of the hexafluorodianhydride solution in the step (1) is 35-40 wt%.
Preferably, the ion chelating exchange resin in the step (1) is CH-90Na, T-62MP or D401.
Preferably, the pH in the step (1) is 3-6, and the product yield can be improved by the pH.
Preferably, the membrane module in the step (2) is a PVDF hollow fiber membrane module.
Preferably, the flow rate of the hexafluorodianhydride crystallization mother liquor in the step (2) is 12-15L/h, and the purity and the yield of the product can be improved by selecting a certain flow rate.
The crystallization temperature of the film in the step (2) is the same as the pretreatment temperature in the step (1). Preferably, the crystallization temperature of the film in the step (2) is 60-90 ℃.
The invention has the beneficial effects that:
compared with the prior art, one or more technical schemes provided by the specific embodiments of the invention have at least the following positive effects:
(1) The invention overcomes the technical difficulties of high metal ion content, low efficiency and the like existing in the purification of the hexafluorodianhydride by using membrane crystallization by carrying out resin pretreatment on the crude product of the hexafluorodianhydride, selecting specific solvent, mother solution concentration and mother solution flow rate, wherein the purity of the purified hexafluorodianhydride can reach more than 99.5 percent, the yield can reach more than 90 percent, and the metal ion content is lower than 1ppm.
(2) According to the invention, the ion chelating exchange resin is added into the hexafluorodianhydride solution to remove Cu, mg, co, mn, zn, ca and Fe metal ions in the hexafluorodianhydride, so that the color grade and purity of the hexafluorodianhydride product are improved, and the metal ion content in the product is greatly reduced.
(3) According to the invention, the PVDF hollow fiber membrane component is adopted to concentrate the crystallization mother liquor, so that the solvent in the mother liquor can permeate the membrane pores in the form of vapor without heating the crystallization mother liquor to boil to reach a supersaturation state, thereby effectively reducing the operation energy consumption of the evaporation crystallization or cooling crystallization process of the hexafluorodianhydride and realizing further purification.
(4) The supersaturation degree of the crystallization operation is generated in the membrane component, the crystal growth is positioned in the fluidized bed crystallizer, the crystal is in fluidized suspension in the circulating crystallization mother liquor, good conditions are provided for the crystal growth, the fluidized bed crystallizer has the particle size grading function, the seeding operation is avoided, the crystal with uniform particle size can be grown, and the particle size distribution is uniform.
Drawings
FIG. 1 is a liquid phase diagram of hexafluorodianhydride measured in example 1.
Detailed Description
The invention is further described in connection with the following detailed description, which is not intended to limit the scope of the invention.
Example 1
The method for purifying the electronic grade hexafluorodianhydride comprises the following specific steps:
(1) Preparing a solution of hexafluorodianhydride with concentration of 40wt% by acetonitrile under the conditions of normal pressure, 60 ℃ and rotating speed of 800 r/min; then adding CH-90Na accounting for 2wt% of the hexafluorodianhydride into the solution of the hexafluorodianhydride, adding an acetic acid regulator into the solution to ensure that the pH value of the solution is=5, carrying out heat preservation and stirring for 1h, carrying out heat preservation and filtering, and obtaining a hexafluorodianhydride crystallization mother liquor.
The metal ion removal rate of the hexafluorodianhydride crystallization mother liquor obtained in the step (1) is more than or equal to 99 percent.
(2) And (3) conveying the hexafluorodianhydride crystallization mother liquor prepared in the step (1) into a membrane module at a flow rate of 12L/h, condensing the solvent in the mother liquor into liquid at the other side of the membrane after the solvent in the mother liquor is distilled by the membrane and penetrates through the membrane in a form of steam, recycling the liquid in a recovery tank for the next time, concentrating the crystallization mother liquor leaving the membrane module to supersaturation, and conveying the concentrated crystallization mother liquor into a crystallizer. The crystal grows in a fluidized suspension way in the circulating crystallization mother liquor, the crystallization mother liquor at the upper layer of the crystallizer is pumped into a membrane component for internal circulation, a crystallization product is led out from the lower part of the crystallizer, and the electronic grade hexafluorodianhydride crystal is obtained through solid-liquid separation and drying. The whole membrane crystallization process in the step (2) keeps constant temperature, and the temperature is the same as the temperature of the configuration mother liquor in the step (1).
(3) The resin particles filtered in the step (1) are subjected to a regeneration treatment, and sulfuric acid solution (the mass concentration of the sulfuric acid solution is 15%) accounting for 15wt% of the resin is introduced to carry out countercurrent regeneration of the resin, so that the resin is recycled.
The quality detection results of the obtained electronic grade hexafluorodianhydride are shown in table 1, wherein data 1 and data 2 are the results of two parallel detection.
TABLE 1 quality test results of electronic grade hexafluorodianhydride obtained in example 1
The liquid spectrum of the hexafluorodianhydride obtained in the example 1 is shown in fig. 1, and the detection result shows that the purity of the product is 99.99% and no obvious impurity exists.
Example 2
The method for purifying the electronic grade hexafluorodianhydride comprises the following specific steps:
(1) Preparing a solution of hexafluorodianhydride with the concentration of 35 weight percent by using N, N-dimethylformamide under the conditions of normal pressure, 80 ℃ and a rotating speed of 700 r/min; then adding T-62MP accounting for 4wt% of the hexafluorodianhydride into the solution of the hexafluorodianhydride, adding a citric acid regulator into the solution to ensure that the pH value of the solution is=3, carrying out heat preservation and stirring for 2 hours, carrying out heat preservation and filtering, and obtaining a hexafluorodianhydride crystallization mother liquor.
(2) Delivering the hexafluorodianhydride crystallization mother liquor prepared in the step (1) into a membrane assembly at a flow rate of 14L/h, allowing a solvent in the mother liquor to permeate the membrane in a form of steam through membrane distillation, condensing the solvent into liquid at the other side of the membrane, feeding the liquid into a recovery tank for next cyclic utilization, concentrating the crystallization mother liquor leaving the membrane assembly to supersaturate, feeding the crystal into a crystallizer, allowing the crystal to flow in the circulating crystallization mother liquor for suspension growth, feeding the crystallization mother liquor at the upper layer of the crystallizer into the membrane assembly through a pump for internal circulation, leading out a crystallization product from the lower part of the crystallizer, and carrying out solid-liquid separation and drying to obtain the hexafluorodianhydride crystal. The whole membrane crystallization process in the step (2) keeps constant temperature, and the temperature is the same as the temperature of the configuration mother liquor in the step (1).
(3) The resin particles filtered in the step (1) are subjected to a regeneration treatment, and sulfuric acid solution (the concentration of the sulfuric acid solution is 15%) accounting for 15wt% of the resin is introduced to carry out countercurrent regeneration of the resin, so that the resin is recycled.
TABLE 2 quality test results of electronic grade hexafluorodianhydride obtained in example 2
Example 3
The method for purifying the electronic grade hexafluorodianhydride comprises the following specific steps:
(1) Preparing a solution of hexafluorodianhydride with the concentration of 35 weight percent by using o-xylene under the conditions of normal pressure, 90 ℃ and the rotating speed of 800 r/min; then adding D401 accounting for 3wt% of the hexafluorodianhydride into the hexafluorodianhydride solution, adding a phosphoric acid regulator into the solution to ensure that the pH value of the solution is=6, carrying out heat preservation and stirring for 1.5 hours, carrying out heat preservation and filtering, and obtaining a hexafluorodianhydride crystallization mother liquor.
(2) Delivering the hexafluorodianhydride crystallization mother liquor prepared in the step (1) into a membrane assembly at a flow rate of 15L/h, allowing a solvent in the mother liquor to permeate the membrane in a form of steam through membrane distillation, condensing the solvent into liquid at the other side of the membrane, feeding the liquid into a recovery tank for next cyclic utilization, concentrating the crystallization mother liquor leaving the membrane assembly to supersaturate, feeding the crystal into a crystallizer, allowing the crystal to flow in the circulating crystallization mother liquor for suspension growth, feeding the crystallization mother liquor at the upper layer of the crystallizer into the membrane assembly through a pump for internal circulation, leading out a crystallization product from the lower part of the crystallizer, and carrying out solid-liquid separation and drying to obtain the hexafluorodianhydride crystal. The whole membrane crystallization process in the step (2) keeps constant temperature, and the temperature is the same as the temperature of the configuration mother liquor in the step (1).
(3) The resin particles thus filtered were subjected to a regeneration treatment, and sulfuric acid solution (sulfuric acid solution concentration: 15%) was introduced in an amount of 15wt% based on the resin to regenerate the resin in a countercurrent manner, thereby recycling the resin.
The results of the quality evaluation of the hexafluorodianhydride in example 3 are shown in Table 3.
TABLE 3 quality test results of electronic grade hexafluorodianhydride obtained in example 3
Example 4
The method for purifying the electronic grade hexafluorodianhydride comprises the following specific steps:
(1) Preparing a solution of hexafluorodianhydride with concentration of 40wt% by acetonitrile under the conditions of normal pressure, 60 ℃ and rotating speed of 800 r/min; then adding CH-90Na accounting for 2wt% of the hexafluorodianhydride into the solution of the hexafluorodianhydride, adding an acetic acid regulator into the solution to ensure that the pH value of the solution is=5, carrying out heat preservation and stirring for 1h, carrying out heat preservation and filtering, and obtaining a hexafluorodianhydride crystallization mother liquor.
(2) Delivering the crystallization mother liquor of the hexafluorodianhydride prepared in the step (1) into a membrane assembly at a flow rate of 18L/h, allowing a solvent in the mother liquor to permeate the membrane in a form of steam through membrane distillation, condensing the solvent into liquid at the other side of the membrane, feeding the liquid into a recovery tank for next cyclic utilization, concentrating the crystallization mother liquor leaving the membrane assembly to supersaturate, feeding the crystal into a crystallizer, allowing the crystal to flow in the circulation crystallization mother liquor for suspension growth, feeding the crystallization mother liquor at the upper layer of the crystallizer into the membrane assembly for internal circulation through a pump, leading out a crystallization product from the lower part of the crystallizer, carrying out solid-liquid separation, and drying to obtain the electronic grade hexafluorodianhydride crystal. The whole membrane crystallization process in the step (2) keeps constant temperature, and the temperature is the same as the temperature of the configuration mother liquor in the step (1).
(3) The resin particles filtered in the step (1) are subjected to a regeneration treatment, and sulfuric acid solution (the concentration of the sulfuric acid solution is 15%) accounting for 15wt% of the resin is introduced to carry out countercurrent regeneration of the resin, so that the resin is recycled.
TABLE 4 quality test results of electronic grade hexafluorodianhydride obtained in example 4
Example 5
The method for purifying the electronic grade hexafluorodianhydride comprises the following specific steps:
(1) Preparing a solution of hexafluorodianhydride with the concentration of 25 weight percent by acetonitrile under the conditions of normal pressure, 60 ℃ and rotating speed of 800 r/min; then adding CH-90Na accounting for 2wt% of the hexafluorodianhydride into the solution of the hexafluorodianhydride, adding an acetic acid regulator into the solution to ensure that the pH value of the solution is=5, carrying out heat preservation and stirring for 1h, carrying out heat preservation and filtering, and obtaining a hexafluorodianhydride crystallization mother liquor.
(2) Delivering the crystallization mother liquor of the hexafluorodianhydride prepared in the step (1) into a membrane assembly at a flow rate of 12L/h, allowing a solvent in the mother liquor to permeate the membrane in a form of steam through membrane distillation, condensing the solvent into liquid at the other side of the membrane, feeding the liquid into a recovery tank for next cyclic utilization, concentrating the crystallization mother liquor leaving the membrane assembly to supersaturate, feeding the crystal into a crystallizer, allowing the crystal to flow in the circulation crystallization mother liquor for suspension growth, feeding the crystallization mother liquor at the upper layer of the crystallizer into the membrane assembly for internal circulation through a pump, leading out a crystallization product from the lower part of the crystallizer, performing solid-liquid separation, and drying to obtain the electronic grade hexafluorodianhydride crystal. The whole membrane crystallization process in the step (2) keeps constant temperature, and the temperature is the same as the temperature of the configuration mother liquor in the step (1).
(3) The resin particles filtered in the step (1) are subjected to a regeneration treatment, and sulfuric acid solution (the concentration of the sulfuric acid solution is 15%) accounting for 15wt% of the resin is introduced to carry out countercurrent regeneration of the resin, so that the resin is recycled.
TABLE 5 quality test results of electronic grade hexafluorodianhydride obtained in example 5
Example 6
The method for purifying the electronic grade hexafluorodianhydride comprises the following specific steps:
(1) Preparing a hexafluorodianhydride solution with the concentration of 50 weight percent by acetonitrile under the conditions of normal pressure, 60 ℃ and rotating speed of 800 r/min; then adding CH-90Na accounting for 2wt% of the hexafluorodianhydride into the solution of the hexafluorodianhydride, adding an acetic acid regulator into the solution to ensure that the pH value of the solution is=5, carrying out heat preservation and stirring for 1h, carrying out heat preservation and filtering, and obtaining a hexafluorodianhydride crystallization mother liquor.
(2) Delivering the crystallization mother liquor of the hexafluorodianhydride prepared in the step (1) into a membrane assembly at a flow rate of 12L/h, allowing a solvent in the mother liquor to permeate the membrane in a form of steam through membrane distillation, condensing the solvent into liquid at the other side of the membrane, feeding the liquid into a recovery tank for next cyclic utilization, concentrating the crystallization mother liquor leaving the membrane assembly to supersaturate, feeding the crystal into a crystallizer, allowing the crystal to flow in the circulation crystallization mother liquor for suspension growth, feeding the crystallization mother liquor at the upper layer of the crystallizer into the membrane assembly for internal circulation through a pump, leading out a crystallization product from the lower part of the crystallizer, performing solid-liquid separation, and drying to obtain the electronic grade hexafluorodianhydride crystal. The whole membrane crystallization process in the step (2) keeps constant temperature, and the temperature is the same as the temperature of the configuration mother liquor in the step (1).
(3) The resin particles filtered in the step (1) are subjected to a regeneration treatment, and sulfuric acid solution (the concentration of the sulfuric acid solution is 15%) accounting for 15wt% of the resin is introduced to carry out countercurrent regeneration of the resin, so that the resin is recycled.
TABLE 6 quality test results of electronic grade hexafluorodianhydride obtained in example 6
Comparative example 1
The method for purifying the electronic grade hexafluorodianhydride comprises the following specific steps:
(1) Preparing a solution of hexafluorodianhydride with the concentration of 40 weight percent by ethanol under the conditions of normal pressure, 60 ℃ and rotating speed of 800 r/min; then adding CH-90Na accounting for 2wt% of the hexafluorodianhydride into the solution of the hexafluorodianhydride, adding an acetic acid regulator into the solution to ensure that the pH value of the solution is=5, carrying out heat preservation and stirring for 1h, carrying out heat preservation and filtering, and obtaining a hexafluorodianhydride crystallization mother liquor.
(2) Delivering the hexafluorodianhydride crystallization mother liquor prepared in the step (1) into a membrane assembly at a flow rate of 12L/h, allowing a solvent in the mother liquor to permeate the membrane in a form of steam through membrane distillation, condensing the solvent into liquid at the other side of the membrane, feeding the liquid into a recovery tank for next cyclic utilization, concentrating the crystallization mother liquor leaving the membrane assembly to supersaturate, feeding the crystal into a crystallizer, allowing the crystal to flow in the circulating crystallization mother liquor for suspension growth, feeding the crystallization mother liquor at the upper layer of the crystallizer into the membrane assembly through a pump for internal circulation, leading out a crystallization product from the lower part of the crystallizer, and carrying out solid-liquid separation and drying to obtain the hexafluorodianhydride crystal.
(3) The resin particles thus filtered were subjected to a regeneration treatment, and sulfuric acid solution (sulfuric acid solution concentration: 15%) was introduced in an amount of 15wt% based on the resin to regenerate the resin in a countercurrent manner, thereby recycling the resin.
TABLE 7 quality test results of purified hexafluorodianhydride in comparative example 1
Comparative example 2
The method for purifying the electronic grade hexafluorodianhydride comprises the following specific steps:
(1) Preparing a solution of hexafluorodianhydride with concentration of 40wt% by acetonitrile under the conditions of normal pressure, 60 ℃ and rotating speed of 800 r/min; and then adding CH-90Na accounting for 2wt% of the hexafluorodianhydride into the hexafluorodianhydride solution, wherein the pH is=7, and filtering after heat preservation and stirring for 1h, thus obtaining the hexafluorodianhydride crystallization mother liquor.
(2) Delivering the crystallization mother liquor of the hexafluorodianhydride prepared in the step (1) into a membrane assembly at a flow rate of 12L/h, allowing a solvent in the mother liquor to permeate the membrane in a form of steam through membrane distillation, condensing the solvent into liquid at the other side of the membrane, feeding the liquid into a recovery tank for next cyclic utilization, concentrating the crystallization mother liquor leaving the membrane assembly to supersaturate, feeding the crystal into a crystallizer, allowing the crystal to flow in the circulation crystallization mother liquor for suspension growth, feeding the crystallization mother liquor at the upper layer of the crystallizer into the membrane assembly for internal circulation through a pump, leading out a crystallization product from the lower part of the crystallizer, performing solid-liquid separation, and drying to obtain the electronic grade hexafluorodianhydride crystal.
(3) The resin particles filtered in the step (1) are subjected to a regeneration treatment, and sulfuric acid solution (the concentration of the sulfuric acid solution is 15%) accounting for 15wt% of the resin is introduced to carry out countercurrent regeneration of the resin, so that the resin is recycled.
TABLE 8 quality test results of electronic grade hexafluorodianhydride obtained in comparative example 2
Comparative example 3
The method for purifying the electronic grade hexafluorodianhydride comprises the following specific steps:
(1) Preparing a solution of hexafluorodianhydride with concentration of 40wt% by acetonitrile under the conditions of normal pressure, 60 ℃ and rotating speed of 800 r/min; adding acetic acid regulator into the solution to ensure that the pH value of the solution is=5, carrying out heat preservation and stirring for 1h, and then carrying out heat preservation and filtration to obtain the hexafluorodianhydride crystallization mother liquor.
(2) Delivering the crystallization mother liquor of the hexafluorodianhydride prepared in the step (1) into a membrane assembly at a flow rate of 12L/h, allowing a solvent in the mother liquor to permeate the membrane in a form of steam through membrane distillation, condensing the solvent into liquid at the other side of the membrane, feeding the liquid into a recovery tank for next cyclic utilization, concentrating the crystallization mother liquor leaving the membrane assembly to supersaturate, feeding the crystal into a crystallizer, allowing the crystal to flow in the circulation crystallization mother liquor for suspension growth, feeding the crystallization mother liquor at the upper layer of the crystallizer into the membrane assembly for internal circulation through a pump, leading out a crystallization product from the lower part of the crystallizer, performing solid-liquid separation, and drying to obtain the electronic grade hexafluorodianhydride crystal.
(3) The resin particles filtered in the step (1) are subjected to a regeneration treatment, and sulfuric acid solution (the concentration of the sulfuric acid solution is 15%) accounting for 15wt% of the resin is introduced to carry out countercurrent regeneration of the resin, so that the resin is recycled.
TABLE 9 quality test results of electronic grade hexafluorodianhydride obtained in comparative example 3
Comparative example 4
The method for purifying the electronic grade hexafluorodianhydride comprises the following specific steps:
(1) Preparing a solution of hexafluorodianhydride with concentration of 40wt% by acetonitrile under the conditions of normal pressure, 60 ℃ and rotating speed of 800 r/min; then adding CH-90Na accounting for 2wt% of the hexafluorodianhydride into the solution of the hexafluorodianhydride, adding an acetic acid regulator into the solution to ensure that the pH value of the solution is=5, carrying out heat preservation and stirring for 1h, carrying out heat preservation and filtering, and obtaining a hexafluorodianhydride crystallization mother liquor.
(2) Delivering the crystallization mother liquor of the hexafluorodianhydride prepared in the step (1) into a membrane assembly at a flow rate of 6L/h, allowing a solvent in the mother liquor to permeate the membrane in a form of steam through membrane distillation, condensing the solvent into liquid at the other side of the membrane, feeding the liquid into a recovery tank for next cyclic utilization, concentrating the crystallization mother liquor leaving the membrane assembly to supersaturate, feeding the crystal into a crystallizer, allowing the crystal to flow in the circulation crystallization mother liquor for suspension growth, feeding the crystallization mother liquor at the upper layer of the crystallizer into the membrane assembly for internal circulation through a pump, leading out a crystallization product from the lower part of the crystallizer, performing solid-liquid separation, and drying to obtain the electronic grade hexafluorodianhydride crystal.
(3) The resin particles filtered in the step (1) are subjected to a regeneration treatment, and sulfuric acid solution (the concentration of the sulfuric acid solution is 15%) accounting for 15wt% of the resin is introduced to carry out countercurrent regeneration of the resin, so that the resin is recycled.
Table 10 results of the quality test of electronic grade hexafluorodianhydride obtained in comparative example 4
Comparative example 5
The method for purifying the electronic grade hexafluorodianhydride comprises the following specific steps:
(1) Preparing a solution of hexafluorodianhydride with concentration of 40wt% by acetonitrile under the conditions of normal pressure, 50 ℃ and rotating speed of 800 r/min; then adding CH-90Na accounting for 2wt% of the hexafluorodianhydride into the solution of the hexafluorodianhydride, adding an acetic acid regulator into the solution to ensure that the pH value of the solution is=5, carrying out heat preservation and stirring for 1h, carrying out heat preservation and filtering, and obtaining a hexafluorodianhydride crystallization mother liquor.
(2) Delivering the crystallization mother liquor of the hexafluorodianhydride prepared in the step (1) into a membrane assembly at a flow rate of 12L/h, allowing a solvent in the mother liquor to permeate the membrane in a form of steam through membrane distillation, condensing the solvent into liquid at the other side of the membrane, feeding the liquid into a recovery tank for next cyclic utilization, concentrating the crystallization mother liquor leaving the membrane assembly to supersaturate, feeding the crystal into a crystallizer, allowing the crystal to flow in the circulation crystallization mother liquor for suspension growth, feeding the crystallization mother liquor at the upper layer of the crystallizer into the membrane assembly for internal circulation through a pump, leading out a crystallization product from the lower part of the crystallizer, performing solid-liquid separation, and drying to obtain the electronic grade hexafluorodianhydride crystal.
(3) The resin particles filtered in the step (1) are subjected to a regeneration treatment, and sulfuric acid solution (the concentration of the sulfuric acid solution is 15%) accounting for 15wt% of the resin is introduced to carry out countercurrent regeneration of the resin, so that the resin is recycled.
TABLE 11 quality test results of electronic grade hexafluorodianhydride obtained in comparative example 5
Comparative example 6
The method for purifying the electronic grade hexafluorodianhydride comprises the following specific steps:
(1) Preparing a solution of hexafluorodianhydride with concentration of 40wt% by acetonitrile under the conditions of normal pressure, 60 ℃ and rotating speed of 800 r/min; then adding active carbon accounting for 2wt% of the hexafluorodianhydride into the solution of the hexafluorodianhydride, adding an acetic acid regulator into the solution to ensure that the pH value of the solution is=5, carrying out heat preservation and stirring for 1h, carrying out heat preservation and filtering, and obtaining a hexafluorodianhydride crystallization mother liquor.
(2) Delivering the crystallization mother liquor of the hexafluorodianhydride prepared in the step (1) into a membrane assembly at a flow rate of 12L/h, allowing a solvent in the mother liquor to permeate the membrane in a form of steam through membrane distillation, condensing the solvent into liquid at the other side of the membrane, feeding the liquid into a recovery tank for next cyclic utilization, concentrating the crystallization mother liquor leaving the membrane assembly to supersaturate, feeding the crystal into a crystallizer, allowing the crystal to flow in the circulation crystallization mother liquor for suspension growth, feeding the crystallization mother liquor at the upper layer of the crystallizer into the membrane assembly for internal circulation through a pump, leading out a crystallization product from the lower part of the crystallizer, performing solid-liquid separation, and drying to obtain the electronic grade hexafluorodianhydride crystal.
(3) The resin particles filtered in the step (1) are subjected to a regeneration treatment, and sulfuric acid solution (the concentration of the sulfuric acid solution is 15%) accounting for 15wt% of the resin is introduced to carry out countercurrent regeneration of the resin, so that the resin is recycled.
Table 12 results of quality test of electronic grade hexafluorodianhydride obtained in comparative example 6
Comparative example 7
The method for purifying the electronic grade hexafluorodianhydride comprises the following specific steps:
(1) Preparing a solution of hexafluorodianhydride with concentration of 40wt% by acetonitrile under the conditions of normal pressure, 60 ℃ and rotating speed of 800 r/min; then adding diatomite accounting for 2wt% of the hexafluorodianhydride into the solution of the hexafluorodianhydride, adding an acetic acid regulator into the solution to ensure that the pH value of the solution is=5, carrying out heat preservation and stirring for 1h, carrying out heat preservation and filtering, and obtaining a hexafluorodianhydride crystallization mother liquor through filtering.
(2) Delivering the crystallization mother liquor of the hexafluorodianhydride prepared in the step (1) into a membrane assembly at a flow rate of 12L/h, allowing a solvent in the mother liquor to permeate the membrane in a form of steam through membrane distillation, condensing the solvent into liquid at the other side of the membrane, feeding the liquid into a recovery tank for next cyclic utilization, concentrating the crystallization mother liquor leaving the membrane assembly to supersaturate, feeding the crystal into a crystallizer, allowing the crystal to flow in the circulation crystallization mother liquor for suspension growth, feeding the crystallization mother liquor at the upper layer of the crystallizer into the membrane assembly for internal circulation through a pump, leading out a crystallization product from the lower part of the crystallizer, performing solid-liquid separation, and drying to obtain the electronic grade hexafluorodianhydride crystal.
(3) The resin particles filtered in the step (1) are subjected to a regeneration treatment, and sulfuric acid solution (the concentration of the sulfuric acid solution is 15%) accounting for 15wt% of the resin is introduced to carry out countercurrent regeneration of the resin, so that the resin is recycled.
TABLE 13 quality test results of electronic grade hexafluorodianhydride obtained in comparative example 7
As can be seen from the above examples and comparative examples, the present invention overcomes the technical difficulties of high metal ion content, low efficiency, etc. existing in the purification of hexafluorodianhydride by using membrane crystallization by carrying out resin pretreatment on crude hexafluorodianhydride, selecting specific solvent, mother liquor concentration and mother liquor flow rate, the purity of the purified hexafluorodianhydride can reach more than 99.5%, the yield can reach more than 90%, and the metal ion content is lower than 1ppm.
Claims (7)
1. The purification method of the electronic grade hexafluorodianhydride is characterized by comprising the following steps of:
(1) Pretreatment of resin: adding 2-4wt% ion chelating exchange resin to 25-50wt% of hexafluorodianhydride solution, adjusting pH to 2-6 with an acid regulator, pre-treating for 0.5-3 h at 60-90 ℃, and filtering to obtain hexafluorodianhydride crystallization mother liquor; the solvent of the hexafluorodianhydride solution is one or a combination of a plurality of acetonitrile, N-dimethylformamide and o-xylene; the ion chelating exchange resin is CH-90Na, T-62MP or D401;
(2) And (3) film crystallization: delivering the hexafluorodianhydride crystallization mother liquor obtained in the step (1) into a PVDF hollow fiber membrane module at a flow rate of 10-20L/h, condensing a solvent in the mother liquor into a liquid at the other side of the membrane for recycling after the solvent in the mother liquor is distilled by the membrane and permeates the membrane in a steam form, and concentrating the crystallization mother liquor to supersaturate; and then sending supersaturated crystallization mother liquor into a fluidized bed crystallizer, pumping the crystallization mother liquor at the upper layer of the crystallizer into a membrane component for internal circulation, enabling crystals to flow in the circulating crystallization mother liquor for suspension growth, leading out a crystallization product from the lower part of the crystallizer, carrying out solid-liquid separation, and drying to obtain the hexafluorodianhydride crystal, wherein the temperature of the membrane crystallization is 60-90 ℃.
2. The purification method according to claim 1, wherein the acidity regulator in the step (1) is one or a combination of several of citric acid, formic acid, acetic acid, phosphoric acid, hydrochloric acid and sulfuric acid.
3. The purification method according to claim 1, wherein the acidity regulator in the step (1) is one or a combination of several of citric acid, acetic acid and phosphoric acid.
4. The purification method according to claim 1, wherein the concentration of the hexafluorodianhydride solution in the step (1) is 35-40 wt%.
5. The purification method according to claim 1, wherein the pH in step (1) is 3 to 6.
6. The purification method according to claim 1, wherein the pretreatment time in step (1) is 1 to 2 hours.
7. The purification method according to claim 1, wherein the flow rate of the crystallization mother liquor of the hexafluorodianhydride in the step (2) is 12-15 l/h.
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| JP2005247701A (en) * | 2004-03-01 | 2005-09-15 | Air Water Chemical Inc | Method for refining fluoroaromatic tetracarboxylic acid dianhydride |
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| CN109678826A (en) * | 2019-02-21 | 2019-04-26 | 浙江诺诚技术发展有限公司 | A kind of method that temperate condition prepares hexafluorodianhydride (6FDA) |
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| JP2005247701A (en) * | 2004-03-01 | 2005-09-15 | Air Water Chemical Inc | Method for refining fluoroaromatic tetracarboxylic acid dianhydride |
| CN204840995U (en) * | 2015-07-31 | 2015-12-09 | 自贡中天胜新材料科技有限公司 | Be used for hexafluorodianhydride (6FDA) distillation purification device |
| CN106349200A (en) * | 2016-08-26 | 2017-01-25 | 山东华夏神舟新材料有限公司 | Synthetic method of 4,4'-(hexafluoroisopropylidene)diphthalic anhydride |
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