CN116217963A - Polyimide resin purification method - Google Patents
Polyimide resin purification method Download PDFInfo
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- CN116217963A CN116217963A CN202310354757.XA CN202310354757A CN116217963A CN 116217963 A CN116217963 A CN 116217963A CN 202310354757 A CN202310354757 A CN 202310354757A CN 116217963 A CN116217963 A CN 116217963A
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- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J3/00—Processes of treating or compounding macromolecular substances
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G73/00—Macromolecular compounds obtained by reactions forming a linkage containing nitrogen with or without oxygen or carbon in the main chain of the macromolecule, not provided for in groups C08G12/00 - C08G71/00
- C08G73/06—Polycondensates having nitrogen-containing heterocyclic rings in the main chain of the macromolecule
- C08G73/10—Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J2379/00—Characterised by the use of macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing nitrogen with or without oxygen, or carbon only, not provided for in groups C08J2361/00 - C08J2377/00
- C08J2379/04—Polycondensates having nitrogen-containing heterocyclic rings in the main chain; Polyhydrazides; Polyamide acids or similar polyimide precursors
- C08J2379/08—Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W30/00—Technologies for solid waste management
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Abstract
The invention provides a purification method of polyimide resin, and relates to the field of polyimide resin. The method for cleaning polyimide by using ultrasonic-composite solvent and the method for filtering ultrasonic semipermeable membrane can effectively remove unreacted monomer, oligomer, catalyst, and other impurities in polyimide, thereby obtaining pure polyimide resin with narrower molecular weight distribution. The invention innovates the technology of ultrasonic cleaning by using the composite solvent and combining ultrasonic waves with the polytetrafluoroethylene semipermeable membrane, thereby greatly improving the purity of polyimide.
Description
Technical Field
The invention relates to the field of polyimide resin, in particular to a novel purification method of polyimide resin.
Background
Polyimide resins are polymeric materials, and generally have a molecular weight distribution within a certain range, and are themselves "mixtures". In the preparation of polyimide resins, it is often necessary to add an auxiliary agent such as a catalyst, and these substances often remain in the polyimide resin to be finally obtained, and in addition, unpolymerized monomers or oligomers often remain in the polyimide resin. The presence of these residual impurities causes a great decrease in the performance of the polyimide resin, and thus purification of the polyimide resin is necessary to improve the performance thereof.
For many reasons of generation of impurities in polymer materials, a suitable and effective purification method needs to be selected according to specific situations, and various purification methods are reported in polymer materials, for example, the property of metal catalyst residues in polymer products is utilized in the prior art to form chelates with other substances, and the obtained chelates are dissolved by using a suitable solvent, and meanwhile, polymers are precipitated and filtered, so that the aim of purifying the polymer products is achieved.
For another example, in order to more thoroughly remove mechanical impurities remaining in the polymer product and molecular chains of low molecular weight in the resin, it is possible to remove impurities such as residual solvent and catalyst, etc. by filtration of the raw material solution and purification method of purifying polyimide resin using a purification solvent (patent CN113817167 a), which mainly uses filtration and a purification agent, by dissolution.
However, the above method is not effective in removing the residual solvent, volatile small molecular compounds, catalyst residues, and molecular chains of low molecular weight, and has poor efficiency.
Disclosure of Invention
In view of the above, the present invention provides a novel purification method of polyimide resin, which can remove unreacted monomers, oligomers, catalysts, and other impurities in polyimide by an ultrasonic-composite solvent cleaning polyimide method and an ultrasonic semipermeable membrane filtration method, thereby obtaining a high-purity polyimide resin. The invention innovates the technology of ultrasonic cleaning by using the composite solvent and combining ultrasonic waves with the polytetrafluoroethylene semipermeable membrane, thereby greatly improving the purity of polyimide.
The invention provides a purification method of Polyimide (PI) resin, which comprises the following steps:
s1, crushing PI resin by using a 200-mesh screen of a crusher;
s2, adding the PI powder into a container with a composite solvent to obtain a PI mixture;
s3, placing the mixture container into an ultrasonic machine with a set temperature for ultrasonic cleaning, performing ultrasonic treatment for a certain time, and then filtering and drying to obtain coarse PI powder;
s4, adding the crude PI powder obtained in the S3 into an electronic grade good solvent to prepare a solution with a certain concentration;
and S5, pushing the solution prepared in the step S4 into an ultrasonic-semipermeable membrane filter through a plunger pump for filtering to obtain a purified PI solution.
According to the polyimide resin purification method provided by the invention, the purpose of crushing in the step S1 is to increase the specific surface area of the PI resin, so that the purification efficiency is improved.
According to the purification method of polyimide resin provided by the invention, the compound solvent in the step S2 is N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-diethylacetamide, N, N-dimethylformamide, N, N-diethylformamide, N-methylcaprolactam, N, N, N ', N' -tetramethylurea and other nitrogen-containing polar solvents; lactone-based polar solvents such as β -propiolactone, γ -butyrolactone, γ -valerolactone, δ -valerolactone, γ -caprolactone, and ε -caprolactone; dimethyl sulfoxide; acetonitrile; fatty acid esters such as ethyl lactate and butyl lactate; ethers such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether, dioxane, tetrahydrofuran, methyl cellosolve acetate and ethyl cellosolve acetate; and a mixture of two or more solvents such as phenols, e.g., cresols, in a predetermined ratio.
According to the purification method of polyimide resin provided by the invention, the ratio of the composite solvent is 1: 10. 1: 9. 1: 8. 1: 7. 1: 6. 1: 5. 1: 4. 1: 3. 1: 2. 1:1, if more than two solvents are selected, the two main solvents are preferably selected for proportioning.
According to the purification method of polyimide resin provided by the invention, the composite solvent in the step S2 mainly dissolves and removes unreacted monomers, organic catalysts, oligomers and other impurities.
According to the purification method of polyimide resin provided by the invention, the temperature of the ultrasonic machine in the step S3 is set to be 40-60 ℃.
According to the purification method of polyimide resin provided by the invention, the cleaning time of the ultrasonic machine in the step S3 is 0.5-2 h.
According to the purification method of polyimide resin provided by the invention, the mass fraction of the solution in the step S4 is 8-15%.
According to the purification method of polyimide resin provided by the invention, the semipermeable membrane used in the step S5 is made of polytetrafluoroethylene, and the polytetrafluoroethylene semipermeable membrane with the membrane aperture of less than 2000 molecular weight can be selected preferentially.
According to the polyimide resin purification method provided by the invention, the flow rate of the PI resin solution in the step S5 is 1-10 mL/min.
According to the purification method of polyimide resin provided by the invention, the purified PI solution obtained in the step S5 has very narrow molecular weight distribution.
According to the purification method of polyimide resin provided by the invention, the residual single rate of the purified PI solution obtained in the step S5 is less than 0.3 percent
According to the purification method of polyimide resin provided by the invention, the residue rate of the purified PI solution catalyst obtained in the step S5 is less than 0.1%.
The invention also provides the high-purity polyimide resin prepared by the purification method.
Advantageous effects
The invention provides a polyimide resin purifying method, which can remove unreacted monomers, oligomers, catalysts, and other impurities in polyimide by an ultrasonic-composite solvent cleaning polyimide method and an ultrasonic semipermeable membrane filtering method, thereby obtaining pure polyimide resin with very narrow molecular weight distribution. The invention innovates the technology of ultrasonic cleaning by using the composite solvent and combining ultrasonic waves with the polytetrafluoroethylene semipermeable membrane, thereby greatly improving the purity of polyimide.
Drawings
FIG. 1 is a schematic diagram of a novel purification method of polyimide resin in an embodiment of the present invention, wherein 1: a pulverizer; 2: a crude polyimide resin + composite solvent tank; 3: an ultrasonic machine; 4: a polyimide resin solution tank; 5: a plunger pump; 6: an electronic grade good solvent tank; 7: an ultrasonic-semipermeable membrane filtration device; 8: a polyimide resin recovery tank after purification; 9: filtering the waste liquid tank; 10. 11, 12 and 13 are valves; 14: a polytetrafluoroethylene semipermeable membrane.
Detailed Description
The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the present invention, but are not intended to limit the invention in any way. It should be noted that variations and modifications could be made by those skilled in the art without departing from the inventive concept. These are all within the scope of the present invention.
Unless the context clearly requires otherwise, throughout the description and the claims, the words "comprise", "comprising", and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is, it is the meaning of "including but not limited to".
A method for purifying polyimide resin, comprising the steps of:
crushing PI resin by using a 200-mesh screen of a crusher, adding the PI resin into PI powder in a composite solvent container according to a certain proportion to obtain PI mixture, placing the mixture container into an ultrasonic machine with a set temperature for ultrasonic cleaning, carrying out ultrasonic cleaning for a certain time, filtering and drying to obtain coarse PI powder, adding the obtained coarse PI powder into an electronic grade good solvent to prepare a solution with a certain concentration, pushing the solution into an ultrasonic-semipermeable membrane filter by using a plunger pump to filter to obtain a purified PI solution, and specifically comprising the following steps (see a flow chart 1):
a. the valves 10, 12 are opened, the other valves are closed, and the crude PI resin solution is pumped into the ultrasonic-semipermeable membrane filter by a plunger pump.
b. After the PI resin solution is completely fed, the valve 10 is closed, the valve 11 is opened, the electronic grade good solvent is introduced, and the resin solution is pushed to be filtered further.
c. After a period of time, valve 12 is closed, valve 13 is opened, and valve 11 is closed after the purified PI resin is collected.
The invention is further illustrated by the following examples:
example 1
1kg of PI resin is crushed by a 200-mesh screen of a crusher, and is added into an ultrasonic container, and 1kg of composite solvent in a mass ratio of NNMP to DMF=1:3 is added into PI powder. Obtaining PI resin suspension, setting an ultrasonic machine at 50 ℃ for ultrasonic cleaning, carrying out ultrasonic treatment for 2 hours, filtering and drying to obtain crude PI powder, adding the obtained crude PI powder into electronic grade 9kg of m-cresol to prepare PI resin solution with the mass fraction of 10%, pushing the solution into an ultrasonic-semi-permeable membrane filter at 3mL/min by a plunger pump for filtering to obtain further purified PI solution, and specifically comprising the following steps of:
a. the valves 10, 12 are opened, the other valves are closed, and the crude PI resin solution is pumped into the ultrasonic-semipermeable membrane filter by a plunger pump.
b. After the PI resin solution is completely fed, the valve 10 is closed, the valve 11 is opened, the electronic interstage cresol is introduced, and the resin solution is pushed to be further filtered, wherein the flow rate of the solution is 8mL/min.
c. After 2h, valve 12 was closed, valve 13 was opened, and after collection of the purified PI resin, valve 11 was closed.
Example 2
Crushing 1kg of PI resin by using a 200-mesh screen of a crusher, adding the crushed PI resin into an ultrasonic machine container, adding the PI powder into a composite solvent container in a ratio of NMP to DMF=1:4 to obtain PI suspension, setting the temperature of the ultrasonic machine to 50 ℃, performing ultrasonic cleaning for 2 hours, filtering and drying to obtain crude PI powder, adding the obtained crude PI powder into 9kg of m-cresol to prepare a solution with the mass fraction of 10%, and pushing the solution into an ultrasonic-semi-permeable membrane filter at 3mL/min by using a plunger pump to perform filtration to obtain further purified PI solution, wherein the method specifically comprises the following steps of:
a. the valves 10, 12 are opened, the other valves are closed, and the crude PI resin solution is pumped into the ultrasonic-semipermeable membrane filter by a plunger pump.
b. After the PI resin solution is completely fed, the valve 10 is closed, the valve 11 is opened, the electronic grade good solvent is introduced, the resin solution is pushed to be further filtered, and the flow rate of the solution is 8mL/min.
c. After 2h, valve 12 was closed, valve 13 was opened, and after collection of the purified PI resin, valve 11 was closed.
Comparative example 1
Crushing 1kg of PI resin by using a 200-mesh screen of a crusher, adding the crushed 1kg of PI resin into an ultrasonic machine, adding a composite solvent in a mass ratio of NNMP to DMF=1:11 into PI powder to obtain PI suspension, setting the ultrasonic machine to 50 ℃ for ultrasonic cleaning, carrying out ultrasonic treatment for 2 hours, filtering and drying to obtain crude PI powder, adding the obtained crude PI powder into 9kg of m-cresol to prepare a PI resin solution with the mass fraction of 10%, and pushing the solution into an ultrasonic-semipermeable membrane filter by using a plunger pump for filtering to obtain further purified PI solution, wherein the method specifically comprises the following steps of:
a. the valves 10, 12 are opened, the other valves are closed, and the crude PI resin solution is pumped into the ultrasonic-semipermeable membrane filter by a plunger pump.
b. After the PI resin solution is completely fed, the valve 10 is closed, the valve 11 is opened, the electronic grade good solvent is introduced, the resin solution is pushed to be further filtered, and the flow rate of the solution is 8mL/min.
c. After 2h, valve 12 was closed, valve 13 was opened, and after collection of the purified PI resin, valve 11 was closed.
Comparative example 2
Crushing 1kg of PI resin by using a 200-mesh screen of a crusher, adding the crushed PI resin into an ultrasonic machine, adding the PI resin into a composite solvent container with the mass ratio NNMP: DMF=1:13 to obtain PI resin suspension, setting the temperature of the ultrasonic machine to 50 ℃, carrying out ultrasonic cleaning, carrying out ultrasonic treatment for 2 hours, filtering and drying to obtain crude PI powder, adding the obtained crude PI powder into 9kg of m-cresol to prepare PI resin solution with the mass fraction of 10%, and pushing the solution into an ultrasonic-semi-permeable membrane filter by using a plunger pump to carry out filtration to obtain further purified PI solution, wherein the method specifically comprises the following steps of:
a. the valves 10, 12 are opened, the other valves are closed, and the crude PI resin solution is pumped into the ultrasonic-semipermeable membrane filter by a plunger pump.
b. After the PI resin solution is completely fed, the valve 10 is closed, the valve 11 is opened, the good solvent is introduced, the resin solution is pushed to be further filtered, and the flow rate of the solution is 8mL/min.
c. After 2h, valve 12 was closed, valve 13 was opened, and after collection of the purified PI resin, valve 11 was closed.
The PI resins obtained in examples 1-2 and comparative examples 1-2 were tested for the residual fraction and the catalyst residual fraction.
The test results are shown in the following table:
from the above results, it can be seen that when the compounding solvent ratio is 1:3 or 1:4, a high-purity PI resin can be obtained.
It is easy to understand by those skilled in the art that the above preferred embodiments can be freely combined and overlapped without conflict.
Claims (9)
1. A method for purifying Polyimide (PI) resin, comprising the steps of:
s1, crushing PI resin by using a 200-mesh screen of a crusher;
s2, adding the PI powder into a container with a composite solvent to obtain a PI mixture;
s3, placing the mixture container into an ultrasonic machine with a set temperature for ultrasonic cleaning, performing ultrasonic treatment for a certain time, and then filtering and drying to obtain coarse PI powder;
s4, adding the crude PI powder obtained in the S3 into an electronic grade good solvent to prepare a solution with a certain concentration;
and S5, pushing the solution prepared in the step S4 into an ultrasonic-semipermeable membrane filter through a plunger pump for filtering to obtain a purified PI solution.
2. The method for purifying a Polyimide (PI) resin according to claim 1, wherein said step S1 is a step of pulverizing the Polyimide (PI) resin for the purpose of increasing the specific surface area of the PI resin, so as to improve the purification efficiency.
3. The method for purifying Polyimide (PI) resin according to claim 1, wherein the complex solvent in the step S2 is N-methyl-2-pyrrolidone or N, N-dimethylacetamide, N-diethylacetamide, N-dimethylformamide, N, nitrogen-containing polar solvents such as N-diethylformamide, N-methylcaprolactam, N' -tetramethylurea, and the like; lactone-based polar solvents such as β -propiolactone, γ -butyrolactone, γ -valerolactone, δ -valerolactone, γ -caprolactone, and ε -caprolactone; dimethyl sulfoxide; acetonitrile; fatty acid esters such as ethyl lactate and butyl lactate; ethers such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether, dioxane, tetrahydrofuran, methyl cellosolve acetate and ethyl cellosolve acetate; and a mixture of two or more solvents such as phenols, e.g., cresols, in a predetermined ratio.
4. The method for purifying Polyimide (PI) resin according to claim 1, wherein the compounding solvent ratio is 1: 10. 1: 9. 1: 8. 1: 7. 1: 6. 1: 5. 1: 4. 1: 3. 1: 2. 1:1, if more than two solvents are selected, the two main solvents are preferably selected for proportioning.
5. The method for purifying Polyimide (PI) resin according to claim 1, wherein said complex solvent in step S2 mainly dissolves and removes unreacted monomers, organic catalysts, oligomers and other impurities.
6. The method for purifying a Polyimide (PI) resin according to claim 1, wherein the temperature of the ultrasonic machine in said step S3 is set to be between 40 ℃ and 60 ℃.
7. The method for purifying Polyimide (PI) resin according to claim 1, wherein said ultrasonic cleaning time in step S3 is 0.5 to 2 hours.
8. The method for purifying Polyimide (PI) resin according to claim 1, wherein the mass fraction of the solution in said step S4 is between 8% and 15%.
9. The method for purifying Polyimide (PI) resin according to claim 1, wherein the semipermeable membrane used in step S5 is made of polytetrafluoroethylene, and the pore size of the semipermeable membrane is preferably selected from polytetrafluoroethylene semipermeable membranes having a molecular weight of 2000 or less;
the flow rate of the PI resin solution in the step S5 is 1 mL/min-10 mL/min;
the purified PI solution obtained in the step S5 has very narrow molecular weight distribution;
the residual single rate of the purified PI solution obtained in the step S5 is less than 0.3 percent;
and the residue rate of the purified PI solution catalyst obtained in the step S5 is less than 0.1%.
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| CN202310354757.XA CN116217963A (en) | 2023-04-06 | 2023-04-06 | Polyimide resin purification method |
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