CN114716723B - Beta-phase polypropylene microporous membrane and preparation method thereof - Google Patents
Beta-phase polypropylene microporous membrane and preparation method thereof Download PDFInfo
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- CN114716723B CN114716723B CN202210476960.XA CN202210476960A CN114716723B CN 114716723 B CN114716723 B CN 114716723B CN 202210476960 A CN202210476960 A CN 202210476960A CN 114716723 B CN114716723 B CN 114716723B
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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
- C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
- C08J9/24—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof by surface fusion and bonding of particles to form voids, e.g. sintering
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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
- C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
- C08J5/18—Manufacture of films or sheets
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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
- C08J2323/00—Characterised by the use of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Derivatives of such polymers
- C08J2323/02—Characterised by the use of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Derivatives of such polymers not modified by chemical after treatment
- C08J2323/10—Homopolymers or copolymers of propene
- C08J2323/12—Polypropene
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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
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Abstract
The invention provides a beta-phase polypropylene microporous membrane and a preparation method thereof, belonging to the technical field of polypropylene microporous membrane preparation. The isotactic polypropylene granule is nucleated into alpha-phase crystal nucleus at room temperature to 130 deg.c after eliminating heat history at 200 deg.c, soaked in Ionic Liquid (ILs) and fast phase-changed into beta-phase crystal at 120-150 deg.c to obtain high beta-content iPP film. Then, stretching the film at a speed of 2-10mm/min for 5-7 times, and heat setting at 100-130 ℃ for 5-10min to obtain the beta-phase polypropylene microporous membrane. The preparation method greatly improves the generation speed of beta-iPP by adopting a method of crystallization and then rapid annealing, and can rapidly prepare the microporous iPP film.
Description
Technical Field
The invention belongs to the technical field of polypropylene microporous membrane preparation, and particularly relates to a beta-phase polypropylene microporous membrane and a preparation method thereof.
Background
Lithium battery separator materials have been receiving extensive attention from all parties, and polypropylene with excellent properties is the focus of research. Isotactic polypropylene is a polycrystalline, semi-crystalline polymer, the most common crystalline form of which has alpha and beta phases. Beta-phase polypropylene is easy to tear under the stretching condition to generate uniform micropores, and is commonly used as a lithium battery separator material. In the prior art, the iPP film containing beta phase is often prepared by high-temperature annealing for a long time or by adding beta phase nucleating agent, but the defects of high energy consumption, high cost and low productivity caused by excessively long annealing time and the defects of reduced mechanical properties of the film caused by solid filling exist.
Disclosure of Invention
The invention aims to provide an iPP film with high beta-phase content, which is prepared by means of low-temperature crystallization, then coating an ionic liquid or a quaternary ammonium salt solution and rapidly annealing at high temperature.
For example, the invention adopts the following technical scheme:
the invention provides a preparation method of a beta-phase polypropylene microporous membrane, which comprises the following steps:
(1) Drying the isotactic polypropylene granules in an oven to obtain dried isotactic polypropylene granules;
(2) Placing the dried isotactic polypropylene granules between two plates of a hot press for hot press molding, and transferring to room temperature for solidification after completion to obtain an isotactic polypropylene film A;
(3) Melting the isotactic polypropylene film on a heating table to eliminate heat history, and transferring to the heating table for 10-30s for heat preservation treatment to obtain an isotactic polypropylene film B;
(4) Uniformly coating a layer of ionic liquid or quaternary ammonium salt solution on the isotactic polypropylene film B by using absorbent cotton, and standing for 5-20min to obtain an isotactic polypropylene film C;
(5) Annealing the isotactic polypropylene film C on a heating table, and preserving heat for 10-60min to obtain an isotactic polypropylene film D;
(6) Stretching the isotactic polypropylene film D for 5-7 times by a pulling machine to obtain an isotactic polypropylene film E;
(7) And (3) carrying out heat setting on the isotactic polypropylene film E to obtain the beta-phase polypropylene microporous film.
Preferably, in the step (1), the drying temperature is 60-100 ℃, and the drying time is 6-24 hours.
Preferably, in the step (2), the conditions of the hot press molding are: the hot pressing temperature is 190-210 ℃, the pressure is 8-12MPa, and the pressure maintaining time is 3-7min.
Preferably, in the step (3), the ionic liquid comprises 1-butyl-3-methylimidazole hexafluorophosphate, 1-butyl-3-methylimidazole tetrafluoroborate and N-butylpyridine hexafluorophosphate; the quaternary ammonium salt solution comprises cetyl trimethyl ammonium bromide, dodecyl trimethyl ammonium bromide and choline chloride, and the temperature of the heating table is between room temperature and 130 ℃.
Preferably, the annealing temperature is 120-150 ℃.
Preferably, the speed of the pulling machine is 2-10mm/min.
Preferably, the temperature of the heat setting is 100-130 ℃, and the time of the heat setting is 5-10min.
Secondly, the invention provides a beta-phase polypropylene microporous membrane, which is prepared by the following preparation method:
(1) Drying the isotactic polypropylene granules in an oven at 60-100 ℃ for 6-24 hours to obtain dried isotactic polypropylene granules;
(2) Placing the dried isotactic polypropylene granules between two plates of a hot press for hot press forming, wherein the hot press temperature is 190-210 ℃, the pressure is 8-12MPa, the dwell time is 3-7min, and transferring to room temperature for curing after completion to obtain an isotactic polypropylene film A;
(3) Melting the isotactic polypropylene film on a heating table at 190-210 ℃ to eliminate heat history, and then transferring to the heating table at room temperature to 130 ℃ for heat preservation treatment within 10-30 seconds to obtain an isotactic polypropylene film B;
(4) Uniformly coating a layer of ionic liquid or quaternary ammonium salt solution on the isotactic polypropylene film B by using absorbent cotton, and standing for 5-20min to obtain an isotactic polypropylene film C;
(5) Annealing the isotactic polypropylene film C on a heating table at 120-150 ℃, and preserving heat for 10-60min to obtain an isotactic polypropylene film D;
(6) Stretching the isotactic polypropylene film D by 5-7 times at a speed of 2-10mm/min by a pulling machine to obtain an isotactic polypropylene film E;
(7) Heat setting the isotactic polypropylene film E at 100-130 ℃ for 5-10min to obtain beta-phase polypropylene microporous film;
the ionic liquid comprises 1-butyl-3-methylimidazole hexafluorophosphate, 1-butyl-3-methylimidazole tetrafluoroborate and N-butylpyridine hexafluorophosphate; the quaternary ammonium salt solution comprises cetyl trimethyl ammonium bromide, dodecyl trimethyl ammonium bromide and choline chloride.
The beneficial effects of the invention are as follows:
the invention adopts a hot-pressing method to prepare a polypropylene (iPP) porous membrane, and the iPP is quickly nucleated into alpha-phase crystal nucleus at the temperature of room temperature to 130 ℃. After the ionic liquid or the quaternary ammonium salt solution is coated, the ionic liquid or the quaternary ammonium salt solution is quickly changed into beta-phase crystals at 120-150 ℃, so that the beta-phase iPP film is quickly prepared. Then, the film is stretched for 5-7 times by the stretching speed of 2-10mm/min, and the iPP porous film with uniform holes is prepared. Compared with the traditional melt crystallization method, the method greatly improves the phase change speed of the beta phase and quickens the phase change degree of the beta phase, thereby being capable of rapidly preparing the beta-phase polypropylene porous membrane.
Drawings
FIG. 1 is a scanning electron microscope image of example 5 of the present invention.
Detailed Description
In order to clearly illustrate the technical characteristics of the scheme, the scheme is explained below through a specific embodiment.
Example 1
(1) Drying isotactic polypropylene (iPP) granules in a 60 ℃ oven for 24 hours to obtain dried isotactic polypropylene granules;
(2) Placing the dried isotactic polypropylene granules between two plates of a hot press for hot press forming, wherein the hot press temperature is 210 ℃, the pressure is 8 MPa, the dwell time is 3 min, and transferring to room temperature for curing after completion to obtain an isotactic polypropylene film A;
(3) Melting the isotactic polypropylene film on a heating table at 190 ℃ to eliminate heat history, and then transferring to the heating table at room temperature for 5min to obtain an isotactic polypropylene film B;
(4) Uniformly coating a layer of 1-butyl-3-methylimidazole hexafluorophosphate on the isotactic polypropylene film B by using absorbent cotton, and standing for 20min to obtain an isotactic polypropylene film C;
(5) Annealing the isotactic polypropylene film C on a heating table at 120 ℃, and preserving heat for 60min to obtain an isotactic polypropylene film D;
(6) Stretching the isotactic polypropylene film D5 times at a speed of 10mm/min by a pulling machine to obtain an isotactic polypropylene film E;
(7) And (3) carrying out heat setting on the isotactic polypropylene film E at 130 ℃ for 10min to obtain the beta-phase polypropylene microporous film 1.
Example 2
(1) Drying the isotactic polypropylene (iPP) granules in a 70 ℃ oven for 18 hours to obtain dried isotactic polypropylene granules;
(2) Placing the dried isotactic polypropylene granules between two plates of a hot press for hot press forming, wherein the hot press temperature is 205 ℃, the pressure is 9MPa, the dwell time is 4 min, and transferring to room temperature for curing after completion to obtain an isotactic polypropylene film A;
(3) Melting the isotactic polypropylene film on a heating table at 195 ℃ to eliminate heat history, and then transferring to the heating table at 60 ℃ for heat preservation for 10min in 25 seconds to obtain an isotactic polypropylene film B;
(4) Uniformly coating a layer of 1-butyl-3-methylimidazole tetrafluoroborate on the isotactic polypropylene film B by using absorbent cotton, and standing for 17min to obtain an isotactic polypropylene film C;
(5) Annealing the isotactic polypropylene film C on a heating table at 130 ℃, and preserving heat for 50min to obtain an isotactic polypropylene film D;
(6) Stretching the isotactic polypropylene film D by 6.5 times at a speed of 8 mm/min by a pulling machine to obtain an isotactic polypropylene film E;
(7) And (3) carrying out heat setting on the isotactic polypropylene film E at 125 ℃ for 8min to obtain the beta-phase polypropylene microporous film 2.
Example 3
(1) Drying isotactic polypropylene (iPP) granules in an oven at 80 ℃ for 15 hours to obtain dried isotactic polypropylene granules;
(2) Placing the dried isotactic polypropylene granules between two plates of a hot press for hot press forming, wherein the hot press temperature is 200 ℃, the pressure is 10MPa, the dwell time is 5min, and transferring to room temperature for curing after completion to obtain an isotactic polypropylene film A;
(3) Melting the isotactic polypropylene film on a heating table at 200 ℃ to eliminate heat history, and transferring to the heating table at 90 ℃ for heat preservation for 120min in 20s to obtain an isotactic polypropylene film B;
(4) Uniformly coating a layer of N-butylpyridinium hexafluorophosphate ethanol solution on the isotactic polypropylene film B by using absorbent cotton, and standing for 12min to obtain an isotactic polypropylene film C;
(5) Annealing the isotactic polypropylene film C on a heating table at 140 ℃, and preserving heat for 30min to obtain an isotactic polypropylene film D;
(6) Stretching the isotactic polypropylene film D by 6 times at a speed of 5 mm/min by a pulling machine to obtain an isotactic polypropylene film E;
(7) And (3) carrying out heat setting on the isotactic polypropylene film E at 120 ℃ for 7min to obtain the beta-phase polypropylene microporous film 3.
Example 4
(1) Drying isotactic polypropylene (iPP) granules in a 100 ℃ oven for 6 hours to obtain dried isotactic polypropylene granules;
(2) Placing the dried isotactic polypropylene granules between two plates of a hot press for hot press forming, wherein the hot press temperature is 190 ℃, the pressure is 12MPa, the dwell time is 7min, and transferring to room temperature for curing after completion to obtain an isotactic polypropylene film A;
(3) Melting the isotactic polypropylene film on a heating table at 210 ℃ to eliminate heat history, and transferring to the heating table at 130 ℃ for heat preservation for 600min within 10 seconds to obtain an isotactic polypropylene film B;
(4) Uniformly coating a layer of hexadecyl trimethyl ammonium bromide aqueous solution on the isotactic polypropylene film B by using absorbent cotton, and standing for 5min to obtain an isotactic polypropylene film C;
(5) Annealing the isotactic polypropylene film C on a heating table at 150 ℃, and preserving heat for 10min to obtain an isotactic polypropylene film D;
(6) Stretching the isotactic polypropylene film D for 5 times at a speed of 2mm/min by a pulling machine to obtain an isotactic polypropylene film E;
(7) And (3) carrying out heat setting on the isotactic polypropylene film E at 130 ℃ for 6min to obtain the beta-phase polypropylene microporous film 5.
The technical features of the present invention that are not described in the present invention may be implemented by or using the prior art, and are not described in detail herein, but the above description is not intended to limit the present invention, and the present invention is not limited to the above examples, but is also intended to be within the scope of the present invention by those skilled in the art.
Claims (2)
1. A method for preparing a beta-phase polypropylene microporous membrane, which is characterized by comprising the following steps:
(1) Drying the isotactic polypropylene granules in an oven to obtain dried isotactic polypropylene granules;
(2) Placing the dried isotactic polypropylene granules between two plates of a hot press for hot press molding, and transferring to room temperature for solidification after completion to obtain an isotactic polypropylene film A;
(3) Melting the isotactic polypropylene film on a heating table to eliminate heat history, and transferring to the heating table for 10-30s for heat preservation treatment to obtain an isotactic polypropylene film B;
(4) Uniformly coating a layer of ionic liquid or quaternary ammonium salt solution on the isotactic polypropylene film B by using absorbent cotton, and standing for 5-20min to obtain an isotactic polypropylene film C;
(5) Annealing the isotactic polypropylene film C on a heating table, and preserving heat for 10-60min to obtain an isotactic polypropylene film D;
(6) Stretching the isotactic polypropylene film D for 5-7 times by a pulling machine to obtain an isotactic polypropylene film E;
(7) Heat setting the isotactic polypropylene film E to obtain a beta-phase polypropylene microporous film;
in the step (1), the drying temperature is 60-100 ℃, and the drying time is 6-24 hours;
in the step (2), the conditions of the hot press molding are as follows: the hot pressing temperature is 190-210 ℃, the pressure is 8-12MPa, and the pressure maintaining time is 3-7min;
in the step (3), the ionic liquid comprises 1-butyl-3-methylimidazole hexafluorophosphate, 1-butyl-3-methylimidazole tetrafluoroborate and N-butylpyridine hexafluorophosphate; the quaternary ammonium salt solution comprises cetyl trimethyl ammonium bromide, dodecyl trimethyl ammonium bromide and choline chloride, and the temperature of the heating table is between room temperature and 130 ℃;
the annealing temperature is 120-150 ℃;
the speed of the pulling machine is 2-10mm/min;
the temperature of the heat setting is 100-130 ℃, and the time of the heat setting is 5-10min.
2. A beta-phase polypropylene microporous membrane, which is characterized in that the microporous membrane is prepared by the following preparation method:
(1) Drying the isotactic polypropylene granules in an oven at 60-100 ℃ for 6-24 hours to obtain dried isotactic polypropylene granules;
(2) Placing the dried isotactic polypropylene granules between two plates of a hot press for hot press forming, wherein the hot press temperature is 190-210 ℃, the pressure is 8-12MPa, the dwell time is 3-7min, and transferring to room temperature for curing after completion to obtain an isotactic polypropylene film A;
(3) Melting the isotactic polypropylene film on a heating table at 190-210 ℃ to eliminate heat history, and then transferring to the heating table at room temperature to 130 ℃ for heat preservation treatment within 10-30 seconds to obtain an isotactic polypropylene film B;
(4) Uniformly coating a layer of ionic liquid or quaternary ammonium salt solution on the isotactic polypropylene film B by using absorbent cotton, and standing for 5-20min to obtain an isotactic polypropylene film C;
(5) Annealing the isotactic polypropylene film C on a heating table at 120-150 ℃, and preserving heat for 10-60min to obtain an isotactic polypropylene film D;
(6) Stretching the isotactic polypropylene film D for 5-7 times at a speed of 2-10mm/min by a pulling machine to obtain an isotactic polypropylene film E;
(7) Heat setting the isotactic polypropylene film E at 100-130 ℃ for 5-10min to obtain beta-phase polypropylene microporous film;
the ionic liquid comprises 1-butyl-3-methylimidazole hexafluorophosphate, 1-butyl-3-methylimidazole tetrafluoroborate and N-butylpyridine hexafluorophosphate; the quaternary ammonium salt solution comprises cetyl trimethyl ammonium bromide, dodecyl trimethyl ammonium bromide and choline chloride.
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| JPH07118429A (en) * | 1993-10-26 | 1995-05-09 | Tonen Chem Corp | Production of polypropylene porous film |
| CN102604203A (en) * | 2012-01-18 | 2012-07-25 | 成都慧成科技有限责任公司 | Improved microporous polymer film and preparation method thereof |
| CN104610647A (en) * | 2013-11-01 | 2015-05-13 | 天津大学 | Method for regulation of polypropylene crystal form composition and yield strain by annealing treatment |
| CN112694662A (en) * | 2019-10-23 | 2021-04-23 | 中国石油化工股份有限公司 | Permeable polypropylene film and preparation method thereof |
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2022
- 2022-05-01 CN CN202210476960.XA patent/CN114716723B/en active Active
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| JPH07118429A (en) * | 1993-10-26 | 1995-05-09 | Tonen Chem Corp | Production of polypropylene porous film |
| CN102604203A (en) * | 2012-01-18 | 2012-07-25 | 成都慧成科技有限责任公司 | Improved microporous polymer film and preparation method thereof |
| CN104610647A (en) * | 2013-11-01 | 2015-05-13 | 天津大学 | Method for regulation of polypropylene crystal form composition and yield strain by annealing treatment |
| CN112694662A (en) * | 2019-10-23 | 2021-04-23 | 中国石油化工股份有限公司 | Permeable polypropylene film and preparation method thereof |
| CN114085425A (en) * | 2021-11-08 | 2022-02-25 | 宁波福天新材料科技有限公司 | Beta-crystal-form compound nucleating agent and application thereof |
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