阅读说明：本技术 一种改性对位芳纶聚合液、涂覆浆料、锂电池隔膜及其制备方法 (Modified para-aramid polymer liquid, coating slurry, lithium battery diaphragm and preparation method thereof ) 是由 陈琪 马海兵 马千里 于 2020-12-16 设计创作，主要内容包括：本发明公开了一种改性对位芳纶聚合液、涂覆浆料、电池隔膜及其制备方法,属于锂电池材料技术领域。本发明制得了改性对位芳纶聚合液,该聚合液可直接配制涂覆浆料并进行锂电池隔膜涂覆使用。本发明有效解决了传统对位芳纶难溶解于极性溶剂而制备涂覆膜的问题,所制备的锂电池隔膜中,陶瓷颗粒包裹在改性对位芳纶的三维网络结构中,有效改善了陶瓷颗粒掉粉的不足,提高了锂电池隔膜热性能和安全使用性能。该发明相对于传统方法具有生产效率高、产品性能好、生产成本低等显著优点。(The invention discloses a modified para-aramid polymer solution, a coating slurry, a battery diaphragm and a preparation method thereof, and belongs to the technical field of lithium battery materials. The modified para-aramid polymer liquid is prepared, and the polymer liquid can be directly used for preparing coating slurry and coating a lithium battery diaphragm. The invention effectively solves the problem that the traditional para-aramid is difficult to dissolve in a polar solvent to prepare a coating film, and ceramic particles are wrapped in a three-dimensional network structure of the modified para-aramid in the prepared lithium battery diaphragm, so that the defect of powder falling of the ceramic particles is effectively overcome, and the thermal performance and the safe use performance of the lithium battery diaphragm are improved. Compared with the traditional method, the method has the remarkable advantages of high production efficiency, good product performance, low production cost and the like.)

1. The modified para-aramid polymerized liquid is characterized by comprising the following raw materials in percentage by mass: 4 to 20 percent of cosolvent, 70 to 92 percent of organic solvent, 0.63 to 3.46 percent of p-phenylenediamine, 0.33 to 2.4 percent of monomer and 1.69 to 8.53 percent of terephthaloyl chloride;

the cosolvent is calcium chloride or lithium chloride;

the organic solvent is any one of N, N-dimethylacetamide, N-methylpyrrolidone, N-dimethylformamide, N-methylformamide and N-ethylpyrrolidone;

the monomer is one or two of 4,4 '-diaminodiphenyl ether, 3, 4' -diaminodiphenyl ether and polyether glycol.

2. The preparation method of the modified para-aramid polymer liquid as claimed in claim 1, characterized by comprising the following steps:

(1) continuous preparation of organic solution of cosolvent: continuously mixing the solid cosolvent and the organic solvent under stirring to prepare an organic solution A, wherein the cosolvent in the organic solution A accounts for 4-20 wt%;

(2) continuous preparation of organic solution of p-phenylenediamine: continuously mixing solid p-phenylenediamine and part of the organic solution A under stirring to prepare an organic solution B, wherein the weight percentage of the p-phenylenediamine in the organic solution B is 1.89-10.38%, and the temperature of the organic solution B is kept at 0-30 ℃ after the preparation;

(3) continuous preparation of an organic solution of terephthaloyl chloride: continuously mixing the molten terephthaloyl chloride with part of the organic solution A under stirring to prepare an organic solution C, wherein the weight percentage of the terephthaloyl chloride in the organic solution C is 5.07-25.59%, and keeping the temperature of the organic solution C at 0-30 ℃ after the preparation;

(4) continuous preparation of organic solution of monomers: continuously mixing the monomers and the residual organic solution A under stirring to prepare an organic solution D, wherein the weight percentage of the third monomer in the organic solution D is 0.99-7.2%, and the temperature of the organic solution D is kept at 0-30 ℃ after the preparation;

(5) pre-polycondensation of modified para-aramid: continuously feeding the prepared organic solution B and the organic solution D from a first feeding hole of a microchannel reactor, simultaneously introducing a part of the prepared organic solution C into a microchannel reaction plate from the first feeding hole and a second feeding hole, reacting at-15-0 ℃ for 10-100s to obtain a modified para-aramid pre-condensation polymer;

(6) polymerization: adding the rest organic solution C into the modified para-aramid pre-condensation polymer through a third feeding hole, and stirring and polymerizing for 15-30min at the temperature of-15-0 ℃; at least two microchannel reaction plates are arranged between the first feed inlet and the second feed inlet and between the second feed inlet and the third feed inlet, and the molar ratio of the terephthaloyl chloride feeding amount of the first feed inlet to the second feed inlet to the terephthaloyl chloride feeding amount of the third feed inlet is (0.07-0.13): (0.03-0.07): (0.8-0.9);

(7) neutralizing: after the polymerization reaction is finished, the polymerization liquid flows out in an overflow mode, then alkaline substances are added into the overflowing polymerization liquid to neutralize the byproduct hydrogen chloride in the polymerization liquid, and the reaction temperature is 30-90 ℃;

(8) continuous filtration and degassing bubble: and (4) continuously filtering and degassing the mixed solution obtained in the step (7) to obtain a modified para-aramid polymerized solution.

3. The preparation method of the modified para-aramid polymerization solution according to claim 2, wherein the volume ratio of the organic solution A in the step (2), the step (3) and the step (4) is 1:1: 1.

4. The preparation method of the modified para-aramid polymer solution as claimed in claim 2, wherein the alkaline substance used in the step (7) is calcium hydroxide, and the mass ratio of the calcium hydroxide to the terephthaloyl chloride is (0.8-1.2): 1.

5. a coating slurry for a lithium battery diaphragm is based on the modified para-aramid polymer liquid as claimed in claim 1, and is characterized by comprising the modified para-aramid polymer liquid and ceramic particles, wherein the weight percentage of the modified para-aramid polymer liquid to the ceramic particles is (30% -90%) (10% -70%).

6. The coating slurry for a lithium battery separator according to claim 5, wherein the ceramic particles are one or more of alumina, zirconia, magnesia, aluminum hydroxide, magnesium hydroxide, silica, and titania, and have a particle size of 10 to 1000 nm.

7. The preparation method of the coating slurry for the lithium battery diaphragm, as recited in claim 5, is characterized in that under the stirring condition, the ceramic particles are added into the modified para-aramid polymer solution and stirred uniformly, so as to obtain the coating slurry for the lithium battery diaphragm.

8. A lithium battery separator, based on the coating slurry for a lithium battery separator as claimed in claim 5, comprising a base film and a coating film, wherein the base film is one of polyethylene, polypropylene, a composite of polyethylene and polypropylene, polyethylene terephthalate non-woven fabric, and cellulose non-woven fabric; the coating film is obtained by coating slurry on a base film and performing post-treatment, wherein in the coating film, modified para-aramid forms a three-dimensional network structure, and ceramic particles are wrapped in the three-dimensional network structure.

9. The method for preparing a lithium battery separator according to claim 8, wherein the coating slurry is coated on one side or both sides of the base film, and then the coated base film is immersed in a coagulation bath of an organic solvent for 10 to 300 seconds and dried at 20 to 80 ℃ to obtain the modified para-aramid coated lithium battery separator, wherein the organic solvent in the coagulation bath is any one or more of N, N-dimethylacetamide, N-methylpyrrolidone, N-dimethylformamide and dimethyl phthalate.

10. The preparation method of the lithium battery diaphragm as claimed in claim 9, wherein the thermal shrinkage of the prepared modified para-aramid coated lithium battery diaphragm is less than or equal to 2.0% after the diaphragm is placed in an oven at 130 ℃ for 1 h; the modified para-aramid in the prepared modified para-aramid coated lithium battery diaphragm has the inherent viscosity of 0.3-3.0 and the molecular weight of 300-15000 Da.

Technical Field

The invention belongs to the field of high polymer materials, and particularly relates to a modified para-aramid polymer solution, a coating slurry, a lithium battery diaphragm and a preparation method thereof.

Background

At present, the lithium battery diaphragm is mostly made of polyolefin materials, such as polyethylene and polypropylene diaphragms, but the heat resistance and the wettability are poor, coating modification is usually carried out on one side or two sides of the polyolefin diaphragm, and ceramic coating films and PVDF coating films are commonly used in the market. But the inorganic ceramic has poor bonding force with polyolefin and is easy to remove powder, and although PVDF improves the bonding property of the diaphragm and the electrode, the high temperature resistance of the diaphragm is still not greatly improved, and the safety of the lithium battery is influenced.

Para-aramid, namely poly (p-phenylene terephthalamide), has the characteristics of intrinsic flame retardance, high strength, high modulus and the like, is widely applied to the fields of bulletproof, individual protection and the like, and is a very important special high-performance high polymer material. The para-aramid fiber is applied to the field of manufacturing membranes such as water treatment membranes, lithium ion battery diaphragms and the like, is one of the application directions of the para-aramid fiber, and the membranes manufactured by adopting the para-aramid fiber have the characteristics of intrinsic flame retardance and high strength, so that the membranes have good application prospects in the fields of high-temperature-resistant filtration, fireproof coatings, high-temperature-resistant lithium ion battery diaphragms and the like. However, para-aramid is difficult to dissolve in polar solvents, thereby limiting its processing utility in the film field.

The inherent viscosity (Iv value) of the polymer solution of the polymer needed by the traditional para-aramid fiber manufacture is more than 5.0dL/g, the molecular weight is generally more than 30000, but the synthesis method of the polymer is different from the synthesis method of the polymer for fiber in consideration of the stability of the polymer solution and the membrane processability. The solubility of the high molecular weight para-aramid in the traditional solvent is very low, and a homogeneous solution with high stability is difficult to form, so that a uniform film is difficult to form in the film preparation process, and the problems of difficult processing and low preparation efficiency are particularly prominent in the application of a coating film. Therefore, the development of a lithium battery diaphragm suitable for the modified para-aramid coating and a preparation method thereof are very necessary, and the development of a high-temperature-resistant, flame-retardant and high-strength lithium battery diaphragm is very important.

At present, methods for synthesizing para-aramid polymers for fibers generally include a low-temperature solution polycondensation method, an interfacial polycondensation method, a direct polycondensation method and the like, wherein the low-temperature solution polycondensation method is applied to large-scale industrialization, polymerization equipment of the low-temperature solution polycondensation method is generally a double-screw extruder, and the equipment is suitable for synthesizing high-viscosity polymers with large molecular weight and needing to dissipate heat in time. The polymerization method is different from the preparation of the para-aramid polymer for the fiber to a certain extent, and the para-aramid polymer for the film is more flexible in synthesis method and synthesis process due to the fact that the para-aramid polymer has the characteristics of relatively low molecular weight, solubility in traditional solvents, low viscosity of polymerization liquid and the like.

The micro-reaction technology originates from Europe in the early 90 s of the 20 th century, the size of a reactor channel is micron-sized, and compared with the traditional reactor, the micro-reactor has the advantages of short molecular diffusion distance, fast mass transfer, laminar flow in the channel, narrow residence time distribution, no back mixing, large specific surface area of unit volume, fast heat transfer speed, strong heat exchange capacity and easy temperature control.

In the aspect of microchannel reaction synthesis of meta-aramid and para-aramid, patents such as CN104667846A and CN110605079A apply for a micro reaction system for preparing meta-aramid and para-aramid resins, but a continuous synthesis method of para-aramid coating slurry for a lithium battery diaphragm does not exist so far.

Therefore, the method for efficiently and conveniently realizing the para-aramid coating slurry for the continuous industrial synthetic membrane is very important and very necessary.

Disclosure of Invention

Aiming at the problems that a para-aramid coating film is difficult to prepare and low in production efficiency, the invention provides a modified para-aramid polymer solution, a coating slurry, a lithium battery diaphragm and a preparation method thereof, the prepared para-aramid polymer solution has the inherent viscosity (Iv value is 0.2-3), the molecular weight is less than 15000, the solution stability is good, and the inherent viscosity of the solution within 3 months cannot change. In addition, the invention adopts the microchannel reactor to continuously synthesize the high-stability para-aramid coating slurry for the lithium battery diaphragm, so as to solve the problems of poor processability and low preparation efficiency caused by difficult dissolution of the para-aramid in a polar organic solvent.

In order to achieve the purpose, the invention adopts the following technical scheme:

a modified para-aramid polymerized liquid is prepared from the following raw materials in percentage by mass: 4 to 20 percent of cosolvent, 70 to 92 percent of organic solvent, 0.63 to 3.46 percent of p-phenylenediamine, 0.33 to 2.4 percent of monomer and 1.69 to 8.53 percent of terephthaloyl chloride;

the cosolvent is calcium chloride or lithium chloride;

the organic solvent is any one of N, N-dimethylacetamide, N-methylpyrrolidone, N-dimethylformamide, N-methylformamide and N-ethylpyrrolidone;

the monomer is one or two of 4,4 '-diaminodiphenyl ether, 3, 4' -diaminodiphenyl ether and polyether glycol.

A preparation method of a modified para-aramid polymerization solution comprises the following steps:

(1) continuous preparation of organic solution of cosolvent: continuously mixing the solid cosolvent and the organic solvent under stirring to prepare an organic solution A, wherein the cosolvent in the organic solution A accounts for 4-20 wt%;

(2) continuous preparation of organic solution of p-phenylenediamine: continuously mixing solid p-phenylenediamine and part of the organic solution A under stirring to prepare an organic solution B, wherein the weight percentage of the p-phenylenediamine in the organic solution B is 1.89-10.38%, and the temperature of the organic solution B is kept at 0-30 ℃ after the preparation;

(3) continuous preparation of an organic solution of terephthaloyl chloride: continuously mixing the molten terephthaloyl chloride with part of the organic solution A under stirring to prepare an organic solution C, wherein the weight percentage of the terephthaloyl chloride in the organic solution C is 5.07-25.59%, and keeping the temperature of the organic solution C at 0-30 ℃ after the preparation;

(4) continuous preparation of organic solution of monomers: continuously mixing the monomers and the residual organic solution A under stirring to prepare an organic solution D, wherein the weight percentage of the third monomer in the organic solution D is 0.99-7.2%, and the temperature of the organic solution D is kept at 0-30 ℃ after the preparation;

(5) pre-polycondensation of modified para-aramid: continuously feeding the prepared organic solution B and the organic solution D from a first feeding hole of a microchannel reactor, simultaneously introducing a part of the prepared organic solution C into a microchannel reaction plate from the first feeding hole and a second feeding hole, reacting at-15-0 ℃ for 10-100s to obtain a modified para-aramid pre-condensation polymer;

(6) polymerization: adding the rest organic solution C into the modified para-aramid pre-condensation polymer through a third feeding hole, and stirring and polymerizing for 15-30min at the temperature of-15-0 ℃; at least two microchannel reaction plates are arranged between the first feed inlet and the second feed inlet and between the second feed inlet and the third feed inlet, and the molar ratio of the terephthaloyl chloride feeding amount of the first feed inlet to the second feed inlet to the terephthaloyl chloride feeding amount of the third feed inlet is (0.07-0.13): (0.03-0.07): (0.8-0.9);

(7) neutralizing: after the polymerization reaction is finished, the polymerization liquid flows out in an overflow mode, then alkaline substances are added into the overflowing polymerization liquid to neutralize the byproduct hydrogen chloride in the polymerization liquid, and the reaction temperature is 30-90 ℃;

(8) continuous filtration and degassing bubble: and (4) continuously filtering and degassing the mixed solution obtained in the step (7) to obtain a modified para-aramid polymerized solution.

Further, the volume ratio of the organic solution A in the step (2), the step (3) and the step (4) is 1:1: 1.

Further, the alkaline substance used in the step (7) is calcium hydroxide, and the mass ratio of the calcium hydroxide to the terephthaloyl chloride is (0.8-1.2): 1.

the coating slurry for the lithium battery diaphragm comprises modified para-aramid polymer liquid and ceramic particles, wherein the weight percentage of the modified para-aramid polymer liquid to the ceramic particles is (30% -90%) (10% -70%).

Further, the ceramic particles are one or more of alumina, zirconia, magnesia, aluminum hydroxide, magnesium hydroxide, silica and titanium dioxide, and the particle size is 10-1000 nm.

Under the condition of stirring, adding ceramic particles into modified para-aramid polymer solution, and uniformly stirring to obtain the coating slurry for the lithium battery diaphragm.

A lithium battery diaphragm comprises a base film and a coating film, wherein the base film is one of polyethylene, polypropylene, a compound of polyethylene and polypropylene, polyethylene terephthalate non-woven fabric and cellulose non-woven fabric; the coating film is obtained by coating slurry on a base film and performing post-treatment, wherein in the coating film, modified para-aramid forms a three-dimensional network structure, and ceramic particles are wrapped in the three-dimensional network structure.

Coating the coating slurry on one side or two sides of a base film, then immersing the base film into a coagulation bath of an organic solvent for 10-300 seconds, and drying at 20-80 ℃ to obtain the modified para-aramid coated lithium battery diaphragm, wherein the organic solvent in the coagulation bath is any one or more of N, N-dimethylacetamide, N-methylpyrrolidone, N-dimethylformamide and dimethyl phthalate.

Further, after the prepared modified para-aramid coated lithium battery diaphragm is placed in an oven at 130 ℃ for 1 hour, the thermal shrinkage is less than or equal to 2.0 percent; the modified para-aramid in the prepared modified para-aramid coated lithium battery diaphragm has the inherent viscosity of 0.3-3.0 and the molecular weight of 300-15000 Da.

Compared with the prior art, the invention has the following beneficial technical effects:

(1) the invention discloses modified para-aramid slurry continuously prepared by adopting a microchannel reactor, which can be directly used for coating a lithium battery diaphragm and effectively solves the problem that the traditional para-aramid is difficult to dissolve in a polar solvent to prepare a coating film. Compared with the traditionally prepared pure solid para-aramid resin or para-aramid fiber, the para-aramid polymerization liquid for the film prepared by the invention has good stability, does not settle or solidify, does not change viscosity within 3 months, can be directly used in the production of film products, and improves the processability of para-aramid materials.

(2) In the modified para-aramid coating, the modified para-aramid forms a three-dimensional network structure, and the ceramic particles are wrapped in the three-dimensional network structure, so that the cohesiveness between the ceramic particles and the diaphragm is increased, the phenomenon of powder falling is effectively avoided, and the cohesive force between the coating and the base film is enhanced.

(3) The heat resistance of the separator is improved. The modified para-aramid coating is added, the heat resistance of the diaphragm is greatly improved, and the transverse heat shrinkage at 130 ℃ for 1 hour is less than or equal to 2.0 percent.

(4) The efficiency of preparing the para-aramid coating liquid is high. The microchannel reactor and the continuous preparation method are adopted, the operation is simple and convenient, the complex process of firstly synthesizing the para-aramid by the polymerization monomer and then dissolving the para-aramid in the concentrated sulfuric acid to prepare the polymerization solution is omitted, the preparation process is shortened, and the cost is reduced.

Drawings

FIG. 1 is a schematic view of a microchannel reactor used in the present invention.

In the figure: 1. a first inlet; 2. a second inlet; 3. a third inlet; 4. a fourth inlet; 5. a fifth inlet; 6. a sixth inlet; 7. a seventh inlet; 10. a second feed port; 11. a third feed inlet; 12. a fourth feed port; 13. a filtration inlet; 14. a deaeration inlet; 15. a liquid storage inlet; 16. a refrigerant inlet; 17. a refrigerant outlet; t1, T2 and T3 are all blending tanks; t5 is a polymerization kettle; t6 is a neutralization tank; t7 is a liquid storage tank.

Detailed Description

The invention is described in further detail below:

a modified para-aramid polymerized liquid is prepared from the following raw materials in percentage by mass: 4 to 20 percent of cosolvent, 70 to 92 percent of organic solvent, 0.63 to 3.46 percent of p-phenylenediamine, 0.33 to 2.4 percent of monomer and 1.69 to 8.53 percent of terephthaloyl chloride; the cosolvent is one of calcium chloride and lithium chloride; the organic solvent is any one of N, N-dimethylacetamide, N-methylpyrrolidone, N-dimethylformamide, N-methylformamide and N-ethylpyrrolidone; the monomer is one or two of 4,4 '-diaminodiphenyl ether, 3, 4' -diaminodiphenyl ether and polyether glycol.

A preparation method of a modified para-aramid polymerization solution comprises the following steps:

(1) continuous preparation of organic solution of cosolvent: continuously mixing the solid cosolvent and the organic solvent under stirring to prepare an organic solution A, wherein the cosolvent in the organic solution A accounts for 4-20 wt%;

(2) continuous preparation of organic solution of p-phenylenediamine: continuously mixing solid p-phenylenediamine and one third of the organic solution A under stirring to prepare an organic solution B, wherein the weight percentage of the p-phenylenediamine in the organic solution B is 1.89-10.38%, and keeping the temperature of the organic solution B at 0-30 ℃ after the preparation;

(3) continuous preparation of an organic solution of terephthaloyl chloride: continuously mixing a part of the terephthaloyl chloride in a molten state with one third of the organic solution A under stirring to prepare an organic solution C, wherein the weight percentage of the terephthaloyl chloride in the organic solution C is 5.07-25.59%, and the temperature of the organic solution C is kept at 0-30 ℃ after the preparation;

(4) continuous preparation of organic solution of monomers: continuously mixing the monomer and one third of the organic solution A under stirring to prepare an organic solution D, wherein the weight percentage of the monomer in the organic solution D is 0.99-7.2%, and the temperature of the organic solution D is kept at 0-30 ℃ after the preparation;

(5) pre-polycondensation of modified para-aramid: continuously feeding the prepared organic solution B and the organic solution D from a first feeding hole of a microchannel reactor, simultaneously introducing a part of the prepared organic solution C into a microchannel reaction plate from the first feeding hole and a second feeding hole, reacting at-15-0 ℃ for 10-100s to obtain a modified para-aramid pre-condensation polymer;

(6) polymerization: adding the rest organic solution C into the modified para-aramid pre-condensation polymer through a third feeding hole, and stirring and polymerizing for 15-30min at the temperature of-15-0 ℃; at least two microchannel reaction plates are arranged between the first feed inlet and the second feed inlet and between the second feed inlet and the third feed inlet, and the molar ratio of the terephthaloyl chloride feeding amount of the first feed inlet to the second feed inlet to the terephthaloyl chloride feeding amount of the third feed inlet is (0.07-0.13): (0.03-0.07): (0.8-0.9), wherein the molar ratio of the total amount of the terephthaloyl chloride to the sum of the p-phenylenediamine and the monomer in the step (3) is 1: (1-1.05);

(7) neutralizing: after the polymerization reaction is finished, the polymerization liquid enters a neutralization tank from a polymerization kettle in an overflow mode, then calcium hydroxide is added into the neutralization tank to neutralize the byproduct hydrogen chloride in the polymerization liquid, the reaction temperature is 30-90 ℃, and the mass ratio of calcium hydroxide to terephthaloyl chloride for neutralization is (0.8-1.2): 1;

(8) continuous filtration and degassing bubble: and (4) continuously filtering and degassing the mixed solution obtained in the step (7) to obtain a modified para-aramid polymerized solution.

The coating slurry for the lithium battery diaphragm comprises modified para-aramid polymer liquid and ceramic particles, wherein the weight percentage of the modified para-aramid polymer liquid to the ceramic particles is (30% -90%) (10% -70%); the ceramic particles are one or more of alumina, zirconia, magnesia, aluminum hydroxide, magnesium hydroxide, silicon dioxide and titanium dioxide, and the particle size is 10-1000 nm.

Under the condition of stirring, adding ceramic particles into modified para-aramid polymer solution, and uniformly stirring to obtain the coating slurry for the lithium battery diaphragm.

A lithium battery diaphragm comprises a base film and a coating film, wherein the base film is one of polyethylene, polypropylene, a compound of polyethylene and polypropylene, polyethylene terephthalate non-woven fabric and cellulose non-woven fabric; the coating film is obtained by coating slurry on a base film and performing post-treatment, wherein in the coating film, modified para-aramid forms a three-dimensional network structure, and ceramic particles are wrapped in the three-dimensional network structure.

Coating slurry on one side or two sides of a base film, then immersing the base film into a coagulation bath of an organic solvent for 10-300 seconds, and drying at 20-80 ℃ to obtain the modified para-aramid coated lithium battery diaphragm, wherein the organic solvent in the coagulation bath is any one or more of N, N-dimethylacetamide, N-methylpyrrolidone, N-dimethylformamide and dimethyl phthalate;

after the prepared modified para-aramid coated lithium battery diaphragm is placed in an oven at 130 ℃ for 1h, the thermal shrinkage is less than or equal to 2.0 percent; the modified para-aramid in the prepared modified para-aramid coated lithium battery diaphragm has the inherent viscosity of 0.3-3.0 and the molecular weight of 300-15000 Da.

The present invention will be described in more detail with reference to examples. It is to be understood that the practice of the invention is not limited to the following examples, and that any variations and/or modifications may be made thereto without departing from the scope of the invention.

In the present invention, all the devices and materials are commercially available or commonly used in the industry, if not specifically mentioned. The methods in the following examples are conventional in the art unless otherwise specified.

Example 1

Dissolving solid calcium chloride in N, N-dimethylacetamide to prepare 4% by mass of calcium chloride organic solution;

under stirring, the p-phenylenediamine and the organic solution of the calcium chloride are respectively and continuously added into a blending tank T1 from a first inlet 1 and a second inlet 2 to prepare the organic solution of the p-phenylenediamine with the weight percentage of 1.89%, and the solution temperature is kept at 0 ℃ after the preparation.

The terephthaloyl chloride and the calcium chloride organic solution are continuously added into a preparation tank T3 from a fifth inlet 5 and a sixth inlet 6 respectively to prepare 5.07 wt% of terephthaloyl chloride organic solution, and the solution temperature is kept at 0 ℃ after the preparation.

4,4 '-diaminodiphenyl ether and the organic solution of calcium chloride are respectively and continuously added into a preparation tank T2 from a third inlet 3 and a fourth inlet 4 to prepare the organic solution of 4, 4' -diaminodiphenyl ether with the weight percentage of 0.99 percent, and the temperature of the solution is kept at 0 ℃ after the preparation.

Continuously adding the prepared organic solution of p-phenylenediamine and the organic solution of 4, 4' -diaminodiphenyl ether into the inlet of a first reaction plate of a microchannel reactor from a first feed inlet 9 by using a delivery pump, simultaneously continuously adding 3 parts of the prepared organic solution of terephthaloyl chloride from a first feed inlet 9, a second feed inlet 10 and a third feed inlet 11 according to the mass ratio of 0.07:0.03:0.9, respectively, mixing and reacting the mixture, controlling the reaction temperature to be-15 ℃ by adjusting the flow of a refrigerant inlet 16, reacting the mixture in the microchannel reactor for 10s, introducing the mixture into a polymerization kettle T5, controlling the mass ratio of the added p-phenylenediamine to monomers and the total terephthaloyl chloride to be 1:1, introducing a polymerization liquid into a neutralization tank T6 from a polymerization kettle T5 in an overflow mode, continuously adding calcium hydroxide into the neutralization tank T6, and stirring the reaction, the mass ratio of calcium hydroxide to terephthaloyl chloride added was 0.8:1 to neutralize the by-product hydrogen chloride dissolved therein. After the reaction is finished, the polymer enters a filter and enters a deaerator from a deaeration inlet 14 to remove insoluble substances and bubbles in the polymer, the filtered and deaerated polymer solution enters a liquid storage tank T7 from a liquid storage inlet 15 to obtain a polymer synthetic solution containing 2% of modified para-aramid, and the polymer Ubbelohde viscosity is 500mpa · s through tests.

Example 2

Dissolving solid calcium chloride in N, N-dimethylacetamide to prepare 10% by mass of calcium chloride organic solution;

under stirring, the p-phenylenediamine and the organic solution of the calcium chloride are respectively and continuously added into a blending tank T1 from a first inlet 1 and a second inlet 2 to prepare the organic solution of the p-phenylenediamine with the weight percentage of 7.5 percent, and the temperature of the solution is kept at 15 ℃ after the preparation.

The terephthaloyl chloride and the calcium chloride organic solution are continuously added into a preparation tank T3 from a fifth inlet 5 and a sixth inlet 6 respectively to prepare a terephthaloyl chloride organic solution with the weight percentage of 15.2%, and the solution temperature is kept at 15 ℃ after the preparation.

Continuously adding 4,4 '-diaminodiphenyl ether and the organic solution of calcium chloride into a blending tank T2 from a third inlet 3 and a fourth inlet 4 respectively to prepare 2.5 wt% of the organic solution of 4, 4' -diaminodiphenyl ether, and keeping the temperature of the solution at 15 deg.C after preparation

Continuously adding the prepared organic solution of p-phenylenediamine and the organic solution of 3, 4' -diaminodiphenyl ether into the inlet of a first reaction plate of a microchannel reactor from a first feed inlet 9 by using a delivery pump, simultaneously continuously adding the prepared organic solution of terephthaloyl chloride 3 parts from a first feed inlet 9, a second feed inlet 10 and a third feed inlet 11 according to the mass ratio of 0.1:0.05:0.8, respectively, mixing and reacting the mixture, controlling the reaction temperature to be-7 ℃ by adjusting the flow of a refrigerant inlet 16, reacting the mixture in the microchannel reactor for 60s, introducing the mixture into a polymerization kettle T5, controlling the mass ratio of the added p-phenylenediamine to monomers and the total terephthaloyl chloride to be 1:1, introducing a polymerization liquid into a neutralization tank T6 from a polymerization kettle T5 in an overflow mode, continuously adding calcium hydroxide into the neutralization tank T6, and stirring the reaction, the mass ratio of calcium hydroxide to terephthaloyl chloride added was 1:1 to neutralize the by-product hydrogen chloride dissolved therein. After the reaction is finished, the polymer enters a filter and enters a deaerator from a deaeration inlet 14 to remove insoluble substances and bubbles in the polymer, the filtered and deaerated polymer solution enters a liquid storage tank T7 from a liquid storage inlet 15, namely the polymer synthetic solution containing 6% of the modified para-aramid fiber, and the polymer Ubbelohde viscosity is 40000mpa & s through tests.

Example 3

Dissolving solid calcium chloride in N, N-dimethylacetamide to prepare 20% by mass of an organic solution of calcium chloride;

under stirring, the p-phenylenediamine and the organic solution of the calcium chloride are respectively and continuously added into a blending tank T1 from a first inlet 1 and a second inlet 2 to prepare the organic solution of the p-phenylenediamine with the weight percentage of 10.38%, and the temperature of the solution is kept at 30 ℃ after the preparation.

The terephthaloyl chloride and the calcium chloride organic solution are continuously added into a preparation tank T3 from a fifth inlet 5 and a sixth inlet 6 respectively to prepare a 25.59 weight percent terephthaloyl chloride organic solution, and the solution temperature is kept at 30 ℃ after the preparation.

Continuously adding 4, 4-diaminodiphenyl ether and the organic solution of calcium chloride into a blending tank T2 from a third inlet 3 and a fourth inlet 4 respectively to prepare 7.2 wt% of the organic solution of 4, 4' -diaminodiphenyl ether, and keeping the temperature of the solution at 30 ℃ after preparation

Continuously adding the prepared organic solution of p-phenylenediamine and the organic solution of 4, 4' -diaminodiphenyl ether into the inlet of a first reaction plate of a microchannel reactor from a first feed inlet 9 by using a delivery pump, simultaneously continuously adding 3 parts of the prepared organic solution of terephthaloyl chloride from a first feed inlet 9, a second feed inlet 10 and a third feed inlet 11 according to the mass ratio of 0.13:0.07:0.8, respectively, mixing and reacting the mixture, controlling the reaction temperature to be 0 ℃ by adjusting the flow of a refrigerant inlet 16, reacting the mixture in the microchannel reactor for 100s, introducing the mixture into a polymerization kettle T5, enabling the mass ratio of the added p-phenylenediamine to monomers and the total terephthaloyl chloride to be 1:1.05, enabling a polymerization liquid to enter a neutralization tank T6 from a polymerization kettle T5 in an overflow mode, continuously adding calcium hydroxide into the neutralization tank T6, and stirring the mixture for reaction, the mass ratio of calcium hydroxide to terephthaloyl chloride added was 1.2:1 to neutralize the by-product hydrogen chloride dissolved therein. After the reaction is finished, the polymer enters a filter and enters a deaerator from a deaeration inlet 14 to remove insoluble substances and bubbles in the polymer, the filtered and deaerated polymer solution enters a liquid storage tank T7 from a liquid storage inlet 15, namely the polymer synthetic solution containing 10% of the modified para-aramid fiber, and the polymer Ubbelohde viscosity is 70000mpa & s through tests.

Example 4

Dissolving solid lithium chloride in N-methyl pyrrolidone to prepare an organic solution of lithium chloride with the mass percentage of 10%;

under stirring, p-phenylenediamine and the organic solution of lithium chloride are continuously added into a blending tank T1 from a first inlet 1 and a second inlet 2 respectively to prepare the organic solution of p-phenylenediamine with the weight percentage of 4.93%, and the solution temperature is kept at 20 ℃ after the preparation.

Terephthaloyl chloride and the lithium chloride organic solution are continuously added into a preparation tank T3 from a fifth inlet 5 and a sixth inlet 6 respectively to prepare a terephthaloyl chloride organic solution with the weight percentage of 12.8%, and the solution temperature is kept at 20 ℃ after the preparation.

Under stirring, 4 '-diaminodiphenyl ether and the organic solution of lithium chloride are continuously added into a preparation tank T2 from a third inlet 3 and a fourth inlet 4 respectively to prepare the organic solution of 4, 4' -diaminodiphenyl ether with the weight percentage of 2.89%, and the temperature of the prepared solution is kept at 20 ℃.

Continuously adding the prepared organic solution of p-phenylenediamine and the organic solution of 4, 4' -diaminodiphenyl ether into the inlet of a first reaction plate of a microchannel reactor from a first feeding hole 9 by using a delivery pump, simultaneously continuously adding 3 parts of the prepared organic solution of terephthaloyl chloride from a first feeding hole 9, a second feeding hole 10 and a third feeding hole 11 according to the mass ratio of 0.09:0.04:0.85 to mix and react, controlling the reaction temperature to be-7 ℃ by adjusting the flow of a refrigerant inlet 16, reacting in the microchannel reactor for 10s, then introducing into a polymerization kettle T5, controlling the mass ratio of the added p-phenylenediamine to monomers and the total terephthaloyl chloride to be 1:1.05, introducing the polymerization liquid into a neutralization tank T6 from a polymerization kettle T5 in an overflow mode, continuously adding calcium hydroxide into the neutralization tank T6 to stir, the mass ratio of calcium hydroxide to terephthaloyl chloride added was 1:1 to neutralize the by-product hydrogen chloride dissolved therein. After the reaction is finished, the polymer enters a filter and enters a deaerator from a deaeration inlet 14 to remove insoluble substances and bubbles in the polymer, the filtered and deaerated polymer solution enters a liquid storage tank T7 from a liquid storage inlet 15 to obtain polymer synthetic solution containing 5% of modified para-aramid, and the polymer Ubbelohde viscosity is 30000mpa & s through tests.

Example 5

Dissolving solid calcium chloride in N-methyl pyrrolidone to prepare 20% by mass of an organic solution of calcium chloride;

under stirring, the p-phenylenediamine and the organic solution of the calcium chloride are respectively and continuously added into a blending tank T1 from a first inlet 1 and a second inlet 2 to prepare the organic solution of the p-phenylenediamine with the weight percentage of 6.57 percent, and the temperature of the solution is kept at 0 ℃ after the preparation.

The terephthaloyl chloride and the calcium chloride organic solution are continuously added into a preparation tank T3 from a fifth inlet 5 and a sixth inlet 6 respectively to prepare a terephthaloyl chloride organic solution with the weight percentage of 12.44%, and the solution temperature is kept at 0 ℃ after the preparation.

Under stirring, 4 '-diaminodiphenyl ether and the organic solution of calcium chloride are continuously added into a blending tank T2 from a third inlet 3 and a fourth inlet 4 respectively to prepare 3.8 wt% of the organic solution of 4, 4' -diaminodiphenyl ether, and the temperature of the solution is kept at 0 ℃ after the preparation.

Continuously adding the prepared organic solution of p-phenylenediamine and the organic solution of 4, 4' -diaminodiphenyl ether into the inlet of a first reaction plate of a microchannel reactor from a first feeding hole 9 by using a delivery pump, simultaneously continuously adding 3 parts of the prepared organic solution of terephthaloyl chloride from a first feeding hole 9, a second feeding hole 10 and a third feeding hole 11 according to the mass ratio of 0.1:0.06:0.85, respectively, mixing and reacting the mixture, controlling the reaction temperature to be-7 ℃ by adjusting the flow of a refrigerant inlet 16, reacting in the microchannel reactor for 60s, then introducing the mixture into a polymerization kettle T5, controlling the mass ratio of the added p-phenylenediamine to monomers and the total terephthaloyl chloride to be 1:1.02, introducing a polymerization liquid into a neutralization tank T6 from a polymerization kettle T5 in an overflow mode, continuously adding calcium hydroxide into the neutralization tank T6, and stirring the reaction, the mass ratio of calcium hydroxide to terephthaloyl chloride added was 1.2:1 to neutralize the by-product hydrogen chloride dissolved therein. After the reaction is finished, the polymer enters a filter and enters a deaerator from a deaeration inlet 14 to remove insoluble substances and bubbles in the polymer, the filtered and deaerated polymer solution enters a liquid storage tank T7 from a liquid storage inlet 15 to obtain polymer synthetic solution containing 5% of modified para-aramid, and the polymer Ubbelohde viscosity is 25000mpa & s through tests.

Example 6

The procedure of example 2 was followed except that "N, N-dimethylformamide" was used instead of N-methylpyrrolidone in example 2, and "3, 4 '-diaminodiphenyl ether" was used instead of 4, 4' -diaminodiphenyl ether ", and other conditions such as preparation process, process parameters, and equipment type were the same as in example 2.

Example 7

The preparation process, process parameters, equipment type and other conditions were the same as in example 3 except that "N-methylpyrrolidone" in example 3 was changed to "N-methylformamide" and "4, 4 '-diaminodiphenyl ether" was changed to "3, 4' -diaminodiphenyl ether".

Example 8

The preparation process, process parameters, equipment type and other conditions were the same as in example 4 except that N-methylpyrrolidone in example 4 was changed to "N-ethylpyrrolidone" and "4, 4' -diaminodiphenyl ether" was changed to "polyether glycol".

Example 9

Adding the ceramic particles into a liquid storage tank T7, and stirring, uniformly stirring the modified para-aramid polymer solution obtained in example 1 and the alumina particles according to the weight percentage of 30:70 to obtain coating slurry.

Example 10

Adding the ceramic particles into a liquid storage tank T7, and stirring, uniformly stirring the modified para-aramid polymer solution obtained in example 2 and the magnesium oxide particles according to the weight percentage of 60:40 to obtain coating slurry.

Example 11

Adding the ceramic particles into a liquid storage tank T7, and stirring uniformly the modified para-aramid polymer solution obtained in example 3 and the zirconia particles according to the weight percentage of 90:10 to obtain coating slurry.

Example 12

Adding the ceramic particles into a liquid storage tank T7, and stirring, uniformly stirring the modified para-aramid polymer solution obtained in example 4 and the silicon dioxide particles according to the weight percentage of 60:40 to obtain coating slurry.

Example 13

Adding the ceramic particles into a liquid storage tank T7, and stirring, uniformly stirring the modified para-aramid polymer solution obtained in example 5 and the titanium dioxide particles according to the weight percentage of 90:10 to obtain coating slurry.

Example 14

Adding the ceramic particles into a liquid storage tank T7, and stirring, uniformly stirring the modified para-aramid polymer solution obtained in example 6 and the magnesium oxide particles according to the weight percentage of 60:40 to obtain coating slurry.

Example 15

Adding the ceramic particles into a liquid storage tank T7, and stirring uniformly the modified para-aramid polymer solution obtained in example 7 and the zirconia particles according to the weight percentage of 90:10 to obtain coating slurry.

Example 16

Adding the ceramic particles into a liquid storage tank T7, and stirring, uniformly stirring the modified para-aramid polymer solution obtained in example 8 and the silicon dioxide particles according to the weight percentage of 60:40 to obtain coating slurry.

Example 17

And (3) coating the coating slurry obtained in the embodiment 9 on one side of a polyethylene base film, then soaking the polyethylene base film into a coagulation bath of N-methyl pyrrolidone for 10 seconds, and drying the polyethylene base film at 20 ℃ to obtain the modified para-aramid coated lithium battery diaphragm.

Example 18

And (3) coating the coating slurry obtained in the embodiment 10 on two sides of a polyethylene terephthalate non-woven fabric, then soaking the non-woven fabric into a coagulation bath of N-methyl pyrrolidone for 160 seconds, and drying at 52 ℃ to obtain the modified para-aramid coated lithium battery diaphragm.

Example 19

And (3) coating the coating slurry obtained in the embodiment 11 on one side of a polypropylene base film, then soaking the polypropylene base film into a coagulation bath of N, N-dimethylformamide for 300 seconds, and drying the polypropylene base film at 80 ℃ to obtain the modified para-aramid coated lithium battery diaphragm.

Example 20

And (3) coating the coating slurry obtained in the embodiment 12 on one side of a cellulose non-woven fabric, then soaking the cellulose non-woven fabric in a dimethyl phthalate coagulation bath for 160 seconds, and drying the cellulose non-woven fabric at 52 ℃ to obtain the modified para-aramid coated lithium battery diaphragm.

Example 21

The coating slurry obtained in example 13 was coated on one side of a composite of polyethylene and polypropylene, and then immersed in a coagulation bath of N, N-dimethylacetamide for 300 seconds, and dried at 80 ℃ to obtain a modified para-aramid coated lithium battery separator.

Example 22

The coating slurry obtained in the example 14 was coated on both sides of a polyethylene terephthalate nonwoven fabric, and then immersed in a coagulation bath of N-methylpyrrolidone for 160 seconds and dried at 52 ℃ to obtain a modified para-aramid coated lithium battery separator.

Example 23

And (3) coating the coating slurry obtained in the embodiment 15 on one side of a polypropylene base film, then soaking the polypropylene base film into a coagulation bath of N, N-dimethylformamide for 300 seconds, and drying the polypropylene base film at 80 ℃ to obtain the modified para-aramid coated lithium battery diaphragm.

Example 24

The coating slurry obtained in example 16 was coated on one side of a cellulose nonwoven fabric, and then immersed in a dimethyl phthalate coagulation bath for 160 seconds and dried at 52 ℃ to obtain a modified p-aramid coated lithium battery separator.

Comparative example 1

The base film was immersed in a coagulation bath of N, N-dimethylacetamide under the same conditions as in example 1 to obtain a separator.

Comparative example 2

The base film was coated with ceramic and then immersed in a coagulation bath of N, N-dimethylacetamide under the same conditions as in example 1 to produce a separator.

Comparative example 3

And (3) carrying out polymerization reaction by adopting a traditional double screw, and obtaining the aramid coating film under the same other conditions as the example 1.

Comparative example 4

An aramid coating film was obtained in the same manner as in example 1 except that 4, 4' -diaminodiphenyl ether was not added.

Comparative example 5

And (3) carrying out polymerization reaction by adopting a traditional double screw, and obtaining the aramid coating film under the same other conditions as the example 5.

Index of polymerization liquid

The polymer liquid and the film obtained in the above examples and comparative examples 1 to 8 were subjected to performance tests, and the test results were as follows:

as can be seen from the table above, the stability and the film thermal shrinkage index of the polymerization solution prepared by the invention are obviously superior to those of the base film, and the function of bonding ceramic particles can be realized without adding an adhesive.

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes will occur to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.