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A kind of preparation method of polyimide porous film

A polyimide, porous film technology, applied in the field of preparation of polyimide porous films, can solve the problems of low porosity, long processing time, low removal rate of pore-forming substances, etc., and achieves improvement of porosity and air permeability Effect

Active Publication Date: 2020-02-21
GUILIN ELECTRICAL EQUIP SCI RES INST
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The pore size of the polyimide porous film prepared by this method is difficult to control, and the porosity is low
[0006] Most of the above-mentioned chemical solvent methods use organic acids such as hydrochloric acid and sulfuric acid or organic solvents to remove the pore-forming agent, but the chemical solvent itself is not easy to penetrate into the interior of the material, and the pore-forming substances used in the prior art are all non-porous inside. Inorganic substances, so there are disadvantages of long treatment time, low removal rate of pore-forming substances and low porosity of the obtained porous film

Method used

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  • A kind of preparation method of polyimide porous film
  • A kind of preparation method of polyimide porous film

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0024] 1) Add 10.8g ODA and dissolve in 127.5g N,N-dimethylacetamide in a three-necked flask, then add a total of 11.7g PMDA in batches, synthesize at room temperature for 6h, and obtain a polyamic acid resin solution ;

[0025] 2) Weigh 4.5g of porous silica (with an internal pore size of 25-50nm and an average particle size of 300nm) in a beaker, add 45.0g of N,N-dimethylacetamide, stir rapidly with a glass rod and ultrasonically Disperse for 15 minutes, add the resulting dispersion into the polyamic acid resin solution synthesized in step 1), and simultaneously use mechanical stirring and ultrasonic dispersion for 2 hours to obtain a polyamic acid / porous silica mixed solution;

[0026] 3) Vacuum degas the polyamic acid / porous silica mixed solution, then lay a film on a clean glass plate, put it in an oven for thermal imidization, and follow the steps of 80°C / 1h, 140°C / 1h, 220°C / 1h, 300℃ / 1h programmed temperature rise curing;

[0027] 4) After cooling to room temperature,...

Embodiment 2

[0029] 1) Add 12.3g ODA and dissolve in 123.0g N,N-dimethylacetamide in a three-necked flask, then add a total of 10.7g PMDA in batches, after it is completely dissolved, add 3.9g BTDA, Synthesize at room temperature for 5h to obtain a polyamic acid resin solution;

[0030] 2) Weigh 10.8g of porous titanium dioxide (with an internal pore size of 45-100nm and an average particle size of 450nm) in a beaker, add 108.0g of N,N-dimethylacetamide, stir rapidly with a glass rod and disperse ultrasonically 20min, the resulting dispersion was added to the polyamic acid resin solution synthesized in step 1), and mechanical stirring and ultrasonic dispersion were used for 2h at the same time to obtain a polyamic acid / porous titanium dioxide mixed solution;

[0031] 3) Vacuum degas the polyamic acid / porous titanium dioxide mixed solution, then lay a film on a clean glass plate, put it in an oven for thermal imidization, and follow the steps of 80°C / 1h, 140°C / 1h, 220°C / 1h, 300℃ / 1h program...

Embodiment 3

[0034] 1) in there-necked flask, add 14.4g ODA and dissolve in 80.0g N-methyl-2-pyrrolidone and 40.0g N, in the N-dimethylformamide, then add the PMDA that total amount is 15.6g in batches, in Synthesize at room temperature for 5h to obtain a polyamic acid resin solution;

[0035] 2) Weigh 15.0g of porous silica (with an internal pore size of 100-150nm and an average particle size of 670nm) in a beaker, add 150.0g of N-methyl-2-pyrrolidone, stir rapidly with a glass rod and disperse by ultrasonic 15min, the resulting dispersion was added to the polyamic acid resin solution synthesized in step 1), and mechanically stirred and ultrasonically dispersed for 2h at the same time to obtain a polyamic acid / porous silica mixed solution;

[0036] 3) Vacuum degas the polyamic acid / porous silica mixed solution, then lay a film on a clean glass plate, put it in an oven for thermal imidization, and follow the steps of 80°C / 1h, 140°C / 1h, 220°C / 1h, 300℃ / 1h programmed temperature rise curing; ...

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Abstract

The invention discloses a method for preparing a porous polyimide film. The method comprises the steps of adopting porous filler as a pore forming substance, uniformly dispersing the pore forming substance in a polyamic acid resin solution, subjecting the obtained mixed solution to defoaming, film laying and imidization so as to obtain a polyamic acid / pore forming substance composite film, etching the obtained polyamic acid / pore forming substance composite film in an etching solution to remove the pore forming substance, and carrying out washing and drying, thereby obtaining the porous polyimide film. Compared with the prior art, the method has the advantages that the porous filler with specific particle size, of which the interior has pores, is selected as the pore forming substance, the polyimide / pore forming substance composite film is etched in the etching solution, then, on one hand, the etching solution can very easily infiltrate inside the composite film, thus, the pore forming substance can be thoroughly removed, and then, the porosity and air permeability of the porous film are effectively improved; and on the other hand, the pore size of the porous film is effectively controlled through defining the particle size of the pore forming substance.

Description

technical field [0001] The invention relates to a polyimide film, in particular to a preparation method of a polyimide porous film. Background technique [0002] Polyimide (PI) has excellent heat resistance, chemical resistance, and good mechanical properties, and is widely used in aerospace, electronics, and microelectronics industries. Holes are introduced into the polyimide matrix to form a polyimide porous film, which can be used in high-temperature filtration, lithium-ion battery separators and other fields. [0003] The preparation of polyimide porous film at home and abroad mainly adopts thermal degradation method and chemical solvent method: [0004] (1) The thermal degradation method, which generates pores by introducing thermally degradable components, but this method has the problem that the mechanical properties are greatly reduced, and the pores generated during thermal degradation will be reclosed. [0005] (2) Chemical solvent method, the composite material ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C08J5/18C08J9/26C08G73/10
CPCC08G73/1071C08J5/18C08J9/26C08J2379/08
Inventor 冯羽风汪英黄孙息青双桂
Owner GUILIN ELECTRICAL EQUIP SCI RES INST