Conductive and hydrophobic expanded polytetrafluoroethylene membrane and application thereof

Abstract

The invention discloses a conductive and hydrophobic expanded polytetrafluoroethylene membrane and an application thereof. The conductive and hydrophobic expanded polytetrafluoroethylene membrane comprises a polytetrafluoroethylene PTFE material and a conductive material. A preparation method of the product comprises the following steps: uniformly mixing 50-85 wt% of the polytetrafluoroethylene PTFE material and 15-50 wt% of the conductive material, and carrying out rolling and directional stretching to form the microporous membrane with the micropore diameter of less than 20 [mu]m. The preparation method is beneficial to large-scale production, and meanwhile the product is good in flatness, high in strength, excellent in electrical conductivity and adjustable in air permeability; oxygen and water vapor can penetrate through the conductive, hydrophobic and breathable PTFE membrane, but water drops cannot penetrate through the conductive, hydrophobic and breathable PTFE membrane; and aliquid in the space can be prevented from leaking outwards, and it can be guaranteed that external oxygen enters the space. The product is high in hydrophobicity, and no aqueous solvent is used in thepreparation process, so that a good liquid blocking effect of the membrane is ensured.

Description

technical field [0001] The invention relates to a conductive and hydrophobic expanded polytetrafluoroethylene film and its application. Background technique [0002] The preparation method of the film in the existing published invention patent uses emulsion-like PTFE as the main raw material, and mixes the materials in the aqueous solution, and all use high-temperature treatment to volatilize the solvent, decompose the pore-forming agent, and decompose the polymer to form pores. . The mixing of materials is carried out in aqueous solution, resulting in a certain degree of hydrophilicity of the product, which is prone to water seepage after long-term use. [0003] For example, in document CN106910924, PTFE fine powder is mixed with conductive powder in water, and ethanol solvent is added after filtering and drying, and then roll pressing and heat treatment make some polymers degrade to form large pores. In this method, filtering and drying operations are more loaded down wit...

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Problems solved by technology

The mixing of materials is carried out in aqueous solution, resulting in a certain degree of hydrophilicity of the product, which is prone to water seepage after long-term use

[0003] For example, in document CN106910924, PTFE fine powder is mixed with conductive powder in water, and ethanol solvent is added after filtering and drying, and then roll pressing and heat treatment make some polymers degrade to form large pores. In this method, filtering and drying operations are more loaded down with trivial details, and at the same time The size of the hole is not easy to control; in the document CN101831123, the concentration of 60% PTFE emulsion is mixed with conductive powder, and after drying, the film is rolled and rolled to prepare a conductive film. The air permeability is not easy to control; the document CN110120531 also uses 60% PTFE emulsion, and polyethylene glycol is used as the wetting agent and pore-forming agent. The filtration and drying operations of this scheme are cumbersome, and the size of the pores is not easy to control

The filtration and drying procedures in the above scheme are cumbersome, which is not conducive to large-scale production, and at the same time, the air permeability of the membrane is not easy to control

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