Preparation method of nano-composite thin film

Abstract

The invention discloses a preparation method of a nano-composite thin film and relates to the field of plastic thin films. The preparation method comprises five process steps of mixing raw materials, preparing polyamic acid / a precursor, laying a film, preparing a composite thin film and drying. In the preparation method, a hydrothermal method is adopted for preparing a sol, the problem that hard agglomerates are easy to form due to the step of converting hydroxides to oxides by calcination in a wet chemical method can be avoided, the time is saved, and the efficiency is improved; furthermore, the preparation effect is good, and the production of other impurities or derivatives is avoided; in the process of laying the film, the temperature and the heat preservation time in an oven are strictly controlled, the generation speed of the thin film is fast, the quality of the thin film is good, the mechanical strength is high, and the thin film is less prone to tension fracture; the prepared composite thin film through the final drying process step has the advantages of excellent performances, a local area network-like distribution structure, excellent physical performances and dielectric performances, significant corona-resistant effect, long service life and good stability in production process, and can completely meet the requirements on insulation performance of cables in power industry.

Description

technical field [0001] The invention relates to the field of plastic film manufacture, in particular to a preparation method of a nanocomposite film. Background technique [0002] In recent years, people have paid more and more attention to the application of variable frequency motors, but at the same time as this new technology is adopted, a troublesome problem has emerged one after another: in the pulse width modulation variable frequency drive system, due to the wave reflection of the long cable, the motor The overvoltage generated on the terminal, coupled with the extremely uneven distribution of the pulse voltage on the winding group, makes the inter-turn voltage of the winding near the head end tens of times higher than the average distribution voltage, resulting in corona discharge between the winding turns, thus Make the motor insulation break down prematurely. Practice has shown that adding a certain amount of inorganic nano-oxides to the existing high heat-resistan...

AI Technical Summary

Problems solved by technology

[0002] In recent years, people have paid more and more attention to the application of variable frequency motors, but at the same time as this new technology is adopted, a troublesome problem has emerged one after another: in the pulse width modulation variable frequency drive system, due to the wave reflection of the long cable, the motor The overvoltage generated on the terminal, coupled with the extremely uneven distribution of the pulse voltage on the winding group, makes the inter-turn voltage of the winding near the head end tens of times higher than the average distribution voltage, resulting in corona discharge between the winding turns, thus Make the motor insulation break down prematurely. Practice has shown that adding a certain amount of inorganic nano-oxides to the existing high heat-resistant insulating materials can greatly improve the high-temperature resistance of the original polymer while maintaining the high-temperature performance of the polymer. The corona resistance performance of insulating materials can meet the operation requirements of variable frequency motors and ensure the life of variable frequency motors. Therefore, it is of great significance to study motor winding insulation materials with good corona resistance performance. The application number is CN201210107660.0, which discloses a Low-density composite film, including the following components by mass percentage: polyethylene tree 86-92%, linear low-density polyethylene resin 7-12%, additives 1-2%

The low-density composite film of the present invention not only has excellent electrical insulation performance, but also has good mechanical properties, which is mainly reflected in that it not only has the good softness, extensibility and transparency of the low-density composite film, but also has linear low-density composite film. The film has high tensile strength, impact resistance, puncture strength and low temperature impact resistance, and is resistant to oxygen and light aging. It can be used as a coating material for wires and cables in harsh environments, but this composite film also has corona resistance. The problem of poor performance, and the mechanical strength is not high, it is easy to be damaged during use, and the service life is restricted