High-performance polyimide film and preparation method thereof

Abstract

The invention provides a preparation method of a high-performance polyimide film. The method comprises the following steps: in an inert atmosphere, adding diamine POSS, ethynyl-containing diamine andfluorine-containing diamine into a phenolic solvent; after dissolving of the above substances, adding rigid and straight dianhydride and twisted dianhydride; carrying out reacting, then adding ethynyl-containing monoamine; performing imidization by adopting a one-step method or a two-step method; pouring the obtained polyimide resin solution into a precipitant for precipitation; dissolving a precipitate obtained in the previous step in an amide solvent to obtain a glue solution; and subjecting the glue solution to tape casting on a stainless steel plate, and performing gradient heating to obtain the high-performance polyimide film. According to the method, ethynyl functional group-containing diamine is introduced into the middle part of a molecular chain structure, monoamine with an acetenyl group is introduced to the tail end of a molecular chain, cross-linking curing is achieved through a cage structure of diamine POSS and an acetenyl group at a certain temperature, a network-shapedmolecular structure is formed, and the solvent resistance, the mechanical property and the heat resistance of the transparent polyimide film are comprehensively improved.

Description

technical field [0001] The invention belongs to the technical field of polymer materials, and in particular relates to a high-performance polyimide film and a preparation method thereof. Background technique [0002] Transparent substrates are widely used as window covering substrates or protective films in the fields of electronic products such as smartphones, notebook computers, billboards and touch panels. The most typical representative is inorganic glass, which has high light transmittance and water resistance. Oxygen barrier and other advantages, but there are many shortcomings such as low flexibility and high brittleness. In recent years, with the rapid development of optoelectronic technology and the continuous upgrading of people's consumption needs, electronic devices have shown a trend of flexibility, large-scale and ultra-thin, and highly transparent plastic substrates are flexible, light, high With the advantages of impact resistance, easy large-area production...

AI Technical Summary

Problems solved by technology

Chinese patents CN104411744B, CN104704057, U.S. patents US20130126940A1, US20140367151A1, etc. firstly mixed silicon dioxide, titanium dioxide or carbon nanotubes into the polyimide resin, and then made the film. This method can significantly improve the heat resistance level of the transparent film , dimensional stability and lower thermal expansion coefficient, but the addition of fillers often leads to uneven distribution, especially the agglomeration of particles, which will not only lead to stress concentration and decrease in mechanical properties, but also increase the scattering ratio of light, resulting in decreased transparency and fog Degree value increases

In addition, the Chinese patent CN103435827B mentions that the polyimide material is modified by hyperbranched polysiloxane containing amino groups to obtain a transparent hybrid film, but there are too many reactive amino groups on this type of hyperbranched molecular structure. It is easy to cause viscose in the resin solution and seriously disturb the arrangement and accumulation of molecular chains, and the overall performance is not high

Images