High-performance colorless transparent polyimide film and preparation method thereof

Abstract

The invention provides a high-performance colorless transparent polyimide film and a preparation method thereof. The method specifically comprises the following steps: under inert gas protection, adding alicyclic diamine and diamine containing a POSS structure into a phenolic solvent; after the diamine is completely dissolved, adding dianhydride; heating and then adding ethynyl monoamine; continuous heating for reaction; cooling a mixture obtained by the reaction; pouring the cooled mixture into an ethanol solution; dissolving precipitated white filamentous polyimide resin into a polar aproticsolvent; carrying out filtration and vacuum degassing defoaming treatment; casting the resin solution on a stainless steel plate; carrying out heating treatment in an inert atmosphere; and carrying out stripping to obtain the polyimide film. The colorless transparent polyimide film prepared by the method has excellent solvent resistance and heat resistance, higher dimensional stability and good mechanical properties, and can be widely applied to multiple fields such as solar cells, substrates or cover plate materials of flexible display screens and the like.

Description

technical field [0001] The invention belongs to the technical field of polymer materials, and in particular relates to a high-performance colorless and transparent polyimide film and a preparation method thereof. Background technique [0002] Polyimide film is a kind of polymer material with excellent comprehensive properties, which is widely used in high-tech fields such as aerospace, electrical and electronics, rail transit, and optoelectronic display. In the fields of flexible display technology and thin-film solar cells, transparent polyimide film is used as a flexible substrate, which not only realizes the transparency, flexibility and light weight of the device itself, but also can be continuously processed by winding technology during device processing. Large-scale production reduces manufacturing costs. Traditional polyimide films such as DuPont's Kapton are brownish-yellow or brown, and their light transmittance is less than 40% at a wavelength of 500nm, which seve...

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Problems solved by technology

At present, there are also relevant reports on the modification of polyimide films by using soluble POSS, such as patent CN105837819A disclosing the introduction of 3-aminopropyl-heptaisobutyl oligomeric silsesquioxane with monoamine structure to The dimensional stability and transparency are enhanced in the molecular structure of polyimide, but the introduction of monoamino POSS fillers is like adding an end-capping agent. For example, when the molar weight exceeds 15%, it will lead to a serious decrease in the number average and weight average molecular weight. The overall performance is reduced, and when the amount that can be added is too small, it has little effect on the overall performance of the film

In addition, patent CN103435827B discloses the use of hyperbranched polysiloxane containing amino groups to modify polyimide materials to obtain transparent hybrid films with high heat resistance and dimensional stability, but this type of hyperbranched molecular structure There are too many amino groups on the reactive sites, which will easily cause the polyamic acid resin to appear viscous and seriously disturb the arrangement and accumulation of molecular chains.

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