4 results about "Polyimide dielectric" patented technology

This invention discloses a high-insulation binaphthalene polyimide dielectric film, its preparation method, and its applications, belonging to the field of high-performance insulating materials technology. Through molecular structure regulation, this invention introduces a large-volume, non-coplanar binaphthalene structure into the polyimide molecular chain. On one hand, the non-planar helical configuration between the two naphthalene rings suppresses the intra-chain conjugation effect, weakening the carrier transition capability along the main chain. On the other hand, the large-volume binaphthalene structural unit effectively disrupts the regular arrangement of the molecular chain, increasing the internal free volume and inter-chain spacing, thus increasing the length and tortuosity of the carrier migration path, increasing the energy barrier height that carriers must overcome during migration, and weakening the inter-chain carrier mobility. The synergistic effect of the above-mentioned intra-chain and inter-chain carrier migration suppression significantly improves the breakdown strength of polyimide and greatly extends its corona resistance lifetime.

This application belongs to the field of capacitor technology, and particularly relates to a modified polyimide dielectric film material, its preparation method, and its application. The provided modified polyimide dielectric film material uses polarized modified dianhydride / titanium dioxide nanoparticles to modify the dielectric film material, thereby improving its energy storage characteristics at high temperatures. The film capacitor assembled after being made into a metallized film is suitable as an energy storage device at high temperatures. This solves the technical problem of low performance of polyimide dielectric film materials in the prior art.

The present invention relates to the technical field of high-temperature energy storage dielectric films, and discloses a preparation method of a porphyrin cross-linker modified polyimide high-temperature energy storage dielectric film. Polyamic acid (PAA) precursor is obtained by condensing 4,4'-diaminodiphenyl ether (ODA) and pyromellitic dianhydride (PMDA), and introducing ultra-low content of 5,10,15,20-tetrakis(4-aminophenyl)porphyrin (TAPP) as a cross-linker. Cross-linked polyimide film (PCPI) is prepared by solution coating and gradient thermal imidization. The terminal amino groups of TAPP molecules form a covalent cross-linking network with PAA, and the porphyrin macrocycle π-conjugated system provides deep-level charge traps, significantly inhibiting high-temperature carrier migration. The breakdown strength of the optimal sample PCPI-0.1 reaches 475 MV / m at 200 °C, and the discharge energy density is 4.97 J / cm 3 , the charge-discharge efficiency is ≥85%. At the same time, it has a high glass transition temperature, high thermal stability, excellent cycle stability and film-forming uniformity. The solution coating process is simple to prepare, and the process conditions are simple and controllable, which is suitable for the batch production of high-temperature and high-energy storage polyimide dielectric films.