Fluorine-containing aromatic diamine compound, preparation method thereof and colorless transparent polyimide film

Abstract

The invention provides a fluorine-containing aromatic diamine compound, a preparation method thereof and a colorless transparent polyimide film. The fluorine-containing aromatic diamine compound has a structure as shown in a formula V or a formula V ', a PI film prepared by polymerizing the compound with commercial diamine and dianhydride monomers has relatively high light transmittance and relatively low yellowness index; meanwhile, the heat stability is excellent, the glass transition temperature is high, and the mechanical property is good; the film can be widely applied to the fields of flexible displays, wearable devices, 5G equipment, thin film solar cells and the like. The glass transition temperature of the PI film is 353-407 DEG C, and the 5wt% thermal weight loss temperature exceeds 480 DEG C; the tensile strength is 121-133 MPa, and the tensile modulus exceeds 2.5 GPa; under high frequency, the dielectric constant is 2.69-3.01, and the dielectric loss is 0.003-0.012; the cut-off wavelength is less than or equal to 351 nm, the optical transmittance at 450 nm is 86-92%, and the yellowness index is far less than 2.5.

Description

technical field [0001] The invention belongs to the technical field of polyimide materials, and in particular relates to a fluorine-containing aromatic diamine compound, a preparation method thereof, and a colorless transparent polyimide film. Background technique [0002] Polyimide (PI) is a kind of special polymer material containing imide ring repeating unit. Among them, colorless and transparent polyimide (colorless polyimide, CPI) film has excellent thermal stability and high light transmittance, and is widely used in high-tech fields such as microelectronics, optoelectronics and new energy. For example, it can replace ultra-thin glass (UTG) as a transparent substrate and cover material for flexible displays, wearable devices, and flexible solar cells. On the one hand, compared with UTG materials, CPI films have the advantages of flexibility, light weight, bending resistance, impact resistance, and long service life. On the other hand, compared with traditional transp...

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Problems solved by technology

[0003] In the patent CN 104017214B, the fluorine-containing diamine monomer needs to be synthesized through four or five steps of reaction, and the route is lengthy, which increases the difficulty of purification and production cost of the compound, and the light transmittance of the polymer prepared from the above diamine is not high. Ideal; the highest transmittance of the PI film at 450nm is only 85%, which is not conducive to subsequent promotion and application

The sulfone-containing and fluorine-containing diamines disclosed in patents CN 111187187A and CN102976983B require a three- to six-step synthesis route, and the yield is low, which limits subsequent applications

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