Method for preparing high thermal conductivity graphite film by using graphene-doped polyamic acid resin

Abstract

The present invention discloses a method for preparing a high thermal conductivity graphite film by using a graphene-doped polyamic acid resin. The method comprises: adding graphene to a strongly polar organic solvent, and carrying out ultrasonic dispersion to prepare a graphene dispersion; respectively adding diamine and dianhydride to the graphene dispersion, and carrying out a stirring reaction to obtain a graphene-doped polyamic acid resin solution obtained through in situ polymerization; adding an imidization reagent, sequentially carrying out deaeration and casting film forming, carrying out crystallization orientation by using two-way stretching equipment, and carrying out high temperature imidization treatment to obtain a graphene-doped polyimide composite film; carrying out high temperature carbonization on the film under vacuum, and naturally cooling to a room temperature to obtain a carbonized film; and finally carrying out high temperature graphitization under argon gas protection, and naturally cooling to a room temperature to obtain the high thermal conductivity graphite film.

Description

technical field [0001] The invention relates to a chemical imidization method for preparing a film, in particular to a method for preparing a graphite film by using graphene-doped polyamic acid resin. Background technique [0002] The heat dissipation performance of electronic products is one of the important performances that consumers pay attention to. In recent years, the miniaturization and thickness reduction of electronic products such as notebook computers has become a design trend. With the thinning of smart electronic products, this puts forward more stringent requirements for the heat dissipation of electronic products, and also brings thermal design engineers. This posed a huge challenge, which required new and effective thermal solutions to keep the surface temperature of the notebook even and free of "hot spots". [0003] Carbon materials have ultra-high thermal conductivity. According to molecular dynamics simulation calculations, the thermal conductivity of g...

AI Technical Summary

Problems solved by technology

The production of polyimide film in my country adopts the thermal imidization film-making process. Compared with the foreign chemical imidization film-making process, the production efficiency is low (about 1 / 6 of the chemical imidization method), and the thermal dimensional stability is poor. Low strength and low thermal stability. The precursor PI base film produced by this process is cracked during high temperature carbonization, the surface is wrinkled and dull, the thermal conductivity is low, and it is not resistant to folding, which cannot meet the film production requirements of high thermal conductivity graphite film process.

[0007] CN103080005A Chinese patent document discloses a method for preparing a graphite film with less graphite powder from a polyimide film. This method belongs to the traditional sintering of a polyimide film to prepare a graphite film. Amine film sintered graphite film has the disadvantage of high energy consumption

CN102560453A Chinese patent document discloses a method of utilizing graphene to strengthen polyimide resin carbonization to prepare carbonized film, but the technical scheme is to add graphene to PAA solution to obtain graphene polyimide film, and then carbonize it The obtained carbonized film is not a real in-situ polymerization, and the film is not graphitized. The carbonized film prepared by this method has poor thermal conductivity or almost no thermal conductivity.

CN102268134A Chinese patent document discloses a preparation method of polyimide / graphene nanocomposite material, which utilizes an in-situ polymerization method to obtain polyimide / graphene nanocomposite material with good dispersion, but the technical scheme The film was not carbonized or graphitized, and the thermal conductivity of the subsequent graphite film was not investigated.

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