Directionally arranged graphene film, preparation method thereof and composite heat dissipating film

Abstract

The invention provides a graphene film. The graphene film comprises the following components by mass: 100 parts of modified graphene, 250-450 parts of solvent, 15-0 parts of film former, 0.5-1.5 partsof curing agent, 0.25-15 parts of modifier and 3-10 parts of auxiliary agent. The thickness of the graphene film is 10-80 Mum. The graphene film is directionally arranged and large in heat dissipating area, has high thermal conductivity, thermal emissivity and good flexibility, bending resistance, impact resistance and processability and is not prone to powder drop. A composite heat dissipating film is further provided. The composite heat dissipating film sequentially comprises ultra-thin thermal conductive silica gel pad and the directionally arranged graphene film from bottom to top. The composite heat dissipating film can directly contact a heat source without double-sided adhesive. The contact thermal resistance is greatly reduced. The composite heat dissipating film has good thermalconductivity and mechanical properties, and can be widely used in the field of heat dissipation of electronic products.

Description

technical field [0001] The invention relates to the field of heat dissipation films, in particular to a graphene film and a composite heat dissipation film. Background technique [0002] In recent years, with the continuous improvement of the performance of industrial and consumer electronic products, the heating problem of various electronic devices has become more and more serious, and heat dissipation is particularly important. The theoretical thermal conductivity of graphene is 3000-5000W / (m·K), which can be applied in the field of heat dissipation of electronic products. However, in practical applications, large interlayer gaps will be generated after the graphene sheets are assembled into a film. The gaps not only form thermal resistance, but also affect the density of the graphene film, thereby reducing the overall heat transfer efficiency of the graphene heat-conducting film. Therefore, in order to obtain a graphene film with high thermal conductivity, it is necessa...

AI Technical Summary

Problems solved by technology

For example, Chinese patent 201410146002.1 discloses a method for directional preparation of graphene film with high electrical conductivity and high thermal conductivity by liquid phase method, that is, graphene oxide film is prepared by vacuum temperature control and vacuum filtration to prepare directional deposited graphene oxide film, and then reduced by chemical vapor deposition. , to obtain a directional deposited graphene film, the method is complicated in steps and requires high equipment, and the prepared graphene film is deposited on copper foil or other substrates, which is difficult to transfer, and the graphene film is easily damaged during transfer, and at the same time In this method, graphene oxide prepared by the hummer method is used as a precursor, and the graphene film is obtained through reduction treatment. It is difficult to achieve complete reduction, resulting in some defects in graphene, which makes it difficult to fully reflect the intrinsic high thermal conductivity of graphene, and obtains The highest thermal conductivity of graphene film is only 800W / (m K), which is still far from its theoretical thermal conductivity.

Chinese patent 201410331358.2 discloses a preparation method of nitrogen-doped oriented graphene, that is, adding ammonia water to graphene oxide solution, performing hydrothermal reaction, reducing graphene oxide to graphene, and then performing directional vacuum treatment. The obtained graphene film is just a simple powder overlapping film, which is easy to drop powder, has poor mechanical properties, is easy to bend and break, is difficult to process, and is difficult to transfer directly from the filter paper. In order to reduce the damage to the film layer during the transfer process, The thickness of the graphene film will be increased to the millimeter level, which cannot meet the requirements of thinning and thinning in the field of electronic equipment

Images