▎ 摘　　要

NOVELTY - Preparing polyethylene terephthalate sheet surface nano-hardened coating comprises (1) carrying melt extrusion on PETG and polycarbonate, and injection molding to obtain PETG composite substrate; and subjecting PETG composite substrate to surface treatment to obtain a pretreated substrate; (2) adding graphene oxide to the ethanol aqueous solution, stirring evenly, adjusting the pH of the system to 4.2-5, continuing stirring for 1-2 hours, adding KH560 coupling agent under stirring, stirring at 70-80°C, continuously adding spherical graphite, polyvinyl alcohol, defoamer, and dispersant, adding thickener, film-forming auxiliary agent, and aqueous acrylic emulsion to continue stirring, adjusting the pH of the system to 7.2-7.5, and shearing to obtain a slurry; and (3) spraying the slurry on the surface of the pretreated substrate, and baking and molding to obtain a nano-hardened coating on the surface of the PETG sheet. USE - The coating is useful for electronic product. ADVANTAGE - The coating: has high thermal conductivity and excellent thermal stability, and is smooth and flat. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for the PETG sheet surface nano-hardened coating is prepared by above mentioned method.