▎ 摘　　要

NOVELTY - Additional coating comprises 10-30 pts. wt. hyper-branched polyurethane acrylic resin, 0.05-3 pts. wt. acrylic based silsesquioxane, 0.5-2 pts. wt. photoinitiator and 65-90 pts. wt. organic solvent. The thickness of the film is 0.3-1 m, coating and curing on the transparent polyimide base material is formed by coating. USE - The additional coating is useful for transparent polyimide film. ADVANTAGE - The coating improves the adhesive force between the polyimide film and the hardened layer and the surface energy of the polyimide film, the hardened layer has excellent wetting performance on the additional coating surface, the surface dyne value is improved after setting the additional coating, the wetting bad points are obviously reduced when the hardened layer and other coating layers are set on the upper surface, improving the surface hardness of the film and does not affect the film stretching performance, optical performance and appearance. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: a method of using an additional coating for a transparent polyimide film, comprising selecting a transparent polyimide base material, dissolving hyperbranched urethane acrylic resin, acrylic silsesquioxane, and photoinitiator in organic solvent, uniformly stirring to prepare the coating for additional coating, coating the coating on the transparent polyimide substrate, and forming an additional coating after UV curing and applying a hardened coat over the additional coat; and a cover plate film, comprising a transparent polyimide film, the thickness of which is 30-100 μm, and the Young's modulus of the film is more than 6 GPa, the additional coating is arranged above the transparent polyimide film with the thickness of 0.3-1 μm and hardened layer provided above the additional coating, where the additional coating is formed by coating and curing on the transparent polyimide substrate.