Transparent PI hardened coating resistant to ultraviolet damp-heat aging and preparation method of transparent PI hardened coating

Abstract

The invention belongs to the technical field of transparent polyimide hardened coatings, and particularly relates to a transparent PI hardened coating resistant to ultraviolet damp-heat aging. Hardening liquid for preparing the transparent PI hardened coating is prepared from the following components in parts by weight: 100 parts of matrix resin, 2-20 parts of low molecular weight resin, 2-20 parts of strong polar monomer, 0.5-5 part of photoinitiator, 0.1-2 part of thermal initiator, 0.05-1 part of leveling agent, 0.05-1 part of ultraviolet absorbent, 0.05-1 part of antioxidant and 100-200 parts of solvent. According to the invention, a proper amount of low molecular weight resin and strong polar monomer are added into the hardening liquid, and the hardening liquid can gradually permeateinto the transparent PI base material by adopting a curing mode of combining thermocuring and photocuring, so that the adhesive force between the hardened coating and the transparent PI base layer isimproved; and therefore, the ultraviolet and damp-heat resistance of the PI hardened film is improved on the premise of not influencing the comprehensive properties such as hardness and wear resistance of the hardened coating.

Description

technical field [0001] The invention belongs to the technical field of transparent polyimide hardened coatings, and in particular relates to a transparent PI hardened coating resistant to ultraviolet, damp and heat aging and a preparation method thereof. Background technique [0002] Curved screen technology has been widely valued and sought after by consumers and the industry in recent years. In the future, with the continuous development and improvement of fixed-curvature curved screen technology, flexible touch screens that can be bent arbitrarily will become an important development direction. Although the flexible screen can be bent, if it is bent frequently, it will have the same fatigue problem as metal paper. If it is bent multiple times and used for a long time, the flexible screen may be damaged by creases in the middle of the screen after being subjected to multiple compression and tensile stresses. In addition, circuit boards, components, after being subjected ...

AI Technical Summary

Problems solved by technology

If it is bent multiple times and used for a long time, after the flexible screen is subjected to multiple compression and tensile stresses, crease damage may appear in the middle of the screen

In addition, circuit boards, components, after being subjected to a lot of bending and non-bending, may also cause damage or other failures during folding

The existing glass panel cannot meet its high frequency requirements, and the transparent polyimide (CPI) film is used to replace the existing glass cover plate because of its good foldability, but polyimide (PI ) The material cannot meet the hardness requirements, and it is necessary to add a hardened coating on the surface of the PI substrate to enhance the hardness

[0003] Among the transparent PI hardened film products, transparent PI is generally modified by fluorine to improve transparency. After fluorine modification, the hardened coating on the surface of the substrate will be more difficult to adhere to. After the UV humidity and heat aging test, the hardened coating will fall off.

Images