Pre-coating liquid for transparent PI hardened film resistant to ultraviolet damp-heat aging and application of pre-coating liquid

Abstract

The invention belongs to the technical field of pre-coating liquid for transparent polyimide hardened films, and particularly relates to pre-coating liquid for a transparent PI hardened film resistantto ultraviolet damp-heat aging and application of the pre-coating liquid. The pre-coating liquid is prepared from the following components in parts by weight: 100 parts of low molecular weight resin,50-100 parts of a strong polar monomer, 1-5 parts of a thermal initiator, 0.05-1 part of a leveling agent and 1000-1500 parts of a solvent. The pre-coating liquid contains a proper amount of low-molecular-weight resin and a strong-polarity monomer, and the low-molecular-weight resin and the strong-polarity monomer are matched with each other, so that the pre-coating liquid can permeate into the transparent PI base material, permeate and bite the transparent PI base material alternately, and the pre-coating layer is firmly attached to the surface of the base material through curing crosslinking, thereby enhancing the adhesive force between the hardened coating and the transparent PI base layer. The composition of the pre-coating liquid determines that a good binding force exists between the pre-coating layer and the hardened layer, so that the ultraviolet and damp-heat resistance of the PI hardened film is improved, and the comprehensive properties such as hardness and wear resistanceof the hardened layer are not influenced.

Description

technical field [0001] The invention belongs to the technical field of precoat liquid for transparent polyimide cured film, and in particular relates to a precoat liquid for transparent PI cured film resistant to ultraviolet, humidity and heat aging and its application. 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 ...

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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] However, in the existing transparent PI hardened film products, the transparent PI is generally modified by fluorine to improve transparency. After fluorine modification, the hardened layer on the surface of the substrate will be more difficult to adhere to. After the ultraviolet humidity and heat aging test, the hardened layer will fall off.

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