Matte polyimide black film with low heat shrinkage rate, and preparation method thereof

Abstract

The invention discloses a preparation method of a matte polyimide black film with a low heat shrinkage rate. The method comprises the following steps: S1, preparing a polyamide acid resin solution: adding a matting agent into an aromatic diamine solution in an inert gas atmosphere, mixing until uniformity, adding aromatic dianhydride, and carrying out a stirring reaction to obtain the polyamide acid resin solution, wherein the aromatic diamine contains rigid aromatic diamine, and the rigid aromatic diamine is at least one of p-phenylenediamine, 2,5-diaminotoluene, 1,5-naphthalenediamine, 2,5-naphthalenediamine and 2,6-naphthalenediamine; S2, preparing a black slurry; and S3, preparing the matte polyimide black film with the low heat shrinkage rate. The invention further discloses the mattepolyimide black film with the low heat shrinkage rate. The matte polyimide black film with the low heat shrinkage rate is prepared through the preparation method of the matte polyimide black film with the low heat shrinkage rate. The matte polyimide black film with the low heat shrinkage rate has the advantages of low shrinkage rate, matt effect, maintenance of mechanical properties and electrical properties, good dimensional stability, low visible light transmittance and low surface gloss.

Description

technical field [0001] The invention relates to the technical field of polyimide films, in particular to a low heat shrinkage matte polyimide black film and a preparation method thereof. Background technique [0002] Polyimide films are widely used in electrical, electronics, aerospace and other fields due to their excellent mechanical, thermal and electrical properties. Electronic-grade polyimide cover film is mainly used to protect flexible printed circuit boards. Due to the needs of various processing processes such as downstream glue coating and etching, the dimensional stability of the cover film is required to be high. [0003] Because of its opacity, black PI film can cover electronic materials such as flexible circuits, electronic components, and lead frames of integrated circuit packages to prevent visual inspection, tampering, and plagiarism, and the market demand is high. There is glare or astigmatism caused by light reflection on the surface of traditional brigh...

AI Technical Summary

Problems solved by technology

There is glare or astigmatism caused by light reflection on the surface of traditional bright polyimide black film, which causes visual discomfort and makes eyes tired when watching for a long time. Therefore, in recent years, matte film with better shielding effect and better appearance Polyimide black film has gradually become the focus of the cover film market, and the black film with a gloss range of 25-60GU is usually called matte polyimide black film

[0004] At present, the thermal shrinkage range of the black film used for conventional cover films in the market is ≤0.15%. For customers with higher requirements, the black film cannot be well applied

In the traditional black polyimide black film preparation process, the carbon black slurry is mainly prepared by ultrasonic dispersion or high-speed dispersion with a solvent and a coupling agent. The storage stability of the slurry is poor and the solid content is low.

[0005] In addition, for the matte black film, the current method of adding matting agent is mainly to mix the matting agent with the solvent through high-speed dispersion, and then disperse it with the synthesized resin in the form of dispersion liquid. The viscosity of the resin solution is quite different, and it is inevitable that there will be uneven dispersion and agglomeration of matting agent particles when mixing again, which will affect various properties of film products.

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