The invention provides a shading high-barrier
composite film capable of replacing aluminizing and a preparation method thereof. The
composite film sequentially comprises a base layer, a shading layer, an
ultraviolet-proof layer and a protective layer from outside to inside. The base layer is a
polyvinyl chloride film layer, the shading layer is prepared by mixing
montmorillonite nano clay, a high-molecular
polymer and a nanoscale
titanium dioxide dispersion liquid, the
ultraviolet-proof layer is an
ultraviolet light absorber formed by mixing a bio-based material and a
benzophenone or
triazole compound, and the protective layer is a glycol terephthalate layer. Wherein the bio-based material is prepared from
sugarcane extract,
anthocyanin and
chitosan according to a specific proportion. The preparation method comprises the following steps: preparing the base layer, the shading layer, the ultraviolet-proof layer and the protective layer, and performing hot-pressing compounding to obtain the
composite film. In addition, specific parameters of the shading layer
coating process, the ultraviolet-proof layer spraying process and the protective layer hot-pressing compounding are also introduced. The composite film has shading and ultraviolet-proof functions, can replace a traditional aluminum laminated film, and has a wide application prospect.