How LG Chem Makes Plastic Films That Block UV Light

A specialized plastic film made of alternating chemical segments that blocks harmful ultraviolet light while remaining perfectly clear.

What it covers

This patent describes a high-performance plastic film made from a polyamide resin. The resin is engineered with a specific backbone structure where two different types of aromatic amide segments alternate. This precise molecular arrangement allows the material to absorb ultraviolet light at 388 nm while maintaining high transparency, measured as a haze value of 1.5% or less. The film is designed to be very thin, around 50 micrometers, yet it effectively filters out UV radiation, which is critical for protecting sensitive components behind the film.

What it doesn't cover

• —Does not cover films that do not use an alternating backbone structure of two distinct aromatic segments.
• —Does not cover materials where the UV transmittance at 388 nm is higher than 15% for a 50-micrometer thickness.
• —Does not cover films with a haze value greater than 1.5%.
• —Does not cover standard polyamides that lack the specific molecular weight or viscosity requirements defined in the claims.

The clever bit

The innovation lies in the alternating backbone structure, which forces the polymer to achieve a steep UV-cut slope—meaning it transitions rapidly from blocking UV to letting visible light through—without sacrificing the clarity of the film.

Why it matters

As foldable and flexible displays become common in smartphones and tablets, manufacturers need protective cover layers that are both durable and optically clear. This technology provides a way to protect internal display components from UV degradation without needing separate, bulky UV-filtering coatings. It is a key material science advancement for the next generation of flexible electronics.

Real-world examples

• 1.Flexible display cover windows
• 2.Protective films for foldable smartphones
• 3.Optical layers for high-end electronic screens