# 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. - **Patent:** US 12031028 - **Original title:** Polyamide resin film and resin laminate using the same - **Owner:** LG Chem Ltd - **Granted:** 2024 - **Status:** Active - **Times cited:** 0 - **Field:** consumer_electronics, materials, semiconductors ## What it does 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 does NOT 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. ## Real-world examples 1. Flexible display cover windows 2. Protective films for foldable smartphones 3. Optical layers for high-end electronic screens ## 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. ## Frequently asked questions ### What does How LG Chem Makes Plastic Films That Block UV Light cover? A specialized plastic film made of alternating chemical segments that blocks harmful ultraviolet light while remaining perfectly clear. ### Who owns patent US 12031028? LG Chem Ltd owns this patent, granted in 2024. ### When does this patent expire? This patent is expected to expire on July 9, 2044, when the invention enters the public domain. ### What problem does this patent solve? 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. ### What does this patent NOT cover? Does not cover films that do not use an alternating backbone structure of two distinct aromatic segments. **Full plain-English explainer:** https://patentbrief.org/patent/us/12031028/starship-eclss **Original patent:** https://patents.google.com/patent/US12031028 --- _Source: PatentBrief — https://patentbrief.org. Patent facts are from public records; the plain-English explanation is PatentBrief's._ ## Related patents Semantically similar inventions in the PatentBrief corpus: - [How Foldable Screens Use Electrochromic Layers to Improve Color and Contrast](https://patentbrief.org/patent/us/12354567/sea-level-raptor) — A method for foldable display panels to adjust their light-filtering properties using electrochromic layers that change color or opacity based on whether the screen is stretched or folded. - [How Wallace Carothers Invented Nylon](https://patentbrief.org/patent/us/2130523/nylon-polyamide-carothers) — The foundational 1935 patent for synthetic linear polyamides, the chemical process that created the material we now call nylon. - [How Stephanie Kwolek Invented the Liquid Crystal Solution for Kevlar](https://patentbrief.org/patent/us/3671542/kevlar-aramid-fiber) — A 1969 chemical discovery describing a specialized liquid mixture that allows for the creation of incredibly strong, high-performance synthetic fibers. - [How to Make Clear, Waterproof Sunscreen That Doesn't Feel Greasy](https://patentbrief.org/patent/us/4810490/tpa-tissue-plasminogen-activator) — A 1989 patent for a transparent, water-resistant sunscreen formula that uses wood rosin to create a non-sticky, long-lasting protective film on the skin. - [How Light-Activated Polymers Deliver Skin Care Ingredients](https://patentbrief.org/patent/us/12178901/dragon-xl) — A chemical structure that holds onto skin-care ingredients like fragrances or cooling agents and releases them only when triggered by specific light conditions.