Automotive rearview mirrors are constructed from a variety of materials. The housings are typically made of plastics such as ABS, TPE, ASA, or PA; these materials offer resistance to harsh weather and UV radiation, while also providing the high strength and toughness needed to withstand long-term environmental exposure. The supporting structures are usually made of iron. Regarding the reflective coating, domestic mirrors often utilize silver or aluminum, with some using chromium; internationally, however, chrome-plated mirrors have largely superseded silver and aluminum versions, and most vehicles are equipped with anti-glare features. The mirror elements themselves are predominantly made of glass with a silicon oxide content exceeding 70%.
Flat mirrors are commonly placed on the driver's side because they accurately reflect the distance of other vehicles, whereas convex mirrors are used on the passenger side to provide a wider field of view. These convex mirrors-also known as wide-angle mirrors-utilize their outer spherical surface for reflection, effectively dispersing light to expand the visual range. Interior rearview mirrors are typically assembled using UV-curing adhesives. Additionally, PC/ASA alloy materials are employed; these combine the superior mechanical properties of PC with the excellent flow and processability of ASA, resulting in a material that offers outstanding mechanical strength, impact resistance, toughness, and weatherability, while maintaining dimensional stability at high temperatures.
Next-generation rearview mirrors incorporate transition metal tungsten oxide powder as a functional ingredient to enhance dimming and anti-glare capabilities. The key component is tungsten trioxide, a pale yellow, orthorhombic crystalline powder that is insoluble in water but soluble in alkalis and slightly soluble in acids. In summary, the materials for various components and functions of automotive rearview mirrors are selected based on specific requirements to ensure optimal performance and safety.