MATERIALS: Novel "Cool Black" PC for High-Gloss Auto Exteriors

Covestro's new Makrolon AX with high-performance coatings targeted to roof trim and pillar applications.

Related Suppliers

The increasing popularity in automotive of large, transparent surfaces and panoramic roofs is further spurring demand for PC resins. Not only are they used in the roof itself, but also in exterior trim and pillars. Covestro has combined its PC with siloxane coatings to provide excellent properties including transparency, high impact resistance and design freedom. The latest innovation is Makrolon AX PC with high-performance coatings for high-gloss roof trim and pillars.Key to this is the development of “cool black” colors that help keep the PC surface cool. With a cool black surface, Makrolon AX is said to prolong the performance of the coating system and increases weathering by 50%.

According to Covestro, while standard black colors absorb IR radiation causing the component to heat up, the cool black colors allow the IR to be transmitted through the part, resulting in prolonged performance of the coating. The cool black colors enable laser welding of the exterior trim’s B-surface to other components. The laser passes through the coating and the PC, but not the underlay material. As the interface heats up, melts and cools, the PC is joined to the underlay material. There are initially two grades: Makrolon AX2677 (with UV stabilization) and AX2675 (without UV stabilization).

Search for more on Covestro’s PC resins in PT’s materials database.