Materials: New Generation of TPVs for Corner Mold Automotive Seals

A reportedly next-generation of Santoprene TPVs from Houston-based ExxonMobil Chemicals was developed in collaboration with DuPont Transportation & Industrial, Wilmington, Del., for automotive corner mold seals. By replacing traditional organic slip additives with DuPont’s engineered silicone-based additives, the two companies formulated this novel Santoprene TPV platform with improved bonding to EDPM rubber substrates and a lower coefficient of friction (COF) for the easy opening and closing of doors and windows.

The Santoprene TPV B260 family of products also delivers improved flow properties, abrasion resistance and UV light stability, according to the collaborators. Said DuPont marketing manager Christophe Paulo,“Our successful collaboration with ExxonMobil Chemical has achieved much more than cutting-edge TPV products. It has also laid the foundation for future projects that take advantage of the unique attributes of our silicone technologies to solve industry challenges and deliver a better consumer experience.”

The DuPont development team found that synergies between a lower molecular weight silicone polymer and an ultra-high molecular weight silicone polymer delivered the low COF ExxonMobil Chemical was looking for. While delivering better sliding properties than the organic additives, the silicone technology enhanced bonding performance to dense EPDM rubber – a critical factor in overmolding. Further, it enabled higher flow for improved processing ease and throughput, better abrasion resistance to protect against damage from slammed doors and improved UV stability to help prevent cracking and discoloration.