New EPDM Grades with Improved Processing Characteristics for Automotive Weatherseal Applications

EPDM continues to be one of the most widely used and fastest growing synthetic rubbers. It includes a broad range of technologies, targeting both specialty and general-purpose applications  While grades polymerized by metallocene catalysts have been commercially available for over 10 years, EPDM rubber grades polymerized by vanadium-based catalyst systems have been available for about 50 years. The recent polymerization and catalyst technologies available through the metallocene platform provide the ability to design high performance polymers that meet the increasingly difficult application and processing needs of today’s demanding markets and further expand the opportunities available to rubber compounders.  This technology enables the development of new grades with tailored properties as a result of the precise control over the molecular architecture allowed by this catalyst platform.

This paper reviews the performance of a recently commercialized EPDM rubber grade, Vistalon^TM 7602 EPDM rubber, prepared using a metallocene catalyst system.  This grade has uniform compositional distribution, a relatively low ethylene content, as well as a diene content and molecular weight distribution specifically designed for extruded automotive weatherseal applications.  Our results indicate that this new grade offers an improved balance of processing, mechanical, and elastomeric properties for automotive weatherseal applications.