Since 1990 BASF has produced and sold the high temp polymers polysulfone and polyethersulfone under the trade names Ultrason S (PSU) and Ultrason E (PES). Both are transparent, high temperature, high-performance thermoplastics. The applications for these high temp polymers span the electronics, automotive, and consumer goods industries. Broad chemical resistance, hydrolysis resistance, constant use temperature of 180 °C (PES) and 160 °C (PSU) and high mechanical strength are the key properties which characterize Ultrason as both outstanding and versatile.