Historical clue formulations

• Kevlar developer — 2020-03-28
• Big employer in Delaware — 2019-09-05
• Spandex source — 2008-10-18
• Company behind nylon and Teflon — 2007-07-23
• Washington's ___ Circle — 2002-10-13
• Company that makes Teflon — 2000-01-24