Beginning of air conditioning in cars in General Discussion Posted January 23 · Edited January 24 by cricket-ny Correct spelling. (see edit history) Fremont is a patent of DuPont Chemicals. Damn spellcheck. What I meant to say was Freon was a trademark of DuPont Chemical. Not all refrigerants are called Freon. Industry refers to refrigerants as r-12 , r-22, r-134a, etc.