RCA Videodisc are coated with a layer of silicone to prevent wear to the disc and to the stylus. The first silicone chosen was a product from the General Electric Silicone Division called SF1147. It was found to have the best properties for videodisc. Dr. Chin-Chun Wang is credited with modifying the SF1147 for use with the videodisc application. The final product was referred to as Wang’s Dupont. It contains 85% F-1 and 15% Wang’s.
The silicone was mixed with heptane and coated to a thickness of 200 to 250 Angstroms, the heptane would then evaporate leaving the silicone bonded to the disc.
Link to Who’s Who Page on CED Magic Website