Silicone (Rochow Direct Process)

Silicones - chains of silicon and oxygen carrying methyl groups - were known from Frederic Kipping's laboratory work, but could only be made a few grams at a time. In 1940 Eugene Rochow at General Electric found a one-step route: pass methyl chloride over hot silicon with copper, and methylchlorosilanes come straight off. Richard Müller found the same reaction independently in Germany, which is why it is also called the Müller-Rochow process. It is how silicones are still made. **US 2,380,995**, "Preparation of organosilicon halides", Rochow, assigned to General Electric, granted 7. August 1945, claims "effecting reaction between silicon and a hydrocarbon halide" with a copper catalyst at 200–500 °C. **Methyl chloride and chlorosilanes are toxic and stay in the plant.** You use the product: a two-part silicone mould of glass marbles, then cast hot wax in it, again and again.