Abstract: In a Rochow process, organohalosilanes are prepared by reacting metallic silicon particles with an organohalide in the presence of a copper catalyst and a co-catalyst. The invention uses as the co-catalyst a powder of co-catalyst active element-copper alloy containing substantial strain energy because this co-catalyst can reduce the activation time taken until a steady state is reached, which has been an outstanding problem in Rochow reaction, maintain the steady state over time and increase the selectivity of desired diorganodihalosilane for eventually increasing the yield based on the starting silicon.

Abstract: A diorganodichlorosilane is prepared by subjecting organochlorosilanes to disproportionation reaction in the co-presence of a SiH group-containing compound and in the presence of a primary catalyst of AlCl3 or AlBr3 and a co-catalyst of Mg, Al, Ca, Ti, Fe, Ni, Cu, Zn or Sn or a compound thereof. The invention enables disproportionation reaction of organochlorosilanes under atmospheric pressure and at a low temperature at which no substantial sublimation of AlCl3 or the like occurs, thus allowing the reaction equipment to be simple and improving the safety of reaction.

Abstract: A diorganodichlorosilane is prepared by subjecting organochlorosilanes to disproportionation reaction in the co-presence of a SiH group-containing compound and in the presence of a primary catalyst of AlCl3 or AlBr3 and a co-catalyst of Mg, Al, Ca, Ti, Fe, Ni, Cu, Zn or Sn or a compound thereof. The invention enables disproportionation reaction of organochlorosilanes under atmospheric pressure and at a low temperature at which no substantial sublimation of AlCl3 or the like occurs, thus allowing the reaction equipment to be simple and improving the safety of reaction.

Abstract: In a Rochow process, organohalosilanes are prepared by reacting metallic silicon particles with an organohalide in the presence of a copper catalyst and a co-catalyst. The invention uses as the co-catalyst a powder of co-catalyst active element-copper alloy containing substantial strain energy because this co-catalyst can reduce the activation time taken until a steady state is reached, which has been an outstanding problem in Rochow reaction, maintain the steady state over time and increase the selectivity of desired diorganodihalosilane for eventually increasing the yield based on the starting silicon.