| 摘要 |
<p>Organochlorosilanes are prepared by reacting at a temperature above 250 DEG C. a compound having the general formula RmSiCl4-m and a compound having the general formula R1nSiCl4-n, wherein m is 1, 2, 3 or 4, n is 0, 1, 2 or 3, and R and R1 are alkyl or aryl radicals which must be dissimilar when m and n have the same value and may be similar or dissimilar when m and n have different values, the reaction being conducted in the presence of a metal halogenoaluminate of the general formula MAIX4, wherein M represents an alkali metal and X is a halogen, the said organochlorosilanes formed containing at least some organochlorosilane in which the ratio of organo group to silicon atom is different from that in any of the starting materials. Suitable reactants which fall within the scope of the above formul are silicon tetrachloride, tetramethyl- and tetraethyl-silane, methyl-, ethyl-, butyl-, amyl- and lauryltrichlorosilane, dimethyl-, diethyl-, dipropyl-, diisopropyl-, dibutyl-, and diphenyl-dichlorosilane, and trimethyl-, triethyl-, tri-isobutyl-and triphenyl-chlorosilane. When m and n in the above formul are not the same, it is preferable for the organic groups attached to the silicon atom of each of the reactants to be the same. The mixture of reactants used may comprise an arylchlorosilane such as a phenyl-chlorosilane and an alkylchlorosilane, an in-organic chlorosilane and an organochlorosilane, an inorganic chlorosilane and tetra-alkyl- or tetra-aryl silane, or an alkylchlorosilane and a tetra-alkyl silane. Specific mixtures of reactants referred to are methyltrichlorosilane and trimethylchlorosilane, trimethylchlorosilane and silicon tetrachloride, tetraphenylsilane or tetra-methylsilane and silicon tetrachloride, tetra-methylsilane and methyltrichlorosilane, di-methyldichlorosilane and silicon tetrachloride, silicon tetrachloride or trimethylchlorosilane and triphenylchlorosilane, dimethyldichloro-silane and diphenyldichlorosilane, and diethyl-dichlorosilane and tetraethylsilane. The process may be carried out at atmospheric or superatmospheric pressures, and suitable reaction temperatures vary up to 500 DEG C. or even higher temperatures. Reaction periods vary from about 15 seconds to 2 to 3 minutes. The preferred metal halogenoaluminates are the sodium and potassium chloroaluminates, a suitable quantity of the aluminate which may be used being from about 0.5 to 5 per cent by weight of the total weight of reactants used. In the examples, methyltrichlorosilane and trimethyl-chlorosilane are reacted to form a reaction product containing dimethyldichlorosilane. Specification 575,667 is referred to.</p> |
