| 摘要 |
Condensed mixed metal alcoholates are obtained by hydrolysing a mixture of two or more alcoholates of different metals having the formula M(OR)x, where M is a metal of Group IIIb, IVb or IVa of the Periodic Table, including boron and silicon, R is a hydrocarbon radical and x is the valency of the metal M. Mixtures consisting only of a titanium alcoholate and a silicon alcoholate are excluded. When the alcoholates have similar rates of hydrolysis they may be mixed and the water added; but when the rates of hydrolysis are different either the alcoholate with the lower hydrolysis rate is first partially hydrolysed before the alcoholate with the higher rate is added, or the hydrolysis is carried out in the presence of a catalyst comprising an alcoholate of a metal of Group IVa of the Periodic Table. In examples, condensed, mixed metal alcoholates are obtained by hydrolysing aluminium s-butylate and tetraethyl silicate in the presence of isopropyl titanate, by hydrolysing tri-n-butyl borate and tetraethyl silicate in the presence of isopropyltitanate, and by hydrolysing tri-n-butyl borate and aluminium-s-butylate in the presence of isopropyl titanate. |
