GB910334A - Process for producing organosilicon compounds - Google Patents

Abstract

Organosilicon compounds of the formula <FORM:0910334/IV(a)/1> wherein each R is a mono-valent hydrocarbon radical (saturated or unsaturated) with or without, as substituent, a halogen atom, or an amino, hydroxyl, cyano, carbalkoxy, aminoalkylamino, alkoxy or aryloxy group, R1 is an alkyl radical or H atom and n is at least 1, are condensed in the presence of a catalytic amount of a compound of the formula (R11COO)aM, wherein M is Hg, Th or Pb, a has the value of the valency of M and R11 is a monovalent aliphatic hydrocarbon radical. Preferably the salts are derived from alkanoic acids of 2 to 10 C atoms, e.g. mercuric, acetates, lead and thallous propanoates, butanoates and octoates. The catalyst is generally used in amount from 0,01 to 20% by weight of the starting material and the process can be effected at a temperature from 25 DEG to 170 DEG C. with continuous removal of water or water and alcohol produced as a by-product. If desired the starting material and catalyst may be dissolved in an inert solvent. After completion of the reaction the catalyst may be removed, such as by washing with water. The products may be oils or gums, and intermediate products containing Si-bonded OH or OR groups may be end-blocked by reacting with trihydrocarbon-halo-silanes. If desired, alkoxysilanes may be co-condensed with the starting material to yield siloxanes containing functional groups. Products containing alkenyl radicals can be cured through these radicals to yield gums, and products containing alkoxy radicals can be hydrolysed to yield resins. In a typical example (1) a mixture of HO[(CH3)2SiO]H20 and mercuric acetate was heated at 150 DEG C. for 40 hours to give a siloxane gum. Uses: For producing elastomers, and as hydraulic fluids.