| 摘要 |
A siloxane having different siloxane units is made by hydrolysing an equilibrated organosilicon polymer having different siloxane units and the average general formula <FORM:0944703/C3/1> in which each R is H or a substituted or unsubstituted hydrocarbon radical, X is halogen or an alkoxy radical, a is 0.9 to 2.2, u is 0.75 to 1.5, v is 0.0001 to 0.5 and 4>(a-2u+2v)>2. The R radicals may be, e.g. methyl, ethyl, cyclohexyl, phenyl, 4-chlorophenyl, 3-fluoropropyl, 3-acetoxypropyl, or 3-cyanopropyl. The starting polymers containing the sulphate and hydrolysable groups are those described in Specification 899,148 and those made in a similar manner but using tetra-, tri- or monofunctional silanes instead of difunctional ones. The starting polymer or mixtures of polymers can be equilibrated with an organo-halo- or organoalkoxy silane of which the organic radicals are at least in part different from those of the polymer, and the resulting product is then hydrolysed. The hydrolysis may be effect is several stages, each stage being followed by equilibration with the silane, and finally any remaining hydrolysable groups are hydrolysed. In a typical example (1) a polymer containing Si-bonded halogen and sulphate groups was mixed with methyl dichlorosilane and tri-methyl-silylsulphate and stirred at 20 DEG C. for 18 hours, volatile constituents being subsequently removed by vacuum distillation; the residue was introduced dropwise into a mixture of water and tetrahydrofuran to yield, on purification, a siloxane oil containing Si-bonded hydrogen. |
