| 摘要 |
The invention relates to a method for producing silicone polyethers. According to said method, (i) in a first step, unsaturated polyethers (3) of the general formula CH2=CR1- (CH2) aO (C2H4O) b (C3H6O) cR1 (I), wherein R1 is a hydrogen atom or a hydrocarbon group with 1 to 6 carbon atoms, a is 0 or an integer from 1 to 16, b is 0 or an integer from 1 to 50 and c is 0 or an integer from 1 to 50, are reacted with organopolysiloxanes (1) having a content in Si-bound hydrogen atoms of 0.2 to 1.6% by weight, and (ii) in a second step, organopolysiloxanes (2) having a content in Si-bound hydrogen atoms of 0.02 to 1.0% by weight are added to the reaction mixture of the first step, with the proviso that the reactions in the first and second step are carried out in the presence of catalysts (4) that promote the addition of Si-bound hydrogen to aliphatic double bonds and that the ratio of the weight concentrations of Si-bound hydrogen in organosiloxane (1) to the weight concentration of Si-bound hydrogen in organosiloxane (2) is at least 0.9, preferably at least 1.0, more preferably at least 1.5. |
