abstract |
Linear triorganosiloxy-terminated organopolysiloxanes are prepared by the condensation of linear organopolysiloxanes having one Si-bonded hydroxyl group in each teminal unit in the presence of phosphonitrilic chloride, and after the organopolysiloxane has reached the desired average viscosity and while still containing the phosphonitrilic chloride, the organopolysiloxane is reacted with from 0.05 to 1 weight percent of hexaorganodisilazane, based on the weight of the starting organopolysiloxane, with the proviso that a filler having a BET surface area of at least 50 m 2 /g does not exceed 1 weight percent, based on the weight of the starting organopolysiloxane. |