Production of SiOC-bonded polyether siloxanes
AssigneeEvonik Operations GmbH
InventorsPhilippe Favresse, Michael Fiedel, Ute Hesse
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Abstract
SiOC-bonded polyether siloxanes are produced by transesterification of alkoxysiloxanes with polyetherols in the presence of trifluoromethanesulfonate as catalyst. The computational total water content of the reactants including alkoxysiloxanes and polyetherols is ≤5000 ppm by mass, advantageously ≤300 ppm by mass, preferably ≤150 ppm by mass, more preferably ≤100 ppm by mass, in particular ≤50 ppm by mass. The determination of the individual water contents is performed beforehand, preferably by titration according to Karl Fischer.
Claims24
A process for producing a SiOC-bonded polyether siloxane, comprising:
- transesterifying an alkoxysiloxane with a polyetherol in the presence of a trifluoromethanesulfonate salt as a catalyst comprising a metal trifluoromethanesulfonate according to formula (I):
- [CF3SO3]x[M]x+ formula (1),
- wherein M is a metal atom selected from the group consisting of zinc, bismuth, aluminium, and iron,
- or
- selected from the group consisting of sodium and potassium, with the proviso that methanesulfonic acid is present, and
- x is a number up to a maximum valency of the metal atom selected for M
- wherein a computational total water content of reactants consisting of the alkoxysiloxane and the polyetherol is <5000 ppm by mass, wherein determination of an individual water content is performed before the transesterifying.
Dependencies are inferred from the claim text.