Preparing reaction products from poly (diorganosiloxanes)
AssigneeBayer Aktiengesellschaft
InventorRobert Friebe
Life of this patent
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Abstract
In the reaction of a polysiloxane with an alkoxysilane to produce polysiloxanes with special terminal groups, the improvement which comprises effecting the reaction in the presence of fluoride ions as activator.
Claims10
A process for the production of triorganyloxysilyl or diorganyloxy-organosilyl-terminated poly(diorganosiloxanes) wherein at least one polysiloxane of the formula ##STR5## in which R and R.sup.1 each independently is C.sub.1 -C.sub.18 -alkyl or alkoxy, phenyl or substituted phenyl or a C.sub.2 -C.sub.18 -alkenyl or alkoxyalkyl group,
- R.sup.2 and R.sup.3 =H,
- X=10-10,000 is reacted with an alkoxysilane in the presence of fluoride ions as activator
- and wherein, after the production of the triorganyloxysilyl or diorganylsilyl-terminated poly(diorganosiloxanes), the reaction is terminated by precipitating the fluoride ions by the addition of alkaline earth metal ions.
In the reaction of polysiloxane wherein at least one polysiloxane of the formula ##STR6## in which R and R.sup.1 each independently is C.sub.1 -C.sub.18 -alkyl or alkoxy, phenyl or substituted phenyl or a C.sub.2 -C.sub.18 -alkenyl or alkoxyalkyl group,
- R.sup.2 and R.sup.3 each independently is a C.sub.1 -C.sub.18 -alkyl, C.sub.6 -C.sub.14 -aryl or SiR.sup.5.sub.3 group,
- R.sup.5 is a C.sub.1 -C.sub.18 -alkyl or a C.sub.6 -C.sub.14 -aryl, C.sub.2 -C.sub.18 -alkenyl or alkoxyalkyl group,
- X=10 to 10,000,
- or a polysiloxane having a network structure is reacted with an alkoxysilane to produce products according to formula III and IV, ##STR7## wherein R.sup.4 represents a C.sub.1 -C.sub.18 -alkyl group or --SiR.sup.5.sub.3 where R.sup.5 =C.sub.1 -C.sub.18 -alkoxy/alkyl, C.sub.6 -C.sub.14 -aryl or C.sub.2 -C.sub.18 -alkenyl/alkoxyalkyl and
- z is 1 to 200,
- the improvement comprises effecting the reaction in the presence of fluoride ions as activator.
Dependencies are inferred from the claim text.