| abstract |
A method of making a dispersion of a high viscosity siloxane in a volatile, especially cyclic siloxane, comprises first dispersing organopolysiloxanes having at least 2 Si-OR groups, wherein R is H or alkyl in a volatile siloxane, and adding a catalyst which is either a phosphonitrile halide having the general formula [X(PX₂=N) n PX₃]⁺[MX (v-t+1) R t ]⁻ , or a heterogeneous catalyst, selected from Li, Mg, Ca, Sr or Ba hydroxide, Na or K borate or phosphate, Rb or Cs carbonate, or carboxylates of Rb or Cs, wherein M is an element having an electronegativity of from 1.0 to 2.0, R is alkyl, X is halide, n is 1 to 6, v is the valence of M and t is from 0 to ( v -1). |