Telomerisation of cyclic polyorganosiloxanes
View Patent ↗A telomerization process is used to prepare a reaction product containing a noncyclic hydrocarbonoxy-functional polyorganosiloxane. The process includes heating a composition including (A) a cyclic polyorganosiloxane, (B) a silane, and (C) a Lewis Acid telomerization catalyst. The cyclic polyorganosiloxane has formula [(R 1 2 SiO) 2/2 ] n , where subscript n is an integer of 4 or more, and each R 1 is independently H, a hydrocarbyl group, or a halogenated hydrocarbyl group. The silane has formula R 2 (4-m) Si(OR 3 ) m , where subscript m is an integer from 1 to 4, each R 2 is independently H, a hydrocarbyl group, or a halogenated hydrocarbyl group, and each R 3 is independently a hydrocarbyl group. The telomerization catalyst is a Lewis Acid of formula [M] x +[R 4 SO 3 − ] X where M is a metal atom selected from Aluminum (Al), Bismuth (Bi), Cerium (Ce), Chromium (Cr), Iron (Fe), Gallium (Ga), Indium (In), Lanthanum (La), Scandium (Sc), Samarium (Sm), and Ytterbium (Yb); R 4 is selected from an oxygen atom (O) and CF 3 ; and x represents a number up to a maximum valence of the metal atom selected for M.
1. A process for preparing a reaction product comprising a noncyclic hydrocarbonoxy-functional polyorganosiloxane comprises:
(1) heating a composition comprising:
(A) a cyclic polyorganosiloxane of formula [(R 1 2 SiO) 2/2 ] n , where subscript n is an integer of 4 or more, and each R 1 is independently H, a hydrocarbyl group, or a halogenated hydrocarbyl group;
(B) a silane of formula R 2 (4-m) Si(OR 3 ) m , where subscript m is an integer from 1 to 4, each R 2 is independently H, a hydrocarbyl group, or a halogenated hydrocarbyl group, and each R 3 is independently a hydrocarbyl group; and
(C) a Lewis Acid telomerisation catalyst of formula [M] X+ [R 4 SO 3 − ] X where M is a metal atom selected from Aluminum (Al), Bismuth (Bi), Cerium (Ce), Chromium (Cr), Iron (Fe), Gallium (Ga), Indium (In), Lanthanum (La), Scandium (Sc), Samarium (Sm), and Ytterbium (Yb); R 4 is O or CF 3 ; and x represents a number up to a maximum valence of the metal atom selected for M.
2. The process of claim 1 , further comprising adding to the composition an ingredient selected from (D) a solvent, (E) a proton scavenger, and both (D) and (E).
3. The process of claim 1 , further comprising: (2) adding water before, during, and/or after step (1).
4. The process of claim 1 , where heating is at a temperature of 80° C. to 150° C. for a time sufficient to form the noncyclic hydrocarbonoxy-functional polyorganosiloxane.
5. The process of claim 1 , where R 1 is selected from H, a hydrocarbyl group selected from alkyl, alkenyl, aryl, and aralkyl; and a halogenated hydrocarbyl group; and subscript n is 4 to 6.
6. The process of claim 1 , where R 2 is selected from H, a hydrocarbyl group selected from alkyl, alkenyl, aryl, and aralkyl; and a halogenated hydrocarbyl group; subscript m is 2 to 4; and R 3 is alkyl.
7. The process of claim 1 , where ingredients (A) and (B) are present in amounts such that molar ratio of (A)/(B) is at least 0.25/1.
8. The process of claim 1 , where ingredient (C) is a metal triflate of formula [M] X+ [CF 3 SO 3 − ] X where M is a metal atom selected from Aluminum (Al), Bismuth (Bi), Iron (Fe), Gallium (Ga), Indium (In), Scandium (Sc), Samarium (Sm), and Ytterbium (Yb).
9. The process of claim 8 , where M is Al, Bi, Fe, Ga, or Sc; and subscript x is 3.
10. The process of claim 1 , where ingredient (C) is a metal sulfate selected from Cr 2 (SO 4 ) 3 and Fe 2 (SO 4 ) 3 .
11. The process of claim 1 , where ingredient (C) is present in an amount from 2 mol % to 5 mol % based on combined weights of ingredients (A), (B), and (C).