Method for preparing functionalized polyorganosiloxane resins by redistribution in the presence of at least one triflic acid derivative

Abstract

The present invention relates to a process for preparing functionalized polyorganosiloxane (POS) resins comprising units M: (R 3 SiO 1/2 ) Q: (SiO 4/2 ) and M′: (Y a R 3−a SiO 1/2 ) and optionally D: (R 2 SiO 2/2 ) and/or D′: (RYSiO 2/2 ) and T: (RSiO 3/2 ) and/or T′: (YSiO 3/2 ), with, in these units: R=C 1 -C 10 alkyl or a C 8 -C 12 aryl and Y a functional group (e.g.: Si—H), by redistribution of POS resins using POSf bearing functional units M′ and/or D′ and/or in the presence of an acid catalyst of the trifluoromethane-sulfonimide (TFSI) type. The present invention also relates to the aforementioned catalyst system.

1 . A process for preparing functionalized polyorganosiloxane (POS) resins comprising units M: (R 3 SiO 1/2 ), Q: (SiO 4/2 ) and M′: (Y a R 3−a SiO 1/2 ) and optionally D: (R 2 SiO 2/2 ) and/or D′: (RYSiO 2/2 ) and T: (RSiO 3/2 ) and/or T′: (YSiO 3/2 )
 wherein:
 the radicals R, which are identical or different, represent C 1 -C 10  alkyl or C 8 -C 12  aryl; and 
   the radicals Y, which are identical or different, represent a functional group Y selected from the group consisting of hydrogen, alkenyl, alkynyl, aryl, (alkyl)epoxy, ether, polyether, carboxylic acid, amide, amine, halide, alcohol, thiol and other sulfur derivative;   said process comprising conducting are distribution reaction between a POS resin and a POSf compound bearing functional units M′ and/or D′ and/or T′, as defined above, in the presence of an acid catalyst, wherein at least one catalyst has formula (I) below:
   (C m F 2m+1 SO 2 ) n A  (I) 
   wherein:   m is an integer greater than or equal to 1; and   n is an integer equal to 1 or 2 and A represents NH 2  or NH with:   (i) n=1 and A=NH 2  or NHR with R being a radical of SO 2 -Z type with Z being a group other than C m F 2m+1 ; or   (ii) n=2 and A=NH.   
     
     
         2 . The process as claimed in  claim 1 , wherein a mixture of catalysts is employed comprising at least one catalyst of formula (I) and at least one catalyst of formula (I′) below:
   (C m F 2m+1 SO 2 )OH  (I′)   
       wherein m is an integer greater than or equal to 1. 
     
     
         3 . The process as claimed in  claim 1 , wherein Y is phenyl. 
     
     
         4 . The process as claimed in  claim 2 , wherein Y is phenyl. 
     
     
         5 . The process as claimed in  claim 1 , wherein the catalyst of formula (I) is trifluoromethanesulfonimide acid (TFSI) of formula (I) (ii) with m=1. 
     
     
         6 . The process as claimed in  claim 2 , wherein the catalyst of formula (I) is trifluoromethanesulfonimide acid (TFSI) of formula (I) (ii) with m=1. 
     
     
         7 . The process as claimed in  claim 1 , wherein the concentration of acid catalyst (I) is between 1 ppm and 2% by weight relative to the starting resin. 
     
     
         8 . The process as claimed in  claim 1 , comprising the following essential steps:
 (1) combining the starting POS resin, the POSf bearing functional units and the acid catalyst (1) in an organic solvent;   (2) reacting at a temperature Or greater than or equal to room temperature and less than or equal to the boiling point of the solvent; and   (3) optionally quenching the reaction by adding an agent for neutralizing the acid catalyst (I).   
     
     
         9 . The process as claimed in  claim 8 , wherein the reaction temperature is between 50° C. and 100° C. 
     
     
         10 . The process as claimed in  claim 8 , wherein a mixture of catalysts is employed comprising at least one catalyst of formula (I) and at least one catalyst of formula (I′) below:
   (C m F 2m+1 SO 2 )OH  (I′)   
       wherein m is an integer greater than or equal to 1. 
     
     
         11 . The process as claimed in  claim 8 , wherein the catalyst of formula (I) is trifluoromethanesulfonimide acid (TFSI) of formula (I) (ii) with m=1. 
     
     
         12 . The process as claimed in  claim 8 , wherein the organic solvent is provided in the reaction medium by means of a solution of starting POS resin in said solvent. 
     
     
         13 . The process as claimed in  claim 12 , wherein the organic solvent is xylene or toluene. 
     
     
         14 . The process as claimed in  claim 1 , wherein Y=H or alkenyl in the functional units M′ and/or D′ and/or T′ of the POSf, and wherein, after the redistribution, other functionalization radicals Y 1  bearing at least one unsaturation or at least one Si—H unit are grafted by hydrosilylation onto the ≡Si—H or ≡Si-alkenyl units, respectively, of the redistributed resin. 
     
     
         15 . The process as claimed in  claim 14 , wherein other functionalization radicals Y 1  bearing at least one ethylenic unsaturation are grafted by hydrosilylation onto the ≡S—H or ≡S-alkenyl units, respectively, of the redistributed resin.