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1. (WO2003054058) METHOD FOR PREPARING POLYORGANOSILOXANES (POS) BY POLYCONDENSATON/REDISTRIBUTION OF OLIGOSILOXANES IN THE PRESENCE OF A STRONG BASE AND STRONG BASES USED

Pub. No.:    WO/2003/054058    International Application No.:    PCT/FR2002/004343
Publication Date: Jul 3, 2003 International Filing Date: Dec 13, 2002
IPC: C07F 9/535
C07F 9/54
C08G 77/08
Applicants: RHODIA CHIMIE
BACEIREDO, Antoine
BERTRAND, Guy
LEMEUNE, Alla
MIGNANI, Gérard
Inventors: BACEIREDO, Antoine
BERTRAND, Guy
LEMEUNE, Alla
MIGNANI, Gérard
Title: METHOD FOR PREPARING POLYORGANOSILOXANES (POS) BY POLYCONDENSATON/REDISTRIBUTION OF OLIGOSILOXANES IN THE PRESENCE OF A STRONG BASE AND STRONG BASES USED
Abstract:
The invention concerns the synthesis of silicone by anionic polymerisation of cyclic organosiloxane oligomers in the presence of a slightly nucleophilic strong base. The invention aims at providing novel strong base catalysts, more efficient in terms of solubility in the silicones, with hydrolysis stability strength and polymerising capacity. To achieve this, the invention provides for the use of ylides derived from aminophosphonium such as for example that of formula: [Me3N)3P-CHMe2]+, MeO or derived from phosphoranylidenes such as that of formula: [Me3P-HC=Pme3]+, t-BuO. The invention also concerns strong base catalysts as novel products.