| 摘要 |
The invention concerns an aqueous silicon dispersion containing polyorganosiloxanes (POS) cross-linkable or cross-linked by condensation polymerisation. The aim of the invention is to provide a dispersion of this type which remedies the drawbacks of known dispersions, and capable of being properly and sufficiently cross-linked into an elastomer which provides the final application (e.g. paint) with suitable properties in particular mechanical and rheological. The invention achieves this aim by providing an aqueous silicon dispersion that can be used particularly in the formulation of paint and is characterised in that the droplets of the non-aqueous phase which constitute it are obtained from a POS resin A cross-linkable by OH/OH or OH/OR condensation and comprising at least 50 % mol of siloxyl units (T(R<a>SiO3/2); and it also comprises a basic activator B such as a hydroxylated POS resin, a condensation catalyst such as tin salt, a co-crosslinking agent D such as trialkoxysilane hydrolysate and a surfactant E; said compounds being selected so as to enable cross-linking inside the droplets of the non-aqueous phase to obtain in situ in emulsion form a cross-linked silicon dispersed phase with increased molecular weight. The invention is applicable to formulation of paints or the like, of sealing materials (sealant) or other building material. |
