| abstract |
The invention concerns a method for preparing a lubricating composition, characterised in that it comprises mixing two previously prepared oil-in-water emulsions (A) and (B): the prior emulsion (A) comprises: (a) at least a non-reactive linear polyorganosiloxane oil comprising per molecule at least 2% in number of organic substituents bound to the silicon atoms which are aryl, alkylarylene and/or arylenealkyl radicals; (b) at least a polyorganosiloxane resin bearing hydroxyl groups and comprising at least two different siloxyl units selected among those formula (R 1 ) 3 SiO 1/2 (M), (R 1 ) 2 SiO 2/2 (D), R 1 SiO 3/2 (T) and SiO 4/2 (Q), one at least of said units being a unit T or Q, R 1 representing an organic substituent; (c) at least a crosslinking agent soluble in the silicone phase comprising at least two functions capable of reacting with the polyorganosiloxane resin(s) (b); (d) a condensation catalyst capable of catalysing the reaction of the constituent (b) with the constituent (c); (e) a surfactant; and (f) water; the prior emulsion (B) comprises: (a′) at least a reactive linear polyorganosiloxane oil comprising at least two OH groups per molecule, and the constituents (b), (c), (d), (e) and (f) mentioned above: each of the prior emulsions (A) and (B) comprises: 5 to 95 parts by weight of constituent (a) or (a′); 0.5 to 50 parts of constituent (b); 0.1 to 20 parts of constituent (c); 0.05 to 10 parts of constituent (d); for 100 parts of the sum (a)+(b)+(c)+(d) or (a′)+(b)+(c)+(d); the amounts of surfactant and water being sufficient to obtain an oil-in-water emulsion; and the weight ratio emulsion (A)/emulsion (B) ranges between 1.5 and 4. |