Siloxane-based lubricant composition, not releasing hydrogen, preparation method and use thereof

Siloxane-based lubricant composition, in the form of an oil-in-water emulsion, that does not release hydrogen, comprising:

• (a) an unreactive polydiorganosiloxane oil with lubricant properties, having a dynamic viscosity from about 5×10−2 to 30×102 Pa.s at 25° C.;
• (b) a reactive linear polydiorganosiloxane oil containing at least two OH groups per molecule, said polydiorganosiloxane having a dynamic viscosity at 25° C. of between 5×10−2 and 30×102 Pa.s;
• (c) a crosslinking agent that is soluble in the silicone phase, comprising at least two functions capable of reacting with the reactive polydiorganosiloxane oil (b);
• (d) a water-soluble crosslinking agent chosen from hydroxylated silanes and/or polydiorganosiloxanes, said crosslinking agent bearing at least one hydroxyl group and at least one organic group containing an Fr function per molecule, Fr representing an optionally substituted amino, epoxy, optionally substituted methacroyl, optionally substituted acroyl, optionally substituted ureido, optionally substituted thiol or halo function;
• (e) a surfactant;
• (f) a condensation catalyst capable of catalyzing the reaction of the oil (b) with the crosslinking agent (c) and/or (d);
• and
• (g) water,
• said composition comprising:
• from 5 to 95 parts by weight of the constituent (a);
• from 1 to 50 parts by weight of the constituent (b);
• from 0.1 to 20 parts by weight of the constituent (c);
• from 0.5 to 15 parts by weight of the constituent (d);
• from 0.05 to 10 parts by weight of the constituent (f);
• per 100 parts by-weight of the sum of the constituents (a)+(b)+(c),+(d)+(f);
• the amounts of surfactants and of water being sufficient to obtain an oil-in-water emulsion;
• compositions comprising a polyorganosiloxane resin that is soluble in the silicone phase and bearing, before emulsification, condensable hydroxyl substituents being excluded.