Patent ID: 7439211

Claim:
A method of preparation of a lubricant composition in the form of an oil-in-water emulsion, comprising the direct mixing of two oil-in-water emulsions (A) and (B) made beforehand, said preliminary emulsions (A) and (B) complying with following compositional characteristics (i) to (4i): (i) preliminary emulsion (A) contains: (a) at least one unreactive, linear polyorganosiloxane oil with lubricant properties, with a dynamic viscosity of the order of 5.10 −2 to 30.10 2 Pa.s at 25° C. and comprising a linear homopolymer or copolymer, of which, per molecule, the monovalent organic substituents, which may be identical to or different from one another, bound to the silicon atoms, are selected from the group consisting of alkyl, cycloalkyl, alkenyl, aryl, alkarylene and aralkylene radicals; (b) at least one polyorganosiloxane resin bearing, before emulsification, condensable hydroxyl substituents and comprising, before emulsification, at least two different siloxyl units selected from the group consisting of 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), at least one of these units being a T or Q unit, and R 1 in these formulae representing a monovalent organic substituent, the average number per molecule of organic radicals R 1 per silicon atom being between 1 and 2; and said resin having a content by weight of hydroxyl substituents ranging from 0.1 to 10 wt. %; (c) at least one crosslinking agent that is soluble in the silicone phase and has at least two functions capable of reacting with the polyorganosiloxane resin(s) (b); (d) a condensation catalyst capable of catalyzing the reaction of constituent (b) with constituent (c); (e) a surfactant; and (f) water, (2i) preliminary emulsion (B) comprises: (a′) at least one reactive linear polyorganosiloxane oil containing at least two OH groups per molecule and with a dynamic viscosity in the range from 5.10 −2 to 30.10 2 Pa.s at 25° C.; and the constituents (b), (c), (d), (e) and (f) mentioned above in relation to the composition of preliminary emulsion (A); (3i) each of the preliminary emulsions (A) and (B) has the following composition by weight, and the composition by weight of (A) can be identical to or different from that of (B): from 5 to 95 parts by weight of constituent (a) for emulsion (A) or of constituent (a′) for emulsion (B); from 0.5 to 50 parts by weight of constituent (b); from 0.1 to 20 parts by weight of constituent (c); from 0.05 to 10 parts by weight of constituent (d); per 100 parts by weight of the total of the constituents (a)=(b)=(c)=(d) or (a′)=(b)=(c)=(d); the quantities of surfactants and of water being sufficient to obtain an oil-in-water emulsion; and (4i) the weight ratio of emulsion (A) to emulsion (B), at the time of mixing of the preliminary emulsions, is in the range from 1.5 to 4.