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AssigneeRhodia Chimie
InventorsYves Giraud, Gerald Guichard, Ian Hawkins
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The invention concerns a lubricating composition, in the form of an oil-in-water emulsion, based on siioxane and not releasing hydrogen comprising: (a) a polydiorganosiloxane oil non-reactive to the lubricating properties having a dynamic viscosity of the order of 5.10−2 to 30.102 Pa.s at 25° C.; (b) a polyorganosiloxane resin bearing, before emulsification, condensable hydroxyl substituents and comprising before emulsification at least two syloxyl units selected among those of formula (R0)3SiO1/2(M); (R0)2SiO2/2(D); R0SiO3/2(T) and SiO4/2(Q), one at least of said units being a T or Q unit, formulae wherein: R0 represents a monovalent organic substituent, the average number per molecule of organic radicals R0 for a silicon atom ranging between 1 and 2; and said resin having a weight content of hydroxyl substituents ranging between 0.1 and 1 0 wt. %, and, preferably between 0.2 and 5 wt. %; (c) a crosslinking agent soluble in the silicone phase comprising at least two functions capable of reacting with the polyorganosiloxane resin (b); a condensation catalyst capable of catalysing the reaction of constituent (b) with constituent (c); (e) a surfactant; and (f) water.
A lubricating composition, in the form of an oil-in-water emulsion, based on siloxane and not emitting hydrogen, comprising:
The composition as claimed in any one of the preceding claims, characterized in that the constituent (c) is chosen from organotrialkoxysilanes, organotriacyloxysilanes, organotrioximosilanes and tetraalkyl silicates.
The composition as claimed in any one of the preceding claims, characterized in that the constituent (a) is a linear polydiorganosiloxane containing recurring units of formula (R)2SiO2/2, terminated at its chain ends by (R)3SiO1/2 units, in which R is a monovalent organic group chosen from alkyl, alkenyl, aryl, cycloalkyl, cycloalkenyl, aralkyl or alkaryl.
The composition as claimed in any one of the preceding claims, characterized in that the resin (b) is a hydroxylated resin DT or MDT comprising at least 20% by weight of T units and having a weight content of hydroxyl groups ranging from 0.1 to 10%, preferably from 0.2 to 5%.
The composition as claimed in any one of the preceding claims, characterized in that the resin (b) has a dynamic viscosity at 25° C. of between 0.2 and 200 Pa.s.
The composition as claimed in any one of the preceding claims, characterized in that it comprises in addition (g) from 0.5 to 15 parts by weight per hundred parts by weight of the sum of the constituents (a)+(b)+(c)+(d)+(g), of a water-soluble crosslinking agent chosen from hydroxylated silanes and/or polydiorganosiloxanes (POSs), said crosslinking agent carrying at least one organic group with an Fr functional group, Fr being chosen from optionally substituted amino functional groups, epoxy, optionally substituted acroyl (CH2═CH—CO), optionally substituted methacroyl (CH2═C(CH3)—CO—), optionally substituted ureido (NH2—CO—NH—), optionally substituted thiol or halogen functional group.
The composition as claimed in any one of the preceding claims, characterized in that it comprises in addition at least (h) a reactive linear polydiorganosiloxane oil having per molecule at least two OH groups, said polydiorganosiloxane having a dynamic viscosity at 25° C. of between 5×10−2 and 30×102 Pa.s.
The composition as claimed in any one of the preceding claims, characterized in that it comprises in addition a film-forming polymer and, for example, a styrene-acrylic copolymer.
The composition as claimed in any one of the preceding claims, characterized in that it comprises from 40 to 95% by weight of water.
The composition as claimed in any one of the preceding claims, characterized in that it comprises from 0.5 to 10% by weight of surfactant.
A method for preparing a lubricating composition as claimed in any one of claims 1 to 17, comprising the steps consisting in:
Dependencies are inferred from the claim text.