Silicone Grease with High Cold Cohesion

Abstract

Silicone grease with high cold cohesion, characterized in that it comprises at least one oily diorganopolysiloxane polymer, 10% to 30% by weight of organometallic soap(s) and 5% to 20% by weight of chloroparaffin(s). Use of said grease as a treating and/or protecting and/or lubricating agent in the field of moving metallic mobile components, with good cohesion, especially when cold, thus making it possible to avoid, inter alia, skating phenomena, especially when cold, between components involved in a drive device.

1 .- 10 . (canceled) 
     
     
         11 . A high cold cohesion silicone grease comprising at least one oily diorganopolysiloxane polymer, 10% to 30% (weight percentage expressed relative to the weight of the grease) of organometallic soap(s) and 5% to 20% by weight of halogenated paraffin(s), said grease comprising chloroparaffins consisting essentially of petroleum distillation-based linear hydrocarbons that have been chlorinated, belonging to one and/or other of the following three categories: C10-C13 short chain chloroparaffins, C14-C17 medium-chain chloroparaffins and C18-C30 long-chain chloroparaffins, each of the abovementioned categories optionally having a weight percentage of chlorine in the range from 30% to 70%. 
     
     
         12 . The grease as claimed in  claim 11 , wherein the C14-C17 medium-chain and C18-C30 long-chain chloroparaffins have a weight percentage of chlorine in the range from 40% to 60%. 
     
     
         13 . The grease as claimed in  claim 11 , further comprising a high flow threshold, of greater than 600 Pa at −40° C. 
     
     
         14 . The grease as claimed in  claim 11 , further comprising 1% to 8% by weight of auxiliary additive(s). 
     
     
         15 . The grease as claimed in  claim 11 , wherein the oily diorganopolysiloxane polymers correspond to the general formula:
   (R) 3 SiO[Si(R) 2 O] n Si(R) 3     
       in which the symbols R, which may be identical or different, represent hydrocarbon-based radicals free of aliphatic unsaturations and containing up to 13 carbon atoms, and the symbol n represents any number from 30 to 1500. 
     
     
         16 . The grease as claimed in  claim 11 , wherein the organometallic soaps are derived from higher fatty acids containing from 10 to 32 carbon atoms and from metallic Li, Na, K, Cs, Mg, Ca, Sr, Cd, Zn, Pb and Co compounds. 
     
     
         17 . The grease as claimed in  claim 11 , further comprising nonhydrolated organometallic soaps derived from nonhydroxylated fatty acids. 
     
     
         18 . A process for preparing a high cold cohesion silicone grease, wherein the grease comprises at least one oily diorganopolysiloxane polymer, 10% to 30% (weight percentage expressed relative to the weight of the grease) of organometallic soap(s) and 5% to 20% by weight of halogenated paraffin(s), said grease comprising chloroparaffins consisting essentially of petroleum distillation-based linear hydrocarbons that have been chlorinated, belonging to one and/or other of the following three categories: C10-C13 short chain chloroparaffins, C14-C17 medium-chain chloroparaffins and C18-C30 long-chain chloroparaffins, each of the abovementioned categories optionally having a weight percentage of chlorine in the range from 30% to 70%, the process comprising melting/recrystallizing the soap in the oily diorganopolysiloxane polymer(s); and incorporating the halogenated paraffin(s) either before or after the melting/recrystallization step. 
     
     
         19 . A method of treating and/or protecting or lubricating a metallic component, the method comprising applying an amount of a high cold cohesion silicone grease to the metallic component, wherein the high cold cohesion silicone grease comprises at least one oily diorganopolysiloxane polymer, 10% to 30% (weight percentage expressed relative to the weight of the grease) of organometallic soap(s) and 5% to 20% by weight of halogenated paraffin(s), said grease comprising chloroparaffins consisting essentially of petroleum distillation-based linear hydrocarbons that have been chlorinated, belonging to one and/or other of the following three categories: C10-C13 short chain chloroparaffins, C14-C17 medium-chain chloroparaffins and C18-C30 long-chain chloroparaffins, each of the abovementioned categories optionally having a weight percentage of chlorine in the range from 30% to 70% and wherein the grease exhibits a high flow threshold, of greater than 600 Pa at −40° C. 
     
     
         20 . The method of  claim 19 , wherein the metallic component is a component used in the motor vehicle field. 
     
     
         21 . The method of  claim 20 , wherein the component is used in a drive device comprising a vehicle clutch cable, a gearbox or a starter.