Lubricating Compositions

Abstract

A lubricating composition suited to use for lubricating a hydraulic system includes an oil of lubricating viscosity and a compound comprising a polyolefin-substituted bridged hydroxyaromatic compound or metal salt thereof, wherein the wherein the polyolefin is derived from a isobutylene having a number average molecular weight of 150 to 800.

What is claimed is: 
     
         1 . A lubricating composition comprising:
 an oil of lubricating viscosity;   a corrosion inhibitor selected from 2,5-bis(tert-dodecyldithio)-1,3,4-thiadiazole, tolyltriazole, or mixtures thereof;   an antioxidant selected from aminic or phenolic antioxidants, or mixtures thereof;   a dispersant;   a neutral of slightly overbased calcium sulfonate;   an anti-wear agent selected from zinc dialkyldithiophosphate, zinc dialkylphosphate, amine salt of a phosphorus acid ester, or mixtures thereof; and   a compound comprising a polyolefin-substituted bridged hydroxyaromatic compound or salt thereof, wherein the polyolefin is derived from isobutylene having a number average molecular weight of 150 to 400 and wherein the compound is bridged with a sulfide bridge.   
     
     
         2 . (canceled) 
     
     
         3 . (canceled) 
     
     
         4 . (canceled) 
     
     
         5 . The lubricating composition of  claim 1 , wherein the compound is a metal salt or pnictogen salt. 
     
     
         6 . The lubricating composition of  claim 5 , wherein the metal in the salt comprises calcium. 
     
     
         7 . The lubricating composition of  claim 1 , wherein the metal is overbased. 
     
     
         8 . (canceled) 
     
     
         9 . (canceled) 
     
     
         10 . The lubricating composition of  claim 1 , wherein the compound is a bridged metal phenate. 
     
     
         11 . The lubricating composition of  claim 1 , wherein the compound is free of C8 and higher unbranched alkyl chains. 
     
     
         12 . The lubricating composition of  claim 1 , wherein the compound includes a bridged phenate unit represented by the formula: 
       
         
           
           
               
               
           
         
         and salts thereof, 
         where each R1 and each R2 represents an isobutylene group; 
         X represents a sulfide bridging group; 
         Y and Z each represent a terminal group; 
         each n is at least 1; 
         m is at least 1; and 
         p is at least 1. 
       
     
     
         13 . The lubricating composition of  claim 12 , wherein the compound is not coupled with cresol. 
     
     
         14 . The lubricating composition of  claim 12 , wherein n is 1. 
     
     
         15 . (canceled) 
     
     
         16 . (canceled) 
     
     
         17 . The lubricating composition of  claim 12 , wherein each R1 is a 300-400 MW polyisobutylene. 
     
     
         18 . The lubricating composition of  claim 1 , wherein the compound has a weight-average molecular weight of 550-5600 in its unsalted form. 
     
     
         19 . The lubricating composition of  claim 1 , wherein the compound has a weight average molecular weight of up to 2800 in its unsalted form. 
     
     
         20 . The lubricating composition of  claim 1 , wherein the dispersant comprises a borated succinimide or a non-borated succinimide dispersant or a substantially nitrogen free dispersant as described herein 
     
     
         21 . The lubricating composition of  claim 1 , wherein the compound is at least 0.01 wt. % of the lubricating composition. 
     
     
         22 . The lubricating composition of  claim 20 , wherein the compound is at least 0.01 wt % of the lubricating composition. 
     
     
         23 . The lubricating composition of  claim 1 , wherein the oil of lubricating viscosity comprises at least one of an API Group I, II, III, IV, or V base oil. 
     
     
         24 . The lubricating composition of  claim 1 , wherein the oil of lubricating viscosity is at least 10 wt. % up to 99.5 wt % of the lubricating composition. 
     
     
         25 . (canceled) 
     
     
         26 . (canceled) 
     
     
         27 . (canceled) 
     
     
         28 . A method of lubricating a hydraulic system, comprising supplying to the hydraulic system a lubricant comprising:
 0.0001 wt % to 0.15 wt % of a corrosion inhibitor selected from 2,5-bis(tert-dodecyldithio)-1,3,4-thiadiazole, tolyltriazole, or mixtures thereof,   an oil of lubricating viscosity,   0.02 wt % to 3 wt % of antioxidant chosen from aminic or phenolic antioxidants, or mixtures thereof,   0.005 wt % to 1.5 wt % of a dispersant,   0.001 wt % to 1.5 wt % of a neutral or slightly overbased calcium sulphonate,   0.001 wt % to 2 wt % of an antiwear agent chosen from zinc dialkyldithiophosphate, zinc dialkylphosphate, amine salt of a phosphorus acid ester, or mixtures thereof; and   0.001 wt % to 5 wt % of a compound comprising a polyolefin-substituted bridged hydroxyaromatic compound or salt thereof, wherein the polyolefin is derived from isobutylene having a number average molecular weight of 150 to 400 and wherein the compound is bridged with a sulfide bridge.   
     
     
         29 . (canceled) 
     
     
         30 . (canceled) 
     
     
         31 . A method of lubricating a turbine system, comprising supplying to the turbine system a lubricant comprising:
 0.0001 wt % to 0.5 wt % of a corrosion inhibitor chosen from 2,5-bis(tert-dodecyldithio)-1,3,4-thiadiazole, tolyltriazole, or mixtures thereof;   an oil of lubricating viscosity;   0.01 wt % to 1.5 wt % of antioxidant chosen from aminic or phenolic antioxidants, or mixtures thereof;   0.01 wt % to 2 wt % of a dispersant,   0.001 wt % to 1.5 wt % of a neutral or slightly overbased calcium sulphonate;   0.001 to 1 wt % of a carboxylic acid or anhydride chosen from polyisobutylene succinic acid or anhydride thereof or dodecenyl succinic acid;   0.05 wt % to 1.5 wt % of an antiwear agent chosen from zinc dialkyldithiophosphate, zinc dialkylphosphate, amine salt of a phosphorus acid ester, or mixtures thereof;   0.01 wt % to 1.5 wt % of a compound comprising a polyolefin-substituted bridged hydroxyaromatic compound or salt thereof, wherein the polyolefin is derived from isobutylene having a number average molecular weight of 150 to 400 and wherein the compound is bridged with a sulfide bridge.