Lubricating Oil Composition

Abstract

A lubricating oil composition comprising (A) an oil of lubricating viscosity; and, (B) as an additive component, an oil-soluble mixture of oxyalkylated hydrocarbyl phenol condensates wherein the oxyalkyl groups have the formula —(R′O) n — where R′ is an ethylene, a propylene or a butylene group; n is independently from 0 to 10; less than 45 mole % of the phenolic hydroxyl groups in the mixture are not oxyalkylated; and more than 55 mole % of the oxyalkyl groups in the mixture have the formula —R′O— where n is 1.

1 . A lubricating oil composition comprising or made by admixing:
 (A) an oil of lubricating viscosity; and   (B) as an additive component, an oil-soluble mixture of oxyalkylated hydrocarbyl phenol condensates wherein the oxyalkyl groups have the formula —(R′O) n — where R′ is an ethylene, propylene or butylene group; and n is independently from 0 to 10; wherein   less than 45 mole % of the phenolic functional groups of the condensates are non-oxyalkylated; and more than 55 mole % of the phenolic functional groups of the condensates are mono-oxyalkylated.   
     
     
         2 . The composition as claimed in  claim 1 , wherein the condensates are represented by the following general structural formula: 
       
         
           
           
               
               
           
         
         wherein: 
         x is 1 to 50; 
         R 1  and R 2  are each independently H, hydrocarbyl groups having 1 to 12 carbon atoms, or hydrocarbyl groups having 1 to 12 carbon atoms and at least one heteroatom; and 
         R is a hydrocarbyl group having 9 to 100 carbon atoms. 
       
     
     
         3 . The composition as claimed in  claim 2 , wherein R 1 ═H, R 2 ═H and R is in the para position in relation to the —O—[CH 2 CH 2 O] n H group. 
     
     
         4 . The composition as claimed in  claim 1 , wherein additive component B has a number average molecular weight (M n ), as measured by GPC, in the range of 1000 to less than 4000. 
     
     
         5 . The composition as claimed in  claim 1 , wherein additive component B has a number average degree of polymerization of 4-20. 
     
     
         6 . The composition as claimed in  claim 1 , wherein additive component B has a weight average molecular weight (M w ) as measured by GPC in the range of 1100 to less than 6000. 
     
     
         7 . The composition as claimed in  claim 1 , wherein additive component B has an M w /M n  ratio in the range of 1.10 to 1.60. 
     
     
         8 . The composition as claimed in  claim 1 , wherein additive component (B) includes less than 1 mole % of unreacted alkyl phenol. 
     
     
         9 . The composition as claimed  claim 1 , wherein more than 60 mole % of the phenolic functional groups of additive component B are mono-oxyalkylated (i.e. n=1). 
     
     
         10 . The composition as claimed in  claim 1 , wherein less than 5 mole % of phenolic functional groups of additive component B are poly-oxyalkylated. 
     
     
         11 . The composition as claimed in  claim 2 , wherein R is independently a branched chain alkyl group. 
     
     
         12 . The composition as claimed in  claim 11 , wherein said branched chain alkyl group has from 9 to 15 carbon atoms. 
     
     
         13 . The composition as claimed in  claim 1 , further including one or more other additive components different from (B). 
     
     
         14 . The composition as claimed in  claim 1 , wherein the oil of lubricating viscosity is present in a major amount and (B), and any other additive components, are present in respective minor amounts, the composition having less than 1.0 mass % sulfated ash, based on the total mass of the composition. 
     
     
         15 . The composition as claimed in  claim 1 , wherein the oil of lubricating viscosity is present in a major amount, and (B) and at least one metal detergent are present in respective minor amounts; and the weight ratio of component (B) to the at least one metal detergent is in the range of 0.1 to 4. 
     
     
         16 . The composition as claimed in  claim 1 , wherein the other additive components, different from (B), are selected from one or more ashless dispersants, corrosion inhibitors, antioxidants, pour point depressants, antiwear agents, friction modifiers such as organo-molybdenum compounds, demulsifiers, anti-foaming agents and viscosity modifiers. 
     
     
         17 . The composition as claimed in  claim 16 , wherein an ashless dispersant is present which is characterized by a highly reactive polyisobutylene of Mn=1000-3000, thermally functionalized without the assistance of chlorine to a polyisobutylene succinic anhydride, and further derivatized to a succinimide dispersant by condensation with a polyamine. 
     
     
         18 . The composition as claimed in  claim 15 , wherein the metal detergent is selected from a metal salicylate, a metal sulfonate, a metal phenate or mixtures thereof; the metal preferably being selected from calcium or magnesium. 
     
     
         19 . The composition as claimed in  claim 13  having a TBN of 5 or more as measured by ASTM D2896. 
     
     
         20 . The composition as claimed in  claim 19 , wherein up to 30% of the TBN originates from non-metal bases. 
     
     
         21 . The composition as claimed in  claim 1 , wherein the oil of lubricating viscosity is present in a concentrate-forming amount. 
     
     
         22 . A method of making additive component (B) as defined in  claim 1 , the method comprising forming an oxyalkylated hydrocarbyl phenol aldehyde condensate by the steps of (1) condensation of a hydrocarbyl phenol with an aldehyde, in the presence of an acid or base catalyst, to form a hydrocarbyl phenol-aldehyde condensate, and (2) oxyalkylating said condensate in the presence of a base catalyst with 0.5 to less than 3 equivalents of ethylene carbonate, propylene carbonate or butylene carbonate for each equivalent of phenolic functional groups within the condensate. 
     
     
         23 . A method of making an additive component (B) as defined in  claim 1 , the method including the steps of forming an oxyalkylated hydrocarbyl phenol-aldehyde condensate by the steps of (1) oxyalkylating a hydrocarbyl phenol in the presence of a base catalyst, with 0.5 to 3 equivalents of ethylene carbonate, propylene carbonate or butylene carbonate, and (2) condensation in the presence of an acid or base catalyst of said oxyalkylated hydrocarbyl phenol with an aldehyde. 
     
     
         24 . The method of making an additive component (B) as defined in  claim 22 , wherein the aldehyde is formaldehyde and the carbonate is ethylene carbonate. 
     
     
         25 . The method of making an additive component (B) as defined in  claim 23 , wherein the aldehyde is formaldehyde and the carbonate is ethylene carbonate. 
     
     
         26 . Use of additive component (B) as defined in any one of  claims 1  to  11  and  24  to A method of improving the deposit control properties of a lubricant whilst not adversely affecting its copper corrosion properties comprising including in said lubricant an additive component (B) as defined in  claim 1 . 
     
     
         27 . A method of lubricating surfaces of an internal combustion engine during its operation by:
 i. providing, in a minor amount, one or more additives (B) as defined in  claim 1  in a major amount of an oil of lubricating viscosity to make a lubricant;   ii. providing the lubricant to the crankcase of the internal combustion engine;   iii. providing a hydrocarbon fuel in the combustion chamber of the engine, and   iv. combusting the fuel in the combustion chamber.