Low emission diesel lubricant with improved corrosion protection

Abstract

The present invention provides engine lubricants for low emission diesel engines featuring low levels of ash, sulfur and phosphorus. Specifically, this invention provides a low emission diesel lubricant comprising from about 0 wt. % to about 1.2 wt. % ash; from about 0.1 wt. % to about 0.5 wt. % sulfur; and from about 0.02 wt. % to about 0.1 wt. % phosphorus. Said lubricant may also comprise a novel unsulfurized, carboxylate-containing additive for lubricating oils, comprising a mixture of alkaline earth metal salts (hydrocarbyl phenate/hydrocarbyl salicylate) and a reduced amount of unreacted hydrocarbyl phenols, in which said hydrocarbyl salicylate is primarily single-aromatic-ring hydrocarbyl salicylate. The invention also provides a method for producing said additive and said LEDL.

What is claimed is:  
     
         1 . A low emission diesel lubricant composition comprising: 
 a major amount of a base oil of lubricating viscosity;    a hydroxy-aromatic surfactant-based detergent-dispersant additive containing less than 40 wt. % free hydrocarbyl phenol;    a dispersant; and    a wear inhibitor,    wherein said composition contains: 
 from about 0 wt. % to about 1.2 wt. % ash;  
 from about 0.1 wt. % to about 0.5 wt. % sulfur; and  
 from about 0.02 wt. % to about 0.1 wt. % phosphorus.  
   
     
     
         2 . The low emission diesel lubricant composition of  claim 1  wherein said composition further comprises a corrosion inhibitor.  
     
     
         3 . The low emission diesel lubricant composition of  claim 2  wherein said additive is unsulfurized.  
     
     
         4 . The low emission diesel lubricant composition of  claim 3  wherein said additive is a carboxylate-containing additive.  
     
     
         5 . The low emission diesel lubricant composition of  claim 4  wherein said additive further comprises: 
 (a) from 10 to 50% alkaline earth metal hydrocarbyl phenate;  
 (b) from 15 to 60% alkaline earth metal single-aromatic-ring hydrocarbyl salicylate; and  
 (c) from 0% to 50% organic diluent.  
 
     
     
         6 . The low emission diesel lubricant composition of  claim 5  wherein from about 1.8 wt. % to about 5.5 wt. % of said composition consists of said additive.  
     
     
         7 . The low emission diesel lubricant composition of  claim 6  wherein: 
 said dispersant is a borated dispersant; and  
 said wear inhibitor is a metal dithiophosphate.  
 
     
     
         8 . The low emission diesel lubricant composition of  claim 7  wherein said composition contains: 
 from about 1.0 wt. % to about 4.0 wt. % of said borated dispersant;  
 from about 0.2 wt. % to about 1.1 wt. % of said wear inhibitor; and  
 from about 0 wt. % to about 0.5 wt. % of said corrosion inhibitor.  
 
     
     
         9 . The low emission diesel lubricant composition of  claim 8  wherein: 
 said dispersant is a succinimide;  
 said wear inhibitor is zinc dithiophosphate; and  
 said corrosion inhibitor is a neutralized terephthalic acid.  
 
     
     
         10 . The low emission diesel lubricant composition of  claim 9  further comprising: 
 from about 3.0 wt. % to about 8.0 wt. % non-borated dispersant;  
 from about 0.6 wt. % to about 1.4 wt. % calcium-sulfonate;  
 from about 0.1 wt. % to about 0.5 wt. % molybdenum anti-oxidant;  
 from about 0 wt. % to about 1.0 wt. % phenolic anti-oxidant;  
 from about 0.1 wt. % to about 1.0 wt. % aminic anti-oxidant;  
 from about 0 wt. % to about 6.0 wt. % dispersant olefin-copolymer; and  
 from about 0 to about 25 ppm foam inhibitor.  
 
     
     
         11 . A low emission diesel lubricant composition comprising: 
 a major amount of a base oil of lubricating viscosity;    a hydroxy-aromatic surfactant-based detergent-dispersant additive containing less than 40 wt. % free hydrocarbyl phenol;    a dispersant; and    a wear inhibitor,    wherein said composition contains: 
 less than 1.0 wt. % ash;  
 less than 0.3 wt. % sulfur; and  
 less than 0.08 wt. % phosphorus.  
   
     
     
         12 . The low emission diesel lubricant composition of  claim 11  wherein said composition further comprises a corrosion inhibitor.  
     
     
         13 . The low emission diesel lubricant composition of  claim 12  wherein said additive is unsulfurized.  
     
     
         14 . The low emission diesel lubricant composition of  claim 13  wherein said additive is a carboxylate-containing additive.  
     
     
         15 . The low emission diesel lubricant composition of  claim 14  wherein said additive further comprises: 
 (a) from 10 to 50% alkaline earth metal hydrocarbyl phenate;  
 (b) from 15 to 60% alkaline earth metal single-aromatic-ring hydrocarbyl salicylate; and  
 (c) from 0% to 50% organic diluent.  
 
     
     
         16 . The low emission diesel lubricant composition of  claim 15  wherein from about 1.8 wt. % to about 5.5 wt. % of said composition consists of said additive.  
     
     
         17 . The low emission diesel lubricant composition of  claim 16  wherein: 
 said dispersant is a borated dispersant; and  
 said wear inhibitor is a metal dithiophosphate.  
 
     
     
         18 . The low emission diesel lubricant composition of  claim 17  wherein said composition contains: 
 from about 1.0 wt. % to about 4.0 wt. % of said borated dispersant;  
 from about 0.2 wt. % to about 1.1 wt. % of said wear inhibitor; and  
 from about 0 wt. % to about 0.5 wt. % of said corrosion inhibitor.  
 
     
     
         19 . The low emission diesel lubricant composition of  claim 18  wherein: 
 said dispersant is a succinimide;  
 said wear inhibitor is zinc dithiophosphate; and  
 said corrosion inhibitor is a neutralized terephthalic acid.  
 
     
     
         20 . The low emission diesel lubricant composition of  claim 19  further comprising: 
 from about 3.0 wt. % to about 8.0 wt. % non-borated dispersant;  
 from about 0.6 wt. % to about 1.4 wt. % calcium-sulfonate;  
 from about 0.1 wt. % to about 0.5 wt. % molybdenum anti-oxidant;  
 from about 0 wt. % to about 1.0 wt. % phenolic anti-oxidant;  
 from about 0.1 wt. % to about 1.0 wt. % aminic anti-oxidant;  
 from about 0 wt. % to about 6.0 wt. % dispersant olefin-copolymer; and  
 from about 0 to about 25 ppm foam inhibitor.  
 
     
     
         21 . A low emission diesel lubricant composition comprising: 
 a major amount of a base oil of lubricating viscosity;    a hydroxy-aromatic surfactant-based detergent-dispersant additive containing less than 40 wt. % free hydrocarbyl phenol;    a dispersant; and    a wear inhibitor,    wherein said composition contains: 
 from about 0.4 wt. % to about 1.0 wt. % ash;  
 from about 0.05 wt. % to about 0.3 wt. % sulfur; and  
 from about 0.02 wt. % to about 0.08 wt. % phosphorus.  
   
     
     
         22 . The low emission diesel lubricant composition of  claim 21  wherein said composition further comprises a corrosion inhibitor.  
     
     
         23 . The low emission diesel lubricant composition of  claim 22  wherein said additive is unsulfurized.  
     
     
         24 . The low emission diesel lubricant composition of  claim 23  wherein said additive is a carboxylate-containing additive.  
     
     
         25 . The low emission diesel lubricant composition of  claim 24  wherein said additive further comprises: 
 (a) from 10 to 50% alkaline earth metal hydrocarbyl phenate;  
 (b) from 15 to 60% alkaline earth metal single-aromatic-ring hydrocarbyl salicylate; and  
 (c) from 0% to 50% organic diluent.  
 
     
     
         26 . The low emission diesel lubricant composition of  claim 25  wherein from about 1.8 wt. % to about 5.5 wt. % of said composition consists of said additive.  
     
     
         27 . The low emission diesel lubricant composition of  claim 26  wherein: 
 said dispersant is a borated dispersant; and  
 said wear inhibitor is a metal dithiophosphate.  
 
     
     
         28 . The low emission diesel lubricant composition of  claim 27  wherein said composition contains: 
 from about 1.0 wt. % to about 4.0 wt. % of said borated dispersant;  
 from about 0.2 wt. % to about 1.1 wt. % of said wear inhibitor; and  
 from about 0 wt. % to about 0.5 wt. % of said corrosion inhibitor.  
 
     
     
         29 . The low emission diesel lubricant composition of  claim 28  wherein: 
 said dispersant is a succinimide;  
 said wear inhibitor is zinc dithiophosphate; and  
 said corrosion inhibitor is a neutralized terephthalic acid.  
 
     
     
         30 . The low emission diesel lubricant composition of  claim 29  further comprising: 
 from about 3.0 wt. % to about 8.0 wt. % non-borated dispersant;  
 from about 0.6 wt. % to about 1.4 wt. % calcium-sulfonate;  
 from about 0.1 wt. % to about 0.5 wt. % molybdenum anti-oxidant;  
 from about 0 wt. % to about 1.0 wt. % phenolic anti-oxidant;  
 from about 0.1 wt. % to about 1.0 wt. % aminic anti-oxidant;  
 from about 0 wt. % to about 6.0 wt. % dispersant olefin-copolymer; and  
 from about 0 to about 25 ppm foam inhibitor.  
 
     
     
         31 . A low emission diesel lubricant composition comprising: 
 a major amount of a base oil of lubricating viscosity;    a hydroxy-aromatic surfactant-based detergent-dispersant additive containing less than 40 wt. % free hydrocarbyl phenol;    a dispersant; and    a wear inhibitor,    wherein said composition contains: 
 from about 0.4 wt. % to about 1.0 wt. % ash;  
 from about 0.05 wt. % to about 0.15 wt. % sulfur; and  
 from about 0.02 wt. % to about 0.08 wt. % phosphorus.  
   
     
     
         32 . A low emission diesel lubricant composition comprising: 
 a major amount of a base oil of lubricating viscosity;    a dispersant;    a wear inhibitor; and    an effective corrosion inhibiting amount of an unsulfurized carboxylate-containing additive prepared by a method comprising: 
 (a) neutralization of hydrocarbyl phenols using an alkaline earth base in the presence of a promoter, to produce a hydrocarbyl phenate;  
 (b) carboxylation of the hydrocarbyl phenate obtained in step (a) using carbon dioxide under carboxylation conditions sufficient to convert at least 20 mole % of the starting hydrocarbyl phenols to hydrocarbyl salicylate; and  
 (c) separation of at least about 10% of thestarting hydrocarbyl phenols from the product produced in step (b) to produce said additive,  
 wherein said composition contains: 
 from about 0 wt. % to about 1.2 wt. % ash;  
 from about 0.1 wt. % to about 0.5 wt. % sulfur; and  
 from about 0.02 wt. % to about 0.1 wt. % phosphorus.  
 
   
     
     
         33 . The low emission diesel lubricant composition of  claim 32 , wherein said hydrocarbyl salicylate comprises single-aromatic-ring hydrocarbyl salicylate and double-aromatic-ring hydrocarbyl salicylate wherein the mole ratio of single aromatic-ring hydrocarbyl salicylate to double-aromatic-ring hydrocarbyl salicylate is at least 8:1.  
     
     
         34 . The low emission diesel lubricant composition of  claim 32 , wherein, in said separation step, at least about 30% of the starting hydrocarbyl phenols is separated from the product produced in step (b) to produce said additive.  
     
     
         35 . The low emission diesel lubricant composition of  claim 32 , wherein, in said separation step, up to 55% of the starting hydrocarbyl phenols is separated from the product produced in step (b) to produce said additive.  
     
     
         36 . The low emission diesel lubricant composition of  claim 32 , wherein, in said separation, step about 45% to about 50% of the starting hydrocarbyl phenols is separated from the product produced in step (b) to produce said additive.  
     
     
         37 . The low emission diesel lubricant composition of  claim 32 , wherein, in said separation step, said starting hydrocarbyl phenols are removed by distillation.  
     
     
         38 . The low emission diesel lubricant composition of  claim 37 , wherein, in said separation step, at least about 30% of the starting hydrocarbyl phenols is separated from the product produced in step (b) to produce said additive.  
     
     
         39 . The low emission diesel lubricant composition of  claim 37 , wherein, in said separation step, up to 55% of the starting hydrocarbyl phenols is separated from the product produced in step (b) to produce said additive.  
     
     
         40 . The low emission diesel lubricant composition of  claim 37 , wherein, in said separation step, about 45% to about 50% of the starting hydrocarbyl phenols is separated from the product produced in step (b) to produce said additive.  
     
     
         41 . The low emission diesel lubricant composition of  claim 37 , wherein said distillation is accomplished via falling film distillation, wiped film evaporator distillation, or short path distillation.  
     
     
         42 . The low emission diesel lubricant composition of  claim 41 , wherein said distillation is carried out at temperatures ranging from about 150° C. to about 250° C. and at pressures from about 0.1 to about 4 mbar.  
     
     
         43 . The low emission diesel lubricant composition of  claim 41 , wherein said distillation is carried out at temperatures ranging from about 190° C. to about 230° C. and at pressures from about 0.5 to about 3 mbar.  
     
     
         44 . The low emission diesel lubricant composition of  claim 41 , wherein said distillation is carried out at temperatures ranging from about 195° C. to about 225° C., and at a pressure of about 1 to about 2 mbar.  
     
     
         45 . The low emission diesel lubricant composition of  claim 32 , wherein an effective viscosity improving amount of organic diluent is added to said additive.  
     
     
         46 . The low emission diesel lubricant composition of  claim 32 , wherein, in said neutralization step: 
 (a) said neutralization operation is carried out in the presence of at least one carboxylic acid containing from one to four carbon atoms, and in the absence of alkali base, dialcohol, and monoalcohol; and    (b) said neutralization operation is carried out at a temperature of at least 200° C.;    (c) the pressure is reduced gradually below atmospheric in order to remove the water of reaction, in the absence of any solvent that may form an azeotrope with water;    (d) said hydrocarbyl phenols contain up to 85% of linear hydrocarbyl phenol in mixture with at least 15% of branched hydrocarbyl phenol in which the branched hydrocarbyl radical contains at least nine carbon atoms; and    (e) the quantities of reagents used correspond to the following molar ratios: 
 (1) alkaline earth base/hydrocarbyl phenol of 0.2:1 to 0.7:1; and  
 (2) carboxylic acid/hydrocarbyl phenol of from 0.01:1 to 0.5:1.  
   
     
     
         47 . The low emission diesel lubricant composition of  claim 32  wherein said composition further comprises a corrosion inhibitor.  
     
     
         48 . The low emission diesel lubricant composition of  claim 47  wherein from about 1.8 wt. % to about 5.5 wt. % of said lubricant consists of said additive.  
     
     
         49 . The low emission diesel lubricant composition of  claim 48  wherein: 
 said dispersant is a borated dispersant; and  
 said wear inhibitor is a metal dithiophosphate.  
 
     
     
         50 . The low emission diesel lubricant composition of  claim 49  wherein said composition contains: 
 from about 1.0 wt. % to about 4.0 wt. % of said borated dispersant;  
 from about 0.2 wt. % to about 1.1 wt. % of said wear inhibitor; and  
 from about 0 wt. % to about 0.5 wt. % of said corrosion inhibitor.  
 
     
     
         51 . The low emission diesel lubricant composition of  claim 50  wherein: 
 said dispersant is a succinimide;  
 said wear inhibitor is zinc dithiophosphate; and  
 said corrosion inhibitor is a neutralized terephthalic acid.  
 
     
     
         52 . The low emission diesel lubricant composition of  claim 51  further comprising: 
 from about 3.0 wt. % to about 8.0 wt. % non-borated dispersant;  
 from about 0.6 wt. % to about 1.4 wt. % calcium-sulfonate;  
 from about 0.1 wt. % to about 0.5 wt. % molybdenum anti-oxidant;  
 from about 0 wt. % to about 1.0 wt. % phenolic anti-oxidant;  
 from about 0.1 wt. % to about 1.0 wt. % aminic anti-oxidant;  
 from about 0 wt. % to about 6.0 wt. % dispersant olefin-copolymer; and  
 from about 0 to about 25 ppm foam inhibitor.  
 
     
     
         53 . A low emission diesel lubricant composition comprising: 
 a major amount of a base oil of lubricating viscosity;    a dispersant;    a wear inhibitor; and    an effective corrosion inhibiting amount of an unsulfurized carboxylate-containing additive prepared by a method comprising: 
 (a) neutralization of hydrocarbyl phenols using an alkaline earth base in the presence of a promoter, to produce a hydrocarbyl phenate;  
 (b) carboxylation of the hydrocarbyl phenate obtained in step (a) using carbon dioxide under carboxylation conditions sufficient to convert at least 20 mole % of the starting hydrocarbyl phenols to hydrocarbyl salicylate; and  
 (c) separation of at least about 10% of the starting hydrocarbyl phenols from the product produced in step (b) to produce said additive,  
 wherein said composition contains: 
 less than 1.0 wt. % ash;  
 less than 0.3 wt. % sulfur; and  
 less than 0.08 wt. % phosphorus.  
 
   
     
     
         54 . The low emission diesel lubricant composition of  claim 53  wherein said composition further comprises a corrosion inhibitor.  
     
     
         55 . The low emission diesel lubricant composition of  claim 54  wherein from about 1.8 wt. % to about 5.5 wt. % of said lubricant consists of said additive.  
     
     
         56 . The low emission diesel lubricant composition of  claim 55  wherein: 
 said dispersant is a borated dispersant; and  
 said wear inhibitor is a metal dithiophosphate.  
 
     
     
         57 . The low emission diesel lubricant composition of  claim 56  wherein said composition contains: 
 from about 1.0 wt. % to about 4.0 wt. % of said borated dispersant;  
 from about 0.2 wt. % to about 1.1 wt. % of said wear inhibitor; and  
 from about 0 wt. % to about 0.5 wt. % of said corrosion inhibitor.  
 
     
     
         58 . The low emission diesel lubricant composition of  claim 57  wherein: 
 said dispersant is a succinimide;  
 said wear inhibitor is zinc dithiophosphate; and  
 said corrosion inhibitor is a neutralized terephthalic acid.  
 
     
     
         59 . The low emission diesel lubricant composition of  claim 58  further comprising: 
 from about 3.0 wt. % to about 8.0 wt. % non-borated dispersant;  
 from about 0.6 wt. % to about 1.4 wt. % calcium-sulfonate;  
 from about 0.1 wt. % to about 0.5 wt. % molybdenum anti-oxidant;  
 from about 0 wt. % to about 1.0 wt. % phenolic anti-oxidant;  
 from about 0.1 wt. % to about 1.0 wt. % aminic anti-oxidant;  
 from about 0 wt. % to about 6.0 wt. % dispersant olefin-copolymer; and  
 from about 0 to about 25 ppm foam inhibitor.  
 
     
     
         60 . A low emission diesel lubricant composition comprising: 
 a major amount of a base oil of lubricating viscosity;    a dispersant;    a wear inhibitor; and    an effective corrosion inhibiting amount of an unsulfurized carboxylate-containing additive prepared by a method comprising: 
 (a) neutralization of hydrocarbyl phenols using an alkaline earth base in the presence of a promoter, to produce a hydrocarbyl phenate;  
 (b) carboxylation of the hydrocarbyl phenate obtained in step (a) using carbon dioxide under carboxylation conditions sufficient to convert at least 20 mole % of the starting hydrocarbyl phenols to hydrocarbyl salicylate; and  
 (c) separation of at least about 10% of the starting hydrocarbyl phenols from the product produced in step (b) to produce said additive,  
 wherein said composition contains: 
 from about 0.4 wt. % to about 1.0 wt. % ash;  
 from about 0.05 wt. % to about 0.3 wt. % sulfur; and  
 from about 0.02 wt. % to about 0.08 wt. % phosphorus.  
 
   
     
     
         61 . The low emission diesel lubricant composition of  claim 60  wherein said composition further comprises a corrosion inhibitor.  
     
     
         62 . The low emission diesel lubricant composition of  claim 61  wherein from about 1.8 wt. % to about 5.5 wt. % of said lubricant consists of said additive.  
     
     
         63 . The low emission diesel lubricant composition of  claim 62  wherein: 
 said dispersant is a borated dispersant; and  
 said wear inhibitor is a metal dithiophosphate.  
 
     
     
         64 . The low emission diesel lubricant composition of  claim 63  wherein said composition contains: 
 from about 1.0 wt. % to about 4.0 wt. % of said borated dispersant;  
 from about 0.2 wt. % to about 1.1 wt. % of said wear inhibitor; and  
 from about 0 wt. % to about 0.5 wt. % of said corrosion inhibitor.  
 
     
     
         65 . The low emission diesel lubricant composition of  claim 64  wherein: 
 said dispersant is a succinimide;  
 said wear inhibitor is zinc dithiophosphate; and  
 said corrosion inhibitor is a neutralized terephthalic acid.  
 
     
     
         66 . The low emission diesel lubricant composition of  claim 65  further comprising: 
 from about 3.0 wt. % to about 8.0 wt. % non-borated dispersant;  
 from about 0.6 wt. % to about 1.4 wt. % calcium-sulfonate;  
 from about 0.1 wt. % to about 0.5 wt. % molybdenum anti-oxidant;  
 from about 0 wt. % to about 1.0 wt. % phenolic anti-oxidant;  
 from about 0.1 wt. % to about 1.0 wt. % aminic anti-oxidant;  
 from about 0 wt. % to about 6.0 wt. % dispersant olefin-copolymer; and  
 from about 0 to about 25 ppm foam inhibitor.  
 
     
     
         67 . A low emission diesel lubricant composition comprising: 
 a major amount of a base oil of lubricating viscosity;    a dispersant;    a wear inhibitor; and    an effective corrosion inhibiting amount of an unsulfurized carboxylate-containing additive prepared by a method comprising: 
 (a) neutralization of hydrocarbyl phenols using an alkaline earth base in the presence of a promoter, to produce a hydrocarbyl phenate;  
 (b) carboxylation of the hydrocarbyl phenate obtained in step (a) using carbon dioxide under carboxylation conditions sufficient to convert at least 20 mole % of the starting hydrocarbyl phenols to hydrocarbyl salicylate; and  
 (c) separation of at least about 10% of the starting hydrocarbyl phenols from the product produced in step (b) to produce said additive,  
 wherein said composition contains: 
 from about 0.4 wt. % to about 1.0 wt. % ash;  
 from about 0.05 wt. % to about 0.15 wt. % sulfur; and  
 from about 0.02 wt. % to about 0.08 wt. % phosphorus.